Wyniki wyszukiwania - BazTech

1

Method for Simultaneous Monitoring of Uterine Contractions and Abdominal Pushing in a Childbirth

Radomski Dariusz S.

International Journal of Electronics and Telecommunications

|

2023

|

Vol. 69, No. 2

247--252

EN

Effective and safe labour requires good cooperation of all the physiological systems. A proper synchronization of uterine and abdominal muscles is necessary for labour progression. Therefore, a new method for simultaneous monitoring of uterine activities and parturient’s pushing efforts is presented. A high sampled, rectified electrohysterographic signal is divided into a low, uterine passband (0.1-3.00Hz) and a high, muscular (40-100Hz) one. The time-dependent mean frequencies arse estimated for each passband separately. At the moments of uterine contraction the time-dependent LOW mean frequency was locally increased. During parturient’s pushing effort the HIGH mean frequency was increased in the manner typical for the skeletal muscles. It seems that the proposed method would be less sensitive to a measuring noise than the previously published RMS based estimators. Moreover, the proposed method enables to monitor fatigue of a uterus or abdominal muscles during the prolonged 2nd stage of a labour. It can be helpful to make a decision of Caesarean section.

2

Uterine myoelectrical activity as biomarker of successful induction with Dinoprostone: Influence of parity

Diaz-Martinez Alba, Monfort-Ortiz Rogelio, Ye-Lin Yiyao, Garcia-Casado Javier, Nieto-Tous Mar, Nieto-Del-Amor Félix, Diago-Almela Vicente, Prats-Boluda Gema

Biocybernetics and Biomedical Engineering

|

2023

|

Vol. 43, no. 1

142--156

EN

The prolonged latent phase of Induction of Labour (IOL) is associated with increased risks of maternal mortality and morbidity. Electrohysterography (EHG) has outperformed traditional clinical measures monitoring labour progress. Although parity is agreed to be of particular relevance to the success of IOL, no previous EHG-related studies have been found in the literature. We thus aimed to identify EHG-biomarkers to predict IOL success (active phase of labour in ≤ 24 h) and determine the influence of the myoelectrical response on the parity of this group. Statistically significant and sustained differences between the successful and failed groups were found from 150 min in amplitude and non-linear parameters, especially in Spectral Entropy and in their progression rates. In the nulliparousparous comparison, parous women showed statistically significantly higher amplitude progression rate. These biomarkers would therefore be useful for early detection of the risk of induction failure and would help to develop more robust and generalizable IOL successprediction systems.

3

Automated detection of preterm condition using uterine electromyography based topological features

Vinothini S., Punitha N., Karthick P.A., Ramakrishnan S.

Biocybernetics and Biomedical Engineering

|

2021

|

Vol. 41, no. 1

293--305

EN

Accurate prediction of preterm birth is a global, public health priority. This necessitates the need for an efficient technique that aids in early diagnosis. The objective of this study is to develop an automated system for an effective detection of preterm (weeks of gestation < 37) condition using Electrohysterography (EHG) and topological features associated with the frequency components of signals. The EHG signals recorded prior to gestational age of 26 weeks are considered. The pre-processed signals are subjected to discrete Fourier transform to obtain the Fourier coefficients. The envelope is computed from the boundary of the complex Fourier coefficients identified using the a-shape method. Topological features namely, area, perimeter, circularity, convexity, ellipse variance and bending energy are extracted from the envelope. Classifications based on threshold-determination method and machine learning algorithms namely, naïve Bayes, decision tree and random forest are employed to differentiate the term and preterm conditions. The results show that the Fourier coefficients of EHG signals exhibit different shapes in the term and preterm conditions. The regularity of signals is found to increase in preterm condition. All the features are found to have significant differences between these two conditions. Bending energy as a single biomarker achieves a maximum accuracy of 80.7%. The random forest model based on the topological features detects the conditions with the maximum accuracy and positive predictive value of about 98.6%. Therefore, the proposed automated system seems to be effective and could be used for the accurate detection of term and preterm conditions.

4

Granger causal analysis of electrohysterographic and tocographic recordings for classification of term vs. preterm births

Saleem Saqib, Saeed Ahmed, Usman Shabnam, Ferzund Javed, Arshad Jahangir, Mirza Jawad, Manzoor Tareq

Biocybernetics and Biomedical Engineering

|

2020

|

Vol. 40, no. 1

454--467

EN

According to World Health Organization, 5-18% births around the world are premature, and this rate is on its rise. Recent trend has been to develop computational tools which could support obstetricians in their daily practice. This work is aimed at extracting novel diagnostic features for term vs. preterm births classification based on the dynamics of contraction and non-contractions (dummy) intervals. To achieve this, 26 uterine records of 18 pregnant women, resulting in 13 term and 13 preterm deliveries, were analyzed in this study. Each record was of 30-min duration, and comprised three electrohysterographic (EHG) and one externally recorded tocographic (Toco) signal. Granger causal analysis of contraction and dummy intervals of recorded signals was performed to extract potential features. These include coupling strength and directionality indices, and were subsequently utilized by a quadratic discriminator to classify between term and preterm births. The extracted features achieved high discriminatory power of 94%, 95%, 91%, and 97% for sensitivity, specificity, classification accuracy, and area under the ROC curve, respectively. These findings show that Granger causal analysis might be adopted as a computational tool to quantify EHG-Toco dynamics for the risk-assessment of the preterm delivery.

5

Early predicting a risk of preterm labour by analysis of antepartum electrohysterograhic signals

Horoba K., Jezewski J., Matonia A., Wrobel J., Czabanski R., Jezewski M.

Biocybernetics and Biomedical Engineering

|

2016

|

Vol. 36, no. 4

574--583

EN

This study is aimed at evaluation of the capability to indicate the preterm labour risk by analysing the features extracted from the signals of electrical uterine activity. Free access database was used with 300 signals acquired in two groups of pregnant women who delivered at term (262 cases) and preterm (38 cases). Signal features comprised classical time domain description, spectral parameters and nonlinear measures of contractile activity. Their mean values were calculated for all the contraction episodes detected in each record and their statistical significance for recognition of two groups of recordings was provided. Obtained results were related to the previous study where the same features were applied but they were determined for entire signals. Influence of electrodes location, band-pass filter settings and gestation week was investigated. The obtained results showed that a spectral parameter – the median frequency was the most promising indicator of the preterm labour risk.

6

Early diagnosis of threatened premature labor by electrohysterographic recordings – The use of digital signal processing

Lemancewicz A., Borowska M., Kuć P., Jasińska E., Laudański P., Laudański T., Oczeretko E.

Biocybernetics and Biomedical Engineering

|

2016

|

Vol. 36, no. 1

302--307

EN

Prevention and early diagnosis of imminent preterm labor are considered to be the most important perinatal challenge nowadays. Significant progress has been observed on postnatal care of premature infants, but without reducing the prevalence of preterm delivery. Our study was focused on comparison of three methods of spectral analysis of electro-hysterographic (EHG) signals: fast Fourier transform (FFT), wavelet transform (WT) and autoregressive modeling (AR). Complexity of the electrohysterographic signals was analyzed by using: the approximate entropy (ApEn), Lempel–Ziv complexity measure (L–Z). Additionally, the work evaluated the applicability of EHG in diagnosing imminent premature labor. EHG signals were recorded among 60 patients with threatened preterm labor symptoms between the 24th and 34th week of pregnancy. Patients included to the study had a shortened cervix (less than 20 mm) without regular uterine contractions recorded on regular cardiotocography (CTG). The women were divided into two groups: those delivering within 7 days – group A (n = 15) and women delivering after 7 days – group B (n = 45). The study confirmed differences in bioelectrical activity of uterus between patients delivering prematurely within 7 days and after from the EHG registration for all analyzed methods.

7

Analysis of electrical uterine contractile activity for prediction of preterm delivery

Horoba K., Jezewski J., Matonia A., Wrobel J., Czabanski R., Jezewski M.

Journal of Medical Informatics & Technologies

|

2015

|

Vol. 24

199--205

EN

This study is aimed at evaluation of the capability to indicate the preterm delivery risk analysing the features extracted from signals of electrical uterine activity. Free access database was used with signals acquired in two groups of pregnant women who delivered at term and preterm. Signal features comprised classical time domain and spectral parameters of contractile activity, as well as the sample entropy. Their mean values were calculated over all contraction episodes detected in each record and their statistical significance for separating the two groups of recordings was provided. Influence of electrodes location, band-pass filter settings and gestation week was investigated. The obtained results showed that a spectral parameter – the median frequency was the most promising indicator of the preterm delivery risk.

8

Identification of a Nonlinear Association between Components of the Electrohysterographical Signal

Radomski D., Małkiewicz A.

International Journal of Electronics and Telecommunications

|

2010

|

Vol. 56, No. 3

287-290

EN

Electrohysterography is a method for measuring of bioelectrical potentials generated by a contracting uterus. It is used for monitoring of uterine activities mainly during a pregnancy and for prediction of an upcoming pretermlabour. However, there is still unknown the best method of EHG analysis which gives clinically useful information about a uterine activity. To achieve this goal we propose to use information about nonlinear associations between EHG signals registered from an uterine fundus and an uterine cervix. The h² index was applied to identify these relationships. The obtained results reveal that there exists a nonlinear correlation between biopotentials generated from two parts of a pregnant uterus. Moreover, this correlation seems to be higher as a labour is upcoming. It suggests a possibility of using the h² index for prediction of an upcoming labour based on EHG signals.

9

The prognostic value of electrohysterography in prediction of premature labour

Sikora J., Matonia A., Horoba K., Ziętek J., Jeżewski J.

Journal of Medical Informatics & Technologies

|

2008

|

Vol. 12

71--76

EN

Premature birth is the leading cause of a neonatal death, so, it is extremely important to distinguish the pregnancy at risk of preterm threatening labour. The electrohysterography seems very promising as a method which enables noninvasive recording of readable bioelectrical signal of uterine muscle. The developed instrumentation enabled simultaneous recording of bioelectrical signals by means of electrodes attached to abdominal wall and mechanical activity of uterine muscle using fetal monitor. Material comprised 27 patients in physiological pregnancy (27 ÷ 40 week), and 21 patients (23 ÷ 36 week) with the symptoms of threatening premature labour. The obtained results showed that quantitative parameters of detected uterine contractions: amplitude and contraction area, obtained both for mechanical and electrical activity, were statistically significant (p < 0.05) to distinguish the patients at risk of premature labour. However, their reliability is low because they strongly depend on individual patient features. We consider the parameters characteristic for electrohysterogram exclusively e.g. contraction power and its median frequency as more useful (p < 0.05). Noninvasive electrohysterography ensures higher sensitivity and specificity for recognition of uterine contraction activity in comparison to classical mechanical method.

10

Recognition of early symptoms of fetal distress with on-line analysis of bioelectrical signals from maternal abdomen

Gacek A., Matonia A., Jeżewski J., Kupka T.

Biocybernetics and Biomedical Engineering

|

2007

|

Vol. 27, no. 1-2

207-216

EN

Conventional fetal monitoring for recognition of fetal distress is based on ultrasound Doppler technique. The new approach proposed in this work relies on analysis of bioelectrical signals recorded from the maternal abdominal wall. Fetal electrocardiogram and uterine electrical signal are extracted from abdominal signals using advanced instrumentation and algorithms for signal processing. Evaluation of the fetal heart rate variability with an additional analysis of fetal electrocardiogram morphology is expected to ensure early detection of fetal hypoxia symptoms and, finally, an appropriate obstetrical intervention.

11

Monitoring of contraction activity of uterine muscle by the use of abdominal electrohysterography

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

Acta of Bioengineering and Biomechanics

|

2006

|

Vol. 8, nr 2

27-34

EN

Monitoring of contraction activity of uterine muscle is important diagnostic tool used both during pregnancy and labour. The strain of pregnant uterus exerted on maternal abdomen is measured via external tocography. However, limitation of this approach has caused a development of other technique – electrohysterography, which is based on recording an electrical uterine activity. The comparison between electrohysterography and tocography was made due to the possibility of the simultaneous recording of mechanical and electrical uterine muscle activity. The results obtained show that both methods demonstrate high agreement in relation to the number of contractions recognized as being consistent.

12

Antenatal fetal surveillance using bioelectrical signals

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

Elektronika : konstrukcje, technologie, zastosowania

|

2004

|

Vol. 45, nr 8-9

110-113

EN

A new approach alternative to cardiotocographic conventional letal monitoring is presented. It relies upon analysis of bioelectrical signals recorded from maternal abdominal wall. Due to strong interferences present in abdominal signal advanced methods of signal processing have been developed to extract letal electrocardiogram and uterine electrical activity signal. The described system allows replacement of more expensive cardiotocographic instrumentation based on ultrasound. Doppler method and ensures the higher diagnostic capacity at the same time.

PL

W pracy przedstawione zostało nowe, alternatywne w stosunku do tradycyjnej kardiotokogralii, podejście do monitorowania stanu płodu w okresie przedporodowym. Zostało ono oparte o rejestrację i analizę biosygnałów rejestrowanych z powierzchni brzucha matki. Występujące w tych sygnałach zakłócenia wymagają stosowania zaawansowanych technik przetwarzania sygnałów w celu wydobycia użytecznej informacji: elektrokardiogramu płodu i sygnału elektrycznej aktywności mięśnia macicy. Opracowany został uniwersalny system do monitorowania płodu pozwalający zastąpić kosztowne aparaty kardiotokograliczne wykorzystujące technikę ultradźwiękową, a zapewniający przy tym znacznie większe możliwości oceny i detekcji stanu zagrożenia płodu.