Computational study for investigating acoustic streaming and heating during acoustic hemostasis

TL;DR

This study develops a comprehensive mathematical model to investigate acoustic streaming and heating effects during acoustic hemostasis, enhancing understanding of physical mechanisms involved in focused ultrasound blood clotting.

Contribution

It introduces a coupled 3D nonlinear model including acoustic, thermal, and hemodynamic equations with convected cooling and streaming effects for acoustic hemostasis.

Findings

Optimal focal point at rear of wound

Optimal sonication angle is 45 degrees

Model reveals key physical interactions in acoustic hemostasis

Abstract

High intensity focused ultrasound (HIFU) has many applications ranging from thermal ablation of cancer to hemostasis. Although focused ultrasound can seal a bleeding site, physical mechanisms of acoustic hemostasis are not fully understood yet. To understand better the interaction between different physical mechanisms involved in hemostasis a mathematical model of acoustic hemostasis is developed. This model comprises the nonlinear Westervelt equation and the bioheat equations in tissue and blood vessel. In the three dimensional domain, the nonlinear hemodynamic equations are coupled with the acoustic and thermal equations. Convected cooling and acoustic streaming effects are incorporated in the modeling study. Several sonication angles and two wound shapes have been studied. The optimal focal point location is at the rear of the wound and the optimal angle is 45$^0$.