Phased Array Ultrasound System for Cardiac Ablation

描述(由申请人提供)： 心脏介入治疗快速性心律失常已从药物治疗发展到以外科手术为基础消除致心律失常的部位，再到以导管为基础的消融程序。经皮置入导管消融已经成为许多快速性心律失常的标准治疗形式，超过了药物和外科方法。尽管有这些重大进展，导管消融术仍有影响疗效和安全性的主要局限性。不能准确识别解剖靶点和创造跨壁、连续的病变限制了疗效。与这一手术相关的许多并发症都是由于其侵入性。此外，该手术是在透视指导下进行的，在延长的手术过程中，患者和医生将暴露在显著剂量的电离辐射中。在这项研究中，我们将测试一种假设，即具有全三维波束引导能力的超声相控阵放置在食道内，并由磁共振成像引导和监测，可以准确地诱导有针对性的跨壁心肌损伤，而不会出现与心内导管放置相关的问题。为了实现这一目标，我们计划：首先，使用我们的线性相控阵进行体内动物试验，以探索诱导足够的组织凝固的超声参数和方法。其次，进行计算机模拟研究，探索经食道心脏消融的阵列设计和超声方法。第三，开发和测试相控阵敷贴器在体外和体内动物组织中的应用；第四，开发可以监测和指导心肌凝固的磁共振测温方法。最后，我们计划开发一套完整的超声波系统，并在动物实验中进行测试。在不暴露于电离辐射的情况下实时成像真实解剖结构的能力，以及精确定位和非侵入性地创建跨壁病变的能力，将是心律失常治疗方面的一次重大革命。这可能会显著节省成本，并治愈数千名患者。

DESCRIPTION (provided by applicant): Cardiologic intervention for the treatment of tachyarrhythrnias has evolved from pharmacological therapy to surgical based elimination of arrhythmogenic loci and circuits to catheter based ablation procedures. Ablation via percutaneously placed catheters has become the standard form of therapy for many tachyarrhythmias, surpassing pharmacologic and surgical methods. Despite these major advances, catheter ablation has major limitations effecting both efficacy and safety. The inability to accurately identify anatomic targets and create transmural, continuous lesions limits efficacy. Many of the complications associated with this procedure are due to its invasive nature. In addition, the procedure is performed under fluoroscopy guidance that during a prolonged procedure exposes the patient and physician to a significant dose of ionizing radiation. In this research we will test a hypothesis that an ultrasound phased array with full three dimensional beam steering capability placed in the esophagus and guided and monitored by magnetic resonance imaging can induce accurately targeted transmural myocardial lesions without the problems associated with the intracardiac catheter placement. To accomplish this we plan to: First, perform in vivo animal tests with our linear phased arrays to explore the sonication parameters and methods for inducing adequate tissue coagulation. Second, perform a computer simulation study to explore the array design and sonication methods for trans-esophageal cardiac ablation. Third, develop and test the phased array applicators both in ex vivo and in vivo animal tissues, and fourth, develop MR thermometry methods that can monitor and guide cardiac muscle coagulation. Finally, we plan to develop a complete sonication system and test it in animal experiments. The ability to image in real time the true anatomy without exposure to ionizing radiation and to precisely target and create transmural lesions non-invasively would be a major revolution in the treatment of cardiac arrhythmias. This could result in significant cost savings and lead to a cure of thousands of patients.