High-fidelity computational analysis of ultrasound-induced cavitation in tissue

Project description

High-intensity focused ultrasound (HIFU) and extra-corporeal shock wave therapy (ESWT) are becoming popular as an alternative to complex surgeries for treating cancerous tumors vital organs, kidney stones, and musculoskeletal disorders to name a few. However, the microscale details of HIFU and shock-induced destruction of tissue are not well understood. It is speculated that the bubble nucleation followed by their expansion and collapse under the action of focused ultrasound and shock wave cause stress localization and consequently mechanical disintegration of tissue in the targeted region. However, it is challenging to study acoustically driven bubble dynamics in tissues through experiments due to the small time and length scales of the phenomenon. In this project, we will develop a 3D computational fluid dynamics model of cavitation in tissue to further understand the mechanisms of tissue destruction during HIFU and ESWT therapies. The tissue will be treated as a compressible viscoelastic material. The bubble interfaces will be tracked using the volume of fluid approach. The high-performance computing facilities will be utilized to perform the high-resolution calculations of bubble-cluster interaction with non-linear acoustic and shock waves. The objective of these calculations is to study the microscale phenomena such as the interactions between oscillating bubbles in tissue in an acoustic field, and the formation of shocklets and high-speed microjets during the violent asymmetric collapse of the bubbles near tissue boundaries, which are otherwise challenging to study through experiments. These calculations will reveal microscale details of the mechanisms of tissue destruction through HIFU and shock-induced cavitation which will help us further optimize these treatment procedures and suppress collateral damage to the healthy tissue during treatment.

Outcomes

1. A computational model of non-linear wave and shock interaction with bubbles in a viscoelastic medium
2. Identification of mechanisms of shear-localization due to acoustically driven cavitation in tissues
3. Guidelines for operating parameters of HIFU and ESWT to avoid unwanted injury.

Essential capabilities

Strong understanding of fluid mechanics, Strong understanding of numerical methods

Desireable capabilities

Experience with compiled code, Open-source software development, Knowledge of compressible flows, finite difference/finite volume methods

Expected qualifications (Course/Degrees etc.)

Masters degree in Mechanical Engineering, Aerospace Engineering, Chemical Engineering, Mathematics or similar