Design And Implement Of Virtual Orthognathic Surgery Simulation System And Usability Improvement

As a major component of the human body,Craniofacial skull bone not only play an important role in supporting the face, also determine its main structure. But trauma and congenital craniofacial deformities and other factors, often lead to mandibular dysfunction and abnormal shape, which resulting in psychological and physical disorder of patients. Craniofacial bone reconstruction surgery are reliable on jaw recovery, but require experienced surgeon to design a accurate and detailed surgery plan, also it's hard to reach agreement with patients about their post-operation facial appearance.Virtual orthognathic surgery applied with Virtual Reality technology simulate the post-operation facial appearance well by calculate the relationship between skin and soft tissue, also along with recoverability and many other features that tradition surgery are not available with. In this paper, we first analyze the software requirement through the process of surgical procedure,propose the soft tissue deformation as the main issue of simulation. By reconstruct soft tissue and craniofacial bone model that suit for virtual surgery with patients' CT image, soft tissue force and deformation can be simulated with Mass Spring Model and Finite Element Model. Then we analyze the usability problems bring by virtual environment, introduce the characteristics of three-dimensional interactive technology and tasks, design a set of user-centered interactive methods. In order to move 3D object precisely in virtual environment, we use 3D mouse as an auxiliary input device which is fit for human perceptual and control principle. At the final part, we list the detailed design process and the structure of a number of key classes, then test and evaluate the system based on real patient data. At the final part, we list the detailed design process and the structure of a number of key classes.The research of this paper was supported by the Open Foundation of State Key Laboratory of Computer Science, the Chinese Academy of Sciences (No. SYSKF0704), the National High-Tech Research and Development Program of China (863 Program) (No.2006AA01Z328), the National Natural Science Foundation of China under grant (No. 60873095), and the Innovation Award of Graduate Student, Northwest University (No. 09YZZ67).