Closed-loop laryngeal pacing for voice restoration

Project Summary and Abstract The most common neurogenic voice disorder is unilateral vocal fold paralysis (UVFP), which can substantially reduce quality of life. Current available surgical treatments offer only temporary improvement in voice through placement of resorbable materials or involve permanent, invasive alteration of the larynx that incompletely restores voice and often requires revision surgeries. There is limited access to advanced surgical procedures with moderately better outcomes due to the need for specialized surgical techniques and an increased risk of invasive procedures. Functional electrical stimulation (FES) has the potential to restore dynamic vocal fold (VF) closure (adduction), improving voice and airway protective outcomes for the UVFP patient population. Laryngeal electromyography (LEMG) studies have shown that about 85% of those with chronic UVFP do not have complete VF denervation, opening the door to low-intensity closed-loop FES to reanimate paralyzed VFs. Several studies have indeed shown that laryngeal muscles with synkinetic reinnervation can be effectively stimulated or “paced” to restore dynamic VF opening (abduction). However, laryngeal pacing devices to date have only stimulated VF abduction to facilitate breathing and have only used preset patterns of stimulation (open-loop control) rather than sensing and responding to the physiological needs of the individual (closed-loop control). Herein we describe a novel closed-loop laryngeal FES system for reanimation of VF closure (adduction) to treat UVFP. The proposed system builds upon proven approaches for implant devices and FES, yet includes multiple key innovative elements, and will create an entirely new medical device tailored for reanimation of paralyzed VF adduction to support voice and airway protection.