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 %.

This master's thesis deals with data processing for an electrodynamic test bench. The thesis presents a theoretical overview of signal distribution, determination of fatigue damage from random vibrations and a description of test benches. The next part deals with setting up the test time reduction in GlyphWorks software. The aim of this thesis is to process and create a procedure for an accelerated fatigue test from data measured during an operational test on a polygon. The data are then verified on an electrodynamic test rig using a Skoda Auto dynamic test room. The final part of the thesis contains data evaluation and a guide explaining how to easily create a test in the relevant software.

This Master's thesis deals with the influence of breathe to baroreceptor reflex. The first chapter is focused on measuring of blood pressure, in reference to later used method. In the second part is detailed analysis and explanation of term baroreflex, relationship between frequency spectra of systolic blood pressure, heart rate and breathing, mechanisms of regulation of blood pressure and heart rate variability. Third chapter deals with possible ways, how to analyze data, which are needed for estimation of baroreflex sensitivity, analyze of heart rate variability and estimation of power spectral density. Next parts of this thesis is paid attention to technical equipment and methods of acqusition of data, using this equipmnent. Part of this work is also software application, which makes possible from the recorded data estimate baroreflex sensitivity.

Bioimpedance spectroscopy is very useful in biomedical field as a safe and non-invasive technique. A stable and safe excitation current below than 0.5 mA for load impedances changing from 100 Ω to 10 kΩ in the full β-dispersion range from kHz up to 1 MHz is a big challenge for the design of the current source addressed by this thesis. For a good stability and high accuracy, the source should have a high output impedance. Different current source types in “current-mode approach” and “voltage-mode approach” were investigated and compared for usability in bioimpedance measurement systems. The “voltage-mode approach” with grounded load was proven to be more suitable and stable for biomedical measurements. Thereby the Tietze and the Howland circuit in dual configuration with negative feedback have shown the lowest error of the output current and the highest output impedance, where the improved Howland circuit in dual configuration with negative feedback is preferred because it has a simple structure, high accuracy and good stability. We suggest to improve the stability of the Howland circuit in dual configuration with negative feedback by introducing compensated operational amplifiers and to reduce stray capacitances at higher frequencies by adding gain compensation capacitor. We reach thereby an accuracy of 0.5% at low frequency and 0.9% at 1 MHz. With the realized accuracy of the designed voltage controlled current source, one decisive prerequisite for portable bioimpedance measurement system is achieved. In order to select the appropriate excitation signals for short measurement time, a comparative study of signals and their parameters was carried out. It leads to the selection of binary chirp signal as a suitable excitation signal due to its short measurement time about 100 μs, low crest factor lower than 2.8 and an energy efficiency higher than 54% in a very noisy signal. Simulation results show that the designed enhanced Howland current source excited by the binary chirp signal has low error and flatness in the whole range. / Die Bioimpedanzspektroskopie gewinnt aufgrund ihrer besonderen Eigenschaften als nicht-invasive, schonende Messmethode zunehmend an Bedeutung im biomedizinischen Bereich. Dabei ergeben sich besondere erausforderungen für den Entwurf der Stromquelle zur Realisierung eines stabilen und sicheren Anregungsstroms. Gefordert ist eine hohe Genauigkeit bis zu einem Maximalstrom von 0.5 mA in einem Frequenzbereich, der der β-Dispersion entspricht, von wenigen kHz bis hin zu 1 MHz. Die Stabilität muss bei variablen Lastimpedanzen im Bereich von 100 Ω bis 10 kΩ gewährleistet sein. Dafür muss die Stromquelle eine hohe Ausgangsimpedanz aufweisen. Diese Arbeit fokussiert auf den Entwurf von spannungsgesteuerten Stromquellen. Verschiedene Arten von Stromquellen wurden untersucht und verglichen. Der 'Voltage-Modus-Ansatz' mit Masse-referenzierter Last hat sich als besser geeignet und stabiler für biomedizinische Messungen erwiesen. Die Tietze-Schaltung und diese Howland-Schaltung zeigen dabei die niedrigsten Fehler des Ausgangsstroms und die höchste Ausgangsimpedanz. Im direkten Vergleich besitzt die verbesserte Howland-Schaltung doch eine einfachere Struktur, höhere Genauigkeit und bessere Stabilität und wird daher gegenüber der Tietze-Schaltung bevorzugt. Um weitere Stabilitätsverbesserungen bei der Howland-Schaltung zu erreichen, werden zwei Maβnahmen vorgeschlagen. Zum einen werden kompensierte Operationsverstärker eingeführt und zum anderen wird der Einfluss von Streukapazitäten bei hohen Frequenzen minimiert indem die Verstärkung mit Kondensatoren kompensiert wird. Durch diese Maβnahmen wird eine Genauigkeit von 0.5% bei niedrigen Frequenzen und 0.9% bei 1 MHz ermöglicht. Mit dem neuen Entwurf der spannungsgesteuerten Stromquelle ist ein entscheidender Meilenstein für die Realisierung tragbarer Messsysteme der Bioimpedanz erreicht. Um eine kurze Messzeit zu realisieren wurde eine vergleichende Studie von Anregungssignalen und deren Signalparameter durchgeführt. Die Ergebnisse zeigen, dass binäre Chirp-Signale aufgrund der reduzierten Messzeit, des niedrigen Crest-Faktors unter 2.8 und hohe Energieeffizienz von mehr als 54% bei hohem Rauschlevel besonders geeignet sind. Simulationsergebnisse zeigen, dass die entwickelte Howland-Stromquelle zusammen mit einem binären Mehrfrequenzsignal den geringsten Amplitudenfehler im gesamten Frequenzbereich realisiert.

Railway signaling is of paramount importance to ensure traffic management andsafety on the rail network. The main lines are divided into sections called ‘blocks’,which are governed by a fixed signal installation. To prevent trains from colliding,each block allows one train at once. In France (and most European countries),train detection is performed by an electrical device called track circuit that consistsof a transmitter and a receiver installed at the track-side, and connected via therails. In the absence of a train, an electrical signal flows from the transmitter tothe receiver through the rails. As a train enters a track circuit, its axles shuntthe rails, provoking a short circuit (also called ‘shunt’): the signal transmitted tothe receiver drops. The detection of that signal drop results in the detection of atrain. This method rarely fails throughout the network, but there can be criticalcases where it may be inefficient. In this Master’s Thesis, new detection criteriaproposed in previous studies have been tested on signals measured in poor shuntingconditions. Three approaches have been tested: one in the time domain and two inthe frequency domain. The time approach compares the short-term and long-termstatistics of the received signals. The observation of a change in the spectra of thereceived signals around the 3rd order harmonic (3OH) has led to the implementationof two frequency criteria: the estimation of the band power around the 3OH andthe detection of the 3OH peaks. The obtained results show that better detection isachieved when the new criteria and the existing one are combined. / Tågsignalsystem är väsentliga för att garantera trafikstyrning och säkerhet i tågnätet.Spåren är indelade i sektioner, s.k. block, som övervakas med fasta signalinstallationer.För att hindra tåg från att krocka, tillåts bara ett tåg i taget per block. IFrankrike (och de flesta andra europeiska länder), detekteras tågen med en elektriskspårkrets som består av en sändare och en mottagare som är installerad bredvidspåret och ansluten till rälsen. När inget tåg finns på spåret, flyter en elektrisk signalfrån sändaren till mottagaren via spåret. När ett tåg anländer, kortsluts kretsenav hjulaxeln och signalen försvinner från mottagaren. Minskningen i signalstyrkaanvänds för att detektera tåget. Denna metod sällan misslyckas i tågnätet, men iovanliga fall kan det uppstå farliga situationer. I detta examensarbete utvärderasnya detektionsmetoder, som har föreslagits i tidigare studier, på signaler som haruppmätts under förhållanden med dålig kontakt mellan hjul och spår. Tre olika metoderhar testats, en i tidsdomänen och två i frekvensdomänen. Tidsdomänsmetodenjämför kortvarig och långvarig statistik för den mottagna signalen. I spektrum förden mottagna signalen, har man observerat en förändring runt den tredje övertonen,samt detektering av frekvenstoppar vid tredje övertonen. De erhållna resultatenvisar på förbättrad detektering när de nya och existerande kriterierna kombineras.

This study seeks to understand upper limb tremor in subjects with essential tremor (ET). A thorough understanding of tremor distribution will allow for the more effective development of tremor suppression devices, which offer an alternative to current treatments. Previous studies primarily focused on tremor in the hand only. This study seeks to characterize the distribution of tremor throughout the upper limb. We measured tremor in 25 subjects diagnosed with ET using motion capture, which provided 0displacement information of the limb during multiple postural and kinetic tasks. Inverse kinematics allowed us to analyze the motion capture data in the 7 major degrees of freedom (DOF) of the upper limb. The power spectral density estimate was used to determine: relative tremor magnitude throughout the DOFs, tremor variation between tasks, variation between subjects, and frequency variations between DOFs. Data analysis revealed that tremor increase is roughly proximal to distal. We also show that tremor magnitude in kinetic tasks is significantly higher than in postural tasks. Although we found some variation in tremor distribution between subjects, the roughly proximal to distal increase in tremor severity holds for several subsets of the study population. Finally, we found that tremor frequency doesnt vary significantly (<<> 1 Hz) between DOFs, in subjects with severe tremor. Our study shows that tremor distribution is quite stereotyped between subjects with ET. Furthermore, we have shown that tremor is greatest in the distal DOFs. This provides a compelling starting point for the development of future tremor suppression devices.

Bien que la majeure partie du génome humain soit présente en deux copies (une copie héritée de chaque parent), certains segments peuvent être délétés (une copie) ou dupliqués (trois copies). La recherche a montré que plusieurs variations du nombre de copies (CNVs) augmentent le risque de troubles neurodéveloppementaux (e.g. autisme, TDAH, schizophrénie). Or, on connait peu les effets des CNVs sur le développement et le fonctionnement cérébral. L’électroencéphalographie (EEG) au repos s’avère être une méthode adaptée pour étudier les perturbations de l’activité neuronale chez les porteurs de CNVs. L’objectif de ce projet était de déterminer s’il existe des signatures EEG à l’état de repos qui sont caractéristiques des enfants porteurs de CNVs pathogéniques. L’activité cérébrale au repos de 109 porteurs de CNVs (66 délétions, 43 duplications) âgés de 3 à 17 ans a été enregistrée en EEG durant 4 minutes. Pour mieux prendre en compte les variations développementales, les indices EEG (puissance spectrale et connectivité fonctionnelle) ont été corrigés avec un modèle normatif estimé à partir de 256 contrôles du Heatlhy Brain Network. Les résultats ont montré une puissance bêta et gamma accrue dans les régions postérieures ainsi qu’une sous-connectivité globale à des échelles temporelles distinctes chez les porteurs de CNVs. Les porteurs d’une délétion et d’une duplication pouvaient être différenciés par leur connectivité dans les fréquences bas-alpha: la connectivité des porteurs d’une duplication était plus perturbée que celle des porteurs d’une délétion. Les perturbations distinctives en connectivité se sont avérées plus proéminentes à l’adolescence. Les résultats suggèrent que les porteurs de CNVs présentent des altérations électrophysiologiques par rapport aux témoins neurotypiques, indépendamment de la région génomique affectée. / Although most of the human genome is present in two copies (one copy inherited from each parent), some segments can be deleted (one copy) or duplicated (three copies). Research has shown that many copy number variations (CNVs) increase the risk of neurodevelopmental disorders (e.g. autism, ADHD, schizophrenia). However, little is known about the effects of CNVs on brain development and function. Resting-state electroencephalography (EEG) is a suitable method to study the disturbances of neuronal functioning in CNVs. We aimed to determine whether there are resting-state EEG signatures that are characteristic of children with pathogenic CNVs. Resting-state brain activity of 109 CNVs carriers (66 deletions, 43 duplications) aged 3 to 17 years was recorded in EEG for 4 minutes. To better account for developmental variations, EEG indices (power spectral density and functional connectivity) were corrected with a normative model estimated from 256 Heatlhy Brain Network controls. Results showed increased beta and gamma power in posterior regions as well as a global under-connectivity at distinct frequency bands in CNVs carriers. Deletion and duplication carriers can be differentiated by their connectivity in low alpha frequencies: the connectivity of the duplication carriers was more disrupted than that of the deletion carriers. The distinctive connectivity perturbations were found to be most prominent during adolescence. The results suggest that CNVs carriers show electrophysiological alterations compared to neurotypical controls, regardless of the gene dosage effect and of their affected genomic region. Moreover, a specific signature of the molecular alterations associated with deletions was found.

No description available.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Bit errors often occur in a wireless communications link when impairments alter the transmitted signal. It is advantageous to be able to predict how well a system will tolerate transmission problems. This paper details laboratory performance measurements and comparisons in terms of evaluating configurations of a digital receiver for Feher patented Quadrature Phase Shift Keying (FQPSK-B) demodulation. The transmitted signal is subjected to calibrated levels of impairments while the receiver performance is monitored in real-time.

Au cours des deux dernières décennies, les signaux chaotiques ont été de plusen plus pris en compte dans les télécommunications, traitement du signal ou transmissionssécurisées. De nombreux articles ont été publiés qui étudient la densitéspectrale de puissance (DSP) des signaux générés par des transformations spécifiques.La concentration sur la DSP est due à l’importance de la fréquence dans lestélécommunications et la transmission sécurisée. Grâce au grand nombre de systèmessans fil, la disponibilité des fréquences de transmission et de réception est de plus enplus rare pour les communications sans fil. Aussi, les médias guidés ont des limitationsliées à la bande passante du signal. Dans cette thèse, nous étudions certainespropriétés associées à la bifurcation collision de frontière pour une transformationunidimensionnelle linéaire par morceaux avec trois pentes et deux paramètres. Nouscalculons les expressions analytiques de l’autocorrélation et de la densité spectralede puissance des signaux chaotiques générés par les transformations linéaires parmorceaux. Nous montrons l’existence d’une forte relation entre les différents typesde densité spectrale de puissance (passe-bas, passe-haut ou coupe-bande) et les paramètresde bifurcation. Nous notons également en évidence une relation entre le typede spectre et l’ordre des cycles attractifs. Le type du spectre dépend de l’existencedes orbites périodiques au-delà de la bifurcation de collision de frontière qui a donnénaissance au chaos. Nous utilisons ensuite les transformations chaotiques pour étudierla fonction d’ambiguïté. Nous combinons quelques transformations chaotiquesbien déterminées pour obtenir un spectre large bande avec une bonne fonction d’ambiguïtéqui peut être utilisée en système radar / During the two last decades, chaotic signals have been increasingly consideredin telecommunications, signal processing or secure transmissions. Many papers haveappeared which study the power spectral density (PSD) of signals issued from somespecific maps. This interest in the PSD is due to the importance of frequency in thetelecommunications and transmission security. With the large number of wirelesssystems, the availability of frequencies for transmission and reception is increasinglyuncommon for wireless communications. Also, guided media have limitations relatedto the bandwidth of a signal. In this thesis, we investigate some properties associatedto the border-collision bifurcations in a one-dimensional piecewise-linear map withthree slopes and two parameters. We derive analytical expressions for the autocorrelationsequence, power spectral density of chaotic signals generated by our piecewiselinearmap. We prove the existence of strong relation between different types of thepower spectral density (low-pass, high-pass or band-stop) and the parameters. Wealso find a relation between the type of spectrum and the order of attractive cycleswhich are located after the border collision bifurcation between chaos and cycles.We use the chaotic transformations to study the ambiguity function. We combinesome chaotic transformations well determined to obtain a broadband spectrum witha good ambiguity function that can be used in radar systems