Evaluation And Feedback Control System For Mental Fatigue

Mental fatigue refers to a series of physiological symptoms caused by the overuse of brain neurons in the state of long-term mental stress.When mental fatigue occurs,it can lead to lower productivity and mistakes.In particular,mental fatigue may cause serious accidents in the industries of aerospace,chemical production and transportation,where mental work is the main work.It has become an important problem for the society to identify mental fatigue and give early warning to its possible harm.It is of great significance for social public security to assess whether mental fatigue occurs in individuals and regulate it when it occurs.In view of the needs of mental fatigue assessment and regulation,the main work and innovation of this paper are as follows:The system structure described in this paper includes hardware system,evaluation and feedback control scheme.The hardware system is divided into two parts: EEG acquisition system and transcranial direct current stimulation system.The EEG acquisition system includes instrument amplifier circuit,common mode suppression circuit,de-DC circuit,low-pass filter circuit,double T-notch,analog-to-digital conversion circuit,main control module and data transmission module.The electrical stimulation system includes How Land current source,digital-to-analog conversion circuit,impedance detection circuit,microcontroller and data transmission module.Evaluation and feedback control schemes include a host computer system responsible for EEG processing and a host computer system that controls the electrical stimulus output mode.The unprocessed EEG signal collected by the hardware system cannot directly reflect the mental fatigue state of the subject,so it needs to be further processed,displayed and analyzed on the PC side.Finally,EEG signals with different rhythms within a period of time were extracted,the power spectral density of EEG signals with different rhythms was calculated,the average power of the θ wave,α wave and β wave was obtained,and the fatigue index F was defined.The occurrence of mental fatigue was assessed by the variation of fatigue index F,and the population with mental fatigue was regulated by transcranial direct current stimulation when mental fatigue occurred.In this study,10 students were recruited as experimental subjects to verify the effectiveness of the experiment,a total of 20 people,60 people were collected EEG data and 60 people were Stanford sleepiness Scale.The system was used to evaluate the mental fatigue of the experimental subjects in awake state.The 2-back task was used to induce mental fatigue,and the transcranial direct current stimulation was used to regulate the mental fatigue.The Stanford Sleepiness Scale was used to verify the degree of mental fatigue assessed by this system,and the control group was set up to verify the effect of transcranial direct current stimulation on mental fatigue.The experimental results show that the system has the functions of EEG acquisition and transcranial direct current stimulation,and realize the function of evaluating and regulating mental fatigue.