Research On Computerized Surgery Simulation For Hip Orthopedics

This paper seeks to investigate the 3-D interaction of bone surgery simulationand the evaluation of surgery simulation for hip orthopedics, which is a continuationof the "Research on computerized surgery simulation for pelvis osteotomy" of theNSFC project. The key technologies on computerized bone surgery simulation beingstudied in the paper are as follows:In the 3-D surface reconstruction, the Discrete Marching Cubes (DiscMC)algorithm is constructed. It simplifies the model, keeps model topology consistentand meets the real-time requirement for 3-D interaction during surgery simulation. Acomparison is then made between DiscMC and Marching Cubes algorithm throughexperimental data, and the evaluation of DiscMC has also been done.In the 3-D interaction, an operation guide method developed from the bonesurgery simulation is presented. First, the methods of blades modeling and bonesgrouping are described. It is a preparation for the operation guide. Second, the basicoperations used by surgery simulation, such as shifting, rotating, picking, measuring,cutting and appending are also been described. Thirdly, the method to design thecontrol module of operation guide has been explained through an example. Forth, aprocedure of interaction and evaluation for surgery simulation is introduced. It helpssurgeons to finish surgery simulation quickly and to compare various kinds ofoperations in order to decide for the most suitable one, as well as to yield thesatisfying results of operations.In the evaluation of surgery simulation, an evaluation method based on mirrortransformation of symmetry of human body is presented. The application of 3-Dmirror transformation is introduced;the algorithms of planning and measurement ofsurgery simulation for hip orthopedics based on mirror transformation have comeinto operation. These includes planning the movement of blades and bones,measuring the distance between femur head and acetabulum from both centers,measuring the difference of feature points, and last but not least measuring themedical parameters based on X-ray in hip joints. Finally, comparisons amongdifferent results of surgical operations of congenital dislocation of hip joints in thevirtual environment are made through experiment by means of the geometric shapeof hip joints.In the fifth chapter of this paper, several methods and implementations of outputmodel for bone surgery simulation are discussed. The output model can be used forbiomechanics analysis and the field of computer aided designing and manufacturingartificial leg. The paper then followed by an analysis on the basic finite element ofhip, such as the analyses on contact force/pressure and displacement. Finite elementanalysis is an important method to evaluate the surgery simulation for hiporthopedics. Finally, by means of comparing the differences in mechanicsparameters between the normal and abnormal models, the basic relationship betweendislocation and mechanics parameters of hip has been concluded.