Safety of active electronic implants operated nearby TETRA-transmitters

The purpose of this work is to investigate potential dangers for people carrying active electronic implants such as cardiac pacemakers resulting from the emissions of TETRA transmitters. The emitted electromagnetic fields of transmitters have the potential to influence the proper function of active electronic implants. Such investigations are very important, because a large part of the employees of the emergency services and authorities already use TETRA transmitters. Based on frequency of use in Austria and transmitted power we selected 5 transmitters used by emergency medical and ambulance services, police forces and fire brigades. The most common 12 cardiac pacemakers and 6 implantable defibrillators used in Austria were selected to investigate their vulnerability against emissions from TETRA transmitters. At 4 of 12 pacemakers and 2 of 6 pacemakers interference with the TETRA-transmitters occurred. The highest distance of interference between implant and transmitter was 40cm. The investigations are still not finished and will be continued with further types of implants. So the preliminary results of our in vitro studies showed that a safety distance of 40cm from the implant to the TETRA-device is reasonable.