Research On Low-does Rapid 3D Reconstruction Of Bone Model And Image Registration For Computer Aided Orthopaedic Surgery

The 3D visualization model of personalized fracture patients plays an important role in computer assisted orthopedic operation. The current practice is usually let the experienced doctors to patients in their bone marker position accurately into the Kirschner wire, using the tracking device to capture Kirschner wire on the marker to registration, using the reference mark points in patients undergoing anatomic 3D volume data to obtain position and preoperative registration. This method firstly need to scan on bone by traditional CT technology, the overall scan that can cause radiation injury of patients and doctors, the reconstruction process and the subsequent need professional personnel, time-consuming longer. Therefore, this kind of intrusive method is not often used in routine diagnosis, but most fractures X light image reset operation are completely dependent on the two-dimensional.The purpose of this study is through the three-dimensional anatomy model into low radiation fast reconstruction, to provide help for the surgical operation doctor in each stage of reduction of femoral fracture operation. The results showed reduction of femoral fracture: to improve the surgical operation of computer aided system by increasing the two-dimensional image guided and interactive 3D bone model can greatly accuracy. This study shows that the positioning errors caused by bone alignment errors and complications in the operation process can be reduced by introducing the 3D visualization of fracture segment. Therefore, 3D visualization of anatomical position in surgical operation based on image guidance plays a very important role, and the biggest contribution is in minimally invasive operation.The target of this research is carried out through the 3D model reconstruction of bone, thus real-time tracking of bone fracture position and posture in the operation. Aiming at this problem, this paper carries out in-depth research on some key techniques in the operation, mainly include the following aspects:1 this paper puts forward an algorithm of automatic extraction model with topological constraint X ray image of bone contour, projection profile using the general model to achieve a fast and accurate extraction of X ray image of bone contour. The algorithm uses the generic 3D model needed to extract the bone contour to define anatomical topology structure, in the general 3D model projection profile and X optical image contour extraction of non rigid registration to obtain topological constraints, the process of learning statistics is usually discarded topological constraints define the required, so that the contour extraction method has more extensive applicability.2 Theproposed 2D and 3D image registration algorithm combining a similarity measure and the gradient search optimization methods, to achieve accurate estimation on the integrity of bone and bone fracture in operation by using X ray attitude during operation; the method modified the similarity measurement method based on Hausdorff distance, and the and the optimization method based on gradient search are combined, thus forming a new 2D and 3D registration algorithm, the concept of in-plane registration and surface registration is put forward in the process of calculation, and interaction, the registration accuracy and stability is improved.3 this paper puts forward a new fast reconstruction method for personalized bones model two X light sheet and a standard bone based on model, implemented using the X ray radiation fast reconstruction in patients with personalized skeleton model. This method simplifies the traditional FFD algorithm, the dimension and consistent concepts will establish the correspondence between the two dimensional X ray film and standard 3D model, 3D reconstruction method to obtain than traditional CT reconstruction method is more rapid, economic and security.Comparative study of 4 eyes of bone surgery operation in the preoperative planning method, analyzed its disadvantages and adverse effects on navigation accuracy. Initially developed on the basis of complete femur preoperative operation planning software system, and through the body test to carry out quantitative analysis on its performance, obtained the related test data before clinical application.In this paper, the key technology of computer assisted orthopaedic low radiation fast 3D reconstruction and image registration method based on the theory of systematic research, and some software design. Initially developed on the basis of the femur before operation, operation planning system. Application of the system is low cost, does not need to add additional equipment or device, to the less developed areas of operation promotion of technical operation planning and computer aided has promoting effect.