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QRS detection using zero crossing counting
Hylmar, Petr ; Janoušek, Oto (referee) ; Vítek, Martin (advisor)
This master's thesis describes basics principles of QRS complex detection. It is focused on QRS detection using zero crossing counts method. There are described princips and program realization of this method. The other part is focused on genetic optimalization algorithm. There are presented obtained optimalization results on standard CSE and MIT-BIH database. The quality of the detector is compared with other authors. The optimalized QRS detector achieves comparable results with other authors. The part of the thesis is graphical user interface which supply view on modified ECG signal and detection results.
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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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Delineation of experimental ECG records
Bucsuházy, Kateřina ; Ronzhina, Marina (referee) ; Vítek, Martin (advisor)
This master thesis deals with QRS complex detection and ECG delineation. The theoretical part of this work describes wavelet transform, some of QRS detection approaches and some of ECG delineation approaches. For algorithm realization in Matlab is used redundant dyadic discrete wavelet transform. Algorithm is designed for experimental electrocardiograms of isolated rabbit hearts and it is evaluated through manually determined references.
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Measurement and anaysis of electrocardiograms
Zimáková, Jana ; Vítek, Martin (referee) ; Kolářová, Jana (advisor)
The aim of my barchelor’s thesis was to become familiar with the methology of measurement of electrocardiographic signals, their description and subsequent analysis. During the measurement I used a computer system Biopac and program Matlab. The work is divided into three parts. The first part is focused on general problems of the heart activity, the generation, measurement and description of ECG curves. The second part is devoted to a description of the systém Biopac – recovery, procedure for the measurement and results measured sleep and stress ECG. The third part describes the actual processing of measured signals in Matlab.
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Averaging of biological signals
Němeček, Tomáš ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
The main objectives of this thesis are to study theory of signal averaging, filtered residue method and methods of stretching/shrinking signal. It will also test the functionality of those methods. Thesis contains theoretical analysis, explanation of principles and testing of behaving of used methods.
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Automatic improvements of images from 1D gel electrophoresis
Kovář, Martin ; Vítek, Martin (referee) ; Škutková, Helena (advisor)
In this bachelor’s thesis are explained the basic principles of electrophoresis and its modalities with focusing on 1D gel electrophoresis. It describes analysis of an electrophoreogram and causes of its possible distortion, and states specifications of applications of the method in microbiology, genomics and proteomics. The practical part presents development, optimization and outputs of a programme for automatic electrophoreogram analysis, which was created in Matlab environment. The analysis contains lane and band detection and computation of samples’ molecular weight. The ending of the thesis is constituted by evaluating efficiency of detection and accuracy of weight computation.
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Compression and Quality Assessment of ECG Signals
Němcová, Andrea ; Tkacz,, Professor Ewaryst (referee) ; Kudrna,, Petr (referee) ; Vítek, Martin (advisor)
Ztrátová komprese signálů EKG je užitečná a v současnosti stále se rozvíjející oblast. Stále se vyvíjí nové a nové kompresní algoritmy. V této oblasti ale chybí standardy pro hodnocení kvality signálu po kompresi. Existuje tedy sice mnoho různých kompresních algoritmů, které ale buď nelze objektivně porovnat vůbec, nebo jen zhruba. V oblasti komprese navíc nikde není popsáno, zda mají na výkon kompresních algoritmů vliv patologie, popřípadě jaký. Tato dizertační práce poskytuje přehled všech nalezených metod pro hodnocení kvality signálů EKG po kompresi. Navíc bylo vytvořeno 10 nových metod. V rámci práce byla provedena analýza všech těchto metod a na základě jejích výsledků bylo doporučeno 12 metod vhodných pro hodnocení kvality signálu EKG po kompresi. Také je zde představen nový kompresní algoritmus „Single-Cycle Fractal-Based (SCyF)“. Algoritmus SCyF je inspirován metodou založenou na fraktálech a využívá jednoho cyklu signálu EKG jako domény. Algoritmus SCyF byl testován na čtyřech různých databázích, přičemž kvalita signálů po kompresi byla vyhodnocena 12 doporučenými metodami. Výsledky byly porovnány s velmi populárním kompresním algoritmem založeným na vlnkové transformaci, který využívá metodu „Set Partitioning in Hierarchical Trees (SPIHT)“. Postup testování zároveň slouží jako příklad, jak by měl vypadat standard hodnocení výkonu kompresních algoritmů. Dále bylo statisticky prokázáno, že existuje rozdíl mezi kompresí fyziologických a patologických signálů. Patologické signály byly komprimovány s nižší efektivitou a kvalitou než signály fyziologické.
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Predictive models in survival analysis
Hadwigerová, Michaela ; Vítek, Martin (referee) ; Škutková, Helena (advisor)
With ever-new methods of treatment in health care occures a requierement of comparing these new methods to the old methods in some effective way. This is particularly important for the further development of these methods. However, data that describe these facts could not be processed by normal procedures and therefore was in the field of statistics to create a new kind of methods. They are known as predictive models of survival analysis.
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Detection of similarity in program codes
Maťašová, Kristýna ; Vítek, Martin (referee) ; Kašpar, Jakub (advisor)
The Bachelor introduces the concept of plagiarism and possible kinds of plagiarism. It focuses on the problem of detecting the similarity of source codes, especially with graphical interfaces in the MATLAB environment. It also describes already existing detectors. The practical part of thesis is focused on finding appropriate flags for detection of similarity in source codes and introduces the metric of detected flags. It also describes the internal logic of created detector of similarity and discusses the results of its testing.
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Gait detection and step counting using smartphone
Kočendová, Kateřina ; Vítek, Martin (referee) ; Němcová, Andrea (advisor)
The focus of this thesis is the detection of walking and running, followed by a step count. Testing is performed on signals of regular daily human activity that involve sections of running, walking or no activity. Those signals are logged using accelerometer in smartphone. The exact type of physical activity performed is distinguished by an average, variation coefficient and wave transformation methods. Basics statistic methods are used to quantify the number of steps taken during either walking or running. Algorithm for activity detection and algorithm for step counting are optimized and tested by a set of signals.
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