Noninvasive fragmentation of urinary calculi with focused ultrasound bursts

 简介(申请人提供)：建议的职业发展奖候选人是Adam Maxwell博士，他是一位生物医学工程师，在医学超声研究，特别是冲击波碎石术和高强度聚焦超声治疗方面拥有10年以上的经验。他研究了声波与组织的物理相互作用，开发了研究和临床原型系统，并研究了超声波疗法的新应用。申请这一职业发展奖的目的是让Maxwell博士在Michael Bailey博士、Jonathan Harper博士和Hunter Wessells博士这三位经验丰富的导师的指导下，培养成为一名成功的独立研究人员所需的品质和能力，并获得尿石症方面的专业知识。华盛顿大学是一家领先的研究机构，麦克斯韦尔博士计划在那里继续他的研究和职业发展。他将得到一个具有结石管理专业知识的协作团队的支持，该团队位于应用物理实验室的工业和医学超声中心的泌尿外科和医学超声学系。他提出的研究将探索一种治疗尿石症的潜在新疗法。尿石症是一种常见的疾病，大约每11个人中就有一个人在一生中受到影响，给美国的医疗资源带来了巨大的负担。在过去的30年里，尿路结石的治疗已经出现了几种新的方法，包括冲击波碎石术(SWL)、输尿管镜和经皮肾镜取石术。SWL是唯一一种治疗结石的非侵入性手术，但患者在一次治疗中排出结石的可能性比其他方法低得多，在较新的碎石器中也有所下降。开发一种更有效的碎石器仍然是一个尚未满足的临床挑战。虽然在这项技术的临床引入过程中，电击和结石之间的物理相互作用还没有得到很好的了解，但最近的研究已经建立了SWL中结石骨折的机制。基于这项工作，提出了一种新型的碎石术，它使用广泛聚焦的超声脉冲而不是冲击波。初步数据显示，冲击波碎石术(BWL)能够在短短10秒内粉碎结石。此外，在手术过程中产生的碎片的大小可以由超声波频率控制，从而加强了一种产生容易被患者通过的小碎片的治疗方法。这项提议的目标是建立一个科学的理论基础，指导冲击波碎石术的发展。特别是，该项目建议研究超声波与结石和组织的物理相互作用，并利用这些信息来确定治疗参数。该建议的具体目标是：1)开发和表征用于BWL研究的合适的超声源，2)确定BWL导致结石骨折的机械相互作用，以及3)确定BWL导致组织损伤的力学效应。麦克斯韦尔博士的长期研究目标是将这项技术转化为临床上有用的治疗方法，以提高结石治疗的护理标准。

 DESCRIPTION (provided by applicant): The candidate of the proposed Career Development Award is Dr. Adam Maxwell, a biomedical engineer with over 10 years of experience in medical ultrasound research, particularly shock wave lithotripsy and high- intensity focused ultrasound therapy. He has investigated physical interactions of acoustic waves with tissues, developed research and clinical prototype systems, and researched new applications for ultrasound therapies. The purpose of applying for this Career Development Award is for Dr. Maxwell to cultivate the qualities and abilities necessary to be a successful independent researcher and obtain expertise in urolithiasis under the guidance of three experienced mentors, Drs. Michael Bailey, Jonathan Harper, and Hunter Wessells. The University of Washington is a leading research institution at which Dr. Maxwell plans to pursue his research and career development. He will be supported by a collaborative team with expertise in stone management within the Department of Urology and medical ultrasound in the Center for Industrial and Medical Ultrasound at the Applied Physics Laboratory. His proposed research will investigate a potential new treatment for urolithiasis. Urolithiasis is a common disease that affects approximately 1 in 11 individuals during their lifetime and presents a large burden on U.S. healthcare resources. In the last 30 years, management of urinary tract stones has seen the introduction of several novel approaches, including shock wave lithotripsy (SWL), ureteroscopy, and percutaneous nephrolithotomy. SWL is the only noninvasive procedure for stones, but the likelihood of rendering patients stone-free in a single session is considerably lower than other methods, and has declined in newer lithotripters. Development of a more effective lithotripter remains an unmet clinical challenge. While the physical interactions between shocks and stones were not well understood during this technology's clinical introduction, recent research has established the mechanisms of stone fracture in SWL. Based on this work, a novel type of lithotripsy using widely focused bursts of ultrasound rather than shock waves is proposed. Preliminary data shows that burst wave lithotripsy (BWL) is capable of disintegrating stones in as little as 10 seconds. Furthermore, the size of fragments generated during the procedure can be controlled by the ultrasound frequency, potentiating a therapy that produces small fragments easily passed by patients. The goal of this proposal is to create a scientific rationale that will guide the development of burst wave lithotripsy. In particular, this project proposes to investigate the physical interactions of ultrasound bursts with stones and tissue, and use this information to determine therapy parameters. The specific aims of the proposal are: 1) Develop and characterize a suitable ultrasound source for BWL research, 2) Determine the mechanistic interactions leading to stone fracture by BWL, and 3) Identify the mechanical effects of BWL leading to tissue damage. Dr. Maxwell's long-term research goal is to translate this technology into a clinically useful treatment that improves the standard of care for stone management.