| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce decline of the accuracy in determining the wakefulness, caused by a noise component included in a detected heartbeat signal. <P>SOLUTION: An acquisition part 11 detects a heartbeat signal representing a signal of the heartbeat of a subject from the subject, and acquires the cycle of the heartbeat signal as a heartbeat interval. An estimation part 12 estimates a model of the heartbeat interval of the subject. The estimation is executed by updating the model of the heartbeat interval, which is estimated based on the past acquired value of the heartbeat interval, based on an error between a new value of the heartbeat interval acquired by the acquisition part 11 and an estimated value of the newly acquired value of the model to reduce the error. A determination part 13 calculates a spectrum to the variation in the heartbeat interval based on the model of the heartbeat interval estimated by the estimation part 12, and determines the degree of wakefulness of the subject based on the spectrum. <P>COPYRIGHT: (C)2013,JPO&INPIT |
