In emergency departments and ICUs, a novel noncontact thermometer is urgently required to measure physical temperatures through common clothing to accomplish body temperature precise measurement for critical patients. Hence, a Ku band digital auto gain compensative microwave radiometer is proposed to get a higher theoretical temperature measurement sensitivity than a Dicke radiometer, benefit miniaturization design and reduce attenuation caused by common clothing. Meanwhile, a novel compensation method for receiver calibration is proposed to improve temperature sensitivity under non-ideal conditions, and the revised systematic calibration method is elaborated. Furthermore, in order to invert body physical temperatures through clothing, a microwave thermal radiation transmission model of clothed human body is constructed, and the microwave radiation apparent temperature equation of clothed human body is derived. Importantly, three groups of experiments are set up to confirm the designed radiometer's performance, especially the biological tissue temperature measurement. Results show that: 1) the designed radiometer has high temperature sensitivity and accuracy for unsheltered targets; 2) amplitude attenuation caused by cotton cloth for Ku band microwave is much smaller than that for infrared thermal radiation; 3) the designed radiometer can track physical temperatures of targets (such as water and swine skin tissue) sheltered or covered by cotton cloth relatively accurately. In conclusion, our designed Ku band microwave radiometer is certificated to have outstanding performance in temperature measurement for biological tissue through common clothing, which can be developed into a promising product in medical monitoring.
2. Lin, S., Microwave and Millimeter-Wave Remote Sensing for Security Applications, 372 pages, Jeffrey A. Nanzer, Artech House, 2012, ISBN 978-1-60807-172-2[J].
3. Enander, B. and G. Larson, "Microwave radiometric measurements of the temperature inside a body," Electronics Letters, Vol. 10, No. 15, 317-317, 1974.
4. Barrett, A. H. and P. C. Myers, "Subcutaneous temperatures: A method of noninvasive sensing," Science, Vol. 190, No. 4215, 669-671, 1975.
5. Maruyma, K., et al., "Feasibility of noninvasive measurement of deep brain temperature in newborn infants by multifrequency microwave radiometry," IEEE Transactions on Microwave Theory and Techniques, Vol. 48, No. 11, 2141-2147, 2000.
6. Hand, J. W., et al., "Monitoring of deep brain temperature in infants using multi-frequency microwave radiometry and thermal modelling," Physics in Medicine & Biology, Vol. 46, No. 7, 1885, 2001.
7. Popovic, Z., et al., Microwave thermometer for internal body temperature retrieval, U.S. Patent Application 15/608,284[P], Nov. 30, 2017.
8. Momenroodaki, P., et al., "Noninvasive internal body temperature tracking with near-field microwave radiometry," IEEE Transactions on Microwave Theory and Techniques, Vol. 66, No. 5, 2535-2545, 2018.
9. McGrath, J. A., R. A. J. Eady, and F. M. Pope, "Anatomy and organization of human skin," Rook's Textbook of Dermatology, Vol. 1, 3.2-3.80, 2004.
10. Black, D., et al., "Measurement of subcutaneous fat thickness with high frequency pulsed ultrasound: Comparisons with a caliper and a radiographic technique," Clinical Physics and Physiological Measurement, Vol. 9, No. 1, 57, 1988.
11. Gabriel, C., S. Gabriel, and E. Corthout, "The dielectric properties of biological tissues: I. Literature survey," Physics in Medicine & Biology, Vol. 41, No. 11, 2231-2249, 1996.
12. Gabriel, S., R. W. Lau, and C. Gabriel, "The dielectric properties of biological tissue II: Measurements in the frequency range 10 Hz to 20 GHz," Physics in Medicine and Biology, Vol. 41, No. 11, 2251-2269, 1996.
13. Gabriel, S., R. W. Lau, and C. Gabriel, "The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues," Physics in Medicine & Biology, 41, 1996.
14. Bigu-Del-Blanco, J., C. Romero-Sierra, and J. A. Tanner, "Some theory and preliminary experiments on microwave radiometry of biological systems," S-MTT International Microwave Symposium Digest, 41-44, 1974.
15. Mamouni, A., Y. Leroy, M. Samsel, and M. Gautherie, "Radiothermometrie micro-onde a 9 GHz: Applications aux cancers du sein et a des localisations tumorales diverses. Resultats preliminaires," Microwave Power Symposium 1979, XIVe Symposium International sur les Applications energetiques des Micro-ondes, Monaco, Jun. 11-15, 1979.
16. Mamouni, A., D. D. N'Guven, M. Robillard, M. Chive, and Y. Leroy, "Physical basis and technology of microwave radiometry," Proc. SPIE 0211, Optics and Photonics Applied to Medicine, May 29, 1980.
17. Gautherie, M., A. Mamouni, M. Samsel, J. L. Guerquin-Kern, Y. Leroy, and C. Gros, "Microwave radiothermometry (9 GHz) applied to breast cancer," Proc. SPIE 0211, Optics and Photonics Applied to Medicine, May 29, 1980.
18. Robert, J., J. Edrich, Y. Leroy, A. Mamouni, J. M. Escanye, and P. Thouvenot, "Clinical applications of microwave thermography," Proc. SPIE 0211, Optics and Photonics Applied to Medicine, May 29, 1980.
19. Abdul-Razzak, M. M., et al., "Microwave thermography for medical applications," IEE Proceedings A (Physical Science, Measurement and Instrumentation, Management and Education, Reviews), Vol. 134, No. 2, 171-174, 1987.
20. Poikalainen, V. and J. Praks, "The use of microwave thermometer for the determination of cows' body surface temperature," Transactions of the Estonian Academic Agricultural Society (Estonia), 1998.
21. Kanakov, V. A. and A. G. Kislyakov, "Human-body temperature measurements using contact radiometer with built-in calibrators," Radiophysics & Quantum Electronics, Vol. 42, No. 2, 150-156, 1999.
22. Tipa, R. and O. Baltag, "Microwave thermography for cancer detection," Romanian Journal of Physics, Vol. 51, No. 3/4, 371, 2006.
23. Stephan, K. D., et al., "A near field focused microstrip array for a radiometric temperature sensor," IEEE Transactions on Antennas and Propagation, Vol. 55, No. 4, 1199-1203, 2007.
24. David, J. I., M. B. Zemel, C. T. Lyster, and N. Feld, Passive microwave assessment of human body core to surface temperature gradients and basal metabolic rate, USA, US 8,013,745 B2[P], Sep. 6, 2011.
25. Zhao, K., J. X. Shi, and H. D. Zhang, "High sensitivity airborne l-band microwave radiometer measurements of sea surface salinity," Journal of Remote Sensing, 2008.
26. Jian, S., et al., "A new airborne Ka-band double-antenna microwave radiometer for cloud liquid water content measurement," Proceedings of SPIE --- The International Society for Optical Engineering, Vol. 8866, 17, 2013.
27. Ulaby, F. T., R. K. Moore, and A. K. Fung, "Microwave remote sensing: Active and passive. Volume 1 | Microwave remote sensing fundamentals and radiometry," Remote Sensing A, Vol. 2, No. 5, 355-356, 1981.
28. Wohlleben, R., H. Mattes, and O. Lochner, "Simple small primary feed for large opening angles and high aperture efficiency," Electronics Letters, Vol. 8, No. 19, 474-476, Sep. 21, 1972.
29. Milligan, T. A., Modern Antenna Design, 2nd Ed., Wiley, 2005.
30. James, G. L., "Radiation properties of 90◦ conical horns," Electronics Letters, Vol. 13, No. 10, 293-294, May 12, 1977.
31. Silver, S., Microwave Antenna Theory and Design, Chapter 11, 1984.
32. Clarricoats, P. J. B. and P. K. Saha, "Radiation pattern of a lens-corrected conical scalar horn," Electronics Letters, Vol. 5, No. 23, 592-593, Nov. 1969.
33. Neto, A., S. Maci, and P. J. I. de Maagt, "Reflections inside an elliptical dielectric lens antenna," IEE Proceedings --- Microwaves, Antennas and Propagation, Vol. 145, No. 3, 243-247, Jun. 1998.
34. Pohl, N., "A dielectric lens antenna with enhanced aperture efficiency for industrial radar applications," IEEE Middle East Conference on Antennas and Propagation (MECAP 2010), 1-5, 2010.
35. Van der Vorst, M. J. M., P. J. L. de Maagt, and M. H. A. J. Herben, "Effect of internal reflections on the radiation properties and input admittance of integrated lens antennas," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, No. 9, 1696-1704, Sep. 1999.
36. Nguyen, N. T., R. Sauleau, and C. J. M. Perez, "Very broadband extended hemispherical lenses: Role of matching layers for bandwidth enlargement," IEEE Transactions on Antennas and Propagation, Vol. 57, No. 7, 1907-1913, Jul. 2009.
39. Pozar, D. M., Microwave Engineering, 4th Ed., Wiley, New York, NY, USA, 2012.
40. Holmes, J., C. Balanis, and W. Truman, "Application of Fourier transforms for microwave radiometric inversions," IEEE Transactions on Antennas and Propagation, Vol. 23, No. 6, 797-806, 1975.
41. Truman, W., C. Balanis, and J. Holmes, "Three-dimensional vector modeling and restoration of flat finite wave tank radiometric measurements," IEEE Transactions on Antennas and Propagation, Vol. 25, No. 1, 95-104, 1977.
42. Li, Q., et al., "Brightness temperature of extended targets," ICMMT'98. 1998 International Conference on Microwave and Millimeter Wave Technology Proceedings (Cat. No.98EX106), 483-487, 1998.
43. Li, Q., et al., "Models for the brightness temperature of extended targets at MM wave frequency," International Journal of Infrared and Millimeter Waves, Vol. 19, No. 9, 1247-1253, 1998.
44. Xiao, Z., J. Xu, and T. Hu, "Research on the transmissivity of some clothing materials at millimeter-wave band," 2008 International Conference on Microwave and Millimeter Wave Technology, 1750-1753, 2008.
45. Susek, W., "Thermal microwave radiation for subsurface absolute temperature measurement," ACTA Phys. Pol. A, Vol. 118, 1246-1249, 2010.
46. Momenroodaki, P., Z. Popovic, and R. Scheeler, "A 1.4-GHz radiometer for internal body temperature measurements," 2015 European Microwave Conference (EuMC), 694-697, Paris, France, Sep. 7-10, 2015.
47. Jacobsen, S. and O. Klemetsen, "Improved detectability in medical microwave radio-thermometers as obtained by active antennas," IEEE Trans. Biomed. Eng., Vol. 55, 2778-2785, 2008.
48. Bonds, Q., J. Gerig, T. M. Weller, and P. Herzig, "Towards core body temperature measurement via close proximity radiometric sensing," IEEE Sensors Journal, Vol. 12, 519-526, 2012.
49. Klemetsen, O., Y. Birkelund, S. K. Jacobsen, P. F. Maccarini, and P. R. Stauffer, "Design of medical radiometer front-end for improved performance," Progress In Electromagnetics Research B, Vol. 27, 289-306, 2011.
50. International Telecommunication Union Radiocommunication Assembly Attenuation due to clouds and fog, Recommendation ITU-R P.840-8, 2019.
51. Mcintyre, M. K., et al., "Initial characterization of the pig skin bacteriome and its effect on in vitro models of wound healing," The FASEB Journal, 30, 2016.
52. Abd, E., et al., "Skin models for the testing of transdermal drugs," Research & Reports in Transdermal Drug Delivery, Vol. 8, 163-176, 2016.
53. Paul, H., et al., "Vital, porcine, gal-knockout skin transplants provide efficacious temporary closure of full-thickness wounds: Good laboratory practice-compliant studies in nonhuman primates," Journal of Burn Care & Research, Vol. 41, No. 2, 229-240, Official Publication of the American Burn Association, 2020.