The Kinect Versus The Proficio: Measuring Hand Position During Exercise Monitoring

Motion capture technology has recently found a new application in physical therapy. The advantages of the Microsoft Kinect and similar devices have motivated researchers to focus on how to leverage the capabilities of motion capture technology to provide therapists with new tools for therapy sessions. Although the Kinect seems to be an affordable, convenient and therapeutic solution, more investigation is required to confirm its accuracy. In this paper, we evaluate the performance of the Kinect to capture the trajectory of the hand in different exercises by comparing it to the trajectory of the same movement recorded by the Proficio robotic arm. The arm provides us with accurate values for the position of the hand during the exercise which serves as a ground truth for the comparison. In our experiment, we trained the Proficio with different exercises and captured the trajectories from the Kinect in different backgrounds and relative orientations between them. Our results show acceptable error in trajectories obtained from the Kinect. We also observed dependence on the margin of the error on the relative position between the Kinect and the Proficio and the direction of the exercise motion.