INTEGRATION OF GEOMETRICAL BOUNDARY CONDITIONS ON SOFT TISSUE CHARACTERIZATION UNDER LARGE DEFORMATION

Abstract

Soft tissue characterization with finite element (FE) modeling is important to develop a realistic model for medical simulation, since it is possible to display complex tool-tissue interactions during medical interventions. However, it is difficult to integrate large deformation and geometrical boundary conditions to the FE computations. In this paper, the force responses and surface deformation fields of the tissues against the indentation were measured by a force transducer and three-dimensional optical system. Large indentation experiments on porcine livers were performed to estimate the radius of influence and to measure the force response. The radius of influence was plotted against depths and indenter shapes, which could be used to determine the model size for the characterization. The tissue behavior of large deformation considering influence of the boundary conditions was characterized with FE modeling via hyperelastic and linear viscoelastic model.