Patent ID: 7206631

Claim:
A sleepiness level detection device comprising: means for detecting a heartbeat signal of a test subject; calculation means for performing frequency analysis on the heartbeat signal and calculating a spectrum signal that indicates the distribution of frequency components included in the heartbeat signal; and evaluation means for settling a band having a lower frequency than a conscious-state peak frequency as a sleepiness level index band for indicating a sleepiness level, in the spectrum signal, with respect to the conscious-state peak frequency in a conscious state of the test subject, and evaluating the sleepiness level of the test subject, on basis of strength of the spectrum signal in the sleepiness level index band; wherein the evaluation means evaluates the sleepiness level of the test subject when the test subject operates predetermined equipment, and the peak frequency of the spectrum signal, at a time after a predetermined time has elapsed since the fully awake test subject began operating the predetermined equipment, is set as the conscious-state peak frequency.