Recent advances in charge balancing for functional electrical stimulation.

Charge balancing is a major concern in functional electrical stimulation, since any excess charge accumulation over time leads to electrolysis with electrode dissolution and tissue destruction. Its major function is to ensure that the mean value of electrode voltage is kept within a safe level. However, it serves as a failure protection as well. This paper presents an overview on recent advances in this field, both passive and active (closed-loop) charge balancing techniques.