On a central problem of the Human Placenta Project

This brief technical note describes a design concept for a low-cost, painless, noninvasive monitor of total placental blood flow during the third trimester of pregnancy. The approach may offer an overlooked solution to a central problem of the human placenta project. A systems level biophysical analysis shows that jets of blood flow emerging from spiral arteries in the placenta generate characteristic 1/f or “pink noise” which is routinely audible, but typically ignored, during fetal phonocardiography. The amplitude of the 1/f noise, recorded at a standardized location in an individual patient, is a measure of total placental blood flow that is potentially useful for monitoring of placental function and better management of third trimester complications such as preeclampsia and maternal diabetes

Performance Analysis of Fetal-Phonocardiogram Signal Denoising Using The Discrete Wavelet Transform

The obligation for comprehensive fetal heart rate investigation had driven to improve the passive and non-invasive diagnostic instruments despite the USG or CTG method. Fetal phonocardiography (f-PCG) utilizing the auscultation method met the above criteria, but its interpretation frequently disturbed by the presence of noise. For instance, maternal heart and body organ sounds, fetal movements noise, and ambient noise from the environment where it is recording are the noise that corrupted the f-PCG signal. In this work, the use of discrete wavelet transforms (DWT) to eliminate noise in the f-PCG signal with SNR as the performance parameters observed. It was observing the effect of changes in wavelet type and threshold type on the SNR value. The test was carried out on f-PCG data taken from physio.net. Initial SNR values ranged from -26.7 dB to -4.4 dB; after application of DWT procedure to f-PCG, SNR increased significantly. Based on the test results obtained, wavelet type coif1 with the soft threshold gave the best result with 11.69 dB in SNR value. The coif1 had a superior result than other mother wavelets that use in this work, so the fPCG signal analysis for fetal heart rate investigation suggested to use it.The obligation for comprehensive fetal heart rate investigation had driven to improve the passive and non-invasive diagnostic instruments despite the USG or CTG method. Fetal phonocardiography (f-PCG) utilizing the auscultation method met the above criteria, but its interpretation frequently disturbed by the presence of noise. For instance, maternal heart and body organ sounds, fetal movements noise, and ambient noise from the environment where it is recording are the noise that corrupted the f-PCG signal. In this work, the use of discrete wavelet transforms (DWT) to eliminate noise in the f-PCG signal with SNR as the performance parameters observed. It was observing the effect of changes in wavelet type and threshold type on the SNR value. The test was carried out on f-PCG data taken from physio.net. Initial SNR values ranged from -26.7 dB to -4.4 dB; after application of DWT procedure to f-PCG, SNR increased significantly. Based on the test results obtained, wavelet type coif1 with the soft threshold gave the best result with 11.69 dB in SNR value. The coif1 had a superior result than other mother wavelets that use in this work, so the fPCG signal analysis for fetal heart rate investigation suggested to use it

The usage of wavelet-transform for weak intensity phonocardiosignal detection

В исследовании приведены данные выделения фонокардиограммы плода и фонокардиограммы, регистрируемой микрофоном мобильного телефона, проведенные с применением вейвлет- анализа. Качество полученных сигналов повзоляют характеризовать ритм деятельности сердца.В дослідженні наведені дані виділення фонокардіограми плода і фонокардіограми, яка зареєстрована мікрофоном мобільного телефона, яке було здійснене з використаннямвейвлетаналізу. Якість отриманих сигналів дозволяє характеризувати ритм діяльності серця.The data on the extraction of fetus phonocardiogram as well as cardiogram detected in adult persons with mobile phone microphones, which was made on the basis of wavelet transform basis, are delivered. The quality of gained signals permits to characterize the rhythm of heart activity

Diseño y construcción de un fonocardiógrafo digital con visualización en LabVIEW

Un buen diagnóstico de enfermedades relacionadas con válvulas cardiacas se debería dar a partir de un fonocardiograma capaz de suministrarle al médico una información confiable de la situación del paciente. Se presenta el diseño de un fonocardiógrafo con la capacidad de amplificar y filtrar las señales acústicas derivadas del corazón. Posteriormente se realiza una conversión análogo-digital de las señales para ser enviadas por puerto serial a un entorno gráfico en LabVIEW para su registro y análisis en tiempo real.The auscultation of the heart noises has always been an important tool in medicine, a good diagnosis of illnesses related to the heart valves should be given from a phonocardiogram able to give the doctor a reliable information of the patients situation. The design presented is a phonocardiograph capable of amplifying and filtering the acoustic signs derived from the heart. After an analog to digital conversion of those signs the information is sent by serial port to a graphic environment in LabVIEW for its registration and analysis in real tim

Non Invasive Foetal Monitoring with a Combined ECG - PCG System

Although modern ultrasound provides remarkable images and biophysical measures, the technology is expensive and the observations are only available over a short time. Longer term monitoring is achieved in a clinical setting using ultrasonic Doppler cardiotocography (CTG) but this has a number of limitations. Some pathologies and some anomalies of cardiac functioning are not detectable with CTG. Moreover, although frequent and/or long-term foetal heart rate (FHR) monitoring is recommended, mainly in high risk pregnancies, there is a lack of established evidence for safe ultrasound irradiation exposure to the foetus for extended periods (Ang et al., 2006). Finally, high quality ultrasound devices are too expensive and not approved for home care use. In fact, there is a remarkable mismatch between ability to examine a foetus in a clinical setting, and the almost complete absence of technology that permits longer term monitoring of a foetus at home. Therefore, in the last years, many efforts (Hany et al., 1989; Jimenez et al., 1999; Kovacs et al., 2000; Mittra et al., 2008; Moghavvemi et al., 2003; Nagal, 1986; Ruffo et al., 2010; Talbert et al., 1986; Varady et al., 2003) have been attempted by the scientific community to find a suitable alternative

Model Identifkasi Sinyal Jantung Pertama (S1) dan Sinyal Jantung Kedua (S2) pada Janin

Process of identifying fetal heart sound signals is imperative in recognizing congenital heart function that caused by many factors, such as hereditary factors and food intake of pregnant mothers. This study developed a method for processing heart signals to separate normal fetal phonocardiogram signals from noise by utilizing the Complete Empirical Mode Decomposition (CEEMD) algorithm which is integrated with the Pearson Distance metric. Heart signals that have been separated from noise are then processed using the Shannon Energy equation in order to sharpen the intensity of the first heart signal (S1) and the second heart signal (S2), but at the same time suppress the intensity of the residual noise in the signal. Based on the experiment results from 75 normal fetal heart sound cycles, the model that has been developed is able to identify the S1 signal and S2 signal, the time duration of T11 (S1-S1), and the time duration of T12 (S1-S2). Average duration of T11 and T12 acquired in this research can possibly be used as a reference for measuring the normal duration of fetal heart sound signals

A phonocardiographic-based fiber-optic sensor and adaptive filtering system for noninvasive continuous fetal heart rate monitoring

This paper focuses on the design, realization, and verification of a novel phonocardiographic-based fiber-optic sensor and adaptive signal processing system for noninvasive continuous fetal heart rate (fHR) monitoring. Our proposed system utilizes two Mach-Zehnder interferometeric sensors. Based on the analysis of real measurement data, we developed a simplified dynamic model for the generation and distribution of heart sounds throughout the human body. Building on this signal model, we then designed, implemented, and verified our adaptive signal processing system by implementing two stochastic gradient-based algorithms: the Least Mean Square Algorithm (LMS), and the Normalized Least Mean Square (NLMS) Algorithm. With this system we were able to extract the fHR information from high quality fetal phonocardiograms (fPCGs), filtered from abdominal maternal phonocardiograms (mPCGs) by performing fPCG signal peak detection. Common signal processing methods such as linear filtering, signal subtraction, and others could not be used for this purpose as fPCG and mPCG signals share overlapping frequency spectra. The performance of the adaptive system was evaluated by using both qualitative (gynecological studies) and quantitative measures such as: Signal-to-Noise Ratio-SNR, Root Mean Square Error-RMSE, Sensitivity-S+, and Positive Predictive Value-PPV.Web of Science174art. no. 89