Embedded platform for ECG biometric recognition

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Electrónica e Telecomunicações

Development of a penetration test for timber impregnation products for use in old buildings

This paper studies the application of commercial biocides to old maritime pine timber structures (Pinus pinaster Ait.) that have previously been impregnated with other products. A method was developed in the laboratory to be used in situ to determine the impregnation depth achieved by a new generation biocide product applied to timber from an old building. This timber had once been treated with an unknown product difficult to characterize without extensive analysis. The test was initially developed in laboratory conditions and later tested on elements of the roof structure of an 18th century building. In both cases the results were promising and mutually consistent with penetration depths for some treatments reaching 2.0 cm. The application in situ proved the tests viability and simplicity of execution giving a clear indication on the feasibility of possible re-treatments.

Paleomagnetic study of the Great Foum Zguid dyke (southern Morocco): A positive contact test related to metasomatic processes

When a paleomagnetic pole is sought for in an igneous body, the host rocks should be subjected to a contact test to assure that the determined paleopole has the age of the intrusion. If the contact test is positive, it precludes the possibility that the measured magnetization is a later effect. Therefore, we investigated the variations of the remanent magnetization along cross-sections of rocks hosting the Foum Zguid dyke (southern Morocco) and the dyke itself. A positive contact test was obtained, but it is mainly related with Chemical/Crystalline Remanent Magnetization due to metasomatic processes in the host-rocks during magma intrusion and cooling, and not only with Thermo-Remanent Magnetization as ordinarily assumed in standard studies. Paleomagnetic data obtained within the dyke then reflect the Earth magnetic field during emplacement of this well-dated (196.9 +/- 1.8 Ma) intrusion.

Development of an in situ penetration test for the uptake of preservatives in applied wood

This paper concerns the study of biocides application in old timber structures of maritime pine (Pinus pinaster Ail.), previously impregnated with other products. A method was developed in laboratory to determine in situ the penetration depth of a product applied superficially. As initial treatment, three traditional products for sawn timber for buildings were used and, for new treatments, two newer, more environmentally benign products were used. Their ability to penetrate the pre-treated surfaces was evaluated after 1, 2 and 3 applications at 24 hours intervals and the results obtained are presented. Finally, the applicability of the developed test to the in-situ evaluation of timber structures is also discussed.

Dispositional optimism is unidimensional or bidimensional? The Portuguese Revised Life Orientation Test

The aim of the study is to adapt and then discuss the appropriateness of the Life Orientation Test as a one or two dimension scale. The research includes two studies; one is composed of a sequential sample of 280 people with multiple sclerosis, 71% female, and another includes a convenience sample of 615 individuals from the community, 51.1% female. Because the construct is built upon a theoretical assumption that has one dimension, we examine the hypothesis of one or two factor solutions through confirmatory factor analysis, and the two-dimension solution premise demonstrates better adjustment for both samples. The other psychometric properties explored show appropriate results for the Portuguese sample, and similar to the original ones; the Test therefore seems appropriate for use in cross cultural studies. Based on our results, we discuss whether the questionnaire is a one or two dimension instrument, concluding that it appears appropriate to accept the recommendations of the original authors to use it as a one-dimensional tool and, when necessary, to use both dimensions. - RESUMO: El objetivo del estudio es adaptar y discutir la adecuación de la prueba de Orientación de la Vida en una o dos escalas de dimensión. La investigación engloba dos estudios, uno constituido por una muestra secuencial de 280 personas con esclerosis múltiple, 71% mujeres y otro con una muestra de conveniencia de la comunidad de 615 individuos, 51,1% del sexo femenino. Como el constructo se asienta sobre la presunción teórica de que tiene una dimensión, inspeccionamos la hipótesis de una o dos soluciones de factor a través del análisis factorial confirmatorio y la hipótesis de dos dimensiones manifiesta un mejor ajuste para ambas muestras. Las otras propiedades psicométricas exploradas muestran los resultados apropiados para la muestra portuguesa, y semejantes a los originales. Parece apropiado para los estudios culturales transversales. Basándonos en nuestros resultados, discutimos si el cuestionario es un instrumento de una o dos dimensiones, concluyéndose que parece conveniente seguir las recomendaciones de los autores originales, para utilizarlo como un instrumento unidimensional y, si fuera necesario necesario, utilizar cada una de las dimensiones.

Design of a new test chamber for evaluation of the toxicity of rubber infill

A test chamber was projected and built (according to ISO 16000-9 Standard) to simulate atmospheric conditions experienced by rubber infill (when applied in synthetic turf pitches) and measure accurately the airborne emissions of pollutants such as dusts and volatile organic compounds (VOC), as well as pollutants present in leachates. It should be pointed out that standard ISO 16000-9 is only concerned with the determination of the emission of VOC from building products and furnishing (not specific of synthetic turf materials), whereas other standards are concerned with the emission of leachates only. This procedure is to be considered as a technical option to the lysimeter "global turf system evaluation" when the rubber infill alone is to be evaluated. The advantage of the proposed option considering this "test chamber" is its simplicity and economy. This test chamber is actually installed and being used for tests in LAIST.

Predicted VO2 on 6 minutes walk test for FAP liver transplanted patients

Physical function is limited post-liver transplantation and exercise training can improve exercise capacity following transplantation but previously assessment of functional capacity is necessary. The 6 minute walk test (6MWT) is routinely used for studying patient’s exercise capacity and is less expensive and time consuming than a Cardiopulmonary Exercise Test (CPXT). There have been some studies looking at the relationship between 6MWT and peak VO2 in patients but few presented an adequate equation for predicted peak VO2 from 6MWT to transplanted patients and none for Familial Amyloidotic Polyneuropathy (FAP) liver transplanted patients (FAPTx). The aim of this study was to compare the validity of 6 equations as predictors of VO2 from the 6MWT and compare it with directly measured VO2 in patients FAPTx.

Reconfigurable SiC Embedded Photonic Structures with Self Optical Bias Control

Multilayered heterostructures based on embedded a-Si:H and a-SiC:H p-i-n filters are analyzed from differential voltage design perspective using short- and long-pass filters. The transfer functions characteristics are presented. A numerical simulation is presented to explain the filtering properties of the photonic devices. Several monochromatic pulsed lights, separately (input channels) or in a polychromatic mixture (multiplexed signal) at different bit rates, illuminated the device. Steady-state optical bias is superimposed from the front and the back side. Results show that depending on the wavelength of the external background and impinging side, the device acts either as a short- or a long-pass band filter or as a band-stop filter. Particular attention is given to the amplification coefficient weights, which allow to take into account the wavelength background effects when a band or frequency needs to be filtered or the gate switch, in which optical active filter gates are used to select and filter input signals to specific output ports in wavelength division multiplexing (WDM) communication systems. This nonlinearity provides the possibility for selective removal or addition of wavelengths. A truth table of an encoder that performs 8-to-1 MUX function exemplifies the optoelectronic conversion.

Scalable Unified Transform Architecture for Advanced Video Coding Embedded Systems

A novel high throughput and scalable unified architecture for the computation of the transform operations in video codecs for advanced standards is presented in this paper. This structure can be used as a hardware accelerator in modern embedded systems to efficiently compute all the two-dimensional 4 x 4 and 2 x 2 transforms of the H.264/AVC standard. Moreover, its highly flexible design and hardware efficiency allows it to be easily scaled in terms of performance and hardware cost to meet the specific requirements of any given video coding application. Experimental results obtained using a Xilinx Virtex-5 FPGA demonstrated the superior performance and hardware efficiency levels provided by the proposed structure, which presents a throughput per unit of area relatively higher than other similar recently published designs targeting the H.264/AVC standard. Such results also showed that, when integrated in a multi-core embedded system, this architecture provides speedup factors of about 120x concerning pure software implementations of the transform algorithms, therefore allowing the computation, in real-time, of all the above mentioned transforms for Ultra High Definition Video (UHDV) sequences (4,320 x 7,680 @ 30 fps).

An application of structural equation modeling of test dispositional optimism as mediator or moderator in quality of life in patients with chronic disease

The aim of the present study was to test a hypothetical model to examine if dispositional optimism exerts a moderating or a mediating effect between personality traits and quality of life, in Portuguese patients with chronic diseases. A sample of 540 patients was recruited from central hospitals in various districts of Portugal. All patients completed self-reported questionnaires assessing socio-demographic and clinical variables, personality, dispositional optimism, and quality of life. Structural equation modeling (SEM) was used to analyze the moderating and mediating effects. Results suggest that dispositional optimism exerts a mediator rather than a moderator role between personality traits and quality of life, suggesting that “the expectation that good things will happen” contributes to a better general well-being and better mental functioning.

Imunohistoquímica no diagnóstico da glomerulonefrite membranosa: estudo comparativo de binómios cromogênio + coloração de contraste

A glomerulonefrite membranosa faz parte das doenças glomerulares que provocam glomerulonefrite crônica, apresentando-se como uma das causas da doença renal terminal. As técnicas de imunofluorescência são o gold standard no estudo imunológico desta patologia em biópsia renal, através da deteção de imunocomplexos (e.g. IgG e C3) e do seu padrão de distribuição granular característico. No entanto, a imunofluorescência não permite uma contextualização histológica e os fluorocromos utilizados possuem um reduzido tempo de atividade, ao contrário das técnicas imunoenzimáticas que utilizam cromogénios coloridos precipitados que permitem a obtenção de uma marcação permanente e a sua contextualização histológica por via da utilização de eficientes colorações de contraste. Com a finalidade de contribuir para a qualidade do diagnóstico da glomerulonefrite membranosa, em biópsias renais, procurou-se, com esta pesquisa, identificar uma técnica imunoenzimática, através da conjugação entre diferentes cromogênios e colorações de contraste, que permita a deteção de depósitos de IgG e C3, com padrão granular. Foram constituídos diferentes binômios cromogênio + coloração, com os cromogênios 3,3›- Diaminobenzidine Tetrahydrochloride e 3-Amino-9-ethylcarbazole e as colorações Periodic Acid Schiff, Periodic Acid Methenamine Silver e Hematoxilina. Foram utilizadas 72 secções de tecido provenientes de seis de casos de biópsias renais com diagnóstico de glomerulonefrite membranosa, fixados em formalina a 10% e incluídos em parafina. A recolha de dados foi realizada por observação microscópica com preenchimento de uma grelha de classificação dos parâmetros: preservação da morfologia, intensidade da marcação específica, quantidade relativa de estruturas marcadas, marcação inespecífica/fundo, contraste e padrão da marcação, que permitiu a classificação dos binómios estudados num score quantitativo de 0-100 pontos. O binômio que apresentou melhores resultados foi 3-Amino-9-ethylcarbazole + Hematoxilina (score 71,81) e o binômio 3,3›- Diaminobenzidine Tetrahydrochloride+Periodic Acid Methenamine Silver (score 7,81), apresentou os piores resultados. O resultado do teste Kruskal-Wallis indica-nos a presença de diferenças estatísticas entre os binómios em estudo (p=0,000). A Hematoxilina pode ser considerada a coloração mais eficaz, pois cumpriu a sua função de auxiliar e facilitar a observação do tipo de padrão com os dois cromogênios utilizados. O cromogênio 3-Amino-9-ethylcarbazole apresentou resultados semelhantes aos produzidos pelo 3,3›-Diaminobenzidine Tetrahydrochloride, no entanto, permitiu identificar em todos os casos o padrão granular de imunomarcação, ao contrário do que aconteceu com este último.

A biosignal embedded system for physiological computing

Thesis submitted in the fulfilment of the requirements for the Degree of Master in Electronic and Telecomunications Engineering

Development of TNBS-induced colitis: animal model to test new pharmacological approaches

IBD is a gastro-intestinal disorder marked with chronic inflammation of intestinal epithelium, damaging mucosal tissue and manifests into several intestinal and extra-intestinal symptoms. Currently used medical therapy is able to induce and maintain the patient in remission, however no modifies or reverses the underlying pathogenic mechanism. The research of other medical approaches is crucial to the treatment of IBD and, for this, it´s important to use animal models to mimic the characteristics of disease in real life. The aim of the study is to develop an animal model of TNBS-induced colitis to test new pharmacological approaches. TNBS was instilled intracolonic single dose as described by Morris et al. It was administered 2,5% TNBS in 50% ethanol through a catheter carefully inserted into the colon. Mice were kept in a Tredelenburg position to avoid reflux. On day 4 and 7, the animals were sacrificed by cervical dislocation. The induction was confirmed based on clinical symptoms/signs, ALP determination and histopathological analysis. At day 4, TNBS group presented a decreased body weight and an alteration of intestinal motility characterized by diarrhea, severe edema of the anus and moderate morbidity, while in the two control groups weren’t identified any alteration on the clinical symptoms/signs with an increase of the body weight. TNBS group presented the highest concentrations of ALP comparing with control groups. The histopathology analysis revealed severe necrosis of the mucosa with widespread necrosis of the intestinal glands. Severe hemorrhagic and purulent exsudates were observed in the submucosa, muscular and serosa. TNBS group presented clinical symptoms/signs and histopathological features compatible with a correct induction of UC. The peak of manifestations became maximal at day 4 after induction. This study allows concluding that it’s possible to develop a TNBS induced colitis 4 days after instillation.

Embedded System for ECG Biometrics

Comunication in Internationa Conference with Peer Review First International Congress on Cardiovasular Technologies - CARDIOTECHNIX, Vilamoura, Portugal, 2013

Feature selection for clustering categorical data with an embedded modelling approach

Research on the problem of feature selection for clustering continues to develop. This is a challenging task, mainly due to the absence of class labels to guide the search for relevant features. Categorical feature selection for clustering has rarely been addressed in the literature, with most of the proposed approaches having focused on numerical data. In this work, we propose an approach to simultaneously cluster categorical data and select a subset of relevant features. Our approach is based on a modification of a finite mixture model (of multinomial distributions), where a set of latent variables indicate the relevance of each feature. To estimate the model parameters, we implement a variant of the expectation-maximization algorithm that simultaneously selects the subset of relevant features, using a minimum message length criterion. The proposed approach compares favourably with two baseline methods: a filter based on an entropy measure and a wrapper based on mutual information. The results obtained on synthetic data illustrate the ability of the proposed expectation-maximization method to recover ground truth. An application to real data, referred to official statistics, shows its usefulness.