远程飞行劳动负荷特点与卫生保障措施研究进展

目的 综述远程飞行劳动负荷特点与卫生保障措施的研究进展. 资料来源与选择 国内外该领域的相关文献. 资料引用 引用国内外公开发表的文献资料47篇. 资料综合 回顾了远程飞行的主要应激因素,例如持续仪表观察、长时间活动受限、频繁出现的生物节律紊乱等.总结了民用和军事航空远程飞行的劳动负荷特点,其中民用航空飞行人员的疲劳问题非常突出:宇宙辐射损伤增加,女乘务员工作相关的肌肉骨骼症状多发;下肢水肿常见,静脉血栓形成和栓塞的发病率增加.军事航空远程飞行常常出现飞行耐力和操作能力降低,如果复合飞行疲劳与生物节律紊乱的影响将威胁飞行安全.介绍了国内外民用和军事航空远程飞行卫生保障措施,主要包括身心机能适应性训练、睡眠保障、营养调节、合理用药以及任务中疲劳监测和预警等,列举了国外远程飞行综合卫生保障的典型实例.在此基础上,提出今后开展军事远程飞行卫生保障工作的建议. 结论 针对远程飞行的劳动负荷特点,强调采用综合卫生保障措施维护飞行人员的作业能力.     

仪表飞行时直升机飞行员脑力负荷的主观评价

目的 脑力工作超负荷可影响人的工作绩效并威胁飞行安全;大部分飞行事故发生在脑力工作负荷强度大的起飞、仪表或手动进近和着陆阶段,而且多是由人为差错引起.因此,为提高飞行作业绩效,维护飞行安全,测量和评定飞行员空中脑力工作负荷具有越来越重要的现实意义.本研究的目的是观察直升机飞行员仪表飞行时的脑力负荷变化.方法 采用修改的美国国家航空航天局任务负荷指数(NASA-TLX)评价量表,对15名直升机飞行员仪表飞行时不同阶段的脑力负荷进行了主观评价;对总脑力负荷评价值和飞行小时数进行了线性回归分析.结果 在起飞爬升阶段、巡航平飞阶段、下滑着陆阶段飞行员的总脑力负荷值分别为34.46±17.25、32.11±13.11和53.95±17.76.下滑着陆阶段飞行员的总脑力负荷值显著高于起飞爬升阶段和巡航平飞阶段的总脑力负荷值(F=25.767,P＜0.01).3个阶段的总脑力负荷的评价值均与飞行小时数呈显著负相关.在起飞爬升阶段,总脑力负荷的评价值与飞行小时数的线性回归方程为:总脑力负荷评价值=42.20-0.012 03×飞行小时数(r=-0.810,P＜0.01);在巡航平飞阶段,线性回归方程为:总脑力负荷评价值=38-51-0.006 04×飞行小时数(r=-0.535,P＜0.05).在下滑着陆阶段,线性回归方程为:总脑力负荷评价值=62.57-0.008 14×飞行小时数(r=-0.532,P＜0.05).结论 军用直升机飞行员仪表飞行时总脑力负荷的评价值与飞行小时数呈显著负相关,在下滑着陆阶段脑力负荷最大.     

Crew workload in JASDF C-1 transport flight: II. Change in urinary catecholamine excretion

Serial changes in urinary catecholamine excretion were determined for 17 cockpit crews (6 captains, 6 copilots and 5 flight engineers) of JASDF C-1 aircraft during 10-hour (h) scheduled flights, in which captains and copilots performed almost the same flight tasks. The norepinephrine/epinephrine ratio (N/E) in copilots decreased significantly during the flight, whereas little decrease of the N/E was found in captains. Flight engineers showed an intermediate N/E value between captains and copilots. Hormonal responses appeared to correlate with differences in the amount of flying experience of crewmembers. Differences between captains and copilots were more significant when handling the aircraft. Results suggested that flight stresses perceived by crewmembers in the same cockpit were influenced by their flying experience and flight position which could be clearly assessed by determining relative excretions of epinephrine and norepinephrine.     

Problem of desynchronosis during space flight

Major problems of biorhythm are discussed. Among the numerous and diverse rhythms inherent in the human body (which is the subject matter of the present paper) circadian (essentially 24-hour) variations play the leading role. This kind of rhythm is of universal and mandatory character which makes it possible to categorize it as a law. The system of circadian rhythms incorporates elements of both synchronization and desynchronization. In the welfare state synchronization elements are prevailing while in space flight the specific weight of desynchronization increases due to the permanent desynchronization factor--weightlessness. Due to this, crewmembers are to adhere strictly to the work-sleep regimen.     

飞行中人体的呼吸生理反应

本文系统地回顾了飞行中飞行人员呼吸生理反应的研究进展，包括高性能飞机飞行时的呼吸生理反应，飞行中的附加呼吸阻力及能量消耗问题，飞行人员的通气过度反应等。对每一项呼吸生理反应均讨论了其飞行中的生理监测及军用标准问题，并给出了有代表性的数据资料。文中还讨论了高性能战斗机飞行时的呼吸生理反应及其监测问题。     

飞行人员胆囊结石的空中B超观察

旨在观察飞行中胆囊结石有无位移及能否诱发空中突然失能。采用日本SDL－32型B超诊断仪，对16名飞行人员胆囊结石患者进行了地面及空中观察。结果表明，地面观察未见胆囊结石有明显位移；跟班飞行观察，从飞机爬升经巡航到下滑几个阶段内，胆囊结石保持原位不动者9例（共有块状结石7枚，泥沙状结石3堆），其中结石位于胆囊颈部3例、胆囊体部6例，为滞留型；结石发生了位移者7例（共有块状结石13枚），其中结石由胆囊颈部降到胆囊体部者4例、由胆囊体部落到胆囊底部者2例，在胆囊体部前后壁间横向移位者1例，为游移型。游移型结石有可能速入胆道，引起突然失能，危及飞行安全，应密切观察。     

The opto-kinetic cervical reflex during formation flight

BACKGROUND: Weather formation flight is a difficult task prone to episodes of spatial disorientation. Therefore, investigation of sensory reflexes under these conditions is critical. Recent studies have shown that the opto-kinetic cervical reflex (OKCR) occurs during VMC flight conditions and serves to establish the horizon retinal image as a stabilized primary visual-spatial cue. The purpose of this research was to investigate the OKCR and field of view (FOV) during formation flight under VMC and IMC. HYPOTHESES: During VMC tasks pilots will align their heads with the visible horizon, but not under IMC. As FOV is decreased, there will be a significant reduction in OKCR-induced head movement. METHODS: There were 2 experiments conducted in which a total of 26 pilots completed simulated flight tasks in a stationary dome. Head tilt was examined as a function of aircraft bank with unrestricted FOV in Experiment I. Experiment II examined head tilt under three FOV conditions (40 degrees , 60 degrees and 100 approximately circular). RESULTS: During VMC maneuvers pilots exhibited significant OKCR. There were no differences in head tilt between Solo Figure 8 and Formation Figure 8 VMC conditions. Pilots did not tilt their heads under IMC Formation Flight. FOV did not significantly affect the OKCR. CONCLUSIONS: Pilots exhibit the OKCR during Formation and Solo VMC tasks. However, the OKCR is reduced when compared with low level navigation tasks, indicating a difference in the visual cues between tasks. Pilots do not exhibit OKCR during IMC flight; therefore, the OKCR will have an impact on formation flights in and out of clouds leading to sensory conflicts caused by repeated realignment of visual and vestibular systems.     

Parasympathetic activity during parabolic flight, effect of LBNP during microgravity

BACKGROUND/HYPOTHESIS: During parabolic flight, in the standing position, changes are partly due to an acute shift in fluid between the lower extremities, the head and the thorax (Va?da P, et al. J Appl Physiol 1997; 82:1091-7; and Bailliart O, et al. J Appl Physiol 1998; 85:2100-5). We hypothesized that modifications of parasympathetic activity associated with changes in hydrostatic pressure gradients induced by changes in gravity could be detected by analysis of short time periods. METHODS: We assessed heart rate variability (HRV) in 11 healthy volunteers by indices of temporal analysis (NN, SDNN, RMSSD) and normalized indices such as coefficients of variation CV-SDNN and CV-RMSSD and ratio SDNN/RMSSD. A lower body negative pressure (LBNP) at -50 mm Hg was randomly applied during the microgravity phase (0 Gz) to counteract the lack of hydrostatic pressure in the lower part of the body. RESULTS: NN, CV-SDNN and CV-RMSSD decreased during hypergravity phases and increased during microgravity and during early normogravity (1 Gz) period at the end of parabolas. With LBNP changes are less pronounced at 0 Gz and in the 1 Gz post parabolic period. CONCLUSION: We concluded that parasympathetic nervous activity is recordable by temporal analysis of HRV during short periods of time. LBNP applied during 0 Gz phase reduced the parasympathetic activation at 0 Gz and post parabolic 1 Gz.     

EEG and ECG changes during selected flight sequences

BACKGROUND: Mental workload has become a critical factor in the design and use of modern aircraft. Because of the complexity of the human-machine system, it is necessary to determine workload, fatigue, and level of performance using noninvasive electrophysiological measures. OBJECTIVE: Our objective was to identify the electrophysiological indicators of mental workload during piloting tasks. METHODS: Electroencephalographic (EEG) and electrocardiographic (ECG) activity was recorded during actual flight, with a profile planned to produce different levels of mental workload. RESULTS: In-flight EEG and ECG recordings enabled us to document mental workload levels. During active segments, delta and theta band activity increased (p < 0.05 or greater); results showed an increase of 22.5% for theta band activity during active flight segments compared with in-flight rest periods. Inversely, alpha band activity diminished: the decrease between ground baseline and all flight sequences was 30% (p < 0.05 or greater). These variations were reversed during the in-flight rest sequences. Instrumental flight caused an increase in the theta and alpha frequency band activity in the parietal-occipital area (p < 0.05 or greater); the alpha/beta ratio also increased. Heart rate increased during the active segments and fell during the in-flight rest periods. The mean difference between active segments and in-flight rest periods was of 8.89 bpm (i.e., an increase of 11.5%; p < 0.01). Heart rate was correlated to the EEG activity of the delta and beta bands in the central area (C3, Cz, C4, p < 0.05). CONCLUSIONS: The electrophysiological measures recorded provide useful indicators of the mental workload required by different flight sequences.     

Diurnal rhythm of body temperature during space flight

The axillary temperature of the Mongolian Salyut-6 crewmember was measured in the daytime before, during and after flight. The temperature was recorded immediately after awakening to going to sleep every 2 hours: a month prelaunch in the Cosmonauts' Training Center during 5 days, a week prelaunch at the Baikonur launch site during 3 days, inflight from the middle of mission day 2 to the middle of mission day 7 every day, and postflight at Baikonur during 4 days. It was found that inflight the axillary temperature decreased significantly by 0.44 degrees C as compared to the data obtained in the Cosmonauts' Training Center and by 0.22 degrees C as compared to the data obtained at the launch site. There were also some changes in the pattern of acrophases on the time scale. It is recommended to continue thermal regulation measurements in space flight.     

Effect of test interruptions on blood lactate during constant workload testing

OBJECTIVE: To determine whether repetitive test interruptions (TI) during constant load testing influence blood lactate concentration (BLC), maximal lactate steady state (MLSS), MLSS workload (P-MLSS), and relative MLSS intensity (Int-MLSS). METHODS: Nineteen males participated in this study. In experiment A, 10 subjects (27.5 +/- 2.9 yr; 183.7 +/- 5.2 cm; 77.4 +/- 3.7 kg) performed 30-min constant load tests: one without TI, one with TI of 30 s, and one with TI of 90 s after every 5 min of cycling at a given workload. In experiment B, nine subjects (28.0 +/- 2.7 yr; 182.9 +/- 6.8 cm; 76.2 +/- 4.5 kg) performed 30-min constant load tests at different workloads until MLSS had been determined for all three TI protocols. RESULTS: In experiment A, the BLC after 30 min net working time (BLC30) was higher (P < 0.001) without TI (6.0 +/- 1.3 mmol.l(-1)) than with TI of 30 s (4.9 +/- 1.4 mmol.l(-1)) or 90 s (4.5 +/- 1.1 mmol.l(-1)). The change in BLC during the final 20 min (DeltaBLC10-30) was greater (P < 0.01) without TI (1.2 +/- 1.0 mmol.l(-1)) than with TI of 30 s (0.2 +/- 0.7 mmol.l(-1)) or 90 s (-0.3 +/- 0.7 mmol.l(-1)). In experiment B, the MLSS was not affected, but P-MLSS and Int-MLSS were lower (P < 0.01) without TI (277.8 +/- 24.4W and 73.7 +/- 7.6%) than with TI of 30 s (300.4 +/- 30.4W and 79.2 +/- 8.0%) or 90 s (310.0 +/- 31.2W and 81.5 +/- 7.1%). Approximately 35% of the variance of BLC30 and DeltaBLC10-30, and 70% of the variance of P-MLSS and Int-MLSS were explained by TI duration (P < 0.001). CONCLUSIONS: TI decreased BLC30 and DeltaBLC10-30 but has no effect on MLSS. Consequently, with TI, the MLSS is achieved at higher P-MLSS and Int-MLSS.     

EEG and ECG changes during simulator operation reflect mental workload and vigilance

BACKGROUND: Performing mission tasks in a simulator influences many neurophysiological measures. Quantitative assessments of electroencephalography (EEG) and electrocardiography (ECG) have made it possible to develop indicators of mental workload and to estimate relative physiological responses to cognitive requirements. OBJECTIVE: To evaluate the effects of mental workload without actual physical risk, we studied the cortical and cardiovascular changes that occurred during simulated flight. METHODS: There were 12 pilots (8 novices and 4 experts) who simulated a flight composed of 10 sequences that induced several different mental workload levels. EEG was recorded at 12 electrode sites during rest and flight sequences; ECG activity was also recorded. Subjective tests were used to evaluate anxiety and vigilance levels. RESULTS: Theta band activity was lower during the two simulated flight rest sequences than during visual and instrument flight sequences at central, parietal, and occipital sites (p < 0.05). On the other hand, rest sequences resulted in higher beta (at the C4 site; p < 0.05) and gamma (at the central, parietal, and occipital sites; p < 0.05) power than active segments. The mean heart rate (HR) was not significantly different during any simulated flight sequence, but HR was lower for expert subjects than for novices. The subjective tests revealed no significant anxiety and high values for vigilance levels before and during flight. CONCLUSIONS: The different flight sequences performed on the simulator resulted in electrophysiological changes that expressed variations in mental workload. These results corroborate those found during study of real flights, particularly during sequences requiring the heaviest mental workload.     

Perceived head-trunk angle during microgravity produced by parabolic flight

INTRODUCTION: Neck proprioceptors are essential for orienting the head relative to the trunk. However, it has been shown that the available information about the relationship of gravity to different body parts would augment the clues about their relative orientation. In weightlessness, the absence of relevant body position signals from the otoliths and other inertial graviceptors requires the substitution of other sensory information. The aim of the present study was to investigate the ability of humans to accurately locate the head relative to the trunk in microgravity. METHODS: Experiments were conducted during two separate sessions: on Earth and during parabolic flights. Volunteers were asked to adjust a visual rod until it looked parallel to their head or trunk axis in two different segmental configurations: head and trunk aligned or head tilted. RESULTS: There was no effect of microgravity when the head and trunk were aligned. However, when the head was tilted with respect to the trunk, the orientation of the visual rod relative to the head or the trunk (visual egocentric coordinates) was deviated toward the head tilt, although the orientation between the body parts themselves (head-trunk angle) was correctly estimated. DISCUSSION: These results suggested that, in microgravity, the proprioceptive signals from neck muscles seem sufficient to provide accurate head on trunk information. However, the representation of orientation in visual space was modified. This experiment provides evidence for the role of gravity on the visual perception of head- and trunk-based egocentric coordinates.     

A case report of spontaneous pneumothorax during flight.

Although spontaneous pneumothorax can usually be considered lightly when it occurs at ground level, its occurrence in aviation may result in the abort of a mission, a serious accident, or a major disaster. A case of spontaneous pneumothorax during chamber altitude and aerial flight is presented. A better understanding of the etiologies, precipitating causes, complications, likelihood of recurrence, and treatment may lead to the prevention of accidents. Diagnostic technics, operative procedures, and evaluation studies are discussed from the point of view of continuing a flying career.     

Foot-ground reaction force during resistive exercise in parabolic flight

INTRODUCTION: An interim resistance exercise device (iRED) was designed to provide resistive exercise as a countermeasure to spaceflight-induced loss of muscle strength and endurance as well as decreased bone mineral density. The purpose of this project was to compare foot-ground reaction force during iRED exercise in normal gravity (1 G) vs. microgravity (0 G) achieved during parabolic flight. METHODS: There were four subjects who performed three exercises (squat, heel raise, and deadlift) using the iRED during 1 G and 0 G at a moderate intensity (60% of maximum strength during deadlift exercise). Foot-ground reaction force was measured in the three orthogonal axes (x, y, z) using a force plate, and the magnitude of the resultant force vector was calculated (r = square root(x2 + y2 + z2)). Linear displacement (LD) was measured using a linear transducer. Peak force (Fpeak) and an index of total work (TWi) were calculated using a customized computer program. Paired t-tests were used to test if significant differences (p < or = 0.05) were observed between 1 G and 0 G exercise. RESULTS: Fpeak and TWi measured in the resultant axis were significantly less in 0 G for each of the exercises tested. During 0 G, Fpeak was 42-46% and TWi was 33-37% of that measured during 1 G. LD and average time to complete each repetition were not different from 1 G to 0 G. CONCLUSIONS: Crewmembers who perform resistive exercises during spaceflight that include the movement of a large portion of their body mass will require much greater external resistive force during 0 G than 1 G exercise to provide a sufficient stimulus to maintain muscle and bone mass.