A Quantitative Operational Performance Measuring System for a Myoelectric Hand: a Preliminary Study

Control methods of the commercial prosthetic hands were categorized into three distinct generations by a previous work [1]; first generation used an on-off switch type control scheme for hand motor activation. Second generation hands have ability to adjust thresholds for motor activation, and proportional controllability of motor speed was provided in this generation. In the third generation, control options can be modified easily, because they utilize programmable microprocessors. Even in the third generation or proportional control systems, motor activation is based on the threshold of controller input signal; therefore, appropriate adjustment of the threshold, or an amplifier gain in a myoelectric sensor, is a significant issue for highperformance uses of the prosthetic hand, which may leads to high acceptance ratio of myoelectric hand prostheses.