Wyniki wyszukiwania - BazTech

1

Automatic identifying of maternal ECG source when applying ICA in fetal ECG extraction

Yu Q., Yan H., Song L., Guo W., Liu H., Si J., Zhao Y.

Biocybernetics and Biomedical Engineering

|

2018

|

Vol. 38, no. 3

448--455

EN

Independent component analysis (ICA) is usually used as a preliminary step for maternal electrocardiogram (ECG) QRS detection in fetal ECG extraction. When applying ICA to do this, a troublesome problem arises from how to automatically identify the separated maternal ECG component. In this paper we proposed a method called PRCH (short for Peak to peak entropy, R-R interval entropy, Correlation coefficient and Heart rate) for the automatic identifying. In the method, we defined four kinds of features, including amplitude, instantaneous heart rate, morphology and average heart rate, to characterize a signal, and determined some decision parameters through machine learning. Experiments and comparison with other three existed methods were given. Through taking metric F1 for evaluation, it showed that the proposed PRCH method has the highest identifying accuracy and generalization capability.

2

Sequential separation of twin pregnancy electrocardiograms

Kotas M., Leski J. M., Wrobel J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2016

|

Vol. 64, nr 1

91--101

EN

We propose to tackle the problem of maternal abdominal electric signals decomposition with a combined application of independent component analysis and projective or adaptive filtering. The developed method is employed to process the four-channel abdominal signals recorded during twin pregnancy. These signals are complicated mixtures of the maternal ECG, the ECGs of the fetal twins and noise of various origin. Although the independent component analysis cannot separate the respective signals, the proposed combination of the methods deals with this task successfully. A simulation experiment confirms high efficiency of this approach.

3

Direct assessment of the fetal heart rate from abdominal composite recordings

Moslem B., Bazzi O., Khalaf J., Diab M.O.

Journal of Medical Informatics & Technologies

|

2013

|

Vol. 22

143--149

EN

In respect to the main goal of our ongoing work for analyzing fetal electrocardiogram (FECG) signals for monitoring the health of the fetus, we investigate in this paper the possibility of extracting the fetal heart rate (FHR) directly from the abdominal composite recordings. Our proposed approach is based on a combination of Independent Component Analysis (ICA) and least mean square (LMS) adaptive filter. The FHR of the estimated FECG signal is finally compared to a reference value extracted from a FECG signal recorded by using a spiral electrode attached directly to the fetal scalp. The experimental results show that FHR can be successfully evaluated directly from the abdominal composite recordings without the need of using any external reference signal.

4

State-space averaging for maternal ECG suppression

Kotas M., Jeżewski J., Kupka T., Matonia A.

Journal of Medical Informatics & Technologies

|

2009

|

Vol. 13

194--200

EN

In this paper a new method of maternal electrocardiogram suppression for fetal component extraction from one-channel maternal abdominal bioelectric signals is proposed. The method performs maternal ECG estimation by application of state-space averaging. The estimated signal is subtracted from the original one and this way suppressed. The method parameters allow us to balance between the precision of maternal ECG suppression and the necessity not to attenuate the fetal QRS complexes. A small database of the maternal abdominal bioelectric signals is used to investigate the developed system for fetal heart rate determination. The final assessment is based on the detection performance index. It is shown that by proper choice of the parameters we can tune the system so that it is more effective than the classical approach based on template subtraction.

5

Separation of abdominal fetal electrocardiograms in twin pregnancy

Kotas M., Jeżewski J., Matonia A., Kupka T.

Journal of Medical Informatics & Technologies

|

2008

|

Vol. 12

83--89

EN

A combined application of independent component analysis and projective filtering of the time-aligned ECG beats is proposed to solve the problem of fetal ECG extraction from multi-channel maternal abdominal electric signals. The developed method is employed to process the four-channel abdominal signals recorded during twin pregnancy. The signals are complicated mixtures of the maternal ECG, the ECGs of the fetal twins and noise of other origin. The independent component analysis cannot separate the respective signals, but the proposed combination of the methods allows to suppress the maternal ECG and when the level of noise is low it leads to an effective separation of the twins' signals.

6

Simultaneous recording and analysis of direct and indirect fetal electrocardiography

Matonia A., Jeżewski J., Kupka T., Horoba K., Bernys M.

Journal of Medical Informatics & Technologies

|

2004

|

Vol. 8

MM111--118

EN

Recording and analysis of fetal heart rate variability is still the most common method for detection of early symptoms of fetal hypoxia. However, fetal heart rate obtained via ultrasound describes only mechanical activity of fetus heart. Limitations of this technique have stimulated the development of fetal electrocardiography. It ensures more precise determination of fetal heart rate and, which is more important, enables assessment of the morphology of the fetal QRS complexes. In this paper two techniques of obtaining the fetal electrocardiogram are described and their comparative study is presented.

7

Reliability and quality of ultrasound measurements of fetal heart rate variability

Jeżewski J., Wróbel J., Kupka T., Matonia A., Horoba K., Widera M.

Journal of Medical Informatics & Technologies

|

2003

|

Vol. 6

IT21--26

EN

This work was aimed at assessment of usability of Doppler ultrasound method for the analysis of fetal heart rate variability at a level of single heart beats. The purpose of this study was to check if today fetal monitors provide the signal of accuracy comparable with an electrocardiography method. The virtual instrumentation software for measurement system and processing of acquired signals was implemented using LABVIEW environment. The results obtained reveal that accuracy of today monitors which use Doppler ultrasound technique is sufficient for visual analysis of the FHR traces. However, for the computerized analysis at a beat-to-beat level, this accuracy is below the acceptable value.

8

Combined analysis of fetal electrocardiogram and systolic time intervals

Matonia A., Jeżewski J., Kupka T., Horoba K., Wróbel J., Widera M.

Journal of Medical Informatics & Technologies

|

2003

|

Vol. 6

IT27--34

EN

Cardiotocography as a simultaneous recording of fetal heart rate (FHR) and uterine contraction activity is a basic method of evaluation of fetal condition. Correct variability of the fetal heart rate is an indirect sign of adequate oxygenation of a fetus. Unfortunately, the reverse case is not always true, signs suggesting pathological changes can also appear in recording when the fetal is not at risk. The cardiotocography shall then be recognized as a more screening than diagnostic method. It will be interesting to develop a non-invasive method being complementary to routine cardiotocography. This method should allow the adequate prediction of a bad neonatal outcome when the test is abnormal. The paper shows the system that makes possible cardiotocograms analysis in parallel with the assessment of additional parameters determined from comparison of mechanical and electrical fetal heart activity signals. The studies are aimed at development of set of parameters that are high correlated with clinical outcome.