An advanced method of tracking three-dimensional body motion has been developed in order to improve upon the accuracy and bandwidth of existing systems. It uses three rotating planes of laser light, fixed and moving photovoltaic diode targets, and a pipe-lined architecture of analog and digital electronics to locate multiple targets in an eight cubic meter volume. Data collection rates are a function of the laser scan rotation speed and are currently selectable up to 480 hz. Tested system performance at a 480 hz data rate includes a resolution of 0. 8 mm (0. 03 inches), a repeatability of plus or minus 0. 635 mm ( plus or minus 0. 025 inches), and an accuracy of plus or minus 2. 0 mm ( plus or minus 0. 08 inches) with all results applicable at the 95% level of confidence along each coordinate direction. The present accuracy in reducing position data to angular body orientation is plus or minus 0. 5 degrees. Moving targets can be tracked at speeds exceeding 2 m/s (typical of ankle motion) with signal integrity tested but not limited to 25 hz motions.
|Original language||English (US)|
|Title of host publication||Unknown Host Publication Title|
|Publisher||Association for the Advancement of Rehabilitation Technology|
|Number of pages||3|
|State||Published - Dec 1 1986|