The influence of different electrode geometries on the current density distribution during radio-frequency ablation. A three-dimensional finite element study

The locations of current density maxima can provide information about the locations of temperature maxima. Our goals were: (1) to find the optimal place of the temperature sensor used for temperature-controlled ablation; (2) to assess at which locations char is more likely to occur. Using finite element modeling, we analyzed the current density distribution for a 8Fr/5 mm straight and a 8Fr/8 mm valve ablation electrodes. The maximal current densities occurred at the tip of the electrodes. Hence, it is best to place the temperature sensor, which provides input for the temperature control, at the electrode tip. Also, the analysis showed that using an electrically insulating coating layer at the junction between the electrode and the catheter body significantly reduced the local current density, therefore the local temperature. This avoids the formation of charring