Movement Synthesis and Regulation in Neuroprostheses

Many movement disorders result from interrupted or disturbed communication from motor centers in the central nervous system to the motorneurons in the spinal cord (i.e., the muscles remain intact, but their activation and control are disturbed). Two prominent examples are spinal cord injury (SCI) and stroke. The ability to activate the muscles electrically via their nerves has opened up the field of motor system neuroprostheses, which has expanded rapidly in the last decade (Peckham and Gray 1996). For a neuroprosthesis to functionally replace part of the damaged nervous system, it must provide appropriate electrical stimuli to the muscles. It must also take on other tasks normally performed by the nervous system to both control and regulate the artificial movements.