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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.
11

Fázová separace v systému aminojíl-biopolymer / Phase separation in the system of aminoclay-biopolymer

Plotěná, Michaela January 2017 (has links)
The aim of this diploma thesis was to study the structure and to evaluate the properties of the hydrogel prepared by the interaction of the aminolclay with the biopolymer. Representatives of the biopolymers were selected from low to medium molecular weight sodium hyaluronate and sodium polystyrenesulfonate. On the basis of the experiments carried out, it was found that phase separation takes place only when the aminolclay interacts with medium molecular weight hyaluronan (MMW). In the experimental part, analyzes of this sample were carried out in order to determine the formation of phase-separated hydrogel by influencing the solution by ionic strength, investigation of hydrogel extinction in various organic solvents, stability of hydrogel under extreme temperature conditions, the effect of storage on its degradation, etc. Viscoelastic properties were experimentally proven by rheology and thermal analysis detected binding water. Inhibition of microorganisms was confirmed by antibacterial diffusion assays. All experiments were carried out for the use of the Aj-HyA hydrogel (MMW) in the field of medical applications, specifically for the modern method of wet wound healing of the skin.
12

The importance of immobilization and localization of gynecological applicators in high dose rate brachytherapy treatments

Unknown Date (has links)
Intracavitary high dose rate (HDR) brachytherapy is a form of radiation therapy generally in which a post-surgical tissue margin is treated. The dose gradient of HDR brachytherapy is very steep, and thus small displacements of the applicator, even as small as 1 mm, could potentially cause significant variations of dose which could result in undesired side effects such as overdose of a critical organ. In this retrospective dosimetric study, the variation of dose due to various small range motions of gynecological applicators is investigated. The results show that the implementation of additional immobilization and localization devices along with other safety measures needs to be further investigated. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection
13

ELICITAÇÃO DE REQUISITOS NÃO FUNCIONAIS EM CONFORMIDADE COM POLÍTICAS DE QUALIDADE PARA APLICAÇÕES MÉDICAS / ELICIT REQUIREMENTS FOR NON FUNCTIONAL PURSUANT POLICIES ON QUALITY FOR MEDICAL APPLICATIONS

BASTOS FILHO, Francisco de Assis Menêzes 30 March 2007 (has links)
Made available in DSpace on 2016-08-17T14:53:09Z (GMT). No. of bitstreams: 1 Francisco de Assis.pdf: 1036916 bytes, checksum: f22914501d5f211716214a40fad5d08a (MD5) Previous issue date: 2007-03-30 / For several years, a lot of research is being done trying to find a solution for various problems concerning requirements engineering. Various approaches have pointed out that the requirements phase is the most important stage in the software development process. In general, requirements that are mistakenly elicited, analyzed and specified, gives rise to the development of low quality software. Non functional requirements gained little attention in the literature and are less understood but they are critical factors to the software development. When these requirements are badly elicited or not elicited at all, this gives rise to a difficulty in their treatment and their validation. Thus, we think that treating non functional requirements from the elicitation phase we contribute to a good software quality. This work deals with two aspects related with non functional requirements, namely how to elicit them and how to guarantee those requirements in conformity with a quality policy, even when new requirements or new technologies are adopted. As to attain this aim, we have elicited the requirements starting from a defined quality set necessary for medical applications. We defined a quality policy based upon these needs in such a way we could measure the conformity of non functional requirements definition specified in the requirements Document (RDs) with the desired quality, specified in the quality policy. / Ao longo dos anos, muitas pesquisas vêm sendo desenvolvidas na tentativa de se encontrar uma solução para os problemas relacionados à engenharia de requisitos. Existe uma unanimidade em certas abordagens, em ressaltar que a fase de requisitos se constitui na etapa mais crucial no processo de desenvolvimento de software. Freqüentemente, requisitos de software são mal elicitados, analisados e especificados, sendo estes fatores decisivos para o desenvolvimento de software de baixa qualidade. Requisitos não funcionais têm recebido muito pouca atenção na literatura, são pouco compreendidos mas são críticos no processo de desenvolvimento de software. O fato destes requisitos serem mal elicitados ou não elicitados os tornam mais difíceis de serem tratados e validados. Acreditamos que ao abordarmos os requisitos não funcionais desde a fase de elicitação, estamos contribuindo para a qualidade geral do software que será produzido. Este trabalho aborda dois aspectos relacionados aos requisitos não funcionais: como elicitá-los e como garantir a conformidade desses requisitos com uma política de qualidade, mesmo quando novos requisitos ou novas tecnologias forem adotadas. Para atingir este objetivo, elicitamos os requisitos a partir de um conjunto de necessidades de qualidade definidas para aplicações médicas. Definimos uma política de qualidade baseada nestas necessidades, de modo que possamos medir a conformidade das definições dos requisitos não funcionais especificados no Documento de Requisitos (DRs) com a qualidade desejada, especificada na política de qualidade.
14

Enabling Automated, Conversational Health Coaching with Human-Centered Artificial Intelligence

Mitchell, Elliot Griffith January 2021 (has links)
Health coaching is a promising approach to support self-management of chronic conditions like type 2 diabetes; however, there aren’t enough coaching practitioners to support those in need. Advances in Artificial Intelligence (AI) and Machine Learning (ML) have the potential to enable innovative, automated health coaching interventions, but important gaps remain in applying AI and ML to coaching interventions. This thesis aims to identify computational approaches and interactive technologies that enable automated health coaching systems. First, I utilized computational approaches that leverage individuals’ self-tracking and health data and used an expert system to translate ML inferences into personalized nutrition goal recommendations. The system, GlucoGoalie, was evaluated in multiple studies including a 4-week deployment study which demonstrated the feasibility of the approach. Second, I compared human-powered and automated/chatbot approaches to health coaching in a 3-week study which found that t2.coach — a scripted, theoretically-grounded chatbot designed through an iterative, user-centered process — cultivated a coach-like experience that had many similarities to the experience of messaging with actual health coaches, and outlined directions for automated, conversational coaching interventions. Third, I examined multiple AI approaches to enable micro-coaching dialogs — brief coaching conversations related to specific meals, to support achievement of nutrition goals — including a knowledge-based system for natural language understanding, and a data-driven, reinforcement learning approach for dialog management. Together, the results of these studies contribute methods and insights that take steps towards more intelligent conversational coaching systems, with resonance to research in informatics, human-computer interaction, and health coaching.
15

Characterizing Bacterial Resistance and Microstructure-Related Properties of Carbon-Infiltrated Carbon Nanotube Surface Coatings with Applications in Medical Devices

Morco, Stephanie Renee 05 April 2021 (has links)
Carbon-infiltrated carbon nanotube (CICNT) forests are carbon nanotube (CNT) forests infiltrated with pyrolytic carbon to increase durability by becoming a solid material. This material can be tuned to maintain the nanotube geometry of a CNT forest and can also be fabricated on a variety of materials and geometries. Additionally, the present work has indicated that CICNT forests may resist bacterial proliferation and biofilm formation. This phenomenon is not due to the CICNT chemistry; it is presumably due to the CICNT nanostructure morphology. Thus, both silicon and stainless steel substrates were used to investigate CICNT's structural resistance to Methicillin-resistant Staphylococcus aureus (MRSA) biofilm. From in vitro experimental testing, CICNT on both these substrates resisted MRSA cell attachment and biofilm proliferation. The discovery of this non-pharmaceutical biofilm resistance expands the potential applications of CICNT to include medical devices that are prone to infection and/or devices that contribute to infection. Two representative applications were investigated: external fixator pins and scalpel blades. CICNT-coated versions of these applications underwent additional MRSA biofilm resistance testing as well as mechanical testing. In particular, external fixator pins were identified as a high potential application of CICNT surface coating technology. Previous work on both CNT and CICNT forests has largely been performed on planar structures. However, any potential medical device applications involve curved substrates. In particular, concave curvatures are challenging due to the potential for stress-related CICNT forest defects. Thus, the present work also included a study of the incidence rates and determining factors of these defects. SEM images of the cross-sections revealed different types of microscale forest defects while the top surface showed morphologies that are largely consistent with flat substrates. CICNT forest height and substrate curvature were identified as contributing factors to CICNT forest defect incidence rates. Thus, the present work advances the understanding of bacterial resistance and microstructure-related properties of CICNT surface coatings, with applications in medical devices.
16

New nitric oxide releasing materials

McKinlay, Alistair C. January 2010 (has links)
The aim of this thesis was to examine the ability of metal organic frameworks (MOFs) to store and controllably release biologically significant amounts of nitric oxide (NO). Initial work involved the synthesis of a series of isostructural MOFs, known as M-CPO-27, which display coordinatively unsaturated metal sites (CUSs) when fully activated (guest solvent molecules both coordinated and uncoordinated to the metal atom are removed). Two of these frameworks (Ni and Co CPO-27) displayed exceptional performance over the entire cycle of activation, storage and delivery showing the largest storage and release of NO of any known porous material (up to 7 mmolg⁻¹). These frameworks would therefore be considered for initial research into the formulation of MOFs, for possible use in medical applications. It was shown that they still release large amounts of NO even when placed inside porous paper bags, creams or hydrocolloids. The other versions of M-CPO-27 also displayed significant adsorption of NO however they show poor total NO release. It was also shown that it is possible to synthesise both Ni and Co CPO-27 using microwave synthesis without any detrimental effect to the porous structure. Several iron-based MOFs were also investigated for NO storage and release. The results showed that Fe MIL-88 based structures adsorb good amounts of NO but only release a small amount of the irreversibly adsorbed NO. Two successfully amine grafted giant pore MOFs were then investigated to attempt to improve the NO adsorption and release. This result was not observed however, due to the poor total amine grafting coverage and pore blockage resulting from the amines. In-situ IR studies reveal that when exposed to NO, activated Fe MIL-100 forms a chemical bond with the NO. The studies also displayed that when water is then allowed to attempt to replace the NO that only a small amount of NO is actually released, the majority of the NO either remains chemically bonded to the Fe atom or forms N₂O in conjunction with a Fe-OH group. Other MOFs were also successfully synthesised and characterised for NO storage and release. Both Ni succinate and Ni STA-12 display good adsorption and excellent release of NO. This indicates that Ni based MOFs show the best results for NO adsorption and release. In the conclusion of the thesis I am able to categorise the NO release ability of MOFs based on composition and formulate a theory as to why this happens.
17

An Evaluation of Digital Methods in Reverse Engineering Using Selected Medical Applications

Parrott, Andrew Mark 17 November 2006 (has links)
Student Number : 9710738R - MSc (Eng) dissertation - Faculty of Engineering and the Built Environment / This dissertation investigates the use of digital modeling methods for selected medical applications. The digital methods include the design of a cranial implant, auricular prosthesis and the duplication of an oral prosthesis. The digital process includes imaging, image processing, design and fabrication steps. Three types of imaging used are contact and non-contact measurement systems and CT scanning. The investigation uses a Phantom haptic device for digital design. The implants and prostheses are fabricated using a Thermojet printer and investment casting. Traditional and digital processes are compared using four case studies on selected criteria. The conclusions of the investigation are that a digital process can be used and is equal to or better than traditional methods in prosthesis and implant design.
18

Mathematical Modeling of Blood Coagulation

Perdomo, Joana L 01 January 2016 (has links)
Blood coagulation is a series of biochemical reactions that take place to form a blood clot. Abnormalities in coagulation, such as under-clotting or over- clotting, can lead to significant blood loss, cardiac arrest, damage to vital organs, or even death. Thus, understanding quantitatively how blood coagulation works is important in informing clinical decisions about treating deficiencies and disorders. Quantifying blood coagulation is possible through mathematical modeling. This review presents different mathematical models that have been developed in the past 30 years to describe the biochemistry, biophysics, and clinical applications of blood coagulation research. This review includes the strengths and limitations of models, as well as suggestions for future work.
19

Knowledge guided processing of magnetic resonance images of the brain [electronic resource] / by Matthew C. Clark.

Clark, Matthew C. January 2001 (has links)
Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 222 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This dissertation presents a knowledge-guided expert system that is capable of applying routinesfor multispectral analysis, (un)supervised clustering, and basic image processing to automatically detect and segment brain tissue abnormalities, and then label glioblastoma-multiforme brain tumors in magnetic resonance volumes of the human brain. The magnetic resonance images used here consist of three feature images (T1-weighted, proton density, T2-weighted) and the system is designed to be independent of a particular scanning protocol. Separate, but contiguous 2D slices in the transaxial plane form a brain volume. This allows complete tumor volumes to be measured and if repeat scans are taken over time, the system may be used to monitor tumor response to past treatments and aid in the planning of future treatment. Furthermore, once processing begins, the system is completely unsupervised, thus avoiding the problems of human variability found in supervised segmentation efforts.Each slice is initially segmented by an unsupervised fuzzy c-means algorithm. The segmented image, along with its respective cluster centers, is then analyzed by a rule-based expert system which iteratively locates tissues of interest based on the hierarchy of cluster centers in feature space. Model-based recognition techniques analyze tissues of interest by searching for expected characteristics and comparing those found with previously defined qualitative models. Normal/abnormal classification is performed through a default reasoning method: if a significant model deviation is found, the slice is considered abnormal. Otherwise, the slice is considered normal. Tumor segmentation in abnormal slices begins with multispectral histogram analysis and thresholding to separate suspected tumor from the rest of the intra-cranial region. The tumor is then refined with a variant of seed growing, followed by spatial component analysis and a final thresholding step to remove non-tumor pixels.The knowledge used in this system was extracted from general principles of magnetic resonance imaging, the distributions of individual voxels and cluster centers in feature space, and anatomical information. Knowledge is used both for single slice processing and information propagation between slices. A standard rule-based expert system shell (CLIPS) was modified to include the multispectral analysis, clustering, and image processing tools.A total of sixty-three volume data sets from eight patients and seventeen volunteers (four with and thirteen without gadolinium enhancement) were acquired from a single magnetic resonance imaging system with slightly varying scanning protocols were available for processing. All volumes were processed for normal/abnormal classification. Tumor segmentation was performed on the abnormal slices and the results were compared with a radiologist-labeled ground truth' tumor volume and tumor segmentations created by applying supervised k-nearest neighbors, a partially supervised variant of the fuzzy c-means clustering algorithm, and a commercially available seed growing package. The results of the developed automatic system generally correspond well to ground truth, both on a per slice basis and more importantly in tracking total tumor volume during treatment over time. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
20

Um estudo de metricas de similaridade em sistemas baseados em casos aplicados a area da saude

Julio, Marcia Regina Ferro Moss 18 February 2005 (has links)
Orientadores: Gilberto Shigueo Nakamiti, Heloisa Vieira da Rocha / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-04T19:58:40Z (GMT). No. of bitstreams: 1 Julio_MarciaReginaFerroMoss_M.pdf: 5134591 bytes, checksum: 7b347ade85c8652d790d671fd0d3bd1c (MD5) Previous issue date: 2005 / Resumo: No momento da escolha da solução para um problema, muitas vezes o ser humano se vale de experiências passadas, ocorridas com problemas semelhantes e que, portanto, podem prever soluções de sucesso ou não. Sistemas Baseados em Casos (SBC) podem utilizar soluções anteriores para interpretar uma nova situação, ou criar uma solução apropriada para um novo problema. Este trabalho apresenta um estudo de métricas de similaridade em sistemas baseados em casos, aplicados à área da saúde, mais especificamente sobre epicondilite lateral, uma tendinite do cotovelo. O estudo sobre métricas de similaridade em sistemas baseados em casos foi realizado a partir de levantamentos bibliográficos sobre Raciocínio Baseados em Casos e sobretudo com o estudo e aprendizado obtido por meio da aplicação de RBC na área da Saúde. A aplicação foi desenvolvida com a participação de profissionais da área da saúde que muito colaboraram na construção da aplicação, bem como com o fornecimento de casos reais para os cadastros na base de casos e aplicação de testes de validação / Abstract: When solving a problem, humans ofien use past experiences with similar situations, which can help the prediction of failure or success. Case-Based Systems use past experiences to interpret a new situation, or to create an appropiate solution for a new problem. For work presents a study on similarity metrics in case-based systems, and an application concerning the health area, more specifically about Lateral Epiconditis, an elbow tendinitis. The study on similarity metrics in case-based systems was conducted from bibliographic research and more importantly, with the study and learning abtained with the health area application development. Health area professionals took part and helped the application development, as well as provided real cases to configure and validate the system / Mestrado / Engenharia de Software / Mestre Profissional em Computação

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