The Research Of The Bleeding Model Based On Particle System In The Virtual Surgery Simulation System

With the continuous research of the Virtual Reality Technology among researchers in many countries, this technology has been widely used in many domains in our society and we will immediately use it in our daily life. Virtual surgery simulation system is an important applicant application of Virtual Reality Technology in medical education. This system not only can provide the junior doctors with a training platform, but also can provide surgeons with a platform with which surgeons can make a surgical planning and do a risk assessment before operations. Therefore, many researchers both in foreign countries and in China devote themselves to simulate a verisimilar virtual surgery context in computer. Meanwhile, during the operation, the bleeding in those organs and tumors is inevitable and the bleeding model can not only increase the fidelity, but also help junior doctors to train their abilities in dealing with bleeding, so we should pay enough attention to the bleeding model in virtual surgery simulation. Through the analysis of other models related to the bleeding model, the dynamics simulation of blood flow as well as the surface render, the bleeding model in virtual surgery simulation system is analyzed in this paper. The detailed content of dissertation is as following:This paper begins with the introduction other parts which are related to the bleeding model in the virtual surgery simulation system. These parts include the haptic devices and the design of their drivers, collision detection algorithm, the method of getting the data of the rumor, suction model. This chapter explains the implement process of bleeding model in virtual surgery simulation from the view of the system.After that, this paper introduces a kinematic simulation method-Smoothed Particle Hydrodynamics(SPH). This method starts with the search of a particle’s neighbouring particles, and then getting this particles’ s density, intensity of pressure, pressure and viscous force. After getting this particle’s resultant force, we can easily know the position of this particle in the next frame. When integrated into this system, this algorithm have a negative effect on the real-time performance and will allocate too much memory. In order to solve this problem, this paper combines this algorithm with space gridding method to find neighboring particles and Height Field. Through these methods, this paper finishes the implement of real-time simulation on the premise of verisimilitude.Then we also need to render the surface of the blood in the virtual surgery simulation system. In this paper, we adopt a fast and easy fluid reconstruction method called Marching Cubes. The cubes which are close to the fluid surface should be found at first through achieving iso-surface, and then the vertexs of triangles in these cubes will be obtained through linear interpolation. Similarly, this method will have a severe impact on the real-time requirement when it is integrated into this system directly, this paper just calculate the cubes nearby those particles instead of calculating all of the cubes to improve the calculating speed. Besides, a texture mapping algorithm is used in this model to improve the render effect.At last, this paper shows some experimental results, including some pictures and some experimental data and does an analysis of data.