Electromagnetic deposition in an anatomically based model of man for leakage fields of a parallel-plate dielectric heater

Chen, J.-Y.; Gandhi, O.P.

doi:10.1109/22.20036

Cited by 29 publications

(5 citation statements)

References 14 publications

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“…For such settings, highly enhanced coupling may occur for parts of the body, such as the hands, that are in the high intensity regions close to the source of radiation. Numerical methods offer the possibility of obtaining internal current and SAR distributions and are beginning to be applied for such purposes (see, e.g., Gandhi and DeFord 1988;Chen and Gandhi 1989). Also, personnel-mounted current measuring devices need to be developed to allow measurements of currents through hand and feet to characterize the exposures in industrial settings.…”

Section: Resultsmentioning

confidence: 99%

“…We have started to solve for SARs because of some of the important industrial sources. Two sources examined to date are the exposure to leakage magnetic fields of an induction heater (Gandhi and Deford 1988) and the dominant electric fields of a parallel-plate applicator typical of those used for RF sealers in industry (Chen and Gandhi 1989 ) .…”

Section: Introduci'ionmentioning

confidence: 99%

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RF Currents Induced in an Anatomically-based Model of a Human for Plane-wave Exposures (20-100 MHz)

Chen

Gandhi²

1989

Health Physics

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The three-dimensional finite-difference time-domain (FDTD) method has been used to calculate local, layer-averaged and whole-body averaged specific absorption rates (SARs) and internal radiofrequency (RF) currents in a 5628-cell, anatomically-based model of a human for plane-wave exposures from 20-100 MHz. The conditions of exposure of the human considered are: 1) isolated from ground, and 2) feet in contact with ground. Also considered are various separations of the model from ground and the use of insulating, rubber-soled footwear close to the grounded resonance frequency of 45 MHz. The calculated results are in agreement with the experimental data of Hill and others. While the existence of large foot currents has been known previously, substantial RF currents (600-800 mA) induced over much of the body are obtained for E-polarized fields suggested in the 1982 ANSI RF safety guideline.

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Section: Resultsmentioning

confidence: 99%

Section: Introduci'ionmentioning

confidence: 99%

RF Currents Induced in an Anatomically-based Model of a Human for Plane-wave Exposures (20-100 MHz)

Chen

Gandhi²

1989

Health Physics

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“…When the internal E fields of the scatterer reaches at steady state condition [12,13] then the local SAR in W/Kg at (i,j,k) th cell inside the head model is obtained from the equation [14]:…”

Section: Jj Gmentioning

confidence: 99%

SAR analysis in human head model exposed to mobile base-station antenna for GSM-900 band

Ali

Mukherjee

Ray

2009

2009 Loughborough Antennas &Amp; Propagation Conference

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Friis transmission equation combined with Finite Difference in Time Domain (FDTD) method has been used to carry out investigation on Specific Absorption Rate (SAR) inside the human head model exposed to a 100 Watt GSM Base Station Antenna (BSA) at GSM-900 band. Maximum local SAR (MLSAR) has been calculated at 925 MHz, keeping distance between head and BSA in the range of 0.5 m to 5.0 m. The human head is modelled as an inhomogeneous sphere of diameter 21.0 cm. The objective of this study is to estimate MLSAR induced in the human head model by BSA and compared with recommended values.

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“…The absorption of the body in the near-field of dielectric heaters and small dipoles representing electrodes has been examined in several studies by employing electromagnetic simulation models based on the finite-difference time-domain (FDTD) method (Gandhi et al 1997;Chen and Gandhi 1989). Computed results on whole body averaged SAR (SAR wba ), local SAR peaks, and total current flowing in wrists and ankles show that SAR depends on the intensity and distribution of the electric field, electrical contact to the ground, posture of the body, and presence of large conducting objects near the operator.…”

Section: Introductionmentioning

confidence: 99%

Measured and Computed Induced Body Currents in Front of an Experimental Rf Dielectric Heater

et al. 2008

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Operators of industrial high-frequency dielectric heaters are exposed to electromagnetic fields that are high enough to significantly increase body temperature. The assessment of exposure based on the measurement of external field strengths is, however, inaccurate due to the non-uniformity of the fields. This paper presents an exposure assessment method based on the measurement of the current induced by the external electric field in the body of the operator. Body current distributions were measured at 27.12 MHz using various current meters under a condition simulating the exposure to stray fields emitted by a dielectric heater. The specific absorption rates and induced body currents were computed with the finite-difference time-domain method using heterogeneous and homogeneous human models. The numerical analysis indicated that the basic restrictions for occupational exposure are not exceeded when the current induced in the limbs is lower than the action level (100 mA), even though the maximum electric field significantly exceeds the action value (61 V m ؊1 ). For the heterogeneous human model the exposure limit for local specific absorption rate was exceeded when the current induced in the ankle was 166 mA at a distance of 0.3 m from the electrode of the device. The vertical component of current density proved to be much more significant than the horizontal components. The importance of the horizontal components was highest near the electrode. The computations showed no concentration of the induced current to the superficial tissues due to the skin effect. Health Phys. 94(2):161-169; 2008

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Electromagnetic deposition in an anatomically based model of man for leakage fields of a parallel-plate dielectric heater

Cited by 29 publications

References 14 publications

RF Currents Induced in an Anatomically-based Model of a Human for Plane-wave Exposures (20-100 MHz)

RF Currents Induced in an Anatomically-based Model of a Human for Plane-wave Exposures (20-100 MHz)

SAR analysis in human head model exposed to mobile base-station antenna for GSM-900 band

Measured and Computed Induced Body Currents in Front of an Experimental Rf Dielectric Heater

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