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   The purpose of the present article is to demonstrate the superiority of the APAS system over all the other systems.  Overall, the APAS system out performed the other systems by a large margin.

   In the present report, each company was ranked according to the results. The company with the best results on a  particular parameter, received 5 points,  the next position received 4 points, and so on.   The company with the worse result for this parameter received only 1 point. (There were 7 different company products that were tested. Only five of the seven were able to produce reliable results).

   The companies included in the comparison testing are pictorially illustrated in the slide below.:

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Slide 8. Device Categories.

  • Ariel Dynamics, Inc.  with their APAS system

  • Motion Analysis Corporation with their HiRes  System

  • Peak Performance Inc. with their  Motus system

  • Qualisys with their ProReflex system

  • Vicon's with their 370 system

  • Elite  (Could not calculate adequate results and was not included in this article)

  • 6D Technology (Produced too many errors due to magnetic interference and was not included in this article. A summary was presented at the conference and is shown in the slide below.)

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Slide 9. Skill 6-D Summary.

   Slide 9 illustrates the Skill 6-D Summary as was presented at the conference. As one can see, this technology is still new and did not meet the required standards. This technology depends on the subject being hard wired to the sensors and is extremely sensitive to interference. This equipment does not allow data collection on the field and movement is limited to an area of  approximately 3M only. Therefore, the present report did not include this technology in the rating.

   Some companies such as Elite and Codex  produced so many errors that the researcher of this study choose not to include them at all.   In other cases, such as with the Peak and the Vicon companies, errors were very large when detection points were switched around, so the researcher of this experiment decided   to choose only the good measurements.  Quoting the original report:   "The Peak Motus and the Vicon 370 systems were unable to correct switching paths at the 0-cm and 1-cm separation distances, despite repeated attempts to adjust tracking parameters".  It could be argued that this biased the experiment to some degree by making the Vicon and the Peak companies score higher then they would otherwise if all the data point had been considered as was the case with the Ariel and the Motion Analysis systems.

   In the case of Peak and Vicon, markers crossed paths.   The data presented at the conference reported only a subset of the data in which paths were correctly identified and this information was used for the analysis. In this case, the Peak and Vicon received only 1 point each while all the other companies that did not have this serious defect in their system received 3 points.  The confusion of markers is considered as the most serious error in Movement Analysis Systems.

   Slide 10 illustrates the serious problem that Peak and Vicon companies had with switching points. Once the points were switched, it was impossible to correct them.  In the case of the APAS system, marker switching can never occur since the detection algorithm can maintain the marker identification at all times.

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Slide 10. Marker Switching occurred with the Peak and Vicon Systems.



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