ELECTRODE DEVELOPMENT

耳蜗的电特性和物理结构 电极阵列定义和界定刺激策略 用来激活听觉神经纤维 任何试图预测或 测量这些神经元对给定刺激的反应必须从 假设的电极设计。 然而，目前所有可用的耳蜗 电极基于主要由以下性质确定的设计： 通常可用的材料和制造工艺，而不是 神经元的基本性质和耳蜗几何形状的基础。 此外，迄今为止人工耳蜗的临床结果表明， 关于最佳电极设计的许多原始前提可以 需要修改。 该项目的目的是开发和 表征电极接触材料，以定制制造内电极 用于动物实验和台架测试的电极，并设计新的 这些电极应该可以改善假肢的功能。 具体 任务包括： 1. 表征现有临床电极阵列。 2. 探索金属/电解质的界面性质 结，包括新材料的制造和表征， 作为有望大大扩展可用阻抗的活性铱， 此接口的属性。 3. 制作用于急、慢性动物的多触点电极阵列 提供各种精确定位电流的实验 源 4. 开发和测试电极的通用数学模型 界面和几何形状，在储罐中使用现场测绘技术 实验 5. 设计改进的电极阵列供人类使用，基于 这一研究项目和其他项目的研究结果，并建立 这些阵列的原型用于动物研究中的评估。 除了优化电性能之外，电极设计还 从这个项目中产生的将考虑手术处理等问题， 性能和制造的经济性，以确保它们可以 容易地转移到临床听觉假体的制造商。

The electrical properties and physical configuration of the cochlear electrode array define and delimit the stimulation strategies that can be employed to activate the auditory nerve fibers. Any attempt to predict or measure the response of these neurons to a given stimulus must start with an assumed electrode design. However, all currently available cochlear electrodes are based on designs determined primarily by the properties of commonly available materials and fabrication processes, rather than on the basis of fundamental properties of neurons and cochlear geometry. Furthermore, clinical results with cochlear prostheses to date suggest that many of the original premises regarding optimal electrode designs may require modification. The purpose of this project is to develop and characterize electrode-contact materials, to custom fabricate intracochlear electrodes for use in animal experiments and bench tests, and to design new electrodes that should lead to improved prosthetic function. Specific tasks include: 1. To characterize existing clinical electrode arrays. 2. To explore the interfacial properties of the metal/electrolyte junction, including fabrication and characterization of new materials such as activated iridium that promise to greatly extend the available impedance properties of this interface. 3. To fabricate multicontact electrode arrays for acute and chronic animal experiments that provide for a variety of accurately positioned current sources. 4. To develop and test generalized mathematical models of electrode interfaces and geometries, using field-mapping techniques in tank experiments. 5. To design improved electrode arrays for human use, based on the findings of this and other projects of the research program, and to build prototypes of these arrays for evaluation in animal studies. In addition to optimizing electrical properties, the electrode designs that emerge from this project will consider issues such as surgical handling properties and economy of manufacture, to assure that they can be transferred readily to manufacturers of clinical auditory prostheses.