Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN.
Department of Biomedical Engineering, Jordan University of Science and Technology, Irbid, Jordan.
Sleep. 2021 Apr 27;44(44 Suppl 1):S11-S19. doi: 10.1093/sleep/zsaa269.
Individuals with obstructive sleep apnea (OSA), characterized by frequent sleep disruptions from tongue muscle relaxation and airway blockage, are known to benefit from on-demand electrical stimulation of the hypoglossal nerve. Hypoglossal nerve stimulation (HNS) therapy, which activates the protrusor muscles of the tongue during inspiration, has been established in multiple clinical studies as safe and effective, but the mechanistic understanding for why some stimulation parameters work better than others has not been thoroughly investigated.
In this study, we developed a detailed biophysical model that can predict the spatial recruitment of hypoglossal nerve fascicles and axons within these fascicles during stimulation through nerve cuff electrodes. Using this model, three HNS programming scenarios were investigated including grouped cathode (---), single cathode (o-o), and guarded cathode bipolar (+-+) electrode configurations.
Regardless of electrode configuration, nearly all hypoglossal nerve axons circumscribed by the nerve cuff were recruited for stimulation amplitudes <3 V. Within this range, monopolar configurations required lower stimulation amplitudes than the guarded bipolar configuration to elicit action potentials within hypoglossal nerve axons. Further, the spatial distribution of the activated axons was more uniform for monopolar versus guarded bipolar configurations.
The computational models predicted that monopolar HNS provided the lowest threshold and the least sensitivity to rotational angle of the nerve cuff around the hypoglossal nerve; however, this setting also increased the likelihood for current leakage outside the nerve cuff, which could potentially activate axons in unintended branches of the hypoglossal nerve.
NCT01161420.
患有阻塞性睡眠呼吸暂停（OSA）的个体由于舌肌松弛和气道阻塞导致睡眠频繁中断，已知受益于舌下神经按需电刺激。刺激舌下神经（HNS）疗法通过在吸气时激活舌的突出肌，已在多项临床研究中被证明是安全有效的，但对于为什么某些刺激参数比其他参数更有效，其机制理解尚未得到彻底研究。
在这项研究中，我们开发了一个详细的生物物理模型，可以通过神经袖带电极预测刺激过程中舌下神经束内的舌下神经纤维和轴突的空间募集。使用该模型，研究了三种 HNS 编程方案，包括分组阴极（---）、单阴极（o-o）和保护阴极双极（+-+）电极配置。
无论电极配置如何，几乎所有被神经袖带包围的舌下神经轴突在刺激幅度<3V 时都被募集。在这个范围内，与保护双极配置相比，单极配置需要更低的刺激幅度才能在舌下神经轴突内引发动作电位。此外，与保护双极配置相比，单极配置激活的轴突空间分布更加均匀。
计算模型预测，单极 HNS 提供了最低的阈值和对神经袖带围绕舌下神经旋转角度的最小敏感性；然而，这种设置也增加了电流在神经袖带外泄漏的可能性，这可能会激活舌下神经的意外分支中的轴突。
NCT01161420。
