Mechanical Science and Engineering, University of Illinois, IL 61801,
J Acoust Soc Am. 2009 Nov;126(5):2746-56. doi: 10.1121/1.3224830.
Shock waves in liquids are known to cause spherical gas bubbles to rapidly collapse and form strong re-entrant jets in the direction of the propagating shock. The interaction of these jets with an adjacent viscous liquid is investigated using finite-volume simulation methods. This configuration serves as a model for tissue injury during shock-wave lithotripsy, a medical procedure to remove kidney stones. In this case, the viscous fluid provides a crude model for the tissue. It is found that for viscosities comparable to what might be expected in tissue, the jet that forms upon collapse of a small bubble fails to penetrate deeply into the viscous fluid "tissue." A simple model reproduces the penetration distance versus viscosity observed in the simulations and leads to a phenomenological model for the spreading of injury with multiple shocks. For a reasonable selection of a single efficiency parameter, this model is able to reproduce in vivo observations of an apparent 1000-shock threshold before wide-spread tissue injury occurs in targeted kidneys and the approximate extent of this injury after a typical clinical dose of 2000 shock waves.
液体中的冲击波会导致球形气泡迅速坍塌，并在冲击波传播的方向上形成强烈的反流射流。使用有限体积模拟方法研究了这些射流与相邻粘性液体的相互作用。这种配置可作为冲击波碎石术期间组织损伤的模型，冲击波碎石术是一种去除肾结石的医疗程序。在这种情况下，粘性流体为组织提供了一个粗略的模型。结果发现，对于与组织中可能预期的粘度相当的粘度，小气泡坍塌形成的射流无法深入穿透粘性流体“组织”。一个简单的模型再现了模拟中观察到的穿透距离与粘度的关系，并导致了一种用于多次冲击波损伤扩展的现象模型。对于单个效率参数的合理选择，该模型能够再现靶向肾脏中广泛组织损伤发生之前的 1000 次冲击波的明显阈值，以及在典型的 2000 次冲击波临床剂量后的这种损伤的大致范围。
