15 research outputs found

    Towards Cognition-Guided Patient-Specific Numerical Simulation for Cardiac Surgery Assistance

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    Motivation. Patient-specific, knowledge-based, holistic surgical treatment planning is of utmost importance when dealing with complex surgery. Surgeons need to account for all available medical patient data, keep track of technical developments, and stay on top of current surgical expert knowledge to define a suitable surgical treatment strategy. There is a large potential for computer assistance, also, and in particular, regarding surgery simulation which gives surgeons the opportunity not only to plan but to simulate, too, some steps of an intervention and to forecast relevant surgical situations. Purpose. In this work, we particularly look at mitral valve reconstruction (MVR) surgery, which is to re-establish the functionality of an incompetent mitral valve (MV) through implantation of an artificial ring that reshapes the valvular morphology. We aim at supporting MVR by providing surgeons with biomechanical FEM-based MVR surgery simulations that enable them to assess the simulated behavior of the MV after an MVR. However, according to the above requirements, such surgery simulation is really beneficial to surgeons only if it is patient-specific, surgical expert knowledge-based, comprehensive in terms of the underlying model and the patient’s data, and if its setup and execution is fully automated and integrated into the surgical treatment workflow. Methods. This PhD work conducts research on simulation-enhanced, cognition-guided, patient-specific cardiac surgery assistance. First, we derive a biomechanical MV/MVR model and develop an FEM-based MVR surgery simulation using the FEM software toolkit HiFlow3. Following, we outline the functionality and features of the Medical Simulation Markup Language (MSML) and how it simplifies the biomechanical modeling workflow. It is then detailed, how, by means of the MSML and a set of dedicated MVR simulation reprocessing operators, patient-individual medical data can comprehensively be analyzed and processed in order for the fully automated setup of MVR simulation scenarios. Finally, the presented work is integrated into the cognitive system architecture of the joint research project Cognition-Guided Surgery. We particularly look at its semantic knowledge and data infrastructure as well as at the setup of its cognitive software components, which eventually facilitate cognition-guidance and patient-specifity for the overall simulation-enhanced MVR assistance pipeline. Results and Discussion. We have proposed and implemented, for the first time, a prototypic system for simulation-enhanced, cognition-guided, patient-specific cardiac surgery assistance. The overall system was evaluated in terms of functionality and performance. Through its cognitive, data-driven pipeline setup, medical patient data and surgical information is analyzed and processed comprehensively, efficiently and fully automatically, and the hence set-up simulation scenarios yield reliable, patient-specific MVR surgery simulation results. This indicates the system’s usability and applicability. The proposed work thus presents an important step towards a simulation-enhanced, cognition-guided, patient-specific cardiac surgery assistance, and can – once operative – be expected to significantly enhance MVR surgery. Concluding, we discuss possible further research contents and promising applications to build upon the presented work

    Simulador Web de Resonancia Magnética como Herramienta Educativa: Diseño, Desarrollo y Evaluación

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    La imagen por resonancia magnética (MRI) es una modalidad médica con una gran popularidad. Esto se debe a varias causas, tales como la consecución de imágenes de gran contraste en tejidos blandos, el hecho de que utiliza radiación no ionizante y su alta versatilidad, ya que puede dar lugar a muy diversos contrastes mediante el ajuste adecuado de parámetros. Esto hace que la resonancia magnética sea una modalidad compleja y, en consecuencia, el proceso de aprendizaje de los técnicos de imagen para el radiodiagnóstico también lo es. En respuesta a tal complejidad, esta tesis se centra en el diseño, desarrollo y evaluación de un simulador web de resonancia magnética que sirve tanto para el aprendizaje de conceptos teóricos sobre resonancia magnética como para la capacitación en la adquisición de esta modalidad. Para su desarrollo se hace uso de ingeniería del software, donde se establecen los pasos que deben llevarse a cabo en una implementación de este carácter. Específicamente, se reúne a un grupo de expertos para recopilar el conjunto de requisitos que debe cumplir esta herramienta y que serán claves para su desempeño. Además, se ha incorporado un sistema de tutoría inteligente (ITS) a esta herramienta. Hasta donde conocemos, ésta es la primera vez que se integra un ITS en un simulador de resonancia magnética. El simulador ha sido evaluado a través de tres experiencias educativas, donde se ha medido tanto la experiencia del usuario como el valor educativo real de la herramienta. Esta última medición se llevó a cabo durante la realización de un experiencia real en una clase y que tuvo una duración de un día. En términos de la experiencia del usuario, nuestros resultados evolucionaron positivamente durante las evaluaciones del simulador. En particular, esta característica mejoró notablemente con la incorporación de un ITS. Los comentarios de los usuarios respaldaron las mediciones cuantitativas obtenidas. Los resultados de la experiencia en el aula mostraron diferencias estadísticas significativas a favor de los participantes que usaron el simulador, tanto en el tamaño del efecto como en las pruebas inferenciales. No somos conscientes de publicación científica alguna en la que se haya descrito la medición del valor educativo real de un simulador de resonancia magnética.Departamento de Teoría de la Señal y Comunicaciones e Ingeniería TelemáticaDoctorado en Tecnologías de la Información y las Telecomunicacione

    MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

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    Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described

    Generalized averaged Gaussian quadrature and applications

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    A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal

    Particle Physics Reference Library

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    This second open access volume of the handbook series deals with detectors, large experimental facilities and data handling, both for accelerator and non-accelerator based experiments. It also covers applications in medicine and life sciences. A joint CERN-Springer initiative, the “Particle Physics Reference Library” provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A,B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access

    Massively parallel CUDA simulations of cardiac and embryonic MRI on a cloud-based cluster

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    Embryonic and cardiovascular Magnetic Resonance Imaging (MRI) in both clinic and research environments is confronted by challenges like motion, flow and low resolution. MRI simulations can be used as a valuable tool against these challenges but they are characterized by high computational intensity. In this study we implemented cardiac and embryonic MR simulations on a cloud-based cluster. For this purpose, an anatomical model of a human embryo was split over a variable number of computer nodes on the cloud. Simulation of a Gradient-Echo pulse sequence was performed and the partial results were aggregated in a central node to produce the simulated MR image, following the MapReduce paradigm. The measured execution times and speedups demonstrated the benefits of this cloud-based approach. © 2015 CCAL

    Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

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    Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018
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