Electromagnetic Field Zones Around an Antenna for Human Exposure Assessment: Evaluation of the human exposure to EMFs

Vallauri, R.; Bertin, G.; Piovano, B.; Gianola, P.

doi:10.1109/map.2015.2474127

Cited by 21 publications

(15 citation statements)

References 6 publications

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“…On the other hand, considering the fact that the tissue properties are those of a lossy medium [ 22 , 23 , 24 ], the E-fields are induced in the human body when the human body is exposed to the RF electromagnetic field [ 26 , 27 , 28 ]. Therefore, as a result, the signal penetration depth for this measurement scenario depends on the thickness of tissue with lower conductivity such as the fat layer.…”

Section: Results and Analysismentioning

confidence: 99%

Split-Ring Resonator Sensor Penetration Depth Assessment Using In Vivo Microwave Reflectivity and Ultrasound Measurements for Lower Extremity Trauma Rehabilitation

Shah

Velander

Mathur

et al. 2018

Sensors

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In recent research, microwave sensors have been used to follow up the recovery of lower extremity trauma patients. This is done mainly by monitoring the changes of dielectric properties of lower limb tissues such as skin, fat, muscle, and bone. As part of the characterization of the microwave sensor, it is crucial to assess the signal penetration in in vivo tissues. This work presents a new approach for investigating the penetration depth of planar microwave sensors based on the Split-Ring Resonator in the in vivo context of the femoral area. This approach is based on the optimization of a 3D simulation model using the platform of CST Microwave Studio and consisting of a sensor of the considered type and a multilayered material representing the femoral area. The geometry of the layered material is built based on information from ultrasound images and includes mainly the thicknesses of skin, fat, and muscle tissues. The optimization target is the measured S11 parameters at the sensor connector and the fitting parameters are the permittivity of each layer of the material. Four positions in the femoral area (two at distal and two at thigh) in four volunteers are considered for the in vivo study. The penetration depths are finally calculated with the help of the electric field distribution in simulations of the optimized model for each one of the 16 considered positions. The numerical results show that positions at the thigh contribute the highest penetration values of up to 17.5 mm. This finding has a high significance in planning in vitro penetration depth measurements and other tests that are going to be performed in the future.

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Section: Results and Analysismentioning

confidence: 99%

Split-Ring Resonator Sensor Penetration Depth Assessment Using In Vivo Microwave Reflectivity and Ultrasound Measurements for Lower Extremity Trauma Rehabilitation

Shah

Velander

Mathur

et al. 2018

Sensors

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“…Field metrics served as a mean of comparison between reference and generated fields. Four criteria were chosen for field discrimination: averaged field impedance when calculated in near-field [Vallauri et al, 2015]. The angles formed between electric and magnetic fields ( ˆ) E H , vary from their plane wave value…”

Section: Near-field Characterization Methods Validation Field Metrics...mentioning

confidence: 99%

“…While providing insights for our study, these studies lack near‐field exposure conditions. The study of plane waves in near‐field is problematic when considering that in the immediate region surrounding the antenna, the angular field distribution of the antenna is distance‐dependent [Vallauri et al, 2015]. Plane‐wave usage suggests that the same electric field is applied on all spots of the human body surface, but in near‐field the electric field is highly variable and cannot be represented by uniform plane waves.…”

Section: Introductionmentioning

confidence: 99%

Near‐Field Exposure in FM Frequencies: New Methodology and Estimation Formulas

Fetouri

Azzi

Ouberehil

et al. 2022

Bioelectromagnetics

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Workers inside transmission pylons with FM antenna arrays are likely to be exposed to near-field radiation exceeding reference levels for occupational exposure. In this study, the near-field behavior of 64 FM pylons was studied using a new methodology. Near-field characterization was done using field metrics without taking into account field sources' size or distance from field source. The specific absorption rate (SAR) was assessed in five hundred different near-field cases using a human phantom. Estimation formulas for both local and whole-body SAR are provided and validated numerically. Local and whole-body SAR are linked to electric field strength.

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“…To ensure repeatability of biomedical research provide stable conditions of exposure. The most optimal solution would be to standardize testing procedures and as far as possibleexposure systems [3]. Example of that exposure system is presented on Fig.…”

Section: Idea Of Exposure Antennamentioning

confidence: 99%

Exposure systems used in the assessment of EMF impact on living organisms

Cała¹,

Bieńkowski²

2017

СІС

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The subject of the study in the article is the processes of analysis and exposure assessment of electromagnetic field on humans. The main goal is to optimize size of the exposure antenna systems, its electrical parameters and generated electromagnetic field (EMF) for different frequency range. Objectives: Electromagnetic field (EMF -Electromagnetic Fields) studies on living organisms are one of the important branches of biomedical research. Most of this type of research is conducted using dedicated exposures system with fixed and controlled EMF exposure conditions. The purpose of biomedical research is to determine the influence of electromagnetic fields on living organisms. For this purpose the exposure systems are designed. The main task of the exposure antenna system, is to produce the EMF with known and controlled parameters in a specific EMF area. Depending on the frequency and the component (E or H) of the electromagnetic field used, different types of systems are used. For low frequencies (for instance 50 Hz common frequency) and magnetic fields, Helmholtz solenoids or coils are used, and for electric fields -flat capacitors (E Field). For higher frequencies field E is used for systems with linear antennas or TEM lines. There are also dedicated probes for invasive tissue heating. Each solution has its advantages and limitations and usually there are no universal solutions for all cases. Results: For the generation of a low frequency magnetic field up to several hundred Hz, the Helmholtz solenoid or coil is generally used because of its relatively simple construction, the ability to obtain high intensity and good homogeneity of the field in a relatively large area relative to the dimensions of the whole system. The homogeneous field area can be determined analytically based on system geometry or measurement. Otherwise it looks for exposure system above few MHZ. To create a homogeneous EMF in the field of radio frequencies, the exposure systems -usually the TEM lines (Crawford compartment) or sometimes the GTEM are very likely to be used. In both cases there are frequency and spatial limitations -the homogeneous field is assumed to be maximally present. At 1/3 the height between the plates of the chamber and at the same time the maximum frequency of operation of the TEM chamber can be described by the approximate dependence of fmax [MHz] = 50 / d [m], resulting in a chamber operating at 1 GHz. The work piece does not exceed a height of about 1.5 cm with a diameter of about 4 cm. Larger working areas, but at the same time, a lower homogeneity of the field can be obtained in the GTEM chamber -but at the same time the GTEM chamber has much larger geometric dimensions. Another way is to produce PEM with the parameters in open space -in the vicinity of the antenna. In this case, it is very important to select an antenna so that the expected homogeneous area can be obtained at an acceptable distance from the antenna -in order to maintain high EMF intensity and to reduce the radiation of the antenna beyond the des...

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Electromagnetic Field Zones Around an Antenna for Human Exposure Assessment: Evaluation of the human exposure to EMFs

Cited by 21 publications

References 6 publications

Split-Ring Resonator Sensor Penetration Depth Assessment Using In Vivo Microwave Reflectivity and Ultrasound Measurements for Lower Extremity Trauma Rehabilitation

Split-Ring Resonator Sensor Penetration Depth Assessment Using In Vivo Microwave Reflectivity and Ultrasound Measurements for Lower Extremity Trauma Rehabilitation

Near‐Field Exposure in FM Frequencies: New Methodology and Estimation Formulas

Exposure systems used in the assessment of EMF impact on living organisms

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