Algorithm of position-based dynamics and cutting simulation for soft tissue using tetrahedral mesh

In order to improve the realism and real-time performance of virtual surgery technique, a cutting algorithm for soft tissue using tetrahedral mesh and position-based dynamics was proposed. Firstly, the tetrahedral mesh was chosen as the geometrical model for soft tissue, and position-based dynamics were employed as the physical model. The external surface of soft tissue was formed by the convex hull of the tetrahedral mesh. Secondly, to support the cutting simulation, we also modified the position-based dynamics method to ensure it worked well when the topology of soft tissue model changed. Moreover, the tetrahedral mesh coupled with texture information was applied for the highly-detailed incision exposure. Finally, the haptic rendering was implemented on this dissection algorithm to enhance the realism of the surgery simulation environment. The experimental result shows that the simulator works effectively and stably with this physical model, when deformation and dissection occurs. Moreover, the algorithm has been used in the virtual surgery simulator designed by State Key Laboratory of Virtual Reality Technology and Systems in Beihang University. The laparoscopic surgeons from cooperative hospitals have given a pilot study and high evaluation has been given from the doctors for this simulator.