Research On Soft Tissue Deformation Modeling And Collision Detection In Virtual Surgery

With the rapid development of virtual reality technology and the continuous improvement of clinical medical level,virtual surgery simulation system has become an indispensable auxiliary tool in surgical training,intraoperative navigation,surgical plan formulation and operation outcome prediction.However,the research of virtual surgery simulation system is one of the most interdisciplinary frontiers of technology,so it is difficult to study.As a core part of the virtual surgery simulation system,soft tissue deformation simulation modeling method of highly realistic research has important significance to break the restrictions,the traditional surgical training in the development of the best operation scheme and improve the success rate of the operation.Therefore,in this paper,the simulation modeling method of organism soft tissue deformation in virtual surgery simulation system is taken as the research content,and focuses on the visual authenticity and real-time performance of organism soft tissue deformation.The main works are as follows:First,this paper studies the biomechanical properties of human soft tissue and describes several widely-used viscoelastic models,which laid the theoretical foundation for further study of realistic soft tissue deformation modeling.And studies the method of the human soft tissue model obtained by Amira software.Secondly,this paper proposes a method of constructing soft tissue deformation simulation model based on filling model.A series of filling models with mass,inertia and volume characteristics are defined.The model of the filling body is connected by springs and the particle springs of the model surface are mixed together to form the soft tissue simulation model.It not only solves the defects of the traditional particle spring,reduces the amount of calculation in the process of virtual surgery soft deformation,but also increases the real-time performance.The model concept,theory and practice show that the model is simple and practical,and the effect is better than the others.Again,this paper proposes the Sphere and AABB based hybrid hierarchy bounding box tree to accelerate the intersection detection between virtual surgical instrument and soft tissue.Corresponding experimental results show that the proposed hybrid hierarchy bounding box method can improve the efficiency of collision detection.Finally,the paper builds a simple virtual operation simulation platform based on the related theory,and carries out the corresponding simulation experiment analysis.Simulation results show that the mass spring and filling algorithm to construct a software model and body model combined with Sphere and AABB hybrid hierarchical bounding box based method to acertain extent to meet biological soft tissue deformation simulation in virtual surgery simulation system based on the requirements of the proposed and verified the superiority of the method proposed in this paper are verified.