Worst Case Temperature Rise in a One-Dimensional Tissue Model Exposed to Radiofrequency Radiation

Samaras, Theodoros; Christ, Andreas; Klingenböck, A.; Kuster, Niels

doi:10.1109/tbme.2006.890498

Cited by 25 publications

(13 citation statements)

References 21 publications

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“…There have been other published studies investigating 1D RF/thermal models, for example, Samaras et al [2007] and Drossos et al [2000]. What distinguishes this study from earlier work is our approach to the specification of the type and thickness of the tissue layers.…”

Section: Introductionmentioning

confidence: 96%

SAR versus S_inc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models

Anderson

Croft

McIntosh³

2010

Bioelectromagnetics

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This is the first of two articles addressing the most appropriate crossover frequency at which incident power flux density (S(inc)) replaces the spatial peak value of the specific energy absorption rate (SAR) averaged over 1 or 10 g (i.e., peak 1 or 10 g SAR) as the basic restriction for protecting against radiofrequency (RF) heating effects in the 1-10 GHz range. Our general approach has been to compare the degree of correlation between these basic restrictions and the peak induced tissue temperature rise (DeltaT) for a representative range of population/exposure scenarios. In this article we particularly address the effect of human population diversity in the thickness of body tissue layers at eight different sites of the body. We used a Monte Carlo approach to specify 32000 models (400 models for each of 8 body sites for 10 frequencies) which were representative of tissue thicknesses for age (18-74 years) and sex at the eight body sites. Histogram distributions of S(inc) and peak 1 and 10 g SAR corresponding to a peak 1 degrees C temperature rise were obtained from RF and thermal analyses of 1D multiplanar models exposed to a normally incident plane wave ranging from 1 to 10 GHz in thermo-neutral environmental conditions. Examination of the distribution spread of the histograms indicated that peak SAR was a better predictor of peak tissue temperature rise across the entire 1-10 GHz frequency range than S(inc), as indicated by the smaller spread in its histogram distributions, and that peak 10 g SAR was a slightly better predictor than peak 1 g SAR. However, this result must be weighed against partly conflicting indications from complex body modeling in the second article of this series, which incorporates near-field effects and the influence of complex body geometries.

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Section: Introductionmentioning

confidence: 96%

SAR versus S_inc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models

Anderson

Croft

McIntosh³

2010

Bioelectromagnetics

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“…Therefore, thermal models exposed to RF radiation with longitudinal dimensions of about 10 cm are reported in the literature. Here, the thermal model taken from [39] and applied for simulating the temperature development due to the EM exposure of the skin is 9.62 cm long; for this reason it is called thorax model [ Fig. 9(a)].…”

Section: A Numerical Thermo-model Of the Thoraxmentioning

confidence: 99%

“…Its spatial distribution in the -direction is adapted to the geometrical dimensions. Here Order of tissues is analog to the layering of the planar model, data are taken from literature [39]. Densities for the skin are given in Fig.…”

Section: A Numerical Thermo-model Of the Thoraxmentioning

confidence: 99%

Numerical Computation of Temperature Elevation in Human Skin Due to Electromagnetic Exposure in the THz Frequency Range

Spathmann

Zang

Streckert

et al. 2015

IEEE Trans. THz Sci. Technol.

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The ongoing development of new applications in the terahertz (THz) frequency range, such as wireless communication systems, full-body scanners, or other imaging procedures for biological and medical techniques, rapidly increases the number of persons who are potentially exposed to the electromagnetic radiation of those devices. Studies of thermal effects in humans caused by electromagnetic (EM) exposure with frequencies in the THz frequency range can rarely be found in the literature. In this paper, a method for the numerical computation of a potential thermal response in human skin due to EM fields between 0.1 and 10 THz is introduced. The method starts with the development of adequate simulation models for EM fields with penetration depths less than 1 mm. In a further step, it covers the provision of absolutely needed dielectric tissue parameters with help of the "effective medium theory," since material properties above 100 GHz are not listed in the commonly consulted databases. The absorbed power in EM exposed human skin models of different complexity is calculated and subsequently used as heat source for temperature simulations. Spatial and time-dependent temperature profiles in the tissue are analyzed for transient and continuous exposures.Index Terms-Dielectric tissue data, human skin exposure, numerical simulations, temperature elevation, terahertz (THz).

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“…Planar models can be considered as sufficient approximations for cylindrical or spherical structures if their diameter is not less than 150 mm (17,18) . Sequences and thicknesses of the tissue layers were chosen according to the worst case compositions determined in Christ and co-workers (10,19) . For the temperature evaluations, an FDTD implementation of the Pennes bioheat equation (20) was solved using a mesh step size of 0.05 mm, which is significantly below the minimum thickness of the tissue layers.…”

Section: Generic Layered Tissue Model For Thermal Worst Case Analysismentioning

confidence: 99%

SAR distribution in human beings when using body-worn RF transmitters

Christ

Samaras

Neufeld³

et al. 2007

Radiation Protection Dosimetry

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Worst Case Temperature Rise in a One-Dimensional Tissue Model Exposed to Radiofrequency Radiation

Cited by 25 publications

References 21 publications

SAR versus S_inc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models

SAR versus S_inc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models

Numerical Computation of Temperature Elevation in Human Skin Due to Electromagnetic Exposure in the THz Frequency Range

SAR distribution in human beings when using body-worn RF transmitters

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Worst Case Temperature Rise in a One-Dimensional Tissue Model Exposed to Radiofrequency Radiation

Cited by 25 publications

References 21 publications

SAR versus Sinc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models

SAR versus Sinc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models

Numerical Computation of Temperature Elevation in Human Skin Due to Electromagnetic Exposure in the THz Frequency Range

SAR distribution in human beings when using body-worn RF transmitters

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SAR versus S_inc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models

SAR versus S_inc: What is the appropriate RF exposure metric in the range 1–10 GHz? Part I: Using planar body models