Real Time Techniques for Nonlinear Tissue Deformation in Surgical Simulation

The requirement of real time performance, crucial to multimodal surgical simulations, imposes severe demands in terms of computational efficiency. A physics-based meshfree computational technique known as the Point-Associated Finite Field (PAFF) approach has been developed to circumvent many outstanding problems associated with traditional mesh-based computational schemes and has been applied in this paper to the modeling of geometrically nonlinear tissue deformations. The technique is based on a novel combination of multiresolution approach coupled with a fast reanalysis scheme in which the response predicted by an underlying linear PAFF model is enhanced in the local neighborhood of the surgical tool-tip by a nonlinear model. We present performance comparisons of PAFF with traditional finite element models.