Flexor tendon repair of the hand and rehabilitation are frequently discussed between hand surgeons and therapists. This is mainly due to the poor outcomes commonly achieved after this type of surgery. There are many patients in public hospitals in South Africa who require flexor tendon repair surgery. They are regularly sent to therapists for rehabilitation, where the early passive motion protocol is commonly implemented. Although the early active motion protocol has yielded improved results globally, there is limited evidence on the comparison of the outcomes of these two protocols in the South African context. The aim of the study was to compare the outcomes of an early active motion protocol to the outcomes of an early passive motion protocol in patients with zone II to IV flexor tendon repairs of the hand, attending rehabilitation at Chris Hani Baragwanath Academic Hospital. The study was a quantitative single-blinded comparative controlled trial. Forty-six patients who sustained a zone II-IV flexor tendon injury were recruited for the study and equally distributed between the two groups (early active motion and early passive motion). Out of these participants, 11 did not return for the initial assessment at four weeks post-surgery and were therefore excluded. There were 19 participants in the early active motion group and 16 participants in the early passive motion group. Results were collected and classified at 4, 8 and 12 weeks post-surgery. Data collection took place from December 2014 to January 2016 in the Chris Hani Baragwanath Academic Hospital Hand Unit. At 12 weeks post-surgery, the total active motion, fingertip to table, and distal palmar crease measurements were similar between the two groups. Tendon rupture occurred in 8.57% (n=3, early active motion = 5.71%, early passive motion = 2.86%) of patients. This study found that there was no difference in outcomes between the two groups. Therefore, either protocol could be implemented in South African public hospitals. However, since the early active motion protocol takes less time to implement, this protocol is recommended. A study with a greater magnitude would be necessary to determine a significant comparison between the two groups; however, this is challenging due to poor patient compliance. / Dissertation (MOccupational Therapy)--University of Pretoria, 2017. / Occupational Therapy / MOccupational Therapy / Unrestricted

Considérant une particule isolée, la différence principale entre un colloïde actif et un colloïde passif réside dans le temps de persistance du régime balistique. La transition du régime balistique vers le régime diffusif est déterminée dans les deux cas par des coefficients de friction ou de manière équivalente par des coefficients de diffusion. Le mouvement d’une particule colloïdale passive micrométrique est diffusif lorsqu’il est observé sur des intervalles de temps d’au moins une microseconde, suffisamment longs pour que la direction de la quantité de mouvement soit rendue aléatoire par des collisions avec les molécules de solvant. A l’échelle macroscopique ces collisions se traduisent par un coefficient de friction de translation. Pour une particule colloïdale active, un mouvement diffusif est observé pour des intervalles de temps de plusieurs secondes, suffisamment longs pour que la direction d’auto-propulsion soit rendue aléatoire par la diffusion rotationnelle de la particule.Dans cette thèse, nous étudions le mouvement d’une particule colloïdale active déposée à la surface de l’eau. Des particules Janus aux propriétés catalytiques ont été préparées par dépôt de platine métal à la surface de particules de silice. La profondeur d’immersion des particules ainsi que leur orientation par rapport à la surface de l’eau ont été caractérisées et discutées en tenant compte des propriétés de mouillage non-uniformes de la surface des particules Janus. Le mouvement de particules isolées en présence de quantités variables d’eau oxygénée utilisée comme source d’énergie, a été enregistré par vidéo-microscopie optique et les trajectoires analysées en termes de déplacement carré moyen et de fonction d’auto-corrélation des vitesses. L’observation de deux types de trajectoires, rectilignes et circulaires, révèle la force effective ainsi que le couple induit par la décomposition catalytique de l’eau oxygénée à la surface de la particule Janus. Le résultat principal de ce travail est que le mouvement des particules actives confinées à l’interface persiste plus longtemps dans le régime balistique que celui de particules actives totalement immergées en solution. Ceci est dû au confinement qui réduit le nombre de degrés de liberté de rotation mais aussi aux conditions de mouillage partiel qui font apparaître des contributions supplémentaires à la friction de rotation. / At the single-particle level, the main difference between active colloids and passive ones is the time scale over which the motion crosses over from ballistic to diffusive regime. In both cases, friction coefficients or equivalently diffusion coefficients determine this time scale. For instance, the motion of a passive colloid of 1m radius is diffusive when observed over lag times longer than a microsecond, once the direction of its momentum has been randomized by collisions with solvent molecules. At the macroscopic scale these collisions are accounted for by the translational friction coefficient. For an active colloid the effective diffusive behavior observed over lag times larger than few seconds results from the randomization of the direction of self-propulsion by rotational diffusion. In this thesis we investigated the motion of an active Janus colloid trapped at air-water interface. Spherical catalytic Janus colloids have been prepared through the deposition of platinum metal at the surface of silica particles. Immersion depth of the Janus colloid as well as their orientation with respect to the water surface, has been characterized and interpreted in terms of the non-uniform wetting properties of the Janus particles. The motion of the active Janus colloids in the presence of various concentration of hydrogen peroxide H2O2 as fuel was characterized by video microscopy and the trajectories analyzed through the mean square displacement and the velocity autocorrelation function. The types of trajectories, directional and circular ones that we observed in our experiments, revealed the effective force and torque induced by the catalytic decomposition of H2O2. At the water surface, active colloids perform more persistent directional motions as compared to the motions performed in the bulk. This has been interpreted as due to the loss of degrees of freedom resulting from the confinement at interface and also to the partial wetting conditions that possibly bring new contributions to the rotational friction at interface.

Due to the large influx of computers in our daily lives, human-computer interaction has become crucially important. For a long time, focusing on what users need has been critical for designing interaction methods. However, new perspective tends to extend this attitude to encompass how human desires, interests, and ambitions can be met and supported. This implies that the way we interact with computers should be revisited. Centralizing human values rather than user needs is of the utmost importance for providing new interaction techniques. These values drive our decisions and actions, and are essential to what makes us human. This motivated us to introduce new interaction methods that will support human values, particularly human well-being. The aim of this thesis is to design new interaction methods that will empower human to have a healthy, intuitive, and pleasurable interaction with tomorrow’s digital world. In order to achieve this aim, this research is concerned with developing theories and techniques for exploring interaction methods beyond keyboard and mouse, utilizing human body. Therefore, this thesis addresses a very fundamental problem, human motion analysis. Technical contributions of this thesis introduce computer vision-based, marker-less systems to estimate and analyze body motion. The main focus of this research work is on head and hand motion analysis due to the fact that they are the most frequently used body parts for interacting with computers. This thesis gives an insight into the technical challenges and provides new perspectives and robust techniques for solving the problem.

Un bras de chargement de gaz est une structure articulée dans laquelle du méthane peut s’écouler à température cryogénique. En haute mer, ces bras sont installés sur le pont de navires-usines et se connectent à des méthaniers pour leur transférer du gaz. En raison de problèmes de sécurité et de performances, il est souhaité que le bras de chargement soit robotisé pour qu’il se connecte automatiquement. Cette thèse a pour objectif l‘automatisation de la connexion. Cette opération nécessite un pilotage de grande précision vis à vie de la taille du bras. Pour cette raison le bras est d’abord étalonné pour augmenter sa précision statique. Ensuite, des analyses modales expérimentales mettent en évidence l’importante souplesse de la structure des bras de chargement. Pour cette raison un générateur de trajectoires « douces », à jerk limité, est développé afin de piloter le bras sans le faire vibrer. Enfin, un système de compensation actif visant à compenser les mouvements relatifs des deux navires est mis en place. Cette compensation combine la génération de trajectoires douces avec une composante prédictive basée sur des réseaux de neurones. Cette dernière permet de prédire et d’anticiper les mouvements des navires sur l’océan, afin d’annuler tout retard dans la compensation. Finalement, cette thèse présente la première connexion automatique d’un bras de chargement, et démontre la validité de cette approche. / Marine loading arms are articulated structures that transfer liquefied gas between two vessels. The flanging operation of the loading arm to the receiving tanker is very sensitive. This thesis aims to robotize a loading arm so it can flange automatically. The required accuracy for the connection is very high. A calibration procedure is thus proposed to increase the accuracy of loading arms. Moreover a jerk-limited trajectory generator is developed to smoothly drive the arm without inducing oscillation. This element is important because the structures of loading arms have a very low stiffness and easily oscillate, as highlighted by modal analyses.A predictive active compensation algorithm is developed to track without delay the relative motion between the two vessels. This algorithm relies on an artificial neural network able to predict the evolution of this relative motion. Finally this thesis presents the first automatic connection of an offshore loading arm. The success of the final tests validate the feasibility the automatic connection and the validity of this approach.