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Digital filtering of ECG signals
Ráček, Tomáš ; Kolář, Radim (referee) ; Kozumplík, Jiří (advisor)
In the thesis there are presented frequency features of disturbing signals as baseline fluctuation, power network interference and myopotentialstion. Methods for removing these signále are discussed too. It iis used a principle of the Lynn’s linear filters, mostly the Lynn’s high pass and Lynn’s band pass filters. For real-time ECG signal filtration there is optimal to use the filter with continuously changing cut-off frequency according to a measured heart rate. Then there is described a simple dynamic linear Lynn's filter with a varying impulse response according to the heart rate.
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Automatic delineation of ECG signals
Tiurina, Mariia ; Kozumplík, Jiří (referee) ; Vítek, Martin (advisor)
This semester’s thesis deals about delineation ECG signals. Semester work consists of two parts. The theoretical part provides a brief introduction to the principles of electrocardiography, sensing methods electrocardiography recording and description of some well-known methods for seasons auto electrocardiographic signals. The practical part is a program that is implemented in programming environment Matlab and the results of its testing twelve lead signals from the CSE database. Using statistical methods, the results are compared with the results of the listed authors methods
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ST-T segments analysis of ECG signals with focusing on T-wave alternance
Tannenberg, Milan ; Sovka, Pavel (referee) ; Tyšler,, Milan (referee) ; Kozumplík, Jiří (advisor)
The Cardiovascular diseases may evocated the high percentual risk of sudden cardiac death in whole world. In several western countries is the number of death higher then number of cancer death. In this time is used a lot of methods for prediction of sudden cardiac death with focus on ECG T-wave alternance. The aim of the theses was to do stronger relation and cooperation with Internal Cardiac Clinic of Faculty Hospital Brno Bohunice on the risk analysis of sudden cardiac death. Secondly, we met the methods used for detection and quantification of simulated TWA. Last but not least was necessary to find TWA detection methods improvement and process the data on real signals obtained from Faculty Hospital Brno Bohunice. First part of the Thesis is focused on summary of pathologic artifacts in ECG signal, which are important for sudden cardiac risk stratification. There are described further known detection and quantification methods for TWA analysis. An interesting part for clinical practice is analysis of TWA trend in time and looking for the best method, which is able to catch and track the short TWA trend changes. Second part describes the new methods improvements, which were tested with interesting outputs. Further, there was developed method for TWA presence statement probability evaluation.
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ECG noise influence on compression using SPIHT algorithm
Bartošovský, Petr ; Vítek, Martin (referee) ; Hrubeš, Jan (advisor)
The thesis provides an analysis of the ECG signal, focusing on the possible types of interference occuring in the signal. These types of interference are closely examined and their realization in the MATLAB programming environment is characterized. The SPIHT algorithm is introduced and the possibilities of its use are discussed. Futher, the application of this algorithm to the ECG signal containing individual types of interference generated by means of the designed interference generator is described and the impact of the SPIHT algorithm on the specific types of signal interference is analyzed. Finally, the obtained results are evaluated.
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Preprocessing of ECG signals for detection of significant points
Strouhal, Martin ; Smital, Lukáš (referee) ; Vítek, Martin (advisor)
This work aims to find out the best filter design method for getting out parasitic elements in ECG signal. There are defined origin and frequency qualities of these elements. Individua filter design methods are compared according to number of filter coefficients, effectivity and influenc to useful signal. I created several digital filters by various design methods and tested them on ten ECG signals. From the experiment ensued: all filters were able to get out brum, but filters designed by distribution of zeros and poles had the lowest number of coefficients. On the other hand same filters were disable to get out drift with very sheer course.
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Microcontroler based ECG Generator
Ruttkay, Michal ; Bubník, Karel (referee) ; Sekora, Jiří (advisor)
This thesis describes the design and realization of the EKG generator which uses a microcontroller in order to generate the EKG signal. The EKG generator is equipped with one input and two outputs for recording the signal on the oscilloscope. The LCD display shows the heart rate that can be changed by means of buttons. In addition to the design and realization of the EKG generator, the thesis describes cardiac activity for the proper conduct of EKG signal as well as the flowchart of the program for the microcontroller.
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controlled pacemaker
Csekes, Attila ; Hrozek, Jan (referee) ; Čech, Petr (advisor)
The Thesis deals with the area of cardio stimulation. It describes the different stimulation modes and their specifics. It describes the creation of a virtual cardio stimulator based on R-waves, designed in the LabVIEW application. Part of the thesis is the software realization of the model and the verification of its functionality.
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Wavelet Filtering of ECG Signal
Slezák, Pavel ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
The thesis deals with possibilities of using wavelet transform in applications dealing with noise reduction, primarily in the field of ECG signals denoising. We assess the impact of the various filtration parameters setting as the thresholding wavelet coefficients method, thresholds level setting and the selection of decomposition and reconstruction filter banks.. Our results are compared with the results of linear filtering. The results of wavelet Wieners filtration with pilot estimation are described below. Mainly, we tested a combination of decomposition and reconstruction filter banks. All the filtration methods described here are tested on real ECG records with additive myopotential noise character and are implemented in the Matlab environment.
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Digital filtering of ECG signals
Ráček, Tomáš ; Kolář, Radim (referee) ; Kozumplík, Jiří (advisor)
The aim of the thesis is to out¬line the present state of digital pre¬processing (especially filtering) of ele¬ctrocardiograms. The frequency featu¬res of disturbing signals (baseline wandering, power network interferan¬ce, myopotentials) are mentioned and methods for removing of them are discussed. Based on this description, requirements for amplitude characterization of phase non-distorting filter for sup¬pressing the drift of isoelectric line of ECG signal are tentatively established. Several digital filters were created so that their application in testing would enable to give even more precision to requirements for amplitude characteristics. The expriments made it clear that ECG sig¬nal may be filtered through high pass filter with linear phase characteristic and cutt-off frequency 0.7 Hz and mi¬ximum attentuation in the filter transmission band 0.5 dB irrespective of rhythm regularity without significant distortion to occur. Also is describe an experiment by means of which they assessed the width of the frequency band of the ideal, not distorting band-stop filter for the suppression of the network hum in the ECG signal. It was found that the width of the band can be as much as +-3 Hz in the area surrounding the network frequency without cau¬sing excessive distortion of the useful signal. Also are discuss the properties, design and inlplementation of band-stop filters, based on the principle of Lynn's filters. It is optimal to use the filter with its cut-off fre¬quency continually changing according to measured heart rate for pre-processing ECG signal to decrease baseline drift by high-pass filter in real time. Easy rea¬lizable non-recursive Lynn's filter with time-varying impulse response adapted to the current frequently of ECG signal is described.
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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.
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