Circular and Magnetron Inductor/Sensor Coils to Detect Volumetric Brain Edema by Inductive Phase Shift

  • C.A. González
  • R. Rojas
  • B. Rubinsky
Part of the IFMBE Proceedings book series (IFMBE, volume 17)


Circular and planar magnetron coils were evaluated and compared for their ability to detect edema in the brain through volumetric inductive phase shift spectroscopy. The circular coil was considered as a single turn wire and the magnetron surface coil configuration was based on the principle of the cavity magnetron with successive slots. The brain cavity was modeled as an idealized sphere transversely centered with respect to the coils. The volumetric sensitivity to changes in the brain was examined by inserting in the brain cavity a spherical hematoma. The magnetic flux densities generated by the inductor and magnetron coils were evaluated through a three-dimensional finite elements solution of the quasi-static equations. Spectra of inductive phase shift induced in a second circular or magnetron receiver coils were estimated in a range of frequencies from 100KHz to 50MHz. In the analyzed range, the sensitivity of the phase shift to the presence of the edema increased with frequency. Using a planar magnetron as an induction coil increased somewhat the sensitivity to volumetric phase shift detection of edema over the use of a circular coil.


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  1. 1.
    C. Ayata, and A. H. Ropper (2002) Ischaemic brain oedema. Journal of Clinical Neuroscience 9(2):113-124CrossRefGoogle Scholar
  2. 2.
    Kyle AH, Chan CT, Minchinton AI (1999) Characterization of three-dimensional tissue cultures using electrical impedance spectroscopy. Biophys J 76:2640-8.CrossRefGoogle Scholar
  3. 3.
    Al-Zeiback and N.H. Saunders (1993) A feasibility study of in vivo electromagnetic imaging. Phys Med Biol 38:151-160.CrossRefGoogle Scholar
  4. 4.
    A.V. Korzhenevskii and V.A. Cherepenin (1997) Magnetic induction tomography. J Comm Technol Electron 42(4):469-474.Google Scholar
  5. 5.
    A.V. Korjenevsky and V.A. Cherepenin (1999) Progress in Realization of Magnetic Induction Tomography. Ann NY Acad Sci 873:346-52.CrossRefGoogle Scholar
  6. 6.
    H. Griffiths (2001) Magnetic Induction tomography. Meas Sci Technol 12:1126-31.CrossRefGoogle Scholar
  7. 7.
    C. A. González and B. Rubinsky (2006) A Theoretical Study on Magnetic Induction Frequency Dependence of Phase Shift in Oedema and Haematoma. Physiol Meas 27:829-838.CrossRefGoogle Scholar
  8. 8.
    C. A. González and B. Rubinsky (2006) Detection of Brain Oedema with Frequency Dependent Phase Shift Electromagnetic Induction. Physiol Meas 27:539-552CrossRefGoogle Scholar
  9. 9.
    B. Rubinsky and C. A. González (2005) Volumetric Induction Phase Shift Detection of Edema and Ischemia. Patent applicationUSA, jun 2005 (application number: 028726-047).Google Scholar
  10. 10.
    A. O. Rodríguez (2006) Magnetron Surface Coil for Brain MR Imaging. Archives of Medical Research 37:804-807.CrossRefGoogle Scholar
  11. 11.
    E. M. Purcell (1984) Electricity and Magnetism, Berkeley Physics Course Vol 2 Berkeley Physics pp 263-265Google Scholar
  12. 12.
    G.R. Hugo and S.K. Burke (1988) Impedance Changes in a Coil due to a Nearby Small Conducting Sphere. J Phys D: Appl Phys 21:33-8CrossRefGoogle Scholar
  13. 13.
    A. D. Taghjian and S. R. Best (2005) Impedance, bandwidth, and Q of antennas. IEEE Trans on Antennas and Propagation 53(4):1298-1325CrossRefGoogle Scholar
  14. 14.
    S. Gabriel, R. W. Lau and C. Gabriel (1996) The Dielectric Properties of Biological Tissues: III. Parametric Models for the Dielectric Spectrum of Tissues. Phys Med Biol 41:2271-93.CrossRefGoogle Scholar
  15. 15.
    COMSOL. Electromagnetic Module User’s Guide, COMSOL, Inc., 2005; 11-15.Google Scholar
  16. 16.
    J. L. Schepps and K. R. Foster (1980) The UHF and microwave dielectric properties of normal and tumor tissues: Variations in dielectric properties with tissue water content. Phys Med Biol 25(6):1149-1159.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • C.A. González
    • 1
    • 2
  • R. Rojas
    • 3
  • B. Rubinsky
    • 4
  1. 1.Laboratorio Multidisciplinario de InvestigaciónUniversidad del Ejército y F.A.M./E.M.G.S.D.F. C.P.Mexico
  2. 2.Escuela Superior de Medicina-Sección de Estudios de Posgrado e Investigación,Instituto Politécnico NacionalD.F. C.P.Mexico
  3. 3.Departamento de Ingeniería Eléctrica-Ingeniería Biomédica,Universidad Autónoma Metropolitana-IztapalapaD.F. C.P.Mexico
  4. 4.Mechanical Engineering and Bioengineering DepartmentUniversity of California-BerkeleyBerkeleyUSA

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