Software System Design Of 3D Location And Navigation Of Cardiac Catheter And Key Technology Research

As one of the most common cardiovascular disease in clinic, Arrhythmia has a serious influence on people's health condition. Nowadays, radio frequency catheter ablation technology has become a common method in various big hospitals to treat arrhythmia, especially to some complex cardiac arrhythmia (for example, atrial fibrillation). There exist many deficiencies by the adoption of traditional catheter localization technology led by 2D X-ray image to direct radio frequency ablation surgery, such as the difficulty to master the mechanism of complex arrhythmia, the indistinctness of the heart anatomic structure information, the uncertainty of the surgery safety and surgery success rate, etc.. Therefore, cardiac electrophysiology mapping system based on 3D localization of cardiac catheter technology developed in recent years has made an extraordinary progress in all aspects, and become the research hotspot of medical and biological engineering in domestic and external.Firstly, in this thesis, we analyzed the functional requirements of software system on the basis of hardware system of 3D location and navigation of cardiac catheter based on the principle of 3D trans-thorax electric field localization, established the functional model of software system using IDEF modeling analysis method, and designed software hierarchical structure. Moreover, we make a partition of the functional modules of the software system, and built software framework combined with visualization class library VTK using Microsoft Visual studio 2008 as a platform.Secondly, in this thesis, we studied the theoretical foundation and methodology to realize the main function of software system design of 3D location and navigation of cardiac catheter. We constructed 3D geometry model of heart anatomic structure utilizing endocardium cloud data collected by hardware system of 3D location and navigation of cardiac catheter, which was taken as reference of localization of cardiac catheter and surgery navigation. Meanwhile, using convex hull algorithm in computation geometry, we processed endocardium cloud data to obtain its surface extreme point, and constructed polyhedron virtual 3D model of heart anatomic structure; in order to build some complex anatomic structure, such as atrium and ventricle, we took the regional tiny polyhedron generated by convex hull operation as basic voxel, using regular set operation based on classification method to constructed 3D geometry model. As was shown in the simulation results, the reconstructed 3D geometry model of heart anatomic structure using this method could ideally meet the requirement of catheter localization and surgery navigation; it would make the 3D model more accurate and understandable which guided the surgery if we fuse the information of 3D model of heart anatomic structure reconstructed through CT/MR slice image sequence and virtual model built by obtaining endocardium cloud data. This would improve the efficiency of modeling and mapping. In addition, we also did elementary research about some related technologies, such as the pretreatment of CT/MR medical image, image segmentation and 3D Reconstruction, and reconstructed a 3D visualization model of men's thorax CT slice sequence using encapsulated class in VTK.Finally, to cope with some defects of the current software system of 3D location and navigation of cardiac catheter, such as the duration of building the 3D modeling of heart anatomic structure is relatively long, as well as the model is rough and difficult to understand. Combining with registering technology, we put forward the assumption of constructing 3D cardiac parametric geometry model guided by priori knowledge, which provide a new approach to explore more efficient and accurate modeling method.