[The sleep staging based on HRV analysis].

In order to deduce the sleep stages from heart rate, we analyze the heart rate variability (HRV) with hidden Markov model (HMM) for the identification of different characters of HRV within different sleep stages. Special technique is used to compensate the individual diversity. The relationship between the sleep stage and the ultra-low frequency components of HRV is also considered. Since the detection of heart rate hardly disturbs the sleep, the proposed method provides a simple approach to evaluating the sleep stage without disturbing the sleep. Our experiments have proved that this method meets the requirements of wide applications, especially the requirement of routine use in monitoring the normal subjects' sleep.