中文摘要：

心率变异性（HRV）体现了自主神经对心脏节律的调节,其动力学特征能够反映心脏的生理功能和健康状态,从短时HRV信号中探测其生理和病理状态的变化具有重要的临床应用价值.本研究采用基本尺度熵中的m-words组合和forbidden words作为特征指标,研究健康年轻人和健康老年人之间以及各自昼夜间对比,以及健康老年人与充血性心力衰竭患者间的对比.首先将m-words组合、forbidden words分别应用于正弦周期信号、白噪声以及1/f噪声,以证明方法的有效性.25名健康年轻人和25健康老年人的数据分别选自PhysioBank中的NormalSinus Rhythm RR Interval Database数据库和MIT-BIH Normal Sinus Rhythm数据库,20名充血性心力衰竭（CHF）患者选自PhysioBank中Congestive Heart Failure RR Interval Database.结果表明：m-words组合几率分布可以反映自主神经调控的变化;健康年轻人和健康老年人各自昼夜间的forbidden words存在显著差异（P＜0.05）,并且健康年轻人和健康老年人对应的时间段forbidden words也存在显著差异（P＜0.05）;相比于健康老年人,CHF患者的forbidden words显著降低（219.2±6.9 vs147.5±12.1,P＜0.05）.相对于传统的非线性方法,所提出方法的计算只需500个心跳间隔的时间序列,为HRV的研究和应用提供了一种简便和有效的方法.

英文摘要：

The heart rate variability （HRV） signal reflects the adjustment of autonomic nervous system on cardiac rhythm, and its dynamic characteristics can reflect the physiological function of the heart and health status. The short time HRV signal has an important value on clinical application on detecting changes in physiological and pathological conditions. We used m-words forms and forbidden words extracted from base- scale entropy as the characteristic index. We compared the differences of short time HRV parameters between day and night of the subjects of healthy young people and the healthy elderly people, as well as the healthy elderly people and congestive heart failure patients. Firstly, in order to prove the effectiveness of the method, m-words forms, forbidden words were respectively applied to the sine signal, white noise and 1/f noise. We chose respectively 25 healthy young subjects, 25 healthy elderly subjects from Normal Sinus Rhythm RR Interval Database and MIT-BIH Normal Sinus Rhythm Database in the PhysioBank, and 20 congestive heart failure subjects from the Congestive Heart Failure RR Interval Database in the PhysioBank. The results showed that the change of m-words forms probability distribution reflected the corresponding change of autonomic regulation. In the healthy young people and the healthy elderly people, there are significant differences（P 〈0.05） between day and night by the forbidden words method. Moreover, the forbidden words of corresponding time periods also have significant differences（P 〈 0. 05）among two groups of subjects. In addition, compared with healthy elderly people, the forbidden words of EHF patients have been significantly reduced（219.2 ±6.9 vs 147.5 ±12.1 ,P 〈 0.05）. Compared with the traditional nonlinear method, this algorithm only need a 500 heart beats series, and it provides a simple and effective method for the research and application of HRV.