A Dynamical System Analysis of the Development of Spontaneous Lower Extremity Movements in Newborn and Young Infants
A Dynamical System Analysis of the Development of Spontaneous Lower Extremity Movements in Newborn and Young Infants
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DOI：
10.2114/jpa2.30.179
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发表时间：
2011-09-01
影响因子：
3.1
通讯作者：
Abe, Koji
中科院分区：
文献类型：
--
作者：
Gima, Hirotaka;Ohgi, Shohei;Abe, Koji
本研究的目的是利用动力系统分析的方法来评估新生儿和幼儿的自发下肢运动特征。研究对象为8例健康足月新生儿（男3例，女5例，平均出生体重3070.6g，平均胎龄39周）。三轴加速度计在三维空间中测量肢体运动加速度。当婴儿处于主动警觉状态并仰卧时（采样率200hz），记录200秒内从脚踝下方开始的运动加速信号。数据进行线性和非线性分析。结果表明，最优嵌入维数在任意时刻均大于5。时间依赖性变化从6、7岁开始，在接下来的4个月里减少到5个月，从6个月开始增加。最大Lyapnov指数对所有线段均为正。互信息在0个月时达到最大值。在3至4个月之间，结果的范围最窄，价值最低。在1 ~ 4月龄间，x轴分量的平均相关系数为负，y轴分量的平均相关系数变为正。非线性时间序列分析表明，新生儿和婴幼儿下肢自发运动具有5 ~ 7个嵌入维数的非线性混沌动力学特征。最优嵌入维数的发展变化呈u型变化。所有区段的最大Lyapnov指数均为正（0.79 ~ 2.99）。婴儿的自发运动涉及能够产生自愿技能运动的混沌动态系统。人类生理学报30(5):179-186,2011 http://www.jstage.jst.go.jp/browse/jpa2 [DOI: 10.2114/jpa2.30.179]
This study's aim was to evaluate the characteristics of newborn and young infants' spontaneous lower extremity movements by using dynamical systems analysis. Participants were 8 healthy full-term newborn infants (3 boys, 5 girls, mean birth weight and gestational age were 3070.6g and 39 weeks). A tri-axial accelerometer measured limb movement acceleration in 3-dimensional space. Movement acceleration signals were recorded during 200 s from just below the ankle when the infant was in an active alert state and lying supine (sampling rate 200 Hz). Data were analyzed linearly and nonlinearly. As a result, the optimal embedding dimension showed more than 5 at all times. Time dependent changes started at 6 or 7, and over the next four months decreased to 5 and from 6 months old, increased. The maximal Lyapnov exponent was positive for all segments. The mutual information is at its greatest range at 0 months. Between 3 and 4 months the range in results is narrowest and lowest in value. The mean coefficient of correlation for the x-axis component was negative and y-axis component changed to a positive value between 1 month old and 4 months old. Nonlinear time series analysis suggested that newborn and young infants' spontaneous lower extremity movements are characterized by a nonlinear chaotic dynamics with 5 to 7 embedding dimensions. Developmental changes of an optimal embedding dimension showed a U-shaped phenomenon. In addition, the maximal Lyapnov exponents were positive for all segments (0.79-2.99). Infants' spontaneous movement involves chaotic dynamic systems that are capable of generating voluntary skill movements. J Physiol Anthropol 30(5): 179-186, 2011 http://www.jstage.jst.go.jp/browse/jpa2 [DOI: 10.2114/jpa2.30.179]