Combined Electro‐chemical Stimulation to Reduce the Required Current for Muscle Contraction

Abstract

Facial nerve dysfunction and the subsequent inability to blink is a common complication caused by numerous medical problems, such as stroke. Denervation and dysfunction of the orbicularis oculi, the muscle responsible for eye blinks can result in corneal abrasions and breakdown. Direct electrical stimulation of the muscle is not a viable solution, as the required electrical stimulus needed to induce a blink in denervated muscle is 3 mA while the human pain threshold is 1 mA. The insufficiency of electrical stimulation alone in triggering painless muscle contraction in denervated orbicularis oculi muscles indicates a need to investigate other methods of stimulation. The aim of this study is to investigate the response of skeletal muscle to combined electrochemical stimulation by initiating the intricate cascade that leads to muscle contraction with the application of acetylcholine in order to reduce the required electrical stimulus. Muscle sheets are used as the model for the orbicularis oculi with electrical field stimulation being applied along with constant and intermittent application of chemical stimuli.