Fast Nonlinear Modeling And Application Of Soft Tissue Deformation

Since the birth of the computer, it has been applied in every aspact of people's daily life. Computer has reached areas from scientific computing to the common entertainment. The development of computer speeds up the pace of integration among different disciplines. Mathematics, physics, biology, medicine and computer science, have had close contact now. And medical virtual surgery simulation system is a subject of all these combination.Virtual surgery system, as a kind of virtual Reality technology, and the three-dimensional modeling of human soft tissue have become important research topics in Computer Graphics. The study of soft tissue deformation is also one of the most challenging in real-time virtual surgery and human-computer interaction systems.In this article, we discuss the requirement analysis and module design of virtual surgery system, and propose detailed analysis and experiments on the soft tissue deformation and simulation in virtual surgery system. The soft tissue has non-linear characteristics. So we focus on discussing the non-linear Finite Element Method (FEM) and its improvement in order to achieve a good balance of both accuracy and efficiency of the calculation.In this research, we propose a novel hybrid approach to calculate soft tissue's deformation. It's based on classic FEM, combines the fast speed of linear model and accuracy of non-linear model. Experimental results have been given to evaluate the feasibility and efficiency. Besides, it includes the introduction of three-dimensional meshing algorithm, parallel computing by Graphics Processing Unit (GPU) to accelerate, as well as human-computer interaction technology.The main works and innovation points are described as follows:1. The detailed overview of the FEM, related mechanics theories, and numerical algorithm. Optimize the organization of solution for problems with large deformation as well as non-linear material model.2. Discussion on meshing algorithm and model selection in FEM analysis.3. We propose hybrid algorithm considering geometrical and material non-linear. And with the proper linear approximation, we could increase the efficiency of FEM solution.4. With the help of GPU parallel computing, we optimize the speed of calculation.5. We propose a rational mechanism to evaluate the simulation results. And validate the authenticity and feasibility.6. Select and optimize mesh model, program coefficient and material parameters based on experiments to find a excellent balance between efficiency and accuracy.7. Our proposed novel algorithm is successfully applied for craniofacial plastic surgery simulation. Also process stress analysis for the simulation outcome.