Evaluation of subjective sleepiness on shift workers and the bright light therapy

分析倒班工人因困倦而导致的工作绩效下降和情绪变化。我检查了明亮的光疗法对嗜睡和情绪的改善。被试为7名大学生，他们在生理和心理方面都有一定的问题。他们的平均年龄为21.9岁。在进入研究之前，我以书面形式向他们解释了实验的过程和风险，他们同意了。我设定了两天作为基线，并将睡眠时间表调整了10个小时。在一个实验中，受试者在500勒克斯（DL条件）下的荧光灯下度过了两天。在另一个实验中，相同的受试者在轮班后的两天内从18：00到22：00暴露于超过2，500勒克斯的强光下（BL条件）。采用多导睡眠图检测睡眠参数，采用多导睡眠潜伏期试验（Multiple Sleep Latency Test，MPEST）检测客观嗜睡，采用视觉模拟量表（Visual Analog Scale，VAS）和斯坦福大学嗜睡量表（Stanford Sleepiness Scale，SSS）检测主观嗜睡。受试者从实验前3天一直戴着Actigraph直到实验结束，证明他们在实验期间没有午睡。方差分析在DL和BL条件下进行统计学处理。DL和BL条件下的睡眠参数无差异。在VAS中，与DL条件相比，BL条件下嗜睡显著减少，警觉性显著增加。MSPs评分显著升高。这样，我们看到第二天的困倦可以通过起床后早期的强光治疗来改善。结果表明，交替工作系统在控制睡意和保持警觉方面是有效的，在醒来后的早期时间暴露在明亮的光线下。

I intend to analyze the decline of performance and the change of mood caused by sleepiness of shift workers. I examined the improvement of sleepiness and mood by the bright light-therapy. The subjects were 7 university students who were physiologically and psychologically. They averaged 21.9 years of age. Before entering the study I gave them the explanation in writing as to the process and risk of the experiment, and they consented to it. I set two days for the baseline, and shifted the sleep schedule for 10 hours. In one experiment, the subjects spent the two days in the fluorescent light under 500 lux (DL condition). In the other experiment, the same subjects were exposed to bright light over 2,500 lux from 18:00 to 22:00 for the two days after the shift (BL condition).. I examined the sleep parameter by the polysomnography, the objective sleepiness by Multiple Sleep Latency Test (MSLT), and the subjective sleepiness by Visual Analog Scale(VAS) and Stanford Sleepiness Scale(SSS). The subjects had worn Actigraph from 3 days before the experiment to the end, and it was proved that they didn't have a nap during the experiment. ANOVA was statistically applied on both DL condition and BL condition. There were no differences in sleep parameters between on DL condition and on BL condition. In VAS sleepiness significantly decreased and alertness significantly increased on BL condition compared to DL condition. MSLT score was significantly elevated. In this way, we see the sleepiness on the next day can be improved by bright-light therapy done soon at the early timing after getting up. It turned out that it was effective for alternate-working system in controlling the sleepiness and keeping the alertness to be exposed to bright light at the early timing after waking up.