Real-time VR Simulation of Laparoscopic Cholecystectomy based on Parallel Position-based Dynamics in GPU

In recent years, virtual reality (VR) based training has greatly changed surgeons learning mode. It can simulate the surgery from the visual, auditory, and tactile aspects. VR medical simulator can greatly reduce the risk of the real patient and the cost of hospitals. Laparoscopic cholecystectomy is one of the typical representatives in minimal invasive surgery (MIS). Due to the large incidence of cholecystectomy, the application of its VR-based simulation is vital and necessary for the residents' surgical training. In this paper, we present a VR simulation framework based on position-based dynamics (PBD) for cholecystectomy. To further accelerate the deformation of organs, PBD constraints are solved in parallel by a graph coloring algorithm. We introduce a bio-thermal conduction model to improve the realism of the fat tissue electrocautery. Finally, we design a hybrid multi-model connection method to handle the interaction and simulation of the liver-gallbladder separation. This simulation system has been applied to laparoscopic cholecystectomy training in several hospitals. From the experimental results, users can operate in real-time with high stability and fidelity. The simulator is also evaluated by a number of digestive surgeons through preliminary studies. They believed that the system can offer great help to the improvement of surgical skills.