Pacing, Sensing and Defibrillation Electrode Coatings

描述（由申请人提供）： 提出了心脏起搏、感知和除颤用低极化电极涂层的发展方向。这些涂层满足了心律管理（CRM）行业在开发低极化起搏、低阻抗除颤和刺激后感知方法方面的需求。涂层是基于溅射氧化铱（SIROF）和IrTi氧化物的薄膜，具有定制的表面形貌，最大限度地降低极化电荷注入。添加钛以形成混合的IrTi氧化物显著增强了涂层的化学和物理稳定性，而不会影响起搏和感知性能。I期IrTi氧化物的开发被认为是重要的，因为它提供了一种通过硅氧烷化学将广泛的功能性有机物质共价连接到电极表面的方法，以增强生物相容性并减轻炎症反应。第二阶段的目标是：1）开发用于心脏电极的坚固的、低成本的涂层，其降低起搏阈值并允许可靠地感测心脏电活动; 2）开发用于心脏电极的有机功能化涂层，其相对于非功能化电极减少纤维化组织封装并降低起搏阈值，以及3）开发降低植入式心律转复除颤器（ICD）电极的除颤阈值（DFT）的低阻抗涂层。降低的阈值和改善的感知将通过增强植入物的功效和增加更换电池所需的外科手术之间的时间而使患者受益。SIROF和IrTi氧化物的成本将低于竞争涂层材料（例如TiN），使其在商业上具有吸引力。在第II阶段，将对共价官能化有机表面涂层的抗炎特性进行体外评估，并通过加速体外试验评价这些涂层的长期稳定性。将通过实验评估SIROF、IrTi-氧化物和功能化IrTi-氧化物用于起搏和除颤的性能。作为临床实施的一个步骤，将在绵羊模型中评价更佳涂层的慢性起搏，并在急性猪模型中评价更佳涂层的DFT减少。体内研究将与亚拉巴马大学的合作者一起完成。

DESCRIPTION (provided by applicant): The development of low polarization electrode coatings for cardiac pacing, sensing and defibrillation is proposed. These coatings address the needs of the cardiac rhythm management (CRM) industry in the development of low-polarization pacing, low impedance defibrillation, and post-stimulus sensing methodologies. The coatings are based on films of sputtered iridium oxide (SIROFs) and IrTi-oxide with tailored surface morphologies that maximizes low-polarization charge-injection. The addition of titanium to form a mixed, IrTi-oxide significantly enhances the chemical and physical stability of the coatings without compromising pacing and sensing performance. The development of IrTi-oxide in Phase I is considered significant, since it provides a means through siloxane chemistry to covalently attach a broad range of functional organic species to the surface of the electrode to enhance biocompatibility and moderate inflammatory responses. The Phase II Aims are 1) To develop robust, low-cost coatings for cardiac electrodes that reduce pacing thresholds and permit reliable sensing of cardiac electrical activity; 2) To develop organically functionalized coatings for cardiac electrodes that reduce fibrotic tissue encapsulation and lower pacing thresholds relative to non-functionalized electrodes, and 3) To develop low-impedance coatings that reduce defibrillation thresholds (DFTs) of implantable cardioverter defibrillator (ICD) electrodes. Reduced thresholds and improved sensing will benefit the patient by enhancing the efficacy of the implant and by increasing the time between surgical procedures necessary to replace batteries. The SIROF and IrTi-oxide will be lower cost than competing coating materials (e.g. TiN), making them attractive commercially. In Phase II, in vitro assessments of the anti-inflammatory properties of covalently functionalized organic surface coatings will be made and these coatings evaluated for long-term stability by accelerated in vitro testing. The performance of SIROF, IrTi-oxide and functionalized IrTi-oxide for pacing and defibrillation will be assessed experimentally. As a step towards clinical implementation, the more optimum coatings will be evaluated for chronic pacing in a sheep model and for reduced DFTs in an acute pig model. The in vivo studies will be done with collaborators at the University of Alabama.