Feedback control of electrical stimulation electrode arrays

•Electrical stimulation electrode arrays have potential to accurately assist movement.•A robust framework is developed to enable principled model-based control design.•The framework provides precise conditions for robust performance.•It is demonstrated by experimental tests with three wrist and hand gestures.•Comparisons between polycarbonate and fabric electrode arrays are presented.

Electrical stimulation electrode arrays are an emerging technology that enables muscles to be artificially contracted through the activation of their associated motor neurons. A principal application of electrical stimulation is to assist human motion for orthotic or therapeutic purposes. This paper develops a framework for the design of model-based electrode array feedback controllers that balance joint angle tracking performance with the degree of disturbance and modeling mismatch that can exist in the true underlying biomechanical system. This framework is used to develop a simplified control design procedure that is suitable for application in a clinical setting. Experimental results evaluate the feasibility of the control design approach through tests on ten participants using both fabric and polycarbonate electrode arrays.