血管内聚焦超声空化多尺度时空动态分布及其瞬态物理机制研究

In order to increase thrombolysis efficiency by ultrasound cavitation enhancement and also decrease mechanical damage to vessel wall, spatial-temporal distributions of cavitation cloud induced by pulsed focused ultrasound of various parameters in a wall-less flow phantom with various vessel diameters, flow velocities, and with or without clot are investigated by high-speed camera, dual passive cavitation detectors and a dynamic thrombolysis evaluation method. The physical mechanisms of cavitation and its interactions with the clot and the vessel wall have been studied. Based on these investigations, the parameter optimization of ultrasound thrombolysis can be done to enhance or inhibit cavitation activity. As a result, thrombolysis efficiency can be increased by cavitation enhancement, while mechanical damage to vessel wall can be avoided or decreased. The research of this project may improve the efficiency, the targetability and safety of ultrasound applications, such as ultrasound thrombolysis and microbubble-enhanced focused ultrasound therapy. Moreover, the study of physical mechanism of cavitation induced by focused ultrasound and the corresponding clinical applications can be promoted.

为了利于空化增效力学机制提高超声溶栓率同时避免空化微泡活动引起的血管损伤，本项目结合高速摄影、双通道被动空化检测和溶栓全程动态监测评价方法，同步研究不同流速、不同管径、不同聚焦超声溶栓参数、有无血栓时血管内空化微泡多尺度时空动态分布，分析空化微泡瞬态物理机制及其与血栓、血管壁的相互作用，探讨其影响因素、可控性以及与溶栓率的相关性，并在此基础上优化聚焦超声溶栓参数，选择性地增强或抑制超声空化强度，一方面利用空化增效力学机制提高超声溶栓治疗的效率，另一方面避免血管损伤。该项目研究有望提高血管内超声溶栓以及超声联合包膜微泡治疗等的靶向性、效率和安全性，推动聚焦超声治疗的空化物理以及临床应用研究。

为了利用空化增效力学机制提高超声溶栓率同时避免空化微泡活动引起的血管损伤，本项目结合高速摄影、双通道被动空化检测和溶栓全程动态监测评价方法，同步研究了不同流速、不同管径、不同聚焦超声溶栓参数、有无血栓时血管内空化微泡多尺度时空动态分布。具体研究工作包括（1）搭建血管内聚焦超声空化多尺度时空动态分布及瞬态物理机制研究实验平台；（2）研究血管内超声溶栓过程中空化微泡振动、坍塌破裂以及所产生的微声流、冲击波和射流等瞬态物理过程；（3）研究空化微泡动力学过程对血管壁的作用，以及可能造成的血管壁损伤；（4）分析多参数下空化微泡时空分布与溶栓率、溶栓碎片粒径分布之间的相关性，并在此基础上优化聚焦超声空化溶栓参数。本项目研究可为进一步提高临床超声溶栓率和安全性提供有效参考。