Myoelectric Prosthesis

An artificial limb, most commonly a hand or arm, controlled by small electrical signals detected on the skin surface over the wearer's remaining muscles, which a built in motor and processor translate into opening, closing, or other movements of the prosthetic hand. Sensors resting against the skin of the residual limb pick up the faint electrical activity generated whenever the wearer contracts a muscle, and the device's electronics interpret the pattern and strength of that signal to decide which motion to produce, letting the wearer control the prosthesis by attempting the same muscle movements that once moved the missing limb. Early experimental myoelectric arms were built and tested in the Soviet Union and several European countries beginning in the 1940s and 1950s, and the approach reached more practical, commercially available prostheses by the 1960s and 1970s as batteries, motors, and electronic amplifiers grew small and reliable enough to fit inside an artificial limb. Later designs added multiple independent sensor channels and more refined software, letting some devices distinguish several different muscle signal patterns and so control more than one kind of grip or movement from the same prosthesis.