Vital Signs Monitoring: Breathing Rate and Heartbeat Rate Detection

Abstract

The Healthcare sector has been hugely impacted by the emergence of non-contact vital signs detection technology. Substituting contact-based vital signs monitoring devices with wireless devices has attracted the attention of the healthcare industry. The frequency-modulated continuous wave (FMCW) radar has recently dominated the literature and has shown a promise to realize the measurement of vital signs remotely. However, the sole reason that prevents wireless technology from replacing standard devices is accuracy. To overcome this, radars with high operating frequencies and large bandwidths are required. These features give the radars high resolution to detect small displacement changes in the order of the sub-millimeter range. Radars of such features require complex hardware architectures and efficient signal processing algorithms.

In this work, an efficient algorithm has been prepared for a state-of-the-art vital sign monitoring FMCW radar that operates at 160 GHz frequency with 10 GHz bandwidth that was designed by Khalifa University of Science and Technology (KUST). The algorithm uses phase-based measurement to detect and estimate the vital signs of a subject. The algorithm further addresses the IQ imbalances caused by hardware imperfections that affect vital measurements. It deploys compressed sensing-based signal reconstruction and wavelet decomposition algorithms which recent papers have claimed to have scored higher accuracy compared to other monitoring algorithms. However, since the measurement of the FMCW radar designed in KUST was not finished, the algorithm was validated using a public dataset that was acquired using FMCW radar manufactured by Texas Instruments. The performance of the algorithm was then compared with vital rates acquired using a clinically approved vital signs monitoring device called Nihon Kohden which was synchronized with the FMCW radar during data acquisition.

This work also addresses the measurement setup for the transmitter and receiver blocks of the radar IC designed in KUST. The challenges of measuring devices operating at high frequencies are also discussed. Moreover, the connection setup of the boards that are to be used to capture the intermediate frequency (IF) signal is also covered. The setup was successfully tested, and it will be used with the radar IC measurement in the future.

Date of Award	Dec 2022
Original language	American English
Supervisor	Mihai Sanduleanu (Supervisor)