152 research outputs found

    Science 2.0 : sharing scientific data on the Grid

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    Mestrado em Engenharia de Computadores e TelemáticaA computação assumese cada vez mais como um recurso essencial em ciência, levando ao surgimento do termo eCiência para designar a utilização de tecnologias de computação avançada para suportar a realização de experiências científicas, a preservação e partilha do conhecimento. Uma das áreas de aplicação do conceito de eCiência é o tratamento e análise de imagens médicas. Os processos que lidam com imagem médica, tanto ao nível clínico como de investigação, são exigentes em relação ao suporte computacional, devido aos algoritmos de processamento de imagem que requerem e à elevada capacidade de armazenamento relacionada com volume das imagens geradas. As políticas públicas e os avanços tecnológicos recentes orientados para a eCiência, têm vindo a apoiar o desenvolvimento da computação em Grid, tanto a nível dos middlewares como da instalação de capacidade de produção, como um sistema de computação avançado que permite a partilha de recursos, instrumentos científicos e boas práticas em comunidades virtuais. Este trabalho tem como objectivo desenvolver uma estratégia e um protótipo para o armazenamento de dados médicos na Grid, visando a sua utilização em investigação. Uma preocupação diferenciadora prendese com o objectivo de colocar as potencialidades da Grid ao serviço de utilizadores não técnicos (e.g. médicos, investigadores), que acedem a serviços de processamento e de armazenamento e catalogação de dados de forma transparente, através de um portal Web. O protótipo desenvolvido permite a investigadores na área das neurociências, sem conhecimentos específicos da tecnologia Grid, armazenar imagens e analisálas em Grids de produção existentes, baseadas no middleware gLite. ABSTRACT: Computing has become an essential tool in modern science, leading to the appearance of the term eScience to designate the usage of advanced computing technologies to support the execution of scientific experiments, and the preservation and sharing of knowledge. One of eScience domain areas is the medical imaging analysis. The processes that deal with medical images, both at clinical and investigation level, are very demanding in terms of computational support, due to the analysis algorithms that involve large volumes of generated images, requiring high storage capabilities. The recent public policies and technological advances are eScience oriented, and have been supporting the development of Grid computing, both at the middleware level and at the installation of production capabilities in an advanced computing system, that allows the sharing of resources, scientific instrumentation and good practices among virtual communities. The main objective of this work is to develop a strategy and a prototype to allow the storage of medical data on the Grid, targeting a research environment. The differentiating concern of this work is the ability to provide the nonexperts users (e.g: doctors, researchers) access to the Grid services, like storage and processing, through a friendly Web interface. The developed prototype allows researchers in the field of neuroscience, without any specific knowledge of Grid technology, to store images and analyse them in production Grid infrastructures, based on the gLite middleware

    The feasibility of an augment reality system to study the psychophysiological correlates of fear-related responses

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    Previous studies have successfully used augmented reality (AR) as an aid to exposure-based treatments for anxiety disorders. However, to the best of our knowledge, none of these studies have measured the physiological correlates of the fear response, relying solely on self-reports and behavioral avoidance tests.publishe

    A Methodology for Creating an Adapted Command Language for Driving an Intelligent Wheelchair

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    Intelligent wheelchairs (IW) are technologies that can increase the autonomy and independence of elderly people and patients suffering from some kind of disability. Nowadays the intelligent wheelchairs and the human-machine studies are very active research areas. This paper presents a methodology and a Data Analysis System (DAS) that provides an adapted command language to an user of the IW. This command language is a set of input sequences that can be created using inputs from an input device or a combination of the inputs available in a multimodal interface. The results show that there are statistical evidences to affirm that the mean of the evaluation of the DAS generated command language is higher than the mean of the evaluation of the command language recommended by the health specialist (p value = 0.002) with a sample of 11 cerebral palsy users. This work demonstrates that it is possible to adapt an intelligent wheelchair interface to the user even when the users present heterogeneous and severe physical constraints

    Multi-voxel fMRI analysis using an high throughput grid framework

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    Mestrado em Engenharia Biomédica - Instrumentação, Sinal e ImagemO presente trabalho apresenta uma nova abordagem à análise de imagens de RMf do cérebro, especificamente a utilização de medidas associativas na análise de séries temporais de RMf. Este tipo específico de análise, computacionalmente intensivo, requer recursos que normalmente não se encontram disponíveis em ambientes clínicos. Redes Grid é um novo paradigma de computação distribuída de elevada performance que pode ser utilizado para potenciar a utilização deste tipo de análise, disponibilizando a capacidade de computação necessária. Implementouse um framework que permite a utilização de uma infraestrutura Grid para correr este tipo de análise de forma transparente, viabilizando a sua utilização em ambientes clínicos, onde o tempo é um factor crítico. ABSTRACT: This work, introduces a new approach to fMRI brain image analysis, namely multivoxel fMRI association analysis. The problem associated with this type of approach is that requires a large computing capacity that is not normally available at clinical sites. To enable this specific type of analysis we are required to use High Performance Computing paradigms. In this context we analysed the use of Grid computing and implemented a framework that allows running the multivoxel fMRI association analysis using a grid infrastructure resources. The use of this framework makes this type of analysis usable in clinical environments where time constraints can have a vital importance

    A web portal for Portuguese brain imaging network

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    Mestrado em Engenharia de Computadores e TelemáticaA Imagiologia Cerebral (IC) está na fronteira entre a neurologia, engenharia e física. écnicas de imagens médicas multimodais, tais como a Ressonância Magnética (MRI e fMRI) e Espectroscopia (MRS), Tomografia Computadorizada por Emissão de Fotões/Positrões (SPECT/PET), entre outros, são emergentes ferramentas de pesquisa médica que pode fornecer informações valiosas para o diagnóstico de doenças do cérebro. Eletroencefalograma de alta resolução (HR-EEG), técnicas para sincronizar e fundir seus resultados de análise e várias técnicas de imagem são também parte de IC. Em Portugal, dado o facto que a maioria das áreas relacionadas com IC (por exemplo, medicina, engenharia ou física) são assuntos de investigação em muitos grupos de P&D, um consórcio de universidades de Aveiro, Coimbra, Minho e Porto criou a Rede Nacional de Imagiologia Funcional Cerebral (RNIFC). A RNIFC é uma associação sem fins lucrativos que foi formalizada e assinada em fevereiro de 2009. Actualmente, com o suporte de sistemas digitais para armazenar imagens médicas, é possível partilhar dados entre essas instituições para melhorar o diagnóstico, e permitir investigações entre a comunidade médica de diferentes instituições. O principal objectivo desta dissertação é descrever a implementação dos serviços de sistemas de informação essenciais para a Brain Imaging Network (BIN) que suportam actualmente o RNIFC acessível através do Portal BIN, o principal ponto de entrada para a BING. O Portal BIN permite aos pesquisadores na comunidade BING espalhadas pelo país e no estrangeiro, quer para solicitar o acesso a instrumentos científicos ou para recuperar os seus casos e executar as suas análises. ABSTRACT: Brain Imaging is in the frontier between neurology, engineering and physics. Multimodal medical imaging techniques, such as Magnetic Resonance Imaging (MRI and fMRI) and Spectroscopy (MRS), Single Photon/Positron Emitting Tomography (SPECT/PET) among others, are emergent medical research tools that can provide valuable information for diagnosis of brain diseases. High-resolution electroencephalogram (HR-EEG), techniques for synchronizing and fuse its analysis results and several imaging techniques are also part of BI. In Portugal, given fact that most of the BI related areas (e.g. medical, engineering or physics) are subjects of research in many R&D groups, a consortium of the universities of Aveiro, Coimbra, Minho and Porto created the National Functional Brain Imaging Network (RNIFC). The RNIFC is a non-profitable association that was formalized and signed in February 2009. Currently, with the support of digital systems to store medical images, it is possible to share data among these institutions to improve diagnosis, and allow investigations by the medical community among different institutions. The main objective of this thesis is to describe the implementation of the essential Brain Imaging Network (BIN) information systems services that currently support the RNIFC accessible through the BIN Portal, the main entry point for the BING. BIN Portal enables researchers in the BING community scattered along the country and abroad either to apply for access to the scientific instruments or to retrieve their cases and run their analysis

    Relación entre la farmacocinética y los cambios hemodinámicos durante la inducción y posicionamiento en pacientes quirúgicos anestesiados con propofol

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    Tesis por compendio de publicaciones[EN]For long years, it was thought that anaesthetic management did not influence patient’s outcome. Surgical morbidity and long-term mortality were attributed to patient’s comorbidity, malignance of the disease, risk infection and type of surgery. Nowadays, there is an increasing evidence that intraoperative anaesthetic management can influence long-term patient outcomes. In the last two decades, surgical mortality rates have been falling and, in part, this is due to a huge improvement in anaesthesia related factors and safety. For an anaesthesiologist, perioperative care is no longer the simple fact of administrating the anaesthetic drug and maintaining the patient “asleep”. Direct-guided fluid therapy, maintaining intraoperative normothermia, minimizing blood transfusion and avoiding low mean arterial pressure and deep hypnotic level are additional procedures the anaesthesiologist is responsible for and that will probably improve patient’s outcome and decrease surgical mortality. Hypotension after induction of anaesthesia is quite common and more prevalent during the late post-induction period and before skin incision (5-10 minutes after), generally thought to be clinically irrelevant. Nowadays, there is some evidence that small haemodynamic changes, such as hypotension, even for small periods, are associated with poor patient outcomes, because they have the potential to cause an ischemia–reperfusion injury which may be manifested as dysfunction of any vital organ, like acute kidney and myocardial injury. Intra-operative management of hypotension is usually guided by conventional monitoring (systolic blood pressure and MAP) but these parameters could mask low levels of blood flow and oxygen delivery, even for short periods, leading to major surgical complications and longer hospital stays

    Individual EEG differences in affective valence processing in women with low and high neuroticism

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    Objective: In this study, individual differences in brain electrophysiology during positive and negative affective valence processing in women with different neuroticism scores are quantified. Methods: Twenty-six women scoring high and low on neuroticism participated on this experiment. A support vector machine (SVM)-based classifier was applied on the EEG single trials elicited by high arousal pictures with negative and positive valence scores. Based on the accuracy values obtained from subject identification tasks, the most distinguishing EEG channels among participants were detected, pointing which scalp regions show more distinct patterns. Results: Significant differences were obtained, in the EEG heterogeneity between positive and negative valence stimuli, yielding higher accuracy in subject identification using negative pictures. Regarding the topographical analysis, significantly higher accuracy values were reached in occipital areas and in the right hemisphere (p < 0:001). Conclusions: Mainly, individual differences in EEG can be located in parietooccipital regions. These differences are likely to be due to the different reactivity and coping strategies to unpleasant stimuli in individuals with high neuroticism. In addition, the right hemisphere shows a greater individual specificity. Significance: An SVM-based classifier asserts the individual specificity and its topographical differences in electrophysiological activity for women with high neuroticism compared to low neuroticism
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