Abstract: An anti-reversal FEM model is proposed.A relationship between compression ratio and pressure within compressed element is introduced in the constitutional equation. In the model elastic energy of an element is a polynomial function of nodal displacement.It simplifies evaluation in the conjugate gradient method and improves efficiency.It shows that the method is applicable to real-time simulation of soft tissues under large deformation.

Key words: deformable model, finite element method (FEM), real-time simulation, virtual surgery