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Characterization and Evaluation of a Commercial WLAN System for Human Provocation Studies.

Zentai N, Fiocchi S, Parazzini M, Trunk A, Juhász P, Ravazzani P, Hernádi I, Thuróczy G - Biomed Res Int (2015)

Bottom Line: Finally, the specific absorption rate (SAR) generated by the CU was estimated computationally in the head of two human models.Results suggest that exposure to RF fields of WLAN systems strongly depends on the sets of the router configuration: the stability of the exposure was more constant and reliable when both antennas were active and vertically positioned, with best signal quality obtained with the R52n router board at channel 9, in UDP mode.The maximum levels of peak SAR were far away from the limits of international guidelines with peak levels found over the skin.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Neurobiology, University of Pécs, 6 Ifjúság Útca, Pécs 7624, Hungary.

ABSTRACT
This work evaluates the complex exposure characteristics of Wireless Local Area Network (WLAN) technology and describes the design of a WLAN exposure system built using commercially available modular parts for the study of possible biological health effects due to WLAN exposure in a controlled environment. The system consisted of an access point and a client unit (CU) with router board cards types R52 and R52n with 18 dBm and 25 dBm peak power, respectively. Free space radiofrequency field (RF) measurements were performed with a field meter at a distance of 40 cm from the CU in order to evaluate the RF exposure at several signal configurations of the exposure system. Finally, the specific absorption rate (SAR) generated by the CU was estimated computationally in the head of two human models. Results suggest that exposure to RF fields of WLAN systems strongly depends on the sets of the router configuration: the stability of the exposure was more constant and reliable when both antennas were active and vertically positioned, with best signal quality obtained with the R52n router board at channel 9, in UDP mode. The maximum levels of peak SAR were far away from the limits of international guidelines with peak levels found over the skin.

No MeSH data available.


Related in: MedlinePlus

The positions for computational modeling of SAR distribution for the female human voxel model “Ella.”
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Related In: Results  -  Collection


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fig4: The positions for computational modeling of SAR distribution for the female human voxel model “Ella.”

Mentions: The CU was modelled as based on the real geometry and the physical characteristics of the device: the case was modelled as an aluminum box with dimensions 180 × 112 × 31 mm. The two antennas were taken as active and operating in upright (vertical) position with 113 mm of length, with a distance of 54 mm between the antennas, and taken as dipoles to obtain a resonance frequency of 2.54 GHz. Two whole body, realistic human models were used, both from the Virtual Family (“Ella,” female, 26 years old, 1.63 m height, 58 kg weight, BMI: 22.0 kg/m2 and “Duke,” male, 34 years old, 1.77 m height, 72.4 Kg, BMI: 23.1 kg/m2), available for research purposes [32]. The models were used in standing and sitting positions (Figure 4), the latter obtained with the “Poser” tool available within the simulation platform SEMCAD X. The model design was based on high-resolution magnetic resonance (MR) images of healthy volunteers, segmented in a voxel-based format at a resolution of 1 mm. Thus, the human models allowed distinguishing up to 77 tissues. The dielectric properties of those tissues were assigned according to the classical parametric model described by Gabriel et al. (1996) [33]. The modelled CU was placed in such a way that the middle point between the two horn antennas was in line and 40 cm away from the intersection of the frontal bone and two nasal bones (i.e., the “nasion”) of the model. A nonuniform mesh with a maximum spatial step of 3 mm (in free space) restricted to 1 mm over the anatomical model and to 0.2 mm over the CU was adopted to discretize the computational domain. The cited positions of the human models were chosen to mimic a realistic notebook use, and as such (also shown in some previous studies [34, 35]) one may expect a considerable rise in whole body SAR and even more in peak SAR when the posture is changed from standing position.


Characterization and Evaluation of a Commercial WLAN System for Human Provocation Studies.

Zentai N, Fiocchi S, Parazzini M, Trunk A, Juhász P, Ravazzani P, Hernádi I, Thuróczy G - Biomed Res Int (2015)

The positions for computational modeling of SAR distribution for the female human voxel model “Ella.”
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4477099&req=5

fig4: The positions for computational modeling of SAR distribution for the female human voxel model “Ella.”
Mentions: The CU was modelled as based on the real geometry and the physical characteristics of the device: the case was modelled as an aluminum box with dimensions 180 × 112 × 31 mm. The two antennas were taken as active and operating in upright (vertical) position with 113 mm of length, with a distance of 54 mm between the antennas, and taken as dipoles to obtain a resonance frequency of 2.54 GHz. Two whole body, realistic human models were used, both from the Virtual Family (“Ella,” female, 26 years old, 1.63 m height, 58 kg weight, BMI: 22.0 kg/m2 and “Duke,” male, 34 years old, 1.77 m height, 72.4 Kg, BMI: 23.1 kg/m2), available for research purposes [32]. The models were used in standing and sitting positions (Figure 4), the latter obtained with the “Poser” tool available within the simulation platform SEMCAD X. The model design was based on high-resolution magnetic resonance (MR) images of healthy volunteers, segmented in a voxel-based format at a resolution of 1 mm. Thus, the human models allowed distinguishing up to 77 tissues. The dielectric properties of those tissues were assigned according to the classical parametric model described by Gabriel et al. (1996) [33]. The modelled CU was placed in such a way that the middle point between the two horn antennas was in line and 40 cm away from the intersection of the frontal bone and two nasal bones (i.e., the “nasion”) of the model. A nonuniform mesh with a maximum spatial step of 3 mm (in free space) restricted to 1 mm over the anatomical model and to 0.2 mm over the CU was adopted to discretize the computational domain. The cited positions of the human models were chosen to mimic a realistic notebook use, and as such (also shown in some previous studies [34, 35]) one may expect a considerable rise in whole body SAR and even more in peak SAR when the posture is changed from standing position.

Bottom Line: Finally, the specific absorption rate (SAR) generated by the CU was estimated computationally in the head of two human models.Results suggest that exposure to RF fields of WLAN systems strongly depends on the sets of the router configuration: the stability of the exposure was more constant and reliable when both antennas were active and vertically positioned, with best signal quality obtained with the R52n router board at channel 9, in UDP mode.The maximum levels of peak SAR were far away from the limits of international guidelines with peak levels found over the skin.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Neurobiology, University of Pécs, 6 Ifjúság Útca, Pécs 7624, Hungary.

ABSTRACT
This work evaluates the complex exposure characteristics of Wireless Local Area Network (WLAN) technology and describes the design of a WLAN exposure system built using commercially available modular parts for the study of possible biological health effects due to WLAN exposure in a controlled environment. The system consisted of an access point and a client unit (CU) with router board cards types R52 and R52n with 18 dBm and 25 dBm peak power, respectively. Free space radiofrequency field (RF) measurements were performed with a field meter at a distance of 40 cm from the CU in order to evaluate the RF exposure at several signal configurations of the exposure system. Finally, the specific absorption rate (SAR) generated by the CU was estimated computationally in the head of two human models. Results suggest that exposure to RF fields of WLAN systems strongly depends on the sets of the router configuration: the stability of the exposure was more constant and reliable when both antennas were active and vertically positioned, with best signal quality obtained with the R52n router board at channel 9, in UDP mode. The maximum levels of peak SAR were far away from the limits of international guidelines with peak levels found over the skin.

No MeSH data available.


Related in: MedlinePlus