Roboticists have built five-fingered prosthetic arms that can allow wearers to toss a ball, but the options for people with partial hand amputations are limited to crude spring-loaded digits. The ProDigits prosthesis offers fully functional individual fingers and thumbs to the 9,200 Americans each year who lose one or more fingers, and could eventually help the 1,700 babies born every year in the U.S. with partial hand loss.
The breakthrough is miniaturization. Most full hand prosthetics stow the electronics and batteries in the palm, but because partial amputees still have their palm, Touch Bionics engineers redesigned everything to fit on the socket. Electrodes in the socket read muscle impulses to control the fingers. Adaptive programming adds functionality: Over time, patients can graduate from making a fist to typing.