Complexity and dynamics of switched human balance control during quiet standing.
Complexity and dynamics of switched human balance control during quiet standing.
复制标题
安静站立时切换人体平衡控制的复杂性和动态性。
DOI：
10.1007/s00422-015-0655-5
复制
发表时间：
2015
影响因子：
1.9
通讯作者：
Nema S
中科院分区：
文献类型：
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作者：
Nema S
在本文中，我们结合数值模拟、时间序列分析和复杂性测量来研究带有噪声的切换系统的动力学，这些系统通常用作安静站立时的人体平衡控制模型。我们将结果与人类安静站立时摇摆运动的实验数据中发现的复杂性度量联系起来。我们使用的确保平衡的控制模型基于“行动等待”控制概念，即当达到一定的摇摆角度时，人类控制器就会启动。否则，不存在主动控制。给定时间序列数据，我们确定模型系统中控制策略的典型模式如何。我们在没有噪声的情况下使用频率分析方法检测系统中的切换非线性。我们还分析了在没有噪声的情况下时滞对系统中极限环存在的影响。我们执行熵和去趋势波动分析，将切换（和死区）与存在噪声的模型系统中复杂性的发生联系起来。最后，我们对实验数据进行熵和去趋势波动分析，并将结果与模型示例中的数值结果联系起来。
In this paper, we use a combination of numerical simulations, time series analysis, and complexity measures to investigate the dynamics of switched systems with noise, which are often used as models of human balance control during quiet standing. We link the results with complexity measures found in experimental data of human sway motion during quiet standing. The control model ensuring balance, which we use, is based on an act-and-wait control concept, that is, a human controller is switched on when a certain sway angle is reached. Otherwise, there is no active control present. Given a time series data, we determine how does it look a typical pattern of control strategy in our model system. We detect the switched nonlinearity in the system using a frequency analysis method in the absence of noise. We also analyse the effect of time delay on the existence of limit cycles in the system in the absence of noise. We perform the entropy and detrended fluctuation analyses in view of linking the switchings (and the dead zone) with the occurrences of complexity in the model system in the presence of noise. Finally, we perform the entropy and detrended fluctuation analyses on experimental data and link the results with numerical findings in our model example.