Towards real-time finite-strain anisotropic thermo-visco-elastodynamic analysis of soft tissues for thermal ablative therapy

TL;DR

This paper introduces a GPU-accelerated, fully coupled nonlinear finite element method for real-time simulation of anisotropic, finite-strain, thermo-viscoelastic soft tissue behavior during thermal ablation, enhancing treatment planning accuracy.

Contribution

It presents the first fully coupled nonlinear thermo-viscoelastic finite element algorithm for soft tissues, enabling real-time simulation with GPU acceleration for thermal ablation applications.

Findings

Enables accurate modeling of anisotropic, finite-strain tissue behavior.

Achieves real-time computation speeds suitable for clinical use.

Demonstrates improved prediction of ablation zones in liver simulations.

Abstract

Accurate and efficient prediction of soft tissue temperatures is essential to computer-assisted treatment systems for thermal ablation. It can be used to predict tissue temperatures and ablation volumes for personalised treatment planning and image-guided intervention. Numerically, it requires full nonlinear modelling of the coupled computational bioheat transfer and biomechanics, and efficient solution procedures; however, existing studies considered the bioheat analysis alone or the coupled linear analysis, without the fully coupled nonlinear analysis. We present a coupled thermo-visco-hyperelastic finite element algorithm, based on finite-strain thermoelasticity and total Lagrangian explicit dynamics. It considers the coupled nonlinear analysis of (i) bioheat transfer under soft tissue deformations and (ii) soft tissue deformations due to thermal expansion/shrinkage. The presented method accounts for anisotropic, finite-strain, temperature-dependent, thermal, and viscoelastic behaviours of soft tissues, and it is implemented using GPU acceleration for real-time computation. We also demonstrate the translational benefits of the presented method for clinical applications using a simulation of thermal ablation in the liver. The key advantage of the presented method is that it enables full nonlinear modelling of the anisotropic, finite-strain, temperature-dependent, thermal, and viscoelastic behaviours of soft tissues, instead of linear elastic, linear viscoelastic, and thermal-only modelling in the existing methods. It also provides high computational speeds for computer-assisted treatment systems towards enabling the operator to simulate thermal ablation accurately and visualise tissue temperatures and ablation zones immediately.