基于近红外光谱的脑氧参量与血压信号的小波交叉谱分析

Correlation analysis between cerebral oxygen and arterial blood pressure signals based on cross wavelet analysis

提出了一种有效的方法来研究近红外(Near-infrared)血氧信号与血压之间的关系,揭示脑中风发生的机理,为脑中风早期诊断提供一种有效的辅助检测手段。总共采集和分析了51位志愿者(24±2岁,19人;70.8±5.2岁,32人)的血氧红外信号和血压信号。血氧信号与血压信号之间的相关性用交叉小波(Cross Wavelet Coherence)进行分析。结果表明,脑血氧与血压脉动在时频域上有较强的共同能量;特征频率段相干图表明二者在第一和第二频率段具有显著的相关性。对血压与血氧脉动信号的相关性统计分析表明,老年人脑氧脉动信号中,心率脉动成分与年轻人有显著性差异(P=0.002,F=11.215)。结果表明,与年轻人相比,老年人心脑血管有明显硬化,老年人心脏脉动到脑部脉动传递增强。

The objective of this study was to assess the correlation between spontaneous oscillations in Near-infrared cer- ebral oxygenation （CO） and arterial blood pressure （ABP） and to propose a method of indicating brain stroke. Contin- uous recordings of NIRS and ABP signals were obtained from simultaneous measurements in nineteen young subjects （ age =24 ±2 years）, thirty two old subjects （age =70. 8±5.2 years） at rest. The correlations between CO signals and ABP signals were analyzed using method based on Cross-wavelet Coherence. High common power can be observed in time-frequency domain between the two signals. What＇s more, the coherency shows that there are significant relation- ships as well in interval I and interval II. Significant difference can be observed （ P = 0. 002, F = 11. 215 ） after statisti- cal analyzing the coherence between CO signals and ABP signals of the three groups in interval I. The results indicated that comparing with the young the coherence of the frequency reflecting cardiac activity between CO signals and ABP signals became higher, which may signify high stiffness of cerebral vascular.