Fetal movements recording system using accelerometer sensor

One of the compelling challenges in modern obstetrics is the monitoring fetal wellbeing. Physicians are gradually becoming cognizant of the relationship between fetal activity, movement, welfare, and future developmental progress. Previous works have developed few accelerometer-based systems to tackle issues related to ultrasound measurement, the provision of remote s1pport and self-managed monitoring of fetal movement during pregnancy. Though, many research questions on the optimal setup in terms of body-worn accelerometers, as well as signal processing and machine learning techniques used to detect fetal movement, are still open. In this work, a new fetal movement system recorder has been proposed. The proposed system has six accelerometer sensors and ARDUINO microcontroller. The device which is interfaced with the MATLAB signal process tool has been designed to record, display and store relevant sets of fetal movements. The sensors are to be placed on the maternal abdomen to record and process physical signals originating from the fetal. Comparison of data recorded from fetal movements with ultrasound and maternal perception technique gave the following results. An accuracy of 59.78%, 85.87%,and 97.83% was achieved using the maternal perception technique, fetal movement recording system, and ultrasound respectively. The findings show that the proposed fetal movement recording system has a better accuracy rate than maternal perception technique, and can be compared with ultrasound

A wearable system for in-home and long-term assessment of fetal movement

International audienceObjectives: This paper presents a novel wearable system for in-home and long-term fetal movementmonitoring on a reliable and easily accessible basis.Material and methods: The system mainly consists of four accelerometers for fetal movement signalacquisition, a microcontroller for signal processing and an Android-based device interacting with the mi-crocontroller via Bluetooth Low Energy (BLE), providing the mother with information related to the fetalmovement in an intelligible way.Results: The proposed system can deliver reliable results with a specicity of 0.99 and a sensitivity of0.77 for fetal movement time series signal classication.Conclusion: The proposed wearable system will provide a good alternative to optimize the use of medicalprofessionals and hospital resources, and has potential applications in the eld of e-Health home care.Besides, the fetal movement acceleration signals acquired with volunteers (pregnant women) helps establishan initial database for future medical analysis of sensor-recorded fetal behaviors

Multi-modal detection of fetal movements using a wearable monitor

The importance of Fetal Movement (FM) patterns as a biomarker for fetal health has been extensively argued in obstetrics. However, the inability of current FM monitoring methods, such as ultrasonography, to be used outside clinical environments has made it challenging to understand the nature and evolution of FM. A small body of work has introduced wearable sensor-based FM monitors to address this gap. Despite promises in controlled environments, reliable instrumentation to monitor FM out-of-clinic remains unresolved, particularly due to the challenges of separating FMs from interfering artifacts arising from maternal activities. To date, efforts have been focused almost exclusively on homogenous (single) sensing and information fusion modalities, such as decoupled acoustic or accelerometer sensors. However, FM and related signal artifacts have varying power and frequency bandwidths that homogeneous sensor arrays may not capture or separate efficiently. In this investigation, we introduce a novel wearable FM monitor with an embedded heterogeneous sensor suite combining accelerometers, acoustic sensors, and piezoelectric diaphragms designed to capture a broad range of FM and interfering artifact signal features enabling more efficient isolation of both. We further outline a novel data fusion architecture combining data-dependent thresholding and machine learning to automatically detect FM and separate it from signal artifacts in real-world (home) environments. The performance of the device and the data fusion architecture are validated using 33 h of at-home use through concurrent recording of maternal perception of FM. The FM monitor detected an impressive 82 % of maternally sensed FMs with an overall accuracy of 90 % in recognizing FM and non-FM events. Consistency of detection was strongest from 32 gestational weeks onwards, which overlaps with the critical FM monitoring window for stillbirth prevention. We believe the multi-modal sensor fusion approach presented in this research will be a major milestone in the development of low-cost wearable FM monitors enabling pervasive monitoring of FM in unsupervised environments

Passive detection of accelerometer-recorded fetal movements using a time–frequency signal processing approach

This paper presents a proof-of-concept that shows that the use of accelerometers can be used for the detection of Fetal Movements. (Additional details can be found in the comprehensive book on Time-Frequency Signal Analysis and Processing (see http://www.elsevier.com/locate/isbn/0080443354). In addition, the most recent upgrade of the original software package that calculates Time-Frequency Distributions and Instantaneous Frequency estimators can be downloaded from the web site: www.time-frequency.net. This was the first software developed in the field, and it was first released publicly in 1987 at the 1st ISSPA conference held in Brisbane, Australia, and then continuously updated).This paper describes a multi-sensor fetal movement (FetMov) detection system based on a time–frequency (TF) signal processing approach. Fetal motor activity is clinically useful as a core aspect of fetal screening for well-being to reduce the current high incidence of fetal deaths in the world. FetMov are present in early gestation but become more complex and sustained as the fetus progresses through gestation. A decrease in FetMov is an important element to consider for the detection of fetal compromise. Current methods of FetMov detection include maternal perception, which is known to be inaccurate, and ultrasound imaging which is intrusive and costly. An alternative passive method for the detection of FetMov uses solid-state accelerometers, which are safe and inexpensive. This paper describes a digital signal processing (DSP) based experimental approach to the detection of FetMov from recorded accelerometer signals. The paper provides an overview of the significant measurement and signal processing challenges, followed by an approach that uses quadratic time–frequency distributions (TFDs) to appropriately deal with the non-stationary nature of the signals. The paper then describes a proof-of-concept with a solution consisting of a detection method that includes (1) a new experimental set-up, (2) an improved data acquisition procedure, and (3) a TF approach for the detection of FetMov including TF matching pursuit (TFMP) decomposition and TF matched filter (TFMF) based on high-resolution quadratic TFDs. Detailed suggestions for further refinement are provided with preliminary results to establish feasibility, and considerations for application to clinical practice are reviewed

Evaluating devices for the measurement of auditory-evoked fetal movement

Determining normal and abnormal fetal function in utero in order to better predict which fetuses are at risk for adverse outcome is critical. However, the medical imaging tools that could assist with diagnosis are very expensive and rarely available in the developing world. In this study, we developed a prototype audio-motio-tachograph (AMTG), which measures fetal movements through the recording of abdominal wall deformations and tested it in Rwanda. First, we showed that AMTG detected fetal signals and that fetuses respond to complex acoustic stimuli. In order to improve the sensitivity of the device, we then measured whole abdominal wall deformations in an automated way using a lab-based 3D optical measurement system, in which fringes are projected and the deflections recorded with a camera. We found that abdominal wall deformations can be measured accurately with a non-invasive measurement apparatus. Overall, we conclude that wearable modalities provide a promising alternative assessment capacity in fetal research, especially in low income countries

Magnetic Resonance Imaging of the Fetus

Hlavním cílem diplomové práce je experimentální ověření metod detekce pohybu plodu z abdominálního EKG (aEKG) záznamu s potenciálem využití během vyšetření magnetickou rezonancí. Signál aEKG obsahuje v sobě obsahuje mateřskou komponentu, plodovou komponentu a další rušivé signály. Pro zhodnocení stavu plodu je důležitým parametrem variabilita tepové, frekvence, ze které lze ověřit pohyby plodu. Teoretická část se věnuje současnému stavu problematiky klinického využití magnetické rezonance v prenatální diagnostice, popisu MR sekvencí vhodných pro fetální magnetickou rezonanci a klasifikaci základních komplikací při monitorování plodu, přičemž důraz je zde kladen na pohybové artefakty, které výrazně ovlivní celkovou metodu zobrazení. Dále je provedena rešerše současného stavu problematiky detekce pohybu plodu. V experimentální části je představeno řešení pomocí neadaptivní metody extrakce fEKG signálu, ze kterého je stanovena variabilita tepové frekvence plodu (fHR) a amplituda fetálního QRS komplexu, přičemž oba parametry jsou závislé na pohybu plodu. Metody byly realizovány v softwarovém prostředí Matlab 2020a. Ověření funkčnosti navržených metod bylo provedeno na reálném záznamu KTG z klinické praxe.The mail goal of this diploma thesis is the experimental verification of fetal movement detection methods from abdominal ECG (aECG) with the potential to be used during magnetic resonance of imaging. The aECG signal contains the maternal component, the fetal component and the other interfering signals. An important parameter for evaluating fetal status is heart rate variability, the frequency from which fetal movements can be verified. The theoretical part deals with the current state of clinical use of magnetic resonance imaging in prenatal diagnosis, description of MR sequences suitable for magnetic resonance and classification of basic monitoring errors, with emphasis on movement artifacts that significantly affect the overall imaging method. Furthemore, a search of the current state of fetal motion detection is perfomed. The experimental part presents a solution a non-adaptive of fetal ECG signal extraction, from which the variability of fetal heart rate and amplitude of the fetal QRS complex are determined, both parametrs being dependent on fetal movement. Methods was used in the Matlab version 2020a software environment. Verification of the functionality of the proposed methods was perfomed on a real KTG record from clinical practice.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn