Multi-frequency Microwave Radiometer System for Measuring Deep Brain Temperature in New Born Infants

Abstract

Hypothermic brain treatment for newborn babies are currently hindered by the lack of appropriate techniques for continuous and non-invasive measurement of deep brain temperature. Microwave radiometry (MWR) is one of the promising methods that is completely passive and inherently safe. Five-band microwave radiometer system and its feasibility were reported with a confidence interval level of the temperature estimation of about 1.6 °C at 5 cm depth from the surface. This result was not good enough for clinical application because clinical requirement is less than 1 °C for both accuracy and stability. This paper describes the improved result of temperature resolutions of the five radiometer receivers, and shows the new confidence interval obtained form temperature measurement experiment using an agar phantom based on a water-bath. Temperature resolutions were 0.103, 0.129, 0.138, 0.105 and 0.111 °C for 1.2, 1.65, 2.3, 3.0 and 3.6 GHz receiver, respectively, and new confidence interval was 0.51 °C at 5 cm from surface. We believe that the system takes a step closer to the clinical hypothermic treatment.