Control of Dynamically Coupled Cavitation Bubbles in Shock Wave Lithotripsy

冲击波碎石术中动态耦合空化气泡的控制

• 批准号: 7380266
• 负责人: Mark F Hamilton
• 金额: $ 33.39万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7380266
• 关键词: 3-Dimensional; Accounting; Adverse effects; Benefits and Risks; Blood; Blood Vessels; Bowman' s space; Calculi; Clinical; Condition; Confined Spaces; Coupled; Coupling; Development; Electromagnetic Energy; Experimental Models; Extracorporeal Shockwave Lithotripsy; Feedback; Film; Frequencies; Goals; Growth; Hemorrhage; Image; In Vitro; Individual; Injury; Kidney; Kidney Calculi; Knowledge; Liquid substance; Lithotripsy; Measurement; Modeling; Monitor; Numbers; Physiologic pulse; Play; Probability; Procedures; Process; Property; Protocols documentation; Public Health; Pulse Rates; Pulse taking; Rate; Recommendation; Reporting; Research; Role; Safety; Shock; Solid; Speed; Stress; Surface; Testing; Tissues; Translations; Treatment Protocols; Tube; Ultrasonography; Ureter; Urinary tract; Width; base; clinically significant; cost; desire; improved; in vivo; mathematical model; models and simulation; movie; novel; particle; polyvinylidene fluoride; pressure; research study; sensor; simulation; theories; transmission process; urinary

DESCRIPTION (provided by applicant) Extracorporeal shock wave lithotripsy (SWL) is the most widely used procedure for comminution of urinary tract calculi, but after two decades of SWL, safety and efficiency appear to be declining, not improving. In some reports, clinically significant hemorrhaging within the kidney has increased tenfold, and the probability of successful treatment has been reduced by half. The effect on public health has been an increased risk/benefit ratio and cost of repeated treatments. In vitro and in vivo experimentation have shown that cavitation plays an important role in both the desired effect, stone comminution, and the undesired side effect, tissue injury, and that whereas some undefined number of bubbles is necessary in comminution, more bubbles, as can be produced by high shock wave delivery rates, inhibit comminution. Recent high-speed camera images indicate that the cavitation bubble cluster can grow to envelop the stone and that the cluster dynamics cannot be predicted by existing theories for single, isolated bubbles. Currently no model in SWL accounts for the dynamic coupling of bubbles to one another or to nearby tissue. The goal of this project and its relevance to public health is to develop accurate analytical models, tested and supported by experiment, to increase our understanding of cavitation clusters near kidney stones and tissue, and to provide guidance for improving the efficacy and safety of SWL. The project has three specific aims. (1) Develop a mathematical model for bubble cluster dynamics and use this model to understand and predict the growth, translation, collapse, and shock wave radiation associated with individual cavitation bubbles in the cluster, and to estimate the collective impact of these effects on the stone. Expand the model to account for solid particles interspersed among the bubbles. Calculate and compare pressures produced by the cluster and the shock wave produced by four clinical lithotripters. Ultimately, determine parameters and predict conditions for shock waveform, shock wave delivery rate, and lithotripter beam width that improve stone comminution. (2) Develop a model for individual and clustered bubble dynamics in urinary tubules, blood vessels, and other spaces confined by tissue. (3) Obtain pressure measurements within the cluster and 3D movies of cluster dynamics using piezoelectric sensors and two high speed cameras to compare to model simulations. Quantify numerically and experimentally the pressure on a stone or vessel wall as an effect of bubble number and therefore SW delivery rate. Simultaneously, characterize inhibitory clusters on B-mode ultrasound as a feedback to clinicians. Together, the model and experimental results may then guide monitoring, protocol, and lithotripter development.

描述（由申请人提供）体外冲击波岩石疗法（SWL）是最广泛使用的尿路计算方法，但是经过二十年的SWL，安全性和效率似乎正在下降，而不是改善。在某些报告中，肾脏内的临床明显出血增加了十倍，成功治疗的可能性减少了一半。对公共卫生的影响是增加的风险/福利比和重复治疗的成本。体外和体内实验表明，空化在所需的效果，石头粉碎和不希望的副作用，组织损伤中都起着重要作用，而尽管有一些不确定的气泡在粉上是必要的，但仍有更多的气泡，而有更多的气泡可以通过高冲击波递送速度产生，但会产生。最近的高速摄像头图像表明，气泡气泡簇可以生长以包裹石头，并且群集动力学无法通过单个孤立气泡的现有理论来预测。目前，SWL中没有模型来彼此或附近组织的动态耦合。该项目的目的及其与公共卫生的相关性是开发经过实验测试和支持的准确的分析模型，以提高我们对肾结石和组织附近的空化簇的理解，并为提高SWL的功效和安全性提供指导。该项目具有三个特定的目标。 （1）开发一个用于气泡群集动力学的数学模型，并使用此模型来理解和预测集群中与单个空化气泡相关的生长，翻译，塌陷和冲击波辐射，并估计这些影响对石材的集体影响。扩展模型以说明气泡中散布的固体颗粒。计算和比较簇产生的压力以及四个临床碎石磨牙器产生的冲击波。最终，确定参数并预测冲击波形，冲击波传递速率和岩石纤维梁宽度的条件，以改善石材的粉刺。 （2）为尿小管，血管和其他被组织限制的空间中的个体和聚集气泡动力学开发模型。 （3）使用压电传感器和两个高速摄像机在群集和3D电影中获得压力测量，与模型模拟进行比较。通过数值和实验量化石头或容器壁上的压力，作为气泡数量的效果，因此是SW输送速率。同时，将B模式超声抑制簇作为对临床医生的反馈。然后，模型和实验结果可以指导监测，方案和岩石纤维发展。