Classification of microsleep by means of analysis EEG signal

Tato diplomová práce se zabývá detekcí mikrospánku na základě změn energetického spektra EEG signálu. Vstupními hodnotami pro klasifikaci jsou výsledky časově-frekvenční analýzy. Navržená metoda klasifikace využívá aparát fuzzy logiky. Jsou navřeny 4 klasifikátory, jejichž základem jsou fuzzy inferenční systémy lišící se bázi pravidel. Pro návrh funkce příslušnosti premis pravidel jsou použity výsledky fuzzy shlukování. První dva klasifikátory pro detekci mikrospánku využívají pouze alfa pásmo spektrogramu EEG signálu. Tedy umožňují detekci jen stavu relaxace. Třetí klasifikátor je na rozdíl od předcházejících doplněn pravidly pro delta pásmo, co dává možnost rozlišovat v spektru 3 stavy: mentace, relaxace a somnolence. Čtvrtý klasifikátor má rozhodovací mechanismus zahrnující celé pásmo signálu. Uvažovaný přístup ke klasifikaci mikrospánku je realizován a implementován prostřednictvím programového vybavení počítače. Je vytvořen uživatelský program s grafickým rozhraním.This master thesis deals with detection of microsleep on the basis of the changes in power spectrum of EEG signal. The results of time-frequency analysis are input values for the classifikation. Proposed classification method uses fuzzy logic. Four classifiers were designed, which are based on a fuzzy inference systems, that are differ in rule base. The results of fuzzy clustering are used for the design of rule premises membership functions. The two classifiers microsleep detection use only alpha band of the EEG signal’s spectrogram then allows the detection of the relaxation state of a person. Unlike to first and second classifiers, the third classifier is supplemented with rules for the delta band, which makes it possible to distinguish the 3 states: vigilance, relaxation and somnolence. The fourth classifier inference system includes the rules for the whole spectrum band. The method was implemented by computer. The program with a graphical user interface was created.

Estimation of myocardial conduction velocity using a coronary sinus catheter

This paper deals with the measurement of theconduction velocity of the depolarization wave through the atrialmyocardium. With the increasing number of electrophysiologicalprocedures performed on people suffering from cardiac arrhythmias,the number of relapses is gradually rising. A reliable toolto predict these relapses is still being sought. One parameter forprediction could be the conduction velocity of the depolarizationwave, which could reflect the degree of myocardial damage.Data from pediatric patients were used to measure it.With knowledge of the electrode placement on the intracardiaccatheter and detection of atrial activity in the measured leads,the average myocardial conduction velocity along the catheterwas calculated (v = 143.77 ± 21.08 cm/s).This method brings simplicity and time saving to the wholeprocess of measuring line speed. The results of this method shouldalso be tested on an adult population where relevant models existfor comparison

Suppression of Motion Artifacts in Optical Action Potential Records by Independent Component Analysis

Optical signals reflect electrical changes in the heart; however, the presence of motion artifact (MA) complicates the evaluation. Possibility of MA suppression by independent component analysis (ICA) method is presented in this article with an analysis of ICA efficiency and its limitations. Suppression of MA by ICA method was compared with results obtained by state-of-the-art signal processing method, the ratio method. Based on this comparison, the ICA was found as highly precise and useful method for motion artifact removal. ICA seems to be a promising tool for analysis of optical signals recorded from the heart surface

Non-steroidal anti-inflammatory drug consumption in a multi stage and a 24-h mountain bike competition

Purpose: Excessive or inappropriate non-steroidal anti-inflammatory drug (NSAID) use during ultra-endurance events could cause potential risk to athletes’ health. Reports on NSAID consumption in mountain bikers or ultra-mountain bikers are scarce. Therefore, the aim of this study was to investigate the prevalence of NSAID consumption immediately before, during and immediately after a mountain bike (MTB) race and to compare NSAID consumption in two different MTB competitions. Methods: This observational study took place at a three-stage MTB race (SMTB) (n = 63) and at a 24-h MTB race (24MTB) (n = 68), both held in the Czechia in 2017. NSAID consumption was evaluated via self-reported electronic questionnaires. Results: Of all finishers (n = 131), fourteen (10%) consumed NSAID at least once during the competition day (immediately before, during or immediately after the race). The number of NSAID consumers was the same in both competitions. Nevertheless, only three athletes (2%), all of them from the 24MTB, consumed NSAID during the race and 5% of all mountain bikers reported consumption after the race. In contrast to the SMTB, the intake reported by the 24MTB participants was quite homogeneous in terms of the timing of NSAID consumption. The NSAID users were older (p = 0.043) than the non-users. Ibuprofen was most commonly used by 79% of all consumers Conclusion: The prevalence of NSAID use was higher in the older participants and seems to be lower in comparison with results from studies about runners, ultra-runners and triathletes suggesting that it is determined by the discipline (i.e., cycling). On the other hand, the timing of NSAID consumption was probably affected by the competition character (e.g., MTBS or 24MTB). Future studies should focus on a larger sample size of cyclists from various disciplines.Účel: Nadměrné nebo nevhodné použití nesteroidních protizánětlivých léků (NSAID) během ultra-vytrvalostních akcí může způsobit potenciální riziko pro zdraví sportovců. Zprávy o spotřebě NSAID u horských a extrémních horských cyklistů jsou vzácné. Proto bylo cílem této studie prozkoumat výskyt spotřeby NSAID bezprostředně před, během a po závodě na horských kolech (MTB) a porovnat spotřebu NSAID ve dvou různých soutěžích MTB. Metody: Tato observační studie proběhla na tří etapovém závodě MTB (SMTB) (n = 63) a na 24hodinovém závodě MTB (24MTB) (n = 68), oba se konaly v České republice v roce 2017. Spotřeba NSAID byla hodnocena prostřednictvím elektronicky vyplněných dotazníků. Výsledky: Ze všech závodníků (n = 131) čtrnáct (10%) konzumovalo NSAID alespoň jednou během soutěžního dne (bezprostředně před, během nebo bezprostředně po závodě). Počet konzumentů NSAID byl v obou soutěžích stejný. Nicméně pouze tři sportovci (2%), všichni z 24MTB, spotřebovali NSAID během závodu a 5% všech horských cyklistů uvedlo spotřebu po závodě. Na rozdíl od SMTB byl příjem uváděný účastníky 24MTB poměrně homogenní, pokud jde o načasování spotřeby NSAID. Uživatelé NSAID byli starší (p = 0,043) než uživatelé, kteří nejsou uživateli. Ibuprofen byl nejčastěji konzumován 79% ze všech běžců. Závěr: Prevalence užívání NSAID byla vyšší u starších účastníků a zdá se, že je nižší ve srovnání s výsledky studií o běžcích, ultra-běžcích a triatlonistech, což naznačuje, že je to ovlivněno disciplínou (cyklistika). Na druhou stranu, načasování spotřeby NSAID bylo pravděpodobně ovlivněno charakterem soutěže (etapový závod na horských kolech nebo 24hodinový závod na horských kolech). Budoucí studie by se měly zaměřit na větší vzorek cyklistů z různých diciplín

HRV in Isolated Rabbit Hearts and In Vivo Rabbit Hearts

Abstract Heart rate variability of seven isolated and five in-vivo rabbit hearts was compared. Heart rate of isolated hearts is lower and RR-intervals longer than those of in-vivo hearts. Characteristic peaks in characteristic frequency bands are different and powers of these bands are almost twice higher in in-vivo hearts than in isolated ones. LF/HF ratio is more than five-times higher in isolated heart than in in-vivo hearts. Introduction Heart rate variability (HRV) is a diagnostic tool based on evaluation of consecutive RR intervals. RR intervals are extracted from standard electrocardiogram; thus, HRV belongs to a group of non-invasive diagnostic methods. Despite decades of usage of HRV as experimental tool, it hasn't been clinically used until 1996, when Task Force society [1] standardized HRV parameters and their evaluation. HRV reflects behaviour of both parts of autonomous nervous system: sympathetic and parasympathetic Method Isolated hearts All experiments followed the guidelines for animal treatment approved by local authorities and conformed to the EU law. Seven New Zealand rabbits were included in the study. Their isolated hearts were perfused according to Langendorff in the mode of constant perfusion pressure (85mmHg) ECG signal was measured by touch-less method Three ECG signals with duration approximately two hours were recorded. Five minutes long part was extracted in Matlab R2006a (MathWorks, 2006), beginning immediately after 30 minutes of heart stabilization. R-peaks were detected automatically by own R-wave detector designed in Matlab R2006a (MathWorks, 2006). The results of automatic analysis were reviewed and any errors in detection were corrected manually by human revision. HRV parameters were computed from RR series interpolated with cubic spline method and resampled at fs=30Hz. Slow trends were removed by detrending procedure based on smoothness priors regularization with regularization parameter =3000. Signals were further analysed by Kubios HRV software 2.2. In-vivo hearts ECG signals of five New Zealand rabbits were included in the study. The signals were recorded using a SEIVA recording system. Body surface wire electrodes were attached to the skin with miniature clips. These electrodes did not restrict free posturing. In order to ge

Effects of Voltage-Sensitive Dye di-4-ANEPPS on Isolated Rat Heart Electrogram

Abstract Mapping of cardiac electrical activity from Langendorff-perfused hearts using the voltage-sensitive dye (VSD) di-4-ANEPPS has yielded important new information. However, data about response of the heart to staining with VSD are scarce. Voltage-sensitive dye di-4-ANEPPS is currently used in our laboratory for recording of monophasic action potentials by optical method in isolated hearts. The most often used species in basic cardiology is the rat heart. In order to describe in more detail the response of the heart tissue exposed to di-4-ANEPPS, heart rate changes and arrhythmia-preceding parameters in isolated rat heart electrogram during staining with di-4-ANEPPS and washout period, were followed. Introduction Mapping of cardiac electrical activity employing the voltage-sensitive dyes (VSDs) represents one of new and promising methods in basic cardiology laboratories. The electrical changes on the membrane either of one cardiomyocyte or from small area on the surface of the heart can be recorded. This approach is now considered as a valuable tool for electrophysiological studies focused on numerous, frequently studied topics in cardiovascular system physiology and pathophysiology, such as ischemia, reperfusion, arrhythmias triggering, preconditioning, postconditioning, etc. Voltage-sensitive dyes undergo changes in their electronic structure, and as a consequence also in their fluorescence spectra. These changes result from changes in the surrounding electric field, in excitable tissues such as myocardium or neurons. Therefore, VSD may be used successfully for recording of monophasic action potentials (MAPs) in such models. Various VSDs have been introduced into everyday laboratory practice (merocyanine, ANEPPS, etc.). Dyes from ANEPPS group (amino-naphthyl-ethenyl-pyridinium) are the most frequently used in cardiac preparations In our previous papers Methods In this study, five adult male Wistar rats (average body mass 322.4 ± 29.49 g) were included. Each experiment consisted of five phases: isolation of the heart, control perfusion, loading with the dye (staining), washout period, and MAPs recording under control conditions (37°C, spontaneously beating heart). In brief, the animals were deeply anaesthetised by inhalation of ether. After subsequent cervical dislocation, the chest was quickly opened and the heart excised with a sufficiently long segment of ascending aorta. After the heart isolation, the heart was firmly fixed to perfusion set-up by the stump of aorta and then placed in thermostat-controlled bath (37°C) filled with KrebsHenseleit (K-H) solution of following composition (in mM): NaCl 118, NaHCO 3 24, KCl 4.2, KH 2 PO 4 1.2, MgCl 2 1.2, glucose 5.5, Taurine 10, and CaCl 2 1.2. The solution was continuously oxygenated with 95% O 2 and 5% CO 2 . The heart was then perfused with the same solution at the constant perfusion pressure (80 mmHg) for 25 -30 minutes -control period. The perfusion was performed on Langendorff apparatus modified previously in our laborator

Effect of increased left ventricle mass on ischemia assessment in electrocardiographic signals: rabbit isolated heart study

Detailed quantitative analysis of the effect of left ventricle (LV) hypertrophy on myocardial ischemia manifestation in ECG is still missing. The associations between both phenomena can be studied in animal models. In this study, rabbit isolated hearts with spontaneously increased LV mass were used to evaluate the effect of such LV alteration on ischemia detection criteria and performance. Electrophysiological effects of increased LV mass were evaluated on sixteen New Zealand rabbit isolated hearts under non-ischemic and ischemic conditions by analysis of various electrogram (EG) parameters. To reveal hearts with increased LV mass, LV weight/heart weight ratio was proposed. Standard paired and unpaired statistical tests and receiver operating characteristics analysis were used to compare data derived from different groups of animals, monitor EG parameters during global ischemia and evaluate their ability to discriminate between unchanged and increased LV as well as non-ischemic and ischemic state. Successful evaluation of both increased LV mass and ischemia is lead-dependent. Particularly, maximal deviation of QRS and area under QRS associated with anterolateral heart wall respond significantly to even early phase (the 1st-3rd min) of ischemia. Besides ischemia, these parameters reflect increased LV mass as well (with sensitivity reaching approx. 80%). However, the sensitivity of the parameters to both phenomena may lead to misinterpretations, when inappropriate criteria for ischemia detection are selected. Particularly, use of cut-off-based criteria defined from control group for ischemia detection in hearts with increased LV mass may result in dramatic reduction (approx. 15%) of detection specificity due to increased number of false positives. Nevertheless, criteria adjusted to particular experimental group allow achieving ischemia detection sensitivity of 89–100% and specificity of 94–100%, respectively. It was shown that response of the heart to myocardial ischemia can be successfully evaluated only when taking into account heart-related factors (such as LV mass) and other methodological aspects (such as recording electrodes position, selected EG parameters, cut-off criteria, etc.). Results of this study might be helpful for developing new clinical diagnostic strategies in order to improve myocardial ischemia detection in patients with LV hypertrophy

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives