Modelling and Evaluation of the Absorption of the 866 MHz Electromagnetic Field in Humans Exposed near to Fixed I-RFID Readers Used in Medical RTLS or to Monitor PPE

Abstract

The aim of this study was to model and evaluate the Specific Energy Absorption Rate (SAR) values in humans in proximity to fixed multi-antenna I-RFID readers of passive tags under various scenarios mimicking exposure when they are incorporated in Real-Time Location Systems (RTLS), or used to monitor Personal Protective Equipment (PPE). The sources of the electromagnetic field (EMF) in the modelled readers were rectangular microstrip antennas at a resonance frequency in free space of 866 MHz from the ultra-high frequency (UHF) RFID frequency range of 865–868 MHz. The obtained results of numerical modelling showed that the SAR values in the body 5 cm away from the UHF RFID readers need consideration with respect to exposure limits set by international guidelines to prevent adverse thermal effects of exposure to EMF: when the effective radiated power exceeds 5.5 W with respect to the general public/unrestricted environments exposure limits, and with respect to occupational/restricted environments exposure limits, when the effective radiated power exceeds 27.5 W.

Limitations of using electro-optical probes for the measurement of the electromagnetic field emitted by the new generations of wireless communication devices

“…Above 2 GHz the limits are expressed in terms of incident power density which require accurate measurement of the EMF in the proximity of the device, as recent findings suggest that in future networks, EMF exposure will be dominated by the end user device [6]. The near field nature of exposure was also observed for various publicly used technologies like short-range wireless RFID technology [7][8] or occupational sources such as military communication technology [9][10]. When conducted in the near field, EMF measurements are complicated and require sophisticated measurement devices and procedures with several sources of uncertainty [11].…”

Computational evaluation of absorption characteristics of ceramic-based auxetic materials in X-band frequency range

“…absorb waves in the context of communication to achieve the highest possible absorption level [1]. On the other hand, these methods can be utilised in the medical field to acquire more detailed images by making use of imaging techniques such as magnetic resonance imaging and computed tomography [2]. Military enclosures are equipped with EM absorption materials for two primary purposes.…”

Modelling and Evaluating Electromagnetic Field Exposure in the Multiple-Source Scenario of Using IoT HF RFID Readers

“…Constant technological development and the subsequent development of the digital society mean, among other things, that people’s daily lives and work environments involve more and more sources of radiofrequency electromagnetic field (RF-EMF) used for wireless communication between various devices. One of the most frequently used technologies for this purpose is High-Frequency (HF) RadioFrequency IDentification (RFID), working as a standalone system or as an integral part of a more sophisticated Internet of Things (IoT) system [ 1 , 2 , 3 , 4 , 5 ].…”

“…It is part of the globally used RFID technologies operating on various frequency bands, from 30 kHz up to 5.9 GHz [ 1 , 6 ]. HF RFID technology is used in the public environment and in many areas of the economy and medical centres [ 1 , 2 , 3 , 4 , 5 ]. Probably the most common application of HF RFID technology integrated in IoT systems today is managing proximity cards used in public transport, payment, access control to buildings or rooms, etc.…”

“…Ein values in the model of a person validating a public transport card in an exposure scenario with two people near to the HF RFID reader (at 13.56 MHz) with an internal antenna with inner dimensions of 8 × 8 cm, assuming that the RR of the considered reader is 4, 10 or 16 cm (according to ISO/IEC 14443-2:2020 requirements for PICCs of various classes). PICC class-proximity integrated circuit card (PICC) classes according to ISO/IEC 14443-2:2020 differing in minimum magnetic field required to energise and read PICCs and dimensions of PICCs; 2 Ein ICNIRP-internal electric field values averaged as rms values over 2 mm × 2 mm × 2 mm contiguous tissue, peak-peak spatial value of Ein required by ICNIRP 2020, 99th perc-99th percentile value of Ein required by ICNIRP 2010;3 Ein IEEE-in situ electric field value evaluated in the direction and location providing the maximum Ein vector as rms values averaged over a 5 mm linear distance in tissues; 4 the maximum RR when exposure is compliant with the GP limit-the maximum RR when the level of emitted EMF does not cause Ein values exceeding the limits of general public exposure (ICNIRP) at 10 MHz or extrapolated linearly for 13.56 MHz or exposure in unrestricted environments (IEEE) at 5 MHz or extrapolated linearly for 13.56 MHz.…”