Immunity tests of implantable cardiac pacemaker against defibrillation: prediction of the induced disturbance

The aim of the present work is to investigate the influence of the high level currents injected by an external defibrillator in a pacemaker (PMK) placed in the human trunk. A modified version of the Scalar Potential Finite Difference algorithm has been used. A network of impedances simulates the human body obtained by the Visible Human Project data. A structure for the PMK leads has been developed for the bipolar case as well as for the unipolar case. Then, a direct comparison between them has been performed. Numerical results show that the parasitic voltages induced by the discharge are ten times greater than those of natural heart signal. Furthermore, the problem of the heart tissue burning has been discussed. It may rise because of the leads heating due to the strong defibrillation currents