Multi-Modal Stimulus Interaction and Optimization in a Vestibular Prosthesis

描述（由申请人提供）：由于耳毒性药物、梅尼埃病、遗传综合征的影响和对内耳的其他损伤引起的双侧前庭功能衰竭（BVF）可导致致残症状。受影响的个体遭受慢性不平衡和失智症，并且那些不能补偿其损失的人增加了福尔斯和其他伤害的风险。目前没有足够的治疗BVF的选择。为了满足这些人的需求，我们开发了一种前庭假体原型，它通过3个陀螺仪对3D头部运动进行编码，并电刺激前庭神经的相应分支。这种设备在龙猫的初步测试是有希望的，但刺激编码的进一步改进将需要可靠地编码的角度前庭眼反射通常稳定凝视的头部运动的全方位。定义每个假体通道的刺激编码特性的十个主要参数的试错优化是不切实际的。为了在临床环境中的成功应用，将需要更有效的刺激协议编程方法。拟议项目的第一部分将建立一个强大而有效的方法来优化刺激参数，然后使用优化过程中获得的数据来完善前庭神经和中枢神经系统如何响应假体电刺激的模型。虽然第一个人类前庭植入物接受者将是严重双侧丧失的个体，但扩大植入候选标准可能会导致植入残留机械敏感性的受试者。了解自然和假体输入是否以及如何集中集成，将有助于设计电极和刺激方案，最大限度地利用剩余的机械灵敏度。与此同时，研究对自然刺激和假肢刺激的反应的相互作用提供了一个机会，可以使用其他不可能的实验范式来研究感觉整合的神经生理学。拟议项目的第二部分将描述角前庭眼反射（aVOR）对电刺激和自然刺激单独和组合的反应。相关性：前庭假体可以恢复因BVF而丧失的功能，就像人工耳蜗恢复听力一样。该项目将直接影响用于人类使用的前庭假体的刺激方案的设计，澄清假体和植入的迷路中的残余机械感觉之间的相互作用，并完善“虚拟龙猫迷路”计算模型，该模型一旦被验证，可以很容易地适应于人体解剖结构，用于植入人体迷路中的电极的最佳设计。

DESCRIPTION (provided by applicant): Bilateral vestibular failure (BVF) due to ototoxic medications, Meniere's disease, effects of genetic syndromes and other insults to the inner ear can cause disabling symptoms. Affected individuals suffer chronic disequilibrium and oscillopsia, and those who fail to compensate for their loss are at increased risk of falls and other injuries. There are currently no adequate treatment options for BVF. Striving to address the needs of these individuals, we have developed a prototype vestibular prosthesis that encodes 3D head movement via 3 gyroscopes and electrically stimulates the corresponding branches of the vestibular nerve. Initial tests of this device in chinchillas have been promising, but further improvement in stimulus encoding will be required to reliably encode the full range of head movements for which the angular vestibulo-ocular reflex normally stabilizes gaze. Trial and error optimization of the ten principal parameters that define stimulus encoding characteristics for each prosthesis channel is impractical. For successful application in a clinical setting, a more efficient approach to stimulus protocol programming will be needed. The first part of the proposed project will establish a robust and efficient approach to optimization of the stimulus parameters, then use data acquired during optimization to refine a model of how the vestibular nerve and central nervous system respond to prosthetic electrical stimuli. While the first human vestibular implant recipients will be individuals with profound bilateral loss, expanding implantation candidacy criteria may lead to implantation of subjects with residual mechanical sensitivity. Understanding whether and how natural and prosthetic inputs are integrated centrally will facilitate design of electrodes and stimulus protocols that make maximal use of residual mechanical sensitivity. At the same time, examining the interplay of responses to natural and prosthetic stimuli offers an opportunity to study the neurophysiology of sensory integration using otherwise impossible experimental paradigms. The second part of the proposed project will characterize the angular vestibulo-ocular reflex (aVOR) in response to electrical and natural stimulation alone and in combination. RELEVANCE: A vestibular prosthesis could restore lost function due to BVF, much as a cochlear implant restores hearing. This project will directly impact the design of stimulus protocols for a vestibular prosthesis for human use, clarify the interaction between prosthetic and residual mechanical sensation in the implanted labyrinth, and refine a "virtual chinchilla labyrinth" computational model which, once validated, can be readily adapted to human anatomy for use in optimal design of electrodes for implantation in the human labyrinth.