High Frequency Ultrasound Arrays for Cardiac Imaging

描述(申请人提供)：心脏节律失常，如房颤和扑动，影响着大约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)消融治疗心律失常的过程是最长和最详细的，因为心血管系统内基于导管的诊断和治疗设备的指导困难。虽然透视仍然是金标准的成像工具，但众所周知，随着更长时间和更具挑战性的操作，迫切需要新的和更有效的实时空间标测工具来改善临床结果，减少患者目前暴露在透视下的辐射剂量。最近一篇关于循环消融方法的综述指出，射频是使用的主要能源，但仍不足以确保病变的连续性和永久性，而不会增加不可接受的手术时间和并发症。需要新的、有效和安全的替代能源来实现对所有形式的房颤(房颤)进行单一、广泛应用的根治程序的最终目标。我们的项目是针对我们老龄化人口中的这一主要心血管问题，与国家心肺和血液研究所的使命一致。我们由来自学术机构和公司的临床医生、电生理学家和工程师组成的合作伙伴计划在可控制的电生理导管上开发新的高度小型化和独一无二的心内成像设备，这种设备可以提供2D和3D超声成像，从而在相同的导管设备中完全集成成像、病变特征和治疗。我们还建议：将这些设备的消融能力从射频能量扩展到较新的方法，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。我们还将开发和提供在线能力，以便能够快速评估EP消融程序的结果和有效性。这些方法包括用于评估组织加热和激光声学组织定征的热应变成像方法，以及用于确定在3D融合显示器上显示的消融组织的改变的机械特性的方法、心腔的电解剖标测以及心律的正常和异常传导的传播。我们建议的项目建立在我们最初5年资金的基础上，结合了最新的最先进和微型化的超声换能器技术和布线和连接方法，以及在相同的EP导管消融设备中将成像和评估与直接能量输送相结合的能力。我们期望，我们的工作成果可以提高这些复杂治疗策略的有效性和可用性，同时减少手术持续时间、辐射暴露和成本。 与公共卫生相关：严重的心律失常，如被称为房颤的快速和不规则心律，通常需要通过导管消融程序进行治疗。这些漫长而复杂的过程成功率各不相同，异常节律发作经常复发。我们的临床医生和工程师合作伙伴计划开发新的基于导管的消融方法，将能量传递和心腔内的超声成像整合在一起，目标是缩短这些程序的持续时间，最大限度地减少对患者和医生的辐射暴露，并改善消融结果。

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.