脑电信号的标度分析及其在睡眠状态区分中的应用

脑电信号具有长程幂律相关性及多重分形的标度特性,并随生理病理状态改变.本文首次针对睡眠脑电信号应用单重分形去趋势波动分析(detrended fluctuation analysis,简记为DFA)方法与多重分形奇异谱对睡眠脑电信号的标度特征进行系统的对比研究.发现DFA标度指数α对于不同导联和样本组间的差异较为敏感,随睡眠状态的变化不规律;而多重分形奇异强度区间Δα随睡眠状态的变化更为规律,睡眠Ⅰ期至Ⅳ期不断增大,并且导联间差异和样本组间差异均较小.多重分形Δα参数更适合作为判定睡眠状态的定量参数.

Scaling analysis on electroencephalogram and its application to sleep-staging

Electroencephalogram (EEG) shows long-range power-law and multifractal scaling behaviors, which varies with physiological and pathological conditions. In the present paper, the scaling behavior of sleep EEG is studied using monofractal detrended fluctuation analysis (DFA) and multifractal singularity spectrum. It is found that, the DFA scaling exponent α is more sensitive to the differences between EEG derivations and subject groups, but irregular with sleep stages. However, the variation of multifractal singularity strength range Δα with sleep stages is more regular, it increases constantly from sleep stage Ⅰ to stage Ⅳ, showing less difference between EEG derivations and subject groups. Thus, it is suggested that multifractal parameter Δα is more suitable than monofractal scaling exponent α to be used as a quantitative parameter for sleep staging.