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Microcontroler based On Demand Pacemaker
Daniš, Václav ; Balogh, Jaroslav (referee) ; Sekora, Jiří (advisor)
Pacemakers have nowadays become an inseparable part of treatment in a wide range of cardiovascular diseases. The topic of this bachelors degree paper refers to and proposes the implementation of a functional type of ´On Demand´ pacemaker controlled by a microcontroller. The introductory chapters focus on a more detailed, theoretical familiarization with the complex issues of permanent heart cardiostimulation. In addition to the actual theory of pacemakers and cardiostimulation, the chapters also include those significant historical aspects in the evolution of permanent cardiostimulation, the basic structures of heart anatomy and the transmission system of the heart. Also included are the recording of heart activity and ECG analysis, both physiological and pathological. In the practical part of the paper I deal with the ´On Demand´ pacemaker controlled by a microcontroller with a firm (solid, strong, steady, fixed) repeating frequency inhibited by the R wave. Subsequently, a proposed system for its implementation is created. The next step is the creation of a scheme for the electrical connections and composition of the microcontroller programme. The final part illustrates the implementation of the model of the pacemaker itself, preceded by a verification of the efficacy of the connections in a non-solder field.
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ECG signal classification
Smělý, Tomáš ; Harabiš, Vratislav (referee) ; Hrubeš, Jan (advisor)
This thesis deals with classification of different types of time courses of ECG signals. Main objective was to recognize the normal cycles and several forms of arrhythmia and to classify the exact types of them. Classification has been done with usage of algorithms of Neural Networks in Matlab program, with its add-on (Neural Network Toolbox). The result of this thesis is application, which makes possible to load an ECG signal, pre-process it and classify its each cycle into five classes. Percentage results of this classification are in the conclusion of this thesis.
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Deep learning based QRS delineator
Malina, Ondřej ; Hejč, Jakub (referee) ; Smíšek, Radovan (advisor)
This thesis deals with the issue of automatic measurement of the duration of QRS complexes in ECG signals. Special emphasis is then placed on the possibility of automatic detection of QRS complexes while exciting cardiac tissue with a pacemaker. The content of this work is divided into four logical units, where the first part deals with the heart as an organ. It describes the origin and spread of excitement in the heart, its possible pathologies and their manifestations in ECG recording, it also deals with pacing and measuring ECG recording during simultaneous pacing. The second part of the thesis contains a brief introduction to the topic of machine and deep learning. The third part of the thesis contains a search of current approaches using methods based on deep learning to solve the detection of QRSd. The fourth part deals with the design and implementation of its own model of deep learning, able to detect the beginnings and ends of QRS complexes from ECG recordings. It describes the data preprocessing implemented in the MATLAB programming environment. The actual implementation of the model was performed in the Python using the PyTorch and NumPy moduls.
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The dynamics of changes of leads' technical parameters during stimulation
Kulík, Tomáš ; Chmelař, Milan (referee) ; Rozman, Jiří (advisor)
The main theme of the thesis is the dynamics of changes of leads’ technical parameters during stimulation. The thesis is dealt with statistical analysis of clinical dates and investigation of time variability of chosen stimulation parameters during the time of implantation to 3 years after surgical intervention. The document consists of theoretical parts about cardiac pacing and one’s own project of statistical solution according to submission.
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Software Tools for the Analysis of Cardiac Depolarization in Patients with Heart Failure
Smíšek, Radovan ; Richter, Aleš (referee) ; Nováková, Marie (referee) ; Kolářová, Jana (advisor)
Heart failure is a disease in which the heart cannot adequately supply the body with oxygenated blood. Approximately 2% of people in the developed world have heart failure, which is increasing. Cardiac resynchronization therapy, which involves the implantation of a biventricular pacemaker, is used in patients with ventricular dyssynchrony to suppress or at least reduce the symptoms of heart failure. The problem is that 30–50% of patients do not benefit from performed resynchronization therapy. The correct patient selection and the pacemaker implantation and set-up method influence the success rate. The thesis proposes methodologies and software to facilitate the selection of patients suitable for cardiac resynchronization therapy, select the correct pacing lead placement, and optimize pacemaker settings. The developed software is based on standard parameters used in clinical practice (QRS duration, presence of left bundle branch block, classification of heart rhythm) and, in addition, on the analysis of ultra-high-frequency ECG, which provides more detailed information on cardiac activation than the standard parameters used. The developed software helps patients in 16 hospitals in the Czech Republic and abroad.
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Deep learning based QRS delineator
Malina, Ondřej ; Ronzhina, Marina (referee) ; Smíšek, Radovan (advisor)
This thesis deals with the issue of automatic measurement of the duration of QRS complexes in ECG signals. Special emphasis is then placed on the possibility of automatic detection of QRS complexes while exciting cardiac tissue with a pacemaker. The content of this work is divided into four logical units, where the first part deals with the heart as an organ. It describes the origin and spread of excitement in the heart, its possible pathologies and their manifestations in ECG recording, it also deals with pacing and measuring ECG recording during simultaneous pacing. The second part of the thesis contains a brief introduction to the topic of machine and deep learning. The third part of the thesis contains a search of current approaches using methods based on deep learning to solve the detection of QRSd. The fourth part deals with the design and implementation of its own model of deep learning, able to detect the beginnings and ends of QRS complexes from ECG recordings. It describes the data preprocessing implemented in the MATLAB programming environment. The actual implementation of the model was performed in the Python using the PyTorch and NumPy moduls.
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Removal of pacing spikes from the electrocardiographic signal
Smíšek, Radovan ; Plešinger,, Filip (referee) ; Postránecká, Tereza (advisor)
The goal of this thesis is to detect pacing pulses in ultra high-frequency ECG so as to remove these pacing pulses. It makes evaluation of higher frequency components of QRS complex possible. This evaluation is impossible while pacing pulses are present. Chosen issue is solved using heuristic algorithm. Algorithm uses spacing of signal by line in the area which is not influenced by pacing pulses. Subsequently this line is made longer and using differences between line and signal (or another rules) edges of pacing pulses are detected. The top of the stimulation tip is detected by thresholding envelope of original signal´s first difference. More algorithms are tested in this thesis. Several methods of removing pacing pulses are suggested in thesis. Envelopes of high-frequency components are created. Envelopes are analyzed subsequently and suggested methods of removing pacing pulses are compared on the basis of these analysis. Finally the detection efficiency is evaluated.
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Cardiac Pacing in Pre-Hospital Care
TOMANCOVÁ, Anna
The theme of this bachelor thesis is cardiostimulation in pre-hospital care. Cardiostimulation in pre-hospital care is performed only externally and temporarily. The procedure is rare and used only in patients with severe hemodynamic conditions. The very rarity of this medical procedure has given cardiostimulation a certain respect. However, this fact should not be a reason for paramedics' lack of preparedness. When using cardiostimulation, paramedics should know the medical procedure, which will depend on the pathophysiology of the particular condition. Furthermore, they should know their responsibility to assist physicians in external temporary stimulation. The purpose of this thesis is to evaluate the theoretical knowledge of paramedics in the field of cardiostimulation, their knowledge of the procedure of external temporary stimulation, and their practical experience with this procedure. Additionally evaluated was possible variability in the performance of external temporary stimulation in pre-hospital treatment conditions in the South Bohemian Region. The thesis is divided into two main parts - theoretical and empirical. The theoretical part first deals with the character of pre-hospital treatment, the role of the paramedic, and their competences. Next is mentioned the anatomy and physiology of the heart, the possibilities of monitoring cardiac functions and arrhythmia, which can be treated with cardiostimulation. This is followed by the topic of cardiostimulation itself - its types, and the procedure of external temporary stimulation in pre-hospital care using a defibrillator. The practical part categorizes and evaluates the results of qualitative research, based on interviews with paramedics from various units of the Emergency Medical Services of South Bohemian Region. The research objectives of evaluating the theoretical knowledge of cardiostimulation were achieved. The interviews identified that paramedics have a good understanding of cardiac arrhythmias and their treatment. Their knowledge of external temporary cardiostimulation shows they would be able to perform this procedure adequately. Comparing individual ambulance units in the Emergency Medical Services, no differences were found in the cardiostimulation procedure in the conditions of pre-hospital emergency care in South Bohemian Region.
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Pathophysiological and clinical aspects of cardiac dyssynchrony in children and adolescents
Kovanda, Jan ; Janoušek, Jan (advisor) ; Bulava, Alan (referee) ; Klásková, Eva (referee)
Pathophysiological and clinical aspects of cardiac dyssynchrony in children and adolescents Electromechanical dyssynchrony is an important factor in the development of heart failure. It is caused by abnormal activation of the working myocardium in case of bundle branch block or ventricular pacing. Asymmetric hypertrophy of the affected ventricle develops together with its dilatation and reduced function and fulfils the picture of dyssynchronous cardiomyopathy. The development of dyssynchronopathy can be prevented by careful selection of the permanent pacing site and treated by cardiac resynchronization therapy. One of the aims of this work was to compare clinical and echocardiographic findings in patients paced from the left-ventricular apex with the healthy population. Using a retrospective cross-sectional study, we have proved that left ventricular function is not adversely affected in long-term follow-up. Another aim of the study was to evaluate the long-term results of resynchronization therapy of the systemic ventricle in patients with congenital heart defects. Using a retrospective study, we have described an acceptable long-term survival at the price of relatively frequent complications. We were extensively working on a new method of resynchronization of the right subpulmonary ventricle in...
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