875 research outputs found

    Exploring the impact of stimulus transparency in ERP-BCI under RSVP.

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    Política de acceso abierto tomada de: https://authors.acm.org/author-resources/author-rightsRapid serial visual presentation (RSVP) is currently one of the most suitable paradigms for implementing a visual brain–computer interface based on event-related potentials (ERP-BCI) for patients with limited ocular motility. This paradigm presents stimuli centered in the user’s field of vision, which may hinder the patient from attending to other elements on the screen. A potential solution to this could be the use of semi-transparent stimuli, allowing both the stimulus and the background to be perceived. Therefore, the objective of this study is to evaluate the impact of stimulus transparency on ERP-BCI performance under the RSVP paradigm. Five participants tested the ERP-BCI under RSVP using three different stimulus transparencies with alpha channels set to 255 (C1), 85 (C2), and 28 (C3). The results showed the following average BCI classification accuracies: C1, 70%; C2, 74.67%; and C3, 60.67%. Although the analyses did not reveal significant differences, the results suggest that the transparency level should be carefully manipulated to maintain a balance between stimulus transparency and performance, with C2 even exhibiting the highest accuracy among the conditions. This finding should be considered by future ERP-BCI proposals aimed at users who need gaze-independent systems.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Predictive Composition of Pictogram Messages for Users with Autism.

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    Communication is a basic need for every person. However, there are many people who present disabilities that prevent communication through natural language. Augmentative and alternative communication (AAC) systems, including those based on pictograms, attempt to facilitate the communication for people with this kind of difficulties. In this paper we present PictoEditor, an augmentative and alternative communication application for the composition of pictogram messages for users with autism that incorporates prediction functionalities. Although such functionalities have been widely studied in text-based augmentative and alternative communication tools, they have not been applied to pictogram based ones. The results show that prediction based on frequency of use of specific pictograms improves the immediate availability of the desired pictograms, but the improvement with prediction based on sequencing of pseudo-syntactic types of pictogram is not as clear.pre-print4500 K

    Messenger Visual, a pictogram-based instant messaging service for individuals with cognitive disability

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    Along history disabled individuals have suffered from social exclusion due to the limitations posed by their condition. For instance, deaf people are not able to watch television programs because of their sensory limitation. Despite this situation has improved thanks to the efforts in adapting the different services —today the majority of television programs offer subtitles or simultaneous translation to sign language—, the arrival of the Internet, as well as the rest of the information and communication technologies, poses new risks to the inclusion of disabled individuals. Taking into account the present digital exclusion situation of disabled individuals this project presents Messenger Visual, an Instant Messaging service based on pictograms for individuals with cognitive disability. Messenger Visual is composed of two different parts. On the one hand, the Instant Messaging service has been designed considering the requirements of communication based on pictograms. On the other hand, the Instant Messaging client has been designed taking into account the user interface usability requirements of individuals with cognitive disability. Finally, the project presents the methodology that we have used to evaluate Messenger Visual with a group of individuals with cognitive disability, as well as the results we have obtained. The evaluation process has lasted for six months and one-hour fortnightly sessions have been held with two groups of individuals from Fundació El Maresme with different cognitive disability profiles. These sessions have allowed us to gain better understanding of the user interface accessibility requirements, as well as to know how individuals with cognitive disability communicate using pictograms

    Development of Criteria for Mobile Device Cybersecurity Threat Classification and Communication Standards (CTC&CS)

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    The increasing use of mobile devices and the unfettered access to cyberspace has introduced new threats to users. Mobile device users are continually being targeted for cybersecurity threats via vectors such as public information sharing on social media, user surveillance (geolocation, camera, etc.), phishing, malware, spyware, trojans, and keyloggers. Users are often uninformed about the cybersecurity threats posed by mobile devices. Users are held responsible for the security of their device that includes taking precautions against cybersecurity threats. In recent years, financial institutions are passing the costs associated with fraud to the users because of the lack of security. The purpose of this study was to design, develop, and empirically test new criteria for a Cybersecurity Threats Classification and Communication Standard (CTC&CS) for mobile devices. The conceptual foundation is based on the philosophy behind the United States Occupational Safety and Health Administration (OSHA)’s Hazard Communication Standard (HCS) of Labels and Pictograms that is mainly focused on chemical substances. This study extended the HCS framework as a model to support new criteria for cybersecurity classification and communication standards. This study involved three phases. The first phase conducted two rounds of the Delphi technique and collected quantitative data from 26 Subject Matter Experts (SMEs) in round one and 22 SMEs in round two through an anonymous online survey. Results of Phase 1 emerged with six threats categories and 62 cybersecurity threats. Phase 2 operationalized the elicited and validated criteria into pictograms, labels, and safety data sheets. Using the results of phase one as a foundation, two to three pictograms, labels, and safety data sheets (SDSs) from each of the categories identified in phase one were developed, and quantitative data were collected in two rounds of the Delphi technique from 24 and 19 SMEs respectively through an online survey and analyzed. Phase 3, the main data collection phase, empirically evaluated the developed and validated pictograms, labels, and safety data sheets for their perceived effectiveness as well as performed an analysis of covariance (ANCOVA) with 208 non-IT professional mobile device users. The results of this study showed that pictograms were highly effective; this means the participants were satisfied with the characteristics of the pictograms such as color, shapes, visual complexity, and found these characteristics valuable. On the other hand, labels and Safety Data Sheets (SDS) did not show to be effective, meaning the participants were not satisfied or lacked to identify importance with the characteristics of labels and SDS. Furthermore, the ANCOVA results showed significant differences in perceived effectiveness with SDSs with education and a marginal significance level with labels when controlled for the number of years of mobile device use. Based on the results, future research implications can observe discrepancies of pictogram effectiveness between different educational levels and reading levels. Also, research should focus on identifying the most effective designs for pictograms within the cybersecurity context. Finally, longitudinal studies should be performed to understand the aspects that affect the effectiveness of pictograms

    Time orientation technologies in special education

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    A device to train children in time orientation has been designed, developed and evaluated. It is framed within a long-term cooperation action between university and special education school. It uses a specific cognitive accessible time display: Time left in the day is represented by a row of luminous elements initially on. Time passing is represented by turning off sequentially and gradually each luminous element every 15 min. Agenda is displayed relating time to tasks with standard pictograms for further accessibility. Notifications of tasks-to-come both for management support and anticipation to changes uses visual and auditory information. Agenda can be described in an Alternative and Augmentative Communication pictogram language already used by children, supporting individual and class activities on agenda. Validation has been performed with 16 children in 12 classrooms of four special education schools. Methodology for evaluation compares both prior and posterior assessments which are based in the International Classification of Functioning, Disability and Health (ICF) from the World Health Organization (WHO), together with observation registers. Results show consistent improvement in performances related with time orientation

    AAL platform with a “de facto” standard communication interface (TICO): Training in home control in special education

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    Framed within a long-term cooperation between university and special education teachers, training in alternative communication skills and home control was realized using the “TICO” interface, a communication panel editor extensively used in special education schools. From a technological view we follow AAL technology trends by integrating a successful interface in a heterogeneous services AAL platform, focusing on a functional view. Educationally, a very flexible interface in line with communication training allows dynamic adjustment of complexity, enhanced by an accessible mindset and virtual elements significance already in use, offers specific interaction feedback, adapts to the evolving needs and capacities and improves the personal autonomy and self-confidence of children at school and home. TICO-home-control was installed during the last school year in the library of a special education school to study adaptations and training strategies to enhance the autonomy opportunities of its pupils. The methodology involved a case study and structured and semi-structured observations. Five children, considered unable to use commercial home control systems were trained obtaining good results in enabling them to use an open home control system. Moreover this AAL platform has proved efficient in training children in previous cognitive steps like virtual representation and cause-effect interaction

    An iconic language for the graphical representation of medical concepts

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    <p>Abstract</p> <p>Background</p> <p>Many medication errors are encountered in drug prescriptions, which would not occur if practitioners could remember the drug properties. They can refer to drug monographs to find these properties, however drug monographs are long and tedious to read during consultation. We propose a two-step approach for facilitating access to drug monographs. The first step, presented here, is the design of a graphical language, called VCM.</p> <p>Methods</p> <p>The VCM graphical language was designed using a small number of graphical primitives and combinatory rules. VCM was evaluated over 11 volunteer general practitioners to assess if the language is easy to learn, to understand and to use. Evaluators were asked to register their VCM training time, to indicate the meaning of VCM icons and sentences, and to answer clinical questions related to randomly generated drug monograph-like documents, supplied in text or VCM format.</p> <p>Results</p> <p>VCM can represent the various signs, diseases, physiological states, life habits, drugs and tests described in drug monographs. Grammatical rules make it possible to generate many icons by combining a small number of primitives and reusing simple icons to build more complex ones. Icons can be organized into simple sentences to express drug recommendations. Evaluation showed that VCM was learnt in 2 to 7 hours, that physicians understood 89% of the tested VCM icons, and that they answered correctly to 94% of questions using VCM (versus 88% using text, <it>p </it>= 0.003) and 1.8 times faster (<it>p </it>< 0.001).</p> <p>Conclusion</p> <p>VCM can be learnt in a few hours and appears to be easy to read. It can now be used in a second step: the design of graphical interfaces facilitating access to drug monographs. It could also be used for broader applications, including the design of interfaces for consulting other types of medical document or medical data, or, very simply, to enrich medical texts.</p

    Predicting mental imagery based BCI performance from personality, cognitive profile and neurophysiological patterns

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    Mental-Imagery based Brain-Computer Interfaces (MI-BCIs) allow their users to send commands to a computer using their brain-activity alone (typically measured by ElectroEncephaloGraphy— EEG), which is processed while they perform specific mental tasks. While very promising, MI-BCIs remain barely used outside laboratories because of the difficulty encountered by users to control them. Indeed, although some users obtain good control performances after training, a substantial proportion remains unable to reliably control an MI-BCI. This huge variability in user-performance led the community to look for predictors of MI-BCI control ability. However, these predictors were only explored for motor-imagery based BCIs, and mostly for a single training session per subject. In this study, 18 participants were instructed to learn to control an EEG-based MI-BCI by performing 3 MI-tasks, 2 of which were non-motor tasks, across 6 training sessions, on 6 different days. Relationships between the participants’ BCI control performances and their personality, cognitive profile and neurophysiological markers were explored. While no relevant relationships with neurophysiological markers were found, strong correlations between MI-BCI performances and mental-rotation scores (reflecting spatial abilities) were revealed. Also, a predictive model of MI-BCI performance based on psychometric questionnaire scores was proposed. A leave-one-subject-out cross validation process revealed the stability and reliability of this model: it enabled to predict participants’ performance with a mean error of less than 3 points. This study determined how users’ profiles impact their MI-BCI control ability and thus clears the way for designing novel MI-BCI training protocols, adapted to the profile of each user

    Advanced Augmentative and Alternative Communication System Based in Physiological Control

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    Dyskinetic Cerebral Palsy (DCP) is mainly characterized by alterations in muscle tone and involuntary movements. Therefore, these people present with difficulties in coordination and movement control, which makes walking difficult and affects their posture when seated. Additionally, their cognitive performance varies between being completely normal and severe mental retardation. People with DCP were selected as the objective of this thesis due to their multiple and complex limitations (speech problems and motor control) and because their capabilities have a great margin for improvement thanks to physiological control systems. Given their communication difficulties, some people with DCP have good motor con-trol and can communicate with written language. However, most have difficulty using Augmentative and Alternative Communication (AAC) systems. People with DCP gen-erally use concept boards to indicate the idea they want to communicate. However, most communication solutions available today are based on proprietary software that makes it difficult to customize the concept board and this type of control system. This is the motivation behind this thesis, with the aim of creating an interface with characteristics, able to be adapted to the user needs and limitations. Thus, this thesis proposes an Augmentative and Alternative Communication System for people with DCP based on physiological control. In addition, an innovative system for direct con-trol of concept boards with EMG is proposed. This control system is based on a physi-cal model that reproduces the muscular mechanical response (stiffness, inertia and viscosity). It allows for a selection of elements thanks to small pulses of EMG signal with sensors on a muscle with motor control. Its main advantage is the possibility of correcting errors during selection associated with uncontrolled muscle impulses, avoid-ing sustained muscle effort and thus reduced fatigue.La Parálisis Cerebral de tipo Discinésica (DCP) se caracteriza principalmente por las alteraciones del tono muscular y los movimientos involuntarios. Por ello, estos pacientes presentan dificultades en la coordinación y en el control de movimientos, lo cual les dificulta el caminar y afecta su postura cuando están sentados. Cabe resaltar que la capacidad cognitiva de las personas con DCP puede variar desde completamente normal, hasta un retraso mental severo. Las personas con DCP han sido seleccionadas como objetivo de esta tesis ya el margen de mejora de sus capacidades es amplio gracias a sistemas de control fisiológico, debido a sus múltiples y complejas limitaciones (problemas de habla y control motor). Debido a sus dificultades de comunicación, algunas personas con DCP se pueden comunicar con lenguaje escrito, siempre y cuando tenga un buen control motor. Sin embargo, la mayoría tienen dificultades para usar sistemas de Comunicación Aumentativos y Alternativos (AAC). De hecho, las personas con DCP utilizan generalmente tableros de conceptos para indicar la idea que quieren transmitir. Sin embargo, la mayoría las soluciones de comunicación disponibles en la actualidad están basadas en software propietario que hacen difícil la personalización del tablero de conceptos y el tipo de sistema de control. Es aquí donde surge esta tesis, con el objetivo de crear una interfaz con esas características, capaz de adaptarse a las necesidades y limitaciones del usuario. De esta forma, esta tesis propone un sistema de comunicación aumentativo y alternativo para personas con DCP basado en control fisiológico. Además, se propone un Sistema innovador de control directo sobre tableros de conceptos basado en EMG. Este Sistema de control se basa en un modelo físico que reproduce la respuesta mecánica muscular (basado en parámetros como Rigidez, Inercia y Viscosidad), permitiendo la selección de elementos gracias a pequeños pulsos de señal EMG con sensores sobre un músculo con control motor. Sus principales ventajas son la posibilidad de corregir errores durante la selección asociado a los impulsos musculares no controlados, evitar el esfuerzo muscular mantenido para alcanzar un nivel y reducir la fatiga.La Paràlisi Cerebral de tipus Discinèsica (DCP) es caracteritza principalment per les alteracions del to muscular i els moviments involuntaris. Per açò, aquests pacients presenten dificultats en la coordinació i en el control de moviments, la qual cosa els dificulta el caminar i afecta la seua postura quan estan asseguts. Cal ressaltar que la capacitat cognitiva de les persones amb DCP pot variar des de completament normal, fins a un retard mental sever. Les persones amb DCP han sigut seleccionades com a objectiu d'aquesta tesi ja el marge de millora de les seues capacitats és ampli gràcies a sistemes de control fisiològic, a causa dels seus múltiples i complexes limitacions (problemes de parla i control motor). A causa de les seues dificultats de comunicació, algunes persones amb DCP es poden comunicar amb llenguatge escrit, sempre que tinga un bon control motor. No obstant açò, la majoria tenen dificultats per a usar sistemes de Comunicació Augmentatius i Alternatius (AAC). De fet, les persones amb DCP utilitzen generalment taulers de conceptes per a indicar la idea que volen transmetre. No obstant açò, la majoria les solucions de comunicació disponibles en l'actualitat estan basades en programari propietari que fan difícil la personalització del tauler de conceptes i el tipus de sistema de control. És ací on sorgeix aquesta tesi, amb l'objectiu de crear una interfície amb aqueixes característiques, capaç d'adaptar-se a les necessitats i limitacions de l'usuari. D'aquesta forma, aquesta tesi proposa un sistema de comunicació augmentatiu i alternatiu per a persones amb DCP basat en control fisiològic. A més, es proposa un sistema innovador de control directe sobre taulers de conceptes basat en EMG. Aquest sistema de control es basa en un model físic que reprodueix la resposta mecànica muscular (basat en paràmetres com a Rigidesa, Inèrcia i Viscositat), permetent la selecció d'elements gràcies a xicotets polsos de senyal EMG amb sensors sobre un múscul amb control motor. Els seus principals avantatges són la possibilitat de corregir errors durant la selecció associat als impulsos musculars no controlats, evitar l'esforç muscular mantingut per a aconseguir un nivell i reduir la fatiga.Díaz Pineda, JA. (2017). Advanced Augmentative and Alternative Communication System Based in Physiological Control [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90418TESI

    Characterizing Computer Access Using a One-Channel EEG Wireless Sensor

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    This work studies the feasibility of using mental attention to access a computer. Brain activity was measured with an electrode placed at the Fp1 position and the reference on the left ear; seven normally developed people and three subjects with cerebral palsy (CP) took part in the experimentation. They were asked to keep their attention high and low for as long as possible during several trials. We recorded attention levels and power bands conveyed by the sensor, but only the first was used for feedback purposes. All of the information was statistically analyzed to find the most significant parameters and a classifier based on linear discriminant analysis (LDA) was also set up. In addition, 60% of the participants were potential users of this technology with an accuracy of over 70%. Including power bands in the classifier did not improve the accuracy in discriminating between the two attentional states. For most people, the best results were obtained by using only the attention indicator in classification. Tiredness was higher in the group with disabilities (2.7 in a scale of 3) than in the other (1.5 in the same scale); and modulating the attention to access a communication board requires that it does not contain many pictograms (between 4 and 7) on screen and has a scanning period of a relatively high tscan 10 s. The information transfer rate (ITR) is similar to the one obtained by other brain computer interfaces (BCI), like those based on sensorimotor rhythms (SMR) or slow cortical potentials (SCP), and makes it suitable as an eye-gaze independent BCI
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