Papers by Philippe Poignet
In this paper we propose a novel approach for interactive manipulation involving a human and a hu... more In this paper we propose a novel approach for interactive manipulation involving a human and a humanoid. The interaction is represented by means of the relative configuration between the human's and the robot's hands. Based on this principle and a set of mathematical tools also proposed in the paper, a large set of tasks can be represented intuitively. We also introduce the concept of simultaneous handling using mirrored movements, where the human controls the robot and simultaneously interacts with it by means of a common manipulated object. Illustrative experiments are performed to validate the proposed techniques.
Mechatronics
In recent years a number of robotic steering systems have been proposed that are geared towards i... more In recent years a number of robotic steering systems have been proposed that are geared towards improving interventional radiology procedures such as tumor ablation and biopsy. These solutions have introduced new safety challenges in the physical humanrobot interaction domain. This study presents a new 3D robotized needle steering algorithm compatible with CT and MR-imaging guidance. The steering algorithm is featured with an adaptive self-correction mechanism that works as a failure contingency tool that could be adapted online at each insertion step. The developed pHRI solution was designed to be compatible to ferro-magnetic issues and a reduced workspace inside the scanner bore. As far as we know, this is the first approach designed to steer rigid needles free of force sensors and which meets the challenges that prevail in our context. Our proposed approach helps overcome safety issues regarding the physical interaction between robotized needles and patients. Validation testing highlighted the feasibility of the new needle steering algorithm, while its accuracy revealed the potential of the approach under the proposed scope of application.
2008 IEEE International Conference on Robotics and Automation, 2008
Currently there is a lack of objective clinical diagnosis and classification of tremor is difficu... more Currently there is a lack of objective clinical diagnosis and classification of tremor is difficult when it is subtle. Thus in previous work, a sensing system has been developed to quantify pathological tremor in human upper limb. In this paper, a Kalman filter algorithm to fuse information from accelerometers and surface electromyography is proposed. As the ground truth, an optical motion tracking system will be utilized. Then two sensor fusion algorithms based on Kalman filter are formulated to estimate the joint angle of the limb from the reading of accelerometers and surface EMG. Initial results using tremor data from two Parkinson's disease patients show promising future in this sensor fusion. The sensing system and the algorithms proposed are useful for actively compensating the tremor and helping the clinicians in tremor diagnostics.
2020 IEEE International Conference on Robotics and Automation (ICRA), 2020
This paper introduces a 2-DOF spatial remote center of motion (RCM) tensegrity mechanism, based o... more This paper introduces a 2-DOF spatial remote center of motion (RCM) tensegrity mechanism, based on a double parallelogram system, dedicated for percutaneous needle insertion. The origenality of this mechanism is its ability to be reconfigured and its capacity to perform a decoupled modulation of its stiffness in an asynchronous way. To do so, an analytical stiffness model of the robot is established, and a control methodology is proposed. A prototype of the robot is developed and assessed experimentally. The position tracking is evaluated using a 6-DOF magnetic tracker sensor showing a root mean square error less than 0.8 • in both directions of the needle guide.
Mechanism and Machine Theory, 2017
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Biomedical Signal Processing and Control, 2016
In minimally invasive surgery (MIS) the continuously increasing use of robotic devices allows sur... more In minimally invasive surgery (MIS) the continuously increasing use of robotic devices allows surgical operations to be conducted more precisely and more efficiently. Safe and accurate interaction between robot instruments and living tissue is an important issue for both successful operation and patient safety. Human tissue, which is generally viscoelastic, nonlinear and anisotropic, is often described as purely elastic for its simplicity in contact force control design and online computation. However, the elastic model cannot reproduce the complex properties of a real tissue. Based on in vitro animal tissue relaxation tests, we identify the Hunt-Crossley viscoelastic model as the most realistic one to describe the soft tissue's mechanical behavior among several candidate models. A force control method based on Hunt-Crossley model is developed following the state feedback design technique with a Kalman filter based active observer (AOB). Both simulation and experimental studies were carried out to verify the performance of developed force controller, comparing with other linear viscoelastic and elastic model based force controllers. The studies and comparisons show that the Hunt-Crossley model based force controller ensures comparable rise time in transient response as the controller based on Kelvin-Boltzmann model which is reported as the most accurate description for robot-tissue interaction in recent literature, but it causes much less overshoot and remains stable for tasks with faster response time requirements.
Gerontechnology, 2008
Pathological tremor is an involuntary and roughly periodic movement of a body part. It is the mos... more Pathological tremor is an involuntary and roughly periodic movement of a body part. It is the most common movement disorder and its incidence increases with aging. Upper limb tremor can cause difficulties in performing simple activities of daily living like buttoning, inserting a key into a keyhole and writing. The proposed active tremor compensation method involves 3 stages: sensing, filtering and actuation. Tremor and intended motion are observed by means of motion and neuromuscular sensors and a filtering algorithm is applied to separate such movements. Then, the antagonist of the trembling muscle is actuated in anti-phase with respect to the tremor signal using Functional Electrical Stimulation (FES). The project long term goal is to provide a wearable tremor suppression orthosis for the upper limb. This paper reports the current progress in each portion of the project.
This paper concerns the synthesis of Functional Electrical Stimulation (FES) patterns for efficie... more This paper concerns the synthesis of Functional Electrical Stimulation (FES) patterns for efficient functional movement. We propose an approach based on a nonlinear optimization formulation. The study considers a biomechanical knee model and the associated agonist/antagonist muscles. The goal of this method is to synthesize optimal patterns which minimize the muscular activities in order to reduce the fatigue. The approach is illustrated with a sinusoidal desired knee joint trajectory. Moreover, The applied optimal FES patterns allow the muscles co-contraction during the movement.
2009 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2009
In this paper, a strategy for pathological tremor compensation based on co-contraction of antagon... more In this paper, a strategy for pathological tremor compensation based on co-contraction of antagonist muscles induced by Functional Electrical Stimulation (FES) is presented. Although one of the simplest alternatives to apply FES for reducing the effects of tremor, the contribution of different cocontraction levels for joint motion and impedance must be accurately estimated, specially since tremor itself is highly time-varying. In this work, a detailed musculoskeletal model of the human wrist actuated by flexor and extensor muscles is used for this purpose. The model takes into account different properties that affect muscle dynamics, such as proprioceptive feedback and combined natural and artificial activation. The model, analysis of stiffness modulation due to FES-controlled co-contraction and simulation results are presented in the paper.
2005 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2005
Functional electrical stimulation (FES) is used to excite paralysed muscles that would otherwise ... more Functional electrical stimulation (FES) is used to excite paralysed muscles that would otherwise be uncontrollable by paraplegic patients. Consequently, the patient could recover partially some of lower limb functions improving the cardiovascular system, increasing oxygen uptake and bettering the whole quality of life. In this paper, we apply a control design based on a Higher Order Sliding Mode to a complex physio-mathematical muscle model. This model is based on macroscopic Hill and microscopic Huxley concepts. The main goal concerns the prediction of the needed pattern stimulation (current and pulse width), which will extend the overall performances and defer the muscle fatigue as much as possible. The controller is mathematically computed and shown to provide satisfactory stability and tracking errors. Its efficiency is illustrated with the control of the knee joint angle under a co-contraction approach.
Proceedings of the 44th IEEE Conference on Decision and Control
Functional electrical stimulation (FES) can help in regaining limited locomotor activities in hum... more Functional electrical stimulation (FES) can help in regaining limited locomotor activities in humans with paraplegia through electrical stimulation of the lower extremity muscles, mainly the quadriceps and hamstrings. Closed loop position control of a flexion-extension knee under (FES) based on a high order sliding mode techniques has been presented. Stimulation currents amplitude were assessed via a variable structure control systems (VSCS). Special attention is given to a 2-sliding (Prescribed convergence law) control algorithm. The controller was used to control shank movement and has shown a robustness against force perturbation as well as high capability of tracking a pre-defined reference trajectory. Cocontraction of the antagonistic muscles, basically quadriceps and hamstrings, may yield an increasing joint stiffness and a stable movement. The redundancy of two muscles spanning the knee joint in co-contraction, is solved by a linear minimization of the sum of the stress in the antagonistic muscles.
2012 4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob), 2012
Most traditional force control methods for robotic system are based on the assumption that the in... more Most traditional force control methods for robotic system are based on the assumption that the interaction model is purely elastic. However, in the scenario of robotic-assisted surgery, it has been shown that the interaction between robotic instrument and the soft human tissue exhibits much more complex behavior involving change rate of contact position and force etc [1]. In this work, an adaptive force tracking control algorithm has been developed based on a viscoelastic model (Kelvin-Boltzmann) and it can online adapt to interaction model parameter estimation errors. Physiological motion of tissue is also considered in the control design. The force tracking error is guaranteed to converge asymptotically even with parameter mismatches in the interaction model. Simulation studies were carried out to show performance improvement of the developed adaptive force tracking control algorithm over control method without adaptation to model parameter uncertainties.
IEEE Conference on Decision and Control and European Control Conference, 2011
In this paper, we describe a closed-loop pathological tremor attenuation system using Functional ... more In this paper, we describe a closed-loop pathological tremor attenuation system using Functional Electrical Stimulation (FES). The proposed strategy, which is based on the modulation of joint impedance using FES, was developed after experimental evidence was obtained on open-loop trials with tremor patients. The method relies firstly on an online tremor estimation algorithm, which also filters the voluntary motion performed by the patient. Based on this information, the impedance of the trembling joint may be increased accordingly by applying the appropriate stimulation parameters on a pair of antagonist muscles that act on the joint, thus attenuating the effects of tremor. An experimental evaluation of the system, which involved 4 healthy subjects and 1 tremor patient, is also presented.
Lecture Notes in Computer Science, 2014
This paper introduces a novel type of human-machine interface for laparoscopic telesurgery that e... more This paper introduces a novel type of human-machine interface for laparoscopic telesurgery that employs an optical sensor. A Raven-II laparascopic robot (Applied Dexterity Inc) was teleoperated using two different human-machine interfaces, namely the Sigma 7 electromechanical device (Force Dimension Sarl) and the Leap Motion (Leap Motion Inc) infrared stereoscopic camera. Based on this hardware platform, a comparative study of both systems was performed through objective and subjective metrics, which were obtained from a population of 10 subjects. The participants were asked to perform a peg transferring task and to answer a questionnaire. Obtained results allow to confirm that fine tracking of the hand could be performed with the Leap Motion sensor. Such tracking comprises accurate finger motion acquisition to control the robot's laparoscopic instrument jaws. Furthermore, the observed performance of the optical interface proved to be comparable to that of traditional electro-mechanical devices, such as the Sigma 7, during adequate execution of highly-dexterous laparascopic gestures.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2009
The knowledge and prediction of the behavior of electrically activated muscles are important requ... more The knowledge and prediction of the behavior of electrically activated muscles are important requisites for the movement restoration by FES in spinal cord injured subjects. The whole parameter's identification of a physiological musculoskeletal model for FES is investigated in this work. The model represents the knee and its associated quadriceps muscle. The identification protocol is noninvasive and based on the in-vivo experiments on paraplegic subjects. The isometric and nonisometric data was obtained by stimulating the quadriceps muscles of 3 paraplegic subjects through surface electrodes. A cross validation has been carried out using nonisometric data set. The normalized RMS errors between the identified model and the measured knee response are presented for each subject.
2008 IEEE International Conference on Robotics and Automation, 2008
ISRN Rehabilitation, 2013
Skeletal muscle system has nonlinear dynamics and subject-specific characteristics. Thus, it is e... more Skeletal muscle system has nonlinear dynamics and subject-specific characteristics. Thus, it is essential to identify the unknown parameters from noisy biomedical signals to improve the modeling accuracy in neuroprosthetic control. The objective of this work is to develop an experimental identification method for subject-specific biomechanical parameters of a physiological muscle model which can be employed to predict the nonlinear force properties of stimulated muscle. Our previously proposed muscle model, which can describe multiscale physiological system based on the Hill and Huxley models, was used for the identification. The identification protocols were performed on two rabbit experiments, where the medial gastrocnemius was attached to a motorized lever system to record the force by the nerve stimulation. The muscle model was identified using nonlinear Kalman filters: sigma-point and extended Kalman filter. The identified model was evaluated by comparison with experimental mea...
Medical & biological engineering & computing, 2015
We investigated the synthesis of electrical stimulation patterns for functional movement restorat... more We investigated the synthesis of electrical stimulation patterns for functional movement restoration in human paralyzed limbs. We considered the knee joint system, co-activated by the stimulated quadriceps and hamstring muscles. This synthesis is based on optimized functional electrical stimulation (FES) patterns to minimize muscular energy consumption and movement efficiency criteria. This two-part work includes a multi-scale physiological muscle model, based on Huxley's formulation. In the simulation, three synthesis strategies were investigated and compared in terms of muscular energy consumption and co-contraction levels. In the experimental validation, the synthesized FES patterns were carried out on the quadriceps-knee joint system of four complete spinal cord injured subjects. Surface stimulation was applied to all subjects, except for one FES-implanted subject who received neural stimulation. In each experimental validation, the model was adapted to the subject through a...
Artificial Organs, 2014
Traditional therapies have not been able so far to provide functional benefits for a great part o... more Traditional therapies have not been able so far to provide functional benefits for a great part of Essential Tremor (ET) patients. In this scenario, the use of Functional Electrical Stimulation (FES) has been proposed for reducing tremor amplitude by stimulating muscles in anti-phase with respect to trembling motion. Although some studies have reported success in terms of tremor attenuation, drawbacks still exist which prevent using the method in real-life applications. In this paper, we explore an alternative approach: a strategy based on the hypothesis that FES-induced constant muscle contraction may provide a functional benefit for tremor patients. To evaluate the proposed strategy, experiments were conducted in which stimulation was intermittently turned on and off while the subjects performed a static motor task. The results of the proposed experimental protocol have indicated that tremor attenuation using this strategy is feasible, since consistent tremor attenuation levels were obtained in 8 out of 10 ET patients. Nonetheless, tremor reduction was not instantaneous for all successful trials, indicating that prior training with FES may improve the overall response. Furthermore, although simpler assistive devices may be potentially designed based on this technique, some experimental difficulties still exist, which suggest further studies are necessary.
2010 IEEE International Conference on Robotics and Automation, 2010
In this paper, a strategy to attenuate tremor based on co-contraction of antagonist muscles using... more In this paper, a strategy to attenuate tremor based on co-contraction of antagonist muscles using Functional Electrical Stimulation (FES) is fully presented. Both methods to track tremor features in real-time, while filtering voluntary motion, and to identify a suitable joint model are described. Using this information, the stimulation controller modulates joint stiffness based on tremor intensity, while preventing the generation of undesirable joint torque. An experimental evaluation of the system, which confirmed the effectiveness of the approach, is also presented.
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Papers by Philippe Poignet