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

Novel hybrid extraction systems for fetal heart rate variability monitoring based on non-invasive fetal electrocardiogram

This study focuses on the design, implementation and subsequent verification of a new type of hybrid extraction system for noninvasive fetal electrocardiogram (NI-fECG) processing. The system designed combines the advantages of individual adaptive and non-adaptive algorithms. The pilot study reviews two innovative hybrid systems called ICA-ANFIS-WT and ICA-RLS-WT. This is a combination of independent component analysis (ICA), adaptive neuro-fuzzy inference system (ANFIS) algorithm or recursive least squares (RLS) algorithm and wavelet transform (WT) algorithm. The study was conducted on clinical practice data (extended ADFECGDB database and Physionet Challenge 2013 database) from the perspective of non-invasive fetal heart rate variability monitoring based on the determination of the overall probability of correct detection (ACC), sensitivity (SE), positive predictive value (PPV) and harmonic mean between SE and PPV (F1). System functionality was verified against a relevant reference obtained by an invasive way using a scalp electrode (ADFECGDB database), or relevant reference obtained by annotations (Physionet Challenge 2013 database). The study showed that ICA-RLS-WT hybrid system achieve better results than ICA-ANFIS-WT. During experiment on ADFECGDB database, the ICA-RLS-WT hybrid system reached ACC > 80 % on 9 recordings out of 12 and the ICA-ANFIS-WT hybrid system reached ACC > 80 % only on 6 recordings out of 12. During experiment on Physionet Challenge 2013 database the ICA-RLS-WT hybrid system reached ACC > 80 % on 13 recordings out of 25 and the ICA-ANFIS-WT hybrid system reached ACC > 80 % only on 7 recordings out of 25. Both hybrid systems achieve provably better results than the individual algorithms tested in previous studies.Web of Science713178413175

Design and fabrication of cost-effective heart-rate pulse monitoring sensor system

A traditional approach of heart rate measurement has always meant that people must go to hospitals to examine the patient disease at Cardiologist and medical officer. Most people have difficult such as no transport and lazy to go to the hospital for the check-ups of their conditions heart rate. This is because, before have a treatment or medical check-up, they should do an appointment. Besides that, demands of works very high nowadays. People busy with their works until forget to do medical check-ups. Additionally, the available portable heart rate monitoring machine is costly to buy for all. In this research, we develop a system which can be accommodate for all while everyone can do their check up at home and do not waste their time by waiting for their turn in the hospital to do the medical check-ups. The prototype is built using low cost electronics components. The prototype can do a self-check-up before seeing a medical practitioner may reduce mortality rate due to the silent killer that is heart attacks

Magnetic resonance imaging compatible non-invasive fibre-optic sensors based on the Bragg gratings and interferometers in the application of monitoring heart and respiration rate of the human body: A comparative study

The publication presents a comparative study of two fibre-optic sensors in the application of heart rate (HR) and respiratory rate (RR) monitoring of the human body. After consultation with clinical practitioners, two types of non-invasive measuring and analysis systems based on fibre Bragg grating (FBG) and fibre-optic interferometer (FOI) have been designed and assembled. These systems use probes (both patent pending) that have been encapsulated in the bio-compatible polydimethylsiloxane (PMDS). The main advantage of PDMS is that it is electrically non-conductive and, as well as optical fibres, has low permeability. The initial verification measurement of the system designed was performed on four subjects in a harsh magnetic resonance (MR) environment under the supervision of a senior radiology assistant. A follow-up comparative study was conducted, upon a consent of twenty volunteers, in a laboratory environment with a minimum motion load and discussed with a head doctor of the Radiodiagnostic Institute. The goal of the laboratory study was to perform measurements that would simulate as closely as possible the environment of harsh MR or the environment of long-term health care facilities, hospitals and clinics. Conventional HR and RR measurement systems based on ECG measurements and changes in the thoracic circumference were used as references. The data acquired was compared by the objective Bland-Altman (B-A) method and discussed with practitioners. The results obtained confirmed the functionality of the designed probes, both in the case of RR and HR measurements (for both types of B-A, more than 95% of the values lie within the +/- 1.96 SD range), while demonstrating higher accuracy of the interferometric probe (in case of the RR determination, 95.66% for the FOI probe and 95.53% for the FBG probe, in case of the HR determination, 96.22% for the FOI probe and 95.23% for the FBG probe).Web of Science1811art. no. 371

Non-invasive fetal monitoring: a maternal surface ECG electrode placement-based novel approach for optimization of adaptive filter control parameters using the LMS and RLS algorithms

This paper is focused on the design, implementation and verification of a novel method for the optimization of the control parameters (such as step size mu and filter order N) of LMS and RLS adaptive filters used for noninvasive fetal monitoring. The optimization algorithm is driven by considering the ECG electrode positions on the maternal body surface in improving the performance of these adaptive filters. The main criterion for optimal parameter selection was the Signal-to-Noise Ratio (SNR). We conducted experiments using signals supplied by the latest version of our LabVIEW-Based Multi-Channel Non-Invasive Abdominal Maternal-Fetal Electrocardiogram Signal Generator, which provides the flexibility and capability of modeling the principal distribution of maternal/fetal ECGs in the human body. Our novel algorithm enabled us to find the optimal settings of the adaptive filters based on maternal surface ECG electrode placements. The experimental results further confirmed the theoretical assumption that the optimal settings of these adaptive filters are dependent on the ECG electrode positions on the maternal body, and therefore, we were able to achieve far better results than without the use of optimization. These improvements in turn could lead to a more accurate detection of fetal hypoxia. Consequently, our approach could offer the potential to be used in clinical practice to establish recommendations for standard electrode placement and find the optimal adaptive filter settings for extracting high quality fetal ECG signals for further processing. Ultimately, diagnostic-grade fetal ECG signals would ensure the reliable detection of fetal hypoxia.Web of Science175art. no. 115

A Comparative Analysis of Fetal Phonocardiograph Acoustical Performance

Táto bakalárska práca sa zaoberá komparatívnou analýzou elementárnych častí fetálneho fonokardiografu pomocou časovo-frekvenčnej analýzy fetálneho fonokardiografického signálu (fFKG). Fetálny FKG signál je ovplyvnený rôznymi aspektami akými sú pohyb senzora, okolitý hluk, pohyb plodu, materské zvuky, časti, z ktorých je fetoskop zložený atď. Práca sa v úvode zaoberá plodovým srdcom a jeho akustickou činnosťou, v ktorej sú popísané jednotlivé srdcové ozvy. Následne sa práca zaoberá problematikou monitorovania plodového srdca. Na problematiku monitorovania nadväzuje rešeršná časť, ktorá popisuje históriu ale aj nové možnosti snímania fFKG signálu. Na základe rešeršnej časti sú testované a analyzované jednotlivé elementárne časti fetálneho fonokardiografu na syntetických dátach, ktoré sú následne vyhodnotené. Na základe týchto výsledkov je navrhnuté najideálnejšie zloženie fetálneho fonokardiografu, ktorý je testovaný na tehotnej žene v 34.týždni tehotenstva.This thesis deals with comparative analysis of elementary parts of fetal phonocardiograph by time-frequency analysis of fetal phonocardiographic signal (fFKG). The fetal FKG signal is affected by various aspects such as sensor movement, ambient noise, fetal movement, maternal sounds, elementary parts of a fetoscope and so on. The thesis also deals with the fetal heart and its acoustic activity, in which the heart sounds are described. Subsequently, the thesis deals with the issue of monitoring the fetal heart. The issue of monitoring is followed by a research section, which describes the history and new possibilities of sensing fFKG signal. Based on the research part, elementary parts of fetal phonocardiograph are tested, analyzed and subsequently evaluated. Based on these results, the most ideal composition of fetal phonocardiography is designed and tested on a pregnant woman at 34th weeks of pregnancy.450 - Katedra kybernetiky a biomedicínského inženýrstvívelmi dobř

Nondestructive fiber optic sensor system for measurement of traffic speed

Disertační práce popisuje návrh, realizaci a otestování nového způsobu detekce a měření rychlosti vozidel s primárním zaměřením na silniční provoz do rychlosti 100km/h, který lze využít v koncepci SMART Cities. Uvedené výsledky v této práci potvrzují, že podobný přístup lze využít rovněž pro monitorování tramvajového provozu, provozu metra a vlakových souprav na železnici. Popsaný měřicí systém je založen na využití interference v optických vláknech. Základem řešení je sériové zapojení senzorických jednotek na bázi Mach-Zehnderova interferometru pracujících s jednovidovými telekomunikačními optickými vlákny standardu G.652.D. a G.653, vlnovou délkou 1550nm a nároky na výkon zdroje záření v řádech jednotek mW. Řešení popsaná v této disertační práci jsou v současné době chráněna autorským osvědčením (patent číslo 306992). Základem tohoto řešení je imunita vůči elektromagnetickým interferencím (EMI) a jednoduchá implementace, protože senzorické jednotky není nutné instalovat destruktivně do vozovky nebo kolejiště. Vzhledem k masivnímu rozšíření optických kabelů podél silnic a železničních tratí, které zabezpečují telekomunikační a bezpečnostní služby, je významnou výhodou i možnost přímého napojení senzorů na stávající infrastrukturu a možnost vzdáleného vyhodnocení. Měřicí systém byl dlouhodobě testován v reálném provozu a je charakterizován chybou v toleranci ± 3km/h udávané u úsekových měřicích systémů do rychlosti 100km/h v České republice.My dissertation thesis describes a design, implementation, and testing of a new way of vehicles detection and speed measurement primarily used in the road transport with the speed limit up to 100kph, which can be utilized in the concept of SMART Cities. Results published in this thesis confirm that a similar approach can be also used for the monitoring of tram, underground and railway transport. The proposed measuring system is based on the interference in optical fibers. The key condition is that sensory units are connected in series on the basis of Mach-Zehnder interferometer working with single-mode optical fibers of G.652.D. and G.653 standards, with the wavelength of 1550nm and demands on the radiation source output in the range of mW. Solutions described in this dissertation thesis are currently protected by copyright (the patent No.306992). The basis of this solution lies in electromagnetic interference immunity (EMI) and simple implementation as the sensory units do not need to be installed destructively into the roadway or railway. With regard to a massive use of optical fibers along roads and railway tracks, which provides telecommunications and security services, the important advantage is also the possibility of direct connections of sensors to existing infrastructure and the possibility of remote evaluation. The measuring system was tested in real traffic over a long period and is characterized by an error with the tolerance of ± 3kph which is given by sectional speed measuring systems up to 100kph in the Czech Republic.440 - Katedra telekomunikační technikyvyhově

Fetal PCG Signal Processing

Tato diplomová práce se zabývá extrakcí plodového fonokardiogramu (fFKG) ze záznamů pořízených na abdominální oblasti matky neinvazivním senzorem pomocí navrženého softwarového řešení. Abdominální fonokardiogram (aFKG) se skládá ze směsi fFKG, mateřského (mFKG) a šumu ve formě pohybů matky a plodu, zvuků z orgánů a vnějších zvuků. V práci je nejprve popsána teorie o vývoji plodu a jeho srdci. Poté je v práci popsána rešerše zabývající se všemi metodami, pomocí kterých lze extrahovat fFKG a poté jsou popsány algoritmy vybraných metod. Navržený systém se zakládá na FIR filtraci a vlnkové transformaci (WT) a primárně je zaměřen na stanovení plodové tepové frekvence (fHR) a vykreslení průběhů fHR. Funkčnost tohoto softwarového systému je testována na syntetických záznamech a reálných záznamech z databází. Hodnocení kvality je provedeno stanovením fHR a odstupu signálu od šumu (SNR).This thesis deals with extraction of fetal phonocardiogram (fFKG) from the recorded signals acquired on the abdominal area of the mother with a non-invasive sensor using the proposed software solution. The abdominal phonocardiogram (aFKG) consists of a mixture of fFKG, maternal (mFKG) and noise in the form of mother and fetal movements, organ sounds and external sounds. The thesis describes first the theory of the development of the fetus and its heart. Then, the research describes all the methods by which fFKG can be extracted and algorithms of the selected methods are described. The proposed system is based on FIR filtering and wavelet transformation (WT) and primarily focuses on determining fetal heart rate (fHR) and plotting the fHR waveforms. Functionality of this software system is tested on synthetic records and real records from databases. Quality assessment is performed by determining fHR and SNR.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn

Passive Fetal Monitoring by Advanced Signal Processing Methods and Analysis in Fetal Phonocardiography

Variabilita srdeční frekvence je velice důležitá pro hodnocení zdravotního stavu plodu. V diplomové práci je navržen komplexní systém zpracování a analýzy plodového fonokardiogramu pro získání srdeční frekvence plodu. První část práce popsuje fyziologickou i patologickou srdeční činnost plodu, možnosti snímání a typické vlastnosti fonokardiogramu plodu. Práce dále popisuje metody adaptivní vlnkové transformace, analýzu nezávislých komponent, empirického rozkladu, souboru empirického rozkladu a Hilbertovu transformaci pro zpracování a analýzu signálu. Sytém byl realizován v programovém prostředí MATLAB. K ovládání programu bylo vytvořeno grafické uživatelské rozhraní, ve kterém je možné simulovat základní typy rušení a provést filtraci signálu.Heart rate variability is crucial for assessing fetal health. The diploma thesis proposes a complex system of processing and analysis of fetal phonocardiogram for obtaining fetal heart rate. The first part describes physiological and pathological heart function of a fetus, possibilities of scanning and typical properties of phonocardiogram of a fetus. The work also describes methods of adaptive wavelet transform, independent components analysis, empirical mode decomposition, ensemble empirical mode decomposition and Hilbert transform for signal processing and analysis. The system was implemented by using MATLAB software. To control the program, a graphical user interface was created in which it is possible to simulate basic types of noise and conduct signal filtering.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn

Hybrid Methods for Processing of Fetal Electrocardiogram

Tato doktorská disertační práce se zaměřuje na návrh, realizaci a následnou verifikaci nového typu hybridního extrakčního systému pro zpracování neinvazivního plodového elektrokardiogramu (NI-fEKG). Navržený systém sdružuje výhody jednotlivých adaptivních a neadaptivních metod. Tato práce ověřuje dva inovativní hybridní systémy s názvem ICA-ANFIS-WT a ICA-RLS-WT. Jedná se o kombinaci analýzy nezávislých komponent (ICA), adaptivního neuro-fuzzy inferenčního systému (ANFIS) nebo algoritmu založeném na rekurzivní optimální adaptaci (RLS) a vlnkové transformace (WT). Studie byla realizována na datech z klinické praxe (rozšířená databáze abdominálního a přímého fetálního elektrokardiogramu (ADFECGDB) a databáze EKG physionet challenge 2013) z pohledu neinvazivního monitorování fetální tepové frekvence (fHR) na základě stanovení celkové pravděpodobnosti správné detekce (ACC), senzitivity (SE), pozitivní prediktivní hodnoty (PPV) a harmonického průměru mezi SE a PPV (F1). Funkcionalita systému byla verifikována vůči relevantní referenci dané anotacemi. Tato práce ukázala, že hybridní systém ICA-RLS-WT dosáhl lepších výsledků než ICA-ANFIS-WT. Při experimentu na záznamech z databáze ADFECGDB dosáhla hybridní metoda ICA-RLS-WT hodnoty ACC > 80 % u 10 z 12 záznamů a hybridní metoda ICA-ANFIS-WT hodnoty ACC > 80 % pouze u 6 z 12 záznamů. Při experimentu na záznamech z databáze EKG physionet challenge 2013 dosáhla hybridní metoda ICA-RLS-WT hodnoty ACC > 80 % u 13 z 25 záznamů a hybridní metoda ICA-ANFIS-WT hodnoty ACC > 80 % pouze u 7 z 25 záznamů. Oba navržené hybridní systémy dosáhly prokazatelně lepších výsledků než jednotlivé metody v předchozích studiích.This dissertation focuses on the design, implementation and subsequent verification of a new type of hybrid extraction system for noninvasive fetal electrocardiogram (NI-fECG) processing. The designed system combines the advantages of individual adaptive and non-adaptive methods. This thesis reviews two innovative hybrid systems called ICA-ANFIS-WT and ICA-RLS-WT. This is a combination of independent component analysis (ICA), adaptive neuro-fuzzy inference system (ANFIS) or recursive least squares (RLS) algorithm and wavelet transform (WT). The study was conducted on clinical practice data (extended abdominal and direct fetal electrocardiogram database (ADFECGDB) and Physionet Challenge 2013 database) from the perspective of non-invasive fetal heart rate (fHR) monitoring based on the determination of the overall probability of correct detection (ACC), sensitivity (SE), positive predictive value (PPV) and harmonic mean between SE and PPV (F1). System functionality was verified against a relevant reference obtained by annotations. The study showed that ICA-RLS-WT hybrid system achieve better results than ICA-ANFIS-WT. During experiment on ADFECGDB database, the ICA-RLS-WT hybrid system reached ACC > 80 % on 10 recordings out of 12 and the ICA-ANFIS-WT hybrid system reached ACC > 80 % only on 6 recordings out of 12. During experiment on Physionet Challenge 2013 database the ICA-RLS-WT hybrid system reached ACC > 80 % on 13 recordings out of 25 and the ICA-ANFIS-WT hybrid system reached ACC > 80 % only on 7 recordings out of 25. Both hybrid systems achieve provably better results than the individual methods tested in previous studies.450 - Katedra kybernetiky a biomedicínského inženýrstvívyhově