中文摘要：

体外冲击波碎石术已经在临床上取得了成功的应用，但其引起的空化对组织的损伤以及如何合理利用空化来提高碎石效率还有待更细致的研究。本文利用兆赫兹频率级别的聚焦超声换能器诱发冲击波作用于结石模型材料，采用不同的声波参数包括频率、强度、占空比等进行了实验。结果表明，聚焦冲击波对结石的损伤呈凹坑状；空化在凹坑形成初期起到主导作用；采用高低频搭配的脉冲超声波可以实现对结石模型最大的损伤。

英文摘要：

ESWL has been successfully applied to clinical use, however, further study is needed on cavitation in ESWL to specify the harm it does and improve the stone fragmentation efficiency. We used a Mega Hz focused transducer to focus on the surface of the calculus model and tried different frequency, intensity, time and duty cycle. The results show that the damage is indentation-like and cavitation plays a leading role in the early period of the pit formation. It is also observed that high-low frequency combined pulsed ultrasound is the most efficient in fragmenting the stone model.