Sleepiness level detection device
US7206631B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2004 |
| Grant date | Apr 17, 2007 |
| Priority date | — |
| Expiry date | Jun 15, 2025 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/7257
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A sleepiness level detection device detects a heartbeat signal when a time equal to or longer than T1 and equal to or shorter than T2 has elapsed since the start of driving. The heartbeat signal is subjected to FFT processing to obtain a spectrum signal. By use of a peak frequency of the spectrum signal, a driver conscious-state peak frequency is estimated. A consciousness level index band α is set with respect to the conscious-state peak frequency. A sleepiness level index band β is set with respect to a frequency, which is calculated by multiplying the conscious-state peak frequency by a predetermined ratio (65 to 90%). A sleepiness level evaluation parameter Sp (=βp/(αp+βp)) for indicating the sleepiness level of the driver is calculated with the use of the strength αp and βp of spectrum signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.