14 research outputs found

    Vision artificielle pour les non-voyants : une approche bio-inspirée pour la reconnaissance de formes

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    More than 315 million people worldwide suffer from visual impairments, with several studies suggesting that this number will double by 2030 due to the ageing of the population. To compensate for the loss of sight the current approaches consist of either specific aids designed to answer particular needs or generic systems such as neuroprostheses and sensory substitution devices. These holistic approaches, which try to restore vision as a whole, have been shown to be very inefficient in real life situations given the low resolution of output interfaces. To overcome these obstacles we propose the use of artificial vision in order to pre-process visual scenes and provide the user with relevant information. We have validated this approach through the development of a novel assistive device for the blind called Navig. Through shape recognition and spatialized sounds synthesis, this system allows users to locate and grab objects of interest. It also features navigational aids based on a new positioning method combining GPS, inertial sensors and the visual detection of geolocalized landmarks. To enhance the performance of the visual module we further developed, as part of this thesis, a bio-inspired pattern recognition algorithm which uses latency-based coding of visual information, oriented edge representations and a cascaded architecture combining detection at different resolutions.La dĂ©ficience visuelle touche aujourd’hui plus de 315 millions de personnes Ă  travers le monde, un chiffre qui pourrait doubler d’ici Ă  2030 du fait du vieillissement de la population. Les deux grandes approches existantes pour compenser la perte de vision sont les aides spĂ©cifiques, rĂ©pondant Ă  un besoin identifiĂ©, et les systĂšmes gĂ©nĂ©riques tels que les neuroprothĂšses ou les systĂšmes de substitution sensorielle. Ces approches holistiques, tentant de restituer l’ensemble de l’information visuelle, s’avĂšrent inadaptĂ©es de par la trop faible rĂ©solution des interfaces de sortie, rendant ces systĂšmes inutilisables dans la vie quotidienne. Face Ă  ce constat, nous proposons dans cette thĂšse une dĂ©marche alternative, consistant Ă  intĂ©grer des mĂ©thodes de vision artificielle, afin de prĂ©traiter la scĂšne visuelle, et de ne restituer au non-voyant que les informations extraites pertinentes. Pour valider cette approche, nous prĂ©senterons le dĂ©veloppement d’un systĂšme de supplĂ©ance baptisĂ© Navig. GrĂące Ă  la reconnaissance de formes et Ă  la synthĂšse de sons spatialisĂ©s, il permet Ă  l’utilisateur de localiser des objets d’intĂ©rĂȘt. Il offre Ă©galement des fonctions de navigation, basĂ©es sur une nouvelle mĂ©thode de positionnement combinant GPS, donnĂ©es inertielles, et dĂ©tections de cibles visuelles gĂ©olocalisĂ©es. Afin d’amĂ©liorer les performances du module de vision artificielle, nous proposerons Ă©galement dans cette thĂšse un nouvel algorithme de reconnaissance de formes bio-inspirĂ©, reposant sur un codage de l’information visuelle par latence, sur des reprĂ©sentations sous forme d’arĂȘtes orientĂ©es, et sur une architecture en cascade combinant des dĂ©tections Ă  diffĂ©rentes rĂ©solutions

    NAVIG: augmented reality guidance system for the visually impaired

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    International audienceNavigating complex routes and finding objects of interest are challenging tasks for the visually impaired. The project NAVIG (Navigation Assisted by artificial VIsion and GNSS) is directed toward increasing personal autonomy via a virtual augmented reality system. The system integrates an adapted geographic information system with different classes of objects useful for improving route selection and guidance. The database also includes models of important geolocated objects that may be detected by real-time embedded vision algorithms. Object localization (relative to the user) may serve both global positioning and sensorimotor actions such as heading, grasping, or piloting. The user is guided to his desired destination through spatialized semantic audio rendering, always maintained in the head-centered reference frame. This paper presents the overall project design and architecture of the NAVIG system. In addition, details of a new type of detection and localization device are presented. This approach combines a bio-inspired vision system that can recognize and locate objects very quickly and a 3D sound rendering system that is able to perceptually position a sound at the location of the recognized object. This system was developed in relation to guidance directives developed through participative design with potential users and educators for the visually impaired

    Adult attention-deficit/hyperactivity disorder among alcohol use disorder inpatients is associated with food addiction and binge eating, but not BMI

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    Introduction: Attention-deficit/hyperactivity disorder (ADHD) is associated with binge eating (BE), food addiction (FA), and obesity/higher BMI in individuals without alcohol use disorder (AUD). ADHD is highly prevalent in patients with AUD, but it is unknown whether the presence of comorbid AUD might change the nature of the association between ADHD, BE, FA and BMI (food and alcohol may either compete for the same brain neurocircuitry or share vulnerability risk factors). Here, we filled this gap by testing the association between ADHD and FA/BE in adult patients hospitalized for AUD, with the strength of simultaneously assessing childhood and adult ADHD. We also investigated the association between ADHD and BMI, and the other factors associated with BMI (FA/BE, AUD severity). Methods: We included 149 AUD inpatients between November 2018 and April 2019. We assessed both childhood and adulthood ADHD (Wender Utah Render Scale and Adult ADHD Self-Report Scale), FA (modified Yale Food Addiction Scale 2.0), BE (Binge Eating Scale), and BMI and AUD (clinical assessment). Results: In multivariable analyses adjusted for age, adult ADHD was associated with higher BE scores (p = .048), but not significant BE (9% vs. 7%; p = .70). ADHD was also associated with FA diagnosis and the number or FA symptoms, with larger effect size for adult (ORs: 9.45[95%CI: 2.82–31.74] and 1.38[1.13–1.69], respectively) than childhood ADHD (ORs: 4.45[1.37–14.46] and 1.40[1.13–1.75], respectively). In multivariable analysis, BMI was associated with both significant BE (p &lt; .001) and FA diagnosis (p = .014), but not adult ADHD nor AUD severity. Conclusion: In patients hospitalized for AUD, self-reported adult ADHD was associated with FA and BE, but not BMI. Our results set the groundwork for longitudinal research on the link between ADHD, FA, BE, and BMI in AUD inpatients.</p

    Navigation and space perception assistance for the visually impaired: The NAVIG project

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    International audienceNavigation, especially in unknown areas, remains a major problem for the visually impaired (VI). Over the past 50 years, a number of electronic travel aids (ETAs) have been developed with the aim of improving the mobility of the VI. Despite the efforts, these systems are rarely used. Although the explanation is likely to be incomplete, it is possible to identify three important factors: (1) positioning accuracy provided by these devices is not sufficient to guide a VI pedestrian, (2) these systems are based on Geographical Information Systems not adapted to pedestrian mobility, and (3) the guidance methods should be adapted to the task of pedestrian navigation. The NAVIG project aims to answer all these limitations through a participatory design framework with the VI and orientation and mobility instructors. The NAVIG device aims to complement conventional mobility aids (i.e. white cane and guide dog), while also adding unique features to localize specific objects in the environment, restore some visuomotor abilities, and assist navigation

    Heterogeneities in Cognitive and Socio-Emotional Development in Children With Autism Spectrum Disorder and Severe Intellectual Disability as a Comorbidity

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    International audienceIntroduction: Intellectual disability (ID) is frequently associated as a comorbidity in autism spectrum disorders (ASD). This study investigated a) how similar the heterogeneity in the cognitive and socio-emotional developmental profiles was for children with ASD and ID, b) the difference between the subjects’ profiles and those of typically developing children (TD) matched for developmental levels, c) the skills existing with the lowest and highest developmental levels, and d) the relationship between developmental profiles in ASD and the severity of autism, ID, and the overall developmental level.Participants: The sample was comprised of 119 children (101 boys and 18 girls) who ranged in chronological age (CA) from 21 months to 14 years (M = 5 years 2 months; SD = 2 years 6 months) with developmental levels lower than 24 months. They came from three countries (France = 40, Brazil = 40, and Algeria = 39). The control group was comprised of 40 TD children from these same countries who ranged in CA from 4 to 24 months (M = 1 year 3 months; SD = 5 months). The ASD diagnosis was carried out according to International Statistical Classification of Diseases and Related Health Problems-10th Edition (ICD-10), Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR), Diagnostic and Statistical Manual of Mental Disorders-5th ed (DSM-5) criteria and the Childhood Autism Rating Scale (CARS).Measures: Children were tested using the Social Cognitive Evaluation Battery (SCEB; Adrien, 2007) by trained psychologists from public and private institutions specialized in the diagnosis of autism and interventions in this field. The SCEB explores 16 functional abilities, in both cognitive and socio-emotional areas, and allows the calculation of domain and area developmental levels and heterogeneity indices for the global, cognitive, and socio-emotional areas.Results: Children with ASD developmental profiles show very high heterogeneity as opposed to TD children. Regardless of the country of origin, there are similarities between the heterogeneous cognitive and socio-emotional developmental profiles of the children with ASD, whose profiles are characterized by lower developmental levels of language and vocal imitation skills, and a relationship between these developmental heterogeneities and the degree of severity of autistic symptomatology, intellectual disability, and overall development level. The implications of this study are presented for clinical assessment and intervention purposes in ASD and ID
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