Search

In order to determine the site of origin (SOO) in outflow tract ventricular arrhythmias (OTVAs) before an ablation procedure, several algorithms based on manual identification of electrocardiogram (ECG) features, have been developed. However, the reported accuracy decreases when tested with different datasets. Machine learning algorithms can automatize the process and improve generalization, but their performance is hampered by the lack of large enough OTVA databases. We propose the use of detailed electrophysiological simulations of OTVAs to train a machine learning classification model to predict the ventricular origin of the SOO of ectopic beats. We generated a synthetic database of 12-lead ECGs (2,496 signals) by running multiple simulations from the most typical OTVA SOO in 16 patient-specific geometries. Two types of input data were considered in the classification, raw and feature ECG signals. From the simulated raw 12-lead ECG, we analyzed the contribution of each lead in the predictions, keeping the best ones for the training process. For feature-based analysis, we used entropy-based methods to rank the obtained features. A cross-validation process was included to evaluate the machine learning model. Following, two clinical OTVA databases from different hospitals, including ECGs from 365 patients, were used as test-sets to assess the generalization of the proposed approach. The results show that V2 was the best lead for classification. Prediction of the SOO in OTVA, using both raw signals or features for classification, presented high accuracy values (>0.96). Generalization of the network trained on simulated data was good for both patient datasets (accuracy of 0.86 and 0.84, respectively) and presented better values than using exclusively real ECGs for classification (accuracy of 0.84 and 0.76 for each dataset). The use of simulated ECG data for training machine learning-based classification algorithms is critical to obtain good SOO predictions in OTVA compared to real data alone. The fast implementation and generalization of the proposed methodology may contribute towards its application to a clinical routine. This work has been funded by Generalitat Valenciana Grant AICO/2021/318 (Consolidables 2021) and Grant PID2020-114291RB-I00 funded by MCIN/10.13039/501100011033 and by “ERDF A way of making Europe”.

Introduction: Circadian rhythms can impact athletes' sports performance, where the plateau occurs between 15 and 21 hours. Swimming is a peculiar case, as athletes perform training and final sessions in competitions at different times, as in the Rio2016 Olympic Games for example, where the semifinal and final competitions took place from ten o'clock at night. Objectives: (1) to present the protocol of an intervention performed with elite athletes of the Brazilian swimming team during the 2016 Olympic Games in Rio; (2) to find out whether the time at which the competitions were held affected the swimming performances of these athletes during the competition. Materials and Methods: Fourteen athletes of the Brazilian swimming team (males: n= 10; 71% and females: n= 4; 29%) participated in the study. They were followed up during two preparation periods (baseline and intervention) for the 2016 Olympic Games in Rio during June and July 2016. During the competition, we recorded the Reaction Time (RT) and Competition Time (CT) of each athlete in different modalities. The intervention strategies used were light therapy and sleep hygiene. The values of RT at the starting block and CT were registered and conferred with the official results. Results: The athletes showed a decrease in the total time awake (Δ = −13%; Effect size [ES] = 1.0) and sleep latency (Δ = −33%; ES = 0.7), and an increase in total sleep time (Δ = 13%; ES = 1.1; p = 0.04) between the baseline and the period of the intervention, pre-competition. We identified an improvement in the RT (Δ = −2.2% to −1.0%; ES = 0.2 to 0.5) during the competition only for the athletes who participated in the competition finals. Conclusion: We conclude that the intervention carried out was effective in mitigating any negative influence of competition time on the RT and CT of elite athletes of the Brazilian swimming team. Level of evidence II; Prospective comparative study.

Reliable patient-specific ventricular repolarization times (RTs) can identify regions of functional block or afterdepolarizations, indicating arrhythmogenic cardiac tissue and the risk of sudden cardiac death. Unipolar electrograms (UEs) record electric potentials, and the Wyatt method has been shown to be accurate for estimating RT from a UE. High-pass filtering is an important step in processing UEs, however, it is known to distort the T-wave phase of the UE, which may compromise the accuracy of the Wyatt method. The aim of this study was to examine the effects of high-pass filtering, and improve RT estimates derived from filtered UEs. We first generated a comprehensive set of UEs, corresponding to early and late activation and repolarization, that were then high-pass filtered with settings that mimicked the CARTO filter. We trained a deep neural network (DNN) to output a probabilistic estimation of RT and a measure of confidence, using the filtered synthetic UEs and their true RTs. Unfiltered ex-vivo human UEs were also filtered and the trained DNN used to estimate RT. Even a modest 2 Hz high-pass filter imposes a significant error on RT estimation using the Wyatt method. The DNN outperformed the Wyatt method in 62.75% of cases, and produced a significantly lower absolute error (p=8.99E−13), with a median of 16.91 ms, on 102 ex-vivo UEs. We also applied the DNN to patient UEs from CARTO, from which an RT map was computed. In conclusion, DNNs trained on synthetic UEs improve the RT estimation from filtered UEs, which leads to more reliable repolarization maps that help to identify patient-specific repolarization abnormalities.

Increasing the size of wind turbines has been one of the most effective ways to decrease the cost of wind energy. If this trend is to continue, we need to ensure that the design loads of wind turbine components do not increase disproportionately with the turbine size. One promising way to do this is by increasing the accuracy of the aeroelastic modeling of wind turbine simulations. As aeroelastic load calculations are a critical part in determining the design loads of the turbine, increasing the model accuracy leads to more detailed load predictions and less conservative safety factors that need to be applied to compensate for model uncertainty.nAnother promising way to obtain competitive design loads for larger wind turbines is through the use of advanced control strategies that aim at reducing the design-driving loads of the turbine components. These loads are varied by nature so a combination of different actuators and strategies is required to effectively reduce them. The present work contributes to this effort in two separate but complementing ways. On the one hand, it includes a study of advanced aerodynamic models in aeroelastic simulations and their quantitative effect on wind turbine loads. On the other hand, it presents a wind turbine controller that is capable not only of performing a complete set of design load calculations but also includes advanced control strategies that mitigate design-driving loads using the generator torque, the blade pitch actuators and active trailing edge flaps distributed along the blade span. This controller is used in separate studies to reduce design-driving fatigue and extreme loads on the turbine. This dissertation is based on three papers that study different ways to achieve a load reduction. The first paper presents the turbine controller in detail. It also presents its advanced load reduction capabilities using traditional pitch and torque actuators and studies the load reduction capabilities of the individual pitch control strategy using the more accurate lifting line free vortex wake aerodynamic model in aeroelastic calculations. The second paper uses the developed controller in a study that quantifies how using more accurate aerodynamic models in aeroelastic simulations affects the loads. It compares the extreme and fatigue loads of key turbine sensors in aeroelastic simulations that are performed with the widely used blade element momentum aerodynamic model with simulations that use the lifting line free vortex wake aerodynamic model. It not only quantifies the loading differences but also finds the reasons that lead to these differences. The third paper explores the potential of active trailing edge flaps in reducing the design-driving extreme loads and critical deflections of the wind turbine blade. It considers the trailing edge flap hinge moment as a robust and readily available sensor that can be used as an input for the controller strategy. The hinge moment, in combination with other sensors, is used in a model-based observer to estimate the local inflow conditions and allow a fast response of the flap actuators. This observer is then used as part of a novel control strategy to effectively lower the extreme blade root loads and critical tip deflections. Each of the papers studies one aspect where load reduction can be obtained for larger wind turbines. This dissertation also includes suggestions for further developing and improving the respective aspects. Including them all in the design process of the next generation of wind turbines is a promising way of making this source of energy even more cost-competitive and its use more widespread. Die Vergrößerung von Windturbinen ist einer der effektivsten Wege die Stromgestehungskosten von Windenergie zu verringern. Um diesen Trend zu erhalten muss gewährleistet werden, dass die designtreibenden Lasten der Turbinenkomponenten nicht überproportional mit der Turbinengröße steigen. Eine versprechende Methode um dies zu erlangen ist die Verbesserung der aeroelastischen Modellierung in Windturbinensimulationen. Da aeroelastische Lastrechnungen eine kritische Rolle beim Design von Windturbinenkomponenten spielen, führt eine Verbesserung der Modellierung zu genaueren Designlasten und weniger konservativen Sicherheitsfaktoren bei den Lasten. Eine andere versprechende Methode um die Designlasten von großen Windturbinen zu verringern ist die Anwendung von fortgeschrittenen lastreduzierenden Regelungsstrategien. Unterschiedliche Lasten beeinflussen die Turbinenkomponenten anders und deshalb müssen auch verschiedene Aktuatoren in Betracht gezogen werden, um die desingtreibenden Lasten mehrerer Komponenten zu reduzieren. Diese Dissertation trägt zu diesem Thema in zwei separaten aber sich ergänzenden Themenbereiche bei. Einerseits beinhaltet die Arbeit eine Studie zu fortgeschrittenen aerodynamischen Modellen und deren quantitativen Effekt auf die Turbinenlasten. Andererseits präsentiert die Arbeit einen Windturbinenregler, der komplette Lastberechnungen durchführen kann und über fortgeschrittene lastreduzierende Regelungsstrategien verfügt. Diese Strategien nutzen verschiedene Aktuatoren wie Generator, Pitchaktuatoren und aktive Hinterkantenklappen und werden in unterschiedlichen Studien für die Verringerung von designtreibenden Extrem- und Ermüdungslasten verwendet. Die Arbeit basiert auf drei Veröffentlichungen die verschiedene Wege zur Lastreduzierung untersuchen. Die erste Veröffentlichung beschreibt den Windturbinenregler im Detail. Die Veröffentlichung beschreibt auch die fortgeschrittenen Lastreduktionsstrategien des entwickelten Reglers, welche auf traditionellen Aktuatoren wie die Pitchaktuatoren und dem Generatormoment beruhen. Die Lastreduktionsfähigkeit der Individual Pitch Control Strategie wird in aeroelastischen Simulationen untersucht, die das fortgeschrittene aerodynamische Modell Lifting Line Free Vortex Wake nutzen. Die zweite Veröffentlichung verwendet den Regler in einer Studie, die die Lasteffekte von fortgeschrittenen aerodynamischen Methoden in aeroelastischen Simulationen untersucht. Die Studie vergleicht Extrem- und Ermüdungslasten von wichtigen Turbinensensoren, die in aeroelastischen Simulationen mit zwei verschieden aerodynamischen Methoden berechnet worden sind. Die erste Methode ist die verbreitete Blade Element Momentum Methode. Die zweite Methode ist die fortgeschrittene Lifting Line Free Vortex Wake Methode. Die Studie quantifiziert nicht nur die Lastunterschiede sondern findet auch die Ursachen dieser Unterschiede. Die dritte Veröffentlichung untersucht das Potential von aktiven Hinterkantenklappen um designtreibende Extremlasten und kritische Durchbiegungen vom Rotorblatt zu reduzieren. Sie betrachtet das Klappengelenk-Moment als ein möglicher Regler-Sensor, der robust und bereits im Klappensystem vorhanden ist. In der Veröffentlichung wird das Klappengelenk-Moment und andere Sensoren für einen modellbasierten Beobachter genutzt, der die aerodynamischen Zustände an der Blattsektion schätzen kann. Dies ermöglicht eine schnelle Reaktion des Klappenreglers. Der Beobachter wird als Teil einer neuen Klappenstrategie verwendet, welche die Extremlasten und kritische Durchbiegung vom Rotorblatt effektiv reduziert. Die Veröffentlichungen untersuchen jeweils ein möglicher Lastreduktionsaspekt für größere Windturbinen. Diese Dissertation enthält Vorschläge, wie man diese einzelnen Aspekte verbessern kann. Alle Aspekte im Turbinen-Designprozess zu verwenden ist eine versprechende Option um die Kosten der Windenergie weiter zu reduzieren und die Nutzung dieser Technologie zu verbreiten.

Objective: The present study aimed to investigate the gender differences for sleep complaints, patterns and disorders of elite athletes during preparation for the Rio 2016 Olympic Games. Methods: The study included 146 athletes from the Brazilian Olympic Team (male: n=86; 59%; female: n=60; 41%). The assessment of the Olympic athletes’ sleep took place in 2015, during the preparation period for the Rio Olympic Games. The athletes underwent a single polysomnography (PSG) evaluation. Sleep specialists evaluated the athletes and asked about their sleep complaints during a clinical consultation. In this evaluation week, the athletes did not take part in any training or competitions. Results: The prevalence of sleep complaints was 53% of the athletes during the medical consultation, the most prevalent being insufficient sleep/waking up tired (32%), followed by snoring (21%) and insomnia (19.2%). In relation to the sleep pattern findings, the men had significantly higher sleep latency and wake after sleep onset than the women (p=0.004 and p=0.002, respectively). The sleep efficiency and sleep stages revealed that men had a lower percentage of sleep efficiency and slow wave sleep than the women (p=0.001 and p=0.05, respectively). Conclusion: Most athletes reported some sleep complaints, with men reporting more sleep complaints than women in the clinical evaluation. The PSG showed that 36% of all athletes had a sleep disorder with a greater reduction in sleep quality in men than in women.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Outra Agência OBJECTIVE: The present study aimed to investigate the gender differences for sleep complaints, patterns and disorders of elite athletes during preparation for the Rio 2016 Olympic Games. METHODS: The study included 146 athletes from the Brazilian Olympic Team (male: n=86; 59%; female: n=60; 41%). The assessment of the Olympic athletes’ sleep took place in 2015, during the preparation period for the Rio Olympic Games. The athletes underwent a single polysomnography (PSG) evaluation. Sleep specialists evaluated the athletes and asked about their sleep complaints during a clinical consultation. In this evaluation week, the athletes did not take part in any training or competitions. RESULTS: The prevalence of sleep complaints was 53% of the athletes during the medical consultation, the most prevalent being insufficient sleep/waking up tired (32%), followed by snoring (21%) and insomnia (19.2%). In relation to the sleep pattern findings, the men had significantly higher sleep latency and wake after sleep onset than the women (p=0.004 and p=0.002, respectively). The sleep efficiency and sleep stages revealed that men had a lower percentage of sleep efficiency and slow wave sleep than the women (p=0.001 and p=0.05, respectively). CONCLUSION: Most athletes reported some sleep complaints, with men reporting more sleep complaints than women in the clinical evaluation. The PSG showed that 36% of all athletes had a sleep disorder with a greater reduction in sleep quality in men than in women.

Actualmente en Colombia existe un gran déficit en materia de educación superior, sobretodo en el departamento del Magdalena. Este departamento cuenta con uno de los índices más bajos de personas con estudios de educación superior. Este índice se debe a que las instituciones de educación superior se encuentren en ciudades capitales, y esto implica costos de transporte, alojamiento y alimentación para los estudiantes de los municipios del Magdalena. Para la solución de esta problemática se propone el diseño de un Centro Educativo Integral en Fundación. Su ubicación en este municipio se debe a su localización estratégica, lo cual permitiría a las personas de este municipio y municipios aledaños a este acceso a Educación. El Centro Educativo brindará programas profesionales como Administración de empresas, contaduría, psicología, zootecnia y un programa técnico en producción agropecuario. Por medio, de estos programas se pretende impulsar el desarrollo de la región. El diseño del centro educativo está basado en los programas académicos propuesto, y en preservar el medio ambiente. Este centro cuenta con dos edificios principales, un edificio principal para las aulas de clases y otro administrativo, una cancha múltiple para práctica deportiva, un espacio destinado para el programa de zootecnia. Este centro contará con una planta de tratamiento de aguas residuales, el agua tratada se usará para el riego de zonas verdes. Actually in Colombia exists a large deficit in higher education, especially in the department of Magdalena. This department has one of the lowest rates of people with higher education studies. This index is due to the fact that higher education institutions are located in the capital cities, and this implies transport, maintenance costs for the students of the Magdalena municipalities. For the solution of this problem the design of an Integral Educational Center in Foundation is proposed. Its location in this municipality is due to its strategic location, both in terms of people and this municipality and municipalities. The Educational Center offered professional programs such as Business Administration, accounting, psychology, animal husbandry and a technical program in agricultural production. Through these programs, the intention is to promote the development of the region. The design of the educational center is based on the academic programs proposed, and on preserving the environment. This center has two main buildings, a main building for classrooms and another administrative, a multiple court for sports, a space for the program of animal husbandry. This center will have a wastewater treatment plant; the treated water will be used to irrigate green areas.

This paper addresses the impact of turbo-roundabouts located in urban areas on pollutant emissions using field measurements of vehicle activity data and road congestion levels. The research also compares the emissions of vehicles moving along a turbo-roundabout and a conventional multi-lane roundabout. Based on field measurements taken at turbo-roundabouts without curb dividers located in Grado (Spain) and multi-lane roundabouts in Aveiro (Portugal), three representative speed profiles for each speed trajectory were identified: no stop (I), stop once (II), and multiple stops (III). This study also develops discrete models for turbo-roundabouts and multi-lane roundabouts in which the relative occurrence of those speed profiles is expressed as a function of the entry and conflicting traffic flows. The Vehicle Specific Power (VSP) methodology is then employed to estimate second-by-second pollutant emissions. This study tests the hypotheses that emissions are impacted by the differences in: 1) the characteristics of speed profiles in each movement; 2) the volumes of entry and conflicting flows; 3) the overall saturation level; and 4) the transportation facility considered (turbo-roundabout /multi-lane roundabout). Considering the selected case studies and traffic demands, vehicles at turbo-roundabouts generated more emissions (15-22%, depending on the pollutant) than multi-lane conventional roundabouts, especially under medium and high congested levels. These findings suggest that there are no advantages in implementing turbo-roundabouts from an environmental point of view, even in no saturated conditions.

The atmospheric dispersion of NO x and PM10 was simulated with a second generation Gaussian model over a medium-size south-European city. Microscopic traffic models calibrated with GPS data were used to derive typical driving cycles for each road link, while instantaneous emissions were estimated applying a combined Vehicle Specific Power/Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (VSP/EMEP) methodology. Site-specific background concentrations were estimated using time series analysis and a low-pass filter applied to local observations. Air quality modelling results are compared against measurements at two locations for a 1 week period. 78% of the results are within a factor of two of the observations for 1-h average concentrations, increasing to 94% for daily averages. Correlation significantly improves when background is added, with an average of 0.89 for the 24 h record. The results highlight the potential of detailed traffic and instantaneous exhaust emissions estimates, together with filtered urban background, to provide accurate input data to Gaussian models applied at the urban scale.

Uno de los objetivos del Espacio Europeo de Educación Superior (EEES) es la incorporación de metodologías docentes innovadoras que conviertan al alumno en una parte activa del proceso de aprendizaje. Una de estas metodologías que fomentan la participación del alumno en el proceso de adquisición de conocimientos es la de aprendizaje colaborativo, que permite a los alumnos, además de facilitar la comprensión y asimilación de los contenidos y la adquisición de las competencias propias de la asignatura, adquirir nuevas competencias relacionadas con el trabajo en grupo. El uso de tecnologías multimedia para desarrollar y presentar el trabajo realizado, combinado con tecnologías web, aumenta el grado de motivación e implicación de los alumnos, y las posibilidades de divulgación de los contenidos. En este artículo se describe la experiencia docente llevada a cabo en la asignatura de Arquitectura de Redes de Computadores de la Universidad de Valencia. Los alumnos divididos en grupos han realizado objetos digitales de aprendizaje, los cuales han sido divulgados libremente a través de la red, logrando con ello, además del aprendizaje colaborativo dentro del propio grupo, también un aprendizaje intergrupal. Los grupos obtienen retroalimentación acerca de su trabajo en base a los comentarios y evaluaciones realizados por alumnos externos al grupo de trabajo y por los profesores de la asignatura. One of the targets of the European Space of Higher Education is the use of innovative teaching methodologies to convert students into active participants during the learning process. One of these methodologies is the collaborative learning, which promotes the students participation throughout the process of knowledge acquisition. The collaborative learning allows students to acquire new skills related to working groups, as well as to reinforce and acquire skills of the own subject. The use of web multimedia technologies increases students’ motivation, students’ integration and the possibilities of broadcasting the outcomes of the work. This paper shows the teaching experience performed in a subject about Computer Network Architecture in the University of Valencia. In this subject, students divided into groups have defined teaching digital objects that have been spread through internet, allowing a collaborative learning inside each working group and among other groups. This way, each group can receive feedback from comments and evaluations performed by students of other groups and by the teachers. Este trabajo ha sido financiado por el Vicerrectorado de Cultura, Igualdad y Planificación de la Universidad de Valencia, dentro del proyecto de innovación educativa con número de expediente UV-SFPIE-FO13-147351, y por el Vicerrectorado de Investigación y Política Científica de la Universidad de Valencia dentro del proyecto con número de expediente UV-INV-PRECOMP13-115032.

International audience; We present a methodology to extract mechanical dyssynchrony indices from an electrophysiological (EP) contact mapping system that was applied to a database of ten patients undergoing Cardiac Resynchronization Therapy (CRT), before and after the therapy. The mechanical dyssynchrony indices were obtained after post-processing high temporal resolution data recorded at several endocardial positions with the measuring catheter of the EP system. Velocity profiles of these catheter trajectories were analyzed to identify abnormal patterns of motion such as septal flash, whose presence is strongly related to a positive response to CRT in patients with left bundle branch block. Septal flash motion was identified in four cases, which was qualitatively validated by visual inspection of imaging data, and a strong correlation with response to CRT was observed a posteriori. Finally, the effect of biventricular pacing was clearly observable by a substantial reduction of the septal flash motion.