NUMERICAL SIMULATION OF SHOCKWAVE LITHOTRIPSY

冲击波碎石术的数值模拟

• 批准号: 7279973
• 负责人: TIM COLONIUS
• 金额: $ 17.68万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7279973
• 关键词: biomechanics; biomedical equipment development; biophysics; cellular pathology; computer simulation; extracorporeal circulation; imaging /visualization /scanning; kidney function; lithotripsy; luminescence; mathematical model; mechanical pressure; mechanical stress; model design /development; nephrolithiasis; sound frequency; tissue /cell culture; ultrasonography; ultrasound biological effect

Research in SWL conducted over the past ten years has shown that stresses sufficient to induce both fragmentation and cellular-level tissue damage can result from direct interaction with the focusing shockwave as well as secondary stresses induced by the expansion and collapse of cavitation bubbles. The proposed research will provide a detailed modeling and simulation of the fluid and solid-dynamical processes that occur both in vitro and in vivo during SWL. The specific aims are: 1. Modeling and computer simulation of the stresses acting on stones and soft tissue that results from the focusing shockwaves and clouds of cavitations bubbles in the fluid state. 2. Computer simulation of the dynamic fracture and fragmentation process in realistic stone models, including tracking the origin and propagation of each fracture. 3. Quantitative assessment of soft tissue damage in anatomically correct finite element models kidneys and individual structures therein. The modeling effort is closely guided by the extent and nature of the experimental evidence, available from close collaboration with the Program Project Group, that can be used to calibrate and validate the models. These data include quantitative assessment of kidney geometry and damage through digital images from a computer segmentation of pig kidneys, detailed pressure hydrophone measurements in vitro and in vivo, ultra-high-speed photography of bubble clouds and shockwaves, data on stone fragmentation, mechanical testing of strain-rate dependent material behavior, and ultrasound tomography of the structure and fracture of stones. Impact on clinical application will be maximized by working toward an integrated simulation facility capable of full-scale analysis of anatomically and mechanically correct models of stone comminution and tissue injury. The simulation facility will allow unprecedented predictive power that may ultimately show how to pulverize stones with fewer shocks and less renal injury.

在过去十年中进行的SWL研究表明，足以导致碎裂和细胞级别组织损伤的应力可以由与聚焦冲击波的直接相互作用以及空化气泡的膨胀和坍塌引起的次要应力产生。 这项拟议的研究将对SWL过程中发生的体内外流体和固体动力学过程进行详细的建模和模拟。具体目标是： 1.流体状态空化气泡集中激波和云团作用于石材和软组织的应力建模和计算机模拟。 2.计算机模拟真实岩石模型中的动态断裂和破碎过程，包括跟踪每个裂缝的起源和扩展。 3.在解剖学上正确的有限元模型中对软组织损伤进行定量评估。 建模工作受到实验证据的范围和性质的密切指导，实验证据可通过与计划项目组的密切合作获得，可用于校准和验证模型。这些数据包括通过计算机分割猪肾脏的数字图像对肾脏几何形状和损伤的定量评估，体外和体内详细的压力水听器测量，气泡云和冲击波的超高速摄影，结石破碎的数据，应变率相关材料行为的机械测试，以及结石结构和骨折的超声波断层扫描。对临床应用的影响将通过努力建立一个集成的模拟设施来最大化，该设施能够对结石粉碎和组织损伤的解剖和力学正确模型进行全面分析。模拟设备将提供前所未有的预测能力，最终可能会展示如何以更少的冲击和更少的肾脏损伤粉碎结石。