Noninvasive Passive Internal Body Thermometry using Microwave Receivers

Zoya Popovic
Distinguished Professor and Lockheed Martin Endowed Chair, University of Colorado, Boulder

Abstract:

This talk presents the fundamentals of operation, design, implementation and testing of a microwave radiometer for near-field internal temperature measurements of the human body. In this approach, the total blackbody power from a tissue stack is received by a 1.4-GHz probe placed on the skin connected to a low-noise receiver. Temperature retrieval for sub-surface tissue layers is performed using near-field weighting functions, obtained by full-wave simulations with known tissue complex electrical parameters. Measurements are presented using several types of calibrated radiometers at 1.4GHz for various phantom tissues and in-vivo tracking in the human cheek is also shown to follow ground-truth thermocouple measurements. With an integration time on the order of a second, temperature can be tracked within a fraction of a degree. Several medical applications are outlined along with their respective technical challenges. These range from brain temperature monitoring during aortic repair open-heart surgery to monitoring soldiers under heavy training.

Speaker’s Bio:

Zoya Popovic is a Distinguished Professor of Electrical Engineering at the University of Colorado, Boulder. She obtained her Dipl.Ing. degree at the University of Belgrade, Serbia, and her Ph.D. at Caltech. She holds an honorary doctorate from the Carlos III University in Madrid. She was a Visiting Professor with the Technical University of Munich in 2001/03, ISAE in Toulouse, France in 2014, and was a Chair of Excellence at Carlos III University in Madrid in 2018/19. She has graduated over 70 PhDs and currently advises 18 doctoral students. Her research interests are in microwave and millimeter-wave high-performance circuits for communications and radar, medical and industrial applications of microwaves, and RF quantum sensing. She is a Fellow of the IEEE and the recipient of two IEEE MTT Microwave Prizes for best journal papers, the White House NSF Presidential Faculty Fellow award, the URSI Issac Koga Gold Medal, the ASEE/HP Terman Medal and the German Alexander von Humboldt Research Award. She was elected as foreign member of the Serbian Academy of Sciences and Arts in 2006 and was named IEEE MTT Distinguished Educator in 2013. Prof. Popovic was elected a Member of the National Academy of Engineering in 2022 and a Fellow of the National Academy of Inventors in 2023. She has a husband physicist and three daughters who can all solder.