The Reconstruction Of Multi-endocardial Cavity Model And The Accuracy Of Registration Of The Three-dimensional Navigation And Positioning System

Objective:To acquire the reconstruction of multi-endocardial cavity with low-frequency current field and to validate the accuracy of registration of the three-dimensional navigation and positioning system with right ventricular Mapping and right atrial ablationMethods:Three orthogonal directions of alternating current generated by three pairs of electrodes develop a three-dimensional low-voltage electric field to cover the area of the heart. Mapping catheter reach the heart cavity and measure positioning signals in the direction and intensity and then determine the catheter the location of three-dimensional space with computer analysis.After mobile catheter acquired a number of data about cavity site, we can reconstruct a precise three-dimensional model of the heart cavity and the location of catheter can be displaied in the model at the same time. Firstly, reconstruct the multi-endocardial cavity model of right atrium ,right ventricle and superior vena cava . through punctured two-side femoral veins, we post in big head electrodes into right atrium ,right ventricle and superior vena cava . Collect voltage locating signals and obtain positional information of mapping catheter while dragging the catheter along endocardium of the measured chamber. when the collected location data are enough. Three-dimensional model of the measured chamber is reconstructed by the computer, Sencondly, with the same model ,pace the right ventricle at a random spot, record 12-lead synchronous electrocardiogram(ECG) and make the spot as the virgin spot in the software. Depart the catheter electrode from the virgin spot for a few minites, then reposit electrode to the virgin spot by the navigation system. Pace the right ventricle at the same spot once more and record 12-lead synchronous electrocardiogram(ECG) again. Comparing the two ECGs to make sure whether they are completely identical or not to validate the accuracy of registration of the navigation system. Do as above three hours later to validate the stability of the postioning and navigation system.Last,with the same model, pace the right atrium at a random spot then depart the big head electrodes from the virgin spot. then reposit big head electrodes to the virgin spot by the navigation system for Radio Frequency Catheter Ablation(RFCA). we investigated the five distances of the necrosis points.Results:(1) Reconstruction of endocardium's models has some deformation, but all model structures are similar and can use it to navigation and positioning. (2) The results of right ventricular pacing ECGs demonstrate that complete identical rate when the electrode is reposited to the virgin spot instantly and complete identical rate when reposited 3 hours after departing from the virgin spot are 100% and 66.67% respectively. The total complete identical rate is 83.33%. (3) The 5 necrosis points with RFCA mixed each other. the diameters of the necrosis focuses were 7 mm.Conclusions:1.The spatial orthonormal low frequency alternating current field generated by three pairs of surface electrodes can reconstruct multi-endocardial cavity model and use it to navigation and positioning.2. Right ventricular pacing, the electrocardiogram immediately reset was in full compliance with the rate of 100%, but long-term success rate was low than the reset instantly 3. This Navigation system enables animals radio frequency current ablation accurate and reproducible.