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Intersections are considered one of the most complex scenarios in a self-driving framework due to the uncertainty in the behaviors of surrounding vehicles and the different types of scenarios that can be found. To deal with this problem, we provide a Deep Reinforcement Learning approach for intersection handling, which is combined with Curriculum Learning to improve the training process. The state space is defined by two vectors, containing adversaries and ego vehicle information. We define a features extractor module and an actor-critic approach combined with Curriculum Learning techniques, adding complexity to the environment by increasing the number of vehicles. In order to address a complete autonomous driving system, a hybrid architecture is proposed. The operative level generates the driving commands, the strategy level defines the trajectory and the tactical level executes the high-level decisions. This high-level decision system is the main goal of this research. To address realistic experiments, we set up three scenarios: intersections with traffic lights, intersections with traffic signs and uncontrolled intersections. The results of this paper show that a Proximal Policy Optimization algorithm can infer ego vehicle-desired behavior for different intersection scenarios based only on the behavior of adversarial vehicles.
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BACKGROUND: The aim of this paper is to implement a system to facilitate the diagnosis of multiple sclerosis (MS) in its initial stages. It does so using a convolutional neural network (CNN) to classify images captured with swept-source optical coherence tomography (SS-OCT). METHODS: SS-OCT images from 48 control subjects and 48 recently diagnosed MS patients have been used. These images show the thicknesses (45 × 60 points) of the following structures: complete retina, retinal nerve fiber layer, two ganglion cell layers (GCL+, GCL++) and choroid. The Cohen distance is used to identify the structures and the regions within them with greatest discriminant capacity. The original database of OCT images is augmented by a deep convolutional generative adversarial network to expand the CNN's training set. RESULTS: The retinal structures with greatest discriminant capacity are the GCL++ (44.99% of image points), complete retina (26.71%) and GCL+ (22.93%). Thresholding these images and using them as inputs to a CNN comprising two convolution modules and one classification module obtains sensitivity = specificity = 1.0. CONCLUSIONS: Feature pre-selection and the use of a convolutional neural network may be a promising, nonharmful, low-cost, easy-to-perform and effective means of assisting the early diagnosis of MS based on SS-OCT thickness data.
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Esclerosis Múltiple , Tomografía de Coherencia Óptica , Diagnóstico Precoz , Humanos , Redes Neurales de la Computación , RetinaRESUMEN
Hepatitis C virus (HCV) and HIV are major causes of worldwide disease. We aimed to evaluate the effect of a combined screening programme, which included a risk-assessment questionnaire and rapid tests for point-of-care diagnosis, on screening and new diagnosis rates. This prospective, cluster randomized study was carried out in primary care. The intervention arm included a 4-hour educational programme, the use of a risk-assessment questionnaire and rapid tests. In the control centres, only the educational intervention was provided. The main variables compared were the screening coverage and the number and rate of new HCV and HIV diagnoses. Of a total of 7991 participants, 4670 (58.5%) and 2894 (36.2%) presented a risk questionnaire for HIV or HCV, respectively. The younger participants, men and those from Latin America and Eastern Europe, showed the greatest risk of presenting with a positive questionnaire. The overall screening coverage was higher within the intervention arm (OR 17.7; 95% CI 16.2-19.5; P < .001). Only two HIV-positives were identified compared to one in control centres. The rate of HCV diagnoses was higher among intervention centres, with 37 versus seven positive tests (OR 5.2; 95% CI 2.3-11.6; P < .001). Of them, 10 were new diagnoses and 27 had been previously diagnosed, although not linked to care. In conclusion, a simple operational programme can lead to an increase in HCV and HIV screening rates, compared to an exclusively educational programme. The selection of at-risk patients with a self-questionnaire and the use of rapid tests significantly increased the diagnostic rate of HCV infection.
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Infecciones por VIH , Hepatitis C , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Hepacivirus , Hepatitis C/diagnóstico , Hepatitis C/epidemiología , Humanos , Masculino , Tamizaje Masivo , Atención Primaria de Salud , Estudios ProspectivosRESUMEN
This paper presents the development process of a robust and ROS-based Drive-By-Wire system designed for an autonomous electric vehicle from scratch over an open source chassis. A revision of the vehicle characteristics and the different modules of our navigation architecture is carried out to put in context our Drive-by-Wire system. The system is composed of a Steer-By-Wire module and a Throttle-By-Wire module that allow driving the vehicle by using some commands of lineal speed and curvature, which are sent through a local network from the control unit of the vehicle. Additionally, a Manual/Automatic switching system has been implemented, which allows the driver to activate the autonomous driving and safely taking control of the vehicle at any time. Finally, some validation tests were performed for our Drive-By-Wire system, as a part of our whole autonomous navigation architecture, showing the good working of our proposal. The results prove that the Drive-By-Wire system has the behaviour and necessary requirements to automate an electric vehicle. In addition, after 812 h of testing, it was proven that it is a robust Drive-By-Wire system, with high reliability. The developed system is the basis for the validation and implementation of new autonomous navigation techniques developed within the group in a real vehicle.
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OBJETIVO: Estimar la prevalencia de la infección por VHC en la población general de un área sanitaria a través de una intervención en Atención Primaria, diferenciando entre nuevos diagnósticos e infecciones previamente diagnosticadas pero no tratadas. MÉTODOS: Se seleccionaron participantes mediante un cuestionario de evaluación de riesgo, realizando un test rápido a todos aquellos con alguna respuesta afirmativa y a todos los mayores de 50 años. Las pruebas positivas se confirmaron en el laboratorio mediante determinación de anticuerpos frente al VHC por enzimoinmunoensayo de micropartículas quimioluminiscente y determinación de la viremia. RESULTADOS: Del total de 7.991 participantes, el 36,2% presentó cuestionario de riesgo para VHC. Se realizaron 4.717 test, encontrando una proporción de anti-VHC de 0,65% en la población cribada, quedando en 0,46% de infecciones activas. El 51,9% de las personas con test positivo tenían un diagnóstico previo conocido pero no habían recibido tratamiento, por no ser conscientes de ello o no encontrarse vinculados al sistema sanitario, y el 19,2% tuvo un resultado positivo por primera vez. La prevalencia de infección oculta fue mayor en hombres, mayores de 50 años, y personas procedentes de Europa del Este. CONCLUSIÓN: Encontramos una prevalencia de infecciones activas superior a la descrita recientemente a nivel nacional, y con mayor porcentaje de pacientes nuevamente diagnosticados que en trabajos similares en otras áreas. Estas diferencias justifican la necesidad de realizar evaluaciones locales de la prevalencia de infección por VHC en cada una de las áreas de salud donde se plantee implementar y monitorizar un programa de microeliminación
OBJECTIVE: To estimate the prevalence of HCV infection in the general population of a health area through an intervention in Primary Care, differentiating between new diagnoses and infections previously diagnosed but not treated. METHODS: Participants were selected through a risk assessment questionnaire, with all those who gave at least one affirmative answer and all those over 50 years of age undergoing a rapid test. Positive tests were confirmed in the lab by determination of anti-HCV antibodies by chemiluminescent microparticle immunoassay and determination of viraemia. RESULTS: Of the 7,991 participants, 36.2% presented a positive HCV risk questionnaire. 4,717 tests were performed, finding an anti-HCV percentage of 0.65% in the screened population, with 0.46% of active infections. Among the individuals with a positive test result, 51.9% had a known prior diagnosis but had not received treatment, because they were not aware of it or were not linked to the health system, and 19.2% had a positive result for the first time. The prevalence of hidden infection was higher in men, those over 50 years of age and people from Eastern Europe. CONCLUSION: We found a prevalence of active infections higher than recently described nationwide, and a higher percentage of newly diagnosed infections than recent similar studies in other areas. These differences justify the need to perform local assessments of the prevalence of HCV infection in each of the health areas where it is planned to implement and monitor a microelimination programme
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Humanos , Masculino , Femenino , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Hepatitis C/epidemiología , Hepatitis C/diagnóstico , Atención Primaria de Salud , Prevalencia , Encuestas y Cuestionarios , Medición de Riesgo , España/epidemiologíaRESUMEN
Automated Driving Systems (ADSs) require robust and scalable control systems in order to achieve a safe, efficient and comfortable driving experience. Most global planners for autonomous vehicles provide as output a sequence of waypoints to be followed. This paper proposes a modular and scalable waypoint tracking controller for Robot Operating System (ROS)-based autonomous guided vehicles. The proposed controller performs a smooth interpolation of the waypoints and uses optimal control techniques to ensure robust trajectory tracking even at high speeds in urban environments (up to 50 km/h). The delays in the localization system and actuators are compensated in the control loop to stabilize the system. Forward velocity is adapted to path characteristics using a velocity profiler. The controller has been implemented as an ROS package providing scalability and exportability to the system in order to be used with a wide variety of simulators and real vehicles. We show the results of this controller using the novel and hyper realistic CARLA Simulator and carrying out a comparison with other standard and state-of-art trajectory tracking controllers.
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OBJECTIVE: To estimate the prevalence of HCV infection in the general population of a health area through an intervention in Primary Care, differentiating between new diagnoses and infections previously diagnosed but not treated. METHODS: Participants were selected through a risk assessment questionnaire, with all those who gave at least one affirmative answer and all those over 50 years of age undergoing a rapid test. Positive tests were confirmed in the lab by determination of anti-HCV antibodies by chemiluminescent microparticle immunoassay and determination of viraemia. RESULTS: Of the 7,991 participants, 36.2% presented a positive HCV risk questionnaire. 4,717 tests were performed, finding an anti-HCV percentage of 0.65% in the screened population, with 0.46% of active infections. Among the individuals with a positive test result, 51.9% had a known prior diagnosis but had not received treatment, because they were not aware of it or were not linked to the health system, and 19.2% had a positive result for the first time. The prevalence of hidden infection was higher in men, those over 50 years of age and people from Eastern Europe. CONCLUSION: We found a prevalence of active infections higher than recently described nationwide, and a higher percentage of newly diagnosed infections than recent similar studies in other areas. These differences justify the need to perform local assessments of the prevalence of HCV infection in each of the health areas where it is planned to implement and monitor a microelimination programme.
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Anticuerpos contra la Hepatitis C , Hepatitis C , Europa Oriental , Femenino , Hepatitis C/epidemiología , Anticuerpos contra la Hepatitis C/sangre , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , España/epidemiología , ViremiaRESUMEN
INTRODUCTION: HIV testing guidelines are poorly implemented in most clinical settings. The best screening strategy and healthcare scenario are still unknown. The aim of our study is to evaluate the impact of a structured HIV testing intervention (DRIVE), compared to HIV testing as routinely performed in clinical practice, in two different clinical settings: a primary care center and an emergency department. METHODS: Prospective evaluation of an HIV testing strategy in two clinical settings from the same healthcare area. The DRIVE program included trained nurse practitioners to perform the screening, a questionnaire to assess the risk of exposure and HIV indicator conditions (RE&IC), and rapid HIV tests. The main variables between the DRIVE program and clinical practice were the absolute number of newly diagnosed HIV infections and testing coverage. RESULTS: The DRIVE program included 5,329 participants, of which 51.2% reported at least one positive answer in the questionnaire. The estimated HIV testing coverage was significantly higher in the DRIVE program than in the routine clinical practice (7.17% vs. 0.96%, p < 0.001), and was better in the primary care center than in the emergency department with the two strategies. Twenty-two HIV-positive people were identified, with a rate of 8.6 in the emergency department vs. 2.2 in the primary care center (p = 0.001). A higher rate of new HIV diagnoses was found in the DRIVE program compared to routine clinical practice (29.6 vs. 3.1 per 100,000 patients attended; p < 0.001). CONCLUSIONS: An easy-to-implement, structured intervention increased the absolute number of new HIV diagnoses and HIV tests, compared to routine clinical practice.
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Serodiagnóstico del SIDA/métodos , Servicio de Urgencia en Hospital , Atención Primaria de Salud , Adulto , Femenino , Infecciones por VIH/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Estudios Prospectivos , Medición de Riesgo , Encuestas y CuestionariosRESUMEN
BACKGROUND: Late HIV diagnosis remains one of the challenges in combating the epidemic. Primary care providers play an important role in screening for HIV infection. Our study aims to evaluate the relationship between knowledge and barriers to HIV testing and screening outcomes. The impact of an education program for primary care providers, towards improving HIV testing and late diagnosis rates, is also assessed. METHODS: A self-administered questionnaire that was developed within the framework of the European project OptTEST was used to examine HIV knowledge and barriers to HIV testing scores before and after being involved in an HIV education program. A quasi-experimental design with pre- and post-intervention measures was performed to investigate its impact. We performed multivariable logistic regression analysis to assess the relationship between variables for the HIV testing offer. RESULTS: A total of 20 primary care centers and 454 primary care staff were included. Baseline OptTEST results showed that more knowledgeable staff offered an HIV test more frequently (OR 1.07; CI 95% 1.01-1.13; p = 0.027) and had lower barrier scores (OR 0.89; CI 95% 0.77-0.95; p = 0.005). Nurses had lower scores in knowledge-related items (OR 0.28; CI 95% 0.17-0.46; p<0.001), but higher scores in barrier-related items than physicians (OR 3.28; CI 95% 2.01-5.46; p<0.001). Specific centers with more knowledgeable staff members had a significant association with a greater level of new HIV diagnosis rates (OR 1.61; CI 95% 1.04-2.49; p = 0.032). After the intervention, we found that 12 out of 14 individual questions showed improved scores. In the 6 months after the training program, we similarly found a higher HIV testing rate (OR 1.19; CI 1.02-1.42; p = 0.036). CONCLUSIONS: This study highlights the association between knowledge and barriers to HIV testing, including HIV testing rates. It shows that it is possible to modify knowledge and reduce perceived barriers through educational programs, subsequently improving HIV screening outcomes.
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Diagnóstico Tardío/prevención & control , Educación Continua , Infecciones por VIH , Personal de Salud/educación , Tamizaje Masivo , Atención Primaria de Salud , Adolescente , Adulto , Anciano , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/terapia , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Alternative processing routes such as powder metallurgy, the extrusion of recycled chips, or equal channel angular pressing (ECAP) have been considered for effective methods of maintaining the high mechanical strength of Mg-Y-Zn alloys containing long-period stacking ordered structures with respect to the alloy processed by the conventional extrusion of as-cast ingots with the advantage of minimizing the yttrium content. A yield stress similar to that found for extruded Mg97Y2Zn1 alloy can be attained with only half of the usual yttrium and zinc additions thanks to the grain refinement induced by ECAP processing. The properties of Mg98.5Y1Zn0.5 subjected to ECAP are maintained up to 200 °C, but superplastic behavior is found above this temperature when the alloy is processed through a powder metallurgy route.
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The aim of this study was proposing gamma band activity (GBA) as an index of training-related brain plasticity in the motor cortex. Sixteen controls underwent an experimental session where electroencephalography (EEG) activity was recorded at baseline (resting) and during a motor task (hand movements). GBA was obtained from the EEG data at baseline and during the task. Index of plasticity (IP) was defined as the relationship between GBA at the end of the motor task (GBAM_FIN), divided by GBA at the beginning of the task (GBAM_INI) for movements of both hands. There was a significant increase in GBA at the end of the task, compared to the initial GBA for the motor task (GBAM_FIN > GBAM_INI). No differences were found at baseline (GBAB_FIN ≈ GBAB_INI). Individual IP values had a positive (r = 0.624) and significant correlation with subject's handedness. Due to plastic changes, GBA could indirectly but objectively reveal changes in cerebral activity related to physical training. This method could be used as a future diagnostic test in the follow-up of patients undergoing rehabilitation. It could also have potential applications in the fields of sports medicine.
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Electroencefalografía/métodos , Corteza Motora/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
This paper presents a sequential non-rigid reconstruction method that recovers the 3D shape and the camera pose of a deforming object from a video sequence and a previous shape model of the object. We take PTAM (Parallel Mapping and Tracking), a state-of-the-art sequential real-time SfM (Structure-from-Motion) engine, and we upgrade it to solve non-rigid reconstruction. Our method provides a good trade-off between processing time and reconstruction error without the need for specific processing hardware, such as GPUs. We improve the original PTAM matching by using descriptor-based features, as well as smoothness priors to better constrain the 3D error. This paper works with perspective projection and deals with outliers and missing data. We evaluate the tracking algorithm performance through different tests over several datasets of non-rigid deforming objects. Our method achieves state-of-the-art accuracy and can be used as a real-time method suitable for being embedded in portable devices.
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The purpose of this paper is to determine whether gamma-band activity detection is improved when a filter, based on empirical mode decomposition (EMD), is added to the pre-processing block of single-channel electroencephalography (EEG) signals. EMD decomposes the original signal into a finite number of intrinsic mode functions (IMFs). EEGs from 25 control subjects were registered in basal and motor activity (hand movements) using only one EEG channel. Over the basic signal, IMF signals are computed. Gamma-band activity is computed using power spectrum density in the 30-60 Hz range. Event-related synchronization (ERS) was defined as the ratio of motor and basal activity. To evaluate the performance of the new EMD based method, ERS was computed from the basic and IMF signals. The ERS obtained using IMFs improves, from 31.00% to 73.86%, on the original ERS for the right hand, and from 22.17% to 47.69% for the left hand. As EEG processing is improved, the clinical applications of gamma-band activity will expand.
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Electroencefalografía , Algoritmos , Mano , Humanos , Movimiento , Procesamiento de Señales Asistido por ComputadorRESUMEN
One of the main challenges of aerial robots navigation in indoor or GPS-denied environments is position estimation using only the available onboard sensors. This paper presents a Simultaneous Localization and Mapping (SLAM) system that remotely calculates the pose and environment map of different low-cost commercial aerial platforms, whose onboard computing capacity is usually limited. The proposed system adapts to the sensory configuration of the aerial robot, by integrating different state-of-the art SLAM methods based on vision, laser and/or inertial measurements using an Extended Kalman Filter (EKF). To do this, a minimum onboard sensory configuration is supposed, consisting of a monocular camera, an Inertial Measurement Unit (IMU) and an altimeter. It allows to improve the results of well-known monocular visual SLAM methods (LSD-SLAM and ORB-SLAM are tested and compared in this work) by solving scale ambiguity and providing additional information to the EKF. When payload and computational capabilities permit, a 2D laser sensor can be easily incorporated to the SLAM system, obtaining a local 2.5D map and a footprint estimation of the robot position that improves the 6D pose estimation through the EKF. We present some experimental results with two different commercial platforms, and validate the system by applying it to their position control.
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OBJECTIVE: Propose a simplified method applicable in routine clinical practice that uses EEG to assess induced gamma-band activity (GBA) in the 30-90 Hz frequency range in cerebral motor areas. DESIGN: EEG recordings (25 healthy subjects) of cerebral activity (at rest, motor task). GBA was obtained as power spectral density (PSD). GBA - defined as the gamma index (Iγ) - was calculated using the basal GBA (γB) and motor GBA (γMOV) PSD values. RESULTS: The mean values of Iγ were (IγR (right hand) = 1.30, IγL (left hand) = 1.22). Manual laterality showed a correlation with Iγ. CONCLUSIONS: Iγ may provide a useful way of indirectly assessing operation of activated motor neuronal circuits. It could be applied to diagnosis of motor area pathologies and as follow up in rehabilitation processes. Likewise, Iγ could enable the assessment of motor capacity, physical training and manual laterality in sport medicine.
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Electroencefalografía/métodos , Ritmo Gamma/fisiología , Corteza Motora/fisiología , Movimiento/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Humanoid robotics is a field of a great research interest nowadays. This work implements a low-cost teleoperated system to control a humanoid robot, as a first step for further development and study of human motion and walking. A human suit is built, consisting of 8 sensors, 6 resistive linear potentiometers on the lower extremities and 2 digital accelerometers for the arms. The goal is to replicate the suit movements in a small humanoid robot. The data from the sensors is wirelessly transmitted via two ZigBee RF configurable modules installed on each device: the robot and the suit. Replicating the suit movements requires a robot stability control module to prevent falling down while executing different actions involving knees flexion. This is carried out via a feedback control system with an accelerometer placed on the robot's back. The measurement from this sensor is filtered using Kalman. In addition, a two input fuzzy algorithm controlling five servo motors regulates the robot balance. The humanoid robot is controlled by a medium capacity processor and a low computational cost is achieved for executing the different algorithms. Both hardware and software of the system are based on open platforms. The successful experiments carried out validate the implementation of the proposed teleoperated system.
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This paper describes a sensory system for implementing a human-computer interface based on electrooculography. An acquisition system captures electrooculograms and transmits them via the ZigBee protocol. The data acquired are analysed in real time using a microcontroller-based platform running the Linux operating system. The continuous wavelet transform and neural network are used to process and analyse the signals to obtain highly reliable results in real time. To enhance system usability, the graphical interface is projected onto special eyewear, which is also used to position the signal-capturing electrodes.
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Sistemas Hombre-Máquina , Electrooculografía , Redes Neurales de la Computación , Umbral Sensorial , Procesamiento de Señales Asistido por Computador , Programas Informáticos , Interfaz Usuario-ComputadorRESUMEN
This paper presents a platform used to acquire, analyse and transmit data from a vehicle to a Control Centre as part of a Pay-As-You-Drive system. The aim is to monitor vehicle usage (how much, when, where and how) and, based on this information, assess the associated risk and set an appropriate insurance premium. To determine vehicle usage, the system analyses the driver's respect for speed limits, driving style (aggressive or non-aggressive), mobile telephone use and the number of vehicle passengers. An electronic system on board the vehicle acquires these data, processes them and transmits them by mobile telephone (GPRS/UMTS) to a Control Centre, at which the insurance company assesses the risk associated with vehicles monitored by the system. The system provides insurance companies and their customers with an enhanced service and could potentially increase responsible driving habits and reduce the number of road accidents.
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Accidentes de Tránsito/prevención & control , Conducción de Automóvil , Sistemas de Información Geográfica/instrumentación , Cobertura del Seguro , Procesamiento de Señales Asistido por Computador/instrumentación , Aceleración , Accidentes de Tránsito/economía , Accidentes de Tránsito/estadística & datos numéricos , Conducción de Automóvil/estadística & datos numéricos , Recolección de Datos/economía , Recolección de Datos/instrumentación , Recolección de Datos/métodos , Interpretación Estadística de Datos , Humanos , Cobertura del Seguro/organización & administración , Proyectos de Investigación , SeguridadRESUMEN
This paper describes an eye-control method based on electrooculography (EOG) to develop a system for assisted mobility. One of its most important features is its modularity, making it adaptable to the particular needs of each user according to the type and degree of handicap involved. An eye model based on electroculographic signal is proposed and its validity is studied. Several human-machine interfaces (HMI) based on EOG are commented, focusing our study on guiding and controlling a wheelchair for disabled people, where the control is actually effected by eye movements within the socket. Different techniques and guidance strategies are then shown with comments on the advantages and disadvantages of each one. The system consists of a standard electric wheelchair with an on-board computer, sensors and a graphic user interface run by the computer. On the other hand, this eye-control method can be applied to handle graphical interfaces, where the eye is used as a mouse computer. Results obtained show that this control technique could be useful in multiple applications, such as mobility and communication aid for handicapped persons.