ICES Database ElectroMagnetic Field Literature Search Engine |
 |
| |
| Home |
| View EMF Studies (Static,ELF) 0-300 Hz |
| View EMF Studies (Intermediate) 300 Hz-300 KHz |
| View EMF Studies (RF/mmW/THz) 300 kHz-300 GHz |
| Advanced Search |
| Citation List (Author Search) |
(Database last updated on Mar 27, 2024)
| ID Number | 1549 | |
| Study Type | Engineering & Physics | |
| Model | Computational Dosimetry & Experimental Models of Humans. (catch all). | |
| Details | Computational Dosimetry & Experimental Models of Humans (catch all) - SIGNIFICANT STUDIES: Dimbylow et al: Numerical (FDTD) SAR calculations were performed using an adult head and eye models and frequencies of common 900 & 1800 MHz (GSM) and 400 MHz (Tetra) mobile phones. For 900 and 1800 MHz (GSM) phones, ICNIRP compliance standards for peak local exposure were not exceeded in the head. For Tetra, SAR was determined to be within ICNIRP compliance for a representative handset operating at a maximal power output of 1 watt at positions both in front of the face and at both sides of the head. For a hypothetical 3 watt handset (no 3 watt handsets currently available as a product, but the Tetra spec allows for handsets to transmit at up to 3 watts) with a helical antenna (the same is not true for a monopole antenna), the ICNIRP public exposure limit can be exceeded by 50% if held in the position of maximal SAR and constantly transmitting at full output power for 6 minutes continuously. In the 2002 study, more detailed numerical (FDTD) SAR calculations were performed using an adult as well as 10-, 5- and 1-year-old children models and frequencies from 10 MHz to 3 GHz. From SAR calculations, corresponding external fields were identified that would produce a whole-body average of 0.4W/kg (NRPB guidelines and ICNIRP occupational guidelines) and 0.08 W/kg (ICNIRP public-exposure guidelines). Calculations revealed that at 2 - 3 GHz, the 0.08 W/kg SAR threshold is exceeded at the external field limit outlined in the current ICNIRP and IEEE C95.1 (1997) guidelines suggesting the current limits basically do not accommodate the current 50x safety factor modeled into the public safety exposure limits. In addition, ankle currents were modeled under grounded conditions and calculations suggested that at the resonant frequency in adults (10 MHz), localized SAR exposure (over 10 grams) as outlined in the ICNIRP guidelines could be exceeded. The author suggests that a secondary reference level for limb current would be necessary at that frequency to comply with the existing threshold limit. In a 2007 paper, the authors report on various errors associated with standard finite models to simulate SAR in human phantoms. Cardis et al (2008): In a study of the SAR distribution pattern measured experimentally within phantom head models from 110 different mobile phone models, the authors report SAR distributions are similar. Phone model and antenna type do not seem to affect the patern significantly. The difference between measurement in the "touch" vs. "tilt" position also did not seem to change the SAR distribution that much, except for Japanese 1500 MHz PDC phones. Most of the energy is absorbed in the temporal area of the head and temporal lobe of the brain, although some significant absorbtion occurs in the occupital, frontal, and cerebellum. At a depth of ~8 cm, however, the relative SAR was ~1% or less. The penetration of 900 MHz was slightly deeper than with 1500 MHz PDC, 1800 Mhz GSM, or 2 GHz UMTS, but significant SAR never penetrated more than 2-3 cm within the brain tissue Martinez-Burdalo et al: Numerical (FDTD) calculations were performed in a scaled human head model with exposure from 900 and 1800 MHz (GSM) mobile phones. Peak SAR (over 1 gram / IEEE as well as over 10 grams / ICNIRP) peak decrease from the compliance limit as the head size increases, while decreasing head size increases energy absorbed in the brain. The authors conclude that childrens brains can be expected to receive higher peak SAR values on average than adult brains with similar mobile phone use / exposure. Similar distributions exist with eye size. However, the standard limits were only exceeded in the unpractical situation where the antenna was located at a very short distance in front of the eye. In a related study, the authors looked at whether exposure of workers in the near-field region of a hypothetical 30 watt base station antenna (operating at either 900, 1800, and 2170 MHz) could exceed occupational exposure limits in terms of SAR even if the basic restrictions in terms of field strength were met. The authors report safe distances for general public exposure limits (per ICNIRP and IEEE C95.1 standards) were approximately 5 to 11 wavelengths away depending upon the antenna and the frequency. For occupational exposures these distances were between 0.5 to 2 wavelengths. However, SAR limits could be exceeded in some cases at these distances. In a subsequent study the authors looked at typical exposure use cases from WiFi (laptop) and Bluetooth devices and reported no levels that were in excess of the ICNIRP limits. AUTHORS' ABSTRACT: Angelone, Bit-Babik and Chou (2010):An electromagnetic analysis of a human head with EEG electrodes and leads exposed to RF-field sources was performed by means of Finite-Difference Time-Domain simulations on a 1-mm(3) MRI-based human head model. RF-field source models included a half-wave dipole, a patch antenna, and a realistic CAD-based mobile phone at 915 MHz and 1748 MHz. EEG electrodes/leads models included two configurations of EEG leads, both a standard 10-20 montage with 19 electrodes and a 32-electrode cap, and metallic and high resistive leads. Whole-head and peak 10-g average SAR showed less than 20% changes with and without leads. Peak 1-g and 10-g average SARs were below the ICNIRP and IEEE guideline limits. Conversely, a comprehensive volumetric assessment of changes in the RF field with and without metallic EEG leads showed an increase of two orders of magnitude in single-voxel power absorption in the epidermis and a 40-fold increase in the brain during exposure to the 915 MHz mobile phone. Results varied with the geometry and conductivity of EEG electrodes/leads. This enhancement confirms the validity of the question whether any observed effects in studies involving EEG recordings during RF-field exposure are directly related to the RF fields generated by the source or indirectly to the RF-field-induced currents due to the presence of conductive EEG leads. AUTHORS' ABSTRACT: Hirata and Fujiwara (2010): The present study investigates the relationship between the mass-averaged specific absorption rate (SAR) and temperature elevation in anatomically based Japanese head models due to the dipole antenna. The frequency region considered is from 1 to 6 GHz. Our attention is focused on the averaging mass of SAR, which maximizes the correlation with local temperature elevation. An averaged SAR over 10 g was found to reasonably correlate with local temperature elevation even for frequencies from 3 to 6 GHz, although the correlation became relatively worse as compared with lower frequencies. The dominant factor influencing the correlation is suggested to be the thermal diffusion length and the penetration depth of electromagnetic waves. The correlation of local temperature elevation to mass-averaged SAR is was influenced by 10% or less due to the pinna, model heterogeneity and the antenna position relative to the head model. AUTHOR'S ABSTRACT: Gasmelseed 2011 (#5091): This article describes the analysis of electromagnetic energy absorption properties of models of the human eye with common visual disorders. The investigation addresses two types of visual disorders, namely hyperopia (or farsightedness) and myopia (or nearsightedness). Calculations were carried out using plane multilayered method with common wireless communication frequencies of 900, 1800, and 2450 MHz. The effect of wireless radiation on the eye is studied by calculation of the specific absorption rate (SAR) in three different eye models. The results of the simulations confirmed the anticipated and more complex relationship between absorption and structural variations of the eye at these frequencies. AUTHORS' ABSTRACT: Bakker et al. 2011 #5095): To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR(wb)) are provided to keep the whole-body temperature increase (T(body, incr)) under 1 °C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR(10g)) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T(incr, max)) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T(incr, max) in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 °C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T(incr, max) as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T(incr, max) for specified durations of exposure. AUTHORS' ABSTRACT: Beard et al. 2006 (IEEE #5105): The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, Sub-Committee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position. AUTHORS' ABSTRACT: Hadjem et al. 2010 (IEEE #5106): This paper deals with the influence of new uses of mobile phones (such as short message service, multimedia messaging service, video, etc.) on the SAR induced in different heads models. In particular, the exposure of children will be analyzed. For this reason, three heterogeneous models have been used in this study, two children head models (9 and 15 years old) and one adult head model ( visible human ). The specific anthropomorphic mannequin (SAM) homogeneous head model has been also used to compare all the results and to confirm that the SAM model always overestimates adult and child head exposure. Two handset models have been used: the first model is a triband mobile phone having a patch antenna and the second model is a generic model (known as IEEE mobile phone) having a monopole antenna inside a metal box covered by plastic. A comparison on SAR between adult and child head is given using the finite-difference time-domain method. The results of new positions are comparedwith respect to the results obtained with the voice position. These studies have been performed at 900, 1800, and 2100 MHz for the triband mobile phone and at 835, 1900, and 2100 MHz for the IEEE mobile phone. The comparison of the maximum SAR over 10 g between the different heads models (9 and 15 year olds and adult) shows that results were nearly similar. It was also pointed out that the value of the maximum local peak SAR in the SAM was always higher than in the adult and children models. AUTHORS' ABSTRACT: Davis and Balzano 2009 (IEEE #4544): This paper describes the results of an international intercomparison of specific absorption rate (SAR) measurements made with actual wireless telephones, following a similar program involving standard dipole antennas and flat phantoms. This study involved 17 laboratories in 11 different countries. All the participating laboratories supplied their data to the University of Maryland. The test of the reliability of dosimetric assessments involved an intercomparison of SAR measurements made in a head phantom filled with simulant fluid. These measurements are made using small electric field probes placed in the head phantoms. Two different wireless phones, a Motorola Model V290 and a Nokia Model 6310, were circulated to each participating laboratory, which provided its own electric field probes, head phantom, base station emulator to activate the phones, scanning system, and a simulant fluid prepared to a required prescription. The measurement technique to be followed was guided by the specifications given in the IEEE 1528 Compliance Standard. At the conclusion of each laboratorys measurements, its results were communicated to the coordinators including 1 and 10 g maximum SARs for each phone at both 900 and 1800 MHz, and for the left and right cheeks, and left and right tilt positions relative to the phantom. AUTHORS' ABSTRACT: Simba et al. 2009 (IEEE #4547): This paper presents a detailed numerical investigation to determine whether or not an increased specific absorption rate (SAR) in an adult using a mobile phone inside an elevator due to the multireflections of electromagnetic fields from the walls exceed the RF-exposure guidelines. A fully realistic heterogeneous human body model and an actual elevator size were employed. The nonuniform mesh finite-difference time-domain technique and a supercomputer were employed to obtain the SAR and other important parameters. The mobile phone was modeled as a lamda/2 dipole antenna placed at a distance of 16 mm from the head. For computations, operating frequencies of 900, 1500, and 2000 MHz with transmitting power of 250 mW were used. Computed results show that the peak spatial-average 10-g SAR depends on the position of the passenger and the antenna against the elevator walls. We observed a substantial increase in the whole-body average SAR and peak 10-g SAR values of the passenger in the elevator over their respective free-space values. However, the maximum values obtained do meet the basic restrictions described in the international RF safety guidelines. For example, the maximum values of the whole-body average and peak spatial-average SAR were 4.4% and 78% of the international RF safety guideline, respectively. AUTHORS' ABSTRACT: Lu and Ueno (2012)[IEEE #5146]: The steady increase of mobile phone usage, especially mobile phones by children, has led to a rising concern about the possible adverse health effects of radio frequency electromagnetic field exposure. The objective of this work is to study whether there is a larger radio frequency energy absorption in the brain of a child compared to that of an adult. For this reason, three high-resolution models, two child head models (6 - and 11-year old) and one adult head model (34-year old) have been used in the study. A finite-difference time-domain method was employed to calculate the specific absorption rate (SAR) in the models from exposure to a generic handset at 1750 MHz. The results show that the SAR distributions in the human brain are age-dependent, and there is a deeper penetration of the absorbed SAR in the childs brain. The induced SAR can be significantly higher in subregions of the childs brain. In all of the examined cases, the SAR values in the brains of a child and an adult are well below the IEEE safety standard. AUTHORS' ABSTRACT: Asmae and Homayoon 2012 (IEEE #5156): This paper describes the various aspects of biological effects of high frequency electromagnetic fields on the human body. Specific Absorption Rate in human model by the IEC62209-1 standard is simulated and evaluated. Also the effect of change in physical parameter on Specific Absorption Rate is simulated and compared by IEC standard model. High Frequency Field Simulation Structure software has been used for simulations. AUTHORS' ABSTRACT: Yu et al. 2012 (IEEE #5172): To investigate the influence of dentures on electromagnetic energy absorption during the daily use of a mobile phone, a high-resolution head phantom based on the Visible Chinese Human dataset was reconstructed. Simulations on phantoms with various dentures were performed by using the finite-difference time-domain method with a 0.47 wavelength dipole antenna and a mobile phone model as radiation sources at 900 and 1800 MHz. The Specific energy Absorption Rate (SAR) values including 1 and 10 g average SAR values were assessed. When the metallic dental crowns with resonance lengths of approximately one-third to one-half wavelength in the tissue nearby are parallel to the radiation source, up to 121.6% relative enhancement for 1 g average SAR and 17.1% relative enhancement for 10 g average SAR are observed due to the resonance effect in energy absorption. When the radiation sources operate in the normal configuration, the 10 g average SAR values are still in compliance with the basic restrictions established by the Institute of Electrical and Electronic Engineers (IEEE) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP), indicating that the safety limits will not be challenged by the usage of dentures. AUTHORS' ABSTRACT: Bamba et al. 2013 (IEEE #5263): Experimentally assessing the whole-body specific absorption rate (SAR(wb) ) in a complex indoor environment is very challenging. An experimental method based on room electromagnetics theory (accounting only the line-of-sight as specular path) is validated using numerical simulations with the finite-difference time-domain method. Furthermore, the method accounts for diffuse multipath components (DMC) in the total absorption rate by considering the reverberation time of the investigated room, which describes all the losses in a complex indoor environment. The advantage of the proposed method is that it allows discarding the computational burden because it does not use any discretizations. Results show good agreement between measurement and computation at 2.8 GHz, as long as the plane wave assumption is valid, that is, at large distances from the transmitter. Relative deviations of 0.71% and 4% have been obtained for far-field scenarios, and 77.5% for the near field-scenario. The contribution of the DMC in the total absorption rate is also quantified here, which has never been investigated before. It is found that the DMC may represent an important part of the total absorption rate; its contribution may reach up to 90% for certain scenarios in an indoor environment. AUTHORS' ABSTRACT: Karampatzakis and Samaras 2013 (IEEE #5266): Human exposure to millimeter wave (MMW) radiation is expected to increase in the next several years. In this work, we present a thermal model of the human eye under MMW illumination. The model takes into account the fluid dynamics of the aqueous humor and predicts a frequency-dependent reversal of its flow that also depends on the incident power density. The calculated maximum fluid velocity in the anterior chamber and the temperature rise at the corneal apex are reported for frequencies from 40 to 100 GHz and different values of incident power density. AUTHORS' ABSTRACT: Vermeeren et al. 2013 (IEEE #5268): Assessing the whole-body absorption in a human in a realistic environment requires a statistical approach covering all possible exposure situations. This article describes the development of a statistical multi-path exposure method for heterogeneous realistic human body models. The method is applied for the 6-year-old Virtual Family boy (VFB) exposed to the GSM downlink at 950 MHz. It is shown that the whole-body SAR does not differ significantly over the different environments at an operating frequency of 950 MHz. Furthermore, the whole-body SAR in the VFB for multi-path exposure exceeds the whole-body SAR for worst-case single-incident plane wave exposure by 3.6%. Moreover, the ICNIRP reference levels are not conservative with the basic restrictions in 0.3% of the exposure samples for the VFB at the GSM downlink of 950 MHz. The homogeneous spheroid with the dielectric properties of the head suggested by the IEC underestimates the absorption compared to realistic human body models. Moreover, the variation in the whole-body SAR for realistic human body models is larger than for homogeneous spheroid models. This is mainly due to the heterogeneity of the tissues and the irregular shape of the realistic human body model compared to homogeneous spheroid human body models. AUTHOR'S ABSTRACT: Kuhn 2013 (IEEE #5275): Mobile phones present the strongest source of radiofrequency electromagnetic held exposure to the human head. Mobile phones are routinely assessed with respect to safety by specific absorption rate measurements at maximum output power. The difference of the exposure due to power control during normal usage was evaluated. A mobile measurement system to assess the effect of the power control in real networks was developed. It presents a realistic load to the phone and is able to measure the output power and band synchronously for the GSM900, DCS1800, and UMTS1950 bands. The system has a dynamic range of 60 dB and a measurement uncertainty of <;1 dB for GSM and <;1.5 dB for UMTS. Using the system, three mobile phones were evaluated in the three Swiss networks in urban and rural areas. The phones were tested in dual system (GSM and UMTS) and GSM only modes. The results show a small change of the mean output power in GSM mode (from -2 to -10 dB) compared to 30-dB power control dynamic range. The mean output power in UMTS was a factor >100 lower than GSM. In urban areas, UMTS was generally available and preferably used by the phones with rare fall backs to GSM. In the suburban/rural area, UMTS was hardly available or used by the phones. AUTHORS' ABSTRACT: Thielens et al. 2013 (IEEE #5292): The organ-specific averaged specific absorption rate (SARosa ) in a heterogeneous human body phantom, the Virtual Family Boy, is determined for the first time in five realistic electromagnetic environments at the Global System for Mobile Communications downlink frequency of 950 MHz. We propose two methods based upon a fixed set of finite-difference time-domain (FDTD) simulations for generating cumulative distribution functions for the SARosa in a certain environment: an accurate vectorial cell-wise spline interpolation with an average error lower than 1.8%, and a faster scalar linear interpolation with a maximal average error of 14.3%. These errors are dependent on the angular steps chosen for the FDTD simulations. However, it is demonstrated that both methods provide the same shape of the cumulative distribution function for the studied organs in the considered environments. The SARosa depends on the considered organ and the environment. Two factors influencing the SARosa are investigated for the first time: conductivity over the density ratio of an organ, and the distance of the organ's center of gravity to the body's surface and exterior of the phantom. A non-linear regression with our model provides a correlation of 0.80. The SARosa due to single plane-wave exposure is also investigated; a worst-case single plane-wave exposure is determined for all studied organs and has been compared with realistic SARosa values. There is no fixed worst-case polarization for all organs, and a single plane-wave exposure condition that exceeds 91% of the SARosa values in a certain environment can always be found for the studied organs. AUTHORS' ABSTRACT: Fiocchi et al. (IEEE #5304): The spread of radio frequency identification (RFID) devices in ubiquitous applications without their simultaneous exposure assessment could give rise to public concerns about their potential adverse health effects. Among the various RFID system categories, the ultra high frequency (UHF) RFID systems have recently started to be widely used in many applications. This study addresses a computational exposure assessment of the electromagnetic radiation generated by a realistic UHF RFID reader, quantifying the exposure levels in different exposure scenarios and subjects (two adults, four children, and two anatomical models of women 7 and 9 months pregnant). The results of the computations are presented in terms of the whole-body and peak spatial specific absorption rate (SAR) averaged over 10 g of tissue to allow comparison with the basic restrictions of the exposure guidelines. The SAR levels in the adults and children were below 0.02 and 0.8 W/kg in whole-body SAR and maximum peak SAR levels, respectively, for all tested positions of the antenna. On the contrary, exposure of pregnant women and fetuses resulted in maximum peak SAR10 g values close to the values suggested by the guidelines (2 W/kg) in some of the exposure scenarios with the antenna positioned in front of the abdomen and with a 100% duty cycle and 1 W radiated power. AUTHORS' ABSTRACT: Zhao et al. 2013 (IEEE #5305): This paper mainly focuses on the specific absorption rate (SAR) of the dual-element LTE MIMO antenna in mobile phones. Four designs of dual-element MIMO antenna (namely, dual semi-ground-free planar inverted-F antenna (PIFA), co-located antenna, dual OG PIFA in parallel position, and dual OG PIFA in orthogonal position) are studied under four typical LTE frequency points (0.75, 0.85, 1.9, and 2.1/2.6 GHz) when the ground plane length varies from 90 to 150 mm. The SAR, when dual elements operate simultaneously, is also studied through the SAR to PEAK location spacing ratio (SPLSR) according to the FCC standard. The simulations are carried out on both an SAM head phantom and a flat phantom by CST 2011, and measurements on the flat phantom are made with iSAR and DASY4 to verify the accuracy of our simulations. AUTHORS' ABSTRACT: Mat et al. 2013 (IEEE 5362): The relationship between specific absorption rate (SAR) and antenna gain inside the head due to the metal-frame spectacles was investigated. The radio frequency (RF) energy source considered is the smartphone used in the frontal face. A computer simulation using CST Microwave Studio 2012 was used for the investigation. Two sets of dipole antennas operated at 900MHz and 1800MHz for GSM applications, were used as representative radiation sources from a mobile phone. Parametric studies were conducted to determine the optimum length of the metal rod, and the length was used to study the possibility of RF irradiation of the metal spectacles model. Then, the spectacles model was used as an analysis tool to study the interaction between gain and SAR in the head. The radiation pattern was plotted to identify the causes of the interactions. The gain decreased when the energy source was very close to the spectacles and SAR increased enormously. AUTHORS' ABSTRACT: Joseph et al. 2012 (IEEE #5378): In five countries (Belgium, Switzerland, Slovenia, Hungary, and the Netherlands), personal radio frequency electromagnetic field measurements were performed in different microenvironments such as homes, public transports, or outdoors using the same exposure meters. From the mean personal field exposure levels (excluding mobile phone exposure), whole-body absorption values in a 1-year-old child and adult male model were calculated using a statistical multipath exposure method and compared for the five countries. All mean absorptions (maximal total absorption of 3.4 µW/kg for the child and 1.8 µW/kg for the adult) were well below the International Commission on Non-Ionizing Radiation Protection (ICNIRP) basic restriction of 0.08 W/kg for the general public. Generally, incident field exposure levels were well correlated with whole-body absorptions (SAR(wb) ), although the type of microenvironment, frequency of the signals, and dimensions of the considered phantom modify the relationship between these exposure measures. Exposure to the television and Digital Audio Broadcasting band caused relatively higher SAR(wb) values (up to 65%) for the 1-year-old child than signals at higher frequencies due to the body size-dependent absorption rates. Frequency Modulation (FM) caused relatively higher absorptions (up to 80%) in the adult male. AUTHORS' ABSTRACT: Kibona et al. 2013 (IEEE #5403): Tanzania telecommunication sector has witnessed fast growth in the number of mobile telephone users now served by seven cellular operators. Until February 2012, there were about 26 million mobile phone subscribers served by more than 4,000 base stations spread all over the country. Despite the many advantages brought by these systems, there is increased public concern over possible adverse health effects due to electromagnetic fields (EMF) radiated by these equipments. This paper aimed to analyze the impact of the electromagnetic radiations from cellular phones to male sperm infertility. The cellular phones with operating frequency of 900MHz and operating frequency 1800MHz were placed at a certain distance near the male reproductive organ (testis) and then electromagnetic wave radiated by the phone were analyzed by measuring the SAR of the testis. It was concluded that there is significant impact on the male sperm fertility on the exposure of the male reproductive organ to the radiations from the cellular phones at the specified operating frequencies near the testis. Several recommendations has been provided, that radiating devices should not be placed on the male pocket trouser for storage and also making calls while the cell phone is in pocket trouser (ie using headphones to receive or make a call) should be completely avoided. AUTHORS' ABSTRACT: Pelts et al. 2014 (IEEE #5547): In this paper, for the first time a heuristic network calculator for both whole-body exposure due to indoor base station antennas or access points (downlink exposure) and localised exposure due to the mobile device (uplink exposure) in indoor wireless networks is presented. As an application, three phone call scenarios are investigated (Universal Mobile Telecommunications System (UMTS) macrocell, UMTS femtocell and WiFi voice-over-IP) and compared with respect to the electric-field strength and localised specific absorption rate (SAR) distribution. Prediction models are created and successfully validated with an accuracy of 3 dB. The benefits of the UMTS power control mechanisms are demonstrated. However, dependent on the macrocell connection quality and on the user's average phone call connection time, also the macrocell solution might be preferential from an exposure point of view for the considered scenario. AUTHORS' ABSTRACT: Valic et al. 2014 (IEEE #5555): A survey study with portable exposimeters, worn by 21 children under the age of 17, and detailed measurements in an apartment above a transformer substation were carried out to determine the typical individual exposure of children to extremely low- and radio-frequency (RF) electromagnetic field. In total, portable exposimeters were worn for >2400 h. Based on the typical individual exposure the in situ electric field and specific absorption rate (SAR) values were calculated for an 11-y-old female human model. The average exposure was determined to be low compared with ICNIRP reference levels: 0.29 ¼T for an extremely low-frequency (ELF) magnetic field and 0.09 V m1 for GSM base stations, 0.11 V m1 for DECT and 0.10 V m1 for WiFi; other contributions could be neglected. However, some of the volunteers were more exposed: the highest realistic exposure, to which children could be exposed for a prolonged period of time, was 1.35 ¼T for ELF magnetic field and 0.38 V m1 for DECT, 0.13 V m1 for WiFi and 0.26 V m1 for GSM base stations. Numerical calculations of the in situ electric field and SAR values for the typical and the worst-case situation show that, compared with ICNIRP basic restrictions, the average exposure is low. In the typical exposure scenario, the extremely low frequency exposure is <0.03 % and the RF exposure <0.001 % of the corresponding basic restriction. In the worst-case situation, the extremely low frequency exposure is <0.11 % and the RF exposure <0.007 % of the corresponding basic restrictions. Analysis of the exposures and the individual's perception of being exposed/unexposed to an ELF magnetic field showed that it is impossible to estimate the individual exposure to an ELF magnetic field based only on the information provided by the individuals, as they do not have enough knowledge and information to properly identify the sources in their vicinity. AUTHORS' ABSTRACT: Dahdouh et al. 2014 (IEEE #5692): Fetal dosimetry studies require the development of accurate numerical 3D models of the pregnant woman and the fetus. This paper proposes a 3D articulated fetal growth model covering the main phases of pregnancy and a pregnant woman model combining the utero-fetal structures and a deformable non-pregnant woman body envelope. The structures of interest were automatically or semi-automatically (depending on the stage of pregnancy) segmented from a database of images and surface meshes were generated. By interpolating linearly between fetal structures, each one can be generated at any age and in any position. A method is also described to insert the utero-fetal structures in the maternal body. A validation of the fetal models is proposed, comparing a set of biometric measurements to medical reference charts. The usability of the pregnant woman model in dosimetry studies is also investigated, with respect to the influence of the abdominal fat layer. AUTHORS' ABSTRACT: Varsier et al. 2014 (IEEE #5693): This paper analyzes the influence of pregnancy stage and fetus position on the whole-body and brain exposure of the fetus to radiofrequency electromagnetic fields. Our analysis is performed using semi-homogeneous pregnant woman models between 8 and 32 weeks of amenorrhea. By analyzing the influence of the pregnancy stage on the environmental whole-body and local exposure of a fetus in vertical position, head down or head up, in the 2100 MHz frequency band, we concluded that both whole-body and average brain exposures of the fetus decrease during the first pregnancy trimester, while they advance during the pregnancy due to the rapid weight gain of the fetus in these first stages. From the beginning of the second trimester, the whole-body and the average brain exposures are quite stable because the weight gains are quasi proportional to the absorbed power increases. The behavior of the fetus whole-body and local exposures during pregnancy for a fetus in the vertical position with the head up were found to be of a similar level, when compared to the position with the head down they were slightly higher, especially in the brain. AUTHORS' ABSTRACT: Karli and Ammor 2014 (IEEE #5749): This article describes in the first, the design of a new microstrip patch antenna for WIFI/WLAN applications (IEEE 802.11 b/g/n). Secondly, the article presents the effect of electromagnetic waves on a model of the human head exposed to the antenna designed in the ISM2450 band. By adopting a model tissue to seven layers of an adult. The objective is to evaluate the specific absorption rate (SAR) due to the propagation of electromagnetic waves along a human head for different antenna-head distances in simulation anatomic based model of the human head at a frequency of 2450 MHz. AUTHORS' ABSTRACT: Ghanmi et al. 2014 (IEEE #5783): Exposure to mobile phone radio frequency (RF) electromagnetic fields depends on many different parameters. For epidemiological studies investigating the risk of brain cancer linked to RF exposure from mobile phones, it is of great interest to characterize brain tissue exposure and to know which parameters this exposure is sensitive to. One such parameter is the position of the phone during communication. In this article, we analyze the influence of the phone position on the brain exposure by comparing the specific absorption rate (SAR) induced in the head by two different mobile phone models operating in Global System for Mobile Communications (GSM) frequency bands. To achieve this objective, 80 different phone positions were chosen using an experiment based on the Latin hypercube sampling (LHS) to select a representative set of positions. The averaged SAR over 10 g (SAR10 g) in the head, the averaged SAR over 1 g (SAR1 g) in the brain, and the averaged SAR in different anatomical brain structures were estimated at 900 and 1800 MHz for the 80 positions. The results illustrate that SAR distributions inside the brain area are sensitive to the position of the mobile phone relative to the head. The results also show that for 510% of the studied positions the SAR10 g in the head and the SAR1 g in the brain can be 20% higher than the SAR estimated for the standard cheek position and that the Specific Anthropomorphic Mannequin (SAM) model is conservative for 95% of all the studied positions. AUTHORS' ABSTRACT: Asayama, Wang and Fujiwara 2014 (IEEE #5784): Safety standards and guidelines for radio-frequency exposure are being set based on whole-body averaged SARs (WBA-SARs) and localized average SARs. In Japan, the WBA-SAR and 1 g localized average SAR are set at 0.4 W/kg and at 8 W/kg, respectively, except for the arms and legs and surface of body. The safety limits of WBA-SARs were determined from observing the behavior destruction of animals for radio-frequency exposure, but those of localized average SARs were determined under the assumption that a spatial peak SAR value does not exceed 20-fold WBA-SARs without their biological evidences. In this paper, to confirm whether or not the above assumption is valid, we calculated WBA-SARs and voxel SARs in the frequency range from 50 MHz to 2 GHz in anatomical-based human numerical models for pregnant woman and 3-year-child for vertically and horizontally polarized far-field exposures, and derived the histogram and cumulative relative frequency of voxel SARs to obtain the quantitative relationship between WBA-SARs and voxel SARs. As a result, we found that 99.90-percentile voxel SARs are not exceeding 20-fold WBA-SARs, while 99.00-percentile voxel SARs are smaller than 10-fold WBA-SARs in both human models. AUTHORS' ABSTRACT: Cabot et al. 2014 (IEEE #5790): This study analyzes the exposure of pregnant women and their fetuses in three different gestational stages to electromagnetic radiation in the radio frequency range in the near- and the far-field using numerical modeling. For far-field exposure, the power density at which the basic restriction for the whole body SAR is reached is calculated for both the mother and the fetus at whole body resonance and at frequencies between 450 MHz and 2,450 MHz. The near-field exposure is assessed at 450 MHz, 900 MHz, and 2,450 MHz using half wavelength dipoles as generic sources located at different locations around the abdomen of the mother. For the investigated cases, the exposure of the mother is always below or on the order of magnitude of the basic restriction for exposure at the reference level. When applying the reference levels for the general public, the fetus is sufficiently shielded by the mother. However, the basic restrictions for general public exposure can be exceeded in the fetus when the mother is exposed at reference levels for occupational conditions. For plane wave exposure at occupational levels, the whole body SAR in the fetus can exceed the basic restrictions for the general population by at least 1.8 dB, and in the near-field of professional devices, the 10 g SAR can be non-compliant with the product standard for the general public by > 3.5 dB. AUTHORS' ABSTRACT: Adibzadeh et al. 2014 (IEEE #5802): Among various possible health effects of mobile phone radiation, the risk of inducing cancer has the strongest interest of laymen and health organizations. Recently, the Interphone epidemiological study investigated the association between the estimated Radio Frequency (RF) dose from mobile phones and the risk of developing a brain tumor. Their dosimetric analysis included over 100 phone models but only two homogeneous head phantoms. So, the potential impact of individual morphological features on global and local RF absorption in the brain was not investigated. In this study, we performed detailed dosimetric simulations for 20 head models and quantified the variation of RF dose in different brain regions as a function of head morphology. Head models were exposed to RF fields from generic mobile phones at 835 and 1900MHz in the tilted and cheek positions. To evaluate the local RF dose variation, we used and compared two different post-processing methods, that is, averaging specific absorption rate (SAR) over Talairach regions and over sixteen predefined 1 cm3 cube-shaped field-sensors. The results show that the variation in the averaged SAR among the heads can reach up to 16.4 dB at a 1 cm3 cube inside the brain (field-sensor method) and alternatively up to 15.8 dB in the medulla region (Talairach method). In conclusion, we show head morphology as an important uncertainty source for dosimetric studies of mobile phones. Therefore, any dosimetric analysis dealing with RF dose at a specific region in the brain (e.g., tumor risk analysis) should be based upon real morphology. AUTHORS' ABSRACT: Iskra, McKenzie and Cosic 2011 (IEEE #5810): Personal dosemeters can play an important role in epidemiological studies and in radiofrequency safety programmes. In this study, a Monte Carlo approach is used in conjunction with the finite difference time domain method to obtain distributions of the electric field strength close to a human body model in simulated realistic environments. The field is a proxy for the response of an ideal body-worn electric field dosemeter. A set of eight environments were modelled based on the statistics of Rayleigh, Rice and log-normal fading to simulate outdoor and indoor multipath exposures at 450, 900 and 2100 MHz. Results indicate that a dosemeter mounted randomly within 10-50 mm of the adult or child body model (torso region) will on average underestimate the spatially averaged value of the incident electric field strength by a factor of 0.52 to 0.74 over the frequencies of 450, 900 and 2100 MHz. The uncertainty in results, assessed at the 95 % confidence level (between the 2.5th and 97.5th percentiles) was largest at 2100 MHz and smallest at 450 MHz. AUTHORS' ABSTRACT: Kos et al. 2011 (IEEE #5815): This study investigates occupational exposure to electromagnetic fields in front of a multi-band base station antenna for mobile communications at 900, 1800, and 2100 MHz. Finite-difference time-domain method was used to first validate the antenna model against measurement results published in the literature and then investigate the specific absorption rate (SAR) in two heterogeneous, anatomically correct human models (Virtual Family male and female) at distances from 10 to 1000 mm. Special attention was given to simultaneous exposure to fields of three different frequencies, their interaction and the additivity of SAR resulting from each frequency. The results show that the highest frequency--2100 MHz--results in the highest spatial-peak SAR averaged over 10 g of tissue, while the whole-body SAR is similar at all three frequencies. At distances > 200 mm from the antenna, the whole-body SAR is a more limiting factor for compliance to exposure guidelines, while at shorter distances the spatial-peak SAR may be more limiting. For the evaluation of combined exposure, a simple summation of spatial-peak SAR maxima at each frequency gives a good estimation for combined exposure, which was also found to depend on the distribution of transmitting power between the different frequency bands. AUTHORS' ABSTRACT: Schmid and Kuster 2015 (IEEE #5816): The objective of this paper is to compare realistic maximum electromagnetic exposure of human tissues generated by mobile phones with electromagnetic exposures applied during in vitro experiments to assess potentially adverse effects of electromagnetic exposure in the radiofrequency range. We reviewed 80 in vitro studies published between 2002 and present that concern possible adverse effects of exposure to mobile phones operating in the 900 and 1800MHz bands. We found that the highest exposure level averaged over the cell medium that includes evaluated cells (monolayer or suspension) used in 51 of the 80 studies corresponds to 2 W/kg or less, a level below the limit defined for the general public. That does not take into account any exposure nonuniformity. For comparison, we estimated, by numerical means using dipoles and a commercial mobile phone model, the maximum conservative exposure of superficial tissues from sources operated in the 900 and 1800MHz bands. The analysis demonstrated that exposure of skin, blood, and muscle tissues may well exceed 40 W/kg at the cell level. Consequently, in vitro studies reporting minimal or no effects in response to maximum exposure of 2 W/kg or less averaged over the cell media, which includes the cells, may be of only limited value for analyzing risk from realistic mobile phone exposure. We, therefore, recommend future in vitro experiments use specific absorption rate levels that reflect maximum exposures and that additional temperature control groups be included to account for sample heating AUTHORS' ABSTRACT: Jawal et al 2014 (IEEE #5832): This paper develops the kriging method to calculate the whole body Specific Absorption Rate (SAR) for any angle of incidence of a plane wave on any body model using a minimum number of Finite Difference Time Domain (FDTD) simulations. Practical application of this method is to study peoples exposure. Thanks to kriging method, it will enable to answer to the challenge of studying the exposure in a realistic environment. This approach develops a new tool in order to improve the field of stochastic dosimetry. The kriging method is applied to a girl body model in order to determine the variogram model, then this model is validated on a boy body model. Thanks to only 40 numerical SAR values, kriging method enables to estimate any SAR value with a mean relative error under 3%. AUTHOR'S ABSTRACT: Yahya 2014 (IEEE #5839): This paper investigates the impact of the in-car mobile call on the electromagnetic interaction of the mobile handset antenna and users head. This impact was evaluated from two different perspectives; First, the antenna performance, e.g., total isotropic sensitivity and total efficiency, and second, the specific absorption rate (SAR) induced in the user's head. A Yee-FDTD based electromagnetic solver was used to simulate a mobile phone in hand close proximity to head at cheek and tilt positions, and working at a frequency of 1900 MHz (GSM 1900/PCS) while making a call inside a car. A Specific Anthropomorphic Mannequin (SAM) was used to simulate the users head, a generic phone was used to simulate the mobile phone, a semi-realistic model with three tissues, i.e., skin, bone and muscle, was used to simulate the users hand, and a CAD model of Ferrari F430-brand was used to simulate the car. The results showed a considerable degradation in the mobile phone antenna performance while making a mobile phone call inside a car that may drive the mobile phone increases its radiated power to establish a successful connection with the base-station antenna, and consequently increases the induced specific absorption rate in the users head. AUTHORS' ABSTRACT: Asif et al. 2014 (IEEE #5842): In the past fifty years it has been clearly identified that the presence of biological tissues effect the performance of the antenna and considerable effort has been made to improve the characteristics of the mobile phone antenna's but very less effort has been put in to evaluate the effects of the radio frequency and energy absorption by the biological organisms and their effect. In this work as part of a bigger work package we have evaluated the effects of the handset orientation on the values of SAR and radiation efficiency as well as the effect of the distance upon these values. The study has produced some very interesting results showing that the most common way of holding the mobile phone i.e. microphone close to the mouth produces the highest SAR values. AUTHORS' ABSTRACT: Nikolovski et al. 2014 (IEEE #5843): This paper presents the effects of wearing rings and earrings on the Specific Absorption Rate (SAR) distribution due to mobile phone exposure using the inhomogeneous human model HUGO. The human model is postured in talk position and exported using the BodyFlex software program. To analyze the SAR distribution, the head and the hand of the human model are included in the simulations. The results show that, in some cases, the presence of the earring and the ring have a noticeable impact on the maximum calculated SAR value and also on the SAR distribution. AUTHORS' ABSTRACT: Moore et al. 2014 (IEEE #5855): This study considers the computationally determined thermal profile of a fully clothed, finely discretized, heterogeneous human body model, subject to the maximum allowable reference level for a 1-GHz radio frequency electromagnetic field for a worker, and also subject to adverse environmental conditions, including high humidity and high ambient temperature. An initial observation is that while electromagnetic fields at the occupational safety limit will contribute an additional thermal load to the tissues, and subsequently, cause an elevated temperature, the magnitude of this effect is far outweighed by that due to the conditions including the ambient temperature, relative humidity, and the type of clothing worn. It is envisaged that the computational modeling approach outlined in this paper will be suitably modified in future studies to evaluate the thermal response of a body at elevated metabolic rates, and for different body shapes and sizes including children and pregnant women. AUTHORS' ABSTRACT: Chan et al. 2014 (IEEE #5861): This study computationally investigates in situ electric field due to low-frequency contact current and specific absorption rate (SAR) due to high-frequency contact currents in a realistic child model and compared with those in the adult model. The in situ electric fields and SAR in the child model are found to exceed the corresponding values in the adult. At the finger tip, the electric field and SAR due to contact currents, both at the ICNIRP reference levels and IEEE Maximum Permissible Exposures, are well beyond the corresponding basic restrictions. In the remaining part, the largest difference was observed in spinal tissue, and the smallest effect was in the heart. With respect to brain and skin conductivities, one needs to strongly consider which values of tissue properties are used to interpret one's results. The in situ electric fields resulting from contact with the metal plane are similar to those for contact with the wire. AUTHORS' ABSTRACT: Li et al. 2015 (IEEE #5862): Realistic anatomical modeling is essential in analyzing human exposure to electromagnetic fields. Infants have significant physical and anatomical differences compared with other age groups. However, few realistic infant models are available. In this work, we developed one 12-month-old male whole body model and one 17-month-old male head model from magnetic resonance images. The whole body and head models contained 28 and 30 tissues, respectively, at spatial resolution of 1 mm × 1 mm × 1 mm. Fewer identified tissues in the whole body model were a result of the low original image quality induced by the fast imaging sequence. The anatomical and physical parameters of the models were validated against findings in published literature (e.g., a maximum deviation as 18% in tissue mass was observed compared with the data from International Commission on Radiological Protection). Several typical exposure scenarios were realized for numerical simulation. Dosimetric comparison with various adult and child anatomical models was conducted. Significant differences in the physical and anatomical features between adult and child models demonstrated the importance of creating realistic infant models. Current safety guidelines for infant exposure to radiofrequency electromagnetic fields may not be conservative. AUTHORS' ABSTRACT: Yang et al. 2015 (IEEE #5867): Wearable devices have been popularly used with people from different age groups. As a consequence, the concerns of their electromagnetic field (EMF) exposure to the human body and their electromagnetic interference (EMI) to the implanted medical devices have attracted many studies. The aim of this study was to evaluate the human exposure to the EMF of an active radiofrequency identification (RFID) armlet as well as its EMI to the cardiac pacemaker (CP). Different human models from various age groups were applied to assess the result variability. The scalar potential finite element method was utilized in the simulation. Local EMF exposure and the exposure to the central nerve system tissues were evaluated using different metrics. EMI to the CP was assessed in terms of the conducted voltage to the CP. The results from all the models revealed that the studied RFID armlet would not produce the EMF exposure exceeding the safety limits. The calculated interference voltage was highly dependent on the distance between the RFID armlet and the CP (i.e. the physical dimension of the individual model). The results proposed to evaluate the appropriateness of the current EMI measurement protocol for this kind of devices used by the infants. AUTHORS' ABSTRACT: Gosselin et al. 2014 (IEEE #5880): The Virtual Family computational whole-body anatomical human models were originally developed for electromagnetic (EM) exposure evaluations, in particular to study how absorption of radiofrequency radiation from external sources depends on anatomy. However, the models immediately garnered much broader interest and are now applied by over 300 research groups, many from medical applications research fields. In a first step, the Virtual Family was expanded to the Virtual Population to provide considerably broader population coverage with the inclusion of models of both sexes ranging in age from 5 to 84 years old. Although these models have proven to be invaluable for EM dosimetry, it became evident that significantly enhanced models are needed for reliable effectiveness and safety evaluations of diagnostic and therapeutic applications, including medical implants safety. This paper describes the research and development performed to obtain anatomical models that meet the requirements necessary for medical implant safety assessment applications. These include implementation of quality control procedures, re-segmentation at higher resolution, more-consistent tissue assignments, enhanced surface processing and numerous anatomical refinements. Several tools were developed to enhance the functionality of the models, including discretization tools, posing tools to expand the posture space covered, and multiple morphing tools, e.g., to develop pathological models or variations of existing ones. A comprehensive tissue properties database was compiled to complement the library of models. The results are a set of anatomically independent, accurate, and detailed models with smooth, yet feature-rich and topologically conforming surfaces. The models are therefore suited for the creation of unstructured meshes, and the possible applications of the models are extended to a wider range of solvers and physics. The impact of these improvements is shown for the MRI exposure of an adult woman with an orthopedic spinal implant. Future developments include the functionalization of the models for specific physical and physiological modeling tasks. AUTHORS' ABSTRACT: Murbach et al. 2013 (IEEE #5895): PURPOSE: Radiofrequency energy deposition in magnetic resonance imaging must be limited to prevent excessive heating of the patient. Correlations of radiofrequency absorption with large-scale anatomical features (e.g., height) are investigated in this article. THEORY AND METHODS: The specific absorption rate (SAR), as the pivotal parameter for quantifying absorbed radiofrequency, increases with the radial dimension of the patient and therefore with the large-scale anatomical properties. The absorbed energy in six human models has been modeled in different Z-positions (head to knees) within a 1.5T bodycoil. RESULTS: For a fixed B1+ incident field, the whole-body SAR can be up to 2.5 times higher (local SAR up to seven times) in obese adult models compared to children. If the exposure is normalized to 4 W/kg whole-body SAR, the local SAR can well-exceed the limits for local transmit coils and shows intersubject variations of up to a factor of three. CONCLUSIONS: The correlations between anatomy and induced local SAR are weak for normalized exposure, but strong for a fixed B1+ field, suggesting that anatomical properties could be used for fast SAR predictions. This study demonstrates that a representative virtual human population is indispensable for the investigation of local SAR levels. AUTHORS' ABSTRACT: De Santis et al. 2015 (IEEE #5905): A previous study found that incident magnetic field exposure from pulsed magnetic field therapy (PMFT) mats can exceed ICNIRP 1998 reference levels. Due to the popularity of PMFT mats for private therapeutic use, regulators need to know if the products are compliant with the basic restrictions and how overexposure can be determined. This case study's objective was to test if such products are intrinsically compliant with ICNIRP 1998 and ICNIRP 2010 basic restrictions by evaluating three different commercially-available PMFT products. In the first step, experimentally validated numerical models of these mats were developed. As a second step, the induced fields were evaluated in high-resolution anatomical models of the IT'IS Virtual Population for various lying positions and compared to the safety guidelines. As expected, a strong influence of exposure on the PMFT design, anatomy, lying position and body orientation was found. The maximum exposure of one PMFT exceeds 3.1 times the basic restrictions of ICNIRP 1998 for the central nervous system tissues and 1.36 times the limit of ICNIRP 2010 for the peripheral tissues. Body loops can significantly increase the electric fields close to the skin, e.g., when the hand and thigh are in contact during mat use. In conclusion, PMFT products are not intrinsically compliant with ICNIRP 1998 and ICNIRP 2010 basic restrictions and therefore require special considerations. AUTHORS' ABSTRACT: Deltour et al. 2011 (IEEE #5907): The three-dimensional distribution of the models was analysed to detect clusters of mobile phones producing similar spatial deposition of energy in the head. The clusters characteristics were described from the phones external features, frequency band and communication protocol. Compliance measurements with phones in cheek and tilt positions, and on the left and right side of a physical phantom were used. Phones used the Personal Digital Cellular (PDC), Code division multiple access One (CdmaOne), Global System for Mobile Communications (GSM) and Nordic Mobile Telephony (NMT) communication systems, in the 800, 900, 1500 and 1800 MHz bands. Each phones measurements were summarized by the half-ellipsoid in which the SAR values were above half the maximum value. Cluster analysis used the Partitioning Around Medoids algorithm. The dissimilarity measure was based on the overlap of the ellipsoids, and the Manhattan distance was used for robustness analysis. Within the 800 MHz frequency band, and in part within the 900 MHz and the 1800 MHz frequency bands, weak clustering was obtained for the handset shape (bar phone, flip with top and flip with central antennas), but only in specific positions (tilt or cheek). On measurements of 120 phones, the three-dimensional distribution of SAR in phantom models did not appear to be related to particular external phone characteristics or measurement characteristics, which could be used for refining the assessment of exposure to radiofrequency energy within the brain in epidemiological studies such as the Interphone. AUTHORS' ABSTRACT: Li and Wu 2015 (IEEE #5908): The use of electronic article surveillance (EAS) systems has become popular in many public sites. As a consequence, concern has risen about infant exposure to magnetic fields (MFs) from this kind of device. To evaluate infant exposure to MFs of an EAS system (operating at 125 kHz and 13.56 MHz), we numerically compared dosimetric results among adult, child and infant models. Results revealed that postures insignificantly influenced dosimetric results if there was a similar cross-sectional area under exposure. Although safety limits are unlikely to be exceeded, the infant has higher SAR values for brain and central nervous system tissues compared with adult (1.5x at 125 kHz and 112x at 13.56 MHz), which deserve further investigation. Infants specific anatomy (e.g., non-proportionally large head and high fat content) did not induce higher SAR values. The numerical models developed in the study (stroller and postured infant models) could be freely used for nonprofit academic research. AUTHORS' ABSTRACT: Bamba et al. 2015 (IEEE #5915): An original experimental protocol is developed to assess the whole-body absorption cross section of objects with arbitrary shapes and materials in diffuse fields at any operating frequency. This approach is important for dosimetry specifically in realistic environments wherein diffuse fields can be prominent. For this application, the knowledge of the whole-body specific absorption rate is critical and can be determined from the human wholebody absorption cross section. The whole-body absorption cross section is obtained from measurements performed in a stirred-mode reverberating chamber processed with the high-resolution parameter estimator RiMAX. To validate the proposed approach and highlight its robustness, the whole-body absorption cross section of a cylindrical phantom is experimentally and numerically determined at 1800 MHz. For both methods, the whole-body absorption cross section is shown to be independent on the orientation of the transceivers, indicating that it is indeed caused by diffuse fields. A good agreement is obtained between experimental and numerical finite-difference time-domain results with a relative deviation of about 17%. From the validation of this approach, the measurement protocol is applied to a real human at 1800 MHz resulting in a whole-body absorption cross section of 0.95 m2, 1.01 m2, and 1.11 m2 for a sitting, standing, and standing with stretched arms posture, respectively. AUTHORS' ABSTRACT: Mat et al. 2015 (IEEE #5939): This study presents a numerical analysis of the specific absorption rate in a head model exposed to electromagnetic fields when a real implant-retained prosthetic ear is attached to the side of the head. A set of dipole antennas operating at 900, 1800 and 2100 MHz were rotated to investigate the effect of frequency and polarisation. The maximum average 1 and 10 g specific absorption rates (SAR) have been presented to show the relative e |
|
| Findings | ||
| Status | Completed With Publication | |
| Principal Investigator | ||
| Funding Agency | ????? | |
| Country | UNITED STATES | |
| References |
|
|
| Comments | AUTHORS' ABSTRACTS CONTINUED: AUTHOR'S ABSTRACT: Keshvari et al. 2016 (IEEE #6381): This paper presents the results of two computational large scale studies using highly realistic exposure scenarios, MRI based human head and hand models, and two mobile phone models. The objectives are (i) to study the relevance of age when people are exposed to RF by comparing adult and child heads and (ii) to analyze and discuss the conservativeness of the SAM phantom for all age groups. Representative use conditions were simulated using detailed CAD models of two mobile phones operating between 900 MHz and 1950 MHz including configurations with the hand holding the phone, which were not considered in most previous studies. The peak spatial-average specific absorption rate (psSAR) in the head and the pinna tissues is assessed using anatomically accurate head and hand models. The first of the two mentioned studies involved nine head-, four hand- and two phone-models, the second study included six head-, four hand- and three simplified phone-models (over 400 configurations in total). In addition, both studies also evaluated the exposure using the SAM phantom. Results show no systematic differences between psSAR induced in the adult and child heads. The exposure level and its variation for different age groups may be different for particular phones, but no correlation between psSAR and model age was found. The psSAR from all exposure conditions was compared to the corresponding configurations using SAM, which was found to be conservative in the large majority of cases. AUTHOR'S ABSTRACT: Liorni et al.2016 (IEEE #6385): So far, the assessment of the exposure of children, in the ages 0-2 years old, to relatively new radio-frequency (RF) technologies, such as tablets and femtocells, remains an open issue. This study aims to analyse the exposure of a one year-old child to these two sources, tablets and femtocells, operating in uplink (tablet) and downlink (femtocell) modes, respectively. In detail, a realistic model of an infant has been used to model separately the exposures due to (i) a 3G tablet emitting at the frequency of 1940 MHz (uplink mode) placed close to the body and (ii) a 3G femtocell emitting at 2100 MHz (downlink mode) placed at a distance of at least 1 m from the infant body. For both RF sources, the input power was set to 250 mW. The variability of the exposure due to the variation of the position of the RF sources with respect to the infant body has been studied by stochastic dosimetry, based on polynomial chaos to build surrogate models of both whole-body and tissue specific absorption rate (SAR), which makes it easy and quick to investigate the exposure in a full range of possible positions of the sources. The major outcomes of the study are: (1) the maximum values of the whole-body SAR (WB SAR) have been found to be 9.5 mW kg(-1) in uplink mode and 65 ¼W kg(-1) in downlink mode, i.e. within the limits of the ICNIRP 1998 Guidelines; (2) in both uplink and downlink mode the highest SAR values were approximately found in the same tissues, i.e. in the skin, eye and penis for the whole-tissue SAR and in the bone, skin and muscle for the peak SAR; (3) the change in the position of both the 3G tablet and the 3G femtocell significantly influences the infant exposure. AUTHOR'S ABSTRACT: Bolte 2016 (IEEE #6433): Personal exposure measurements of radio frequency electromagnetic fields are important for epidemiological studies and developing prediction models. Minimizing biases and uncertainties and handling spatial and temporal variability are important aspects of these measurements. This paper reviews the lessons learnt from testing the different types of exposimeters and from personal exposure measurement surveys performed between 2005 and 2015. Applying them will improve the comparability and ranking of exposure levels for different microenvironments, activities or (groups of) people, such that epidemiological studies are better capable of finding potential weak correlations with health effects. Over 20 papers have been published on how to prevent biases and minimize uncertainties due to: mechanical errors; design of hardware and software filters; anisotropy; and influence of the body. A number of biases can be corrected for by determining multiplicative correction factors. In addition a good protocol on how to wear the exposimeter, a sufficiently small sampling interval and sufficiently long measurement duration will minimize biases. Corrections to biases are possible for: non-detects through detection limit, erroneous manufacturer calibration and temporal drift. Corrections not deemed necessary, because no significant biases have been observed, are: linearity in response and resolution. Corrections difficult to perform after measurements are for: modulation/duty cycle sensitivity; out of band response aka cross talk; temperature and humidity sensitivity. Corrections not possible to perform after measurements are for: multiple signals detection in one band; flatness of response within a frequency band; anisotropy to waves of different elevation angle. An analysis of 20 microenvironmental surveys showed that early studies using exposimeters with logarithmic detectors, overestimated exposure to signals with bursts, such as in uplink signals from mobile phones and WiFi appliances. Further, the possible corrections for biases have not been fully applied. The main findings are that if the biases are not corrected for, the actual exposure will on average be underestimated. AUTHORS' ABSTRACT: In this article, the effect of the existence and position of dental implants on antenna parameters, specific absorption rate (SAR), and current density induced by the metal part in the human head is investigated. A SAM phantom, belonging to the Computer Simulation Technology (CST) Microwave Studio, and a dipole antenna radiating at 900 and 1,800 MHz are used in this investigation. SAR and current density distribution are compared in a head model with different positions of implants In addition, the antennas scattering parameter (S-parameter) differences caused by the implant location are presented. Finally, according to the clinical reports in the literature, some possible explanations are provided about the dysregulation balance and headaches caused by implants. AUTHORS' ABSTRACT: Imran et al. 2016 (IEEE #6623): In this paper the presented research work analyzes the effects of electromagnetic (EM) radiation of mobile phone on human head. The EM radiation is measured based on Specific Absorption Rate (SAR). The human head is generally exposed to mobile phones operating at communication (GSM, CDMA etc) frequency bands. The radiation absorption analyzed through simulations by applying frequency domain using Comsole Multiphysics software. The specific absorption rate (SAR) was measured for different positions of mobile phone. SARs exhibited in much lower values as the mobile phone held in far position from human brain. This measurement demonstrates SAR is high at close distance; effectively the temperature increase is also high as the distance reduces. Comparative analysis also shows that FR4 substrate demonstrates higher SAR and temp raise compared to Rogers RO3006 and Rogers RO4003 substrates. AUTHORS' ABSTRACT: Hashimoto et al. 2017 (IEEE #6678): Incident power density is used as the dosimetric quantity to specify the restrictions on human exposure to electromagnetic fields at frequencies above 3 or 10 GHz in order to prevent excessive temperature elevation at the body surface. However, international standards and guidelines have different definitions for the size of the area over which the power density should be averaged. This study reports computational evaluation of the relationship between the size of the area over which incident power density is averaged and the local peak temperature elevation in a multi-layer model simulating a human body. Three wave sources are considered in the frequency range from 3 to 300 GHz: an ideal beam, a half-wave dipole antenna, and an antenna array. One-dimensional analysis shows that averaging area of 20 mm × 20 mm is a good measure to correlate with the local peak temperature elevation when the field distribution is nearly uniform in that area. The averaging area is different from recommendations in the current international standards/guidelines, and not dependent on the frequency. For a non-uniform field distribution, such as a beam with small diameter, the incident power density should be compensated by multiplying a factor that can be derived from the ratio of the effective beam area to the averaging area. The findings in the present study suggest that the relationship obtained using the one-dimensional approximation is applicable for deriving the relationship between the incident power density and the local temperature elevation. AUTHORS' ABSTRACT: Masumnia-Bisheh et al. 2017 (IEEE #6687): AbstractIn this paper, the stochastic finite-difference time domain (S-FDTD)method is employed to calculate the standard deviation of specific absorption rate (SAR) in a two-dimensional (2-D) slice of human head. S-FDTD calculates both the mean and standard deviation of SAR caused by variability or uncertainty in the electrical properties of the human head tissues. The accuracy of the S-FDTD result is controlled by the approximations for correlation coefficients between the electrical properties of the tissues and the fields propagating in them. Hence, different approximations for correlation coefficients are tested in order to evaluate their effect on the standard deviation of SAR. The 1-D Monte Carlo correlation coefficient (MC-CC) approximation reported in our previous work is successfully extended to 2-D and also tested for the head model. Then, all the results are compared with that of full-fledged Monte Carlo method (considered as gold standard in statistical simulations). In order to accelerate the simulations, the proposed algorithm is run on graphics processing unit by exploiting OpenACC application program interface. Using different correlation coefficients shows that the extended 2-D MC-CC S-FDTD results are very close to that ofMonte Carlo and yield more accurate results than other approximations in SAR calculations. AUTHORS' ABSTRACT: Fernandez-Rodriquez and de Salles 2016 (IEEE #6695): Specific absorption rate (SAR) simulation may be used to assess exposure levels, health risk and compliance with recommendations of wireless devices EMF exposure limits. When developing a numerical model of a human head the segmentation system decides the boundary between the modeled tissues. E.g., using different strategies (thresholds or parameters) some tissues may be modeled thinner or thicker. The objective of this work is to investigate the sensitivity of the skull thickness in the SAR. Starting with a single DICOM study, two models differing only in the skull thickness were developed. The bones mass of one of the models were 35% lighter than the other's. Under the same exposure conditions, the 1g-psSAR in the brain of the thin skull model was 5% higher than the 1g-psSAR of the thick skull model. This difference applies to the particular conditions of the performed simulations, then we can conclude that the expected uncertainty related to the skull modelling is of this order of value. We also can expect higher SAR differences corresponding to age related skull thickness differences between children and adults. AUTHORS' ABSTRACT: Moore et al. 2017 (IEEE #6714): This study considers the computationally determined thermal profile of a finely discretized, heterogeneous human body model, simulating a radiofrequency electromagnetic field (RF-EMF) worker wearing protective clothing subject to RF-EMF exposure, and subject to various environmental conditions including high ambient temperature and high humidity, with full thermoregulatory mechanisms in place. How the human body responds in various scenarios was investigated, and the information was used to consider safety limits in current international RF-EMF safety guidelines and standards. It was found that different environmental conditions had minimal impact on the magnitude of the thermal response due to RF-EMF exposure, and that the current safety factor of 10 applied in international RF-EMF safety guidelines and standards for RF-EMF workers is generally conservative, though it is only narrowly so when workers are subjected to the most adverse environmental conditions. AUTHORS' ABSTRACT: Fiedler et al. 2017 (IEEE #6720): At ultra-high fields, the assessment of radiofrequency (RF) safety presents several new challenges compared to low-field systems. Multi-channel RF transmit coils in combination with parallel transmit techniques produce time-dependent and spatially varying power loss densities in the tissue. Further, in ultra-high-field systems, localized field effects can be more pronounced due to a transition from the quasistationary to the electromagnetic field regime. Consequently, local information on the RF field is required for reliable RF safety assessment as well as for monitoring of RF exposure during MR examinations. Numerical RF and thermal simulations for realistic exposure scenarios with anatomical body models are currently the only practical way to obtain the requisite local information on magnetic and electric field distributions as well as tissue temperature. In this article, safety regulations and the fundamental characteristics of RF field distributions in ultra-high-field systems are reviewed. Numerical methods for computation of RF fields as well as typical requirements for the analysis of realistic multi-channel RF exposure scenarios including anatomical body models are highlighted. In recent years, computation of the local tissue temperature has become of increasing interest, since a more accurate safety assessment is expected because temperature is directly related to tissue damage. Regarding thermal simulation, bio-heat transfer models and approaches for taking into account the physiological response of the human body to RF exposure are discussed. In addition, suitable methods are presented to validate calculated RF and thermal results with measurements. Finally, the concept of generalized simulation-based specific absorption rate (SAR) matrix models is discussed. These models can be incorporated into local SAR monitoring in multi-channel MR systems and allow the design of RF pulses under constraints for local SAR. AUTHORS' ABSTRACT: Chiaramello et al. 2017 (IEEE #6806): The continuous development of Radio-Frequency (RF) devices used in every-day life highlights the need of conducting appropriate health risk assessment due to Radio- Frequency Electromagnetic Fields (RF-EMF) exposure, especially for the fetal exposure in realistic scenarios. In this study, we used stochastic dosimetry, an approach that combines electromagnetic computational techniques and statistics, to assess the fetal exposure to a 4G LTE tablet in realistic scenarios, assessing the influence of the position of the tablet, the gestational age of the fetus and the frequency of the emitting antenna. Results showed that the exposure in terms of Specific Absorption Rate (SAR) was within the limits of the ICNIRP 1998 general public Guidelines in all the considered scenarios. The position of the tablet was very influential for the induced SAR in the fetus, resulting in Quartile Coefficient of Dispersion always higher than 40%. The level of exposure for the later pregnancy was found to be higher than those for the early pregnancy. As to the effect of the emitting frequency of the tablet, we found that the higher the frequency, the lower the induced SAR in the fetus. AUTHORS' ABSTRACT: Sasaki et al. 2017 (IEEE #6823): In this study, we present an assessment of human-body exposure to an electromagnetic field at frequencies ranging from 10 GHz to 1 THz. The energy absorption and temperature elevation were assessed by solving boundary value problems of the one-dimensional Maxwell equations and a bioheat equation for a multilayer plane model. Dielectric properties were measured [Formula: see text] at frequencies of up to 1 THz at body temperature. A Monte Carlo simulation was conducted to assess variations of the transmittance into a skin surface and temperature elevation inside a body by considering the variation of the tissue thickness due to individual differences among human bodies. Furthermore, the impact of the dielectric properties of adipose tissue on temperature elevation, for which large discrepancies between our present measurement results and those in past works were observed, was also examined. We found that the dielectric properties of adipose tissue do not impact on temperature elevation at frequencies over 30 GHz. The potential risk of skin burn was discussed on the basis of the temperature elevation in millimeter-wave and terahertz-wave exposure. Furthermore, the consistency of the basic restrictions in the international guidelines set by ICNIRP was discussed. AUTHORS' ABSTRACT: Fernandez et al. 2017 (IEEE #6833): The interaction of body-worn antennas with the human body causes a significant decrease in antenna efficiency and a shift in resonant frequency. A resonant slot in a small conductive box placed on the body has been shown to reduce these effects. The specific absorption rate is less than international health standards for most wearable antennas due to small transmitter power. This paper reports the linear relationship between power absorbed by biological tissues at different locations on the body and radiation efficiency based on numerical modeling (r¼0.99). While the 10 dB bandwidth of the antenna remained constant and equal to 12.5%, the maximum frequency shift occurred when the antenna was close to the elbow (6.61%) and on the thigh (5.86%). The smallest change was found on the torso (4.21%). Participants with body-mass index (BMI) between 17 and 29 kg/m2 took part in experimental measurements, where the maximum frequency shift was 2.51%. Measurements showed better agreement with simulations on the upper arm. These experimental results demonstrate that the BMI for each individual had little effect on the performance of the antenna. AUTHORS' ABSTRACT: Guraliuc et al. 2017 (IEEE #6876): The development of millimeter-wave (mmW) technologies comes with concerns related to the user exposure. A detailed numerical dosimetry study is performed for a terminal with a 60-GHz antenna module for several representative human body exposure scenarios within 5G small cells. First, numerical considerations are made regarding the user terminal and human body modeling. Then, the user exposure levels in the near field are analyzed for phone call and browsing scenarios. Results show that power absorption is locally distributed on the ear helix and fingertips. Moreover, we demonstrate that the presence of a hand in the phone call scenario increases absorption in the head. The impact of the human body on the antenna performance is also analyzed. AUTHORS' ABSTRACT: Colombi et al. 2018 (IEEE #6919): In this work, mechanisms of RF energy absorption by body tissue in close proximity to wireless equipment, are studied using numerical simulations at frequencies above 24 GHz. It is shown that at millimeter wave (mmW) frequencies, of relevance for 5G mobile communications, and for realistic source to body separation distances, the contribution from the reactive near-field to the energy deposition in the tissue is small. Furthermore, the interaction between the source and the exposed body is modest. The results suggest that the effects of the near-field body interactions are small when evaluating electromagnetic field compliance at mmW frequencies. AUTHORS' ABSTRACT: Lan et al. 2018 (IEEE #6932): This paper evaluates the effect of glasses on the Specific Absorption Rate (SAR) and the absorbed power in the human head exposed to microwave from wireless eyewear device at phone call state. Due to the sensitivity of eyes to microwave, this paper mainly concentrates on the SAR and the absorbed power in ocular tissues. The calculated results indicate that wearing glasses can obviously increase the maximal SAR and the absorbed power in ocular tissues. Glasses has almost doubled the maximal SAR in ocular tissues. The absorbed power with glasses is about 3.14.5 times as big as that without glasses. Furthermore, we find that the maximal SAR and absorbed power are sensitive to the width of glass leg and the thickness of spectacle lens, while variation trends with the varying glasses size are quite different. Hypermyopia patient might suffer from higher risk of getting the oculopathy due to the larger SAR caused by the thicker spectacle lens. In conclusion, wearing glasses may pose higher health risk on eyes of wireless eyewear device user. This paper would provide valuable reference data for the future evaluation of microwave biological effect on eyes. |