Potentialities of optimal design methods and associated numerical tools for the development of new micro- and nanointelligent systems based on structural compliance - An example -

11 pagesInternational audienceThis paper deals with the interest and potential use of intelligent structures mainly based on compliant mechanisms (and optionally including smart materials), for the development of new micro- and nano-robotics devices. The state of the art in optimal design methods for the synthesis of intelligent compliant structures is briefly done. Then, we present the optimal method developed at CEA LIST, called FlexIn, and its new and still in development functionalities, which will be illustrated by a few simple design examples. An opening will be given about the possibility to address the field of Nanorobotics, while adding functionalities to the optimal design method

Dedicated and industrial robotic arms used as force feedback telerobots at the AREVA-La Hague recycling plant

ISBN: 978-1-4244-6635-1/10International audienceCEA LIST and AREVA have been developing remote operations devices, also called telerobotics for 15 years. These tools were designed for interventions in the AREVA nuclear spent fuel facilities hot cells. From these 15 years of joint research and development, several technological bricks have been industrialized and used at the AREVA La Hague facilities. This article presents some of these bricks and their industrial developments. The “TAO2000” CEA LIST telerobotics generic software controller will be first discussed. This controller has been used to teleoperate dedicated slave arms like the MT200 TAO (an evolution of the conventional wall-transmission mechanical telemanipulator (MSM)) as well as industrial robotic arms like the Stäubli RX robots. Both the MT200 TAO and Stäubli RX TAO telerobotics systems provide force-feedback and are now ready to be used as telemaintenance tools at the AREVA La Hague facilities. Two recent maintenance operations using these tools will be detailed at the end of this pape

Design study and first performance simulation of the ELT/MICADO focal plane coronagraphs

In this paper, we present the design and the expected performance of the classical Lyot coronagraph for the high contrast imaging modes of the wide-field imager MICADO. MICADO is a near-IR camera for the Extremely Large Telescope (ELT, previously E-ELT), with wide-field, spectroscopic and coronagraphic capabilities. MICADO is one of the first-light instruments selected by the ESO. Optimized to work with a multi-conjugate adaptive optics corrections provided by the MOARY module, it will also come with a SCAO correction with a high-level, on-axis correction, making use of the M4 adaptive mirror of the telescope. After presenting the context of the high contrast imaging modes in MICADO, we describe the selection process for the focal plane masks and Lyot stop. We will also show results obtained in realistic conditions, taking into account AO residuals, atmospheric refraction, noise sources and simulating observations in angular differential imaging (ADI) mode. Based on SPHERE on-sky results, we will discuss the achievable gain in contrast and angular separation provided by MICADO over the current instruments on 10-m class telescopes, in particular for imaging young giant planets at very short separations around nearby stars as well as planets on wider orbits around more distant stars in young stellar associations.Comment: 10 pages, 5 figures, AO4ELT 5 conference proceedin

Design and acceptability assessment of a new reversible orthosis

International audience— We present a new device aimed at being used for upper limb rehabilitation. Our main focus was to design a robot capable of working in both the passive mode (i.e. the robot shall be strong enough to generate human-like movements while guiding the weak arm of a patient) and the active mode (i.e. the robot shall be able of following the arm without disturbing human natural motion). This greatly challenges the design, since the system shall be reversible and lightweight while providing human compatible strength, workspace and speed. The solution takes the form of an orthotic structure, which allows control of human arm redundancy contrarily to clinically available upper limb rehabilitation robots. It is equipped with an innovative transmission technology, which provides both high gear ratio and fine reversibility. In order to evaluate the device and its therapeutic efficacy, we compared several series of pointing movements in healthy subjects wearing and not wearing the orthotic device. In this way, we could assess any disturbing effect on normal movements. Results show that the main movement characteristics (direction, duration, bell shape profile) are preserved

Transition numérique et pratiques de recherche et d’enseignement supérieur en agronomie, environnement, alimentation et sciences vétérinaires à l’horizon 2040.

Pour citer ce document:Barzman M. (Coord.), Gerphagnon M. (Coord.), Mora O. (Coord.),Aubin-Houzelstein G., Bénard A., Martin C., Baron G.L, Bouchet F., Dibie-Barthélémy J., Gibrat J.F., Hodson S., Lhoste E., Moulier-Boutang Y., Perrot S., Phung F., Pichot C., Siné M., Venin T. 2019. Transition numérique et pratiques de recherche et d’enseignement supérieur en agronomie, environnement, alimentation et sciences vétérinaires à l’horizon 2040.INRA, France, 161pagesTransition numérique et pratiques de recherche et d’enseignement supérieur en agronomie, environnement, alimentation et sciences vétérinaires à l’horizon 2040

Evaluation of the dose deposited by electron beams in radiotherapy in voxelized phantoms using the Monte Carlo GATE simulation platform based on GEANT4 in a grid environment

La planification de traitement en radiothérapie nécessite un calcul précis de la dose délivrée au patient. La méthode la plus fiable pour y parvenir est la simulation du transport des particules par technique Monte Carlo. Cette thèse constitue la première étude concernant la validation de la plateforme de simulation Monte Carlo GATE (GEANT4 Application for Tomographic Emission), basée sur les librairies de GEANT4 (GEometry ANd Tracking), pour le calcul de la dose absorbée déposée par des faisceaux d’électrons. L’objectif de cette thèse est de montrer que GATE/GEANT4 est capable d’atteindre le niveau d’exigences requis pour le calcul de la dose absorbée lors d’une planification de traitement, dans des situations où les algorithmes analytiques, actuellement utilisés dans les services de radiothérapie, n’atteignent pas un niveau de précision satisfaisant. L’enjeu est de prouver que GATE/GEANT4 est adapté pour la planification de traitement utilisant des électrons et capable de rivaliser avec d’autres codes Monte Carlo reconnus. Cet enjeu a été démontré par la simulation avec GATE/GEANT4 de faisceaux et des sources d’électrons réalistes utilisées en radiothérapie externe ou en radiothérapie moléculaire et la production de distributions de dose absorbée en accord avec les mesures expérimentales et avec d’autres codes Monte Carlo de référence pour la physique médicale. Par ailleurs, des recommandations quant à l’utilisation des paramètres de simulation à fixer, assurant un calcul de la distribution de dose absorbée satisfaisant les spécifications en radiothérapie, sont proposées.Radiation therapy treatment planning requires accurate determination of absorbed dose in the patient. Monte Carlo simulation is the most accurate method for solving the transport problem of particles in matter. This thesis is the first study dealing with the validation of the Monte Carlo simulation plateform GATE (GEANT4 Application for Tomographic Emission), based on GEANT4 (GEometry And Tracking) libraries, for the computation of absorbed dose deposited by electron beams. This thesis aims at demonstrating that GATE/GEANT4 calculations are able to reach treatment planning requirements in situations where analatycal algorithms are not satisfactory. The goal is to prove that GATE/GEANT4 is useful for treatment planning using electrons and competes with well validated Monte Carlo codes. This is demonstrated by the simulations with GATE/GEANT4 of realistic electron beams and electron sources used for external radiation therapy or targeted radiation therapy. The computed absorbed dose distributions are in agreement with experimental measurements and/or calculations from other Monte Carlo codes. Furthermore, guidelines are proposed to fix the physics parameters of the GATE/GEANT4 simulations in order to ensure the accuracy of absorbed dose calculations according to radiation therapy requirements

Evaluation de la dose déposée par des faisceaux d'électrons en radiothérapie dans des fantômes voxelisés en utilisant la plateforme de simulation Monte Carlo GATE fondée sur GEANT4 dans un environnement de grille

Radiation therapy treatment planning requires accurate determination of absorbed dose in the patient. Monte Carlo simulation is the most accurate method for solving the transport problem of particles in matter. This thesis is the first study dealing with the validation of the Monte Carlo simulation plateform GATE (GEANT4 Application for Tomographic Emission), based on GEANT4 (GEometry And Tracking) libraries, for the computation of absorbed dose deposited by electron beams. This thesis aims at demonstrating that GATE/GEANT4 calculations are able to reach treatment planning requirements in situations where analatycal algorithms are not satisfactory. The goal is to prove that GATE/GEANT4 is useful for treatment planning using electrons and competes with well validated Monte Carlo codes. This is demonstrated by the simulations with GATE/GEANT4 of realistic electron beams and electron sources used for external radiation therapy or targeted radiation therapy. The computed absorbed dose distributions are in agreement with experimental measurements and/or calculations from other Monte Carlo codes. Furthermore, guidelines are proposed to fix the physics parameters of the GATE/GEANT4 simulations in order to ensure the accuracy of absorbed dose calculations according to radiation therapy requirements.La planification de traitement en radiothérapie nécessite un calcul précis de la dose délivrée au patient. La méthode la plus fiable pour y parvenir est la simulation du transport des particules par technique Monte Carlo. Cette thèse constitue la première étude concernant la validation de la plateforme de simulation Monte Carlo GATE (GEANT4 Application for Tomographic Emission), basée sur les librairies de GEANT4 (GEometry ANd Tracking), pour le calcul de la dose absorbée déposée par des faisceaux d’électrons. L’objectif de cette thèse est de montrer que GATE/GEANT4 est capable d’atteindre le niveau d’exigences requis pour le calcul de la dose absorbée lors d’une planification de traitement, dans des situations où les algorithmes analytiques, actuellement utilisés dans les services de radiothérapie, n’atteignent pas un niveau de précision satisfaisant. L’enjeu est de prouver que GATE/GEANT4 est adapté pour la planification de traitement utilisant des électrons et capable de rivaliser avec d’autres codes Monte Carlo reconnus. Cet enjeu a été démontré par la simulation avec GATE/GEANT4 de faisceaux et des sources d’électrons réalistes utilisées en radiothérapie externe ou en radiothérapie moléculaire et la production de distributions de dose absorbée en accord avec les mesures expérimentales et avec d’autres codes Monte Carlo de référence pour la physique médicale. Par ailleurs, des recommandations quant à l’utilisation des paramètres de simulation à fixer, assurant un calcul de la distribution de dose absorbée satisfaisant les spécifications en radiothérapie, sont proposées

Requirements of modelling tools for the understanding of radiation-induced biological damage at the cellular level

International audienceOur group at the French Institute for Radioprotection and Nuclear Safety (IRSN) is working on the development of a method in order to improve knowledge of the risks of complications during radiotherapy treatments. It combines a Track Structure Monte Carlo (TSMC) simulation tool of the interactions of ionizing radiation and radiolytic species [1] based on Geant4-DNA [2, 3, 4, 5] with a multi-scale modeling tool of the exposed cell populationbased on new functionalities implemented in the DNAFabric software [6]. The benchmarking with experimental data [7] and the integration of mathematical functions derived fromexperimental biological data on cell fate in a broad sense is ongoing

Isochore Nuclear Geometry for modeling the radiation-induced DNA damage toplogy

International audienceResearch dealing with a better understanding of the origin and mechanisms behind deleterious effects of radiation therapies on healthy tissues is a crucial topic in radiation protection. These side effects can result from damage to the nuclear DN molecule of healthy cells exposed to ionizing radiation during treatment. In order to better describe the molecular mechanisms underlying these undesirable effects, our laboratory is developing a simulation chain to calculate early radiation-induced damage to DNA for different beam qualities. Studies at this scale require a nanodosimetric description of energy deposits, enabled by the Geant4-DNA Monte-Carlo toolkit, coupled to DNA geometrical models with molecular precision. The current version of this simulation chain allows a realistic modeling of the topology of DNA damage (number of DSBs, complexity, spatial distribution) at the cellular scale. Up to now the geometries of the cell genome used in the simulation take into account chromatin compaction by implementing 52% euchromatin and 48% heterochromatin, distributed randomly along the genome which makes it possible to account for experimental observations.To improve the quality of these DNA damage results, a more realistic nuclear geometric model is presented. It is based on the isochoric biological model carrying out a mapping of the genome, by segmenting it into portions of 1 Mbp in our application. Each of these segments is then classified into one of five isochoric families (L1, L2, H1, H2, H3) based on the ratio of CG base pairs it contains and related to different degrees of chromatin fiber compaction. To evaluate the influence of these new geometric models on the topology of radiation-induced DNA damage, simulations are performed for perpendicular irradiations of protons (4.28 keV.μm-1, 19.51 keV.μm-1, 43.24 keV.μm-1).The DNA damage results obtained for a cell using the new geometric isochoric model are compared with those obtained previously with a random distribution of chromatin compaction respecting the same overall heterochromatin / euchromatin ratio. This comparison indicates that the organization of chromatin fiber compaction in accordance with the isochore theory of our new model has an impact via different mechanisms on the number and type of calculated damages