title: Unconstrained monitoring of long-term heart and breath rates during sleep.
abstract: An unconstrained method for the long-term monitoring of heart and breath rates during sleep is proposed. The system includes a sensor unit and a web-based network module. The sensor unit is set beneath a pillow to pick up the pressure variations from the head induced by inhalation/exhalation movements and heart pulsation during sleep. The measured pressure signal was digitized and transferred to a remote database server via the network module. A wavelet-based algorithm was employed to detect the heart and breath rates, as well as body movement, during sleep. The overall system was utilized for a total six-month trial operation delivered to a female subject. The profiles of the heart and breath rates on a beat-by-beat and daily basis were obtained. Movements during sleep were also estimated. The results show that the daily average percentage of undetectable periods (UPs) during 881.6 sleep hours over a 180 day period was 17.2%. A total of 89.2% of sleep hours had a UP of not more than 25%. The profile of the heart rate revealed a periodic property that corresponded to the female monthly menstrual cycle. Our system shows promise as a long-term unconstrained monitor for heart and breath rates, and for other physiological parameters related to the quality of sleep and the regularity of the menstrual cycle.
authors.affiliation: School and Graduate School of Computer Science and Engineering, University of Aizu, Aizu-Wakamatsu, Fukushima 965-8580, Japan. wenxi@u-aizu.ac.jp
authors.forename: Wenxi
authors.initials: W
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Zhu
authors.forename: Tetsu
authors.initials: T
authors.lastname: Nemoto
authors.forename: Kei-Ichiro
authors.initials: K
authors.lastname: Kitamura
authors.forename: Kayo
authors.initials: K
authors.lastname: Sugitani
authors.forename: Daming
authors.initials: D
authors.lastname: Wei
mesh_terms: D000328:Adult; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D004562:Electrocardiography / Q000295:instrumentation*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D020407:Internet / Q000295:instrumentation; D008365:Manometry / Q000295:instrumentation / Q000379:methods; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods; D017286:Polysomnography / Q000295:instrumentation* / Q000379:methods; D012016:Reference Values; D015656:Respiratory Mechanics / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D017216:Telemedicine / Q000295:instrumentation*; D014159:Transducers