132 research outputs found

    CAT-CAD: A Computer-Aided Diagnosis Tool for Cataplexy

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    Narcolepsy with cataplexy is a severe lifelong disorder characterized, among others, by sudden loss of bilateral face muscle tone triggered by emotions (cataplexy). A recent approach for the diagnosis of the disease is based on a completely manual analysis of video recordings of patients undergoing emotional stimulation made on-site by medical specialists, looking for specific facial behavior motor phenomena. We present here the CAT-CAD tool for automatic detection of cataplexy symptoms, with the double aim of (1) supporting neurologists in the diagnosis/monitoring of the disease and (2) facilitating the experience of patients, allowing them to conduct video recordings at home. CAT-CAD includes a front-end medical interface (for the playback/inspection of patient recordings and the retrieval of videos relevant to the one currently played) and a back-end AI-based video analyzer (able to automatically detect the presence of disease symptoms in the patient recording). Analysis of patients’ videos for discovering disease symptoms is based on the detection of facial landmarks, and an alternative implementation of the video analyzer, exploiting deep-learning techniques, is introduced. Performance of both approaches is experimentally evaluated using a benchmark of real patients’ recordings, demonstrating the effectiveness of the proposed solutions

    A deep learning palpebral fissure segmentation model in the context of computer user monitoring

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    The intense use of computers and visual terminals is a daily practice for many people. As a consequence, there are frequent complaints of visual and non-visual symptoms, such as headaches and neck pain. These symptoms make up Computer Vision Syndrome and among the factors related to this syndrome are: the distance between the user and the screen, the number of hours of use of the equipment and the reduction in the blink rate, and also the number of incomplete blinks while using the device. Although some of these items can be controlled by ergonomic measures, controlling blinks and their efficiency is more complex. A considerable number of studies have looked at measuring blinks, but few have dealt with the presence of incomplete blinks. Conventional measurement techniques have limitations when it comes to detecting and analyzing the completeness of blinks, especially due to the different eye and blink characteristics of individuals, as well as the position and movement of the user. Segmenting the palpebral fissure can be a first step towards solving this problem, by characterizing individuals well regardless of these factors. This work investigates with the development of Deep Learning models to perform palpebral fissure segmentation in situations where the eyes cover a small region of the images, such as images from a computer webcam. The segmentation of the palpebral fissure can be a first step in solving this problem, characterizing individuals well regardless of these factors. Training, validation and test sets were generated based on the CelebAMask-HQ and Closed Eyes in the Wild datasets. Various machine learning techniques are used, resulting in a final trained model with a Dice Coefficient metric close to 0.90 for the test data, a result similar to that obtained by models trained with images in which the eye region occupies most of the image.A utilização intensa de computadores e terminais visuais é algo cotidiano para muitas pessoas. Como consequência, queixas com sintomas visuais e não visuais, como dores de cabeça e no pescoço, são frequentes. Esses sintomas compõem a Síndrome da visão de computador e entre os fatores relacionados a essa síndrome estão: a distância entre o usuário e a tela, o número de horas de uso do equipamento e a redução da taxa de piscadas, e, também, o número de piscadas incompletas, durante a utilização do dispositivo. Ainda que alguns desses itens possam ser controlados por medidas ergonômicas, o controle das piscadas e a eficiência dessas é mais complexo. Um número considerável de estudos abordou a medição de piscadas, porém, poucos trataram da presença de piscadas incompletas. As técnicas convencionais de medição apresentam limitações para detecção e análise completeza das piscadas, em especial devido as diferentes características de olhos e de piscadas dos indivíduos, e ainda, pela posição e movimentação do usuário. A segmentação da fissura palpebral pode ser um primeiro passo na resolução desse problema, caracterizando bem os indivíduos independentemente desses fatores. Este trabalho aborda o desenvolvimento de modelos de Deep Learning para realizar a segmentação de fissura palpebral em situações em que os olhos cobrem uma região pequena das imagens, como são as imagens de uma webcam de computador. Foram gerados conjuntos de treinamento, validação e teste com base nos conjuntos de dados CelebAMask-HQ e Closed Eyes in the Wild. São utilizadas diversas técnicas de aprendizado de máquina, resultando em um modelo final treinado com uma métrica Coeficiente Dice próxima a 0,90 para os dados de teste, resultado similar ao obtido por modelos treinados com imagens nas quais a região dos olhos ocupa a maior parte da imagem

    Symbiotic deep learning for medical image analysis with applications in real-time diagnosis for fetal ultrasound screening

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    The last hundred years have seen a monumental rise in the power and capability of machines to perform intelligent tasks in the stead of previously human operators. This rise is not expected to slow down any time soon and what this means for society and humanity as a whole remains to be seen. The overwhelming notion is that with the right goals in mind, the growing influence of machines on our every day tasks will enable humanity to give more attention to the truly groundbreaking challenges that we all face together. This will usher in a new age of human machine collaboration in which humans and machines may work side by side to achieve greater heights for all of humanity. Intelligent systems are useful in isolation, but the true benefits of intelligent systems come to the fore in complex systems where the interaction between humans and machines can be made seamless, and it is this goal of symbiosis between human and machine that may democratise complex knowledge, which motivates this thesis. In the recent past, datadriven methods have come to the fore and now represent the state-of-the-art in many different fields. Alongside the shift from rule-based towards data-driven methods we have also seen a shift in how humans interact with these technologies. Human computer interaction is changing in response to data-driven methods and new techniques must be developed to enable the same symbiosis between man and machine for data-driven methods as for previous formula-driven technology. We address five key challenges which need to be overcome for data-driven human-in-the-loop computing to reach maturity. These are (1) the ’Categorisation Challenge’ where we examine existing work and form a taxonomy of the different methods being utilised for data-driven human-in-the-loop computing; (2) the ’Confidence Challenge’, where data-driven methods must communicate interpretable beliefs in how confident their predictions are; (3) the ’Complexity Challenge’ where the aim of reasoned communication becomes increasingly important as the complexity of tasks and methods to solve also increases; (4) the ’Classification Challenge’ in which we look at how complex methods can be separated in order to provide greater reasoning in complex classification tasks; and finally (5) the ’Curation Challenge’ where we challenge the assumptions around bottleneck creation for the development of supervised learning methods.Open Acces

    Intelligent Sensors for Human Motion Analysis

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    The book, "Intelligent Sensors for Human Motion Analysis," contains 17 articles published in the Special Issue of the Sensors journal. These articles deal with many aspects related to the analysis of human movement. New techniques and methods for pose estimation, gait recognition, and fall detection have been proposed and verified. Some of them will trigger further research, and some may become the backbone of commercial systems

    Computational Intelligence in Healthcare

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    This book is a printed edition of the Special Issue Computational Intelligence in Healthcare that was published in Electronic

    Computational Intelligence in Healthcare

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    The number of patient health data has been estimated to have reached 2314 exabytes by 2020. Traditional data analysis techniques are unsuitable to extract useful information from such a vast quantity of data. Thus, intelligent data analysis methods combining human expertise and computational models for accurate and in-depth data analysis are necessary. The technological revolution and medical advances made by combining vast quantities of available data, cloud computing services, and AI-based solutions can provide expert insight and analysis on a mass scale and at a relatively low cost. Computational intelligence (CI) methods, such as fuzzy models, artificial neural networks, evolutionary algorithms, and probabilistic methods, have recently emerged as promising tools for the development and application of intelligent systems in healthcare practice. CI-based systems can learn from data and evolve according to changes in the environments by taking into account the uncertainty characterizing health data, including omics data, clinical data, sensor, and imaging data. The use of CI in healthcare can improve the processing of such data to develop intelligent solutions for prevention, diagnosis, treatment, and follow-up, as well as for the analysis of administrative processes. The present Special Issue on computational intelligence for healthcare is intended to show the potential and the practical impacts of CI techniques in challenging healthcare applications

    A Learning-Style Theory for Understanding Autistic Behaviors

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    Understanding autism's ever-expanding array of behaviors, from sensation to cognition, is a major challenge. We posit that autistic and typically developing brains implement different algorithms that are better suited to learn, represent, and process different tasks; consequently, they develop different interests and behaviors. Computationally, a continuum of algorithms exists, from lookup table (LUT) learning, which aims to store experiences precisely, to interpolation (INT) learning, which focuses on extracting underlying statistical structure (regularities) from experiences. We hypothesize that autistic and typical brains, respectively, are biased toward LUT and INT learning, in low- and high-dimensional feature spaces, possibly because of their narrow and broad tuning functions. The LUT style is good at learning relationships that are local, precise, rigid, and contain little regularity for generalization (e.g., the name–number association in a phonebook). However, it is poor at learning relationships that are context dependent, noisy, flexible, and do contain regularities for generalization (e.g., associations between gaze direction and intention, language and meaning, sensory input and interpretation, motor-control signal and movement, and social situation and proper response). The LUT style poorly compresses information, resulting in inefficiency, sensory overload (overwhelm), restricted interests, and resistance to change. It also leads to poor prediction and anticipation, frequent surprises and over-reaction (hyper-sensitivity), impaired attentional selection and switching, concreteness, strong local focus, weak adaptation, and superior and inferior performances on simple and complex tasks. The spectrum nature of autism can be explained by different degrees of LUT learning among different individuals, and in different systems of the same individual. Our theory suggests that therapy should focus on training autistic LUT algorithm to learn regularities

    Explainable deep learning classifiers for disease detection based on structural brain MRI data

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    In dieser Doktorarbeit wird die Frage untersucht, wie erfolgreich deep learning bei der Diagnostik von neurodegenerativen Erkrankungen unterstützen kann. In 5 experimentellen Studien wird die Anwendung von Convolutional Neural Networks (CNNs) auf Daten der Magnetresonanztomographie (MRT) untersucht. Ein Schwerpunkt wird dabei auf die Erklärbarkeit der eigentlich intransparenten Modelle gelegt. Mit Hilfe von Methoden der erklärbaren künstlichen Intelligenz (KI) werden Heatmaps erstellt, die die Relevanz einzelner Bildbereiche für das Modell darstellen. Die 5 Studien dieser Dissertation zeigen das Potenzial von CNNs zur Krankheitserkennung auf neurologischen MRT, insbesondere bei der Kombination mit Methoden der erklärbaren KI. Mehrere Herausforderungen wurden in den Studien aufgezeigt und Lösungsansätze in den Experimenten evaluiert. Über alle Studien hinweg haben CNNs gute Klassifikationsgenauigkeiten erzielt und konnten durch den Vergleich von Heatmaps zur klinischen Literatur validiert werden. Weiterhin wurde eine neue CNN Architektur entwickelt, spezialisiert auf die räumlichen Eigenschaften von Gehirn MRT Bildern.Deep learning and especially convolutional neural networks (CNNs) have a high potential of being implemented into clinical decision support software for tasks such as diagnosis and prediction of disease courses. This thesis has studied the application of CNNs on structural MRI data for diagnosing neurological diseases. Specifically, multiple sclerosis and Alzheimer’s disease were used as classification targets due to their high prevalence, data availability and apparent biomarkers in structural MRI data. The classification task is challenging since pathology can be highly individual and difficult for human experts to detect and due to small sample sizes, which are caused by the high acquisition cost and sensitivity of medical imaging data. A roadblock in adopting CNNs to clinical practice is their lack of interpretability. Therefore, after optimizing the machine learning models for predictive performance (e.g. balanced accuracy), we have employed explainability methods to study the reliability and validity of the trained models. The deep learning models achieved good predictive performance of over 87% balanced accuracy on all tasks and the explainability heatmaps showed coherence with known clinical biomarkers for both disorders. Explainability methods were compared quantitatively using brain atlases and shortcomings regarding their robustness were revealed. Further investigations showed clear benefits of transfer-learning and image registration on the model performance. Lastly, a new CNN layer type was introduced, which incorporates a prior on the spatial homogeneity of neuro-MRI data. CNNs excel when used on natural images which possess spatial heterogeneity, and even though MRI data and natural images share computational similarities, the composition and orientation of neuro-MRI is very distinct. The introduced patch-individual filter (PIF) layer breaks the assumption of spatial invariance of CNNs and reduces convergence time on different data sets without reducing predictive performance. The presented work highlights many challenges that CNNs for disease diagnosis face on MRI data and defines as well as tests strategies to overcome those
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