Development and control of a hybrid motor neuroprosthesis
A hybrid motor neuroprosthesis (HMN) is a neuroprosthetic in the form of functional electrical stimulation (FES) augmented by an active robotic exoskeleton (ARE). We are currently developing a single degree-of-freedom HMN that controls the knee joint of a human subject. FES is applied to the quadriceps muscles to control the joint trajectory, and an ARE at the knee will assist when the muscles begin to fatigue or when the loads are too high for the muscles to handle alone. Applications include rehabilitation of patients with an upper motor neuron lesion and restoration of every-day functionality like walking. The highly time-varying, uncertain, nonlinear, and hybrid nature of such a system presents a plethora of difficult but exciting controls challenges.