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

我打算分析轮班工人的困倦导致的工作表现下降和情绪变化。我检查了强光疗法对睡意和情绪的改善。研究对象为7名大学生，分别在生理和心理上进行了测试。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准，并将睡眠时间调整了10个小时。在一个实验中，受试者在500勒克斯（DL）的荧光灯下呆了两天。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暴露在2500勒克斯以上的强光下（BL条件）。用多导睡眠仪检测睡眠参数，用多重睡眠潜伏期测试（MSLT）检测客观嗜睡，用视觉模拟量表（VAS）和斯坦福嗜睡量表（SSS）检测主观嗜睡。受试者从实验前3天起至实验结束佩戴Actigraph，证明受试者在实验过程中没有午睡。DL和BL两种情况均采用方差分析进行统计学分析。DL组与BL组的睡眠参数无显著差异。在VAS评分中，BL组与DL组相比，嗜睡明显减少，警觉性明显增加。MSLT评分显著升高。通过这种方式，我们看到第二天的困倦可以通过早起后不久进行的强光疗法得到改善。结果表明，在交替工作系统中，早起暴露在明亮的光线下对控制睡意和保持警觉性是有效的。

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.