DETECTION OF PEAK AND BOUNDARIES OF P AND T WAVES IN ECG SIGNALS

The ECG elimination is a vital tool for physiologist in detecting and classifying arrhythmia among human beings. One of the major challenges in ECG analysis is the delineation of ECG segments, that is P and T waves detection and delineation of an ECG waveform. Here we presents a new approach to address this problem, where delineation and detection can be done simultaneously. The proposed methodology shows accurate detection of P and T wave peaks and boundaries and enables precise calculations of waveforms for each analysis window

Investigating the effects of an on-chip pre-classifier on wireless ECG monitoring

In past years, heart disease has been the leading cause of death in most developed countries. Timely detection of a heart condition is necessary in order to prevent life threatening situations. Even when the problem is not a heart condition, the activity of the heart can supply vital information, which makes its monitoring extremely important. A new approach to patient monitoring was taken recently by introducing wireless sensor networks into medical care. The capability of monitoring multiple patients at once makes such a system ideal for pre-hospital and in-hospital emergency care. The main problems associated with wireless sensor networks are power consumption and scaling. The power consumption is a problem due to the need for increased mobility of such a system, while scaling is of concern because a large number of nodes is desired in order to monitor more patients. This thesis addresses the power and bandwidth problems associated with monitoring patients using wireless networks by introducing another level of signal processing at each node. The goal is to design a digital circuit that would detect any abnormality in the ECG signal and enable the data transmission only if such has occurred. Reducing the amount of data being transmitted reduces the necessary bandwidth for each node and with the introduction of the proposed chip, the power consumption of each node is affected as well

Diseño de red neuronal 1D para detectar arritmias cardiacas

This article shows a neuronal network for deep learning focused on recognizing and classification five types of cardiac signals (Sinus, Ventricular Tachycardia, Ventricular Fibrillation, Atrial Flutter, and Atrial Fibrillation). The final objective is to obtain an architecture that can be implemented in an embedded system as a pre-diagnostic device linked to a Holter monitoring system. The network was designed using the Keras API programmed in Python, where it is possible to obtain a comparison of different types of networks that vary the presence of a residual block, with the result that the network with said block obtains the best response (100% success rate) and a model loss of approximately 0.15%. On the other hand, a validation by means of confusion matrices was carried out to verify the existence of false positives in the network results and evidence what type of arrhythmia can be presented according to the network output against an input signal through the console.El presente artículo muestra el diseño de una red neuronal para aprendizaje profundo enfocado al reconocimiento y clasificación de cinco tipos de señales cardiacas (Sinusal, taquicardia ventricular, fibrilación ventricular, flutter atrial y fibrilación atrial). El objetivo es obtener una arquitectura que pueda ser implementada en un sistema embebido como un dispositivo de prediagnóstico que se pueda vincular a un sistema de monitorización de un holter. La red fue diseñada por medio de la API de Keras programada en Python, en donde se logra obtener una comparación de diferentes tipos de redes que varían la presencia de un bloque residual, teniendo como resultado que la red con dicho bloque obtiene la mejor respuesta (porcentaje de aciertos de 100%) y una pérdida del modelo aproximadamente del 0.15%. Por otro lado, se realizó una validación mediante matrices de confusión para verificar la existencia de falsos positivos en los resultados otorgados por la red y adicionalmente evidenciar que tipo de arritmia se puede presentar conforme la salida de la red frente a una señal de entrada por medio de la consola

Bottom-up design of artificial neural network for single-lead electrocardiogram beat and rhythm classification

Performance improvement in computerized Electrocardiogram (ECG) classification is vital to improve reliability in this life-saving technology. The non-linearly overlapping nature of the ECG classification task prevents the statistical and the syntactic procedures from reaching the maximum performance. A new approach, a neural network-based classification scheme, has been implemented in clinical ECG problems with much success. The focus, however, has been on narrow clinical problem domains and the implementations lacked engineering precision. An optimal utilization of frequency information was missing. This dissertation attempts to improve the accuracy of neural network-based single-lead (lead-II) ECG beat and rhythm classification. A bottom-up approach defined in terms of perfecting individual sub-systems to improve the over all system performance is used. Sub-systems include pre-processing, QRS detection and fiducial point estimations, feature calculations, and pattern classification. Inaccuracies in time-domain fiducial point estimations are overcome with the derivation of features in the frequency domain. Feature extraction in frequency domain is based on a spectral estimation technique (combination of simulation and subtraction of a normal beat). Auto-regressive spectral estimation methods yield a highly sensitive spectrum, providing several local features with information on beat classes like flutter, fibrillation, and noise. A total of 27 features, including 16 in time domain and 11 in frequency domain are calculated. The entire data and problem are divided into four major groups, each group with inter-related beat classes. Classification of each group into related sub-classes is performed using smaller feed-forward neural networks. Input feature sub-set and the structure of each network are optimized using an iterative process. Optimal implementations of feed-forward neural networks provide high accuracy in beat classification. Associated neural networks are used for the more deterministic rhythm-classification task. An accuracy of more than 85% is achieved for all 13 classes included in this study. The system shows a graceful degradation in performance with increasing noise, as a result of the noise consideration in the design of every sub-system. Results indicate a neural network-based bottom-up design of single-lead ECG classification is able to provide very high accuracy, even in the presence of noise, flutter, and fibrillation

An approach to diagnose cardiac conditions from electrocardiogram signals.

Lu, Yan."October 2010."Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.Includes bibliographical references (leaves 65-68).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.ivChapter 1. --- Introduction --- p.1Chapter 1.1 --- Electrocardiogram --- p.1Chapter 1.1.1 --- ECG Measurement --- p.2Chapter 1.1.2 --- Cardiac Conduction Pathway and ECG Morphology --- p.4Chapter 1.1.3 --- A Basic Clinical Approach to ECG Analysis --- p.6Chapter 1.2 --- Cardiovascular Disease --- p.7Chapter 1.3 --- Motivation --- p.9Chapter 1.4 --- Related Work --- p.10Chapter 1.5 --- Overview of Proposed Approach --- p.11Chapter 1.6 --- Thesis Outline --- p.13Chapter 2. --- ECG Signal Preprocessing --- p.14Chapter 2.1 --- ECG Model and Its Generalization --- p.14Chapter 2.1.1 --- ECG Dynamic Model --- p.14Chapter 2.1.2 --- Generalization of ECG Model --- p.15Chapter 2.2 --- Empirical Mode Decomposition --- p.17Chapter 2.3 --- Baseline Wander Removal --- p.20Chapter 2.3.1 --- Sources of Baseline Wander --- p.20Chapter 2.3.2 --- Baseline Wander Removal by EMD --- p.20Chapter 2.3.3 --- Experiments on Baseline Wander Removal --- p.21Chapter 2.4 --- ECG Denoising --- p.24Chapter 2.4.1 --- Introduction --- p.24Chapter 2.4.2 --- Instantaneous Frequency --- p.26Chapter 2.4.3 --- Problem of Direct ECG Denoising by EMD : --- p.28Chapter 2.4.4 --- Model-based Pre-filtering --- p.30Chapter 2.4.5 --- EMD Denoising Using Significance Test --- p.33Chapter 2.4.6 --- EMD Denoising using Instantaneous Frequency --- p.35Chapter 2.4.7 --- Experiments --- p.39Chapter 2.5 --- Chapter Summary --- p.44Chapter 3. --- ECG Classification --- p.45Chapter 3.1 --- Database --- p.45Chapter 3.2 --- Feature Extraction --- p.46Chapter 3.2.1 --- Feature Selection --- p.46Chapter 3.2.2 --- Feature Dimension Reduction by GDA --- p.48Chapter 3.3 --- Classification by Support Vector Machine --- p.50Chapter 3.4 --- Experiments --- p.53Chapter 3.4.1 --- Performance of Feature Reduction --- p.54Chapter 3.4.2 --- Performance of Classification --- p.57Chapter 3.4.3 --- Performance Comparison with Other Works --- p.60Chapter 3.5 --- Chapter Summary --- p.61Chapter 4. --- Conclusions --- p.63Reference --- p.6

Automated Classification for Electrophysiological Data: Machine Learning Approaches for Disease Detection and Emotion Recognition

Smart healthcare is a health service system that utilizes technologies, e.g., artificial intelligence and big data, to alleviate the pressures on healthcare systems. Much recent research has focused on the automatic disease diagnosis and recognition and, typically, our research pays attention on automatic classifications for electrophysiological signals, which are measurements of the electrical activity. Specifically, for electrocardiogram (ECG) and electroencephalogram (EEG) data, we develop a series of algorithms for automatic cardiovascular disease (CVD) classification, emotion recognition and seizure detection. With the ECG signals obtained from wearable devices, the candidate developed novel signal processing and machine learning method for continuous monitoring of heart conditions. Compared to the traditional methods based on the devices at clinical settings, the developed method in this thesis is much more convenient to use. To identify arrhythmia patterns from the noisy ECG signals obtained through the wearable devices, CNN and LSTM are used, and a wavelet-based CNN is proposed to enhance the performance. An emotion recognition method with a single channel ECG is developed, where a novel exploitative and explorative GWO-SVM algorithm is proposed to achieve high performance emotion classification. The attractive part is that the proposed algorithm has the capability to learn the SVM hyperparameters automatically, and it can prevent the algorithm from falling into local solutions, thereby achieving better performance than existing algorithms. A novel EEG-signal based seizure detector is developed, where the EEG signals are transformed to the spectral-temporal domain, so that the dimension of the input features to the CNN can be significantly reduced, while the detector can still achieve superior detection performance

P- and T-Wave Delineation in ECG Signals Using a Bayesian Approach and a Partially Collapsed Gibbs Sampler

Detection and delineation of P- and T-waves are important issues in the analysis and interpretation of electrocardiogram (ECG) signals. This paper addresses this problem by using Bayesian inference to represent a priori relationships among ECG wave components. Based on the recently introduced partially collapsed Gibbs sampler principle, the wave delineation and estimation are conducted simultaneously by using a Bayesian algorithm combined with a Markov chain Monte Carlo method. This method exploits the strong local dependency of ECG signals. The proposed strategy is evaluated on the annotated QT database and compared to other classical algorithms. An important feature of this paper is that it allows not only for the detection of P- and T-wave peaks and boundaries, but also for the accurate estimation of waveforms for each analysis window. This can be useful for some ECG analysis that require wave morphology information

Advanced Pipelines For Artifact Removal From EEG Data

Feature extraction and working with EEG data has become one the most challenging studies these years. The raw EEG signal has various artifacts and needs to be detected and separated from brain components. This study is part of ERC. For removing artifacts from EEG data , this procedure done by a method known as “semi-automatic ICs selection pipeline”.This method was developed and verified by Cosynclab directed by Prof. Betti in Rome (where I spent my internship). In particular, the thesis work aims to investigate another method for complementing semi-automatic ICs selection pipeline and evaluate results which conveys to increasing the accuracy of semi-automatic ICs selection pipeline.The ICA algorithm derives independent sources from highly correlated EEG signals statistically without concern for the actual location or configuration of the EEG signal source . It is used to locate concurrent signal sources that are either too close together or too broadly scattered to be separated using conventional localization techniques. The primary issue in understanding ICA output is determining the right dimension of the input channels and the physiological and/or psychophysiological relevance of the resulting ICA source channels.With semi-automatic ICs selection pipeline method more than 2600 ICs evaluated and 405 ICs labeled as brains and the rest classified as artifacts. To evaluate these 405 ICs and increase possible accuracy another method was used known as ICLabel. ICLabel projects had been proposed by EEGLAB. This is a method based on Deep Learning and provides classification based on EEG IC classifier1 . After running and comparing the two methods pipeline, then,we designed an application for comparison and visualization output for both methods which name is IC selection.With this application we realize some modification needed for future steps for labeling with semi-automatic ICs selection pipeline method and some artifacts could change from artifacts to brain.Feature extraction and working with EEG data has become one the most challenging studies these years. The raw EEG signal has various artifacts and needs to be detected and separated from brain components. This study is part of ERC. For removing artifacts from EEG data , this procedure done by a method known as “semi-automatic ICs selection pipeline”.This method was developed and verified by Cosynclab directed by Prof. Betti in Rome (where I spent my internship). In particular, the thesis work aims to investigate another method for complementing semi-automatic ICs selection pipeline and evaluate results which conveys to increasing the accuracy of semi-automatic ICs selection pipeline.The ICA algorithm derives independent sources from highly correlated EEG signals statistically without concern for the actual location or configuration of the EEG signal source . It is used to locate concurrent signal sources that are either too close together or too broadly scattered to be separated using conventional localization techniques. The primary issue in understanding ICA output is determining the right dimension of the input channels and the physiological and/or psychophysiological relevance of the resulting ICA source channels.With semi-automatic ICs selection pipeline method more than 2600 ICs evaluated and 405 ICs labeled as brains and the rest classified as artifacts. To evaluate these 405 ICs and increase possible accuracy another method was used known as ICLabel. ICLabel projects had been proposed by EEGLAB. This is a method based on Deep Learning and provides classification based on EEG IC classifier1 . After running and comparing the two methods pipeline, then,we designed an application for comparison and visualization output for both methods which name is IC selection.With this application we realize some modification needed for future steps for labeling with semi-automatic ICs selection pipeline method and some artifacts could change from artifacts to brain