Quasi-non-linear deformation modeling of a human liver based on artificial and experimental data

Background: Researchers working on error-prevention theories have shown that the use of replica models within simulation systems has improved operating skills, resulting in better patient outcomes. Methods: This study aims to provide material test data specifically for a human liver to validate the accuracy of viscoelastic soft tissue models. This allows the validation of virtual surgery simulators by comparison with physical test data obtained from material tests on a viscoelastic silicone gel pad. Results: The results proved that stress behavior and relaxation curves of Aquaflex® experiment and FEM simulation are close if average liver response and respective material parameters and model are used. Conclusions: The precise representation of manipulated tissues used in virtual surgery trainers involves the accurate characterization of mechanical properties of the tissue. Consequently, successful implementations of these mechanical properties in a mathematical model of the deforming organ are of major importance.