open access

https://hdl.handle.net/2115/47143

Shock wave–bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method

英語

Biological physics

2011-09-15

Physics in Medicine and Biology

56(19)

6421-6440

In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave–bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave–bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective method for elucidating the mechanism of these interactions. However, the mechanism has not been examined in detail because, at present, numerical simulations capable of incorporating the acoustic impedance of various tissues do not exist. Here, we show that the improved ghost fluid method (IGFM) can treat shock wave–bubble interactions in various media. Nonspherical bubble collapse near a rigid or soft tissue boundary (stone, liver, gelatin and fat) was analyzed. The reflection wave of an incident shock wave at a tissue boundary was the primary cause for the acceleration or deceleration of bubble collapse. The impulse that was obtained from the temporal evolution of pressure created by the bubble collapse increased the downward velocity of the boundary and caused subsequent boundary deformation. Results of this study showed that the IGFM is a useful method for analyzing the shock wave–bubble interaction near various tissues with different acoustic impedance.

学術雑誌論文

Accepted Manuscript

Copyright © (2011) IOP Publishing Ltd. This is an author-created, un-copyedited version of an article accepted for publication in [Physics in Medicine and Biology]. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version is available online at [10.1088/0031-9155/56/19/016].

0031-9155

1361-6560

AA00774048