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Time Varying Filters for ECG Signals
Peterek, Jan ; Vítek, Martin (referee) ; Kozumplík, Jiří (advisor)
The aim of this master’s thesis is to create a multiband stop derived from Lynn filters for suppressing mains hum and baseline variation (drift). The first part of the thesis is focused on brief theoretical introduction to the distortion types affecting ECG signal and twelve lead connection. The following practical part describes free realizations of ECG filter and ECG signal filtration. The filter has been tested both on distorted and on non-distorted signal. Finally filters’ error rate was computed from CSE database signals.
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Evaluation of cardiac output by bioimpedance method with patients with pacemaker
Soukup, Ladislav ; Cimbálník, Jan (referee) ; Vondra, Vlastimil (advisor)
This thesis deals with the possibility of using impedance cardiography for calculating cardiac output. Kubicek’s, Sramek‘s and Sramek-Bernstein‘s methods are discussed here. These methods were applied to a data set, obtained by measuring on subjects with implanted cardiostimulators. The subjects’ heart rate was being changed by the programing of cardiostimulators. Thanks to this procedure the measured data were not affected by artifacts, connected with the heart rate change caused by a body stress, or other influences. An influence of heart rate on a cardiac output value based on the statistical processing of the data set was studied.
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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.
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Load effect on baroreflex sensitivity
Kamenec, Jan ; Čmiel, Vratislav (referee) ; Kolářová, Jana (advisor)
KAMENEC, J. Load effect on baroreflex sensitivity. Brno: Brno University of technology, Faculty of electrical engineering and communication, 2008. 52 p. Supervisor of bachelor’s thesis Ing. Jana Bardoňová, Ph.D. The aim of this baccalaureate thesis was study problems of the metering baroreflex and verify, whether the physical stress affects baroreflex sensitivity. The metering proceeded on the computer system Biopac, in which was projected the record of the metering. For the calculation was elected noninvasion spectral method. Measuring data by the computer system Biopac were processed by the help of the Matlab program that worked out found dependencies.
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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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Wavelet Filtering of ECG Signals
Mrázek, Jiří ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
This thesis deals myopotential denoising of ECG signals with using wavelet transform. There was used wavelet denoising subsequently wiener wavelet filtering. In both cases were found the most suitable coeficients for the best denoising. It is meant mainly settings suitable parameters for ideal filtration setting value of threshold, number of decomposition level, selection of thresholding and type of filter. These parameters are tested on real signals. Denoising is realized in Matlab version R2009b.
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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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Wavelet filtering of ECG Signals
Ryšánek, Jan ; Smital, Lukáš (referee) ; Kozumplík, Jiří (advisor)
This work deals with the possibilities of filtering the ECG signal, representing the first part, which is the basis for successful delineation and follow diagnosis of the ECG signal. Filtration in this case is mean to suppress interference from electrical grid, noise of electrical grid. The content of the work is description of filters realized trough wavelet transform and linear filtering as a means to successful filtration of interference. There are method of stationary wavelet transform - dyadic wavelet transform, wavelet packet transform and wavelet wiener filtering method. Linear filtering includes two narrow-band FIR filters. The objective of this work is to propose different methods of wavelet and linear filters in Matlab, filtering of ECG signals and compare the success of filtration methods. ECG signals used in this work are from the CSE database.
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Optimal detection of QRS boundaries in ECG signals
Spáčil, Jakub ; Hrubeš, Jan (referee) ; Vítek, Martin (advisor)
This diploma thesis deals with location optimal wavelet for detecton charakterics points of QRS complex in ECG signals. The first part of this thesis deals with description of heart, genesis of electric signals on heart and problem of noise. The second part describes the wavelet transform and the designed program and the third part evaluate detection results. The created program is working with 10 ECG signals from the CSE database and is testing 12 different mother wavelets. The program was developed in Matlab environment and is based on the finding zero-points in the transformed signal.
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QRS detection in ECG signals
Kuna, Zdeněk ; Vítek, Martin (referee) ; Kozumplík, Jiří (advisor)
This project considers methods of construction QRS detectors. It focus in detection complexes of QRS single leads and space speed, which are calculated from three orthogonal leads. In theory was refer to various methods, which lead to design detector. It were designed two algoritms (constant and adaptive detecting threshold), which were implemented into detector and the signal was preprocessed by Hilbert transformation. Toward algoritms were completed by modification, which improved detection effectivity. Function of algoritms were tested in all signals of CSE (V2,V5,aVF).
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