Method for extracting Doppler fetal heart sound signals on basis of delay estimation

Abstract

The invention discloses a method for extracting Doppler fetal heart sound signals on the basis of delay estimation. The method includes steps of acquiring abdominal ultrasonic Doppler echo signals of mothers; respectively acquiring delay estimation prior information of the Doppler fetal heart sound signals, uterus noise signals of the mothers and abdominal aorta sound signals of the mothers; performing k-level signal differential operation on the prior information; performing linear irrelevancy processing on the prior information; solving optimization problems to obtain weight vectors; respectively creating Vandermonde equation sets, solving the Vandermonde equation sets and determining delay of the various signals; acquiring delay of interference signals of the mothers; extracting Doppler fetal heart sound signals from the acquired signals by the aid of a single-channel blind separation process on the basis of oblique projection to acquire the pure Doppler fetal heart sound signals. The k is a positive integer. The method has the advantages that the method is applicable to extracting the Doppler fetal heart sound signals during fetal health condition examination, and the interference signals of the mothers can be effectively separated from the signals.

Description

technical field [0001] The invention relates to the technical field of obstetric fetal monitoring, and more particularly, to a method for extracting Doppler fetal heart sound signals based on delay estimation. Background technique [0002] Fetal heart rate monitoring is an important method of fetal monitoring in obstetrics, and it is an important means to avoid fetal distress and ensure the safety of mother and fetus. Common fetal heart rate monitoring methods include fetal electrocardiographic monitoring methods and fetal heart sound monitoring methods. [0003] Fetal ECG monitoring is a method for extracting and analyzing fetal ECG phenomena. Specific detection methods can be divided into two types: one is the indirect method of placing electrodes on the abdominal wall. The abdominal wall fetal ECG method is a method in which three electrodes are placed on the abdominal wall of the mother to induce the fetal ECG. This method will detect the maternal ECG signal and the we...

AI Technical Summary

Problems solved by technology

However, since the uterine murmur and abdominal aortic sound of the pregnant woman basically overlap with the fetal Doppler heartbeat, conventional frequency-domain filtering techniques cannot be used to eliminate the interference, but only by adjusting the position of the sensor to avoid excessive noise components

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