Electrodeposited Noble Metal Oxide Nerve Electrodes

描述(由申请人提供)： 介绍了用于神经记录和刺激电极的低阻抗、大容量电荷注入涂层电沉积氧化Ir膜的研究进展。在第一阶段中，通过定量组织学方法评价EIROF涂层在金属支架上的生物相容性，发现其与活性氧化Ir(AIROF)和金属Ir对照相当。在60天的植入期间，这些材料中的任何一种都没有观察到不良的神经病理。体外测量确定了EIROF与神经记录和刺激相关的电化学性质，并为刺激电极提供了电荷注入限制。这些数据被用来确定EIROF比传统金属电极或其他类型的电活性涂层更具优势的神经假体和电刺激疗法。这些应用包括外周神经电极、耳蜗和视网膜感官植入物以及皮质内刺激和记录电极。还确定了在基于刺激的治疗中的应用，如脑深部刺激和心脏起搏。与AIROF和其他竞争电极涂层相比，EIROF的独特优势是电沉积过程简单，适用于覆盖用作神经假体导体的大多数金属，并且显著降低了涂层成本，同时对实施大批量涂层操作所需的资本设备的投资最少。基于这些发现，第二阶段的目标是：1)证明用于长期慢性记录和刺激的EIROF涂层的生物兼容性和功能性能，使用EIROF涂层的PTLR微电极植入皮质长达一年的时间；2)广泛表征EIROF涂层相对于神经假体和基于刺激的治疗的要求的电化学和机械性能；3)通过将EIROF结合到穿透性、皮质内微电极、柔性电极阵列和微机械硅基电极中，证明EIROF涂层适用于广泛的神经假体；4)开发和演示EIROF沉积过程的放大，并建立植入前涂层处理和灭菌的协议，5)通过开发和提供体内使用、监测和维护EIROF涂层的协议，促进终端用户和设备制造商采用EIROF，并通过在皮质中测试来验证这些协议。

DESCRIPTION (provided by applicant): The development of electrodeposited iridium oxide films (EIROFs) as low impedance, high-capacity charge-injection coatings for neural recording and stimulation electrodes is proposed. In Phase I, the biocompatibility of EIROF coatings on metal shafts implanted in rabbit cortex was evaluated by quantitative histology and found comparable with activated iridium oxide (AIROF) and iridium metal controls. No adverse neural pathology was observed with any of these materials for a 60 day implantation period. In vitro measurements established the electrochemical properties of EIROF relevant to neural recording and stimulation, and provided charge-injection limits for stimulation electrodes. These data were used to identify neuroprosthetic and electrical-stimulation based therapies for which EIROF could provide advantages over conventional metal electrodes or other types of electroactive coatings. The applications include peripheral nerve electrodes, cochlear and retinal sensory implants, and intracortical stimulation and recording electrodes. Applications in stimulation-based therapies such as deep-brain stimulation and cardiac pacing were also identified. The particular advantages of EIROF over AIROF and other competing electrode coatings are the simplicity of the electrodeposition process, suitability for coating most metals used as conductors in neural prostheses, and a significantly reduced coating cost with minimal investment in capital equipment required to implement high-volume coating operations. Based on these findings, the Phase II objectives are 1) to demonstrate biocompatibility and functional performance of EIROF coatings for long-term chronic recording and stimulation using EIROF-coated Ptlr microelectrodes implanted in cortex for periods up to one year, 2) to broadly characterize the electrochemical and mechanical properties of EIROF coatings relative to the requirements of neural prostheses and stimulation-based therapies, 3) to demonstrate suitability for a wide range of neural prostheses by incorporating EIROF into penetrating, intracortical microelectrodes, flexible electrode arrays, and micromachined silicon-based electrodes, 4) to develop and demonstrate scale-up of the EIROF deposition process and to establish protocols for handling and sterilization of coatings prior to implantation, and 5) to facilitate adoption of EIROF by end-users and device manufacturers by developing and providing protocols for in vivo use, monitoring and maintenance of EIROF coatings and to validate these protocols by testing in cortex.