Acoustically Active Catheter for Echocardiographic Navigation

描述(申请人提供)：基因和细胞制剂的再生疗法正在开发中，用于恢复梗死心肌的功能，以及许多其他微创的心脏和非心脏研究和治疗干预措施，使用可引导的导管作为高风险、昂贵和要求严格的手术的替代方案。一种实时的、非透视的、便携的、经济实惠的导管导航解决方案代表着对微创介入治疗指导的普遍和迫切的需求。透视、机电测绘或磁共振成像满足这些要求的能力有限，会增加辐射暴露，并且需要专门的团队和专用房间。我们提出了一种满足所有这些要求的方法，并将在特定的心内导航领域进行测试，尽管其预期的用途是广泛的。我们充分利用了我们创新的声学活性导管(AAC)的工作原型：可定向导管的尖端配备了以指定频率振动的压电晶体，并充当可在超声扫描平面中检测到的“信标”。因此，AAC的尖端可以沿着超声扫描平面被引导朝向测试解剖目标。目的1：对声学导管的工作模式进行表征、优化和初步测试。提出了AAC尖端振动晶体的接收、干涉和发射工作模式，并将对其进行研究，以使AAC尖端在超声导航扫描平面上能够最佳和明确地检测到。目的2：测试AAC导航系统的精度、准确度和实用性。由四维超声心动图实时生成的双平面经胸多普勒扫描平面将作为一种新的导航路径概念进行测试，以引导AAC尖端朝向心脏内的测试解剖目标。建议的方法打破了目前的现状，引入了一种创新的声学活性导管，并结合4D回波成像和导航，集成了超声图像引导导航系统，用于微创干预。公共卫生相关性：在西方世界，与梗塞相关的心力衰竭仍然是发病率和死亡率的主要原因。通过微创干预将基因或干细胞直接注入心肌可以恢复其功能。微创介入技术也在开发中，用于许多其他心脏和非心脏研究和治疗应用，其基础是仅通过最小的皮肤和血管穿刺术，使用包括可引导导管在内的特殊工具进入目标器官。通过这种方式，可以避免风险大、费用高、要求高的手术。微创介入的共同需求是导航至解剖靶点。然而，不需要暴露在X光下、不需要昂贵的成像设备或不需要专门的房间--而且准确地导航微创介入工具，如可引导的心内导管--的系统并不存在。我们建议探索一种利用我们创新的声学活性导管的解决方案。这种导管的远端产生一种独特的声学信号，在超声图像中被检测为“Bea-con”。通过超声描绘心脏和特定的解剖靶点，这种新型导管可以通过完全相同的技术导航。因此，相对便宜、便携和广泛使用的超声检查既可以作为成像工具，也可以作为导航工具。这项拨款申请旨在初步验证所提出的超声图像导航系统的可行性、精确度和准确性。

DESCRIPTION (provided by applicant): Regenerative therapies with genes and cellular agents are being developed for restoration of function in in-farcted myocardium along with many other minimally invasive cardiac and noncardiac investigative and therapeutic interventions with steerable catheters as alternatives to risky, costly, and demanding surgery. A real-time, nonfluoroscopic, portable, and cost-effective solution for steerable catheter navigation repre- sents a common and critical need for guidance of the miniminally invasive interventions. Fluoroscopy, elec- tromechanical mapping, or magnetic resonance imaging have limited ability to fulfill these requirements, in- volve exposure to radiation, and require a specialized team and a dedicated room. We propose an approach that satisfies all these requirements and is to be tested in a specific field of in- tracardiac navigation, although its anticipated utility is broad. We capitalize on our innovative working proto- type of an Acoustically Active Catheter (AAC): A tip of a steerable catheter is outfitted with a piezoelectric crystal that vibrates at a prescribed frequency and acts as a "beacon" detectable in ultrasound scan planes. As such, the tip of the AAC can be guided along ultrasound scan planes toward a testing anatomic target. Aim 1: Characterize, optimize, and initially test operating modes of the acoustic catheter. Receive, interfer- ence, and transmission operating modes of the crystal vibrating at the AAC tip are proposed and will be ex- plored to make the tip optimally and unambiguously detectable in ultrasound navigation scan planes. Aim 2: Test the precision, accuracy, and utility of the AAC navigation system. Biplane transthoracic Doppler scan planes, generated in real-time by 4-dimensional echocardiography, will be tested as a novel concept of navigation pathways for steering the AAC tip towards a testing anatomic target within the heart. The proposed approach disrupts the current status quo by introducing an innovative acoustically active catheter and, in conjunction with 4D echo imaging and navigation, an integrated ultrasound image-guided navigation system for minimally invasive interventions. PUBLIC HEALTH RELEVANCE: Infarction-related heart failure remains a major cause of morbidity and mortality in the Western world. Deliv- ery of genes or stem cells directly into the cardiac muscle by using minimally invasive interventions can re- store its function. The minimally invasive interventions are being developed also for many other cardiac and noncardiac investigative and therapeutic applications, and are based on accessing a target organ only through a minimal skin and vascular puncture with special tools including steerable catheters. In this way, a risky, costly, and demanding surgery can be avoided. The common need of the minimally invasive interventions is navigation to an anatomic target. However, a system that does not require exposure to X-rays, expensive imaging devices, or a specialized room - and yet, accurately navigates the minimally invasive intervention tool, such as a steerable intracardiac catheter - does not exist. We propose to explore a solution that capitalizes on our innovative Acoustically Active Catheter. The distal end of such a catheter produces a unique acoustic signal that is detected in ultrasound images as a "bea- con". By depicting the heart and the specific anatomic target with ultrasound, the novel catheter can be navigated by the very same technique. Thus, the relatively inexpensive, portable, and broadly available ul- trasonography has a role as both an imaging and navigation tool. This grant application is designed to initially validate the feasibility, precision, and accuracy of the proposed ultrasound image-guided navigation system.