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The project´s objective was to examine the possible coupling of an induced interference voltage into the cardiac pacemaker electrode from an electromagnetic field. A new hybrid calculation method was developed combining the conventional method of moments (MoM) and the multiple multipole method (MMP). Computer simulations of interference voltages in cardiac pacemaker electrodes from coupled EMF between 50 MHz and 500 MHz in a body model were performed by following tests: computerized modeling of interference voltage distribution under near field and far field conditions; measurements done in a simplified and in a realistic body model both filled with physiological saline solution. Electric field strength resp. irradiated power: 1 V/m (far field), 1 W (near field); Frequencies in MHz: 50, 100, 200, 300, 400, 500. Following parameters were investigated: coupled interference voltage dependent on near field or far field conditions, frequency, direction of incidence, EMF polarization, ellipsoid model or head-shoulder model, implant position. Under far field exposure conditions, interference voltages of up to 0.4 V (peak-peak, i.e. for electric waves, the difference between wave peak and wave low) were reached. The size of interference voltage tendentially decreased with increasing frequency. For the more complicated near field exposure, maximum interference voltages of up to 30 V were detected (peak-peak). Here, the size of interference voltage also decreased with increasing frequency, thus showing a maximum interference voltage of 6 V. |