A sleep state measuring apparatus and method, a phase coherence calculating apparatus, a living body vibration signal measuring apparatus, a stress state measuring apparatus and a sleep state measuring apparatus, and a heartbeat waveform extracting method

摘要

[PROBLEMS] To provide a means for easily measuring, observing, or evaluating a sleep state. [MEANS FOR SOLVING PROBLEMS] A phase coherence calculation for calculating a phase coherence in accordance with an instantaneous phase difference between an instantaneous phase of a change in heartbeat interval acquired during an animal's sleep and an instantaneous phase of an animal's breathing pattern in a time series equal to a change in a heartbeat interval And means for measuring the state of the sleeping surface.