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Automated detection of fetal movements in Doppler ultrasound signals versus maternal perception

Wróbel J., Kupka T., Horoba K., Matonia A., Roj D., Jeżewski J.

Journal of Medical Informatics & Technologies

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2014

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Vol. 23

43--50

EN

Analysis of movement activity is important since it enables detection of nonreactive fetal heart rate recordings. The aim of the study was to develop an algorithm for automated detection of the fetal movement activity (actogram), based on analysis of the Doppler ultrasound signal, and to evaluate a reliability of the actogram as a source of information about the fetal movements. Bandpass filtering (20-80 Hz) was used to separate the actogram signal describing the fetal movement activity. Simultaneously there were recorded the markers of fetal movements perceived by mother, being the reference information. For the determination of the binary actogram, the authors proposed an algorithm in which the classification threshold was estimated at the beginning of each recording and was adaptively modified during its duration. The algorithm ensured detection of up to 89% of movement episodes corresponding to movements perceived by mother. At the same time almost as high number of episodes not related to the reference information was recognized. Obtained results revealed that the automated analysis of fetal movements is characterized by much higher sensitivity of movement episode detection compared to the maternal perception.

2

Monitoring of fetal movements based on actogram signal analysis

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

Journal of Medical Informatics & Technologies

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2004

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Vol. 8

MM119--128

EN

At present, biophysical fetal monitoring relies mainly on evaluation of a fetal heart rate (FHR). Absence of the FHR variability indicates central nervous system depression associated with hypoxia. The analysis of fetal heart rate segments identified with the aid of information on fetal movement activity provides much better results than analysis of the whole signal. Automatic recording of the fetal movement activity in a form of actogram signal provided by new models of fetal monitors becomes very common. For evaluation of information content of the actogram signal, the measurement instrumentation has been developed. The examined group comprised 20 patients and the total time of recording was 10 hours. Correlation between movements observed by clinical experts on ultrasonographic image and actogram trace recorded by fetal monitor was analysed. Although for head, arms, legs and trunk movements just visual analysis let observe their correlation with actogram signal, but in case of breathing movement no correlation was noted. Depending on movement type the detection efficiency was in range from 54 % to 80 %.

3

Ultrasonographic validation of the software system for online analysis of ultrasonic Doppler signals of fetal activity

Kret T., Kałużyński K.

Elektronika : konstrukcje, technologie, zastosowania

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2004

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Vol. 45, nr 8-9

127-129

EN

Fetal motor activity (pseudobreathing movements, trunk and limb movements) and the fetal heart rate are important indicators of fetal well-being. The software developed using the LabVIEW environment processes in real time Doppler signals acquired from the CW fetal Doppler activity monitor via the PC sound card. Displacements of the structures, velocities and accelerations of these displacements as well as histograms of the velocities and accelerations are computed. The fetal heart rate and breathing movements are determined. The software performance was tested against ultrasonographic recordings. Four pregnancies were submitted to a 15-20 minutes long examination. The ultrasonographic images and Doppler quadrature data were taped simultaneously with Hi-Fi video recorder, then used as signal source for laboratory tests of the software. The movements detected with the software environment were compared with the concurrent USG images. The experiments show that the elaborated software is capable of detecting different kinds of fetal movements. Some artifacts, specifically those resulting from maternal movements, may be eliminated on the basis of their amplitude. The software is a promising diagnostic tool for obstetrics.

PL

Aktywność ruchowa płodu (ruchy pseudooddechowe, ruchy tułowia i kończyn) oraz rytm serca są ważnymi wskaźnikami stanu płodu. Oprogramowanie stworzone z użyciem środowiska LabVIEW przetwarza, w czasie rzeczywistym, sygnały dopplerowskie uzyskiwane z monitora aktywności ruchowej płodu z falą ciągłą przez kartę dźwiękową komputera PC. Wyznaczane są ruchy płodu, prędkości i przyśpieszenia tych ruchów, jak również histogramy prędkości i przyśpieszeń. Wykrywane są rytm serca płodu, jak również ruchy pseudooddechowe. Wyniki uzyskiwane przez oprogramowanie porównano z wynikami obserwacji ultrasonograficznej. Cztery przypadki ciąż bez powikłań zostały poddane 15-20 minutowemu badaniu. Obrazy ultrasonograficzne i kwadraturowe sygnały dopplerowskie były rejestrowane jednocześnie z użyciem magnetowidu Hi-Fi, następnie zostały użyte jako źródło sygnału podczas testów oprogramowania w warunkach laboratoryjnych. Opracowane oprogramowanie wykrywa różne rodzaje ruchów płodu. Niektóre zakłócenia, szczególnie te wynikające z ruchów matki, mogą być eliminowane w oparciu o ich amplitudę. Oprogramowanie jest obiecującym narzędziem w diagnostyce położniczej.