Research On Soft Tissue Deformation Technology In Virtual Surgery

Virtual surgery system is a product of the virtual reality technology combined with modern medicine, by establishing the visual displaying, touching, hearing and smelling. With the help of multi-awareness virtual surgery environment, the surgery trainees can be given a very vivid surgery scene to realize surgery training and three-dimensional operation scheme making. A typical virtual surgery system contains soft-tissue modeling, collision detection,+deformation calculation, cutting calculation, graphics rendering and touching rendering. The research of visual surgery system exist a conflict between the accuracy of simulation and the computing time. Researchers are been the challenge that how to balance the contradiction. In this paper, deformation calculation is deeply studied, which is Common and representative in visual surgery simulation. The main work is as follows:Firstly, the biomechanical properties of soft tissue are analyzed from the point of mechanics, linear elastic model and viscoelastic model are introduced in detail, and the scope of their application.Secondly, using three-dimensional Delaunay mesh generation algorithm to mesh the soft tissue model. For the judgement of the grid quality, this paper proposes a fast and effective judgment criteria.Thirdly, this paper proposes a new idea that use the local model to replace the whole model, the idea does a good job in solving the problem of poor real-time performance when we use the finite element method to calculate the deformation of soft tissue. And the digraph matrix is used to extract local model from the whole soft tissue model.Finally, this paper makes optimization of the finite element method and simulates deformation of the soft tissue. The contrast experiment proves that our algorithm improves the calculation speed and affects a little of the calculation accuracy.