| In the past, on the pressure analysis of the hip joint, a doctor mostly analysed the pressure according to the provided information of the patient on the software such as Matlab and could not give a visual result. What the doctor really needs is the preoperative planning under the real environment of the patient, by which an optimal structure shape for the hip joint is determined. This thesis devises a method which can provide virtual environment preoperatively and perform the pressure analysis of the hip joint in this environment, in order to choose a surgery project and ensure the adaptability and accuracy of the surgery.This thesis firstly introduces the characteristics of the virtual reality technique and the developments at home and abroad. The application of the virtual reality technique on the medical field has been focused on. The virtual surgery simulation, the long-distance surgery, the 3D navigation in the volume image and the virtual endoscope are all good application directions.The 3D reconstruction is the basis of the visualization for medical images and the important premise for the application of the virtual reality technique in the hip joint surgery. With the development of the 3D reconstruction, up to the present there have been many algorithms, including the outline reconstruction surface method, Cuberille method, moving cube method, the ray projection method and the track method. This thesis has a higher requirement on the accuracy of the hip joint and so adopts the splatting method in the body drawing algorithm. This thesis carries out the reconstruction of the hip joint with VC++ 6.0 and VTK.By analyzing the physiological anatomy of hip joint, according to bio-mechanics, this thesis selects the acetabulum and the femoral head as the research objects and sets them as the rigid-body spring model usually seen in physics. Applying the physical characteristic of the rigid-body, this thesis carries out the pressure adding and analysis to the two 3D objects.In the application of the virtual reality technique, with the softwares OpenGL and Quest3D, this thesis puts the 3D model of the acetabulum and the femoral head in the virtual environment and adds to it the pressure formula of the rigid-body using the characteristics of the software. The revolving, moving and other man-machine interactive operations are completed by the mouse. The pressure area of the femoral head changed when being revolved, the background can compute the change of the press on the femoral head in time and shows it in the virtual environment. Finally, through a case of patient's real data verified this method.Thorough the pressure data offerd by this method, the doctor can choose a suitable hip joint through a series of pressure data analysis, so as to alleviate the pain of the patient and increase the success rate of the surgery. |
