247 research outputs found
Algorithms for information extraction and signal annotation on long-term biosignals using clustering techniques
Dissertação para obtenção do Grau de Mestre em
Engenharia BiomédicaOne of the biggest challenges when analysing data is to extract information from it,
especially if we dealing with very large sized data, which brings a new set of barriers to be overcome. The extracted information can be used to aid physicians in their diagnosis since biosignals often carry vital information on the subjects.
In this research work, we present a signal-independent algorithm with two main goals: perform events detection in biosignals and, with those events, extract information
using a set of distance measures which will be used as input to a parallel version of
the k-means clustering algorithm. The first goal is achieved by using two different approaches.
Events can be found based on peaks detection through an adaptive threshold defined as the signal’s root mean square (RMS) or by morphological analysis through the computation of the signal’s meanwave. The final goal is achieved by dividing the distance measures into n parts and by performing k-means individually. In order to improve speed performance, parallel computing techniques were applied.
For this study, a set of different types of signals was acquired and annotated by our
algorithm. By visual inspection, the L1 and L2 Minkowski distances returned an output
that allowed clustering signals’ cycles with an efficiency of 97:5% and 97:3%, respectively.
Using the meanwave distance, our algorithm achieved an accuracy of 97:4%. For the downloaded ECGs from the Physionet databases, the developed algorithm detected
638 out of 644 manually annotated events provided by physicians.
The fact that this algorithm can be applied to long-term raw biosignals and without
requiring any prior information about them makes it an important contribution in biosignals’ information extraction and annotation
OpenDataHub: an open dataset management system
This thesis presents a cloud-based software platform for sharing publicly available scientific datasets. The proposed platform leverages the potential of NoSQL databases and asynchronous IO technologies, such as Node.JS, in order to achieve high performances and flexible solutions. This solution will serve two main groups of users. The dataset providers, which are the researchers responsible for sharing and maintaining datasets, and the dataset users, that are those who desire to access the public data. To the former are given tools to easily publish and maintain large volumes of data, whereas the later are given tools to enable the preview and creation of subsets of the original data through the introduction of filter and aggregation operations. The choice of NoSQL over more traditional RDDMS emerged from and extended benchmark between relational databases (MySQL) and NoSQL (MongoDB) that is also presented in this thesis. The obtained results come to confirm the theoretical guarantees that NoSQL databases are more suitable for the kind of data that our system users will be handling, i. e., non-homogeneous data structures that can grow really fast. It is envisioned that a platform like this can lead the way to a new era of scientific data sharing where researchers are able to easily share and access all kinds of datasets, and even in more advanced scenarios be presented with recommended datasets and already existing research results on top of those recommendations
Análise da influência das variáveis de rendimento e contextuais no resultado final
Este relatório foi elaborado com o intuito de descrever as tarefas realizadas enquanto estagiário no Benfica Lab – Sport Lisboa e Benfica, durante a época desportiva 2016/2017 na área de Observação e Análise de Jogo. A realização do mesmo ocorreu em três áreas distintas. A primeira, procura explicar as tarefas de um analista de jogo e o seu papel num clube de elite. Neste capítulo são abordados diversos temas, desde a formação inicial necessária até à sua operacionalização, suportada por uma componente teórica que permite a compreensão de cada uma das tarefas. No segundo capítulo é apresentado um estudo de investigação realizado durante o período de estágio. Este estudo teve como base três equipas da Liga Portuguesa de Futebol, onde se pretendeu identificar um conjunto de variáveis e a forma como estas influenciam o resultado final, tendo sido possível concluir a influência de algumas variáveis no resultado final dos jogos, principalmente as variáveis contextuais. O último capítulo, correspondente à relação com a comunidade, descreve a organização de uma conferência pelo grupo de estagiários, tendo como tema “O Desenvolvimento do Jovem Atleta”. O objetivo foi criar um evento vocacionado para todos os agentes desportivos, com intuito de partilhar conhecimento e novas experiências.This report was developed with the purpose of describing the all the tasks that were part of the internship program at Benfica Lab - Sport Lisboa and Benfica, during the 2016/2017 football season in Observation and Game Analysis Department. The report is divided in three distinct areas. The first one explains the daily tasks of a performance analyst and his role in an elite club. In this chapter the topics covered go from the initial training to its practical operationalization, supported by a theoretical component that allows us understand each task. The second chapter presents a study research carried out during the internship process. This study was based on three Portuguese teams, it aimed to identify a set of variables and how they influenced the final result. It was possible to conclude the influence of some variables on the final result, essentially the contextual variables. The last chapter theme is the relationship with the community and describes the organization of a conference by the group of trainees, named "The Development of the Young Athlete". The aim was to create an event to share knowledge and new experiences on the theme, targeting all sports agents
Efficacy and Brain Imaging Correlates of an Immersive Motor Imagery BCI-Driven VR System for Upper Limb Motor Rehabilitation: A Clinical Case Report
To maximize brain plasticity after stroke, a plethora of rehabilitation strategies have been explored. These include the use of intensive motor training, motor-imagery (MI), and action-observation (AO). Growing evidence of the positive impact of virtual reality (VR) techniques on recovery following stroke has been shown. However, most VR tools are designed to exploit active movement, and hence patients with low level of motor control cannot fully benefit from them. Consequently, the idea of directly training the central nervous system has been promoted by utilizing MI with electroencephalography (EEG)-based brain-computer interfaces (BCIs). To date, detailed information on which VR strategies lead to successful functional recovery is still largely missing and very little is known on how to optimally integrate EEG-based BCIs and VR paradigms for stroke rehabilitation. The purpose of this study was to examine the efficacy of an EEG-based BCI-VR system using a MI paradigm for post-stroke upper limb rehabilitation on functional assessments, and related changes in MI ability and brain imaging. To achieve this, a 60 years old male chronic stroke patient was recruited. The patient underwent a 3-week intervention in a clinical environment, resulting in 10 BCI-VR training sessions. The patient was assessed before and after intervention, as well as on a one-month follow-up, in terms of clinical scales and brain imaging using functional MRI (fMRI). Consistent with prior research, we found important improvements in upper extremity scores (Fugl-Meyer) and identified increases in brain activation measured by fMRI that suggest neuroplastic changes in brain motor networks. This study expands on the current body of evidence, as more data are needed on the effect of this type of interventions not only on functional improvement but also on the effect of the intervention on plasticity through brain imaging.info:eu-repo/semantics/publishedVersio
Herramienta de monitorización para mejorar las prestaciones de los grupos electrógenos fueloil en Cuba
En emplazamientos de grupos electrógenos de tecnología Hyundai instalados en Cuba se han presentado algunos problemas de funcionamiento que imposibilitan una rápida y correcta respuesta de los operarios ante distintas situaciones ocurridas. Por ejemplo, los reguladores de viscosidad en las baterías de los emplazamientos han sufrido averías debido a las vibraciones y altas temperaturas, ocasionando interrupciones, aumento del consumo de combustible, afectaciones en el suministro energético, elevación de los costes de explotación, incremento de la frecuencia de mantenimiento, afectación en la eficacia del Grupo y disminución de su vida útil, haciéndose más sensible al estar enlazado con el sistema nacional. Además, debido a la mala calidad y ubicación deficiente de los termómetros encargados de medir la temperatura de los gases a la salida de los cilindros de los motores hay una tendencia creciente a un daño irreparable en los mismos, ya que en algunos casos la lectura no es posible y no se garantiza la fiabilidad de la medición. En este trabajo se propone una posible solución a los problemas anteriormente mencionados mediante una herramienta de monitorización que permite incorporar a la aplicación de supervisión y control las mediciones de temperatura, la posibilidad de interactuar con la viscosidad, nuevas alarmas y acciones correctivas que el operador debe realizar. Las acciones anteriormente reseñadas se espera que contribuyan a la mejora de la disponibilidad energética de los grupos de esta tecnología, ya que garantizan que las válvulas de escape no se quemen y por tanto no se pierda la energía térmica que se convierte en energía mecánica de rotación. Además de aportar a la eficiencia energética se elimina el gasto por continuas adquisiciones de válvulas, montaje y mantenimiento. Con relación a la viscosidad se garantiza el funcionamiento del emplazamiento a plena capacidad y se ahorra en la adquisición de instrumentos como viscosímetr
USING MODELING TO PREDICT THE EFFECTS OF AUTOMATION ON MEDEVAC PILOT COGNITIVE WORKLOAD
The Holistic Situational Awareness - Decision Making (HSA-DM) program is researching ways to aid pilots via avionics essential to the Future Vertical Lift (FVL) rotor-wing platform. As pilots manage the new avionics that FVL will bring to the battlefield, automation assistance will be essential.
This study’s goal is to determine to what extent automation reduces pilot cognitive workload particularly when performing communication tasks. The quantitative analysis is based on cognitive walkthroughs with active-duty helicopter pilots. Pilot interviews were also conducted to assess how tasks are completed, and more importantly, to ascertain the cognitive workload associated with those tasks. This information is implemented into computer models of a routine helicopter flight to accurately predict pilot workload during a mission. These models also predict which tasks would add the most value to pilots and FVL if automated mission tasks were implemented.
The research indicates that by automating communication tasks for the pilot and copilot, workload is reduced to an optimal level. Based on these findings, monitor radio nets, adjust volume, input channel, select channel, and send JVMF messages should be automated. In addition, this analysis establishes a cost-effective, valid, and repeatable framework for future workload studies on automated tasks in FVL.Major, United States Army ReserveMajor, United States ArmyCaptain, United States ArmyMajor, United States ArmyMajor, United States ArmyApproved for public release. Distribution is unlimited
Gestión prospectiva estratégica para el desarrollo académico de los docentes de una universidad pedagógica: el estudio retrospectivo
La investigación sobre el estudio prospectivo para la gestión del desarrollo académico de los docentes de la Universidad de Ciencias Pedagógicas Félix Varela (UCPFV) en los últimos 15 años ha realizado una etapa inicial con un primer acercamiento a los posibles escenarios en que se deberá asegurar el desarrollo académico. Parte principal de la investigación con un enfoque prospectivo es poder contar con un estudio de las tendencias históricas que se manifiestan. Fueron establecidos los indicadores que nos posibilitan poder desarrollar el estudio retrospectivo, se procedió a la búsqueda de estos indicadores aplicando diferentes métodos, y se diseñó y procesó una base de datos individual con toda la información recopilada. Con todos estos datos se están realizando las valoraciones preliminares y se determinarán las tendencias históricas que tienen los indicadores que definen el desarrollo de los docentes. Estas tendencias establecerán las áreas e indicadores que presentan mayores debilidades y a las que se les debe prestar atención especial en la continuidad de la investigación
Evaluation of cases of concussion and subluxation in the permanent dentition: a retrospective study
Objectives: This study evaluated the evolution of cases of concussion and subluxation through a retrospective study of 20 years. Material and Methods:Were examined clinical and radiographic records of 1,309 patients who underwent treatment of dentoalveolar trauma in the discipline of Integrated Clinic of the School of Dentistry of Araçatuba, UNESP, of which we selected 137 whose patients had concussion and subluxation injuries, with average age of 23.3 (SD – 10.96). The variables collected were: gender, age, history of previous and actual trauma, treatments performed, the presence of necrotic pulp, and time elapsed until the same trauma. The concussion and subluxation groups were subjected to statistical analyses using the SPSS 16.0 version software (α=0.05), Chi-square, and t-tests. Results: Of the 301 teeth involved, 49 (16.3%) suffered concussion and 252 (83.7%), subluxation, being the upper anterior teeth the most affected (75.1%) for both conditions. Subluxation and concussion traumas were more prevalent in men aged 10 to 20 years, most caused by cycling accidents (36.2%). There was a concomitant presence of crown fracture in 21% of cases of concussion and 34.7% of subluxation. Pulp necrosis was detected in 16.3% (concussion) and 27.1% (subluxation) (p=0.12), and most occurred within 6 months after the trauma (p=0.29). The pulp necrosis shows a positive correlation with motorcycle accidents (p=0.01), direct impact (p≤0.0001), crown fracture with pulp exposure (p≤0.0001), darkening of the crown (p=0.004) and spontaneous pain (p≤0.0001); and negative correlation with indirect impact (p≤0.0001). Conclusions: Although concussion and subluxation traumas are considered of minor degrees, they must be monitored, since the possibility of pulp necrosis exists, and its early treatment favors a good prognosis
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