[Investigating the complexity of heart rate variability during anesthesia]

By use of the complexity analysis indices (approximate entropy, complexity), the heart rate variability signals obtained from 38 subjects' ECG during anesthesia were analyzed. The results showed that there is an obvious chaos change of heart rate variability during anesthesia, both the complexity and approximate entropy of heart rate variability during anesthesia are evidently less than those during consciousness (P<0.05). In this dissertation, we decompose the heart rate variability during anesthesia into 1/f part and non-fractal part, and then analyze these parts. The results reveal that the sensitivity of the complexity indices can be improved by decomposing the heart rate variability.