Abstract This thesis describes the laser Doppler technique based on a self-mixing effect in a diode laser to noninvasive cardiovascular pulse detection in a human wrist above the radial artery. The main applications of self-mixing interferometry described in this thesis in addition to pulse detection are arterial pulse shape and autonomic regulation measurements. The elastic properties of the arterial wall are evaluated and compared to pulse wave velocity variation at different pressure conditions inside the radial artery. The main advantages of self-mixing interferometry compared to conventional interferometers are that the measurement set up is simple, because basically only one optical component, the laser diode, is needed. The use of fewer components decreases the price of the device, thus making it inexpensive to use. Moreover, an interferometer can be implemented in a small size and it is easy to control because only one optical axis has to be adjusted. In addition, an accuracy, which corresponds to half of the wavelength of the light source, can be achieved. These benefits make this technique interesting for application to the measurement of different parameters of the cardiovascular pulse. In this thesis, measurement of three different parameters from cardiovascular pulsation in the wrist is studied. The first study considers arterial pulse shape measurement. It was found that an arterial pulse shape reconstructed from the Doppler signal correlates well to the pulse shape of a blood pressure pulse measured with a commercial photoplethysmograph. The second study considers measurement of autonomic regulation using the Doppler technique. It was found that the baroreflex part of autonomic regulation can be measured from the displacement of the arterial wall, which is affected by blood pressure variation inside the artery. In the third study, self-mixing interferometry is superimposed to evaluate the elastic properties of the arterial wall. It was found that the elastic modulus of the arterial wall increases as blood pressure increases. Correlations between measurements and theoretical values were found but deviation in measured values was large. It was noticed that the elastic modulus of the arterial wall and pulse wave velocity behave similarly as a function of blood pressure. When the arterial pressure increases, both the elastic modulus and pulse wave velocity reach higher values than in lower pressure.

Ce travail de thèse porte sur la croissance par dépôt laser pulsé (PLD) et l’étude des propriétés dedifférents systèmes d’oxydes pérovskites. Ainsi, les hétérostructures LaAlO3/SrTiO3, SrVO3/SrTiO3,LaAlO3/SrVO3 ont fait l’objet de travaux de recherche. Ces études ont été menées afin d’analyser lespropriétés des interfaces de ces différents systèmes composés, notamment, de titane et devanadium, deux métaux de transition et ainsi d’étudier et de comparer les effets de l’orbitale 3d enpassant d’une configuration 3d0, pour Ti, à 3d1, pour V.Dans une première partie, les travaux réalisés sur le système LaAlO3/SrTiO3 sont présentés. Lacroissance des échantillons, les caractérisations structurales, de transport et de magnétisme sontdétaillées. A partir cette étude, des résultats majeurs ont été obtenus, concernant l’effet desconditions de croissance par PLD sur la stoechiométrie des films minces et les conséquences sur lespropriétés électroniques de l’interface, avec la mise en évidence de différentes phases électroniques.Dans une seconde partie, la croissance de films minces et ultraminces de SrVO3 par PLD et la mise enévidence expérimentale de la Transition Métal-Isolant (TMI) sont développées. Les mesures despropriétés structurales et de transport ont permis de déterminer l’origine de cette TMI. Enfin, lesmécanismes physiques de conduction dans ce système sont révélés à partir de modélisations.Enfin, la dernière partie est consacrée aux travaux réalisés sur les hétérostructures LaAlO3/SrVO3réalisées sur substrats de SrTiO3 et de LaAlO3. Pour ces systèmes, les caractérisations de transportainsi que les analyses chimiques menées dans le but d’étudier les propriétés des interfaces de cessystèmes et de les comparer avec le système LaAlO3/SrTiO3. Différents mécanismes de conductionont ainsi été mis en évidence, corrélés par une analyse chimique, pour les échantillons réalisés surSrTiO3, démontrant l’effet de la couche de LaAlO3. / This thesis work has been led to study the growth by Pulsed Laser Deposition (PLD) and theproperties of different perovskite oxide systems including heterostructures of LaAlO3/SrTiO3,SrVO3/SrTiO3 and LaAlO3/SrVO3. This work is motivated by the need to measure and analyze theinterface properties in these systems which are composed with transition metal elements titaniumand vanadium but with different electronic configuration, 3d0 for Ti and 3d1 for V that can modify theproperties.In a first part, growth and characterizations – structural, transport and magnetism – is presented.Major results are obtained and demonstrate the effect of growth conditions – oxygen pressure andlaser fluence – on LaAlO3 thin films stoichiometry and interface electronic properties finally provingthe existence of an electronic phase transition.In the second part, growth of thin and ultrathin SrVO3 films is detailed and an experimentalobservation of the Metal-Insulator Transition (MIT) is brought out. The origin of this MIT isdemonstrated by structural and Transport properties investigation. Furthermore, physicalmechanisms of conduction in this system are revealed through modelisation work.Finally, the last part is devoted to the work done on LaAlO3/SrVO3 heterostructures grown on SrTiO3and LaAlO3 substrates. Transport characterizations and chemical analysis realized in order to studythe interface properties and to compare with LaAlO3/SrTiO3. Different conduction mechanisms havebeen brought out which are correlated by chemical analysis – for samples grown on SrTiO3 – anddemonstrate the effect of LaAlO3 thin films in this hétérostructure.

Pulse oximeters are used in operating rooms and recovery rooms as a monitoring device for oxygen in the respiratory system of the patient. The advantage of pulse oximeters over other methods of oxygen monitoring is that they are easy to use and they are non-invasive, which means it is not necessary break the skin to extract blood for information to be obtained. The standard for the measurement of partial pressure of CO2 and O2 is an arterial blood gas analysis (ABG). However routine monitoring using this method on a continuous basis is impractical since it is slow, painful and invasive. Measuring carbon dioxide is critical to preventing ailments such as carbon dioxide poisoning or hypoxia. The problem is, currently there is no known effective non-invasive method for accurately measuring carbon dioxide in the body to properly assess the adequacy of ventilation. The objective of this study was to experimentally use spectroscopy in the visible spectrum and the principles of operation of a pulse oximeter to incorporate a method of non-invasive real-time carbon dioxide monitoring that is as quick and easy to use.

The thesis is concerned with the analysis of measuring pulse wave velocity in human body with the aid of whole-body multichannel bioimpedance which was developed at ISI AS CR, v.v.i.. The evaluation of pulse wave velocity can provide us with important information about the state of vessel compliance which is one of the basic parameters informing on their physiological state. The examination of the state of vascular system is a very important part of early diagnostics because its pathological states are the main contributor to the rise of cardiovascular diseases and disease mortality. The thesis is concerned with the theoretical analysis together with the available methods of valuation of the state of vascular system that use measuring of pulse wave velocity. The main part of the thesis deals with the analysis of the whole-body multichannel bioimpedance measurement. The proposed and programmed protocol that summarizes and visualizes all obtained information is a part of this thesis. This is currently used as an output of the experimental measurement by this method. Data file for statistical processing contains the values of the pulse wave velocity of 35 healthy volunteers and subsequently the properties of pulse wave are assessed at various excitations.

The lead-acid batteries are the most commonly used electrochemical power sources and are the oldest type of secondary battery cells. This master thesis provides a short introduction to the lead-acid batteries and shows possible ways of sorting from different points of view. Thesis describes construction of lead-acid batteries, parameters of lead-acid batteries, electrochemical and physical reactions inside the battery. Futher the thesis deals with pulse charging of lead-acid batteries. In the next part of the thesis is described the production of a set of experimental electrodes for electrochemical workplace resources. The final part of this thesis are experiments focusing on the pulse charging using negative current pulses and evaluate the effect of different pulse modes on cells.

No description available.

In dieser Arbeit werden elektronische und strukturelle Dynamiken durch Femtosekundenpuls injizierte kleine Polaronen in Lithiumniobat betrachtet, sowie die Auswirkungen auf die nichtlineare Optik mit Schwerpunkt auf die Holographie und den mittleren infraroten Spektralbereich untersucht.

The Induction Linac System Experiment (ILSE) is a heavy-ion fusion (HIF) device that is being designed at Lawrence Berkeley Laboratory (LBL). The machine will be capable of accelerating 16 carbon ion beams, which are subsequently merged into 4 beams, to energies in the neighborhood of 10 MeV (10 million electron- volts). The purpose of the experiment will be to demonstrate the process of simultaneous acceleration and current amplification for a multiple beam accelerator configuration. If this process can be mastered, the beams produced by a machine such as ILSE would be used to implode and heat a deuterium-tritium (D-T) fuel pellet and produce a thermonuclear inertial confinement fusion (ICF) burn. This technology of achieving a fusion reaction using ion beams is referred to as Heavy-Ion Fusion (HIF) [1].

The objective of this research was to increase the independence and safety of the sight impaired by developing an enhanced travel aid in the form of a sensor embedded long-cane to reduce the risk of injury from walking into suspended or overhanging objects while providing the sight impaired community with a familiar and well accepted tool. Prior research at the Electromechanical Systems Laboratory had established a theoretical framework for ultrasound-based ranging and spatial obstacle localization from the moving reference frame of a long-cane. A prototype was implemented using analog threshold detection techniques. This research focused on a new approach. A coded pulse was transmitted and correlation techniques were used to identify echoes and determine time of flight. Compared to the prior effort this new approach was more sensitive, had greater noise immunity, and provide greater spatial resolution for obstacle detection. The first step in the coded pulse approach was to generate a transmit pulse with an embedded binary code that is highly distinguishable. A transmit pulse generated by phase modulating a 40 kHz carrier signal with a 13-bit Barker code word, with each bit consisting of 4 cycles of the 40 kHz carrier was used. Digitized representative echoes were used as reference vectors for correlation to account for the effect of the impulse responses of the transducers, the air, and the reflection, on the transmitted pulse. In a detection cycle, the coded pulse was transmitted, the A/D converters took 2600 samples at the 150 kHz sampling rate to capture any echoes from objects between 1 and 4 meters in front of the cane. The receiver data was cross-correlated with the stored echo image to find echoes in the received signal. The correlation peak positions from the upper receiver were then compared to the peak positions from the lower receiver and if they collaborated within the synthetic aperture, the range and height were calculated annunciation was made by a synthesized voice. The new obstacle detection system described above was designed and a prototype was constructed and embedded into the shaft of an 18 mm diameter body of a long cane.

No description available.