Heart Rate Variability Analysis Based On Entropy Method

Abstract:By studying the coRRelation between heart rate variability and age among healthy people, the automatic nervous status of the elderly can get further understanding, and more evidence for the prevention and treatment of cardiovascular and cerebrovascular disease of human can be obtained. In this paper, the coRRelation between them were studied mainly by entropy method, and that the approximate entropy, sample entropy, multiscale entropy were mainly introduced and applied to heart rate variability analysis and research.There were two parts in our study:the first part, the coRRelation between heart rate variability and age among healthy people were studied by multiscale entropy. The scale factor were from1to5, the former4800points of each RR interval sequence of each20healthy subjects from the elderly and the young group were selected as experimental data, their sample entropy under different scales were calculated respectively. We obtained:while the scale factor is2, the sample entropy values of the elderly group and young group were1.0255±0.2377,1.3594±0.1631, the elderly group was significantly less than the young group by t test (P＜0.01). Compared with the results under other scales, the entropy values difference between the two groups was the most obvious when the scale was2. The second part, the symbol sequence and its entropy were applied to the study of the coRRelation between heart rate variability and age among healthy people. In the process of transforming RR interval sequence into binary sequence, a new way to determine the threshold was proposed. After the RR interval sequences were binarized by this method, the approximate entropy and sample entropy of the original sequences of RR interval and the binary sequences of each20healthy subjects from the two groups were calculated respectively. We get that the approximate entropy values of the young group and the elderly group were0.5923±0.1071and0.3270±0.2057, the sample entropy values were0.5315±0.1528and0.2238±0.1993. The two indicators of the young group were significantly greater than the elderly group by t test (P＜0.01). The results showed that:with the increase of age, the heart rate variability among people gradually reduced, and compared with the original sequences of RR interval, the difference between the entropy values of the binary sequences between the two groups were more obvious. The results showed that the entropy value is a valid indicator of measuring heart rate variability.