Ligaturing Simulation Of Blood Vessel In Virtual Simulation Training System Of Liver Surgery

Virtual surgery combines surgical operation with virtual reality,and it is an important application of computer graphics in the field of modern medicine.With the development of computer technology and virtual reality technology,virtual surgery has played an increasingly important role in medical education and training now.Virtual surgery provides the surgeon with a safe and lowcost medical surgery training method,and many institutions at home and abroad have carried out extensive research in this field.Virtual Simulation Training System of Liver Surgery is for liver surgery training.The system can provide effective training for liver surgery surgeon.In Virtual Simulation Training System of Liver Surgery,ligaturing blood vessel of liver is of critical importance for the success of a liver surgery.The focus of this thesis lies in the ligaturing simulation of Virtual Simulation Training System of Liver Surgery.Ligaturing simulation consists of five parts: vision,haptics,suture simulation,collision detection,deformation and haptic feedback.In order to simulate the blood vessel ligaturing of the system,firstly,FTL(Follow The Leader)algorithm is employed to configure the motion of suture,“Safe margin parameter” is used to achieve the “equivalent friction” of suture,then Cardinal spline is employed to smooth suture for a better visual effect.An improved method is proposed for collision detection in ligaturing simulation,the improved method mainly contains three parts: self-collision detection of suture and collision detection between suture and blood vessel.Specifically,BVH method(Sphere)is employed to handle the self-collision detection of suture,motion decomposition method is proposed to prevent penetrations of suture,and BVH method is integrated with grid method to handle the collision detection of suture and blood vessel.Moreover,a rigid core is employed to limit the deformation of blood vessel,and haptic feedback is implemented by a novel way which is based on the deformation of blood vessel.Based on the above work,a blood vessel ligaturing simulation algorithm is proposed and applied to Virtual Simulation Training System of Liver Surgery.The simulation result shows that the proposed algorithm is efficient and realistic.