Experimental Study Of Assessing Methods To Mental Fatigue

Flight is a job which needs heavy mental workloads. Flight fatigue is an important factor as contributing to most aircraft accidents. To preventing errors and accidents caused by flight fatigue, how to detect mental fatigue of flighters in good time, it is very important in the practical significance. There are the subjective ones and the objective ones in the assessment methods of the mental fatigue. The subjective assessment methods are simple, direct, low-cost, being easily accept and widely adopted. However, they have lower validity and reliability of the subjective assessment methods. Wherefore, it is very necessary that physiological indicators should be intervent to the accurate measurement to the fatigue. With the advancement of technology, there are more and more methods to research mental fatigue on the objective means, which are not limited to EEG, ECG, HRV, body temperature, pulse and blood pressure, et al. Whereas, there was a progressive development of the testing methods of ERP and EOG. Mental fatigue is a psychological and physiological process. It could cover shortages that the testing methods were singly used at present, that mental fatigue could be comprehensively assessed by use of psychological and physiological methods.The sleep deprivation was used as a model of mental fatigue in this study, which purpose was to observe the changes of NCV, DP-OAE, FAI, NASA-TLX, HRV and static posturoraphy after 24 hours sleep deprivation. Follow conclusions:(1)MVC and SCV of left upper limb did not significantly change.(2)DP-OAE did not significantly change.(3)The mental fatigue could be comprehensively reflected by uses of NASA-TLX, work efficiency and FAI. The subjective sense of fatigue increased and simulation results did not significantly change, but the score of NASA-TLX significantly change significantly increased. This could indicate that the mental workload increased and the work-performance decreased.(4)The mental fatigue could be reflected by the changes of HRV. TP and VLF significantly increased after sleep deprivation, which could indicate that the activity of ANS increased. RMSSD, LF and HF significantly increased, which could indicate that the activity of PNS increased. LFnu, HFnu and LF/HF did not significantly change, which could indicate that the relative strength of SPS and PNS did not significantly change while the activity of PNS increased.(5)Some indicators of the static posturoraphy significantly changes after sleep deprivation. WPL significantly decreased, which could indicate that the body spontaneous movement decreased. CA, RA, SDx and SDy significantly decreased, which could indicate that the postural control weakened after sleep deprivation. RQ did not significantly change, which could indicate that the visual system was not impacted by sleep deprivation.