Low Impedance Electrodes for Neural Stimulation

描述（由申请人提供）：该项目的目的是评估新型低阻抗刺激电极的技术可行性。植入刺激器的功耗取决于电极-组织界面的阻抗。电力消耗需要更大的植入包装来容纳合适的电池，而有限的电池寿命需要手术更换设备。电极阻抗的降低将降低功耗，从而延长电池寿命和/或更小的植入物封装。我们将开发和评估新的高周长电极，旨在利用电流密度在电极表面的不均匀分布。增加周长的电极旨在增强“边缘效应”；电极表面沿电极周长方向的电流密度较高，并且更明显的边缘效应有望降低电极阻抗。我们将在三个领域评估周长增加的电极的性能。首先，我们将在体外测量在增加电极周长设计的几何谱的阻抗。这些数据将用于测试增加电极周长降低电极阻抗的假设，并为随后的电极设计提供信息。其次，电极的几何形状可以影响周围组织中产生的神经兴奋模式，我们将量化高周长电极几何形状产生的神经元兴奋模式，并将其与传统电极产生的模式进行比较。第三，电极的几何形状会影响电极表面电流密度的空间分布，这是刺激引起神经损伤和电极腐蚀的重要因素。我们将进行电极腐蚀的体外脉冲测试，并量化增加周长对电极表面电流密度大小和分布的影响，以评估导致组织损伤的倾向。这些研究的结果将是对一种新型低阻抗刺激电极的技术可行性进行全面的分析和体外评估，并将为随后的慢性体内电极安全性和有效性测试提供基础。该项目的目标是设计和分析更有效的电极，用于神经系统的电刺激，以治疗神经系统疾病或损伤。这些电极将增加电池供电的植入式电刺激器的使用寿命。这将降低因电池耗尽而外科更换植入刺激器的风险和成本。

DESCRIPTION (provided by applicant): The objective of this project is to evaluate the technical feasibility of novel low impedance stimulating electrodes. The power consumption of implanted stimulators is dependent on the impedance of the electrode- tissue interface. Power consumption requires larger implanted packages to accommodate appropriate batteries, and finite battery lifetimes require surgical replacement of devices. Reductions in electrode impedance will reduce power consumption leading to prolonged battery life and/or smaller implant packages. We will develop and evaluate novel high-perimeter electrodes designed to exploit the non-uniform distribution of current density on the electrode surface. Electrodes with increased perimeter are intended to enhance the "edge effect"; the current density on the electrode surface is higher toward the perimeter of the electrode, and a more pronounced edge effect is expected to lower the electrode impedance. We will evaluate the performance of electrodes with an increased perimeter in three domains. First, we will make in vitro measurements of the impedance of across a spectrum of geometries designed in increase the electrode perimeter. These data will be used to test the hypothesis that increasing the electrode perimeter decreases electrode impedance and to inform subsequent electrode designs. Second, the electrode geometry can affect the pattern of neural excitation generated in the surrounding tissue, and we will quantify the patterns of neuronal excitation generated by high-perimeter electrode geometries and compare these to patterns generated by conventional electrodes. Third, the electrode geometry can affect the spatial distribution of current density over the electrode surface, an important factor in stimulation induced neural damage and electrode corrosion. We will conduct in vitro pulse testing of electrode corrosion, and quantify the effects of increasing the perimeter on the magnitude and distribution of current density across the electrode surface to assess the propensity to cause tissue damage. The outcome of these studies will be a comprehensive analytical and in vitro assessment of the technical feasibility of a new class of low impedance stimulating electrodes, and will provide the foundation for subsequent chronic in vivo testing of electrode safety and efficacy. The objective of this project is to design and analyze more efficient electrodes for use in electrical stimulation of the nervous system to treat neurological disease or injury. These electrodes will increase the lifetime of battery-powered implantable electrical stimulators. This will reduce the risks and costs associated with surgical replacement of implanted stimulators due to depletion of the batteries.