Search

The study aimed at expanding the knowledge about the assessment of radio-frequency electromagnetic fields (RF-EMF) exposure, considering the novelties introduced by the incoming 5G networks. Specifically, a possible future case of indoor exposure scenario is investigated, where the presence of a 5G access point (AP) in a room is simulated. The AP was modelled by two different indoor uniform planar array (UPA) antennas at 3.7 GHz and at 14 GHz, to evaluate how the beamforming and the higher frequency use could impact the exposure levels. Different scenarios were evaluated, considering the maximum antenna gain, two different human computational models, an adult model and a child one, and by varying the distance and the orientation between the UPA antenna and the two models head. All the simulations were conducted using the Sim4Life platform and in particular the exposure levels were expressed by the specific absorption rate averaged on 10 g of tissue ( $SA{R_{10g}})$ , which was analyzed for the skin and for some specific tissues. The work underlined that the highest $SA{R_{10g}}\ $ values were obtained in the head area for all scenarios, with the skin $SA{R_{10g}}$ highest peaks when the UPA is placed laterally to the human model (195.73 mW/kg and 223.29 mW/kg for the adult and child model, respectively, for 100 mW input power). Furthermore, the work permitted to highlight that the $SA{R_{10g}}\ $ exposure levels are slightly higher for the child model, compared to the adult one and that the distance between the UPA antenna and the human models could greatly lower the $SA{R_{10g}}$ levels. At last, it was found that the $SA{R_{10g}}$ exposure levels obtained with the UPA antenna at 14 GHz were lower than the ones at 3.7 GHz, although further investigations will be necessary.

Transcutaneous spinal direct current stimulation is a neuromodulation technique recently exploited to regulate the activity and enhance plasticity of spinal neural structure. Despite the few side-effects reported by clinical studies, the assessment of potential localized temperature increases in tissues is still not solved. In this study, the temperature increase induced by a 3 mA stimulation in the tissue target (i.e., the spinal cord), in its surrounding tissues and in other tissues possibly more vulnerable to temperature increase were assessed through a computational approach. That solves Laplace equation and BioHeat equation for electric field and temperature distribution, respectively, on six whole body high resolution anatomical models, including three models of pregnant women at different gestational ages. Results show that temperature increase distribution in those targets is guided by a complex interaction between different mechanism in which electric stimulation plays a secondary role, in particular when blood perfusion is active. The very low heating assessed (below 1.5 m °C) is not consistent with the hypothesis that the induced temperature increase would critically activate metabolic changes in the target tissues here considered or would contribute to the few side effect that the applications of spinal direct current stimulation protocols have shown.

The objective of the present work was to assess the children exposure variability due to low frequency near-field sources using an approach based on stochastic dosimetry. These scenarios represent a topic of high interest, because it was found that domestic appliances could be relevant for children exposure level. In details, in this paper the exposure of two child models to a hairdryer model was evaluated. Following the ICNIRP guidelines, the electric field amplitudes induced in specific tissues composing the central nervous system and the peripheral nervous system were analyzed. The analysis of the results permitted to highlight a high exposure variability depending on the near-field source position and to individuate the regions where the source could cause the highest levels of exposure, not limiting the analysis only to some worst-case exposure scenarios.

Exposure to electromagnetic fields (EMFs) has prominently increased during the last decades due to the rapid development of new technologies. Among the various devices emitting EMFs, those based on Radio-frequency identification (RFID) technologies are used in all aspects of everyday life, and expose people unselectively. This scenario could pose a potential risk for some groups of the general population, such as pregnant women, who are expected to be possibly more sensitive to the thermal effects produced by EMF exposure. This is the first paper that addresses the estimation of temperature rise in two pregnant women models exposed to ultrahigh frequency RFID by computational techniques. Results show that the maximum temperature increase of the fetus and of the pregnancy-related tissues is relatively high (even about 0.7 °C), not too far from the known threshold of biological effects. However, this increase is confined to a small volume in the tissues.

This paper implements a filtering technique to enhance the signal-to-noise ratio (SNR) and, in turn, the detection of transient-evoked otoacoustic emissions (TEOAE's), generated by healthy human cochlea. One can increase the SNR by compiling an image of recorded TEOAE from more than one stimulus intensity, averaged over a few sweeps, which can be further processed by means of two-dimensional spatial mean filters. Averaging some 60 sweeps recorded to stimuli at several intensity levels requires one-forth of the collection time needed for a classical set of responses (average of 260 sweeps), and obtains approximately the same final SNR. The relation between the performances of the proposed technique and the SNR of the rapidly acquired responses before filtering is also investigated.