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1
Torricella, Giulia. "Bioelettronica organica: Nuovi approcci tecnologici per la stimolazione e la rilevazione della comunicazione di cellule neuronali." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8520/.
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Il campo della Bioelettronica si è sviluppato a partire dal 18 secolo con l’ esperimento di Luigi Galvani che, applicando uno stimolo elettrico ai muscoli di una rana dissezionata, ne osservò il movimento. Da questo esperimento si è aperta la strada che ha portato ad oggi ad un grande sviluppo tecnologico nella realizzazione di dispositivi elettronici che permettono di offrire un miglioramento generale delle condizioni di vita.
Come spesso accade con le tecnologie emergenti, i materiali sono la maggiore limitazione nello sviluppo di nuove applicazioni. Questo è certamente il caso della Bioelettronica.
I materiali elettronici organici, nella forma di polimeri conduttivi, hanno mostrato di poter dotare gli strumenti elettronici di grandi vantaggi rispetto a quelli tradizionali a base di silicio, in virtù delle loro proprietà meccaniche ed elettroniche, della loro biocompatibilità e dei bassi costi di produzione.
E’ da questi studi che nasce più propriamente il campo della Bioelettronica Organica, che si basa sulla applicazione di semiconduttori a base di carbonio in forma di piccole molecole coniugate e di polimeri, e del loro utilizzo nei dispositivi elettronici.
Con il termine di ‘Bioelettronica organica’, quindi, si descrive l’accoppiamento tra dispositivi elettronici organici e il mondo biologico, accoppiamento che si sviluppa in due direzioni: da un lato una reazione o un processo biologico può trasferire un segnale ad un dispositivo elettronico organico, dall’altro un dispositivo elettronico organico può avviare un processo biologico.
2
Guan, Guangying. "Micro-motion detection by optical coherence tomography (OCT) and its clinical applications." Thesis, University of Dundee, 2015. https://discovery.dundee.ac.uk/en/studentTheses/f2ac8e9f-aee4-4e70-9c79-de7de35fae43.
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Detection of micro-motion on biological tissues has various applications such as ultrasound elastography and magnetic resonance elastography (MRE). Ultrasound transducers, the most commonly used tool to detect endogenous and exogenous micro-motions, have a number of drawbacks: including the requirements of the physical contact with the sample and limited spatial resolution (millimetre scale). The aim of this thesis is to develop a non-contact phase-sensitive imaging technique which is suitable for functional imaging in the micron range which also has the potential for quantitative analysis of relative properties resulting from an appropriate image processing. Concerning imaging techniques, this thesis focused on optical coherence tomography (OCT) and in particular on phase-sensitive optical coherence tomography (PhS-OCT). In this thesis, a PhS-OCT system is developed for micro-motion detection and a dual camera PhS-OCT system is developed to double the imaging acquiring speed and improve the sensitivity to small phase change. Two applications of PhS-OCT combining micro-motions detection are preformed: 1) Photo-thermal OCT (PT-OCT) system is developed to detect the photo-thermal phenomenon of nanoparticles. A mathematic model is proposed to analyse and reconstruct the distribution of nanoparticles in biological tissues. 2) A quantitative 3D optical coherence elastography (OCE) system and algorithm are developed to analysis the mechanical property of tissue. A feasibility study is carried for the diagnosis of prostate cancer (PCa) using this technique. Results show that PhS-OCT is a powerful tool for the detection of micro-motions (micron range). Functional OCT based on it such as PT-OCT and OCE offers potential in diagnostic and therapeutic in clinical applications, e.g. PT-OCT can be used to detect and map the distribution and concentration of dye and drug in tissues or organs. 3D OCE can provide useful information for early localization and diagnosis of cancer.
3
Liang, Kaicheng. "Forward viewing OCT endomicroscopy." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87948.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014."February 2014." Cataloged from PDF version of thesis.
Includes bibliographical references (pages 60-69).
A forward viewing fiber optic-based imaging probe device was designed and constructed for use with ultrahigh speed optical coherence tomography in the human gastrointestinal tract. The light source was a MEMS-VCSEL at 1300 nm wavelength running at 300 kHz sweep rate, giving an effective A-line rate of 600 kHz. Data was acquired with a 1.8 GS/s A/D card optically clocked by a maximum fringe frequency of 1 GHz. The optical beam from the probe was scanned by a freely deflecting optical fiber that was mounted proximally on a piezoelectric tubular actuator, which was electrically driven in two perpendicular dimensions to produce a spiral scan pattern. The probe has a 3.3 mm outer diameter and is intended for endoscopic imaging. Multiple optical systems were designed to enable microscopic imaging at variable fields. The probe could also be electrically zoomed by tuning the driving voltage to the piezoelectric actuator, reducing the deflection range of the scanning fiber and thus the scanned field. The optical and mechanical design of the probe was optimized for both axial and transverse compactness.
by Kaicheng Liang.
S.M.
4
Adler, Desmond Christopher 1978. "Digital signal processing techniques for optical coherence tomography : OCT and OCT image enhancement." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28486.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (p. 132-135).
Digital signal processing (DSP) techniques were developed to improve the flexibility, functionality, and image quality of ultrahigh resolution optical coherence tomography (OCT) systems. To reduce the dependence of OCT research systems on fixed analog electronics and to improve overall system flexibility, a digital demodulation scheme implemented entirely in software was developed. This improvement allowed rapid reconfiguration of the OCT imaging speed and source center wavelength without having to construct new analog filters and demodulators. This demodulation scheme produced a highly accurate envelope and was immune to local variations in carrier frequency. To provide an alternative contrast modality to conventional intensity-based OCT imaging, spectroscopic OCT technology was investigated. Preliminary studies on animal models were carried out, with the ultimate goal of enabling the early detection of dysplastic lesions in epithelial tissue through spectroscopic changes not visible with conventional OCT. Various spectral analysis techniques were investigated and evaluated for their ability to provide enhanced contrast of specific tissue types. Areas of concern such as red-shifting of the spectrum with increasing imaging depth, Doppler shifts induced by the optical path length scanner, and determination of an optimal spectroscopic metric were addressed. To improve the quality of ultrahigh resolution OCT images, wavelet processing techniques for speckle noise reduction were investigated. Spatially adaptive wavelet denoising techniques were compared to basic wavelet denoising techniques and time domain filtering. By using a set of image quality metrics, it was possible to quantify the effectiveness of the various filtering methods and determine an optimal
(cont.) process for removing speckle noise while maintaining feature sharpness.
by Desmond Christopher Adler.
S.M.
5
Nilsson, Tommy. "Retinal Thickness in Myopes with OCT." Thesis, Linnéuniversitetet, Institutionen för naturvetenskap, NV, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-19646.
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Purpose: To investigate whether retinal thickness varies with refractive error. Also secondary to see if there is any difference in retinal thickness between the right and left eye. Methods: The inclusion criteria for the study was subjects without any pathologies, age between 18-45 and refractive error of maximum +0.75 SER and the myopia had no limit, as well as no astigmatism higher then -1.00D. Subjects, which fitted the inclusion criteria for the study, was shown to the OCT room were retinal thickness measurements were acquired first on the right and then left eye. To get the same reading area, the same setup was used and the fixation point was always centered for each patient. After all subjects had undergone the same method the results were analyzed using t-test and regression analysis. Results: The analysis showed a difference between emmetropic eyes and myopic eyes in the peripheral retinal thickness, having the myopes being significantly thinner. The inter myopic analysis showed no difference in retinal thickness in any of the points. This could however be due to the smaller sample size. The comparison between right and left eye showed a good symmetry between the two eyes both in the emmetropic and the myopic group. Conclusions: From this study we can conclude that the myopic group has a thinner peripheral retinal thickness than the emmetropic group. Central retinal thickness is not significantly different but could be due to the smaller sample size. There is no difference in retinal thickness between right and left eye.
6
Koch, Klaus Peter [Verfasser]. "Lineare OCT Verfahren / Klaus Peter Koch." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2016. http://d-nb.info/1090921489/34.
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Schaack, Sofiane. "Orienting OCS with an electric field." Thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-287790.
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Gärdin, Christoffer, and George Shnouda. "Characterization of clients-side revocation checks and their security-performance tradeoffs." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177327.
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There are several different methods for checking whether certificates on the web have been revoked, timely discovery of revoked certificates are important to ensure security when authentication within the HTTPS protocol is used. These methods have both advantages and disadvantages as they can contribute to security but at the same time worsen performance on the web browsers. This thesis examines these methods in more detail to identify the pros and cons and whether it is possible to find a good tradeoff between security and performance. This is important as a user is exposed to major security flaws if the integrity of a domain cannot be verified. Our analysis includes to which extent OCSP and CRL are used, how much OCSP affects the browser Firefox's performance, and how many web servers implement methods to verify revoked certificates, such as OCSP staple and must-staple. We also compare web browsers own lists of revoked certificates and look for patterns and differences between them. The analysis shows that OCSP and CRL have largely been replaced by other methods of verifying revoked certificates such as OneCRL and CRLSet. It turned out that OneCRL and CRLSet only cover a small fraction of the total number of certificates available. Often, it takes several weeks for certificates to appear in these lists after being revoked. We also found that OCSP's impact on the web pages performance is minimal. We concluded that the existing methods for verifying revocation statuses are inadequately used by CAs, web browsers and web servers, which poses a major security risks for users. Many certificates are not checked at all. However, we believe that it is possible to increase the security without reducing performance if CAs, web browsers and web servers can collaborate in the development of improving and combining current methods for checking revoked certificates.
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Suzuki, Luis Claudio. "Desenvolvimento de biofilme formado por Candida albicans in vitro para estudo do efeito fotodinâmico." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-17112009-103750/.
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A terapia fotodinâmica, do inglês photodynamic therapy (PDT) é uma fototerapia baseada na utilização de um fotossensibilizador (FS) na presença da luz em baixa intensidade em comprimento de onda ressonante à absorção do FS e que podem sensibilizar sistemas biológicos, gerando espécies reativas de oxigênio. Estudos mostram que a PDT apresenta um efeito letal em Candida albicans. O biofilme formado por C. albicans é a causa mais freqüente de infecções associadas a cateteres, possuindo uma comprovada resistência a antifúngicos, sendo que a remoção do cateter colonizado é quase sempre necessária. No entanto, poucos trabalhos na literatura relatam o comportamento e a resposta de C. albicans organizado em biofilme frente à PDT. Os objetivos deste trabalho foram desenvolver uma metodologia para formação in vitro de biofilme de C. albicans, verificar a sensibilidade do biofilme de C. albicans frente à terapia fotodinâmica antimicrobiana utilizando como FS o azul de metileno (AM) e a hipocrelina B:La+3 e analisar o biofilme através da Tomografia de Coerência Óptica (OCT) antes e depois da PDT. Para a formação do biofilme, foram confeccionados discos de silicone elastomérico oriundos de cateteres. Os fotossensibilizadores foram diluídos em solução de PBS, sendo que o AM teve duas concentrações diferentes testadas no biofilme: 100M e 1mM e a HBLa+3 somente uma de 10M. A irradiação de ambos os corantes com os microrganismos foi feita através de dois LEDs diferentes, um vermelho com = 630nm ± 20nm e outro azul com = 460nm ± 30nm. Foi realizada uma curva de fração de sobrevivência em função do tempo de irradiação de cada amostra com biofilme e de suspensão do microrganismo em formato de leveduras para verificar a susceptibilidade destes frente à PDT. As leveduras apresentaram 100% de redução em ambos os fotossensibilizadores, porém em tempos de irradiação diferentes (30s para a HBLa+3 e 6 min para o AM na concentração de 100M). Quando a terapia foi aplicada em biofilme, o AM em 100M não apresentou nenhuma redução significativa, enquanto que em concentração de 1mM houve redução de 100% após 6 min de irradiação. Já a HBLa+3 mostrou pouca redução em biofilme na concentração de 10M (menos de 1 log de redução. Concluímos que o microrganismo C. albicans se organizou em biofilme padronizado nos discos elastoméricos oriundos de cateteres e através do OCT, o biofilme medido apresentou 110m de espessura, informando uma mudança óptica ao ser submetido pela PDT com o AM 1mM.Photodynamic therapy (PDT) is a phototherapy based on the use of a photosensitizer (PS) in the presence of low intensity light with resonant wavelength of absorption of the PS and biological systems that can raise awareness, generating reactive oxygen species. Studies show that PDT has a lethal effect on Candida albicans. The biofilm formed by C. albicans is the cause of infections associated with medical devices such as catheters, with a proven resistance to antifungal agents, and the removal of the catheter colonized almost always is necessary. However, few studies in literature report the behavior and response of biofilm organized by C. albicans against PDT. The aims of this study were to develop a methodology for in vitro biofilm formation of C. albicans, evaluate the sensitivity of the biofilm of C. albicans to antimicrobial photodynamic therapy using PS as the methylene blue (MB) and hypocrellin B: La+3 (HBLa+3) and analyze the biofilm by Optical Coherence Tomography (OCT). For biofilm formation, discs were made from elastomeric silicone catheters. The PS were dissolved in solution of PBS, and the MB had two different concentrations tested in the biofilm: 100M and 1mM; HBLa+3 only one of 10M. The irradiation of both dyes with the microorganism was done by two different LEDs, one with red emission at = 630nm ± 20nm and the other one blue emission at = 460nm ± 30nm. We performed a curve of survival fraction versus time of irradiation of each sample with biofilm and suspension of the microorganism in the yeast form to verify the susceptibility of the front PDT. The yeast showed 100% reduction using both PS, but at different times of irradiation (30s to HBLa+3 and 6 min for the MB at 100M). When the therapy was applied in biofilm, the MB 100M did not show any significant reduction, while at concentration of 1mM was reduced by 100% after 6 min of irradiation. The HBLa+3 biofilm group showed a lower reduction in the concentration of 10M in biofilm (less than 1 log reduction). OCT was performed for visualization and measurement of the thickness of the biofilm formed. The composition of the extracellular matrix of the biofilm polymer hindered the diffusion of PS inside, requiring higher concentrations of MB to disseminate it and to obtain satisfactory reduction for PDT. HBLa+3 group, in higher concentration, formed aggregates difficulting its use for PDT. We conclude that the organism C. albicans was organized in biofilms in a standardized way using elastomeric discs from catheters and the OCT showed that the biofilm measured 110m at thickness, showing an optical change when subjected to the PDT with MB 1mM.
10
Pretto, Lucas Ramos de. "Desenvolvimento de um algoritimo otimizado para caracterização de fluxos microfluídicos utilizando padrões de speckle presentes no sinal de Tomografia por Coerência Óptica." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-21052015-131941/.
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O presente trabalho abordou o sistema de Tomografia por Coerência Óptica (OCT) e sua aplicação à área de microfluídica. Para tanto, foram realizados testes de caracterização física de circuitos microfluídicos, utilizando modelos 3D (tridimensionais) construídos a partir de imagens de OCT destes circuitos. A técnica foi, assim, avaliada como potencial ferramenta de auxílio na aferição de microcanais. Indo além, este trabalho estuda e desenvolve técnicas de análise para fluxos microfluídicos, em especial técnicas baseadas no padrão de speckle. Em primeiro momento, métodos já existentes foram estudados e aprimorados, como o Speckle Variance OCT, em que foi obtido um ganho de 31% em tempo de processamento. Outros métodos, como o LASCA (Laser speckle Contrast Analysis), baseados na autocorrelação de speckle, são adaptados às imagens de OCT. Derivado do LASCA, o método de análise desenvolvido baseado na autocorrelação de intensidade motivou o desenvolvimento de um arranjo de OCT próprio e software de aquisição customizado, com taxa de amostragem da ordem de 8 kHz. O método proposto foi, então, capaz de distinguir fluxos volumétricos variados, e seus limites de detecção foram testados, comprovando sua viabilidade de aplicação para análise de movimento browniano e fluxos volumétricos abaixo de 10 μl/min.This work discusses the Optical Coherence Tomography system (OCT) and its application to the microfluidics area. To this end, physical characterization of microfluidic circuits were performed using 3D (three-dimensional) models constructed from OCT images of such circuits. The technique was thus evaluated as a potential tool to aid in the inspection of microchannels. Going further, this workpaper studies and develops analytical techniques for microfluidic flow, in particular techniques based on speckle pattern. In the first instance, existing methods were studied and improved, such as Speckle Variance - OCT, where a gain of 31% was obtained in processing time. Other methods, such as LASCA (Laser Speckle Contrast Analysis), based on speckle autocorrelation, are adapted to OCT images. Derived from LASCA, the developed analysis technique based on intensity autocorrelation motivated the development of a custom OCT system as well as an optimized acquisition software, with a sampling rate of 8 kHz. The proposed method was, then, able to distinguish different flow rates, and limits of detection were tested, proving its feasibility for implementation on Brownian motion analysis and flow rates below 10 μl/min.
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Mc, Enery Winifred. "FiliÌocht dhiaga Thaidhg Ghaelaigh UiÌ ShuÌilleabhaÌin I." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252290.
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UiÌ, Cheallaigh MaÌiriÌn Bean. "Cor ur : staideÌar ar filiÌocht comhaimseartha na Gaeilge." Thesis, University of Ulster, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268537.
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Harding, Heather Darby. "Oct-4 expression in equine embryonic cells." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4793.
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The Oct-4 transcription factor is believed to co-regulate early embryonic
development of mammals due to the correlation of its presence with the maintenance of
pluripotency. It is commonly used as a marker for the identification of embryonic stem
(ES) cells for this reason. Until 1999, Oct-4 studies were limited to in vivo-produced
embryos; equine embryos have not been studied for their Oct-4 expression patterns. In
addition, equine stem-like cells (defined by marker expression, induced differentiation,
passage survival, and morphology) have recently been isolated from in vivo-produced
embryos, but no work has been performed in horses to isolate ES cells from in vitroproduced
embryos.
This study investigated the expression of Oct-4 transcription factor using
immunocytochemistry in 42 in vitro-produced embryos aged 1-10 days and in 5 in vivoproduced
blastocysts aged 7-10 days. Effective conditions for rapid establishment of a
feeder layer of equine fetal fibroblasts were established, and this feeder layer was used to
grow isolated equine inner cell mass (ICM) cells from in vitro-produced embryos. The
expression of Oct-4 was examined in resultant cell growths.
In vitro-produced embryos less than 6 days of age showed variable staining
within blastomeres of the same embryo, and the peak of variability correlated with maternal-zygotic transition. After Oct-4 staining of in vitro-produced blastocysts, no
cells could be identified as an ICM based on a difference in fluorescent intensity from
the other cells of the blasyocysts. However, in vitro-produced blastocysts that were
subsequently cultured in vivo contained a presumptive ICM, visible based on greater
fluorescent intensity of Oct-4 stain. The trophoblast of all blastocysts also stained
positively for Oct-4 protein. Fibroblasts were successfully isolated from equine feti.
Treatment with 20 õg/ml of Mitomycin C arrested cell growth without causing excessive
death. Fibroblasts were inactivated and frozen, then thawed as needed to establish a
confluent monolayer for ICM isolation overnight. ICMs from in vitro-produced
embryos formed outgrowths, but none that could be identified morphologically as ES
cells. Outgrowth cells contained about 20% Oct-4 expressing cells in sporadic
groupings. Assuming appropriate binding of the Oct-4 antibody, Oct-4 expressing cells
(potentially indicating pluripotency) are found throughout the embryo in early
development and in the feeder layer after co-culture.
14
Walther, Julia, Lars Kirsten, and Edmund Koch. "Optimal processing of Doppler signals in OCT." SPIE, 2015. https://tud.qucosa.de/id/qucosa%3A35190.
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Besides structural imaging, OCT can be used to estimate axial velocities of the sample resolved in depth by Dopplerprocessing. In Fourier domain OCT (FD-OCT), this is accomplished by measuring the phase difference (i.e. phase shift) between timely separated A-scans at the same depth. In most cases, these data are disturbed by noise caused by intrinsic noise of the OCT system, specified by the SNR, and decorrelation noise caused by the transversal movement of the optical beam relative to the sample. Since the first use of Doppler methods in OCT, many methods to reduce the phase shift noise by averaging have been presented. While all these methods use a fixed set of consecutive A-scans, the best method, exhibiting no bias and having the smallest standard deviation, was questionable. Recently, Doppler processing methods depending on the mentioned noise sources and delivering the most likely phase shift and thereby axial velocity became available. The relation of these methods to previously known methods like the Kasai estimator, maximum likelihood estimator (MLE) and joint spectral and time domain OCT (jSTdOCT) will be discussed.
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Morin, Craig E. "Characterization and Hydration with the SL-OCT." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218601774.
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Garcia, José Mauricio Botto de Barros. "Estudo comparativo entre a angiografia por OCT e a angiografia aom fluoresceína sódica sa maculopatia isquêmica diabética." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6601.
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The purpose of this study is to compare fluorescein angiography and optical coherence tomography (OCT) angiography images of foveal avascular zone (FAZ) in patients with diabetic retinopathy (DR) with and without diabetic macular ischemia. Regarding our methods, the Wilcoxon signedrank test was used to compare area measurements and P values of < 0.05 were considered statistically significant. Fluorescein angiography and OCT angiography images were independently graded by 2 observers that reached agreement regarding quantitative diabetic macular ischemia according established protocols. The ischemic area was divided into “moderate” and ‘‘large’’ macular ischemia (with diabetic macular ischemia) and ‘‘small’’ (without diabetic macular ischemia) groups. Quantitative analyses of the FAZ were performed using custom software (ImageJ64; National Institute of Health - NIH; http://rsbweb.nih.gov/ij/; public domain). Considering our results, thirty-four eyes from 34 diabetic patients were enrolled. Subjects with diabetic macular ischemia presented a mean area on fluorescein angiography and OCT angiography of 0.68 + 0.53 mm2 and 0.58 + 0.35 mm2, respectively (p = 0.1374). Patients without diabetic macular ischemia presented a mean area on fluorescein angiography and OCT angiography of 0.19 + 0.67 mm2 and 0.20 + 0.79 mm2, respectively (p = 0.9594). The ICC for the FAZ measurements between the 2 observers on fluorescein angiography and OCT angiography was 0.96 and 0.92, respectively. Thereby, OCT angiography may represent a novel technique for the diagnosis of diabetic macular ischemia and could become an alternative to FA for this purpose.
O objetivo do presente estudo é comparar as imagens da zona avascular foveal (ZAF) obtidas por meio da angiografia fluorescente e da angiografia por OCT em pacientes com retinopatia diabética (RD), com e sem maculopatia isquêmica diabética. Na metodologia, o Wilcoxon signed-rank test foi usado para comparar as medidas de área e o P valor menor que 0,05 foi considerado estatisticamente significativo. As imagens de angiografia fluorescente e angiografia por OCT foram classificadas de maneira independente por dois observadores. A área de isquemia foi dividida em isquemia macular “moderada” e “grande” (com maculopatia isquêmica diabética) e “pequena” (sem maculopatia isquêmica diabética). Análises quantitativas da ZAF foram realizadas usando software adequado (ImageJ64; (National Institute of Health - NIH; http://rsbweb.nih.gov/ij/ sob domínio público). De acordo com os nossos resultados, trinta e quatro olhos de 34 pacientes com retinopatia diabética foram avaliados. Indivíduos com maculopatia isquêmica diabética apresentaram uma área média na angiografia fluorescente e angiografia por OCT de 0,68 + 0,53 mm2 e 0,58 + 0,35 mm2, respectivamente (p = 0,1374). Pacientes sem maculopatia isquêmica diabética apresentaram uma área media na angiografia fluorescente e angiografia por OCT de 0,19 + 0,67 mm2 e 0,20 + 0,79 mm2 respectivamente (p = 0,9594). O ICC para as medidas de ZAF entre os dois examinadores usando angiografia fluorescente e angiografia por OCT foi de 0,96 e 0,92, respectivamente, demonstrando a concordância entre os examinadores nas medidas da ZAF. Concluiu-se que, a angiografia por OCT pode representar uma nova técnica para o diagnóstico de maculopatia isquêmica diabética, e pode vir a ser uma alternativa à angiografia fluorescente para este propósito.
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Raele, Marcus Paulo. "Desenvolvimento de um sistema de tomografia por coerência óptica no domínio de Fourier sinsível á polarização e sua utilização na determinação das matrizes de Mueller." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-16112009-165948/.
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Este estudo abordou os aspectos teóricos e experimentais relacionados ao desenvolvimento de um sistema de tomografia por coerência óptica (OCT) no domínio de Fourier sensível à polarização (PS-FD-OCT) e a sua utilização na determinação da Matriz de Mueller (MM-OCT). O estudo iniciou-se com uma revisão bibliográfica que abordou desde os primeiros estudos relacionados à técnica até o estado da arte, bem como o formalismo matemático da interferometria de baixa coerência no domínio espectral e polarização da luz. Realizaram-se estudos baseados em simulação numérica sobre três tipos diferentes de algoritmos, responsáveis pela recuperação do sinal de espalhamento, sendo eles: a Transformada de Fourier Direta; Interpolação e Zero-Filling. Ao fim dessa etapa concluiu-se que o algoritmo Zero-Filling 2N apresentou melhores características quando comparado aos outros algoritmos. Na parte experimental, primeiramente, diferentes arranjos OCT foram montados e medidas realizadas para verificação aspectos relacionados à teoria. Consecutivamente, utilizando uma amostra polimérica, realizaram-se imagens de birrefringência, que permitiram a determinação da birrefringência da amostra quantitativamente. Finalmente, imagens em diferentes estados de polarização foram realizadas, através delas determinou-se as imagens referentes aos elementos das Matrizes de Mueller, que foram analisadas individualmente.This study approached theoretical and experimental aspects related with the development of a polarization sensitive, Fourier domain, optical coherence tomography system (PS-FD-OCT) and its utilization on the Mueller Matrix determination. This work began with a bibliographic revision, which describes since the early studies to the actual state of the art of the technique. The mathematical formalism of Fourier domain low coherence interferometry and light polarization was performed as well. Studies based on numerical simulations, of three different algorithm types, responsible to recover the scattering profile, were done. The implemented algorithms were: Direct Fourier Transform, Interpolation and Zero-Filling. By the end of the simulation study, was possible to conclude that the algorithm Zero-Filling 2N presented better characteristics when compared with the others. In the experimental part, firstly different OCT setups were assembled and measurements were done in order to verify aspects related with the theory. Then, using a polymeric sample, birefringence images were performed, which allowed determining the sample birefringence quantitatively. Finally, images taken of different polarization states were collected, and through then images related with the Mueller Matrix elements were calculated, which were analyzed individually.
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Schulz-Wackerbarth, Cyriak Nathanael [Verfasser]. "Evaluation der Spaltlampen Spectral Radar Optischen Kohärenztomographie (SL SR OCT) und Vergleich mit SL OCT und Stratus OCT bei physiologischen und pathologischen Befunden des vorderen und hinteren Augenabschnittes / Cyriak Nathanael Schulz-Wackerbarth." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2011. http://d-nb.info/1018316558/34.
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Louie, Tiffany M. "Clinical assessment of early demineralization using PS-OCT." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1465486.
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Ferreira, Andreia Patrícia Soares. "Estudo comparativo através do OCT da retinopatia diabética." Master's thesis, Universidade da Beira Interior, 2013. http://hdl.handle.net/10400.6/1398.
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A diabetes mellitus constitui um grave problema de saúde a nível mundial pela crescente incidência, como também pela elevada morbilidade e mortalidade que lhe está associada. Sendo a retinopatia diabética a manifestação ocular mais grave da doença e uma das principais causas de cegueira no mundo ocidental, despertou o interesse de realizarmos um estudo comparativo através do OCT (Tomografia de Coerência Ótica) em indivíduos com o diagnóstico de diabetes até 10 anos e entre 10 e 20 anos, medicados com antidiabéticos orais, com idades de 56 e os 80 anos, acompanhados na Clínica Oftalmológica das Antas.
O objetivo da investigação consistiu em saber se os indivíduos diabéticos com diagnóstico de diabetes mellitus até 10 anos apresentavam menos alterações retinianas que os indivíduos diabéticos há mais de 10 anos.
A amostra foi constituída por 28 indivíduos, com diagnóstico de diabetes mellitus de ambos os sexos. Dos 28 doentes, 14 com diagnóstico de diabetes até 10 anos e os restantes 14 com diagnóstico de diabetes entre 10 e 20 anos, ambos os grupos com idades compreendidas entre os 56 e os 80 anos.
Para comparação e análise de resultados, entrou no estudo um grupo controlo de 28 indivíduos, sem diabetes mellitus ou outras complicações sistémicas ou oftalmológicas, de ambos os sexos com idades compreendidas entre os 50 e os 75 anos.
Foi consultado o processo clínico de todos os pacientes, com recolha de dados clínicos e dos exames oftalmológicos realizados na consulta de Oftalmologia (OCT - Tomografia de Coerência Ótica).
A análise dos resultados obtidos permite concluir que foram alcançados todos os objectivos propostos na realização do presente trabalho, confirmando-se a hipótese geral de investigação: “os indivíduos diabéticos com diagnóstico de diabetes mellitus até 10 anos apresentam menos alterações retinianas que os indivíduos diabéticos com diagnóstico de diabetes mellitus entre 10 e 20 anos”.
Concluímos que o valor médio da espessura central da retina, de um modo geral entre o grupo dos saudáveis e cada um dos grupos diabéticos não foram encontradas alterações estatisticamente significativas, embora a espessura média no grupo dos diabéticos há menos de 10 anos seja ligeiramente inferior ao grupo dos diabéticos há mais de 10 anos.
Relativamente ao aumento dos valores médios da espessura retiniana, nos diferentes quadrantes analisados pelo OCT, as diferenças mais estatisticamente significativas surgiram nos quadrantes 2 e 6 do olho direito nos doentes diabéticos há mais de 10 anos e nos quadrantes 1, 2 e 6 do olho esquerdo dos diabéticos há menos de 10 anos.The mellitus diabetes is a serious worldwide health problem due to the increasing incidence as well as the huge morbidity and mortality which is associated to it. Being the diabetic retinopathy the most serious ocular manifestation of the disease and one of the main causes of blindness in the western world, it arouse interest to a comparative study through the OCT in individuals with diabetes diagnosis up to 10 years and among those between 10 and 20, prescribed with oral antidiabetic medicines aged from 56 and 80 years old, followed by Ophthalmic Antas Clinic. The purpose of the research consisted in being aware of knowing if diabetic individuals with mellitus diabetes till 10 years presented less retinal disorders than diabetic individuals for more than 10 years. The sample was constituted by 28 individuals, with mellitus diabetes from both genders. From the 28 patients, 14 with diabetes diagnostic until 10 years the remain 14 with diabetes diagnostic between 10 and 20 years, both groups aged among 56 and 80 years old. For the comparison and analysis of the results, a control group of 28 individuals, without mellitus diabetes or other systemical complications or ophthalmological, was used in this study from both genders aged between 50 and 75 years old. It was consulted the clinic process of all patients with a gathering of clinic data and ophthalmological trials made in the ophthalmology consultation (OCT). The analysis of the obtained results allows to conclude that the main goals proposed in this work were achieved, confirming the general research hypothesis: “Diabetic individuals with mellitus diabetes diagnosis till 10 show less retinal disorders than diabetic individuals with mellitus diabetes diagnosis among 10 and 20 years”. We conclude that the average value of the central retina thickness, generally among the healthy group and each diabetic groups there weren`t any significative statistic disorders, although the average thickness in the diabetic groups for less than 10 years is slightly inferior to the diabetic groups for more than 10 years. In relation to the increase of the average values of retina`s thickness, in the different analyzed dials by the OCT, the most significant statistic differences appeared in quadrants 2 and 6 of the right eye on diabetic patients for more than 10 years and on the quadrants 1, 2 and 6 of the left eye on the diabetics for less than 10 years.
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Le, Guennec Mireille. "Spectroscopie de rotation et structures de : BrCN, OCSe, FC103, GeH3F, CH3CN, CH2CHPH2." Lille 1, 1992. http://www.theses.fr/1992LIL10009.
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La spectroscopie de rotation est considérée comme l'une des techniques les plus précises de détermination de la structure géométrique des molécules en phase gazeuse. Cependant dans la pratique, la structure déterminée est le plus souvent une structure empirique (dite «effective») car même lorsque les données expérimentales sont suffisantes pour déterminer tous les paramètres géométriques (ce qui n'est pas le cas général), on est amené à négliger les interactions de rotation-vibration. Or il est bien établi que ces interactions ne sont pas négligeables et qu'en particulier elles peuvent induire une erreur systématique importante. Dans ce travail, nous nous sommes donc attachés à étudier l'influence de ces interactions de rotation-vibration sur la structure géométrique de molécules simples, linéaires (BrCN, OCSe) ou symétriques (FC103, GeH3F, CH3CN), et de comparer les différentes méthodes existantes pour déterminer une structure expérimentale:―la structure à l'équilibre (structure re),―la structure effective (structure ro),―les structures de substitution (rs, rss, rm,. . . ). Finalement, il est montré qu'une méthode semi-empirique permet de calculer une structure très proche de la structure re. Ce travail a également permis de caractériser une nouvelle molécule phosphorée instable : la vinylphosphine E
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Smith, Alexander. "Characterization of Oct-4 function and assessment of potential relationships between Oct-4 and E1A-like cofactors specific to undifferentiated EC cells." Thesis, King's College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407338.
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Castro, Vinícius Monteiro de. "Papel do VEGF nas alterações retinianas provocadas pela hipóxia normobárica em coelhos." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/17/17150/tde-07012016-090259/.
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Objetivos: Avaliar as alterações retinianas em modelo experimental de hipóxia em coelhos aclimatizados em ambiente hipóxico-normobárico e investigar os efeitos do tratamento com bevacizumabe intravítreo (IV). Métodos: Vinte e dois coelhos New Zealand, com pesos entre 2,4 a 3,8 kg, foram divididos em quatro grupos. Os grupos S12% (n=5) e B12% (n=5) foram aclimatizados durante três dias consecutivos em concentrações de oxigênio (O2) a 12%. Os grupos S8% (n=5) e B8% (n=7) foram aclimatizados durante três dias consecutivos, com reduções graduais da concentração de O2, até atingir o nadir de 8%. Os olhos direitos (OD) foram mantidos como controle e os olhos esquerdos (OE) dos animais dos grupos S12% e S8% receberam injeção IV de 0,05 ml de solução salina balanceada (SSB), enquanto os OE dos grupos B12% e B8% receberam 0,05 ml (1,25 mg) de bevacizumabe IV. Foram realizados exames de tomografia de coerência óptica (OCT) para avaliação da espessura dos segmentos retinianos (SR) e coroidianos (SC), angiografia por fluoresceína sódica (AF) para observação da presença ou ausência de vasodilatação e tortuosidade da vasculatura retiniana e quantificação do Vascular Endothelial Growth Factor (VEGF) do humor aquoso e soro no primeiro dia (D0), antes do tratamento, no terceiro dia de hipóxia (D7) e no décimo primeiro dia (D11), utilizando-se a técnica do Luminex®. Após, os animais foram sacrificados e amostras do tecido retiniano foram avaliadas por histologia e imuno-histoquímica (IHQ). Resultados: Comparando-se os cortes horizontais dos OD (controle) nos períodos D0 e D7, notou-se redução de 8% (p<0,0001) e 10% (p<0,0001) da espessura do SR nas concentrações de O2 a 12% e 8%, respectivamente. Comparando-se os cortes verticais nos mesmos períodos, verificou-se redução da espessura do SR de 7%, tanto nas concentrações a 12% (p<0,0001) como a 8% (p<0,0001). Nos olhos tratados com bevacizumabe, a redução das médias das espessuras do SR para os cortes horizontais entre os períodos D0 e D7 foi de 6% (<0,0001) e 9% (<0,0001), para as concentrações de O2 a 12 e 8%, respectivamente. Enquanto que nos olhos tratados com SSB no mesmo período, observou-se redução de 8% (<0,0001) e 6% (<0,0001) para as concentrações de O2 a 12 e 8%, respectivamente, nos cortes horizontais. Nos cortes verticais, para os olhos tratados com bevacizumabe, houve redução de 5% (p=0,0005) e 8% (<0,0001) para concentrações de O2 a 12% e 8%, respectivamente; e para os olhos tratados com SSB foi encontrada redução de 7% (<0,0001) e 8% (<0,0001) nas concentrações de O2 a 12% e 8%, respectivamente. As espessuras dos SC não apresentaram alterações. O grupo B8 apresentou diferença estatisticamente significativa na análise da proporção dos olhos que não evidenciaram vasodilatação e tortuosidade dos vasos retinianos durante o período hipoxêmico, e não foram observados neovasos retinianos. A histologia e IHQ dos olhos tratados com SSB e bevacizumabe não demonstraram alterações quando comparados com os controles. Conclusões: A aclimatização de coelhos em ambiente hipóxico-normobárico resultou na redução da espessura do SR no terceiro dia de hipóxia. Notou-se, ainda, aumento da tortuosidade e vasodilatação. O bevacizumabe IV não inibiu a redução da espessura retiniana, mas sim a vasodilatação e tortuosidade vascular.Objectives: Evaluate retinal changes in experimental model of hypoxia in rabbits acclimatized in normobaric-hypoxic environment and to investigate the effects of the treatment by intravitreal (IV) bevacizumab drug. Methods: Twenty two New Zealand rabbits weighing between 2,4 to 3,8 kg were divided into 4 groups. The groups S12 (n=5) and B12 (n=5) were acclimatized for 3 consecutive days in oxygen concentration (O2) to 12%. The groups S8 (n=5) and B8 (n=7) were acclimatized for 3 consecutive days with gradual reductions in O2 concentration until the nadir of 8%. The right eye (RE) were kept as controls and the left eye (LE) of the animals belonging to S12 and S8 groups received IV injection of 0,05 ml of balanced salt solution (BSS), while the LE belonging to groups B12 and B8 received 0,05 ml (1,25 mg) of bevacizumab IV. Optical coherence tomography (OCT) to evaluate the thickness of the retinal segments (RS) and choroidalsegments (CS), sodium fluorescein angiography (FA) for evaluation of the presence or absence of vasodilation and tortuosity of the retinal vasculature and quantification of VEGF in the aqueous fluid and peripheral blood sample were conducted at the first day (D0) before treatment, on the third day of hypoxia (D7) and day 11 (D11) using the Luminex® technique. After the animals were sacrificed, the retinal tissue samples were evaluated by histology and immunohistochemistry (IHC). Results: Comparing the horizontal sections of the RE (control) in D0 and D7 periods, a reduction of 8% (p<0,0001) and 10% (p<0,0001) the thickness of the RS in O2 concentration at 12% and 8%, respectively. Comparing the vertical cuts in the same period, there was reduced RS thickness of 7% in both concentrations to 12% (p<0,0001) and 8% (p<0,0001). In the eyes treated with bevacizumab, to reduce the average thickness of the retinal segment for horizontal cuts between D0 and D7 periods were 6% (<0,0001) and 9% (<0,0001) for O2 concentrations to 12 and 8%, respectively. While in the eyes treated with BSS in the same period, there was an 8% reduction (<0,0001) and 6% (<0,0001) for the O2 concentration at the 12% and 8%, respectively, in the horizontal cuts. In the vertical sections is observed for the eyes treated with bevacizumab, 5% reduction (p=0.0005) and 8% (<0,0001) O2 concentration at 12% and 8%, respectively; and BSS treated eyes was reduced by 7% (<0,0001) and 8% (<0,0001) in the O2 concentrations of 12% and 8%, respectively. The thickness of the CS did not show changes. The B8 group showed statistical difference in the analysis of the eyes that did not have vasodilation and tortuosity of the retinal vessels during the hypoxic period. Retinal neovascularization were not observed. Histology and IHC of the eyes treated with BSS and bevacizumab showed no changes compared to the control eyes. Conclusions: The acclimatization of the rabbits in normobaric-hypoxic environment has the effect of reducing the thickness RS on the third day of hypoxia. It is observed also increased tortuosity and vasodilation. The intravitreal bevacizumab does not inhibit retinal thickness decrease, but inhibits vasodilation and vascular tortuosity.
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Soares, Fernando Augusto Neves. "Análise morfológica e biomecânica do âmnio conservado em glicerol esterilizado com diferentes doses de radiação ionizante." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-08082013-125722/.
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A membrana amniótica é a camada interna das membranas fetais (placenta), amplamente utilizada em transplantes por ser um tecido que combina propriedades anti-inflamatórias, antimicrobianas e antifibróticas, além da limitada capacidade de provocar reações imunológicas. O uso da membrana fresca tem algumas limitações, como a necessidade de rápida utilização e a impossibilidade de obter total segurança diante de certas infecções. Qualquer tecido biológico utilizado para transplante deve ser estéril. A radioesterilização é uma alternativa para garantir a qualidade e segurança dos tecidos usados em transplantes e outras aplicações clínicas, a fim de minimizar os riscos de contaminação do receptor do tecido, porém a mesma pode causar alterações indesejáveis no tecido. No presente trabalho, foram testadas doses de 10, 15, 25 e 35 kGy, utilizando duas fontes de radiação ionizante: raios gama proveniente de fonte de Cobalto-60 e feixe de elétrons. Na análise qualitativa visual e táctil foi observado que, nas doses mais elevadas (a partir de 25 kGy) para ambas as fontes de radiação, as membranas irradiadas sofreram maior alteração de cor, tornando-se mais amareladas e com diminuição da elasticidade, deixando-as mais rígidas. A colorimetria sólida possibilitou minimizar a subjetividade da análise visual e a microscopia óptica foi essencial para avaliar as alterações histológicas comprovando, respectivamente, que a alteração de cor da membrana e o grau de degradação das camadas subjacentes do tecido tem relação direta com a dose de radiação empregada. Desse modo, as doses de 10-35 kGy podem ser aplicadas nas membranas amnióticas para sua utilização como bandagem biológica, porém, para as doses a partir de 25 kGy deve-se levar em consideração a alteração de coloração e condensação das camadas da membrana se estas forem destinadas para o uso oftálmico ou como substrato transportador para transplante de tecido cultivado in vitro. Com as técnicas de OCT, TG e ensaio de tração não foi possível avaliar as alterações biomecânicas encontradas na análise qualitativa, nas condições experimentais realizadas devido aos desvios-padrão obtidos para as cinco membranas testadas.The amniotic membrane is the inner layer of the fetal membranes (placenta), widely used in transplantation as it is a tissue that combines properties anti-inflammatory and antifibrotic antimicrobial, and limited ability to induce immune reactions. The use of fresh membrane has some limitations such as the need for rapid deployment and not being completely safe against of certain infections. Any biological tissue used for transplantation should be sterile. The radiosterilization is an alternative to ensure the quality and safety of tissues used in transplants, and other clinical applications to minimize the risk of contamination of the tissue´s receptor, but it can cause undesirable changes in the tissue. In this study, we tested doses of 10, 15, 25 and 35 kGy, using two sources of ionizing radiation: gamma rays from cobalt-60 source and electron beam. In qualitative, visual and tactile analysis it has been observed that higher doses (25 kGy and up, to both sources of radiation) irradiated membranes had a greater color change, becoming yellowed and decreased elasticity, becoming more rigid. The solid colorimetry minimized the subjectivity of visual analysis and optical microscopy was essential to evaluate the histological changes showing, respectively, the color change of the membrane and the degree of degradation of the underlying layers of tissue is directly related to the dose of radiation employed. Thus, doses of 10-35 kGy can be applied in the amniotic membranes for application as a biological bandage, however doses from 25 kGy and up should take into account the changes in color and condensation of the layers of the membrane for ophthalmic use or as a carrier substrate for transplantation of cultured tissue in vitro. With the techniques of OCT, TG and tensile testing was not possible to evaluate the biomechanical findings in the qualitative analysis, the experimental conditions due to the standard-deviations obtained for the five membranes tested.
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Neagu, Liviu. "Multiple path configurations for optical coherence tomography at 1050 nm." Thesis, University of Kent, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593912.
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Plesea, Lucian. "Shape reconstruction in OCT imagery with applications in ophthalmology." Thesis, University of Kent, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504646.
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Běťák, Ondřej. "Multimodální registrace retinálních snímků z fundus kamery a OCT." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219716.
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V první části se práce se zabývá rešerší metod a principů potřebných při registraci obrazu. Dále pak popisuje zobrazovací systémy očního pozadí jako jsou OCT, fundus kamera a SLO. Druhá část práce je zaměřena na praktickou realizaci programů pro registraci snímků z OCT, SLO a fundus kamery v programovém prostředí Matlab.
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Zagra, Sara. "I risultati italiani e ticinesi nelle prove di Matematica Ocse-Pisa a confronto." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3676/.
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Perchè, nelle competenze di matematica, i risultati riportati dagli studenti della Svizzera Italiana sono migliori di quelli dell'Italia?
Domanda interessante in quanto nei due Paesi confinanti si utilizza la stessa lingua e in più molti italiani, lasciano l'Italia per trasferirsi in Ticino, una realtà quindi con cui l'Italia si confronta.
Vengono presi in considerazione vari aspetti per cercare di dare una risposta.
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Toscano, Daniela Araújo. "Análise da reprodutibilidade da espessura da camada de fibras nervosas da retina utilizando-se o Spectralis SLO OCT e sua concordância com Stratus OCT." reponame:Repositório Institucional da UnB, 2012. http://repositorio.unb.br/handle/10482/10834.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Ciências Médicas, 2012.Submitted by Jaqueline Ferreira de Souza (jaquefs.braz@gmail.com) on 2012-06-27T13:19:21Z No. of bitstreams: 1 2012_DanielaAraujoToscano.pdf: 1639141 bytes, checksum: 9269a3edec99fb2ad296cfabf7f193e7 (MD5)
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Este estudo teve por objetivo analisar a reprodutibilidade do SD SLO OCT Spectralis e comparar os dados deste OCT com outro já bastante difundido no mercado, como o TDOCT Stratus. Esse estudo foi dividido em duas partes: na primeira delas foram estudados 151 olhos de 79 pacientes sem glaucoma (grupo 1) e 72 pacientes com glaucoma (grupo 2). Para a segunda parte, foram incluídos 110 olhos, sendo 60 sem glaucoma e 50 com glaucoma. Foram realizados em todos os olhos e em apenas uma visita, três B-scans circulares centrados no disco óptico utilizando-se o Spectralis, e na segunda fase, também o Stratus. A média da idade foi de 58 ±11 e 68±10 anos, para o grupo 1 e 2, respectivamente. O ICC, COV e TRV para a média de espessura da camada de fibras nervosas da retina (CFNR) foram respectivamente: 0,94, 2,56% e 4,85m para o grupo 1, e 0,93, 4,65% e 6,61m para o grupo 2. As medidas de espessuras da CFNR foram semelhantes comparando-se os dois aparelhos, com exceção do quadrante superior no grupo 1, e do temporal, no grupo 2 (p<0,0001). Analisando o gráfico de Bland-Altman, foi observado um boa concordância entre as medidas de espessura da CFNR entre o Spectralis e o Stratus. Concluiu-se que o Spectralis apresentou uma excelente reprodutibilidade da espessura da CFNR. Além disso, não houve diferença estatisticamente significante entre as espessuras aferidas com o Spectralis versus o Stratus, exceto no quadrante superior para pacientes sem glaucoma e quadrante temporal para pacientes com glaucoma. Houve uma excelente concordância entre os dois OCTs. _________________________________________________________________________________ ABSTRACT
The goal of the present study was to analyze the reproducibility of SD SLO OCT Spectralis and compare this data with other OCT used worldwide, as TDOCT Stratus. This study was divided in two parts: in the first part a total of 151 eyes of 79 patients without glaucoma (group 1) and 72 glaucomatous patients (group 2) were analyzed. For the second part, 110 eyes, 60 without glaucoma and 50 with glaucoma were enrolled. All patients’ eyes were scanned using the Spectralis and in the second part of the study, also the Stratus. Three consecutive circular B-scan centered at the optic disc were performed in one visit. The average age was 58±11 and 68±10 years old for the group 1 and 2, respectively. The ICC, COV and TRV for the mean RNFL thickness were respectively: 0.94, 2.56% and 4.85m for the group 1, and 0.93, 4.65% and 6.61m for the group 2. Only in the superior quadrant for the group 1 and temporal for the group 2, the RNFL thickness difference was statistically significant (p0.0001). Analyzing the Bland-Altman concordance graphs it was observed excellent concordance between the RNFL thickness measured by Spectralis and Stratus. The Spectralis showed excellent reproducibility with regard to RNFL thickness measurements. In addition, there were no statistically significant differences between RNFL measurements by Spectralis and Stratus, except for superior quadrant in the patients without glaucoma and temporal quadrants in glaucomatous patients. In conclusion, there was an excellent concordance between the two OCTs.
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Tanna, Hitesh Pratapkumar. "Analytical tools for high resolution OCT imaging of human retina." [Milwaukee, Wis.] : e-Publications@Marquette, 2009. http://epublications.marquette.edu/theses_open/24.
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Bakheet, Saleh Abdulrahman. "Identification of OCT-2 as a mediator of lead neurotoxicity /." View online ; access limited to URI, 2005. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3206242.
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李杰憲. "Valuing economic benefit of cardiovascular disease prevention:an applicaiton of ocst of illness and population attributable risk methods." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/61712615112355043615.
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博士東吳大學
經濟學系
92
As a result of economic development and high standard of living, compatriot diseases have developed from acute diseases to chronic diseases. American Heart Association predict that Cardiovascular Disease（CVD） will be a global main death disease and the disease of maximum medical cost for every country in the world at 2020. Recently, the study for CVD was just for the risk factor, prevalence and post medical cost of CVD. It was not faultless that the study did not consider the economic behavior and utility of people in microeconomic research. This dissertation will build up prevalence function of CVD by using the concept of risk function of epidemiology. We also try to make use of Hedonic Price Method（HPM）to establish the medical cost function and continue to develop an economic model to evaluate the economic benefits of CVD prevention. The next, we make use of our economic model to investigate the decisive factor of prevalence and medical cost of CVD and use Taiwan’s local data to explore the economic benefits and the change of welfare by improving the risk factor of CVD and reducing the prevalence of CVD. At last, we make a comparison for the estimative result of our economic model and traditional Population Attributable Risk. The conclusion of estimation as follow： 1.By the economic model, we have the following result. If the patient of CVD could improve their condition of hypertension, cholesterol, diabetes and obesity to ordinary standard, then the medical cost of CVD will reduce 9.73﹪,10.0﹪,5.70﹪,8.37﹪respectively. It means the medical cost of CVD can reduce 13.8 hundred million,14.2 hundred million,8.1 hundred million,11.9 hundred million respectively by the total medical cost of CVD 142.3 hundred million（estimative value）at Taiwan in 2000. 2.By Population Attributable Risk Method, we also have the following result. If the patient of CVD could improve their condition of hypertension, cholesterol, diabetes and obesity to ordinary standard, then the medical cost of CVD will reduce 27.7﹪,6.88﹪,4.32﹪,9.53﹪respectively. It means the medical cost of CVD can reduce 39.4 hundred million,9.7 hundred million,6.1 hundred million,13.5 hundred million respectively by the total medical cost of CVD 142.3 hundred million（estimative value）at Taiwan in 2000. 3.By multifactor Population Attributable Risk method, we estimate that the Population Attributable Risk of hypertension, cholesterol, diabetes and obesity with regard to CVD is 35.77﹪in sample. If the patient of CVD could improve their condition of hypertension, cholesterol, diabetes and obesity to ordinary standard at the same time, then the medical cost of CVD will reduce 27.7﹪. I t means the medical cost of CVD can reduce 51 hundred million by the total medical cost of CVD 142.3 hundred million（estimative value）at Taiwan in 2000.
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Gaspar, António Pedro Rodrigues. "Ocsi Simple." Master's thesis, 2018. http://hdl.handle.net/10400.6/9900.
Full textAbstract:
Atualmente existem diferentes formas de produzir uma aplicação World Wide Web
(WEB). Várias linguagens de programação dão suporte direto ou indireto a este tipo
de desenvolvimento e sobre estas existem inúmeras frameworks já desenvolvidas. Com
a fragmentação do desenvolvimento WEB distribuído por várias tecnologias, uma simples
aplicação WEB, na grande maioria dos casos contém código PHP, HTML e JavaScript.
Esta situação pode dar azo a erros sintáticos e semânticos durante o processo de
produção, que vão ser refletidos no cliente. De forma a resolver grande parte destes
problemas foi criada a framework Ocsigen. O seu slogan é ”develop once, safely deploy
everywhere” e tem como mais valia, a possibilidade de construir uma aplicação
WEB completa, tanto parte cliente como parte servidor, exatamente com a mesma linguagem
de programação, nomeadamente a linguagem Objective Categorical Abstract
Machine Language (OCaml). Esta é também, a linguagem utilizada na construção da
framework Ocsigen. O OCaml é uma linguagem de base funcional, multiparadigma de
alto nível e fortemente tipificada. Tem por base, um poderoso compilador capaz de
tornar o código produzido em algo extremamente determinístico a nível de segurança
de tipos. Apesar da framework Ocsigen herdar características subjacentes à linguagem
OCaml esta apresenta algumas limitações relativas à curva de aprendizagem, utilização
devido à falta de documentação atualizada e instalação em diferentes sistemas
operativos, como é o caso do Windows.
A presente dissertação tem como objetivo encontrar soluções para as limitações mencionadas.
Para conseguir o objetivo proposto é então delineado um plano, que passa
numa primeira fase, pelo estudo aprofundado da framework Ocsigen. Para que com
base nos resultados obtidos seja possível compreender o seu funcionamento e contexto,
como também as suas limitações, de forma mais detalhada, assim como os respetivos
pontos críticos, nomeadamente a sua utilização e o suporte a diferentes sistemas operativos.
Posteriormente, com base nestes dados é então projetada uma solução, que
irá concretizar-se na forma de uma nova framework, a framework Ocsi_Simple. Esta
nova framework irá agora permitir o uso da tecnologia Ocsigen, de forma mais amigável,
simples e mais apetecível para a indústria do desenvolvimento WEB. É importante
frisar que esta solução pretende completar a framework Ocsigen.Currently there are different ways to produce a WEB application. There are several programing languages backed by many frameworks that either directly or indirectly support WEB programming. With the fragmentation of WEB development, distributed by various technologies, a simple WEB application, in most cases contains PHP, HTML and JavaScript code. This situation can give rise to syntactic and semantic errors during the production process, which will be reflected on the client side. In order to solve a large part of these problems, the Ocsigen framework was created. The slogan is ”develop once, safely deploy everywhere” and its added value, the possibility of building a complete WEB application, both client side and server side, exactly with the same programming language, namely OCaml. This is also the language used in the construction of the Ocsigen framework. OCaml is a high-level, multi-paradigm, strongly typed language with emphasis on functional programming, which is based on a powerful compiler, able to make very type safe programs. Though Ocsigen naturally shares common properties to the OCaml language, the former presents some limitations, such as, learning curve, lack of susbtantial documentation and installation issues with some operating systems like Windows. The present dissertation aims to find solutions to the mentioned limitations. In order to achieve the proposed objective, a plan is outlined, of which, the first phase consists of an in-depth study of the Ocsigen framework. So that, based on the results obtained, it is possible to understand its operation and context, as well as its limitations in a more detailed way as well as the respective critical points, namely its use and support for different operating systems. Subsequently, based on this data, a solution is then designed, which will materialize, in the form of a new framework, the Ocsi_Simple framework. This new framework will now allow the use of Ocsigen in a friendlier, simpler and more appealing way for the WEB development industry. It is important to stress out that this solution intends to complete the Ocsigen framework.
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Santos, Andoni Calvo Y. "Development of an image captation system using simple reflectivity and scanning control improvements in SS-OCT." Master's thesis, 2017. http://hdl.handle.net/10316/83300.
Full textAbstract:
Dissertação de Mestrado Integrado em Engenharia Física apresentada à Faculdade de Ciências e TecnologiaTomografia de Coerência Óptica é uma tecnologia utilizada em medicina para diagnóstico e investigação. Permite recolher dados in vivo na sobre a estrutura tridimensional de uma amostra translúcida, tal como o olho humano. A resolução dos dados estruturais é tipicamente inferior a 10 um.Um aparelho OCT dedicado a adquirir imagens dos olhos de pequenos animais para investigação está actualmente a ser desenvolvido no IBILI. O trabalho aqui apresenado está integrado no desenvolvimento deste sustema, na medida em que é um passo em frente para melhorar o seu desempenho e usabilidade. O propósito deste trabalho é a implementação de duas melhorias ao sistema existente. A primeira é a criação de um módulo que permita prever a área alvo do OCT em tempo real, idealmente conseguindo ver o fundo ocular dos pequenos animais a estudar. Isto melhoraria o processo actual de apontar o OCT e alinhar os alvos com o aparelho. A segunda melhoria é a integração de um módulo desenvolvido para substituir o actual sistema de controlo. Este novo módulo permitirá atingir velocidades superiores e criará ainda a possibilidade de controlar todo o processo de aquisição a partir do software do OCT, em vez de ser necessário recorrer a controlos e ajustes manuais. Ambas as melhoria permitirão reduzir algumas dificuldades actuais no processo de aquisição. Por exemplo, no processo de posicionamento dos animais devidamente alinhados com o feixe laser e na facilidade de utilização do sistema, sendo estes alguns dos pontos fracos actualmente existentes.
Optical Coherence Tomography (OCT) is a technology commonly used in medical fields for diagnosis and research. It allows to retrieve data in vivoabout the 3-dimensional structure of a translucent sample, such as the human eye. The resolution of the structural data is typically under 10 um. An OCT device dedicated to imaging the eyes of small animals for research purposes is currently under active development at IBILI. The workhereby presented is integrated in the development of this system, as it is a step forward toward improving its performance and usability.The purpose of this work is on the implementation of two improvements to the existing setup. The first is the creation of a module to enable previewing the target area of the OCT in real time, ideally being able to see the retinal fundus of the small animals to be studied. This would greatly improve the current process to aim the OCT and align the targets with the apparatus. The second improvement is the integration of the module developed to replace the current control system for the positioning of the OCT beam. This new module allows controlling the whole acquisition process through the OCT software, without resorting to manual controls or adjustments.Both improvements will diminish some of the current difficulties in the acquisition process. For instance, in the process to position the small animals properly aligned with the laser beam and in easiness of usage. These two factors are some of the current weak points of the system.
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