Development of dynamic feedback system to improve sleep environment by means of signal of autonomic nerve activity

为了改善睡眠时的睡眠深度和心脏副交感神经活动以及早晨的主观睡眠质量，我们进行了实验来开发和验证动态馈送，一种反馈控制系统，通过对RR间期变异性的频谱分析，以固定的时间间隔反馈信号，以调节卧室环境温度。这里测试的系统操作原理基于以下三个观察结果，来自于一项关于卧室温度顺序控制对睡眠深度和RR间期变异性影响的研究。本文研究了28℃恒温和U型恒温两种卧室环境（7名受试者）下心电图或脑电图的差异。结果表明：（1）两种水平的RR间期变异性频谱功率的高频带（HF，0.15-0.4Hz，单位：毫秒），这是已知的代表心脏副交感神经活动，而睡眠 ...更多信息 和δ波段的脑电波谱功率（δ，0.5- 4 Hz，单位：（2）睡眠时HF和δ在室温变化时有时同向增减，但在室温变化时，HF和δ在室温变化时同向增减，而δ在室温变化时同向增减。（3）HF和δ值与室温的关系在个体间存在很大差异，即使在个体间也存在很大差异。我们建立了一个环境温度反馈系统，从中性温度（25℃）开始，当HF增加时，每隔5分钟将温度升高1℃，当HF减少时，温度向相反方向变化相同程度。实验设22℃、25℃、28℃三个恒定室温作为对照。为了证实动态反馈系统的作用，比较了睡眠期间HF和δ的所有这些转变。在睡眠期间将相对湿度调节到50%，当室温保持在22℃、25℃和28℃时，整个睡眠期间的平均HF在22℃时最高，在28 ℃时最低，而平均δ在28℃时最高，在22℃时最低（受试者人数为10人）。当本研究开发的反馈系统运行时，HF和δ8的平均值均比25℃时高10%或更多，尽管早晨的主观睡眠质量在热控制类型之间存在差异。在反馈系统下实现的平均室温低于25℃。本研究为睡眠热环境动态反馈控制系统的实用化迈出了一步。少

In order to improve sleep depth and cardiac parasympathetic nerve activity while sleeping and subjective sleep quality in the morning, we undertook experiments to develop and verify a dynamic feed-back control system that signals by means of spectral analysis of RR interval variability were fed back at regular time intervals to adjust bedroom ambient temperature.The principle of system operation tested here was based on the following three observations which were derived from a study on the effect of sequential control of bedroom temperature on the sleep depth and RR interval variability. We examined the differences of electrocardiogram or electroencephalogram between two bedroom environments with 28℃ constant and U-shaped controlled temperatures (number of subjects were 7). In the results, we observed (1) both levels of RR interval variability spectrum power of high frequency band (HF, 0.15-0.4Hz, unit : msec^2), which is known to represent cardiac parasympathetic activity while sleep … More ing, and of brain wave spectral power of delta band (δ, 0.5-4Hz, unit : μV^2), which is known to represent sleep depth, were depend on the room temperature, (2) HF and δ sometimes increased and decreased in the same direction when the room temperature was changed while sleeping, however, (3) the relationships between room temperature and HF or δ were suggested to differ considerably in individuals, as well as in the elapsed hours after the onset of sleep even in an individual.With these observations, we constructed a feed-back system of ambient temperature that starts from neutral temperature (25℃), then, every 5 minutes, increases temperature by 1℃ when HF has increased, and changed temperature by same degree in the counter direction when HF has decreased. Sleep experiments with three constant room temperatures (22℃, 25℃, and 28℃) were set as control ones. To confirm the effect of the dynamic feed-back system, all these transitions of HF and δ during sleep were compared. Relative humidity has been adjusted to 50% during sleep.When room temperature was kept constant at 22℃, 25℃, or 28℃, average HF over whole sleep was highest at 22℃ and lowest at 28℃, while average δ was highest at 28℃ and lowest at 22℃ (number of subjects were 10). When the feed-back system developed in the study was operated, both average values of HF and δ8 were higher by 10% or more than those at 25℃, although subjective sleep quality in the morning differed between the types of thermal control. The average room temperature achieved under the feed-back system was lower than 25℃. The present study showed a step toward the practical use of dynamic feed-back control system of thermal environment during sleep. Less