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Significant RF‐EMF and thermal levels observed in a computational model of a person with a tibial plate for grounded 40 MHz exposure
Author(s) -
McIntosh Robert L.,
Iskra Steve,
Anderson Vitas
Publication year - 2014
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/bem.21846
Subject(s) - bioelectromagnetics , non ionizing radiation , tibia , implant , electric field , plane wave , physics , materials science , magnetic field , biomedical engineering , nuclear magnetic resonance , medicine , optics , surgery , quantum mechanics
Using numerical modeling, a worst‐case scenario is considered when a person with a metallic implant is exposed to a radiofrequency (RF) electromagnetic field (EMF). An adult male standing on a conductive ground plane was exposed to a 40 MHz vertically polarized plane wave field, close to whole‐body resonance where maximal induced current flows are expected in the legs. A metal plate (50–300 mm long) was attached to the tibia in the left leg. The findings from this study re‐emphasize the need to ensure compliance with limb current reference levels for exposures near whole‐body resonance, and not just rely on compliance with ambient electric ( E ) and magnetic ( H ) field reference levels. Moreover, we emphasize this recommendation for someone with a tibial plate, as failure to comply may result in significant tissue damage (increases in the localized temperature of 5–10 °C were suggested by the modeling for an incident E ‐field of 61.4 V/m root mean square (rms)). It was determined that the occupational reference level for limb current (100 mA rms), as stipulated in the 1998 guidelines of the International Commission on Non‐Ionizing Radiation Protection (ICNIRP), is satisfied if the plane wave incident E ‐field levels are no more than 29.8 V/m rms without an implant and 23.4 V/m rms for the model with a 300 mm implant. Bioelectromagnetics. 35:284–295, 2014. © 2014 Wiley Periodicals, Inc.