Chen Hong, Li Xiaojing, Wan Mingxi, Wang Supin
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, PR China.
Ultrason Sonochem. 2007 Mar;14(3):291-7. doi: 10.1016/j.ultsonch.2006.08.003. Epub 2006 Oct 27.
Cavitation bubble clouds in the focal region of HIFU play important roles in therapeutic applications of HIFU. Temporal evolution and spatial distribution of cavitation bubble clouds generated in the focal region of a 1.2 MHz single element concave HIFU transducer in water are investigated by high-speed photography. It is found that during the initial 600 micro s insonation cavitation bubble clouds organize to the "screw-like structure" or "cap-like structure". The screw-like structure is characterized by a nearly fixed tip at the geometrical focus of the HIFU transducer, and the cap-like structure is marked by a dent formed in the direction of ultrasound transmission. After 600 micro s, another two structures are recorded - "streamer structure" and "cluster structure". The streamer structure is also featured by a nearly fixed bottom position at the focus, while the cluster structure is distinguished by agglomerations of bubbles around the focus.
高强度聚焦超声（HIFU）聚焦区域内的空化泡群在HIFU治疗应用中发挥着重要作用。通过高速摄影研究了在水中1.2MHz单元素凹面HIFU换能器聚焦区域产生的空化泡群的时间演化和空间分布。研究发现，在最初600微秒的声辐射期间，空化泡群会组织成“螺旋状结构”或“帽状结构”。螺旋状结构的特征是在HIFU换能器的几何焦点处有一个几乎固定的尖端，而帽状结构的特征是在超声传播方向上形成一个凹痕。600微秒后，记录到另外两种结构——“流光结构”和“簇状结构”。流光结构的特征也是在焦点处有一个几乎固定的底部位置，而簇状结构的特征是焦点周围有气泡团聚。
