volume | PIER Journals

Abstract

A Green's function based methodology has been developed and implemented with the view to optimize the focusing properties and thus the performance of a Microwave Radiometry Imaging System (MiRaIS). The system consists of an ellipsoidal conductive wall cavity and a sensitive radiometric receiver and its operation principal is based on the convergence of the radiation from one focal point, where the subject or phantom is placed, on the other, where the receiver antenna is positioned. A two-layered cylinder is used to model the human head with the semi-analytical Green's function technique. The imaging configuration is enhanced by different matching structures of various materials which are placed on the surface of both the human head model and the antenna inside the ellipsoidal. Numerical code executions have been realized and the results for the electric field distribution inside the head are presented for materials of various dielectric properties and for left handed materials at two different frequencies (0.5 GHz and 1.0 GHz). Increased sensitivity of the system focusing properties is observed using particular matching structures.

1. Karanasiou, I. S., "Development of a non invasive brain imaging system using microwave radiometry," Doctor of Philosophy in Engineering, School of Electrical and Computer Engineering, National Technical University of Athens, Dec. 2003(in Greek). Google Scholar

2. Karanasiou, I. S., N. K. Uzunoglu, and C. Papageorgiou, "Towards functional non-invasive imaging of excitable tissues inside the human body using focused microwave radiometry," IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 8, 1898-1908, Aug. 2004.
doi:10.1109/TMTT.2004.831999 Google Scholar

3. Karanasiou, I. S., N. K. Uzunoglu, and A. Garetsos, "Electromagnetic analysis of a non-invasive 3D passive microwave imaging system," Progress In Electromagnetics Research, PIER 44, 287-308, 2004. Google Scholar

4. Karanasiou, I. S., N. K. Uzunoglu, S. Stergiopoulos, and W. Wong, "A passive 3D imaging thermograph using microwave radiometry," Innovation and Technology in Biology Medicine, Vol. 25, 227-239, 2004. Google Scholar

5. Karanasiou, I. S. and N. K. Uzunoglu, "Development and feasibility study of a functional brain passive microwave tomography system," URSI 2004 Proceedings, 1194-1196, Pisa, Italy, 2004. Google Scholar

6. Karanasiou, I. S. and N. K. Uzunoglu, "Experimental study of 3D contactless conductivity detection using microwave radiometry: A possible method for investigation of brain conductivity fluctuations," EMBC'04 Proceedings, 2303-2306, San Fransisco, USA, 2004. Google Scholar

7. Karanasiou, I. S., M. I. Giamalaki, A. Oikonomou, and N. K. Uzunoglu, "Passive four-frequency microwave tomography: An experimental feasibility study," IFMBE Proceedings, Vol. 11, 2086-1- 2086-5, Prague, 2005. Google Scholar

8. Giamalaki, M. I., I. S. Karanasiou, and N. K. Uzunoglu, "Enhancement of the focusing properties of a passive radiometry imaging system: A theoretical electromagnetic study," CEAA'07 Proceedings, No. 263, Torino, Italy, 2007. Google Scholar

9. Giamalaki, M. I., I. S. Karanasiou, and N. K. Uzunoglu, "Focused microwave radiometry from a possible functional imaging perspective: Theoretical optimization of the properties of a microwave radiometry system," ITBS 2007 Proceedings, 36-37, Milos Island, Greece, 2007. Google Scholar

10. Acar, R. C. and G. Dural, "Mutual coupling of printed elements on a cylindrically layered structure using closed-form Greens functions," Progress In Electromagnetics Research, PIER 78, 103-127, 2008. Google Scholar

11. Gao, G., C. Torres-Verdin, and T. M. Habashy, "Analytical techniques to evaluate the integrals of 3D and 2D spatial dyadic Greens functions," Progress In Electromagnetics Research, PIER 52, 47-80, 2005. Google Scholar

12. Li, L.-W., N. H. Lim, and W. Y. Yin, "Eigenfunctional expansion of dyadic Green's functions in gyrotropic media using cylindrical vector wave functions," Progress In Electromagnetics Research, PIER 43, 101-121, 2003. Google Scholar

13. Li, L. W., S. B. Yeap, M. S. Leong, T. S. Yeo, and P. S. Kooi, "Dyadic Green's functions in multilayered stratified gyroelectric chiral media," Progress In Electromagnetics Research, PIER 35, 53-81, 2002. Google Scholar

14. Li, L. W., N. H. Lim, and J. A. Kong, "Cylindrical vector wave function representation of Green's dyadic in gyrotropic bianisotropic media," Progress In Electromagnetics Research, 127-145, 2008. Google Scholar

15. Attiya, M., "Dyadic Green's function of an elementary point source above a periodically-defected-grounded dielectric slab," Progress In Electromagnetics Research B, Vol. 4, 127-145, 2008.
doi:10.2528/PIERB08011001 Google Scholar

16. Lamultree, S., C. Phongcharoenpanich, S. Kosulvit, and M. Krairiksh, "Analysis of radiation characteristics of a probeexcited rectangular ring antenna by the dyadic Green's function approach," Progress In Electromagnetics Research B, Vol. 11, 79-101, 2009. Google Scholar

17. Gabriel, C., S. Gabriel, and E. Corthout, "The dielectric properties of biological tissues: I. Literature survey," Physics in Medicine and Biology, Vol. 41, 2251-2269, 1996.
doi:10.1088/0031-9155/41/11/002 Google Scholar

18. Gabriel, S., R. W. Lau, and C. Gabriel, "The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz," Physics and Medicine and Biology, Vol. 41, 2251-2269, 1996.
doi:10.1088/0031-9155/41/11/002 Google Scholar

19. Gabriel, S., R. W. Lau, and C. Gabriel, "The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues," Physics and Medicine and Biology, Vol. 41, 2271-2293, 1996.
doi:10.1088/0031-9155/41/11/003 Google Scholar

20. Veselago, V. G., "The electrodynamics of substances with simultaneously negative values of ε and μ," Soviet Physics USPEK, Vol. 10, 509-514, 1968.
doi:10.1070/PU1968v010n04ABEH003699 Google Scholar

21. Pendry, J. B., "Electromagnetic materials enter the negative age," Physics World, Vol. 14, 47-51, 2001. Google Scholar

22. Smith, D. R. and N. Kroll, "Negative refractive index in left handed materials," Physical. Review. Letters, Vol. 85, 2933-2936, 2000.
doi:10.1103/PhysRevLett.85.2933 Google Scholar

23. Smith, D. R., W. J. Padilla, D. C. Vier, S. C. Nermat-Nasser, and S. Schultz, "A composite medium with simultaneously negative permeability and permittivity," Physical. Review. Letters, Vol. 84, 4184-4187, 2000.
doi:10.1103/PhysRevLett.84.4184 Google Scholar

24. Zainud-Deen, S. H., A. Z. Botros, and M. S. Ibrahim, "Scattering from bodies coated with metamaterial using FDFD method," Progress In Electromagnetics Research B, Vol. 2, 279-290, 2008.
doi:10.2528/PIERB07112803 Google Scholar

25. Valagiannopoulos, C. A., "Electromagnetic scattering from two eccentric metamaterial cylinders with frequency-dependent permittivities differing slightly each other," Progress In Electromagnetics Research B, Vol. 3, 23-34, 2008.
doi:10.2528/PIERB07112906 Google Scholar

26. Ahmed, S. and Q. A. Naqvi, "Electromagnetic scattering of two or more incident plane waves by a perfect electromagnetic conductor cylinder coated with a metamaterial," Progress In Electromagnetics Research B, Vol. 10, 75-90, 2008.
doi:10.2528/PIERB08083101 Google Scholar

27. Yu, G. X. and T. J. Cui, "Imaging and localization properties of LHM superlens excited by 3D horizontal electric dipoles," J. of Electromagn. Waves and Appl., Vol. 21, No. 1, 35-46, 2007.
doi:10.1163/156939307779391795 Google Scholar

28. Wang, M. Y., J. Xu, J. Wu, Y. B. Yan, and H. L. Li, "FDTD study on scattering of metallic column covered by double-negative metamaterial," J. of Electromagn. Waves and Appl., Vol. 21, No. 14, 1905-1914, 2007.
doi:10.1163/156939307783152777 Google Scholar

Dr. Melpomeni I. Giamalaki

Dr. Irene Karanasiou

Professor Nikolaos Uzunoglu