To see the other types of publications on this topic, follow the link: Computer.assisted diagnostic interview.
Dissertations / Theses on the topic 'Computer.assisted diagnostic interview'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 41 dissertations / theses for your research on the topic 'Computer.assisted diagnostic interview.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Hoyer, Jürgen, Uwe Ruhl, Denis Scholz, and Hans-Ulrich Wittchen. "Patients' feedback after computer-assisted diagnostic interviews for mental disorders." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-118556.
Full textAbstract:
Little is known about how psychotherapy patients perceive and evaluate computer-assisted diagnostic interviews for mental disorders. Using the World Health Organization's Composite International Diagnostic Interview in its computer-administered form, psychologists interviewed 236 psychotherapy patients, who evaluated the interview with regard to content, comprehensibility, and acceptance. More than 87% of patients evaluated the interview positively. Higher symptom severity and comorbidity, but not depression, were associated with a slightly lower but still favorable appraisal. The results indicate that the use of computerized clinical diagnostic interviews, previously usually restricted to research, seems to be a time-efficient, economical, and acceptable approach for the diagnostic phase of psychotherapy. The indications of diminished acceptability among multimorbid and severely disturbed patients warrant further study. Implications for quality assurance and practice research networks are discussed<br>Wir wissen wenig darüber, wie Psychotherapiepatienten computergestützte Interviews für psychische Störungen erleben und bewerten. Trainierte Psychologen untersuchten 236 konsekutive Patienten einer Psychotherapieambulanz mit dem Composite International Diagnostic Interview (CIDI) in seiner computergestützen Version.. Danach beurteilten die befragten Patienten das Interview auf der Basis einer 15 Items umfassenden Liste hinsichtlich Inhalt, Verständlichkeit und Akzeptanz. 87% der Patienten bewerteten das Interview positiv, und gaben z.B. an froh zu sein, dass “die Befragung so genau und ausführlich war”. Größere Symptombelastung und höhere Komorbidität, nicht aber das Ausmaß an Depression, waren mit einer etwas schlechteren, absolut gesehen aber immer noch guten Bewertung des Interviews assoziiert. Die Ergebnisse zeigen, dass computergestützte Interviews, die bisher fast nur im Forschungsbereich eingesetzt wurden, eine zeit- und kosteneffiziente sowie für den Patienten akzeptable Möglichkeit für die Eingangsdiagnostik psychotherapeutischer Behandlungen darstellen. Die Hinweise auf eine geringere Akzeptanz bei multi-morbiden und stärker beeinträchtigten Patienten sollten weiter untersucht werden. Implikationen für die Qualitätssicherung und Praxisforschungsnetzwerke werden diskutiert
2
Hoyer, Jürgen, Uwe Ruhl, Denis Scholz, and Hans-Ulrich Wittchen. "Patients' feedback after computer-assisted diagnostic interviews for mental disorders." Technische Universität Dresden, 2006. https://tud.qucosa.de/id/qucosa%3A27055.
Full textAbstract:
Little is known about how psychotherapy patients perceive and evaluate computer-assisted diagnostic interviews for mental disorders. Using the World Health Organization's Composite International Diagnostic Interview in its computer-administered form, psychologists interviewed 236 psychotherapy patients, who evaluated the interview with regard to content, comprehensibility, and acceptance. More than 87% of patients evaluated the interview positively. Higher symptom severity and comorbidity, but not depression, were associated with a slightly lower but still favorable appraisal. The results indicate that the use of computerized clinical diagnostic interviews, previously usually restricted to research, seems to be a time-efficient, economical, and acceptable approach for the diagnostic phase of psychotherapy. The indications of diminished acceptability among multimorbid and severely disturbed patients warrant further study. Implications for quality assurance and practice research networks are discussed.<br>Wir wissen wenig darüber, wie Psychotherapiepatienten computergestützte Interviews für psychische Störungen erleben und bewerten. Trainierte Psychologen untersuchten 236 konsekutive Patienten einer Psychotherapieambulanz mit dem Composite International Diagnostic Interview (CIDI) in seiner computergestützen Version.. Danach beurteilten die befragten Patienten das Interview auf der Basis einer 15 Items umfassenden Liste hinsichtlich Inhalt, Verständlichkeit und Akzeptanz. 87% der Patienten bewerteten das Interview positiv, und gaben z.B. an froh zu sein, dass “die Befragung so genau und ausführlich war”. Größere Symptombelastung und höhere Komorbidität, nicht aber das Ausmaß an Depression, waren mit einer etwas schlechteren, absolut gesehen aber immer noch guten Bewertung des Interviews assoziiert. Die Ergebnisse zeigen, dass computergestützte Interviews, die bisher fast nur im Forschungsbereich eingesetzt wurden, eine zeit- und kosteneffiziente sowie für den Patienten akzeptable Möglichkeit für die Eingangsdiagnostik psychotherapeutischer Behandlungen darstellen. Die Hinweise auf eine geringere Akzeptanz bei multi-morbiden und stärker beeinträchtigten Patienten sollten weiter untersucht werden. Implikationen für die Qualitätssicherung und Praxisforschungsnetzwerke werden diskutiert.
3
Briggs, Jean L. "An investigation into the use of a computer assisted interview (the MacInterview) with children who have Asperger Syndrome." Thesis, Bangor University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263191.
Full text
4
Vasandani, Vijay. "Intelligent tutoring for diagnostic problem solving in complex dynamic systems." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/24934.
Full text
5
Robinson, Stuart Ivan. "The role of the microcomputer as a diagnostic, prescriptive and learning instrument in remedial education." Master's thesis, University of Cape Town, 1986. http://hdl.handle.net/11427/15892.
Full textAbstract:
Bibliography: pages 222-229.<br>The number of pupils with learning disabilities is on the increase and effective ways of attempting to remediate such pupils are always being sought. Current technology has presented remedial teachers with a potentially dynamic aid in the form of the microcomputer. Many of the attributes of computer-aided learning closely parallel the principles of remedial teaching and to this end it was attempted to establish the role of the microcomputer in remedial education. An in-depth study of the literature was undertaken. In the practical sphere, a survey was conducted to obtain the views of practicing remedial teachers as well as to establish the extent of applications in schools. Learning disabled pupils were observed interacting with microcomputers. The study revealed that the prognosis for embracing microcomputers in remedial education is encouraging. Applications exist for diagnosis and prescription of specific deficits as well as for prescribing the microcomputer in the sphere of general educational development of learning disabled pupils. Further applications for administrative and management purposes have reached-an advanced stage of development. With the development of appropriate software and proper "teacher education" the microcomputer has the potential to become a dynamic educational aid for the learning disabled; especially because of its motivational and user-friendly nature.
6
Hult, Peter. "Bioacoustic principles used in monitoring and diagnostic applications /." Linköping : Univ, 2002. http://www.bibl.liu.se/liupubl/disp/disp2002/tek778s.pdf.
Full text
7
Chow, Chi Ping. "An investigation of the validity of the computer assisted child interview (CACI) as a self-report measure of children's academic performance and school experience /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1404336121&sid=3&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Full textAbstract:
Thesis (Ph. D.)--University of Oregon, 2007.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 103-108). Also available for download via the World Wide Web; free to University of Oregon users.
8
Berninger, Christoph [Verfasser]. "Analyse des aktuellen Standes der niedergelassenen Kieferorthopäden in Deutschland bezüglich der Themen Erwachsenenkieferorthopädie, Ananmeseerhebung und Bisphosphonattherapie auf Basis einer Computer-Assisted Telephone Interview (CATI)-Studie / Christoph Berninger." Mainz : Universitätsbibliothek der Johannes Gutenberg-Universität Mainz, 2020. http://d-nb.info/122481049X/34.
Full text
9
Hansen, Andrew. "Semi-automated geomorphological mapping applied to landslide hazard analysis." Curtin University of Technology, Dept. of Spatial Sciences, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17998.
Full textAbstract:
Computer-assisted three-dimensional (3D) mapping using stereo and multi-image (“softcopy”) photogrammetry is shown to enhance the visual interpretation of geomorphology in steep terrain with the direct benefit of greater locational accuracy than traditional manual mapping. This would benefit multi-parameter correlations between terrain attributes and landslide distribution in both direct and indirect forms of landslide hazard assessment. Case studies involve synthetic models of a landslide, and field studies of a rock slope and steep undeveloped hillsides with both recently formed and partly degraded, old landslide scars. Diagnostic 3D morphology was generated semi-automatically both using a terrain-following cursor under stereo-viewing and from high resolution digital elevation models created using area-based image correlation, further processed with curvature algorithms. Laboratory-based studies quantify limitations of area-based image correlation for measurement of 3D points on planar surfaces with varying camera orientations. The accuracy of point measurement is shown to be non-linear with limiting conditions created by both narrow and wide camera angles and moderate obliquity of the target plane. Analysis of the results with the planar surface highlighted problems with the controlling parameters of the area-based image correlation process when used for generating DEMs from images obtained with a low-cost digital camera. Although the specific cause of the phase-wrapped image artefacts identified was not found, the procedure would form a suitable method for testing image correlation software, as these artefacts may not be obvious in DEMs of non-planar surfaces.<br>Modelling of synthetic landslides shows that Fast Fourier Transforms are an efficient method for removing noise, as produced by errors in measurement of individual DEM points, enabling diagnostic morphological terrain elements to be extracted. Component landforms within landslides are complex entities and conversion of the automatically-defined morphology into geomorphology was only achieved with manual interpretation; however, this interpretation was facilitated by softcopy-driven stereo viewing of the morphological entities across the hillsides.In the final case study of a large landslide within a man-made slope, landslide displacements were measured using a photogrammetric model consisting of 79 images captured with a helicopter-borne, hand-held, small format digital camera. Displacement vectors and a thematic geomorphological map were superimposed over an animated, 3D photo-textured model to aid non-stereo visualisation and communication of results.
10
Fängström, Karin. "‘I don’t even remember anything’ : Optimising the choice of method when interviewing preschoolers." Doctoral thesis, Uppsala universitet, Socialmedicin, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-331193.
Full textAbstract:
There is increasing need and demand in various contexts to take children’s perspectives into account, including the views and opinions of the youngest children. However, listening to the voices of children is a challenging and complex task, and the field is normatively loaded. There is thus a growing need for valid and reliable methods and techniques that aid children to verbalise their experiences. The overall aim of this thesis was to examine the ability of the In My Shoes computer assisted interview and a Standard verbal interview to elicit accurate information and evaluative content, when used with preschool-aged children and determine their suitability in relation to situationally shy children. Our studies show that the two interview methods, in general, provided equally accurate and complete statements. In addition, the IMS interview can be a more useful and suitable tool during the rapport phase with situationally shy children compared to the Standard verbal method. For non-shy children, the interview methods were equally adequate. In relation to evaluative information, the recommended open-ended questions in the Standard verbal interview were insufficient. Children appeared to need evaluative questions in order to provide evaluative content. Examining the ability of IMS to elicit subjective experiences showed that using IMS aided children to provide detailed and varied descriptions of emotions, somatic experiences, and objects such as toys. Thus, when choosing the optimal child interview method, there are several aspects that need to be considered, including the degree to which children’s statements need to be accurate and complete and/or contain evaluative information and the child’s level of shyness. These studies have increased the number of evaluated methods for interviewing children and contributed to new knowledge about the challenging task of optimising the choice of method for interviewing preschoolers.<br><p>Forskningsfinansiering: Stiftelsen Allmänna Barnhuset, FB13-0014 </p>
11
Palies, Odile. "Méta-connaissances pour la modélisation de l'élève : contribution au diagnostic cognitif par système expert." Paris 6, 1988. http://www.theses.fr/1988PA066461.
Full textAbstract:
Presentation d'electre, un modele de l'eleve de sectoriel intelligent realise par systeme expert. Elle comprend deux parties: la description du modele de l'eleve et la presentation d'un expert qui traite les meta-connaissances
12
Bezerra, Cristiano Guedes. "Processamento de imagens médicas e parâmetros hemodinâmicos: validação clínica de modelos cardiovasculares assistidos por computação científica." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5131/tde-13062018-110733/.
Full textAbstract:
Introdução: A doença arterial coronária (DAC) é avaliada através dos aspectos anatômicos da placa aterosclerótica ou a partir da repercussão funcional da estenose, por métodos diagnósticos diversos. O ultrassom intravascular (IVUS) fornece uma avaliação anatômica precisa do lúmen e da parede do vaso, tendo sido validado como uma ferramenta útil para guiar a intervenção coronária percutânea (ICP). No entanto, do ponto de vista diagnóstico, o IVUS representa mal o estado funcional (isto é, informação relacionada ao comprometimento de fluxo) do vaso interrogado. A reserva de fluxo fracionada (FFR) é método importante para identificação de isquemia, discriminando as estenoses coronárias que podem se beneficiar de ICP. Objetivamos desenvolver e avaliar o desempenho diagnóstico de um novo algoritmo computacional para estimar a FFR à partir das imagens do IVUS tridimensional (IVUSFR), comparando-o com o método padrão ouro para estimação de fluxo coronário invasivo (FFRPW). Métodos: Pacientes com DAC estável conhecida ou suspeita encaminhados para cateterismo cardíaco eletivo foram submetidos a avaliação complementar com medida de fluxo coronário pelo FFRPW e com imagem intravascular pelo IVUS, no mesmo procedimento, a fim de avaliar lesões intermediárias. As imagens do IVUS foram processadas para gerar uma malha computacional tridimensional que condensa as características geométricas do vaso. O IVUSFR foi obtido utilizando dinâmica de fluido computacional, configurando-se as condições de contorno a partir de características específicas do paciente e do território coronário irrigado. As medidas de FFRPW foram dicotomizadas no limiar de 0,80 para definir lesões hemodinamicamente significativas e avaliar o desempenho diagnóstico do IVUSFR. Resultados: Um total de 34 artérias coronárias de 24 pacientes foi analisado. A área luminal mínima média avaliada pelo IVUS de 4,14 ± 1,74 mm2, e carga de placa média de 66±10% caracterizam o grau intermediário das lesões. O IVUSFR correlacionou significativamente (r = 0,79; p < 0,001) e mostrou boa concordância com a FFRPW, apresentando diferença média de -0,008 ± 0,067 (p = 0,47). O IVUSFR apresentou acurácia, sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo de 91%, 89%, 92%, 80% e 96%, respectivamente, para detectar estenoses hemodinamicamente significativas. Conclusão: O processamento computacional do IVUSFR é um novo método que permite a avaliação funcional da estenose coronária intermediária de forma acurada, enriquecendo as informações anatômicas do IVUS<br>Introduction: Coronary artery disease (CAD) is assessed through the anatomical aspects of the atherosclerotic plaque or through the functional impairment of the stenosis, by different diagnostic methods. Intravascular ultrasound (IVUS) provides accurate anatomic assessment of lumen and vessel wall and has been validated as a useful tool to guide percutaneous coronary intervention (PCI). However, from the diagnostic point of view, IVUS poorly represents the functional status (i.e. flow-related information) of the imaged vessel. Fractional flow reserve (FFR) is an important tool to identify ischemia, discriminating coronary stenosis that may benefit from PCI. We aimed to develop and evaluate the diagnostic performance of a novel computational algorithm based on three-dimensional IVUS imaging in estimating fractional flow reserve (IVUSFR), compared to gold-standard invasive measurements (FFRPW). Methods: Patients with known or suspected stable coronary disease scheduled for elective cardiac catheterization underwent FFRPW measurement and IVUS imaging in the same procedure to evaluate intermediate lesions. A processing methodology was applied on IVUS to generate a computational mesh condensing the geometric characteristics of the vessel. Through computational fluid dynamics, IVUSFR was obtained from patient-level morphological definition of arterial districts and from territory-specific boundary conditions. FFRPW measurements were dichotomized at the 0.80 thresholds to define hemodynamically significant lesions and evaluate diagnostic performance of IVUSFR. Results: A total of 24 patients with 34 vessels were analyzed. The mean minimum luminal area assessed by IVUS was 4.14 ± 1.74 mm2, and mean plaque burden was 66 ± 10%, characterizing intermediate lesions. IVUSFR significantly correlated (r = 0.79; p < 0.001) and showed good agreement with FFRPW, with a mean difference of -0.008 ± 0.067 (p = 0.47). IVUSFR presented an overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 91%, 89%, 92%, 80%, and 96% respectively to detect significant stenosis. Conclusion: The computational processing of IVUSFR is a new method that allows the evaluation of the functional significance of coronary stenosis in an accurate way, enriching the anatomical information of IVUS
13
Melo, Saulo Leonardo Sousa 1982. "Influência da segmentação e reconstrução de imagem na capacidade de diagnóstico da Tomografia Computadorizada de Feixe Cônico utilizando softwares com plataforma DICOM." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288977.
Full textAbstract:
Orientador: Francisco Haiter Neto<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba<br>Made available in DSpace on 2018-08-22T03:09:52Z (GMT). No. of bitstreams: 1
Melo_SauloLeonardoSousa_D.pdf: 2218152 bytes, checksum: 8cf34e11fc626dc8ea70836a2401feb5 (MD5)
Previous issue date: 2013<br>Resumo: As fraturas radiculares apresentam diagnóstico clínico limitado visto que os sinais e sintomas apresentados pelo paciente são inespecíficos. Como a maioria das fraturas leva à extração do dente, torna-se necessário um diagnóstico mais preciso. A tomografia computadorizada de feixe cônico (TCFC) é considerada um método de diagnóstico avançado na aquisição de imagens livres de sobreposições das estruturas orofaciais. Geralmente as imagens por TCFC são segmentadas e reconstruídas em DICOM, visto que existe uma grande disponibilidade de softwares que utilizam este formato. Por se tratar de uma tecnologia relativamente recente, e que rapidamente vem se difundindo no meio odontológico, o presente estudo avaliou a influência do uso de softwares com plataforma DICOM na capacidade de diagnóstico das imagens por TCFC na detecção de fraturas radiculares verticais induzidas experimentalmente. Foram utilizados cento e noventa dentes unirradiculares humanos, com os condutos radiculares modelados, divididos em 3 grupos, de acordo com a condição do canal radicular: não-preenchido (NP); preenchido com guta-percha (GP); e parcialmente preenchido por núcleo metálico fundido (NM). Metade dos elementos de cada grupo foi fraturada artificialmente, com posterior reposicionamento dos fragmentos. Um cone de guta-percha bem adaptado foi inserido no canal dos dentes do grupo GP e núcleos metálicos fundidos foram confeccionados nos dentes do grupo NM. Todos os dentes foram posicionados em um crânio seco humano e escaneados em um aparelho de TCFC, conforme o protocolo de escaneamento da maxila utilizando voxel de 0.2 mm. As imagens foram salvas no formato original (.xstd), assim como segmentadas e reconstruídas em DICOM. As imagens originais foram analisadas no software do tomógrafo (Xoran) e as imagens DICOM nos softwares Dolphin, InVivo e KDIS3D. Foram selecionados três cirurgiões-dentistas radiologistas para avaliar as imagens quanto à ausência ou presença de fratura radicular, em uma escala de 5 pontos. Sensibilidade, especificidade, acurácia e área sob a curva ROC foram calculadas. A influência do material intracanal e do software utilizado foi verificada por meio do modelo de análise de variância (ANOVA) e comparações pareadas realizadas por meio do teste de Tukey, considerando-se um nível de significância de 5%. Não houve diferença estatisticamente significativa entre os softwares quando a mesma condição era apresentada. No entanto, quando comparada com os grupos NP e GP, a acurácia de diagnóstico foi menor no grupo NM em qualquer software utilizado (p < 0,05). Concluiu-se que o diagnóstico de fratura radicular não depende do software, podendo o profissional utilizar o de sua preferência. Todavia, a presença de núcleo metálico diminui a possibilidade de um diagnóstico correto<br>Abstract: Root fractures have limited clinical diagnosis because signs and symptoms are nonspecific. However, an accurate diagnosis is necessary as most fractures result in tooth extraction. In the last years, Cone beam computed tomography (CBCT) technology has been considered an advanced procedure to obtain images free from overlaps of maxillofacial structures. Usually CBCT images are exported in DICOM format, since there is a wide availability of software that uses this format. Since it is a relatively new technology and that is spreading quickly among dental routine, this study evaluated the influence of segmentation and reconstruction of CBCT images in the diagnostic ability of experimentally induced vertical root fractures using software with DICOM platform. One hundred and ninety extracted, single-rooted, human teeth were included in the study. Each tooth had its root canal prepared, randomly coded and divided into 3 groups according to the pulp canal status: unrestored (UR); filled with gutta-percha (GP); and restored with a metallic custom post (Post). One-half of the samples of each group were artificially fractured and segments repositioned. The experimental sample was artificially fractured. A well-fitting gutta-percha cone was placed into the canal of GP group teeth, and a well-fitting post casted was placed into the canal of Post group ones. All teeth were placed in an empty maxillary anterior socket of a dentate dry human skull and scanned on a CBCT device according to the protocol recommended by the manufacturer for a 0.2-mm voxel resolution (8-cm FOV, 120kVp, 8mA, 40-sec). The images were converted to DICOM files, imported, reconstructed and analyzed into Dolphin, InVivo and KDIS3D software. The original images were also reconstructed and evaluated using the software of the scanner (Xoran). The images were coded and shown to three previously calibrated oral radiologist observers, who performed a dynamic evaluation. The observer's evaluation of the presence of root fracture was scored using a 5-point confidence rating scale. Sensitivity, specificity, and accuracy were calculated, and from the values found, ROC curves were constructed to assess the relationship between sensitivity and specificity (area under the ROC curve). The influence of intra-canal material and software used was verified by an analysis of variance model (ANOVA) and pairwise comparisons performed using Tukey test, considering a significance level of 5%. Overall, there was not a statistically significant difference between softwares. Thus, the efficiency of the software was similar among them when the same condition (type of material present inside the canal) was shown. However, there was a statistically significant difference between the materials, considering accuracy, sensitivity and area under the ROC curve. Compared with UR and GP groups, the accuracy of diagnosis was significantly lower in the Post group when any software was used (p <0.05). In conclusion, the diagnosis of root fracture does not depend on the software, which means that the professional should choose the one of his preference. However attention should be drawn to the fact that, regardless of the software used, the presence of metallic post decreases the chance of a correct diagnosis<br>Doutorado<br>Radiologia Odontologica<br>Doutor em Radiologia Odontológica
14
Garcia, David. "Études exploratoires dédiées au diagnostic de corrosion assisté par ordinateur des structures de génie civil." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30247.
Full textAbstract:
La thèse "Études exploratoires dédiées au diagnostic de corrosion assisté par ordinateur des structures de génie civil" traite de la phénoménologie et de la modélisation de la corrosion de l'acier de construction. Le poids sécuritaire, sociétal, environnemental du vieillissement des infrastructures fait de ce thème un enjeu économique majeur de développement de tout pays. Les développements proposés portent principalement sur la corrosion des armatures dans le béton armé. La corrosion des structures métalliques enterrées est également adressée concernant les problématiques relatives aux couplages galvaniques induits par l'hétérogénéité des sols et aux courants vagabonds. Les méthodes d'investigation usuelles (mesures de potentiel des aciers, de résistivité du béton ou de résistance de polarisation), jointes à des hypothèses empiriques consacrées par l'usage, conduisent à des interprétations souvent incertaines ou n'ayant qu'une valeur qualitative. L'ambition de cette thèse, motivée par les enjeux évoqués, est de montrer comment une meilleure compréhension de la physique de la corrosion, conjuguée à la puissance du calcul aux éléments finis, permet de construire des modèles élaborés et robustes, utiles pour poser un diagnostic et/ou un pronostic quantifié et fiable. La thèse est abondamment illustrée par des études de cas réels ou numériques et étayée par des essais originaux conduits en laboratoire. Afin d'améliorer la compréhension des phénomènes prévalant dans le processus de corrosion, les concepts-clés de thermodynamique et de cinétique électrochimique sont rappelés et contextualisés. L'assemblage de différentes lois physiques, chimiques et électrochimiques permet d'élaborer une approche de modélisation avancée, intégrant notamment la diffusion du dioxygène jusqu'aux armatures en contexte insaturé, mais aussi la production et la précipitation des produits de la corrosion et leur influence sur l'équilibre dynamique d'un système de corrosion. Cette approche de modélisation, nécessairement tridimensionnelle ou a minima bidimensionnelle, donne lieu à une transcription dans un code de calcul par éléments finis. Elle est appliquée dans un premier temps à l'étude numérique d'un premier cas typique de corrosion : pile en béton armé partiellement immergée en mer. L'influence du rôle du dioxygène (disponibilité et diffusion) sur la cinétique de dissolution de l'acier et sur la nature des produits de corrosion formés est notamment étudiée. Afin d'illustrer l'apport effectif de la modélisation 3D dans le processus de diagnostic de la corrosion, une étude de cas réelle est proposée concernant un ouvrage métallique enterré, en l'occurrence des palplanches servant au soutènement des culées d'un passage supérieur d'autoroute, situées à proximité d'une conduite enterrée sous protection cathodique. Des mesures effectuées in-situ mais aussi en laboratoire à partir d'échantillons judicieusement choisis, permettent d'alimenter le modèle de calcul. Le modèle numérique ainsi construit, qualifié de jumeau numérique, permet de mettre en évidence l'existence de courants vagabonds circulant dans la structure, mais également le risque de corrosion galvanique induit par l'hétérogénéité du sol. Le jumeau numérique électrochimique constitue alors un outil puissant pour estimer la cinétique et le faciès de corrosion de l'ouvrage et poser un pronostic en termes de durée de vie. [...]<br>The PhD thesis "Exploratory studies dedicated to computer-assisted corrosion diagnosis of civil engineering structures" deals with the phenomenology and modeling of corrosion of structural steel. The safety, societal and environmental impact of aging infrastructures makes this theme a major economic issue for the development of any country. The proposed developments focus mainly on the corrosion of reinforcements in reinforced concrete. The corrosion of buried metallic structures is also addressed concerning the problems related to galvanic couplings induced by the heterogeneity of soils and stray currents. The usual methods of investigation (measurements of steel potential, concrete resistivity or polarization resistance), combined with empirical hypotheses established by experience, lead to interpretations that are often uncertain or have only a qualitative value. The ambition of this thesis, motivated by the issues at stake, is to show how a better understanding of the physics of corrosion, combined with the power of finite element calculation, allows the construction of elaborate and robust models, useful for a quantified and reliable diagnosis and/or prognosis. The thesis is abundantly illustrated by real or numerical case studies and supported by original laboratory tests. In order to improve the understanding of the phenomena prevailing in the corrosion process, the key concepts of thermodynamics and electrochemical kinetics are recalled and contextualized. The assembly of different physical, chemical and electrochemical laws allows the elaboration of an advanced modeling approach, integrating in particular the diffusion of oxygen to the reinforcement in an unsaturated context, but also the production and precipitation of corrosion products and their influence on the dynamic equilibrium of a corrosion system. This modeling approach, necessarily three-dimensional or at least two-dimensional, gives rise to a transcription in a finite element calculation code. It is first applied to the numerical study of a first typical case of corrosion: a reinforced concrete pile partially submerged in the sea. The influence of the role of oxygen (availability and diffusion) on the dissolution kinetics of the steel and on the nature of the corrosion products formed is studied in particular. In order to illustrate the effective contribution of 3D modeling in the process of corrosion diagnosis, a real case study is proposed concerning a buried steel structure, in this case sheet piles used to support the abutments of a freeway overpass, located near a pipe buried under cathodic protection. Measurements carried out in-situ but also in the laboratory from judiciously chosen samples are used to feed the calculation model. The numerical model thus constructed, qualified as a digital twin, makes it possible to highlight the existence of stray currents circulating in the structure, but also the risk of galvanic corrosion induced by the heterogeneity of the soil. The electrochemical digital twin is then a powerful tool for estimating the kinetics and the corrosion facies of the structure and making a prognosis in terms of service life. Within a concrete structure, the presence of chlorides is associated with various effects, notably associated with the local electric field. If this phenomenon is ignored, the interpretation of field data, for example potential maps, can lead to a biased diagnosis. This thesis addresses the question of corrosion initiation.[...]
15
Welfer, Daniel. "Métodos computacionais para identificar automaticamente estruturas da retina e quantificar a severidade do edema macular diabético em imagens de fundo de olho." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/34777.
Full textAbstract:
Através das imagens de fundo do olho, os especialistas em oftalmologia podem detectar possíveis complicações relacionadas ao Diabetes como a diminuição ou até a perda da capacidade de visão. O Edema Macular Diabético (EMD) é uma das complicações que lideram os casos de danos à visão em pessoas em idade de trabalho. Sendo assim, esta tese apresenta métodos para automaticamente identificar os diferentes níveis de gravidade do Edema Macular Diabético visando auxiliar o especialista no diagnóstico dessa patologia. Como resultado final, propõe-se automaticamente e rapidamente identificar, a partir da imagem, se o paciente possui o EMD leve, moderado ou grave. Utilizando imagens de fundo do olho de um banco de dados livremente disponível na internet (ou seja, o DIARETDB1), o método proposto para a identificação automática do EMD obteve uma precisão de 94,29%. Alguns métodos intermediários necessários para a solução desse problema foram propostos e os resultados publicados na literatura científica.<br>Through color eye fundus images, the eye care specialists can detect possible complications related to diabetes as the vision impairment or vision loss. The Diabetic Macular Edema (DME) is the most common cause of vision damage in working-age people. Therefore, this thesis presents an approach to automatically identify the different levels of severity of diabetic macular edema aiming to assist the expert in the diagnosis of this pathology. As a final result, a methodology to automatically and quickly identify, from the eye fundus image, if a patient has the EMD mild, moderate or severe EMD is proposed. In a preliminary evaluation of our DME grading scheme using publicly available eye fundus images (i.e., DIARETDB1 image database), an accuracy of 94.29% was obtained. Some intermediate methods needed to solve this problem have been proposed and the results published in scientific literature.
16
Ullman, Gustaf. "Quantifying image quality in diagnostic radiology using simulation of the imaging system and model observers." Doctoral thesis, Linköping : Department of Medicine and Health, Linköping University, 2008. http://www.bibl.liu.se/liupubl/disp/disp2008/med1050s.pdf.
Full text
17
Traore, Lamine. "Semantic modeling of an histopathology image exploration and analysis tool." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066621/document.
Full textAbstract:
La formalisation des données cliniques est réalisée et adoptée dans plusieurs domaines de la santé comme la prévention des erreurs médicales, la standardisation, les guides de bonnes pratiques et de recommandations. Cependant, la communauté n'arrive pas encore à tirer pleinement profit de la valeur de ces données. Le problème majeur reste la difficulté à intégrer ces données et des services sémantiques associés au profit de la qualité de soins. Objectif L'objectif méthodologique de ce travail consiste à formaliser, traiter et intégrer les connaissances d'histopathologie et d'imagerie basées sur des protocoles standardisés, des référentiels et en utilisant les langages du web sémantique. L'objectif applicatif est de valoriser ces connaissances dans une plateforme pour faciliter l'exploration des lames virtuelles (LV), améliorer la collaboration entre pathologistes et fiabiliser les systèmes d'aide à la décision dans le cadre spécifique du diagnostic du cancer du sein. Il est important de préciser que notre but n'est pas de remplacer le clinicien, mais plutôt de l'accompagner et de faciliter ses lourdes tâches quotidiennes : le dernier mot reste aux pathologistes. Approche Nous avons adopté une approche transversale pour la représentation formelle des connaissances d'histopathologie et d'imagerie dans le processus de gradation du cancer. Cette formalisation s'appuie sur les technologies du web sémantique<br>Semantic modelling of a histopathology image exploration and analysis tool. Recently, anatomic pathology (AP) has seen the introduction of several tools such as high-resolution histopathological slide scanners, efficient software viewers for large-scale histopathological images and virtual slide technologies. These initiatives created the conditions for a broader adoption of computer-aided diagnosis based on whole slide images (WSI) with the hope of a possible contribution to decreasing inter-observer variability. Beside this, automatic image analysis algorithms represent a very promising solution to support pathologist’s laborious tasks during the diagnosis process. Similarly, in order to reduce inter-observer variability between AP reports of malignant tumours, the College of American Pathologists edited 67 organ-specific Cancer Checklists and associated Protocols (CAP-CC&P). Each checklist includes a set of AP observations that are relevant in the context of a given organ-specific cancer and have to be reported by the pathologist. The associated protocol includes interpretation guidelines for most of the required observations. All these changes and initiatives bring up a number of scientific challenges such as the sustainable management of the available semantic resources associated to the diagnostic interpretation of AP images by both humans and computers. In this context, reference vocabularies and formalization of the associated knowledge are especially needed to annotate histopathology images with labels complying with semantic standards. In this research work, we present our contribution in this direction. We propose a sustainable way to bridge the content, features, performance and usability gaps between histopathology and WSI analysis
18
McKenna, Frederick W. "Studies of cell survival curve fitting, effective doses for radiobiological evaluation in SBRT treatment techniques and the dependence of optical density growth in Gafchromic EBT film used in IMRT." Oklahoma City : [s.n.], 2009.
Find full text
19
Adjaoute, Akli. "Rylm : générateur de systèmes experts pour les problèmes d'aide aux diagnosticsYkra : système d'enseignement." Paris 6, 1988. http://www.theses.fr/1988PA066005.
Full text
20
Zuluaga, Valencia Maria Alejandra. "Methods for automation of vascular lesions detection in computed tomography images." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10010/document.
Full textAbstract:
Les travaux de cette thèse sont consacrés à la détection et le diagnostic des lésions vasculaires, particulièrement dans le cas la maladie coronaire. La maladie coronaire continue à être la première cause de mortalité dans les pays industrialisés. En général, l'identification des lésions vasculaires est abordée en essayant de modéliser les anormalités (lésions). Le principal inconvénient de cette approche est que les lésions sont très hétérogènes, ce qui rend difficile la détection de nouvelles lésions qui n'ont pas été prises en compte par le modèle. Dans cette thèse, nous proposons de ne pas modéliser directement les lésions, mais de supposer que les lésions sont des événements anormaux qui se manifestent comme points avec une faible densité de probabilité. Nous proposons l'utilisation de deux méthodes de classification basées sur les Machines à Vecteurs de Support (SVM) pour résoudre le problème de détection du niveau de densité. Le principal avantage de ces deux méthodes est que la phase d'apprentissage ne requiert pas de données étiquetées représentant les lésions. La première méthode est complètement non supervisée, alors que la seconde exige des étiquettes seulement pour les cas qu'on appelle sains ou normaux. L'utilisation des algorithmes de classification sélectionnés nécessite des descripteurs tels que les anomalies soient représentées comme des points avec une densité de probabilité faible. A cette fin, nous avons développé une métrique basée sur l'intensité de l'image, que nous avons appelée concentric rings. Cette métrique est sensible à la quasi-symétrie des profils d'intensité des vaisseaux sains, mais aussi aux écarts par rapport à cette symétrie, observés dans des cas pathologiques. De plus, nous avons sélectionné plusieurs autres descripteurs candidats à utiliser comme entrée pour les classifieurs. Des expériences sur des données synthétiques et des données de CT cardiaques démontrent que notre métrique a une bonne performance dans la détection d'anomalies, lorsqu'elle est utilisée avec les classifeurs retenus. Une combinaison de plusieurs descripteurs candidats avec la métrique concentric rings peut améliorer la performance de la détection. Nous avons défini un schéma non supervisé de sélection de descripteurs qui permet de déterminer un sous-ensemble optimal de descripteurs. Nous avons confronté les résultats de détection réalisée en utilisant le sous-ensemble de descripteurs sélectionné par notre méthode avec les performances obtenues avec des sous-ensembles sélectionnés par des méthodes supervisées existantes. Ces expériences montrent qu'une combinaison de descripteurs bien choisis améliore effectivement les performances des classifieurs et que les meilleurs résultats s'obtiennent avec le sous-ensemble sélectionné par notre méthode, en association avec les algorithmes de détection retenus. Finalement, nous proposons de réaliser un recalage local entre deux images représentant différentes phases du cycle cardiaque, afin de confronter les résultats de détection dans ces images (phases). L'objectif ici est non seulement d'attirer l'attention du praticien sur les anomalies détectées comme lésions potentielles, mais aussi de l'aider à conforter son diagnostic en visualisant automatiquement la même région reconstruite à différents instants du cycle cardiaque<br>This thesis presents a framework for the detection and diagnosis of vascular lesions with a special emphasis on coronary heart disease. Coronary heart disease remains to be the first cause of mortality worldwide. Typically, the problem of vascular lesion identification has been solved by trying to model the abnormalities (lesions). The main drawback of this approach is that lesions are highly heterogeneous, which makes the detection of previously unseen abnormalities difficult. We have selected not to model lesions directly, but to treat them as anomalies which are seen as low probability density points. We propose the use of two classification frameworks based on support vector machines (SVM) for the density level detection problem. The main advantage of these two methods is that the learning stage does not require labeled data representing lesions, which is always difficult to obtain. The first method is completely unsupervised, whereas the second one only requires a limited number of labels for normality. The use of these anomaly detection algorithms requires the use of features such that anomalies are represented as points with low probability density. For this purpose, we developed an intensity based metric, denoted concentric rings, designed to capture the nearly symmetric intensity profiles of healthy vessels, as well as discrepancies with respect to the normal behavior. Moreover, we have selected a large set of alternative candidate features to use as input for the classifiers. Experiments on synthetic data and cardiac CT data demonstrated that our metric has a good performance in the detection of anomalies, when used with the selected classifiers. Combination of other features with the concentric rings metric has potential to improve the classification performance. We defined an unsupervised feature selection scheme that allows the definition of an optimal subset of features. We compared it with existent supervised feature selection methods. These experiments showed that, in general, the combination of features improves the classifiers performance, and that the best results are achieved with the combination selected by our scheme, associated with the proposed anomaly detection algorithms. Finally, we propose to use image registration in order to compare the classification results at different cardiac phases. The objective here is to match the regions detected as anomalous in different time-frames. In this way, more than attract the physician's attention to the anomaly detected as potential lesion, we want to aid in validating the diagnosis by automatically displaying the same suspected region reconstructed in different time-frames
21
Fiard, Gaëlle. "Apprentissage des biopsies prostatiques par la simulation : vers la validation du simulateur Biopsym." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAS037/document.
Full textAbstract:
Le cancer de la prostate est le premier cancer en fréquence et la 3ème cause de mortalité chez l’homme en France, enjeu majeur de santé publique avec environ 50 000 nouveaux cas diagnostiqués par an. Son diagnostic est suspecté devant un toucher rectal anormal ou une élévation du taux de l’antigène spécifique prostatique (PSA). Les biopsies prostatiques randomisées, écho-guidées, sont actuellement recommandées en première intention pour confirmer le diagnostic et définir la localisation, le volume, et l’agressivité tumorale par le score de Gleason. Les difficultés de l’enseignement du geste de biopsie prostatique par compagnonnage, sans retour réellement quantifié sur la répartition des biopsies, sont une des explications du manque de précision des biopsies.C’est dans ce contexte qu’a été développé le simulateur Biopsym, environnement pédagogique permettant l’enseignement des biopsies prostatiques à l’aide de 7 exercices et d’un module simulant une série de 12 biopsies randomisées. Plusieurs niveaux d’assistance et un retour sur les performances réalisées par l’apprenant sont proposés. Une première étude avait permis de valider l’apparence et le contenu du simulateur, mais sa capacité à discriminer experts et novices (construit) n’avait pu être mise en évidence notamment en raison d’un manque de réalisme. Au cours de cette thèse, 2 nouvelles études de validation ont donc été réalisées sur une nouvelle version du simulateur. La première a permis d’en valider le construit. La seconde a permis de valider le transfert des compétences, c’est à dire la capacité des étudiants à reproduire les compétences acquises sur le simulateur en situation réelle<br>Prostate cancer is the most common malignancy and the 3rd cause of death among men in France. It is a major public health problem with around 50 000 new cases diagnosed each year. The diagnosis is suspected based on an abnormal digital rectal examination or an increase in the prostatic specific antigen level (PSA). Systematic, randomized, ultrasound-guided prostate biopsies are currently recommended first-line to confirm the diagnosis and define the tumor location, volume, and aggressiveness using the Gleason grading system. The conventional training method, based on mentoring, without quantitative feedback on the distribution of the biopsies, has limitations which can partly explain the lack of precision offered by systematic prostate biopsies.The Biopsym simulator was designed in this context to enhance prostate biopsy teaching through 7 exercises and a module replicating the performance of a 12-core systematic biopsy scheme. Several levels of assistance can be offered and a performance feedback is provided. A first validation study allowed to validate face, content and reliability of the simulator, but failed to prove its ability to discriminate between experts and novices (construct validity), in part due to a lack of realism. Two new validation studies on the new version of the simulator were set up during this thesis. The first one allowed for validation of the construct. The second one was able to demonstrate the transfer of skills acquired on the simulator under real-life conditions
22
Mundeleer, Laurent. "Modélisation d'un système de navigation chirurgicale pour le traitement par radio-fréquences des tumeurs du foie." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210264.
Full textAbstract:
Radiofrequency ablation (RFA) is a minimally invasive treatment for either hepatocellular carcinoma or metastasis liver carcinoma. In order to resect large lesions, the surgeon has to perform multiple time-consuming destruction cycles and reposition the RFA needle for each of them. The critical step in handling a successful ablation and preventing local recurrence is the correct positioning of the needle. For small tumors, the surgeon places the middle of the active needle tip in the center of the tumor under intra-operative ultrasound guidance. When one application is not enough to cover the entire tumor, the surgeon needs to repeat the treatment after repositioning of the needle, but US guidance is obstructed by the opacity stemming from the first RFA application. In this case the surgeon can only rely on anatomical knowledge and the repositioning of the RFA needle becomes a subjective task limiting the treatment accuracy. We have developed a computer assisted surgery guidance application for this repositioning procedure. Our software application handles the complete process from preoperative image analysis to tool tracking in the operating room. Our framework is mostly used for this RFA procedure, but is also suitable for any other medical or surgery application.<br>Doctorat en Sciences de l'ingénieur<br>info:eu-repo/semantics/nonPublished
23
Anselmi, Amedeo. "Ajustement anatomique des dispositifs d’assistance cardiaque mécanique de longue durée par exploitation de l’imagerie et de la simulation." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1B001.
Full textAbstract:
Les assistances circulatoires mécaniques de longue durée (ACM) sont une stratégie de plus en plus répandue pour le traitement des patients porteurs d’insuffisance cardiaque avancée. Cependant, cette option thérapeutique reste associée à des complications immédiates at au suivi parfois particulièrement graves (telles que la thrombose de pompe, les évènements thromboemboliques et le dysfonctionnement du dispositif). Nous formulons l’hypothèse que l’analyse du positionnement postopératoire du dispositif (et notamment, de sa canule d’admission intraventriculaire) peut fournir des informations utiles à la prédiction des évènements cliniques cités ci-dessus. Nous formulons aussi l’hypothèse qu’il est possible d’optimiser la prise en charge de ces patients (choix du dispositif, choix du site ventriculaire et des modalités d’implantation) par le moyen d’une planification préopératoire assistée par ordinateur. Nous avons donc mis en place deux axes de recherche. Dans le premier, nous proposons un système original d’analyse d’orientation intraventriculaire de la canule d’admission (par rapport à la valve mitrale native) ; celui-ci démontre une association significative entre orientation de la canule en direction du septum interventriculaire et apparition clinique des complications. Ce moyen supplémentaire de prédiction spécifique-patient sera validé sur des cohortes plus large et testé dans le cadre d’une étude prospective. Dans le deuxième axe, nous proposons une solution d’implantation virtuelle spécifique patient. Elle est basée sur une segmentation semi-automatique des structures cardiaques, une visualisation augmentée du scanner préopératoire, un positionnement virtuel d’une représentation numérique des différents dispositifs, et une analyse de collision de celui-ci avec la paroi thoracique (ACM mono-ventriculaire et coeur artificiel total) ou le ventricule droit (ACM mono-ventriculaires). Nous ouvrons enfin les perspectives vers une approche d’analyse et prédiction physiologique basée sur la simulation par ordinateur de l’hémodynamique du ventricule gauche assisté<br>Long-term circulatory mechanical assist devices are increasingly employed in the management of patients with advanced heart failure. Nonetheless, this therapeutic strategy is still associated with immediate and long-term complications; among these, pump thrombosis, thromboembolic events and pump dysfunction are particularly dreadful. Mechanical factors are involved in their pathogenesis. We hypothesize that the analysis of the post-implantation positioning of the devices (and particularly of the admission cannula for left ventricular assist devices) might provide additional useful information for the prediction of the above events. We also hypothesize that it is possible to optimize the management of these patients (under the perspective of device selection, choice of the left ventricular implantation site and implantation modalities) through computer-assisted preoperative planning. We have therefore established two axes of research. With the first axis, we propose an original system for orientation analysis of the intraventricular admission cannula with respect to the mitral valve (postoperative CT scan). This analysis indicates a significant association between the cannula orientation towards the interventricular septum and the occurrence of early/delayed complications. This novel method will be validated in larger cohorts and tested in a prospective clinical investigation. With the second axis, we propose a virtual implantation solution (environment Cami-TK), based on semi-automatic segmentation of cardiac structures (preoperative CT scan), augmented visualization of the CT scan images, virtual positioning of a 3D mesh representing the devices, and collision analysis with the thoracic structures (left ventricular assist devices and total artificial heart) or the right ventricle (ventricular assist devices only). We finally indicate future investigations concerning the application of computational fluid dynamics to facilitate computer simulation of the hemodynamics within the assisted left ventricle, and refined prediction of adverse events
24
MACHADO, Luciana Pimenta e. Silva. "Critérios de Diagnóstico para Pesquisa das Desordens Temporomandibulares (RDC/TMD): avaliação de radiologistas sobre adequação." Universidade Federal de Goiás, 2011. http://repositorio.bc.ufg.br/tede/handle/tde/1368.
Full textAbstract:
Made available in DSpace on 2014-07-29T15:21:57Z (GMT). No. of bitstreams: 1
dissertacao luciana pimenta e silva machado.pdf: 1454474 bytes, checksum: 09a4d7c1496bba377b1749ce79194bbc (MD5)
Previous issue date: 2011-02-28<br>The aim of this study was to investigate the opinion of specialists in radiology, from different parts of the world, regarding to the proposed criteria for image acquisition and interpretation by Computed Tomography (CT), Cone Beam Computed Tomography (CBCT) and Resonance imaging (MRI) in diagnosing temporomandibular joint disorders (DATM) as part of Diagnostic Criteria for Research of Temporomandibular Disorders (RDC/TMD). Radiology specialists were invited by email to participate as volunteers in the study from three different eligible populations: researchers with publication DATM indexed on PubMed, ORADLIST members and individual
contact. The link to access the questionnaire was mailed to volunteers interested in participating who matched the inclusion criteria. The sample was composed of specialists in radiology with experience in the interpretation of sectional images (CT, CBCT and/or MRI) of the temporomandibular joint (TMJ) who answered a questionnaire in English, which was developed and maintained online (LimeSurvey 1.87+). In a three months period, two recalls were sent and a period of 40 days after the last notification was given for responses submission. The questionnaire was divided into three parts with closed and open questions. Part I was related to
issues of participant identification (gender, age, country of activity, area of activity, time and experience as a radiologist in the interpretation of sectional images of the TMJ and monthly time dedicated to the activity of interpreting sectional images of ATM). Part II contained questions
related to the adequacy of the proposed criteria for the interpretation of sectional images of the ATM as part of the RDC/TMD. The criteria were presented into two columns' tables and the participants were asked whether that set of criteria was considered adequate or not for assessement and diagnosis of TMJ osseous and non-osseous tissues according to each imaging modality. If the respondent not considered criteria appropriate, he/she should indicate what type of suggestion: if insertion of new items, the modification or deletion of existing items. Part III had questions related to the need to include a minimal technical protocol for TMJ CT,
CBCT and MRI acquisition as part of the RDC/TMD. If deemed necessary, the respondent should indicate which would be his/her suggestion protocol for acquisition of each imaging
technique (CT, CBCT and MRI). Fifty-seven radiologists from different countries completed the questionnaire. The results indicate that 87 to 98% of radiologists considered the criteria
adequate and that 81.6% of respondents considered necessary to include a minimal technical protocol for CT, CBCT and MRI acquisition as part of the RDC/TMD. Two to thirteen percent of respondents suggested insertion, modification and deletion of items in the proposed criteria.
Ninety percent of respondents considered necessary to include a minimal technical protocol for CT/CBCT and 81.7% for MRI. We conclude that, according to the opinion of the worldwide community of specialists in radiology, the need for adjustments in the criteria for assessment of sectional images of the ATM is minimal, however, the need for the inclusion of a protocol to acquire minimal technical parameters of those images as part of protocol standardization of studies using the RDC/TMD is clear.<br>O objetivo desse estudo foi investigar a opinião de especialistas em radiologia, de várias partes do mundo, quanto aos critérios propostos para aquisição e interpretação de imagens por Tomografia Computadorizada (TC), Tomografia Computadorizada por Feixe Cônico (TCFC) e Ressonância Magnética (RM) no diagnóstico das desordens da articulação temporomandibular (DATM) como parte dos Critérios de Diagnóstico para Pesquisa das Desordens emporomandibulares (RDC/TMD). Especialistas em radiologia foram convidados por meio de e-mail a participar como voluntários do estudo a partir de três diferentes populações elegíveis: pesquisadores com publicação indexada sobre DATM no PubMed, membros da ORADLIST e contato individual. O link de acesso ao questionário foi enviado por email aos voluntários interessados em participar os quais preencheram os critérios de inclusão. A amostra foi composta por especialistas em radiologia com experiência na interpretação de imagens seccionais (TC, TCFC e/ou RM) da articulação temporomandibular (ATM) que responderam um questionário na língua inglesa, desenvolvido e mantido online (LimeSurvey 1.87+). Num período de três meses, duas notificações foram enviadas e um prazo de 40 dias após a última notificação foi estabelecido para o envio das respostas. O questionário foi dividido em três partes com perguntas fechadas e abertas. A parte I relacionava-se às questões de identificação do participante (gênero, idade, país de atuação, área de atividade, tempo de experiência como
radiologista e na interpretação de imagens seccionais da ATM e o tempo de dedicação mensal à atividade de interpretar imagens seccionais da ATM). A parte II continha questões
relacionadas à adequação dos critérios propostos para interpretação das imagens seccionais da ATM como parte do RDC/TMD. Os critérios foram apresentados em tabelas de duas colunas e os participantes eram questionados se aquele conjunto de critérios era considerado adequado ou não para a interpretação e diagnóstico dos tecidos ósseos e não-ósseos da ATM de acordo com cada modalidade de imagem. Caso não os considerasse adequado, deveria indicar qual o tipo de sugestão: se inserção de novos items, a modificação ou eliminação de itens existentes. A parte III continha perguntas relacionadas à necessidade de se incluir um protocolo técnico
mínimo para a aquisição de TC, TCFC e RM como parte do RDC/TMD. Caso considerasse necessário, deveria indicar qual seria sua sugestão de protocolo para aquisição de cada uma
das técnicas de imagem (TC, TCFC e RM). Cinqüenta e sete radiologistas de vários países responderam o questionário. Os resultados indicam que 87 a 98% dos radiologistas
consideraram os critérios adequados e que 81,6% dos respondentes consideram necessária a inclusão de um protocolo técnico mínimo para aquisição das imagens por TC, TCFC e RM como parte do RDC/TMD. Dois a treze porcento dos respondentes sugeriram inserção, modificação e eliminação de items nos critérios propostos. Noventa porcento dos respondentes consideram necessária a inclusão de protocolo técnico mínimo para TC/TCFC e 81.7% para a
RM. Conclui-se que, de acordo com a opinião da comunidade mundial de especialistas em radiologia, é mínima a necessidade de ajustes nos critérios para interpretação de imagens seccionais da ATM, entretanto, é clara a necessidade da inclusão de um protocolo técnico mínimo para a aquisição das referidas imagens como parte do protocolo de normatização das pesquisas que utilizam o RDC/TMD.
25
Zanetti, Marcus Vinicius. "Classificação automatizada de padrões morfológicos cerebrais complexos em indivíduos com primeiro episódio psicótico: avaliação de desempenho diagnóstico." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5142/tde-10072012-153852/.
Full textAbstract:
INTRODUÇÃO: Os transtornos mentais psicóticos são condições frequentes na população em geral e estão associados à grande morbidade e elevadas taxas de comprometimento funcional, tornando-os um grave problema de saúde pública. O desenvolvimento de novos métodos de auxílio diagnóstico e prognóstico a pratica clínica psiquiátrica possibilitando que intervenções efetivas sejam feitas precocemente na história natural da doença são, dessa forma, desejáveis. A classificação de padrões neuroanatômicos é uma robusta técnica para processamento e análise de imagens médicas que permite tanto a realização de comparações voxel-a-voxel entre grupos com alta dimensionalidade de variáveis, como a classificação individualizada das imagens. OBJETIVOS: Avaliar o desempenho diagnóstico de um classificador de padrões morfológicos complexos baseado em support vector machine (SVM) na discriminação entre diferentes transtornos psicóticos no momento do primeiro episódio, utilizando-se uma abordagem epidemiológica para a seleção de casos e controles, bem como na determinação de prognóstico de 1 ano em pacientes com primeiro episódio de esquizofrenia. MÉTODOS: Uma amostra de 62 pacientes com primeiro episódio de esquizofrenia/ transtorno esquizofreniforme, 23 casos de primeiro episódio de mania psicótica (transtorno bipolar tipo I, TB-I), e 19 indivíduos com depressão maior (DM) psicótica foram estudados com ressonância magnética (RM) estrutural de 1.5T, assim como um total de 89 controles residentes na mesma região dos casos. As imagens T1 foram inicialmente registradas a uma imagem molde comum através de um método com preservação de massa, permitindo a obtenção de volumes cerebrais regionais. Um classificador neuroanatômico multivariado baseado em redução de dimensionalidade e SVM foi utilizado para identificar o melhor conjunto de características morfológicas que diferencia cada transtorno psicótico (esquizofrenia/ transtorno esquizofreniforme, TB-I e DM psicótica) de subgrupos de controles saudáveis pareados por idade, gênero e anos de escolaridade. Os resultados obtidos pelo classificador foram, então, analisados com o auxílio de uma curva ROC, e um mapa espacial de alta dimensionalidade daquelas regiões cerebrais que constituem um padrão de distribuição tecidual cerebral característico de cada transtorno psicótico em relação aos controles foi gerado. RESULTADOS: O classificador obteve uma discriminação apenas modesta entre pacientes com primeiro episódio de esquizofrenia/ transtorno esquizofreniforme e controles saudáveis, com uma medida de área sob a curva (AUC) de 0,75 e acurácia de 73,4%. O mapa espacial discriminatório resultante mostrou um padrão complexo de alterações volumétricas comprometendo regiões fronto-límbicas tanto de substância cinzenta como de substância branca cerebral bilateralmente, fascículos cerebrais associativos, terceiro ventrículo e o ventrículo lateral esquerdo. Um desempenho diagnóstico pobre foi observado nas comparações entre pacientes com TB-I e MD psicótica e controles. Além disso, o classificador baseado em SVM não conseguiu predizer satisfatoriamente o prognóstico de 1 ano (evolução de remissão versus não remissão) dos pacientes com primeiro episódio de esquizofrenia. CONCLUSÃO: Utilizando uma amostra de pacientes com psicoses afetivas e não afetivas com características clínicas semelhantes aos pacientes vistos na nossa prática psiquiátrica (comorbidade com transtornos de uso de substâncias e curso clínico variável) e selecionados através de uma abordagem epidemiológica populacional, o classificador de padrões neuroanatômicos não obteve bom desempenho diagnóstico na discriminação entre as formas esquizofreniformes e afetivas de primeiro episódio psicótico, e também não conseguiu predizer satisfatoriamente o prognóstico de 1 ano em primeiro episódio de esquizofrenia, utilizando apenas imagens estruturais de RM<br>INTRODUCTION: Psychotic disorders are prevalent medical conditions in the general population, and are usually associated with high morbidity and functional impairment rates, which make them a major concern for public health. The development of new methods aiming to aid diagnostic and prognostic value in clinical psychiatric practice thus allowing effective interventions at an early course of the illness are, therefore, desirable. Neuroanatomical pattern classification is a powerful technique for image processing and analysis which allows both high-dimensional voxelwise group comparisons and classification of images at an individual basis. OBJECTIVES: To evaluate the diagnostic performance of a support vector machine (SVM)-based complex morphological pattern classifier was used to discriminate different non-affective and affective psychotic disorders at the first episode using a population-based approach to recruit both cases and healthy controls, and also to predict 1-year prognosis (i.e., remitting versus non-remitting course) in a group of patients with first-episode schizophrenia. METHODS: A sample of 62 patients with first-episode schizophrenia/ schizophreniform disorder, 23 cases presenting with their first-episode of psychotic mania (bipolar I disorder, BD-I) and 19 individuals with psychotic major depressive disorder (MDD) was studied with 1.5T structural magnetic resonance imaging (MRI), as well as a pool of 89 epidemiologically recruited controls. T1-weighted images were first registered to a common template through a robust mass-preserving routine allowing regional volumetric analysis. A high-dimensional multivariate classification method based on dimensionality reduction and SVM was employed to identify the best and most parsimonious set of morphological features that discriminate each psychotic group (schizophrenia/ schizophreniform disorder, BD-I & psychotic MDD) from subgroups of age, gender and educationally-matched healthy controls. The abnormalities scores generated by the classifier were analyzed with a ROC curve analysis and a high-dimensional spatial map of the brain regions that constitute a pattern of brain tissue distribution characteristic of each of the non-affective and affective groups relative to controls was created. RESULTS: The SVM-classifier afforded modest discrimination between subjects with first-episode schizophrenia/ schizophreniform disorder and controls, with an area under the curve (AUC) value of 0.75 and overall accuracy of 73.4%. The resulting discriminative spatial map revealed a complex pattern of regional volumetric abnormalities affecting both gray and white matter fronto-limbic regions bilaterally, long associative fasciculi, besides the third and lateral ventricles. A poor diagnostic performance was observed in the pairwise comparisons between BD-I and psychotic MDD versus controls. Also, the SVM-classifier failed to predict 1-year prognosis (remitting versus non-remitting course) in the first-episode schizophrenia group. CONCLUSION: The present results suggest that at the population level and using a real world sample of affective and non-affective psychotic patients with comorbid substance use disorders and variable disease course, we failed to achieve good discrimination between schizophreniform and affective forms of first-episode psychosis, and also in predicting 1-year prognosis of first-episode schizophrenia patients, using structural images
26
"AI-assisted local area network diagnostic system." Chinese University of Hong Kong, 1993. http://library.cuhk.edu.hk/record=b5887709.
Full textAbstract:
by Chi-kwong Fong.<br>Thesis (M.Sc.)--Chinese University of Hong Kong, 1993.<br>Includes bibliographical references (leaves 30-[31]).<br>Chapter 1 --- Introduction --- p.1<br>Chapter 2 --- Data Capture Subsystem --- p.7<br>Chapter 3 --- Anomaly Detection Subsystem --- p.10<br>Chapter 4 --- Descriptive Language Translation System --- p.14<br>Chapter 5 --- Rule-based Analysis Subsystem --- p.20<br>Chapter 6 --- Testing Results --- p.22<br>Chapter 7 --- Summary --- p.27<br>Bibliography --- p.30
27
Guo, Ya-Jing, and 郭雅菁. "Predicting Applicants’Emotional Intelligence in Selection Context: Computer-Assisted and Face-to-Face Interview." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/66396343329881201229.
Full textAbstract:
碩士<br>國立中興大學<br>企業管理學系所<br>97<br>With the competition in the service industry is fiercer and fiercer, many companies have set up customer service department or outsourced call center to enhance their capability of customer relationship management. To offer quality service, how to select good customer service representatives is the important issue that companies need to concern. Nowadays, although many companies have relied on interview to select new customer service representatives, there are still no specific open–ended interview questions to examine applicants'' emotional intelligence. Besides, the prevailing interviewing questions adopted by companies are in lack of validity and reliability. Hence, there are two parts of the study; the first part is designed to develop the open-ended interview questions of emotional intelligence and to examine whether we can understand the applicants’ emotional intelligence by means of computer-assisted interview. The second part is to examine whether we can understand the applicants’ emotional intelligence through face-to-face interview. Further, we compared situational interview with pattern-behavior description interview to determine which method is better in terms of criterion-related validity for emotional intelligence.
The experiment is conducted in this study. There are two hundred and twenty-one students in the study one and twenty students in the study two. The former valid responded rate are: the basic data of sample 91.9%, WLEIS 91.5%, WEIS 88.2%, Big-five 79.6% and interview answer sheet 86.7%,the latter valid participated rate is 100%.The results show that using computer-assisted and face-to-face interview are surly can understand the applicants’ emotional intelligence. In the structured interview, pattern-behavior description interview may have the better criterion-related validity for emotional intelligence.
As a result, this research suggested that when companies have to select new customer service representatives, they can choose either computer -assisted or face-to-face interview that can depend on their selecting scale and selecting budget.
28
Lee, Sun-Jen, and 李樹人. "The study of Computer-Assisted Telephone Interview user and the applieation of effect." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/28878367805947343410.
Full text
29
Kistan, Trevor. "Neural network assisted software engineered refractive fringe diagnostic of spherical shocks." Thesis, 1996. http://hdl.handle.net/10413/4859.
Full textAbstract:
A shock is essentially a propagating variation in the pressure or density of a medium. If the medium is transparent, such as air, and the shock radially symmetric, the refractive fringe diagnostic can be
used to examine its general features. A laser beam probes the shock, the central part of the beam, refracted to different degrees by the different density features within the shock, interferes with itself and
with the outer unrefracted part creating a series of coarse and fine fringes. By examining this interference pattern one can gain insight into the density profile underlying the shock. A series of such experiments was conducted by the Plasma Physics Research Institute at the University of Natal in 1990. To model the situation computationally, they developed a ray-tracer which produced
interference patterns for modified theoretical density profiles based on those predicted by Sedov. After numerous trials, an intensity pattern was produced which agreed approximately with experimental
observations. Thus encouraged, the institute then sought to determine density profiles directly from the interference patterns, but a true mathematical deconvolution proved non-trivial and is still awaited. The work presented in this thesis reconstructs the ray-tracer using software engineering techniques and achieves the desired deconvolution by training a neural network of the back-propagation type to behave as an inverse ray-tracer. The ray-tracer is first used to generate numerous density profile - interference pattern pairs. The neural network is trained with this theoretical data to provide a density profile when presented with an interference pattern. The trained network is then tested with experimental interference patterns extracted from captured images. The density profiles predicted by the neural network are then fed back to the ray-tracer and the resultant theoretically determined interference patterns compared to those obtained experimentally. The shock is examined at various times after the initial explosion allowing its propagation to be tracked by its evolving density profile and interference pattern. The results obtained prove superior to those first published by the institute and confirm the neural network's promise as a research tool. Instead of lengthy trial and error sessions with the unaided ray-tracer, experimental interference patterns can be fed directly to an appropriately trained neural network to yield an initial density profile. The network, not the researcher, does the pattern association.<br>Thesis (M.Sc.)-University of Natal, 1996.
30
Ku, Chia-Chen, and 谷佳臻. "A Study on the Application of Computer Assisted Qualitative Data Analysis Software to Qualitative Research Interview Manuscript Content Analysis." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/pss4yb.
Full textAbstract:
碩士<br>國立臺灣師範大學<br>圖書資訊學研究所<br>96<br>With the rising of social thoughts, qualitative research has been gradually emphasized in the domain of social science. Qualitative interview is the most extensively used method of data collection. After qualitative interview, researchers need to create an interview manuscript and cluster the interviewees’ responses based on the theoretical framework of the research, before analyzing the collected data. Conventional manual clustering requires a large amount of time and efforts. Therefore, this study aimed to use computer assisted qualitative data analysis software (CAQDAS) to analyze interview manuscripts and investigate if consistency exists between the results of CADQAS and manual clustering. Finally, how CAQDAS could benefit the analysis of interview manuscripts would also be explained.
In this study, a CAQDAS, ClustanGraphics 8.02, and a topic extraction system were utilized in the experiment on the interview manuscripts of graduates (interviewees) in the domain of social science. CAQDAS was first used to analyze the interview manuscripts and obtain computer assisted analysis results. Later, according to the analysis results, the interviewees were interviewed again, and rand index was applied to cross verify the similarity between the results of CAQDAS and manual analysis to find out the benefits of CAQDAS for the analysis of qualitative research interview manuscripts.
The experimental and interview results revealed that CAQDAS and manual clustering results were not consistent but the results produced by CAQDAS could provide a primary concept of clustering for manual analysis of interview manuscripts. Moreover, if CAQDAS was applied to structured or semi-structured interview manuscripts, the results would be better. From the similarity calculated by rand index between CAQDAS and manual clustering results and comprehensive results, no significant difference was found. From the interview results, it was also found that the general analysis results were not reliable, indicating that the use of a single or multiple computer assisted software systems would not produce any significant difference.
31
"Image segmentation using prior information and its application on medical ultrasound image processing." 2004. http://library.cuhk.edu.hk/record=b6073669.
Full textAbstract:
Xie Jun.<br>"July 2004."<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2004.<br>Includes bibliographical references (p. 177-204).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Mode of access: World Wide Web.<br>Abstracts in English and Chinese.
32
"Development of histologic color image analysis system." Chinese University of Hong Kong, 1994. http://library.cuhk.edu.hk/record=b5888199.
Full textAbstract:
by Chung-fai Kwok.<br>Thesis (M.Sc.)--Chinese University of Hong Kong, 1994.<br>Includes bibliographical references (leaves 65).<br>Contents --- p.i<br>Table of Figures --- p.iii<br>Abstract --- p.v<br>Acknowledgment --- p.vii<br>Introduction --- p.viii<br>Chapter 1. --- Overview : Medical image network system --- p.1<br>Chapter 1.1 --- MAGNET --- p.1<br>Chapter 1.2 --- Medical image --- p.2<br>Chapter 2. --- System configuration --- p.4<br>Chapter 2.1 --- Hardware setting --- p.4<br>Chapter 2.2 --- Software functions design --- p.5<br>Chapter 3. --- Color handling --- p.7<br>Chapter 3.1 --- Color --- p.7<br>Chapter 3.2 --- Colormap and color display --- p.9<br>Chapter 3.3 --- Static and dynamic color mapping --- p.10<br>Chapter 4. --- Color image processing --- p.11<br>Chapter 4.1 --- Color image quantization --- p.11<br>Chapter 4.1.1 --- Pre-quantization --- p.13<br>Chapter 4.1.2 --- Median cut Algorithm --- p.15<br>Chapter 4.1.3 --- Remapping colors --- p.16<br>Chapter 4.1.4 --- Hashing --- p.17<br>Chapter 4.1.5 --- Distortion Measures --- p.21<br>Chapter 4.1.6 --- Experiment results and Discussion --- p.22<br>Chapter 4.2 --- Intensity mapping --- p.30<br>Chapter 4.2.1 --- Graylevel image contrast enhancement and reduction --- p.30<br>Chapter 4.2.2 --- Graylevel image brightness increment and reduction --- p.36<br>Chapter 4.2.3 --- Contrast enhancement and reduction on color components --- p.40<br>Chapter 4.2.4 --- Brightness increment and reduction on color components --- p.41<br>Chapter 4.3 --- Pseudocoloring --- p.45<br>Chapter 5. --- Color image analysis --- p.47<br>Chapter 5.1 --- Region Measures --- p.47<br>Chapter 5.1.1 --- Region measures function design --- p.47<br>Chapter 5.1.2 --- Region growing mechanism --- p.48<br>Chapter 5.1.3 --- Region smoothing --- p.49<br>Chapter 5.2 --- Distance measures --- p.53<br>Chapter 5.3 --- Statistical analysis --- p.53<br>Chapter 6. --- Summary and future work --- p.57<br>Appendix : User interfaces and functions --- p.58<br>Bibliography --- p.65
33
"Three dimensional medical image visualization." Chinese University of Hong Kong, 1994. http://library.cuhk.edu.hk/record=b5888229.
Full textAbstract:
by Tin Pong.<br>Thesis (M.Sc.)--Chinese University of Hong Kong, 1994.<br>Includes bibliographical references (leaf 73).<br>Abstract --- p.2<br>Acknowledgement --- p.4<br>Table of Contents --- p.5<br>Chapter I. --- Introduction --- p.8<br>Chapter II. --- Segmentation Tools --- p.11<br>Chapter 2.1. --- Segmentation of Object --- p.11<br>Chapter 2.1.1. --- Segmentation algorithm --- p.11<br>Chapter 2.1.2. --- Region growing algorithm --- p.16<br>Chapter 2.2. --- Noise Reduction --- p.19<br>Chapter 2.2.1. --- Median filtering --- p.19<br>Chapter 2.2.2 --- Mean filtering --- p.20<br>Chapter 2.3. --- Other functions --- p.21<br>Chapter 2.3.1. --- Contrast enhancement and reduction --- p.21<br>Chapter 2.3.2. --- Brightness increment and reduction --- p.22<br>Chapter III. --- 3D Visualization Tools --- p.23<br>Chapter 3.1. --- Interpolation --- p.23<br>Chapter 3.1.1. --- Estimate distance between slices --- p.23<br>Chapter 3.1.2. --- Trilinear Interpolation --- p.24<br>Chapter 3.2. --- Projection --- p.26<br>Chapter 3.2.1. --- Parallel projection --- p.26<br>Chapter 3.2.2. --- Z-Buffers --- p.27<br>Chapter 3.3. --- Rotation of 3D image --- p.29<br>Chapter 3.4. --- Shading --- p.30<br>Chapter IV. --- Description of the software developed --- p.32<br>Chapter 4.1. --- Programming environment --- p.32<br>Chapter 4.2. --- Software developed --- p.32<br>Chapter 4.3. --- 2D object segmentation panel --- p.35<br>Chapter 4.4. --- 3D object segmentation panel --- p.45<br>Chapter V. --- Results and analysis --- p.56<br>Chapter 5.1. --- Results of segmentation of object --- p.56<br>Chapter 5.2. --- Results of 3D visualization tools --- p.64<br>Chapter VI. --- Future Development --- p.70<br>Chapter VII. --- Conclusion --- p.72<br>References --- p.73
34
"Variational and spline based multi-modal non-rigid medical image registration and applications." Thesis, 2005. http://library.cuhk.edu.hk/record=b6074158.
Full textAbstract:
In the brain mapping case, the geodesic closest points are used as the anatomical constraints for the inter-subject non-rigid registration. The method uses the anatomical constraint in the non-rigid registration which is much more reasonable for the anatomical correspondence. The registration result shows significant improvement comparing with the iterative closest points based method.<br>In the third application, we use the non-rigid registration method to register the different sweeps of freehand ultrasound images. We setup a 3D freehand ultrasound imaging system to capture images of a human anatomy such as liver, prostate, brain tumor and fetus. The arbitrary scanned image slices are reconstructed and resliced into volumetric dataset. We use a B-spline based non-rigid registration method to compounding different freehand ultrasound sweeps. This technique can be used to make 3D ultrasound models of fetus and other organs.<br>Medical image registration is an active research area during the last two decades. The registration technique can be widely used in the applications of the computer aided surgery, brain mapping and pathological detection and analysis. With the development of the computing power, fast and accurate registration techniques have been developed into necessary tools for quantitative analysis of the medical image.<br>Non-rigid registration methods can be used in atlas based image segmentation, inter-subject brain image registration and 3D freehand ultrasound modeling. In one of our proposed novel segmentation methods, we interleave the segmentation and the registration processes by using the segmentation to provide the anatomical constraints for registration to improve the atlas based non-rigid registration. This updated registration can be used to improve the new segmentation. This process is repeated until a good result in segmentation is obtained.<br>The registration methods can be classified into rigid and non-rigid registrations according to whether the anatomy is locally deformed or not. According to the sensor by which the images are taken, the registration will be divided into mono-modal and multi-modal image registration. Since the invention of the medical imaging devices, great diversity of medical imaging sensors have been developed with different physical principles. In practice we have to face the problem of multi-modal registration. In medical image analysis, we often have to consider the images of the human anatomy with deformable characteristics. In order to achieve this goal we need to use the voxel based registration method which considers all of the voxel information of the images in matching. There are several non-rigid registration approaches. However, the variational approach of non-rigid registration can represent the registration problem into a well-posed problem with a well-founded mathematical base. In our work, we considered the forward and backward deformation functions and proposed a variational approach for a new consistent multi-modal non-rigid registration method. By this way, we will find the forward and backward transform to be close to the inverse of each other. This makes the correspondence between two images more consistent and accurate. We use both explicit and implicit difference method to solve the Euler-Lagrange equation and the results show significant improvements in the transformation inverse consistency. Although variational approach for multi-modal non-rigid registration can solve the non-rigid registration problem well, generally speaking, it is slow. The displacement of each voxel has to be calculated and the iteration time is very long since the number of the unknowns are large. Although a multi-resolution strategy can be used to speed up, the registration problem is still slow when registering large medical datasets. The 3D B-spline based method has been used as an efficient method to register medical images since only a small number of control points are used to manipulate the local deformation field. In our work, we developed a 3D B-spline based consistent multi-modal non-rigid registration method with an explicit representation of derivatives. The conventional optimization methods can be used to find the optimal parameters. We use a hierarchical B-spline refinement method to approximate the deformation function from larger to smaller scale. Since the derivatives of the cost function is represented in an explicit way, the computing is reduced. It is more efficient than directly computing the derivative of the cost function by using a numerical evaluation method. The method can be considered as a multi-grid method for solving the consistent variational registration problem. The computing speed is increased by several times. The B-spline based method needs far less iterations to converge as its number of unknowns is small.<br>Zhang Zhijun.<br>"October 2005."<br>Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6645.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2005.<br>Includes bibliographical references (p. 209-233).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Abstracts in English and Chinese.<br>School code: 1307.
35
"A study on computer-aided diagnosis for wireless capsule endoscopy images." Thesis, 2008. http://library.cuhk.edu.hk/record=b6074670.
Full textAbstract:
A feature extraction approach based on color is firstly proposed. Exploiting color histogram of an image, we can obtain distribution of different colors in images. Then we employ minimum distance classifier based on a new distance criterion to judge status of regions. In this section, we also validate benefits of WCE image enhancement to the proposed CAD system.<br>Finally, we propose a new approach of chrominance moment as another kind of feature to discriminate normal regions from abnormal regions, which makes full use of Tchebichef polynomials and HSI color space. This new feature extraction scheme preserves illumination invariance without numerical approximation.<br>In conclusion, this thesis investigates several major and challenging problems such as WCE images enhancement and feature extractions in CAD for WCE images, and proposes several novel schemes to solve those problems. Extensive experiments are reported to demonstrate effectiveness of the proposed algorithms.<br>Next, we investigate automatic diseases detection for WCE images to partially solve the second problem. In this part we explore different features that are suitable for detection of diseases from three viewpoints, i.e., color, texture and chromaticity, because clinicians mainly use these clues to diagnose. At the same time, we introduce their corresponding classifiers.<br>We further advance a new texture feature extraction method, curvelet based local binary pattern, to detect abnormal regions in WCE images. This method takes advantage of curvelet transform and local binary pattern to describe textural features of WCE images.<br>Wireless capsule endoscopy (WCE) is a state-of-the-art technology to diagnose gastrointestinal (GI) tract diseases without invasiveness. However, there exist two major problems concerning WCE images. One problem is that many images for diagnosis have rather low contrast and are noisy, which causes difficulties to diagnosis and also to computer-aided detection, so it is necessary to enhance these images. The other one is that the viewing process of video data per examination is very time consuming because of the great amount of video data. If we can use computerized methods to help the physicians detect some abnormal regions in WCE images, it will certainly reduce the burden of physicians. Focusing on these two goals, this thesis mainly studies some main challenging problems in computer-aided diagnosis (CAD) system for WCE images. To solve the first problem, we put forward an adaptive curvature strength diffusion method to enhance WCE images. Based on local characteristics analysis of WCE images, we propose a new concept of curvature strength. Then, we employ curvature strength diffusion to enhance WCE images with an adaptive choice of conductance parameter. Finally, we extend the curvature strength diffusion to color space since WCE images are color images.<br>Li, Baopu.<br>Adviser: Max Q. H. Meng.<br>Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3640.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2008.<br>Includes bibliographical references (leaves 126-150).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Abstracts in English and Chinese.<br>School code: 1307.
36
"Inverse problems in transcient [sic] elastography." 2012. http://library.cuhk.edu.hk/record=b5549130.
Full textAbstract:
由線性彈性模型引起的多維系數反問題在很多範疇都有其應用，如斷層探測、油田檢測、鹽石檢測、礦石檢測及醫療成像等。瞬時成像技術是其中最有用的應用。它提供了一個快速及安全的醫療成像技術，可以用來檢測在身體內快速移動的器官的一些異常組織，如肝腫瘤。在這篇論文中，我們會重點討論兩個解決瞬時弹性成像反問題的數值方法，即水平集反演方法和近似全局收斂方法。我們會研究這兩種方法的推導和數值結果。<br>特別地，近似全局收斂方法是一種由Klibanov 新提出用來解決由雙曲偏微分引起的多維系數反問題的方法。因為這佪方法沒有使用求泛函極小值的步驟，因此能避免了一些眾所周知的問題，所以它特別穩定。數值結果顯示近似全局收斂方法對噪聲有很高的穩定性。這表明近似全局收斂方法是一個解決由線性彈性模型引起的多維系數反問題的其中一個有效方法。<br>Multi-dimensional coefficient inverse problem (MCIP) in linear elasticity has found many applications, such as crack detection, oil/salt/ore detection, medical imaging. Transient elastography is among one of the most useful applications, providing a fast and safe medical imaging technique which can be used to detect tumors or abnormal tissue in “fast-moving“ organs such as the liver. In this thesis focus is casted on two of the numerical algorithms to solve inverse problems related to transient elastography, namely the level-set inversion method and the approximate globally convergent method. The derivations of both methods and numerical results are presented. In particular, the approximate globally convergent method is a newly developed stable method to solve coefficient determination inverse problem for hyperbolic partial differential equation proposed by Beilina and Klibanov in [6]. It achieves pproximately a global convergence by avoiding construction of a least squares functional, thus averting some of the well-known problems of trapping in the neighborhoods of local minima when one minimizes such a nonlinear functional. The results of the approximate globally convergent method have shown its strong stability and robustness. This suggests a good way for the reconstruction of the distribution of the shear modulus in the coefficient inverse problem of linear elasticity.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Chow, Yat Tin.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2012.<br>Includes bibliographical references (leaves 98-102).<br>Abstracts also in Chinese.<br>Chapter 1 --- Introduction --- p.6<br>Chapter 2 --- Linear Elasticity Model --- p.9<br>Chapter 2.1 --- Introduction to Linear Elasticity Model --- p.9<br>Chapter 2.2 --- Physical Meanings of Elasticity Equation --- p.12<br>Chapter 2.3 --- Derivations of Linear Elasticity Equation --- p.14<br>Chapter 2.4 --- Discussion of Christoffel’s Equation --- p.17<br>Chapter 3 --- Formulations of the Forward and Inverse Problem --- p.27<br>Chapter 3.1 --- The Forward Problem --- p.29<br>Chapter 3.2 --- The Inverse Problem --- p.29<br>Chapter 3.3 --- A Uniqueness Result --- p.30<br>Chapter 4 --- Algorithms for Inverse Problems in Elasticity --- p.33<br>Chapter 5 --- Level Set Inversion Method --- p.37<br>Chapter 5.1 --- Arrival Time Acquisition: Cross-Correlation --- p.37<br>Chapter 5.2 --- The Distance Inversion Method --- p.41<br>Chapter 5.3 --- Solving the Forward Eikonal Equation --- p.43<br>Chapter 5.3.1 --- Discretizing the eikonal equation --- p.43<br>Chapter 5.3.2 --- A forward eikonal solver: fast marching algorithm --- p.47<br>Chapter 5.3.3 --- A forward eikonal solver: fast sweeping algorithm --- p.50<br>Chapter 5.4 --- Level Set Inversion Scheme --- p.54<br>Chapter 5.5 --- Numerical Implementation --- p.57<br>Chapter 5.6 --- Results of Reconstructions --- p.58<br>Chapter 6 --- Approximate Globally Convergent Method --- p.63<br>Chapter 6.1 --- The Forward Problem --- p.65<br>Chapter 6.1.1 --- Forward problem in time domain --- p.65<br>Chapter 6.1.2 --- Forward problem in Laplace domain --- p.67<br>Chapter 6.2 --- The Inverse Problem --- p.67<br>Chapter 6.2.1 --- Inverse problem in time domain --- p.67<br>Chapter 6.2.2 --- Inverse problem in Laplace domain --- p.68<br>Chapter 6.3 --- A Nonlinear Integral Differential Equation --- p.69<br>Chapter 6.4 --- Approximation of the First Tail --- p.71<br>Chapter 6.5 --- The Algorithm --- p.72<br>Chapter 6.6 --- Notes About the Convergence Analysis --- p.76<br>Chapter 6.6.1 --- Approximate global convergence --- p.76<br>Chapter 6.6.2 --- Basic formulation of Theorem 2.9.4 of [6] --- p.78<br>Chapter 6.6.3 --- Some ideas of the convergence analysis for the algorithm in section 6.5 --- p.80<br>Chapter 6.7 --- Numerical Implementation --- p.81<br>Chapter 6.8 --- Results of Reconstructions --- p.88<br>Chapter 7 --- Conclusions --- p.96<br>Bibliography --- p.98
37
"Multiscale geodesic active contours and local phase information in ultrasonic applications: 多尺度測地主動輪廓線和局部相位信息在超聲應用中的使用". 2014. http://library.cuhk.edu.hk/record=b6115456.
Full textAbstract:
在各种临床应用广泛使用的诊断和治疗工具中，超声成像是其中的一个。与其他成像模式相比，比如计算机断层照相法和磁共振成像，超声波检查法有许多优点:没有辐射风险，设备价格低以及能够实时获取图像。很多超声应用的第一步通常是对感兴趣组织和结构的检测和定位。然而，超声图像存在一些特有的伪影，比如高噪声，低信噪比和灰度不均，这些伪影使得检测任务变得困难。此外，感兴趣区域之间的低对比度也使得这一任务变得更加复杂。在这篇论文里，我们深入研究这些图像伪影并提出新的方法来促进临床中的超声应用。<br>首先，我们提出一个多尺度的框架来进行超声图像的分割，这个框架是基于各向异性去噪扩散和测地主动轮廓线的。各向异性去噪扩散是对边缘敏感且专门用于斑点噪声图像的扩散过程，这里它被用来去除超声图像的斑点噪声，我们对每幅输入图像构造一个多尺度的表示方法，随着尺度的增加，噪声被逐渐地消除。之后，多尺度测地主动轮廓线从粗到细渐进地应用到这些尺度来提取物体的边界线。为了避免在低对比度区域出现边界泄漏的情况，我们把不同尺度之间的边界形状相似性结合到传统的测地主动轮廓线模型里作为一个外部约束来指导轮廓线的演化。在合成和临床图像的实验结果证明了我们的方法的优越性。<br>其次，我们提出一个基于相位的方法来检查和测量超声图像里的胎儿腹部轮廓线。我们定义了一个基于局部相位的度量来检测胎儿腹部的边界线，这个度量称为多尺度特征非对称性，它与图像的亮度无关，并且能为图像里特征的重要程度提供一个绝对的测量。为了估计与腹部轮廓线相吻合的椭圆，我们使用一个迭代随机霍夫变换来排除内腹部边界线的影响，从而使得估计的椭圆逐渐收敛到外边界线。在临床超声图像里进行腹部周长测量的实验结果验证了我们的方法与手工的方法有很高的一致性，这也表明我们的方法可以作为一个可靠的工具来进行产科的护理和诊断。<br>Ultrasound imaging is one of the most widely used diagnostic and therapeutic tools for a variety of clinical applications. Compared with other imaging modalities, such as computed tomography and magnetic resonance imaging, ultrasonography has a lot of advantages: free of radiation risk, low cost of acquisition and images are available in real-time. The first step in many ultrasonic applications is usually the detection and localization of interested tissues and structures. However, there are a number of characteristic artifacts in ultrasound images that make the task difficult such as high speckle noise, low signal-to-noise ratio and intensity inhomogeneity. Besides, the low contrast between regions of interest further complicates the processing. In this thesis, we deeply investigate these image artifacts and propose new techniques to facilitate ultrasonic applications in clinic.<br>First, we propose a multiscale framework for ultrasound image segmentation based on speckle reducing anisotropic diffusion(SRAD) and geodesic active contours (GAC). SRAD is an edge-sensitive diffusion tailored for speckled images, and it is adopted here to reduce speckle noise by constructing a multiscale representation for each input image, where the noise is gradually removed as the scale increases. Multiscale geodesic active contours are then applied along the scales in a coarse-to-fine manner to capture the object boundaries progressively. To avoid boundary leakages in low contrast regions, traditional GAC model is modified by incorporating the boundary shape similarity between different scales as an external constraint to guide the contour evolution. Experimental results in both synthetic and clinical images demonstrate the superiority of the proposed approach.<br>Second, we propose a phase-based approach for fetal abdominal contour detection and measurement in ultrasound images.We define a local phase-based measure, called multiscale feature asymmetry (MSFA), from the monogenic signal to detect the boundaries of fetal abdomen. The MSFA measure is intensity invariant and provides an absolute measurement for the significance of features in the image. In order to estimate the ellipse that fits to the abdominal contour, we employ an iterative randomized Hough transform to exclude the interferences of the inner boundaries of the abdomen, after which the estimated ellipse gradually converges to the outer boundaries. Experimental results in clinical ultrasound images validate the high agreement between our approach and manual approach in the measurement of abdominal circumference, indicating that the proposed approach can be used as a reliable tool for obstetric care and diagnosis.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Wang, Weiming .<br>Thesis (Ph.D.) Chinese University of Hong Kong, 2014.<br>Includes bibliographical references (leaves 68-84).<br>Abstracts also in Chinese.<br>Wang, Weiming .
38
"Shape morphometry using Riemannian geometry with applications in medical imaging." 2013. http://library.cuhk.edu.hk/record=b5884489.
Full textAbstract:
Tsang, Man Ho.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2013.<br>Includes bibliographical references (leaves 57-60).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Abstracts also in Chinese.
39
Quddus, Azhar. "Semantic Assisted, Multiresolution Image Retrieval in 3D Brain MR Volumes." Thesis, 2010. http://hdl.handle.net/10012/5623.
Full textAbstract:
Content Based Image Retrieval (CBIR) is an important research area in the field of multimedia information retrieval. The application of CBIR in the medical domain has been attempted before, however the use of CBIR in medical diagnostics is a daunting task. The goal of diagnostic medical image retrieval is to provide diagnostic support by displaying relevant past cases, along with proven pathologies as ground truths. Moreover, medical image retrieval can be extremely useful as a training tool for medical students and residents, follow-up studies, and for research purposes. Despite the presence of an impressive amount of research in the area of CBIR, its acceptance for mainstream and practical applications is quite limited. The research in CBIR has mostly been conducted as an academic pursuit, rather than for providing the solution to a need. For example, many researchers proposed CBIR systems where the image database consists of images belonging to a heterogeneous mixture of man-made objects and natural scenes while ignoring the practical uses of such systems. Furthermore, the intended use of CBIR systems is important in addressing the problem of "Semantic Gap". Indeed, the requirements for the semantics in an image retrieval system for pathological applications are quite different from those intended for training and education. Moreover, many researchers have underestimated the level of accuracy required for a useful and practical image retrieval system. The human eye is extremely dexterous and efficient in visual information processing; consequently, CBIR systems should be highly precise in image retrieval so as to be useful to human users. Unsurprisingly, due to these and other reasons, most of the proposed systems have not found useful real world applications. In this dissertation, an attempt is made to address the challenging problem of developing a retrieval system for medical diagnostics applications. More specifically, a system for semantic retrieval of Magnetic Resonance (MR) images in 3D brain volumes is proposed. The proposed retrieval system has a potential to be useful for clinical experts where the human eye may fail. Previously proposed systems used imprecise segmentation and feature extraction techniques, which are not suitable for precise matching requirements of the image retrieval in this application domain. This dissertation uses multiscale representation for image retrieval, which is robust against noise and MR inhomogeneity. In order to achieve a higher degree of accuracy in the presence of misalignments, an image registration based retrieval framework is developed. Additionally, to speed-up the retrieval system, a fast discrete wavelet based feature space is proposed. Further improvement in speed is achieved by semantically classifying of the human brain into various "Semantic Regions", using an SVM based machine learning approach. A novel and fast identification system is proposed for identifying a 3D volume given a 2D image slice. To this end, we used SVM output probabilities for ranking and identification of patient volumes. The proposed retrieval systems are tested not only for noise conditions but also for healthy and abnormal cases, resulting in promising retrieval performance with respect to multi-modality, accuracy, speed and robustness. This dissertation furnishes medical practitioners with a valuable set of tools for semantic retrieval of 2D images, where the human eye may fail. Specifically, the proposed retrieval algorithms provide medical practitioners with the ability to retrieve 2D MR brain images accurately and monitor the disease progression in various lobes of the human brain, with the capability to monitor the disease progression in multiple patients simultaneously. Additionally, the proposed semantic classification scheme can be extremely useful for semantic based categorization, clustering and annotation of images in MR brain databases. This research framework may evolve in a natural progression towards developing more powerful and robust retrieval systems. It also provides a foundation to researchers in semantic based retrieval systems on how to expand existing toolsets for solving retrieval problems.
40
"Synopsis of video streams and its application to computer aided diagnosis for GI tract abnormalities based on wireless capsule endoscopy (CE) video." 2012. http://library.cuhk.edu.hk/record=b5549629.
Full textAbstract:
無線膠囊內窺鏡（CE）是一種用於檢查整個胃腸道，尤其是小腸的無創技術。它極大地改善了許多小腸疾病的診斷和管理方式，如不明原因的消化道出血，克羅恩病，小腸腫瘤，息肉綜合征等。儘管膠囊內窺鏡有很好的臨床表現，但它仍然有一定的局限性。主要問題是每次檢查產生約50,000 幅低質量的圖像，對於醫生來說，評估如此大量的圖像是一項非常耗時、耗力的工作。<br>到目前為止，對於膠囊內窺鏡的分析和評估，學者們都把膠囊內窺鏡圖像視為單獨的，獨立的觀測對象。事實並非如此，因為圖像之間往往有顯著的重疊。特別是當膠囊內窺鏡在被小腸蠕動緩緩推動時，它可以捕捉同一病灶的多個視圖。我們的研究目的是使用所有可用的資訊，包括多幅圖像，研究對於膠囊內窺鏡的電腦輔助診斷（CAD）系統。<br>在這篇論文中，我們提出了一個嵌入分類器的多類隱馬爾可夫模型（HMM）的方案，它可以融合多幅相鄰圖像的時間資訊。由於膠囊內窺鏡圖像的品質比較低，我們首先進行預處理，以加強膠囊內窺鏡圖像，增加其對比度，消除噪聲。我們調查研究了多種圖像增強的方法，並調整了它們的參數使其適用於膠囊內窺鏡圖像。<br>對於基於單幅圖像的有監督的分類，AdaBoost 作為一個集成分類器來融合多個分類器，即本論文中的支持向量機（SVM），k-近鄰（k-NN），貝葉斯分類。在分類之前，我們提取和融合了顏色，邊緣和紋理特徵。<br>對於無線膠囊內窺鏡的視頻摘要，我們提出了有監督和無監督的兩類方法。對於有監督方法，我們提出了一個基於隱馬爾可夫模型的，靈活的，可擴展的框架，用於整合膠囊內窺鏡中連續圖像的時間資訊。它可以擴展到多類別，多特徵，多狀態。我們還提出了聯合隱馬爾可夫模型和並行隱馬爾可夫（PHMM）模型對系統進行改進，它們可以被看作是決策級的資訊融合。聯合隱馬爾可夫模型通過多層次的隱馬爾可夫模型，結合不同的資訊來源，對膠囊內窺鏡視頻進行分類和視頻摘要。 並行隱馬爾可夫模型採用貝葉斯推理，在決策時融合多個不同來源的資訊。對於無監督的方法，我們首先提出了一種基於顏色的特徵提取方法。在反色顏色空間中對亮度不變的色度不變矩用來表示膠囊內窺鏡圖像的顏色特徵。接著，我們又提出了一種基於輪廓元（Contourlet）變換的局部二元模式（LBP）作為紋理特徵。在特徵空間中，我們測量了相鄰圖像的距離，並把它視為一個位於二維平面上的開放輪廓上的點。 然後，我們採用一個無參數的關鍵點檢測方法檢測在視頻片段上的突變關鍵點。基於這些突變關鍵點，我們對膠囊內窺鏡視頻進行分割。最後，在每段被分割的視頻片段上，我們通過提取有代表性的關鍵幀來實現膠囊內窺鏡視頻摘要。我們分別用模擬和真實的病人數據進行實驗，對提出的方法進行驗證，結果表明了我們所提出的方案的有效性。它在實現自動評估膠囊內窺鏡圖像上具有很大的潛力。<br>Wireless Capsule Endoscopy (CE) is a non-invasive technology to inspect the whole gastrointestinal (GI) tract, especially the small intestine. It has dramatically changed the way of diagnosis and management of many diseases of the small intestine, such as obscure gastrointestinal bleeding, Crohn’s disease, small bowel tumors, polyposis syndromes, etc. Despite its promising clinical findings, it still has some limitations. The main problem is that it requires manual assessment of approximately 50,000 low quality images per examination which is highly time-consuming and labor-intense.<br>CE analysis and assessment so far treated CE images as individual and independent observations. It is obviously not the case as there is often significant overlap among images. In particular, CE captures multiple views of the same anatomy as the capsule is slowly propelled by peristalsis. Our broader work aims to perform computer aided diagnosis (CAD) in endoscopy using all available information, including multiple images.<br>In this dissertation, a framework of multi-class Hidden Markov Models (HMM) embedded with statistical classifiers for combining information from multiple CE images is proposed. Due to the low quality of CE image, pre-processing is performed to enhance CE images by increasing the contrast and removing noises. Several image enhancement methods are investigated and customized for CE images. For frame-based supervised classification, AdaBoost is used as the ensemble classifier to combine multiple classifiers, i.e. support vector machine (SVM), k-nearest neighbor (k-NN), and Bayes classifier. Before classification, color, edge and texture features are extracted and fused. Finally, both supervised and unsupervised methods are proposed for CE study synopsis. For supervised method, a flexible and extensible framework based on HMM is developed to integrate temporal information in CE images. It can be extended to multi-class, multi-features, and multi-states. Improvements can be made by combined HMM and Parallel HMM (PHMM) which are introduced as decision-level fusion schemes. Combined HMM considers different sources via a multi-layer HMM model to perform classification and video synopsis. PHMM employs Bayesian inference to combine the recognition results at decision level. For unsupervised method, illumination-independent opponent color moment invariants and local binary pattern (LBP) based on Contourlet transform are explored as color and texture features, respectively. Pair-wise image dissimilarity is measured in the feature space and treated as points on an open contour in a 2-D plane. CE video is segmented based on sudden change points which are detected using a non-parametric key-point detection method. From each segment, representative frames are extracted to summarize the CE video. Validation results on simulated and real patient data show promising performance of the proposed framework. It has great potential to achieve automatic assessment for CE images.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Zhao, Qian.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2012.<br>Includes bibliographical references (leaves 142-175).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Abstract also in Chinese.<br>Abstract --- p.ii<br>Acknowledgments --- p.vii<br>List of Tables --- p.xiii<br>List of Figures --- p.xv<br>Chapter 1 --- The Relevance of Synopsis --- p.1<br>Chapter 1.1 --- Problem Statement --- p.1<br>Chapter 1.2 --- Application - Capsule Endoscopy Assessment --- p.4<br>Chapter 1.3 --- Literature Review --- p.9<br>Chapter 1.3.1 --- Methods Based on Frame Classification --- p.11<br>Chapter 1.3.2 --- Methods Integrating Temporal Information --- p.14<br>Chapter 1.4 --- Contributions --- p.19<br>Chapter 1.5 --- Organization --- p.23<br>Chapter 2 --- Preliminary --- p.25<br>Chapter 2.1 --- Hidden Markov Model (HMM) --- p.25<br>Chapter 2.2 --- Factorial HMM --- p.35<br>Chapter 3 --- Temporal Integration in Capsule Endoscopy Image Analysis --- p.37<br>Chapter 3.1 --- Pre-processing --- p.38<br>Chapter 3.2 --- Feature Extraction --- p.43<br>Chapter 3.3 --- Frame-based Supervised Classification --- p.47<br>Chapter 3.3.1 --- Supervised Classification using Individual Frames --- p.47<br>Chapter 3.3.2 --- Ensemble Learning Based on AdaBoost --- p.50<br>Chapter 3.4 --- Sequence-based Supervised Classification --- p.52<br>Chapter 3.5 --- Experiments --- p.58<br>Chapter 3.5.1 --- Capsule Endoscopy Image Enhancement --- p.60<br>Chapter 3.5.2 --- Frame-based Supervised Classification --- p.67<br>Chapter 3.5.3 --- Image Sequence Classification --- p.68<br>Chapter 3.6 --- Discussion --- p.80<br>Chapter 3.7 --- Summary --- p.82<br>Chapter 4 --- Capsule Endoscopy Study Synopsis --- p.98<br>Chapter 4.1 --- Supervised Synopsis Using Statistical Models --- p.98<br>Chapter 4.2 --- Unsupervised Synopsis via Representative Frame Extraction --- p.100<br>Chapter 4.2.1 --- Feature Extraction --- p.100<br>Chapter 4.2.2 --- Non-parametric Key-point Detection --- p.111<br>Chapter 4.2.3 --- Representative Frame Extraction --- p.112<br>Chapter 4.3 --- Experiments --- p.119<br>Chapter 4.3.1 --- Supervised Synopsis Based on HMM --- p.119<br>Chapter 4.3.2 --- Unsupervised Synopsis --- p.125<br>Chapter 4.4 --- Discussion --- p.132<br>Chapter 4.5 --- Summary --- p.133<br>Chapter 5 --- Conclusions and Future Work --- p.138<br>Chapter 5.1 --- Conclusions --- p.138<br>Chapter 5.2 --- Future Work --- p.141<br>Bibliography --- p.142
41
Liao, Ying-Chieh, and 廖盈絜. "The Effects of Using Computer- Assisted Instruction Based on the Outcomes of the Bayesian Networks Based Computerized Adaptive Diagnostic Test of Junior High School Students with Mild disabilities in the Mathematics domain." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/81633244586626280687.
Full textAbstract:
碩士<br>國立臺中教育大學<br>特殊教育學系碩士班<br>97<br>This study attempts to investigate the effects of using computer-assisted instruction based on the outcomes of the Bayesian Networks based computerized adaptive diagnostic test (BNAT) of junior high school students with mild disabilities in the mathematics domain and the identification of the thoughts of students participating in the program.
The research measure used the pre-posttest equivalent groups design. The research sample was 20 students with mild disabilities in two resource classes in Taichung City. The students are divided into two groups, the experimental group and the control group. Then the two groups took the pretest, posttest, and tracing test. All the test data and evidences were analyzed. With the pretest used as covariance, all the test data were utilized ANCOVA for analyzing the comprehension of the sample. Finally, the comments from the questionnaire that reflected the computer-assisted instruction were collected and analyzed.
The results of this study are briefly outlined as follows:
1. The computer-assisted instruction based on the outcomes of the Bayesian Networks based computerized adaptive diagnostic test（BNAT）to find the mistakes of students of the experimental group could upgrade the immediate effects of junior high school students with mild disabilities in the mathematics domain.
2. The students of the experimental group found that computer-assisted instruction based on the outcomes of the Bayesian Networks based computerized adaptive diagnostic test（BNAT）could arouse the interest in the learning of mathematics domain. The students not only expressed great satisfaction with computer-assisted instruction based on the outcomes of the Bayesian Networks based computerized adaptive diagnostic test（BNAT）,but also looked forward to the implementation of BNAT in the future.
Keywords: mild disabilities, computer-assisted instruction, Bayesian Networks based computerized adaptive diagnostic test（BNAT）, mathematics domain