Technological Development Towards a Cortical Prosthesis

描述(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人工耳蜗的发展，这是世界上第一个也是最成功的听觉神经假体。今天，持续的科学进步为神经假体的下一个时代--直接脑机接口(BMI)时代奠定了基础。初步证据表明，对人类听觉皮质的直接电刺激可以诱导听觉感知。然而，目前尚不清楚这种知觉是否能为一些无法从人工耳蜗术中受益的聋人患者提供有效的听觉假体。为了评估这种可能性，我们建议开发一种专门的电极阵列，以便在这一领域进行人体实验。 我们的研究有两个具体目标：1)使用计算机辅助设计和分析来创建研究柔性电极的有效模型，然后基于这些模型制造柔性脑电极，并在粘弹性材料或脑组织中进行测试；2)在广泛的老鼠研究和猴子研究中评估优化装置的生物学性能。为了用于人体研究，新的电极阵列必须能够进入赫氏回(人类听觉皮质的位置)，必须有多个电极位置，并且必须为皮质组织提供安全和非破坏性的电激活。具体目标旨在演示这些设备规范。我们将使用计算机模型来优化电极特性，然后在实验室台面上通过盐水浸泡测试和电气/机械特性实验来评估优化后的电极阵列。然后，我们将把改进版本的电极阵列植入大鼠和猴子体内，以测试它们的有效性。为了为以后的人类工作做准备，我们将使用身体大脑获得人类赫氏回的平均大小和形状，并为插入电极阵列提供测试模型。这项拟议的工作代表了一种基本的生物工程方法在创建持久的皮质界面这一传统的、尚未解决的生物学问题上的应用。它代表了听觉假体系统发展的新方向，并对基础神经科学产生了影响，同时也为那些无法从人工耳蜗术中受益但对假体感兴趣的聋人提供了希望。

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.