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Sensors 2015, 15(8), 18950-18964;

Monitoring of Weekly Sleep Pattern Variations at Home with a Contactless Biomotion Sensor

Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
Technology and Intellectual Property H.Q., Omron Corporation, Kyoto 619-0283, Japan
Author to whom correspondence should be addressed.
Academic Editor: Yoshiteru Ishida
Received: 9 June 2015 / Revised: 15 July 2015 / Accepted: 27 July 2015 / Published: 3 August 2015
(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Japan 2015)
Full-Text   |   PDF [545 KB, uploaded 11 August 2015]   |  


Many people find that their sleep is restricted or disturbed by social obligations, including work. Sleep phase delays can affect an individual’s circadian rhythms on the following day and cause daytime sleepiness and/or poor performance. In this study, to examine weekly variations in sleep patterns, we analyzed sleep data for seven-day periods (from Sunday to Saturday) that had been collected from 2914 subjects (aged 20–79 years) over a total of 24,899 subject-weeks using contactless biomotion sensors. On the weekend, the subjects’ mean sleep midpoint, bedtime, and wake-up time were delayed by 40, 26 and 53 min, respectively, compared with those seen on weekdays. In addition, on weekdays, the mean difference between the maximum and median sleep midpoint ranged from 35 to 47 min among the subjects in their 20 s–70 s. The weekend delay and weekday variation in the subjects’ sleep patterns tended to decrease with age. This study detected sleep pattern disturbances on both weekdays and weekends. The serial changes in weekday bedtimes detected in this study suggest that sleep habits are influenced by changes in the temporal patterns of social activities/duties. We need further study the advantages of getting extra sleep and the disadvantages of sleep pattern disturbances in daily lifestyle. View Full-Text
Keywords: contactless; sensor; circadian rhythm; delay; weekend; schedule contactless; sensor; circadian rhythm; delay; weekend; schedule

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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

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Hashizaki, M.; Nakajima, H.; Kume, K. Monitoring of Weekly Sleep Pattern Variations at Home with a Contactless Biomotion Sensor. Sensors 2015, 15, 18950-18964.

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