Engineering Commons^™

A New Approach For Congestive Heart Failure And Arrhythmia Classification Using Downsampling Local Binary Patterns With Lstm, Süleyman Akdağ, Fatma Kuncan, Yilmaz Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

Electrocardiogram (ECG) is a vital diagnosis approach for the rapid explication and detection of various heart diseases, especially cardiac arrest, sinus rhythms, and heart failure. For this purpose, in this study, a different perspective based on downsampling one-dimensional-local binary pattern (1D-DS-LBP) and long short-term memory (LSTM) is presented for the categorization of Electrocardiogram (ECG) signals. A transformation method named 1DDS-LBP has been presented for Electrocardiogram signals. The 1D-DS-LBP method processes the bigness smallness relationship between neighbors. According to the proposed method, by downsampling the signal, the histograms of 1D local binary patterns (1D-LBP) calculated from the obtained signal groups are …

Development Of A Hybrid System Based On Abc Algorithm For Selection Of Appropriate Parameters For Disease Diagnosis From Ecg Signals, Ersi̇n Ersoy, Gazi̇ Erkan Bostanci, Mehmet Serdar Güzel

Turkish Journal of Electrical Engineering and Computer Sciences

The number of people who die due to cardiovascular diseases is quite high. In our study, ECG (electrocar-diogram) signals were divided into segments and waves based on temporal boundaries. Signal similarity methods such as convolution, correlation, covariance, signal peak to noise ratio (PNRS), structural similarity index (SSIM), one of the basic statistical parameters, arithmetic mean and entropy were applied to each of these sections. In addition, a square error-based new approach was applied and the difference of the signs from the mean sign was taken and used as a feature vector. The obtained feature vectors are used in the artificial …

Investigating Arrhythmia Potential In Cardiac Myocytes In Presence Of Long Qt Syndrome, Victoria Lin Lam

Biomedical Engineering Theses & Dissertations

Long QT Syndrome (LQTS) is an increasingly studied condition that leads to potentially fatal heart rhythm disorders, called arrhythmias, and sudden cardiac death. The alterations in the electrocardiograms (ECGs) seen in LQTS patients is caused by mutations to genes related to ion channels in cardiac cells. Computational modeling allows the mechanistic study of these ion channel mutations in LQTS by providing quantitative predictors of cardiac behavior in human and rabbit heart models. This work hypothesizes that the repolarization reserve in cardiac Purkinje cells (PC), that form the cardiac conduction system, is lower than that of ventricular myocytes (VM), resulting in …

Optimal Analytical Methods For High Accuracy Cardiac Disease Classification And Treatment Based On Ecg Data, Jianwei Zheng

Computational and Data Sciences (PhD) Dissertations

This work constitutes six projects. In the first project, a newly inaugurated research database for 12-lead electrocardiogram signals was created under the auspices of Chapman University and Shaoxing People's Hospital (Shaoxing Hospital Zhejiang University School of Medicine). This database aims to enable the scientific community in conducting new studies on arrhythmia and other cardiovascular conditions. In the second project, we created a new 12-lead ECG database under the auspices of Chapman University and Ningbo First Hospital of Zhejiang University that aims to provide high quality data enabling detection of the distinctions between idiopathic ventricular arrhythmia from right ventricular outflow tract …

Model Based Analysis Of The Accuracy And Precision Of Auscultatory Blood Pressure Measurements In Patients With Atrial Fibrillation, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

Accurate measurement of blood pressure in the presence of atrial fibrillation remains an open problem. The present study combines the techniques of stochastic mathematical modeling with physiological models of the systemic circulation, cuff, and arm (1) to explore mechanisms underlying both the lack of accuracy and the lack of precision in cuff-based arterial pressure measurements during atrial fibrillation and (2) to develop strategies to correct for errors. Both the cardiovascular system and the measurement technique are described using mathematics, including both numerical techniques and analytical probability theory. Preliminary results with numerical models suggested that, despite variability, average systolic pressures tend …

Molecular Basis Of Class Ib Drug Interactions With The Nav Channel Macromolecular Complex: A Route To Personalized Medicine For Cardiac Arrhythmia, Wandi Zhu

McKelvey School of Engineering Theses & Dissertations

The heart rhythm is precisely controlled by the electrical impulse that propagate in the cardiac tissue. In single cardiomyocytes, the electrical activity generated by action potentials (AP). Cardiac NaV channels (NaV1.5) carry a large influx of Na+ that mediates the initiation and propagation of the AP in both atria and ventricles. Disruption of NaV1.5 function by genetic variants or external factors can result in deadly arrhythmias, such as long QT syndrome and Brugada syndrome. Thus, NaV channels are import therapeutic targets. The class I antiarrhythmics are the modulators of the NaV channels. Although they have been used clinically for over …

Transcriptional Regulation Of Arrhythmia: From Mouse To Human, Yun Qiao

McKelvey School of Engineering Theses & Dissertations

In the last two decades, our understanding of cardiac arrhythmias has been accelerated immensely by the development of genetically engineered animals. Transgenic and knockout mice have been the “gold standard” platforms for delineating disease mechanisms. Much of our understanding of the pathogenesis of atrial and ventricular arrhythmias is gained from mouse models that alter the expression of specific ion channels or other proteins. However, cardiac arrhythmias such as atrial fibrillation are heterogeneous diseases with numerous distinct conditions that could not be explained exclusively by the disruption of ionic currents. Increasing evidence suggests disruption of signaling pathways in the pathogenesis of …

Optical Mapping Of Cardiac Electromechanics, Hanyu Zhang

All ETDs from UAB

Sudden cardiac arrest is a leading cause of death in the world. One of the common causes of sudden cardiac arrest is acute regional ischemia due to coronary occlusion. However, the mechanism of arrhythmia onset in this setting is still unclear. Previous stud-ies suggest that abnormal mechanical stretch during acute regional ischemia may play a role in initiating arrhythmia through triggering ectopic electrical activation. Optical map-ping has been widely used in cardiac electrophysiological research in the past decades. Compared with conventional electrical mapping techniques, optical mapping offers a number of advantages. But a major limitation of optical mapping is that …

Probabilistic Dynamic Security Assessment Of Large Power Systems Using Machine Learning Algorithms, Sevda Jafarzadeh, Veysel Murat İstemi̇han Genç

Turkish Journal of Electrical Engineering and Computer Sciences

Arrhythmia, also known as dysrhythmia, is a condition involving an irregular heartbeat. A problem in the heart may cause problems in other organs, and as time passes, this will lead to more severe problems. Arrhythmia must be detected at an early stage to prevent such a problem occurring in the heart. Detection of arrhythmia from an electrocardiogram is an easy method that does not need much equipment and does not harm the patient. The purpose of this research is to find a faster and more accurate system to classify nine classes of arrhythmia. The St. Petersburg Institute of Cardiological Technics …

Bagged Tree Classification Of Arrhythmia Using Wavelets For Denoising, Compression, And Feature Extraction, Özgür Tomak, Temel Kayikçioğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Arrhythmia, also known as dysrhythmia, is a condition involving an irregular heartbeat. A problem in the heart may cause problems in other organs, and as time passes, this will lead to more severe problems. Arrhythmia must be detected at an early stage to prevent such a problem occurring in the heart. Detection of arrhythmia from an electrocardiogram is an easy method that does not need much equipment and does not harm the patient. The purpose of this research is to find a faster and more accurate system to classify nine classes of arrhythmia. The St. Petersburg Institute of Cardiological Technics …

On Designing An Ecg-Based Intelligent System: Utilizing The Heart’S Electrical Activity To Recognize Humans And Detect Arrhythmia, Sara Saeed Abdeldayem

Graduate Theses, Dissertations, and Problem Reports

The electrocardiogram (ECG) signal is the bioelectrical signal that reflects the heart's activity. It has been extensively used as a diagnostic tool since it holds information about the cardiac health condition. However, recent researches have shown that it exhibits an inter-subject variability property. Therefore, it can be used as a biometric-based modality for either identification or verification purposes. Nevertheless, some of the challenges are faced while employing such a signal. For instance, ECG signal is prone to noise, accordingly, noise filters should be designed to remove the noise while keeping the signal properties. Moreover, factors such as medications, health condition, …

Development Of High Resolution Tools For Investigating Cardiac Arrhythmia Dynamics, Christopher Reed Gloschat

McKelvey School of Engineering Theses & Dissertations

Every year 300,000 Americans die due to sudden cardiac death. There are many pathologies, acquired and genetic, that can lead to sudden cardiac death. Regardless of the underlying pathology, death is frequently the result of ventricular tachycardia and/or fibrillation (VT/VF). Despite decades of research, the mechanisms of ventricular arrhythmia initiation and maintenance are still incompletely understood.

A contributing factor to this lack of understanding is the limitations of the investigative tools used to study VT/VF. Arrhythmias are organ level phenomena that are governed by cellular interactions and as such, near cellular levels of resolution are needed to tease out their …

Automatic Arrhythmia Beat Detection: Algorithm, System, And Implementation, Wisnu Jatmiko, I Md. Agus Setiawan, Muhammad Ali Akbar, Muhammad Eka Suryana, Yulistiyan Wardhana, Muhammad Febrian Rachmadi

Makara Journal of Technology

Cardiac disease is one of the major causes of death in the world. Early diagnose of the symptoms depends on abnormality on heart beat pattern, known as Arrhythmia. A novel fuzzy neuro generalized learning vector quantization for automatic Arrhythmia heart beat classification is proposed. The algorithm is an extension from the GLVQ algorithm that employs a fuzzy logic concept as the discriminant function in order to develop a robust algorithm and improve the classification performance. The algorithm is tested against MIT-BIH arrhythmia database to measure the performance. Based on the experiment result, FN-GLVQ is able to increase the accuracy of …

A Mechanistically Guided Approach To Treatment Of Multi-Wavelet Reentry: Experiments In A Computational Model Of Cardiac Propagation, Richard T. Carrick

Graduate College Dissertations and Theses

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the United States today. However, treatment options remain limited despite the enormous magnitude of both AF prevalence and the associated economic cost. Of those treatment options that are available, ablation-based interventional methods have demonstrated the highest rates of long-term cure. Unfortunately, these methods have substantially lower efficacy in patients with heavier burdens of disease, thus leaving the most affected individuals with the least hope for successful treatment.

The focus of this research is to develop a mechanistically guided approach towards the treatment of multi-wavelet reentry (MWR), one of the primary …

Ablation Of Myocardial Tissue With Nanosecond Pulsed Electric Fields, Fei Xie, Frency Varghese, Andrei G. Pakhomov, Iurii Semenov, Shu Xiao, Jonathan Philpott, Christian Zemlin

Bioelectrics Publications

Background

Ablation of cardiac tissue is an essential tool for the treatment of arrhythmias, particularly of atrial fibrillation, atrial flutter, and ventricular tachycardia. Current ablation technologies suffer from substantial recurrence rates, thermal side effects, and long procedure times. We demonstrate that ablation with nanosecond pulsed electric fields (nsPEFs) can potentially overcome these limitations.

Methods

We used optical mapping to monitor electrical activity in Langendorff-perfused New Zealand rabbit hearts (n = 12). We repeatedly inserted two shock electrodes, spaced 2–4 mm apart, into the ventricles (through the entire wall) and applied nanosecond pulsed electric fields (nsPEF) (5–20 kV/cm, 350 ns duration, …

A Comparative Study Of Two Different Fpga-Based Arrhythmia Classifier Architectures, Ahmet Turan Özdemi̇r, Kenan Danişman

Turkish Journal of Electrical Engineering and Computer Sciences

Early diagnosis of dangerous heart conditions is very important for the treatment of heart diseases and for the prevention of sudden cardiac death. Automatic electrocardiogram (ECG) arrhythmia classifiers are essential to timely diagnosis. However, most of the medical diagnosis systems proposed in the literature are software-based. This work focused on the hardware implementation of a mobile artificial neural network (ANN)-based arrhythmia classifier that is implemented on a field programmable gate array (FPGA) as a single chip solution, as an alternative to various software models of ANNs. Due to the parallel nature of ANNs, hardware implementation of ANNs needs a large …

From Cardiac Optical Imaging Data To Body Surface Ecg: A Three Dimensional Ventricle Model, Yihua Zhao

Theses and Dissertations--Biomedical Engineering

Understanding the mechanisms behind unexplained abnormal heart rhythms is important for diagnosis and prevention of arrhythmias. Many studies have investigated the mechanisms at organ, tissue, cellular and molecular levels. There is considerable information available from tissue level experiments that investigate local action potential properties and from optical imaging to observe activity propagation properties at an organ level. By combining those electrophysiological properties together, in the present study we developed a simulation model that can help in estimation of the resulting body surface potentials from a specific electrical activity pattern within the myocardium. Some of the potential uses of our model …

Hysteresis In Repolarization Of Cardiac Action Potentials: Effects Of Spatial Heterogeneity And Slow Repolarization Currents, Linyuan Jing

Theses and Dissertations--Biomedical Engineering

Repolarization alternans, i.e. beat-to-beat variation of repolarization of action potential, is proposed as a predictor of life-threatening arrhythmias. Restitution relates repolarization duration with its previous relaxation time, i.e. diatstolic interval (DI), and is considered a dominant mechanism for alternans. Previously, we observed that different repolarization durations at the same DI during decelerating and accelerating pacing, i.e. restitution displays hysteresis, which is a measure of “cardiac memory”.

Objective of the current study was to investigate in the pig 1) the mechanism for a previously observed hysteresis type phenomenon, where alternans, once started at higher heart rate, persists even when heart rate …

The Impact Of Fine Sensor Spacing On Complex Tissue Impedance Spectra Measurements In Rabbit Ventricular Epicardium, Charlotte Mae Kent Waits

All ETDs from UAB

Our research group recently developed an instrumentation and signal processing approach that overcomes many of the obstacles associated with using small sensors to complete complex composite impedance (uCI) measurements, whose amplitude and phase depend upon the tissue's resistive and capacitive properties. The goal of this study was to test the feasibility of using smaller electrodes with finer separations than sizes traditionally employed in cardiac electrophysiologic studies with whole hearts to resolve uCI spectra in terms of magnitude (|uCI|) and phase (

Calcium Cycling Disturbances And Arrhythmogenesis, Namit Gaur

McKelvey School of Engineering Theses & Dissertations

In this work, a detailed multiscale computational model of Ca cycling and action potential in a ventricular myocyte is developed and used to study mechanisms of arrhythmias associated with mutations in the ryanodine receptor (RyR). The multiscale ventricular myocyte model reproduces experimentally observed Ca dynamics both at the local dyadic scale and at the global whole-cell scale, while also simulating the action potential (AP) shaped by membrane ionic currents. The model represents stochastic activation of L-type Ca channels (LCCs) and RyRs in the dyads and simulates random generation of Ca sparks both during excitation-contraction coupling (ECC) and during diastole. The …

Mathematical Modeling Of Dc Cardiac Ablation, Sowmya Reddy Narala

ETD Archive

This thesis presents a mathematical modeling of the cardiac DC ablation procedure. The model treats the procedure as a one dimensional heat transfer phenomenon taking place across the thickness of the myocardium. The model further considers a constant 37 oC for one of the boundary condition of the affected tissue, and the temperature of the other boundary condition is set to be a time dependent square-pulse variations. The parameters defining this time dependent boundary condition is used to perform parametric studies to predict tissue temperature at different depth of the myocardium. The initial condition of the myocardium prior to the …

Fully Parallel Ann-Based Arrhythmia Classifier On A Single-Chip Fpga: Fpaac, Ahmet Turan Özdemi̇r, Kenan Danişman

Turkish Journal of Electrical Engineering and Computer Sciences

Recognition of cardiac arrhythmias by electrocardiogram (ECG) is an important issue for diagnosis of cardiac abnormalities. Many studies on recognition of cardiac arrhythmias by ECG, using various techniques, have been performed in the past 20 years. Artificial neural networks (ANNs) are the most widely used tool in medical diagnosis systems (MDS) because of their powerful prediction characteristics. An ANN model is inspired by real biological neural networks, with a parallel structure that is potentially fast for computation. However, the suggested ANN architectures in the literature can only be run sequentially, on powerful processors, due to their complexity. Our approach enables …

Correlation Between Alternans Of Early And Late Phases Of Ventricular Action Potential, Sonam Chourasia

Theses and Dissertations--Biomedical Engineering

Several studies suggest that action potential duration (APD) alternans play an important role in initiation of arrhythmias, while less is known about the alternans of early phases of action potential (AP) and phase relation between the two. Transmembrane potentials recorded from swine and canine ventricles were analyzed to determine the correlation and phase relation between alternans of early and late phases of an AP. In both species, for activation intervals ≤ 400 ms, action potential amplitude (APA) alternans occurred≥ 50% of times when APD alternans occurred and vice versa, both were mostly in phase. Also, alternans of APA and APD …

Optical Mapping Of The Interactions Between Cardiac Geometry And Electrical Activity, Elliot B. Bourgeois

All ETDs from UAB

In healthy hearts, the synchronized spread of electrical activation drives contraction. To investigate the role of cardiac geometry in modulating normal and abnormal electrical rhythms, we stained cardiac tissues with a fluorescent, voltage sensitive dye and imaged activation patterns with fast video cameras (optical mapping). This work is presented in three projects. Computer modeling has shown that conduction velocity increases when fibers are bowed toward the oncoming wavefront and decreases when fibers are bowed in the opposite direction. In the first project, cultured monolayers of cardiac myocytes were optically mapped to experimentally verify the theoretical effect of fiber curvature on …

An Authentic Ecg Simulator, Paul Michalek

Electronic Theses and Dissertations

An ECG (electrocardiogram) simulator is an electronic tool that plays an essential role in the testing, design, and development of ECG monitors and other ECG equipment. Principally an ECG simulator provides ECG monitors with an electrical signal that emulates the human heart's electrical signal so that the monitor can be tested for reliability and important diagnostic capabilities. However, the current portable commercially available ECG simulators are lacking in their ability to fully test ECG monitors. Specifically, the portable simulators presently on the market do not produce authentic ECG signals but rather they endeavor to create the ECG signals mathematically. They …