Spark discharges from power lines rarely interfere with cardiac pacemakersSpark discharges beneath power lines may interfere with implanted cardiac pacemakers (PMs). The effects of spark discharges on PMs were investigated by a research team from Tampere University of Technology in a study reported in the January issue of Health Physics.
Spark discharges can occur beneath power lines where the electric field is sufficiently strong to induce them. When the human body approaches a long metal fence, a motor vehicle, or another large metal object that is charged, due to the presence of an electric field beneath a power line, and is insulated from the ground, a spark discharge may occur before contact is initiated.
A total of 29 PMs were tested, most of which in both unipolar and bipolar mode. In bipolar mode, no interference was observed in any of the devices tested, while in unipolar mode, one PM incorrectly identified ventricular extra systoles (more than 400 beats per minute for 2 s).
– This means that the probability of a spark discharge interfering with a PM is low. The use of unipolar configuration in new PMs is extremely rare, which further minimizes the risk of interference with the passage of time, says Professor Leena Korpinen from Tampere University of Technology.
The tests were performed in a high-voltage laboratory, where spark discharges could be produced experimentally. The effects of spark discharges on PMs were investigated using a human-sized, human-shaped phantom, specially designed for the purpose, which was filled with saline and fitted with a PM.
– Normally, PM users are not exposed to spark discharges in a way that would make any effects likely. However, to minimize any possibility of interference from electric fields or spark discharges, PM users are advised to avoid the mid-span area, where the power line is closest to the ground, says Professor Korpinen.
Professor Korpinen emphasizes that the results of this study should be considered keeping in mind that the tests were performed in a high-voltage laboratory, not beneath a power line, and that a phantom was used instead of human subjects. Therefore, the conditions were not completely identical to those a PM user would be exposed to in a "real-world" spark discharge beneath a power line.
A number of projects have been conducted at Tampere University of Technology to investigate the potential effects of power lines on PMs. The latest project report can be found in the January 2016 issue of Health Physics. The results were published in international collaboration. The project was financed by the Finnish Electricity Research Pool and Fingrid Oyj.
Further information: Professor Leena Korpinen, Tampere University of Technology. Tel. +358 40 595 2035, leena.korpinen (at) tut.fi