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Analysis and dosimetry of the coupling of electromagnetic waves with biological tissues : application to applicator design for biomedical and study of health effects

Abstract : The evolution and increasing use of mobile communications systems was associated with laboratory investigations to study radiofrequency electromagnetic waves exposure safety. In this context, this thesis focuses on the characterization of exposure systems allowinglaboratory in vitro studies on cell models. A dual numerical and experimental approach is implemented to perform the devices dosimetry allowing to determine and control the exposure levels. One of the limitations associated with this dosimetry is due to the micrometric dimensions involved. Therefore, a microscopy technique based on a temperature-dependent fluorescent dye named Rhodamine B was set up and evaluated. This assessment recommends an optimal concentration of the dye at around 50 μM. After calibration, it is possible to estimate the specific absorption rate (SAR) from the temperature variation, even for low levels of SAR (< W / kg) with a spatial resolution of less than ten micrometers i.e. microdosimetry. The two main exposure systems studied, based on microelectrode arrays (MEA), allow the recording of neurons electrophysiological activity. Exposure to electromagnetic waves is achieved simultaneously by inserting these MEAs into TEM cells exposure systems. Dosimetry carried out at 1.8 GHz shows a higher sensitivity of one MEA to its environment. It was shown that the modifications made to the second MEA such as its aperture size and ground planes, have reduced the proximity environment influence. The microdosimetry demonstrated good homogeneity of the SAR between the electrodes with an estimated value of 7 ± 1 W / kgfor 1 W incident power. Finally, a microfluidic exposure device based on a coplanar waveguide was characterized under static conditions.
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https://tel.archives-ouvertes.fr/tel-03174410
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Submitted on : Friday, March 19, 2021 - 10:48:09 AM
Last modification on : Saturday, March 20, 2021 - 3:18:57 AM

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  • HAL Id : tel-03174410, version 1

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Amani Nefzi. Analysis and dosimetry of the coupling of electromagnetic waves with biological tissues : application to applicator design for biomedical and study of health effects. Electromagnetism. Université de Limoges, 2021. English. ⟨NNT : 2021LIMO0011⟩. ⟨tel-03174410⟩

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