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K-complex detection in sleep EEG
Bjelová, Martina ; Mézl, Martin (referee) ; Králík, Martin (advisor)
This paper addresses detecting of K-complexes in sleeping EEG records. Polysomnography is the method, which is used for diagnostic and following therapy of many sleep disorders. For identifnging of sleep stages it is fundamental to know graphoelements, in which they are situate. K-complex is important indicator of second sleep stange and hence is essencial to know to detect this pattern. In this paper we focus on design and implementation of more algorithms for detection of these patterns with various characteristics. Among the proposed methods, the wavelet transform method was best evaluated. Performance of this detection reached values the average senzitivity 63,83 % and average positive predictive value 44,07 %.
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Sleep dynamics analysis using electrophysiological features
Lampert, Frederik ; Janoušek, Oto (referee) ; Mívalt, Filip (advisor)
Táto práca sa zaoberá metódami detekcie spánku pomocou elektrofiziologických príznakov, bez dostupnosti anotácií v podobe hypnogramov. Vyhodnocovanie spánku pomocou polysomnografických (PSG) dát je časovo apersonálne náročný proces, ktorý sa odohráva zväčša vnemocničnom prostredí. Moderné implantabilné zariadenia schopné kontinuálneho snímania azdieľania dát otvárajú možnosť dlhodobého akontinuálneho monitorovania spánkovej aktivity upacientov snurologickými chorobami v domácom prostredí. Súčasné metódy na spánkovú detekciu využívajú intrakraniálne elektroencefalografické (iEEG) spánkové klasifikátory, ktoré sú tvorené a validované na štandardných polysomnografických dátach. Tie však nie sú vždy kdispozícii čo vedie kpotrebe vyvinutia metódy spánkového hodnotenia, ktorá by bola schopná analyzovať spánok pomocou elektrofyziologických príznakov aj bez dostupnosti anotácií v podobe hypnogramov ato obecne z malého počtu zvodov. Za týmto účelom bola navrhnutá metóda spánkového hodnotenia, ktorá vyhodnocuje spánok na základe výkonu elektroencefalografické (EEG) signálu v spektrálnej oblasti pomocou metrík zvaných Power in Band (PIB) metriky. V tejto práci bol analyzovaný výkon vdelta pásme (0,5-4 Hz), keďže EEG signál má vňom najvyššiu amplitúdu azároveň je jeho aktivita najviac výrazná počas N2 aN3 spánkových cyklov, ktoré sú najviac zastúpené vspánku počas noci, takže poskytujú najlepšiu informáciu orozložení spánku počas noci. Scieľom validácie PIB metrík boli taktiež predstavené štandardné metriky založené na hypnogramoch. Tieto metriky boli následne implementované do programovacieho prostredia Python a aplikované na dva voľne dostupné datasety, Dreem Open Dataset-Healthy (DOD-H) a Dreem Open Dataset-Obstructive (DOD-O) obsahujúce polysomnografické merania 25 zdravých jedincov (DOD-H dataset) a56 jedincov so syndrómom spánkového apnoe (OSA)(DOD-O dataset). Výsledky analýz boli vyhodnotené pomocou vizuálnej analýzy vo forme boxplotov, korelačných matíc a štatistických testov. Z výsledkov analýz vyplýva, že navrhnuté PIB metriky majú schopnosť rozlišovať medzi fyziologickým a patofyziologickým spánkom, avšak ich schopnosť rozlišovať niektoré aspekty spánku sa líši od štandardných metrík založených na hypnogramoch. Ztoho vyplýva, že PIB metriky nenahrádzajú štandardné metriky, ale skôr ponúkajú inú perspektívu na analýzu spánku.
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Cortical-subcortical interactions in EEG data of patients with pharmacoresistant epilepsy
Šíma, Jan ; Králík, Martin (referee) ; Lamoš, Martin (advisor)
This bachelor's thesis deals with the elaboration of a literature search on epilepsy and electroencephalography signals with a focus on patients with drug-resistant epilepsy and the analysis of cortico-subcortical relationships. The theoretical part describes the chapters of epilepsy, electroencephalography, the possibility of pre-processing EEG data and analytical methods, which describe the cortico-subcortical interactions. The practical part contains pre-processing of EEG data, analysis of methods used, data analysis, results, discussion, and conclusion. The data analysis itself is performed by the Phase-amplitude coupling method. The discussion discusses the results, limitations, and other possible connections. The conclusion summarizes the whole bachelor thesis.
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Methods for sleep spindles detection from EEG records
Matoušek, Šimon ; Mézl, Martin (referee) ; Králík, Martin (advisor)
This bachelor work focuses on the detection of sleep spindles in EEG signals. The introductory chapter deals with the EEG signal, describes its components and describes the signal recording process. Explains the term sleep spindle and clarifies polysomnography. In the following chapter, some findings concerning studies that examined and practically used individual methods of sleep spindle detection are summarized in the form of research. The practical part of the work is focused on some sleep spindle detectors. At the end of the work is a comparison of the success of these detectors in comparison with other, previously performed studies. The highest success was achieved with the detector based on signal envelope calculation, where the sensitivity was 56.00 \% and the specificity 55.19 %, and also with the detector using wavelet transforms, where the sensitivity was 81.22 % and the specificity 46.15 %
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Detection of K-complexes in sleep EEG signals
Hlaváčová, Kristýna ; Ronzhina, Marina (referee) ; Kozumplík, Jiří (advisor)
This master’s thesis deals with issues of the detection of K-complexes in EEG sleep signals. Record from an electroencephalograph is important for non-invasive diagnosis and research of brain activity. The scanned signal is used to examine sleep phases, disturbances, states of consciousness and the effects of various substances. This work follows the automatic detection of K-complexes, because the manual labeling of graphoelements is complicated. Two approaches were used –Stockwell transform and bandpass filtration followed by TKEO operator application. All algorithms were created in the MATLAB R2014a.
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Automatic sleep scoring
Schwanzer, Miroslav ; Kozumplík, Jiří (referee) ; Ronzhina, Marina (advisor)
This master thesis deals with classification of sleep stages on the base of polysomnographic signals. On several signals was performed analysis and feature extraxtion in time domain and in frequency domain as well. For feature extraxtion was used EEG, EOG and EMG signals. For classification was selected classification models K-NN, SVM and artifical neural network. Accuracy of classifation is different depending on used method and spleep stages split. The best results achieved classification among stages Wake, REM, and N3, with neural network usage. In this case the succes was 93,1 %.
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Microstates analysis in EEG data of sleep-deprived subjects
Křápková, Monika ; Koudelka, Vlastimil (referee) ; Lamoš, Martin (advisor)
This bachelor’s thesis deals with the processing and analysis of EEG data in sleep deprived subjects. In the theoretical part, the electroencephalography method is presented first. Further, there are possibilities of preprocessing and analysis of EEG data, introduction to statistics, and the last one is a research on the influence of sleep deprivation on human electrophysiology. The practical part consists of the preprocessing of EEG data, EEG microstates analysis and statistical evaluation of the results from the study of sleep deprivation. Finally, the results of this part are discussed in a separate chapter.
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K-complex detection in sleep EEG
Bjelová, Martina ; Mézl, Martin (referee) ; Králík, Martin (advisor)
This paper addresses detecting of K-complexes in sleeping EEG records. Polysomnography is the method, which is used for diagnostic and following therapy of many sleep disorders. For identifnging of sleep stages it is fundamental to know graphoelements, in which they are situate. K-complex is important indicator of second sleep stange and hence is essencial to know to detect this pattern. In this paper we focus on design and implementation of more algorithms for detection of these patterns with various characteristics. Among the proposed methods, the wavelet transform method was best evaluated. Performance of this detection reached values the average senzitivity 63,83 % and average positive predictive value 44,07 %.
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The EEG segmentation
Nečadová, Anežka ; Kozumplík, Jiří (referee) ; Kubicová, Vladimíra (advisor)
Subject of this bachelor project is the introduction of the EEG signal. Are discussed his characteristics, application and methods of processing. The main part deals with the segmentation of the EEG signal. Two methods are implemented in program Matlab - adaptive segmentation based on differential average amplitude and differential average frequency and adaptive segmentation based on differential estimated based on FFT. Functionality of algorithms is verified on real EEG signals.
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Automated EEG data segmentation
Krupka, Ondřej ; Ronzhina, Marina (referee) ; Bubník, Karel (advisor)
This bachelor's thesis deals with EEG signal, its properties, usage and its processing methods. The main task is introduction with different methods of automatic EEG data segmentation. Furthermore the subject of this project is realization of some methods in MATLAB software, verification of functionality and mutual comparison of segmentation results.
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