First Place Platform Award (BEMS Joseph James Morrissey Memorial Award): Arno Thielens

Published on: Sep 29, 2013

Personal Distributed Exposimeter for Radio Frequency Electromagnetic Field Assessment

Arno Thielens1, Hans De Clercq, Sam Agneessens, Jeroen Lecoutere, Leen Verloock, Frederick Declerq, Gunter Vermeeren, Emmeric Tanghe, Hendrik Rogier, Robert Puers, Luc Martens & Wout Joseph

1Department of Information Technology (INTEC), Ghent University/ iMinds, Ghent, Belgium, 9050

My presentation at the BioEM2013 conference was on the development of an on-body distributed personal exposimeter for radio frequency exposure assessment. This work is part of the research that I perform in the Wireless and Cable Group (Ghent University/iMinds).

I graduated in 2010 from Ghent University as a master of science in engineering specialized in applied physics. During my master studies and thesis, I mainly studied electromagnetism and optical properties of different materials, in particular nanostructures in Si and binary semiconductors. After graduating, I decided to make a frequency shift from the visible and infrared region towards the radio frequency (RF) region and joined the Wireless and Cable Group of prof. Martens and prof. Joseph at the same university. In the first years of my PhD, my research was mainly focused on finite-difference time-domain simulations using the virtual population, developed by IT’IS. In particular, I focused on determining organ-specific averaged specific absorption rate (SAR) and compliance boundaries of multi-band base station antennas. Nowadays, I am mainly involved in the development and calibration of personal exposimeters, with the goal to reduce the measurement uncertainty on personal measurements using these devices. To this aim, the focus of my research is now shifting from simulations to (calibration) measurement, both in the anechoic chamber and in real environments. However, I still perform quite a lot of simulations for the same project.

The work presented at BioEM2013 dealt with my current work, where I am developing a personal, distributed exposimeter (PDE) for RF measurements. Our goal is to reduce the influence of the body on personal measurements with exposimeters. To this aim, textile antennas interconnected with wearable electronics are placed on predefined positions on the human body. These flexible textile antennas are designed to have an optimal on-body performance and could be integrated in clothing, while the wearable electronics enable us to read out measurements while a subject is wearing the PDE, without impeding the subject’s movements or interfering with the subject’s daily routine. At BioEM2013, I presented the first results of a prototype that we developed to measure exposure in the global system for mobile communication (GSM900) frequency downlink band. A calibration of this prototype shows that, using a PDE, we are able to reduce the uncertainty on measurement of incident electric fields by an order of magnitude. A brief communication on this same subject has been accepted in Bioelectromagnetics.

In the same project, we are now working on an improved calibration procedure, where an optimal placement of the textile antennas can be determined using a limited number of calibration measurement, this for different RF communication bands. In parallel, the electronic architecture is further optimized to minimize the number of necessary nodes and interconnections and a new design of smaller textile antennas is tested and validated. Moreover, we are also aiming at validating the measurements with our PDE in real environments. It is our goal to present a more robust and improved version of our PDE in 2014. Hopefully, this concept will be able to improve dosimetry and measurement campaigns of RF exposure in the future. Any feedback from or collaboration with BEMS and EBEA members, especially those involved in epidemiology, could off course help us to improve this concept.

I would like to thank BEMS and EBEA for offering me this award and I would also like to thank my co-authors for their work in this project, in particular Sam, Hans, and Jeroen for their time spend in and around the anechoic chamber. The work presented at BioEM2013 is funded by the Flemish government (FWO-V) under grant agreement No 3G004612.