The Implementation Of Key Modules In Virtual Surgery System

Those technologies employed in endoscopic surgery are very complicated, so they are difficult to grasp for most doctors even those who have many years of surgical experiences. Therefore a long-term and rigorous training is very necessary. Almost all endoscopic images are two dimensional, which cause the loss of depth information. In this situation, most doctors can't locate a surgical instrument to the exact position. And as one of the most common operations, suture is a basic skill that every doctor must master, especially the suture operation under the endoscope which requires doctors to clip a needle to sew the wound. However, under the endoscope, needle is too fine to be distinguished, which greatly increases the difficulties to complete the suture operation. What's more, the location information obtained from the endoscope doesn't match the factual information, so tying a knot is even harder.Virtual Reality(VR) is a new technology which tries to generated a kind of virtual environment and allows users to interact with the virtual objects. Based on this technology, Virtual Surgery System is developed. It will provide an ideal surgery training platform on which some high-resolution three-dimensional tissues will be observed and the sensations of force feedback will be expressed by feedback equipments. However, the studies on this kind of system just focus on a greater visual effect so far, and ignores other sensory channels.With the aid of VR Technology and other important theories, we try to find out some solutions for the existing problems. On functions, all should be solved in this paper fall into two parts: suture simulation and depth training. The main achievements and work of this paper is listed following: 1. We still use Mass-spring Model and"control points"method to simulate the suture. Meanwhile, the trajectory of the suture is configured by a constraint-based technique -"follow-the-leader"(FTL). To get better performance, some algorithms will be further modified. And a mass of experimental data obtained prove the feasibility and validity of such improvements. Finally, a technology named"Whiteboard Mode"will be introduced to integrate the suture module into our virtual surgery system. This kind of technology can help to reduce the coupling of modules and promote the scalability of the system greatly.2. The Collision Detection Algorithm mentioned will be optimized, which includes two aspects: reducing the times of intersection testing and improving the detection efficiency. These optimizations not only reduce the storage, but also largely short the computational time.3. Surgical instruments will be modeled to realize the interaction between the users and our system. As to the problem of losing the depth information under endoscope, we design several training programs which require users to do some practices such as clipping and orientating to strength their sense of spacing. Once there is a mistake during a training, the system will give some attentions to help users correct their mistakes.4. We also design a simple orientation system to help users locate objects to the center of screen quickly.5. Audio rendering is applied to enhance the immersion of virtual environment.