Department of Mathematics, University of North Carolina at Chapel Hill, 329 Phillips Hall, CB 3250, Chapel Hill, North Carolina 27599, USA.
J Acoust Soc Am. 2013 Aug;134(2):1598-609. doi: 10.1121/1.4812881.
A multiphysics computational model of the focusing of an acoustic pulse and subsequent shock wave formation that occurs during extracorporeal shock wave lithotripsy is presented. In the electromagnetic lithotripter modeled in this work the focusing is achieved via a polystyrene acoustic lens. The transition of the acoustic pulse through the solid lens is modeled by the linear elasticity equations and the subsequent shock wave formation in water is modeled by the Euler equations with a Tait equation of state. Both sets of equations are solved simultaneously in subsets of a single computational domain within the BEARCLAW framework which uses a finite-volume Riemann solver approach. This model is first validated against experimental measurements with a standard (or original) lens design. The model is then used to successfully predict the effects of a lens modification in the form of an annular ring cut. A second model which includes a kidney stone simulant in the domain is also presented. Within the stone the linear elasticity equations incorporate a simple damage model.
本文提出了一种体外冲击波碎石术过程中聚焦声脉冲和后续冲击波形成的多物理计算模型。在本工作中建模的电磁碎石机中，聚焦通过聚苯乙烯声透镜实现。通过线性弹性方程模拟声脉冲穿过固体透镜的传输，通过带有泰特状态方程的欧拉方程模拟水内的后续冲击波形成。这两组方程在 BEARCLAW 框架内的单个计算域的子集内同时求解，该框架使用有限体积黎曼求解器方法。该模型首先通过标准（或原始）透镜设计的实验测量进行验证。然后，该模型成功预测了透镜环形切割形式的透镜修改的效果。还提出了一个包含域内肾结石模拟物的第二个模型。在石头中，线性弹性方程包含一个简单的损伤模型。
