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Dielectric properties of body tissues - Overview

An Internet resource for the calculation of the dielectric properties of body tissues in the frequency range 10 Hz - 100 GHz.

The need for extensive data on the dielectric properties of human tissues is often and strongly felt among scientists and researchers involved in the interactions of electromagnetic (EM) fields and biological systems.

Numerical dosimetry, for instance (the discipline devoted to calculate, by means of numerical algorithms, current densities and specific absorption rates (SARs) in tissues and organs of individuals exposed to EM fields), deals with digitized 2D or 3D human models each element of which (pixel in 2D and voxel in 3D models) has to be recognized as being constituted by a given, well defined tissue and thus must have assigned unique dielectric properties, consisting of a pair of values, one for the relative permittivity and one for the electrical conductivity at each frequency of interest.

This application is aimed to calculate the dielectric properties of human body tissues in the frequency range from 10 Hz to 100 GHz using the parametric model and the parameter values developed by C. Gabriel and colleagues (see the Credits and References below). It is based on a client-server approach.

The server

The server program runs in background on a central system and is responsible for the management of the parameter database (14 parameters for each defined tissue) and for the calculation of the dielectric properties of requested tissues at requested frequencies. These properties comprise the relative permittivity, the electrical conductivity and a few significant derived quantities: the loss tangent, the wavelength and the penetration or skin depth.

The client

The client program is executed by the user on a remote system connected to the server by a Local or a Wide Area Network supporting the TCP/IP protocol; the client program implements the user interface and translates user requests into commands for the server; it also has to deal with reception and display of the requested data.

The main advantage of the client/server approach consists in the centralized management of the tissue parameters, allowing new tissues to be defined or parameter values to be changed without having to redistribute software to the users. The users, on their side, also get rid of the need to implement the code for the calculation of the dielectric properties from the parameter values. The availability of the server documentation makes it possible, for users who need it and can afford it, to develop their own applications devoted to specific tasks or platforms. The reverse of the medal obviously is the need of a TCP/IP link between the client and the server.

Credits

This application has been prepared at IFAC-CNR (formerly IROE-CNR) as a side project among the activities of the research line devoted to Protection against exposures to low-frequency, radiofrequency and microwave electromagnetic fields. It would not have been possible without the huge work of C. Gabriel and colleagues at the Brooks Air Force Base (USA), who developed the parametric model for the calculation of the dielectric properties of body tissues used here (see the References below).

At IFAC-CNR, the following people took part in the project:

Daniele Andreuccetti
Project design and management; mathematical background; parametric data processing; HTML, PHP and C/C++ coding.
Roberto Fossi and Caterina Petrucci
Research and critical review of bibliographic data on the dielectric properties of body tissues.

This website and the results of its analysis may be used freely for scientific purposes and for any other use permitted by law. Those who use this website should mention it in their own publications as follows:

D. Andreuccetti, R. Fossi and C. Petrucci: An Internet resource for the calculation of the dielectric properties of body tissues in the frequency range 10 Hz - 100 GHz. IFAC-CNR, Florence (Italy), 1997. Based on data published by C. Gabriel et al. in 1996. [Online]. Available: http://niremf.ifac.cnr.it/tissprop/

References

Each entry links to the publisher's official page. The third-party papers are not redistributed here: the direct download from our archive is available to administrators only.

Parametric model and tissue data (C. Gabriel and co-workers)
  • C. Gabriel: Compilation of the dielectric properties of body tissues at RF and microwave frequencies, Report N. AL/OE-TR-1996-0037, Occupational and environmental health directorate, Radiofrequency Radiation Division, Brooks Air Force Base, Texas (USA), June 1996 (approved for public release). — DTIC · IFAC mirror · Appendix C · PDF
  • C. Gabriel, S. Gabriel and E. Corthout: The dielectric properties of biological tissues: I. Literature survey, Phys. Med. Biol. 41 (1996), 2231-2249. — IOPscience
  • S. Gabriel, R.W. Lau and C. Gabriel: The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz, Phys. Med. Biol. 41 (1996), 2251-2269. — IOPscience
  • S. Gabriel, R.W. Lau and C. Gabriel: The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues, Phys. Med. Biol. 41 (1996), 2271-2293. — IOPscience
  • C. Gabriel: Dielectric properties of biological tissue: variation with age, Bioelectromagnetics Suppl. 7 (2005), S12-S18. — Wiley Online Library
  • C. Gabriel, A. Peyman and E.H. Grant: Electrical conductivity of tissue at frequencies below 1 MHz, Phys. Med. Biol. 54 (2009), 4863-4878. — IOPscience
  • C. Gabriel: Dielectric spectroscopy of biological materials: its role in dosimetry, book chapter (first page only).
Dielectric properties of tissues: further reading
  • R. Pethig: Dielectric properties of biological materials: biophysical and medical applications, IEEE Trans. Electr. Insul. EI-19 (1984), 453-474. — IEEE Xplore
  • S.R. Smith and K.R. Foster: Dielectric properties of low-water-content tissues, Phys. Med. Biol. 30 (1985), 965-973. — IOPscience
  • S.S. Seker, G. Apaydin and M. Kuzu: Comparison of electrical parameters of human body parts with vegetation, Proc. 25th Annual Int. Conf. IEEE EMBS, Cancun (2003).
  • S. Seker and H. Abatay: New frequency-dependent parametric modeling of dielectric materials, Int. J. Electron. Commun. (AEÜ) 60 (2006), 320-327. — ScienceDirect
  • J. Wang, O. Fujiwara and S. Watanabe: Approximation of aging effect on dielectric tissue properties for SAR assessment of mobile telephones, IEEE Trans. Electromagn. Compat. 48 (2006), 408-413. — IEEE Xplore
  • J. Sierpowska: Electrical and dielectric characterization of trabecular bone quality, doctoral dissertation, Kuopio University Publications C 214.
  • M.J. Schroeder, A. Sadasiva and R.M. Nelson: An analysis on the role of water content and state on effective permittivity using mixing formulas (2008).
  • A. Peyman: Dielectric properties of tissues; variation with age and their relevance in exposure of children to electromagnetic fields; state of knowledge, Prog. Biophys. Mol. Biol. 107 (2011), 434-438. — ScienceDirect
Dielectric relaxation, water and reference liquids
  • K.S. Cole and R.H. Cole: Dispersion and absorption in dielectrics: I. Alternating current characteristics, Journal of Chemical Physics 9 (1941), 341-351. — AIP Publishing
  • C.G. Malmberg and A.A. Maryott: Dielectric constant of water from 0° to 100°C, J. Res. Natl. Bur. Stand. 56 (1956), 1-8, RP 2641. — NIST
  • M. Zahn, Y. Ohki, D.B. Fenneman, R.J. Gripshover and V.H. Gehman Jr.: Dielectric properties of water and water/ethylene glycol mixtures for use in pulsed power system design, Proc. IEEE 74 (1986). — IEEE Xplore
  • S. Ray and J. Behari: Microwave absorption in lossy liquids, Phys. Med. Biol. 31 (1986), 1031-1040. — IOPscience
In Italian
  • D. Andreuccetti e R. Fossi: Proprietà dielettriche dei tessuti umani: definizioni, modello parametrico, codici di calcolo, Report N. TR/ICEMM/13.00, IFAC-CNR, Firenze (I), settembre 2000. — PDF

IFAC-CNR, Florence (Italy), 1997-2024. Project by Daniele Andreuccetti.

Keywords: Dielectric properties, Body tissues, Permittivity, Conductivity, Gabriel, Cole-Cole, Numerical dosimetry