Body movement and vital signs (heart rate and respiration) of elderly persons in a nursing home were non-invasively recorded with piezoelectric sensor while they slept overnight in bed without restraint. Heart rate data were automatically analyzed by using the method originally proposed by Penzel et al (2003) in order to objectively classify the four stages of wake and sleep. This study attempted to improve Penzel’s method by using Z-Score of feature parameters that will be expected to reduce individual difference and hence lead to improvement of estimations of stages of wake and sleep. The stages of wake and sleep were compared between elderly persons in a nursing home and those at home. Sleep variables, including sleep time, sleep efficiency, sleep latency, percent appearance of sleep stages, and percent time and the number of wake after sleep onset, as well as subjectively perceived depth of sleep, were measured and statistically were tested between two groups of elderly persons.
The following results were obtained. (1) Average sleep time for elderly persons in the nursing home was significantly longer by 50% than that for elderly healthy persons at home; (2) Elderly persons in the nursing home showed significantly lower percent appearance of deep sleep and higher percent appearance of REM sleep than elderly persons at home.
It was discussed that the elderly persons in the nursing home are likely to have a poorer quality of sleep, although further examination seems to be required to ensure the validity of the results.
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