33 research outputs found
Classificação de pacientes para adaptação de cadeira de rodas inteligente
Doutoramento em Engenharia InformáticaA importância e preocupação dedicadas à autonomia e independência das
pessoas idosas e dos pacientes que sofrem de algum tipo de deficiência tem
vindo a aumentar significativamente ao longo das últimas décadas. As
cadeiras de rodas inteligentes (CRI) são tecnologias que podem ajudar este
tipo de população a aumentar a sua autonomia, sendo atualmente uma área
de investigação bastante ativa. Contudo, a adaptação das CRIs a pacientes
específicos e a realização de experiências com utilizadores reais são assuntos
de estudo ainda muito pouco aprofundados.
A cadeira de rodas inteligente, desenvolvida no âmbito do Projeto IntellWheels,
é controlada a alto nível utilizando uma interface multimodal flexível,
recorrendo a comandos de voz, expressões faciais, movimentos de cabeça e
através de joystick. Este trabalho teve como finalidade a adaptação automática
da CRI atendendo às características dos potenciais utilizadores.
Foi desenvolvida uma metodologia capaz de criar um modelo do utilizador. A
investigação foi baseada num sistema de recolha de dados que permite obter
e armazenar dados de voz, expressões faciais, movimentos de cabeça e do
corpo dos pacientes. A utilização da CRI pode ser efetuada em diferentes
situações em ambiente real e simulado e um jogo sério foi desenvolvido
permitindo especificar um conjunto de tarefas a ser realizado pelos
utilizadores. Os dados foram analisados recorrendo a métodos de extração de
conhecimento, de modo a obter o modelo dos utilizadores. Usando os
resultados obtidos pelo sistema de classificação, foi criada uma metodologia
que permite selecionar a melhor interface e linguagem de comando da cadeira
para cada utilizador.
A avaliação para validação da abordagem foi realizada no âmbito do Projeto
FCT/RIPD/ADA/109636/2009 - "IntellWheels - Intelligent Wheelchair with
Flexible Multimodal Interface". As experiências envolveram um vasto conjunto
de indivíduos que sofrem de diversos níveis de deficiência, em estreita
colaboração com a Escola Superior de Tecnologia de Saúde do Porto e a
Associação do Porto de Paralisia Cerebral. Os dados recolhidos através das
experiências de navegação na CRI foram acompanhados por questionários
preenchidos pelos utilizadores. Estes dados foram analisados estatisticamente,
a fim de provar a eficácia e usabilidade na adequação da interface da CRI ao
utilizador. Os resultados mostraram, em ambiente simulado, um valor de
usabilidade do sistema de 67, baseado na opinião de uma amostra de
pacientes que apresentam os graus IV e V (os mais severos) de Paralisia
Cerebral. Foi também demonstrado estatisticamente que a interface atribuída
automaticamente pela ferramenta tem uma avaliação superior à sugerida pelos
técnicos de Terapia Ocupacional, mostrando a possibilidade de atribuir
automaticamente uma linguagem de comando adaptada a cada utilizador.
Experiências realizadas com distintos modos de controlo revelaram a
preferência dos utilizadores por um controlo compartilhado com um nível de
ajuda associado ao nível de constrangimento do paciente. Em conclusão, este
trabalho demonstra que é possível adaptar automaticamente uma CRI ao
utilizador com claros benefícios a nível de usabilidade e segurança.The importance and concern given to the autonomy and independence of
elderly people and patients suffering from some kind of disability has been
growing significantly in the last few decades. Intelligent wheelchairs (IW) are
technologies that can increase the autonomy and independence of this kind of
population and are nowadays a very active research area. However, the
adaptations to users’ specificities and experiments with real users are topics
that lack deeper studies.
The intelligent wheelchair, developed in the context of the IntellWheels project,
is controlled at a high-level through a flexible multimodal interface, using voice
commands, facial expressions, head movements and joystick as its main input
modalities. This work intended to develop a system enabling the automatic
adaptation, to the user characteristics, of the previously developed intelligent
wheelchair.
A methodology was created enabling the creation of a user model. The
research was based on the development of a data gathering system, enabling
the collection and storage of data from voice commands, facial expressions,
head and body movements from several patients with distinct disabilities such
as Cerebral Palsy. The wheelchair can be used in different situations in real
and simulated environments and a serious game was developed where
different tasks may be performed by users.
Data was analysed using knowledge discovery methods in order to create an
automatic patient classification system. Based on the classification system, a
methodology was developed enabling to select the best wheelchair interface
and command language for each patient.
Evaluation was performed in the context of Project FCT/RIPD/ADA/109636/
2009 – “IntellWheels – Intelligent Wheelchair with Flexible Multimodal
Interface”. Experiments were conducted, using a large set of patients suffering
from severe physical constraints in close collaboration with Escola Superior de
Tecnologia de Saúde do Porto and Associação do Porto de Paralisia Cerebral.
The experiments using the intelligent wheelchair were followed by user
questionnaires. The results were statistically analysed in order to prove the
effectiveness and usability of the adaptation of the Intelligent Wheelchair
multimodal interface to the user characteristics. The results obtained in a
simulated environment showed a 67 score on the system usability scale based
in the opinion of a sample of cerebral palsy patients with the most severe cases
IV and V of the Gross Motor Function Scale. It was also statistically
demonstrated that the data analysis system advised the use of an adapted
interface with higher evaluation than the one suggested by the occupational
therapists, showing the usefulness of defining a command language adapted to
each user. Experiments conducted with distinct control modes revealed the
users' preference for a shared control with an aid level taking into account the
level of constraint of the patient. In conclusion, this work demonstrates that it is
possible to adapt an intelligent wheelchair to the user with clear usability and
safety benefits
Text mining applications to facilitate economic and food safety law enforcement
Economic and Food Safety Authority receives on a daily basis reports and complaints regarding infractions, delicts and possible food and economic crimes. These reports and complaints can be in different forms, such as e-mails, online forms, letters, phone calls and complaint books present in every establishment. This paper aims to apply text mining and classification algorithms to textual data extracted from these reports and complains in order to help identify if the responsible entity to analyze the content is, in fact, the Economic and Food Safety Authority. The paper describes text preprocessing and feature extraction procedures applied to Portuguese text data. Supervised multi-class classification methods such as Naïve Bayes and Support Vector Machine Classifiers are employed in the task. We show that a non-semantical text mining approach can achieve good results, scoring around 70% of accuracy.info:eu-repo/semantics/publishedVersio
Applications of brain wave classification for controlling an intelligent wheelchair
The independence and autonomy of both elderly and disabled people have been a growing concern in today’s society. Therefore, wheelchairs have proven to be fundamental for the movement of these people with physical disabilities in the lower limbs, paralysis, or other type of restrictive diseases. Various adapted sensors can be employed in order to facilitate the wheelchair’s driving experience. This work develops the proof concept of a brain–computer interface (BCI), whose ultimate final goal will be to control an intelligent wheelchair. An event-related (de)synchronization neuro-mechanism will be used, since it corresponds to a synchronization, or desynchronization, in the mu and beta brain rhythms, during the execution, preparation, or imagination of motor actions. Two datasets were used for algorithm development: one from the IV competition of BCIs (A), acquired through twenty-two Ag/AgCl electrodes and encompassing motor imagery of the right and left hands, and feet; and the other (B) was obtained in the laboratory using an Emotiv EPOC headset, also with the same motor imaginary. Regarding feature extraction, several approaches were tested: namely, two versions of the signal’s power spectral density, followed by a filter bank version; the use of respective frequency coefficients; and, finally, two versions of the known method filter bank common spatial pattern (FBCSP). Concerning the results from the second version of FBCSP, dataset A presented an F1-score of 0.797 and a rather low false positive rate of 0.150. Moreover, the correspondent average kappa score reached the value of 0.693, which is in the same order of magnitude as 0.57, obtained by the competition. Regarding dataset B, the average value of the F1-score was 0.651, followed by a kappa score of 0.447, and a false positive rate of 0.471. However, it should be noted that some subjects from this dataset presented F1-scores of 0.747 and 0.911, suggesting that the movement imagery (MI) aptness of different users may influence their performance. In conclusion, it is possible to obtain promising results, using an architecture for a real-time application.info:eu-repo/semantics/publishedVersio
Recommendations for a new portuguese teacher placement system
Portuguese teacher placements’ system is a centralized system managed by the Portuguese government, specifically by the Ministry of Education and Science. It is a system with some issues and, therefore, has been criticized by its stakeholders, mainly by teachers. This paper aims to do a systematic review and a meta-analysis of the Portuguese teacher placements’ system. An objective is to understand and describe how similar system works in European Union countries. Another objective is to interview school specialists, in this particular case - teachers, to find solutions for teacher placements’ system. Finally, from solutions from European Union countries and from solutions arising from schools’ specialists, a set of requirements is identified that the teacher placements’ system should take into account, in order to avoid the issues identified.This project was funded by Fundo Europeu de Desenvolvimento Regional (FEDER), by Programa Operacional Factores de Competitividade (POFC) - COMPETE and by Fundacao para a Ciencia e Tecnologia, on the Scope of projects: PEstC/EEI/UI0319/2015, PEstC/EEI/UI0027/2015 and POCI-01-0145-FEDER-006961.info:eu-repo/semantics/publishedVersio
Special Issue Robótica 2014
This special issue presents extended and revised versions of a selection of papers presented on the IEEE
International Conference on Autonomous Robot Systems and Competitions (ICARSC-2014), that took place 14-15 May 2014 in the city of Espinho, Portugal.info:eu-repo/semantics/publishedVersio
Affinity coefficient for clustering autoregressive moving average models
In various fields, such as economics, finance, bioinformatics, geology, and medicine, namely, in the cases of electroencephalogram, electrocardiogram, and biotechnology, cluster analysis of time series is necessary. The first step in cluster applications is to establish a similarity/dissimilarity coefficient between time series. This article introduces an extension of the affinity coefficient for the autoregressive expansions of the invertible autoregressive moving average models to measure their similarity between them. An application of the affinity coefficient between time series was developed and implemented in R. Cluster analysis is performed with the corresponding distance for the estimated simulated autoregressive moving average of order one. The primary findings indicate that processes with similar forecast functions are grouped (in the same cluster) as expected concerning the affinity coefficient. It was also possible to conclude that this affinity coefficient is very sensitive to the behavior changes of the forecast functions: processes with small different forecast functions appear to be well separated in different clusters. Moreover, if the two processes have at least an infinite number of π- weights with a symmetric signal, the affinity value is also symmetric.info:eu-repo/semantics/publishedVersio
iiBOARD - Development of a low-cost interactive whiteboard using the wiimote controller
Interactive whiteboards are gaining importance in our society, both at a business level and, especially, at an educational level. However, the products offered by the major manufacturers have a major barrier to their acquisition: very high prices. There is an urgent need to use new technologies in order to provide solutions that present the same performance levels than typical interactive whiteboards, but with a significantly reduced cost. Throughout this paper the steps taken for the development of an innovative low-cost interactive whiteboard are described. The proposed system is based on the Wii Remote command of the Nintendo Wii video-game console. This command, although very inexpensive has an infrared camera, and supports Bluetooth communication. The system control is based on a wireless device, based on infrared emitters, which supports most of the mouse events. A complete whiteboard application was also developed using Borland Delphi for Windows. This application may be used with either one or two Wiimotes and has a very simple and efficient calibration method. The application also includes viewing capabilities of some of the Wiimote characteristics, as well as a flexible Notebook to increase its range of possible uses. The results obtained through a survey conducted to a small set of whiteboard users were very positive indicators about the acceptance of the inexpensive solution proposed.info:eu-repo/semantics/publishedVersio
Research through development: When words “Count”
A investigação científica baseada na metodologia Investigação & Desenvolvimento (I&D) tem uma prevalência para estudos quantitativos. Primordialmente, interessa ao investigador testar/provar alguma teoria, através das acções dos indivíduos implicados no estudo. O investigador pretende generalizar e usa, normalmente, dados numéricos. Quando aplicamos a I&D à concepção de pacotes de software, torna-se redutor que o investigador não tente percepcionar o contexto em que o estudo ocorre, interpretando os significados dos participantes recorrendo a processos interativos e iterativos. Assim, a metodologia de I&D (“Design Research” surgindo também a expressão “Research through Design”) tem vindo a ganhar espaço nos projetos de software que, segundo Pierce (2014), “include devices and systems that are technically and practically capable of being deployed in the field to study participants or end users / incluem dispositivos e sistemas que são tecnicamente e na prática capazes de ser implantados para estudar participantes ou utilizadores finais (p. 735).” Zimmerman, Forlizzi, & Evenson (2007) afirmam que o Design Research “mean an intention to produce knowledge and not the work to more immediately inform the development of a commercial product / significa uma intenção de produzir conhecimento e não o trabalho de informar mais imediatamente o desenvolvimento de um produto comercial (p. 494).“info:eu-repo/semantics/publishedVersio
Sono e dor musculoesquelética cervical em atletas de voleibol
A dor cervical é frequente em jogadores de voleibol e pode comprometer o desempenho ocupacional e a participação no sono. A terapia ocupacional, numa compreensão holística da problemática da dor cervical e do sono nestes atletas (Leive et al., 2020), enquanto seres ocupacionais (Gomes et al., 2021), poderá desempenhar um relevante papel na avaliação e intervenção terapêutica, e consequentemente na promoção da saúde (Bisht et al., 2021).info:eu-repo/semantics/publishedVersio
Special Issue JOMS – Journal of Medical Systems, 2016 on Agent-Empowered HealthCare Systems
The Agent-Empowered HealthCare Systems Special Issue includes a selection of papers that provide discussion on the most recent and innovative work regarding the study and application of agent-based technology to healthcare.info:eu-repo/semantics/publishedVersio