Coupling of element-free Galerkin and mass-spring for deformation simulation of soft tissue

Simulation for the soft tissue deformation is a key technique in the virtual surgery. Addressing the issues existed in the simulation for the soft tissue deformation in the virtual surgery, a coupling deformable model integrating the element-free Galerkin (EFG) with the mass-spring (MS) based on viscoelastic mechanics equations was proposed. The EFG was used to model material behavior close to large deformation or topology change and the MS was used in area away from large deformation. In the interface area of two regions, some transitional elements including transitional joint points were built. Seamless connection of two regions was realized according to the balance conditions of forces and displacements that should be satisfied by transitional joint points. The experimental simulation results of the human liver show that the proposed methodology is valid.