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Le présent travail s’inscrit dans une perspective descriptive analytique des comportements des pianistes aveugles et déficients visuels durant la mise en mémoire et la restitution au piano de diverses tâches présentées à l’oreille ou sur un support écrit adapté au handicap visuel de ceux-ci. Cette adaptation qui consiste à transcrire en braille pour les aveugles ou à imprimer en gros caractères pour les malvoyants des partitions ordinaires, se révèle lourde de conséquences. Ainsi, deux conditions font qu’un travail mental d’intégration et de synthèse très coûteux s’impose à ces musiciens : d’un côté la complexité du braille musical due à un degré d’abstraction très élevé et à une linéarité spatiale permanente, de l’autre la non-conformité de la technique d’agrandissement des textes ordinaires avec une lecture synthétique et avec un champ visuel très réduit. De telles circonstances invitent à s’interroger sur les effets de la structure de ces notations musicales et des représentations mentales qu’elles génèrent sur la conduite de mémorisation en l’absence totale ou partielle de la vision. L’objectif principal est de relever la spécificité des processus qui sous-tendent l’assimilation des données inscrites sur le matériau de la lecture. Pour ce faire, j’ai mené une étude de cas portant sur des jeunes pianistes aveugles et malvoyants non professionnels utilisant des procédures de déchiffrage diverses. / The present work involves an analytical description of the behaviors of blind and visually impaired pianists when memorizing and rendering on the piano various tasks presented to the ear or on written material adapted to their visual disability. This adaptation, which consists in transcribing ordinary music scores in braille, for the blind, or in large print, for the visually impaired, entails important consequences. Two conditions result in those musicians having to perform a very difficult integrating and synthesizing task: on the one hand, musical braille is complex, being highly abstract and characterized by permanent spatial linearity; on the other hand, the technique for enlarging ordinary texts is not compatible with synthetic reading and a very restricted visual field. Those circumstances lead us to investigate how those musical notations and the mental representations they generate affect the memorizing process when vision is totally or partially lacking. The main objective is to pinpoint the specific processes underlying the assimilation of the data inscribed on the reading material. To this end, I have carried out a case study involving young non-professional blind and visually impaired pianists using diverse reading procedures.

A partir da constatação do limitado investimento no design de produtos de auxílio à visão subnormal no Brasil e de sua crescente demanda, esta tese teve por objetivo analisar o estado da arte dos produtos existentes no mundo, particularmente dos que oferecem ampliação eletrônica da imagem, propor um projeto de equipamento inovador que agrega videomagnificação a uma prancha de leitura, e analisar alguns casos pioneiros de design para a saúde no Brasil, inclusive oftalmológico. Como método foram realizadas entrevistas, pesquisas bibliográficas, por internet e observação de pacientes para embasar a proposta de projeto de prancha de leitura acoplada a câmera de videomagnificação para deficientes visuais. A proposta resultante tem como base comum o produto prancha de leitura acoplada a lupa já disponível no mercado em que no lugar da lupa será colocada uma câmera de vídeomagnificação para leitura de perto. Nesta prancha de base o usuário poderá ler de modo estável comandando por sua mão o movimento do anel em volta da câmera que por sua vez excursionará horizontalmente num trilho para manter a linha e o foco de leitura constantes. Evidenciam-se os elementos indicadores de que o design inovador deste equipamento apresenta vantagens em relação aos equipamentos atualmente existentes e que poderão contribuir para facilitar a leitura dos portadores de baixa visão. Por meio do design com responsabilidade social, este trabalho pretende dar uma contribuição para a inclusão do deficiente visual no Brasil. / Low investment in design for low vision and growing demand for low vision products in Brazil were the reason for proposing the goals of this thesis: analysis of the state of the art of low vision products in the world, particularly those with video magnification; proposal of a product that aggregates video-magnification to a reading stand in an innovative product; analysis of representative cases of design for health in Brazil, including ophthalmic design. As method, interviews, bibliographic and internet search along with patient observation were performed in order to support the project of a reading stand with a sliding video-magnification camera for low vision people. The resulting project has as common platform the commercially available product: a reading stand with a sliding magnifier in which the magnifier is replaced by a near reading video-magnification camera. This reading stand allows the user to read on a steady basis as the hand moves the ring around the camera to the right or to the left on a rail, maintaining the reading line and focus constant. Indicative elements are shown that the innovative design of this equipment presents advantages which may contribute favorably for the reading of low vision people, comparing with the equipment currently in the market. Through the socially responsible design, this thesis is meant to contribute to social inclusion of low vision people in Brazil.

Um dos problemas para desenvolvimento de trabalhos multicêntricos é a falta de protocolos padronizados compatíveis às políticas de saúde, que sejam de fácil entendimento e inserção de dados confiáveis, mesmo por pesquisadores não envolvidos no desenvolvimento do projeto. Por outro lado, algumas políticas de saúde pública não estão sintonizadas às necessidades populacionais nem aos programas de especialização, necessitando, portanto, da criação de cursos de treinamentos objetivos que garantam qualidade de entendimento dos assuntos abordados pelos protocolos. O Brasil possui grande número de portadores de deficiência visual. A reabilitação para portadores de baixa visão é pouco conhecida e praticada pela classe oftalmológica. No país, existe falta de programas de capacitação em Baixa Visão durante a residência médica e não existe sistematização do uso de protocolo multicêntrico para coletar dados confiáveis que permitam o levantamento do perfil nacional da baixa visão. A padronização, registro e intercâmbio dos dados multicêntricos necessários para estudos podem ser obtidos pela utilização de um protocolo para formação de um banco de dados nacional com grande valor para o desenvolvimento de programas em saúde pública. Este estudo teve como objetivo desenvolver e estruturar um protocolo multicêntrico para trabalhos em Baixa Visão, baseado no protocolo adotado pela OMS, com lançamento dos dados via Internet, mantendo a qualidade da informação inserida na ficha de pesquisa. Material e Método: Adequação do protocolo da OMS para a necessidade brasileira, integrado na Web. Desenvolvimento do curso básico de baixa visão, utilizando recursos de teleducação interativa. O protocolo foi preenchido por dois grupos de residentes, mas apenas um deles (grupo B) teve acesso prévio ao curso disponível na Web. O preenchimento dos protocolos foi avaliado por quatro especialistas. Para cada item da ficha de pesquisa foi atribuída uma nota segundo o grau de concordância do preenchimento com o padrão-ouro. Resultado: Foi criado um protocolo simplificado e implementado na Web que pôde ser aplicado em pacientes adultos e crianças, sua utilização não interferiu na rotina do atendimento ambulatorial. O curso foi executado pelo grupo B entre 2 e 3 dias. O nível de melhoria da qualidade das informações inseridas foi medido pela análise comparativa do preenchimento entre os dois grupos. O grupo B apresentou superioridade no preenchimento da ficha de pesquisa. Discussão: A elaboração do protocolo multicêntrico pode ser o ponto inicial para integração e intercâmbio das informações. O lançamento dos dados via Internet possibilita a formação do banco de dados que pode ser incrementado por diversos centros. A construção do programa de teleducação via Internet para a formação objetiva em Baixa Visão é uma ferramenta para difusão dos conhecimentos básicos desta especialidade, garantindo a melhoria das informações inseridas na ficha de pesquisa. A análise dos dados pode favorecer o delineamento do perfil da deficiência visual e estabelecimento de estratégias nacionais de atenção primária. Conclusão: É viável a construção de um protocolo de pesquisa multicêntrica, com dados relevantes sobre deficiência visual, orientado pela necessidade de desenvolver estratégia de política de saúde compatível com o protocolo Internacional. A utilização da Internet para lançamento dos dados possibilitou a formação do banco de dados que pode ser incrementado por diferentes centros oftalmológicos, passando a ter abrangência nacional. A construção do curso de teleducação proporcionou aumento da qualidade da inserção de dados. / One of the problems in the development of multicentric projects is the lack of standardized protocols compatible with health policies, which are easy to understand and to use in recording reliable data even by researchers not involved in developing the project. On the other hand, some public health policies are not in tune wit h the needs of the population or with specialization programs, and require the creation of objective training courses that guarantee the quality of understanding of the topics covered by the protocols. Brazil has a great number of visual impaired individuals. Rehabilitation for Low Vision patients is not well known or widely practiced by ophthalmologists. Besides a lack of professional qualification training programs in Low Vision during medical residency, there is no systematization of use of the multicentric protocol to collect reliable data in order to map out a national profile of Low Vision. Standardization, register, and interchange of the multicentric data necessary for studies can be obtained by the use of a protocol to construct a national data base that would be vital for the development of Public Health programs. This study has the objective of developing and structuring a multicentric protocol for Low Vision projects, based on the protocol adopted by the World Health Organization -WHO, with data entered via the Internet, maintaining the quality of the information inserted on the research form. Material and Method: Adaptation of the Web-integrated WHO protocol to the needs of Brazil, and development of a basic course in Low Vision using interactive Tele-Education resources. The protocol form was completed by two groups of medical residents, but only one of them (Group B) had had prior access to the course available on the Web. The answers to the protocol questions were evaluated by four specialists. For each item on the research form, a grade was attributed according to the degree of agreement with the gold standard. Result: A simplified Web-implemented protocol was developed which could be applied to adult and child patients, and its application did not interfere in the out-patient routine of patient care. The course was taken by Group B for 2 to 3 days. The level of improvement in quality of the information entered was measured by a comparative analysis between the two groups. Group B showed superiority in terms of the answers given on the research form. Discussion: The preparation of a multicentric protocol may be the starting point for the integration and exchange of information. Data insertion via the Internet enables the construction of a data bank that can be incremented by several centers. The Internet-based Tele-Education program for objective professional qualification training in Low Vision is a tool for divulging basic knowledge in this specialty, guaranteeing an improvement in the information entered on the research forms. Analysis of the data may outline the profile of visual deficiency and enable the establishment of national primary care strategies. Conclusion: the construction of a multicentric research protocol with relevant data on visual deficiency is viable, guided by the need to develop a strategy of health care policies compatible with the international protocol. The use of the Internet for data insertion has made it possible to form a data base that can receive information from different ophthalmology centers, thus presenting a national scope. The preparation of the Tele-Education course led to an improvement in the quality of data inserted.

Les travaux de cette thèse sont menés dans le cadre d’un projet porté par le centre de recherche LGI2P, (IMT Mines Ales). L’objectif final de ce projet vise à permettre le retour à l’emploi et à améliorer le quotidien des personnes malvoyantes atteintes de rétinite pigmentaire et de glaucome. Le dispositif final est conçu pour aider les personnes dans leurs activités en mobilité : détection d’obstacles, recherche d’indices visuels, en adressant les problèmes liés à l’éblouissement et à l’héméralopie dont souffrent ces utilisateurs potentiels.La contribution de cette thèse au projet se situe sur plusieurs plans. Tout d’abord, il était demandé de définir les paramètres caractérisant la vision résiduelle de chaque utilisateur. En effet, chaque patient a ses propres conditions de confort lumineux, qui dépendent en particulier de l’état d’avancement de sa pathologie : à chaque étape de l’évolution de leur maladie, les patients ont des limites spécifiques de luminosité minimale en dessous de laquelle ils ne perçoivent plus les détails dans une scène, et aussi de la luminosité maximale au-dessus de laquelle ils ressentent gêne et douleur. La définition de ces limitations en luminosité va permettre de paramétrer le dispositif et l’adapter à chaque utilisateur. Mais il n’existe pas de méthode pour mesurer ces niveaux de luminance limite. Nous avons donc participé à la conception et au développement de tests dédiés, et à la réalisation d’essais sur des sujets déficients visuels, dans le cadre d’un essai clinique piloté par le CHU de Nîmes et l’ARAMAV (institut spécialisé dans la rééducation fonctionnelle basse vision), pour l’aspect médical. Nous avons également proposé un nouveau test pour mesurer la sensibilité au contraste chromatique, toujours dans le but de mieux adapter les images affichées à la vision des utilisateurs.Nous avons ensuite travaillé sur la mise au point d’un prototype du dispositif (caméras et visiocasque de réalité virtuelle). Pour cela, nous avons dû choisir les équipements de capture et d’affichage d’images. Un travail de calibration colorimétrique sur ces équipements nous permet de relier grandeurs numériques (code RGB) et grandeurs physiques (luminance et chrominance). Cette étape est nécessaire pour réaliser les tests précités dans des conditions physiquement connues. Elle nous permet également de définir les caractéristiques physiques que devront posséder les équipements qui seront choisis pour réaliser le produit final, s’ils sont différents de ceux utilisés pendant nos travaux.Enfin, nous avons abordé la question des traitements à appliquer au signal capturé par la caméra. Nous avons proposé des traitements en temps réel sur la luminosité dans le but d’augmenter la luminosité dans les zones sombres de l’image et de baisser la luminosité dans les zones qui éblouissent le patient. Nous avons montré les limitations de l’imagerie classique et la nécessité de travailler sur des images HDR (high dynamic range) Nous avons comparé plusieurs méthodes pour permettre l’affichage de ces images HDR sur les écrans de plus faible dynamique, en recherchant les caractéristiques de l’image que ces méthodes doivent préserver au mieux, et en prenant en compte les performances visuelles des utilisateurs potentiels. Nous avons aussi proposé des traitements sur la couleur en augmentant le contraste et la saturation pour rendre les images mieux perceptibles par les patients qui souffrent de troubles de vision des couleurs. / This thesis is part of a project conducted by the LGI2P research center (IMT Mines Ales). The project's final aim is to help people with vision disorders suffering from retinitis pigmentosa and glaucoma get back to work and improve their daily lives. The final device is designed to help people in their mobility activities: detecting obstacles, searching for visual signals, by addressing problems related to dazzling and haemeralopia affecting these potential users.The research of this thesis has several contributions to the project. First of all, parameters characterizing the residual vision of each user had to be defined. Indeed, each patient has his own light comfort conditions, which depend in particular on his pathology's progress: at each stage of the evolution of their disease, patients have specific minimum luminosity limits below which they no longer perceive the details in a scene, and also on the maximum luminosity above which they feel discomfort and pain. The definition of these limitations in luminosity will make it possible to parameterize the device and adapt it to each user. But there is no method to measure these limiting luminance levels. We have therefore participated in the design and development of specialized tests, and in the conduct of trials on visually impaired subjects, as part of a clinical trial led by the Nîmes University Hospital and the ARAMAV (institute specializing in low vision functional rehabilitation), for medical research. We have also proposed a new test to measure sensitivity to chromatic contrast, always with the aim of better adjusting the images displayed to users' vision.Then, we developed a prototype of the device (cameras and virtual reality video headset). In order to achieve these results, we had to choose the image capture and display equipment. A colorimetric calibration work on these equipments allowed us to link digital quantities (RGB code) and physical quantities (luminance and chrominance). This stage is required to perform the above tests under physically known conditions. It also allowed us to define the physical characteristics of the equipment that would be selected to produce the final product, whether they are different from those required during our work.Finally, we discussed the processing to be applied to the signal captured by the camera. We have proposed real-time brightness treatments to increase brightness in dark areas of the image and decrease brightness in areas that dazzle the patient. We have presented the limitations of conventional imaging and the necessity to work on HDR (high dynamic range) images. We have compared several methods to allow the display of these HDR images on screens with lower dynamic range, looking for the image characteristics that these methods should better preserve, and taking into consideration the visual performance of potential users. We have also suggested color treatments by increasing contrast and saturation to make images more perceptible to patients with color vision disorders.

Um dos problemas para desenvolvimento de trabalhos multicêntricos é a falta de protocolos padronizados compatíveis às políticas de saúde, que sejam de fácil entendimento e inserção de dados confiáveis, mesmo por pesquisadores não envolvidos no desenvolvimento do projeto. Por outro lado, algumas políticas de saúde pública não estão sintonizadas às necessidades populacionais nem aos programas de especialização, necessitando, portanto, da criação de cursos de treinamentos objetivos que garantam qualidade de entendimento dos assuntos abordados pelos protocolos. O Brasil possui grande número de portadores de deficiência visual. A reabilitação para portadores de baixa visão é pouco conhecida e praticada pela classe oftalmológica. No país, existe falta de programas de capacitação em Baixa Visão durante a residência médica e não existe sistematização do uso de protocolo multicêntrico para coletar dados confiáveis que permitam o levantamento do perfil nacional da baixa visão. A padronização, registro e intercâmbio dos dados multicêntricos necessários para estudos podem ser obtidos pela utilização de um protocolo para formação de um banco de dados nacional com grande valor para o desenvolvimento de programas em saúde pública. Este estudo teve como objetivo desenvolver e estruturar um protocolo multicêntrico para trabalhos em Baixa Visão, baseado no protocolo adotado pela OMS, com lançamento dos dados via Internet, mantendo a qualidade da informação inserida na ficha de pesquisa. Material e Método: Adequação do protocolo da OMS para a necessidade brasileira, integrado na Web. Desenvolvimento do curso básico de baixa visão, utilizando recursos de teleducação interativa. O protocolo foi preenchido por dois grupos de residentes, mas apenas um deles (grupo B) teve acesso prévio ao curso disponível na Web. O preenchimento dos protocolos foi avaliado por quatro especialistas. Para cada item da ficha de pesquisa foi atribuída uma nota segundo o grau de concordância do preenchimento com o padrão-ouro. Resultado: Foi criado um protocolo simplificado e implementado na Web que pôde ser aplicado em pacientes adultos e crianças, sua utilização não interferiu na rotina do atendimento ambulatorial. O curso foi executado pelo grupo B entre 2 e 3 dias. O nível de melhoria da qualidade das informações inseridas foi medido pela análise comparativa do preenchimento entre os dois grupos. O grupo B apresentou superioridade no preenchimento da ficha de pesquisa. Discussão: A elaboração do protocolo multicêntrico pode ser o ponto inicial para integração e intercâmbio das informações. O lançamento dos dados via Internet possibilita a formação do banco de dados que pode ser incrementado por diversos centros. A construção do programa de teleducação via Internet para a formação objetiva em Baixa Visão é uma ferramenta para difusão dos conhecimentos básicos desta especialidade, garantindo a melhoria das informações inseridas na ficha de pesquisa. A análise dos dados pode favorecer o delineamento do perfil da deficiência visual e estabelecimento de estratégias nacionais de atenção primária. Conclusão: É viável a construção de um protocolo de pesquisa multicêntrica, com dados relevantes sobre deficiência visual, orientado pela necessidade de desenvolver estratégia de política de saúde compatível com o protocolo Internacional. A utilização da Internet para lançamento dos dados possibilitou a formação do banco de dados que pode ser incrementado por diferentes centros oftalmológicos, passando a ter abrangência nacional. A construção do curso de teleducação proporcionou aumento da qualidade da inserção de dados. / One of the problems in the development of multicentric projects is the lack of standardized protocols compatible with health policies, which are easy to understand and to use in recording reliable data even by researchers not involved in developing the project. On the other hand, some public health policies are not in tune wit h the needs of the population or with specialization programs, and require the creation of objective training courses that guarantee the quality of understanding of the topics covered by the protocols. Brazil has a great number of visual impaired individuals. Rehabilitation for Low Vision patients is not well known or widely practiced by ophthalmologists. Besides a lack of professional qualification training programs in Low Vision during medical residency, there is no systematization of use of the multicentric protocol to collect reliable data in order to map out a national profile of Low Vision. Standardization, register, and interchange of the multicentric data necessary for studies can be obtained by the use of a protocol to construct a national data base that would be vital for the development of Public Health programs. This study has the objective of developing and structuring a multicentric protocol for Low Vision projects, based on the protocol adopted by the World Health Organization -WHO, with data entered via the Internet, maintaining the quality of the information inserted on the research form. Material and Method: Adaptation of the Web-integrated WHO protocol to the needs of Brazil, and development of a basic course in Low Vision using interactive Tele-Education resources. The protocol form was completed by two groups of medical residents, but only one of them (Group B) had had prior access to the course available on the Web. The answers to the protocol questions were evaluated by four specialists. For each item on the research form, a grade was attributed according to the degree of agreement with the gold standard. Result: A simplified Web-implemented protocol was developed which could be applied to adult and child patients, and its application did not interfere in the out-patient routine of patient care. The course was taken by Group B for 2 to 3 days. The level of improvement in quality of the information entered was measured by a comparative analysis between the two groups. Group B showed superiority in terms of the answers given on the research form. Discussion: The preparation of a multicentric protocol may be the starting point for the integration and exchange of information. Data insertion via the Internet enables the construction of a data bank that can be incremented by several centers. The Internet-based Tele-Education program for objective professional qualification training in Low Vision is a tool for divulging basic knowledge in this specialty, guaranteeing an improvement in the information entered on the research forms. Analysis of the data may outline the profile of visual deficiency and enable the establishment of national primary care strategies. Conclusion: the construction of a multicentric research protocol with relevant data on visual deficiency is viable, guided by the need to develop a strategy of health care policies compatible with the international protocol. The use of the Internet for data insertion has made it possible to form a data base that can receive information from different ophthalmology centers, thus presenting a national scope. The preparation of the Tele-Education course led to an improvement in the quality of data inserted.

Electrical stimulation of the retina affected by photoreceptor loss (e.g., cases of retinitis pigmentosa) elicits the perception of luminous spots (so-called phosphenes) in the visual field. This phenomenon, attributed to the relatively high survival rates of neurons comprising the retina's inner layer, serves as the cornerstone of efforts to provide a microelectronic retinal prosthesis -- a device analogous to the cochlear implant. This thesis concerns phosphenes -- their elicitation and modulation, and, in turn, image analysis for use in a prosthesis. This thesis begins with a comparative review of visual modelling of electrical epiretinal stimulation and analogous acoustic modelling of electrical cochlear stimulation. The latter models involve coloured noise played to normal listeners so as to investigate speech processing and electrode design for use in cochlear implants. Subsequently, four experiments (three psychophysical and one numerical), and two statistical analyses, are presented. Intrinsic signal optical imaging in cerebral cortex is canvassed appendically. The first experiment describes a visual tracking task administered to 20 normal observers afforded simulated prosthetic vision. Fixation, saccade, and smooth pursuit, and the effect of practice, were assessed. Further, an image analysis scheme is demonstrated that, compared to existing approaches, assisted fixation and pursuit (but not saccade) accuracy (35.8% and 6.8%, respectively), and required less phosphene array scanning. Subsequently, (numerical) information-theoretic reasoning is provided for the scheme's superiority. This reasoning was then employed to further optimise the scheme (resulting in a filter comprising overlapping Gaussian kernels), and may be readily extended to arbitrary arrangements of many phosphenes. A face recognition study, wherein stimuli comprised either size- or intensity-modulated phosphenes, is then presented. The study involved unpracticed observers (n=85), and showed no 'size' --versus--'intensity' effect. Overall, a 400-phosphene (100-phosphene) image afforded subjects 89.0% (64.0%) correct recognition (two-interval forced-choice paradigm) when five seconds' scanning was allowed. Performance fell (64.5%) when the 400-phosphene image was stabilised on the retina and presented briefly. Scanning was similar in 400- and 100-phosphene tasks. The final chapter presents the statistical effects of sampling and rendering jitter on the phosphene image. These results may generalise to low-resolution imaging systems involving loosely packed pixels.

Functional vision refers to the use of vision to perform day-day tasks and is assessed by the ability to perform these tasks. Assessment of functional vision is an integral component of the management of children with visual impairment. The results of the assessment help in designing appropriate educational and rehabilitation intervention strategies. The L V Prasad-Functional Vision Questionnaire (LVP-FVQ) is a reliable and valid tool for assessing self-reported functional vision performance (FVP) in children. Self-reports are obviously the child's perception of his or her ability to perform certain tasks but they may not reflect actual performance. Various studies of FVP in adults have used actual performance measures of everyday tasks, but very few studies, even in adults with visual impairment, have compared self-reports and performance measures and none have included identical tasks on the 2 methods of assessment. To date, no study has assessed FVP using performance measures of daily tasks in the paediatric population. Therefore, the aims of the current study were: (1) To develop performance measures of FVP and compare them with self-reports of FVP from the LVP-FVQ in a prospective cohort of Indian school-going children with visual impairment. (2) To investigate the effect of a psychological attribute, self-concept, on self-reports, performance measures and the relationships between the 2 measures. (3) To investigate the relationship between clinical measures of vision and FVP. Performance measures of FVP for children with visual impairment were developed for 17 day to day tasks for comparison with self-reports of the same tasks for the LVP-FVQ. The LVP-FVQ was verbally administered by the researcher to 178 Indian school-going children aged between 8 and 17 years with visual impairment. Similarly, the performance of each of the tasks by these children was measured by the researcher. The performance measures for most of these tasks were recorded on continuous scales and later categorized to match the ordinal ratings from the LVP-FVQ. The self-report and performance measure ratings for the 17 tasks were then converted into the same metric using a Rasch model allowing an accurate picture of whether and how these two measures of FVP compared with each other. Rasch analysis was used to estimate the person ability and item difficulty for FVP from the 2 methods of assessment. Self-reports showed stronger correlations with performance measures of FVP than were hypothesized. Similar to some studies in adults, binocular high-contrast visual acuity was found to be the single most significant predictor of a child's functional vision performance. Contrary to expectations, self-concept did not have a significant effect on the relationship between the 2 measures. A few reasons for the stronger than expected relationship between the 2 methods of assessment of FVP in children with visual impairment are suggested. Firstly, the use of identical tasks for self-reports and performance measures of FVP is likely to improve the relationship. Secondly, the LVP-FVQ was developed using focus groups of children with visual impairment, their parents, low vision specialists and rehabilitation professionals leading to good content validity. Since children were included in the development of the LVP-FVQ, the tasks were representative of a child's typical daily life. Thus, the performance measures were also suited to the day-day tasks of school-going children but were not tapping any social and psychological issues relating to visual impairment. Thirdly, the use of Rasch analysis which addresses many of the issues of unequal measurement and defines a hierarchy of items for self-reports and performance measures could have led to higher correlations in the present study. Finally, the high reliability and validity of self-reports and performance measures of FVP in the present study may have contributed to the higher than expected correlations. None of the demographic variables or self-concept affected the relationship between self-reports and performance measures of FVP, but self-concept had a weak significant association with self-reports. This result is unique to this study and warrants further investigation. Binocular high-contrast visual acuity alone, the most common visual function measured in ophthalmic clinics, explained between one-third and two-thirds of the variance in functional vision performance. This confirms the expected trend that with worse visual impairment, FVP is lower. The addition of the variable, self-concept, resulted in a very small increase in the variability explained for self-reported FVP. Similarly, the addition of other clinical measures of vision such as binocular low contrast visual acuity and colour vision resulted in a small increase in the variability explained for performance measures of FVP. The correlation between binocular high-contrast visual acuity and performance measures of FVP was statistically significantly higher than that between binocular high-contrast visual acuity and self-reports of FVP. There are a few possible reasons for this higher correlation. Firstly, performance measures are considered to be a more "objective" form of assessment, while self-reports are a child's perception of his or her ability and therefore lack a context, which may result in either over-estimation or under-estimation of actual ability. Furthermore, performance measures include dimensions such as the time taken to perform a task or other criteria specific to a task, while self-reports do not use such qualifiers. Secondly, the higher correlation may be the result of the visual complexity of some of the tasks. While self-concepts of children with visual impairment played a small but significant role in the self-reported FVP, studies in adults with visual impairment have suggested that other psychological factors such as mood, anxiety, motivation etc. are associated with an individual's perception of visual performance. Future studies are required to explore the possible role of these and other factors in FVP in Indian school-going children with visual impairment. This thesis makes a significant contribution to the field of paediatric low vision rehabilitation by providing performance measures of FVP and relating them to self-reports in children with visual impairment and their relationship with common measures of visual function. With self-reports, the child is reporting his or her perception of ability to complete a task, where performance measures examine the child's ability to complete a task by observing his or her performance. Thus, although the two methods are comparable, it is because of the different yields from each of these measures that they are not considered interchangeable. A combination of the 2 measures where practical would perhaps provide a richer depiction of the FVP of children with visual impairment. As developing countries such as India have limited resources allocated for eye care services where less than seven percent of the gross national product is spent on health care, self-reports can be utilized together with clinical measures of vision (mainly visual acuity) to assess the FVP in children with visual impairment in a community setting. However, both methods of assessment of FVP together with clinical measures of vision are essential if a comprehensive assessment of FVP is to be carried out in children with visual impairment. Information from these assessments can help clinicians better understand the functioning of children with visual impairment and incorporate them in the management of low vision in school-going children with visual impairment in India.

Electrical stimulation of the retina affected by photoreceptor loss (e.g., cases of retinitis pigmentosa) elicits the perception of luminous spots (so-called phosphenes) in the visual field. This phenomenon, attributed to the relatively high survival rates of neurons comprising the retina's inner layer, serves as the cornerstone of efforts to provide a microelectronic retinal prosthesis -- a device analogous to the cochlear implant. This thesis concerns phosphenes -- their elicitation and modulation, and, in turn, image analysis for use in a prosthesis. This thesis begins with a comparative review of visual modelling of electrical epiretinal stimulation and analogous acoustic modelling of electrical cochlear stimulation. The latter models involve coloured noise played to normal listeners so as to investigate speech processing and electrode design for use in cochlear implants. Subsequently, four experiments (three psychophysical and one numerical), and two statistical analyses, are presented. Intrinsic signal optical imaging in cerebral cortex is canvassed appendically. The first experiment describes a visual tracking task administered to 20 normal observers afforded simulated prosthetic vision. Fixation, saccade, and smooth pursuit, and the effect of practice, were assessed. Further, an image analysis scheme is demonstrated that, compared to existing approaches, assisted fixation and pursuit (but not saccade) accuracy (35.8% and 6.8%, respectively), and required less phosphene array scanning. Subsequently, (numerical) information-theoretic reasoning is provided for the scheme's superiority. This reasoning was then employed to further optimise the scheme (resulting in a filter comprising overlapping Gaussian kernels), and may be readily extended to arbitrary arrangements of many phosphenes. A face recognition study, wherein stimuli comprised either size- or intensity-modulated phosphenes, is then presented. The study involved unpracticed observers (n=85), and showed no 'size' --versus--'intensity' effect. Overall, a 400-phosphene (100-phosphene) image afforded subjects 89.0% (64.0%) correct recognition (two-interval forced-choice paradigm) when five seconds' scanning was allowed. Performance fell (64.5%) when the 400-phosphene image was stabilised on the retina and presented briefly. Scanning was similar in 400- and 100-phosphene tasks. The final chapter presents the statistical effects of sampling and rendering jitter on the phosphene image. These results may generalise to low-resolution imaging systems involving loosely packed pixels.

Made available in DSpace on 2016-12-06T17:06:59Z (GMT). No. of bitstreams: 1 Daniela B Prestes.pdf: 5940422 bytes, checksum: efbd27d7ed1b157341a9fb48050ac197 (MD5) Previous issue date: 2013-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Diversos estudos sobre a inclusão de crianças com deficiência na escola já foram realizados. Diante das questões estudas e das especificidades características da deficiência múltipla, constatou-se que existem poucas pesquisas que abordam a questão do desenvolvimento motor destas crianças no contexto escolar. Desta forma, o presente estudo procura avaliar a quantidade e a qualidade das oportunidades de estimulação motora presentes nos contextos vivenciais (familiar e escolar) e sua relação com o comportamento motor da criança com deficiência múltipla inserida na rede pública de ensino regular de Florianópolis. Foi realizado um estudo de caso, com uma criança do sexo feminino de 11 anos de idade, com diagnóstico de deficiência múltipla apresentando baixa visão, que frequentava o ensino fundamental da rede municipal de ensino de Florianópolis. Para avaliar as características biopsicossociais, clínicas e escolares do indivíduo do estudo foi utilizada uma ficha cadastral e avaliação multiprofissional disponibilizada pela escola. Para avaliar a funcionalidade do indivíduo do estudo, foi utilizado o protocolo Avaliação Pediátrica de Incapacidade (PEDI). A verificação das oportunidades de estimulação motora presentes no contexto familiar se deu pelo instrumento Affordances in the Home Environment Motor Development (AHEMD) e a verificação das oportunidades de estimulação motora presentes no contexto escolar, pelo instrumento Affordances in the School Environment Motor Development (ASEMD). As vivências motoras do indivíduo do estudo foram registradas a partir da gravação de vídeo, utilizando o protocolo de observação naturalística proposto por Ramalho (1996). Os resultados do estudo apontam que o indivíduo apresentava diagnóstico de deficiência múltipla, com sinais de déficit de atenção e hiperatividade (TDAH), estereotipias provavelmente secundárias à toxoplasmose congênita e afacia após catarata infantil. Verificou-se que o indivíduo do estudo era capaz de executar um pouco mais da metade das habilidades relacionadas ao autocuidado e à função social e todas as habilidades funcionais de mobilidade. Os resultados do questionário AHEMD apontaram que a classificação total para a casa do indivíduo do estudo foi média. Os itens espaço interior e variedade de estimulação foram avaliados como muito bons. Entretanto, o espaço exterior da casa foi avaliado como fraco e a provisão de materiais de motricidade fina e de materiais de motricidade ampla foram classificadas como muito fracas. A escola do indivíduo do estudo foi considerada ampla, oferecendo espaço externo e interno suficientes para estimulação motora. Contudo, a variedade de estimulação e a provisão de materiais de motricidade fina e materiais de motricidade grossa foi fraca. Com relação às vivências motoras no contexto escolar, ficou evidente o predomínio de atividades orientadas. Os movimentos realizados pelo indivíduo do estudo foram predominantemente segmentares, prevalecendo os movimentos manipulativos. As posturas sentado e em pé foram as mais adotadas pelo indivíduo do estudo. As interações do indivíduo do estudo se deram na maior parte do tempo com o professor e a disponibilidade de materiais e equipamentos foi bastante variada no contexto escolar. Diante dos resultados, foi possível contatar que tão importante quanto a quantidade de materiais e equipamentos, estão a variedade e a qualidade destes como fatores que influenciam o desenvolvimento motor do indivíduo. Além da disponibilidade de mais materiais e equipamentos, é necessário que haja tempo suficiente para que a criança explore os recursos existentes, sobretudo, é necessário que existam recursos humanos que favoreçam esta vivência.