Soft Tissue Deformation Simulation And Parallel Accelerating Method In Virtual Surgery

Virtual operation is a concrete application of virtual reality in medicine,technology and virtual surgery is a multidisciplinary integration of complex technology,a complete set of its content can be used in the practical work of virtual surgery system covers all research fields,such as computer software and hardware,biological,medical,mechanics,etc.In virtual surgery training in recent years,virtual autopsy,the respect such as telemedicine development is very rapid,especially surgery training system has received the widespread attention.Virtual operation training system is designed to provide a doctor a realistic virtual environment,let the doctor in the virtual environment of operation objects with natural physical properties for various surgical training operation,with the promotion of the clinical medical level of medical staff,provide a reference for the real operation,etc.Here the so-called realistic virtual environment and virtual surgery with physical properties of the implementation of the object needs to depend on the key technology of virtual surgery system namely,physical modeling and collision detection.Physical modeling and real-time performance,stability and accuracy of collision detection is a virtual surgery system can reach the important index that surgery training effect,the main content of this article is also around the physical modeling and collision detection technology of real-time,stability and accuracy to expand.This article on physical modeling and the improvement of real-time collision detection using the GPU acceleration,so you need to introduce the development situation of the GPU,and general computing framework based on GPU CUDA,for subsequent use by physical modeling and collision detection of GPU acceleration method.Physical modeling of the object software surgery is the main content of this article.In virtual surgery system,for a variety of physical modeling method of the software,is one of the most commonly used particle-Spring(Mass-Spring Model,among MSM)with FEM(Finite Element Model and FEM)method,both have its advantages and disadvantages.Particle spring system is characterized by simple physical principle,the advantage of high real-time performance,stability and accuracy but it is hard to meet the complex soft tissue deformation features,when the soft tissue large deformation occurs,there will be a distortion even difficult to recovery of deformation.The finite element method has the advantage of high stability,accuracy,the physical mechanism is more complicated,but its solving calculation takes longer,resulting in real time is difficult to meet the requirements of large-scale operation scene.Based on the finite element method in the process of physical modeling of the disadvantage of not high to improve the real-time performance,using the way of finite element solving process of the GPU acceleration sparse matrix vector multiplication is optimized,make the improved finite element method in deformation under the condition of invariable effect greatly increase the real-time performance of the system.Secondly,this article on how to use the GPU acceleration method to improve the performance of collision detection was explored.According to different bounding box method is applicable to different basic figure yuan rate characteristics of the collision situation by the intersection in advance collision detection stage is proposed using the AABB bounding box method,the experimental results prove that the number of triangles yuan objects in virtual surgery more cases,this algorithm is compared with the traditional method of collision detection based on CPU method has higher detection efficiency,reduces the time consuming of collision detection module.In the last part of this article introduces the use of image 3 d reconstruction system Amira soft tissue liver model is established,and process based on OpenGL using collision detection and physical modeling method proposed in this paper set up the liver virtual surgery system simulation experiment,the experiment the effect of deformation and good real-time performance meet the requirement of the simulation of virtual surgery system,and to verify the physical modeling method in this paper,the finite element of CUDA and hierarchical bounding box collision detection method is effective,real-time,virtual surgery training can be applied to the actual system.