Collision Characteristics And Mechanics Analysis Of The Vascular Interventional Surgery VR Training System

Minimally invasive vascular surgery(MIVS)is an emerging medical technology that uses interventional catheter and guide wire to reach the lesion through the blood vessels for diagnosis and treatment.The traditional interventional surgery training methods includes corpses,human models,animals and even patients.But all of them have some limitations,so that doctors have fewer opportunities for training and culture period of an interventional surgeon is too long.Based on this situation,this study combines computer technology with modern medical technique,and designs an interventional surgery virtual training system that provides a convenient and low-cost training way for interventional surgeon.On the basis of the developed system,this study puts forward some improvement measures,in order to improve the system of real-time,accuracy,and the concrete research content is as follows:(1)Improve the virtual environment In vascular three-dimensional modeling,We use the improved Marching Cubes algorithm to merge related points,on the premise of guarantee performance simplify the three-dimensional mathematical model of blood vessels.(2)Improved collision detection method Our local scene interception collision was proposed based on motion object detection,based on space decomposition and hybrid bounding box level improvement methods of collision detection.Improve system ultimately choose to airborne decomposition-mixed bounding box collision tests,the method can effectively shorten the time of collision detection,to better achieve real-time performance of the system.At the same time by the CPU to GPU mix calculation method to improve the application architecture.(3)Mechanical analysis and force feedback.We analyzed the contact force between the catheter and vessel and it can be divided into three kinds of force: the collision force between the catheter tip and vessel,the frictional force between catheter body and vessels,and the viscous force between the catheter and blood.Then according to the three kinds of force,we achieved catheter controlling and force feedback based on Phantom haptic device.The experiment results show that the virtual training system can control the catheter model to have some basic operations such as insertion,retraction and rotation.And it can detect the collision between the catheter model and vessel model then feedback the force to the operator.Therefore,the virtual training system can simulate the operation of interventional surgery and has a good training effect.Furthermore,it can have a realistic preoperative simulation to improve the security of the interventional surgery.