Akerstedt T, Folkard S
Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
Occup Environ Med. 1996 Feb;53(2):136-41. doi: 10.1136/oem.53.2.136.
Irregular working hours severely disturb sleep and wakefulness. This paper presents a modification of the quantitative (computerised) three process model of regulation of alertness to predict duration of sleep in connection with irregular sleep patterns.
The model uses a circadian "C" (sinusoidal) and homeostatic "S" (exponential) component (the duration of previous periods awake and asleep), which are summed to yield predicted alertness (on a scale of 1-16). It assumes that waking from sleep will occur at a given alertness level (S' + C') when recuperation is complete. Variables of electroencephalographic duration of sleep from two studies of irregular sleep were used to model the S and C variables in a regression approach to maximise prediction. The model performance was cross validated against published field and laboratory data.
The model parameters were defined with a high degree of precision R2 = 0.99 and the validation yielded similar values R2 = 0.98-0.95, depending on the acrophase. The paper also describes a simplified graphical version of the computation model seen as a two dimensional duration of sleep nomogram.
The model seems to predict group means for duration of sleep with high precision and may serve as a tool for evaluating work and rest schedules to reduce risks of sleep disturbances.
不规律的工作时间严重干扰睡眠和清醒状态。本文提出了一种对警觉性调节的定量（计算机化）三过程模型的修正，以预测与不规律睡眠模式相关的睡眠时间。
该模型使用昼夜节律的“C”（正弦）和稳态的“S”（指数）成分（先前清醒和睡眠阶段的时长），将它们相加得出预测的警觉性（范围为1 - 16）。它假定当恢复完成时，睡眠会在给定的警觉性水平（S'+C'）下结束。在回归分析中，使用来自两项不规律睡眠研究的脑电图睡眠时长变量来模拟S和C变量，以实现最大程度的预测。该模型的性能通过已发表的现场和实验室数据进行交叉验证。
模型参数的定义具有高度精确性，R2 = 0.99，验证结果根据相位得出了相似的值，R2 = 0.98 - 0.95。本文还描述了计算模型的简化图形版本，可视作二维睡眠时长列线图。
该模型似乎能高精度地预测睡眠时间的群体均值，可作为评估工作和休息时间表以降低睡眠干扰风险的工具。
