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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Léčba srdečních arytmií ve vztahu k ošetřovatelské péči / Treatment of cardiac arrhythmias related to nursing care

NOVÁKOVÁ, Jaroslava January 2011 (has links)
Nursing care continuing the treatment of cardiac arrhythmias is an inseparable part of the patient?s care. As there are various types of arrhythmias and different types of treatment, similarly, the subsequent nursing care has its specifics as well. It relates not only to the post-treatment care but also to pre-surgery preparation and subsequent education. The theoretical part of the thesis contains the information on arrhythmias, their development and treatment. Organizations associating nurses working in arrhythmologic centres are mentioned as well. The practical part consists of the survey research. The quantitative enquiry is conducted in arrhythmologic centres by means of questionnaires addressing the nurses. The qualitative part contains interviews with patients who underwent some of the types of cardiac arrhythmia treatment. The objective of the thesis was to find out whether the nurses are aware of the specifics of the nursing care that follows the treatment of cardiac arrhythmia, in which stage the treatment is the most demanding for nurses and whether they can apply standardized nursing procedures in their work. Another objective is focused on mapping of the educative activity within the nursing care. Interviews with the patients are aimed at the areas of admission, prior to surgery, after surgery and during education. They should outline the view from ?the other side?. All the defined hypotheses were confirmed. The cardinal hypothesis of the thesis was the assumption that nurses, when providing nursing care to patients undergoing treatment of cardiac arrhythmias, do not work according to standardized nursing procedures. Subsequently, a draft of standardized nursing procedure focused on nursing care of patients undergoing implantation of a permanent cardiostimulator was prepared ? it could be applied in the University Hospital in Plzeň where most of the enquiry was conducted.
12

Identifikace abnormálních EKG segmentů pomocí metody Multiple-Instance Learning / Identification of Abnormal ECG Segments Using Multiple-Instance Learning

Šťávová, Karolína January 2021 (has links)
Heart arrhythmias are a very common heart disease whose incidence is rising. This thesis is focused on the detection of premature ventricular contractions from 12-lead ECG records by means of deep learning. The location of these arrhythmias (key instances) in the record was found using a technique based on Multiple-Instance Learning. In the theoretical part of the thesis, basic electrophysiology of the heart and deep learning with a focus on the convolutional neural networks are described. Afterward, a program was created using the Python programming language, which contains a model based on the InceptionTime architecture, using which classification of the signals into the selected classes was performed. Grad-CAM was implemented to find locations of the key instances in the ECGs. The evaluation of the arrhythmia detection quality was done using the F1 score and the results were discussed at the end of the thesis.
13

Shluková analýza v oblasti biosignálů / Cluster analysis in biosignal processing

Kalous, Stanislav January 2008 (has links)
This diploma thesis deals with cluster analysis for long-term electrocardiograms (ECG) clustering. The linear filtration is used for ECG preprocessing. The ECG sign segmenting in single heart cycles is based on the detection QRS complex and consequently to an application of dynamic time warping algorithms. To an application of all these mentioned processes and to results interpretation, a program called Cluster analysis has been created in the Matlab background. The results of this diploma thesis confirm that cluster analysis is able to distinguish cardiac arrhythmias which are typical with their shape distinctness of normal heart cycles.
14

Umělá aorta pro demonstraci činnosti intraaortální balonkové kontrapulzace / Artificial aorta for activity demonstration of intraaortal baloon contrapulsation

Bičiště, Jan January 2009 (has links)
This dissertation work describes design and construction of simulated aorta device intended to demonstrate performance of the intra-aortal balloon catheter (IAB), and to test reaction of the contra-pulsation pump during simulated cardiac output in conditions of tachycardia, bradycardia and arrhythmia. The major part of the device is transparent plastic tube. The pressure pulses (waves) are generated inside this plastic tube to simulate real cardiac output. These pressure pulses are generated by step motor with membrane. The step motor is controlled by programmable control system AMiNi-E. Individual pressure pulses simulate cardiac output in conditions of tachycardia, bradycardia and arrhythmia. Required simulated cardiac output is selected by control switches. Generated pressure pulses are read by pressure sensor and are transferred to the control system of the configuration computer. Read data can be displayed as graphs in program Microsoft Excel. The intra-aortal balloon catheter (IAB) is inserted inside the aorta and is connected with contra-pulsation pump which on pressure pulse is responding.
15

Vliv teploty na vznik arytmií během vývoje srdce / Effect of temperature on arrhythmogenesis during heart development

Vostárek, František January 2018 (has links)
5 Abstract: Aims: The main objective of this work was to analyze in detail the effects of acute temperature changes on the function of isolated chick embryonic heart in vitro in comparison with natural conditions in ovo. Methods: The effects of temperature change (34 řC, 37 řC and 40 řC - hypo-, normo- and hyperthermia, respectively) on calcium dynamics in four days old isolated chick hearts in vitro were investigated by high-speed calcium optical imaging. For comparison and validation of in vitro measurements, experiments were also performed in ovo using videomicroscopy. Artificial electrical stimulation experiments were performed in vitro and in ovo to uncover conduction limits of different heart segments. Results: We observed almost linear dependence of sinus frequency on temperature in our temperature range. Sinus frequency during hypothermia and hyperthermia in vitro and in ovo changed about 20% in comparison with normothermia. We observed no significant changes in amplitude of calcium transients during temperature change to hypothermia but hyperthermia caused a significant decrease in amplitude of calcium transients (atria 35%, ventricles 38%). We observed a wide spectrum of arrhythmias, which occurred spontaneously even during normothermia in vitro. Occurrence of arrhythmias in vitro significantly...
16

Kvalita života pacientů v závislosti na typu implantovaného defibrilačního zařízení (ICD a S-ICD) / Quality of life in relation to the type of implantable defibrillation divice (ICD and S-ICD)

Gabrišková, Markéta January 2021 (has links)
In recent years, clinical studies have shown that the most effective method of treatment to reduce the incidence of sudden cardiac death in patients at increased risk of malignant arrhythmias is to provide the patient with an implantable cardioverter-defibrillator (ICD). Complications associated with the transvenous implanted system, especially lead disorders and systemic infections, and have led to the development of a so-called subcutaneous defibrillator, which is thought to minimize these complications. Despite the medical benefits of implantable defibrillator treatment, which is generally well accepted by patients, anxiety, depression, and deterioration in their quality of life have been reported in clinical trials examining patients' psychopathology and quality of life after defibrillator implantation. Methodology: The objective of the diploma thesis was to find out which group of patients better assesses the quality of life depending on the type of implanted defibrillation device (ICD and S-ICD). For the purposes of the survey, the method of quantitative research was chosen in the form of its own questionnaire survey. The questionnaire contained a total of seventeen questions in which patients evaluated quality of life in five areas. Patients who met the following criteria were included in...
17

Vliv časného postnatálního období na rozvoj pro-arytmogenního substrátu po tlakovém přetížení srdce potkana / Impact of early postnatal period on pro-arrhytmogenic substrate development caused by pressure overload in rat heart

Zábrodská, Eva January 2021 (has links)
In adult heart, pressure overload leads to cardiac hypertrophy. Higher propensity of hypertrophied myocardium to life-threatening arrhythmia is attributed to structural, mechanical and electrical remodeling. Pro-arrhythmogenic remodeling comprise several factors depending on an experimental model and a stage of heart failure. This thesis aims to characterize the impact of these factors in our unique model of pressure overloaded neonatal rat heart. The constriction of abdominal aorta was performed at postnatal day 2 in male Wistar rats. Decreased body weight, significant since week 6, was observed during development of cardiomegaly. At 12 weeks, the heart to body weight ratio was increased by 45 % and by 109 % in group with compensated (AC I) and decompensated (AC II) heart failure, respectively. At this age, the ECG was recorded and histological and immunohistochemical measurements were performed to analyze the pro-arrhythmogenic remodeling of working myocardium and cardiac conduction system. The markers of pro-arrhytmogenic remodeling such as significant prolongation of QT and QTc intervals were observed in the ECG recordings of AC II animals. However, spontaneously occurring arrhythmias was not detected. Further analysis of working myocardium showed decrease in Cx43 expression and its...
18

Detekce fibrilace síní v krátkodobých EKG záznamech / Detection of atrial fibrillation in short-term ECG

Ambrožová, Monika January 2019 (has links)
Atrial fibrillation is diagnosed in 1-2% of the population, in next decades, it expects a significant increase in the number of patients with this arrhythmia in connection with the aging of the population and the higher incidence of some diseases that are considered as risk factors of atrial fibrillation. The aim of this work is to describe the problem of atrial fibrillation and the methods that allow its detection in the ECG record. In the first part of work there is a theory dealing with cardiac physiology and atrial fibrillation. There is also basic descreption of the detection of atrial fibrillation. In the practical part of work, there is described software for detection of atrial fibrillation, which is provided by BTL company. Furthermore, an atrial fibrillation detector is designed. Several parameters were selected to detect the variation of RR intervals. These are the parameters of the standard deviation, coefficient of skewness and kurtosis, coefficient of variation, root mean square of the successive differences, normalized absolute deviation, normalized absolute difference, median absolute deviation and entropy. Three different classification models were used: support vector machine (SVM), k-nearest neighbor (KNN) and discriminant analysis classification. The SVM classification model achieves the best results. Results of success indicators (sensitivity: 67.1%; specificity: 97.0%; F-measure: 66.8%; accuracy: 92.9%).
19

Model fibrilace síní / Atrial fibrillation model

Ředina, Richard January 2021 (has links)
The aim of this master thesis is to create a 3D electroanatomical model of a heart atria, which would be able to perform atrial fibrillation. To control the model, the differential equations of the FitzHugh-Nagumo model were chosen. These equations describe the change of voltage on the cell membrane. The equations have established parameters. The modification of them leads to changes in the behavior of the model. The simulations were performed in the COMSOL Multiphysics environment. In the first step, the simulations were performed on 2D models. Simulations of healthy heart, atrial flutter and atrial fibrillation were created. The acquired knowledge served as a basis for the creation of a 3D model on which atrial fibrillation was simulated on the basis of ectopic activity and reentry mechanism. Convincing results were obtained in accordance with the used literature. The advantages of computational modeling are its availability, zero ethical burden and the ability to simulate even rarer arrhythmias. The disadvantage of the procedure is the need to compromise between accuracy and computational complexity of simulations.
20

Klasifikace signálu EKG / ECG signal classification

Smělý, Tomáš January 2008 (has links)
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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