Les avancées technologiques ont ouvert la voie à des approches de biopsie optique innovantes. Elles permettent à l'inverse des méthodes physiques de profiter des avantages d'une procédure mini-invasive, temps réels et répétitive. Le système de tomographie par cohérence optique (OCT) (la technique de biopsie optique utilisée dans cette thèse) propose des approches qui naviguent dans le corps humain grâce à des sondes endoscopiques robotisées. Toutefois, leur contrôle une fois à l’intérieur du corps devient difficile, surtout si l’objectif est de suivre l’évolution d'une zone cible, en faisant un travail de repositionnement dans le temps. L'asservissement visuel est un outil de choix pour le contrôle et le positionnement directement par l'image. Néanmoins, la richesse des informations présentes dans les images autorisent l'utilisation de plusieurs types d'information visuelle. Dans ce contexte, nous proposons l'utilisation de primitives visuelles innovantes fondées sur les ondelettes. Ainsi, deux approches d'asservissements visuels fondées sur les ondelettes ont été développées. La première approche est un asservissement visuel 2D pose fondé sur les ondelettes spectrales continues qui assure une convergence sur un espace plus important avec une bonne robustesse au bruit et une commande découplée. La deuxième est un asservissement visuel 2D direct fondé sur les ondelettes multirésolution, principalement pour faire du positionnement aux petits déplacements. Par ailleurs, la deuxième méthode couvre les 6 DDL quand la première se limite aux 3 DDL dans les images CCD. De plus, ces deux approches ont prouvé leurs aptitudes à faire du positionnement des coupes OCT. Mais encore, nous avons proposé une méthode de positionnement partitionnée que nous pouvons qualifier d'hybride, car elle exploite deux modalités d'images (OCT - CCD) pour assurer un positionnement sur SE(3) d'un échantillon. De même, nous avons proposé une méthode d'étalonnage des images de coupe et de volume OCT, liée aux distorsions générées par le chemin optique parcouru par le faisceau laser OCT. Finalement, ces travaux ouvrent la voie vers des applications dans le positionnement des volumes OCT, la compensation de mouvement physiologique et le suivi d'outils par des images OCT. / The technological advances have facilitated the optical biopsy approaches, unlike physical methods to take advantage of a minimally invasive, real time and repetitive procedure. The optical coherence tomography system is one of the optical biopsy techniques used in this thesis to prospect in the human body with robotized OCT endoscopic probes. Nevertheless, their control once inside the body becomes difficult, especially if the goal is following changes in the target area. The visual servoing is an ideal tool for the control and positioning of the robot. However, the amount of information present in the images allows the use of several types of visual features. In this thesis, we propose to use an innovative visual servoing feature based on wavelets. This representation developed as the evolution of the Fourier transform for non-stationary signals provides a time-frequency representation of the signal with a better extraction of the relevant information. Indeed, two visual servoing approaches based on wavelets were developed. The first approach is a 2D pose visual servoing based on spectral continuous wavelets, which ensures convergence over a larger area and decoupled control. The second is a direct 2D visual servoing based on multiresolution wavelets, mainly for small displacements positioning. However, the latter covers the 6 DOF when the previous one is limited to 3 DDL with a CCD camera. Both approaches have proven their ability to make the positioning of B-Scan OCT images. After that, we have proposed a method of partitioned positioning, that we can qualify by hybrid because it uses two image modalities to ensure SE(3) positioning of a sample. On the other side, we proposed a calibration method of B-Scan and 3D-Scan OCT images, due to the distortions generated by the optical path of the laser beam in OCT. Finally, these thesis is a beginning work for applications in positioning of 3D-Scan OCT, physiological motion compensation and monitoring tools by OCT images.

Abstract Fibromyalgia syndrome is associated with a number of symptoms and conditions that can impact extensively on quality of life. These include pain, sleeping problems, fatigue and depression. This research describes the sense of coherence, social support and quality of life of fibromyalgia patients, as well as the changes taking place in these areas over the course of a year. The aim is to generate knowledge that can be used to develop the care and rehabilitation of fibromyalgia patients. The key theoretical and empirical concept used is Sense of Coherence (SOC) based on the theory by Aaron Antonovsky. The data were gathered by means of a questionnaire at the beginning of the rehabilitation and then after approximately 4 and 12 months of rehabilitation. The data were gathered from a total of 169 patients in rehabilitation, 151 of them were involved at all stages. Statistical methods were used to describe and analyse the data. Differences between groups were tested using the t-test and variance analysis, the Mann-Whitney test, the Kruskall-Wallis test and the Chi-square test. Repeat measurements were carried out using the mixed model. The Pearson and Spearman coefficients were used as correlation coefficients. SOC remained fairly stable during the one-year monitoring period, standing at 59 (SD 11) for the whole group at the beginning of the rehabilitation. Social support also remained also stable during the one-year monitoring period. Health-related quality of life (15D) improved in the lowest SOC category. Depression fell over the year, while life satisfaction did not increase significantly. The interaction effect between the four SOC categories and time was statistically significant for sense of coherence and almost significant for fatigue. SOC was higher among those who were satisfied with their life as a whole, with their ability to manage self-care, leisure, vocational and financial situation, sexual life, partnership relations, family life, contacts with friends and acquaintances, health, mental resources and physical fitness. However, no differences in SOC could be seen between those who were satisfied with their vocational life and those who were not. SOC correlated positively with the support received from relatives, health-related quality of life and life satisfaction and negatively with sleep, fatigue, general wellbeing and depression. SOC correlated negatively, but not significantly, with pain. SOC correlated most strongly with depression and to almost the same extent with health-related quality of life. The research provides knowledge regarding the resources and quality of life of fibromyalgia patients who have undergone rehabilitation, and into any changes that occurred in these areas during a one-year process of rehabilitation. / Tiivistelmä Fibromyalgia-oireyhtymään liittyy useita elämän laatuun laajasti vaikuttavia oireita ja vaivoja, kuten kipua, univaikeuksia, uupumusta ja masentuneisuutta. Tämän tutkimuksen tarkoituksena on kuvata fibromyalgiaa sairastavien koherenssintunnetta, sosiaalista tukea ja elämänlaatua ja niissä vuoden aikana tapahtuvia muutoksia. Lisäksi tarkastellaan koherenssintunteen yhteyttä sosiaaliseen tukeen sekä sosiaalisen tuen ja koherenssintunteen yhteyttä elämänlaatuun. Tavoitteena on tuottaa tietoa, jota voidaan käyttää fibromyalgiaa sairastavien hoitotyön ja kuntoutuksen kehittämiseen. Keskeinen teoreettinen ja empiirinen käsite on Aaron Antonovskyn teoriaan pohjautuva koherenssintunne (SOC). Aineisto on koottu kyselylomakkeella kuntoutuksen alussa sekä noin 4 ja 12 kuukauden kuluttua kuntoutuksesta yhteensä 169 kuntoutujalta, joista 151 oli mukana kaikissa vaiheissa. Aineiston kuvaamisessa ja analyysissa käytettiin tilastollisia menetelmiä. Ryhmien välisiä eroja testattiin käyttäen t-testiä ja varianssianalyysiä, Mann-Whitneyn testiä, Kruskall-Wallisin testiä ja Khiin neliötestejä. Toistomittaukset suoritettiin käyttäen lineaarisia sekamalleja. Korrelaatiokertoimena käytettiin Pearsonin tai Spearmanin kertoimia. SOC oli melko pysyvä vuoden seuranta-aikana ollen kuntoutuksen alussa koko ryhmällä 59 (kh. 11). Myös sosiaalinen tuki läheisiltä oli pysyvä vuoden seurannassa. Terveyteen liittyvä elämänlaatu (15D) koheni alimmassa SOC-luokassa. Masentuneisuus väheni vuoden aikana, sen sijaan elämään tyytyväisyys ei merkitsevästi lisääntynyt. Neljän SOC-luokan ja ajan välinen yhdysvaikutus oli tilastollisesti merkitsevä koherenssintunteen ja melkein merkitsevä uupumuksen kohdalla. SOC oli korkeampi sellaisilla, jotka olivat tyytyväisiä elämään, kykyyn huolehtia itsestä, vapaa-aikaan, taloudelliseen tilanteeseen, sukupuolielämään, parisuhteeseen, perhe-elämään, ystävä- ja tuttavasuhteisiin, terveyteen, henkisiin voimavaroihin ja fyysiseen kuntoon, kuin niillä, jotka olivat näihin tyytymättömiä. Sen sijaan SOC ei eronnut työtilanteeseen tyytyväisten ja tyytymättömien välillä. SOC korreloi positiivisesti läheisiltä saatuun tukeen, terveyteen liittyvään elämänlaatuun ja elämään tyytyväisyyteen ja negatiivisesti uneen, uupumukseen, yleisvointiin ja masentuneisuuteen. SOC korreloi negatiivisesti, mutta ei merkitsevästi kipuun. SOC korreloi korkeimmin masentuneisuuden kanssa ja lähes samantasoisesti terveyteen liittyvän elämän laadun kanssa. Tutkimus antaa tietoa kuntoutuksessa olleiden fibromyalgiaa sairastavien voimavaroista ja elämänlaadusta ja niissä tapahtuvista muutoksista vuoden kuntoutusprosessin aikana.

The emergence of microneedle (MN) technologies offers a route for a pain free, straightforward and efficient way of transdermal drug delivery, but technological barriers still exist which pose significant challenges for manufacture of MN systems with high volume outputs at low cost. The main aim of this research was to develop new ways for MN manufacture primarily using micro-injection moulding processes with high performance engineering thermoplastics. During the moulding process these polymeric melts will be subjected to extreme stress and temperature gradients and detailed material characterisation combined with in-line monitoring is desirable to optimise the moulding parameters and will help in achieving sharp microneedles with acceptable quality. Hence high shear rheology of these selected materials was performed at wall shear rates carried out in excess of 107 s-1 over a range of temperatures to predict the flow behaviour of polymer melts at such high shear strain rates. This information was fed into injection moulding simulation software tools (Moldflow) to assist the MN production process design. The optimal design was then used to produce a full 3D solid model of the injection mould and mould insert. Furthermore various design of experiments were conducted considering input parameters such as injection pressure, injection speed, melt temperature, filling time and mould cavity temperature. Response variables including product quality and data acquired from the cavity pressure and temperature transducers were used to optimise the manufacturing process. The moulded MNs were geometrically assessed using a range of characterisation techniques such as atomic force microscopy, confocal microscopy and scanning electron microscopy. An attempt to make hollow MNs was performed and encountered many challenges like partial cavity filling and part ejection during processing. Studies were carried out to understand the problem and identified the major problem was in tool design and improvements to the moulding tool design were recommended. Plasma treatment and mechanical abrasion were employed to increase the surface energy of the moulded polymer surfaces with the aim of enhancing protein adsorption. Sample surface structures before and after treatment were studied using AFM and surface energies have been obtained using contact angle measurement and calculated using Owens-Wendt theory. Adsorption performance of bovine serum albumin and release kinetics for each sample set was assessed using a Franz diffusion cell. Results indicate that plasma treatment significantly increases the surface energy and roughness resulting in better adsorption and release of BSA. To assist design-optimisation and to assess performance, a greater understanding of MN penetration behaviour is required. Contact stiffness, failure strength and creep behaviour were measured during compression tests of MN against a steel surface, and in-vitro penetration of MNs into porcine skin. The MN penetration process into porcine skin was imaged using optical coherence tomography. Finally, a finite element model of skin was established to understand the effect of tip geometry on penetration. The output of findings from this research will provide proof of concept level development and understanding of mechanisms of MN penetration and failure, facilitating design improvements for micro-injection moulded polymeric MNs.

In this study, we have examined if and how parents who receive financial support from the social services experience that their children are being affected by financial stress, as well as whether the parents experience that they are given satisfactory support from the social services. Empowerment and Sense of coherence were used as a theoretical framework to analyze the results. Interviews with three informants who all were receiving financial support at the time, and have at least one child below the age of 18 in their custody were performed. The parents were devising strategies attempting to give the children the experienced of a better financial situation, in order to protect them from being adversely affected. The conclusion is that all informants experienced a lack of support from the social services. Further results show that the parents experienced that their children were adversely affected by financial stress, especially when comparing themselves with other children. Further the results show that the parents develop their own strategies in order to protect the children from being affected by financial stress. These strategies are for example to draw the children’s attention away from the family’s economic issues and to ignore their own basic needs to be able to give the children more varied opportunities. / I denna studie har vi undersökt hur föräldrar som uppbär försörjningsstöd upplever att barnen påverkas av den ekonomiska utsattheten. Vidare undersöktes på vilket sätt föräldrarna upplever att de får stöd från socialtjänsten till att förändra den ekonomiska situationen. Empowerment och KASAM har använts som teoretisk referensram för att analysera resultatet. Studien har genomförts genom kvalitativa intervjuer med 3 informanter som alla uppbär försörjningsstöd och har barn under 18 år i hemmet. Resultatet visar att föräldrarna upplever att barnen påverkas negativt av den ekonomiska situationen, främst i relation till andra barn då barn jämför sig mycket med varandra. Resultatet visar även att föräldrarna skapar egna strategier för att skydda barnen från att påverkas negativt, dessa är bland annat att avleda uppmärksamhet från den ekonomiska situationen samt att föräldrarna bortser från egna basala behov för att istället erbjuda barnen fler möjligheter.

Le milieu océanique est sujet à de nombreuses sources de fluctuations. Les plus importantes sont les ondes internes, très fréquentes et entrainant des fluctuations de la distribution spatiale du champ de célérité du son. En raison de la longue période de ces phénomènes comparée au temps de propagation des ondes acoustiques pour des applications sonar, le processus peut être considéré figé dans le temps pour chaque réalisation stochastique du milieu. Le développement de bancs d’essais permettant de reproduire les effets de la turbulence atmosphérique a permis des avancées considérables dans le domaine de l’optique adaptative. Nous voyons donc un fort intérêt dans la possibilité de reproduire les effets des ondes internes sur la propagation du son en environnement contrôlé. Un protocole expérimental dans une cuve d’eau est proposé: une onde ultrasonore est transmise à travers une lentille acoustique aléatoirement rugueuse, ce qui produit des distorsions du front d’onde reçu. Les fluctuations des signaux reçus sont contrôlées en modifiant les paramètres statistiques de rugosité de la lentille. Ces paramètres sont reliés à l’analyse dimensionnelle permettant de classifier les configurations étudiées selon des régimes de fluctuations et de prédire les moments statistiques du champ acoustique jusqu’à l’ordre quatre. Une excellente correspondance est observée entre notre protocole expérimental et des résultats théoriques et numériques.La dégradation des performances des techniques de détection classiques appliquées à nos données expérimentales souligne le besoin de techniques correctives. Un état de l’art des techniques existantes dans divers domaines est proposé. / The ocean medium is subject to many sources of fluctuations. The most critical ones were found to be internal waves, occurring frequently and inducing fluctuations of the spatial distribution of the sound speed field. Because of the fairly long period of this phenomenon as compared to the propagation time of acoustic waves for sonar applications, the process can be considered frozen in time for each stochastic realization of the medium. The development of testbenches allowing to reproduce the effect of atmospheric turbulence on optic waves propagation under laboratory conditions lead to considerable advancements in the field of adaptive optics. We therefore see a vivid interest in being able to reproduce the effects of internal waves on sound propagation in controlled environments. An experimental protocol in a water tank is proposed: an ultrasonic wave is transmitted through a randomly rough acoustic lens, producing distortions of the received wavefront. The induced signal fluctuations are controlled by tuning the statistical parameters of the roughness of the lens. Especially, they are linked to dimensional parameters allowing to classify the configurations into regimes of fluctuations and to predict the statistical moment of the acoustic pressure up to the fourth order. A remarkable relevance of our experimental scheme is found when compared to theoretical and simulation results. The degradation of classical signal processing techniques when applied to our acquired data highlights the need for corrective detection techniques. A review of the existing techniques in other domains is proposed.

Advent of ultrashort lasers made it possible to probe various scattering phenomena in materials that occur in a time scale on the order of few femtoseconds to several tens of picoseconds. Nonlinear optical spectroscopy techniques, such as pump-probe, transient four wave mixing (TFWM), etc., are very common to study the carrier dynamics in various material systems. In time domain, the transient FWM uses several ultrashort pulses separated by time delays to obtain the information of dephasing and population relaxation times, which are very important parameters that govern the carrier dynamics of materials. A recently developed multidimensional nonlinear optical spectroscopy is an enhanced version of TFWM which keeps track of two time delays simultaneously and correlate them in the frequency domain with the aid of Fourier transform in a two dimensional map. Using this technique, the nonlinear complex signal field is characterized both in amplitude and phase. Furthermore, this technique allows us to identify the coupling between resonances which are rather difficult to interpret from time domain measurements. This work focuses on the study of the coherent response of a two dimensional electron gas formed in a modulation doped GaAs/AlGaAs quantum well both at zero and at high magnetic fields. In modulation doped quantum wells, the excitons are formed as a result of the inter- actions of the charged holes with the electrons at the Fermi edge in the conduction band, leading to the formation of Mahan excitons, which is also referred to as Fermi edge singularity (FES). Polarization and temperature dependent rephasing 2DFT spectra in combination with TI-FWM measurements, provides insight into the dephasing mechanism of the heavy hole (HH) Mahan exciton. In addition to that strong quantum coherence between the HH and LH Mahan excitons is observed, which is rather surprising at this high doping concentration. The binding energy of Mahan excitons is expected to be greatly reduced and any quantum coherence be destroyed as a result of the screening and electron-electron interactions. Such correlations are revealed by the dominating cross-diagonal peaks in both one-quantum and two-quantum 2DFT spectra. Theoretical simulations based on the optical Bloch Equations (OBE) where many-body effects are included phenomenologically, corroborate the experimental results. Time-dependent density functional theory (TD-DFT) calculations provide insight into the underlying physics and attribute the observed strong quantum coherence to a significantly reduced screening length and collective excitations of the many-electron system. Furthermore, in semiconductors under the application of magnetic field, the energy states in conduction and valence bands become quantized and Landau levels are formed. We observe optical excitation originating from different Landau levels in the absorption spectra in an undoped and a modulation doped quantum wells. 2DFT measurements in magnetic field up to 25 Tesla have been performed and the spectra reveal distinct difference in the line shapes in the two samples. In addition, strong coherent coupling between landau levels is observed in the undoped sample. In order to gain deeper understanding of the observations, the experimental results are further supported with TD-DFT calculation.

The debate over the legitimacy of Fibromyalgia as a pain syndrome is often highlighted in the literature. The result of this is that patients are left feeling demoralised by the lack of acknowledgement of their symptoms and the innuendos of hypochondria or malingering. This study proposes that professionals move beyond this and into a more solution-focused stage that encourages the examination of predisposing factors and the implementation of means of improving the lives of patients. The aim of this study was to describe the psychological profiles of Fibromyalgia patients in terms of attachment styles, Sense of Coherence, Attributional Style and depression. Twenty-nine patients aged between twenty-two and sixty-four participated in the study, completing the relevant questionnaires. The design is a quantitative one, with both descriptive and inferential statistical procedures being employed to analyse the data. It is argued that key elements in the onset, maintenance and augmentation of Fibromyalgia Syndrome symptoms are to be found by examining the psychological feature of patients with the disorder. Although some research has been conducted into psychological factors in Fibromyalgia, the field is not nearly as well explored as the physical elements. This research is therefore of great importance to the Fibromyalgia knowledge base. Moreover, it offers a Salutogenic perspective, which may be useful in combating the devastating effects of this chronic pain syndrome. The study is limited by its cross-sectional design and lack of control group. Nonetheless, it does give rise to some intriguing findings. If attachment is to be regarded as the working model that an individual maintains of self and other, then it is possible that disorders that are believed to be related to depression (such as FMS) will also be correlated to insecure attachment styles. The research, however, indicates that the FMS patients in this sample do not display the predicted high percentage of insecure attachment styles. An almost even split between those having a high Sense of Coherence and those with a low score was also found. When relating these findings to other psychological parameters (such as Attributional Style and level of depressive symptoms), a discussion is born that allows for more complex interactions than a linear argument does. The research is then lifted from its pathogenic origins to embrace the origins of health. Further research is then prompted by this study and framed in the Salutogenic question: how do some patients with FMS maintain healthy attachment styles and a high Sense of Coherence despite their illness? / Dissertation (MA (Clinical Psychology))--University of Pretoria, 2007. / Psychology / unrestricted

No description available.

The present work describes coherence structure of English and Czech book introductions. The account of coherence is based on Rhetorical Structure Theory (Mann and Thompson, 1988; Mann and Taboada, 2006) which posits that majority of texts have one main effect which can be described by one of their inventory of thirty-two rhetorical relations; other relations are organized in a hierarchical structure and contribute to the main effect. Out of thirty monographs compiled for each language, four book introductions were chosen to represent the English language and four to represent the Czech language. The data were annotated in terms of rhetorical structure. The qualitative analysis showed that the genre of book introduction does not differ across languages as all texts were described by the same top-level relations; the only difference concerns the position of the goal of the monograph. The queantitative analysis showed that the difference on lower levels concerns the presentation of past research: Czech focused more on presenting elements of subject-matter. Key words: coherence, rhetorical relations, Rhetorical Structure Theory, book introductions, English, Czech, monographs, genre

A stochastic leaky integrate-and-fire neuron model was implemented in this study to simulate the spiking activity of the electrosensory "P-unit" receptor neurons of the weakly electric fish Apteronotus leptorhynchus. In the context of sensory coding, these cells have been previously shown to respond in experiment to natural random narrowband signals with either a linear or nonlinear coding scheme, depending on the intrinsic firing rate of the cell in the absence of external stimulation. It was hypothesised in this study that this duality is due to the relation of the stimulus to the neuron's excitation threshold. This hypothesis was validated with the model by lowering the threshold of the neuron or increasing its intrinsic noise, or randomness, either of which made the relation between firing rate and input strength more linear. Furthermore, synchronous P-unit firing to a common input also plays a role in decoding the stimulus at deeper levels of the neural pathways. Synchronisation and desynchronisation between multiple model responses for different types of natural communication signals were shown to agree with experimental observations. A novel result of resonance-induced synchrony enhancement of P-units to certain communication frequencies was also found.