Simulator for evaluating shoulder motion as a command source for FES grasp restoration systems.

A simulator has been developed to evaluate the command channels through which a quadriplegic patient controls an upper limb neural prosthesis. The simulator consists of an animated grasping task implemented on a video screen. The patient controls the motion of an animated hand on the screen by moving his or her own hand while the animated hand opens and closes under control of the tested command channel. Experiments were performed using both able-bodied and quadriplegic subjects to evaluate shoulder motion as a command-channel source. The results demonstrated that optimal combinations of shoulder command-channel parameters are subject specific, which suggests using the simulator in the prescription of upper limb neural prostheses and in training quadriplegic persons who use them. Additionally, the experimental results quantified the reduction in performance that came from using ipsilateral vs contralateral shoulder control and the enhancement in performance realized when using substitute sensory force-feedback displays.