Repetitive control based tremor suppression using electrical stimulation

Tremor is a common, debilitating movement condition commonly occurring in neurological disorders, with invasive and pharmacological treatment methods often ineffective. Functional electrical stimulation (FES) holds potential to supress tremor, but previous control methods have proven of limited success. This paper establishes the feasibility of using repetitive control, a framework which is able to eliminate the effect of periodic disturbances by including an internal model of the oscillation within the control structure. A model of the wrist is developed and two different repetitive control algorithms are applied to suppress tremor via stimulation of wrist flexors and extensors. Experimental results are compared with filter-based methods to establish the efficacy of the proposed approach.