Leitgeb N, Cech R, Schröttner J
Institute of Health Care Engineering, European Notified Body of Medical Devices, Graz University of Technology, Inffeldgasse 18, A-8010 Graz, Austria.
Radiat Prot Dosimetry. 2008;131(2):251-8. doi: 10.1093/rpd/ncn132. Epub 2008 Apr 11.
In daily life as well as at workplaces, exposures to inhomogeneous magnetic fields become very frequent. This makes easily applicable compliance assessment methods increasingly important. Reference levels have been defined linking basic restrictions to levels of homogeneous fields at worst-case exposure conditions. If reference levels are met, compliance with basic restrictions can be assumed. If not, further investigations could still prove compliance. Because of the lower induction efficiency, inhomogeneous magnetic fields such as from electric appliances could be allowed exceeding reference levels. To easily assess inhomogeneous magnetic fields, a quick and flexible multi-step assessment procedure is proposed. On the basis of simulations with numerical, anatomical human models reference factors were calculated elevating reference levels to link hot-spot values measured at source surfaces to basic limits and allowing accounting for different source distance, size, orientation and position. Compliance rules are proposed minimising assessment efforts.
