脑电中不同类型的基本节律在不同生理条件下特征不同,有效提取这些特征对于实现脑电定量分析具有重要作用。简要分析了谐波小波独特的优势,研究了基于离散谐波小波包方法精确提取脑电基本节律的问题,得到了两种反映节律特征的量化参数:单个导联上各节律在某时刻的频带能量比例(FBER—S)和某一导联脑电信号在某一频段内的能量占所有导联在该频段内能量的百分比(FBER—A)。对临床病例数据分析表明,这两种特征参数呈现的特点与确诊病例的病症特点吻合得很好,说明它们能够作为临床诊断和长时程脑电监护的有效辅助诊断依据。
Electroencephalogram (EEG) basic rhythms in different brain states possess different features, so it is important for quantitative EEG analysis to extract them efficiently. The distinct advantages of harmonic wavelet are briefly discussed, and discrete harmonic wavelet packet transformation is employed to extract EEG basic rhythms accurately. Based on the above results, two kinds of quantitative parameters can be obtained: frequency band energy ratio of all basic rhythms from single electrode (FBER-S) at some time and the proportion of the energy of EEG signal within some frequency region from single electrode to that from all electrodes (FBER-A). These two parameters simulated by clinical data agree well with the diagnosed conclusions, indicating that they can be effective bases in clinical EEG monitoring.