为了探究频域信号的有用信息,提出了将不同频段的谱功率作为一个独立的信源计算其信息熵的新方法.以年轻(21~34岁)与年老(68~81岁)二组健康人及一组心率不齐患者(66~89岁)的心电图(ECG)为实验数据,根据其频域特征选取多个不同频段计算功率谱熵.结果表明,在0.7~1.5Hz和1.5~5Hz频段内的ECG功率谱熵,年轻健康组明显大于年老健康组(P〈0.01,P〈0.001),年老健康组明显小于其年龄相近的心率不齐病人组(P〈0.001,P〈0.001),用全频段分割法也得出了类似的结果.不同频段的功率谱熵是分析ECG信号的有效指标.
In order to explore the useful information of frequency-domain signals, a new method was proposed, in which the spectral power of various frequency segments was taken as an independent information source to calculate its information entropy. The electrocardiograms (ECGs) were used as the experimental data, which were collected from young (21-34 yr) and elderly (68-81 yr) groups of healthy subjects, as well as a group of arrhythmia patients (66-89yr). Based on the ECG's features of frequency-domain, we chose multiple various frequency segments and calculated their power spectral entropy(PSE). The results showed that the PSEs of ECGs within 0.7 - 1.5 Hz and 1.5 - 5 Hz were obviously greater in the young group than the elderly healthy group (P〈 0.01, P 〈 0. 001), but were obviously less in the elderly healthy group than in the arrhythmia patient group of similar age (P 〈 0. 001, P 〈 0. 001). Similar results could be obtained by dividing up the whole frequency segment. The PSE of various frequency segments was an available index to analyze ECG signals.