Compliance Testing Methodology for Wireless Power Transfer Systems

Jagadish Nadakuduti, Mark Douglas, Lin Lu, Andreas Christ, Paul Guckian, and Niels Kuster, IEEE Transactions on Power Electronics, Volume PP, Issue 99, online February 19, 2015





Inter-Individual and Intra-Individual Variation of the Effects of Pulsed RF EMF Exposure on the Human Sleep EEG

Caroline Lustenberger, Manuel Murbach, Laura Tüshaus, Flavia Wehrle, Niels Kuster, Peter Achermann, and Reto Huber, Bioelectromagnetics, Volume 36, Issue 3, pp. 169–177, April 2015, online February 17, 2015





The Discrepancy between Maximum In Vitro Exposure Levels and Realistic Conservative Exposure Levels of Mobile Phones Operating at 900/1800 MHz

Gernot Schmid and Niels Kuster, Bioelectromagnetics, Volume 36, Issue 2, pp. 133–148, February 2015, online January 30, 2015

Human Exposure from Pulsed Magnetic Field Therapy Mats: A Numerical Case Study with Three Commercial Products

Human Exposure from Pulsed Magnetic Field Therapy Mats: A Numerical Case Study with Three Commercial Products

Valerio De Santis, Mark Douglas, Jagadish Nadakuduti, Stefan Benkler, Xi Lin Chen, and Niels Kuster, Bioelectromagnetics, Volume 36, Issue 2, pp. 149–161, February 2015, online January 16, 2015

Due to the popularity of pulsed magnetic field therapy (PMFT) mats for private therapeutic use, regulators need to evaluate whether the products are compliant with the basic restrictions and how overexposure can be determined. In a previous study, it was found that incident magnetic field exposure from PMFT mats can exceed ICNIRP 1998 reference levels.

Electromagnetic exposure from three different commercially available PMFT products was assessed. Experimentally validated numerical models of these mats were developed, and the induced fields, evaluated in high-resolution adult, child, and pregnant anatomical models of the IT’IS Virtual Population, were compared to the safety guidelines. As expected, PMFT design, anatomy, lying position, and body orientation were found to significantly influence exposure. The maximum exposure of one PMFT exceeds 3.1 times the basic restrictions of ICNIRP 1998 for the central nervous system tissues and 1.36 times the limit of ICNIRP 2010 for the peripheral tissues. Body loops can significantly increase the electric fields close to the skin, e.g., when the hand and thigh are in contact during mat use. PMFT products are therefore not intrinsically compliant with ICNIRP 1998 and ICNIRP 2010 basic restrictions and require special considerations.

The scientific and technical impact of the study can be summarized as:

  • An approach for determining the level of compliance of PMFT mats with the basic restrictions of safety guidelines is described.
  • The induced fields from exposure to the PMFT mats at 50 Hz were numerically assessed with the Magneto Quasi-Static solver of SEMCAD X in highly detailed adult, child, and pregnant anatomical models.
  • The influence on induced fields of body posture, position on the mat, body orientation, and body loops was investigated.
  • For some PMFT mats, worst-case exposures can significantly exceed the basic restrictions. 
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