Zhong P, Cioanta I, Cocks F H, Preminger G M
Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA.
J Acoust Soc Am. 1997 May;101(5 Pt 1):2940-50. doi: 10.1121/1.418522.
The inertial cavitation and associated acoustic emission generated during electrohydraulic shock wave lithotripsy were studied using high-speed photography and acoustic pressure measurements. The dynamics of cavitation bubble clusters, induced in vitro by an experimental laboratory lithotripter, were recorded using a high-speed rotating drum camera at 20,000 frames/s. The acoustic emission, generated by the rapid initial expansion and subsequent violent collapse of the cavitation bubbles, was measured simultaneously using a 1-MHz focused hydrophone, The expansion duration of the cavitation bubble cluster was found to correlate closely with the time delay between the first two groups of pressure spikes in the acoustic emission signal. This correlation provides an essential physical basis to assess the inertial cavitation produced by a clinical Dornier HM-3 shock wave lithotripter, both in water and in renal parenchyma of a swine model. In the clinical output voltage range (16-24 kV), the expansion duration of the primary cavitation bubble cluster generated by the HM-3 lithotripter in water increases from 158 to 254 microseconds, whereas the corresponding values in renal parenchyma are much smaller and remain almost unchanged (from 71 to 72 microseconds). In contrast, subsequent oscillation of the bubble following its primary collapse is significantly prolonged (from 158-235 microseconds in water to 1364-1373 microseconds in renal parenchyma). These distinctive differences between lithotripsy-induced inertial cavitation in vitro and that in vivo are presumably due to the constraining effect of renal tissue on bubble expansion.
利用高速摄影和声压测量技术，研究了液电冲击波碎石术中产生的惯性空化及其相关声发射。使用一台20000帧/秒的高速旋转鼓式相机，记录了实验室内碎石机在体外诱导产生的空化泡团簇的动力学过程。同时，使用一个1兆赫聚焦水听器测量了空化泡快速初始膨胀及随后剧烈塌陷产生的声发射。结果发现，空化泡团簇的膨胀持续时间与声发射信号中前两组压力峰值之间的时间延迟密切相关。这种相关性为评估临床使用的多尼尔HM-3冲击波碎石机在水中和猪模型肾实质中产生的惯性空化提供了重要的物理基础。在临床输出电压范围（16 - 24千伏）内，HM-3碎石机在水中产生的初级空化泡团簇的膨胀持续时间从158微秒增加到254微秒，而在肾实质中的相应值要小得多且几乎保持不变（从71微秒到72微秒）。相比之下，空化泡初次塌陷后的后续振荡明显延长（从水中的158 - 235微秒延长到肾实质中的1364 - 1373微秒）。体外和体内碎石术诱导的惯性空化之间的这些显著差异可能是由于肾组织对泡膨胀的约束作用。
