Monitoring brown fat metabolic activity using microwave radiometry: Antenna design and frequency selection

This paper describes the use of microwave radiometry for monitoring brown fat metabolism (mBAT). The radiometric frequency band and receive antenna were optimized for coupling to 2-6 ml BAT depots in the supraclavicular region. Radiometric signal variations induced by higher metabolic activity resulting from a cold stimulus were calculated with electromagnetic and thermal simulations in a segmented computational model of the human neck including BAT. A 2.5 cm dia. log spiral antenna was selected as optimum using a 500 MHz bandwidth and center frequency 2.75 GHz. Results suggest sufficient sensitivity to track sub-surface temperature variations during long term mBAT monitoring for potential use in obesity and diabetes research.