Soft Tissue Ablation Model for Surgical Simulation by Applying a Combination of Multiple Hypotheses

This study aimed to provide a simulation model for virtual ablation of soft tissue, focusing on simulating soft tissue deformation and destruction. The authors applied two hypotheses, the maximum shear stress hypothesis and the crack stress hypothesis, to simulate soft tissue rupture progression based on stress distribution. This combination of hypotheses realizes dynamic definition of the direction of rupture progression. The proposed model also supports multiple sources of manipulation, i.e. two or more hands working on the tissue simultaneously, because the direction definition algorithm requires only the stress distribution of the entire object. The simulation model was implemented on a thin square board model. The first experiment evaluated the direction of rupture progression when the board model was expanded at two manipulation points. The second experiment compared the simulated crack progression with crack progression in a silicon rubber. The third experiment assessed the length of rupture progression resulting from the same force applied to different positions. The fourth experiment evaluated the effect of rupture direction related to pressures. The final experiment was conducted to estimate the calculation time required for the rupture model to run. The simulations revealed that final crack length is strongly affected by the preset crack length. A similar phenomenon occurs in real-world crack progression. Also, the direction of rupture progression is affected plausibly by manipulations. Therefore, the authors conclude that the proposed model accurately represents the dynamic ablation of soft tissue.