A Modified Mixed Domain Method for Modeling Acoustic Wave Propagation in Strongly Heterogeneous Media

TL;DR

This paper introduces a modified mixed domain method (MMDM) with phase correction, amplitude compensation, and multiple reflections to improve acoustic wave modeling accuracy in strongly heterogeneous media, such as biological tissues.

Contribution

The paper presents a novel MMDM that enhances wave propagation modeling accuracy in complex media by incorporating phase correction, amplitude compensation, and multiple reflections.

Findings

MMDM outperforms previous methods in accuracy for strongly heterogeneous media.

Second-order reflections are sufficient for modeling in lossy biological tissues.

The method is applicable to therapeutic ultrasound in brain treatments.

Abstract

In this paper, phase correction and amplitude compensation are introduced to a previously developed mixed domain method (MDM), which is only accurate for modeling wave propagation in weakly heterogeneous media. Multiple reflections are also incorporated with the one-way model to improve the accuracy. The resulting model is denoted as the modified mixed-domain method (MMDM) and is numerically evaluated for its accuracy and efficiency using two distinct cases: a layered medium and a human skull. It is found that the MMDM is significantly more accurate than the MDM for strongly heterogeneous media, especially when the phase aberrating layer is roughly perpendicular to the acoustic beam. Additionally, convergence study suggests that the second-order reflection is sufficient for wave modeling in lossy biological media. The method developed in this work could be used to facilitate therapeutic ultrasound for treating brain-related diseases and disorders.