Electromagnetic compatibility of active cardiovascular implants to occupational magnetic field environments: impact of the field direction

Active Implantable Medical Devices (AIMD) are nowadays a part of everyday life, with for example more than one million pacemakers (PMs) implanted each year worldwide. Like every electronic devices they are sensitive to electromagnetic interferences but the consequences are potentially severe. A large number of publications deals with electromagnetic compatibility (EMC) with common equipment but only a few concern industrial sources. Furthermore, the field encountered at workplace is potentially higher. Taking these into account, a new test method to assess the EMC of AIMDs against occupational magnetic field sources was developed. It is based on an experimental approach using a specific test bench able to generate a controlled magnetic field in all space directions up to the high occupational exposure limits between 50 Hz and 3 kHz. To do this, three Helmholtz coil systems are combined on three orthogonal space directions. This specificity makes it possible to take into account the high variability of the operator's position compared to the industrial source.