A Low Cost Compact Output Amplifier for Multichannel Muscle Stimulation

Functional Electrical Stimulation (FES) is a technique widely used in different application fields. Among them, rehabilitation treatments, sports training activity and aesthetics. A critical component in FES is the output amplifier, which must be designed to accomplish both functional and safety specifications. In this paper, a novel power amplifier architecture with current controlled output is presented, specifically tailored to FES needs, but optimized to reduce cost and size, as needed in a multichannel electrical stimulator. The output amplifier topology, and the techniques adopted to satisfy both functional and safety specifications are herein detailed. Simulation and real circuit results are included, too.