Design And Implementation Of Virtual Liver Surgery System

As a new cross technology,virtual reality technology is widely used in many fields.Virtual surgery system is a typical application of virtual reality technology in the field of medicine.With the rapid development of virtual reality technology,virtual surgery has become a hot research topic,virtual surgery can be helpful for preoperative planning,intraoperative guided surgery and surgical skills training,however,due to the limitation of the development of computer software and hardware and the immaturity of key technologies,virtual surgery simulation has shortcomings in authenticity,real-time and accuracy.In this paper,the soft tissue modeling,collision detection algorithm and tactile interaction in virtual surgery system are deeply studied,The main research contents are as follows:Firstly,in order to present realistic visual effect,high-precision mesh model is used for visual rendering,however,the high-precision mesh model will increase the difficulty of calculation,so tetgen is used to divide the simplified surface triangular mesh into tetrahedral model to calculate the deformation.Several commonly used software deformation algorithms are analyzed and compared.Position based dynamics algorithm is selected as the software deformation algorithm in this paper,and the principle of the algorithm is studied.Position based dynamics algorithm is used to realize the deformation simulation of liver and other soft tissues.Secondly,the principle and application scope of traditional collision detection algorithms are analyzed and compared,a hybrid hierarchical bounding box tree algorithm combining AABB bounding box and OBB bounding box is used to detect the collision between virtual surgical instrument and soft tissue model,the top-down retrieval method is used to effectively reduce the time complexity and ensure the real-time and accuracy of the simulation interaction system.Thirdly,the common force feedback algorithm is analyzed,the improved Euler algorithm is selected as the calculation method of the force feedback model in this system,the tactile interaction is realized by Geomagic touch force feedback device.This algorithm has the advantages of short execution time and high computational efficiency,and improves the authenticity and fluency of tactile feedback.Finally,a virtual liver surgery system with tactile feedback is built,the human-computer interaction between users and the system is realized,through the force feedback device to control the virtual surgical instrument,the deformation simulation experiments and time efficiency analysis of the soft tissue model were carried out,the interactive simulation results show that the system has the characteristics of realistic visual effect,high stability,smooth operation,timely force feedback and so on.