[FrontPage Include Component]

NAVIGATOR: Back - Home > Adi > Services > Support > Faq :

Categories

Search

Contact us

General info

+1 949 858 4216

Sales & support

+1 619 992 3089

E-mail

Information

Sales

Support

CHECK OUT

[FrontPage Include Component]

General Information asked about the APAS System

Hello Laura,
Thank you for your interest in the Ariel Performance Analysis System (APAS).  The APAS is a 3D video-based movement analysis system which accurately quantifies function and provides objective data the professional may use to justify or evaluate treatment.  Areas of successful application for the APAS include human performance, injury and rehabilitation assessment, quantification of loss for compensation claims, equipment and product testing and development, determination of potential or actual risks for products and activities in liability litigation, as well as applied research in the areas of orthopedic medicine, therapeutics, and physical training.

The APAS integrates state-of-the-art computer and video processing hardware with specialized software modules that perform data collection, analysis, and presentation.  Objective quantifiable documentation is provided for both 2-Dimensional and 3-Dimensional analysis.  Specific points of interest can be digitized with user intervention or automatically using contrasting markers.  Stick figures are then generated and can be synchronized with kinematics data.  Additionally, up to 32 channels of analog data (i.e. force platform, EMG, goniometers etc.) can be synchronized with the kinematics data.

The APAS product information can be found on the Ariel internet site (www.arielweb.com).  The direct address to several areas that might be of interest are listed below.

APAS Product Information
www.arielnet.com/Main/adw-04.html

Comparison of Commercially Available Systems
www.arielnet.com/topics/comparison/default.htm

Selected Applications Of APAS
www.arielnet.com/Main/adw-85.html

Selected Publications Utilizing the Ariel Technology
www.arielnet.com/Main/adw-86.html

APAS Price List
www.arielnet.com/Main/adw-54.html

Purchasing Options
www.arielnet.com/topics/FAQ/Purchasing_Options.htm


You can even download a full version of the APAS for a free 30 day trial.

Please review the information and feel free to contact us for any additional questions.

Sincerely,

John Probe
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, CA 92111
Tel:  (858) 874-2547
Fax:  (858) 874-2549
Internet:  www.arielnet.com
 
 
 
----- Original Message -----
Sent: Monday, March 26, 2001 8:32 AM

could you send me a brochure and a price list
thank you,
Laura Crawford
1205 N Ave A
Portales NM 88130
 

Hello Chris,
 
Thank you for your interest in the Ariel Performance Analysis System (APAS).  I will supply answers below each of your questions.
 
Please do not hesitate to contact us for any additional information.
 
Sincerely,
 
John Probe
Ariel Dynamics, Inc.
 
----- Original Message -----
From: Chris Kelley
Sent: Monday, April 02, 2001 6:18 AM
Subject: RE: APAS Information

Mr. Ariel,

I have reviewed some of the information you have sent me and I have some more questions.  I read the report that compares the various packages.

bulletSince the APAS system had to be set up with 5 cameras instead of two, does the $10,000 price accurately reflect the cost of the equipment used for that test?  From your price list, I assume the $10,000 does not include any of the cameras.

ADI:  You are correct!  The $10,000 price includes the Basic APAS system (computer, 2D and 3D software, automatic digitizing, and support for panning cameras).  We do not include cameras in the price of the Basic APAS because the APAS is not "locked-in" to a specific model camera.  Any video camera can be used with the APAS while other companies require the users to purchase their proprietary cameras for use with the system.

The APAS can be used with any number of cameras.  A single camera is used to supply 2D data while 2 or more cameras are required for 3D data analysis.  Most 3D studies can be accurately analyzed using 2 or 3 cameras.  However, the industry standard Gait programs usually require 5 cameras.
bulletDo the other systems that were tested include hardware such as cameras in the price or are they just including the computer and software?

ADI:  The prices listed in the study were those supplied to the investigator.  Since this was a third-party study (completely independent of Ariel Dynamics) we do not know the options included with each system.  Additionally, the APAS includes many options in the Basic package that are added value options in competing systems.  For example, the Basic APAS includes 3D capabilities, autodigitizing, and panning camera support.  The important point to note is that the APAS provides accurate data at a fraction of the cost of other commercially comparable systems.
bulletIf I wanted to set up an APAS system with six cameras, and I bought the cameras from you, what would the system cost be?  Can you use two high speed cameras (for the occasional test where they might be needed) and 4 lower speed cameras?

ADI:  As you can see from the price list sent in the previous Email message, there are many options for purchasing the APAS.  The best option for your situation seems to be the APAS-240 system listed for $17,500.00 USD.  This system includes the computer, 2D AND 3D software, autodigitizing capabilities, support for panning cameras, and two JVC high speed (60/120/240 Hz) digital camcorders.  Additional JVC camcorders can be included for $3,000.00 USD each.  The computer monitor is not included since most or our users have indicated they had plenty of monitors and did not require another one.  This can be supplied with the APAS as an option if desired. 

The APAS has no problem performing analysis using different speed cameras.  Your suggestion of using high speed only when required is good.  Additionally, you can use a high speed and lower speed camera to simultaneously record and analyze a single activity.

If you are going to use the system for Gait Analysis, you should also consider the optional APAS-Gait and 3D-Renderer software modules.  The force platforms and Analog module are also available as options.
bulletIf 6 cameras are used, would the 16 channel A/D unit also be required, or would some other piece of equipment be needed to handle the additional cameras?

ADI:  The number of cameras used is completely independent of the analog module.  The APAS supports any number of cameras, though most analysis can be accurately measured using 2 or 3 cameras.  The analog module is only required for sampling analog data signals (force platform, EMG, etc).
bulletWhat is the converter unit with the VRG package?  I saw the VCR listed as a separate item, but not this converter unit.  If I was to purchase a VCR elsewhere, would I then need to purchase this converter unit from you?

ADI:  The Video Report Generator (VRG) is normally used for transferring the analyzed data back to a video format.  This package consists of color monitor, VRG unit, VCR and microphone.  The converter unit is required for converting the computer signal into a format compatible for recording to the VCR.  The microphone can be used for Audio Dubbing to narrate the taped analysis.

Ariel Dynamics uses "off-the-shelf" hardware whenever possible.  This has several advantages.  First, it does not commit the user to a single vendor.  In the event of equipment malfunctions, the hardware can be checked locally to avoid shipping and the possibility of other problems.  Many users also have "extra" equipment available that can be used with the APAS (monitors, computers, video cameras etc..)
bulletWhat is the high precision calibration unit and what is it for?

ADI:  As with any system, there must be a "calibration" device that is used to calibrate the recorded image.  This is simply and object that has points of known distances relative to a single origin.  These points are digitized as part of the analysis and are used in the Transformation algorithms to compute the spatial coordinates from the digitized information.  Any object can be used for the calibration as long as there are points with "known" X, Y, Z coordinates.  Since this is the basis of all the computed data, the points should be measured as accurately as possible.

I'm sure I'll have more questions.

Thank you for your time,

Chris Kelley
Engineer
Ohio Willow Wood
15441 Scioto Darby Rd.
Mount Sterling, OH 43143
PH: (740)869-3377
FX: (740)869-4374
Chrisk@owwco.com

Hello Brad,
Thank you for your message and your interest in the Ariel Performance Analysis System (APAS).  I will provide answers below each of your questions.
Please contact us for any additional information.
Sincerely,
John Probe
Ariel Dynamics, Inc.
 
 
 
----- Original Message -----
Sent: Friday, April 06, 2001 8:31 AM
Subject: APAS questions

Hi There, I got your message today and thought I would put my question in writing so we can touch base.  I am doing my thesis on the shoulder joint complex.  I want to take baseline mesurements of abduction of the shoulder before a series of Osteopathic treatments.  After each treatment and then again at the end of he study.  I wish to make the data as accurate as possible, which is why I have chosen your product.  The motions will be slow so I assume I can get away with a 60 hz camera. 
 
 
ADI:  Almost all human motion can be measured using 60 Hz cameras.  The shoulder is a relativley slow moving joint so 60 Hz analysis should not be any problem.  If the movements are very slow, the user has the option of skipping additional frames without losing any data.
 
 
Would you recommend more than one camera or can I do this simple measurement with one?
 
ADI:  The APAS supports both 2D and 3D analysis.  The only difference is the number of cameras used for the study.  Three-dimensional analysis requires that at least 2 cameras (approximately 90 degrees apart) "see" each point that will be digitized.  Two-dimensional analysis requires a single camera perpendicular to the plane of activity.  You will have to determine the purpose of your study to determine whether to use 2D or 3D.  If possible, we recommend 3D analysis since that is the "real-world" situation.  You can always look at 2D data as a subset of the 3D data.
 
 
Secondly, I have downloaded your software to try for 30 days.  I assume again there are a number of components I will not need.  Will I be able to analyse the motions of each patient to compare their progress with your software?  I have tried to use the sample data from your site, but cannot seem to get a good idea of how to use it.  I have gone to your tutorial site and will proceed through them. 
 
 
ADI:  Once you download and install the APAS software, you should Email the System parameter and Site Code numbers to us.  We will use these numbers to generate a SITE KEY that will activate the software.  You will require a Pentium computer ( or equivalent) and a frame grabber capable of capturing your video to Microsoft AVI format.  The you should proceed through the modules as listed below:
 
   Capture (used to capture analog video format to hard disk)
   Trim (used to "clip" desired portion of captured video for analysis)
   Digitize (used to digitize up to 4 simultaneous images)
   Transform (used to convert digitized coordinates to spatial coordinates)
   Filter (used to remove random digitizing error and "smooth" the data)
   Display (used for presenting the data)
 
Within each of these modules, you can access the pull-down Help menu for steop-by-step instructions.  Specifically, you can refer to the section titled "Quick Reference" for short concise instructions.
 
 
Any other suggestions?
 
I wont be starting the study for a couple of months, but I would like to describe my set up by the end of this month, including the use of your software.  Is there a way to email me a manual for the software? 
 
ADI:  There are a number of methods for obtaining the manual.
   1.  They can be viewed on-line at the Ariel internet site.  The direct address is:
 
   2.  They can be downloaded directly from the main Ariel page.  Refer to the section titled "Help And Documentation" for each module.
 
   3.  The full manual is contained in the pull-down Help menu within each module.
 
   4.  If absolutely necessary, we could probably Email them.
 
I have the ftp address, but do not have a ftp program installed on my computer at this time.  If this is the only solution I will install a ftp program and proceed as your website instructs. 
 
Finally, could you send me the original copy of the study by Dr. James Richards that you have on your site?  It will come in very handy in my protocol presentation at the end of the month.
 
 
ADI:  We do not have "hard" copies of this study available for distribution.  We placed the information on the website so that it could be printed by any interested parties.
 
 
Thanks for your time.
 
Brad McCutcheon

Hello Adrian Burden,
 
Thank you for your message.  I will provide answers below each of your questions.  Please feel free to contact me for any additional information.
Sincerely,
John Probe
Ariel Dynamics, Inc.
 
----- Original Message -----
Sent: Monday, April 16, 2001 7:15 PM
Subject: Compatability/Finance Questions

John,
I'm currently in the middle of the 30 day trial for APAS. Could you answer the following questions please (I've tried to check through the FAQs as much as I can).
 
We currently use Panasonic AG7355 video recorders, Panasonic 50 Hz (PAL, not digital) cameras for 2D/3D analysis.
 
1. Does the hardware/software that is supplied with the basic $10000 APAS 2000 contain all that is necessary to capture video, from the above recorders and cameras, and digitise it?
 
ADI:  The current system includes the Digital Video frame grabber, however, I am sure that we could supply your system with an Analog frame grabber for the 50 Hz PAL video format. 
 
Does the Panasonic AG7355 VCR include the optional Serial Interface module?  If so, this should work just fine using a standard serial cable for control.  If you already have the VCR and Cameras, you would only require the computer, frame grabber and APAS software (the $10,000 system).
 
 
2. If we decide to install APAS 2000 to other workstations, for $500 as stated, what additional hardware (if any) would our existing Pentium computers need. For example would each need a frame grabber and IOmega Buzz capture card for each?
 
ADI:  You do not require any additional hardware for the APAS workstations.  You will probably only require the necessary video codecs (used for capturing and compressing the video into AVI format).  This is only software and is included with most frame grabbers.
 
 
3. What is your conversion rate from US$ to ´┐Żsterling, if we decide to purchase within the next month or so?
 
ADI:  Looking at today's financial information, $1 US dollar is equal to approximately 0.70 ´┐Żsterling.  I will have to check this tomorrow to make certain.
 
 
4. How long does hardware delivery from US to UK usually take, and are there any hidden extras such as 'shipping costs' extra from sales to the UK?
 
ADI:  We ship all international orders by Air so the delivery time should only be about 4 or 5 days (depending on customs clearance).  Shipping costs would be additional charges and can be provided as soon as we know the exact equipment you wish to purchase.  All duties, taxes etc are the customer's responsibility.
 
 
Look forward to your responses.
 
Adrian Burden
Senior lecturer in Biomechanics
University of Brighton.

 

Hello Mr. Imran Sharif,

 
Thank you for your interest in the Ariel Dynamics technology.  We manufacture two lines of biomechanical research equipment: the Ariel Performance Analysis System (APAS) and the Ariel Computerized Exercise Systems (ACES).
 
The APAS is a 3D video-based movement analysis system which accurately quantifies function and provides objective data the professional may use to justify or evaluate treatment.  Areas of successful application for the APAS include human performance, injury and rehabilitation assessment, quantification of loss for compensation claims, equipment and product testing and development, determination of potential or actual risks for products and activities in liability litigation, as well as applied
research in the areas of orthopedic medicine, therapeutics, and physical training.

The APAS integrates state-of-the-art computer and video processing hardware with specialized software modules that perform data collection, analysis, and presentation.  Objective quantifiable documentation is provided for both 2-Dimensional and 3-Dimensional analysis.  Specific points of interest can be digitized with user intervention or automatically using contrasting markers.  Stick figures are then generated and can be synchronized with kinematics data.  Additionally, up to 32 channels of analog data (i.e. force platform, EMG, goniometers etc.) can be synchronized with the kinematics data.

The APAS product information can be found on the Ariel internet site (www.arielnet.com).  The direct address to several areas that might be of interest are listed below.

 APAS Product Information
 www.arielnet.com/Main/adw-04.html

 Comparison of Commercially Available Systems
 www.arielnet.com/topics/comparison/default.htm

 Selected Applications Of APAS
 www.arielnet.com/Main/adw-85.html

 Selected Publications Utilizing the Ariel Technology
 www.arielnet.com/Main/adw-86.html

ARIEL 3D-Renderer Module
 
APAS-GAIT Analysis Modue
 /Gait/index.html

 
You can even download a full version of the APAS for a free 30 day trial.

The ARIEL CES is a computerized exercise/rehabilitation system that is capable of isokinetic, isometric, isotonic and user-defined exercise protocols.  Additional information can be found on the Ariel internet site.  The direct address for the CES information is listed below.
 
 
 
 
Please review the information and feel free to contact us for any additional questions.

 Sincerely,

John Probe
Ariel Dynamics, Inc.

 
----- Original Message -----
From: imran sharif
Sent: Saturday, March 17, 2001 4:16 PM
Subject: GAIT ANALYSIS SYSTEM

Dear Sir/Madam,
I am currenly writting a reseach paper on the gait analysis systems available on the market and will be greatful if you could send literature/ information/ researh material of the the two types of systems offered by you.(APAS,ACES) 
thanks,
Kind regards,
Mr Imran Sharif
Consutant orthopaedic surgeon.
11, BREWS HILL, NAVAN. Co.MEATH. IRELAND.
Fax no. 00-353-46-74936
 

Hello Dr. Strong,
 
Thank you for your interest in the Ariel Performance Analysis System (APAS).  The APAS is a 3D video-based movement analysis system which accurately quantifies function and provides objective data the professional may use to justify or evaluate treatment.  Areas of successful application for the APAS include human performance, injury and rehabilitation assessment, quantification of loss for compensation claims, equipment and product testing and development, determination of potential or actual risks for products and activities in liability litigation, as well as applied research in the areas of orthopedic medicine, therapeutics, and physical training.

The APAS integrates state-of-the-art computer and video processing hardware with specialized software modules that perform data collection, analysis, and presentation.  Objective quantifiable documentation is provided for both 2-Dimensional and 3-Dimensional analysis.  Specific points of interest can be digitized with user intervention or automatically using contrasting markers.  Stick figures are then generated and can be synchronized with kinematics data.  Additionally, up to 32 channels of analog data (i.e. force platform, EMG, goniometers etc.) can be synchronized with the kinematics data.

The APAS product information can be found on the Ariel internet site (www.arielweb.com).  The direct address to several areas that might be of interest are listed below.  I have also listed addresses for Equine applications.

APAS Product Information
www.arielnet.com/Main/adw-04.html

Comparison of Commercially Available Systems
www.arielnet.com/topics/comparison/default.htm

Selected Applications Of APAS
www.arielnet.com/Main/adw-85.html

Selected Publications Utilizing the Ariel Technology
www.arielnet.com/Main/adw-86.html

APAS Price List
www.arielnet.com/Main/adw-54.html


You can even download a full version of the APAS for a free 30 day trial.

The project you describe sound very interesting and we would like to help you meet your requirements.  There are several questions that might help to better explain how the APAS could meet your needs.
   1.  Are you interested in 2D or 3D data analysis?
   2.  Three-dimensional analysis would require that the digitized points be simultanously visible from 2 or more cameras.  Will this be possible?
 
Please review the information and feel free to contact me for any additional questions.

Sincerely,

John Probe
Ariel Dynamics, Inc.
 
 
 
 
----- Original Message -----
From: dan strong
Sent: Saturday, April 07, 2001 12:32 PM
Subject: Motion capture to assess cervical spine immobilization.

Hello.
 
I'm a junior orthopedic surgeon, planning a research project to evaluate the efficacy of a number of different cervical spine immobilization devices. As I expect you already know, when someone is involved in an accident we use certain methods to move them with the minimum amount of movement to their spine. This involves strapping them into or onto various boards, jackets and vacuum matresses, and may mean carrying them at any angle to extract them from mangled vehicles, cliffsides, etc. Obviously, the less spinal movement, the better.
 
I want to compare different devices and methods according to the amount of movement produced in volunteers under controlled circumstances. The movement in the neck and spine is likely to be small, and will need accurate assessment in not only angular, but rotational and axial movement (ie the 6 degrees of freedom)
 
I appreciate this is difficult to model & measure accurately, especially for someone with a medical rather than a biomechanical background. Would your software allow me to do so? If you think it is possible what exactly would I need (ie software & hardware etc.)
 
Any advice gratefully recieved,
 
Yours,
 
Dr Dan Strong

 

 

Hello Dr. Andreas Bruessel

Thank you for your interest in the Ariel Performance Analysis System (APAS).
The APAS is a 3D video-based movement analysis system which accurately
quantifies function and provides objective data the professional may use to
justify or evaluate treatment.  Areas of successful application for the APAS
include human performance, injury and rehabilitation assessment,
quantification of loss for compensation claims, equipment and product
testing and development, determination of potential or actual risks for
products and activities in liability litigation, as well as applied research
in the areas of orthopedic medicine, therapeutics, and physical training.

The APAS integrates state-of-the-art computer and video processing hardware
with specialized software modules that perform data collection, analysis,
and presentation.  Objective quantifiable documentation is provided for both
2-Dimensional and 3-Dimensional analysis.  Specific points of interest can
be digitized with user intervention or automatically using contrasting
markers.  Stick figures are then generated and can be synchronized with
kinematics data.  Additionally, up to 32 channels of analog data (i.e. force
platform, EMG, goniometers etc.) can be synchronized with the kinematics
data.

The APAS product information can be found on the Ariel internet site
(www.arielweb.com).  The direct address to several areas that might be of
interest are listed below.

APAS Product Information
www.arielnet.com/Main/adw-04.html

Comparison of Commercially Available Systems
www.arielnet.com/topics/comparison/default.htm

Selected Applications Of APAS
www.arielnet.com/Main/adw-85.html

APAS-Gait Software Module
/Gait/index.html

Selected Publications Utilizing the Ariel Technology
www.arielnet.com/Main/adw-86.html

APAS Price List
See Attached Price List

Purchasing Options
www.arielnet.com/topics/FAQ/Purchasing_Options.htm


You can even download a full version of the APAS for a free 30 day trial.

Please review the information and feel free to contact us for any additional
questions.

Sincerely,

John Probe
Ariel Dynamics, Inc.
Email:  ARIEL1@ix.netcom.com




----- Original Message -----
From: <Dr.A.Bruessel@t-online.de>
To: <ariel1@ix.netcom.com>
Sent: Tuesday, February 27, 2001 9:08 AM
Subject: gait analysis system


> Dear Sirs,
>
> I would very likely receive a complete informational package concerning
your
> gait analysis system. Please add detailed technical information as far as
> available, too.
>
> With kind regards
>
> Dr. Andreas Bruessel
> a.b.c. - Technical Consultancy
> Baroper Kirchweg 61
> D - 44227 Dortmund
> Germany
>

 

Attached is a recent update to the Biomechanics Yellow Pages (BYP).
For more information about the BYP, please see below.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Ariel Dynamics, Inc.
Trabuco Canyon, CA, USA

One of the premier products designed, manufactured, and marketed, by
Ariel Dynamics, Inc. is the Ariel Performance Analysis System
(APAS).  The APAS is an advanced video-based system operating from
the Windows 95/98/NT/2000  environments.   Resulting from over 30
years of research and development, the APAS integrates
state-of-the-art computer and video processing hardware with
specialized software modules that perform data collection, analysis,
and presentation.  Objective quantifiable documentation is provided
for both 2-Dimensional and 3-Dimensional analysis.  Specific points
of interest are digitized with user intervention or automatically
using contrasting markers.  Additionally, analog data (i.e. force
platform, EMG, goniometers etc.) can be collected and synchronized
with the kinematic data.  Although  the system has primarily been
used for quantification of human activities, it has also been
utilized in many industrial, non-human applications.

Optional software modules include real-time 3D (6 degree of freedom)
rendering capabilities and full gait pattern analysis utilizing all
industry standard marker sets.

A second unique product from Ariel Dynamics, Inc. is the
Computerized Exercise System (CES). The CES is an interactive
computerized exercise system that automatically monitors, controls
and modifies resistance and velocity.  In addition, the CES can be
interfaced to operate with the APAS.

URL: http://www.arielnet.com
Contact: Gideon Ariel  Ph.D.
Position: President
Address: Ariel Center
6 Alicante
Trabuco Canyon, California, 92679  USA
Phone: (949) 858-4216
Fax: (949) 858-5022
E-mail: ariel1@ix.netcom.com
Last Update: 9/21/2000


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Biomechanics Yellow Pages is a free service, listing companies
that offer biomechanics-related products and services.  As you know,
these companies may not post commercial announcements directly to
Biomch-L.  However, new Yellow Pages listings and updates (no more
than once per year) are posted to Biomch-L by the maintainer of the
Yellow Pages or the Biomch-L moderator.


Dear Claire,

Before you buy either the MA or Vicon systems make sure you have a look at
the APAS system.

It is much less expensive, user friendly, and better in my opinion.  I am
not up to date with the latest systems of Motion Analysis and Vicon but I
find that the APAS system is very versatile in offering high speed data
capture (240 HZ) at low prices, error free digitising with the capability
of mixing automatic and manual digitising and with digitising black not
just bright spots.  This saves an enormous amount of time with trying to
get exactly the right lighting enviroment for automatic digitising and
having the endless frustrations of trying to get 'clean' 3D data of
numerous markers.  We have just used the APAS system to collect data on
golf puts using specatators at the British Open.  We were outside in
bright sunshine and collected data at 240 Hz from 2000 subjects.  We are
now happily digisiting that data automatically on the APAS system.  For
this project I needed to export the data to run my own Fortran programs on
it.  This was easy to do on the APAS system.

I am normally a believer in 'you get what you pay for'.  This is an
exception.  You get better for much less with the APAS system for several
reasons.  1.  Gideon Ariel has the ability and drive to develop everything
himself and uses only a small support staff.  2.  He does this part of his
business because he loves biomechanics - he is extremely wealthy from
other business ventures  and does not rely on this side of his business to
make vast sums of money.

I have not seen the lastest versions of Vicon and MA.  However, I have had
experiences with MA and did not stop throwing money at expensive upgrades
etc.  In the three years I was at Perth we didn't have one study published
from the Motion Analysis system  and despite the time and money that was
thrown at it, the system didn't ever work in a friendly way. It kept
seizing up, was unfriendly for downloading data for other programs, had to
be used indoors in highly controlled lighting environements and, even
then, there was so much time spent in trying to get clean continuous paths
and interpolating excessively that we would have been better off
digitising manually (if it had given us that option). Their newer system,
which I think is Window's based, may be much better (it would certainly
need to be). What you should be aware of though, is that the service was
extremely slow, they passed the buck from one staff member to another, and
their solution to any problem was generally an expensive upgrade rather
than providing technical assistance.  In contrast,  whenever I need
clarification of anything on the APAS system I e-mail Gideon directly. The
reply is always within one day and often within the first hour of sending
the message. 

Claire, I have no vested insterest in the APAS system and have taken the
time to write to you for two reasons:

1.  I am grateful to Gideon for his concern for individuals and the growth
of biomechancis rather than simply making large amounts of money.

2.  As the current President of the ISBS I am eager to see an increase in
the volume of biomechanics research.  Progress is currently thwarted by
uneccessarily expensive systems that prevent many people from contributing
to the science.  The APAS system has brought analysis within the reach of
ordinary departments and individuals.  If one has a reasonable budget, the
saving on video analysis equipment can be used towards other equipment
such as force plates and EMG etc (by the way, Gideon has an analogue
module that integrates nicely with the video system).  You could have a
much more versatile, friendly, and complete system for less than you will
pay for a Vicon or MA system. Further, you can get a site license for
little extra cost and have your students, even at undergraduate level,
doing some real research on a powerful and friendly system.

I too was sceptical of the offers made by the Ariel company.  In fact,
when I hosted the 1999 ISBS conference in Perth I initially rejected
Gideon's offer to give delegates free Ariel software.  As I got to know
Gideon I realised that he is genuine in his desire to facilitate
biomechanics research.  If I was not convinced of this I would not be
risking my reputation as the President of the ISBS. 

I strongly suggest that you have a look at the APAS system before spending
excessively and unecessarily on either the MA or Vicon systems.

Sincerely,

Ross

Professor Ross Sanders PhD
Chair of Sport Science
Department of Physical Education Sport and Leisure Studies
Moray House Institute of Education
The University of Edinburgh
Cramond Road North
Edinburgh EH4 6JD

Email r.sanders@ed.ac.uk
Telephone  (+44) 131 312 6001 ext 208 or 212
Fax (+44) 131 312 6335

ISBS:  http://www.uni-stuttgart.de/External/isbs

Hello Eric,
 
Thank you for your message and your interest in the Ariel Performance Analysis System (APAS).  Based on the description of your activities, the APAS should work very well for your applications.  Also, the APAS is modular so you can upgrade the system at a later date (depending on the current technology).
 
Please send us your Company Name, Address, Telephone and Fax numbers so we can provide the requested Price Quote.
 
I will provide answers in Bold Italics below each of your questions.  Please feel free to contact us for any additional information.
 
Sincerely,
 
John Probe
Ariel Dynamics, Inc.
 
----- Original Message -----
Sent: Friday, February 23, 2001 8:34 AM

Dear Ariel,
 
My name is Eric de Ruijter. I am living and working in the Netherlands in the field of sport biomechanics. I got my degree in Human Movement Science from the Free University of  Amsterdam. Our officially registered company is called Sport Assistance (KvK number 20100108). 
 
We wants to buy your APAS system for video based movement analyses. Our main clients are professional speedskating on ice clubs. As you know in Holland this is a professional sport. Our budget at the moment is low as we started our company 4 monthes ago. However we are growing to a very high budget already about 1,5 years. We want to start with a mimimal APAS system for 2D or 3D which could be used for fieldwork and in our laboratory. In future we want to upgrate this minimal system with highspeed cameras, EMG, force plate, extra cameras, ecc.
 
1) I ask you to send us an official price quotation. We need a minmal APAS system without hardware as we want to buy this hardware in the Netherlands to save money from taxes. We are also in the posession of a personal computer (1000mhz, 20gb, sony 17inch monitor).
 
ADI:  The minimum system that can be purchased is the Basic APAS (software only).  This includes the capability for 2D and 3D analysis with support for automatic digitizing and panning cameras.  You would be required to supply the computer, frame grabber, monitor, cameras etc.  The cost for this option is $5,000.00 USD.
 
 
2) However, could you give us a good description of which hardware we have to buy here in the Netherlands to make our system functional (for example the specific type of two 60 hz cameras). This is important as it is difficult to understand what exactally we need for our system.
 
ADI:  There are many options to the hardware, however, the basic APAS we sell consists of the following:
   Computer 650 MHz (Pentium or equivalent)
   *Frame Grabber (Digital Video IEEE 1394 Firewire compliant)
   Video Card (8 MB Memory or better)
   *2 Digital Video Cameras w/ tripods
   Computer Monitor
   Calibration Cube
 
Notes: 
*1.  If you plan to use analog (VHS, SVHS) cameras, then you will require an analog frame grabber.  Digital Cameras require a Digital Video frame grabber.  The APAS software will work with raw Digital Video or Microsoft compatible AVI video files.
 
2.  If you require the high speed modes (100/120 H and 200/240 Hz) of the JVC Cameras, you will also require the Ariel Software drivers to support the JVC cameras.  No additional software is required to 50/60Hz analysis.
 
3.  Two-dimensional analysis requires only a single camera.  Three-dimensional analysis requires a minimum of 2 cameras but will support any number.  Most users use 2 or 3 cameras for 3-D analysis.
 
 
3) could you tell us if our computer could be used for analyses without a special driver or other components or something like that?
 
ADI:  If you purchase the $5,000.00 Basic APAS, you will be able to perform 2D/3D analysis.  You can download the software and test it for 30 days absolutely free-of-charge to verify this!
 
 
4) If we buy your system can I fly to your company to have a (2 days?) instruction?
 
ADI:  Definitely, if you purchase the system you can come to California for training.  We would have to verify the schedule and to make sure there are no other conflicts.
 
We hope to hear from you soon,
 
Sinceraly yours,
Eric de Ruijter - Sport Assistance 
 

Hello Baihua,
Thank you for your message.  The Ariel Performance Analysis System (APAS)
utilizes an algorithm that incorporates position, velocity and acceleration
as well as the brightness and contrast of the marker.  The APAS supports
markers that are light or dark relative to the imediate background.

In the event of a missing marker or two markers crossing paths, the
automatic digitizing software will temporarily stop and wait for user
intervention to confirm the location of the missing and/or conflicting
marker.  Once the user confirms the location, the automatic digitizng
process resumes.

If markers move out of the field of view (a hit ball for example) for
extended periods, then the APAS also includes an option where the user can
label the point as "missing" so the software will not look for that marker
until it is labeled as "visible" again.

I hope this helps to answer your questions.

Sincerely,

John Probe
Ariel Dynamics, Inc.
Email:  ARIEL1@ix.netcom.com

----- Original Message -----
From: "Baihua Li" <bbl00@aber.ac.uk>
To: <ariel1@ix.netcom.com>
Sent: Sunday, March 04, 2001 3:07 PM


>
> Dear Sir,
>
> I am a PhD student in computer science. I am very interested in
marker-based
> optical Mocap system.
>
> I know motion analysis has very advanced technologies in this area, would
> you please give me some suggestion on marker auto-labeling and how you
handle
> missed marker data by software in your system? if you can recommend some
> papers and
> Web sits of research group, I will be very grateful.
>
> I am so sorry, maybe I touch your commercial secrets, But I am so looking
> forward to your help, even some general information are still very helpful
!
>
>
> Thank you very much!
>
> Regards,
>
> Baihua.

 

Hello Dr. Sabick,

 
Thank you for the message.  I am glad to hear that you are happy with the software.  Answers to your questions are listed below.
 
Please feel free to contact us for any additional information.
 
Sincerely,
 
John Probe
Ariel Dynamics, Inc.
 
 
DIGI4
====
System defined points are normally used when analyzing the human body.  The software utilizes a specified set of points and "knows" the manner in which to connect the points.  Default segmental information is entered based on Dempster's data, however, the user always has the option to change these numbers.  Extra points (such as golf clubs, baseball bats, tennis raquets etc) are entered using the R1 R2....L1, L2 etc points.  When "System" is selected, the software will automatically connect sequential "extra" points (R1 to R2 to R3 etc.).
 
User-defined points are usually selected to customize the point labels or when digitizing something other than a human body.  Since the software has no idea what is being digitized, there are no automatic connections between points.  The user must specify the connections using the SEGMENT tables.  Each point can be connected with up to 5 other points, though points can only connect to lower number points.  For example, point #2 can connect to point #1, however, point #1 cannot connect to anything (since #1 is the lowest number).
 
ADDING NEW CONNECTIONS (See attached diagram)
=========================================
New connections (or segments) can be performed by selecting the SEGMENTS button from the Sequence Information menu.  Then follow the steps below.
1.  Select the NEXT POINT button to advance to the desired point.  The current point is listed in the Joint Name field at the top of the menu box.
2.  Click the mouse on the next available row in the connection table.
3.  Click the black arrow and select the point to which the current joint will be conntected.
4.  Enter the Segment Name, Mass, CG Fraction,  Radius of Gyration, Type and Color.
5.  Select either the Previous Point or Next Point button to save the new connection.  At this point, you can return to Step #1 to make additional connections.
6.  Select the OK button to return to the Sequence Information menu.
 
TRANSFORM
===========
The best method to check the accuracy of the digitizing is to digitize the control points and then digitize points of known dimensions within the calibrated area.  This is often performed by digitizing the same control points as data points and then graphing the X, Y, Z coordinates of these points.  This provides the "calculated" coordinates whcih can then be compared to the "known" coordinates.
 
 
 
----- Original Message -----
From: "Michelle B. Sabick, Ph.D." <michelle@phoenixbiomech.com>
To: <gideon@arielnet.com>
Sent: Wednesday, February 07, 2001 8:58 AM
Subject: Question regarding Digi4 and Transform modules


> Greetings-
>
> I am currently "test driving" the APAS system on the Windows98 platform.
> After completing about half of my trial, I am very happy with the software
> and am trying to figure out how to budget a purchase of the full version.
> However, I have a couple of questions regarding the Digi4 and Transform
> modules that I have not been able to answer from the online documentation.
>
> DIGI4:  When creating or modifying the points and connections in a
sequence
> I am confused.  Assuming I use the "system" points, how do I enter a point
> that is not on the selection list? For example, a point on a golf club.
Am
> I supposed to use the R.1, R.2 selections as "generic" points?  If not,
what
> do these abbreviations stand for, and how do I enter additional points?
>
> I also do not understand how to use the "segments" dialog box.  I have
tried
> to enter values in several different places, but have not succeeded in
> creating any new connections between points.  I have not found any
reference
> in the documentation to how you use this particular window.
>
> TRANSFORM:  Is there a way for me to view the accuracy with which I
> digitized the calibration object and quantify my errors?  I know the DLT
> parameters can be displayed after the 3-D transformation is complete, but
is
> there a way for me to see which calibration points had the most error,
etc?
> This is especially important since I use a "sputnik" type calibration
> object, and it is possible to digitize the wrong rod completely in certain
> orientations.  Right now I do not know how I would figure out I had made a
> mistake in digitizing the calibration object.
>
> Thanks in advance for your help.  I look forward to using the APAS system
in
> the future.
>
> Sincerely,
>
> Michelle Sabick
>
> ******************************************************
> Michelle B. Sabick, Ph.D.
> President & Chief Biomechanist
> Phoenix Biomechanics, LLC
> 7351 S. Brook Forest Drive, Evergreen, CO 80439-6844
> phone: 303-679-1230  fax: 303-679-1164
> michelle@phoenixbiomech.com  www.phoenixbiomech.com
> "Professional Biomechanics Consulting Services"
> ******************************************************
>

 

 

Hi James,
 
Thank you for your message.  Listed (in Bold Italics) below you will find answers to each of your questions
----- Original Message -----
To: Ariel
Sent: Friday, February 02, 2001 6:43 AM
Subject: Re: Requested APAS Information
Hi
 
Many thanks for the information about APAS-2000, if I may ask specific questions:
 
1)  What is the maximum number of cameras which can be synthesized in a 3-D reconstruction?
 
ADI:  The APAS system will support any number of cameras.  A single camera is required for 2D analysis while a minimum of 2 cameras is required for 3D analysis.  Most APAS users find that 2 or 3 cameras will provide accurate data for most applications.  If you wish to look at activities with rotations (ie figure skating, gymnastics etc.) or with to determine segment rotations (ie gait analysis) as many as 5 or 6 cameras may be required.
 
2)  What metrics are available to the user to assess the quality of the re-construction?
 
ADI:  The APAS software utilizes the well-published Direct Linear Transformation (DLT) algorithm for spatial reconstruction.  The DLT Transform Parameters are also provided for each view used for the transformation.  Since the APAS is video-based, the user always has the option to superimpose the digitized image directly on top of the video to examine the source of the original data.
 
3)  What is the maximum resolution and maximum sampling rate of typical cameras?
 
ADI:  Standard NTSC cameras are capable of recording at 60 fields/second (30 frames/second).  Analog video frame grabbers usually capture at a resolution of 720x480 at 30 frames per second with up to 24 bit color. European PAL video format has resolution up to 768x576 at 25 frames per second.
 
Almost any camera can be used with the APAS.  We are currently using Digital Video cameras from JVC.
 
4)  Is there a maximum number of markers which can be automatically tracked?
 
ADI:  The APAS currently supports up to 40 markers.  These can be digitized using the manual or automatic modes.
 
5)  What tools are available for the user when the inevitable break in the track occurs?
 
ADI:  I assume you are referring to when there is a conflict of markers in the automatic digitizing process.  The APAS is designed to stop and wait for user input whenever there is a conflict.  For example, if two markers cross paths, or a marker is no longer visible from the camera, the APAS will stop at that point and wait for the user to verify the location of the current marker.
 
6)  Is it possible to email to me photographs of the system being used in a sports environment and typical output?
 
ADI:  There are several Powerpoint presentations listed directly on the Ariel internet site (www.arielnet.com).  From the main page, look in the sections titled "Slide Presentations" and "Galleries"
 
Also check the following links:
 
World Record Long Jump
 
Biomechanics Of Power Golf
 
You are also welcome to contact the following APAS users for their input.  Both contact are involved in the analyis of Olympic Level Sports.
 
Dr. Erik Simonsen
University of Copenhagen
 
Dr. Alfred Finch
Indiana State University
 
 
Many thanks
 
James Shippen
 
 
Dr James Shippen
School of Manufacturing and Mechanical Engineering
The University of Birmingham
Edgbaston
Birmingham  B15 2TT
Tel 0121 - 414 - 4153
Fax 0121 - 414 - 7484

 

Hello Kieran Moran,

Thank you for considering Ariel Dynamics Inc. (ADI) in your call for tender. We have provided a description below each of your listed items.

Please feel free to contact us for any additional information.


At 06:16 PM 08/14/2000 +0100, you wrote:
>The newly formed centre for Sport Science and Health is establishing a
>full 3-D analysis laboratory in its new building in the next few months.
>This is a call for tender to manufacturers of 3-D motion analysis
>systems. The finances for the system have not been finalised yet, but
>will be in the region of ´┐Ż100,000. The systems will be judged on the
>following criteria and requirements of the laboratory users. Addition
>features identified by manufacturers will also be taken into account. If
>manufacturers suggest a different system for inside and outside use, or
>for laboratory and roving use (e.g. a hospital setting one day, a
>factory another day), please provide full details and costing for both
>systems.
>
>1. Cost for full 3-D analysis system
>
ADI: Please refer to /Main/adw-54.html for the price list.


>2. Linear accuracy of the system: (a) a simple test of rotating a rod
>(1m long) in the field of analysis, and (b) a performer strapping 0.2m
>long rods (with markers attached to its ends) and performing turning
>motions. In condition b, the rods will be attached to the upper and
>lower aspects of the upper and lower extremities. Rods will also be
>attached to the chest and back.
>
ADI: Please refer to a 3rd party study presented at the International 3D conference in Tennessee. The report is listed on the Ariel internet site. The direct address is:

 /topics/comparison/default.htm 

>3. Angular accuracy of the system: as for liner accuracy, but two
>attached rods and three markers (of known relative orientation) will be
>used.
>
ADI: Please refer to the study mentioned in item 2 above.


>4. The ability of the system to automatically track the markers motions.
>
ADI: Though markers are not required, the APAS supports the ability to automatically track markers from up to 4 views simultaneously. An important advantage of the APAS is the fact that markers are not required to perform an analysis. For example, if you wish to analyze an event in the Olympics, you would not be allowed to place markers on the athletes. With the APAS, you would just video the activity, capture the video to the computer and manually select the desired joints for the first image. In the following images, the APAS software will predict the location of the next joint, however, it will wait for user confirmation to digitize the point. This feature allows "real-world" analysis to take place. Many times, the subject does not even realize that they have been analyzed.


>5. The ability of the system to allow manual marker identification when
>markers are hidden.
>
ADI: When markers are hidden or conflict with other markers, the APAS software pauses the automatic digitizing process and waits for user input to distinguish the correct marker locations.


>6. The ability of the system to interpolate (and the selection of
>interpolation algorithms offered to the user) for lost markers.
>
ADI: When markers are defined as "missing" the APAS software performs a linear interpolation between the "known" points.


>7. The ability of the system's software to determine joint centres when
>markers are placed on the body segment (and not when placed on a single
>anatomical site representing the joint centre). For example the shoulder
>joint.
>



>8. Rate of sampling: 50, 100, 250 Hz etc. Where higher frequency of
>sampling results in a reduction in the number of markers that can be
>used, this should be indicated.
>
ADI: The APAS supports video of any frame rate. The standard rates are 50 Hz PAL and 60 Hz NTSC. Higher rates of 100/120 and 200/240 Hz are supported for high speed digital camcorders. The APAS also allows the ability to use multiple frame rates within the same sequence.


>9. Is there any limitation on the number of markers that can be used?
>
ADI: The current limit is set to 50, however this can be increased if required.


>10. Software that will allow calculation of joint kinetics when a force
>plate (and force plates) is added.
>
ADI: The APAS-Gait program is designed to calculate joint kinetics using a force platform and 5 cameras. This program supports the industry standard marker sets (Helen Hayes and Kit Vaughn). Please refer to the following internet address for additional information.

/Gait/index.html 


>11. Software for easy production of patient reports.
>
ADI: All APAS software is Windows compatible so patient reports are easliy generated.

>12. Software to allow exportation of data.
>
ADI: The APAS allows data (raw and filtered) to be exported in ASCII or worksheet format.


>13. Software (either of the companies or a linked function to other
>software) for producing high quality, full body animated (rendered)
>figures, which ACCURATELY depict the movement of the subject wearing the
>markers. The software should allow the user to design different full
>body figures.
>
ADI: The APAS 3D-Renderer program is used to render any activity analyzed using the APAS. Please refer to the following internet address for additional information.

/Renderer/index.html 


>14. The ability of the systems to incorporate synchronous data from
>other devices (force plate, emg, ecg, eeg etc)
>
ADI: The APAS Analog module is required for collecting analog data. This module supports all commercially made force platforms, EMG and other analog signals.


>15. Support and training
>
ADI: The APAS system consists of "off-the-shelf" hardware items with specialized software. The majority of our support is conducted using Email and FTP capabilities of the internet. APAS software upgrades are provided free of charge (as long as your hardware supports the software) and can be downloaded directly from the Ariel internet site at your convenience.

Training can be conducted at the Ariel office or "on-site" at the customer facility. Costs will vary depending on locations, lenght of training etc. An approximate cost would be $1,500 USD per day, plus expenses.


>16. Servicing contract
>
ADI: Service contracts for the APAS can be purchased at a cost of 10% of the original system cost per year.


>17. Extra cost for allowing multiple computer usage of software for
>teaching purposes.
>
ADI: With the purchase of the "master" APAS system, the same customer can purchase additional workstation software licenses at a cost of $575 USD per computer. The APAS-Workstation allows full data analysis capabilites but does not support data collection.


>The system will be used for sports as well as athletic, hospital and
>factory (ergonomics) based studies.
>
>While I am sure that manufacturers have recorded data regarding the
>accuracy of their system and the degree to which many of the above
>system factors are addressed, I would like to have at least one day
>examining these issues in our laboratory. Therefore, an open invitation
>will be extended to all interested parties.
>
>Finally, examples in the UK where your system is being employed for
>similar usage would be advantageous.
>
ADI: Select APAS users in the UK include

Manchester Metropolitan University
Sheffield Hallam University
Canterbury Christ Church University College
Glasgow University Veterinary Hospital
St. Martin's College
University College Salford
University of Edinburgh
Keele University Bionic Gait Laboratory
University of Sunderland
Total Fitness Limited, Dublin



>If you have any questions, please do not hesitate in contacting me.
>
>Yours Sincerely
>
>Kieran

>--
>Dr Kieran Moran
>Director
>Biomechanics Research Group
>Centre for Sport Science and Health
>Dublin City University
>Dublin 9
>Ireland
>
>tel: 00353 - 1 - 7008011
>fax: 00353 - 1 - 7008888
>
>e-mail: kieran.moran@dcu.ie
>

 

Hello Dr. Chung-huang Yu:

Thank you for your Email message. Answers are provided below each of your questions.

Please feel free to contact us for any additional information.



----- Original Message -----
From: "chyu" <chyu@tmc.edu.tw>
To: "Ariel" <ariel1@ix.netcom.com>
Sent: Monday, October 16, 2000 12:10 AM
Subject: Price?


> Dear Ariel,
>
> After reviewing the information from your web and discussion with you, we
> decided to have a go to setup a motion analysis with APAS. In order to
save
> tax, we would like to purchase the hardware here and but the software and
> support from you. Now, come to the questions about software and some
other
> special hardware:
> 1. From the internet the APAS is US$5,000, any discount from an
educational
> institute?
>
ADI: The APAS system is the least expensive system on the market and provides manymore functions than competing systems. The listed prices have already been discounted.


> 2. How many computers can I installed the software on?
>
The APAS can be installed on as many computer as you like. Once the first "master" system is purchased, then additional licenses are $500 per computer within the same facility.

> 3. How about software upgrade? Any charge for that?
>
ADI: Ariel Dynamics Inc. provides free upgrades for the life of the equipment (as long as the hardware supports the software). Upgrade software is posted on the Ariel internet site and can be downloaded and installed at the customer's convenience.

> 4. Where can I get the calibration cube for gait, or how can I make it ?
>
ADI: You can purchase the calibration cube directly from us or you can also make your own. The idea behind the calibration cube is precisely known measurements that can be setup on a repeated basis. Calibration cubes can be made out of PVC pipe, galvanized pipe, aluminum tubing etc. Many users have also hung strings from the ceiling of the lab. Each string has "known" points that are measured relative to a single origin. When the calibration device is not required, the strings are simply retstrained off to the side by hooks on the wall. A typical calibration cube for gait analysis should be approximately 3m long x 1m wide x 2 meter high since the calibration device should encompass the area of activity to be analyzed.

> 5. Where can I get the calibration cube for hand/finger function analysis,
or
> how can I make it?
>
ADI: Refer to the information listed above. The same rules apply. This simply means that you would require a much smaller calibration cube. One option that has been used here is plastic building sets for children. This consists of varying lengths of hollow tubes approximately 1 cm in diameter. These tubes can be configured to different sizes and then measured for the calibration device.

> 6. What kind of markers (size/shape/color...) do you suggest for gait and
where
> to get it?
>
ADI: The standard markers that are sold as options with the APAS consist of Retro-reflective tape wrapped around a 0.75 inch diameter ball. We can special order markers of any size. Just let us know what size you require. We can also supply the tape if you wish to make your own. We have used markers from several mm in diameter up to several inches.

> 7. The same as 6, but for hand /finger function analysis?
>
ADI: Refer to answer #6 above.

> 8. Where to put the markers for hand function analysis ?
>
ADI: When using markers, they should be placed as close as possible to the joints to be analyzed. I am not aware of any industry standard placement for hand analysis. The location is decided upon by the researcher.

> Thanks for your kind help in advance.
>
>
> Yours Sincerely,
>
>
> Chung-huang Yu PhD
> Assistant Professor
> 252 Wu-Hsing Street,
> Department of Physical Medicine & Rehabilitation
> Taipei Medical University Hospital
> Taipei, Taiwan
>
> Tel: +886 2 27297717
> FAX: +886 2 23776781
> chyu@tmc.edu.tw
>
>
>

 

Hello Brian,

Thank you for your message and your interest in the Ariel Performance
Analysis System (APAS).  It appears that you have already viewed some of
the information on the Ariel internet site (www.arielweb.com).   Also note
that you can download a Fully Functional copy of the APAS software at no
charge.  This allows you to test the software prior to purchase.

I have listed several direct links to pages on the Ariel web site that may
be of interest.

1. Third party evaluation of commercially available systems
www.arielnet.com/topics/comparison/default.htm

2. Universities and Studies Using the APAS
www.arielnet.com/topics/Selected_Universities_and_Studies/Default.htm

3. APAS Validation Studies
www.arielnet.com/topics/Selected_Universities_and_Studies/Default.htm

4. Online APAS Manuals
www.arielnet.com/Main/adw-91.html

5. APAS Price List
www.arielnet.com/Main/adw-54.html


Based on the information provided in your Email, it sound like the best
option for your applications would be the Ariel High Speed System.
Information can be found at the link below.

www.arielnet.com/topics/High_Speed_Cameras/default.htm

This system sells for $15,000 and includes the following:  450 MHz
computer, 64 MB RAM, CD-ROM, 1.44 FDD, mouse, keyboard, 2D and 3D APAS
software (includes automatic digitizing and panning capabilities), and two
60/120 Hz digital camcorders with the Ariel software drivers.  (Monitor is
not included).

In order to support the analog signals from the foce plate, you would also
require the 16 Channel Analog option (Hardware & Software).  In general,
the prices for the system you mentioned are listed below.

APAS High Speed $15,000.00
Ariel 16 Channel A/D: $ 9,000.00
AMTI Force Platform: $15,950.00
======================================
Total: $39,950.00

This would be a fully functional analysis system with the following
capabilities.
2D/3D system with 60 Hz and 120 Hz capabilities
Automatic digitizing
Support for Panning Cameras
Support for 16 analog channels
Force Plate

Please feel free to contact me for any additional information or if you
require a formal quotation.

Sincerely,

John Probe
Ariel Dynamics, Inc.
4891 Ronson Court, Ste. F
San Diego, CA 92111-1815
Tel:  (858) 874-2547
Fax:  (858) 874-2549
Email:  ARIEL1@ix.netcom.com
Internet:  www.arielweb.com


Hello Nikolaus Troje,

Please check on the Ariel Performance Analysis System (APAS99) at
(www.arielweb.com).  The APAS is the world's most advanced computerized
system for biomechanical analysis and the study of human motion.  Areas of
successful application for the APAS include athletic performance, injury
and rehabilitation assessment, quantification of loss for compensation
claims, equipment and product testing and development, determination of
potential or actual risks for products and activities in liability
litigation, as well as applied research in the areas of orthopedic
medicine, therapeutics, and physical training.

The APAS integrates state-of-the-art computer and video processing hardware
with specialized software modules that perform data collection, analysis,
and presentation.  Objective quantifiable documentation is provided for
both 2-Dimensional and 3-Dimensional analysis.  Specific points of interest
can be digitized with user intervention or automatically using contrasting
markers.  Stick figures are then generated and can be synchronized with
kinematics data.  Additionally, up to 32 channels of analog data (i.e.
force platform, EMG, goniometers etc.) can be synchronized with the
kinematics data.

The Internet site provides technical specifications, pictures,
publications, Ariel Users, on-line manuals, price lists and much more. You
can also download the APAS software for evaluation prior to purchasing.

After reviewing the enclosed information, please feel free to contact me
for any questions you may have or additional information you require.

Sincerely,


John Probe
Ariel Dynamics, Inc.
4891 Ronson Court, Ste. F
San Diego, California 92111  USA
Tel:  (858) 874-2547
Fax:  (858) 874-2549
Email:  ARIEL1@IX.NETCOM.COM
Internet:  www.arielweb.com




At 08:45 PM 9/1/99 PDT, you wrote:
>Dear Biomch-lers,
>
>I want to purchase a 6 camera motion tracking system to acquire motion
>data from both humans and animals (mainly pigeons). 60 Hz is sufficient,
>real-time is not necessary. The data will be used for motion analysis as
>well as for animation purposes. Working with animals requires
>lightweight, passive, i.e. non-wired markers. Some features may not be
>trackable at all with retroreflective markers and will require manual
>tracking (I mean this tedious mouse clicking). For that reason I am
>looking into systems that allow direct access to the video/ccd footage.
>Vicon is offering me a systems with additional video cameras genlocked
>to their CCD tracking system. Otherwise I know only the system by Peak
>Performance that would fulfill all the requirements. Does anybody know
>about alternative systems? Can you provide me with info about your
>experience with the Peak system?
>
>Thanks,
>
>Niko Troje
>
>--
>-----------------------------------------
>Nikolaus Troje
>Fakultaet fuer Biopsychologie
>Ruhr-Universitaet-Bochum
>
>currently at:
>
>Xerox PARC
>3333 Coyote Hill Rd.
>Palo Alto, CA 94304, USA
>phone:   (650) 812 4401
>
>email:   niko@psyc.queensu.ca
>WWW: http://psyc.queensu.ca/~niko
>-----------------------------------------
>
>---------------------------------------------------------------
>To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
>For information and archives:   http://isb.ri.ccf.org/biomch-l
>---------------------------------------------------------------
>
++++++++++++++++++++++++++++++++++
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California  92111  USA
(858) 874-2547 Tel
(858) 874-2549 Fax
Email:  ARIEL1@ix.netcom.com
Web Site:  http://www.arielweb.com
++++++++++++++++++++++++++++++++++

Frederike,
Answers are provided below each question


----- Original Message -----
From: <m.j.van-wyck@ncl.ac.uk>
To: <gideon@arielnet.com>
Sent: Wednesday, August 02, 2000 8:48 AM
Subject: APAS specifications please


> Dear Dr. Ariel,
>
>
> thank you for your information in your email to me dated 25/05/00. 
> I'm sorry about the delay in getting back to you.  You may remember
> my previous request:
>
> ------------------
> Here at CREST (the lead of a European Consortium), we are developing
> an educational CD-ROM about movement assessment in neurology  for
> health professionals and researchers. The CD-ROM will contain
> information on state-of-the-art motion analysis systems and will
> indicate the potential benefits of integrating measurement technology
> with clinical assessments.
>
> If you approve, we would like to include the name of your company, as
> well as some examples from your product range and illustrations of how
> the technology has been applied, in our CD-ROM.  Should you have any
> objections, please inform me so I can ensure the information will not
> be included in our CD-ROM.
> ----------------------
>
> We are now in the process of putting the final version together and I
> am in the process of updating my information.  I should be very
> grateful if you could help me with the folowing points, which I
> didn't seem to be able to find on your website - apologies if I
> missed the information!  Here we
> go:
>
> 1. what is the accuracy and precision of the instrument at a
> specified range?
>
Answer 1:
Please refer to 3rd party independant studies for these measures.  Results
can be found at the following internet sites:

www.arielnet.com/topics/comparison/default.htm
www.arielnet.com/topics/ApasValidation/ApasValidationStudies.html



> 2. what is the maximum resolution at a specified range?
>
Answer 2:
Please see studies above.



> 3. what are the sources of error?
>
Answer 3:
As with any system, sources of error include digitizer error, frame shifts
between cameras, smoothing algorithms etc.


> 4. how long does it take to set up the system (for non-technical
> staff)
>
Answer 4:
Minimal set-up is required with the APAS.  Digitizing is performed from
captured video images so setup only requires placing the cameras on
tripods.  Equipment for a full 3D analysis could easily be setup in less
than 5 or 10 minutes.


> 5. does the system require specialist technical support (I'm thinking
> from the perspective of the busy, non-technically oriented clinician)
>
Answer 5:
No, the APAS does not require special technical support.  Non-technical
users regularly learn the APAS system in a matter of 1 or 2 days.  Due to
the friendly nature of the APAS software, most users are self-taught as
oppsed to receiving any formal training by Ariel personnel.


> 6. does the system need calibrating, if so, what are the routines the
> operator needs to carry out?
>
Answer 6:
All movement analysis systems must calibrate the area around the sequence
to be analyzed.  With the APAS, this is performed by placing a
"calibration" object in the field of view of all cameras.  This calibration
object has points with precisely known coordinates.  The calibration object
is recorded from each camera view and then can be removed.  The calibration
points are digitized in the software and the corresponding X, Y, Z
coordinates values are entered in the software.


> 7. in how far is data collection automated?
>
Answer 7:
Data collection is performed by simply recording the desired activity with
standard video cameras.  Data collection is performed by simply starting
the cameras, recording the activity and stopping the cameras.


> 8. how are joint centres of movement identified and can this process
> be automated?
>
Answer 8:
The APAS supports two methods for identifying joint centers.  When using
the automatic digitizing option, reflective markers are placed over each
joint center.  This allows the APAS software to automatically digitize the
marker.  A second (and recommended) method is "semi-automatic" digitizing.
This means that each joint center is initially digitized by the user.  Then
for each successive image, the program predicts the location of the joint
center but waits for the user to confirm the point location.  This allows
the user to analyze "real-world" activites without the subject even knowing
that an analysis is being performed.  Reflective markers are not required
for this type of digitizing.


> 9. in how far is data analysis (3D reconstruction of movement)
> automated?
>
Answer 9:
As stated above, digitizing can be performed automatically or
"semi-automatic" modes.  The 3D recontruction is performed using one of two
algorithms; the well published Direct Linear Transformation (DLT) or the
Physical Parameter Transformation (PPT) developed by Ariel Dynamics, Inc.


> 10.  can data be displayed in real-time?
>
Answer 10:
The Ariel Display module allows simultaneous display of Video, Worksheet,
Stick Figure and Graphical data.  All windows are automatically
synchronized and can be viewed in either step-by-step or real-time modes.


> 11. can the system be integrated with other instruments (e.g. EMG)?
>
Answer 11:
Yes, the APAS can be integrated with EMG, Force Platform, Goniometers,
Accelerometers etc.


> 12. is the system compatible with Windows software?
>
Answer 12:
Yes, the APAS can operate from Windows 95/98, NT or Windows 2000 environments.


> 13. is there an automatic report facility?
>
Answer 13:
The APAS Display module has an option for creating User-Defined Templates
for data analysis.  Once a Template is defined, the user specifies any
sequence and the selected data is displayed.  This data can be video,
graphical, stick figure and/or worksheet format.


> 14. what is/ are the output format(s) of the data?
>
Answer 14:
As stated above, the output formats for APAS data include:  ASII,
Worksheet, AVI files, graphs and stick figure data.


> 15. are there special requirements for the lab (e.g. no direct
> sunlight?)
>
Answer 15:
There are no special requirements for using the APAS in the lab.  Because
of the portability, the APAS can be easily and effectively used in either
indoor or outdoor environments.


>
> I will be grateful for your assistance and look forward to receiving
> your information.
> Thank you very much again for all your help.
>
> Yours sincerely,
>
>
> Frederike
> Frederike M.J. van Wijck
> Centre for Rehabilitation and Engineering Studies (CREST)
> Department of Mechanical, Materials and Manufacturing Engineering
> G26 Stephenson Building
> University of Newcastle
> Newcastle upon Tyne NE1 7RU
> UK
> phone: + 44 (0)191 2226000 ext 6193
> fax:+44 (0)191 222 8600
> email: "F.M.J. van Wijck"<m.j.van-wyck@ncl.ac.uk>
> http://www.ncl.ac.uk/crest/
>
>
>

 

Dear Tomislav-

Gideon asked me to help you with your request for information regarding the
3D transformation algorithms the the APAS system uses.

Underlying the DLT is a physical model of the camera with 10 physical
parameters. These are:
       XYZ location of camera origin [3]
       Orientation of the camera axis [3]
       [u,v] offset if the intersection
           of the camera axis with the projection plane [2]
       "u" & "v" distances from camera origin to projection plane [2]

These 10 parameters define the transformation from lab xyz units to camera
digitizer units. Unfortunately the equations are non-linear and lead to a
rather messy solution when trying to calculate xyz from two or more sets of
(u,v) information. The DLT solution to the problem allows one to write a set
of linear equations with 11 DLT parameters which  make solving the problem of
reconstructing  xyz's in the lab  much easier. These 11 DLT parameters can be
written in terms of the 10 physical parameters first discussed.

The problem with the 11 DLTs is that they are not all independent since there
are really only 10 degrees of freedom. The upshot of this is one can [and
actually always does] end up with a set of 11 parameters which describe an
inconsistent set of 10 physical parameters. This expresses itself in a
transformation  the orientation part of that does not preserve length which
is definitely not desired.

Our PPT [physical parameters transformation] sidesteps this shortcoming by
not calculating the DLT from the control point information directly but
rather calculates the 10 PPT parameters directly from the control point
information. This process finds the "best" set of 10 PPTs which minimize the
total square deviation of the (u,v)'s digitized for a camera view from the
projected (u,v)'s when run through the PPT given the known lab xyz's for the
control points using standard non-linear minimization techniques. With the
PPTs known one can then generate the 11 DLTs in a completely consistent way.

When one uses a panning camera it is essential to work with the physical
parameters of the camera since these are changing in time.

I know your request was for source code. Unfortunately the actual
implementation of the algorithm is proprietary and something which we do not
distribute.

You will find a good  & detailed presentation on the relationship between the
DLT & camera parameters in at thesis by James Walton, 1979, "Close-Range
Cine-Photogrammetry". Also I made a presentation on this topic about 6 years
ago at the ISB when it was at Poitiers, France. I cannot seem to find my copy
of the proceeding at the moment. If you are interested in that & have trouble
locating the proceedings let me know.

I hope this information helps.

Sincerely,
         Jeremy Wise
         Dir R&D



In a message dated 9/28/99 9:03:48 AM Eastern Daylight Time,
gideon@arielnet.com writes:

<<
 Dear Sir,
 
     it has been a week since I attended your lecture in Zagreb, Croatia.
You were nice to forward my questions, concerning some source codes, to your
associates. So far I haven't heard from them . I do want to sound impatient,
but just to remind you in a case a message has got lost somewhere (Also if
there is any kind of problem I would like to be aware of it). Thank you again
for your time and patient. Looking forward to hear from you,
 
                     Tomislav.
 
 P.S. I do not mind to contact your associates directly with your permission.
  >>

Hello Steve Bailey,

Thank you for your interest in the Ariel technology.  Unfortunately, there
is no margin in our prices to spend $3,000.00 for an on-site demonstration.
 Our prices are low because we sell directly from our main company. We do
not have to pay the salaries of the "middle-man" and area sales
representatives.  I would like to make the following recommendations to
help eliminate any uncertanties.

First, you should compare all available systems for features and price.  I
fully understand having reservations on purchasing a system because I was
once in the same situation.  I worked in the Anthropometry and Biomechanics
Lab at the Johnson Space Center and was tasked with purchasing a movement
analysis system.  I checked all the commercially available systems by
personally visiting each company.  There was no comparison between the APAS
and other systems!  I purchased a single APAS and was so pleased with the
results that 4 more systems were purchased at a later date.  Please do not
take my word for this.  I encourage you to fully examine all available
systems and compare them feature-by-feature. 

I also want to refer you to a 3rd party independent study performed by Dr.
James G. Richards at the University of Deleware.  Dr. Richards was the
keynote speaker at the Fifth International Symposioum On The 3-D Analysis
Of Human Motion, July 2-6, 1998 in Chattanooga, TN.  His presentation was a
comparison of the commercially available systems for movement analysis.  I
have provided a direct link to his presentation below:

www.arielweb.com/Topics/comparison/default.htm

Make certain that you review the full report by scrolling down to the
bottom and selecting the NEXT button for additional pages.

As a second option, you can download the software directly from the Ariel
internet site (www.arielweb.com) and evaluate it for 30 days prior to
purchasing.  No other system in the world will let you do this!  You can
find on-line manuals and tutorials for detailed explainations on the APAS
system operation.

Manuals:  www.arielweb.com/Main/adw-91.html
Tutorials:  www.arielweb.com/topics/Tutorials/default.htm

Contact existing Ariel customers as a third option.  I know that you have
already visited Dr. Brian Bergemann at Campbell University.  He purchased
the APAS and CES systems at the United States Sport Academy (as well as the
APAS at Campbell University) and used them extensivley for sport analysis.

Other contacts that have multiple APAS systems:

Erik B. Simonsen, Ph.D.
University of Copenhagen, Denmark
Email:  E.Simonsen@mai.ku.dk

Alfred Finch, Ph.D.
Indiana State University
Email:  pmfinch@scifac.indstate.edu

Mike Greenisen, Ph.D.
NASA, Johnson Space Center
Email:  michael.c.greenisen1@jsc.nasa.gov

Sun G. Chung, M.D., Ph.D.
Seoul National University
Email:  suncg@medicine.snu.ac.kr

Pierre Gervais, Ph.D.
University of Alberta, Canada
Email:  pgervais@per.ualberta.ca


Lastly, we would be happy to provide an APAS demonstration at the Ariel
office in San Diego, California.  If you are interested in this option,
please contact us so we can make arrangements for a convenient time.

I hope this provides additional information and several options to help
eliminate any doubts about purchasing the Ariel system.  Please feel free
to contact me for any additional questions.  I would be happy to help.

I look forward to your reply!

Sincerely,

John Probe
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, CA 92111-1815
Tel:  (858) 874-2547
Fax:  (858) 874-2549
Email:  ARIEL1@ix.netcom.com



At 04:46 PM 6/10/99 -0400, you wrote:
>Dr. Mr. Probe,
>
>I am the research coordinator in the Department of Physical Therapy
>Education of Elon College in Elon College, NC. We have been
>communicating with various Ariel employees and have visited the lab at
>Campbell University. At this time it is very likely we will purchase an
>Ariel system for motion analysis. This would include the following:
>
>1. Software and license for 2 computers        $5500
>2. High precision calibration cube             $1500
>3. Reflective markers (30/order) X 2           $600
>4. 3 Industrial light cameras                  $900
>5. Time code read/write                    $1500
>6. Intreface to forceplate and EMG            $1500
>
>Total
>$11,500
>
>We also expect to purchase from a local company 1 Super VHS recorder
>($3100), 2 SVHS cameras ($1800 each), and gem locks. In the future we
>hope to purchase up to 4 High speed cameras (120-240 Hz); however, we
>are presently financially limted to the SVHS cameras.
>
>While we are 90% sure that purchasing an Ariel system is right for us,
>our biomechanist (Sue Chinworth) still has some reservations.
>Consequently, I am writing you to see if you consider the following.
>Will you allow somebody from your company to come to our institution,
>set up and demonstrate the system to us prior to purchase ? If you are
>willing to do so, I believe that I can guarrentee that the individual
>visiting us will walk away with a completed P.O. if we are satisfied. If
>this process is not acceptable to you could you suggest a way that Sue
>C. can get some in depth experience with the system from someone who
>knows it inside and out prior to purchase. Also, if you think we can
>purchase those extra items through you more economically please let me
>know.
>
>Thank you for your time and consideration in this matter. I look forward
>to hearing from you.
>
>Stephen Bailey, PT, Ph.D.
>
>

 

Hi Jim:

  I will answer between the lines:

---- Original Message -----

From: Jim Luk <biomechanics@cuhk.edu.hk>

Sent: Tuesday, June 01, 1999 7:56 PM

Subject: Enquiry on APAS

 

> Dear Sir/Madam,
>
> I am the participant of ISBS99. As I know that Ariel Dynamic will be the
> major sponsor in ISBS99 at Perth. Moreover, a compact disc with the full
> APAS system, valued at over $5000.00 US, will be distributed to every
> delegate at ISBS99. I have gone through the Ariel Dynamic homepage. As I
> know that the *.avi formating file will be suitable in using APAS system. I
> would like to ask some questions about the APAS motion analysis system.
>
> 1. Does the full version of APAS system, which distributed at Perth,
> including the Panning & Tilting & Zooming Module ? If not, can I buy this
> module individually. What is the price for this module ? US$ 5000 ?

The APAS include the Panning module with it.  There are two options:

a. Software, which included

b. Hardware which cost $5000

  You do not need to spend $5000 on the hardware. The software option is as good or better. Check on our help screens on our web site at: http://www.arielweb.com

>
> 2. Does the full version of APAS system, which distributed at Perth,
> supporting the Panning & Tilting & Zooming Module ?

 

The software support the Panning module.


>
> 3. I can get the full version of APAS system at Perth. Can I buy the high
> speed camera JVC DVL7 individually if I want to perform motion analysis at
> 120 Hz. If so, what is the price. Does it US$3500 for one camera ?

 

Yes.


>
> 4. I would like to use the high speed camera at 120 Hz with the APAS
> system, any optional items should be included.

 

The APAS only knows about .avi files. You do not need additional hardware


>
> 5. Does the APAS system contains synchronization unit when 3-D video
> filming in two DV cameras ?

 

 

We are using a "Software GanLock" It is included with the APAS system. You always can spend more money buying hardware to do the same.


>
> 6. Besides 120 Hz JVC high-speed video camera, will there have any other
> choice, such as 100 Hz(PAL), 200 Hz or 500 Hz, avaiable in the future.

 

It is available now. You can go to 1000hz with the Redlake capture board, for example.


>
> 7. If I want to get further information, can I contact our nearest agents
> (Hong Kong). If so, what is the contact information.

 

In the Internet World, who need an agent. Why would you spend money on an agent. Our system cost 1/50 of any other systems in the World primarily because we do not have an agents.  Agents always mark the system at least 100 percent. You do not need an agent. Just download the system from the web. It is the same as the one that is going to be given to you at Perth. So, just download it and I will send you the site key.


>
> I am looking forward to hearing from you. Thank you very much for your
> attention.
>
> Best regards,
>
> Jim
>
>
>
>
> Biomechanics Laboratory
> Department of Sports Science and Physical Education
> The Chinese University of Hong Kong
> Shatin
> Hong Kong
> Tel : (852) 2609 6079 or (852) 2681 6187
> Fax : (852) 2603 5781 or (852) 2681 6330
>
>

Dear Dr. Wieslaw Chwala,

Thank you for your interest in the Ariel Performance Analysis System (APAS-99). You can view all ofourproduct information on the Ariel internet site (www.arielweb.com). I will provie answers below each of your questions:


At 11:53 AM 4/1/99 +0200, you wrote:
>>>>

Wieslaw Chwala, PhD

Academy of Physical Education in Cracow

Laboratory of Biomechanics

Krakw, 28 March 1999


Dear Sir (Madam)


We are going to purchase a system for capturing human motion in 3D for its biomechanical analysis. We are interested in getting your offer.


We would like to know the following parameters of your equipment:


* Type of marker coordinate data acquisition (video, optoelectronic, etc.)
*

<<<<
The Ariel Performance Analysis System (APAS-99) is a video-based movement analysis system that supports BOTH automatic and semi-automatic digitizing using any type of marker. Note: One advantage of the APAS is that markers are not required to obtain data.
>>>>


* Method of markers identification, its tracking and its 3D coordinates calculation
*
<<<<
When markers are utilized, the markers are defined by the user and then the APAS software utilizes a combination of brightness, color and contrast as well as position, velocity and acceleration measures to automatically track th e points.
>>>>

* Available sampling rates (with specified maximum available number of markers for each )
*

<<<<
The maximum sampling rate is determined by the video cameras. The APAS is not dependant on the cameras, thus any video cameras can be used. The standards are 50 Hz PAL or 60 Hz NTSC, however, the APAS also supports high speed cameras up to 10,000 Hz.
>>>>

* Type of markers (passive, active - type of current source, IR LED, size)
*

<<<<
The APAS system is capable of using any type of marker. Most of the Ariel users that use automatic digitizing utilize passive reflective markers. As I stated above, markers are not required. Body joints can be manually digitized by the operator. This means that subjects can be recorded in "real-life" activites and their motion can be analyzed without the subject even knowing they are analyzed.
>>>>

* Type and number of cameras in the system (passive, active, IR LED)
*

<<<<
The APAS supports any numbe of cameras. If a single camera is used, then you can only obtain 2-Dimensional data. If 2 or more cameras record the activity simultaneously, then you can obtain 3-Dimensional data. Most of the time, accurate 3-D data can be obtained with 2 or 3 cameras.
>>>>


* Type of space calibration
*

<<<<
Anything can be useed to calibrate the space as long as a few important points are included:
1. 2-D data requires a minimum of 4 co-planar points with the Z coordinate =0
2. 3-D data requires a minimum of 6 non-coplanar points (though 12 to 16 are recommended).
3. The X, Y and Z coordinates for all points must be measured relative to a single origin of coordinates (0, 0, 0).
4. The calibration fixture should encompass the area that will be used for analysis. Analysising hand movements on a computer keyboard requires a small calibration fixture while analyzing the Olympic pole vault would require a very large calibration system. For example, the height of the bar could be used as 2 of the control points.

Some Ariel users utilize strings hanging from the ceiling with points of known dimensions. Many others use aluminum or plastic "cubes" of 1m x 1m x 1m or greater.
>>>>
* Range of field of view
*


<<<<
The range of field of view depends on the camera used and calibration fixture. We have analyzed the movement of cells looking through the lens of a microscope as well as Olympic sporting activities being filmed from the stadium seats.
>>>>

* Possibility of measurements in environmental conditions (sensibility to spurious light, reflections and other environmental noise) such as: sport stadiums, swimming pools, etc.
*

<<<<
As stated above, the APAS-99 system is the most versatile and portable system on the market. You simply need battery operated camcorders to record the activities "in-the-field" where they occur. This could be the stadium, swimming pool, etc. Then the videos are taken back to the lab for analysis on the computer.
>>>>

* System robustness (damage protection, transport requirements)
*
<<<<
As I stated above, for the video analysis, you simply need to transport the video cameras and tripods. The computer can stay in the lab. The APAS system is the most portable system on the market.
>>>>

* System precision
*
* System accuracy
*
* System resolution
*

<<<<
Please refer to the following sections of the Ariel internet site for 3rd party independent studies comparing the APAS system to other commercially available systems.

/Topics/comparison/default.htm

/topics/ApasValidation/ApasValidationStudies.html

>>>>* Another errors and main errors sources
*

<<<<
Error sources are the same for all systems:
Marker placement
calibration measurements
etc.
>>>>

* Software to calculate biomechanical system parameters (velocity, acceleration, center of mass, indirect dynamic analysis joint torque calculation, etc)
*

<<<<
The software used to calculate velocity and acceleration are basic formulas that are well documented in the literature. The most common algorithm for tramsforming the 3-D data is the Direct Linear Transformation also known as the DLT. All the companies use the same algorithms.
>>>>

* Software for automatic identification of joint centers on the basis of markers locations
*

<<<<
This was described above.
>>>>
* Possibility of acquisition of another data EMG, force platform, etc. (number of available digital and analog input/output channels, possibility to its synchronization to motion analysis system data)
*

<<<<
The APAS is well suited for collecting data from other sources such as EMG and force platforms. This requires the optional Analog Module. This data can then be synchronized to the video data.
>>>>
* Temperature, dust and humidity requirements
*

<<<<
The same requirements as for any computer system.
>>>>

* Requirements for host computer
*

<<<<
The computer must have the following minimum specifications:
Pentium 200 MHz with MMX capabilities
32 MB RAM
4 GB hard disk drive
CD_ROM and Floppy Drive

Additionally, you can purchase just the software from Ariel Dynamics and pruchase the hardware locally in Poland. This has the advantage of saving money on duties and taxes. It also provides the ability for the customers to obtain local service for any hardware problems.

>>>>

* References (Laboratories using your system if this information is available)
*


<<<<
A list of selected Ariel users can be found at the following section on the Ariel internet site:

/Main/adw-85.html

Additionally, you might want to contact the following customer in Poland. He has been an Ariel customer for many years.

Akademia Wychowania Fizycznego
Jozefa Pilsudskiego
ul. Marymancka 34
UDN-794
01-800 Warszawa 45
350004-853
Attention: Prof. Andrzej Wit
Telephone: 011-482-28340636
Fax: 011-482-28340636
Email: "Andrzej Wit" <andrwit@polbox.com>

>>>>
* Prices (are there any research or university discounts, what system configurations could you offer in different prices)
*


<<<<
The APAS prices are listed at:

/Main/adw-54.html

These prices are much lower than any other commercially available system on the market and the APAS provides many more functions. We do not have any room to offer any discounts because the prices are already very low.

A MAJOR advantage of the Ariel system is that once you purchase the "main" system, we allow you to purchase software for additional computers at a cost of $500 USD per computer. This allows the opportunity to have many systems for a minimal cost. For example, if you just purchased the software from Ariel Dynamics it would cost $5,000 USD for the first system, then $500 for each additional system. Thus, $7,000.00 USD would be able to purchase 5 APAS systems (and you can supply the hardware). No other system in the world provides these capabilities.
>>>>

* Is there a possibility of demonstration of your system abilities on our Academy before purchase
*

<<<<
You might be able to coordinate a demonstration from Prof Andrej Wit.

As another possibility, you can download the APAS software directly from the Ariel internet site. This software is valid for 14 days and allows potential users the opportunity to test and evaluate the software prior to purchase.
>>>>

We will appreciate sending to us the information mentioned above together with another presentation materials (demo software, folders, videotapes, etc.).


<<<<
All of our product information is listed directly on the Ariel internet site (www.arielweb.com) and can be downloaded directly to your computer.
>>>>
This year there will be organized an open auction for mentioned equipment purchase. Data acquired after this request will allow us to specify the auction criteria.


<<<
We would be happy to provide any information that you require. Please keep us informed with your progress and the status of the auction.
>>>>

Thank you again for your interest in the Ariel technology. Please feel free to contact me for any additional information.

Sincerely,

John Probe


++++++++++++++++++++++++++++++++++
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California 92111 USA
(619) 874-2547 Tel
(619) 874-2549 Fax
Email: ARIEL1@ix.netcom.com
Web Site: http://www.arielweb.com
++++++++++++++++++++++++++++++++++

 

John-

You will have to forward this response to the customer as I do not have the
e-mail address.

The rotational angular momentum is as you describe. It is the sum of the
rotational angular momentum of the segment about its center of mass and the
angular momentum of the center of mass of the segment about the center of
mass of the whole body.

When you refer to "All segments" I assume you are referring to the PRINT
module. In this module, the "All segments" will generate output for all
segments defined . If you are referring to something else, please let me
know.

Thank you for your questions and if we cqan be of any further assistance
please do not hesitate to contact us.

Sincerely,

Jeremy Wise  Dir R&D

----------
> From: John Probe <john@arielnet.com>
> To: jeremy@arielnet.com
> Subject: Question From Croatia Customer
> Date: Wednesday, April 21, 1999 6:12 PM
>
> Hi Jeremy,
>
> I received the following question from one of our customers in Croatia.
> Could you please explain the details on this?
>
> Thanks,
>
> John
> ========================
>
> >Also, I have some questions about functioning of the old (MSDOS) APAS
> >system. More specifically, could you tell me how it calculates the
> >rotational momentum?
> >
> >Generally rotational momentum of human body can be described as a sum of
a
> >segmental rotational momentum's around their segmental axis of rotation
and
> >segmental rotational momentum's around CG (or other fixed axis of
rotation).
> >
> >How is it on old APAS? What exactly means if I chose "All segments"?
What
> >exactly are the data I'm getting out from this?
> >I am aware of reliability of those data, but I'm just curious how it
works.
> >

Dear Dr. Chung -

Thank you for your question concerning joint angles greater that 180 deg
being reported by the DISPLAY module when looking at projections into a
plane.  Consider for example the Z viewing axis. In calculating the angle
between two segments the  two segments of interest are projected into the x-y
plane. The angle of interest is then the angle when rotating about the Z axis
in a CCW direction from the 1st segment to the 2nd. Because the rotation axis
is well defined, one can get the sin of the angle from the cross product.
Knowing both the sin & cos allows the calculation of the angle in a range of
0 to 360 deg. However when one looks at the 3D angle one does not know both
and the result is in the raange of 0 to 180 deg.

I hope this helps,

Jeremy Wise, Dir R&D



> Question about joint angle : In the display module, I saw the
hyperextended
> knee joint angle viewed from an axis (eg, z axis - mediolateral axis) has
> more than 180 degree. I am not able to calculate more than 180 degree when
I
> use the dot product and arccosine. Of course, all of the z coordinates of
> the vectors are substituted with zero.
>
> How do you calculate the angles which are more than 180 degree, like
> hyperextended knee joint? What is the secret?
>

Dear Mr. Wise,

Thank you for your letting me know the secret.

May I ask you further question if I have more about the joint angles ?

Sun


>Dear Dr. Chung -
>
>Thank you for your question concerning joint angles greater that 180 deg
>being reported by the DISPLAY module when looking at projections into a
>plane.  Consider for example the Z viewing axis. In calculating the angle
>between two segments the  two segments of interest are projected into the
x-y
>plane. The angle of interest is then the angle when rotating about the Z
axis
>in a CCW direction from the 1st segment to the 2nd. Because the rotation
axis
>is well defined, one can get the sin of the angle from the cross product.
>Knowing both the sin & cos allows the calculation of the angle in a range
of
>0 to 360 deg. However when one looks at the 3D angle one does not know both
>and the result is in the raange of 0 to 180 deg.
>
>I hope this helps,
>
>Jeremy Wise, Dir R&D
>
>
>
>> Question about joint angle : In the display module, I saw the
>hyperextended
>> knee joint angle viewed from an axis (eg, z axis - mediolateral axis) has
>> more than 180 degree. I am not able to calculate more than 180 degree
when
>I
>> use the dot product and arccosine. Of course, all of the z coordinates of
>> the vectors are substituted with zero.
>>
>> How do you calculate the angles which are more than 180 degree, like
>> hyperextended knee joint? What is the secret?
>>

Thank you for your question regarding how missing points are managed with the
Ariel system. When the software calculates 3D coordinates from the digitized
views, all views which have data present for a particular point are used in
the calculation. If there are less than 2 camera views the calculation cannot
be performed and the point is flagged as "Missing" in the RAW 3D data. When
the data is smoothed any points missing in the RAW are interpolated with a
simple linear algorithm and then this interpolated data is smoothed with the
selected algorithm. So the SMOOTHED data has no missing points. Whether or
not you should use the data that has been interpolated is a question I cannot
answer. If a point is missing for a couple of frames [not visable from
atleast 2 cameras] I personally would not be concerned. However if there are
long sections of data that are missing I would not trust the interpolated
data.

I Hope this helps,

Jeremy Wise  Dir R&D

In a message dated 4/29/99 1:23:11 AM Eastern Daylight Time,
ariel1@ix.netcom.com writes:

<<
 > Sorry about the quick question concerning the missing points.
 > I have written an e-mail to ariel about three days ago and I did not
 > receive any reply, and therefore, I thought you had the original
 > message concerning the question. 
 >
 > Currently, I am working on 3-D modeling of whole body Center of
 > Gravity (cog)during walking over slippery surfaces to investigate slip
 > and fall accidents.
 >
 > In my pilot study, I experienced some missing markers (currently we
 > are using 31 markers to locate cog in both sagittal and frontal view
 > to achieve transversal model), the accuracy is of concern, due to the
 > oversimplication of this method.  However, looking at the smoothed
 > "displacement" data, the missing points were filled in.
 >
 > I am currently using C++ to calculate the cog, and need to know if I
 > can use this data or not.
 >
 > can you give me the algorithm concerning this case?
  >>

 

The Angular momentum reported by the GRAPHING module of the older DOS based system is reporting the momentum either angular or linear of a segment. In the case of angular, the momentum reported is the angular momentum of the segment about the segmental center of mass. When "ALL_SEGS"  is selected this quantity is summed over all segments in the system.

We are currently implementing these same features in our new system. Please let us know what you would like the system to report.

Sincerely,

Jeremy Wise Dir R&D


1.) You wrote:

"The rotational angular momentum is as you describe. It is the sum of the
>rotational angular momentum of the segment about its center of mass and the
>angular momentum of the center of mass of the segment about the center of
>mass of the whole body."

How it works when the whole body rotates around the fixed axis of rotation (Giant swing on the high bar, takeoff after the roundoff and a back handspring, and similar)?

2.) If we agree in the previous statement, there are several different contributions to that equation:

          a) - segmental angular momentum about segmental center of mass
          b) - sum of those from previous line
          c) - segmental angular momentum about CG or (?) fixed axis of rotation of the whole body
          d) - sum of those from previous line

In a GRAPH module there are only two options.

           - to select a SEGMENT
           - or, to select ALL SEGMENTS

If I select a segment, what do I get out - a), or c), or a)+c), or something else?
Also, if I select ALL SEGMENTS  is it b), or d), or b)+d), or something else?

3. On the example of double back somersault layout, performed by one of the world top ten gymnasts, I got this graph (angular momentum, transverse axis):

How to compare this with the data reported from Jesus Dapena:

         Activity:              Principal axis:         Angular momentum (kg m2 sec-1):

      Double back layout              Transverse                          138


...
I hope this is not too much. Hope to hear from you.
Sincerely,
Zeljko Hraski

Hello Darren,

Dr. Ariel has asked me to respond to your Email. I have listed the answers below each of your questions.

a. I looked at the comparison article which showed that on many tests APAS was as accurate or more accurate than the super expensive systems, but I didn't notice what type of cameras they'd used. I assume I must expect less accuracy with cheaper cameras right?


The cameras that were used in this study were standard Panasonic camcorders. I understood that 5 cameras were used. I believe the cameras consisted of Panasonic models AG-196 (VHS) and AG-456 (SVHS) models.

The APAS accuracy is not directly related to the price of the camera. As long as the camera provides a relatively clear picture the results will be the same. System accuracy is much more dependent upon the actual digitizing.

>>>>

b. Related to a., is there a step required to calibrate the lens distortion of each camera (I assume there must be to get accuracy right?)

<<<<
The calibration process involves digitizing "known" coordinate points on a calibration fixture. Three-dimensional data requires a minimum of 6 non coplanar points (though 12 or more are recommended). Two-dimensional data requires a minimum of 4 coplanar points. Calibration devices can be almost anything as long as the dimensions of the control points are precisely known.

>>>>

c. 3D Studio Max and Character Studio specify the markers I must use, which are things like LFHD (left front head), RFHD (right front head), LKNE (left knee) ,STERN (sternum), etc. Can I define my own marker set in APAS to match what Max and Character studio require, down to the level of even specifying these exact four letter names?

<<<<
The APAS allows for both "System" and "User-Defined" points. System defined points assume that the human body is being analyzed and the software automatically connects the points (right foot to the right ankle etc).

User-Defined points can be any name that the user desires. This is often used when analyzing animals or systems other than the human body. In the example listed above, the marker definitions would not be any problem.

>>>>

d. Would the 3D data that exports into an excel spreadsheet format truly be x,y,z coordinates for the marker positions on each frame? Does a spreadsheet row specify a frame and the columns specify the markers? And is there a column heading to indicate which column is which marker?

<<<<
The APAS system supports several options for exporting data. One of the APAS modules is specifically written to export the APAS data directly to an ASCII file. This can be Raw coordinates, Displacement (smoothed position), Velocity, and/or Acceleration values.

Within the APAS software modules, the user also has the ability to display the desired graphs and export the data used for the graph directly to spreadsheet format.

Additionally, the file formats for the APAS files are posted on the Ariel internet site (www.arielweb.com). This allows users to write their own software to extract the data directly from the APAS files. Look at the Appendix section in the APAS modules for the File Formats.

>>>>

e. I assume there must be some type of image processing to extract the markers on the video from the background (i.e. since the cameras aren't infra-red or whatever - like the Vicon where it only "sees" the markers).

<<<<
The APAS supports both Semi-Automatic and Automatic digitizing modes. When using the Semi-Automatic mode, markers are not required. The user selects the desired points using the computer mouse. When one point is digitized, the software will "jump" the cursor to the expected location of the next point but will wait for the user to verify the location with a mouse click.

The Automatic mode obviously requires some sort of markers with a high contrast to the immediate background. These markers can be light against a dark background OR dark against a light background. Many image enhancement options are available to aid the software in finding the markers. If markers are obscured, the APAS system prompts the user to identify the marker.

>>>>

You said I could use pretty much any camera but I bet there's some requirements to ensure that the markers stand out clearly, right? Do you have people wear dark clothing and then use white markers to get good contrast? And is this where there would be a benefit to S-VHS or Hi-8 over VHS or 8mm (i.e. will the higher resolution of these formats enable APAS to see the markers more clearly?) I'm hoping you can guide me here, esp. since I can't afford the super expensive custom cameras.

<<<<
The APAS is not dependent upon any cameras. The Ariel software simply requires that the images be captured in the standard AVI format. Requirements for getting a "good" picture for autodigitizing are individualized with each user's specific environment. The dark clothing with white markers would be a good starting point. Other very important factors to consider are lighting, background "clutter" and camera placements.

The benefits of using the S-VHS and Hi-8 cameras over the VHS and 8mm are minimal when working with the APAS since the limiting factor is usually the frame grabber. We currently use the Iomega Buz with a capture resolution of 720 x 480 at 24 bit color.

>>>>

f. You said APAS can handle any sampling rate, but I don't have enough experience to understand the importance of a faster rate. Why do the Vicons, etc. use such fast sampling rates, and what am I losing if I only use a camcorder with it's lower sampling rate?

<<<<
The required sampling rate is determined by the activity being analyzed. The Nyquist Theorem states that the sampling rate must be at least 2 times that rate of the activity being analyzed to avoid aliasing errors. Most human activites are performed below 15 Hz, therefore a minimum sampling rate of 30 Hz should be used. Let's use a golf swing for an example. If you are analyzing the movement of the player, 60 Hz would be sufficient to accurately document the human movement. However, if you want to analyze the impact of the club on the ball, a much faster rate would have to be used since this activity occurs in such a short time period.

>>>>

g. Regarding my question of using "live" cameras, you said I can capture the video directly to hard disk. But do you mean there's a way I could set up a 5 camera system with all 5 cameras hooked up to a single PC, and actually capture all 5 camera's video directly to hard disk all at once - live as I do the "take"?

<<<<
The current APAS systems are sold with a single Iomega Buz. This means that the camcorders can be taken directly to "the field" to record the activity of interest. Then the cideo out of the camera is connected directly to the Buz and the camera is used as a VCR to playback the recorded image and capture it to the computer hard disk. This process is repeated for each camera view.

>>>>

My experience with things like the Buz (I have one), is that they really tax the system (e.g. they told me I *had* to use it in PCI slot 0) and so I'm guessing you could never get more than one working simultaneously on a single machine, at least not reliably.

<<<<
The Iomega Buz is not compatible with all hardware. There are known problems with some video displays as well as selected motherboard chipsets. Please check the Iomega web site (www.iomega.com) for compatibility problems with the Buz. The systems that are configured by Ariel Dynamics have not had any problems with the Buz device. The Buz has been installed in any of the available PCI slots and reliably captures images.

>>>>

I don't know about other brands or the videoconferencing cameras though(?) Do you know if multiple QuickCams be captured at the same time on one PC? I'm sorry for so many questions.

<<<<
We have also used the Matrox Marvel G200 capture card. It is a more expensive card, however, it eliminates alot of the compatibility problems since the capture device and video adapter are integrated into a single AGP card.


I hope this information is helpful. Please conact us for any additional questions.

Sincerely,

John Probe


>>>>

I appreciate that your cost of $5000 is a lot cheaper than the Vicons, etc. but for me it's still a lot of money so I'm being extra careful. If you would like to call me to discuss these questions instead of e-mail, my phone # is (314)645-8242. Thanks, Darren -----Original Message-----
From:
Gideon Ariel <gideon@arielnet.com>
To: Darren Cruse <dcruse@anet-stl.com>
Date: Monday, May 03, 1999 7:35 PM
Subject: Re: Questions about using APAS for Animation

Hi Darren: I will answer between the lines: ----- Original Message ----- From: Darren Cruse <dcruse@anet-stl.com> To: <gideon@arielnet.com> Sent: Monday, May 03, 1999 4:29 PM Subject: Questions about using APAS for Animation
> Hi,
>
> I was referred by several people on the BIOMECH-L list to your APAS system
> in response to my question about inexpensive ways to do motion capture for
> animations I'm doing with 3D Studio Max. I have downloaded the demo and
> have played with it some, and I would like to ask the following:
>
> a. Is there a way to export the 3D marker position data to a motion capture
> file format such as Acclaim (.asf/.amc), biovision (.bvh), or Character
> Studio (.csm)? If not, is the 3D file format used by APAS documented openly
> such that I could write my own conversion software? You can export all the data to an ascii file or mathlab or excell spreadsheet and then import any data you need from there.
>
> b. I do have some experience using a Vicon system (so I'm familiar with the
> basic ideas - though still pretty green :), and I'm wondering if you can
> clarify for me how the lower sampling rate of a camcorder (versus the high
> speed cameras the expensive Vicon system uses) will affect the captured
> motion that I get... i.e. will I have trouble with fast motions such as a
> golf swing for example? Will the resultant data be less smooth and
> realistic looking? You can use any heigh speed camera with the APAS system. We are not limited to any sampling rate.
>
> c. Still on the camcorder issue - and related to the total cost of the
> system - can I actually use inexpensive 8mm or VHS camcorders? Or maybe
> even postage stamp CCD security or QuickCam type video conferencing cameras
> (i.e. those little round cameras you can mount on your monitor for video
> conferencing)? As opposed to S-VHS, Hi-8, or Mini-DV? If I spend extra on
> the better cameras, am I gaining much (i.e. they're still 60 fields per
> second so am I gaining much?). Any video source will work and capture to the hard disk. From QuickCam to Redlake to Buz to Marvel etc. The APAS system is a software system, not propriotory hardware that suck your money out.
>
> d. Also related to the total cost - I'm a little confused about the
> software pricing... There's a mention of a "lite" version or something? Or
> is it always $5000 no matter what? In my case I won't use any of the
> biomechanics specific features regarding force plates, etc. My only need is
> to convert the marker positions to 3D and get them out to a file. The full APAS system price is $5000 (Les functions from Vicon would cost you $300,000)
>
> e. Is there any option/way to use live cameras without having to capture
> video off the camcorders after the fact? i.e. to capture the video from the
> live cameras as you do the take (i.e. in the manner I'm used to with the
> Vicon where the video data is immediately ready for translation to 3D upon

> completing the take). You can capature directly to the hard disk Good luck and hope to hear from you Gideon Ariel, Ph.D.

 

Dear Zeljko Hraski,

The APAS system is only calculating the 1st part of the angular momentum, that of the momentum of the segment about its CG. This is true in both the Graph & Print modules. We do make all the APAS data available to the user in the form of text files or worksheet files so that if there is a quantity of interest that the APAS system does not directly output, the item of interest can be calculated from outside of APAS.

We are currently adding these capabilities to our new, Windows system. We will try to implement these capabilities that you are requesting at that time.

Sincerely, Jeremy Wise

-----Original Message-----
From: Željko Hraski <zhraski@ffk.hr>
To: Jeremy Wise <jeremy@arielnet.com>
Date: Tuesday, May 04, 1999 3:30 PM
Subject: Re: Angular Momentum

Hi Jeremy Wise,

Thanks for your reply, but I need more help.

   What I'm actually trying to get is the angular momentum of the gymnasts during the takeoff and backward somersault. So, if we agree that:

Angular momentum of the body is the sum of the angular momentum's of the segments about the segmental center of mass plus sum of  the angular momentum's of the segmental centers of mass about the center of mass of the whole body (or any other fixed axis of rotation of the whole body),

   ... following your explanation, it means that using the report from GRAPHING module (momentum, rotational), I still miss the second part of the equation - sum of  the angular momentum's of the segmental centers of mass about the center of mass of the whole body (or any other fixed axis of rotation, for example - feet on the floor during the takeoff).

Can you help me how to get that out?

Thanks again.

Zeljko Hraski

 

-----Original Message-----
From: Jeremy Wise <jeremy@arielnet.com>
To: zhraski@ffk.hr <zhraski@ffk.hr>
Cc: Gideon Ariel <gideon@arielnet.com>
Date: 1999. svibanj 04 18:03
Subject: Angular Momentum

The Angular momentum reported by the GRAPHING module of the older DOS based system is reporting the momentum either angular or linear of a segment. In the case of angular, the momentum reported is the angular momentum of the segment about the segmental center of mass. When "ALL_SEGS"  is selected this quantity is summed over all segments in the system.

 

We are currently implementing these same features in our new system. Please let us know what you would like the system to report.

Sincerely,

Jeremy Wise Dir R&D

Dear Dirk & Pierre-

Gideon asked me to help you with some of your difficulties.

1) Missing COP values in new Analog-

This was an oversite and we will add this capability with the next rev of the software. In the meantime, you should be able to open the files generated with the Analyze module of the old system and look at your data there.

2) Vectors & Kistler-

This too is an oversite & we will fix it right away.

3) Buz problems-

I had this same problem once with my system. I believe the problem was a hardware/driver combination problem and that & fixed by loading new drivers. I will contact John & he can help you with this.

4)  Capture & Timecodes-

When you refer to time codes, are referring to SMPTE code on audio2? If so how are they being put onto the tape and are you sure the VCR you are using can read them? Under any circumstances it would be very difficult to use them for synchronizing  2 or more views as the codes are put down asynchronously for the different cameras and are only accurate to a few frames under any circumstances. I know Gideon has a scheme that he uses very successfully. Just before the start of collecting video he moves a panel into view of each camera which has a number uniquely identifying the data about to be collected. He then drops a ball in the field of view as he starts collecting and uses this ball drop for synchronizing purposes. We now have software which analyzes the falling ball and is able to use it to synchronize the camera offsets to a small fraction of the time between images.

Hopefully this is of some help & thank you for informing us of these difficulties. We will do our best to remedy these difficulties as quickly as possible.

Sincerely,

Jeremy Wise

Hello John,

The RealCap module does not provide the option of skipping frames during
the Capture process.  In order to do this option, you would need to use the
CAPTURE module with the RS-232 computer controlled VCR.  Select the Capture
menu and then CAPTURE PARAMETERS.  Set the mode to Step-Capture and the
skip factor to 59 images.  The software will then capture 1 image, skip 59
images and then capture image #2.

If you have a VCR that will accurately skip the desired number of images,
you could also manually advance the VCR and capture the desired images, but
this would be rather tedious.

You would need to accurately know the number of images skipped to determine
velocity and acceleration measures.  However, if you are only interested in
position, you could capture the desired images.

I hope this information is helpful.  Please contact me for any additional
information.

Sincerely,

John Probe



At 05:04 PM 5/10/99 -0700, you wrote:
>Greetings,
>
>I have a question regarding the RealCap module of the APAS system.  I plan
>to analyze very long segments of video (45 mins. to 1 hr.), so I don't need
>to capture 60 fps from the video feed.  Is there a way I could decrease the
>frame acquisition rate to 1 fps, for example, so that I could reduce the
>size of the captured .AVI files as well as analysis time in the digitize
>step?
>
>Sincerely,
>
>John Person
>University of British Columbia
>Vancouver, BC, Canada
>person@mech.ubc.ca
>
>
>
>
>
>
++++++++++++++++++++++++++++++++++
John Probe
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California  92111  USA
(619) 874-2547 Tel
(619) 874-2549 Fax
Email:  ARIEL1@ix.netcom.com
Web Site:  http://www.arielnet.com
++++++++++++++++++++++++++++++++++
Hello John,

The RealCap module does not provide the option of skipping frames during
the Capture process.  In order to do this option, you would need to use the
CAPTURE module with the RS-232 computer controlled VCR.  Select the Capture
menu and then CAPTURE PARAMETERS.  Set the mode to Step-Capture and the
skip factor to 59 images.  The software will then capture 1 image, skip 59
images and then capture image #2.

If you have a VCR that will accurately skip the desired number of images,
you could also manually advance the VCR and capture the desired images, but
this would be rather tedious.

You would need to accurately know the number of images skipped to determine
velocity and acceleration measures.  However, if you are only interested in
position, you could capture the desired images.

I hope this information is helpful.  Please contact me for any additional
information.

Sincerely,

John Probe



At 05:04 PM 5/10/99 -0700, you wrote:
>Greetings,
>
>I have a question regarding the RealCap module of the APAS system.  I plan
>to analyze very long segments of video (45 mins. to 1 hr.), so I don't need
>to capture 60 fps from the video feed.  Is there a way I could decrease the
>frame acquisition rate to 1 fps, for example, so that I could reduce the
>size of the captured .AVI files as well as analysis time in the digitize
>step?
>
>Sincerely,
>
>John Person
>University of British Columbia
>Vancouver, BC, Canada
>person@mech.ubc.ca
>
>
>
>
>
>
++++++++++++++++++++++++++++++++++
John Probe
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California  92111  USA
(619) 874-2547 Tel
(619) 874-2549 Fax
Email:  ARIEL1@ix.netcom.com
Web Site:  http://www.arielnet.com
++++++++++++++++++++++++++++++++++

Hi Moshe:
  Was nice to hear from you.
Not only we have manuals on the web but also we have tutorials. I will add
the links here:

1.  /Main/adw-91.html   Help screen for all the
modules
2.  /APAShelp/DOS/adw-56.html   Detail manuals and
file formats
3.  /topics/Tutorials/default.htm   Tutorials, step
by step with video
4.  /topics/FAQ/Default.htm    FAQ on all aspects of
the APAS
5.  /topics/ApasValidation/ApasValidationStudies.html
Validation studies
6.  /topics/comparison/default.htm   Comparison study
to other systems

  Please let me know if you found this information.
  After you will go through the tutorials (only RealCap and Digitizing) you
will realize the power of this system. This system was developed over 35
years and still making improvement every week.
  Hope to hear from you and have a good day
Gideon Ariel



----- Original Message -----
From: Dr. Nissan Moshe <nissan@tasmc.health.gov.il>
To: <gideon@arielnet.com>
Sent: Monday, May 10, 1999 11:19 PM
Subject: APAS


> Hello Gideon
> At long last it seems I am going to be an APAS user as well, together
> with Jeremy Lewis.
>  I need some help now, and to start with I am looking for the manual.
> Where is it? all I could find on the net was 2 Raspel manuals.
> Moshe Nissan
>

Dear Jim,
The Ariel APAS system has software called the APASview which permits
simultaneous viewing of multiple camera views of the same movement or
you can do comparative studies between athletes or performances. I
have used this software during the past year and it is easy to use
and very powerful. In addition to the multiple camera views it can
display the 3 D stickfigure of the person, the kinematic and kinetic
data in graph format,bar graph, or spreadsheet for numerous
variables. It also,can combine analog data from EMG or force plate
data and synchronize all the images and display the information frame
by frame. A demonstration of some of the functions are published in
the proceedings from the 1998 ISBS conference held in Konstanz
Germany in an article by A. Finch & G. Ariel, Kinematic Comparison
between the best and worst discus throws by the top four men's discus
throwers at the 1996 Atlanta Olympics. I will be presenting papers
using this software on evaluation of basketball free throw kinematic
during actual competition, elite collegiate high jumpers, back
lifting, baseball throwing. This past week I used it for technique
analysis of middle school shotputters, high jumpers, hurdlers, long
jumpers, sprint start, elite collegiate hurdlers and long jumpers.
If you have any further questions contact me or Gideon Ariel and
you'll be able to see the great applications already done with the
system.
Sincerely,
Alfred Finch
Biomechanics Lab
Indiana State University

 

Hi Dr. Aziz:

 Was so nice to hear from you. I will answer between the lines:

----- Original Message -----

From: Aziz Rahmatalla <osa10@keele.ac.uk>

Sent: Wednesday, May 12, 1999 7:42 AM

Subject: installing network card


> Dear Gideon and John,
> It is now sometime since I last contacted you. Hope you are well and
> every thing running smoothly. From time to time, I open the ariel
> website to see if there are any new development and there were many
> exciting news. From our corner, we are accupied by our clinical work and
> our gait system running without problems.
>
> However, I need your advice on the following issues:
>
> 1. Can I install network card on the Ariel Computer to enable me to get
> access to it from my office. This is more convenient for me and I do not
> need to go to the lab. every time I need some information. With
> exception to APAS computer, all our computers in the research department
> are networked.

 

Yes, You can install network card and work from your home or office. Also, please download another APAS from our web site and I will issue you the site key so you will have the APAS on your home cmputer. This is my present to you...


>
> 2. The other issue, you know I have another computer with Iomega Buz, it
> works fine, my question is that: can I install another card in order to
> capture directly from two cameras instead of one. If the answer is yes,
> I wonder if the existing computer is fast enough, or do I need to change
> it for example to a faster one such as
> Pentium III 450 or 500 MHz!

You should get another Pentium III 500 and do it. I will issue you the site key for this one. Do not change anything on the one that work already. Lets not do anything to something that work....

Hope to hear from you

Gideon

 
> I look forward to hearing from you.
>
> Best regards
>
> Sincerely
>
> Aziz Rahmatalla
>
>
>
>



Hello Normand,

I will provide answers below your questions.



----- Original Message -----
From: Normand Teasdale <Normand.Teasdale@pmh.ulaval.ca>
To: <gideon@arielnet.com>PQ
Sent: Tuesday, May 11, 1999 11:06 AM
Subject: panning


> Dear Gideon/John;
>
> I have collected some pilot avi to get familiar with the panning option
and I have a few questions regarding the theory of operation of the module.
>
> Actually, my question regards the PANNING POINTS. My understanding of the
documentation is that a number of panning points must be given. These
panning points lie in between the two calibration frames that have their own
control points. Thus, the panning points are more or less the equivalent of
the fixed control point in the regular mode. Obviously, I suspect that at
least one panning point must always be visible.  Am I right up to this
point?
>
The panning module requires two calibration fixtures, one to the left and
another to the right.  Each calibration fixture must have a minimum of 8
non-coplanar points but it is recommended to have 12 or more.  The
coordinates of all the points are measured relative to a single origin.  In
between the two calibration fixtures, there must be panning points.  At
least one of these points must be visible at all times though it does not
matter which one.  These panning points are digitized in place of the fixed
point and you must specify the panning point being digitized.  This is
designated using the CONTROL and PAN POINT command.

You must also digitize the Left and Right calibration fixtures
individually.  This is accomplished using the PAN LEFT and PAN RIGHT
commands in the CONTROL menu.


> Is there a minimum number of points that has to be given?
>
There is no minimum number of panning points that have to be given.  You
just need to make certain that at least one of the points is visible at all
times from the panning camera view. 


> What is the minimum distance between each point?
>
As a general rule, I have always used points approximately 1.5 to 2 feet
apart.



>
> Thanks in advance
>
> Normand
> Normand Teasdale (Normand.Teasdale@kin.msp.ulaval.ca)
> Universit´┐Ż Laval, Laboratoire de performance motrice humaine, PEPS
> Facult´┐Ż de m´┐Żdecine
> D´┐Żpartement de m´┐Żdecine sociale et pr´┐Żventive
> division de Kin´┐Żsiologie
> Qu´┐Żbec, Qu´┐Żbec G1K 7P4
> T´┐Żl: (418) 656-2147
> Fax: (418) 656-2441
>


++++++++++++++++++++++++++++++++++
John Probe
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California  92111  USA
(619) 874-2547 Tel
(619) 874-2549 Fax
Email:  ARIEL1@ix.netcom.com
Web Site:  http://www.arielnet.com
++++++++++++++++++++++++++++++++++

Thank you for your questions!  I will do my best to answer them.

Concerning the coordinates for control points in Digi4, they should be entered in the units as specified in the sequence parameters. When you are at the Sequence Information dialog & click on the "Control" button, a spreadsheet style dialog appears for entering the XYZ control values for each control point. The columns should have the proper label as given in the "units" of Seq. Info. I just checked it out and that is the case on my system. If your system is not labeling the spreedsheet correctly then possibly  you have a version of the software which is not the most recent or there is some other explanation. Contact Gideon or John Probe to get the latest off of our WEB site if you don't know how.

Concerning force plate values with the DOS version ANALOG/ANALYZE module, the  "-" indeed is a direction. There is a general convention with force plates that the "X" & "Y" axies are in the plane of the plate and "Z" is perpendicular to the plate. If you consult your plate manual there should be a description of this. The sign is the direction of the force relative to the axis.

I hope this helps & please contact me if you have other questions/problems.

Sincerely,

   Jeremy Wise, Dir R&D

To whom it may concern,

Are the  XYZ coordinates in Digi4 to be entered in CM always?  If you choose IN in the sequence parameters will there be a conflict?  Do you need to have both the same?

When doing a print out of the linear forces, what do the "-" numbers mean?  If they occurred in the Y plane at ground contact only, I would understand.  Do they indicate direction?  If so what direction?  This is in reference to the DOS version of the software.

Hello John,

The RealCap module does not provide the option of skipping frames during
the Capture process. In order to do this option, you would need to use the
CAPTURE module with the RS-232 computer controlled VCR. Select the Capture
menu and then CAPTURE PARAMETERS. Set the mode to Step-Capture and the
skip factor to 59 images. The software will then capture 1 image, skip 59
images and then capture image #2.

If you have a VCR that will accurately skip the desired number of images,
you could also manually advance the VCR and capture the desired images, but
this would be rather tedious.

You would need to accurately know the number of images skipped to determine
velocity and acceleration measures. However, if you are only interested in
position, you could capture the desired images.

I hope this information is helpful. Please contact me for any additional
information.

Sincerely,

John Probe



At 05:04 PM 5/10/99 -0700, you wrote:
>Greetings,
>
>I have a question regarding the RealCap module of the APAS system. I plan
>to analyze very long segments of video (45 mins. to 1 hr.), so I don't need
>to capture 60 fps from the video feed. Is there a way I could decrease the
>frame acquisition rate to 1 fps, for example, so that I could reduce the
>size of the captured .AVI files as well as analysis time in the digitize
>step?
>
>Sincerely,
>
>John Person
>University of British Columbia
>Vancouver, BC, Canada
>person@mech.ubc.ca <mailto:person@mech.ubc.ca>
++++++++++++++++++++++++++++++++++
John Probe
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California 92111 USA
(619) 874-2547 Tel
(619) 874-2549 Fax
Email: ARIEL1@ix.netcom.com <mailto:ARIEL1@ix.netcom.com>
Web Site: <http://www.arielnet.com>
++++++++++++++++++++++++++++++++++

Here is a copy of my response to the guys in Ireland.

John

Date: Thu, 13 May 1999 13:15:26 -0700
To: <jimkilty@tinet.ie>
From: Ariel <ariel1@ix.netcom.com>
Subject: Re: workstations for total fitness
Cc: kenpl@juno.com

Hello Jim,

Sorry for the delay in my response. I had some Email problems yesterday and was not able to retrieve messages! I will provide answers below each of your questions.


At 09:23 PM 5/12/99 +0100, you wrote:


John
Regarding workstations that Liam has spoken to Ken about, may I ask the following questions:

1 What specs are needed on the four computers to operate a workstation

<<<<
The computer should be a Pentium II w/ MMX (or equivalent), A minimum of 32 MB RAM, At least a 4 GB hard disk drive.
>>>>



2How are the copies of ariel system down loaded

<<<<
You can download the latest version directly from the internet. This is currently Revision 3.4 of APAS99. A single copy of the software can be used to load as many computers as you desire (@ $500 USD each). You can also use the version supplied to you on the ARIEL CD-ROM that came with your previous system.
>>>>



* Must each of the four computers that we designate, have e-mail ? and you directly send the info to them individually

<<<<
No, the computers do not require Email capabilities. Just as we did before, you provide Ariel Dynamics with the System Parameter number and the System Code number for each computer. Upon receipt of the full payment, Ariel will supply you with the Site Keys for each workstation.
>>>>


* Will it do to download one copy and to transfer to the other three computers

<<<<
Yes, as stated above, you can download the software from the internet or you can even use the software on the Ariel CD-ROM that you already possess.
>>>>







3What is the extent of the work that can be done on the workstations


* Capturing is out
* Editing and production are out, I assume
* Digitising ?
* Filtering/smoothing ?
* Analysing ?(i.e working with APAS-DOS)
* Getting the numbers ?

<<<<
The workstations can perform any of the capabilities as the main system except for Capturing.

>>>>






Looking forward to hearing from you.



Please contact Ken or myself for any additional information.

Sincerely,

John Probe

Hello Ismail EL MAACH,

I am not certain that I understand your question.  I think you are getting
the origin of the calibration cube confused with the "fixed" point in the
video data file.

The origin of the calibration cube (as well as the calibration points) must
be the same point(s) regardless of the camera view.  All coordinates must
be measured in X, Y, Z values relative to this single origin.

When digitizing the video sequence data, one must digitize a "fixed" point
for each image.  This fixed point must be the same point within a single
camera view, however, it does not have to be the same point between camera
views.  In other words, Camera #1 must use the same "fixed" point in the
calibration image and data images while Camera #2 can use a different
"fixed" point than Camera #1.

I hope I understood your question correctly and provided sufficient
information to answer it.  Please contact us for any additional information.

Sincerely,

John Probe



At 01:55 PM 5/17/99 -0400, you wrote:
>
>Hi,
>
>Here in the lab, we'd like to know if it's necessary when using a cubic
>calibration frame to use the same marker to indicate the origin on both the
>actual frame and the grabbed image. Our fear is that by having two different
>points as origins (one on the calibration frame i.e: first digitized marker,
>and one extra-frame anywhere in the lab);we will have a discrepancy between
>the actual coordinates and the digitized ones. We have looked this matter up
>in the literature, however, we did not find any reference to it.
>
>regards,
>
>Ismail El Maach, B.Eng., M.A.Sc.
>Research Associate
>Biomechanics of  Hockey Research Laboratory
>University of Ottawa/ Universit´┐Ż d'Ottawa
>e-mail: ielmaach@uottawa.ca

MJPEG IMAGE ORDER

 

 

A standard video picture is made up of odd and even lines across the screen. Television standards require these lines to be interlaced. This means only half of the lines are displayed in one field. The first (odd) set of lines is displayed in the first field while the second (even) set of lines is displayed in the second field. These two fields comprise a frame, which is a complete picture.

When capturing a video sequence utilizing the full speed provided with today's video standards, it is normally required to use special VCR equipment with field-by-field stepping capabilities. Industry standard hardware and APAS software modules make it possible to capture video sequences from a VCR or camcorder directly to the computer hard drive without special requirement of expensive VCR equipment. Any VCR can be used as a video source with the APAS.

The APAS system uses hardware and software that has Motion JPEG image hardware compression that also complies with the major hardware vendors. After capturing the video to the hard drive, the APAS system allows separation of each frame to its two component fields.

Depending on the hardware and software combinations used for recording and displaying the AVI files, it is possible for the order of the displayed fields to be reversed. It is also possible for the same AVI file to play in normal order on one computer and in reverse order on another computer! For this reason, the Ariel CAPTURE, TRIM and DIGITIZE programs provides the option to specify the order for displaying the images of the AVI files.

If it appears that the images are "jerky" or are being displayed in a "zigzag" manner, the field order probably needs to be reversed. The field order is specified using the following steps.

 

 

CAPTURE PROGRAM

  1. Select CAPTURE and CAPTURE PARAMETERS. The Algorithm Defaults menu will be displayed. Click on the STREAM tab to display the Streaming Capture options menu. Select either Normal or Reverse order in the MJPEG section. The current selection is indicated by the black dot to the left of the option. NOTE: When this option is changed, it affects all other APAS software modules where the AVI file can be displayed (Capture, Trim, Digitize, Display, Vectors etc.)
  2. Select OK to proceed or CANCEL to abort.

 

 

TRIM PROGRAM

  1. Select OPTIONS and MJPEG. The MJPEG Options menu will be displayed. Left-click either Normal or Reverse order. The current selection is indicated by the black dot to the left of the option. NOTE: When this option is changed, it affects all other APAS software modules where the AVI file can be displayed (Capture, Digitize, Display, Vectors etc.)
  2. Select OK to proceed or CANCEL to abort.

 

 

DIGITIZE PROGRAM

  1. Select FILE, SEQUENCE and NEW (or OLD) and specify the Sequence Name.
  2. Select FILE, NEW (or OLD) VIEW and specify the View File and the corresponding AVI file.
  3. Select IMAGES and VIDEO to display the Video Options menu. Left-click either Normal or Reverse order. The current selection is indicated by the black dot to the left of the option. NOTE: When this option is changed, it affects all other APAS software modules where the AVI file can be displayed (Capture, Trim, Digitize, Display, Vectors etc.)
  4. Select OK to proceed or CANCEL to abort.

 

WINDOWS WIN.INI FILE

The Image Order information is stored in the WIN.INI file. Once this parameter is set in the Capture, Trim, or Digitize module, the Ariel software will remember the current setting. The following information is listed in the WIN.INI file of the APAS computer.

[APAS System Information]

ReverseFields=0

NtscPal=0

When Reverse Fields is set to 0, the APAS software reads the video fields in normal order. When the Reverse Fields is set to 1, the video fields are displayed in reverse order.

 

Hello Steve,

I have checked all the information in your customer file and cannot find
anything that states you purchased 5 licenses.  Our standard policy (for
Ariel Customers that have purchased a full system) is $500 USD per computer
for the APAS Workstation software.

Whenever you load the file on a new computer, it will generate different
codes.  This is how Ariel Dynamics keeps track of the Registered versions
of software.

You should be able to transfer the current software license to any existing
computer.  Please refer to the APAS System License Frequently Asked
Questions (FAQ) on the Ariel internet site.  The direct address is:

/Main/licensefaq.html

Thanks for your message.  Please contact me for any additional information.

Sincerely,

John Probe




At 10:11 AM 5/24/99 +1200, you wrote:
>hi John
>
>I hope all is well over your way.  I have just got a new laptop and
>want to load one of our 5 licenses on it.  I downloaded the new
>version at the start of the year and you gave me the codes for that
>and it works fine.  But when I use the same zipped file to load it
>onto the laptop it throws up a different code.  The when i try to
>"license in" and license out" from the computer that it is fully
>loaded on it does not give me that option.  It is greyed out.  Do i
>send you the new code site code from the laptop for you to send
>me a new site key or am I missing something basic????
>
>Thanks again
>
>Cheers Steve
>Stephen Stanley MPhEd (Dist)
>Research Officer
>Faculty of Health Studies
>Auckland Institute of Technology
>Private Bag 92006
>Auckland
>New Zealand
>Ph  +64 9 3079999 ext 7177
>Fax +64 9 3079988
>
>
++++++++++++++++++++++++++++++++++
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California  92111  USA
(619) 874-2547 Tel
(619) 874-2549 Fax
Email:  ARIEL1@ix.netcom.com
Web Site:  http://www.arielweb.com
++++++++++++++++++++++++++++++++++

 

Hello Darren,

I will provide answers below each of your questions.

At 08:56 PM 5/27/99 -0500, you wrote:
>>>>

OK. Tommorrows the big day for me to capture. I've decided to use black markers with me wearing a white t-shirt and shorts, and I've lined up 4 cameras and tripods. I am just going to use your System marker set, and if time enough I will try and also use the 30+ marker set which is the standard supported by 3D Studio Max & Character Studio. After looking over the APAS help files and (briefly) the user manuals on your web site, my only questions now (I think) are: a. I am not sure what the best choice of a "fixed point" is. Reading your description at first I thought I should just glue down a black painted half of a ping pong ball (or something like this) right in the center of the floor of the capture area, with all the cameras up relatively high on their tripods pointed somewhat downwards (i.e. like the Vicon does) where they would each see this mark on the floor toward the lower third of their respective views. But then your manual says that I must ensure the subject never obscures the fixed point in any of the frames - and I'm thinking there's no way I can ensure that for *any* point can I? Not unless you mean there's a *different* "fixed point" for each camera? I'm confused... what's an example of a good "fixed point"?

<<<<
The fixed point can be anything in the field of view of each camera that does not move. This can be a mark on wall or floor, a ping pong ball glued to the floor, the corner of a door....etc. It does not matter what this fixed point is as long as it does not move. The fixed point must remain the same for each view but can be a different object between view. For example, the fixed point for View #1 calibration and View #1 data should be the same. The fixed point for View #2 calibration and View #2 data should be the same. However, the fixed point for View #1 and View #2 can be different points.

>>>>

b. I may have overlooked it, but I never saw a picture of an example calibration rig... My thoughts are either a cube with markers at each of the 8 corners (is 8 enough points?), or else these vertical rods like I've seen with measured marks vertically up the rods... Would either of these do the trick?

<<<<
The Direct Linear Transformation (DLT) requires a minimum of 6 non-coplanar points to satisfy the equations, however, it is recommended to use 12 or more points. The situation you describe above should be fine. You might also include a diagonal rod with points of know locations.

>>>>

If I was imaging it right the cube would be smaller like 1 meter square or something right in the center of the capture volume, whereas these vertical rods are taller and spread over a larger coverage of the capture area? What would you recommend (and is there a picture somewhere?)

<<<<
It is recommended that the Control Points encompass the area that includes the activity to be analyzed. If you are analyzing the movement of fingers on a keyboard, you would require a much smaller calibration fixture than if you were going to analyze a golf swing.

The main points to remember are that you use 12 or more points that completely encompass the area where the activity will be analyzed. It does not matter what shape the calibration fixture is, you just need to know the X, Y and Z coordinates (based on the right-hand-rule) relative to a single origin.

>>>>

c. I'm just going to make up my own markers. The Vicon uses markers that are 2.5 cm around, so I was going to see if I can find some round beads or something about this size and then just tape them to me with double sided tape. Does this sound about the right size? Any suggestions? (e.g. I'd always thought of ping pong balls as being close to what's needed - but they're actually too big, right? Anything as easy to find as ping pong balls that would be the right size?) Thanks again (getting close to not having to pester you anymore :),

<<<<
The standard reflective markers we sell are 0.75 inch diameter styrofoam balls covered with retro-reflective tape. There are Ariel users that use markers as small as 1 mm and up to ping-pong ball size or larger. This really depends on the field of view and the ability to see the markers. It seems for most applications, markers of 0.75 inch diameter or smaller are used.

I hope this information is helpful!

Sincerely,

John Probe



>>>>

Darren Cruse
www.anet-stl.com/~dcruse
Freak Accident Digital Media


++++++++++++++++++++++++++++++++++
John Probe
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California 92111 USA
(619) 874-2547 Tel
(619) 874-2549 Fax
Email: ARIEL1@ix.netcom.com
Web Site: http://www.arielnet.com
++++++++++++++++++++++++++++++++++

 

 

Hello Darren-Gideon asked me to help you with your list of questions. I Have sprinkled my responses below your questions.

Sincerely,

Jeremy Wise Dir R&D

Captured video with four cameras on Friday, and have been using esp. the Trim, Digi4, and Transform programs.  My biggest questions have come from using Digi4:

1)  Can I turn the bell off during Auto Digitize?  Even when Auto Digitize works it's running quite slow and I'm wondering if things would speed up without the bell, or if there is any other way to speed up the process.

>>The bell cannot be turned off at the moment but that would not cause the program to run slowly. The one think that will most directly  impact the time for locating the markers is the size of the search window specified for the markers. When the search window is large there are multiple candidates per joint and many combinations which must be checked. You want a search area large enough that the frame to frame motion will result in the marker lying inside the search rectangle centered on the expected location of the point and not unnecessarily large. Usually a 50x50 rectangle works.

>>

2) Auto digitize is failing to recognize point markers when there is motion blur due to movement during the frame... and it doesn't take as much movement as I'd expected to cause a problem.  Even just some fairly brisk walking seemed enough to do it.  Any way to make it work or is manual digitizing required here?  (I can send you some sample images if you'd like to see what I'm talking about BTW).

>>

The blurring is a result of recording with an unshuttered camera. The software has loose requirements regarding size, shape & brightness and it appears that those requirements are being exceeded. The use of an unshuttered camera not only results in a blurred, elongated image but also the time for the image is not known. Use of an unshuttered camera with APAS is not recommended & I cannot help you with this.

>>

3)  I always get an error upon opening the AVI file for a View which says:  "Video Image Info does not match Tracefile Filmspeed".  What does this mean?

>>

When a sequence of video is saved to an AVI file an image rate is saved in the AVI file. For example, if you capture NTSC at full rate the image speed stored in the file is 60 hz. When that same file is opened with Digi4 one can specify a skip factor giving possible image rates of  60, 30, 20, 15, etc  Hz. When a new "View" is created in Digi4 one specifies the rate for the view which specifies the time between consecutive images in the traced file. The message is alerting you to the fact that the AVI rate modified by the skip factor does not match the "View" rate. This message is a warning only. The "View" rate always overrides the rate from the AVI.

>>

4)  I did a capture where I was walking in a circle around the center of my capture area.  As I turned relative to a camera's view that would mean of course that different markers would disappear and appear to that camera.  To handle this do I simply have to mark the markers visible at the beginning frame, let the auto digitize run until new markers appear/disappear as I turn or change position, then stop the auto digitize and restart it again where I mark the newly visible markers during it's "learning" frame?  (this is what I did - my *real* question is if there is a faster way :)

>>

Typically, for a given camera, a particular marker is either visible or not for a number of consecutive frames. When a marker leaves the field of view for a camera, I would mark it as " Invisible" and when it returns mark it as "Visible". It should not be necessary to stop & restart auto-digitizing to go thru the learning phase. When a marker appears for which there has been no learning the program will request the operator to manually digitize the point. If you hold down the SHIFT+CONTROL keys while digitizing this will force the program to go through the "Learning phase" for the point. You can do this whenever the program does not locate a point the you think it should have.

>>

5) Should I expect to have the above issue from markers being occluded by the subject's body?  For example during my walk cycle the left camera's view would intermittently see the right hip, knee, ankle, foot, etc. as the legs scissor back and forth with the walk cycle.  So my question is should I have to manually mark the right side markers each time they reappear from having been occluded by the left side of the body?  Or is auto-digitize smart enough that it should be able to reaquire these markers when they reappear?   (it didn't appear to me that it was in my little test)

>>

When a marker temporarily cannot be seen it should be flagged as "MISSING". This can be done by pressing the "Esc" key or by clicking on the icon for "Missing". It will be smart enough if the marker re-appears within the search rectangle centered about the expected location of the point.

>>

6) Should I be concerned about markers like the above not being labeled?  i.e. my goal is to generate 3D data, and you say you need two cameras to see a marker to get the 3D coordinate, so maybe I shouldn't care that the left camera view doesn't have the right side markers identified?  (i.e. since I know the right camera view and front camera views will see them?)

>>

This is correct, as long as 2 or more cameras cann "see" a marker 3D can be calculated with mre being better. It has been our experience that one needs 6 cameras to compeletely cover a 360 degree twist. When using changing sets of cameras which see a point it is particularly critical to have very accurate calibration data. Otherwise small jumps in the data will appear when a different set of camera sees a point.

>>

7)  If auto-digitizing misses a marker (e.g. due to the "motion blurring" problem) is there an easy way to manually identify that single marker, i.e. *without* having to *unlabel* all the subsequent markers with the "correct" function?  Ideally I would like to use the auto-advance feature to batch process the whole sequence (e.g. over lunch), then go back and review the results and correct these problem markers.

>>

Under Automatic/GlobalOptions there is a checkbox for "Confirm missing pts". If you check this box, the program will pause at the missing point and require you to manually digitize the point.

>>

8)  The real concern behind most of my above questions is that it looks to me from my limited test example that there is a *lot* more manual digitizing required than I had hoped for to generate a motion capture file.  You had told me last week that you are working on supporting different colored markers in a future release of APAS...  so now I'm wondering if these colored markers will actually be used to enhance the auto-digitizer to auto-identify the markers based on color?  My gut feeling right now is that if that's the case that feature might make the difference for my uses (where I am doing computer animation, not gait analysis) between APAS being a once in a blue moon tool for very short captures and it being a really valuable daily use tool. 

>>

It sounds to me like your automatic digitizing was not properly "tuned" . Hopefully it will perform more to your satisfaction after you have implemented some of the suggestions I have made above. However, one cannot expect the system to find markers which are missing, obscured or blurred. If you would send me a shork clip of your video data I will take a look at it. Can you also tell me what version of the APAS software you are running.

>>

 

Hi Daren,

My name is Erik B. Simonsen. I have a gaitlab, in which we use the APAS
system with 5 cameras and two forceplates. I may be able to help you a bit.

I will try to answer your questions between the lines:
>
>Hi -
>
>Captured video with four cameras on Friday, and have been using esp. the
Trim, Digi4, and Transform programs.  My biggest questions have come from
using Digi4:
>
>1)  Can I turn the bell off during Auto Digitize?  Even when Auto Digitize
works it's running quite slow and I'm wondering if things would speed up
without the bell, or if there is any other way to speed up the process.

It seems something is wrong with your PC. Automaticmatic digitizing is
normally not a slow process. If you choose AUTOADVANCE and provided the
markers can be found automatically it should take less than 5 seconds for
100 frames.

>
>2) Auto digitize is failing to recognize point markers when there is motion
blur due to movement during the frame... and it doesn't take as much
movement as I'd expected to cause a problem.  Even just some fairly brisk
walking seemed enough to do it.  Any way to make it work or is manual
digitizing required here?  (I can send you some sample images if you'd like
to see what I'm talking about BTW).

You should always use a shutter on the camera. For walking I use a rather
long shutter: 1/250 s

>
>3)  I always get an error upon opening the AVI file for a View which says:
"Video Image Info does not match Tracefile Filmspeed".  What does this mean?

I dont know the reason. I always ignore it.

>
>4)  I did a capture where I was walking in a circle around the center of my
capture area.  As I turned relative to a camera's view that would mean of
course that different markers would disappear and appear to that camera.  To
handle this do I simply have to mark the markers visible at the beginning
frame, let the auto digitize run until new markers appear/disappear as I
turn or change position, then stop the auto digitize and restart it again
where I mark the newly visible markers during it's "learning" frame?  (this
is what I did - my *real* question is if there is a faster way :)

Well, the most difficult situation you can imagine is what you describe:
walking on a circle or doing a twisting sommersault.

I wont recommend that you let the auto digitize run, you should always
advance each frame your self. In this way you can avoid mixing of markers
and other errors. Only if I have a very simple marker setup, where I know
nothing can go wrong, I let it run by it self.

For each camera view you should tell the system, which markers are
invisible, but you have to make sure that each marker will always be visible
for at least two cameras. Actually, it is best to make a strategy for this.

If a marker becomes invisible temporarily it is better to guess where it is
rather than digitize it as "missing" by the ESC key or define it as
invisible. As you suggest is possible to turn a marker on and off as visible
or invisible during the whole process, but often it is much better to guess.
The system does not look for an invisible marker to become visible again.
>
>5) Should I expect to have the above issue from markers being occluded by
the subject's body?  For example during my walk cycle the left camera's view
would intermittently see the right hip, knee, ankle, foot, etc. as the legs
scissor back and forth with the walk cycle.  So my question is should I have
to manually mark the right side markers each time they reappear from having
been occluded by the left side of the body?  Or is auto-digitize smart
enough that it should be able to reaquire these markers when they reappear?
(it didn't appear to me that it was in my little test)

Please see my comments above.
>
>6) Should I be concerned about markers like the above not being labeled?
i.e. my goal is to generate 3D data, and you say you need two cameras to see
a marker to get the 3D coordinate, so maybe I shouldn't care that the left
camera view doesn't have the right side markers identified?  (i.e. since I
know the right camera view and front camera views will see them?)

I use 5 cameras for walking, two from a side view and one from a frontal
view. The two cameras from e.g. the left side are never expected to see the
markers on the right side of the body. Furthermore, it is my impression that
accuracy does not suffer from using only two instead of three cameras to see
a marker.
>
>7)  If auto-digitizing misses a marker (e.g. due to the "motion blurring"
problem) is there an easy way to manually identify that single marker, i.e.
*without* having to *unlabel* all the subsequent markers with the "correct"
function?  Ideally I would like to use the auto-advance feature to batch
process the whole sequence (e.g. over lunch), then go back and review the
results and correct these problem markers.

You just correct any mistakes on every frame during the process. This is why
you should also establish good contrast in your recordings. I have painted
the floor and walls dark to enhance contrast and often we dress the subjects
in a tight blach suit with white markers. With five cameras we never through
light on the subject, we rather dirict light to the ceiling.
>
>8)  The real concern behind most of my above questions is that it looks to
me from my limited test example that there is a *lot* more manual digitizing
required than I had hoped for to generate a motion capture file.  You had
told me last week that you are working on supporting different colored
markers in a future release of APAS...  so now I'm wondering if these
colored markers will actually be used to enhance the auto-digitizer to
auto-identify the markers based on color?  My gut feeling right now is that
if that's the case that feature might make the difference for my uses (where
I am doing computer animation, not gait analysis) between APAS being a once
in a blue moon tool for very short captures and it being a really valuable
daily use tool. 

We digitize about 80 frames from 5 cameras (a total of 400 frames) in less
than 60 minutes by a semiautomatic approach AND then the digitizing is over
and done and error free, which is seldom the case for online systems.

Darren, I hope this information helps, otherwise send me an email.


>
>Thanks again,

 

Hi Gideon/Jeremy,

Thanks a lot for the answer. Indeed, my student did not really understood the necessity and utility of the synch option. We were using a software synch. There was a rather long delay between the synch light and the moment the skater was arriving. After all views were synch manually in DIGI-4, she was just trimming a few frames before the onset of the jump without determining the synch frame which explains this rather long delay!!

Thanks again.

Normand

At 10:47 10-06-99 -0700, you wrote:

Hi Normand:
  We have never had a situaiton of synch so many fields before the activity. In our old DOS program this was not possible. However, we are going to add the ability to have any number of synch before and after and will publish it on the new version soon.
Gideon

----- Original Message -----
From: Jeremy Wise
To: Normand.Teasdale@pmh.ulaval.ca
Cc: Gideon Ariel
Sent: Thursday, June 10, 1999 8:53 AM
Subject: Display Module Difficulty

Normand-

I received your files and have diagnosed the problem. You did nothing wrong, however the software was not handling having a synch frame so far outside the data for the sequence. In your case it was some 6 sec [-172]  images before the start of the data for the sequence. In the short run you can get around the problem by adding the same #frames to each view as the concept is relative. Since all 4 of your view had a synch = -172, I would suggest making the synch = 0 for all your views. Then re-run the 3D Transformation & Smoothing and you should be set. In the meantime we will fix the problem more permanently.

Best, Jeremy

Normand Teasdale (Normand.Teasdale@kin.msp.ulaval.ca)

Universit´┐Ż Laval, Laboratoire de performance motrice humaine, PEPS

Facult´┐Ż de m´┐Żdecine

D´┐Żpartement de m´┐Żdecine sociale et pr´┐Żventive

division de Kin´┐Żsiologie

Qu´┐Żbec, Qu´┐Żbec G1K 7P4

T´┐Żl: (418) 656-2147

Fax: (418) 656-2441

 

 

Gideon,

Here is a copy of the message that I sent.

John



>>>>

Date: Thu, 10 Jun 1999 09:46:59 -0700
To: "Strojnik, Vojko" <VStr@sp.uni-lj.si>
From: Ariel <ariel1@ix.netcom.com>
Subject: Re: Faculty of Sport, Ljubljana, Slovenia
X-Attachments: F:\Download\VidDecom\iv5devl.exe;

Hello Vojko Strojnik,

Thank you for your message. In my last reply to you, I provided answers based on a different frame grabber. It appears that you are using the Intel Smart Video Pro frame grabber. The maximum resolution on this is 640 x 480. It is not capable of supporting the 720 x 480 resolution.

The reason that you cannot read the files on other computers is due to the fact that your other computers do not have the appropriate decompressor. You Main APAS works because this software is included with the installation of the frame grabber software. Since your other computers do not have frame grabbers, they are missing the decompressor software.

I have attached a file from Intel that will provide the required decompressor software. You should install this file on all computers that will be digitizing AVI files captured with the "Main APAS" computer. Accept all the default settings during the installation.

I apologize for the confusion. Please contact us for any additional information.

Sincerely,

John Probe





At 02:21 PM 6/10/99 +0200, you wrote:
>>>>

Faculty of Sport, Ljubljana, Slovenia

Dear Mr. Ariel,
thank you for your response. However, things seem to be more complicated. We have a computer with your video card, connected to Panasonic VCR AG-7350, entitled to move data from video tapes to AVI format. The other computers have no video cards and are ment for digitalization and data analysis. Here is a list of our troubles:

Computer with video card: After selecting VIDEO FORMAT command, Video compression method is to choose (not CAPTURE FORMAT as you suggested). There are two possiblities: INTEL INDEO (TM) RAW VIDEO and and INTEL INDEO (TM) R 3.2. We are using Raw Video version since it enables capturing with 640x480. What to do to enable Motion JPEG option with 720x480?

Once AVI is captured in 640x480 resolution, it can not be read by other APAS computers to digitize these data. They can work only when data are captured with 320x240. At these computers, no video card is installed. It is also not posible to start Capture command from the command line to set driver and resolution in these computers. How to enable other APAS computers to be capable to digize in higher resolution (we hope to get 720x480)?

We have recently bought a digital video system from Sony including cameras, Digital Video Player DSR-60P and FAST-DV-master pro video card? Is it possible to connect this hardware to APAS?

best regards,
Vojko Strojnik

Hello Leonard,

I am writing to inform you that your APAS order has been shipped by United
Parcel Service.  Everything has been included into one computer box.  You
should receive it by the middle of next week.

The tracking number is:  T169 066 266 0 for your reference.

I faxed the invoice to Ralph Madison in the Purchasing Department on May
19,1999.

The Hardware for the Serial Interface has been included.  You will need to
install this on your Panasonic AG-7350 VCR using the steps below.

1.  Remove the 4 screws holding the 34 pin controller on the back of the VCR.
2.  Disconnect the connector to the 34 pin controller.  This will connect
to the new Serial controller.
3.  Connect the 3 seperate connectors to the new Serial Controller.  You
might have to "fish" theother two connectros out from inside the VCR.
Sometimes they are located under the top cover of the VCR but you should be
able to get to them through the opening in the back.  Also be careful
because the metal opening is sharp! It can cut fingers and/or wires!
4.  Use the four screws removed in Step #1 to attach the Serial Connector
to the VCR.
5.  The switch setting on the Serial Control should be left in the default
positions. 

NOTE:  You will need a standard 25pin (male) to 9pin (female) Serial Cable.
 The 25 pin side connects to the RS-232 IN connector on the back of the VCR
while the 9 pin connector connects to either COM1 or COM2 on the back of
the computer.

Please do what you can to expedite the payment and feel free to contact me
for any additional information.  Payment should be sent to our San Diego
address.  Also not that effective June 12, 1999 the area code for the San
Diego office changes from 619 to 858.

Sincerely,

John Probe

++++++++++++++++++++++++++++++++++
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California  92111  USA
(858) 874-2547 Tel
(858) 874-2549 Fax
Email:  ARIEL1@ix.netcom.com
Web Site:  http://www.arielweb.com
++++++++++++++++++++++++++++++++++

Paul-

The "zero" on the acceleration graph does not represent "stillness" but rather constant velocity. Zero on a velocity graph would represent stillness.

Sorry about getting back to you concerning the AVI file. I tried it on my laptop using the Morgan software & it worked fine. This is not to say that you are not experiencing a problem I just cannot duplicate it.

I have a couple of suggestions for you to try. First try to access this file from the Display & the Capture modules & if it is possible to access the video from these modules. Also try running Windows Explorer & locate the file & double click on it. This should start the Player for the AVI. See if it runs with Player. Make sure that you are accessing the same AVI file for all these tests.

Let me know what happens.

Best, Jeremy

-----Original Message-----
From: aida zorrilla & paul scheuer <pscheuer@texas.net>
To: Jeremy Wise <jeremy@arielnet.com>
Date: Tuesday, June 22, 1999 10:08 AM
Subject: Acceleration graphs

Jeremy,

Does the "0" line on an acceleration graph represent stillness?  so that "-" numbers define direction?  could you then denote eccentric and concentric strength of muscles?

Thank you,

Paul Scheuer

Hello Dr. Oscar Rocha Barbosa.

The APAS software was originally desiged to capture images using a computer
controlled VCR.  At this time, only Panasonic manufactured the necessary
VCR with the computer control interface.  For this reason, we standardized
the APAS on the Panasonic equipment.  However, with the new advances in
video technology, the APAS no longer requires the computer controlled VCR.
Images can be captured in Real Time directly to the hard disk using the
Iomega Buz supplied with your system.

Your APAS computer was shipped with APAS98 Revision 9.5 software.  We have
had many improvements and are currently shipping APAS99 Revision 3.5
software.  Ariel Dynamics always provides free software upgrades to our
customers.  Therefore, I recommend that you download the latest version
from the Ariel internet site (www.arielweb.com) and install it on your
computer using the following steps.

1.  Select START, SETTINGS and CONTROL PANEL.
2.  Double-Click on the ADD/REMOVE PROGRAMS icon
3.  Select the APAS SYSTEM software and then click on the ADD/REMOVE button.
4.  Click YES to Completely Remove APAS System and all of its components.
5.  Select NO when asked to Remove Shared Files
6.  Select OK and then OK to exit the ADD/REMOVE Programs.
7.  Download the latest version of APAS from www.arielweb.com to a
temporary directory.  This file is currently APAS99WIN3_5.EXE
8.  Execute the APAS99WIN3_5.EXE file to decompress the system files to the
C:\TEMP directory.
9.  Select START, RUN and C:\TEMP\SETUP.EXE to install the software,
10.  Select NEXT and YES to accept the License Agreement.
11.  You can enter your name and Company and Serial Number if desired but
this is not required.  Select NEXT to proceed.
12.  Accept the default destination folder of C:\PROGRAM FILES\ARIEL
DYNAMICS\APAS and select NEXT to proceed.
13.  Accept the APAS SYSTEM folder name and select NEXT to proceed.
14.  Select OK to install the program.
15.  Select FINISH to complete the installation.

The APAS SYSTEM folder will be created on the Windows Desktop.  Double
click this folder to access the APAS software modules.

The APAS99 Revision 3.5 software provides two software modules for
capturing images to the hard disk.  These programs are called REALCAP and
CAPTURE.  I recommend that you use the STREAMING function in the CAPTURE
module.  You can access the HELP menu to provide step-by-step intructions
for image capture.

You can also find on-line manuals and Tutorials directly on the Ariel
internet site.

Please feel free to contact me for any additional information.  We are
always happy to help!

Sincerely,

John Probe

++++++++++++++++++++++++++++++++++
Ariel Dynamics, Inc.
4891 Ronson Court
Suite F
San Diego, California  92111  USA
(858) 874-2547 Tel
(858) 874-2549 Fax
Email:  ARIEL1@ix.netcom.com
Web Site:  http://www.arielweb.com
++++++++++++++++++++++++++++++++++

 

Paul-

 

It means that the element is slowing down.

 

Best, Jeremy

 

-----Original Message-----
From: aida zorrilla & paul scheuer <pscheuer@texas.net>
To: Jeremy Wise <jeremy@arielnet.com>
Date: Wednesday, June 23, 1999 11:22 AM
Subject: Re: Acceleration graphs

Jeremy,

What does it mean when the graph of Acceleration goes into "-" (negative) numbers?  Is that a change in direction of the joint?

Paul

----- Original Message -----

Sent: Tuesday, June 22, 1999 12:59 PM

Subject: Re: Acceleration graphs


Paul-

The "zero" on the acceleration graph does not represent "stillness" but rather constant velocity. Zero on a velocity graph would represent stillness.

Sorry about getting back to you concerning the AVI file. I tried it on my laptop using the Morgan software & it worked fine. This is not to say that you are not experiencing a problem I just cannot duplicate it.

I have a couple of suggestions for you to try. First try to access this file from the Display & the Capture modules & if it is possible to access the video from these modules. Also try running Windows Explorer & locate the file & double click on it. This should start the Player for the AVI. See if it runs with Player. Make sure that you are accessing the same AVI file for all these tests.

Let me know what happens.

Best, Jeremy

-----Original Message-----
From: aida zorrilla & paul scheuer <pscheuer@texas.net>
To: Jeremy Wise <jeremy@arielnet.com>
Date: Tuesday, June 22, 1999 10:08 AM
Subject: Acceleration graphs

Hello Dr. Ariel,

How are you doing? Are you there in Australia?
I am so happy with APAS99. We analyze about 4 to 5 patients a week since 3
weeks ago. I developed mat lab scripters and functions to calculate and
display joint angle(by Euler/Cardan angle of Grood and Suntay) from APAS 3d
file. It was very hard work for me. But was inevitable to do that work for
our patients.

You may download the matlab tool and patient case from my ftp site as below.
   Host address : plaza1.snu.ac.kr
 
Download the matlab tool and add path to your matlab. Then, run scripter
"HHdisp" which means data display for Helen Heyes marker set. You may select
4 mat files, two for the patient data and 2 for normal data. Patient and
normal data in mat file format are in the directory "gait cases" of my ftp.
You can see the joint angles, COG pathway, angle and angle diagram.
You can run "HHcal" to generate the mat files of joint angles and time
distant values.

The marker set and displaying format are same with Vicon and more. I have an
idea to calculate the joint angles better than the Vicon clinical manager.
Will do the work for " Beyond the Vicon".

I would like to ask you some help.
I like the apas2mat.m very much. Can you make an m file as "mat2apas" which
can make an apas 3d and cf files from matlab matrix containg x,y,z data of
several points in frames?
During the processing of my HHcal.m(helen heyes calculation), I calculate
the joint centers' x,y,z data. I would like to see animated stick figure of
my joint center data in the apas view.
Will you do that?

Until now, I found that the digitizing capability of APAS99 is better than
Vicon or Elite because we can see the patients with digitizing.
Digital video cameras will make the APAS win the world in every aspect of
motion analysis!!!

Please, tell me after you download my gait case. The ftp site for me is
limited upto 10Mbyes, so, I should delete them to upload another cases.

Hope to hear from you....

More than two of my Korean freinds(M.D. in rehabilitation medicine) will
come to the ISBS in Australia. They - A man and a woman -  may give
greetings to you because they met you in Korea, DanKook univ in 1994, when
you gave a lecture for my alumni and Prof. Han.


sun



Dear Dr. Dohle,

Gideon Ariel has asked me to answer your inquiry about the opposition
movement and automatic tracking of that.

We have had the apas system here for several years and use it on a daily
basis for 3D analysis of walking. It should be perfectly OK to use the
system for tracking the thumb movement in 3 dimensions. After experimenting
a little with the type of markers and their size, it will be possible to
track the movement automatically. You will have to use at least two
videocameras and a rather small calibration cube. You may build the cube
yourself, but I guess it is easier to order one from Ariel Dynamics.

The 3D coordinates can be exported in ascii, but you may also export the
apas files directly to Matlab, we always do that. Then it is easy to perform
an FFT in Matlab.

The apas system can also perform a frequency (FFT) analysis, but I think it
will be better to use Matlab or another signal processing program.

You are welcome to visit my lab if you want to see how we use the system
here. We have been very satisfied with the system and also with the service
from the company.

Sincerely yours

Erik B. Simonsen, associate prof. Ph.D.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Erik B. Simonsen, Associate Professor, M.Sc. Ph.D.
Institute of Medical Anatomy section C.
Panum Institute. University of Copenhagen
Blegdamsvej 3., DK-2200 Copenhagen N
DENMARK
Phone:  +45 35 32 72 30 (work)  Fax: +45 35 32 72 17
Phone:  +45 45 80 93 04 (home)  
http://www.biomechanics.mai.ku.dk/ebs.htm
E-mail: E.Simonsen@mai.ku.dk
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Hello Mr. Balmer,

Thank you for your message.  Please provide a detailed explaination as to
why you are "unable to proceed" with operating the APAS software.  This may
help us determine any problems and assist you in operating the APAS system.

Is the problem with the software installation?  Or, in operating the software?
What operating system are you using (Win95/98 WinNT)?

In order to assist customers, each APAS module has an integrated help
screen.  There are also help screens on the Ariel internet site:

www.arielweb.com/Main/adw-91.html

There is also on-line tutorials at the following address:

www.arielweb.com/topics/Tutorials/default.htm

I hope this information is helpful.

Sincerely,

John Probe
Email:  ARIEL1@ix.netcom.com



At 02:09 PM 8/16/99 +0100, you wrote:
>
>Dear Sir/Madam
>
>I am a lecturer of sports biomechanics at Canterbury Christ Church
>University College and I ma interested in acquiring the APAS system for
>teaching and research purposes. I have attempted to download the
>software and have completed the installation procedure. However I am
>unable to proceed. I have read the information provided on your website
>and the system software appears to be exactly what I require, however I
>would like to discuss with you what my requirements involve and which
>items I ish to purchase, please can you get back to me as soon as
>possible or give me a contact address/phone number for your UK
>distributor.
>
>Yours Faithfully
>
>James Balmer
>----------------------
>jb10@canterbury.ac.uk
>
>

Hi John,

I will provide answers below each of your questions.


At 03:25 PM 8/22/99 -0700, you wrote:
>8-22-99
>
>John,
>
>I successfully captured a video clip from NTSC video (composite input)
>Friday PM and trimmed it OK.
>Several problems in progressing have occurred:
>(1) During capture the video window was small (zoom 1x ??) but OK. I
>reviewed the clip in 5x zoom (the system warned
>"is your video system capable" OR some like that).
>
The warning message is expected to check on the ability of the video hardware.

>The 5x was distorted
>with the horizontal dimension too big relative to the vertical. I think
>I tried to go back to 1x but could not. It was very hard to see when the
>plates lost contact with the ground in my weightlifting clip with the
>distorted view. In the trim module the images are small and when I
>doubled clicked the image can up large and distorted as above. Had to
>guess where to start trim.
>
The distorted image is something that we have not run into before.  I will
check onthis tomorrow when I get into the office.  I know we used the ZOOM
function on your system in the office and did not experience any problems.


>(2) Saved the trim and copied the resulting AVI file to a zip disk to
>work on - digitize on my office computer. But when I try to load the
>file in trim or digitize module on my office computer I get the message
>"Unable to Locate Compatible Video DeCompressor" followed by odd / even
>field order question??
>
Yes, this message is normal also. It simply means that your system does not
have a compatible video driver.  Please refer to the following internet
address for assistance:

www.arielweb.com/topics/FAQ/Installing_Video_Driver.htm


>I note that selecting a file in DIGI4 (the quick reference calls it
>DIGI4 but the module is Digitize) should have the *.CF extension. Where
>does this come from??
>
Yes, you are correct on the Digitize and DIGI4.  The reason that there are
two different names was that many APAS customers use both the DOS version
of Digitize and Windows version of Digitize.  The Windows version was
referred to as DIGI4 becaue it allows up to 4 images to be digitized
simultaneously.  Recently, we stopped distributing the DOS version of
Digitize because the current video cards no longer support the DOS
software.  Therefore, Digitize and DIGI4 are the same program.  Sorry for
the confusion.

The *.cf file is created in the Digitize (or DIGI4) module when you select
FILE, SEQUENCE and NEW.  The *.cf stands for the "Common File" and stores
the information that is common to ALL the camera views (number of points,
number of control points,point ID's, point connections... etc).


>Perhaps I copied the AVI file to Zip disk when I
>needed a CF file for Digitize, but even the Capture and Trim modules
>cannot read the AVI file I copied to Zip disk even though APAS just
>generated that file. WHAT'S UP???? I can't find any info on this in the
>Help files.
>
As mentioned above, the AVI file cannot be read by the Capture or Trim
modules because of the missing video driver.  The driver is on the "main"
APAS computer because it is loaded with the Frame Grabber software.

I hope this information is helpful!

John

The reason you get a horizontal bar in the topview is that it is 2D. It is
like you are looking at a piece of paper  looking from the end. All you see
is a line corresponding to the thickness of the pper.

Best, Jeremy


In a message dated 9/8/99 7:12:54 PM Eastern Daylight Time, john@arielnet.com
writes:

<< Hi Jeremy,
 
 I was testing the software today and noticed a problem when transforming 2D
 data.  I have attached the files in the hopes that you can duplicate the
 problem.
 
 When transforming the following 2D file, the correct *.1t image and Front
 View are displayed correctly, however, the Top View Window shows a
 horizontal bar in the same color as specified for the XYZ.
 
 I have duplicated this situation on 2 different computers so it seems to be
 consistent.
  >>

Thank you so much for your instruction Mr. Probe,
We have solved the problem.

Happy Thanksgiving!

Yung-Shen Tsai, PT
yst200@is8.nyu.edu
Lab Assistant
Human Performance Laboratory
Department of Physical Therapy
New York University


>From: Ariel <ariel1@ix.netcom.com>
>To: yst200@is8.nyu.edu
>Subject: Reported APAS problem
>Date: Wed, 24 Nov 1999 09:55:53 -0800
>
>To Whom It may Concern:
>
>Thank you for the telephone call.  The problems that you reported with the
>software are most often caused by not shutting down the computer properly.
>You should always exit the APAS DOS programs and get back to the Windows
>desktop to exit.  Then select the START, SHUT DOWN option.
>
>In order to resolve this problem, you must re-configure the software using
>the following steps.
>
>1.  Use the Windows startup disk to boot to the DOS prompt
>2.  Get to the C: and use the DOS "rename" command to rename the following
>files:
> ren autoexec.bat autoexec.bak
> ren config.sys config.bak
>3.  Remove the diskette and reboot the computer.  This should get you back
>to the Windows desktop
>4.  Select START, RUN, BROWSE to find the /ARIELCBA/SETUP/SETUP.EXE file.
>This is probably located on your D drive of the computer but may also be on
>the C drive.
>5.  Run the SETUP program.  Set the APAS drive to the location where the
>SETUP file was found (C or D).  Set the Windows drive to C.  Leave the
>OPTIONS blank.  Select APPEND for Autoexec/config.  Then select the PROCEED
>button.
>6.  After the program is installed, you must reboot the computer for the
>changes to take affect.
>
>This should resolve the problems that you reported.
>
>Sincerely,
>
>John Probe
>
>++++++++++++++++++++++++++++++++++
>Ariel Dynamics, Inc.
>4891 Ronson Court
>Suite F
>San Diego, California  92111  USA
>(858) 874-2547 Tel
>(858) 874-2549 Fax
>Email:  ARIEL1@ix.netcom.com
>Web Site:  http://www.arielnet.com
>++++++++++++++++++++++++++++++++++
>
>

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

 

Giannis-

We have a document on our WEB site which contains the specifications for the
different file formats You can find it at:
/APAShelp/DOS/adw-56w.html

The CF/3D files are binary files. When one uses the EXPORT capabilities of
the APAS software, data is extracted from these binary files and presented
in rows/cols of ascii tables.

I hope this helps,

Jeremy Wise, Dir R&D

Hello Dan,

You should read the documentation papers that were delivered with your APAS
computer.  You should alse read the pull-down Help files in each module.
You will find a section titles "Quick Refernce" that provides step-by-step
procedures for each of the modules.  The Video and Analog data are handled
separately at fist and then integrated at the end.

The EMG module is really a subset of the Display module.  Therefore, I
would recommend that you use the DISPLAY module for both video and analog
data.

The steps for video analysis are:
1.  Record the activity
2.  Use the CAPTURE program to capture the video to the hard drive.
3.  Use the TRIM module to "clip" the desired video for analysis.
4.  Use the Digitize module to digitize each camera view.
5.  Use the Transform module to convert the 2D digitized information into a
3D file.
6.  Use the FILTER module to remove "digitizing error"
7.  Use the DISPLAY module to present and analyze the results.


The steps for analog analysis:
1.  Collect EMG and/or force plate data.  Make certain there is a
synchronizing event that can be "seen" in both the video and analog
signals.  This could be something as simple as a footstrike on a force plate.
2.  Combine the analog data with the Display data (from step 7 above).  The
Display module allows the ability to "partition" the data.  This is similar
to the TRIM module for the video data.  One can "clip" the synchronized
portion of the Analog data to match the video data.

John Probe
Email:  ARIEL1@ix.netcom.com




At 02:27 PM 8/11/00 GMT, you wrote:
>
>
>
>Dear John,
>
>I am confused about the order to go about the modules after recording data.
>
>We took forceplate and emg data simultaneously while recording video.
>And I am hesitant about what module to go to next.
>
>For instance what do we do with the emg and forceplate data we collected in
>the analog module?  I can't open it in the EMG module b/c there is
>forceplate data with it.
>
>And the video file captured in real cap can't be opened in DIGI4 b/c the
>file extension is different.
>
>If you could just suggest a order to go from start to finish starting with
>RealCap and Analog to whatever the last step is to get the finished
>product(i think it's ApasView) would be wonderful.
>
>Thank you.
>Dan Moon
>________________________________________________________________________
>Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
>
>

Hello Dr. Cialone,

Thank you for your interest in the Ariel Performance Analysis System
(APAS).  The APAS is a 3D video-based movement analysis system which
accurately quantifies function and provides objective data the professional
may use to justify or evaluate treatment.  Areas of successful application
for the APAS include human performance, injury and rehabilitation
assessment, quantification of loss for compensation claims, equipment and
product testing and development, determination of potential or actual risks
for products and activities in liability litigation, as well as applied
research in the areas of orthopedic medicine, therapeutics, and physical
training.

The APAS integrates state-of-the-art computer and video processing hardware
with specialized software modules that perform data collection, analysis,
and presentation.  Objective quantifiable documentation is provided for
both 2-Dimensional and 3-Dimensional analysis.  Specific points of interest
can be digitized with user intervention or automatically using contrasting
markers.  Stick figures are then generated and can be synchronized with
kinematics data.  Additionally, up to 32 channels of analog data (i.e.
force platform, EMG, goniometers etc.) can be synchronized with the
kinematics data.

The APAS product information can be found on the Ariel internet site
(www.arielweb.com).  The direct address to several areas that might be of
interest are listed below.

APAS Product Information
www.arielnet.com/Main/adw-04.html

Comparison of Commercially Available Systems
www.arielnet.com/topics/comparison/default.htm

Selected Applications Of APAS
www.arielnet.com/Main/adw-85.html

Selected Publications Utilizing the Ariel Technology
www.arielnet.com/Main/adw-86.html

APAS Price List
www.arielnet.com/Main/adw-54.html


You can even download a full version of the APAS for a free 30 day trial.

Your question about the "what-if" scenario is very interesting.  We have
had this same idea for quite some time.  Currently, the APAS is utilized
for documenting and analyzing movements that have actually occured.

Please review the information and feel free to contact me for any
additional questions.

Sincerely,

John Probe
Email:  ARIEL1@ix.netcom.com




At 10:35 AM 08/13/2000 EDT, you wrote:
>Dear Sir;
>
>I and my partners are involved in plans for a sports training center in
>upstate NY in the USA.  We are interested in focusing primarily on soccer in
>that the set-up for income sources will be leagues and training for soccer
>first, then other sports as openings are available. 
>
>My personal interest in being involved with the project is to be able to
>perform research on sports-related performance, again with soccer as the
>primary focus.  However, I would also like to provide that type of service
to
>the community at large, which is a small metropolitan/suburban combined
>population of about 1million people. 
>
>As a group, we are interested in having some sort of simulator that will
>allow analysis of soccer and sports related movement and technique
>evaluation.  That, I think, can be provided by the available products your
>website describes.  However, we would also be interested, if it can be
>designed or otherwise made available, in having a way to show players their
>on-field movements and decisions during a game, and then show them the
>alternative options they could've followed.  For example, a player receives
>the ball and turns to his right with it.  Given the same pass for that
player
>to receive, and the same presentation of the field and the other players on
>it at the moment he receives the pass, we want to be able to present to him
>the other options that were available.  What if he turned to his left?  What
>if he passed to another player than the one he did pass to during the game? 
>What if he carried the ball to one side or another?  I would assume the
video
>capture would enable this to be done, but I don't see it described on the
>website. 
>
>Would you please send me information, including pricing and description of
>equipment we would need, for such an application.  We would like to be able
>to expand this into services for other sports, but being soccer people first
>and foremost, this is the sport upon which we would focus, at least
>initially. 
>
>Thank you for your consideration.  I am looking forward to hearing from you
>soon.
>
>Sincerely,
>
>Paul Cialone, M.D.
>

Hello Kieran Moran,

Thank you for your message. Answers are listed below each question.

NOTE: There are two models of the JVC 9800 high-speed camcorder. One is PAL and the other is NTSC format. The PAL version of the camera records at 50 Hz, 100 Hz or 200 Hz. The NTSC version of the camera records at 60 Hz, 120 Hz, and 240 Hz. All cameras purchased from Ariel Dynamics are NTSC version (60/120/240 Hz).


At 02:49 PM 08/16/2000 +0100, you wrote:
>Hi
>
>Thank you for your prompt reply. I find the possibility of purchasing a
>system at such a price as yours thrilling, however I have just a few
>questions which will help me in my selection process at this stage:
>
>1. How many cameras can the APAS system support? Does this differ if the
>high rate of sampling cameras are used?
>
ADI: The APAS system can support any number of cameras regardless of the sampling rate that is used. Most Ariel users utilize 2 or 3 cameras for their analysis. The Gait programs require 5 cameras.


>2. If the high rate of sampling is used, can the pictures/frames be
>stored directly to the system?
>
ADI: Unfortunately, the current IEEE-1394 Firewire technology only supports capturing 1 camera directly to the hard drive. Each camera is capable of recording to a mini-DV cassette. Each camera view is then played back and captured to the hard drive independently.


>3. When you refer to automatic digitisation (with reflective markers
>being used), do you mean
>(a) the software will determine APPROXIMATELY where the marker will
>appear in the next frame and make it easier for the user to digitise
>that point MANUALLY. or
>
ADI: This is what happens when markers are not used. Ariel Dynamics refers to this as "manual" or "semi-automatic" digitizing.

>(b)the software will determine where the marker is in the next frame and
>AUTOMATICALLY digitise it without ANY NEED for manual input (unless the
>user requests the option for manual input).
>
ADI: When using the Automatic-digitizing option, the software will determine the centroid of the detected marker and digitize it without manual input (unless there is a conflict with another marker etc). The user has the option to pause at the end of every image or "auto-advance" to the next image.

>4. If a 5 camera system is used to analyse gait (looking at 3-D motion
>of the lower extremities, pelvis and trunk), and say 2 seconds of
>filming is gathered, how long would the digitising process take
>approximately?
>How long would the report generation take if using the APAS-GAIT system?
>
ADI: The following response is from an APAS user that consistantly utilizes 5 cameras for Gait Analysis.
A. Speed of camera: I have not used hi speed camera for gait analysis. I
didn't need it. I think 60Hz is enough for gait analysis even for a person
walking faster. If he would like to deal with patients who always walk
slower, 30 Hz would be enough. We always use 60Hz.

B. Duration: One and half stride (one stride = two steps, is from foot-on to
the second foot-on the same leg) or one stride is needed for gait analysis
at minimum. Normally we take 65 to 70 strides per minute. So, 2 seconds are
enough for one and half stride. But because we have many slower walking
subjects, we usually take 3 seconds and sometimes more.

C. Digitizing time: It totally depends on the quality of video. If the
filming status would be optimal, it will take less than 5 min. for each
view(camera) by adequately set auto-digi parameters. But if filming status
would be bad, more than 20 min for a view. We usually take around 5 min for
a view. It is very important to make every effort to improve something to reduce
digitizing time up to 5 min. Documentation about optimum condition for
filming and digitization can be found on my site,

http://plaza.snu.ac.kr/~suncg/residents/tipsautodigi.htm



>5. If the JVC cameras are bought and operated at 200/240 Hz (as
>available with utilisation of APAS software), is their any reduction in
>horizontal or vertical resolution? This could be easily checked using
>the same footage taken with these cameras, since the higher frequency
>(as I understand it) is achieved post filming. Have any tests been done?
>Is their any way of viewing the raw data?
>
ADI: The JVC camera achieves the faster frame rates by reducing the resolution. At 60 Hz, the image is full screen. At 120 Hz, the full screen image is split either horizontally or vertically (user specified). At 240 Hz, the full screen image is split into quarters. For NTSC, the panel sizes are approximately

60 Hz 720 x 480
120 Hz Horiz 720 x 240
120 Hz Vert 300 x 480
240 Hz 300 x 185

The JVC cameras are great cameras that offer much higher than standard image rates at an affordable price. This makes them an attractive choice for biomechanical analysis.
<?fontfamily><?param Arial><?color><?param 7070,6c6c,7979><?bigger>
<?/bigger><?/color><?/fontfamily>
>Also, is there ANY difference in accuracy in using the JVC cameras and
>APAS software for getting the data at 200/240 Hz, in comparison to using
>a specific high speed camera?
>
ADI: We have not noticed any difference in accuracy when using the JVC cameras.


>6. You provided me with a list of users in the UK and one in Dublin. Are
>any of these actually gathering 3-D data using 5, 6 or more cameras? Are
>any using the high speed camera option?
>
ADI: I am not aware of any of these users using 5 or 6 cameras for data collection. Sheffield Hallum University and University of Edinburgh are both using the High Speed options. Two Ariel users that do use 5 or 6 cameras for gait analysis are listed below:

Eric Simonsen, Ph.D.
University of Copenhagen, Denmark
Email: E.Simonsen@forum.dk

Sun G. Chung, M.D., Ph.D.
Seoul National University, Korea
Email: suncg@medicine.snu.ac.kr

>
>Many thanks for taking the time for this correspondance.
>
>
>Kieran
>
>
>Ariel wrote:
>>
>> Hello Kieran Moran,
>>
>> Thank you for considering Ariel Dynamics Inc. (ADI) in your call for tender. We have provided a description below each of your listed items.
>>
>> Please feel free to contact us for any additional information.
>>
>> At 06:16 PM 08/14/2000 +0100, you wrote:
>> >The newly formed centre for Sport Science and Health is establishing a
>> >full 3-D analysis laboratory in its new building in the next few months.
>> >This is a call for tender to manufacturers of 3-D motion analysis
>> >systems. The finances for the system have not been finalised yet, but
>> >will be in the region of ´┐Ż100,000. The systems will be judged on the
>> >following criteria and requirements of the laboratory users. Addition
>> >features identified by manufacturers will also be taken into account. If
>> >manufacturers suggest a different system for inside and outside use, or
>> >for laboratory and roving use (e.g. a hospital setting one day, a
>> >factory another day), please provide full details and costing for both
>> >systems.
>> >
>> >1. Cost for full 3-D analysis system
>> >
>> ADI: Please refer to attached international price list.
>>
>> >2. Linear accuracy of the system: (a) a simple test of rotating a rod
>> >(1m long) in the field of analysis, and (b) a performer strapping 0.2m
>> >long rods (with markers attached to its ends) and performing turning
>> >motions. In condition b, the rods will be attached to the upper and
>> >lower aspects of the upper and lower extremities. Rods will also be
>> >attached to the chest and back.
>> >
>> ADI: Please refer to a 3rd party study presented at the International 3D conference in Tennessee. The report is listed on the Ariel internet site. The direct address is:
>>
>> /topics/comparison/default.htm
>>
>> >3. Angular accuracy of the system: as for liner accuracy, but two
>> >attached rods and three markers (of known relative orientation) will be
>> >used.
>> >
>> ADI: Please refer to the study mentioned in item 2 above.
>>
>> >4. The ability of the system to automatically track the markers motions.
>> >
>> ADI: Though markers are not required, the APAS supports the ability to automatically track markers from up to 4 views simultaneously. An important advantage of the APAS is the fact that markers are not required to perform an analysis. For example, if you wish to analyze an event in the Olympics, you would not be allowed to place markers on the athletes. With the APAS, you would just video the activity, capture the video to the computer and manually select the desired joints for the first image. In the following images, the APAS software will predict the location of the next joint, however, it will wait for user confirmation to digitize the point. This feature allows "real-world" analysis to take place. Many times, the subject does not even realize that they have been analyzed.
>>
>> >5. The ability of the system to allow manual marker identification when
>> >markers are hidden.
>> >
>> ADI: When markers are hidden or conflict with other markers, the APAS software pauses the automatic digitizing process and waits for user input to distinguish the correct marker locations.
>>
>> >6. The ability of the system to interpolate (and the selection of
>> >interpolation algorithms offered to the user) for lost markers.
>> >
>> ADI: When markers are defined as "missing" the APAS software performs a linear interpolation between the "known" points.
>>
>> >7. The ability of the system's software to determine joint centres when
>> >markers are placed on the body segment (and not when placed on a single
>> >anatomical site representing the joint centre). For example the shoulder
>> >joint.
>> >
>>
>> >8. Rate of sampling: 50, 100, 250 Hz etc. Where higher frequency of
>> >sampling results in a reduction in the number of markers that can be
>> >used, this should be indicated.
>> >
>> ADI: The APAS supports video of any frame rate. The standard rates are 50 Hz PAL and 60 Hz NTSC. Higher rates of 100/120 and 200/240 Hz are supported for high speed digital camcorders. The APAS also allows the ability to use multiple frame rates within the same sequence.
>>
>> >9. Is there any limitation on the number of markers that can be used?
>> >
>> ADI: The current limit is set to 50, however this can be increased if required.
>>
>> >10. Software that will allow calculation of joint kinetics when a force
>> >plate (and force plates) is added.
>> >
>> ADI: The APAS-Gait program is designed to calculate joint kinetics using a force platform and 5 cameras. This program supports the industry standard marker sets (Helen Hayes and Kit Vaughn). Please refer to the following internet address for additional information.
>>
>> /Gait/index.html
>>
>> >11. Software for easy production of patient reports.
>> >
>> ADI: All APAS software is Windows compatible so patient reports are easliy generated.
>>
>> >12. Software to allow exportation of data.
>> >
>> ADI: The APAS allows data (raw and filtered) to be exported in ASCII or worksheet format.
>>
>> >13. Software (either of the companies or a linked function to other
>> >software) for producing high quality, full body animated (rendered)
>> >figures, which ACCURATELY depict the movement of the subject wearing the
>> >markers. The software should allow the user to design different full
>> >body figures.
>> >
>> ADI: The APAS 3D-Renderer program is used to render any activity analyzed using the APAS. Please refer to the following internet address for additional information.
>>
>> /Renderer/index.html
>>
>> >14. The ability of the systems to incorporate synchronous data from
>> >other devices (force plate, emg, ecg, eeg etc)
>> >
>> ADI: The APAS Analog module is required for collecting analog data. This module supports all commercially made force platforms, EMG and other analog signals.
>>
>> >15. Support and training
>> >
>> ADI: The APAS system consists of "off-the-shelf" hardware items with specialized software. The majority of our support is conducted using Email and FTP capabilities of the internet. APAS software upgrades are provided free of charge (as long as your hardware supports the software) and can be downloaded directly from the Ariel internet site at your convenience.
>>
>> Training can be conducted at the Ariel office or "on-site" at the customer facility. Costs will vary depending on locations, lenght of training etc. An approximate cost would be $1,500 USD per day, plus expenses.
>>
>> >16. Servicing contract
>> >
>> ADI: Service contracts for the APAS can be purchased at a cost of 10% of the original system cost per year.
>>
>> >17. Extra cost for allowing multiple computer usage of software for
>> >teaching purposes.
>> >
>> ADI: With the purchase of the "master" APAS system, the same customer can purchase additional workstation software licenses at a cost of $575 USD per computer. The APAS-Workstation allows full data analysis capabilites but does not support data collection.
>>
>> >The system will be used for sports as well as athletic, hospital and
>> >factory (ergonomics) based studies.
>> >
>> >While I am sure that manufacturers have recorded data regarding the
>> >accuracy of their system and the degree to which many of the above
>> >system factors are addressed, I would like to have at least one day
>> >examining these issues in our laboratory. Therefore, an open invitation
>> >will be extended to all interested parties.
>> >
>> >Finally, examples in the UK where your system is being employed for
>> >similar usage would be advantageous.
>> >
>> ADI: Select APAS users in the UK include
>>
>> Manchester Metropolitan University
>> Sheffield Hallam University
>> Canterbury Christ Church University College
>> Glasgow University Veterinary Hospital
>> St. Martin's College
>> University College Salford
>> University of Edinburgh
>> Keele University Bionic Gait Laboratory
>> University of Sunderland
>> Total Fitness Limited, Dublin
>>
>> >If you have any questions, please do not hesitate in contacting me.
>> >
>> >Yours Sincerely
>> >
>> >Kieran
>> >

>> >Dr Kieran Moran
>> >Director
>> >Biomechanics Research Group
>> >Centre for Sport Science and Health
>> >Dublin City University
>> >Dublin 9
>> >Ireland
>> >
>> >tel: 00353 - 1 - 7008011
>> >fax: 00353 - 1 - 7008888
>> >
>> >e-mail: kieran.moran@dcu.ie
>> >
>>
>> Name: Price_Int.doc
>> Price_Int.doc Type: Winword File (application/msword)
>> Encoding: base64
>

Hello Saiwei Yang,

Thank you for the message.  I will provide answers below each of your
questions.

Sincerely,

John Probe


At 10:02 AM 9/2/00 +0800, you wrote:
>Hi, it may due to the decoding of fonts. my mail was
>
>Dear John:
>So how am I able to synchronize more than one DV cameras at the one time?
>
Most APAS users use an event recorded in the video to synchronize multiple
cameras.  This is usually the foot striking the ground, a 35mm camera flash
or a dropping object.  If a falling object is utilized, the APAS software
includes a "software-genlock" option.  I have included a description below.

=====================
The ARIEL TRANSFORMATION synchronizing algorithm uses the fact that when
calculating 3D from two 2D views the situation is over-constrained. Four
numbers are used to calculate three unknown numbers using a least squares
criteria.  In such a situation the fit is not likely to be exact and there
is a residual left over from the fitting calculation. The better the fit
the smaller the residual. Think of fitting 3 points to a line. The "best"
fit" may not go through any of the three points.  The deviation from the
"best-fit" line is the residual.

In the case of 3D reconstruction, each camera determines a line in 3D space
on which the point lies.  In a perfect world the two lines, one for each
camera, would intersect, the point of intersection being the 3D point of
interest.  In the real world, the lines don't actually intersect but there
is a point of closest approach with the distance of closest approach being
related to the residual.
Consider the "ideal" situation of a normal lab setup consisting of two
cameras recording a falling object.  As the object falls, the two lines of
projections track the falling object intersecting exactly at the falling
object. Now think of introducing a synch error so that one camera is now
"seeing" the falling object at an earlier time from the other. For this
camera the line of projection will point too high and the two lines will
not intersect. The earlier the camera "sees" the falling object relative to
the second camera, the greater the "miss" and the larger residual.

For this algorithm to work properly there must be a single point with a
large amount of motion out of the plane which contains the camera
projection centers.  In most cases, this relates to VERTICAL (Y) motion.
NOTE:  If everything is in one plane this approach will not work!
The Ariel TRANSFORMATION Synch algorithm utilizes a point with large
vertical motion and calculates a total residual value for this point
summing over all frames as follows:
         ResidualSQ = SUM( Res[i]**2) for all frames "i"of interest

Then the program finds the time shift that minimizes the above
"ResidualSQ". The time shift that produces a minimum value is the synch error.
Several studies have been performed that suggests the data improves when
this analysis is performed. However other factors could contribute which
have nothing to do with a synch error. For example, suppose one view always
has the falling object digitized low due to the person's digitizing
inability to estimate the point center. This would appear as a synch shift
because the program could improve the ResidualSQ by making that view
slightly earlier thus raising slightly the projection line causing it to
more closely intersect the other camera's projection line. Then for all
other points in the study the data would be moved to this slightly earlier
time as well.
=====================

>Does APAS support National Instrument A>D card.  if not would you have in
>the future?
>
The current APAS does not support the National Instrument cards.  The APAS
currently supports the ComputerBoards family of A/D cards.  This could
definitely be included in the future, but I cannot provide an exact date.
This would have to be discussed directly with Dr. Ariel.


>the 5000US software only, does it include rendering program ( what your
>meaning of upgrade?)
>
The Basic APAS $5000 software does not include the Rendering program.  The
Basic APAS software includes the 2D/3D software modules listed below:

Capture Module (for Analog video capture)
Trim Module
Digitize (includes automatic digitizing and panning options)
Transformation Module (includes software genlockoption)
Filter Module (removes "random" digitizing error)
Display Module (for presentation/analysis of results)

Optional modules that are not required but can be added to "upgrade" the
capabilities of the Basic APAS include:

JVC Software Drivers (for 120/240 Hz analysis) $5000 USD
3D-Rendering Module $1500 USD
APAS-Gait Software Module $5,000 USD
APAS Analog (software only) $1500 USD
APAS Analog (Software & hardware) $9000 USD

The term "upgrade" means that it is not required for basic operation of the
APAS.  This simply adds extra options and/or capabilities.

Please feel free to contact us for any additional information.

Hello Rebecca,

I had a chance to look over your data.  It is hard to tell exactly without
the video, however, it appears that the 4 control points are in a different
plane than the activity being analyzed.  The 4 control points seem like
they might be on a treadmill while the activity is taking place above the
calibrated area.  Is this correct?  If so, this could account for the
irratic results.

For 2-D analysis, a minimum of 4 control (or calibration) points must be
used.  Ideally, these four points should encompass the area of the activity
to be analyzed and also lie in the same plane of the activity.  The Z
coordinate must be equal to zero so the activity should take place in the
XY plane.

Is there any method to use 4 or more points to make a "calibration box"
around the turkey leg?

It appears that you are performing the correct procedures but just need to
rearrange the calibration points.  Would it be possible to also send a
small video file (maybe 3 to 5 images).

Also, do not forget to contact Dr. Ariel in Brisbane.  You can Email him at
the address listed below to find his location or schedule a meeting with him.

I look forward to your reply.

Sincerely,

John Probe / Dr. Gideon Ariel
Email:  ARIEL1@ix.netcom.com



At 04:52 PM 9/5/00, you wrote:
>Hi John,
>
>OK - I got the additional options up in the display module after I filtered
>the data - I had thought that the filtering done in the transformation
>module was enough.
>
>Anyway, I still can't make any sense of the data once I'm into the display
>section.
>
>I have attached new files.
>
>My problem lies at this point:
>I open the 3D file in display, then I have been choosing Joint Angles,
>displacement, and then I don't understand what to do - I chose distal toe
>and prox toe, prox toe and TMT, and TMT and TT, in the hope that it would
>give me the JA info for digits, IT and ankle respectively.  Also chose the
>3D rather than x,y,z because I need the whole point.
>
>But then the thing that is graphed doesn't make any sense to me, nor do the
>headings on the tabulation that shows the data points that the graphs are
>made from.
>
>All I need to obtain is the joint angles from the digitised data, both as a
>stick figure and as raw data.
>
>I hope that you can help!
>
>Is there an Ariel display at the Pre-Olympics conference that is happening
>here in Brisbane this weekend?  Would there be someone there that I could
>talk to about this???
>
>Thanks again,
>
>Rebecca.
>
>Attachment Converted: "F:\MAIL\ATTUCH~1\t43sp4.1t"
>
>Attachment Converted: "F:\MAIL\ATTUCH~1\t43sp4.3d"
>
>Attachment Converted: "F:\MAIL\ATTUCH~1\t43sp4.cf"
>
>
>
>
>
>***************************************************
>Rebecca Campbell
>Department of Anatomical Sciences
>The University of Queensland
>QLD
>AUSTRALIA 4072
>
>Ph + 61 7 3365 2961
>Fax + 61 7 3365 1299
>
>Email:  Rebecca.Campbell@mailbox.uq.edu.au
>
>**************************************************

Hello Eric Cheng,

I will provide answers below each of your questions.


At 02:19 AM 11/18/2000 +0800, you wrote:
>Hello,
>I am a graduated student in Taiwan. I want to use the APAS system to analyze the rearfoot motion.
>But I have some problems when I use the APAS system and need your help.
>
>1. I can't open the *.avi file in Digitize, RealCap and Capture, but I can open the *.avi file in the Trimmer. Something wrong ?
>
ADI: Have you purchased the software license for the APAS? Or have you obtained the SITE KEY for the 30-Day trial? If not, you will not be able to perform analysis using the APAS.

If you have obtained either the 30-Day Site Key or purchased the APAS software license then follow these steps. When you open the AVI file in the TRIM module, you must specify the folloiwng points: Start of trimming, End of trimming and the Synchronizing point. After these points have been specified, you should select the "SAVE TRIMMING" option. Then you should be able to open the "new" file in other modules.

>2. When I open the Capture, It told me " Failure to open Comm Connection". After I press "Enter", It told me "Problem connecting to VCR". I am sure that I have opened the JVC-9800 Digital Video power and it works very well. I can see the image on the computer when I use the Ulead VideoStudio 4.0.
>
ADI: This is correct! This means that the computer is not connected to the Panasonic computer controlled VCR. This is not a problem. The software is just notifying the user that the hardware is not connected.

If you are using the JVC-9800 camera, then you should be using an IEEE 1394 FireWire capture card and program. You should not use the Capture program. The Capture program is designed to work with Analog frame grabbers. The JVC 9800 is a Digital camera so you should use a Digital frame grabber.

>3. where can I transfer the *.avi to *.cf? what is the next step shoud I do defore Digitizing Module after I finished trimming the Video Sequences. I can't find the answer in the web site.
>
ADI: The logical order of the APAS modules is as follows:

Digital Video Capture Program (using FireWire capture card and software)
Trim Module (used to "clip" desired video for analysis)
Digitize Module (used to digitize individual camera views)
Transform Module (used to transform individual views into 2D or 3D image)
Filter Module (used to remove random digitizing errors)
Display Module (used to present the results of the analysis)

The Digital Video Capture program is usually supplied with the DV frame grabbing hardware and should include an operating manual. All other modules are written by Ariel programmers. Each module has a pull-down help screen that provides step-by-step instructions for performing the required tasks. For a condensed version of the steps required, you can refer to the "Quick Reference" section of each module.

I hope this answers your questions. Please contact us for any additional information.

>Could you give me the answers?
>Thanks a lot.
>
>Eric Cheng

Hello Milan Elfmark,

Thank you for your message.  I will provide answers below each of your
questions.

Please contact us for any additional information.

Sincerely,

John Probe
Email:  ARIEL1@ix.netcom.com

================================

At 10:06 AM 12/06/2000 MET-1, you wrote:
>Dear friends.
>Hello John.
>
>We have any questions :
>
>1. We would like to install one additional software licence on a new
>computer for prof. Vaverka. We will know site code and hardware code
>next week, but we want realize payment (500$) now. Can you send us
>your account number.
>
Payment can be made by either of two methods.

1. Certified check drawn on a United States bank.  Payment should be sent
to the address listed below.
Ariel Dynamics, Inc.
4891 Ronson Court, Suite F
San Diego, California  92111  USA

OR

2. Wire Transfer using the information listed below.
***

>2. We have your software APASWin. We would like to provide upgrade
>this software, but we have to format our hard disk drive too, because
>we have any problem with system. Could you give us a piece of advise?
>
We have provided "upgrade" instructions on the Ariel internet site.  Please
do not format the hard drive unless absolutely necessary.  In this case, we
will issue another Site Key.  Just E-mail the System parameter and Site
Code number and the Site Key will be provided by return E-mail.

>Sincerely
>
>Milan Elfmark
>Laboratory of Human Movement Studies
>Faculty of Physical Culture
>Palacky University Olomouc
>Czech Republic
>e-mail elfmark@ftknw.upol.cz

Hello Jiji,
 
The size of the calibration cube depends on the activity you wish to analyze.  The calibration cube should "surround" the area where the activity will take place.  For example, if you wish to analyze someone's hands typing on a keyboard, the calibration cube might be 50 cm wide x 20 cm deep by 10 cm in height.
 
As another example, if you wish to analyze a golf swing, then you would probably require a cube that is approximately 2 m wide x 1 m deep by 3 m in height.
 
As you can see, in each case, the calibration device will surround the activity that will be analyzed.  A good general size calibration device for full-body human activities is 1m x1m x 2m.
 
I hope this answers your questions.  Please contact us for any additional information.
 
Sincerely,
 
John Probe
Ariel Dynamics, Inc.
 
 
----- Original Message -----
Sent: Sunday, May 27, 2001 12:51 AM
Subject: Re: APAS Trim Module

Thank you for answering so quickly....when I'm changing camera , I'd
sometimes surprise compared to what I'm used to have.
A question about the calibration cube: what's the minimum size of the cube
you're used to bring with you outside, as I'd to make one I'll like to have
your opinion.

Thank you and hope to see you soon in San Diego

Amiti´┐Żs

JIJI Rivet

Hello Rick,

The most likely reason that you are getting this error is that the files are
marked as "Read-Only."  This happens when you transfer files from the CD
back to the hard drive.

You can correct this by right-clicking on the file name, then select
Properties.  Then "Un-Check" the Read-Only box and check the Archive box.
Select Apply and repeat this with all the files.

This should correct the reported problem.

Sincerely,

John Probe
Ariel Dynamics, Inc.
Email:  ARIEL1@ix.netcom.com


----- Original Message -----
From: "Rick and Jill Essner" <essner@covad.net>
To: "Ariel" <ariel1@ix.netcom.com>
Sent: Sunday, June 03, 2001 12:27 PM
Subject: APAS CF registration error


> John,
>
> I transferred a bunch of files (e.g., sequence, view, 3d, and avi) to a
> CD in order to clear up space on my notebook's hard drive.  Now, I want
> to go back and make some corrections in digi-4; but, haven't been able
> to do so.  I tried transferring the needed files back to the hard drive;
> but, when I open up the old sequence file I get an error message that
> says "CF file not properly registered."  How can I correct this problem?
>
> Thanks,
> -Rick
>
> Rick Essner
> Department of Biological Sciences
> Ohio University
> Athens, OH 45701
> (740)593-9510
> re354987@ohiou.edu
>


 

This page was last modified on 12/07/2008 at 22:47 PST. Copyright ´┐Ż 1994 - 2002, all rights reserved, Ariel Dynamics Inc. Please send your comments or feedback to webmaster@arielnet.com or proceed to our feedback form. This page has been accessed many times since Dec 12, 2002. Our privacy policy is here.