Tsuzuki Kazuyo, Okamoto-Mizuno Kazue, Mizuno Koh, Iwaki Tatsuya
National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 6, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8566, Japan.
Int J Biometeorol. 2008 Mar;52(4):261-70. doi: 10.1007/s00484-007-0120-9. Epub 2007 Sep 26.
Airflow is an effective way to increase heat loss-an ongoing process during sleep and wakefulness in daily life. However, it is unclear whether airflow stimulates cutaneous sensation and disturbs sleep or reduces the heat load and facilitates sleep. In this study, 17 male subjects wearing short pyjamas slept on a bed with a cotton blanket under two of the following conditions: (1) air temperature (Ta) 26 degrees C, relative humidity (RH) 50%, and air velocity (V) 0.2 m s(-1); (2) Ta 32 degrees C, RH 80%, V 1.7 m s(-1); (3) Ta 32 degrees C; RH 80%, V 0.2 m s(-1) (hereafter referred to as 26/50, 32/80 with airflow, and 32/80 with still air, respectively). Electroencephalograms, electrooculograms, and mental electromyograms were obtained for all subjects. Rectal (Tre) and skin (Ts) temperatures were recorded continuously during the sleep session, and body-mass was measured before and after the sleep session. No significant differences were observed in the duration of sleep stages between subjects under the 26/50 and 32/80 with airflow conditions; however, the total duration of wakefulness decreased significantly in subjects under the 32/80 with airflow condition compared to that in subjects under the 32/80 with still air condition (P<0.05). Tre, Tsk, Ts, and body-mass loss under the 32/80 with airflow condition were significantly higher compared to those under the 26/50 condition, and significantly lower than those under the 32/80 with still air condition (P<0.05). An alleviated heat load due to increased airflow was considered to exist between the 32/80 with still air and the 26/50 conditions. Airflow reduces the duration of wakefulness by decreasing Tre, Tsk, Ts, and body-mass loss in a warm humid condition.
气流是增加热量散失的一种有效方式，这在日常生活中的睡眠和清醒状态下都是一个持续的过程。然而，气流是刺激皮肤感觉并干扰睡眠，还是降低热负荷并促进睡眠，目前尚不清楚。在本研究中，17名穿着短睡衣的男性受试者在铺有棉被的床上睡觉，实验设置了以下两种条件：(1) 气温（Ta）26摄氏度，相对湿度（RH）50%，风速（V）0.2米/秒；(2) Ta 32摄氏度，RH 80%，V 1.7米/秒；(3) Ta 32摄氏度，RH 80%，V 0.2米/秒（以下分别简称为26/50、有气流的32/80和无气流的32/80）。记录了所有受试者的脑电图、眼电图和精神肌电图。在睡眠期间持续记录直肠温度（Tre）和皮肤温度（Ts），并在睡眠前后测量体重。在26/50和有气流的32/80条件下，受试者睡眠阶段的持续时间没有显著差异；然而，与无气流的32/80条件下的受试者相比，有气流的32/80条件下的受试者清醒的总时长显著减少（P<0.05）。有气流的32/80条件下的Tre、Tsk、Ts和体重减轻显著高于26/50条件下的，且显著低于无气流的32/80条件下的（P<0.05）。在无气流的32/80和26/50条件之间，由于气流增加导致热负荷减轻。在温暖潮湿的环境中，气流通过降低Tre、Tsk、Ts和体重减轻来减少清醒时长。
