A physical workstation, body tracking interface, and immersive virtual environment for rehabilitating phantom limb pain

Virtual agency, the perceived intentional initiation of movement by an amputee of his or her phantom limb, can help reduce pain associated with the missing limb. One key aspect of enhancing virtual agency may lie in recreating a realistic residual limb in an immersive virtual environment. The apparatus described herein seeks to track an amputee's residual forearm and virtually render its restored movement. Specifically, magnetic position sensors and surface electromyography signals are used to track the absolute position of the residual forearm and the intentional grasp from the residual muscles. This information is inputted to software that creates the visual rendering. In the X3D virtual environment, the amputee user interacts with balls in a task that involves picking up one of six colored balls and dropping it into a bin. The image is produced by reflecting projected light off of a mirror and onto a tabletop where the user views the virtual environment. Use case studies indicate that this device can successfully detect when a user attempts to grasp his or her hand and provides visual feedback collocating the virtual limb with the missing limb. Thus, this device gives the user a sense of proprioceptive control of his or her phantom limb, enhancing virtual agency, and increasing the likelihood pain relief.