2D Analysis with the APAS step by step

VIDEO ACTIVITY

Make certain entire activity will be in the field of view of the camera

Record calibration points
Must be at least 4 coplanar points
Points should "encompass" activity to be analyzed
Activity should take place in same plane as calibration points

CAPTURE VIDEO TO COMPUTER

Connect video camera to computer using DV cable to frame grabber

Turn camera to VTR mode

Double click the STUDIO DV icon to open the capture program

Select the CAPTURE tab and use the VCR buttons to position the videotape. Make certain that you position the video before the section that you would like to capture. (Use the file cabinet icon to change the location of the stored files)

Click the PLAY button to start the video and then click the START CAPTURE button. At this point you can enter a name for the video file.

Enter the name and select Start Capture.

Select the STOP CAPTURE to stop recording the video to the computer.

Perform the steps listed above for both the Data and the Calibration video.

Select FILE, EXIT to close the program.

TRIM THE VIDEO

Double click the APAS SYSTEM icon and then double click the TRIMMER icon.

Click the AVI icon and select the video DATA file that has been captured. The video file will open and the individual images will be displayed in the top panel. Double click the image to make it full screen. Double click again to return to reduced size.

Use the VCR buttons to position the video to the starting image. Click the TRIM START icon and the SYNCH icon when the first image is selected.

Click the PLAY icon to advance the video to the last image.

Click TRIM END when the last image is selected.

Select FILE, SAVE TRIMMING. You will see the Source file and a field for the Destination file. Enter the name and path for the destination file. NOTE: If you leave the same name, the original file will be overwritten.

Repeat the steps listed above for the calibration point video file.

Select FILE, EXIT

DIGITIZE VIDEO FILES

Double-click the DIGITIZE icon in the APAS System folder.

Select FILE, NEW PROJECT and enter the path and filename for the analysis.

Enter the Sequence Parameters
Title- This is a label for the activity and for future reference
Units Used to specify the units for the analysis. This will be used for reporting results.
#Points Used to specify how many points will be digitized
#Control Used to specify how many calibration points
TYPE Leave at System
Height Subjects height (in the units specified)
Weight Subjects weight

Select the POINT IDs button to specify the point names. Select OK when done.

Select Control XYZ to enter the calibration coordinates (in units specified).

Select OK from the Sequence Parameters menu to proceed to the View Information menu.

Enter the View Information
Title Used to specify information particular to this camera view.
FrameRate Leave at 60
CameraID used as optional label
Camera X,Y,Z Not used
View Type leave at Stationary
Select OK to proceed

Click the AVI icon to open the video data file.

Select OK at the Video File Information menu.

Start the Digitizing process. The current point is listed on the lower portion of the screen. All images begin with a "Fixed Point" This is any point in the field of view that DOES NOT MOVE. Then digitize the points in the order specified. Proceed image by image until complete.

DIGITIZE CONTROL POINTS

Select CONTROL, DIGITIZE and then CONTROL, OPEN VIDEO, AVI FILE and select the video calibration file. The file will be displayed in multi-panel format. Just select the best image and then click OK.

Now digitize the Fixed Point and the Control Points in the order specified.

When complete, select CONTROL, FINISH.

TRANSFORM/SMOOTH THE DATA

Select the DLT icon from the toolbar to open the Transform Options menu.

In the View tab, select the file to be transformed from the available views. There will usually only be one view available.

Leave the options in the Transormation and Smooth tabs at the default settings.

Click OK to proceed and then click OK when Filtering has been completed.

ANALYZE THE DATA

Click the ANALYZE icon from the toolbar.

Click the NEW GRAPH icon from the toolbar

Click the FILE button and specify the analyzed file for display.

Click the ADD button to specify the desired parameters.
For example:
Type Linear
Quantity Displacement
JointSeg #1 R.Foot, R.ankle, R.Knee, R.Hip
Joint/Seg#2 Not used for displcement
Component X (horizontal) or Y (vertical)

Select OK and then OK to graph the data.