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QRS complex detector in ECG signals
Kosíř, Kamil ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
The aim of this thesis is to introduce issues and basic principles of QRS complex detection in ECG signals. This work is separated into several parts. The first part deals with anatomy and functions of the heart, for example the emergence and spread of potentials. The next part includes distribution ECG leads and explanation of ECG signal. Afterwards are described some detectors of QRS complex. The main part of this work is realization of two algorithms implemented in Matlab program. The first detector is based on squaring algorithm and the the second is based on a spreading of the signal into several frequency bands. The effectivness of both detectors is tested on signals from CSE library at the end of the work.
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Methods for respiration estimates from ECG signal
Mitrengová, Jana ; Mézl, Martin (referee) ; Králík, Martin (advisor)
The thesis deals with the realization of methods for estimation of the respiratory curve from the ECG signal. The first part of the thesis deals with the anatomy and physiology of the respiratory and cardiovascular system. In this part of the thesis are also described ways of the breathing monitoring. The second part of the thesis is dedicated to the description of individual methods for the ECG derived respiration. The third part deals with the realization of selected methods, application of method algorithms on real data and comparison of resulting respiratory curves with the respiratory signals available from the PhysioNet database. In conclusion, the individual methods are compared with each other.
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Preprocessing of R-R interval tachogram
Had, Filip ; Kozumplík, Jiří (referee) ; Kubičková, Alena (advisor)
Heart rate variability (HRV) is a parameter, which monitors variability of the time intervals between consecutive heart beats. Signal HRV contains artefacts and trends, which is necessary to remove before further processing. This work contains a brief information about the HRV and ECG signal processing. Further on the most frequently methods of heart rate variability preprocessing are described. The work includes a brief assessment of each method. Further on, several of the mentioned preprocessing algorithms are realized and described in this work. The last part is testing an evaluating of programmed algorithms on generated data and then demonstration on real data.
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ECG Wave Delineation
Trnová, Kateřina ; Provazník, Ivo (referee) ; Kozumplík, Jiří (advisor)
This thesis deals with the detailed measurement of one cycle of the ECG signal. data samples of the beginning and end of major sections of this cycle are obtained from the values referred to in the database TESTRO. There is found a representative cycle. The text describes basic types of measuremend intervals, principles of multiple methods of measurement and description of the implemented program. Algorithm for measurement of functional units of ECG cycle signal, which was designed, is based on the detection of trend growth, of the field of signal using the first difference. Functionality was tested on a standard CSE database.
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Linear and Adaptive Filters for ECG Signals
Kubát, Milan ; Lamoš, Martin (referee) ; Kozumplík, Jiří (advisor)
In this work, I deal with ECG signal interference suppression using linear and adaptive filters. This falls in field of signal preprocessing. The aim is to properly filter the signal, while maintaining its diagnostic value. I designed filters based on spectral lines resetting, Lynn’s filters and two types of adaptive filters. In the next part, results of different filtering ways are compared.
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Averaging of biological signals
Kubík, Adam ; Čmiel, Vratislav (referee) ; Smital, Lukáš (advisor)
The main aim of this thesis is to introduce issue of averaging of biological signals. The first part of the thesis deals with the principles of individual averaging methods (constant, floating and exponential window) and describes their basic features. Moreover, the principle of filtered residue, detection of QRS complex, and stretching/shrinking the length of RR-interval to the standardized length are explicated. In the second part of the thesis the outcomes of practically realized (Matlab and GUI) methods of averaging (by final signal-to-noise ratio) are evaluated. Signals from MIT-BIH database are used.
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Segmentation of Hidden P Waves Using Deep Learning Methods
Boudová, Markéta ; Ronzhina, Marina (referee) ; Hejč, Jakub (advisor)
The aim of this thesis is segmentation of P waves in ECG signals. The theoretical part of the thesis describes the physiology of the heart and the basics of deep learning methods. Preprocessing of the signals is performed and neural network U-Net is implemented in the Python software environment in the practical part. Afterwards, optimization of network architecture is performed in order to reduce model complexity. Lastly the success rate of the model is evaluated.
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Maximization of ECG signals diagnostic yield
Beháňová, Andrea ; Smital, Lukáš (referee) ; Vítek, Martin (advisor)
This bachelor thesis deals with the maximization of ECG signals diagnostic yield. In the theoretical section we deal with the physiology of the heart, electrocardiography, types of ECG noises. It describes some known methods for the estimation of quality of the ECG signal. The practical section contains two parts. The first one contains a continuous Signal-to-Noise Ratio (SNR). It includes generating artificial ECG signal, artificial myopotentials and implementation of Adaptive Wiener Wiener Filtrate (AWWF). After verification of the correctness of the filter on the artificial data, we started to use real data from MIT-BIH database. The second part involves a segmentation process that divides the ECG signal into three categories: a signal suitable for full analysis, suitable for detection of QRS complexes and a signal unsuitable for further analysis.
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ECG Signal Distortion Measures
Požár, Pavel ; Kozumplík, Jiří (referee) ; Vítek, Martin (advisor)
This master's thesis deals with electrocardiogram and its distortion, which causes errors, due to which a doctor can make a wrong diagnosis. In the theoretical part electrocardiogram is briefly described, further theory of wavelet transform, introduction to the signal compression and some information about ECG delineation. Methods used for the signal evaluation and therefore determination of the distortion size are described in the main theoretical part. This thesis contains known methods and also a method of own design based on the ECG delineation. Some of the described methods are checked in the practical part. These methods are tested for two different compression algorithms, which cause various distortion. In the final part distortion was tested on the influence on setting the wrong diagnosis.
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Ion balance and its effect on heart function, measurement and analysis of ECG
Štrbková, Lenka ; Nováková, Zuzana (referee) ; Wilhelm,, Zdeněk (advisor)
Mechanical heart function is based on electrical changes at the level of cardiac cells. These electrical changes are primarily affected by the distribution of ions, intra-and extracellularly. Kidneys are very important for the physiological regulation of ion homeostasis in the body. The ion homeostasis is disrupted in case of the kidney function failure. The aim of this thesis is to compare ion values, acid-base balance before and after dialysis, and also possible changes in ECG time intervals before and after dialysis of these patients. The thesis also deals with the description of the electrocardiographic signals and the implementation of the program for ECG signal analysis. I used the ECG signals from the available database „PhysioBank“ for testing the developed program.
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