327 research outputs found

    Real-Time Equilibrium Reconstruction in a Tokamak

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    This paper deals with the numerical reconstruction of the plasma current density in a Tokamak and of its equilibrium. The problem consists in the identification of a non-linear source in the 2D Grad-Shafranov equation, which governs the axisymmetric equilibrium of a plasma in a Tokamak. The experimental measurements that enable this identification are the magnetics on the vacuum vessel, but also polarimetric and interferometric measures on several chords, as well as motional Stark effect or pressure measurements. The reconstruction can be obtained in real-time using a finite element method, a non-linear fixed-point algorithm and a least-square optimization procedure

    The use of Biofeedback in Clinical Virtual Reality: The INTREPID Project

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    Generalized anxiety disorder (GAD) is a psychiatric disorder characterized by a constant and unspecific anxiety that interferes with daily-life activities. Its high prevalence in general population and the severe limitations it causes, point out the necessity to find new efficient strategies to treat it. Together with the cognitive-behavioral treatments, relaxation represents a useful approach for the treatment of GAD, but it has the limitation that it is hard to be learned. The INTREPID project is aimed to implement a new instrument to treat anxiety-related disorders and to test its clinical efficacy in reducing anxiety-related symptoms. The innovation of this approach is the combination of virtual reality and biofeedback, so that the first one is directly modified by the output of the second one. In this way, the patient is made aware of his or her reactions through the modification of some features of the VR environment in real time. Using mental exercises the patient learns to control these physiological parameters and using the feedback provided by the virtual environment is able to gauge his or her success. The supplemental use of portable devices, such as PDA or smart-phones, allows the patient to perform at home, individually and autonomously, the same exercises experienced in therapist's office. The goal is to anchor the learned protocol in a real life context, so enhancing the patients' ability to deal with their symptoms. The expected result is a better and faster learning of relaxation techniques, and thus an increased effectiveness of the treatment if compared with traditional clinical protocols

    Life gain in Italian smokers who quit

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    This study aims to estimate the number of life years gained with quitting smoking in Italian smokers of both sexes, by number of cigarettes smoked per day (cig/day) and age at cessation. All-cause mortality tables by age, sex and smoking status were computed, based on Italian smoking data, and the survival curves of former and current smokers were compared. The more cig/day a man/woman smokes, and the younger his/her age of quitting smoking, the more years of life he/she gains with cessation. In fact, cessation at age 30, 40, 50, or 60 years gained, respectively, about 7, 7, 6, or 5, and 5, 5, 4, or 3 years of life, respectively, for men and women that smoked 10-19 cig/day. The gain in life years was higher for heavy smokers (9 years for >20 cig/day) and lower for light smokers (4 years for 1-9 cig/day). Consistently with prospective studies conducted worldwide, quitting smoking increases life expectancy regardless of age, gender and number of cig/day. The estimates of the number of years of life that could be gained by quitting smoking, when computed specifically for a single smoker, could be used by physicians and health professionals to promote a quit attempt. © 2014 by the authors; licensee MDPI, Basel, Switzerland

    La realidad virtual como entorno fortalecedor para el cambio personal: la contribuciĂłn del laboratorio de tecnologĂ­a aplicada a la neuropsicologĂ­a

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    When we exercise real choice, we gain increased control over our lives and are able to change ourselves. However for many subjects it is not easy to exercise effective choices: patients often don’t have the knowledge, skills, assertiveness, or self esteem needed. In this situation Virtual Reality (VR), an artificial reality that projects the user into a 3D space generated by the computer, may offer a critical advantage to the therapist. The enriched experience and the total level of control on its features, transform VR in an “empowering environment”, where patients can start to explore and act without feeling actually threatened. The attempt of defining, developing and testing VR tools supporting personal empowerment is the main goal of the Applied Technology for Neuro-Psychology Laboratory –ATN-P Lab– at the Istituto Auxologico Italiano. The paper describes the actual work done by the ATN-P Lab. in this area. Specifically, the open source "NeuroVR" system and its potential clinical applications –anxiety disorders, obesity and eating disorders– are presented and discussed.La capacidad de elección nos proporciona control sobre nuestras vidas y nos ofrece posibilidades de cambio. Sin embargo, para muchas personas no es fácil realizar elecciones efectivas; por ejemplo, los pacientes carecen muchas veces del conocimiento, la habilidad, la asertividad o autoestima necesarias. En esas situaciones, la realidad virtual (RV), una realidad artificial que coloca al sujeto en un espacio generado por el ordenador, puede ser para el terapeuta un recurso decisivo. La experiencia enriquecida y el control total sobre todos sus aspectos transforman la RV en un “entorno fortalecedor”, en el que los pacientes pueden comenzar a explorar y actuar sin sentirse amenazados. El principal objetivo del “Applied Technology for Neuro-Psychology Laboratory” (ATN-P Lab), perteneciente al Instituto Auxologico Italiano, es intentar definir, desarrollar y probar aplicaciones basadas en RV que faciliten el fortalecimiento personal. En este artículo se describe el trabajo que se viene realizando sobre este tema en ese laboratorio. Se presenta y discute, específicamente, el sistema de código abierto denominado “NeuroVR”, así como sus aplicaciones clínicas potenciales sobre los trastornos de ansiedad, la obesidad y los trastornos alimentarios
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