Fleming P J, Goncalves A L, Levine M R, Woollard S
J Physiol. 1984 Feb;347:1-16. doi: 10.1113/jphysiol.1984.sp015049.
Serial respiratory recordings using impedance pneumography and barometric plethysmography were made from shortly after birth to 7 months in fifteen normal full-term infants. Each recording was made with the infant asleep and sleep state was estimated from records of electroencephalogram and electro-oculogram made in parallel. The respiratory records obtained during non-rapid eye movement (r.e.m.) sleep were analysed with computer assistance and stretches of the record, approximately 1 min before and up to 2 min after a spontaneous sigh and ensuing apnoeic pause, were processed and presented as sequential values of the fractional deviation of VE, the breath by breath minute volume, from the mean. That part of the sequence which represented the respiratory response to the sigh was then fitted with second order equations representing the critically or underdamped response. The results were presented for each curve in terms of xi, the damping ratio and omega n, the frequency of the undamped respiratory oscillation. Three-quarters of the responses could be so fitted with an error of 20% or less. The residual responses were mainly from infants within a few days of birth. In the youngest infants (4 days or less), the respiratory response to a sigh was highly stable but sluggish: during the period 4-8 days to 3-4 months, the oscillatory period diminished from ca. 25-12 s and respiration was potentially unstable since a small reduction in the damping factor would cause prolonged oscillation while, from 3-4 months, the more mature type of response which was stable with a rapid recovery supervened. The possible mechanisms responsible for this trend are discussed in terms of the factors thought to determine respiratory stability in the adult together with the possible relevance of the results to the normal process of respiratory adaptation at birth and to the respiratory difficulties encountered by some infants in the new-born period and early infancy.
对15名正常足月婴儿从出生后不久到7个月进行了使用阻抗式肺量计和气压体积描记法的连续呼吸记录。每次记录时婴儿均处于睡眠状态，并根据同时记录的脑电图和眼电图来估计睡眠状态。在非快速眼动（REM）睡眠期间获得的呼吸记录在计算机辅助下进行分析，对自发叹息及随后的呼吸暂停之前约1分钟至之后2分钟的记录片段进行处理，并以每分钟通气量（VE）相对于平均值的分数偏差的连续值呈现。然后将代表对叹息的呼吸反应的那部分序列用代表临界或欠阻尼反应的二阶方程拟合。结果以ζ（阻尼比）和ωn（无阻尼呼吸振荡频率）表示每条曲线的情况。四分之三的反应可以如此拟合，误差在20%或更小。剩余的反应主要来自出生后几天内的婴儿。在最年幼的婴儿（4天或更小）中，对叹息的呼吸反应高度稳定但迟缓：在4 - 8天至3 - 4个月期间，振荡周期从约25秒减少到12秒，呼吸可能不稳定，因为阻尼因子的小幅降低会导致长时间振荡，而从3 - 4个月起，出现了更成熟的稳定且快速恢复的反应类型。根据被认为决定成年人呼吸稳定性的因素，讨论了导致这种趋势的可能机制，以及这些结果与出生时呼吸适应的正常过程以及一些婴儿在新生儿期和婴儿早期遇到的呼吸困难的可能相关性。
