Virtual Cornea Modeling And Research On Key Technology Of Real-Time Surgical Simulation

The modeling and simulation of virtual organ currently have become one of the frontier research areas in our world. As one of the most important and tiny organs of human body, the modeling and simulation of eye have a great significance to human world. As one of the most important part of eye, cornea, whose characteristic have a great significance to diagnosis and cure of eyes' diseases. So, the construction of virtual eye cornea has very important theory meaning and application value for the ophthalmologic physiology, pathology, and clinic.Firstly, a theoretical model has been constructed to numerically simulate the HO: YAG laser corneal thermal keratoplasty. Then the basic mathematical model of corneal anterior surface of general adult human was deducted. Based on this model, the visualization of corneal anterior surface was realized. Then, based on a sequence of eyeball slice images, a geometrical modeling method for virtual real-time surgical simulation was proposed. Lastly, the spring-mass model was applied to human eyeball; it provides an available basis for the further research on surgical simulation of virtual eyeball.The main contributions of this thesis are mainly lie in the following aspects:1. Using the parameters in practical laser corneal thermal keratoplasty, a theoretical model has been established to simulate the situation, in which the Gauss-distributed laser irradiates the surface of cornea. Then the temperature distribution of cornea was numerically simulated.2. According to the apical curvature radius and the shape coefficient of two principal meridians of corneal anterior surface collected by Guillon, using randomization, the mathematical model of corneal anterior surface of general adult human was deducted. Then make use of the characteristic of different slices, among which the number of sample point and the sample sequence are same, the visualization of corneal anterior surface was realized.3. According to the main features of biomembrane tissues, the spring-mass model for human eyeball is established. The data structure, including particles queue and half-edge data structure, and Verlet integral method which compute the displacement of particles were used to accelerate the computation of simulation procedure. The contact with virtual eyeball was realized, the basic biomembrane feature of human eyeball was simulated well.