Dissertations / Theses on the topic 'Endoscopy'

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A cirurgia dos tumores selares é tradicionalmente um campo de atuação dos neurocirurgiões. Contudo, desde a retomada da abordagem transeptaltransesfenoidal para acessar a sela túrcica, na década de sessenta do século passado, os otorrinolaringologistas têm exercido importante parceria neste procedimento. A divulgação da cirurgia endoscópica nasossinusal na otorrinolaringologia criou o interesse pela sua aplicação na cirurgia da região selar. a uso do endoscópio permitiu acesso transnasal direto ao seio esfenoidal sem a necessidade de descolamento do septo nasal, com menor desconforto para o paciente, além de morbidade pós-operatória inferior aos métodos tradicionais. Objetivo: O objetivo deste trabalho foi verificar as dificuldades técnicas, intercorrências e complicações pós-operatórias, no manejo otorrinolaringológico do acesso transnasal endoscópico à sela túrcica. Método: Foram analisados retrospectivamente os prontuários e imagens de arquivo de 159 pacientes submetidos à cirurgia da região selar entre março de 2001 e dezembro de 2005, na Universidade Federal de São Paulo / Escola Paulista de Medicina. Foram incluídos neste estudo 91 pacientes submetidos a um total de 95 procedimentos por via transnasal endoscópica. Resultados: Foi possível a realização da técnica endoscópica transnasal em todos os pacientes estudados, independente de idade, presença de variações anatômicas, características e etiologia do tumor, e antecedente de cirurgia prévia. Não houve necessidade de remoção da concha média ou correção de desvios septais para realização do procedimento cirúrgico em nenhum dos casos. A principal intercorrência foi a abertura do diafragma selar durante a remoção de tumores, causando fístula liquórica intra-operatória em 13,68 por cento dos casos. As complicações pós-operatórias encontradas foram: sangramento nasal (8,42 por cento), fístula liquórica (8,42 por cento), e meningite (2,19 por cento). Conclusão: O acesso endoscópico transnasal aos tumores selares pôde ser realizado de forma minimamente invasiva, preservando-se as estruturas nasais nos 95 procedimentos estudados, independente da idade do paciente, características e etiologia do tumor.
Sellar tumor surgery is traditionally a neurosurgeon´s field. However, since the renewed interest in the transseptal-transsphenoidal approach to access the sellar region in the sixties, otolarynngologists have played an important partnership in this procedure. Divulging of endoscopic sinus surgery in otolaryngology created an interest in its application in sellar region surgery. The use of endoscopes allowed a direct transnasal approach to the sphenoidal sinus without need of dissection of the septal mucosa, with less post-operative discomfort and morbidity inferior to that of traditional methods. Objective: The objective of this work was to verify the technical difficulties, intercurrences and post-operative complications in the otolaryngological handling of the endoscopic transnasal approach to the sellar region. Method: The analisys comprised both the files and archive images of 159 patients submitted to sellar region surgery between march 2001 and December 2005, at Universidade Federal de São Paulo / Escola Paulista de Medicina. 91 patients submitted to a total of 95 endoscopic transnasal procedures were included in this study. Results: It was possible to apply the endoscopic transnasal tecnique in all studied patients, independent of age, anatomical variations, tumor characteristics and etyology, and previous surgery history. There was no need of middle turbinate removal, or septal deviations corrections for the surgical procedure in any of the cases. The main intercurrence was the opening of the sellar diaphragm during the removal of the the tumors, causing intra-operative CSF leak in 13.68% of the cases. The post-operative complications encountered were: nasal bleeding (8.42%), CSF leak (8,42%), and meningitis (2.19%). Conclusion: Transnasal endoscopic approach to sellar tumors was done in a minimally invasive form, preserving the nasal structures in the 95 studied procedures, independently of patient age, tumor characteristics and etyology.
TEDE
BV UNIFESP: Teses e dissertações

INTRODUÇÃO: A técnica de ESD (Endoscopic Submucosal Dissection) é um procedimento endoscópico de grande complexidade, com alto índice de complicações e dificuldades técnicas. Para superar este problema, muitos centros de treinamento em endoscopia vêm publicando a aplicabilidade dos modelos animais para a aquisição de competência em ESD. Em todas as publicações sobre o assunto, a habilidade do aluno é acompanhada pela evolução de variáveis como o tempo de ressecção, ressecção em bloco e complicações tais como sangramento e perfuração; entretanto a profundidade de ressecção nunca foi utilizada como parâmetro de aprendizagem, o que pode ser um fator relevante a ser ensinado, dado que atingir o plano de dissecção ideal é de suma importância para uma ressecção curativa e na prevenção de complicações intraoperatórias. O objetivo do estudo foi analisar o aprendizado em ESD em treinamentos de curta duração através da avaliação da profundidade de submucosa ressecada; e sua associação com complicações. MÉTODOS: estudo experimental; incluídos 25 endoscopistas com experiência em procedimentos terapêuticos ( > 5anos) e 75 peças ressecadas por ESD sendo uma média de 3 resseções por endoscopista. Os parâmetros de aprendizagem (tempo de ressecção, tamanho, taxa de ressecção em bloco, sangramento, perfuração e análise histológica da camada submucosa) foram prospectivamente avaliados. Antes, durante e ao final do treinamento os participantes foram submetidos a um questionário sobre a dificuldade e insegurança em realizar o procedimento. RESULTADOS: Todas as ressecções foram realizadas no corpo gástrico (n=75). O tamanho médio das peças ressecadas foi de 23,97 ± 7,2 mm. O número de complicações como sangramento, perfuração e morte foram respectivamente, 17 (22,67%), 3 (4%) e 0 casos. Na terceira dissecção, tempo médio do procedimento diminuiu de 28,44 ± 9,73 para 18,72 ± 8,81 minutos (p < 0,001). Quando comparada a primeira com a terceira dissecção houve uma diminuição significativa na taxa de sangramento (p=0,047) em contraste com a percentagem de submucosa ressecada que foi aumentando progressivamente quando comparada a primeira (53.5 ± 23.76%), segunda (61.8±26.47%) e terceira (69.82 ± 27.86) dissecção (p=0,073). O número de participantes que se sentiam inseguros diminuiu de 100(IC95%: 83,88-100) para 32(IC95%: 17,18-51,78), (p < 0,001). O grupo que teve sangramento durante o procedimento ressecou 37,97±21,13% da camada submucosa e o grupo sem sangramento ressecou 68,66±23,99%, demonstrando uma associação significante entre a profundidade de dissecção submucosa e a incidência de sangramento (p < 0,001). De acordo com a análise de curva ROC, o valor de corte da profundidade de submucosa ressecada para a ocorrência de sangramento é de 61%(64% sensibilidade, 94% especificidade), logo quando o ESD é realizado em uma profundidade maior do que 61% da camada submucosa o risco de sangramento durante o procedimento diminui (VPP=0,97; IC95%:0,85-0,99). CONCLUSÃO: O modelo de treinamento de curta duração possibilitou um aprendizado da técnica de ESD mostrando uma melhora cognitiva dos alunos já na terceira dissecção através de parâmetros como tempo de ressecção, diminuição dos casos de sangramento, um menor nível de insegurança e um maior percentual de submucosa ressecada comprovada na análise histológica. Existe uma associação significativa entre a profundidade de ressecção da submucosa com o risco de sangramento, ou seja, quanto mais profundo a ressecção na camada submucosa menor serão os episódios de sangramento
BACKGROUND: Endoscopic submucosal dissection is a complex endoscopic technique, with several technical difficulties to overcome and potentially high complication rates. To overcome that problem many endoscopic training centers in the west have been reporting the usefulness of animal models to achieve some expertise. In most of these reports the variables used to evaluate their learning curve are resection time, complete en-bloc resection rate and complications as bleeding and perforation; however the depth of the submucosal resection has never been analyzed. That might be a relevant factor since appropriate depth of submucosal dissection is important to a curative resection and prevent intraoperative complications which could be a very important concept to be taught during ESD training. The aim of this study is to evaluate the association between the depth of submucosal resection with the learning curve in ESD and their complications. METHODS: Twenty-five senior endoscopists with experience in therapeutic procedures ( > 5years) undergone seventy-five en bloc ESDs in live porcine models. Each participant did at least 3 endoscopic resections. The learning curve parameters (procedure time, specimen size, en-bloc resection rate, perforation, bleeding and histological analysis of the submucosal layer) were prospectively evaluated. During and after each procedure the participants were submitted into a questionnaire about difficulties and insecurities in doing this procedure. RESULTS: ESDs were all completed at the gastric body (n=75). Medium sizes of the specimens resected were 23.97 ± 7.2 mm. Complication as bleeding, perforation and death were seen respectively in 17 (22.67%), 3 (4%) and 0 cases. After the third ESD, procedure mean time has progressively reduced from 28.44 ± 9.73 to 18.72±8.81 minutes (p < 0.001). Bleeding rate were significantly lower when comparing the first to the third resection (p=0.047) and the depth of submucosal resection, in contrast, has increased when comparing the first (53.5±23.76%), second (61.8±26.47%) and third (69.82±27.86) dissection (p=0.073). Results of the questionnaire showed that participants felt increasingly less insecure from the first (95%CI: 100(83.88-100)) until the third (95%CI: 32(17.18-51.78)) ESD procedure (p < 0.001). The group that had bleeding during the procedure resected 37.97±21.13% of the submucosal layer and the non-bleeding group resected 68.66±23.99%, showing a significant association between the depth of submucosal dissection and the incidence of bleeding (p < 0.001). According to the ROC curve analysis, the resulting cutoff value of the submucosal dissection depth for bleeding is 61 %( 64% sensitivity, 94% specificity). When ESD is done deeper than 61% of the submucosal layer the risk of bleeding decreases during the procedure (PPV=0.97, 95%CI: 0.85-0.99). CONCLUSION: The short term ESD training course in live porcine models made a significant improvement on ESD skills regarding on resection time, bleeding rate, insecurity and increased depth of submucosal resection. Association between the depths of submucosal resection with the incidence of bleeding might be significant, which means that deeper in the submucosal layer undergoes the procedure; lower will be the risk of bleeding

Introduction: Oesophagogastroduodenoscopy is the investigation of choice to identify mucosal lesions of the upper gastrointestinal tract, but it is poorly tolerated by patients. A simple non-invasive technique to image the upper gastrointestinal tract, which could be made widely available, would be beneficial to patients. Capsule endoscopy is well tolerated by patients but the stomach has proved difficult to visualise accurately with capsule technology due to its’ capacious nature and mucosal folds, which can obscure pathology. MiroCam Navi (Intromedic Ltd, Seoul, Korea) is a capsule endoscope containing a small amount of magnetic material which has been made available with a handheld magnet which might allow a degree of control. This body of work aims to address whether this new technology could be a feasible alternative to conventional flexible endoscopy of the stomach. Methods: Four studies were conducted to test this research question. The first explores the feasibility of magnetically assisted capsule endoscopy of the stomach and operator learning curve in an ex vivo porcine model. This was followed by a randomised, blinded trial comparing magnetically assisted capsule endoscopy to conventional flexible endoscopy in ex vivo porcine stomach models. Subsequently a prospective, single centre randomised controlled trial in humans examined whether magnetically assisted capsule endoscopy could enhance conventional small bowel capsule endoscopy by reducing gastric transit time. Finally a blinded comparison of diagnostic yield of magnetically assisted capsule endoscopy compared to oesophagogastroduodenoscopy was performed in patients with recurrent or refractory iron deficiency anaemia. Results: In the first study all stomach tags were identified in 87.2% of examinations and a learning curve was demonstrated (mean examination times for the first 23 and second 23 procedures 10.28 and 6.26 minutes respectively (p<0.001). In the second study the difference in sensitivities between oesophagogastroduodenoscopy and conventional flexible endoscopy for detecting beads within an ex vivo porcine stomach model was 1.11 (95% CI 0.06, 28.26) proving magnetically assisted capsule endoscopy to be non-inferior to flexible endoscopy. In the first human study, although there was no significant difference in gastric transit time or capsule endoscopy completion rate between the two groups (p=0.12 and p=0.39 respectively), the time to first pyloric image was significantly shorter in the intervention group (p=0.03) suggesting that magnetic control hastens capsular transit to the gastric antrum but cannot impact upon duodenal passage. In the last study, a total of 38 pathological findings were identified in this comparative study of magnetically assisted capsule endoscopy and conventional endoscopy. Of these, 16 were detected at both procedures, while flexible endoscopy identified 14 additional lesions not seen at magnetically assisted capsule endoscopy and magnetically assisted capsule endoscopy detected 8 abnormalities not seen by oesophagogastroduodenoscopy. No adverse events occurred in either of the human trials. Finally magnetically steerable capsule endoscopy induced less procedural pain, discomfort and distress than oesophagogastroduodenoscopy (p=0.0009, p=0.001 and p=0.006 respectively). Conclusion: Magnetically assisted capsule endoscopy is safe, well tolerated and a viable alternative to conventional endoscopy. Further research to develop and improve this new procedure is recommended.

Optical polarization is sensitive to morphological, structural and compositional changes of tissue and has attracted much interest as a tool in tissue sensing and characterisation. The fusion of polarisation imaging techniques and medical endoscopy resulting in polarisation resolved endoscopy is one of the most significant steps to translate the technique from an optical laboratory to clinic so as to benefit the whole spectrum of endoscopic investigations and intra-operative guidance in situ during minimally invasive surgery. The work in this thesis focuses on the proof-of-concept studies concerning the development of polarisation resolved endoscopy. In particular, polarised light scattering spectral imaging, 3x3 and 4x4 Mueller polarimetric imaging are successfully integrated to a rigid endoscope with accompanying validation experiments performed. The results have shown that polarisation resolved endoscopy based on light scattering spectroscopy and Mueller polarimetry is feasible to implement and has great potential to become a powerful tool for tissue imaging and characterisation.

Examination of the gastrointestinal(GI) tract has traditionally been performed using tethered endoscopy tools with limited reach and more recently with passive untethered capsule endoscopy with limited capability. Inspection of small intestines is only possible using the latter capsule endoscopy with on board camera system. Limited to visual means it cannot detect features beneath the lumen wall if they have not affected the lumen structure or colour. This work presents an improved capsule endoscopy system with locomotion for active exploration of the small intestines and tactile sensing to detect deformation of the capsule outer surface when it follows the intestinal wall. In laboratory conditions this system is capable of identifying sub-lumen features such as submucosal tumours. Through an extensive literary review the current state of GI tract inspection in particular using remote operated miniature robotics, was investigated, concluding no solution currently exists that utilises tactile sensing with a capsule endoscopy. In order to achieve such a platform, further investigation was made in to tactile sensing technologies, methods of locomotion through the gut, and methods to support an increased power requirement for additional electronics and actuation. A set of detailed criteria were compiled for a soft formed sensor and flexible bodied locomotion system. The sensing system is built on the biomimetic tactile sensing device, Tactip, \cite{Chorley2008, Chorley2010, Winstone2012, Winstone2013} which has been redesigned to fit the form of a capsule endoscopy. These modifications have required a $360^{o}$ cylindrical sensing surface with $360^{o}$ panoramic optical system. Multi-material 3D printing has been used to build an almost complete sensor assembly with a combination of hard and soft materials, presenting a soft compliant tactile sensing system that mimics the tactile sensing methods of the human finger. The cylindrical Tactip has been validated using artificial submucosal tumours in laboratory conditions. The first experiment has explored the new form factor and measured the device's ability to detect surface deformation when travelling through a pipe like structure with varying lump obstructions. Sensor data was analysed and used to reconstruct the test environment as a 3D rendered structure. A second tactile sensing experiment has explored the use of classifier algorithms to successfully discriminate between three tumour characteristics; shape, size and material hardness. Locomotion of the capsule endoscopy has explored further bio-inspiration from earthworm's peristaltic locomotion, which share operating environment similarities. A soft bodied peristaltic worm robot has been developed that uses a tuned planetary gearbox mechanism to displace tendons that contract each worm segment. Methods have been identified to optimise the gearbox parameter to a pipe like structure of a given diameter. The locomotion system has been tested within a laboratory constructed pipe environment, showing that using only one actuator, three independent worm segments can be controlled. This configuration achieves comparable locomotion capabilities to that of an identical robot with an actuator dedicated to each individual worm segment. This system can be miniaturised more easily due to reduced parts and number of actuators, and so is more suitable for capsule endoscopy. Finally, these two developments have been integrated to demonstrate successful simultaneous locomotion and sensing to detect an artificial submucosal tumour embedded within the test environment. The addition of both tactile sensing and locomotion have created a need for additional power beyond what is available from current battery technology. Early stage work has reviewed wireless power transfer (WPT) as a potential solution to this problem. Methods for optimisation and miniaturisation to implement WPT on a capsule endoscopy have been identified with a laboratory built system that validates the methods found. Future work would see this combined with a miniaturised development of the robot presented. This thesis has developed a novel method for sub-lumen examination. With further efforts to miniaturise the robot it could provide a comfortable and non-invasive procedure to GI tract inspection reducing the need for surgical procedures and accessibility for earlier stage of examination. Furthermore, these developments have applicability in other domains such as veterinary medicine, industrial pipe inspection and exploration of hazardous environments.

Throughout history, developments in medicine have aimed to improve patient quality of life, and reduce the trauma associated with surgical treatment. Surgical access to internal organs and bodily structures has been traditionally via large incisions. Endoscopic surgery presents a technique for surgical access via small (1 Omm) incisions by utilising a scope and camera for visualisation of the operative site. Endoscopy presents enormous benefits for patients in terms of lower post operative discomfort, and reduced recovery and hospitalisation time. Since the first gall bladder extraction operation was performed in France in 1987, endoscopic surgery has been embraced by the international medical community. With the adoption of the new technique, new problems never previously encountered in open surgery, were revealed. One such problem is that the removal of large tissue specimens and organs is restricted by the small incision size. Instruments have been developed to address this problem however none of the devices provide a totally satisfactory solution. They have a number of critical weaknesses: -The size of the access incision has to be enlarged, thereby compromising the entire endoscopic approach to surgery. - The physical quality of the specimen extracted is very poor and is not suitable to conduct the necessary post operative pathological examinations. -The safety of both the patient and the physician is jeopardised. The problem of tissue and organ extraction at endoscopy is investigated and addressed. In addition to background information covering endoscopic surgery, this thesis describes the entire approach to the design problem, and the steps taken before arriving at the final solution. This thesis contributes to the body of knowledge associated with the development of endoscopic surgical instruments. A new product capable of extracting large tissue specimens and organs in endoscopy is the final outcome of the research.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A utilização de novas técnicas complementares de imagem no auxílio diagnóstico das afecções respiratórias é fundamental à rotina clínica. As técnicas de endoscopia e vídeocirurgia são comuns em medicina humana, mas pouco empregadas na medicina veterinária. Esta pesquisa teve como objetivo principal correlacionar os padrões pulmonares ilustrados em projeções radiográficas com as observações obtidas por meio da broncoscopia, toracoscopia, citologia e histologia de estruturas respiratórias de suínos. Secundariamente, relacionar os valores do peso, temperatura e do hemograma observados antes e após os procedimentos cirúrgicos. Foram utilizados 40 suínos da raça Landrace, machos ou fêmeas, com idade entre quatro a seis semanas. Os animais foram alocados em dois grupos denominados de grupo controle (Gc) e grupo doente (Gd). As mensurações do peso e temperatura e as colheitas de sangue foram realizadas em momentos pré-determinados. As imagens radiográficas, broncoscópicas e toracoscópicas foram categorizadas em escores de acordo com a severidade das lesões pulmonares. A análise estatística dos resultados permitiu estabelecer diversas correlações positivas e negativas entre as imagens radiográficas, broncoscópicas e toracoscópicas. A histologia e citologia possibilitaram caracterizar as alterações pulmonares. Logo, a radiografia deve ser utilizada na triagem de lesões pulmonares a serem investigadas por meio da broncoscopia e toracoscopia, visto que estes procedimentos permitiram a aquisição de imagens e fragmentos pulmonares para o exame histológico e não interferiram nos parâmetros fisiológicos dos suínos
Using of new complementary image techniques is important in diagnostic approach of respiratory diseases during clinical routine. Endoscopic and videosurgery techniques are commonly used in human medicine, however, they are poorly used in veterinary medicine. The main purpose of this research was to correlate pulmonary radiographic patterns with findings obtained by bronchoscopy, thoracoscopy, cytology and histology of the respiratory structures of swine. Moreover, correlate values of body weight, body temperature and blood count cells before and after surgery and anesthesia procedures. A total of 40 Landrace pigs, males or females, from 4 to 6 weeks were used. Animals were divided into two groups: control group (Gc) and sick group (Gd). Body weight, body temperature and blood samples were taken before and after surgery procedure. The radiographic, bronchoscopic and thoracoscopic images were categorized in scores, according to the severity of the observed lung lesions. Bronchoscopy and thoracoscopy provide better details of pulmonary lesions, mainly in the group of sick animals (Gd). Based on statistical analysis, it was possible to stablish positive and negative correlations among radiographic, bronchoscopic and thoracoscopic findings. Histological and cytological alterations were useful to evaluate pulmonary changes related. Therefore, radiography should be used as a screening method to identify pulmonary lesions to be investigated by bronchoscopy and thoracoscopy, since they add useful images images and lung samples for histopathological analysis and did not affect physiological parameters of pigs

Orientadores: Luiz Roberto Lopes, Nelson Adami Andreollo
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Após a comprovação da relação entre a presença da bactéria Helicobacter pylori e a gênese da gastrite, úlcera gástrica e duodenal em humanos, outras espécies de bactérias espiraladas foram identificadas e descritas em diversas espécies de animais incluindo os cães. A associação da amoxicilina, metronidazol e um inibidor de secreção ácida tem sido utilizada na erradicação do Helicobaacter spp. em cães e geralmente são acompanhados de recorrência ou recrudescência a longo prazo. Os mecanismos de transmissão das helicobactérias ainda não estão bem esclarecidos. O objetivo deste trabalho foi avaliar a eficácia da terapia tríplice à base de claritromicina, amoxicilina e lanzoprazol em cães naturalmente infectados pelo Helicobacter spp. e analisar a recorrência da infecção. Neste estudo, foram utilizados 20 cães naturalmente infectados, submetidos à endoscopia digestiva alta seguida de biopsia gástrica usando teste rápido da urease e histopatologia corada pelo Giemsa. Dez animais foram tratados com terapia tríplice preconizada para humanos e divididos em grupo controle e experimento. O grupo controle foi mantido em isolamento enquanto que o grupo experimento foi colocado em contato com os animais positivos durante 60 dias. A prevalência da infecção nos animais deste experimento foi de 100% e mais frequente no fundo e corpo gástrico. A terapia por 7 dias foi eficaz em 100% dos animais. Houve recorrência da infecção em 80% dos cães do grupo experimento enquanto que o grupo controle manteve-se erradicado após 60 dias. Ambientes aglomerados e o íntimo contato com cães infectados por helicobactérias é fator determinante para transmissão do Helicobacter spp entre caninos
Abstract: After stating the relation between the presence of the Helicobacter pylori bacteria and the gastritis genesis, gastric and duodenal ulcer in human, other species of spiral bacteria were identified and described in many animal species including dogs. Metronidazol, amoxiciline and acid secretion inhibitor are the most used drugs of Helicobacter spp. eradication in dogs, as a general to occur recurrence or recrudescence. The helicobacter transmission mechanisms aren't clear yet. The purpose of this study was to analyze the triple antimicrobial therapy, with claritromicine, amoxiciline and lansoprazol in positive Helicobacter spp. dogs and investigate recurrence. Twenty dogs were submitted to superior endoscopy, gastric biopsy, urease test and histopathology blushed with Giemsa. Ten dogs ware submitted the triple therapy in isolate kennel, divided in control group and experiment group. The experiment group were to keep in touch with infected dogs for sixty days. The prevalence of Helicobacter spp. was 100%. The triple therapy was effective in all dogs after 7 days. Recurrence was observed in 80% of the experiment group after sixty days. The triple antimicrobial therapy is effective in eradication gastric Helicobacter spp. in dogs. The contact with infected dogs determine recurrence cases
Mestrado
Pesquisa Experimental
Mestre em Cirurgia

La cirurgia transesfenoïdal tradicional amb microscopi i la cirurgia endoscòpica transesfenoïdal són dues tècniques utilitzades per l'exèresis d'adenomes hipofisaris que han demostrat molt bons resultats en grau d'exèresi, funció hormonal postoperatòria i complicacions. No s'ha realitzat cap assaig clínic amb grau d'evidència I que demostri que una tècnica és superior a una altra. Realitzem un estudi comparatiu entre una sèrie retrospectiva de 63 pacients amb adenomes hipofisaris operats per via transesfenoïdal amb microscòpi amb una sèrie prospectiva de 60 pacients operats per via endoscòpica transesfenoïdal. Les variable comparades van ser: grau d’exèresi, funció hormonal, funció hormonal postoperatòria i complicacions al mes i a l’any. Temps de seguiment un any. L’anàlis del grau d’exèresi segons la técnica es varen observar uns resultats favorables per la cirurgia endoscópica versus cirurgia amb microscopi peró que no van arribar a ser estadísticament significatius. Els resultats obtinguts sobre la funció hormonal postoperatòria van ser similars entre les dues tècniques quan es van comparar només els adenomes funcionants. Quan es van analitzar els resultats incloent a tots els pacients, es van obtenir un millor estat hormonal en els pacients operats amb endoscop comparat amb els operats amb microscopi. Aquests resultats s’han de considerar amb prudència donat que els dos grups no eren del tot homogenis, destacant que en el grup d’endoscop van haver més pacients amb una situació de hipo/panhipopituitarisme preoperatòria que els del grup de microscopi. L’estat final del pacient a l’any de la cirurgia va mostrar uns resultats superiors en la cirurgia amb endoscop respecte a la cirurgia amb microscopi. En el grup endoscòpic es van trobar més vius sense malaltia que al grup microquirúrgic, siguent aquestes diferències estadísticament significatives. Respecte a les complicacions al mes i a l’any els resultats van ser similars sense poder demostrar la superioritat d’una técnica sobre l’altre en cap de les variables estudiades. L’anàlisi del resultats de la tècnica segons la grandària dels adenomes, ja siguin microadenomes o macroadenomes, van donar uns resultats favorables de l’endoscòpia en quant a grau d’exèresi i millora hormonal a tots dos grups sense arribar a ser estadísticament significatius. La comparació de l’estat final a l’any de la cirurgia es van trobar uns resultats estadísticament significatius a favor de l’endoscòpia en els macroadenomes. Respecte a les complicacions, no es van trobar diferències significatives segons grandària del tumor. En el subgrup de pacients amb adenomes funcionants, les variables grau d’exèresi, funció hormonal postoperatòria i taxa de complicacions al mes i a l’any no es van trobar diferències estadísticament significatives.
Traditional transsphenoidal surgery with microscope and transsphenoidal endoscopic surgery are two techniques used for resection of pituitary adenomas. They have shown very good results in the degree of resection, postoperative hormonal function and postoperative complications. There is no clinical trial with a good level of evidence that demonstrates a technique is superior to the other. We perform a comparative study of a retrospective series of 63 patients with pituitary adenomas operated through a transsphenoidal surgery with microscope compared to a prospective series of 60 patients operated through an endoscopic transsphenoidal approach. The analyzed variables were: degree of resection, postoperative hormonal function, final status and complications at one month and one year. The follow-up time was one year. The analysis of degree of resection depending on the technique showed better results for the endoscopic surgery group versus the traditional microscope group but the results were not statistically significant. The results obtained about postoperative hormonal function were similar in both techniques only if we compare functioning adenomas. When analyzing the results including all patients, patients operated by endoscop got a better hormonal status compared to the microscope group. These results must be taken with prudence because both groups were not entirely homogeneous, the endoscopic group had more patients with preoperative status of hypo/panhipopituitarism than the microscope group. The final status of the patient after the surgery showed superior results in the endoscopic group compared to the microscope group. In the endoscopic group, there were more patients alive without disease than the microscope group, and these differences were statistically significant. Regarding the month and year complications, the results were similar so there were no statistically significant differences. The analysis of the results of the technique according to the size of adenomas (microadenoma or macroadenoma), endoscopic group had better results in both groups regarding to degree of resection and hormonal improvement, but these results were not statiscally significant. Comparing the final status at one year from the surgery, the results in macroadenomas were statistically significant in favor of endoscopic surgery. Regarding complications, the differences did not reach statistical significance. No significant differences were found in the subgroup of patients with functioning adenomas about the main analyzed variables: degree of resection, hormonal function and complications at one month and one year.

Introducción: La hemorragia digestiva alta (HDA) es una de las emergencias más frecuentes en medicina. Parte de su abordaje incluye la realización de una segunda endoscopia de control programada llamada “second look” (SL) con el propósito de reducir la incidencia de resangrado. No obstante, existe controversia en cuando su indicación y utilidad. Objetivo: Evaluar la efectividad del SL en la prevención del resangrado intrahospitalario en pacientes adultos con HDA no variceal. Métodos: Se llevó a cabo un estudio de cohorte retrospectivo sobre 1 144 pacientes con diagnóstico de HDA admitidos en la Unidad de Hemorragia Digestiva de un centro de referencia de la Seguridad Social en Lima, Perú; durante los años 2012 y 2014. La variable de respuesta fue el resangrado y la variable de exposición fue la programación a SL. Además se midió la hemoglobina al ingreso, comorbilidades, trasfusión de paquetes globulares y variables endoscópicas. Se calculó la incidencia acumulada (IA), riesgo relativo (RR), efectividad y mediante un modelo lineal generalizado de familia Poisson link log con errores estándar robustos se estimaron razones de tasas de incidencia (RTI). Resultados: La IA global de resangrado fue de 24,48% (n=280). Se encontró diferencia significativa entre las incidencias acumuladas (IA) entre el grupo de SL y el grupo de control (11,7 % vs 29,0 %, respectivamente, p<0,01). El RR fue 0,40 (IC95%:0,29-0,56) y la efectividad fue de 59,81% (IC95%: 44,17-71,08). En los modelos de regresión también se encontró una disminución de las tasas de incidencia tanto en el modelo crudo (RTI: 0,34 IC95%: 0,24-0,49), como en el modelo ajustado con diferencia estadística significativa entre los sometidos y no sometidos a SL (RTI: 0,12 IC95%: 0,08-0,18), por las variables asociadas con el resangrado (RTI: 0,21 IC95%: 0,15-0,30) y por las variables que cumplían los criterios clásicos de confusión (RTI: 0,12 IC95%: 0,08-0,18). Conclusiones: El SL es efectivo en la prevención de resangrado intrahospitalario en pacientes adultos con HDA en un hospital de referencia nacional.
Background: Upper gastrointestinal bleeding (UGIB) is one of the most common medical emergencies. Part of its approach includes performing a second endoscopy, known as second look (SL). However, its indications and usefulness are controversial. Objectives: To evaluate the effectiveness of SL in preventing nosocomial rebleeding in adult patients with non-variceal upper gastrointestinal bleeding. Methods: A retrospective cohort of 1144 patients diagnosed with UGIB admitted at a Digestive Bleeding Unit of a reference center for Social Security in Lima, Peru was performed; during the years 2012 and 2014. The response variable was rebleeding and the exposure variable was programmed SL. Besides hemoglobin on admission, comorbidities, blood transfusion and endoscopic variables were measured. The cumulative incidence, relative risk (RR) and effectiveness were calculated, and using a generalized linear model of the Poisson family link log with robust standard errors, incidence rate ratios (IRR) were estimated. Results: The cumulative incidence rebleeding overall was 24.48% (n = 280). Significant difference between the cumulative incidences (IA) between the SL group and the control group (11.7% vs 29.0%, respectively, p <0.01) was found. The RR was 0.40 (95% CI 0.29 - 0.56) .The calculated effectiveness was 59.81% (95% CI: 44.17 - 71.08). The regression models also found a decrease in incidence in both crude model (IRR: 0.34 95% CI 0.24 to 0.49) and in the adjusted models. The first model was adjusted for variables with statistically significant differences between exposed and unexposed (IRR: 0.12 95% CI 1.8 to 0.18), the second was adjusted for variables that were significantly associated with rebleeding (IRR 0.21 95% CI 0.15-0.30). The third model was adjusted for variables that met classical criteria of confusion (IRR: 0.12 95% CI 0.08 to 0.18).

Contexto: A hemorragia digestiva alta (HDA) resulta em 200 a 300 mil internações por ano nos Estados Unidos, com uma mortalidade de 2,5% a 10%. A úlcera péptica representa a causa mais comum de HDA, correspondendo por um terço a metade de todos os casos. Apesar das melhorias na compreensão de sua etiologia, a incidência de sangramento da úlcera péptica, sua complicação mais comum, não se alterou nas últimas décadas. A terapia endoscópica para HDA pode reduzir drasticamente o risco de ressangramento ou sangramento contínuo, a necessidade de cirurgia de urgência, o número de unidades de concentrado de hemácias para transfusão, o tempo de internação hospitalar e a mortalidade. O tratamento endoscópico da úlcera hemorrágica já percorreu um longo caminho desde injeções de adrenalina e outras soluções, o uso da termocoagulação, até a aplicação de dispositivos mecânicos, como o clipe metálico e a ligadura elástica. Objetivo: Permanece por esclarecer qual é a modalidade endoscópica (ou combinação de modalidades) que apresenta os melhores resultados no tratamento da hemorragia digestiva decorrente da úlcera péptica. Portanto, o objetivo desta revisão sistemática é comparar as diferentes modalidades de tratamento endoscópico da HDA decorrente da úlcera péptica, utilizando ensaios clínicos randomizados. Fontes de dados: Os estudos foram identificados através de pesquisa em bases de dados eletrônicas e listas de referência de artigos. As bases de dados pesquisadas foram Medline, Embase, Cochrane, LILACS, Dare e CINAHL. Critérios de elegibilidade de estudo, participantes e intervenções: Os estudos selecionados foram os ensaios clínicos randomizados comparando as diferentes modalidades endoscópicas para o tratamento de pacientes com hemorragia digestiva alta causada por úlcera péptica. Os estudos incluídos avaliaram técnicas endoscópicas contemporâneas de hemostasia: terapia de injeção endoscópica (todas as soluções, simples ou múltiplas), termocoagulação (heater probe, coagulação com plasma de argônio, coagulação com micro-ondas, eletrocoagulação monopolar, bipolar e multipolar), aplicação de clipes metálicos e tratamento combinado. Os desfechos avaliados foram as taxas de hemostasia inicial, ressangramento, cirurgia de urgência e de mortalidade. Avaliação de vieses: Ao nível de cada estudo, os revisores determinaram a adequação da randomização e da alocação; cegamento de pacientes, profissionais de saúde, coletores de dados e avaliadores de resultados; bem como o relato e a extensão das perdas de seguimento. Também foi avaliado se as técnicas de hemostasia endoscópica foram devidamente descritas e, se os desfechos foram adequadamente definidos em cada estudo. A análise de sensibilidade foi realizada quando a heterogeneidade (I2) foi superior a 50% e uma nova meta-análise foi calculada excluindo o(s) estudo(s) discrepante(s). Uma análise adicional foi realizada em cada comparação, incluindo apenas os ensaios de qualidade metodológica mais elevada. Resultados principais: Um total de 28 ensaios clínicos randomizados (envolvendo 2988 pacientes) foram avaliados nesta revisão, eles foram divididos em sete grupos de comparação de acordo com as modalidades estudadas em cada estudo. A terapia de injeção endoscópica como modalidade única foi inferior à sua combinação com o clipe metálico e com a termocoagulação na avaliação de taxa de ressangramento (diferença dos riscos [DR] = -0,10, intervalo de confiança de 95% [IC95%] = -0,18 a -0,03 e [DR] = -0,08, [IC95%] = -0,14 a -0,02, respectivamente) e na necessidade de cirurgia de urgência ([DR] = -0,11, [IC95%] = -0,18 a -0,04 e [DR] = -0,06, [IC95%] = -0,12 para -0,00, respectivamente). A aplicação de clipes metálicos foi superior à terapia de injeção endoscópica na avaliação da taxa de ressangramento ([DR] = -0,13, [IC95%] = -0,19 para -0,08), e os resultados da comparação entre a aplicação de clipes metálicos como monoterapia e a sua combinação com a terapia de injeção endoscópica não apresentaram diferenças estatísticas. A comparação entre o clipe metálico e a termocoagulação encontrou uma considerável heterogeneidade entre as intervenções utilizadas em cada estudo e nos resultados encontrados das meta-análises. A comparação da termocoagulação com a terapia de injeção endoscópica não evidenciou qualquer diferença estatística entre as modalidades, e a combinação delas é superior à técnica de termocoagulação sozinha ao avaliar a taxa de ressangramento ([DR] = -0,11, [IC95%] = -0,21 para - 0,02). Conclusões: A terapia de injeção endoscópica não deve ser empregada isoladamente. A aplicação de clipes metálicos é superior à terapia de injeção endoscópica, e a associação da injeção endoscópica não melhora a eficácia hemostática do uso isolado do clipe metálico. Como modalidade única, uma técnica de termocoagulação tem uma eficácia hemostática semelhante à terapia de injeção endoscópica, e estas modalidades combinadas parecem ser superiores à técnica de termocoagulação sozinha. Portanto, recomendamos a aplicação de clipes metálicos ou o uso combinado de uma terapia de injeção endoscópica com um método de termocoagulação para o tratamento de pacientes com hemorragia digestiva alta por úlcera péptica
Background: Upper Gastrointestinal bleeding (UGIB) results in 200,00 to 300,000 hospital admissions annually in the United States, with a mortality of 2,5% to 10%. Peptic ulcer disease represents the most common cause of UGIB, accounting for a third to a half of all episodes. Despite improvements in the understanding of its etiology, the incidence of bleeding from peptic ulcer disease, the most common complication, has not changed. Endoscopic therapy for active UGIB can dramatically reduce the risk of rebleeding or continued bleeding, the need for surgery, the number of units of packed erythrocytes required for transfusion, the length of hospital stay and mortality. Endoscopic treatment for ulcer bleeding has come a long way from injections of epinephrine and other solutions, the use of thermocoagulation, to the application of mechanical devices such as hemoclips and banding ligator. Objective: It remains unclear which is the endoscopic modality (or combination of modalities) that presents the best results in the treatment of peptic ulcer bleeding. Therefore, the objective of this systematic review is to compare the different modalities of endoscopic hemostatic therapy, using randomized clinical trials. Data sources: Studies were identified by searching electronic databases and scanning reference lists of articles. The searched databases were Medline, Embase, Cochrane, LILACS, DARE and CINAHL. Study eligibility criteria, participants and interventions: The studies selected were the randomized clinical trials comparing different endoscopic modalities for the treatment of patients presenting with acute upper gastrointestinal bleeding caused by peptic ulcer disease. The included trials assessed contemporary endoscopic hemostatic techniques: endoscopic injection therapy (all injectates, single or multiple), thermal coagulation (heater probe, argon plasma and microwave coagulation, monopolar, bipolar and multipolar electrocoagulations), hemoclip placement and combination treatment. The outcomes measured were the rates of initial hemostasis, rebleeding, emergency surgery and overall mortality. Risk of bias assessment: At the study level, the reviewers determined the adequacy of randomization and concealment of allocation; blinding of patients, of health care providers, of data collectors, and of outcome assessors; and the correct report and extent of loss to follow-up. It was also evaluated whether the endoscopic hemostatic techniques were properly described and if the outcomes were appropriately defined in each study. A sensitivity analysis was held when the heterogeneity (I2) was over 50% and a new meta-analysis was calculated excluding the outlier(s). An additional analysis was made at each comparison, including only the higher methodological quality trials. Main results: A total of 28 trials, involving 2988 patients were evaluated in this review, they were divided into seven comparison groups according to the modalities studied in each trial. Injection Therapy as single modality was inferior to its combination with Hemoclip and with Thermal Coagulation Therapy when evaluating rebleeding rate (risk difference [RD] = -0.10, 95% confidence interval [95%CI] = -0.18 to -0.03 and [RD] = -0.08, [95%CI] = -0.14 to -0.02, respectively) and need for emergency surgery ([RD] = -0.11, [95%CI] = -0.18 to -0.04 and [RD] = -0.06, [95%CI] = -0.12 to -0.00, respectively). Hemoclip was superior to Injection Therapy in the evaluation of rebleeding rate ([RD] = -0.13, [95%CI] = -0.19 to -0.08), and the results of the comparison between Hemoclip alone versus its combination with Injection Therapy did not present any statistical differences. The comparison between Hemoclip and Thermal Coagulation encountered a considerable heterogeneity between the trials in the interventions used and in the results found. The comparison of Thermal Coagulation versus Injection Therapy did not evidence any statistical difference between the modalities, and the combination of these is superior to the Thermal Coagulation alone when evaluating rebleeding rate ([RD] = -0.11, [95%CI] = -0.21 to -0.02. Conclusions: Injection therapy should not be used as single modality. The application of Hemoclip is superior to injection therapy, and the combined application of an injectate does not improve the hemostatic efficacy of the use of Hemoclip alone. As single modality, a thermal coagulation technique has a similar hemostatic efficacy as injection therapy, and these combined modalities appear to be superior to thermal coagulation technique alone. Therefore, we recommend the application of Hemoclips or the combined use of an Injection Therapy with a Thermal Coagulation method for the treatment of patients presenting with acute peptic ulcer bleeding

Cancer is a major health problem in the world today. Almost all cancers have a significantly better chance for therapy and recovery if detected at their early stage. The capability to perform disease diagnosis at an early stage requires high-resolution imaging that can visualise the physiological and morphological changes at a cellular level. However, resolving powers of current medical imaging systems are limited to sub-millimeter sizes. Furthermore, the majority of cancers are associated with morphological and functional alterations of cells in epithelial tissue, currently assessed by invasive and time-consuming biopsy. Optical imaging enables visualisations of tissue microstructures at the level of histology in non-invasive means. Optical imaging is suitable for detecting neoplastic changes with sub-cellular resolution in vivo without the need for biopsy. Nonlinear optical microscopy based on multi-photon absorption and higher harmonic generation has provided spectacular sights into visualisation of cellular events within live tissue due to advantages of an inherent sectioning ability, the relatively deep optical penetration, and the direct visualisation of intrinsic indicators. Two-photon excited uorescence (TPEF) from intrinsic cell components and second harmonic from asymmetric supermolecular structures can provide complementary information regarding functionalities and morphologies in tissue environments, thus enabling premalignant diagnosis by detecting the very earliest changes in cellular structures. During the past sixteen years, nonlinear optical microscopy has evolved from a photonic novelty to a well-established laboratory tool. At present, in vivo imaging and long-term bedside studies by use of nonlinear optical microscopy have been limited due to the fact that the lack of the compact nonlinear optical instrument/imaging technique forces the performance of nonlinear optical microscopy with bulk optics on the bench top. Rapid developments of fibre-optics components in terms of growing functionalities and decreasing sizes provide enormous opportunities for innovation in nonlinear optical microscopy. Fibre-based nonlinear optical endoscopy will be the soul instrumentation to permit the cellular imaging within hollow tissue tracts or solid organs that are inaccessible with a conventional optical microscope. Lots of efforts have been made for development of miniaturised nonlinear optical microscopy. However, there are major challenges remaining to create a nonlinear optical endoscope applicable within internal cavities of a body. First, an excitation laser beam with an ultrashort pulse width should be delivered eciently to a remote place where ecient collection of faint nonlinear optical signals from biological samples is required. Second, laser-scanning mechanisms adopted in such a miniaturised instrumentation should permit size reduction to a millimeter scale and enable fast scanning rates for monitoring biological processes. Finally, the design of a nonlinear optical endoscope based on micro-optics must maintain great exibility and compact size to be incorporated into endoscopes to image internal organs. Although there are obvious diculties, development of fibre-optic nonlinear optical microscopy/endoscopy would be indispensible to innovate conventional nonlinear optical microscopy, and therefore make a significant impact on medical diagnosis. The work conducted in this thesis demonstrates the new capability of nonlinear optical endoscopy based on a single-mode fibre (SMF) coupler or a double-clad photonic crystal fibre (PCF), a microelectromechanical system (MEMS) mirror, and a gradientindex (GRIN) lens. The feasibility of all-fibre nonlinear optical endoscopy is also demonstrated by the further integration of a double-clad PCF coupler. The thesis concentrates on the following key areas in order to exploit and understand the new imaging modality. It has been known from the previous studies that an SMF coupler is suitable for twoii photon excitation by transmitting near infrared illumination and collecting uorescence at visible wavelength as well. Although second harmonic generation (SHG) wavelength is farther away from the designed wavelength of the fibre coupler than that of normal TPEF, it is demonstrated in this thesis that both SHG and TPEF signals can be collected simultaneously and eciently through an SMF coupler with axial resolution of 1.8 um and 2.1 um, respectively. The fibre coupler shows a unique feature of linear polarisation preservation along the birefringent axis over the near infrared and the visible wavelength regions. Therefore, SHG polarisation anisotropy can be potentially extracted for probing the orientation of structural proteins in tissue. Furthermore, this thesis shows the characterisation of nonlinear optical microscopy based on the separation distance of an SMF coupler and a GRIN lens. Consequently, the collection of nonlinear signals has been optimised after the investigation of the intrinsic trade-off between signal level and axial resolution. These phenomena have been theoretically explored in this thesis through formalisation and numerical analysis of the three-dimensional (3D) coherent transfer function for a SHG microscope based on an SMF coupler. It has been discovered that a fibreoptic SHG microscope exhibits the same spatial frequency passband as that of a fibreoptic reection-mode non-uorescence microscope. When the numerical aperture of the fibre is much larger than the convergent angle of the illumination on the fibre aperture, the performance of fibre-optic SHG microscopy behaves as confocal SHG microscopy. Furthermore, it has been shown in both analysis and experiments that axial resolution in fibre-optic SHG microscopy is dependent on the normalised fibre spot size parameters. For a given illumination wavelength, axial resolution has an improvement of approximately 7% compared with TPEF microscopy using an SMF coupler. Although an SMF enables the delivery of a high quality laser beam and an enhanced sectioning capability, the low numerical aperture and the finite core size of an SMF give rise to a restricted sensitivity of a nonlinear optical microscope system. The key innovation demonstrated in this thesis is a significant signal enhancement of a nonlinear optical endoscope by use of a double-clad PCF. This thesis has characterised properties of our custom-designed double-clad PCF in order to construct a 3D nonlinear optical microscope. It has been shown that both the TPEF and SHG signal levels in a PCF-based system that has an optical sectioning property for 3D imaging can be significantly improved by two orders of magnitude in comparison with those in an SMF-based microscope. Furthermore, in contrast with the system using an SMF, simultaneous optimisations of axial resolution and signal level can be obtained by use of double-clad PCFs. More importantly, using a MEMS mirror as the scanning unit and a GRIN lens to produce a fast scanning focal spot, the concept of nonlinear optical endoscopy based on a double-clad PCF, a MEMS mirror and a GRIN lens has been experimentally demonstrated. The ability of the nonlinear optical endoscope to perform high-resolution 3D imaging in deep tissue has also been shown. A novel three-port double-clad PCF coupler has been developed in this thesis to achieve self-alignment and further replace bulk optics for an all-fibre endoscopic system. The double-clad PCF coupler exhibits the property of splitting the laser power as well as the separation of a near infrared single-mode beam from a visible multimode beam, showing advantages for compact nonlinear optical microscopy that cannot be achieved from an SMF coupler. A compact nonlinear optical microscope based on the doubleclad PCF coupler has been constructed in conjunction with a GRIN lens, demonstrating high-resolution 3D TPEF and SHG images with the axial resolution of approximately 10 m. Such a PCF coupler can be useful not only for a fibre-optic nonlinear optical probe but also for double-clad fibre lasers and amplifiers. The work presented in this thesis has led to the possibility of a new imaging device to complement current non-invasive imaging techniques and optical biopsy for cancer detection if an ultrashort-pulsed fibre laser is integrated and the commercialisation of the system is achieved. This technology will enable in vivo visualisations of functional and morphological changes of tissue at the microscopic level rather than direct observations with a traditional instrument at the macroscopic level. One can anticipate the progress in bre-optic nonlinear optical imaging that will propel imaging applications that require both miniaturisation and great functionality.

Thesis (PhD) - Swinburne University of Technology, Faculty of Engineering and Industrial Sciences, Centre for Micro-Photonics, 2007.
A thesis submitted for the degree of Doctor of Philosophy, Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, 2007. Typescript. Bibliography: p. 146-162.

Despite the tremendous advances witnessed in light microscopy over the past two decades, non-invasive optical imaging is still limited to penetration depths smaller than 1 mm into tissue. Multiple scattering caused by the refractive index inhomogeneities of biological matter rapidly distort any optical wavefront prop-agating through, rendering tissues opaque. Such turbidity restricts imaging, as well as other biophotonics techniques, to the most superficial layers of tissue. A perspective strategy to overcome the turbidity of living matter exploits holographic light control in multimode optical fibres. This allows devising min-imally invasive imaging probes with footprints far bellow those of conventional endoscopes, as well as enhanced spatial resolution up to the diffraction limit de-termined by the numerical aperture (NA) of the fibre. In this Thesis, high-resolution focussing is demonstrated with unprecedented ability across novel specialty fibres offering very-high NAs, by devising a system and methodologies which allow counteracting the severe mode-dependent loss affecting such fibres. The high quality and NA of the generated foci is capable of 3D optical confinement of dielectric microparticles, thus enabling the deliv-ery of holographic optical tweezers introduced through a bare optical fibre with cross-section comparable to a single cell. The holographic methods developed allow the manipulation of complex 3D arrangements of particles, as well as their independent positioning with nanometre-scale precision in all three dimensions. Separately, a multimode fibre based deep-brain fluorescence imaging is demonstrated in animal models in vivo, allowing the identification of neuronal structures at depths exceeding 2 mm and resolving fine details down to ≈1 µm resolution.

This thesis presents advances in the fabrication and application of multicore optical fibres, specifically pertaining to nonlinear endomicroscopy. Chapters 1 and 2 present the necessary background material to understanding the results presented in chapters 3 and 4. Through chapter 1 the properties of optical fibres are described. The basic structure of silica fibres and the parameters used to classify them are discussed. Typical methods of fabrication are outlined along with post fabrication processes. The experimental procedures required in the later stages of the thesis are also covered. Chapter 2 introduces and reviews nonlinear endoscopy. Various nonlinear process involved are described and the current positions of each in the field of nonlinear imaging discussed. In chapter 3 a method for minimising the variation in group indices of cores within a multicore fibre is outlined, experimentally examined and verified. The minimisation is achieved by specifically controlling the core diameters within the multicore fibre for a given wavelength. The fourth chapter introduces a ‘proof of concept’ method for reducing the bend sensitivity of a multicore fibre. Here a helical path is followed by the cores within the fibre. The specific challenges of fabrication are also described.

Operative endoscopy has proven to be a discipline that continually renews itself. Referrals for treatment using flexible endoscopes in the gastroenteric tract are in fact on the rise. Diagnoses made at earlier phases of the disease uncover pre cancerous lesions that can be treated locally. The technological development of endoscopic instruments, on the other, make it possible to enter into the abdominal cavity and to go beyond the intestinal lumen and to carry out mini-invasive surgical procedures. Operative endoscopy must, of course, confront and collaborate with other traditional disciplines such as pharmacological therapy, interventistic radiology, and, above all, traditional surgery. It must, in particular, join hands with the latter placing itself at its service in the treatment of anastomic complications and imitating it in the development of miniinvasive endoluminal surgery. Some fields of application of operative endoscopy used in the treatment of benign lesions of the gastroenteric tract have been considered here. These include: endoscopic therapy of telangiectasia which represents its principal therapy once the disease has been staged and controlled; prophylactic ligation of esophageal varices in trasplant candidates who, due to their limited follow up, present more disadvantages than advantages with regards to propranolol therapy, laser therapy of Barrett's esophagus which aims to reduce the risk of adenomacarcinoma of the esophagus by ablating metaplasic tissue - further studies are warranted here to quantify its effect; laser therapy of large colorectal adenomas found to be an efficacious alternative to surgery in inoperable patients or those who reject surgery, avoiding the risk of degeneration; treatment of anastomic complications in esophageal surgery and in liver transplant patients in whom endoscopic therapy is the first choice therapy, and finally drainage of abdominal abscesses and necrosectomy carried out endoscopically with the aid of ecoendoscopy, which has taken operative endoscopy beyond the intestinal lumen. The latter field of application is a first step, already in fact utilized in clinical practice, towards the development of NOTES, the new miniinvasvie surgical discipline, still in an experimental stage but already being watched with great interest by the endoscopic and surgical worlds.

Aim: To independently evaluate the NHS Modernisation Agency’s “Modernising Endoscopy Services” (MES) project using routinely collected, service-related endoscopy data. Methods: A random selection of 10 sites who had participated in the MES project (called MES sites) were compared to a random selection of 10 sites who were unsuccessful applicants for the MES project but had indicated their intention to redesign independently (called Non-MES sites). Data on Referral numbers, Number of patients waiting, Number of lost appointment slotsand Activity werecollected from all 20 sites for eight specific time periods ranging from January 2003 to April 2006 to evaluate the endoscopy services of MES and Non-MES sites and to compare both site types at specific points in time using various statistical tests. Activitydata were validated where appropriate using an equivalent HES dataset. Details of innovations introduced were collected to explore possible trends. Results: Data were not routinely collected by endoscopy units. NHS Trust datasets were subsequently included to ensure a full dataset for analysis. The accuracy of the Activitydata was successfully validated. There were relatively few statistically significant results to report. Consequently, this study found that the MES project did not significantly improve the endoscopy services of the MES sites over time. It also found that there was no significant difference between the MES sites and the Non-MES sites in the improvement of their endoscopy services over time and that the Non-MES sites appeared to implement changes that led to improvements to their services, although they were not statistically significant. Conclusions: Data was not routinely collected by most NHS endoscopy units participating in this study. Based on the data analysed, the MES project did not appear to have significantly improved NHS endoscopy services over and above what could have been achieved independently with only the intention to redesign.

We propose a computer integrated endoscopic simulator for training in upper endoscopy as a low-cost alternative to the traditional training methods and virtual reality simulators. The use of a real endoscope in conjunction with our simulator and computer system in an actual operating room setup makes the training environment similar to a real procedure. Endoscopic surgery is the performance of surgery through a small incision with the aid of special medical equipment called a flexible endoscope. The advantage of this technique over open surgery is that there is significantly less operative trauma, resulting in less pain and a shorter recovery time. Side effects of the surgery, such as the risk of infection, are also reduced. While endoscopy procedure has tremendous benefits, surgeons require considerable practice and time to develop competency. Traditionally, the procedure has been taught at the expense of patient comfort and safety, in other words, gastroenterology training fellows have performed the surgery under the supervision of physicians. Patients who undergo the endoscopies performed by fellows, particularly early in the training period, have been more likely to suffer more discomfort and prolonged procedures. In this study, we introduce a new type of simulator which combines the use of mechanical model and computer system as an additional or low-cost alternative for training in upper endoscopy. Our approach is to integrate a computer system with a realistic mechanical model to create a computer-based simulator for upper endoscopy training. The simulator will cover the basics of flexible endoscopy and teach a trainee the skills required to perform upper endoscopy. The mechanical training model with a sensor system that simulates a human upper gastrointestinal tract, including pathologies such as ulcers and polyps, will be built and integrated with computer software. The software offers the following functions: provides help to the trainee, provides curriculum-required learning tasks, and assesses the performance and diagnostic skills. Due to the optical nature of an endoscopic lens, the obtained image suffers from a barrel-type spatial distortion, which results in an inconsistent measurement of object size and distance. Our distortion correction system with automatic calibration, based on least squares estimation, offers a better perception of size and distance from the endoscopic images. In order to examine the endoscopic maneuvering skills of the trainee, the automatic evaluation system is created. The system uses images from the exam procedure to verify the trainee skills. We use Support Vector Machine to classify endoscopic images of different regions in upper gastrointestinal tract. The experimental results on the distortion correction and image classification are reported. Simulator validation survey result from gastroenterology surgeons and fellows is included in this dissertation. A recommendation for further study is also enclosed.

Orientadores: Adriana Maria Alves De Tommaso, Elizete Aparecida Lomazi da-Costa-Pinto
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: A história natural da hipertensão portal (HP) é pouco conhecida em crianças e dados relacionados à evolução em longo prazo são escassos. O objetivo desse estudo foi descrever a evolução endoscópica da HP em 98 pacientes (0 a18 anos) admitidos no Hospital de Clínicas da UNICAMP, no período de março de 1986 a dezembro de 2006 e seguidos, em média, por 6,4 anos. Estudo descritivo e longitudinal. Dados coletados por meio de revisão de prontuários. Analisadas informações referentes a gênero; idade; etiologia; avaliações clínicas, laboratoriais e endoscópicas; tratamentos clínico, endoscópico e cirúrgico da hipertensão portal; complicações do tratamento endoscópico; episódios de hemorragia digestiva alta; evolução das varizes esofagogástricas e da gastropatia da hipertensão portal; causas de óbito. Realizada análise estatística descritiva, comparação de proporções Qui-Quadrado ( c2) com Correção de Yates ou o método Exato de Fisher, comparação entre grupos Teste T (de Student) com Correção de Welch. O nível de significância estabelecido foi p0,05. A maioria dos pacientes era do gênero feminino (58,2%). A causa mais comum de HP foi obstrução da veia porta extra-hepática (OVPEH) (44,9%), seguida pelas doenças que evoluem para cirrose (40,8% dos pacientes). A idade mediana à admissão foi de 4,3 anos. Os sinais endoscópicos de risco de sangramento à admissão, o antecedente de HDA e sua ocorrência durante o seguimento foram mais frequentes nos pacientes não cirróticos (p= 0,0001, p= 0,0001 e p= 0,0015, respectivamente). Cerca de 40% (3998) dos pacientes, em sua maioria cirróticos, não apresentaram HDA durante o seguimento. A profilaxia endoscópica primária associou-se a período livre de sangramento digestivo significativamente mais longo (p= 0,036) no grupo de cirróticos. A erradicação das varizes de esôfago, em cirróticos e não cirróticos, associou-se a diminuição do risco de sangramento dessas varizes (p= 0,0001) e não ocasionou aumento quantitativo de varizes gástricas (p=0,12) e(ou) gastropatia da hipertensão portal (p= 0,87). No entanto, ocorreu aumento do número de episódios de sangramento de origem gástrica. Após tratamento para erradicação ou redução do risco de sangramento, 3342 (78,5%) pacientes foram seguidos por um período superior a 1 ano. Os sinais de risco de sangramento reapareceram em 72,7% dos pacientes, em média 16,2 meses após interrupção do tratamento endoscópico. O óbito foi mais frequente entre os cirróticos (p= 0,001). Em conclusão, os sinais endoscópicos de risco de sangramento e a frequencia de HDA predominaram entre os não cirróticos. A profilaxia endoscópica primária foi mais efetiva entre os cirróticos. O tratamento endoscópico é eficaz para diminuição dos sinais de risco de sangramento de varizes de esôfago, porém há um alto índice de recidiva desses sinais e aumento dos episódios de HDA por variz gástrica e gastropatia da HP após erradicação das varizes de esôfago. A mortalidade foi superior entre os cirróticos
Abstract: The natural evolution of portal hypertension (PH) is little known in children and data related to long term evolution are scarce. The aim of this study was to evaluate the endoscopic evolution of PH in 98 patients. This is a descriptive and transversal study, in which were included both male and female patients with PH, aged from 0 to 18 years, enrolled at the Clinical Hospital of the FCM/UNICAMP. The mean follow-up was 6.4 years. Data from March 1986 to December 2006 were collected through review of medical records, and information analyzed were related to gender; age; etiology; clinical, laboratory and endoscopic evaluation; clinical, endoscopic and surgical treatments of PH; complications of endoscopic treatment; upper gastrointestinal bleeding episodes; evolution of esophagogastric varices and PH gastropathy; causes of death. Descriptive statistical analysis and comparison of proportions were accomplished, through Chi-Square (c2) with Yates correction or the Fisher's exact method; comparison among groups: Student's t Test with Welch's Correction. The significance level was p<0,05. Most patients were female (58.2%). The main cause of PH was obstruction of extra-hepatic portal vein (OEHPV) (44.9%), followed by diseases that progress to cirrhosis (40.8%). The median age at admission was 4.3 years. Endoscopic signs of bleeding risk at admission, the history of upper gastrointestinal bleeding (UGB) and its occurrence during follow-up were more frequent among noncirrhotic patients. Among patients who were included in this study, 39.8% (39/98) has not showed UGB during follow-up, most of them cirrhotic. Primary endoscopic prophylaxis in cirrhotic group was associated to a longer period without showing digestive bleeding. Total eradication of esophageal varices in both cirrhotic and noncirrhotic patients was associated to a reduction of bleeding risk in those varices. It was not detected a quantitative increase of gastric varices (p=0.12) and/or PH gastropathy (p=0.87). However, it was observed an increase in the number of bleeding episodes from gastric varices. After treatment for eradication or reduction of bleeding risk, 33/42 patients were followed for a period over 1 year. Signs of bleeding risk reappear in 72.7% of patients, on average 16.2 months after interruption of endoscopic treatment. Death was more frequent among cirrhotics (p=0.001). In conclusion, endoscopic signs of bleeding risk and frequency of UGB episodes was predominant among non-cirrhotic. Primary endoscopic prophylaxis was more effective among cirrhotic. Although endoscopic treatment is effective in reducing the risk of bleeding from esophageal varices, there is a high index of recurrence of that signs and an increase in episodes of UGB from gastric varices and gastropathy from PH after eradication of espophageal varices. The mortality was higher among cirrhotic
Mestrado
Pediatria
Mestre em Saude da Criança e do Adolescente

Wireless Capsule Endoscopy (WCE) is a technique for inner-visualization of the entire small intestine and, thus, offers an interesting perspective on intestinal motility. The two major drawbacks of this technique are: 1) huge amount of data acquired by WCE makes the motility analysis tedious and 2) since the capsule is the first tool that offers complete inner-visualization of the small intestine, the exact importance of the observed events is still an open issue. Therefore, in this thesis, a novel computer-aided system for intestinal motility analysis is presented. The goal of the system is to provide an easily-comprehensible visual description of motility-related intestinal events to a physician. In order to do it, several tools based either on computer vision concepts or on machine learning techniques are presented. A method for transforming 3D video signal to a holistic image of intestinal motility, called motility bar, is proposed. The method calculates the optimal mapping from video into image from the intestinal motility point of view. To characterize intestinal motility, methods for automatic extraction of motility information from WCE are presented. Two of them are based on the motility bar and two of them are based on frame-per-frame analysis. In particular, four algorithms dealing with the problems of intestinal contraction detection, lumen size estimation, intestinal content characterization and wrinkle frame detection are proposed and validated. The results of the algorithms are converted into sequential features using an online statistical test. This test is designed to work with multivariate data streams. To this end, we propose a novel formulation of concentration inequality that is introduced into a robust adaptive windowing algorithm for multivariate data streams. The algorithm is used to obtain robust representation of segments with constant intestinal motility activity. The obtained sequential features are shown to be discriminative in the problem of abnormal motility characterization. Finally, we tackle the problem of efficient labeling. To this end, we incorporate active learning concepts to the problems present in WCE data and propose two approaches. The first one is based the concepts of sequential learning and the second one adapts the partition-based active learning to an error-free labeling scheme. All these steps are sufficient to provide an extensive visual description of intestinal motility that can be used by an expert as decision support system.

In a near future, the computation power will be widely used in endoscopy rooms. It will enable the augmented reality already implemented in some surgery. Before reaching this, a preliminary step is the development of a 3D reconstruction endoscope. In addition to that, endoscopists suffer from a lack of quantitative data to evaluate dimensions and distances, notably for the polyp size measurement.

In this thesis, a contribution to more a robust 3D reconstruction endoscopic device is proposed. Structured light technique is used and implemented using a diffractive optical element. Two patterns are developed and compared: the first is based on the spatial-neighbourhood coding strategy, the second on the direct-coding strategy. The latter is implemented on a diffractive optical element and used in an endoscopic 3D reconstruction device. It is tested in several conditions and shows excellent quantitative results but the robustness against bad visual conditions (occlusions, liquids, specular reflection,) must be improved.

Based on this technology, an endoscopic ruler is developed. It is dedicated to answer endoscopists lack of measurement system. The pattern is simplified to a single line to be more robust. Quantitative data show a sub-pixel accuracy and the device is robust in all tested cases. The system has then been validated with a gastroenterologist to measure polyps. Compared to literature in this field, this device performs better and is more accurate.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

Interventional Magnetic Resonance Imaging (MRI) is a developing field that aims to provide intra-operative MRI to a clinician to guide diagnostic or therapeutic medical procedures. MRI provides excellent soft tissue contrast at sub-millimetre resolution in both 2D and 3D without the need for ionizing radiation. Images can be acquired in near real-time for guidance purposes. Operating in the MR environment brings challenges due to the high static magnetic field, switching magnetic field gradients and RF excitation pulses. In addition high field closed bore scanners have spatial constraints that severely limit access to the patient. This thesis presents a system for MRI-guided Endoscopic Retrograde Cholangio-pancreatography (ERCP). This includes a remote actuation system that enables an MRI-compatible endoscope to be controlled whilst the patient is inside the MRI scanner, overcoming the spatial and procedural constraints imposed by the closed scanner bore. The modular system utilises non-magnetic ultrasonic motors and is designed for image-guided user-in-the-loop control. A novel miniature MRI compatible clutch has been incorporated into the design to reduce the need for multiple parallel motors. The actuation system is MRI compatible does not degrade the MR images below acceptable levels. User testing showed that the actuation system requires some degree of training but enables completion of a simulated ERCP procedure with no loss of performance. This was demonstrated using a tailored ERCP simulator and kinematic assessment tool, which was validated with users from a range of skill levels to ensure that it provides an objective measurement of endoscopic skill. Methods of tracking the endoscope in real-time using the MRI scanner are explored and presented here. Use of the MRI-guided ERCP system was shown to improve the operator's ability to position the endoscope in an experimental environment compared with a standard fluoroscopic-guided system.

The technological developments seen in recent years have facilitated remarkable progress in the field of flexible gastrointestinal (GI) endoscopy. Smaller high-resolution charge-coupled devices (CCDs) have facilitated the manufacture of ultrathin (UT) (<6mm) endoscopes, while the introduction of device assisted enteroscopy (balloon-assisted and spiral enteroscopy) has allowed endoscopists to access the deep small bowel (SB) without the need for recourse to major surgery. Furthermore, the application of double-balloon colonoscopy (DBC) has shown promise to improve outcomes in patients with 'technically difficult' colons. Although these 3 types of innovative endoscopic technologies all share the potential capacity to enhance minimally invasive patient care, research into their optimal role and effectiveness (particularly within UK clinical practice) remains limited. This thesis has examined the potential role of this selection of advanced flexible GI endoscopic technologies for the enhancement of minimally invasive patient care. The first study evaluated transnasal upper GI endoscopy in the UK and confirmed that within this clinical paradigm, transnasal endoscopy using UT endoscopes, is a feasible, effective and more acceptable alternative to patients than conventional oral upper GI endoscopy. The next series of studies were dedicated to device assisted enteroscopy (DBE in particular) and showed that DBE is capable of providing a safe and effective, minimally invasive alternative to major surgery in selected cases. A comparison of spiral enteroscopy as an alternative to DBE, showed that spiral enteroscopy (in its current, manual form), appears to be inferior to DBE in its ability to facilitate deep enteroscopy. The final study evaluated technically difficult colonoscopy and included the development and validation of a score for technical difficulty which may in the future be applied to routine clinical practice. This study also highlighted the usefulness of DBC as a potentially more effective tool than conventional colonoscopy for technically difficult cases.

Wireless Capsule Endoscopy (WCE) is a technical break-through that allows to produce a video of the entire intestine without surgery. Interpretation of WCE video is nowadays largely left to the visual inspection of a medical specialist. This tedious and time consuming task could greatly benefit from techniques that automatically classify and exclude from further processing the non-relevant frames in the video. In this dissertation several distinctive methods to tackle the problem of automatic classification of image frames belonging to a WCE video are presented. In particular we focuses two areas: sudden changes discrimination and intestinal motility detection in a WCE video. The achieved high detection accuracy of the proposed systems have provided an indication that such intelligent schemes could be used as a supplementary diagnostic tool in endoscopy.

INTRODUÇÃO: O esôfago de Barrett (EB) é uma patologia que aumenta substancialmente o risco de adenocarcinoma esofágico. Os pacientes portadores de EB devem ser seguidos ao longo de toda a vida na tentativa da detecção de neoplasia em estágio precoce. A endoscopia digestiva alta (EDA) é, atualmente, o método de eleição. OBJETIVO: Avaliar a eficácia da cápsula endoscópica do esôfago (CEE) comparada à EDA com cromoscopia com azul de metileno para detecção de lesões suspeitas de neoplasia esofágica, avaliação da extensão e padrão do EB, e identificação da presença de hérnia de hiato; além de comparar a segurança e grau de desconforto dos dois métodos. MÉTODOS: Estudo de casos transversal, realizado em 22 pacientes sabidamente portadores de EB que foram submetidos à fundoplicatura à Nissen há mais de 5 anos. Os pacientes realizaram os exames de CEE e EDA com cromoscopia esofágica por médicos diferentes e desconhecedores dos achados do outro exame. Após a realização dos exames, foi aplicado um questionário onde foi anotado o grau de desconforto do paciente em cada exame e eventuais complicações. Foi avaliado o índice de concordância (kappa) entre os dois métodos para pesquisa de lesões suspeitas de neoplasia esofágica, características do EB e detecção de hérnia hiatal. RESULTADOS: Dezenove pacientes completaram o estudo. A CEE apresentou sensibilidade e valor preditivo negativo de 100% e acurácia de 79% para detecção de lesão suspeita de neoplasia esofágica e concordância razoável com EDA (kappa = 0,27). A acurácia da CEE para avaliação da extensão do EB foi de 89% e concordância moderada (kappa = 0,60) com EDA. A acurácia da CEE para avaliação de EB digitiforme, circunferencial e misto foram, respectivamente, 74%, 79% e 74% com concordância moderada nos casos de EB circunferencial e misto e não significante no EB digitiforme. Quanto à detecção de hérnia de hiato a CEE apresentou sensibilidade de 43% e acurácia de 74%, com concordância razoável (kappa = 0,38) com EDA. Não houve diferença estatística de desconforto entre os exames e não houve complicação em ambos os métodos endoscópicos. CONCLUSÕES: A CEE mostrou-se um bom método de detecção de lesões suspeitas de neoplasia esofágica. Quanto a avaliação da extensão e padrão do EB, a CEE apresentou resultados razoáveis, quando comparada à EDA com cromoscopia esofágica. A CEE apresentou resultados insatisfatórios quanto à detecção de hérnia hiatal. Não houve diferença significativa de desconforto entre CEE e EDA. Os dois métodos mostraram-se seguros
INTRODUCTION: Barrett\'s esophagus (BE) is a condition that substantially increases the risk of esophageal adenocarcinoma. Patients with BE should be followed throughout life in an attempt to detect cancer at an early stage. Upper gastrointestinal endoscopy (GIE) is currently the method of choice. OBJECTIVE: To evaluate the efficacy of esophageal capsule endoscopy (ECE) compared to methylene blue (MB) chromoendoscopy for detection of suspicious lesions of esophageal cancer, evaluation of extent and pattern of BE, and identifying the presence of hiatal hernia, in addition to compare the safety and patients discomfort of the two methods. METHODS: Transverse study, conducted on 22 Barretts patients submitted to Nissen fundoplication with more than five years follow-up. Patients underwent examinations of ECE and MB chromoendoscopy by different physicians blinds to each procedures. After the exams, patients discomfort and possible complications that occurred in each method were recorded. It was evaluated the concordance index between the two methods for detection of suspicious lesions of esophageal cancer, extent and pattern of BE and hiatal hernia detection. RESULTS: Nineteen patients completed the study. The ECE sensitivity, negative predictive value and accuracy were, respectively, 100%, 100% and 79% for detecting suspicious lesion of esophageal cancer and had reasonable agreement with MB chromoendoscopy (kappa = 0.27). The ECE accuracy for assessing the extent of BE was 89% and had moderate agreement (kappa = 0.60) with MB chromoendoscopy. The accuracy of the ECE for evaluation of finger-like, circumferential, and mixed BE were respectively 74%, 79% and 74%, and moderate agreement in cases of circumferencial and mixed BE and not significant agreement for finger-like BE. ECE sensitivity and accuracy for detecting hiatal hernia were, respectively, 43 % and 74%, and fair agreement (kappa = 0.38) with MB chromoendoscopy. There was no statistical difference between the discomfort of examinations and there was no complication in both endoscopic methods. CONCLUSIONS: The ECE has proved to be a good method for detecting suspicious lesions of esophageal cancer. As the evaluation of the extent and pattern of BE, the ECE had reasonable results, when compared to MB chromoendoscopy. The ECE had unsatisfactory results regarding the detection of hiatal hernia. There was no significant difference in discomfort between the ECE and GIE. Both methods proved to be safe

This record of study describes work done in the capacity of Research and Development (R&D) Engineer at Byrne Medical Incorporated, Conroe, TX. The company manufactures accessories used for endoscopic irrigation. The endoscopy system requires a supply of pressurized distilled water that is used by the physician for certain procedures. It becomes the responsibility of the irrigation subsystem to fulfill this need. It consists of a pressurization system, distilled water holder, tubing to convey this to the endoscope and fittings to interface the tubing to the endoscope body. Byrne Medical Inc. manufactures products from every stage of the system for many of the larger endoscope manufacturers. As an R&D Engineer, I was placed in the operations facility to aid the engineering team in its role to develop, test, prototype and refine products. In performing this role, I had to work with managers and staff from different functional areas of the company. Projects did not stop with technical design; they called for effective communication, planning and decision making. This document covers salient projects completed during the course of the internship. Designing an endoscopic irrigation pump to be sold in conjunction with an instrument cart was one. An automated measurement system comprising of instrumentation interfaced with a personal computer and LabVIEW software is another. To facilitate assembly, tools to insert plastic components into extruded tubes were designed in SolidWorks. Another project that involved mechanical design and elements of project management was designing a tubeset to be used with an Endoscopic Retrograde Cholangiopancreatography (ERCP) system. This was done by Byrne Medical Inc. for Boston Scientific Corporation, the manufacturers of the core ERCP system. These projects not only called for engineering skills but inputs from other departments and personnel also. Inputs from regulatory affairs, technicians and clean room staff were critical to the success of all these projects.

Dissertação de Mestrado Integrado em Medicina Veterinária
ABSTRACT - Gastrointestinal foreign bodies are a common reason for presentation in small animal practice. The clinical presentation is often variable, different therapeutic interventions are available, and complications affecting the outcome may be observed. This retrospective multicentric study aimed to characterise a sample of dogs and cats with upper gastrointestinal foreign bodies and evaluate the clinical presentation, removal techniques and findings, the success rate of endoscopic removal, identify factors that could predict the need for surgery, assess the complication rate, hospitalisation period and identify potential risk factors for complications and outcome. Medical records at the Kingston Veterinary Group Hospital (UK) and Anjos de Assis Veterinary Medicine Centre (PT) were reviewed and a total of 73 dogs and cats with non-linear foreign bodies located in the upper gastrointestinal tract from the cervical oesophagus to the duodenum, and patients with linear foreign bodies anchored anywhere from the oral cavity to the duodenum were included in the study. Results showed that patients whose owners did not witness ingestion of the foreign body were significantly more likely to have reported clinical signs (p < 0.001). Furthermore, witnessed ingestion was associated with a significantly shorter duration of clinical signs or time since ingestion (p < 0.001). Foreign objects were categorised as linear in 20.5% of the cases reported and, compared to dogs, cats were significantly more likely to have ingested a linear foreign body (p < 0.001). Results showed a significant association between linear foreign bodies and painful abdominal palpation (p < 0.05). The overall success rate of endoscopic removal was 76.9%. Successful endoscopy was not significantly associated with linear or non-linear objects, or the duration of clinical signs (p > 0.05). Nevertheless, when surgery was required, the removal of linear foreign bodies was significantly associated with the need for multiple surgical techniques (p < 0.001). The overall complication rate was 28.8%. The presence of a linear foreign body, the surgical procedure performed, and prompt versus delayed removal were not significantly associated with the occurrence of complications or a worse outcome (p > 0.05). An abnormal patient mentation and painful abdominal palpation were significantly associated with the occurrence of complications (p < 0.05). In conclusion, even though undergoing surgery and the occurrence of complications were significantly associated with increased hospitalisation; performing surgery did not appear to increase the risk of complications nor affect the overall outcome. An abnormal mentation and painful abdominal palpation may be potential indicators for the occurrence of complications, thus possibly affecting the overall outcome.
RESUMO - Fatores de risco e indicadores de prognóstico após remoção de corpos estranhos esofágicos e gástricos em cães e gatos - Corpos estranhos gastrointestinais são frequentes na clínica de pequenos animais. Este estudo retrospetivo multicêntrico teve como objetivo caracterizar uma amostra de cães e gatos com corpos estranhos de localização gastrointestinal superior, quanto à sua apresentação clínica, técnicas cirúrgicas, bem como avaliar a taxa de sucesso de endoscopia, identificar fatores que permitissem prever a necessidade de cirurgia, avaliar a taxa de complicações, o período de hospitalização e identificar possíveis fatores de risco para a ocorrência de complicações e prognóstico. Foram revistos os registos clínicos do Kingston Veterinary Group Hospital (UK) e do Centro de Medicina Veterinária Anjos de Assis (PT) e um total de 73 cães e gatos com corpos estranhos não-lineares no trato gastrointestinal superior, e animais que tinham corpos estranhos lineares ancorados em qualquer localização desde a cavidade oral até ao duodeno foram incluídos neste estudo. Os resultados obtidos demonstraram que pacientes em que a ingestão não foi testemunhada tinham uma maior susceptibilidade para apresentar sinais clínicos (p < 0.001). Adicionalmente, a ingestão testemunhada mostrou estar significativamente associada com uma duração inferior dos sinais clínicos (p < 0.001). Em 20.5% dos casos os corpos estranhos foram classificados como lineares e os gatos mostraram maior susceptibilidade para ingerir um corpo estranho linear (p < 0.001). Verificou-se uma associação significativa entre a presença de um corpo estranho linear e dor à palpação abdominal (p < 0.05). A taxa de sucesso de endoscopia foi de 76.9%. Não se observou uma associação significativa entre a presença de corpos lineares ou a duração dos sinais clínicos, e o sucesso da endoscopia (p > 0.05). Casos em que cirurgia foi indispensável, a remoção de corpos estranhos lineares mostrou estar significativamente associada à necessidade de múltiplas técnicas cirúrgicas (p < 0.001). A taxa de complicações observada foi de 28.8%. Não se verificou uma associação significativa entre a presença de um corpo estranho linear, o procedimento cirúrgico realizado, ou a intervenção precoce versus tardia e a ocorrência de complicações, ou um prognóstico desfavorável (p > 0.05). Um comportamento alterado e palpação abdominal dolorosa mostraram estar significativamente associados com a ocorrência de complicações (p < 0.05). Em conclusão, embora a realização de cirurgia e a ocorrência de complicações estivessem significativamente associadas a um maior período de hospitalização; a realização de cirurgia não aparentou aumentar o risco de complicações, nem afectar o prognóstico. Um comportamento alterado do paciente e palpação abdominal dolorosa poderão ser potenciais indicadores da ocorrência de complicações, possivelmente afetando o prognóstico.
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Este relatório foi realizado no âmbito do estágio curricular no Hospital Veterinário do Baixo Vouga de 1 de Setembro de 2015 a 31 de Janeiro de 2016. A primeira componente trata da casuística acompanhada no estágio. A área médica mais comum foi a gastroenterologia. A segunda componente consiste na revisão bibliográfica da aspergilose canina complementada com um caso clínico acompanhado no estágio. A aspergilose sino-nasal canina ocorre principalmente em indivíduos jovens ou de meia-idade, mesaticéfalos ou dolicocéfalos e saudáveis. O seu diagnóstico implica o conjunto de vários exames, nomeadamente imagiológicos, cultura de fungos, histopatologia, serologia e diagnóstico molecular. O tratamento recomendado é o tópico. A aspergilose disseminada é menos frequente, sendo mais comum na raça Pastor Alemão. Sendo geralmente mais grave, o tratamento passa essencialmente pela terapia antifúngica sistémica. O uso de fungicidas tem sido muito associado à ocorrência de resistências cruzadas a antifúngicos azóis, dificultando o tratamento destas infeções; Abstract: Small Animal Medicine This report was elaborated following a traineeship at the Hospital Veterinário do Baixo Vouga from September 1st, 2015 to January, 31st, 2016. The first component covers the casuistry accompanied during the same. The most prevalent medical field was the gastroenterology. The second component consists of a literature review of canine aspergillosis along with the report of a case followed during the internship. Canine sinonasal aspergillosis primarily affects young to middle-aged, mesaticephalic or dolichocephalic and healthy dogs. Its diagnosis involves a conjunction of medical exams, namely imagiologic, fungal culture, histopathology, serology and molecular diagnosis. The recommended treatment is the topical one. Disseminated aspergillosis is more infrequent, occurring usually in German Shepard Dogs. Being more grievous, its treatment is based upon the administration of systemic antifungals. The use of azole fungicides has been linked to the development of cross-resistances between these and the antifungal azoles, making it difficult to treat such infections.

The significant development in medical diagnostics and imaging has brought up a lot of new wireless capsule endoscopes coming to health care market. The capsule has been able to minimize patient discomfort and pain during digestive tract screening with less risk of infection and harmless to body organs. This kind of medical procedure is less invasive and gives a great impact compared to the traditional method. Although pill-shaped capsules have existed for over 11 years by now and are currently being used successfully in medical screening to study the GI tract, these systems are passive and are dependent to the peristaltic movement of the gastric wall to propel. The aim of this work is to provide the electronics needed to control an endoscopic capsule robot and the electronics needed to enable active locomotion and advanced vision functions (like autofocus). Enabling such functions the capsules will be able to perform screening, diagnosis and therapy. Such capsule robot has been designed in the framework of the “Versatile Endoscopic Capsule for Gastrointestinal Tumour Recognition and Therapy” (VECTOR) project. This project pursues the goal of realizing smart pill technologies and applications for gastrointestinal (GI) diagnosis and therapy. The overall medical goal of the project is to enable medical devices through advanced technology that can dramatically improve early detection and treatment of GI early cancers and cancer precursors. The main technological objective of the project is the take-up of microsystems and sub-components and their integration into robotic, mobile pill devices for useful and large impact applications in the medical field.

Dans cette thèse, nous proposons l'utilisation d'un nouveau type de fibre à cristal photonique, la fibre Kagomé à coeur creux, pour la livraison d'impulsions ultra-courtes en endoscopie non linéaire. Ces fibres permettent la livraison d'impulsions sans distorsion sur une large bande spectrale, avec un faible bruit de fond, grâce à la propagation dans le cœur creux. Nous avons résolu le problème de la résolution spatiale, à l'aide d'une microbille en silice, insérée dans le cœur de la fibre Kagomé. Nous avons développé un système d'imagerie compacte, qui utilise un tube piézo-électrique pour le balayage du faisceau, un système achromatiques de microlentilles et une fibre Kagomé double gaine, spécialement conçue pour l'endoscopie. Avec ce système, nous avons réussi à imager des tissus biologiques, à l'extrémité distale de la fibre (endoscopie), en utilisant des différentes techniques tels que TPEF, SHG et CARS, un résultat qui ne trouve pas d'égal dans la littérature actuelle. L'intégration dans une sonde portable (4,2 mm de diamètre) montre le potentiel de ce système pour de futures applications en endoscopie multimodale in-vivo
In this thesis, we propose the use of a novel type of photonic crystal fiber, the Kagomé lattice hollow core fiber, for the delivery of ultra-short pulses in nonlinear endoscopy. These fibers allow undistorted pulse delivery, over a broad transmission window, with minimum background signal generated in the fiber, thanks to the propagation in a hollow-core. We solved the problem of spatial resolution, by means of a silica micro-bead inserted in the Kagomé fiber large core. We have developed a miniature imaging system, based on a piezo-electric tube scanner, an achromatic micro-lenses assembly and a specifically designed Kagomé double-clad fiber. With this system we were able to image biological tissues, in endoscope modality, activating different contrasts such as TPEF, SHG and CARS, at the distal end of the fiber, a result which finds no equal in current literature. The integration in a portable probe (4.2 mm in diameter) shows the potential of this system for future in-vivo multimodal endoscopy

This project involved developing a surgical robot assistant using an articulated robot running on a linear axis. The research concentrated on studying the localization of an endoscopic tool. The kinematics involved in this type situation requires that a constant point in space (trocar point) is maintained along a rigid tool while repositioning the manipulator. Results show that the localization algorithm and interactive interface developed is capable of using this unique robot configuration to perform the desired task. For this system, error was used as the performance metric. Positioning of the endoscopic manipulator relative to the world coordinate frame was possible to within 0.05 inch. Error in maintaining a constant point in space is evident during repositioning however this was caused by limitations in the robot arm.

Wireless video capsule endoscopy has been in use for over a decade and it uses radio frequency (RF) signals to transmit approximately fifty five thousands clear pictures of inside the GI tract to the body-mounted sensor array. However, physician has no clue on the exact location of the capsule inside the GI tract to associate it with the pictures showing abnormalities such as bleeding or tumors. It is desirable to use the same RF signal for localization of the VCE as it passes through the human GI tract. In this thesis, we address the accuracy limits of RF localization techniques for VCE localization applications. We present an assessment of the accuracy of cooperative localization of VCE using radio frequency (RF) signals with particular emphasis on localization inside the small intestine. We derive the Cramer-Rao Lower Bound (CRLB) for cooperative location estimators using the received signal strength(RSS) or the time of arrival (TOA) of the RF signal. Our derivations are based on a three-dimension human body model, an existing model for RSS propagation from implant organs to body surface and a TOA ranging error model for the effects of non-homogenity of the human body on TOA of the RF signals. Using models for RSS and TOA errors, we first calculate the 3D CRLB bounds for cooperative localization of the VCE in three major digestive organs in the path of GI tract: the stomach, the small intestine and the large intestine. Then we analyze the performance of localization techniques on a typical path inside the small intestine. Our analysis includes the effects of number of external sensors, the external sensor array topology, number of VCE in cooperation and the random variations in transmit power from the capsule.

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.
Includes bibliographical references (leaves 106-109).
by Delphine Nain.
M.Eng.