In-Situ Lead Tester for Implantable Devices

 描述（由申请人提供）：植入式心律转复除颤器（ICD）系统包括通过经静脉多腔除颤电极导线连接到心脏的皮下发生器。电极导线的绝缘电缆将生理电信号从心脏传输到发生器，并在必要时将治疗性电击从发生器传输到心脏，以纠正危及生命的心律失常。电极导线是ICD系统中最薄弱的环节，影响数十万患者的召回事件就是明证。当前ICD和正在开发的ICD中的引线故障诊断遭受固有的和不可补救的限制，特别是对于检测绝缘破坏，这是引线故障的最常见原因。因此，绝缘破坏通常存在严重的并发症。我们的目标是开发一种新的仪器，准确地检测亚临床电极导线故障，并适用于 评估原位电极导线。这个仪器背后的原理是亚临床的身体变化 在绝缘中，电极导线导体与外部导电血液和组织之间的电容发生变化，导致阻抗的高频（HF）测量值发生变化。在我们的1期研究中，我们使用新型电磁（EM）建模和体外测试证实了绝缘破坏会改变HF阻抗。在本研究中，我们建议（1）扩展EM建模和体外测试，（2）构建一种将高频电极导线完整性（HFLI）测试应用于植入电极导线的仪器，以及（3）在动物中测试该仪器。这样的仪器将满足显著的未满足的临床需求。在ICD发生器更换时，准确识别在新发生器的预期10年使用寿命内将失效的电极导线将允许预防性电极导线更换，从而降低患者发病率和电极导线失效的成本以及多次手术的风险和成本。最终，HFLI技术可以被整合到ICD发生器的电路中。对于新的电极导线设计，HFLI测试可以发挥关键作用，以确认预期性能或识别亚临床绝缘问题，允许在早期阶段撤回有问题的电极导线。

 DESCRIPTION (provided by applicant): Implantable cardioverter-defibrillator (ICD) systems comprise a subcutaneous generator connected to the heart by a transvenous, multilumen defibrillation lead. The lead's insulated cables carry physiological electrical signals from the heart to the generator and, when necessary, transmit therapeutic shocks from the generator to the heart to correct life-threatening arrhythmias. Leads comprise the weakest link in ICD systems, as evidenced by recalls affecting hundreds of thousands of patients. Lead-failure diagnostics in present ICDs and those under development suffer from inherent and irremediable limitations, especially for detecting insulations breaches, the most common cause of lead failure. Thus insulation breaches commonly present with serious complications. Our objective is to develop a novel instrument that detects subclinical lead failures accurately and is suitable for evaluating in-situ leads. The principle behind this instrument is that subclinical physical changes in insulation alter the capacitance between lead conductors and external conductive blood and tissue, resulting in changes in high-frequency (HF) measurements of impedance. In our phase 1 study, we confirmed that insulation breaches alter HF impedance using both novel electromagnetic (EM) modeling and in-vitro testing. In the present study, we propose (1) to expand both EM modeling and in-vitro testing, (2) to construct an instrument that applies high-frequency lead integrity (HFLI) testing to implanted leads, and (3) to test this instrument in animals. Such an instrument would fulfill a significant unmet clinical need. At ICD generator change, accurate identification of leads that will fail within the anticipated 10-year service lifeof new generators would permit prophylactic lead replacement, reducing both patient morbidity and costs from lead failures and risks and costs of multiple operations. Ultimately, HFLI technology could be incorporated into the ICD generator's circuitry. For new lead designs, HFLI testing could play a critical role either to confirm expected performance or identify subclinical insulation problems, permitting a problematic lead to be withdrawn at an earlier stage.