Comparison of SAR calculation algorithms for the finite-difference time-domain method

@article{Laakso2010ComparisonOS,
  title={Comparison of SAR calculation algorithms for the finite-difference time-domain method},
  author={Ilkka Laakso and Tero Uusitupa and Sami Ilvonen},
  journal={Physics in Medicine \& Biology},
  year={2010},
  volume={55},
  pages={N421 - N431}
}
Finite-difference time-domain (FDTD) simulations of specific-absorption rate (SAR) have several uncertainty factors. For example, significantly varying SAR values may result from the use of different algorithms for determining the SAR from the FDTD electric field. The objective of this paper is to rigorously study the divergence of SAR values due to different SAR calculation algorithms and to examine if some SAR calculation algorithm should be preferred over others. For this purpose, numerical… 

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References

SHOWING 1-10 OF 19 REFERENCES

The effect of finite-difference time-domain resolution and power-loss computation method on SAR values in plane-wave exposure of Zubal phantom

In this paper, the anatomically realistic body model Zubal is exposed to a plane wave and it is investigated how the FDTD resolution, power-loss computation method and positioning of the material voxels in theFDTD grid affect the SAR results.

An algorithm for computations of the power deposition in human tissue

The finite-difference time-domain is the most often used method for evaluation of electromagnetic fields in human tissue, and extensive investigations are shown of the resultant SAR due to the number of electric field components used in field averaging, and the volume of air within the cube.

FDTD calculation of whole-body average SAR in adult and child models for frequencies from 30 MHz to 3 GHz

The results show that the whole-body average SAR under the ICNIRP reference level exceeds the basic safety limit nearly 30% for the child model both in the resonance frequency and 2 GHz band.

Variations in calculated SAR with distance to the perfectly matched layer boundary for a human voxel model

Results show that an increase in this width from 2 cells to 70 cells caused variations in the calculated whole-body averaged SAR of less than 2% for the FDTD code employing split-field pmls.

Assessment of the computational uncertainty of temperature rise and SAR in the eyes and brain under far-field exposure from 1 to 10 GHz

  • I. Laakso
  • Environmental Science
    Physics in medicine and biology
  • 2009
Limiting the incident plane-wave power density to smaller than 100 W m(-2) was sufficient for ensuring that the temperature rise in the eyes and brain were less than 1 degrees C in the whole frequency range.

Performance of convolutional PML absorbing boundary conditions in finite-difference time-domain SAR calculations

Results show that no additional free-space layers are needed between the numerical phantom and properly implemented CPML absorbing boundary, and that the numerical uncertainties due to CPML can be made negligibly small.

FDTD calculations of the whole-body averaged SAR in an anatomically realistic voxel model of the human body from 1 MHz to 1 GHz.

  • P. Dimbylow
  • Physics, Medicine
    Physics in medicine and biology
  • 1997
This paper presents finite-difference time-domain (FDTD) calculations of the whole-body averaged SAR in an anatomically realistic voxel model of the human body, NORMAN, and presents SAR values for an adult phantom and for scaled 10, 5 and 1 year old models.

Computational Electrodynamics the Finite-Difference Time-Domain Method

This paper presents background history of space-grid time-domain techniques for Maxwell's equations scaling to very large problem sizes defense applications dual-use electromagnetics technology, and the proposed three-dimensional Yee algorithm for solving these equations.

SAR variation study from 300 to 5000 MHz for 15 voxel models including different postures

The basic restriction of whole-body SAR is exceeded in the smallest models at the reference level of exposure, but also some adult phantoms are close to the limit, and the present ICNIRP guidelines should be revised by lowering the reference levels.

Effects of frequency, permittivity, and voxel size on predicted specific absorption rate values in biological tissue during electromagnetic-field exposure

Current electromagnetic-field (EMF) exposure limits have been based, in part, on the amount of energy absorbed by the whole body. However, it is known that energy is absorbed nonuniformly during EMF