Analysis of the interaction between a layered spherical human head model and a helical dipole

Nikita, Konstantina S.; Starnatakos, G.S.; Koulouridis, Stavros; Uzunoglu, N.K.

doi:10.1109/aem.2000.943202

Cited by 12 publications

(20 citation statements)

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“…It represents indeed a good average of more complex models. For instance, radiation efficiencies, specific absorption rate (SAR) and power profiles have been presented in [2], [18], [20] and [17], [21]. Obviously, depending on the source modeling, unrealistically high values of the absolute electric field (therefore SAR) can be obtained [24].…”

Section: A Human Body Model and Biocompatible Insulation Layermentioning

confidence: 99%

The Effect of Insulating Layers on the Performance of Implanted Antennas

Merli

Fuchs

Mosig

et al. 2011

IEEE Trans. Antennas Propagat.

122

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Abstract-This work presents the analysis of the influence of insulation on implanted antennas for biotelemetry applications in the Medical Device Radiocommunications Service band. Our goal is finding the insulation properties that facilitate power transmission, thus enhancing the communication between the implanted antenna and an external receiver. For this purpose, it has been found that a simplified model of human tissues based on spherical geometries excited by ideal sources (electric dipole, magnetic dipole and Huygens source) provides reasonable accuracy while remaining very tractable due to its analytical formulation. Our results show that a proper choice of the biocompatible internal insulation material can improve the radiation efficiency of the implanted antenna (up to six times for the investigated cases). External insulation facilitates the electromagnetic transition from the biological tissue to the outer free space, reducing the power absorbed by the human body. Summarizing, this work gives insights on the enhancement of power transmission, obtained with the use of both internal, biocompatible and external, flexible insulations. Therefore, it provides useful information for the design of implanted antennas.

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Section: A Human Body Model and Biocompatible Insulation Layermentioning

confidence: 99%

The Effect of Insulating Layers on the Performance of Implanted Antennas

Merli

Fuchs

Mosig

et al. 2011

IEEE Trans. Antennas Propagat.

122

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“…A very important issue in forming the equivalent MAS model for the monopole is the type of the fictitious sources. In a recent paper [Nikita et al, 2000] it has been shown that the choice of elementary dipoles as fictitious sources leads to a convergent solution. However, other more convenient types of sources can be found with the aid of some physical insight to the examined problem.…”

Section: Formulationmentioning

confidence: 99%

“…In a more recent work [Nikita et al, 2000] the EM interaction of a finite-length dipole with a three-layer lossy dielectric sphere representing a simplified model of the human head was analyzed by combining the Green's function methodology with the MAS, which was used to develop a model for the dipole with the aid of a set of axially distributed infinitesimally small dipoles. In this paper, the radiated EM field by a coaxially fed circular cylindrical monopole antenna is approximately described as a weighted superposition of the radiated EM fields by a set of sinusoidal dipoles.…”

Section: Introductionmentioning

confidence: 99%

Analysis of coaxially fed monopole antennas using an auxiliary sources technique

Papakanellos

Capsalis

2002

Radio Science

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[1] In this paper, the radiation from a circular cylindrical monopole fed through a perfectly conducting ground plane by a coaxial transmission line is analyzed using the method of auxiliary sources. The proposed method is applied by introducing a set of fictitious sources aligned with the monopole's axis for the direct description of the radiated electromagnetic field above the ground plane, under the assumption of a single transverse electromagnetic mode existing in the annular aperture of the line. The currents of the fictitious sources are derived by imposing the continuity condition of the tangential electric field on the physical surface of the dipole. For the occasion, the fictitious sources are chosen to be spatially overlapped sinusoidal dipoles. It is substantiated that this choice results in a noteworthy acceleration of the convergence rate of the solution in comparison with the one associated with infinitesimal dipoles, which are usually used in currentmodel-based techniques. Since the currents of the fictitious sources are determined, pertinent quantities of great interest, including the current distribution along the monopole, the input impedance/admittance, and the field intensities in the near and the far region, can be determined in a straightforward manner. Several examples concerning various geometries are established and compared with previously published data.

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“…In these methods, an anatomical human head is usually modeled based on magnetic resonance imaging (MRI). The analytical and semianalytical methods are necessary for validation and assessment of the numerical techniques [13,14].…”

Section: Introductionmentioning

confidence: 99%

“…These methods may be divided into two parts; 1) analytical and semi-analytical methods [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] based on idealized head geometry, such as homogenous or multilayered concentric spheres [2][3][4][5][6][7][8][9][10][11][12][13][14], eccentric spheres [15], multilayered planar model [16,17], and 2) numerical methods dealing with complex head geometry. These numerical methods include the finite difference time domain (FDTD) [18][19][20][21][22][23][24] and the 3-D method of moments (MOM) [25].…”

Section: Introductionmentioning

confidence: 99%

Complex Image Solution of Sar Inside a Human Head Illuminated by a Finite-Length Dipole

Omar

2010

PIER B

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Abstract-This paper uses the accurate and computationally efficient complex image technique (CIT) to find the electric field and SAR distributions inside a human head illuminated by a finite-length dipole. The human head model used consists of 3 planar layers of lossy dielectrics. The accuracy of the results is verified by comparison with HFSS software. It was found that the CIT requires about 1 minute and 16 MB of RAM, while HFSS requires about 2 hours and 1.5 GB of RAM to find the SAR distribution using a 2.19 GHz Core 2 Due PC. The CIT method can also efficiently solve other types of antennas on other planar head models.

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Analysis of the interaction between a layered spherical human head model and a helical dipole

Cited by 12 publications

References 0 publications

The Effect of Insulating Layers on the Performance of Implanted Antennas

The Effect of Insulating Layers on the Performance of Implanted Antennas

Analysis of coaxially fed monopole antennas using an auxiliary sources technique

Complex Image Solution of Sar Inside a Human Head Illuminated by a Finite-Length Dipole

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