3D Surface Bleed Effect Simulation In Virtual Liver Surgery System

Virtual Reality Technology have applied to various fields of production and living. The liver surgery has always been a kind of difficult operation in medical surgical, due to power metabolism of liver and various kinds of vessel inside. A skilled liver surgery doctor training often needs a lot of human body trials, and the virtual liver surgery simulation system which based on virtual reality technology simulator can provide doctors with a good training platform.In virtual liver surgery system, bleed simulation is a very important part, as the surface bleeding and wound internal bleeding in liver surgery are constantly along with the whole operation process, so bleeding simulation related to the reality and completion of the whole surgery system. In this paper, we introduced the fluid dynamic model, the collision detection between blood and liver surface, the rendering of blood surface in bleed model, at the same time we carried on the experiment by combining with the several aspects of virtual liver surgery 3D surface bleeding simulation. The main content can be stated as follows:1) In the aspect of dynamic model, on the base of simplified compare to other researcher about fluid dynamics model, then for the problem of difficult to obtain the analytic solution of Navier-Stokes equation,used the method of Smoothed Particle Hydrodynamics(SPH) to get out the numerical solution. The experiment showed out, it can demonstrate well feature of bleed by method of fluid dynamics model which based on Navier-Stokes. And it can meet the demand of real time request in bleed model of virtual liver surgery system by SPH method.2) In the aspect of detection collision between particle and triangle mesh of liver surface, we introduced some common type of collision detection firstly, then according to the characteristics of fluid particle and triangle mesh of liver surface, proposed a kind of collision detection algorithm which based on 3D space grid divide, this algorithm not only achieved the collision detection and collision response between fluid particle and triangle mesh, but also can conduct collision detecting by the good cubic grid settled by SPH, which save much resource.3) In the aspect of surface rendering of blood, according to the fluid dynamics model in the article, adopted the surface tracking algorithm which based on the Marching Cubes. In addition, we simplified the algorithm upon the character of bleed simulation to improving the real-time performance, and speed-up the surface rendering on the liquid surface with GPU.The article carried on bleed simulation in virtual liver surgery by synthesizing the algorithm above all, from the two points of reality and real-time, all meet the demand of bleed simulation in virtual liver surgery.