National Repository of Grey Literature 56 records found  beginprevious37 - 46next  jump to record: Search took 0.01 seconds. 
Analysis of measured parameters of the cardiovascular system
Lysoň, Jakub ; Vítek, Martin (referee) ; Kratochvíla, Jiří (advisor)
This bachelor thesis talks about the measurement of heart electrical activity by twelve lead ECG. The diagnostic system Biopac is used for measurement, featured by the computer program Acqknowledge. The own authentic method is designed to detect effect of load on increasing in blood pressure and heartbeat. Using a statistical procedure for testing hypotheses in this area the measurement results will be evaluated. For the analysis of measured data in time and frequency domain was used program Matlab, in which the measured results were imported. It was created functions that are implemented in an medium of Guide to the graphic design program.
Efficient implementation of Stockwell Transform for real-time embedded processing of physiologic signals
Holmes, D. ; Pinto, S.C. ; Felton, Ch. ; Smítal, L. ; Leinveber, P. ; Jurák, Pavel ; Gilbert, B. ; Haider, C.
Physiologic monitoring enables scientists and physicians to study both normal and pathologic signals of the body. While wearable technologies are available today, many of these technologies are limited to data collection only. Embedded processors have minimal computational capabilities. We propose an efficient implementation of the Stockwell Transform which can enable real-time time-frequency analysis of biological signals in a microcontroller. The method is built upon the fact that the Stockwell Transform can be implemented as a compact filter bank with pre-computed filter taps. Additionally, due to the long tails of the gaussian windowing function, low amplitude filter taps can be removed. The method was implemented on a TI MSP430 processor. Simulated ECG data was fed into the processor to demonstrate performance and evaluate computational efficiency.
Biventricular pacing optimization by means of the dyssynchrony parameter
Jurák, Pavel ; Leinveber, P. ; Halámek, Josef ; Plešinger, Filip ; Postránecká, T. ; Lipoldová, J. ; Novák, M.
To improve Cardiac Resynchronization Therapy (CRT), different interventricular delay (VVD) settings can be used. However, relatively small VVD induced hemodynamic changes cannot be measured by standard echocardiographic methods. The QRS complex duration (QRSd) is mostly the main criterion. Here we introduce a new dyssynchrony parameter (DYS) that is able to more accurately detect improved electrical synchrony. Methods: 12-lead 5 kHz ECG during 3-10 minute rest period was measured in 46 patients with CRT OFF and CRT ON with VVD 0 ms (CRT0) and -20 ms (CRT20). We detected QRSd and the dyssynchrony parameter DYS as the time difference between 500-1000 Hz averaged envelopes positions in the V1 and V6 leads in the QRS complex region. Results: 32 of 46 patients had a positive CRT response manifested by QRSd shortening and a DYS decrease. 28 of 32 patients had a positive LV pre-excitation effect: additional QRSd shortening of 4.7+/-.9 ms and a DYS decrease of 12.6+/-7.5 ms. The correlation coefficient of QRSd and DYS changes (CRT 0 vs CRT 20) was 0.23 and indicates information diversity. The DYS parameter differs from QRSd and provides a significantly higher response to VVdelay changes (p <; 0.001).
Alternative ECG measurement using flexible electrodes for scanning of electrical potentials on the human body
Hylský, Václav ; Šteffl, Michal (advisor) ; Malý, Petr (referee)
The objective of this bachelor thesis is to measure ECG signal using experimental textile electrodes. The theoretical part deals with heart anatomy, the placement of the heart within the rib cage, heart's electrical activity and ways of measuring it using electrocardiography as well as alternative ECG systems. The practical part of this thesis deals with the use of an experimental ECG T-shirt and wearable electronic equipment. This part also includes the description of the examination method as well as of the equipment which processes and records the signal. The next part this thesis deals with laboratory testing of the experimental ECG T-shirt on a selected sample of people. It also includes an assessment of the measurement results. Keywords: Conductive fabric, electrocardiography, electrocardiogram, electrodes
The acquisition system for electrogram recording
Fajmon, František ; Ronzhina, Marina (referee) ; Janoušek, Oto (advisor)
This thesis deals with acquisition and wireless transmission of EKG from isolated heart. Basic of heart anatomy and physiology are discussed in thesis. Practical part of thesis covers the idea of ECG acqusition system design and development. Arduino platform is used for implementation of proposed device. Evaluation of ECG is performed in Matlab workspace.
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
Relationship between breath and electrocardiogram
Hamerský, Jan ; Janoušek, Oto (referee) ; Kolářová, Jana (advisor)
The main goal of this thesis is to familiarize readers with the problem of influence on the cardiac cycle. Thesis analyzes necessary concepts to understand electrophysiology of heart, mechanisms affecting heart beats, respiratory identifides methods for detection of respiratory frequency presents in electrocardiogram, proposes own measurement protocol of the influence of respiratory rate on electrcardiogram, implements detection of respiratory rate of the measured records, compares the measured results
Suppression of power-line interference in ECG signals
Gregorová, Kateřina ; Vítek, Martin (referee) ; Kozumplík, Jiří (advisor)
This work includes an overview of the different methods of filtering of ECG signals that suppress the network interference. It focuses on the parameters that affect the quality of filtration for the three main groups of filters: FIR, IIR and adaptive filters. The main objective is to evaluate proposed methods in terms of the quality of filtration. This quality is rated an average output SNR, standard deviation and time filtering. The criteria of success is based on the filtration of the basic requirements on digital filters. Design of filter is realized in the Matlab programming environment.
Evaluation of electrical axis of the heart
Temelová, Kristýna ; Vítek, Martin (referee) ; Janoušek, Oto (advisor)
This bachelor's thesis describes the issue of electrocardiography focusing on the methodology of automatic evaluation of heart's electrical axis. Part of this work is a description of an application created in Matlab which enables to plot the tilt of the cardiac axis. The cardiac axis is evaluated in terms of its dependence on the examined person's position. This bachelor's thesis includes a database of ECG signals of twelve volunteers measured in various positions (supine, sitting, tilted), obtained using the Biopac system, accompanied by video documentation. The created application serves both the data analysis from the database and other experimental signals. A guide for students performing practical exercises is included.

National Repository of Grey Literature : 56 records found   beginprevious37 - 46next  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.