Shock wave-bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved...

Area of Science:

• Biomedical Engineering
• Acoustic Physics
• Computational Fluid Dynamics

Background:

• Extracorporeal shock wave lithotripsy (ESWL) involves shock wave-bubble interactions causing stone fragmentation and potential tissue damage.
• Understanding these high-speed phenomena in heterogeneous tissues is crucial but limited by current numerical simulation capabilities.

Purpose of the Study:

• To introduce and validate the improved ghost fluid method (IGFM) for analyzing shock wave-bubble interactions in various tissue-like media.
• To elucidate the mechanism of bubble collapse and its impact on tissue boundaries during ESWL.

Main Methods:

• Numerical simulation using the improved ghost fluid method (IGFM).
• Analysis of nonspherical bubble collapse near boundaries with differing acoustic impedances (stone, liver, gelatin, fat).

Main Results:

• The IGFM successfully modeled shock wave-bubble interactions across various media.
• Incident shock wave reflection at tissue boundaries significantly influenced bubble collapse dynamics.
• Bubble collapse generated impulses that deformed the tissue boundary.

Conclusions:

• The IGFM is a valuable tool for simulating shock wave-bubble interactions near diverse tissues.
• This method advances the understanding of ESWL mechanisms, potentially leading to improved treatment strategies and reduced tissue damage.