Evaluation Methods And Index Study Of Stress Load Of Navy Servicemen During Long-term Navigation

“Speeding up the construction of a maritime power” has become a new development strategy of the PLA navy.As one of the core forces of the navy fleet,long-voyage forces bear an important combat role.With the continuous upgrading of maritime technology,the sustainable working time and efficiency of the officers and soldiers on long voyage mission have become an important link restricting naval combat capability.The working and living environment of the long-voyage forces is very harsh,and there are a lot of stressors,including physical ones,such as confined space,noise,radiation,artificial lighting and dirty air,as well as physiological ones,such as biological rhythm changes and biological clock disorders.There also exist psychological claustrophobia,isolation,lack of solitude,lack of sensory stimulation,and lack of social support.All these factors will have important effects on the officers and soldiers on the voyage both physiological and psychologically.What's more,fatigue,cognitive function and decision-making ability will decline,leading to operational errors and other serious consequences.Therefore,it is necessary to conduct in-depth research in this regard.In this study,a variety of technologies are applied to deeply study the changing characteristics of stress load related indicators of officers and soldiers before and after long voyage,and to explore its evaluation methods.This thesis mainly includes the following three parts.1.Study on the effects of long voyage mission on the cognitive function of officers and soldiers.This part focuses on the stress load of officers and soldiers on long voyage,and systematically studies the psychological cognition and psychological movement of officers and soldiers on long voyage from three aspects: questionnaire,psychological assessment scale and cognitive test.The results show that :(1)The psychological questionnaire survey of 91 officers and soldiers show that more than 86% of them feel varying degrees of stress,indicating that the long voyage mission is a stress source for officers and soldiers,and the psychological and physiological stress load increases with the extension of the long voyage,and more than 70% of the officers and soldiers report that they are in the worst physical and mental state for 60 days of continuous underwater navigation.(2)Compared with the officers and soldiers in the detention group,the officers and soldiers in the task group generally suffer from increased fatigue,serious decline in sleep quality and sleep disorder.(3)The officers and soldiers in the task group are affected in sensation,perception,memory,attention,thinking and other aspects,and their attention,alertness reaction and fine operation ability generally decrease,indicating impaired cognitive function.2.Influence of long voyage mission on physiological and biochemical indexes of officers and soldiers.This part tests and analyzes the salivary composition and heart rate variation rate of 48 long-voyage officers and soldiers after long voyage mission and after recuperation period.The results show that after the mission the detection results of 5 biochemical indexes of officers and soldiers decrease significantly,indicating that:(1)The officers and soldiers suffer from hypothalamus-pituitary-adrenal axis disorders,decreased secretion of the hormone.Their anti-inflammatory,antioxidant capacity and body immunity are also reduced.(2)The results of heart rate variability reflect that the activity of the autonomic nervous system of officers and soldiers decreases after a long voyage,and the balance regulation ability of the autonomic nervous system increases,which is mainly caused by the increased stress load and fatigue degree of officers and soldiers.(3)Hierarchical comparison results show that education level and age has no effect on the changes of physiological and biochemical indicators,while the difference of self-comparison before and after the mission is significant.As a stress source,the physiological and psychological functions of officers and men in the mission group are affected,which further indicates that the physiological and biochemical functions of officers and soldiers in the mission group are closely related to the mission itself.3.The construction of a comprehensive evaluation model of the stress load of the officers and soldiers on long voyage mission.This part conducts statistical analysis of the results of the previous two parts through a series of statistical analysis strategies such as Bartlett KMO test,Bartlett spherical test,component matrix factor rotation and principal component analysis.The results find that biological components of saliva and related indicators of heart rate variability are the most important factors to interpret the stress load of officers and soldiers after long voyage mission.The heart rate variability index contained in common factor 1 and common factor 7 explains 25.275% of the stress load.Common factor 2 and 3 mainly explain the detection difference of the five main physiological composition of saliva and can explain up to 27.707% of the stress load.Therefore,heart rate variability index and saliva composition index can explain more than half of the stress load of officers and soldiers on long voyage,so the related indexes of heart rate variability and saliva components can be used as an objective biological marker,effectively monitoring the stress load of officers and soldiers on long voyage.To sum up,the research in this thesis,through literature research,designed questionnaire,psychological measurement scale,psychological test,saliva composition detection and the test of heart rate variation conducts a systematic research of officers and soldiers on long voyage mission and carries out objective evaluation of the important factors that affect psychological state of those crew members.Through objective analysis of indicators,this thesis comes up with sensitive,reliable and universal indexes and provides a theoretical basis for promoting the use of more simple and portable detection equipment in grassroots forces in the future,playing a positive role in improving the combat effectiveness of the long voyage forces.