| 摘要 |
PROBLEM TO BE SOLVED: To objectively and accurately judge the presence of a steady mental stress by measuring a brain wave of a subject using a simple measuring device. SOLUTION: While a temporary stress is applied by a task/rest presenting device 1, a brain wave data is measured by a simple brain wave data measuring device 2 with an electrode mounted on the forehead of the subject and a frequency power calculating circuit 13 of a brain data signal processing circuit 3 discards a noise data such as myoelectric signal or the like attributed to winking to calculate a power spectrum in terms of frequency band. A power spectrum is added per frequency under a task and a rest with quietly closed of eyes by a frequency power addition circuit 14 and an αwave power normalization circuit 15 calculates a ratio between the power spectrum in all frequency bands of the brain wave and the power spectrum in the frequency band of αwave separately under the task and the rest. A mental stress judging circuit 4 compares the ratio obtained under the task and the ratio under the rest to judge the presence of a mental stress. |
