Novel Approaches to Pervasive and Remote Sensing in Cardiovascular Disease Assessment

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, responsible for 45% of all deaths. Nevertheless, their mortality is decreasing in the last decade due to better prevention, diagnosis, and treatment resources. An important medical instrument for the latter processes is the Electrocardiogram (ECG). The ECG is a versatile technique used worldwide for its ease of use, low cost, and accessibility, having evolved from devices that filled up a room, to small patches or wrist- worn devices. Such evolution allowed for more pervasive and near-continuous recordings. The analysis of an ECG allows for studying the functioning of other physiological systems of the body. One such is the Autonomic Nervous System (ANS), responsible for controlling key bodily functions. The ANS can be studied by analyzing the characteristic inter-beat variations, known as Heart Rate Variability (HRV). Leveraging this relation, a pilot study was developed, where HRV was used to quantify the contribution of the ANS in modulating cardioprotection offered by an experimental medical procedure called Remote Ischemic Conditioning (RIC), offering a more objective perspective. To record an ECG, electrodes are responsible for converting the ion-propagated action potential to electrons, needed to record it. They are produced from different materials, including metal, carbon-based, or polymers. Also, they can be divided into wet (if an elec- trolyte gel is used) or dry (if no added electrolyte is used). Electrodes can be positioned either inside the body (in-the-person), attached to the skin (on-the-body), or embedded in daily life objects (off-the-person), with the latter allowing for more pervasive recordings. To this effect, a novel mobile acquisition device for recording ECG rhythm strips was developed, where polymer-based embedded electrodes are used to record ECG signals similar to a medical-grade device. One drawback of off-the-person solutions is the increased noise, mainly caused by the intermittent contact with the recording surfaces. A new signal quality metric was developed based on delayed phase mapping, a technique that maps time series to a two-dimensional space, which is then used to classify a segment into good or noisy. Two different approaches were developed, one using a popular image descriptor, the Hu image moments; and the other using a Convolutional Neural Network, both with promising results for their usage as signal quality index classifiers.As doenças cardiovasculares (DCVs) são a principal causa de morte no mundo, res- ponsáveis por 45% de todas estas. No entanto, a sua mortalidade tem vindo a diminuir na última década, devido a melhores recursos na prevenção, diagnóstico e tratamento. Um instrumento médico importante para estes recursos é o Eletrocardiograma (ECG). O ECG é uma técnica versátil utilizada em todo o mundo pela sua facilidade de uso, baixo custo e acessibilidade, tendo evoluído de dispositivos que ocupavam uma sala inteira para pequenos adesivos ou dispositivos de pulso. Tal evolução permitiu aquisições mais pervasivas e quase contínuas. A análise de um ECG permite estudar o funcionamento de outros sistemas fisiológi- cos do corpo. Um deles é o Sistema Nervoso Autônomo (SNA), responsável por controlar as principais funções corporais. O SNA pode ser estudado analisando as variações inter- batidas, conhecidas como Variabilidade da Frequência Cardíaca (VFC). Aproveitando essa relação, foi desenvolvido um estudo piloto, onde a VFC foi utilizada para quantificar a contribuição do SNA na modulação da cardioproteção oferecida por um procedimento mé- dico experimental, denominado Condicionamento Isquêmico Remoto (CIR), oferecendo uma perspectiva mais objetiva. Na aquisição de um ECG, os elétrodos são os responsáveis por converter o potencial de ação propagado por iões em eletrões, necessários para a sua recolha. Estes podem ser produzidos a partir de diferentes materiais, incluindo metal, à base de carbono ou polímeros. Além disso, os elétrodos podem ser classificados em húmidos (se for usado um gel eletrolítico) ou secos (se não for usado um eletrólito adicional). Os elétrodos podem ser posicionados dentro do corpo (dentro-da-pessoa), colocados em contacto com a pele (na-pessoa) ou embutidos em objetos da vida quotidiana (fora-da-pessoa), sendo que este último permite gravações mais pervasivas . Para este efeito, foi desenvolvido um novo dispositivo de aquisição móvel para gravar sinal de ECG, onde elétrodos embutidos à base de polímeros são usados para recolher sinais de ECG semelhantes a um dispositivo de grau médico. Uma desvantagem das soluções onde os elétrodos estão embutidos é o aumento do ruído, causado principalmente pelo contato intermitente com as superfícies de aquisição. Uma nova métrica de qualidade de sinal foi desenvolvida com base no mapeamento de fase atrasada, uma técnica que mapeia séries temporais para um espaço bidimensional, que é então usado para classificar um segmento em bom ou ruidoso. Duas abordagens diferentes foram desenvolvidas, uma usando um popular descritor de imagem, e outra utilizando uma Rede Neural Convolucional, com resultados promissores para o seu uso como classificadores de qualidade de sinal

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 3rd International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2003, held 10-12 December 2003, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

On Solving Selected Nonlinear Integer Programming Problems in Data Mining, Computational Biology, and Sustainability

This thesis consists of three essays concerning the use of optimization techniques to solve four problems in the fields of data mining, computational biology, and sustainable energy devices. To the best of our knowledge, the particular problems we discuss have not been previously addressed using optimization, which is a specific contribution of this dissertation. In particular, we analyze each of the problems to capture their underlying essence, subsequently demonstrating that each problem can be modeled as a nonlinear (mixed) integer program. We then discuss the design and implementation of solution techniques to locate optimal solutions to the aforementioned problems. Running throughout this dissertation is the theme of using mixed-integer programming techniques in conjunction with context-dependent algorithms to identify optimal and previously undiscovered underlying structure

Recent Advances in Social Data and Artificial Intelligence 2019

The importance and usefulness of subjects and topics involving social data and artificial intelligence are becoming widely recognized. This book contains invited review, expository, and original research articles dealing with, and presenting state-of-the-art accounts pf, the recent advances in the subjects of social data and artificial intelligence, and potentially their links to Cyberspace

Exploiting Spatio-Temporal Coherence for Video Object Detection in Robotics

This paper proposes a method to enhance video object detection for indoor environments in robotics. Concretely, it exploits knowledge about the camera motion between frames to propagate previously detected objects to successive frames. The proposal is rooted in the concepts of planar homography to propose regions of interest where to find objects, and recursive Bayesian filtering to integrate observations over time. The proposal is evaluated on six virtual, indoor environments, accounting for the detection of nine object classes over a total of ∼ 7k frames. Results show that our proposal improves the recall and the F1-score by a factor of 1.41 and 1.27, respectively, as well as it achieves a significant reduction of the object categorization entropy (58.8%) when compared to a two-stage video object detection method used as baseline, at the cost of small time overheads (120 ms) and precision loss (0.92).</p

An investigation of the accessible information process for adults with learning disabilities

Background: The importance of accessible information within modern learning disability services and the wider society cannot be underestimated. This research aimed to explore both the production and implementation of accessible information for adults with learning disabilities. A novel approach to the accessible information ‘process’ was adopted; resulting in a movement away from specific resource focused research to a process focused approach. The research was conducted in three stages: a comprehensive review of the literature; a qualitative scoping exercise which investigated the firsthand experience of producing and implementing accessible information; and a qualitative investigation of the dynamic behaviours involved in the implementation of health related accessible information at a clinical level. Methodology: The purpose of the first stage was to comprehensively review and critically appraise the literature relating to accessible information, learning disabilities and symbolic development. This was achieved through a detailed search of electronic databases and hand-searches of the grey literature. For the scoping exercise, eighteen participants were recruited from four distinct sampling groups: adults with learning disabilities; staff from a specialist learning disability service; mainstream NHS and local authority staff; and speech and language therapists. Each participant took part in either a semi- structured focus group or interview. Eight participants (four community learning disability nurses and four of their learning disabled clients) took part in a non- participatory observational study. Conversational analysis was used to explore the sequence of both the vocal and non-vocal behaviours. Findings: The literature review revealed that there was a dearth of high quality primary research that has investigated accessible information within the field of learning disabilities. Of the seven relevant primary research studies, two quantitative studies measured the effectiveness of specific accessible resources through pre and post comprehension scores. Three mixed method studies, which were generally poorly reported, described a qualitative process of developing and/or appraising a specific accessible resource or guidelines as well as a quantitative element to investigate its effectiveness. Two qualitative studies attempted to answer broader questions relating to the human dimensions and experiences of accessible information. One explored the use of accessible information with a wider population and the other explored issues relating to the implementation of a specific accessible resource. These findings highlighted the largely resource-focused research and failed to report on accessible information as a process which involves the implementation of such resources. A Framework approach to thematic analysis was used to analyse the data collected from the scoping exercise which led to three main classifications: the ideology of accessible information, accessible information practice and the outcomes of accessible information. Firsthand experience varied across the stakeholders, highlighting differences in the operationalisation of national policies and legislation. The notion of accessible information being relevant to more than just people with learning disabilities was introduced. The data supported the approach of accessible information as a process, although the practice of implementing accessible resources appeared less advanced. Three main clusters of episodes were identified through the conversational analysis of the non-participatory observations. Cluster one related to providing the accessible health information; cluster two to topic development; and cluster three to consent. The findings revealed numerous intricacies in the vocal and non-vocal exchange. The use of an accessible resource appeared to promote joint attention; communicative style appeared influenced by the primary and secondary reported outcomes of the resource; practical considerations of the topic development were evident; and contradictory goals in the decision making process were highlighted. The notion of the implementation of accessible information as a dynamic process was confirmed. Conclusions: The combination of the chosen methodology and subsequent findings generated a novel approach to accessible information within the field of learning disability. In conceptualising accessible information as a process, with a particular focus on the implementation phase, the findings illustrated that it was the implementation phase that allowed for personalisation in providing and developing the information, which was dependent on the intersubjectivity of the communication partner and the person with learning disabilities. This in turn supported the accessibility of the information. These findings would not have been apparent without the movement away from specific resource focused research to a process focused approach.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

An investigation of the accessible information process for adults with learning disabilities

Background: The importance of accessible information within modern learning disability services and the wider society cannot be underestimated. This research aimed to explore both the production and implementation of accessible information for adults with learning disabilities. A novel approach to the accessible information ‘process’ was adopted; resulting in a movement away from specific resource focused research to a process focused approach. The research was conducted in three stages: a comprehensive review of the literature; a qualitative scoping exercise which investigated the firsthand experience of producing and implementing accessible information; and a qualitative investigation of the dynamic behaviours involved in the implementation of health related accessible information at a clinical level. Methodology: The purpose of the first stage was to comprehensively review and critically appraise the literature relating to accessible information, learning disabilities and symbolic development. This was achieved through a detailed search of electronic databases and hand-searches of the grey literature. For the scoping exercise, eighteen participants were recruited from four distinct sampling groups: adults with learning disabilities; staff from a specialist learning disability service; mainstream NHS and local authority staff; and speech and language therapists. Each participant took part in either a semi- structured focus group or interview. Eight participants (four community learning disability nurses and four of their learning disabled clients) took part in a non- participatory observational study. Conversational analysis was used to explore the sequence of both the vocal and non-vocal behaviours. Findings: The literature review revealed that there was a dearth of high quality primary research that has investigated accessible information within the field of learning disabilities. Of the seven relevant primary research studies, two quantitative studies measured the effectiveness of specific accessible resources through pre and post comprehension scores. Three mixed method studies, which were generally poorly reported, described a qualitative process of developing and/or appraising a specific accessible resource or guidelines as well as a quantitative element to investigate its effectiveness. Two qualitative studies attempted to answer broader questions relating to the human dimensions and experiences of accessible information. One explored the use of accessible information with a wider population and the other explored issues relating to the implementation of a specific accessible resource. These findings highlighted the largely resource-focused research and failed to report on accessible information as a process which involves the implementation of such resources. A Framework approach to thematic analysis was used to analyse the data collected from the scoping exercise which led to three main classifications: the ideology of accessible information, accessible information practice and the outcomes of accessible information. Firsthand experience varied across the stakeholders, highlighting differences in the operationalisation of national policies and legislation. The notion of accessible information being relevant to more than just people with learning disabilities was introduced. The data supported the approach of accessible information as a process, although the practice of implementing accessible resources appeared less advanced. Three main clusters of episodes were identified through the conversational analysis of the non-participatory observations. Cluster one related to providing the accessible health information; cluster two to topic development; and cluster three to consent. The findings revealed numerous intricacies in the vocal and non-vocal exchange. The use of an accessible resource appeared to promote joint attention; communicative style appeared influenced by the primary and secondary reported outcomes of the resource; practical considerations of the topic development were evident; and contradictory goals in the decision making process were highlighted. The notion of the implementation of accessible information as a dynamic process was confirmed. Conclusions: The combination of the chosen methodology and subsequent findings generated a novel approach to accessible information within the field of learning disability. In conceptualising accessible information as a process, with a particular focus on the implementation phase, the findings illustrated that it was the implementation phase that allowed for personalisation in providing and developing the information, which was dependent on the intersubjectivity of the communication partner and the person with learning disabilities. This in turn supported the accessibility of the information. These findings would not have been apparent without the movement away from specific resource focused research to a process focused approach.EThOS - Electronic Theses Online ServiceGBUnited Kingdo