Technological Development Towards a Cortical Prosthesis

描述（由申请人提供）：40年前，神经科学、生物材料、电子学和微型化的令人兴奋的进步推动了世界上第一个也是最成功的听觉神经假体人工耳蜗的发展。今天，持续的科学进步已经为神经假体的下一个时代-直接脑机接口（BMI）奠定了基础。初步证据表明，直接电刺激人类听觉皮层可以诱导听觉感知。然而，目前尚不清楚这种感知是否可以为一些无法从人工耳蜗植入中受益的失聪患者提供工作听觉假体的基础。为了评估这种可能性，我们提出了技术发展，以创建一个专门的电极阵列，允许在这一领域进行人体实验。 我们的研究有两个具体目标，概括为：1）使用计算机辅助设计和分析创建用于柔性电极研究的有效模型，然后基于模型制造柔性脑电极，并在粘弹性材料或脑组织中对其进行测试，以及2）在广泛的大鼠研究和猴研究中评价优化器械的生物学性能。为了在人类研究中使用，新的电极阵列必须能够进入Heschl's gyrus（人类听觉皮层的部位），必须具有多个电极部位，并且必须提供安全和非损伤性的皮层组织电激活。具体目的旨在证明这些器械规格。我们将使用计算机模型来优化电极特性，然后通过盐水浸泡测试和实验室工作台上的电/机械特性实验来评估优化的电极阵列。然后，我们将电极阵列的改进版本植入大鼠和猴子体内，以测试其体内有效性。为了为以后的人类工作做准备，我们将使用尸体大脑来获得人类Heschl's gyrus的平均大小和形状，并为插入电极阵列提供测试模型。拟议的工作代表了一个基本的生物工程方法的应用，以传统的，但尚未解决的生物学问题，创造持久的皮质界面。它代表了听觉假体系统发展的一个新方向，并对基础神经科学产生了影响，同时为那些无法从人工耳蜗植入中受益但对假体感兴趣的耳聋患者提供了希望。

DESCRIPTION (provided by applicant): Forty years ago, exciting advances in neuroscience, biomaterials, electronics and miniaturization fueled development of the cochlear implant, the world's first and most successful auditory neuroprosthesis. Today, continued scientific advances have set the stage for the next era in neuroprosthetics - that of the direct Brain-Machine Interface (BMI). Preliminary evidence suggests that direct electrical stimulation of the human auditory cortex can induce auditory perceptions. However, it is not yet clear whether such perceptions can form the basis of a working auditory prosthesis for some deaf patients who are unable to benefit from a cochlear implant. In order to evaluate this possibility, we propose technological developments to create a specialized electrode array that would allow for human experimentation in this area. Our study has 2 specific aims summarized as: 1) To use computer-aided design and analysis to create effective models for the study of flexible electrodes and to then manufacture flexible brain electrodes based on the models and test them in viscoelastic materials or in brain tissue, and 2) To evaluate the biological performance of optimized devices in extensive rat studies followed up by a monkey study. In order to be employed in human studies, the new electrode array must be able to access Heschl's gyrus (site of auditory cortex in humans), must have multiple electrode sites and must provide safe and non-damaging electrical activation of the cortical tissue. The specific aims are designed to demonstrate these device specification. We will use computer models to optimize the electrode characteristics and then evaluate optimized electrode arrays via saline soak tests and electrical/mechanical charecterization experiments on the laboratory bench-top. We will then implant refined versions of the electrode arrays into rats and a monkey to test their effectiveness in vivo. To prepare for later human work, we will use cadaver brains to obtain average size and shape of the human Heschl's gyrus and provide a test model for inserting the electrode array. The proposed work represents the application of a fundamental bioengineering approach to a traditional and as yet unsolved biological problem of creating long-lasting cortical interfaces. It represents a new direction in the development of auditory prosthesis systems, and has implications for basic neuroscience while providing hope for those deaf patients unable to benefit from a cochlear implant but interested in a prosthesis.