Mitigating the effect of non-stationarity in spectral analysis-an application to neonate heart rate analysis.
Mitigating the effect of non-stationarity in spectral analysis-an application to neonate heart rate analysis.
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DOI：
10.1016/j.compbiomed.2013.09.019
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发表时间：
2013-12
影响因子：
7.7
通讯作者：
du Plessis A
中科院分区：
文献类型：
--
作者：
Govindan RB;Massaro AN;Niforatos N;du Plessis A
为了减少数据频域分析中非平稳性的影响，我们提出了一种改进的功率谱估计方法，这是一种广泛用于表征生理信号的技术。频谱分析需要将数据划分为由所需频率分辨率确定的较小历元。这里提出的改进方法包括将每个历元内的数据除以该历元的数据的标准差。我们应用这种改进的方法记录了一名新生儿因出生窒息而接受低温治疗的心脏搏动间期数据。这名危重婴儿在整个研究过程中有零星分布的快速性心律失常的发作，这影响了心率的稳定性。在连续的心率记录期间，婴儿的临床病程逐渐恶化，最终导致死亡。与这种临床恶化相吻合的是，心率信号在低频和高频功率上都显示出显著的变化，表明自主神经系统显著受损。由于信号的非平稳性，标准谱方法未能捕捉到这些现象。相反，这里提出的改进方法清楚地捕捉到了婴儿不断恶化的生理状况。
In order to mitigate the effect of non-stationarity in frequency domain analysis of data, we propose a modification to the power spectral estimation, a widely used technique to characterize physiological signals. Spectral analysis requires partitioning data into smaller epochs determined by the desired frequency resolution. The modified approach proposed here involves dividing the data within each epoch by the standard deviation of the data for that epoch. We applied this modified approach to cardiac beat-to-beat interval data recorded from a newborn infant undergoing hypothermia treatment for birth asphyxia. The critically ill infant had episodes of tachyarrhythmia, distributed sporadically throughout the study, which affected the stationarity of the heart rate. Over the period of continuous heart rate recording, the infant’s clinical course deteriorated progressively culminating in death. Coinciding with this clinical deterioration, the heart rate signal showed striking changes in both low-frequency and high-frequency power indicating significant impairment of the autonomic nervous system. The standard spectral approach failed to capture these phenomena because of the non-stationarity of the signal. Conversely, the modified approach proposed here captured the deteriorating physiology of the infant clearly.