A Method for Collision Response between Deformable Objects in Virtual Surgery

Virtual surgery has drawn a lot of attention during the past few years for its repeatability and low cost. In a virtual surgical environment, collision between organs or between organs and surgical instruments occurs frequently. Therefore, an efficient and stable method is needed to simulate these collision processes. Nevertheless, contrary to rigid solid animation where complete analytical solutions have been found, simulating colliding response process between deformable objects still remains a challenge. In this paper, we present an advanced method to model collision response between tissues. It computes response force and generates an exact contact surface between colliding objects. Our method considers both geometric features such as penetration depth and physical properties such as relative velocity and friction to compute proper collision forces. Further, a breadth-first searching algorithm is applied in distributing these calculated reaction forces in different parts of the object in order to generate exact contact surface between interacting objects. Its application in a minimal invasion virtual surgery is used for case study.