Prosthetic command signals following targeted hyper-reinnervation nerve transfer surgery.

High-level upper-limb amputations result in prostheses with many degrees-of-freedom to be controlled, with very few control signals. A novel method for the control of myoelectric upper limb prostheses has been developed. By transferring the residual nerves to spare muscles in or near the residual limb, additional myoelectric control signals are created that allow the simultaneous control of multiple degrees-of-freedom in the prostheses. Since the nerve function correlates physiologically to the prosthetic function, operation is more natural and thus easier than current control paradigms. This surgical procedure and subsequent prosthetic fitting have been successfully completed on one shoulder disarticulation and one transhumeral amputee. The shoulder disarticulation amputee has also been fit with a unique 6 motor system, allowing him to control 3 motors (hand, elbow, and humeral rotator) with the use of 6 myoelectric signals; there was marked increase in functional range-of-motion. He was able to control multiple joints simultaneously and could perform tasks that he could not do before, including reaching out to pick up objects.