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Changes in fractal structure of heart rate variability during a nap in one case
1Medical Information & Intelligence Center, Saga Medical School Hospital, Saga, Japan. shonoh@post.saga-med.ac.jp
Abstract:
The objective of the present study was to analyze fractal structures of adult heart rate (HR) variability during a nap. Fractal analysis was carried out in one case over consecutive 10-min time series of HR, which were simultaneously recorded with electroencephalogram. Scaling relationships showed cross-over patterns characterized by alphas and alphal (i.e. slopes above and below a cross-over point). The alphas and alphal were black and white noise at Stage 4 of NREM sleep, and black and 1/f noise in REM sleep. Cross-over points changed from the first to second sleep cycle. We demonstrate the multifractal structures of HR variability during a nap in the present case.
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