Research On Virtual Organ Representation For Delivery Simulation

Delivery Simulation System made "Mechanism of Labor", which was difficult to be explained distinctly owing to its invisibility, displayed clearly and vividly. This greatly improved the quality of delivery education and operation training, as well as saved the expense and time. As the indispensable element of Delivery Simulation System, virtual organ must be realistic, thus giving the sense of immersion. In order to enhance the reality of Delivery Simulation System, this dissertation studied a new approach to represent virtual organ vividly. The main contents of this thesis are presented as follows:Firstly, CT image processing is the primary links for three-dimensional-reconstructing (3D-reconstructing). This dissertation was dedicated to the processing methods of CT image, such as filtering the noise with Median Algorithm, producing binary CT Image via threshold value and gaining the contour data of pelvis by means of 8-chained algorithm. Then we reconstructed the 3D model of pelvis in software 3D-D0CT0R, making use of the profile data gained by the former CT image processing.Secondly, we analyzed the anatomical structure of uterus and discussed the difficulties existing in uterus modeling. The solution for how to represent the key frame of uterus and implement the deformation real timely was given. The paper described the whole process of uterus modeling in detail, and also summarized the experience and lessons of it.Thirdly, we made much detailed study on the characteristic of female pelvis, according to which we modified the pelvis model carefully in software 3D Studio MAX, including the modification of pubis symphysis, pubis falls, sacrum and ischium. This guaranteed the validity of delivery training.Fourthly, this thesis discussed the principle and algorithm of texture mapping for complicated model. Two common mapping methods in 3D Studio MAX: Bitmap and Procedural Map were respectively used to endow uterus model with texture. We compared the effect of these two mapping methods and chose one of them applied to the Delivery Simulation System.Fifthly, we studied the means of simulating pubis deformation. Based on the principle of pubis deformation, the design idea and implementation of animation simulation were given. 3D geometric model of pelvis is stored in the software 3D Studio MAX and then we transformed its 3DS data structure into three-dimensional representation of entities with VC++ language and displayed it by OpenGL. Since OpenGL provides double-buffering ability to complete animation, the simulation of pubis deformation was accomplished.Sixthly, through the key frame animation of 3D Studio MAX, we accomplished the simulation of uterus real-time deformation. The control principle of key frame animation and representation of deformation data were also discussed.Finally, the thesis summarized the study work and experience during development process and offered the reference for following development work.