Electromyogram analysis and electrical stimulation control of paralysed wrist and hand.

Restoring paralysed hand functions with functional electrical stimulation (FES) essentially requires control of joint angles in their functional positions as well as control of speed and power for grasping. In this study, standard FES patterns were created from the electromyogram (EMG) analysis of 15 healthy subjects in order to restore hand and wrist joint functions in C4 and C5 quadriplegics. Stimulating the hand muscles with the standard patterns produced both wrist joint fixation in a functional position and grasping movement similar to that of healthy subjects. To control the joint angle, certain stimulation voltages were read at the same memory address. Similarly, motion speed was adjusted by changing the reading speed at the stimulation data memory address. Since stimulation patterns created from the EMG analysis of healthy subjects restored the hand and wrist joint functions in C4 and C5 quadriplegics, this method was found to be successful in allowing some normal daily activity for quadriplegics.