title: Five-band microwave radiometer system for non-invasive measurement of brain temperature in new-born infants: system calibration and its feasibility.
abstract: Recent simulation studies have shown that a technique of multi-frequency microwave radiometry is feasible for non-invasive measurement of deep brain temperatures in the new-born infants. A five-band microwave radiometer system has been developed, and its operation in a normal electromagnetic environment is checked. Five receivers operating with a waveguide antenna and at center frequencies of 1.2, 1.65, 2.3, 3.0 and 3.6 GHz (0.4 GHz bandwidth) are calibrated using a temperature-controlled water-bath. Temperature resolutions obtained for each receiver are 0.183, 0.273, 0.148, 0.108 and 0.118 K, respectively. A temperature retrieval simulation based on these resolutions and the previously proposed algorithm shows that the confidence interval, as produced by thermal noise, is 0.62 K for the retrieved central brain temperature. If the conductivity of brain is estimated wrong by 10 %, this will result in an error of 0.3-0.4 K. The result of this work is encouraging for realization of radiometric measurement of temperature profile in a baby's head.
authors.affiliation: Research Institute of Electronics, Shizuoka University, Hamamatsu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sugiura
authors.forename: Y
authors.initials: Y
authors.lastname: Kouno
authors.forename: A
authors.initials: A
authors.lastname: Hashizume
authors.forename: H
authors.initials: H
authors.lastname: Hirata
authors.forename: J W
authors.initials: JW
authors.lastname: Hand
authors.forename: Y
authors.initials: Y
authors.lastname: Okita
authors.forename: S
authors.initials: S
authors.lastname: Mizushina