TY - JOUR
T1 - Vital Sign Monitoring Using FMCW Radar in Various Sleeping Scenarios
AU - Turppa, Emmi
AU - Kortelainen, Juha M.
AU - Antropov, Oleg
AU - Kiuru, Tero
N1 - Funding Information:
This research was partially funded by the Academy of Finland HISENS project under grant 310879 and Business Finland MAIWAY project under grant 2638/31/2018. The authors thank Johanna Närväinen, Kati Pettersson, Lic. Sc. (Tech.) Johan Plomp, and Mark van Gils of VTT Technical Research Centre of Finland Ltd, and Moncef Gabbouj of Tampere University, Finland, for their valuable comments on the manuscript.
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/11/14
Y1 - 2020/11/14
N2 - Remote monitoring of vital signs for studying sleep is a user-friendly alternative to monitoring with sensors attached to the skin. For instance, remote monitoring can allow unconstrained movement during sleep, whereas detectors requiring a physical contact may detach and interrupt the measurement and affect sleep itself. This study evaluates the performance of a cost-effective frequency modulated continuous wave (FMCW) radar in remote monitoring of heart rate and respiration in scenarios resembling a set of normal and abnormal physiological conditions during sleep. We evaluate the vital signs of ten subjects in different lying positions during various tasks. Specifically, we aim for a broad range of both heart and respiration rates to replicate various real-life scenarios and to test the robustness of the selected vital sign extraction methods consisting of fast Fourier transform based cepstral and autocorrelation analyses. As compared to the reference signals obtained using Embla titanium, a certified medical device, we achieved an overall relative mean absolute error of 3.6% (86% correlation) and 9.1% (91% correlation) for the heart rate and respiration rate, respectively. Our results promote radar-based clinical monitoring by showing that the proposed radar technology and signal processing methods accurately capture even such alarming vital signs as minimal respiration. Furthermore, we show that common parameters for heart rate variability can also be accurately extracted from the radar signal, enabling further sleep analyses.
AB - Remote monitoring of vital signs for studying sleep is a user-friendly alternative to monitoring with sensors attached to the skin. For instance, remote monitoring can allow unconstrained movement during sleep, whereas detectors requiring a physical contact may detach and interrupt the measurement and affect sleep itself. This study evaluates the performance of a cost-effective frequency modulated continuous wave (FMCW) radar in remote monitoring of heart rate and respiration in scenarios resembling a set of normal and abnormal physiological conditions during sleep. We evaluate the vital signs of ten subjects in different lying positions during various tasks. Specifically, we aim for a broad range of both heart and respiration rates to replicate various real-life scenarios and to test the robustness of the selected vital sign extraction methods consisting of fast Fourier transform based cepstral and autocorrelation analyses. As compared to the reference signals obtained using Embla titanium, a certified medical device, we achieved an overall relative mean absolute error of 3.6% (86% correlation) and 9.1% (91% correlation) for the heart rate and respiration rate, respectively. Our results promote radar-based clinical monitoring by showing that the proposed radar technology and signal processing methods accurately capture even such alarming vital signs as minimal respiration. Furthermore, we show that common parameters for heart rate variability can also be accurately extracted from the radar signal, enabling further sleep analyses.
KW - Biomedical monitoring
KW - Biomedical signal processing
KW - Contactless
KW - Health monitoring
KW - Heart rate
KW - Heart rate variability
KW - Millimeter wave radar
KW - Respiratory rate
UR - http://www.scopus.com/inward/record.url?scp=85096037663&partnerID=8YFLogxK
U2 - 10.3390/s20226505
DO - 10.3390/s20226505
M3 - Article
C2 - 33202567
SN - 1424-8220
VL - 20
SP - 1
EP - 19
JO - Sensors
JF - Sensors
IS - 22
M1 - 6505
ER -