Time-frequency-transformation-based blind extraction method of fetal electrocardiography

Abstract

The invention relates to a time-frequency-transformation-based blind extraction method of fetal electrocardiography, which is based on the characteristic that the time domain of an original signal is relatively sparse. The method comprises the following steps: extracting a plurality of paths of mother-fetal mixed electrocardiosignals from different parts of mother's abdomen, and preprocessing thecollected mixed signal, wherein the preprocessing comprises the steps of correcting the baseline shift of the signals, filtering off 50Hz power frequency interference, filtering off high-frequency noise interference such as myoelectricity and the like; selecting two paths of the mother-fetus mixed electrocardiosignals according to the maximal signal-to-noise ratio and separately searching mother-fetal electrocardio wave group positions of the two paths of mixed signals with an R-wave positioning technology to obtain time intervals in which the mother-fetus electrocardio in the two paths of mixed signals are relatively sparse, converting the obtained relatively sparse time intervals into a time frequency domain by using a fuzzy function, calculating signal items and cross items in each time frequency distribution, constructing a comparison function by using generalized Rayleigh's quotient, and finally separating fetal electrocardiosignals from the two paths of mother-fetal mixed electrocardiosignals. The method provided by the invention is tested on the basis of actual collected data, and can well separate fetal electrocardiosignals.

Description

technical field [0001] The invention is a method for blindly extracting fetal electrocardiogram based on time-frequency transformation, which belongs to the transformation technology of the method for blindly extracting fetal electrocardiogram based on time-frequency transformation. Background technique [0002] Research has found that the health of the baby is the mother's biggest source of stress during pregnancy. About 8 in 1,000 babies are born each year with congenital heart defects. Therefore, perinatal fetal monitoring is very necessary, it is directly related to the safety of pregnant women and fetuses, the development and growth of newborns and long-term intellectual development. With the society's increasing demands on the health and safety of mothers and infants, the physiological and pathological research on fetal development has become an important topic. [0003] At present, a routine inspection clinically used to obtain the fetal health status of the mother ...

AI Technical Summary

Problems solved by technology

At present, the clinical acquisition and waveform research of adult ECG is relatively mature, but the research on fetal ECG has just started. There are many reasons for this. It is several orders of magnitude lower, and accompanied by a lot of noise in the process of signal conduction and acquisition, the signal of the fetus is often submerged in these noises, the signal-to-noise ratio (SNR) of the fetal ECG is not high, and secondly, there is no complete information about the fetus Research on the clinical significance of ECG waveforms. Furthermore, there is a lack of research databases on fetal ECG waveforms

[0005] At present, the methods for obtaining fetal ECG signals mainly include invasive and non-invasive ECG signal acquisition methods. The invasive type, that is, the scalp electrode method, is traumatic and can only be operated after the rupture of the amniotic membrane.

Non-invasive method, the ECG signal is collected in the mother's abdomen, and the fetal ECG signal is extracted after denoising and algorithm separation, which is harmless to the mother and fetus, but due to the characteristics of the mother and fetus' ECG signals, it cannot A clear fetal ECG waveform is extracted with a simple method, therefore, choosing a suitable and robust algorithm becomes the key to determine the quality of the fetal ECG

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