Abstract
This paper introduces a new method, bed actigraphy (BACT) for user-friendly sleep-wake monitoring. BACT provides a non-intrusive acquisition of activity data, and in particular does not require that sensors be attached to the subject’s body. The system consists of four load-sensing cells supporting the bed, an A/D converter, and a microcontroller with appropriate software. The performance of BACT was compared to that of standard polysomnography (PSG) recordings and wrist-worn actigraphy (ACT). Ten normal volunteers underwent overnight PSG recordings and were examined simultaneously with BACT and ACT. An automatic scoring algorithm scored each 30-s epoch of the BACT recordings for either ‘Wake’ or ‘Sleep.’ A sleep specialist manually scored the PSG recordings, and the results were divided into ‘Wake’ and ‘Sleep’ categories. The three methods showed a significant correlation when compared with in the contingency test. The mean epoch-by-epoch agreements between the BACT and PSG, ACT and PSG, and BACT and ACT recordings were 95.2, 92.9, and 94.3%, respectively. The mean absolute differences in sleep percentage (SP) between them were 1.8 ± 0.82, 3.4 ± 1.45, and 1.9 ± 1.16 %, respectively. BACT differentiation of the ‘Wake’ and ‘Sleep’ stages proved to be sufficiently robust, and its results were comparable to PSG analysis. This finding supports the experimental and clinical value of bed-activity monitoring during sleep.
References
Aaronson ST, Rashed S, Biber MP, Hobson JA (1982) Brain state and body position. A time-lapse video study of sleep. Arch Gen Psychiatry 39(3):330–335
Adami AM, Hayes TL, Pavel M (2003) Unobtrusive monitoring of sleep patterns. In: Proceedings of the 25th annual international conference of the IEEE EMBS. Cancun, Mexico, pp 1360–1363
Cole RJ, Kripke DF, Gruen W, Mullaney DJ, Gillin JC (1992) Automatic sleep/wake identification from wrist activity. Sleep 15(5):461–469
Hobson JA, Spagna T, Malenka R (1978) Ethology of sleep studied with time-lapse photography: postural immobility and sleep-cycle phase in humans. Science 201(4362):1251–1253
Kayed K, Hesla PE, Rosjo O (1979) The actioculographic monitor of sleep. Sleep 2(2):253–260
Kripke DF, Mullaney DJ, Messin S, Wyborney VG (1978) Wrist actigraphic measures of sleep and rhythms. Electroencephalogr Clin Neurophysiol 44(5):674–676
Mullaney DJ, Kripke DF, Messin S (1980) Wrist-actigraphic estimation of sleep time. Sleep 3(1):83–92
Rechtschaffen A, Kales A (1968) A manual of standard terminology, technique and scoring system for sleep stages of human subjects (Brain Information Service/Brain Research Institute, UCLA, Los Angeles)
Sadeh A, Acebo C (2002) The role of actigraphy in sleep medicine. Sleep Med Rev 6(2):113–124
Sander LW, Julia HL (1966) Continuous interactional monitoring in the neonate. Psychosom Med 28(6):822–835
Webster JB, Kripke DF, Messin S, Mullaney DJ, Wyborney G (1982) An activity-based sleep monitor system for ambulatory use. Sleep 5(4):389–399
Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics 33:159–174
Acknowledgments
This work was supported by the Korea Science and Engineering Foundation’s Advanced Biometric Research Center Program, Republic of Korea. The authors thank all the partners and the participants in the ABRC project for their help.
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Choi, B.H., Seo, J.W., Choi, J.M. et al. Non-constraining sleep/wake monitoring system using bed actigraphy. Med Bio Eng Comput 45, 107–114 (2007). https://doi.org/10.1007/s11517-006-0134-1
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DOI: https://doi.org/10.1007/s11517-006-0134-1