67 research outputs found

    Bruère-Allichamps – Le Patureau des Chaumes

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    Date de l'opération : 1986 (SP) ; 1985 (SP) ; 1984 (SU) Inventeur(s) : Chalvignac Laurent ; Barbé Hervé A l'emplacement d'une concentration de 600 m2 de fragments de poterie non tournée, de nombreuses fosses, fortement arasées, ont été fouillées de 1984 à 1986. Creusées pour extraire du sable et de l'argile, sans doute en vue de la fabrication de poterie, ces fosses ont été utilisées comme dépotoirs au Hallstatt ancien mais l'habitat correspondant n'a pas été repéré (Gallia Préhistoire, 1986,..

    Hydraulically-actuated compliant revolute joint for medical robotic systems based on multimaterial additive manufacturing

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    IEEE International Conference on Robotics and Automation (ICRA), Montréal, Canada, janvier 2019 Research team : AV

    Compliant grasping device for robotized medical applications

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    Needle manipulation is a very common need in several specialties. This paper presents the development of NGDs (needle grasping devices) capable of handling elongated objects such as surgical needles. After describing the main demands of medical needle-based procedures, a requirement list for a typical NGD is presented. Some solution principles for a grasping device are generated, combined and then classified to obtain a set of principle variant solutions. The design study of some of these variant solutions is then developed and a discussion on two device candidates constructed using either interconnected rigid bodies or compliant parts will be presented. The mechanical behavior of the compliant mechanism acting on a needle barrel is simulated with a FEM analysis including the model of non-linearities induced by large deformations and the contact between the needle and the grasping device. Functional prototypes of both NGDs have been constructed and a first experimental assessments of their service capability are finally exposed

    Observations And Experiments For The Definition Of A New Robotic Device Dedicated To CT, CBCT And MRI-Guided Percutaneous Procedures.

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    In this paper, we present the work achieved to define the robotic functionalities of interest for percutaneous procedures as performed in interventional radiology. Our contributions are twofold. First, a detailed task analysis is performed with workflow analysis of biopsies, one of the most frequent tasks, under three imaging modalities, namely CT, CBCT and MRI. Second, the functionalities of a robotic assistant are identified, and we analyze whether a single device can bring an added value during procedures in the three modalities while keeping the robotized workflow close to manual tasks, to minimize learning time and difficulty of use. Experimental analysis on CBCT is notably used to confirm the interest of the determined robotic functionalities.journal articleresearch support, non-u.s. gov't2018 07importedIEEE Engineering in Medicine and Biology Society, Honolulu, United States, juillet 2018 Research team : AV

    Erwinia amylovora Novel Plasmid pEI70: Complete Sequence, Biogeography, and Role in Aggressiveness in the Fire Blight Phytopathogen

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    Comparative genomics of several strains of Erwinia amylovora, a plant pathogenic bacterium causal agent of fire blight disease, revealed that its diversity is primarily attributable to the flexible genome comprised of plasmids. We recently identified and sequenced in full a novel 65.8 kb plasmid, called pEI70. Annotation revealed a lack of known virulence-related genes, but found evidence for a unique integrative conjugative element related to that of other plant and human pathogens. Comparative analyses using BLASTN showed that pEI70 is almost entirely included in plasmid pEB102 from E. billingiae, an epiphytic Erwinia of pome fruits, with sequence identities superior to 98%. A duplex PCR assay was developed to survey the prevalence of plasmid pEI70 and also that of pEA29, which had previously been described in several E. amylovora strains. Plasmid pEI70 was found widely dispersed across Europe with frequencies of 5–92%, but it was absent in E. amylovora analyzed populations from outside of Europe. Restriction analysis and hybridization demonstrated that this plasmid was identical in at least 13 strains. Curing E. amylovora strains of pEI70 reduced their aggressiveness on pear, and introducing pEI70 into low-aggressiveness strains lacking this plasmid increased symptoms development in this host. Discovery of this novel plasmid offers new insights into the biogeography, evolution and virulence determinants in E. amylovora

    Téléopération avec retour d'efforts pour les interventions percutanées

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    Interventional radiology is a minimally-invasive surgical technique, which allows to reach internal organs with a needle, thanks to CT-scan guidance. It has several benefits in comparison with classical surgery but, unfortunately it also expose the radiologists to harmful X-rays. To cope with this problem, we have developed a force-feedback teleoperation system. Its specifications have been established from in vivo experiments, which have also been used to model the interaction forces during needle insertion. The proposed teleoperation system is consistent with the constraints of CT-images and the needs of practitioners. We have studied several bilateral structures and determined the best one for the application. To enhance the haptic perception, we have developed two methods. The first one is based on the automatic tuning of the force controller at the master side. The second method is an algorithm to detect and enhance transitions during the insertion.La radiologie interventionnelle est une technique chirurgicale minimallement invasive qui permet d'atteindre des organes à traiter avec des aiguilles, guidées à partir d'images scanner. Bien que cette technique offre de nombreux avantages, l'exposition aux rayons X qu'elle occasionne est nocive pour le radiologue. Pour résoudre ce problème, nous avons développé un système de téléopération avec retour d'efforts. Son cahier des charges a été établi à partir d'expériences in-vivo, qui ont notamment conduit à la modélisation des forces lors d'une insertion. Le système développé répond aux contraintes liées à l'utilisation des rayons X et aux besoins des praticiens. Une étude approfondies a permis de déterminer la commande bilatérale la mieux adaptée à l'application. Pour améliorer la perception des efforts, deux approches ont été étudiées. La première est une synthèse automatique de la commande en effort côté maître. La seconde vise à accroître la sensation de passage entre les tissus
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