Reaearch On The Electric-field Of Three-dimensional Mapping Technology With Simulation And Experiment

The catheter ablation has become a common way to treat the complex arrhythmia. In the procedure of ablation, the accurate localization of the electrodes is the key to the success of ablation. Compared to the conventional fluoroscopic endocardiac mapping technique, nonfluoroscopic 3D localization techniques increase the success rate of ablation and reduce radiation of X-ray.Localization using electric field was introduced in this thesis. Regular catheter electrodes are used as sensors for electric field, which is applied via skin electrodes. Through transforming the voltages sensed by catheter electrodes into position coordinates, the technique locates the position of the catheter at last. Compared to localization using magnetic field, localization using electric field doesn't need special catheters.Based on the principle for localization of catheter using electric field, this thesis established evenness index and directivity index to evaluate the electric field. Through numerical simulation method, the influence on the electric field of sources, skin electrodes and mediator was analyzed. At last, the simulation results and system accuracy were examined.With this technique of localization, this thesis mainly completed the following research work from theory and the experiment:1. This thesis supplied a numerical simulation method for the electric field. Because the electric field is generated by three sources which have different frequencies, before simulation of the electric field, the electric field was decomposed into three simple harmonic alternating fields based on principle of superposition, and then Finite Element Method (FEM) was used for simulation.2. This thesis supplied the evenness index and directivity index which impacted accuracy of localization, and analyzed the influence on the indexes of the factors which include source connection, skin electrode parameters and mediator distribution through numerical simulation and experiment. 3. The correction method of position deviation was proposed. The method corrected the intensity coefficients based on the simulation result which was calculated using a finite element model of human body.4. Fast Fourier Transform (FFT) was used as the main algorithm in the process of the voltage signal, and accuracy of the localization system was examined.