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ECG quality evaluation
Vencel, Michal ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
This seminar work deals with the topic of evaluating the quality of ECG signals. The introductory chapters explain the basic characteristics of ECG signals - measurement, the form of the measured signal, methods of analysis. The cardiac physiology and pathology is presented. The most common types of noise that occur in ECG signals are also mentioned. Further, the reader is acquainted with the importance of the issue of evaluating the quality of ECG signals. In the practical part of the work, two own methods for ECG quality evaluation are presented. First, a brief theoretical introduction to the techniques used in the creation of methoda is given, followed by a description of the principle of algorithms. In order to compare the functionality of the proposed methods, three more methods from other authors are presented. Their principle is briefly described. In the final chapter, all methods are subjected to functionality testing. The results are examined and all methods are compared with each other.
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Automatic delineation of ECG signals
Žiak, Milan ; Smital, Lukáš (referee) ; Vítek, Martin (advisor)
This thesis deals about automatic delineation of ECG. We use algorithm, which is descriped by autors Lagune, Jané and Caminale. Their work uses first derivation for delineation ECG signal. This bachelor thesis also uses a wavelet transform to reach better results.
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Atrial fibrillation detection using time-domain methods
Sámel, Maroš ; Ronzhina, Marina (referee) ; Janoušek, Oto (advisor)
The purpose of this work is to get better understanding of the problems of atrial fibrillation followed by the processing methods for detection of atrial fibrillation based on an analysis of the ventricular rhythm. Methods that are described: method of medians, methods based on histograms (using coefficient of variation and density histograms of RR and RR intervals), method using RdR map, method using complexity of RR intervals and methods based on a statistical framework by Gaussian distribution and Laplace function The practical part of this work is focused on comparing these methods and selecting the best one – method of medians is the chosen one. This is followed by implementation of this method in the Matlab and testing it on the real data from a selected database. In the end, the detection ability of our method is evaluated and compared with the thoeretical detection abilities of the other methods. Our algorithm for detection of atrial fibrillations, based on the median method, achieved excellent results with the highest value of specificity obtained at 93,976%, sensitivity at 89,182% and AUC (area under the curve) at 0,973.
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Heart rhythm disorders in prehospital emergency care
BUGAJ, Petr
The thesis Heart rhythm disorders in the pre-hospital emergency care is divided into the theoretical and practical part. The theoretical part includes the general description of the anatomy of the heart and its function, the electrical conduction system of the heart and the electrocardiography. The following chapters of the theory are divided according to the ECG of the heart in normal sinus rhythm. The author also mentioned the classification of heart rhythm disorders, including the clinic symptomatology with the EKG pathological heart rhythm and basic therapeutic practices. The practical part of this thesis examined the knowledge of paramedic of the heart rhythm disorders in the pre-hospital emergency care. The survey has three main questions: How do the paramedics value their own knowledge in the field of heart rhythm disorders? How are the paramedics prepared to deal with these disorders? What is the practice of the paramedics when dealing with heart rhythm disorders? The survey was focused on the interviews with the paramedics from Emergency Medical Service in the south of the Czech Republic. They answered 13 questions and the data were divided into 10 categories according to the qualitative research. The results of the research show that the knowledge of the paramedic of the heart rhythm disorders needs to be improved. The author suggests preparing education trainings and regular revisions, because the right anamnesis and the following treatment is essential, especially with malign arrhythmias.
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Automatic detection of myocardial infarction in ECG
Nejedlý, Lukáš ; Kozumplík, Jiří (referee) ; Smíšek, Radovan (advisor)
This master’s thesis deals with the automatic detection of myocardial infarction in ECG. Semester work consists of two parts. The theoretical part provides a description of the electrical conduction system of the heart, spreading of electrical activity through the heart muscle, the methods of ECG scanning and the ECG curve. There are also mentioned the causes of myocardial ischemia and various methods of its detection. Another part is devoted to high-frequency ECG, analysis of HFQRS and clinical studies which describe the use of high-frequency ECG in diagnosis of myocardial infarction. In the practical part is proposed an algorithm using low-frequency components ECG and an algorithm using high-frequency components ECG for automatic detection of myocardial infarction. The proposed algorithms are implemented in programming environment MATLAB and tested on signals from the PTB database. The final part of the master‘s thesis is devoted to the comparison of the success of myocardial infarction by means of low frequency and high frequency components of ECG and comparison of achieved results with results from clinical studies.
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Analysis of measured parameters of the cardiovascular system
Lysoň, Jakub ; Vítek, Martin (referee) ; Kratochvíla, Jiří (advisor)
This bachelor thesis talks about the measurement of heart electrical activity by twelve lead ECG. The diagnostic system Biopac is used for measurement, featured by the computer program Acqknowledge. The own authentic method is designed to detect effect of load on increasing in blood pressure and heartbeat. Using a statistical procedure for testing hypotheses in this area the measurement results will be evaluated. For the analysis of measured data in time and frequency domain was used program Matlab, in which the measured results were imported. It was created functions that are implemented in an medium of Guide to the graphic design program.
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Efficient implementation of Stockwell Transform for real-time embedded processing of physiologic signals
Holmes, D. ; Pinto, S.C. ; Felton, Ch. ; Smítal, L. ; Leinveber, P. ; Jurák, Pavel ; Gilbert, B. ; Haider, C.
Physiologic monitoring enables scientists and physicians to study both normal and pathologic signals of the body. While wearable technologies are available today, many of these technologies are limited to data collection only. Embedded processors have minimal computational capabilities. We propose an efficient implementation of the Stockwell Transform which can enable real-time time-frequency analysis of biological signals in a microcontroller. The method is built upon the fact that the Stockwell Transform can be implemented as a compact filter bank with pre-computed filter taps. Additionally, due to the long tails of the gaussian windowing function, low amplitude filter taps can be removed. The method was implemented on a TI MSP430 processor. Simulated ECG data was fed into the processor to demonstrate performance and evaluate computational efficiency.
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Biventricular pacing optimization by means of the dyssynchrony parameter
Jurák, Pavel ; Leinveber, P. ; Halámek, Josef ; Plešinger, Filip ; Postránecká, T. ; Lipoldová, J. ; Novák, M.
To improve Cardiac Resynchronization Therapy (CRT), different interventricular delay (VVD) settings can be used. However, relatively small VVD induced hemodynamic changes cannot be measured by standard echocardiographic methods. The QRS complex duration (QRSd) is mostly the main criterion. Here we introduce a new dyssynchrony parameter (DYS) that is able to more accurately detect improved electrical synchrony. Methods: 12-lead 5 kHz ECG during 3-10 minute rest period was measured in 46 patients with CRT OFF and CRT ON with VVD 0 ms (CRT0) and -20 ms (CRT20). We detected QRSd and the dyssynchrony parameter DYS as the time difference between 500-1000 Hz averaged envelopes positions in the V1 and V6 leads in the QRS complex region. Results: 32 of 46 patients had a positive CRT response manifested by QRSd shortening and a DYS decrease. 28 of 32 patients had a positive LV pre-excitation effect: additional QRSd shortening of 4.7+/-.9 ms and a DYS decrease of 12.6+/-7.5 ms. The correlation coefficient of QRSd and DYS changes (CRT 0 vs CRT 20) was 0.23 and indicates information diversity. The DYS parameter differs from QRSd and provides a significantly higher response to VVdelay changes (p <; 0.001).
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