Heaton James T, Kobler James B, Otten David M, Tynan Monica A, Petrillo Robert H, Ottensmeyer Mark P, Slate Andrea R, Hillman Robert E, Zeitels Steven M
Department of Surgery, Harvard Medical School, Boston, MA.
Center for Laryngeal Surgery and Voice Rehabilitation, Massachusetts General Hospital, Boston.
J Speech Lang Hear Res. 2023 Dec 11;66(12):4812-4827. doi: 10.1044/2023_JSLHR-23-00377. Epub 2023 Nov 16.
Medialization procedures for unilateral vocal fold (VF) paralysis generally improve voice but do not fully replace dynamic VF adduction. Paralyzed VFs typically experience synkinetic reinnervation, which makes it feasible to elicit movement through electrical stimulation. We tested a novel laryngeal pacing implant capable of providing closed-loop (automatic) stimulation of a VF triggered by electromyography (EMG) potentials from the contralateral VF.
A custom, battery-powered, microprocessor-based stimulator was tested in eight dogs with bipolar electrodes implanted for recording EMG from the left VF and stimulating adduction of the right VF. A cuff electrode on the left recurrent laryngeal nerve (RLN) stimulated unilateral VF adduction, modeling voluntary control in anesthetized animals. Closed-loop stimulation was tested in both acute and chronic experiments. Synkinetic reinnervation was created in two animals by right RLN transection and suture repair to model unilateral VF paralysis.
In all animals, left VF activation through RLN stimulation generated a robust EMG response that rapidly triggered stimulation of contralateral thyroarytenoid and lateral cricoarytenoid muscles, causing nearly simultaneous bilateral adduction. Optimal triggering of VF stimulation from elicited EMG was achieved using independent onset and offset thresholds. Real-time artifact blanking allowed closed-loop stimulation without self-perpetuating feedback, despite the proximity of recording and stimulation electrodes.
Using a custom implant system, we demonstrated real-time closed-loop stimulation of one VF triggered by the activation of the contralateral VF. This approach could potentially restore dynamic glottic closure for reflexive behaviors or phonation in cases of unilateral VF paralysis with synkinetic reinnervation.
单侧声带麻痹的内移手术通常可改善嗓音，但无法完全替代动态声带内收。麻痹的声带通常会经历协同性再支配，这使得通过电刺激引发运动成为可能。我们测试了一种新型喉部起搏植入物，它能够根据对侧声带的肌电图（EMG）电位触发对一侧声带进行闭环（自动）刺激。
在八只狗身上测试了一种定制的、由电池供电的、基于微处理器的刺激器，植入双极电极用于记录左侧声带的肌电图并刺激右侧声带内收。左侧喉返神经（RLN）上的袖带电极刺激单侧声带内收，模拟麻醉动物的自主控制。在急性和慢性实验中均测试了闭环刺激。通过右侧RLN横断和缝合修复在两只动物中创建协同性再支配，以模拟单侧声带麻痹。
在所有动物中，通过RLN刺激激活左侧声带产生了强烈的肌电图反应，迅速触发了对侧甲杓肌和环杓侧肌的刺激，导致几乎同时的双侧内收。使用独立的起始和偏移阈值可实现从诱发的肌电图中最佳地触发声带刺激。尽管记录和刺激电极距离很近，但实时伪迹消除允许进行闭环刺激而不会产生自我持续的反馈。
使用定制植入系统，我们展示了由对侧声带激活触发的对一侧声带的实时闭环刺激。这种方法有可能在单侧声带麻痹伴有协同性再支配的情况下恢复反射行为或发声时的动态声门闭合。
