Research And Application On Digital Modeling And Deformation Simulation Technology

Digital modeling is a technology using virtual digital model to describe the geometric shape,structure and properties of a real object in computer system which is widely applied in the fields ofvirtual manufacturing, virtual assembly, animation and so on. Deformation simulation is a technologythat uses computer technology to simulate the process of an object deforming under the effect of forcewith suitable accuracy and real-time according to the application situations. The gradual maturity ofthe two technologies above makes a brand new field of virtual surgery developing rapidly.Virtual surgery can bring more practicing resources to doctors, reduce training cycle and trainingcost. The difficulty of obtaining a living tissue makes cornea virtual surgery a more impendingdomain to develop and research in the field of virtual surgery.Based on geometric modeling, physical modeling and deformation simulation, the keytechnologies of cornea virtual surgery are studied. The main research contents are listed as follows:(1) Digital modeling and deformation simulation technology is studied. A cornea virtual surgerysystem is designed generally including hardware system and software system.(2) The key technologies of cornea virtual surgery are studied including geometric modeling,physical modeling, numerical calculating algorithms, collision detection and force feedback.(3) A personalized cornea geometric modeling is proposed which uses the precise3D point clouddata obtained from corneal topography to build the cornea surface. A novel physical modeling ofcorneal deformation is proposed using a supporting ball-spring model. Proper physical laws andnumerical solution are chosen to solve cornea displacement to realize its deformation simulation.(4) AABB and SBB collision detection methods are used to implement collision detectionbetween cornea and virtual surgery instrument. Force feedback between cornea and virtual surgeryinstrument is realized under the help of Falcon force feedback device.A cornea virtual surgery simulation experiment platform is put up based on the related researchabove which is verified to provide the technical basis for developing a commercial cornea virtualsurgery system in the future through a series of tests, the results of which are satisfied therequirements of a cornea virtual surgery.