High Frequency Ultrasound Arrays for Cardiac Imaging

描述（由申请人提供）：心房颤动和扑动等心律失常影响了大约240万美国人，仅在美国每年就有大约16万新病例。电生理（EP）和射频（RF）消融治疗心律失常是最漫长和详细的，因为导管诊断和治疗设备在心血管系统内的指导困难。虽然透视检查仍然是金标准成像工具，但众所周知，随着时间的延长和更具挑战性的程序，迫切需要新的和更有效的实时空间测绘工具来改善临床结果并减少患者目前暴露的透视辐射剂量。此外，《循环》杂志最近对消融方法的回顾指出，“射频是使用的主要能量来源，但仍然不足以确保病变的连续性和永久性，而不会增加手术时间和并发症。”需要新的、有效的、安全的替代能源来实现单一的、广泛适用的、治疗所有形式房颤的最终目标。”我们的项目是针对这个主要的心血管问题在我们的人口老龄化与国家心脏，肺和血液研究所的使命一致。我们的合作伙伴是来自学术机构和公司的临床医生、电生理学家和工程师，他们正在提议开发新的高度小型化和独特的心脏内成像设备，该设备可以在可操控的电生理导管上提供2D和3D超声成像，在同一导管设备内完全集成成像、病变表征和治疗。我们还建议：将这些设备的消融能力从射频能量扩展到更新的方法，包括高强度聚焦超声（HIFU）和激光消融，这两种方法都可以产生更集中和离散的连续病变。我们还将开发并提供在线功能，以允许快速评估EP消融程序的结果和有效性。这些方法包括热应变成像，用于评估组织加热和激光声学组织表征，以及超声方法，用于定义在心脏腔室电解剖映射的3D融合显示器上显示的消融组织的改变机械性能，以及正常和异常心律传导的传播。我们提出的项目建立在我们前5年的资金基础上，结合了最新最先进的微型超声换能器技术、电缆和连接方法，以及在相同的EP导管消融设备中集成成像和评估与直接能量输送的能力。我们期望我们的工作结果可以提高这些复杂治疗策略的有效性和可用性，同时减少手术时间，辐射暴露和成本。

DESCRIPTION (provided by applicant): Cardiac dysrhythmias such as atrial fibrillation and flutter affect about 2.4 million Americans, with approximately 160,000 new cases in the US alone every year. Electrophysiological (EP) and radiofrequency (RF) ablation procedures to treat cardiac arrhythmias are among the most prolonged and detailed due to the difficulties in the guidance of catheter based diagnostic and therapeutic devices within the cardiovascular system. Although fluoroscopy is still the gold standard imaging tool, it is well recognized that with longer and more challenging procedures, new and more effective real time spatial mapping tools are vitally needed to improve clinical outcomes and to reduce the fluoroscopic radiation doses to which patients are currently exposed. Also a recent review of ablation methods in Circulation stated that "Radiofrequency is the dominant energy source used but remains inadequate to ensure lesion continuity and permanence without an unacceptable increase in procedural time and complications. New, effective, and safe alternative energy sources are needed to achieve the ultimate goal of a single, widely applicable, curative procedure for all forms of AF (atrial fibrillation)." Our project is targeted at this major cardiovascular problem in our aging population concordant with the mission of the National Heart, Lung, and Blood Institute. Our Partnership of clinicians, electrophysiologists and engineers from academic institutions and companies is proposing to develop new highly miniaturized and unique intracardiac imaging devices on steerable electrophysiology catheters which can provide 2D and 3D ultrasound imaging to fully integrate imaging, lesion characterization and therapy within the same catheter devices. We also propose: to expand the capabilities for ablation with these devices from RF energy to newer methods including High Intensity Focused Ultrasound (HIFU) and laser ablation both of which can create more focused and discrete continuous lesions. We will also develop and provide on-line capabilities to allow rapid evaluation of the results and effectiveness of EP ablation procedures. These include methods such as thermal strain imaging to assess tissue heating and laser acoustic tissue characterization and ultrasound methods for defining altered mechanical properties of ablated tissue displayed on 3D fusion displays of electroanatomical mapping of the chambers of the heart and the propagation of normal and abnormal conduction of cardiac rhythms. Our proposed project builds on our first 5 years of funding combining the newest most advanced and miniaturized ultrasound transducer technologies and cabling and connection methods, with the ability to integrate imaging and assessment with direct energy delivery for ablation within the same EP catheter-based ablation devices. It is our expectation that the results of our work can improve the efficacy and availability of these complex treatment strategies while reducing procedure duration, radiation exposure and cost. PUBLIC HEALTH RELEVANCE: Serious abnormalities of cardiac rhythms, such as the rapid and irregular rhythms referred to as atrial fibrillation, often require treatment by trans-catheter ablation procedures. These long and complicated procedures have variable success rates and the abnormal rhythm episodes often recur. Our Partnership of clinicians and engineers is planning to develop new catheter-based methods for performing ablation with integration of energy delivery and ultrasound imaging from inside the heart chambers, with the goal of reducing the duration of these procedures, minimizing radiation exposure to the patient and the physician and improving the results of ablation.