Single-bubble dynamics in histotripsy and high-amplitude ultrasound: Modeling and validation

TL;DR

This study validates various bubble dynamics models against experimental data for histotripsy bubbles, showing simple models with inferred waveforms can accurately predict bubble behavior with minimal computational complexity.

Contribution

The paper introduces a strategy to infer histotripsy waveforms from experimental data and validates simple bubble models, demonstrating their effectiveness in representing bubble dynamics.

Findings

Minimal difference (<1%) among models for compressibility and thermal effects.

Inferred waveforms enable accurate modeling of bubble dynamics.

Simple models suffice for accurate predictions near maximum bubble radius.

Abstract

A variety of approaches have been used to model the dynamics of a single, isolated bubble nucleated by a microsecond length high-amplitude ultrasound pulse (e.g., a histotripsy pulse). Until recently, the lack of single--bubble experimental radius vs. time data for bubble dynamics under a well-characterized driving pressure has limited model validation efforts. This study uses radius vs. time measurements of single, spherical histotripsy-nucleated bubbles in water [Wilson et al., Phys. Rev. E, 2019, 99, 043103] to quantitatively compare and validate a variety of bubble dynamics modeling approaches, including compressible and incompressible models as well as different thermal models. A strategy for inferring an analytic representation of histotripsy waveforms directly from experimental radius vs. time and cavitation threshold data is presented. We compare distributions of a calculated validation metric obtained for each model applied to $88$ experimental data sets. There is minimal distinction ($< 1\%$) among the modeling approaches for compressibility and thermal effects considered in this study. These results suggest that our proposed strategy to infer the waveform, combined with simple models minimizing parametric uncertainty and computational resource demands accurately represent single-bubble dynamics in histotripsy, including at and near the maximum bubble radius. Remaining sources of parametric and model-based uncertainty are discussed.