Implementation of a thermomechanical model to simulate laser heating in shrinkage tissue (effects of wavelength, laser irradiation intensity, and irradiation beam area)

Coupled thermo-electro-mechanical models for thermal ablation of biological tissues and heat relaxation time effects

“…Existing experimental studies available in literature have highlighted that the exposure of biological tissue to elevated temperatures (> 50 o C) during thermal ablative procedures can result in varying degree of mechanical deformation (including both expansion and contraction) within the tissue [24][25][26][27][28][29][30][31][32][33][34][35][36]. Several computational studies have also been reported to capture such mechanical deformations, but mainly limited to only thermal expansion [37][38][39][40][41][42][43]. Importantly, ignorance of the impact of tissue contraction/shrinkage during thermal ablative procedures has resulted in significant underestimation of the predicted ablation volume (see, e.g.…”

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

“…The displacements 𝐔(𝐱) 𝑡+∆𝑡 at the next time step can be computed based on the explicit central-difference scheme [63], yielding (23) where 𝐟 𝑒 𝑡ℎ𝑒𝑟−𝑒𝑙𝑎𝑠 is the vector of nodal forces due to thermal and elastic stresses in an element 𝑒, and 𝐟 𝑡ℎ𝑒𝑟−𝑒𝑙𝑎𝑠 is the vector of global nodal forces. 𝐟 𝑒 𝑡ℎ𝑒𝑟−𝑒𝑙𝑎𝑠 0 𝑡 can be computed by…”

“…Most of the reported methods [20,21] were focused on sophisticated thermo-elastic models but failed to consider computational speed where solutions are often computationally expensive to obtain (e.g., Kröger et al [22] reported a simulation of an 8 minutes RFA in three-dimensional (3D) space took about 6 hours). Some studies were focused on solely the steady-state thermo-elastic analysis [23], which ignored the transient thermo-elastic response of soft tissues in dynamics. Finally, some works considered only homogeneous and isotropic material properties with linear thermo-elasticity [21,23] or linear thermo-visco-elasticity [24].…”

“…Some studies were focused on solely the steady-state thermo-elastic analysis [23], which ignored the transient thermo-elastic response of soft tissues in dynamics. Finally, some works considered only homogeneous and isotropic material properties with linear thermo-elasticity [21,23] or linear thermo-visco-elasticity [24]. As a result, these works did not describe anisotropic viscoelastic properties of soft tissues and are incompatible with the nonlinear problem of soft tissues undergoing large deformations where geometric and material nonlinearities are involved.…”

Thermomechanical Modeling of Laser Ablation Therapy of Tumors: Sensitivity Analysis and Optimization of Influential Variables

“…For instance, Wong Chadakul et al (2018) developed a numerical model based on the finite element method (FEM) for thermal-mechanical deformation of 3-layered skin during laser-induced thermotherapy. They presented optimum skin treatment conditions by varying the wavelength, laser irradiation intensities, irradiation beam area, and blood perfusion rate [14]. Keangin et al (2019) presented a simulation for liver cancer treated using a microwave coaxial antenna and included the deformation analysis to approach realistic tissue modeling [15].…”