Two Degrees of Freedom of EMG-Based Proportional Control in a Hand-Wrist Prosthes

SUMMARY: Upper limb amputation is experienced by approximately 18,496 persons annually in the U.S., with most of these amputations transradial or more distal. Existing commercial prosthesis devices only allow such users to control one device at a time (e.g., choose between hand actuation and wrist actuation), commonly via EMG-based inputs. Users then switch between devices sequentially. It is reported that direct control of two joints simultaneously-two degrees of freedom of proportional control-is the greatest desired prosthesis improvement described by these users. Several recent research advancements have demonstrated independent, proportional association between 7-128 electrodes and 2-5 degrees of freedom in the fingers or in the hand-wrist. However, the use of high-channel electrode systems will not be practical in the near future in most commercial systems. Other research systems apply multifunction pattern recognition so that amputees can select between a limited set of pre-programmed multi-joint mov