PHYSICAL ASPECTS OF CAVITATION IN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY

体外冲击波碎石术中空化的物理方面

• 批准号: 6570860
• 负责人: LAWRENCE A CRUM
• 金额: $ 29.59万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6570860
• 关键词: animal tissue; biophysics; human tissue; iatrogenic disease; imaging /visualization /scanning; kidney function; lithotripsy; luminescence; mathematical model; mechanical pressure; model design /development; nephrolithiasis; photography; physical process; sound frequency; ultrasonography; ultrasound biological effect

Despite the fact that SWL has been in clinical use for over fifteen years, the physical mechanisms for stone communication are still not well understood. However, there is now a growing body of experimental evidence and an evolving general acceptance by the clinical community, that SWL leads to some degree of permanent damage to treated kidneys. The mechanisms responsible for this tissue damage are also not well understood. We hypothesize that acoustic cavitation is a dominant factor in both stone comminution and kidney damage. A competing mechanism is the shear stress produced in tissue by the SWL shock wave. Acoustic cavitation results from the growth and violent collapse of cavitation bubbles produced by the SWL acoustic waveform. We have developed a set of sophisticated experimental tools that permit us to detect cavitation in a broad range of environments and with some degree of spatial and temporal resolution. Using these tools, we have acquired a significant body of evidence that demonstrates that SWL generates cavitation in both the parenchyma and the collecting system of the human kidney. We have also discovered a method of modifying an electrohydraulic lithotripter to produce a waveform that has a similar shock wave amplitude, pulse length, and acoustic energy to that of a conventional SWL waveform, but does not generate cavitation. Furthermore, we have found a way to enhance the violence cavitation collapse, as well as a way to confine cavitation to a highly localized volume. We propose to use these various discoveries and tools to ascertain to ascertain the relative roles of cavitation and shear in stone comminution and tissue damage. We have also made considerable progress toward the development of a set of theoretical models that would permit us to compute the SWL waveform at any position and time, either in vitro or in vivo. Furthermore, give a specific waveform, we can compute the response of the cavitation field to this waveform, and determine, albeit in a crude way, the potential for cavitation damage in a variety of in vitro and in vivo environments. We propose to test our hypotheses by undertaking a series of experiments in which we will apply SWL to various in vitro and in vivo models, during which we will use our cavitation detection techniques to determine the presence and location of this cavitation; later, we shall correlate the tissue damage with either the presence or absence of cavitation. We shall also undertake a series of similar experiments involving stone comminution. Using these results, we shall use our theoretical models to design a waveform that would optimize stone comminution and minimize tissue damage.

尽管SWL从事临床用途已有15年了，但 石材交流的物理机制仍然不好 理解。但是，现在有越来越多的实验证据 以及临床社区不断发展的一般接受，SWL 导致对经过治疗的肾脏的永久性损害。这 负责此组织损伤的机制也不很好 理解。我们假设声气水是主要因素 在石头粉碎和肾脏损害中。竞争机制是 SWL冲击波在组织中产生的剪切应力。声气水 气泡气泡的生长和暴力崩溃的结果 由SWL声波形产生。我们已经开发了一套 复杂的实验工具，使我们能够在一个 广泛的环境以及一定程度的空间和时间 解决。使用这些工具，我们获得了一大堆 证明SWL在两者中都产生空化的证据 实质和人类肾脏的收集系统。我们也有 发现了一种将电含水岩石磨牙剂修改为 产生具有相似冲击波幅度的波形，脉冲长度， 和传统SWL波形的声学能量 产生空化。此外，我们找到了一种增强的方法 暴力空气崩溃，以及一种将气孔限制在一个 高度局部的体积。我们建议使用这些各种发现， 确定确定空化和剪切的相对作用的工具 在石头粉碎和组织损伤中。我们也做了很多 朝着开发一组理论模型的进展 允许我们在任何位置和时间计算SWL波形，要么在 体外或体内。此外，给出特定的波形，我们可以计算 空化场对此波形的响应，并确定 尽管以一种粗略的方式，但在多种多样的气损伤的可能性 体外和体内环境。我们建议通过 进行一系列实验，我们将将SWL应用于各种 体外和体内模型，在此期间我们将使用空化 检测技术来确定此的存在和位置 空化；后来，我们将组织损伤与任何一员 存在或不存在空化。我们还将进行一系列 类似的实验涉及石粉。使用这些结果，我们 应使用我们的理论模型设计将优化的波形 石头粉碎并最大程度地减少组织损伤。