• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 184
  • 71
  • 15
  • 14
  • 13
  • 12
  • 6
  • 4
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 352
  • 169
  • 53
  • 47
  • 33
  • 33
  • 31
  • 30
  • 30
  • 30
  • 30
  • 29
  • 29
  • 28
  • 28
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

Estudo da anatomia do seio esfenoidal através da dissecção endoscópica em cadáveres / Study of the anatomy of the sphenoid sinus using endoscopic cadaver dissection

Bernardo Cunha Araújo Filho 30 April 2008 (has links)
Introdução: O seio esfenoidal apresenta relações anatômicas extremamente importantes com estruturas neurovasculares. Estas podem apresentar diversas variações, tornando as suas relações com seio esfenoidal bastante complexas e potencialmente associadas a graves lesões durante sua abordagem. Objetivo: O objetivo deste estudo prospectivo foi descrever, através da dissecção endoscópica em cadáveres, os detalhes das variações anatômicas do SE, avaliando a concordância entre os lados e as diferenças dessas variações entre o gênero e a cor da pele. Casuística e Métodos: Quarenta e cinco cadáveres (90 fossas nasais) de ambos os sexos com idade no óbito entre 30 e 83 anos foram submetidos à dissecção endoscópica meticulosa do seio esfenoidal. A distância da parede anterior do SE à espinha nasal anterior; a localização e o formato do óstio do SE, o grau de pneumatização do SE, a presença de células de Onodi, a dominância entre os lados, a inserção de septo interssinusal e de cristas, a presença de proeminências e/ou deiscências da artéria carótida interna, do nervo óptico, do nervo maxilar e do nervo vidiano, assim como a presença de recessos óptico-carotídeo, pterigóide e lateral foram descritos. As prevalências foram comparadas entre o gênero e diferentes cor da pele. Também foi analisada a simetria entre os lados direito e esquerdo. Resultados: O óstio estava localizado medialmente à inserção póstero-inferior da concha superior em 85,6% das fossas nasais estudadas e em 50% apresentava-se com formato arredondado. A distância média do óstio do seio esfenoidal à espinha nasal anterior foi de 68 mm (+- 4,6mm) para ambos os lados. Não havia dominância dos lados direito ou esquerdo em 21 (46,7%) dos cadáveres. Em 17 cadáveres (37,8%) o seio esquerdo se apresentou mais pneumatizado e em 7 (15,6%), o seio esfenoidal direito apresentou dominância em relação ao esquerdo. O tipo selar foi o mais prevalente (53%) seguido do pré-selar (38%). O recesso mais prevalente foi o pterigóide (47,8%). As cristas estivaram presentes em 22,7% dos lados. O septo intersinusal se inseriu no trajeto da artéria carótida interna e do nervo óptico, respectivamente, em 16,7% e 2,2%. A artéria carótida interna esteve proeminente em 48,9% e deiscente em 31,1% das fossas estudadas. O nervo óptico estava proeminente e deiscente em 35,6% e 8,9%, respectivamente. O nervo vidiano foi a estrutura com proeminência mais prevalente (50%). O nervo maxilar esteve deiscente em 5,6% dos lados estudados. Uma célula de Onodi esteve presente em 23 (25,6%) dos lados dissecados. A análise da simetria mostrou concordância perfeita com relação ao grau de pneumatização e se apresentou bastante variável de acordo com a estrutura estudada. Cadáveres do sexo feminino apresentaram de forma estatisticamente significante maior prevalência de deiscência de carótida interna (p=0,002) e do nervo maxilar (p=0,02), assim como proeminência do nervo óptico (p < 0,001). Conclusão: Os dados demonstram a complexa anatomia interna do seio esfenoidal, e o conhecimento desta anatomia é de grande importância para evitar as potenciais complicações cirúrgicas nesta região. / Introduction: There are extremely important anatomic relationships between the sphenoid sinus (SS) and neurovascular structures. These structures may have several anatomic variations, which makes their relationship with the sphenoid sinus complex and carries risks of severe injuries during surgery. Objective: This prospective study used endoscopic cadaver dissection to describe details of SS anatomic variations and to evaluate agreement between sides and differences between sexes and ethnic groups. Casuistic and Methods: Fourty-five cadavers (90 nasal fossae) of both sexes ageing between 30 and 83 years underwent careful dissection of the sphenoid sinus. Distance from the SS anterior wall to the anterior nasal spine, the position and shape of the SS, the degree of SS pneumatization, the presence of Onodi cells, the dominance between sides, the insertion of the intersinus septum and crests, the presence of dehiscence and protrusions of the internal carotid artery (ICA), optic nerve (ON), maxillary and vidian nerves, and the presence of optic-carotid, pterygoid and lateral recesses were described. Data were analyzed according to sex, skin color and symmetry between nasal fossae of each cadaver. Results: Ostia were located medially to the posteroinferior insertion of the superior turbinate in 85.6% of the nasal fossae, and were circular in 50% of the cases. The mean distance from the ostium to the anterior nasal spine was 68 mm (+- 4.6 mm) for both sides. No dominance of right or left side was found in 21 (46.7%) of the cadavers. In 17 cadavers (37.8%), the left sinus was more pneumatized, and in 7 (15.6%), the right sphenoid sinus showed dominance over the left sinus. The sellar type was the most prevalent (53%), followed by the presellar type (38%). Pterygoid recesses were the most prevalent (47.8%). Crests were found in 22.7% of the sides. The intersinus septum was inserted on the course of the internal carotid artery and optic nerve in 16.7% and 2.2 % of the cases. ICA protrusions were found in 48.9% of the cases, and dehiscence in 31.1% of the fossae under study. Dehiscence and protrusion of the ON were found in 35.6% and 8.9% of the cases. The vidian nerve was the structure with the most prevalent protrusion (50%). Dehiscence over the maxillary nerve was found in 5.6% of the sides. Onodi cells were found in 23 (25.6%) of the dissected sides. The analysis of symmetry revealed perfect agreement of the degree of pneumatization and was greatly variable depending on the structure analyzed. Female cadavers had a statistically greater prevalence of dehiscence over the internal carotid artery (p = 0.002) and over the maxillary nerve (p = 0.02), as well as greater prevalence of optic nerve protrusion (p < 0.001). Conclusion: Our data showed that the SS internal anatomy is complex, and its knowledge is essential during surgical approaches to the sphenoid sinus.
312

A contribution to mouth structure segmentation in images towards automatic mouth gesture recognition / Une contribution à la segmentation structurale d’une image de la bouche par reconnaissance gestuelle automatique

Gómez-Mendoza, Juan Bernardo 15 May 2012 (has links)
Ce travail présente une nouvelle méthodologie pour la reconnaissance automatique des gestes de la bouche visant à l'élaboration d'IHM pour la commande d'endoscope. Cette méthodologie comprend des étapes communes à la plupart des systèmes de vision artificielle, comme le traitement d'image et la segmentation, ainsi qu'une méthode pour l'amélioration progressive de l'étiquetage obtenu grâce à la segmentation. Contrairement aux autres approches, la méthodologie est conçue pour fonctionner avec poses statiques, qui ne comprennent pas les mouvements de la tête. Beaucoup d'interêt est porté aux tâches de segmentation d'images, car cela s'est avéré être l'étape la plus importante dans la reconnaissance des gestes. En bref, les principales contributions de cette recherche sont les suivantes: La conception et la mise en oeuvre d'un algorithme de rafinement d'étiquettes qui dépend d'une première segmentation/pixel étiquetage et de deux paramétres corrélés. Le rafineur améliore la précision de la segmentation indiquée dans l'étiquetage de sortie pour les images de la bouche, il apporte également une amélioration acceptable lors de l'utilisation d'images naturelles. La définition de deux méthodes de segmentation pour les structures de la bouche dans les images; l'une fondée sur les propriétés de couleur des pixels, et l'autre sur des éléments de la texture locale, celles-ci se complétent pour obtenir une segmentation rapide et précise de la structure initiale. La palette de couleurs s'avére particuliérement importante dans la structure de séparation, tandis que la texture est excellente pour la séparation des couleurs de la bouche par rapport au fond. La dérivation d'une procédure basée sur la texture pour l'automatisation de la sélection des paramètres pour la technique de rafinement de segmentation discutée dans la première contribution. Une version améliorée de l'algorithme d'approximation bouche contour présentée dans l'ouvrage de Eveno et al. [1, 2], ce qui réduit le nombre d'itérations nécessaires pour la convergence et l'erreur d'approximation finale. La découverte de l'utilité de la composante de couleur CIE à statistiquement normalisée, dans la différenciation lévres et la langue de la peau, permettant l'utilisation des valeurs seuils constantes pour effectuer la comparaison. / This document presents a series of elements for approaching the task of segmenting mouth structures in facial images, particularly focused in frames from video sequences. Each stage is treated separately in different Chapters, starting from image pre-processing and going up to segmentation labeling post-processing, discussing the technique selection and development in every case. The methodological approach suggests the use of a color based pixel classification strategy as the basis of the mouth structure segmentation scheme, complemented by a smart pre-processing and a later label refinement. The main contribution of this work, along with the segmentation methodology itself, is based in the development of a color-independent label refinement technique. The technique, which is similar to a linear low pass filter in the segmentation labeling space followed by a nonlinear selection operation, improves the image labeling iteratively by filling small gaps and eliminating spurious regions resulting from a prior pixel classification stage. Results presented in this document suggest that the refiner is complementary to image pre-processing, hence achieving a cumulative effect in segmentation quality. At the end, the segmentation methodology comprised by input color transformation, preprocessing, pixel classification and label refinement, is put to test in the case of mouth gesture detection in images aimed to command three degrees of freedom of an endoscope holder.
313

Automatização do processo de mapeamento de laudos médicos para uma representação estruturada / Automating the process of mapping medical reports to estructured database

Oliva, Jefferson Tales 28 April 2014 (has links)
Made available in DSpace on 2017-07-10T17:11:48Z (GMT). No. of bitstreams: 1 Dissertacao Jefferson Tales Oliva 2.pdf: 8591439 bytes, checksum: 6970719a05f60fc1f4fccba9893f38d5 (MD5) Previous issue date: 2014-04-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In the health area, large amounts of data from different sources, such as clinical examinations and procedures, are stored in hospitals and medical clinics databases. Characteristics observed in these examinations and procedures are described in textual medical reports. These findings are indispensable for professionals of any medical specialty, as they are used to maintain the clinical history of the patients. The data contained in these reports can be analyzed, in a more complete manner, through the use of computational resources, such as the Data Mining process supported by computational intelligence techniques. However, for the application of such process, it is essential that the data is represented in a structured format, as Computational Data Bases. In this sense, the Laboratory of Bioinformatics from the West Paraná State University in partnership with the Coloproctology Service of the Faculty of Medical Sciences from the State University of Campinas, developed the Mapping Medical Digital Findings Process (PMLM) using ontologies with the aim of providing support for the transformation of unstructured textual medical reports into a structured representation. Nevertheless, the techniques employed in PMLM must be performed manually and separately by means of computer instructions, hampering its use by professionals who are not from the computational area. The objective of this work is to automate and optimize PMLM using ontologies by integrating its preprocessing methods in a computational tool. For this purpose, a Collaborative Computer System (SCC) was built using the prototyping development model, which is applied in five stages: communication, fast plan, modeling, prototype construction, and evaluation and feedback. The developed computational system was evaluated in conjunction with domain experts, confirming that SCC meets the required specifications and presents a great value for the extraction and the study of patterns that may be discovered in medical findings. SCC was also evaluated experimentally, using a set of 100 artificial medical reports that simulate the Upper Digestive Endoscopy (EDA), showing good results. Thus, the automated PMLM using ontologies, implemented in the SCC, enables the performance of more complete and detailed studies, contributing to the generation of new knowledge. / Na área da saúde, grandes quantidades de dados provenientes de diversas fontes, como exames clínicos e de procedimentos, são armazenadas em bases de dados de hospitais e clínicas médicas. As características observadas nesses exames são descritas em laudos médicos textuais. Esses laudos constituem ferramenta indispensável para profissionais de qualquer especialidade médica para a manutenção do histórico clínico de pacientes. Os dados contidos nesses laudos podem ser analisados, de modo mais completo, através de recursos computacionais, como o processo de Mineração de Dados apoiado por técnicas de Inteligência Computacional. No entanto, para a aplicação desse processo, é imprescindível que os dados estejam representados em formato estruturado, como as Bases de Dados Computacionais. Nesse sentido, no Laboratório de Bioinformática da Universidade Estadual do Paraná em parceria com o Serviço de Coloproctologia da Faculdade de Ciências Médicas da Universidade Estadual de Campinas foi desenvolvido o Processo de Mapeamento de Laudos Médicos (PMLM) por ontologias com o propósito de prover apoio para a transformação de laudos médicos textuais não estruturados em uma representação estruturada. Entretanto, as técnicas empregadas no PMLM devem ser executadas separadamente e manualmente por meio de instruções computacionais, dificultando o seu uso por profissionais que não sejam da área computacional. Assim, o objetivo deste trabalho consiste em automatizar e otimizar o PMLM por ontologias mediante a integração de suas técnicas de processamento de textos em uma ferramenta computacional. Para isso, foi construído um Sistema Computacional Colaborativo (SCC) utilizando o modelo de desenvolvimento por prototipagem, que é aplicado de cinco etapas: comunicação; plano rápido; modelagem; construção do protótipo; e avaliação e feedback. Esse sistema computacional foi avaliado em conjunto com especialistas do domínio, os quais constataram que o SCC atende às especificações determinadas e apresenta-se de grande valia para a extração e o estudo de padrões que podem ser encontrados em textos médicos. O SCC foi também submetido a uma avaliação experimental, por meio da aplicação do PMLM automatizado em um conjunto de 100 laudos médicos textuais artificiais que simulam descrições de exames de Endoscopia Digestiva Alta (EDA), apresentando bons resultados. Desse modo, com o PMLM por ontologias automatizado, implementado no SCC, é possível a realização de estudos mais completos e detalhados, contribuindo com a geração de novos conhecimentos.
314

"Avaliação dos resultados tardios de megaesôfago chagásico avançado operado pela técnica de esofagectomia com gastroplastia e operação de Serra Dória: estudo clínico, nutricional, endoscópico, anatomopatológico e avaliação da qualidade de vida" / Assessment of the late results of advanced Chagasic megaesophagus after two treatments esophagectomy with an associated gastroplasty and the Serra Dória procedure - clinical, nutritional, endoscopic, and anatomopathological study and assessment of the quality

Nakano, Simone Moraes Stefani 24 November 2005 (has links)
O objetivo deste trabalho foi avaliar comparativamente os resultados tardios da esofagectomia transdiafragmática com gastroplastia e da operação de Serra Dória para o tratamento do megaesôfago avançado. Foi realizado estudo coorte em 44 pacientes. O seguimento tardio no Grupo EG foi de 77,0 meses, e no Grupo SD de 62,1 meses. Utilizou-se interrogatório para queixas gastrointestinais, escalas de Schechter e de Visick, assim como dois questionários. Incluíram-se dados antropométricos, bioquímicos e endoscópicos. A satisfação com a cirurgia medida pela escala de Visick foi equivalente nas duas operações praticadas, sem diferenças estatísticas. Também nos questionários o perfil foi equilibrado. Houve maior a incidência de esofagite no grupo EG; Não houve diferenças significativas com relação à avaliação clínica, nutricional, histológica e de qualidade de vida / The objective of the paper was to carry out a comparative evaluation of the late results of a transdiaphragmatic esophagectomy with an associated gastroplasty and of the Serra Dória procedure, for the treatment of advanced megaesophagus. A cohort study was done on 44 patients. Late follow up for the EG Group was 77.0 months, and for the SD Group, 62.1 months. Several tools were used, such as a series of questions for gastrointestinal complaints, the Schechter and the Visick scales. Anthropometric data were included, as well as the biochemical and endoscopic parameters. Satisfaction with the surgery, as measured by the Visick scale, was equivalent in the two types of surgery, and no statistical differences were observed. There was a higher incidence of the esophagitis in the SD group; There were no significant differences with regards to clinical and nutritional evaluation, histology and quality of life
315

Tratamento endoscópico versus cirúrgico para adenomas de papila: revisão sistemática e metanálises / Endoscopic versus surgical treatment of ampullary adenomas: systematic review and meta-analysis

Mendonça, Ernesto Quaresma 28 April 2017 (has links)
Objetivos: Avaliar os desfechos da ressecção endoscópica em comparação à cirurgia no tratamento dos adenomas de papila. Métodos: Foi realizada uma revisão sistemática com metanálise de acordo com as recomendações do Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). As bases de dados Medline, Embase, Cochrane, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) foram escaneadas. Os estudos incluíram pacientes com adenoma de papila e dados de comparação dos tratamentos endoscópico e cirúrgico para os seguintes desfechos: Ressecção primária completa; Sucesso primário; Recorrência; Sucesso final; e Complicações. A análise foi baseada em modelos de efeito randômico e fixo. Resultados: Cinco estudos de coorte retrospectivo foram selecionados, com um total de 465 pacientes. Todos os estudos tinham dados de ressecção primária completa disponível, mostrando uma diferença favorável ao tratamento cirúrgico (Diferença de riscos = -0,22; Intervalo de confiança de 95% = -0,41 a -0,04). Dados de Sucesso primário também foram identificados em todos os cinco estudos. A análise mostrou que a abordagem cirúrgica supera o tratamento endoscópico neste desfecho (DR = -0,13; IC 95% = -0,24 a -0,02). Dados de recorrência foram encontrados em todos os estudos (465 pacientes), com benefício para o tratamento cirúrgico (DR = 0,12; IC 95% = 0,01 a 0,22). Analisando o desfecho de Sucesso final, disponível em todos os estudos, não encontramos diferença entre as duas abordagens terapêuticas (DR = -0,06; IC 95% = -0,15 a 0,04). Três estudos (251 pacientes) apresentaram dados de complicação, e a análise não mostrou diferença entre os tratamentos endoscópico e cirúrgico (DR = -0,15; IC 95% = -0,53 a 0,23), sem a possibilidade de descartar o viés de seleção para este desfecho. Conclusões: Considerando os desfechos de ressecção primária completa, sucesso primário e recorrência na comparação do tratamento cirúrgico com o tratamento endoscópico para adenomas de papila, a abordagem cirúrgica tem resultados significativamente melhores. Com relação ao sucesso final, não houve diferença entre os dois tratamentos. No desfecho das taxas de complicação, esta revisão sistemática não permite uma conclusão confiável devido à presença de alta heterogeneidade e provável viés de publicação nesta comparação / Objectives: To address the outcomes of endoscopic resection compared to surgery in the treatment of ampullary adenomas. Methods: A systematic review and meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Medline, Embase, Cochrane, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were scanned. Studies included patients with ampullary adenomas and comparison data considering endoscopic treatment and surgery for the following outcomes: Complete primary resection; Primary success; Reccurence; Final success; and Complications. The analysis were based on both random and fixed effects model. Results: Five retrospective cohort studies were selected, with 465 patients. All five studies had complete primary resection data available, showing a difference that favours surgical treatment (Risk Difference = -0.22, 95% Confidence Interval = -0.41 to -0.04). Primary success data were identified in all five studies too. Analysis showed that surgical approach overcome endoscopic treatment in this outcome (RD = -0.13, 95% CI = -0.24 to -0.02). Recurrence data was found in all studies (465 patients), with benefit for the surgical treatment (RD = 0.12, 95% CI = -0.01 to 0.22). Analyzing the final success outcome, available in all studies, we found no difference between the two therapeutic approaches (RD = -0.06, 95% CI = -0.15 to 0.04). Three studies (251 patients) presented complication data and analysis shown no difference between the approaches (RD = -0.15, 95% CI = -0.53 to 0.23), not discarding the possibility of presence of selection bias for this outcome. Conclusions: Considering complete primary resection, primary success and recurrence outcomes, surgical approach achieves significantly better results. Regarding the final success, there was no difference between the two treatments. Addressing complication data, this systematic review does not allow for a reliable conclusion due to the presence of high heterogeneity and likely publication bias in this comparison
316

Untersuchung der Patientenzufriedenheit und der Qualität einer Propofol/Midazolam-Sedierung bei endoskopischen Eingriffen in der Gastroenterologie / Investigation on patients´ satisfaction and quality of sedation with propofol/midazolam for endoscopic procedures in gastroenterology

Haß, Mirja Ingibjörg 22 February 2010 (has links)
No description available.
317

Diagnostische Nachweisverfahren für Helicobacter pylori im Vergleich: Prospektive Untersuchung bei 132 Patienten der Universitätsmedizin Göttingen / Comparison of test methods for the detection of helicobacter pylori: the study is based on a prospective comparison of 132 patients

Baumann, Nicola 26 November 2012 (has links)
No description available.
318

Κατάσκευη και έλεγχος ρομποτικού πολυαρθρωτού εργαλείου με χρήση έξυπνων υλικών / Design and control of a redundant robotic tool using smart materials

Ευαγγελίου, Νικόλαος, Γιαταγάνας, Πέτρος 04 October 2011 (has links)
Ο στόχος αυτής της εργασίας είναι να αποκτήσουμε μία βασική γνώση όλων των διαφορετικών σχεδιαστικών παραμέτρων που πρέπει να εξεταστούν για να είναι εφικτή η κατασκευή και ο έλεγχος ενός πολυαρθρωτού εργαλείου. Επιπλέον, όλες οι αναλυτικές μέθοδοι ελέγχου που βασίζονται στις ιδιαιτερότητες των SMA παρουσιάζονται λεπτομερώς, ώστε να παραχθεί μία ικανοποιητική λύση βασιζόμενη στις μεταβολές κατάστασης των κραμάτων και του συγκεκριμένου βραχίονα. Με άλλα λόγια, μία πλήρης γνώση του πώς σχεδιάζουμε, κατασκευάζουμε, προσομοιώνουμε, ελέγχουμε και απεικονίζουμε ένα λειτουργικό μικροσκοπικό πολυαρθρωτό βραχίονα, με τένοντες βασισμένους σε SMA για ελάχιστα επεμβατική χειρουργική είναι ο στόχος της παρούσας εργασίας. / The purpose of this work is to acquire a fundamental knowledge of all the different design parameters, which must be evaluated in order to be able to fabricate and control a multi-DOF manipulator. Moreover, all the analytical control techniques based on the particularities of the shape memory alloys will be shown in details, in order to provide an efficient solution based on the variations of the alloys and the specific manipulator. In other words, the knowhow of building, evaluating, controlling and displaying a functional tiny multi- DOF SMA-based manipulator for minimally invasive surgery is the purpose of this work.
319

Estudo da degradação de ponteiras de endoscópios utilizadas em endoscopia digestiva alta. / Study of the degradation of endoscopes tips used in upper digestive endoscopy.

ANDRADE, Antônio Augusto Fraga de. 17 April 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-17T12:25:43Z No. of bitstreams: 1 ANTÔNIO AUGUSTO FRAGA DE ANDRADE - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2871535 bytes, checksum: c0965a012ab765af77feb84c2c22a016 (MD5) / Made available in DSpace on 2018-04-17T12:25:43Z (GMT). No. of bitstreams: 1 ANTÔNIO AUGUSTO FRAGA DE ANDRADE - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2871535 bytes, checksum: c0965a012ab765af77feb84c2c22a016 (MD5) Previous issue date: 2014-12-18 / O aparelho endoscópico utilizado atualmente para estudo do trato gastro-intestinal (o video-endoscópio) é resultado de quase 200 anos de evolução tecnológica. Estes endoscópios não podem ser esterilizados pelos métodos clássicos. Por sua complexidade, o processo de limpeza e desinfecção de endoscópios não é somente uma preocupação da enfermagem, ela se tornou multidisciplinar, pois exige discussão sobre riscos físicos, biológicos e químicos, tanto para o paciente quanto para a equipe. A borracha da ponta flexível dos endoscópios é uma peça fundamental para a preservação da vedação do endoscópio e principalmente preservação do paciente. Esta borracha sofre desgaste tanto durante o exame como pelos processos de desinfecção do equipamento que acabam agredindo a superfície do material. O seu desgaste ou ruptura pode acarretar na queima do gerador de imagem. A troca da borracha da ponta é considerada uma manutenção parcial e deve sempre ser executada periodicamente. Baseado no exposto este trabalho teve como objetivo principal estudar e avaliar a degradação ocorrida em ponteiras flexíveis de endoscópios digestivos submetidos a procedimentos médicos. Como resultados pode-se verificar nas microscopia, tanto ótica como eletrônica, morfologia rugosa com presença de poros para a ponteira virgem, nas ponteiras utilizadas por diferentes períodos de tempo verificou-se intensificação destas rugosidades. Por DRX pode-se observar um perfil praticamente amorfo típico de elastômero, além de identificar a presença de compostos de carga no polímero. Por FTIR pode-se comprovar diferentes estruturas para as amostras estudadas, levando a crer que algumas possuem polidimetilsiloxana em excesso com relação ao fluorelastômero. Por EDS pode-se verificar a exteriorização de compostos presentes no interior do elastômero após o período de degradação. No ensaio de tração foi verificada diminuição das propriedades físicas do elastômero devido a degradação ocorrida. No ensaio de ângulo de molhabilidade verificou-se que mesmo após o processo de degradação todas as amostras ainda apresentavam-se hidrofóbicas. Em síntese, este trabalho observou a necessidade de se desenvolver um material específico para utilização como ponteiras de endoscópios, já que os existentes no mercado aparentemente não tem destino especifico para aplicações biológicas. Ou seja, mesmo em sua forma virgem o elastômero em questão já apresenta fatores que não tornam sua utilização em meio biológico tão viável. / The endoscopic device currently used to study the gastrointestinal tract (the videoendoscope) is the result of nearly 200 years of technological evolution. These endoscopes can not be sterilized by the classical methods. Due to its complexity, the process of cleaning and disinfection of endoscopes is not only a concern of nursing, she became multidisciplinary, since it requires discussion of physical, biological and chemical hazards, both for the patient and for the team. The flexible rubber tip of the endoscope is a key piece to preserve the seal of the endoscope and especially preservation of the patient. This rubber wears out both during the test as the disinfection of equipment that processes attacking the end surface of the material. Your wear or breakage may result in the image generator burns. The replacement of the rubber tip is considered a partial maintenance and must always be performed periodically. Based on the above this work aimed to study and evaluate the degradation occurred in flexible tips of digestive endoscopes undergoing medical procedures. The results can be seen in microscopy, both optical and electronic, rough morphology with the presence of pores to the virgin tip, the tips used for different periods of time there was intensification of these ridges. XRD can observe typical listing a substantially amorphous elastomer, and identify the presence of compounds in the polymer charge. FTIR can prove different structures for the studied samples, leading to the belief that some have polydimethylsiloxane in excess with respect to the fluoroelastomer. EDS can verify the externalization of compounds within the elastomer after the degradation period. In the tensile test was observed decrease in physical properties of the elastomer due to degradation occurred. On test wetting angle was found that even after the degradation process all the samples still had become hydrophobic. In summary, this study observed the need to develop a specific material for use as tips of endoscopes, since on the market apparently has no specific target for biological applications. That is, even in its virgin form the elastomer in question already has factors that do not make their use in biological environment as possible.
320

Apport de la combinaison de méthodes de mesure de formes tridimensionnelles dans le contexte de l'endoscopie flexible / Contribution of the combination of methods for three-dimensional shapes measurements in the context of flexible endoscopy

Hou, Yingfan 27 January 2016 (has links)
Les techniques de reconstruction de formes tridimensionnelles sont très largement utilisées dans de nombreux domaines, et notamment dans le domaine industriel ou médical. Et dans ces domaines, les techniques de mesure sans contact sont particulièrement étudiées, principalement parce qu'elles permettent de ne pas détériorer l'objet mesuré. Ce travail de thèse se place donc dans ce contexte et plus particulièrement dans le cas des dispositifs endoscopiques de mesure tridimensionnelle de surface par moyen optique. Dans le domaine médical, ce type d'instrument peut être appliqué à la coloscopie 3D ou à la chirurgie mini-invasive pour la détection de forme en surface de tissus biologiques. Dans cette thèse ce sont plus particulièrement les méthodes à base de stéréovision active ou passive, qui vont être étudiées et intégrées dans un dispositif miniaturisé. Différents modes de mesure vont être intégrés simultanément dans un unique instrument miniaturisé afin de permettre d'augmenter les performances de mesure : l'instrument peut adapter son principe de mesure à la texture de l'objet ou également à l'orientation des surfaces mesurées et plus généralement au contexte de la mesure. Ce travail de thèse est donc basé sur une étude algorithmique et instrumentale d'intégration de ces différents modes de mesure dans un unique instrument endoscopique miniaturisé. L'étude des modes de mesure par stéréovision a été réalisée en trois phases. Tout d'abord, c'est l'influence de l'orientation de la surface des objets mesurés dans un cas de stéréovision active qui est analysé. Puis une technique de basculement entre les voies de projection et d'acquisition du système de stéréovision active par actionnement bistable est proposé, ce qui permet d'adapter la mesure à l'orientation des surfaces à mesurer. Enfin, l'étude est orientée vers la possibilité de basculer d'un mode de stéréovision active vers un mode de stéréovision passive, toujours par actionnement bistable, le mode de stéréovision passive étant particulièrement adapté aux objets fortement texturés. Ainsi, trois modes de mesure sont réalisés dans ce nouveau système : deux modes de stéréovision active (avec inversion des voies de capture et de projection) et un mode de stéréovision passive. Pour réaliser la reconstruction tridimensionnelle, deux méthodes actives (par décalage de phase et par transformation de Fourier) et une méthode passive sont étudiées. Différentes performances de mesure sont obtenues selon les méthodes sélectionnées : un résultat de mesure plus précis est obtenu par les méthodes à. décalage de phase, une vitesse de mesure plus élevée est obtenu par les méthodes à transformée de Fourier ou par les méthodes passives. Le développement instrumental est également décrit dans cette thèse. Après modélisation optique et conception mécanique du système de mesure, un prototype de l'instrument endoscopique est fabriqué avec divers équipements spécifiques, tels qu'un DMD (Digital Micromirror Device), des guides d'images et des actionneurs électromagnétiques bistables. La validation expérimentale de la mesure tridimensionnelle est réalisée essentiellement sur objets mécaniques (du type mesure de détails sur pièce de monnaie), les deux méthodes actives et la méthode passives sont ainsi testées et confrontées. Enfin, une mesure sur un colon artificiel est réalisée par ce système pour se placer dans un contexte applicatif médical. / The techniques of three dimensional shapes reconstruction are widely used in many fields, particularly in the industrial or medical field. And in these areas, non-contact measurement techniques are particularly studied, mainly because they don't damage the measured object. This work therefore falls within this context and in particular in the case of endoscopic devices of surface coordinate measuring by optical methods. ln the medical field, this type of instrument can be applied to 3D colonoscopy or minimally invasive surgery to the surface in the form of biological tissues. In this thesis, methods based on active or passive stereo vision are the principle, which will be studied and integrated into a miniaturized device. Different measurement modes will be incorporated simultaneously into a single miniaturized instrument to help increase measurement performance: the instrument can adjust its measurement principle to the texture of the object or also to the orientation of measured surfaces more generally to the context of the measurement. This thesis is based on an algorithmic study and instrumental integration of these different measurement modes into a single miniaturized endoscopic instrument. The study of the measurement modes stereovision was conducted in three phases. First, it is the influence of the orientation of the measured objects' surface in a case of active stereovision being analyzed. And a technique of switching between the projection and acquisition in an active stereovision system by bistable actuation is proposed, which allows to adapt the measurement to the orientation of the measured surfaces. Finally, the study is oriented towards the ability to switch from one active stereovision mode to one passive stereovision mode, always by bistable actuator operation, the passive stereovision mode is particularly suitable for highly textured objects. Thus, three measurement modes are made in the new system: two modes of active stereovision (reversing capture and projection channels) and a mode of passive stereovision. To achieve three-dimensional reconstruction, two active methods (phase shift and Fourier Transform) and a passive method are studied. Different performance measurements are obtained according to methods selected: a more accurate measuring result is obtained by the phase shift methods; a high measurement speed is obtained by the Fourier transform methods or by passive methods. The instrumental development is also described in this thesis. After optical modeling and mechanical design of the measuring system, a prototype of the endoscopic instrument is manufactured with various specific devices such as a DMD (Digital Micromirror Deviee),images guides and bistable electromagnetic actuators. The experimental validation of the three-dimensional measurement is performed mainly on mechanical objects (such as details measurement on a coin), both active and passive method methods are well tested and compared. Finally, an artificial colon is measured by this system to be placed in a medical application context.

Page generated in 0.16 seconds