Force-Based Calibration of a Particle System for Realistic Simulation of Nonlinear and Viscoelastic Soft Tissue Behavior

We present a new approach for realistic visio-haptic simulation of nonlinear and viscoelastic behavior of an organ tissue using a particle model. The spring and damper coefficients of the particle model are calibrated using a derivative-free optimization technique such that its behavior mimics the behavior of a corresponding finite element (FE) model. In our approach, we first conduct static indentation and stress relaxation experiments on the FE model to record a) force versus displacement and b) force versus time responses of the surface nodes, respectively. We then use these data sets to calibrate the spring and damper coefficients of the particle model such that its force response is similar to that of the FE model. To test the feasibility of our approach, we compare the static and dynamic behavior of the particle model to that of the FE model under the influence of gravity.