Alertness monitoring based on time evolution of electroencephalographic signal´s power spectral density

Human alertness varies very quickly in time domain affecting tasks requiring sustained vigilance. This can have huge consequences in various occupations that require a very high level of attention. Changes in the level of alertness are correlated with fluctuations in the electroencephalographic signal´s power spectral density. This can be revealed with fast Fourier transform (FFT) of an EEG signal obtained with a single channel electroencephalograph connected to a data acquisition system (DAQ). In real life, the bioelectric signals can be acquired by masked electrodes placed, for example, in protective helmets or in eye glasses, depending on the operator´s job description. In attention-critical environment, the operators can be monitored for evaluating their cognitive mental state.