Virtual liver surgical simulator by using Z-buffer for object deformation

Abstract

Virtual surgical simulator which is using computer graphics is much popular system than before. It is generally used in the medical areas, such as medical hospital or medical university. The simulator uses virtual organ models like liver, brain and so on. These models are usually based on the scanning data from patients and are used as volume models. Fortunately, the volume model is familiar with its cutting or deforming operation in a surgical system. For this reason, there are many kinds of surgical simulation or navigation systems using the volume model. However, visual reality of the volume model is not sufficient for human being including doctors. This means that the doctors cannot identify shape or location of a target organ from volume objects. In order to overcome this, we should use the translating method, such as marching cubes method and so on, for getting precisely polygon models which is included normal vectors of volume object. However, the method is quite time consuming and consequently the doctors cannot operate the virtual model in real-time. On these observations, we propose the virtual surgical simulator for operating the human liver in a virtual environment, which is based on the cooperation of polygon models and Z-buffer in GPU. By using parallel processing of GPU, the simulator allows uses to cut or deform a virtual liver model by using several kinds of medical tools like a scalpel in this system. In addition, visual reality of polygon model is wonderful for a doctor to identify its shape or location because this model maintains their precise normal vector.