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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

High-quality dense stereo vision for whole body imaging and obesity assessment

Yao, Ming, Ph. D. 12 August 2015 (has links)
The prevalence of obesity has necessitated developing safe and convenient tools for timely assessing and monitoring this condition for a broad range of population. Three-dimensional (3D) body imaging has become a new mean for obesity assessment. Moreover, it generates body shape information that is meaningful for fitness, ergonomics, and personalized clothing. In the previous work of our lab, we developed a prototype active stereo vision system that demonstrated a potential to fulfill this goal. But the prototype required four computer projectors to cast artificial textures on the body which facilitate the stereo-matching on texture-deficient images (e.g., skin). This decreases the mobility of the system when used to collect a large population data. In addition, the resolution of the generated 3D~images is limited by both cameras and projectors available during the project. The study reported in this dissertation highlights our continued effort in improving the capability of 3Dbody imaging through simplified hardware for passive stereo and advanced computation techniques. The system utilizes high-resolution single-lens reflex (SLR) cameras, which became widely available lately, and is configured in a two-stance design to image the front and back surfaces of a person. A total of eight cameras are used to form four pairs of stereo units. Each unit covers a quarter of the body surface. The stereo units are individually calibrated with a specific pattern to determine cameras' intrinsic and extrinsic parameters for stereo matching. The global orientation and position of each stereo unit within a common world coordinate system is calculated through a 3Dregistration step. The stereo calibration and 3Dregistration procedures do not need to be repeated for a deployed system if the cameras' relative positions have not changed. This property contributes to the portability of the system, and tremendously alleviates the maintenance task. The image acquisition time is around two seconds for a whole-body capture. The system works in an indoor environment with a moderate ambient light. Advanced stereo computation algorithms are developed by taking advantage of high-resolution images and by tackling the ambiguity problem in stereo matching. A multi-scale, coarse-to-fine matching framework is proposed to match large-scale textures at a low resolution and refine the matched results over higher resolutions. This matching strategy reduces the complexity of the computation and avoids ambiguous matching at the native resolution. The pixel-to-pixel stereo matching algorithm follows a classic, four-step strategy which consists of matching cost computation, cost aggregation, disparity computation and disparity refinement. The system performance has been evaluated on mannequins and human subjects in comparison with other measurement methods. It was found that the geometrical measurements from reconstructed 3Dbody models, including body circumferences and whole volume, are highly repeatable and consistent with manual and other instrumental measurements (CV < 0.1$%, R2>0.99). The agreement of percent body fat (%BF) estimation on human subjects between stereo and dual-energy X-ray absorptiometry (DEXA) was found to be improved over the previous active stereo system, and the limits of agreement with 95% confidence were reduced by half. Our achieved %BF estimation agreement is among the lowest ones of other comparative studies with commercialized air displacement plethysmography (ADP) and DEXA. In practice, %BF estimation through a two-component model is sensitive to body volume measurement, and the estimation of lung volume could be a source of variation. Protocols for this type of measurement should still be created with an awareness of this factor. / text
2

Reliability of 3D laser-based anthropometry and comparison with classical anthropometry

Kühnapfel, Andreas, Ahnert, Peter, Löffler, Markus, Broda, Anja, Scholz, Markus 08 June 2016 (has links) (PDF)
Anthropometric quantities are widely used in epidemiologic research as possible confounders, risk factors, or outcomes. 3D laser-based body scans (BS) allow evaluation of dozens of quantities in short time with minimal physical contact between observers and probands. The aim of this study was to compare BS with classical manual anthropometric (CA) assessments with respect to feasibility, reliability, and validity. We performed a study on 108 individuals with multiple measurements of BS and CA to estimate intra- and inter-rater reliabilities for both. We suggested BS equivalents of CA measurements and determined validity of BS considering CA the gold standard. Throughout the study, the overall concordance correlation coefficient (OCCC) was chosen as indicator of agreement. BS was slightly more time consuming but better accepted than CA. For CA, OCCCs for intra- and inter-rater reliability were greater than 0.8 for all nine quantities studied. For BS, 9 of 154 quantities showed reliabilities below 0.7. BS proxies for CA measurements showed good agreement (minimum OCCC > 0.77) after offset correction. Thigh length showed higher reliability in BS while upper arm length showed higher reliability in CA. Except for these issues, reliabilities of CA measurements and their BS equivalents were comparable.
3

Mosquito popper: a multiplayer online game for 3D human body scan data segmentation

Nolte, Zachary 01 May 2017 (has links)
Game with a purpose (GWAP) is a concept that aims to utilize the hours spent in the world playing video games by everyday people to yield valuable data. The main objective of this research is to prove the feasibility of using the concept of GWAP for the segmentation and labeling of massive amount of 3D human body scan data. The rationale behind using GWAP as a method for mesh segmentation and labeling is that the current methods use expensive, time consuming computational algorithms to accomplish this task. Furthermore, the computer algorithms are not as detailed and specific as what natural human ability can achieve in segmentation tasks. The method presented in this paper overcomes the shortcomings of computer algorithms by introducing the concept of GWAP for human model segmentation. The actual process of segmenting and labeling the mesh becomes a form of entertainment rather than a tedious process, from which segmentation data is produced as a bi-product. In addition, the natural capabilities of the human visual processing systems are harnessed to identify and label various parts of the 3D human body shape, which in turn gives more details and specificity in segmentation. The effectiveness of the proposed game play mechanism is proven by experiments conducted in this study.
4

Designing for Body Awareness - A Study on Enabling Body Awareness in Mindfulness Through Wearable Haptic Thermal Technology

Brolin, Lisa January 2017 (has links)
A stressful society with a deficiency of attention has led to a growing demand for meditation techniques. One meditation technique is mindfulness, which is a tool used to reduce stress, intensify body awareness and to help us be more present. However, as mindfulness requires extensive training and dedication, many beginners may decide to quit practicing in the initial phase and may risk not ever experiencing the benefits of body awareness. Previous studies indicate that technology is often blamed for the deficiency of attention. Therefore, this study addresses the possibilities to design technology for sustained attention. More precisely, the study aims to investigate what potential possibilities wearable haptic technology has in enabling body awareness in body scan meditation in mindfulness. It also aims to explore how beginners in mindfulness experience the use of wearable haptic technology in body scan meditation. The study explores these problems by combining research through design and action research, with three phases of iteration, resulting in the design, implementation and evaluation of the wearable prototype HeatCue with haptic thermal feedback. The study implies that HeatCue provides an intimate, subtle and skin-close interaction, suitable for the context of body scan mediation. The results indicate that wearable haptic technology with thermal feedback holds the possibility to enable body awareness in body scan meditation through acting as a reminder for the body part where the feedback is applied, a reference for the rest of the body as well as encouragement. Furthermore, the study shows that wearable haptic technology is beneficial in evoking emotions and interest. The study also indicates some key aspects when designing for body awareness, namely; subtlety and interplay of the feedback, a secluded environment and an understanding that each individual is different. The study contributes to a deeper understanding of designing for body awareness and to new knowledge in the field of wearable haptic technology with thermal feedback and techno-spirituality in human-computer interaction
5

Reliability of 3D laser-based anthropometry and comparison with classical anthropometry

Kühnapfel, Andreas, Ahnert, Peter, Löffler, Markus, Broda, Anja, Scholz, Markus January 2016 (has links)
Anthropometric quantities are widely used in epidemiologic research as possible confounders, risk factors, or outcomes. 3D laser-based body scans (BS) allow evaluation of dozens of quantities in short time with minimal physical contact between observers and probands. The aim of this study was to compare BS with classical manual anthropometric (CA) assessments with respect to feasibility, reliability, and validity. We performed a study on 108 individuals with multiple measurements of BS and CA to estimate intra- and inter-rater reliabilities for both. We suggested BS equivalents of CA measurements and determined validity of BS considering CA the gold standard. Throughout the study, the overall concordance correlation coefficient (OCCC) was chosen as indicator of agreement. BS was slightly more time consuming but better accepted than CA. For CA, OCCCs for intra- and inter-rater reliability were greater than 0.8 for all nine quantities studied. For BS, 9 of 154 quantities showed reliabilities below 0.7. BS proxies for CA measurements showed good agreement (minimum OCCC > 0.77) after offset correction. Thigh length showed higher reliability in BS while upper arm length showed higher reliability in CA. Except for these issues, reliabilities of CA measurements and their BS equivalents were comparable.
6

Place de l'iode 131 et de l'imagerie scintigraphique dans la prise en charge des cancers différenciés de la thyroïde / Role of I131 and Scintigraphic Imaging in the Management of Differentiated Thyroid Cancer

Leboulleux, Sophie 11 October 2013 (has links)
Le traitement initial des cancers différenciés de la thyroïde (CTD) consiste en une thyroïdectomie totale suivie, dans de nombreux cas par l’administration d’iode 131. Après thyroïdectomie totale, un traitement par iode 131 est indiqué en fonction des caractéristiques tumorales initiales. Chez les patients à risque élevé de rechute il est recommandé d’administrer une forte activité d’iode 131. Chez les patients à très faible risque il est recommandé de ne pas administrer d’iode 131. Dans le groupe intermédiaire, il a été montré par deux études prospectives multicentriques randomisées (ESTIMABL et HILO) qu’une activité de 1,1 GBq (30 mCi) administrée après TSHrh (Thyroid Stimulating Hormon recombinante humaine) était adaptée. La désescalade thérapeutique se poursuit dans le cadre d’un autre essai prospectif randomisé (ESTIMABL 2) comparant une activité de 30 mCi après injection de TSHrh à une simple surveillance. Chez les patients avec maladie résiduelle la tomographie par émission de positon couplée à un scanner (TEP/TDM) au fluorodesoxyglucose (FDG) est un examen clé avec une valeur à la fois diagnostique et thérapeutique. Les fixations de FDG permettent de localiser la maladie résiduelle, surtout lorsqu’elle ne capte pas l’iode. Chez les patients dont le site de récidive n’est pas déterminé par l’échographie cervicale, la TEP/TDM au FDG est plus sensible que la scintigraphie post-thérapeutique réalisée après administration d’une forte activité d’iode 131 (dite activité empirique) et est considéré comme l’examen de première intention. La réalisation d’une stimulation par TSHrh avant la TEP au FDG augmente le nombre de lésions détectées et donc sa sensibilité sans que les modifications thérapeutiques qui en découlent soient néanmoins significatives. Le rôle de la TEP FDG dans la sélection des patients nécessitant un traitement par inhibiteur de tyrosine kinase et dans l’évaluation antitumorale des inhibiteurs de tyrosine kinase reste à démontrer. L’utilisation d’ITK pour ré-induire les fixations d’iode 131 sont une voie majeure de développement pour les patients ayant une maladie réfractaire à l’iode 131. / Initial treatment of differentiated thyroid cancer is based on a total thyroidectomy and in many cases on the administration of radioactive iodine. Following total thyroidectomy, radioactive iodine is given, based on the primary tumor characteristics. In case of a very low risk of recurrence it is recommended not to give radioactive treatment. In case of high risk patients, a high activity of radioactive iodine is given after TSH stimulation. In case of intermediate risk patients, two randomized prospective studies (ESTIMABL and HILO) have shown that an activity of 1,1 GBq (30 mCi) given after rhTSH (recombinant human Thyroid Stimulating Hormon) was adequate. A further step is taken towards less treatment has now been undertaken with the ESTIMABL2 study, a prospective randomized study comparing a treatment with 1,1 GBq (30 mCi) of radioactive iodine treatment to follow-up without ablation. In patients with persistent disease, positron emission tomography with computed tomography (PET/CT) is a key examination used for its diagnostic and prognostic value. Foci of FDG uptake can localize residual disease, especially when it does not take up radioactive iodine. In patients in whom the site of recurrence remains unknown after a neck ultrasonography PET/CT with FDG is more sensitive than a post-therapeutic whole body scan performed after the administration of a high activity of radioactive iodine (empiric iodine) and should be considered as the first examination to perform. Injections of rhTSH before doing FDG PET/CT allow to increase the number of lesions detected, however the treatment changes linked to this preparation remains minor. The role of FDG PET/CT in the selection of patients to tyrosine kinase inhibitors (TKI) and to assess metabolic tumor response remains to be explored. The use of TKI to reinduce radioactive iodine uptake is a major research subject for patients with radioactive iodine refractory disease.
7

Passformsgrund till formad sportjacka : Digital framtagningsmetod med fokus på passform och gradering / Pre-shaped jacket for active wear

Forsbäck, Katarina January 2015 (has links)
Vid digital mönsterkonstruktion för ett plagg krävs ett befintligt grundmönster som utgångspunkt för att kunna tidseffektivisera framtagningsprocessen. På konfektionsföretag där tid för mönsterkonstruktion är bristfällig lämnas detta moment ofta till fabriksanställda trots att kompetens finns inom företaget. Denna studie syftar till att ta fram en passformsgrund till ett sportföretags formade jackor för att främja framtida konstruktionsprocess för företagets konstruktörer. Resultat har uppnåtts med hjälp av metoder som digital mönsterkonstruktion, sömnad av provplagg och avprovningar. För att grunden ska kunna användas till företagets hela storleksintervall har denna graderats. Verifiering av graderingen har utförts genom virtuell avprovning på inskannade provpersoner i ett 3D-simuleringsprogram. Resultatet visar en passformsgrund där företagets återkommande passformsproblem över byst har korrigerats. Till passformsgrunden har tre ärmar konstruerats för att bredda användningen av mönstret. Passformsproblemet och ärmarnas form har korrigerats i mönsterkonstruktionen genom förflyttning av skärlinjer, vridningar och formtillägg. Graderingens utfall visas genom digitala avprovningar i företagets brytstorlekar. Skärmdumpar från 3D-simuleringsprogrammet visualiserar skärlinjernas placering och plaggets passform. / When developing a digital pattern for a new garment a basic pattern is required to efficient the construction time. In companies where the construction process is handed over to the producing factory is the reason sometimes a lack of time for this process at the head office. This report aim is to develop a basic pattern to a sports company’s shaped jackets for women. The pattern is intended to efficient the construction time for the company's constructors when developing future jacket models. In order to achieve the result digital pattern making, toile sewing and fitting will be crucial methods to use. The basic pattern will be graded in the company’s size range. To verify the fit of the graded pattern test persons will be scanned and a virtual fitting session will be done on avatars in a 3D simulation program. The results show’s a basic pattern were the fit problem over bust area has been corrected. To enhance the usability of the pattern, three different sleeve types have been developed. The fit problem and the form of the sleeves have been solved in the pattern construction by moving the cut lines, twists and adding shape. The digital fitting process shows the grading’s outcome when the garment is tested in the company's bigger and smaller sizes. Screenshots from the 3D simulation software visualizes the cut lines placement and the fit of the garment.
8

Investigation of the Efficacy of Integrative Treatment Methods for Chronic Cough

Garvin, Natalie Tyrey 26 April 2023 (has links)
No description available.

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