Patent ID: 8594774
Filing Date: 2013-11-26
Classification: A61B

Abstract:
1. A sleep determination device comprising: a heartbeat obtaining unit that obtains a heartbeat of a subject; a difference calculating unit that calculates a heartbeat cycle for each heartbeat based on the heartbeat obtained by the heartbeat obtaining unit, and calculates difference values until obtaining Nth-degree difference values set in advance with difference values between the successive heartbeat cycles as first-degree difference values and difference values between the successive first-degree difference values as second-degree difference values; a distribution data generating unit that generates distribution data indicative of a distribution of the respective values in a predetermined period of time for each of the heartbeat cycles and the difference values from the first-degree difference values to the Nth-degree difference values calculated by the difference calculating unit; and a sleep determining unit that determines a sleep stage of the subject based on the distribution data generated by the distribution data generating unit by referring to distribution data for determination set in advance for each sleep stage.