National Repository of Grey Literature 22 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Reccurence plot for heart rate variability analysis
Franěk, Pavel ; Čmiel, Vratislav (referee) ; Janoušek, Oto (advisor)
The aim of this thesis is to describe the variability of cardiac rhythm and familiarity with the methods of the analysis, ie by monitoring changes in heart rhythm electrogram signal recording and using the methods in the time domain using recurrent diagram. The work describes the quantification of the methods and possibilities of quantifiers in the evaluation of heart rate variability analysis. It also describes the clinical significance of heart rate variability and diagnostic capabilities changes of heart rate variability caused by ischemic heart disease. The practical part describes how to create applications in Matlab to calculate the quantifiers analysis of heart rate variability in the time domain using recurrent diagram. The calculation was made of the positions R wave elektrogram signal isolated rabbit hearts. The calculated values of quantifiers both methods were statistically evaluated and discussed.
Clustering of ECG cycles
Němečková, Karolína ; Kozumplík, Jiří (referee) ; Ronzhina, Marina (advisor)
This bachelor thesis deals with application of cluster analysis to different ECG records in order to identify particular cardiac pathologies. The work is mainly focused on the detection of premature atrial and premature ventricular beats. Presented approach is based on the signal correlation and further beat type identification and beats clustering via specific ECG features. By evaluation the method on test data, we obtained TPR 73.40 %, FPR 91.00 %, PPV 29.00 %, ACC 90.00 %, F1 41.40 % for PAC detection and TPR 76.50 %, FPR 94.20 %, PPV 45.90 %, ACC 93.10 %, F1 57.40 % for PVC detection. Pure F1 and PPV is due to high number of false positive detections mainly in noisy ECG or ECG with manifested atrial fibrillation.
ECG quality evaluation
Scholasterová, Viktorie ; Němcová, Andrea (referee) ; Smital, Lukáš (advisor)
This bachelor’s thesis deals with ECG quality evaluation. Its main goal is to examine the theoretical basis for a realization of selected methods for ECG quality evaluation. In the theoretical part of the thesis there is described electrocardiography, morphology of electrocardiogram, types of signal interference and Holter recorders. A basic procedure of ECG quality evaluation including filtration, detection of important characteristics of ECG signal and an overview of chosen methods follows. The practical part contains a description of three methods for ECG quality evaluation – a method of average heart rate, a method of calculation signal-to-noise ratio (SNR) and a method of band-pass filters. Finally, the results of the methods using artificial data, real-time data and data from a competition PhysioNet/Computing in Cardiology Challenge 2011 are evaluated.
Biological data averaging
Mlčoch, Marek ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
The thesis deals with the biological data averaging applied to a periodical and repetitive signal, specifically to an ECG signals. There were used signals from MIT-BIH Arrhythmia database and ÚBMI database. Averaging was realized with constant, floating and exponential Windows, where was used the method of addition of the filtered residue. This method is intended to capture the slow variations from the input to the output signal. The outcomes of these methods can be used as a basis for further work, or function as an example of principled methods. Methods and its outcomes were created in Matlab.
Accuracy of methods for detection of atrial fibrillation in ECG signals
Veleba, Josef ; Janoušek, Oto (referee) ; Provazník, Ivo (advisor)
This thesis focuses on the issue of atrial fibrillation and the success of their detection in the ECG signal. It provides a description of electrical activity of the heart with the theoretical analysis of atrial fibrillation and methods for their detection. Additionally the work describes procedures for the implementation of three selected methods for the detection of atrial fibrillation in the MATLAB environment, presents the results of their tests on two atrial fibrillation signal databases and assesses the accuracy of each method.
HRV analysis in the context of daily activities
Indrák, Václav ; Smital, Lukáš (referee) ; Novotná, Petra (advisor)
The aim of this bachelors thesis is to measure ECG recordings on voulenteers, and following analysis of HRV from these recordings. It persues the explanation of basic metrics used to evaluate HRV, used both in clinical and scientific practice and their following programming implementation in Matlab environment to achieve the most accurate results possible, which are than assessed.
ECG Biofeedback
Macková, Pavlína ; Kolářová, Jana (referee) ; Sekora, Jiří (advisor)
The master’s thesis is focused on the possibilities of measuring heart rate of ECG signal and its use in therapeutic game of ECG biofeedback. This thesis describes the way of measuring ECG with acquisition unit Biopac and analyzes signal processing for measurement of heart rate – algorithms of QRS detection, HRV analysis. Realisation of therapeutic is designed for applications in Matlab.
Cluster Analysis of ECG Signals
Dvořáček, Tomáš ; Chrobák, Martin (referee) ; Kozumplík, Jiří (advisor)
This bachelor thesis is engaged in problematics of automatic cluster analysis for ECG sinals. This bachelor thesis contains theory of pathology in cardiac rhythm and problematics of cluster analysis. Based on a gained knowledge, set of symptoms is made, which are used for cluster analysis using MATLAB interface and which results are evaluated.
Short time Fourier transform for heart rate variability analysis
Osičková, Kristýna ; Slávik, Vladimír (referee) ; Janoušek, Oto (advisor)
The thesis describes the heart rate variability (HRV), its physiological and clinical significance and the means of its analysis. It includes a thorough dissection of the methods applied in the process of HRV evaluation in a time domain and using the short-time Fourier transform. The thesis compare both of the methodologies regarding changes of HRV caused by global ischaemia. The practical part descibes the application created in Matlab for analysis in the time domain and using short-time Fourier transform. The resulsts were calculated from the positions R wave EG signal isolated rabbit hearts.
Detection of atrial fibrilation in long-term ECG
Polcer, Simon ; Kozumplík, Jiří (referee) ; Maršánová, Lucie (advisor)
The bachelor’s thesis deals with the automatic detection of atrial fibrillations in the long-term ECG signals. First, it provides a description of the electrophysiology of the heart, the atrial fibrillation and the automatic methods of their detection. The first method, implemented in this work, is based upon the parameters that were calculated from the irregularities of the RR intervals. The second method uses the stationary wavelet transform and other parameters are computed after the signal transformation. The calculated parameters are subsequently statistically evaluated in the STATISTICA software. Parameters are assessed by the non-parametric Mann-Whitney test, which selects parameters that exhibit statistically significant differences between signals containing atrial fibrillation and sinus rhythm. At the end, the classification is performed by two approaches such as Support vector machine and k-Nearest Neighbours.

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