Research On The Relative Theory And The Important Technology Of The Artificial Joint CAD/CAM

There is a wide variety of artificial joint. Different patient has artificial joint of different size and shape. At present, the manufacture of artificial is standardized and serialized. Because that the stem of artificial joint cannot match with marrow cavity closely, the distribution of stress and load transmission is uneven. As a result, the standard artificial joint product seriation may leads to complications after operation as well as the decrease of artificial joint life. We apply the CAD&CAM technology into the bionic design and manufacture of artificial to make the individualized artificial joint design and manufacture into reality. By doing that, the artificial can match the patient's anatomical structure accurately; the design for individual patient can be optimized from the aspect of geometry and mechanics; the stress distribution in the match area is well controlled; the fixation of artificial joint is in the best condition so that the function of patient's joint can recover in the best way. This kind of artificial joint can help extremely release the patient's pain as well as improve the success ratio of operation and the cure effect.In this paper, we do research on several common problem and important technology in the artificial joint CAD/CAM system. Our research involves the medical image disposal and analyse, 3D reconstruction theory and method, bionic design and manufacture of artificial bone based on RP technology and simulation on bioceramic degrading process in the biological body. We develop a artificial joint CAD/CAM system based on medical image disposal, 3D reconstruction, RP technology and bioceramic degrading process simulation.The main research result and conclusion are:(1) Realize decode of CT file according to the DICOM protocol. By disposing the human's joint's CT image, we apply K-mean clustering subdivision method which takes the CT value as the character of clustering as well as the contour obtaining method based on B-spline to construct 3D data field base on the crossing image.(2) Research on the important technology of artificial joint 3D reconstruction. We put forward the internal registration method based on the maximum overlapping ratio and geometric transform of characteristic points according to the facts that theshape of organism is continuous and integrated. By improving the internal registration method, we make a better result.(3) Dissertate the theory of Marching Cubes algorithm. Because of the large quantity of data and low speed of display, we adopt the algorithm of contour tracking to find cubs on the edge to reduce the cubes number. We also take the midpoint of cube's edge to take place the point calculated from three-degree interpolating as the acme of triangle to reduce the computation.(4) For the first of time, we try to apply the fractal geometry in the construction of micro-structure of artificial bone. We put forward an algorithm for the micro-structure bionic design based the fractal theory and Monte-Carlo method. This method can efficiently construct the multi-porosity and uneven scaffold and design the 3D scaffold of artificial bone.(5) Develop an interface of artificial joint CAD/CAM system. This software can generate STL file automatically and cut the STL model into crossing section. This is a interface of artificial joint design and RP manufacture.(6) Research on the relationship between the material crystal's growth and degradation. By applying crystals' growth theory to construct material degradation model and investigate on the hexagon cell model.(7) For the fist time, we put forward the algorithm and process simulation on 3D biological material degradation and realize the visual simulation degradation model. By comparing the simulation result and reality, we find that the two results is similar to prove the rationality of simulation. This research has provided a scientific method of applying the simulation model into the bio-material design and research.(8) Develop a individualized artificial joint CAD/CAM system based on the project m...