Cette thèse porte sur la prise en compte des variations anatomiques, notamment les déformations d’organes à risque (rectum, vessie), pouvant survenir lors du traitement de radiothérapie conformationnelle par modulation d’intensité du cancer de la prostate. Ces variations peuvent entrainer d’importants écarts dosimétriques par rapport au plan de traitement initialement optimisé, et augmenter le risque de complications. Grâce à l’évolution des dispositifs d’imagerie et des méthodes de traitement d’images, des approches permettant de cumuler la dose au cours du traitement ont été récemment proposées mais restent mal évaluées et leur intégration dans un schéma de radiothérapie adaptative suscite de nombreuses questions. Ainsi, la première partie de ce travail a consisté à évaluer, à l’aide d’un fantôme numérique, une méthode de suivi de dose développée récemment au LTSI. Les résultats obtenus ont montré que les incertitudes dosimétriques liées à l’algorithme de cumul de dose sont limitées par rapport aux dérives dosimétriques observées chez les patients. La seconde partie de ce travail a consisté à proposer une stratégie de radiothérapie adaptative reposant sur le suivi de dose et à évaluer son bénéfice dosimétrique sur trois patients pour lesquels des dérives avaient été observées. Le principe de cette méthode est de détecter les dérives dosimétriques entre la dose planifiée et la dose réellement délivrée et, si besoin, de les compenser grâce à une ou plusieurs replanifications. Les résultats obtenus ont montré que cette approche permet une réduction de la dérive aux organes à risque, tout en augmentant la dose au volume cible en comparaison à un traitement standard par IGRT, avec un nombre limité de replanifications (une ou deux) permettant d’envisager une implémentation clinique. / This thesis concerns the compensation of the anatomical variations, mainly the organs at risk (rectum, bladder) deformations, which occur during intensity modulated radiotherapy of the prostate cancer. These variations can lead to significant dose drift compared to the initially planned dose, increasing the risk of toxicity. Thanks to the evolution of imaging devices and of image processing methods, dose accumulation processes, allowing to estimate the cumulated dose during the treatment, have been recently proposed. Nevertheless those strategies suffer of a lack of evaluation and their integration into an adaptive radiotherapy raises many questions. Thus, in the first part of this work, a dose accumulation method recently developed at the LTSI was evaluated using a numerical phantom. The results obtained showed that the dosimetric uncertainties related to the cumulated dose process remain low compared to the dose drifts observed for patients. The second part of this work aimed to develop a dose guided adaptive radiotherapy process and to evaluate its dosimetrical benefit using three patients showing a dose drift. The principle of this method is to detect a potential drift between the planned and actually delivered doses and, if necessary, to compensate them thanks to one or more replanning(s). The results have shown that this approach has reduced the dose drift to the organs at risk, while increasing the dose to the prostate compared to standard IGRT treatment, with a limited number of replannings (one or two), enabling to consider a clinical implementation.

This thesis proposes a multidirectional methodological framework for a comprehensive ergonomic analysis and modelling of workflow for multi-modal vascular image-guided procedures (IGPs). Two approaches are employed to analyse the workflow: Discrete Event Simulation (DES) and purpose-oriented physical models. In contrast to previous studies, the proposed methodology looks in detail the actions carried out within the intervention rooms and the clinical experience during the procedures with three main objectives: to provide a deeper understanding of vascular procedures, to predict the impact of protocol modifications and to offer a framework to develop new image-guided protocols for the alternative use of Magnetic Resonance (MR) imaging in comparison with X-Ray Digital Subtraction Angiography (DSA). The methodological framework includes an assessment of commercial simulation software packages to evaluate their fitness to the specific requirements of this research. The novel methodology is applied to several cases studies of common vascular IGPs. In addition, a case of MR – guided focused ultrasound intervention demonstrates how it is possible to extend the framework to study non-vascular IGPs. The multi-disciplinary methodological framework described opens a new way to understand IGPs that could be used in prospective applications such as medical education and medical devices regulations.

Students Learn when they are actively engaged and thinking in class. The activities in this book are the primary classroom materials for teaching Anatomy and Physiology, sing the POGIL method. The result is an "I can do this" attitude, increased retention, and a feeling of ownership over the material. / https://dc.etsu.edu/etsu_books/1027/thumbnail.jpg

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 2012

No description available.

Every year, millions of Americans suffer from either chronic or acute pain that results in tremendous healthcare cost, rehabilitation, and loss of work productivity. Pain is an unpleasant sensation associated with sensory and emotional experiences that can cause potential or actual tissue damage. One plausible solution to managing pain is the use of nonpharmacological modalities such as guided imagery. The purpose of this project was to determine if there was a difference in pain scores following pharmacological interventions and the use of guided imagery among postoperative same day surgical patients. Guided imagery is a nonpharmacological modality that uses pictures, music, and imaginary scenes to help heal the body in addition to using relaxation techniques and mental images for the management of pain. This project included the translation of evidence into practice using guided imagery on a 25-bed same day surgery unit (N = 34 patients), guided by Kolcaba's comfort theory. The findings of this project included using guided imagery for same day surgery patients who rated their pain greater than 4 on the traditional pain scale of one to ten, with one equaling no pain and ten equaling worst pain. The results of the evaluation showed a significant decrease in pain scores between premedication to postmedication (p < 0.001), premedication and postguided imagery (p < 0.001), and postmedication and postguided imaginary (p < 0.001). Guided imagery has been demonstrated to be efficient and cost effective methods to reducing pain. This project indicated that use of nonpharmacological and pharmacological interventions working together could be more effective for pain management in same day surgical patients.

Within a Southwestern school system, deficits in early literacy skills exist as is illustrated by kindergarten students not meeting the requirements on the Phonological Awareness and Phonics Inventory (PAPI). To address this deficit in early literacy skills, the school system instituted the use of the Guided Reading Approach (GR); however, it was unknown how the kindergarten teachers were implementing GR. The purpose of this study was to investigate the experiences and challenges of kindergarten teachers who implement GR. Vygotsky's sociocultural theory of learning and constructivist theory provided the conceptual framework. Research questions explored the thoughts, attitudes, and beliefs teachers hold about GR as well as the challenges teachers face when incorporating GR. A case study methodology was used to investigate 6 kindergarten teachers' experiences with implementing GR through the use of interviews and document analysis. Analysis of data revealed that teachers believed that GR was a necessary component of teaching and increased student success. However, teachers did not have enough training, collaboration, or time to invest in GR. A professional training was developed for teachers as a result. The 3-day training will provide teachers with an overview of GR, opportunities for the participants to collaborate with colleagues, and time for the development of GR lesson plans that can immediately be transferred to the classroom. Positive social change may result by helping teachers better understand GR (components and implementation), which may result in an improved reading program, higher student performance, and information to influence others to improve reading programs.

Différents modèles sont développés de façon à constituer des outils génériques pour la simulation de méthodes de contrôle non-destructif par ondes élastiques guidées de plaques métalliques ou composites. Diverses méthodes de contrôle de ces structures existent ou sont à l’étude. La plupart font appel à des sources ultrasonores de taille finie ; toutes sont confrontées aux phénomènes de réflexion résultant de la taille finie des objets contrôlés. Les modèles développés traitent des phénomènes de diffraction associés aux sources et de réflexion sur un bord de plaques. Comme l’interprétation des signaux mesurés lors de contrôle par ondes guidées fait souvent appel à la notion de modes guidés, les modèles sont eux-mêmes modaux. Les cas de plaques isotropes (métalliques) et anisotropes (composites multicouches) sont considérés ; une approche générale suivant l’approximation de la phase stationnaire permet de traiter tous les cas d’intérêt. Pour les premiers, la validité d’une approximation de type Fraunhofer permet de traiter très efficacement les champs directs et réfléchis rayonnés par une source. Pour les derniers, une attention particulière est portée sur le traitement des caustiques. La méthode de la phase stationnaire étant difficile à généraliser, un modèle de pinceau, de nature plus géométrique, est proposé présentant un haut degré de généricité. Il met en cascade des termes de propagation en milieu isotrope ou anisotrope et d’interaction avec une frontière. L’équivalence de la méthode de la phase stationnaire au modèle de pinceau est démontrée pour le rayonnement et la réflexion dans une plaque isotrope, cas faisant l’objet d’une validation expérimentale. / Different models are developed to provide generic tools for simulating nondestructive methods relying on elastic guided waves applied to metallic or composite plates. Various inspection methods of these structures exist or are under study. Most of them make use of ultrasonic sources of finite size; all are sensitive to reflection phenomena resulting from the finite size of the monitored objects. The developed models deal with transducer diffraction effects and edge reflection. As the interpretation of signals measured in guided wave inspection often uses the concept of modes, the models themselves are explicitly modal. The case of isotropic plates (metal) and anisotropic (multilayer composites) are considered; a general approach under the stationary phase approximation allows us to consider all the cases of interest. For the first, the validity of a Fraunhofer-like approximation leads to a very efficient computation of the direct and reflected fields radiated by a source. For the second, special attention is paid to the treatment of caustics. The stationary phase approximation being difficult to generalize, a model (so-called “pencil model”) of more geometrical nature is proposed with a high degree of genericity. It chains terms of isotropic or anisotropic propagation and terms of interaction with a boundary. The equivalence of the stationary phase approximation and the pencil model is demonstrated in the case of the radiation and reflection in an isotropic plate, for which an experimental validation is proceeded.

Obesity is a serious public health issue within the U.S. and minimal long-term success is found with standard behavioral weight-loss treatments. Typical weight-loss interventions do not acknowledge psychological factors, such as weight-related stigma, which may play a role in the development and maintenance of poor coping behaviors, such as unhealthy eating patterns. Individuals who are obese may often experience weight-related stigma present in society and are ultimately at risk for weight self-stigma, which is related to poor health behaviors and increased psychological distress. Acceptance and commitment therapy (ACT), can be effective for treating numerous mental health presentations, might also be effective in decreasing weight self-stigma and improving health behaviors. Guided self-help may be particularly attractive to individuals struggling with weight self-stigma because it allows for greater flexibility and personal choice. There have been no previous randomized controlled trials evaluating guided self-help for weight self-stigma and health behavior change in obese populations. This study reports the results of a randomized controlled trial of ACT guided self-help for weight self-stigma comparing two versions of guided self-help with varying levels of support versus waitlist control. Each active condition provided unique levels of guided self-help to evaluate whether phone coaching enhanced the program. Results showed both active conditions were highly acceptable, although greater satisfaction with support and greater follow-through with book reading was found for those who received phone coaching. There were significant improvements at post in binge eating, physical activity, psychological distress, weight self-stigma, and weight-related psychological flexibility for both active conditions versus waitlist. Mediational analyses showed significant treatment effects, such that weight self-stigma and weight-related psychological flexibility fully and separately accounted for the relation between ACT guided self-help and binge eating behavior. The findings from this study provide the first randomized controlled trial data of an effective intervention for weight self-stigma. Clinical implications, limitations, and future directions are discussed.

Radiation therapy seeks to effectively irradiate the tumor cells while minimizing the dose to adjacent normal cells. Prior research found that the low success rates for treating brain tumors would be improved with higher radiation doses to the tumor area. This is feasible only if the target volume can be precisely identified. However, the definition of tumor volume is still based on time-intensive, highly subjective manual outlining by radiation oncologists. In this study the effectiveness of two automated Magnetic Resonance Imaging (MRI) segmentation methods, k-Nearest Neighbors (kNN) and Knowledge-Guided (KG), in determining the Gross Tumor Volume (GTV) of brain tumors for use in radiation therapy was assessed. Three criteria were applied: accuracy of the contours; quality of the resulting treatment plan in terms of dose to the tumor; and a novel treatment plan evaluation technique based on post-treatment images. The kNN method was able to segment all cases while the KG method was limited to enhancing tumors and gliomas with clear enhancing edges. Various software applications were developed to create a closed smooth contour that encompassed the tumor pixels from the segmentations and to integrate these results into the treatment planning software. A novel, probabilistic measurement of accuracy was introduced to compare the agreement of the segmentation methods with the weighted average physician volume. Both computer methods under-segment the tumor volume when compared with the physicians but performed within the variability of manual contouring (28% plus/minus12% for inter-operator variability). Computer segmentations were modified vertically to compensate for their under-segmentation. When comparing radiation treatment plans designed from physician-defined tumor volumes with treatment plans developed from the modified segmentation results, the reference target volume was irradiated within the same level of conformity. Analysis of the plans based on post- treatment MRI showed that the segmentation plans provided similar dose coverage to areas being treated by the original treatment plans. This research demonstrates that computer segmentations provide a feasible route to automatic target volume definition. Because of the lower variability and greater efficiency of the automated techniques, their use could lead to more precise plans and better prognosis for brain tumor patients.