Power Prosthetics

This article presents an overview of the bionic limbs designed by Hugh Herr. They include the powered foot and ankle prostheses with multiple tendon-like actuators that stiffen and power gait. Each ankle holds three computers that perform various computations enabling one to walk at different speeds across different terrains. They were distinct in the prostheses world because these bionic limbs are powered, while all other foot ankle prostheses are energetically passive. In effect, Herr has to mimic the mechanism of a natural limb. The bionic limb is running spinal-like reflexes on a computer chip. A commercial product—called emPOWER—is being sold through Herr’s startup called BioneX Medical Technologies. In the lab, Herr and his colleagues are working on developing neural interfaces, essentially connecting the bionic limbs to muscles and nerves so a person can think and move the limbs and also feel the movement as a feedback into the nervous system.