MEMS Sensors for Arrhythmia Detection and Interventions

描述(申请人提供)：尽管经过几十年的深入研究，继发于室颤(VF)的猝死仍然是美国和其他发达国家的主要死亡原因。最近，关于室颤发生机制的几个有希望的假说已经被提出。然而，使用目前可用的实验技术来确定哪一种(或哪些)理论最适用于VF是不可能的。为了解决这个问题，我们建议：1)构建一个基于纳米级组件的心脏标测系统，该系统能够以高时空分辨率和最小的组织损伤来评估心脏的激活和复极；2)使用新的相位标测技术来分析标测数据，目的是识别窦性心律、室性心动过速和室性心动过速期间相位奇点的位置和数量；3)使用相位奇点数据来区分室颤的三种可能机制--具有纤颤传导的锚定转子、蜿蜒的转子或多个转子。MEMS技术将被用来构建具有集成电极的微型机械针状结构，这些电极通过超声激活，以将插入过程中的组织损伤降至最低。该电极阵列将用于在固定起搏和室颤过程中原位定位犬体外和正常及急性缺血猪心的激活和复极。测绘数据将使用快速傅立叶解调技术进行分析，以识别VF期间的奇点和波矢量。2-D和3-D心肌的计算机模型也将被用来生成用于测试分析算法的替代数据集。这项研究的结果将导致三个关键领域的重大进展：以前所未有的空间分辨率绘制心脏电活动图的设备的开发；应用更新和更复杂的技术来分析大型标测数据集；在有关室性心动过速和纤颤的新假设的背景下解释高分辨率标测数据。综上所述，这些在数据采集、分析和解释方面的进展有望带来新的、更有效的手段来识别和治疗有发生致死性室性快速性心律失常风险的患者。

DESCRIPTION (provided by applicant): Despite decades of intensive investigation, sudden death secondary to ventricular fibrillation (VF) remains a leading cause of mortality in the US and other developed countries. Recently, several promising hypotheses regarding the mechanism for VF have been introduced. However, it has not been possible using currently available experimental techniques to determine which theory (or theories) is most applicable to VF. To address this issue, we propose to: 1) construct a cardiac mapping system from nanofabricated components that is capable of assessing cardiac activation and repolarization with high spatial and temporal resolution and with minimal tissue damage; 2) use a novel phase mapping technique to analyze the mapping data, with the objective of identifying the location and number of phase singularities during sinus rhythm, ventricular tachycardia and VF; 3) use the phase singularity data to distinguish between three putative mechanisms for VF - an anchored rotor with fibrillatory conduction, a meandering rotor or multiple rotors. MEMs technology will be used to construct microscale mechanical needle-like structures with integrated electrodes that are ultrasonically activated, to minimize tissue damage during insertion. The electrode arrays will be used to map activation and repolarization in canine ventricular myocardium in vitro and in normal and acutely ischemic pig hearts in situ during fixed pacing and during VF. The mapping data will be analyzed using a fast Fourier-demodulation technique to identify singularities and wave vectors during VF. Computer models of 2- and 3-D myocardium also will be used to generate surrogate data sets for testing the analysis algorithms. The results of this study will lead to significant advances in three key areas: development of devices to map cardiac electrical activity with unprecedented spatial resolution; application of newer and more sophisticated techniques to analyze large mapping data sets; interpretation of high resolution mapping data within the context of novel hypotheses regarding the genesis of ventricular tachycardia and fibrillation. Taken together, these advances in data acquisition, analysis and interpretation are expected to lead to new and more effective means of identifying and treating patients at risk for the development of lethal ventricular tachyarrhythmias.