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

Jinao Zhang; Remi Jacob Lay; Stuart K Roberts; Sunita Chauhan

doi:10.1016/j.cmpb.2020.105789

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

Comput Methods Programs Biomed. 2021 Jan:198:105789. doi: 10.1016/j.cmpb.2020.105789. Epub 2020 Oct 8.

Authors

Jinao Zhang¹, Remi Jacob Lay², Stuart K Roberts³, Sunita Chauhan⁴

Affiliations

¹ Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, Australia. Electronic address: Jinao.zhang@monash.edu.
² Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, Australia.
³ Department of Gastroenterology, The Alfred Hospital, Melbourne, Victoria, Australia.
⁴ Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, Australia. Electronic address: Sunita.chauhan@monash.edu.

PMID: 33069033
DOI: 10.1016/j.cmpb.2020.105789

Abstract

Background and objectives: 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.

Methods: 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.

Results: The presented method can achieve thermo-visco-elastodynamic analysis of anisotropic soft tissues undergoing large deformations with high computational speeds in tetrahedral and hexahedral finite element meshes for surgical simulation of thermal ablation. We also demonstrate the translational benefits of the presented method for clinical applications using a simulation of thermal ablation in the liver.

Conclusion: 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.

Keywords: Bioheat transfer; Biomechanics; Finite-strain thermo-visco-elastodynamics; Surgical simulation; Thermal ablation.

MeSH terms

Algorithms
Anisotropy
Computer Simulation
Finite Element Analysis
Hyperthermia, Induced*
Models, Biological*