Research on multiscale energy distribution of fetal heart rate signal based on fractal features
10.3969/j.issn.1673-9701.2025.13.007
- VernacularTitle:基于分形特征的胎心率信号多尺度能量分布
- Author:
Xueli BAI
1
;
Shuxuan ZHANG
1
Author Information
1. 徐州市第一人民医院产科,江苏徐州 221000
- Publication Type:Journal Article
- Keywords:
Fetal heart rate;
Energy distribution;
Multiscale;
Multi-resolution;
R/S analysis;
Fractal analysis
- From:
China Modern Doctor
2025;63(13):29-32,45
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the multifractal features of fetal heart rate(FHR)signals,and to investigate the multiscale energy distribution features of FHR variability.Methods The study focuses on FHR signals from an open database released by Czech Technical University-University Hospital in Brno(CTU-UHB).Daubechies second-order wavelets db2 was applied to decompose FHR signals into level d1-d7 detail components and approximation components.R/S analysis was performed on the decomposed components,and Hurst index was used to study the multifractal features of the decomposed signals.Hurst index＜0.5 indicated that the signal had anti-persistence,Hurst index＞0.5 indicated that the signal had positive persistence,and the decomposed signal was reconstructed by using fractal features.The distribution law of energy was analyzed.Results The Hurst index of d1-d7 approximation components was＞0.5,which indicates that the approximation components of FHR signal have positive persistent single fractal characteristics.The Hurst index of d1-d3 detail components was＞0.5,the Hurst index of d7 detail components was＜0.5,and the Hurst index of d4-d6 detail components contained both＞0.5 and＜0.5,showing the bi-fractal feature.Based on the above multi-fractal analysis results,the FHR decomposed signals were reconstructed into three different subsequences,i.e.microscale sequence,mesoscale sequence,and macroscale sequence.The statistical results showed that the energy of these three sequences accounts for approximately 5％,70％,and 25％of the total energy,respectively(P＜0.05).Conclusion The FHR signal was characterized by complex multifractal features,and the energy of the fetal heart rate signal was mainly concentrated in the mesoscale.
