Brain Fatigue Identification Method Based On EEG For Confined Space Operations

Object: By analyzing the subjective and objective indexes of mental load in the baseline group and the fatigue group,determine the characteristics of the subjective and objective indexes before and after confined space operations,and establish a method for identifying brain fatigue in confined space operations.Methods:(1)Selection of test subjects: 20 male youths,aged 18-25 years,healthy,without history of physical and mental illness,test subjects participated in 2 kinds of experiments,namely normal working and living conditions(baseline group)and closed Space operation state experiment(fatigue group),fatigue experiment is a closed space operation.(2)Subjective and objective indicators: Subjective scale indicators: Pittsburgh Sleep Quality Index Scale,Fatigue Consciousness Questionnaire,Neurosensory Symptoms Questionnaire,Psycho-Sensory Symptoms Questionnaire,and Somatosensory Symptoms Questionnaire;Behavioral Index:Spatial Attention,Target tracking,digital decoding,psychomotor alertness;physiological indicators: heart rate variability(RMSSD,LF/HF),heart function index.(3)EEG index: The EEG index uses the German ANT eego TMrt 32-lead EEG acquisition system to collect EEG data from the baseline group and the fatigue group.There are 32 leads in EEG,and EEG records are divided into two states: open and closed eyes.EEG analysis indicators include the spectrum values of 4waveforms(?,?,?,?)and 4 algorithm ratios(?+?)/(?+?),(?+?)/?,?/?,? / ?);Matlab software is used to calculate the above waveform spectrum value and algorithm ratio.Results:(1)The effect of confined space work on subjective and objective evaluation indexes of mental fatigue.The influence of confined space work on the subjective scale indicators: compared with the baseline group,the fatigue group Pittsburgh sleep quality index,fatigue symptoms,neurosensory symptoms and somatosensory symptoms scores decreased significantly(P < 0.05);the influence of confined space work on behavioral indicators : Compared with the baseline group,the fatigue group's psychomotor alert test score increased(P<0.05);the impact of confined space work on physiological indicators: compared with the baseline group,the fatigue group RMSSD decreased significantly(P < 0.05),LF / HF and cardiac function The index increased significantly(P<0.05).(2)The effect of confined space operations on EEG indicators.Delta wave EEG characteristic results,compared with the baseline group,the fatigue group delta wave closed eye most of the lead spectrum value significantly increased(P < 0.05);? wave EEG characteristic results,compared with the baseline group,fatigue group ? wave In closed-eye state,the spectrum value of lead significantly increased and decreased(P < 0.05);compared with the baseline group,the analysis of ?-wave EEG characteristics showed that in the fatigue group,part of the lead-spectrum value of ?-wave open state was significantly increased(P<0.05),The spectral value of some leads decreased significantly in the closed-eye state(P<0.05);compared with the baseline group,the ?-wave EEG characteristic analysis showed that the spectral value of most leads in the beta-wave closed-eye state of the fatigue group decreased significantly(P < 0.05);(?+?)/(?+?)algorithm ratio EEG feature analysis: compared with the baseline group,the fatigue group significantly increased the ratio of partial leads in the eye-open state and closed-eye state in the partial lead algorithm(P < 0.05);(?+?)/? algorithm ratio EEG feature analysis:compared with the baseline group,the fatigue group significantly increased the ratio of the partial lead-open state and closed-eye state partial lead algorithms(P < 0.05);?/? algorithm Ratio EEG characteristics analysis: Compared with the baseline group,the fatigue group's open-eye state partial lead and closed-eye state partial lead algorithm ratios increased significantly(P < 0.05);?/? algorithm ratio EEG feature analysis: compared with the baseline group In the fatigue group,the ratio of the partial leads in the open-eye state and the partial leads in the closed-eye state decreased significantly(P<0.05).(3)The establishment of EEG recognition method for brain fatigue in confined space operation.Eye-closed state(?+?)/(?+?)algorithm ratio: the change in the ratio of some lead algorithms is positively correlated with the change of fatigue self-consciousness symptom index(P<0.05),suggesting that as the ratio of the above lead algorithms increases,the sense of fatigue increases;The change of the ratio of some lead algorithms is positively correlated with the change of the somatosensory symptom index(P<0.05),suggesting that as the ratio of the above lead algorithms increases,the degree of worry about physical health or disease increases.Eye closed state(?+?)/? algorithm ratio: the change in the ratio of some lead algorithms is positively correlated with the change in Pittsburgh sleep quality index(P<0.05),suggesting that as the ratio of the above lead algorithm increases,the Pittsburgh sleep quality index increases and sleep Quality decline;the change in the ratio of some lead algorithms is positively correlated with the change of the fatigue self-conscious symptom index(P < 0.05),suggesting that as the ratio of the above lead algorithm increases,the sense of fatigue increases;the change in the ratio of some lead algorithms is positively related to the change of the neurosensory symptoms Correlation(P < 0.05),suggesting that as the ratio of the above lead algorithms increases,anxiety and pressure increase;some lead algorithm ratios are positively correlated with somatosensory symptoms indicators(P<0.05)suggest that as the above lead algorithm ratio increases,Increased concern about physical health or disease.Conclusions:(1)The effect of confined space work on subjective and objective evaluation indexes of mental fatigue.After confined space work,sleep quality decreased,fatigue level increased,anxiety level increased,alertness decreased,cardiovascular function and health level decreased,mental load increased,and confined space work entered a state of mental fatigue.(2)EEG characteristics of brain fatigue in confined space work.After working in a confined space,the delta waveform spectrum value showed a significant decrease in the state of open eyes,a significant increase in the beta wave spectrum value,and a significant increase in the ratio of the four algorithms,indicating that the sleep quality and alertness of the fatigue group had a tendency to decline,and the mental load increased.(3)(?+?)/?algorithm ratio of forehead area,frontal apex area and forehead central area in closed eyes,(?+?)/(?+?)of right frontal area,central area and apical area in closed eyes ?)The algorithm ratio can be used as an EEG sensitive indicator for identifying mental fatigue in confined space operations.