标题：Experimental and numeric investigation
about electromagnetic interference
between implantable cardiac pacemaker
and magnetic fields at power line frequency
摘要：The present contribute describes the investigation about the implantable pacemaker (PM)
immunity against high level magnetic interfering fields at 50 Hz that a pacemaker wearer could find in
his working environment. To this purpose, a test bench has been set up based on a Helmholtz coil for
producing extremely low frequency (ELF) magnetic fields and a heart simulator rightly fed by electric
signals that simulate atrium and ventricle signals. A widely diffused PM has been tested, under different
operation modes and configurations, for both continuous interfering waves (CW) and variously pulsed
interfering waves (PW). Pertaining the obtained results, high levels of CW field, only in unipolar mode,
produce a behaviour called “asynchronous mode” (not dangerous). For PW fields, under particular
and rare conditions, the complete inhibition occurred (the most dangerous effect for PM wearer).
In order to validate experimental results, a numerical 3-D model has been developed to simulate the
whole bench system formed by Helmholtz coil, human trunk, pacemaker case and its electric leads. In
this model the electromagnetic problem is solved by reconstructing the inhomogeneous bench system
associating the relative values of conductivity to each cubic cell in which the whole system is discretized.
Application of Maxwell’s equations in their integral form has allowed to obtain a 3-D electrical
network, whose solution gives the current density distribution inside the heart simulator.
关键词：artificial pacemaker, electromagnetic fields, immunity, electric power supplies.
