Drag'n Go: Simple and Fast Navigation in Virtual Environment

4 pages.International audienceIn this paper we introduce the Drag'n Go technique to navigate in multi-scale virtual 3d environment. This new technique takes its root from the point of interest (POI) approach where the user selects a target to reach. The biggest difference between the two is that with Drag'n Go the user keeps full control of its position relative to the target as well as its traveling speed. The technique requires only a 2d input and consequently, can be used with a large amount of devices like mouse, touch or pen screen. We conducted preliminary experiment that highlights that Drag'n Go is an efficient and appreciated method for touch-based device and a competitive approach for mouse-based device

Real-time electrochemical LAMP: a rational comparative study of different DNA intercalating and non-intercalating redox probes

International audienceWe present a comparative study of ten redox-active probes for use in real-time electrochemical loop-mediated isothermal amplification (LAMP). Our main objectives were to establish the criteria that need to be fulfilled for minimizing some of the current limitations of the technique and to provide future guidelines in the search for ideal redox reporters. To ensure a reliable comparative study, each redox probe was tested under similar conditions using the same LAMP reaction and the same entirely automatized custom-made real-time electrochemical device (designed for electrochemically monitoring in real-time and in parallel up to 48 LAMP samples). Electrochemical melt curve analyses were recorded immediately at the end of each LAMP reaction. Our results show that there are a number of intercalating and non-intercalating redox compounds suitable for real-time electrochemical LAMP and that the best candidates are those able to intercalate strongly into ds-DNA but not too much to avoid inhibition of the LAMP reaction. The strongest intercalating redox probes were finally shown to provide higher LAMP sensitivity, speed, greater signal amplitude, and cleaner-cut DNA melting curves than the non-intercalating molecules

Drag'n Go: Simple and Fast Navigation in Virtual Environment

4 pages.International audienceIn this paper we introduce the Drag'n Go technique to navigate in multi-scale virtual 3d environment. This new technique takes its root from the point of interest (POI) approach where the user selects a target to reach. The biggest difference between the two is that with Drag'n Go the user keeps full control of its position relative to the target as well as its traveling speed. The technique requires only a 2d input and consequently, can be used with a large amount of devices like mouse, touch or pen screen. We conducted preliminary experiment that highlights that Drag'n Go is an efficient and appreciated method for touch-based device and a competitive approach for mouse-based device

Toward Shape Optimization of Soft Robots

International audienceIn this paper we present our work on shape optimization for soft robotics where the shape is optimized for a given soft robot usage. To obtain a parametric optimization with a reduced number of parameters, we rely on an approach where the designer progressively refines the parameter space and the fitness function until a satisfactory design is obtained. In our approach, we automatically generate FEM simulations of the soft robot and its environment to evaluate a fitness function while checking the consistency of the solution. Finally, we have coupled our framework to an evolutionary optimization algorithm, and demonstrated its use for optimizing the design of a deformable leg of a locomotive robot

e-VLBI with the SFXC correlator

oS(EXPReS09)04

Towards a better understanding of pelvic system disorders using numerical simulation

International audienceGenital prolapse is a pathologic hyper-mobility of the organs that forms the pelvic system. Although this is common condition, the pathophysiology of this disorder is not well known. In order to improve the understanding of its origins, we recreate - virtually - this biomechanical pathology using numerical simulation. The approach builds on a finite element model with parameters measured on several fresh cadavers. The meshes are created from a MRI of a healthy woman and the simulation includes the mechanical interactions between organs (contacts, ligaments, adhesion...). The model is validated through comparison of functional mobilities of the pelvic system observed on a dynamic MRI. We then propose to modify, step by step, the model and its parameters to produce a pathologic situation and have a better understanding of the process. It is not a formal proof but the numerical experiments reinforce the clinical hypothesis on the multifactorial origins of the pathology

Characterizing Latency in Touch and Button-Equipped Interactive Systems

International audienceWe present a low cost method to measure and characterize the end-to-end latency when using a touch system (tap la-tency) or an input device equipped with a physical button. Our method relies on a vibration sensor attached to a finger and a photo-diode to detect the screen response. Both are connected to a micro-controller connected to a host computer using a low-latency USB communication protocol in order to combine software and hardware probes to help determine where the latency comes from. We present the operating principle of our method before investigating the main sources of latency in several systems. We show that most of the latency originates from the display side. Our method can help application designers characterize and troubleshoot latency on a wide range of interactive systems

SofaGym: An open platform for Reinforcement Learning based on Soft Robot simulations

International audienceOpenAI Gym is one of the standard interfaces used to train Reinforcement Learning (RL) Algorithms. The Simulation Open Framework Architecture (SOFA) is a physics based engine that is used for soft robotics simulation and control based on real-time models of deformation. The aim of this paper is to present SofaGym, an open source software to create OpenAI Gym interfaces, called environments, out of soft robot digital twins.The link between soft robotics and RL offers new challenges for both fields: representation of the soft robot in a RL context, complex interactions with the environment, use of specific mechanical tools to control soft robots, transfer of policies learned in simulation to the real world, etc. The article presents the large possible uses of SofaGym to tackle these challenges by using RL and planning algorithms. This publication contains neither new algorithms nor new models but proposes a new platform, open to the community, that offers non existing possibilities of coupling RL to physics based simulation of soft robots. We present 11 environments, representing a wide variety of soft robots and applications, we highlight the challenges showcased by each environment. We propose methods of solving the task using traditional control, RL and planning and point out research perspectives using the platform

Modélisation des mobilités du système pelvien : vers une meilleure compréhension des troubles de la statique pelvienne

International audienceLe prolapsus génital est un trouble d'hyper-mobilité des organes du système pelvien touchant 60% des femmes de plus de 60 ans, dont la physiopathologie est encore mal connue. Afin de mieux comprendre les mécanismes à l'origine de cette pathologie, un modèle élément fini permettant de simuler les mobilités fonctionnelles du système pelvien a été développé. Ce modèle a été modifié pour tendre vers la situation pathologique, permettant de quantifier l'influence de chaque modification (propriétés mécaniques, évolution topologique des ligaments...) sur les mobilités du système

Software toolkit for modeling, simulation and control of soft robots

International audienceThe technological differences between traditional robotics and soft robotics have an impact on all of the modeling tools generally in use, including direct kinematics and inverse models, Jacobians, and dynamics. Due to the lack of precise modeling and control methods for soft robots, the promising concepts of using such design for complex applications (medicine, assistance, domestic robotics...) cannot be practically implemented. This paper presents a first unified software framework dedicated to modeling, simulation and control of soft robots. The framework relies on continuum mechanics for modeling the robotic parts and boundary conditions like actuators or contacts using a unified representation based on Lagrange multipliers. It enables the digital robot to be simulated in its environment using a direct model. The model can also be inverted online using an optimization-based method which allows to control the physical robots in the task space. To demonstrate the effectiveness of the approach, we present various soft robots scenarios including ones where the robot is interacting with its environment. The software has been built on top of SOFA, an open-source framework for deformable online simulation and is available at https://project.inria.fr/softrobot