Neri David F, Oyung Raymond L, Colletti Laura M, Mallis Melissa M, Tam Patricia Y, Dinges David F
Fatigue Countermeasures Group, NASA Ames Research Center, Moffett Field, CA, USA.
Aviat Space Environ Med. 2002 Jul;73(7):654-64.
A major challenge for flight crews is the need to maintain vigilance during long, highly automated nighttime flights. No system currently exists to assist in managing alertness, and countermeasure options are limited. Surveys reveal many pilots use breaks as an in-flight countermeasure, but there have been no controlled studies of their effectiveness.
We hypothesized that brief, regular breaks could improve alertness and performance during an overnight flight.
A 6-h, uneventful, nighttime flight in a Boeing 747-400 flight simulator was flown by fourteen two-man crews. The 14 subjects in the treatment group received 5 short breaks spaced hourly during cruise; the 14 subjects in the control group received 1 break in the middle of cruise. Continuous EEG/EOG, subjective sleepiness, and psychomotor vigilance performance data were collected.
During the latter part of the night, the treatment group showed significant reductions for 15 min post-break in slow eye movements, theta-band activity, and unintended sleep episodes compared with the control group. The treatment group reported significantly greater subjective alertness for up to 25 min post-break, with strongest effects near the time of the circadian trough. There was no evidence of objective vigilance performance improvement at 15-25 min post-break, with expected performance deterioration occurring due to elevated sleep drive and circadian time.
The physiological and subjective data indicate the breaks reduced nighttime sleepiness for at least 15 min post-break and may have masked sleepiness for up to 25 min, suggesting the potential usefulness of short-duration breaks as an in-flight fatigue countermeasure.
对于飞行机组人员而言，一项重大挑战是在漫长且高度自动化的夜间飞行中保持警觉。目前不存在协助管理警觉性的系统，且应对措施选择有限。调查显示，许多飞行员在飞行中利用休息作为应对措施，但尚无关于其有效性的对照研究。
我们假设短暂、定期的休息可以提高夜间飞行期间的警觉性和表现。
14个两人机组在波音747 - 400飞行模拟器中进行了一次6小时的平稳夜间飞行。治疗组的14名受试者在巡航期间每小时有5次短暂休息；对照组的14名受试者在巡航中途有1次休息。收集了连续的脑电图/眼电图、主观嗜睡程度以及心理运动警觉性表现数据。
在夜间后期，与对照组相比，治疗组在休息后15分钟内慢眼动、θ波活动和意外睡眠发作显著减少。治疗组报告称，休息后长达25分钟内主观警觉性显著更高，在昼夜节律低谷附近效果最强。休息后15 - 25分钟没有客观警觉性表现改善的证据，由于睡眠驱动力增加和昼夜节律时间的原因，预期表现会恶化。
生理和主观数据表明，休息可在休息后至少15分钟内减少夜间嗜睡，并且可能在长达25分钟内掩盖嗜睡，这表明短时间休息作为飞行中疲劳应对措施具有潜在用途。
