Analyse biomécanique multidimensionnelle du geste de tourner le volant chez les conducteurs sans déficiences motrices

Tourner le volant d une automobile peut s avérer difficile pour les conducteurs ayant des déficiences motrices des membres supérieurs. En effet, ce mouvement demande une grande mobilité et une force musculaire non négligeable. A ce jour, les directions assistées automobiles sont réglées uniquement sur le ressenti des conducteurs sans déficiences motrices. Le projet ANR VTT VolHand, dans lequel ce travail de recherche s inscrit, ambitionne d apporter une réponse à cette problématique. L objectif de cette thèse est de renseigner la biomécanique du geste déjà chez le conducteur sans déficiences motrices (sain). Pour cela, l interaction main/volant, ainsi que la cinématique (ex. angles articulaires) et la dynamique (ex. efforts sur volant, efforts articulaires) du geste de tourner le volant sont étudiés au travers de plusieurs analyses multidimensionnelles multivariables (atemporelle et temporelle). La méthode originale proposée s appuie sur un découpage flou du volant et des variables cinématiques et dynamiques. La population expérimentée compte une centaine de sujets, dont 23 sujets sans déficience motrice. La plateforme expérimentale regroupe principalement un simulateur automobile compact permettant le recueil des efforts développés par chaque main, une consigne de suivi de trajectoire incitant le conducteur à reproduire un angle désiré et un système optoélectronique mesurant le geste de tourner le volant.Les résultats de l analyse de l interaction main/volant mettent en évidence 3 profils de conducteurs : les conducteurs croiseurs, les conducteurs croiseurs asymétriques et les conducteurs non croiseurs. L analyse des variables cinématiques et dynamiques montrent que les variables dynamiques résultant du tirer/pousser le volant sont discriminantes. Deux nouveaux profils sont alors identifiés : les pousseurs moyens et les tireurs. En majorité, les conducteurs sains tendent à croiser les mains et à pousser sur le volant lors de la réalisation d un geste de tourner le volant à basse vitesse.Plusieurs perspectives sont proposées à court terme, à moyen terme et à long terme. L une d entre elles concerne l adaptation de l assistance aux caractéristiques motrices des conducteurs avec déficience motrice.Steering wheel can be difficult for divers with disabilities on upper limb. Indeed, the steering action might require a large range of motion of upper limb and some muscular strength. Power steering systems that are currently proposed in car were implemented to match non disabled driver feelings and needs. ANR VTT VolHand project wants to enlarge the field of power steering system to drivers with disabilities on upper limbs. The present work is a part of this project. As a preliminary approach, the objective was to analyze the upper limb motion of healthy drivers during a steering exercise. Different multivariable analyses (low level of time summarizing and high level of time summarizing) were done to study hand/wheel interactions, kinematics variables (e.g. joint angles) and dynamics variables (e.g. joint torques). An original fuzzy windowing was proposed to describe hand position on steering wheel, kinematic and dynamics variables. One hundred subjects participated to experiment, included 23 healthy subjects, which consisted on a low speed steering task. The experimental platform was composed of a compact driving simulator, that allow the measurement of each hand effort on the steering wheel, a steering exercise based on a line following protocol, and a motion capture system.Analysis of hand/wheel interaction showed the existence of three driver profiles: hand crossing, asymmetric hand crossing and non hand crossing. Analysis of kinematics and dynamics variables showed that pulling/pushing forces were also discriminating. As a consequence, two additional profiles were identified: mean pushing drivers and pulling drivers. Overall, healthy drivers were hand crossing and mean pushing drivers during a low speed steering task.Short, middle and long prospects are proposed. One of them concerns automotive power steering system adaptation for disabled drivers.VALENCIENNES-Bib. électronique (596069901) / SudocSudocFranceF

A Modeling Approach towards Identifying Potential Bivalent Sensitizers of Neuromuscular Blocking Agents

ABSTRACT Objective: Anaphylactic reactions induced by neuromuscular blocking agents (NMBAs) can occur at first contact and might be due to cross-sensitization by other drugs or chemicals. Our aim was to investigate whether divalent molecules sharing chemical features with NMBAs might potentially cause cross-sensitization. Methods: We constructed a pharmacophore key from chemical features common to all NMBAs (two positive or ionizable features 1.0807 nm apart) and used the key to screen FDA-approved small drug molecules of the Drug Bank® database (1541 molecules). The selected molecules were categorized on the basis of the values for three main parameters (fit value, relative energy and mean polar surface area). Results: Screening from the pharmacophore key selected 13 NMBAs and 88 non-NMBA drugs. Of these 88 drugs, 42 had high-ranking parameter values and were considered preferential cross-sensitizers. These included the dopamine D2 receptor ligands aripiprazole and domperidone. Pholcodine, as well as nizatidine, ranitidine, antrafenine, cabergoline and, to some extent, chlorhexidine best fulfilled the required criteria of apolar character, bioavailability and ionization rate. Conclusion: Our data support the hypothesis that pholcodine might be a potential NMBA cross-sensitizer. They confirmed the results of inhibition tests on patient serum suggesting that dopamine D2 receptor ligands might be cross-sensitizers. They also identified chlorhexidine, a widely used disinfectant incriminated in several cases of immediate hypersensitivity reactions, as a potential cross-sensitizer. Pharmacophore modelling is an inexpensive, straightforward approach that can be used to identify potential NMBA cross-sensitizing agents

Effets de l'augmentation de la cadence sur le geste du rameur

Exploration des modifications de la trajectoire de la poignée et du geste du rameur expert (en aviron) pour des cadences de 18 à 40 coups.min-1 sur ergomètre Concept II. Mesure du mouvement du rameur et de la trajectoire de la poignée à l'aide d'un système opto-électronique de type VICON. Les résultats montrent que, lorsque la cadence augmente, les principales caractéristiques de la trajectoire diminuent, le meilleur rameur sur bateau maintient sur ergomètre les phases d'attaque et de dégagé, le meilleur rameur sur ergomètre produit la trajectoire la plus horizontale et la plus lisse, le meilleur rameur sur bateau modifie essentiellement son geste lors du retour

Virtual Prototyping of an Electric Power Steering Simulator

International audienceThis paper presents a simulation tool for an electrical steering system whose aim is twofold: 1) to investigate the possibility of designing a minimum clearance mechatronic platform with sensorless control methods and 2) to evaluate assistance torque control feedback by considering technological specifications and human factor consideration. The choice has been made for a driving simulator having at least a real steering system with an electrical power steering (EPS) device and an adequate motor to reproduce the rack load force resulting from tire/road contact, as in a real driving situation. These components are gathered to form a virtual simulator platform, which serves as a basis for future realization. Our main contributions concern the vehicle's front assembly kinematics modeling and the evaluation of the load rack force resulting from tire/road interaction. In addition, a real application of the most recent virtual sensor algorithms, arising from the sliding-mode observer theory for states and unknown input estimation, is described

Silver économie, vulnérabilités, territoires

coll. Silver autonomie et handicap.International audienceLe vieillissement de la population est un phénomène désormais identifié, qui met les individus et nos sociétés face à des enjeux considérables. Cet ouvrage rassemble les contributions de chercheurs des Hauts-de-France, traitant de ces enjeux, et des réponses pouvant contribuer à les relever. En proposant des angles différents (psychologie, démographie, biologie, économie, gestion, informatique et sociologie), cet ouvrage apporte un éclairage complémentaire à la problématique transversale du vieillissement et plus spécifiquement aux questions de silver économie, de territoires et de prise en charge des populations vulnérables.Chercheurs et acteurs de terrain s’efforcent ici de croiser différentes approches sur ces sujets complexes. Au cœur de ces échanges, et du présent ouvrage, il s’agit de prendre en compte le vieillissement comme un phénomène général, tout en considérant ses multiples dimensions, jusqu’à la considération des besoins et du bien-être de chacu

Rack force feedback for an electrical power steering simulator

International audienceThis paper presents a force feedback control approach to enhance the realism and the fidelity of an electric power steering simulator. This simulator includes a real steering system with its electric assistance and a DC motor intended for the load rack force restitution. This motor allows to compensate for the lack of real tires and to simulate the tire/road contact as in a real driving situation. Besides, two different scenarios case study are introduced to prove the effectiveness of the various algorithms: virtual sensor based on sliding mode observer for the unknown input estimation and a sliding mode control for the force feedback

Silver économie, vulnérabilités, territoires. Valenciennes : Presses universitaires de Valenciennes, coll. Silver autonomie et handicap

International audienc

New finite element human models representing elderly, disabled and overweight people for aircraft seat comfort simulation

International audienceIn the growing but highly competitive market of the airline industry, airliners have todifferentiate themselves from their competitors while increasing or maintaining theirprofitability. They request innovations in aircraft interior design to increase aircraftcapacity, reduce airplane turn time through fast boarding and unloading operations,improve passenger comfort and living space, lighten aircrafts and meet safetyrequirements. So many necessary yet conflicting expectations, which make aircraftinterior and seat design very challenging. In this context, it is easier to only manageaverage standard passenger population in product development phase. Butmorphology of passengers is evolving, as our population ages and increases in sizeand weight. More and more elderly people travel, and the senior market cannot beneglected by airliners. Regulations prevent also discrimination and airliners must nowcater to all types of passengers, whatever their age, weight or disability.While standard passengers can board an airplane, walk in the cabin and sit withoutdifficulties, overweight, age and disability are usually associated with lower mobility,which raises difficulties and lowers the air travel experience. If seat access is onecertain issue, seat comfort is somehow more important, especially for long rangeflight. The more severe is the impairment or the higher is the weight, the least is thesatisfaction for the aircraft seat. That highlights the need for adapted design ofaircraft seat for overweighted, senior passengers as well as the ones with severemobility impairment, such as passengers that rely on permanent seating posture.Such design investigation, fitting to these populations, is not easy, request lots ofdifficult experimental tests with large group of volunteers. One alternative solution isthe use of digital human model, more specifically finite element models, representingall these different populations, during the conception and development phases ofaircraft seat.The present paper will describe the development methodology of new finite humanmodels, adapted to non-standard population of passengers, such as elderly,overweighted and disabled people. These models have been developed starting froman existing human model representing standard aircraft population as reference 89model, and based on literature review. These models have been then used in seatingsimulations for the evaluation of aircraft seat comfort and comparison for differentpostures.For severe mobility impairment passengers, there is a need of accurate figures formorphometric modification on the lower limb and lower trunk, as those segments maynot be fully functional and are the most stressed segments during sitting. In order toidentify morphometric modifications induced by permanent sitting posture,methodologies and methods of the reviewed process are presented and focused onpermanent wheelchair users. Proposed modifications concern mainly bone, muscle,fat, and skin tissues. The most of those changes are applied to the reference finiteelement human model at pelvis region and lower extremities. That consists of theadaptation of muscle and fat distribution as well as the modification of radius ofischial apex curvature. Then, bony properties of these segments are updated.For the senior and overweighted human models, an equivalent modification processhas been applied for the whole body, based on the available data and specificities ofthe reference model. It concerns the adaptation of morphology as well as muscle andfat distribution. For the senior model, bone properties are also modified.Seating simulations have been then performed with these dedicated models toevaluate their capabilities to highlight comfort problems encountered by thesepassenger population with respect to the reference standard passenger population.Three different postures, taxi, take-off and landing, inclined and relaxed ones, havebeen evaluated and compared