Fast computation of soft tissue thermal response under deformation based on fast explicit dynamics finite element...

Area of Science:

• Biomedical Engineering
• Computational Biology
• Medical Physics

Background:

• Surgical procedures like electrosurgery and hyperthermia rely on precise thermal energy delivery.
• Soft tissue deformation during surgery and patient movement complicates accurate thermal energy distribution.
• Existing models, like the Pennes bio-heat transfer model, are limited to static tissue states.

Purpose of the Study:

• To develop a bio-heat transfer formulation that accounts for soft tissue deformation for rapid temperature prediction.
• To enable real-time or near real-time thermal analysis for immediate surgeon visualization during procedures.
• To improve the precision of thermal energy delivery in dynamic surgical environments.

Main Methods:

• A novel bio-heat transfer formulation using the fast explicit dynamics finite element algorithm (FED-FEM) for transient heat transfer.
• Transformation of deformed tissue states to initial static states via a mapping function for analysis.
• Evaluation on a virtual human liver model simulating thermal ablation of hepatic cancer.

Main Results:

• Achieved typical normalized relative errors of 10⁻³ at nodes and 10⁻⁴-10⁻⁵ for total errors, validated against commercial software.
• Demonstrated computational efficiency with a processing time of 2.518 × 10⁻⁴ ms per element for deformation analysis.
• Showcased performance improvements compared to formulations without deformation and for isotropic properties.

Conclusions:

• The proposed formulation prioritizes computational performance for fast tissue thermal analysis, unlike conventional methods.
• It enables rapid thermal analysis of deformed tissues, overcoming limitations of the classical Pennes model.
• Offers significant translational potential for dynamic tissue temperature analysis and thermal dosimetry in personalized medicine and surgical training.