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International audience; Haptic simulators are used in many education domains to improve hands-on training performance. Many of these simulators are used in the medical domain, where it is particularly important to be trained, guided by an expert. However, the majority of haptic hands-on training devices are usable by only one user at the same time, either the trainer or the trainee. Dual-user approaches have enhanced this situation by allowing both trainer and trainee to use the same simulator to introduce guided training into the simulation. In this paper, we introduce a multi-trainee architecture that expands further a former dual-user hands-on haptic training solution designed according to an energetic approach. This system will permit several trainees to be involved in the same simulation at the same time, guided by a single trainer. It paves the way to the multi-trainee hands-on training on haptic simulators.

The classification of human hand gestures has gained widespread recognition as a natural and powerful way to interact intuitively and efficiently with computers. Specifically, this approach has facilitated the development of a number of important applications in the medical training field, specially as a way to objectively evaluate surgical tasks of novices compared to an expert surgeon. In this paper, 3D medical gestures, acquired by an instrumented laparoscopic forceps, were classified using Long Short Term Memory (LSTM) recurrent neural networks (RNN). Recognition results are based on gesture dynamics and a comparison of gesture trajectories between novices to an expert motion are presented. Using LSTM RNN, we were able to achieve a recognition rate of 99.1%.

International audience; This paper proposes a general approach to design a feedback control law for DC/DC power converters. These last ones can be modeled as switched port-Hamiltonian systems. Based on Lyapunov theory, a candidate Lyapunov function representing the energy of the system is proposed. Advantages of the resulting control law include ease of design and implementation in real time applications. The proposed control is applied in simulation for Buck, Buck-Boost, SEPIC and Ćuk converters. A comparison with a PWM state feedback control law is given for the last two converters.

International audience; A pneumatic actuator with solenoid valves is a discontinuous-input system because each valve can be either in on or off state. For such an actuator, this paper proposes a sliding-mode control scheme based on an averaged continuous-input equivalent model for the open-loop system. The averaged model is obtained from the nonlinear dynamics of the open-loop discontinuous-input system undergoing pulse-width-modulation (PWM) at the input (i.e., valve open/close action). The PWM duty cycle will be regarded as a continuous input to the proposed averaged model, and thus generated by the proposed sliding-mode controller. By adjusting the PWM duty cycle, the controller switches between seven modes of operation of the open-loop system in order to select the ones with necessary and sufficient amounts of drive energy to achieve position tracking. We will show that this results in reduced position error and valve switching activity for the actuator. The proposed control scheme is experimentally used in the position control of a pneumatic actuator and the results are presented.

Pneumatic actuators are not only low-cost, safe, clean, and exhibit a high power to weight ratio, but also provide alternative technology for MRI-compatible application, like robotic surgery. This paper will present a soft continuum robot which is fully MRI-compatible for medical surgery. Characteristics of static flow stage of actuators for this robot will be firstly analyzed based on standard experimental tests. Mathematical model of the static flow rate stage will be developed using polynomial function and validated. The results of this study will be used to design control scheme for late work.

International audience; This paper presents an upper extremity exoskele- ton with an original application in neuroscience. The novelty of this study is the investigation of the self-advantage phenomenon under various experimental conditions. Usually this kind of experiments lies only on human visual ability to explicitly and/or implicitly recognize their own arm movements. Using an exoskeleton to replay recorded trajectories allows to give another perspective to the previous studies in including the proprioceptive ability of humans. Twelve healthy subjects were involved in this study. The results show that the self advantage phenomenon is even more present in the implicit tasks.

International audience; This paper presents a nonlinear observer based control of a Single Ended Primary Inductor Converter. A Lyapunov-based control law of the voltage output is proposed. This control law has the property to be simple to implement. The proposed technique uses a nonlinear observer of an averaged model of the converter. The asymptotic stability of the observer error is shown using port Hamiltonian formalism. Stability of the closed loop, including the observer and the control law, is discussed. The proposed observer and control law were validated in simulation and experimentation.

International audience; This paper presents a novel bilateral control scheme for pneumatic teleoperation systems that are actuated by low cost solenoid valves. A sliding mode control is incorporated into a two-channel, bilateral teleoperation architecture involving position-position, force-force, or force-position schemes. An analysis of stability and transparency of the closed-loop teleoperation system is carried out. The proposed control design is experimentally verified on a single-degree-of-freedom pneumatic teleoperation system actuated by on/off valves. Moreover, experiment results demonstrate high accuracies in terms of position and force tracking in the teleoperation system.

International audience; New contraceptive methods like the subcutaneous implant offers a new kind of comfort for women with an efficiency similar to the contraceptive pill. Unfortunately, the few numbers of unintended pregnancies that have been reported, are generally due to a bad insertion of the implant. In order to give more security to patients, we have designed, in close collaboration with physicians, a new kind of medical simulator. This simulator can be used for two purposes: one for training novice physicians in the correct gesture and the other for doctor certification which will help to determine if they are capable of inserting the implant in vivo. This paper describes the approach which has led to the design of this simulator. It describes its functionalities, its several components but also methods used to analyze the gesture of the implant insertion inside the patient. Finally, first experimental results are reported and discussed.

International audience; This paper presents work resulting from a collaboration between obstetricians and researchers. It shows the benefits from the use of an instrumented childbirth simulator for the training of obstetricians and midwives. This new tool allows to surpass the constraints linked to the traditional training in a childbirth ward. This simulator training is designed to complete the traditional training used in teaching hospitals. Such a training allows residents to acquire a beginning experience before training in a childbirth ward but it also allows instructors to improve the teaching gestures without constraints. A clinical study of the forceps blades placement gesture with several residents who trained on a childbirth simulator is made. The results clearly show the progress in the obstetric gestures of all the residents who have used the simulator

International audience; Birth represents for each human being one the most wonderful days of his life but also one of the most dangerous. Being born in safe conditions requires to be surrounded by professionals who acquire a rigorous knowledge of diagnostic and therapeutic procedures. Nowadays, midwives and obstetricians learn mainly in delivery ward during real childbirths. For difficult childbirths, the use of obstetrical instruments (forceps, spatulas or vacuum extractors) is unavoidable. However, the use of such instruments increases the risks of lesions for the mother and the fetus. In practical, only clinical experience acquired in the delivery ward enables these risks to be reduced. Nowadays, simulators in medicine have a real appeal in the medical environment. These tools enable doctors to visualize the position of the organs in the human body, to plan their movements or to carry out a more complete post operational control. A birth simulator provides a training tool and a research tool to compare various techniques for the use of obstetrical instruments or to validate new methods. It is in this context that we have developed, in collaboration with researchers and medical doctors, a new type of instrumented forceps to offer new solutions for training obstetricians for the safe use of obstetrical forceps delivery. The main contributions of this paper are the design of instrumented forceps coupled with the BirthSIM simulator and the path analysis during the forceps blades placement. This analysis leads to the comparison of the repeatability of the movement between novice obstetricians and expert obstetricians. The results highlight the lack of teaching tool to correctly train the novice obstetricians

During the conventional procedure of the colonoscopy, there are two important movements, the introduction of colonoscope in the colon and the maneuver of the distal end. In this paper, the authors focus on a new type of automatic bendable tip while keeping the advance of the colonoscope in the colon by endoscopist. The main purpose of this tip is to make the colonoscope overcome acute intestinal bends and make easier the progression of the colonoscope for the surgeon. Firstly, we model our current prototype tip, named EDORA (distal extremity with automatic orientation). Next, the parameters of the system are estimated by using the Levenberg-Margquardt's algorithm. Finally, by using the maximum of the sensitivity function a gain margin specification is made. A set point for a position controller is designed, thus the tip can stay in the middle of the colon with disturbance rejection due to the manipulation of the colonoscope. In the same time, this controller has been designed to make the tip have some degrees of compliance to reduce the contact force due to the undesirable contact with the colon. Simulation and experimental results for the controller would be presented by emulating the real environments.

Proposes a method to identify the joint stiffness of a robot using a bandpass filter. It is based on moving one axis at a time. The dynamic model reduces to a model which is linear in relation to a minimum set of dynamical parameters which have to be identified. These parameters are estimated using the least squares solution of an over determined linear system obtained from the sampling of the dynamic model along a closed loop tracking trajectory. Conditions for a good data processing before identification are exhibited through practical aspects concerning data sampling and data filtering. An experimental study shows the efficiency of the method with two sets of data depending on motor joint position measurements.

Proposes a method for the automatic tuning of cascade structure CNC controllers. The design takes into account constraints on the system such as delays induced by numerical control effects and elasticity of bodies. The robustness of the algorithm is ensured by requiring minimal stability margins.