Patent Document ID: 10098583
Application ID: 14379458
Patent Flag: 1

Claim One:
1. A sleep quality estimation device comprising: a respiration sensor that detects a respiratory waveform of a subject; a processor configured to: estimate a depth of sleep of the subject during sleep based on the detected respiratory waveform of the subject, estimate an appearance time of δ-wave of the subject during sleep from the estimated depth of sleep of the subject, and estimate a sleep quality of the subject based on an accumulated appearance time of δ-wave; a database in which models associated with an appearance probability of δ-wave for the depth of sleep during sleep are recorded, wherein the processor is configured to estimate the appearance time of δ-wave of the subject during sleep based on the depth of sleep of the subject during sleep and the models associated with the appearance probability of δ-wave for the depth of sleep during sleep recorded in the database and to estimate the sleep quality of the subject based on the appearance time of δ-wave, wherein the models recorded in the database are associated with the appearance probability of δ-wave for a stay time when the depth of sleep of each sleep cycle from non-REM sleep to REM sleep stays with a value deeper than a predetermined value, and the processor estimates the stay time of each sleep cycle from the depth of sleep of the subject during sleep and estimates the appearance time of δ-wave of the subject during sleep based on the stay time and the models associated with the appearance probability of δ-wave for the stay time of each sleep cycle, wherein, in the models recorded in the database, the longer the elapsed time from the onset of sleep is, the lower the appearance probability of δ-wave for the sleep depth is set.