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Comparison of heart activity sensing devices
Babicová, Martina ; Smital, Lukáš (referee) ; Smíšek, Radovan (advisor)
The goal of this work is comparison of heart activity sensing devices. However, an ECG record cannot be evaluated with the presence of muscle interference. Removing this noise is one of the needs for device success. The theoretical part represents electrophysiology of the heart, electrocardiography, various interferences types, theoretical basis for recording of biosignals including used devices and methods signal quality estimation. The practical part is SNR (signal-to-noise ratio) calculation. The Wavelet filter and Wiener filter-based wavelet domain are used to separate the useful and noise component.
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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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An Arrhytmia Classifiication Based on RR Interval
Novotný, Jiří ; Škutková, Helena (referee) ; Kozumplík, Jiří (advisor)
This bachelor’s thesis deals with automatic classification of cardiac rhytm based on the sequence of RR intervals. The theoretical part deals both with characteristics of arrhytmias, which have been classified and the principles of the detectors and classificators used in this thesis. In the practical part, the QRS detector based on the calculation of the envelope of the ECG signal was realized in Matlab. Furthermore, the algoritm classifying arrhytmias based on the analysis of RR intervals was created. The reliability of the detector and the efficiency of the classificator was tested on the standard database CSE. The sensitivity of the detector was 98,28% and its positive predictive value was 98,38%. The diagnoses of the implemented classificator concurred in 73,17% with the cardiologists‘ diagnoses.
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ECG analysis
Heczko, Marian ; Smital, Lukáš (referee) ; Vítek, Martin (advisor)
The topic of this master's thesis is the analysis of ECG signals using wavelet transform. In the introductory chapters there is a brief description of heart anatomy, the emergence and spread of potentials, which evocating activities of myocardium. There is an overview of techniques used for ECG signals analysis and explanation of ECG curve diagnostic importance. Work also containts an ECG signal analysis common procedure explanation and different approaches brief overview. The main part of this work is an application detecting significant intervals in the ECG signal, developed in Matlab. In several chapters the detection procedure is described in more details and gave reasons for chosen methods. In the last chapter there is a preview of several signals as a result of developed application, together with evaluation of the tests carried out at the CSE database. Detector sensitivity was quantified over 99,10%.
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A Wavelet-Based QRS-Complex Detection
Kocian, Ondřej ; Provazník, Ivo (referee) ; Kozumplík, Jiří (advisor)
This project investigates methods of construction the wavelet-based QRS-complex detector. QRS-complex detection is very important, because it helps automatically calculate heart rate and in some cases it is used for compression ECG signal. The design of QRS detector can be made with many methods, in this project were mentioned and consequently tested only a few variants. The principle of designed detector used a wavelet-based decomposition of the original ECG signal to several frequency-coded bands. These bands are consequently transformed to absolute values and with the help of the threshold value are marked positions of assumed QRS complexes. Then are these assumed positions from all bands compared between themselves. If the position is confirmed at least at one nearby band, then is this position marked as true QRS complex. To increase efficiency of designed detector, two modifications were additionally mentioned. The first one, using the envelope of the signal, had rather negative effect on detectors efficiency. The second modification, using combined signal from three pseudoorthogonal leads, had reversely very good effect on detectors efficiency. In the end, the designed detector and all its modifications were tested on signals from CSE library (exactly on leads II, V2 and V6).
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Detection of QRS complex using leads transformation
Nerušil, Václav ; Smital, Lukáš (referee) ; Vítek, Martin (advisor)
The aim of this bachelor’s thesis is to become familiar with methods of detection of the QRS complex and the one chosen detection method realize by the Matlab. The detection of QRS is tested on a database CSE and the results are compared with other methods. The second part of this thesis is devoted to the theory of transformation methods leads and their use to increase the success of QRS detection.
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ECG data recorder
Hruškovský, Antonín ; Krajsa, Ondřej (referee) ; Burda, Karel (advisor)
The master thesis deals with the issue of long-term ECG recording, used in medicine for monitoring of cardiac anomalies. Author focuses on explaning the general concepts in the first part. Author describes measuring methods and issues associated with measuring. Comparison of existing devices and design of solution with own features are in next chapter. Next is comparison and selecting of formats for recording measured data and description of device connectivity. In next chapter author focuses on hardware design and implementation of device. After that author describes software solution design for microcontroller, Bluetooth module and smartphone. Author introduces possible improvements for future generation of the device and then describes results of testing at the end of this work.
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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.
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Automatic delineation of ECG signals
Olšanská, Eva ; Kozumplík, Jiří (referee) ; Vítek, Martin (advisor)
This bachelor´s thesis deals with the delineation of ECG signals. The aim of this bachelor´s thesis is to become familiar with ECG delineation and realize one chosen delineation method in Matlab. The delineation algorithm was tested on a CSE database. The theoretical part of the work describes methods of QRS complex detection and ECG delineation.
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