National Repository of Grey Literature 103 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Sleep apnea detection from ECG records
Trnková, Simona ; Smital, Lukáš (referee) ; Králík, Martin (advisor)
The aim of this work is to propose an algorithm for the detection of sleep apnea from the respiratory signal that was extracted from the ECG signal. The work includes the theory of sleep medicine, methods for extracting the respiratory curve from the ECG signal and methods for detecting apnoeic sections. In the practical part, the algorithm for estimating the breathing curve and models classifying apnoeic sections are described and evaluated.
Calculation of the cyclist's power output based on data from shoe pressure insoles
Teturová, Iveta ; Smital, Lukáš (referee) ; Hrbotický, Lukáš (advisor)
Překlad abstraktu The Bachelor’s thesis deals with the question of utilizing pressure values measured by pressure inserts for calculating the performance of cyclists. Since this method has not been used in cycling before, the result of this work can be applied to expanding the methods of measuring performance in this sport in the future. The goal was to verify whether the use of this conversion is applicable in practice. This goal was verified by obtaining data during practical measurements, subsequent analysis of this data, and comparison of the results with other methods currently used for measuring performance in cycling.
Detection of interictal activity in long-term stereo-EEG recordings
Šikyňová, Soňa ; Králík, Martin (referee) ; Smital, Lukáš (advisor)
In patients with pharmacoresistant focal epilepsy, complete prevention of the clinical manifestation of epilepsy is achievable through surgical removal of the epileptic zone. Accurate localization of the epileptic zone relies on the detection of interictal epileptic discharges, which serve as an essential tool. However, the effectiveness of automated interictal epileptic discharge detectors may be influenced by the patient's state of vigilance. This study demonstrates a statistically significant difference in performance between different detectors during different sleep phases. The precise temporal and spatial distribution of interictal activity holds paramount importance for identifying the epileptic zone. Inaccurate determination of the epileptic zone and unsuccessful resection can occur if the sensitivity and accuracy of detectors vary across sleep stages. Consequently, it is crucial to consider the patient's consciousness status when pinpointing the epileptic zone. One approach to address these variations in detector performance at different states of vigilance is to optimize the parameters of detection algorithms. This study includes an investigation into the optimized parameters for two interictal epileptic discharge detectors.
Segmentation of ECG signals based on their quality
Roháček, Adam ; Smital, Lukáš (referee) ; Vítek, Martin (advisor)
This work is about ECG quality assessment. In the first part of this work I am introducing the reader to the theory of this topic. I am also explaining basic terms and possible methods of quality assessment. In the second part I am trying to solve the assessment by either creating an algorithm of my own or applying an existing algorithm. In the end I am testing the algorithm and judging the results.
HRV analysis based on PPG signal
Kadlčík, Jindřich ; Hrbotický, Lukáš (referee) ; Smital, Lukáš (advisor)
Heart rate variability analysis has lately gained remarkable popularity as a tool in training optimalization and in prevention of cardiac disease. It is usually based on the ECG signal, the acquisition of which is uncomfortable during activity. Therefore, the option to base the analysis on the PPG signal instead was proposed, but not yet sufficiently studied. This study compiles the necessary information for correct heart rate variability analysis and introduces our own implemented detectors of fiducial points in the PPG signal, and compares their usability for calculation of HRV analysis metrics.
Automatic diagnosis of the 12-lead ECG using deep learning
Blaude, Ondřej ; Smital, Lukáš (referee) ; Provazník, Valentine (advisor)
The aim of this diploma thesis is to investigate the problematics of automatic ECG diagnostics, namely on twelve-lead recordings. In the first chapter the heart and its electrical activity measurement is described shortly. In addition to that, the abnormalities which are going to be classified in this thesis are also briefly described. In the second chapter, it is described how the ECG was diagnosed earlier, by classical methods that preceded deep learning. Some of the shortcomings that the classical methods have compared to deep learning are also described here. The third part already pays attention to deep learning itself, and its contribution and advantages compared to classical methods. Convolutional neural networks and their individual blocks are also described here, later attention is paid to selected architectures that were used in some studies. The fourth chapter already focuses on the practical part, in which the data used from the PhysioNet database, the proposed algorithm and its implementation are described in more detail. In the fifth chapter the results are discussed and compared to the corresponding publications.
HRV analysis based on PPG signal
Martinů, Žaneta ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
The thesis deals with the detection of systolic and diastolic peaks of pulse waves in a photoplethysmographic database. The detectors are implemented in MATLAB. The following part of the thesis uses the signal delineation of the photoplethysmographic signal to determine pulse rate variability. The final part of the thesis evaluates the use of pulse rate variability and compares it to the heart rate variability.
Wattmeters for cycling
Hrbotický, Lukáš ; Smital, Lukáš (referee) ; Korvas, Pavel (advisor)
Bachelor thesis talking about problematics of measuring the wattage of cycling on a road bike. It describes ways in which it is possible to measure the wattage on the bike and explains functional principle of power meters. As practical part of this thesis the measurement is performed according to the proposed test protocol. Based on the analysis and processing of the obtained data, the accuracy of individual types of meter performance is discussed.
HRV analysis in the context of daily activities
Indrák, Václav ; Smital, Lukáš (referee) ; Novotná, Petra (advisor)
The aim of this bachelors thesis is to measure ECG recordings on voulenteers, and following analysis of HRV from these recordings. It persues the explanation of basic metrics used to evaluate HRV, used both in clinical and scientific practice and their following programming implementation in Matlab environment to achieve the most accurate results possible, which are than assessed.
Robust detection of systolic peaks in PPG signal
Gálík, Pavel ; Smital, Lukáš (referee) ; Němcová, Andrea (advisor)
This bachelor thesis deals with systolic peak detection and their usage within the PPG signal. PPG signal is widely used by portable devices like smartwatch which contributes to monitoring of vital functions during the day. The theoretical part describes heart morphology and ECG signal development which is related to PPG. Furthermore, the PPG signal is described together with its usage and recording methods. Other part describes chosen methods for systolic peak detection. The practical aim of this bachelor’s thesis is to record data and to create own PPG signal database. ECG signal has been recorded as a referential value. The algorithm for systolic peak detection has been developed and tested. In conclusion achieved results are discussed with findings of different authors.

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