Soft-tissue material properties under large deformation: strain rate effect.

Biomechanical model of soft tissue derived from experimental measurements is critical for developing a reality-based model for minimally invasive surgical training and simulation. In our research, we have focused on developing a biomechanical model of the liver with the ultimate goal of using this model for local tool-tissue interaction tasks and providing feedback to the surgeon through a haptic display. We are interested in finding the local effective elastic modulus (LEM) of the liver tissue under different strain rates. We have developed a tissue indentation equipment for characterizing the biomechanical properties of the liver and compared the local effective elastic modulus (LEM) derived from experimental data with plane stress, plane strain, and axisymmetric element types in ABAQUS under varying strain rates. Our results show that the experimentally derived local effective modulus matches closely with the plane stress analysis in ABAQUS.