Research And Application On Real-time Deformation Technology Based On Finite Element Method

Deformation simulation is a technology that uses computer technology to simulate the process ofan object deforming under the effect of force with suitable accuracy and real-time. Finite elementmethod with performed physical foundation, is particularly applicable to the situations which needaccurate simulation, such as virtual surgery simulation and so on. The only drawback is the largeamount of calculation. Virtual surgery not only can bring more practicing resources to doctors, butalso reduce training cycle and training cost. The difficulty of obtaining a living tissue makes corneavirtual surgery a more impending domain to develop and research in the field of virtual surgery.Firstly, the thesis parameterized establishes the finite element model of human eye, and simulatesthe human eye under IOP, pressed by the instrument, and acupunctured. Then, to speed up thesimulation, we simplify the model, and construct a local finite element model and an improved finiteelement model. Finialy, the mass-spring model of cornea is established. and its facticity and real-timeperformance are compared with the finite element model. The ultimate goal is to provide suitablemodel for corneal virtual surgery. The main research contents are listed as follows:(1) We analyse the key technologies, and hardware system and software system of cornea virtualsurgery. We focus on the principle and calculation model of deformation simulation by using finiteelement model in virtual surgery.(2)We discuss the physiological structure and mechanical property of human eye, and build athree-dimensional finite element model on the clinical data. The model is feasible by contrasting thesimulation data with the test data.(3) The method constructing local calculation model is proposed, which effectively reduces thecomputing complexity of real-time simulation. The local finite element model of cornea and part ofsclera is built, and we make the model optimized to strike the best balance between cost and accuracy,and improve the speed of contact deformation simulation. Considering that the cutting or stitching ofcorneal sugery in a particular area, we build an improved scheme of an interactive finite elementmodel, which reduces the computing complexity of acupuncture simulation.(4) Based on CHAI3D, we build the corneal model using a improved mass-spring method. Thefacticity and real-time performance are compared between FEM and mass-spring simulation,indicating that finite element model is more suitable for the virtual surgery simulation.