Fig. 5From: Heart rate variability-derived features based on deep neural network for distinguishing different anaesthesia statesComparison between anaesthesia states. The Y-axis is logarithmically transformed. (A)–(D) Distributions of (a) HF, (b) LF, (c) the ratio of HF/LF, and (d) the RR interval SampEn values. I, II, and III represent anaesthesia induction, anaesthesia maintenance, and anaesthesia recovery, respectively. Vertical coordinates represent the four feature values. HF: high-frequency; LF: low-frequency; HF/LF: high-to-low-frequency ratio; EACL: expert assessment of consciousness levelBack to article page