Stimulation model and experiments for a vestubular prosthesis.

描述(由申请人提供)：前庭系统的性能可以通过监测由于前庭-眼反射(VOR)引起的眼睛的运动来量化，因为它是通过对实验对象施加旋转运动或通过直接刺激半规管来激活的。我们实验室研制了一种前庭假体。该设备包含陀螺仪，可以感知围绕三个旋转轴的运动，并具有向连接到设备的电极提供电刺激脉冲的能力。将电极植入栗鼠半规管的初步测试表明，前庭神经分支之间的间隔太窄，无法将干净的刺激信号分别发送到前庭神经的每个目标分支。这个项目的目标是建立电刺激范式，它将向大脑提供一组有意义的前庭信号，尽管由于非特异性刺激导致信号串扰。我们将研究电极相互作用问题的两种可能的解决方案，并采用尖峰积分器模型来预测刺激训练参数对VOR响应的影响。目的1)电刺激与VOR反应之间的线性关系将使我们能够使用成熟的3D旋转运动学来处理来自假体的陀螺仪信号，而不考虑电极的相互作用。我们假设电刺激和VOR反应之间的线性关系成立。目的2)低幅度刺激提高电极的特异性，但降低VOR反应的强度。高刺激率已被证明引入了强烈的VOR反应。我们假设，使用以高刺激调制率提供的低幅度刺激脉冲将在低电极相互作用下产生强烈的VOR响应。目的3)最后，我们将扩展生物物理模型，以预测传递到躯体感觉皮层的刺激脉冲序列的感知强度，以达到前庭刺激的目的。我们假设该模型将提供对各种电刺激参数的VOR响应的准确表示。相关：双侧前庭系统功能障碍对患者具有衰弱作用，患者被迫慢动作生存，以弥补平衡系统的不足。这项研究考察了几种使能和增强可植入前庭假体功能的技术。

DESCRIPTION (provided by applicant): The performance of the vestibular system can be quantified by monitoring the motion of the eyes due to the vestibular-ocular reflex (VOR) as it is being activated by applying a rotation motion to the experimental subject or by directly stimulating the semicircular canals. Our laboratory developed a vestibular prosthesis. This device contains gyroscopes that can sense motion about three axes of rotation and it has the ability to provide electrical stimulation pulses to the electrodes, attached to the device. The initial tests of this device with the electrodes implanted in the semicircular canals of chinchillas indicate that the separation between the branches of the vestibular nerve is too narrow to allow a clean stimulation signal to be delivered separately to each targeted branch of the vestibular nerve. The goal of this project is to establish the electrical stimulation paradigm which would provide a meaningful set of vestibular signals to the brain despite the signal crosstalk due to non-specific stimulation. We will examine two possible solutions to the problem of electrode interaction and adapt a spike integrator model to predict the effect of stimulus train parameters on the VOR response. Aim 1) Linear relationship between electrical stimulation and VOR response would allow us to use well- established 3D rotational kinematics to process the gyroscope signals from the prosthesis, despite electrode interaction. We hypothesize that linear relationships hold true between electrical stimulation and VOR responses. Aim 2) Low amplitude stimulation improves electrode specificity, but decreases the strength of the VOR response. High stimulation rates have been shown to introduce strong VOR response. We hypothesize that using low amplitude stimulation pulses delivered at high stimulation modulation rates will produce strong VOR responses with low electrode interaction. Aim 3) Finally, we will extend a biophysical model developed for predicting perceived intensity of stimulation pulse trains delivered to the somatosensory cortex, for the purposes of vestibular stimulation. We hypothesize that the model will provide accurate representation of VOR response to a wide variety of electrical stimulation parameters. RELEVANCE: Bilateral dysfunction of the vestibular system has debilitating effects on the patients, who are forced into a slow motion existence so as to compensate for the lack of their balance system. This study examines several techniques to enable and enhance the functioning of an implantable vestibular prosthesis.