Objective: Near-field microwave radiometry has emerged as a tool for real time passive monitoring of local brain activation possibly attributed to local changes in blood flow that correspond to temperature and/or conductivity changes. The aim of this study is to design and evaluate a prototype system based on microwave radiometry intended to detect local changes of temperature and conductivity in depth in brain tissues. A novel radiometric system that comprises a four port total power Dicke-switch sensitive receiver that operates at 1.5 GHz has been developed. Methods and Results: The efficacy of the system was assessed through simulation and experiment on brain tissue mimicking phantoms under different setup conditions, where temperature and conductivity changes were accurately detected. In order to validate the radiometer's capability to sense low power signals occurring spontaneously from regions in the human brain, the somatosensory cortices of one volunteer were measured under pain inducing psychophysiological conditions. The promising results from the initial in-vivo measurements prove the system's potential for more extensive investigative trials. Conclusion and significance: The significance of this study lies on the development of a compact and sensitive radiometer for totally passive monitoring of local brain activation as a potential complementary tool for contributing to the research effort for investigating brain functionality.Index Terms-Microwave radiometry, real time monitoring, non-invasive passive measurement, measurement of local brain temperature and / or conductivity variations maria.koutsoupidou@kcl.ac.uk).Irene S. Karanasiou is with the

In this article, we describe recent advances regarding a novel microwave imaging system intended to be used for in‐depth inspection of breast tissues. The system is made of a circular five‐element antenna array surrounding the breast that can be moved axially to perform a scan of the entire breast. The performance of the system is studied, both numerically and experimentally with a realistic anthropomorphic breast phantom, as a proof of concept of its fast and accurate screening ability to detect tumor‐like inclusions. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:6–10, 2017

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Microwave radiometry is a passive technique used to measure in-depth temperature distributions inside the human body, potentially useful in clinical applications. Experimental data imply that it may provide the capability of detecting in-depth local variations of temperature and/or conductivity of excitable tissues at microwave frequencies. Specifically, microwave radiometry may allow the real-time monitoring of brain temperature and/or conductivity changes, associated with local brain activation. In this paper, recent results of our ongoing research regarding the capabilities of focused microwave radiometry for brain intracranial applications are presented. Electromagnetic and thermal simulation analysis was performed using an anatomically detailed head model and a dielectric cap as matching medium placed around it, in order to improve the sensitivity and the focusing attributes of the system. The theoretical results were compared to experimental data elicited while exploring that the sensing depth and spatial resolution of the proposed imaging method at 2.1 GHz areas located 3 cm deep inside the brain can be measured, while at 2.5 GHz, the sensing area is confined specifically to the area of interest. The results exhibit the system's potential as a complementary brain imaging tool for multifrequency in-depth passive monitoring which could be clinically useful for therapeutic, diagnostic, and research applications.