Medição automática do diâmetro da aorta torácica em imagens de tomografia computorizada

O calibre da artéria aorta torácica é avaliado em situações de suspeita de patologia ou em pacientes com pre-disposição para desenvolverem doenças vasculares. A medição das suas dimensões, em duas direcções diametralmente opostas e, assim, fulcral na avaliação desta estrutura. Para tal, o exame de primeira linha definido é a Angiografia por Tomografia Computorizada (Angio-TC), injectando-se um produto de contraste na veia radial que irá opacificar os vasos, permitindo a sua distinção das estruturas adjacentes. O presente trabalho, inserido na disciplina de Dissertação/ Projecto/ Estágio Profissional do Mestrado em Engenharia de Computação e Instrumentação Médica e com a cooperação da empresa Efficientia, foi sugerido pela equipa de Angio-TC do Centro Hospitalar de Vila Nova de Gaia (CHVNG) e tem por objectivo o desenvolvimento de uma aplicação para a medição e registo automático do diâmetro da aorta torácica em nove pontos anatómicos pre-definidos em imagens de Tomografia Computorizada (TC). A aplicação foi desenvolvida no ambiente integrado de processamento e análise de imagem, Fiji, sendo a metodologia composta pelas etapas de segmentação, desenho da linha central, determinação dos planos de cortes, segmentação e medição da aorta nos planos de corte. Os resultados obtidos pela metodologia proposta são concordantes com os obtidos por especialistas para o conjunto de teste utilizado neste trabalho.

Dosimetria das exposições em imagiologia clínica

A importância da radiação ionizante na prática médica, nãoo só como diagnóstico mas também como terapia, ganhou, no último meio século, uma importância fulcral. Devido aos efeitos secundários da radiação ao ser humano, torna-se fundamental definir regras para aumentar a segurança de todos os seus utilizadores, surgindo assim a radioprotecção. Nesse sentido a Comunidade Europeia da Energia Atómica (EURATOM) define directrizes para os países membros da Comunidade Europeia de forma a poder orientá-los nesse processo. Torna-se assim importante registar e monitorizar os valores de dose de radiação num exame radiológico para o aumento de segurança dos pacientes e técnicos. O presente trabalho desenvolvido no âmbito da disciplina anual Dissertação/Projecto/ Estágio Profissional do Mestrado em Computação e Instrumentação Médica teve como objectivo registar esses valores através da comunicação com medidores de doses. A luz do dia-a-dia da Dr. Campos Costa - Consultório de Tomogra a Computarizada S.A, é apresentada nesta tese uma aplicação computacional capaz de obter os valores de dose de um estudo radiológico a um paciente e guardá-los numa base de dados projectada exclusivamente para esse fim. Os resultados obtidos são animadores uma vez que provam ser possível automatizar a monitorização desses valores através de aplicações com ferramentas capazes de auxiliar os responsáveis por essa monitorização em qualquer centro clínico.

Construção de interfaces em Flex para sistemas de experimentação remota

Os laboratórios de experimentação remota estão normalmente associados a tecnologias ou soluções proprietárias, as quais restringem a sua utilização a determinadas plataformas e obrigam ao uso de software específico no lado do cliente. O ISEP possui um laboratório de experimentação remota, baseado em instrumentação virtual, usado no apoio ao ensino da electrónica e construído sobre uma plataforma NIELVIS da National Instruments. O software de controlo da plataforma recorre à linguagem gráfica de programação LabVIEW. Esta é uma ferramenta desenvolvida pela National Instruments que facilita o desenvolvimento de aplicações de sistemas de experimentação remota, mas que possui várias limitações, nomeadamente a necessidade de instalação do lado do cliente de um plug-in, cuja disponibilidade se encontra limitada a determinadas versões de sistemas operativos e de Web Browsers. A experiência anterior demonstrou que estas questões limitam o número de clientes com possibilidade de acesso ao laboratório remoto, para além de, em alguns casos, se ter verificado não ser transparente a sua instalação e utilização. Neste contexto, o trabalho de investigação consistiu no desenvolvimento de uma solução que permite a geração de interfaces que possibilitam o controlo remoto do sistema implementado, e que, ao mesmo tempo, são independentes da plataforma usada pelo cliente.

BIT: Biosignal Igniter Toolkit

The study of biosignals has had a transforming role in multiple aspects of our society, which go well beyond the health sciences domains to which they were traditionally associated with. While biomedical engineering is a classical discipline where the topic is amply covered, today biosignals are a matter of interest for students, researchers and hobbyists in areas including computer science, informatics, electrical engineering, among others. Regardless of the context, the use of biosignals in experimental activities and practical projects is heavily bounded by the cost, and limited access to adequate support materials. In this paper we present an accessible, albeit versatile toolkit, composed of low-cost hardware and software, which was created to reinforce the engagement of different people in the field of biosignals. The hardware consists of a modular wireless biosignal acquisition system that can be used to support classroom activities, interface with other devices, or perform rapid prototyping of end-user applications. The software comprehends a set of programming APIs, a biosignal processing toolbox, and a framework for real time data acquisition and postprocessing. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

Instrumentação e monitorização de estruturas geotécnicas na Rede Ferroviária Nacional: estudo de caso do talude de aterro entre os Km's 236+450 e 236+720 da Linha do Sul

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Vias de Comunicação e Transportes

Permanent vascular access in patients with end-stage renal disease, Brazil

OBJECTIVE: To assess factors associated with the establishment of permanent vascular access for patients with end-stage renal disease. METHODS: Cross-sectional study conducted in a nationally representative sample of Brazilian end-stage renal disease patients in dialysis and transplant centers during 2007. The sample comprised only patients who received hemodialysis as a primary therapy modality and reported the type of vascular access for their primary hemodialysis treatment (N=2,276). Data were from the TRS Project - "Economic and Epidemiologic Evaluation of Modalities of Renal Replacement Therapy in Brazil". Multiple logistic regression analysis was used to assess factors associated with the establishment of permanent vascular access in these patients. RESULTS: About 30% of the patients studied had an arteriovenous vascular access. The following factors were associated with a lower likelihood of having an arteriovenous vascular access as a primary type of access: time of hemodialysis start since the diagnosis of chronic renal failure < 1 year; shorter dialysis therapy; having no private health insurance; living in the central-western, northeastern and southeastern regions of Brazil; and living in the northern region plus having no private health insurance. In the final model there was found a positive association between the outcome and pre-dialysis care and no were association with socioeconomic and comorbidity variables. CONCLUSIONS: The study results showed that the focus should on pre-dialysis care to increase the establishment of an arteriovenous vascular access before starting hemodialysis in Brazil.

Instrumentação e monitorização na avaliação do comportamento de maciços e estruturas envolventes: caso de poços em meio urbano

Atualmente, a escavação de poços em locais densamente ocupados requer medidas severas para reduzir riscos e possíveis influências quer na própria obra quer em estruturas próximas. Neste campo, a instrumentação geotécnica e a sua monitorização tem um papel determinante na execução de obras geotécnicas, sendo que neste trabalho é dado um especial realce à instrumentação utilizada, às atividades de observação geotécnica, bem como à análise e interpretação das leituras para o controlo de movimentos induzidos no terreno pelas escavações. Este acompanhamento é baseado num plano de instrumentação, sendo descrito de uma forma transversal a importância do projeto e em particular das fases do processo de investigação geotécnica. O acompanhamento da execução dos poços para a futura Estação da Reboleira, permitiu validar as soluções de projeto para um determinado método construtivo, determinadas através de métodos numéricos e semi-empíricos, e abordados neste trabalho. A monitorização sistemática desde o início das escavações até ao revestimento secundário, permitiu tecer apreciações sobre os valores obtidos, apresentando-se alguns registos. Todas estas ações visam controlar e antecipar riscos de acidentes provocados pela execução de escavações, pelo que nesta tese é também realçada a importância da segurança e higiene no trabalho na prevenção dos riscos profissionais, independentemente da sua origem.

BITalino: a novel hardware framework for physiological computing

Physical computing has spun a true global revolution in the way in which the digital interfaces with the real world. From bicycle jackets with turn signal lights to twitter-controlled christmas trees, the Do-it-Yourself (DiY) hardware movement has been driving endless innovations and stimulating an age of creative engineering. This ongoing (r)evolution has been led by popular electronics platforms such as the Arduino, the Lilypad, or the Raspberry Pi, however, these are not designed taking into account the specific requirements of biosignal acquisition. To date, the physiological computing community has been severely lacking a parallel to that found in the DiY electronics realm, especially in what concerns suitable hardware frameworks. In this paper, we build on previous work developed within our group, focusing on an all-in-one, low-cost, and modular biosignal acquisition hardware platform, that makes it quicker and easier to build biomedical devices. We describe the main design considerations, experimental evaluation and circuit characterization results, together with the results from a usability study performed with volunteers from multiple target user groups, namely health sciences and electrical, biomedical, and computer engineering. Copyright © 2014 SCITEPRESS - Science and Technology Publications. All rights reserved.

Virtual laboratory for educational environments

In this paper a new simulation environment for a virtual laboratory to educational proposes is presented. The Logisim platform was adopted as the base digital simulation tool, since it has a modular implementation in Java. All the hardware devices used in the laboratory course was designed as components accessible by the simulation tool, and integrated as a library. Moreover, this new library allows the user to access an external interface. This work was motivated by the needed to achieve better learning times on co-design projects, based on hardware and software implementations, and to reduce the laboratory time, decreasing the operational costs of engineer teaching. Furthermore, the use of virtual laboratories in educational environments allows the students to perform functional tests, before they went to a real laboratory. Moreover, these functional tests allow to speed-up the learning when a problem based approach methodology is considered. © 2014 IEEE.

A sensor classification strategy for robotic manipulators

In practice the robotic manipulators present some degree of unwanted vibrations. The advent of lightweight arm manipulators, mainly in the aerospace industry, where weight is an important issue, leads to the problem of intense vibrations. On the other hand, robots interacting with the environment often generate impacts that propagate through the mechanical structure and produce also vibrations. In order to analyze these phenomena a robot signal acquisition system was developed. The manipulator motion produces vibrations, either from the structural modes or from endeffector impacts. The instrumentation system acquires signals from several sensors that capture the joint positions, mass accelerations, forces and moments, and electrical currents in the motors. Afterwards, an analysis package, running off-line, reads the data recorded by the acquisition system and extracts the signal characteristics. Due to the multiplicity of sensors, the data obtained can be redundant because the same type of information may be seen by two or more sensors. Because of the price of the sensors, this aspect can be considered in order to reduce the cost of the system. On the other hand, the placement of the sensors is an important issue in order to obtain the suitable signals of the vibration phenomenon. Moreover, the study of these issues can help in the design optimization of the acquisition system. In this line of thought a sensor classification scheme is presented. Several authors have addressed the subject of the sensor classification scheme. White (White, 1987) presents a flexible and comprehensive categorizing scheme that is useful for describing and comparing sensors. The author organizes the sensors according to several aspects: measurands, technological aspects, detection means, conversion phenomena, sensor materials and fields of application. Michahelles and Schiele (Michahelles & Schiele, 2003) systematize the use of sensor technology. They identified several dimensions of sensing that represent the sensing goals for physical interaction. A conceptual framework is introduced that allows categorizing existing sensors and evaluates their utility in various applications. This framework not only guides application designers for choosing meaningful sensor subsets, but also can inspire new systems and leads to the evaluation of existing applications. Today’s technology offers a wide variety of sensors. In order to use all the data from the diversity of sensors a framework of integration is needed. Sensor fusion, fuzzy logic, and neural networks are often mentioned when dealing with problem of combing information from several sensors to get a more general picture of a given situation. The study of data fusion has been receiving considerable attention (Esteban et al., 2005; Luo & Kay, 1990). A survey of the state of the art in sensor fusion for robotics can be found in (Hackett & Shah, 1990). Henderson and Shilcrat (Henderson & Shilcrat, 1984) introduced the concept of logic sensor that defines an abstract specification of the sensors to integrate in a multisensor system. The recent developments of micro electro mechanical sensors (MEMS) with unwired communication capabilities allow a sensor network with interesting capacity. This technology was applied in several applications (Arampatzis & Manesis, 2005), including robotics. Cheekiralla and Engels (Cheekiralla & Engels, 2005) propose a classification of the unwired sensor networks according to its functionalities and properties. This paper presents a development of a sensor classification scheme based on the frequency spectrum of the signals and on a statistical metrics. Bearing these ideas in mind, this paper is organized as follows. Section 2 describes briefly the robotic system enhanced with the instrumentation setup. Section 3 presents the experimental results. Finally, section 4 draws the main conclusions and points out future work.

Unbalance and field balacing virtual labs

One of the most common problems of rotating machinery is the rotor unbalance. The effects of rotor unbalance can vary from the malfunction of certain equipment to diseases related to the exposure to high vibration levels. However, the balancing procedure is known, it is mandatory to have qualified technicians to perform it. In this sense, the use of virtual balancing experiments is of great interest. The present demo is dedicated to present two different balancing simulators, which can be explored in conjunction, as they have complementary outputs. © 2014 IEEE.

Reshaping higher education systems in the MENA region: the contribution of remote and virtual labs

Learning is not only happening in school or university; it is also an important aspect of the daily life that allows students to remain in their biological and physical environment helping to reshape it, by applying what they have learnt. Today, the higher education sector is a part of important strategies used by countries in order to foster their development. Despite its geographical location, i.e. its closeness to Europe and Asia, the MENA (Middle East and North Africa) region still needs an integrated strategy for the advancement, reform, and update of its higher educational landscape. Although some solutions have been experimented in the region in the field of higher education, they have not been able to raise the quality of education to the level comparable that observed in developed countries. In other words, many MENA higher education systems are facing problems, for which solution ought to be sought. We analyse the situation of higher education systems in the MENA countries and the factors that affect the delay in achieving the level of education existing in other world regions, e.g. Europe, especially in the higher education sector. During the discussion, the impact of new technology-enhanced tools, such as remote laboratories, in the process of development and consolidation of MENA universities, is particularly stressed.

Design state exploration applied to the development of a remote lab for projectile launch experiments

This paper describes the application of Design State Exploration techniques in the development of a remote lab for projectile motion experiments. The application was enabled by the existence of two independent teams: one composed of a series of internships that started first and another with two grantees that started a few months later. The paper presents evidence on how this approach provided gains in the development process conducted by the second team that benefited from design state exploration studies performed by the first team. This particular aspect is highlighted in relation to the work already presented in the 10th Remote Engineering and Virtual Instrumentation (REV) conference.

Educational application of remote experimentation for mobile devices

In this article the authors describe the application development RExMobile and the importance of remote experimentation via mobile devices, especially smartphones simple, beyond the space provided for this application in education. The article deals the creation, software and hardware that provide an interactive and dynamic way to attract more students to use these experiments remote, serving as support to teachers to science teaching from its initial series. The ease and availability of smartphones, even these students of basic education, permits the reach of new users and in different places. Thus, the practice of remote experimentation in mobile devices enables new spaces for access and interaction. Are used for developing software free or low cost, HTML5 and jQuery Mobile framework, that enable the creation of pages compatible with different mobile operating systems such as iOS, Android, Windows Phone, some Symbian, among others. Also are demonstrated patterns layouts that allow greater accessibility.

Using remote labs to serve different teacher's needs a case study with VISIR and RemotElectLab

Remote Laboratories are an emergent technological and pedagogical tool at all education levels, and their widespread use is an important part of their own improvement and evolution. This paper describes several issues encountered on laboratorial classes, on higher education courses, when using remote laboratories based on PXI systems, either using the VISIR system or an alternate in-house solution. Three main issues are presented and explained, all reported by teachers that gave support to students use of remote laboratories. The first issue deals with the need to allow students to select the actual place where an ammeter is to be inserted on electric circuits, even incorrectly, therefore emulating real world difficulties. The second one deals with problems with timing when several measurements are required at short intervals, as in the discharge cycle of a capacitor. And the last issue deals with the use of a multimeter in DC mode when reading AC values, a use that collides with the lab settings. All scenarios are presented and discussed including the solution found for each case. The conclusion derived from the described work is that the remote laboratories area is an expanding field, where practical use leads to improvement and evolution of the available solutions, requiring a strict cooperation and information sharing between all actors, i.e. developers, teachers and students.