2025Activity reportProject-TeamCAMIN
RNSR: 201622042U- Research center Inria Branch at the University of Montpellier
- Team name: Control of Artificial Movement & Intuitive Neuroprosthesis
Creation of the Project-Team: 2019 March 01
Each year, Inria research teams publish an Activity Report presenting their work and results over the reporting period. These reports follow a common structure, with some optional sections depending on the specific team. They typically begin by outlining the overall objectives and research programme, including the main research themes, goals, and methodological approaches. They also describe the application domains targeted by the team, highlighting the scientific or societal contexts in which their work is situated.
The reports then present the highlights of the year, covering major scientific achievements, software developments, or teaching contributions. When relevant, they include sections on software, platforms, and open data, detailing the tools developed and how they are shared. A substantial part is dedicated to new results, where scientific contributions are described in detail, often with subsections specifying participants and associated keywords.
Finally, the Activity Report addresses funding, contracts, partnerships, and collaborations at various levels, from industrial agreements to international cooperations. It also covers dissemination and teaching activities, such as participation in scientific events, outreach, and supervision. The document concludes with a presentation of scientific production, including major publications and those produced during the year.
Keywords
Computer Science and Digital Science
- A1.2.6. Sensor networks
- A1.3. Distributed Systems
- A2.3. Embedded and cyber-physical systems
- A2.5.2. Component-based Design
- A4.4. Security of equipment and software
- A5.1.4. Brain-computer interfaces, physiological computing
- A5.9.2. Estimation, modeling
- A5.10.5. Robot interaction (with the environment, humans, other robots)
- A6.1.1. Continuous Modeling (PDE, ODE)
- A6.3.2. Data assimilation
- A6.4.1. Deterministic control
- A6.4.6. Optimal control
Other Research Topics and Application Domains
- B1.1.9. Biomechanics and anatomy
- B1.2.1. Understanding and simulation of the brain and the nervous system
- B2.2.1. Cardiovascular and respiratory diseases
- B2.2.2. Nervous system and endocrinology
- B2.2.6. Neurodegenerative diseases
- B2.5.1. Sensorimotor disabilities
- B2.5.3. Assistance for elderly
1 Team members, visitors, external collaborators
Research Scientists
- Christine Azevedo Coste [Team leader, INRIA, Senior Researcher, HDR]
- François Bailly [INRIA, Researcher]
- François Bonnetblanc [INRIA, Researcher, HDR]
- Thomas Guiho [INRIA, ISFP]
- Olivier Rossel [INRIA, Researcher, from Oct 2025]
Post-Doctoral Fellows
- Sabrina Otmani [INRIA, Post-Doctoral Fellow, until May 2025]
- Pierre Schegg [INRIA, Post-Doctoral Fellow]
PhD Students
- Paul Andre [INRIA]
- Jonathan Baum [INRIA]
- Kloe Bonnet [INRIA, from Oct 2025]
- Laurence Colas [REEV SAS, CIFRE, until Feb 2025]
- Amina Ferrad [INRIA, from Nov 2025]
- Gabriel Graffagnino [INRIA]
- Charlotte Le Goff [Association APPROCHE]
- Valentin Maggioni [INRIA]
- Clotilde Turpin [INRIA, CIFRE]
Technical Staff
- Tiago Coelho Magalhaes [INRIA, Engineer, from Mar 2025]
- Jean De Gheldere [INRIA, Engineer, until Sep 2025]
- Baptiste Faraud [INRIA, Engineer]
- Ronan Le Guillou [INRIA, Engineer]
- Emilie Ouraou [INRIA, Engineer, from Jul 2025]
- Olivier Rossel [INRIA, Engineer, until Sep 2025]
- Felix Schlosser–Perrin [INRIA, Engineer, from Feb 2025 until Jun 2025]
Interns and Apprentices
- Ali Boukhsibi [UNIV MONTPELLIER, Intern, from May 2025 until Jun 2025]
- Jean-Baptiste Bronzini De Caraffa [LYCEE JEAN MERMOZ, Intern, from May 2025 until Jun 2025]
- Amani Hamdi [INRIA, Intern, from Mar 2025 until Aug 2025]
- Mahoua Safiatou Kone [UNIV MONTPELLIER, Intern, from Apr 2025 until Jun 2025]
- Saouda Padavia [UNIV MONTPELLIER, Intern, from Jun 2025 until Aug 2025]
- Maria Fernanda Pereira Betim Paes Leme [INRIA, Intern, from May 2025 until Aug 2025]
- Daniel Reyes Rapalo [UNIV MONTPELLIER, Intern, from Oct 2025]
Administrative Assistants
- Claire-Marine Parodi [INRIA]
- Giulia Petrarulo [INRIA, AI-Hand Project Manager]
Visiting Scientists
- Ali Boukhsibi [UNIV MONTPELLIER, until Jan 2025]
- Eve Charbonneau [UNIV SHERBROOKE, from Sep 2025]
External Collaborators
- Charles Fattal [USSAP, HDR]
- David Guiraud [NEURINNOV, HDR]
- Benoît Sijobert [INSTITUT ST-PIERRE]
2 Overall objectives
CAMIN research team is dedicated to the design and development of realistic neuroprosthetic solutions for sensorimotor deficiencies in collaboration with clinical partners. Our efforts are focused on clinical impact: improving the functional evaluation and/or patients quality of life. Movement is at the center of our investigative activity, and the exploration and understanding of the origins and control of movement are one of our two main research priorities. Indeed, optimizing the neuroprosthetic solutions depends on a deeper understanding of the roles of the central and peripheral nervous systems in motion control. The second research priority is movement assistance and/or restoration. Based on the results from our first research focus, neuroprosthetic approaches are deployed (Figure 1).
Electrical stimulation (ES) is used to activate muscle contractions by recruiting muscle fibers, just as the action potentials initiated in motoneurons would normally do. When a nerve is stimulated, both afferent (sensitive) and efferent (motor) pathways are excited. ES can be applied externally using surface electrodes positioned on the skin over the nerves/muscles intended to be activated or by implantation with electrodes positioned at the contact with the nerves/muscles or neural structures (brain and spinal cord). ES is the only way to restore movement in many situations.
Although this technique has been known for decades, substantial challenges remain, including: (i) detecting and reducing the increased early fatigue induced by artificial recruitment, (ii) finding solutions to nonselective stimulation, which may elicit undesired effects, and (iii) allowing for complex amplitude and time modulations of ES in order to produce complex system responses (synergies, coordinated movements, meaningful sensory feedback, high-level autonomic function control).
We investigate functional restoration, as either a neurological rehabilitation solution (incomplete Spinal Cord Injury (SCI), hemiplegia) or for permanent assistance (complete SCI, chronic hemiplegia). Each of these contexts imposes its own set of constraints on the development of solutions.
Functional ES (FES) rehabilitation mainly involves external FES, with the objective to increase neurological recuperation by activating muscle contractions and stimulating both efferent and afferent pathways. Our work in this area naturally led us to take an increasing interest in brain organization and plasticity, as well as central nervous system (brain, spinal cord) responses to ES. When the objective of FES is a permanent assistive aid, invasive solutions can be deployed. We pilot several animal studies to investigate neurophysiological responses to ES and validate models. We also apply some of our technological developments in the context of human per-operative surgery, including motor and sensory ES.
CAMIN research is focused on exploring and understanding human movement in order to propose neuroprosthetic solutions in sensorimotor deficiency situations to assist or restore movement. Exploration and understanding of human movement will allow us to propose assessment approaches and tools for diagnosis and evaluation purposes, as well as to improve FES-based solutions for functional assistance.
The image depicts a cyclical process involving exploration, analysis, and assistance for movement restoration. It features two main phases: "Exploration Analysis" includes components like electrophysiology, signal processing, sensors, technology, and experimentation. "Assistance Restoration" involves neuroprostheses, automatic control, technology, and experimentation. The diagram shows arrows indicating a continuous process.
We have chosen not to restrict our investigation spectrum to specific applications but rather to deploy our general approach to a variety of clinical applications in collaboration with our medical partners. Our motivation and ambition is to have an effective clinical impact.
3 Research program
3.1 Exploration and understanding of the origins and control of movement
One of CAMIN’s areas of expertise is motion measurement, observation and modeling in the context of sensorimotor deficiencies. The team has the capacity to design advanced protocols to explore motor control mechanisms in more or less invasive conditions in both animal and human.
Human movement can be assessed by several noninvasive means, from motion observation (MOCAP, IMU) to electrophysiological measurements (afferent ENG, EMG, see below). Our general approach is to develop solutions that are realistic in terms of clinical or home use by clinical staff and/or patients for diagnosis and assessment purposes. In doing so, we try to gain a better understanding of motor control mechanisms, including deficient ones, which in turn will give us greater insight into the basics of human motor control. Our ultimate goal is to optimally match a neuroprosthesis to the targeted sensorimotor deficiency.
The team is involved in research projects including:
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Peripheral nervous system (PNS): modeling, exploration and electrophysiology
Electroneurography (ENG) and electromyography (EMG) signals inform about neural and muscular activities. The team investigates both natural and evoked ENG/EMG through advanced and dedicated signal processing methods. Evoked responses to ES are very precious information for understanding neurophysiological mechanisms, as both the input (ES) and the output (evoked EMG/ENG) are controlled. Camin has the expertise to perform animal experiments (rabbits, rats, earthworms and big animals with partners), design hardware and software setups to stimulate and record in harsh conditions, process signals, analyze results and develop models of the observed mechanisms. Experimental surgery is mandatory in our research prior to invasive interventions in humans. It allows us to validate our protocols from theoretical, practical and technical aspects.
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Central nervous system (CNS) exploration
Stimulating the CNS directly instead of nerves enables direct activation of the neural networks responsible for generating functions. Once again, if selectivity is achieved the number of implanted electrodes and cables would be reduced, as would the energy demand. We have investigated spinal electrical stimulation in animals (pigs) for urinary track and lower limb function management. This work is very important in terms of both future applications and the increase in knowledge about spinal circuitry. The challenges are technical, experimental and theoretical, and the preliminary results have enabled us to test some selectivity modalities through matrix electrode stimulation. This research area will be further intensified in the future as one of the ways to improve neuroprosthetic solutions.
We intend to gain a better understanding of the electrophysiological effects of Direct Electrical Stimulation (DES) through electroencephalographic (EEG) and electrocorticographic (ECoG) recordings in order to optimize anatomo-functional brain mapping, to better understand brain dynamics and plasticity, and to improve surgical planning, rehabilitation, and the quality of life of patients.
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Muscle models and fatigue exploration
Muscle fatigue is one of the major limitations in all FES studies. Simply, the muscle torque varies over time even when the same stimulation pattern is applied. As there is also muscle recovery when there is a rest between stimulations, modeling the fatigue is almost an impossible task. Therefore, it is essential to monitor the muscle state and assess the expected muscle response by FES to improve the current FES system in the direction of greater adaptive force/torque control in the presence of muscle fatigue.
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Movement interpretation
We intend to develop ambulatory solutions to allow ecological observation. We have extensively investigated the possibility of using inertial measurement units (IMUs) within body area networks to observe movement and assess posture and gait variables. We have also proposed extracting gait parameters like stride length and foot-ground clearance for evaluation and diagnosis purposes.
3.2 Movement assistance and/or restoration
The challenges in movement restoration are: (i) improving nerve/muscle stimulation modalities and efficiency and (ii) global management of the function that is being restored in interaction with the rest of the body under voluntary control. For this, both local (muscle) and global (function) controls have to be considered.
Online modulation of ES parameters in the context of lower limb functional assistance requires the availability of information about the ongoing movement. Different levels of complexity can be considered, going from simple open-loop to complex control laws (Figure 2).
The image depicts a flowchart demonstrating the relationship between natural and artificial controllers in managing individuals with different movement disorders. It shows three conditions: spinal cord injury, Parkinson's disease, and post-stroke hemiplegia. Posture and gait observation guide artificial controllers. The flowchart visually connects the conditions to the types of controllers used for management of assistive technologies.
Real-time adaptation of the stimulation patterns is an important challenge in most of the clinical applications we consider. The modulation of ES parameters requires more advanced adaptative controllers based on sensory information in order to adapt to muscle fatigue or environmental changes. A special care in minimizing the number of sensors and their impact on patient motion should be taken.
4 Application domains
4.1 Movement Assistance
CAMIN develops neuroprosthetic solutions dedicated to restore or assist movements of paralyzed limbs. Among the considered functions we can cite: pedalling, grasping or walking. Different users are considered: individuals with post-stroke hemiplegia, people with spinal cord lesions and persons with Parkinson disease.
We have also started to develop skills in orthosis design.
4.2 Movement Analysis
For the purpose of assisting movement, CAMIN has developed an important expertise in movement interpretation using a large range of sensors: inertial measurement units, MOCAP systems, encoders, goniometers... Various Classification methods are used depending on the objective.
This knowledge is applied in other applications than movement assistance, like in the MEDITAPARK project where we developed an application (PARAKEET) embedded in a smartwatch to monitor hand tremor in persons with parkinson disease.
4.3 Evoked electrophysiology
CAMIN develops solutions to trigger, record and process electrophysiological signals evoked by electrical stimulation applied to various neural tissues. These evoked responses are used to control the activity of the excitable tissue, to probe its electrophysiological status for diagnostic purposes and to investigate the conductivity/connectivity between the stimulation and the recording sites (electrophysiological mapping).
These neural engineering procedures can be applied to muscle, nerve, spinal cord and brain, in animals and humans.
For instance, electrical stimulations can be applied externally and non-invasively on muscles to induce muscle contractions as well as invasively on the human brain in order to guide neurosurgeries.
5 Social and environmental responsibility
5.1 Impact of research results
CAMIN research is clearly dedicated to applications which intend to improve quality of life and/or self esteem of individuals with sensorimotor deficiencies.
Our activities are associated with an important working load on designing protocols and obtaining authorizations from ethical committees and/or health agencies. We list in the following the protocols that have obtained authorizations and were valid in 2024.
- Measure of the Potential Evoked by Electric Stimulation (PE & CE). CHU Montpellier. Autorisation CPP RCB 2014-A00056-43. ClinicalTrials.gov Identifier: NCT02509442
- Prehens-Stroke 2: Prospective multicenter study on the evaluation in clinical setting of a Grasp NeuroProsthesis and self-triggering control modalities for the restauration of paretic side prehension capabilities in post-stroke subjects. Study carried by the University Hospital (CHU) of Toulouse in collaboration with the Le Grau du Roi rehabilitation center from the University Hospital (CHU) of Nîmes (ClinicalTrial.gov ID: NCT04804384; Autorisation CPP ID-RCB: 2020-A01660-39).
- Grasp-Again: Prospective monocentric, real-life, feasibility case series study on 2 months long usage of a wearable grasp neuroprosthesis, at home in autonomy by post-stroke participants. Study carried by the University Hospital (CHU) of Toulouse (ClinicalTrial.gov ID: NCT05625113; Autorisation CPP ID-RCB: 2022-A01202-41).
- AI-Hand CT1 - Sensors: Evaluation of Non-Invasive Control Interfaces for Operating Assistive Devices for Individuals with Tetraplegia. Autorisation CPP ID-RCB: 2024-A01014-43 / Dispositif médical classe I
- AI-Hand CT2 - I-Grip: Relevance of virtual reality–based evaluation of control interfaces for an upper-limb neuroprosthesis using stimulation in people with tetraplegia. Autorisation CPP ID-RCB: 2025-A01444-45 / RIPH2
- Freewheels: Impact of training a tetraplegic subject in pedaling a tricycle assisted by electrical simulation of sub-lesional muscles: A Pilot Study. Autorisation CPP ID-RCB: 2025-A01444-45 / RIPH2
- CoCoS: Quantify the correlation between muscle co-activation in each agonist/antagonist muscle group of interest during the phases of the gait cycle and the spasticity assessment associated with each of these muscle groups. COERLE (autorisation nº 2024-44)
- i-grip: Evaluation of an Algorithm for Detecting Object Grasping Intent and Selecting an Appropriate Grip. COERLE (autorisation nº 2024-01)
- AI-Hand - Animal studies: Experimentations in pigs to support the development of an implantatable stimulation device designed to eventually restore prehension in people with tetraplegia (Ethical agreement from the Ministry of Higher Education and Research nº 47593-2024021614231926 v2).
5.2 HLI: Handitechlab INRIA
Humanlabs are collaborative spaces for digital fabrication or repair of objects, open to people with disabilities to enable them to appropriate technology for their own use. In 2021, Christine Azevedo and Roger Pissard-Gibollet (SED INRIA Montbonnot) have launched the Inria’s HumanLab intiative. This action was sustained by a decision of INRIA's management under the name of Handitechlab INRIA (HLI) and contributes to meeting the needs expressed by individuals with disabilities within the framework of the Humanlabs network or via clinical partners. Our action is part of a frugal and opensource innovation approach and aims to implement the scientific and technological know-how of Inria’s staff to meet specific needs. www.inria.fr/en/hli
About ten team members participated in the 3-day hackathon FABRIKARIUM organized by the HumanLab Saint Pierre (LINK). Several of them have been involved in projects throughout the year.
5.3 Awareness-raising on disability
Christine Azevedo organized, during SEEPH (Semaine Européenne pour l'Emploi des Personnes en situation de handicap) week, a talk at the Montpellier branch by a blind speaker to raise awareness about disability and combat stereotypes.
6 Highlights of the year
6.1 Awards
- Clotilde Turpin (39) won the 2024 Herbert Jasper Young Investigator Paper Award for Clinical Neurophysiology.
- Eve Charbonneau won the best poster award at the 50ème Congrès de la société de biomécanique held in Marseille, France, in October 2025.
6.2 Other
- 8 team members attended a 2-day training on: Evaluation in clinical investigations of medical devices: regulatory aspects (EU 2017/745) and good clinical practice (EN ISO 14155)
7 Latest software developments, platforms, open data
7.1 Latest software developments
7.1.1 i-GRIP
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Keywords:
Handicap, Computer vision, Persons attendant, Exoskeleton, Detection
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Scientific Description:
Detection of object grasping intention and automatic selection of grasp type for shared control of (neuro)prostheses.
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Functional Description:
From a video stream of hands and objects, i-GRIP detects the intention to grasp one of them and identifies the grip the hand should adopt to appropriately seize it based on the approaching movement. i-GRIP will enable intuitive and low cognitive load control of hand movement assistive devices (exoskeletons, functional electrical stimulation, prosthetics).
- Publication:
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Contact:
Etienne Moullet
7.1.2 SMS
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Name:
Software for Manual Segmentations
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Keyword:
Image segmentation
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Functional Description:
Software that combines various ways of segmenting images, whether by drawing or placing points.
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Contact:
Baptiste Faraud
7.1.3 TARGETTRACK
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Name:
TARGETTRACK
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Keywords:
Motor reeducation, Health
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Functional Description:
Software for playfully visualizing actions performed by users, with the aim of offering rehabilitation.
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Contact:
Baptiste Faraud
7.1.4 IMUSEF
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Keywords:
Inertial module unit, Adaptive algorithms, Human Movement Analysis
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Scientific Description:
Modular embedded framework for real-time control of Functional Electrical Stimulation in closed loop with sensor feedback.
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Functional Description:
IMUSEF enables the collection of data from various sensors, including inertial measurement units, to detect interactions with the user or evaluate events or information about the user, such as the orientation of a segment or a joint angle. With this information, a decision-making algorithm selected from a modular panel can detect events and control actuators such as an electrical stimulator to assist movement.
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Release Contributions:
1.0 : First fully functional version application focused with stimulator control, sensor data acquisition and analysis and decisional algorithm (https://www.mdpi.com/545320). 2.0 : Full rework as a modular framework, allowing selection of decisional algorithm, stimulator system, sensors etc. and optional communication and control in real time from a remote fully featured Graphical User Interface through autonomous hotspot wifi.
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News of the Year:
New software features were designed and integrated in preparation for new experimentations, along with adaptations to conform to new platform changes and upgrades on related hardware and firmware. The improvements aimed at preparing this platform and its capabilities to allow for standardized and generalized use.
- URL:
- Publication:
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Contact:
Ronan Le Guillou
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Participant:
4 anonymous participants
7.2 New platforms
Within AI-Hand project, we have developed 2 experimental platforms.
7.2.1 AI-Hand platforms
AI-HAND first clinical trial (CT1) experimental platform to assess the capacity to modulate stimulation intensity to adjust grasping force
Participants: Baptiste Faraud, Christine Azevedo, François Bailly.
The content of this experimental platform consists in two main aspects : the control modalities (Fig. 3, top) and the Target-Track software in static mode (Fig. 3, bottom). Users included in CT1, with tetraplegia without functional electrical stimulation) can use several control modalities to adjust a virtual grasping force which is displayed through the Target-Track software. The force adjustment is performed thanks to two distinct control inputs, "+" and "-", respectively. The Target-Track software provides a visual feedback to the user (through the display of the current grasping force achieved through the control inputs) and a reference value (static or dynamic) to be tracked by the user. The overall objective is to evaluate the performances of the several control modalities to achieve force adjustments.
This image depicts, on the top, examples of control modalities such as ear-based, microphone or joystick. The user operates these devices to send control signals to a software to control a serious game.
The Target-Track software has two modes: a static gauge (Fig. 3 bottom) and a dynamic serious game (Fig. 4).
The image shows a video game with a UFO at the center of the screen. The UFO is surrounded by vertical blue columns. The UFO appears to be navigating through the vertical columns. One of them is highlighted in red.
Force estimation of fingers during hand grasping movements
Participants: Jean De Gheldere, Christine Azevedo, François Bailly.
As a part of the AI-HAND project, in the scope of the indirect measurement of hand grasping forces, we continued the development of the robotic platform able to directly assess grasp forces in various configurations. This platform will help us assess hand dynamics, particularly to calibrate the indirect measurement methods, by simulating rigid or soft contacts while measuring the force developed by such movements and grasping patterns.
The system consists of two parts: a ’robot’ part and an ’interface’ part. The robot is an assembly of two torque-controlled axes, incorporating a capstan drive mechanism, enabling backlash-free transmission between the motors and the ’interface’ subsystem. The interface is a 4-bar mechanism, which can reach a wide range of configurations, and transmit the forces from the hand to the robot rigidly.
The device was fully prototyped (Fig. 5), and is now in the last development stage. It integrates custom made torque sensors that are also in their final phase of development (Fig. 6). Most of the technical choices are now validated, and we are working on the device's reliability and deployability for future experiments.
The image shows the mechanical assembly of the device placed on a perforated workbench. The assembly includes a black and orange structure with various components. There are wires connecting these parts.
CAD assembly featuring a cylindrical shaft and various components attached along its length.
7.2.2 IMUSEF modular platform for research experimentations with FES)
Participants: Le Guillou Ronan, Azevedo Christine, Gasq David [CHU Toulouse].
This platform, developped in the team initially for FES-assisted cycling with SCI participants, evolved into a modular platform to support diverse research experimentations on various pathologies (e.g. Stroke, SCI, Cerebral Palsy etc.). A desired Functional Electrical Stimulator can be controlled by this platform through a chosen decisional algorithm using sensor feedback. New sensors, algorithms and electrical stimulators or other actionners can be added in a modular way. This embedded platform, upgraded to become fully autonomous and wearable, allows for ambulatory experimentations.
The lack of devices available for practical use in daily-life conditions in Stroke survivors led to work with the Hospital of Toulouse in previous years and the acquisition of significant know-how on the design requirements, user feedback, and characteristics needed for high acceptability in daily usage. Through collaboration with Toulouse Tech Transfer, the French Society for Acceleration of Technological Transfer (SATT) of Toulouse, this acquired knowhow was deposited this year as a e-Soleau Intellectual Property envelope. In preparation for future experimentations, various new features and upgrades were added, hardware, firmware and software wise. New capabilities of this platform will allow future generalization and standardization of its usage as a shared platform for other experimentations in the team.
The image shows three parts of an assistive device, designed to assist grasping for individuals with limited prehension capabilities. Part A shows a single board computer stored in a waist bag. Part B is a wearable sleeve garment with an electrode array that sticks to the forearm skin, enabling evoked muscle contractions through electrical currents. Part C is a small handheld device with buttons and a screen, used for controlling the system and its modes of activations. The setup is presented worn by a person which is using it to grasp a spoon in a clinical testing situation.
8 New results
We have organized the results around 3 main subsections: 8.1) Online Guidance of Neurosurgery with Brain Potentials Evoked by Direct Electrical Stimulation or Computer Vision, 8.2) Movement analysis, detection and modeling and 8.3) Motor functions assistance.
8.1 Online Guidance of Neurosurgery with Brain Potentials Evoked by Direct Electrical Stimulation or Computer Vision
8.1.1 Influence of myelo-architecture on direct cortical response evoked by electrical stimulation
Participants: Clotilde Turpin, Olivier Rossel, Félix Schlosser-Perrin, Riki Matsumoto [Neurology Dpt Kyoto Hospital, Japan], Emmanuel Mandonnet [Neurosurgery Dpt APHP, Paris], Sam Ng [Neurosurgery Dpt Montpellier Hospital], Hugues Duffau [Neurosurgery Dpt Montpellier Hospital], François Bonnetblanc.
The measurement of evoked potentials (EPs) by direct electrical stimulation (DES) during brain surgery allows identifying structural or anatomical connectivity in real time, while aiming to preserve it (39, 19, 20). Classically, the evoked response is composed of an early positive component, denoted P0, occurring after the DES artifact when measurable, followed by a more robust negative deflection, denoted N1. As DES initially activates larger elements, and given its early onset, P0 is assumed to reflect a summation of highly synchronized action potentials (APs).
Cyto-myelo architecture varies across brain regions, particularly between primary areas (motor M1, sensory S1), the premotor cortex and the more associative areas such as the Broca, Wernicke, and other association areas. Precentral motor cortex and S1 are distinguished by the presence of larger diameter, heavily myelinated fibers. Due to the specific characteristics of electrical stimulation, these architectural variations should be reflected in cortical responses evoked by DES.
Among the first elements to be activated, pyramidal axons (particularly abundant in the precentral motor and primary somatosensory (S1) areas) generate high-amplitude signals, are more readily excitable, and propagate action potentials more rapidly. This is expected to result in a shorter latency but higher-amplitude P0 component, producing a steeper downward slope in the signal (relaxation slope) in motor and somatosensory cortices compared to more associative regions such as Broca’s area, Wernicke’s area, and other associative cortices. We sought to test this hypothesis.
DES was administered directly to different regions of the cortex while recording DCRs (direct cortical responses) in 10 patients. The shapes of the first components P0 and N1 of the signals were analyzed.
The downward slope of the first component (P0) of the signal is statistically greater for responses recorded in precentral motor cortex and S1 than that of EPs recorded in more associative areas (Fig. 8).
Anatomical features of (pre) motor and somatosensory explain the response and the increased slope of the P0 component in these regions, compared to associative areas. The first component of DES-evoked responses reflects myelo architecture in particular. This could form the basis of an electrodiagnostic method using the evoked response or to better distinguish between specific areas intra-operatively.
The figure is composed of 3 parts. The part A is an image showing a map of the human brain with highlighted cortical regions and markers positionned at recording sites, each tagged with patient numbers (P1 to P10). Part B is a graph of amplitude versus time showing an average waveform of evoked potential and illustrating the different metrics. Part C presents multiple amplitude versus time graphs for brain responses recorded at the various markers for the subjects.
8.1.2 noCNN : No-brain-shift and Comprehensive Neurosurgical Navigation using computer vision
Participants: Paul André, Emilie Ouraou, François Bailly, François Bonnetblanc, Emmanuel Mandonnet [Neurosurgery Dpt APHP, Paris], Sam Ng [Neurosurgery Dpt Montpellier Hospital], Hugues Duffau [Neurosurgery Dpt Montpellier Hospital].
Brain neurosurgeons have a particular need for reliable images to plan and guide their procedures. This is especially true because brain shift occurs immediately upon opening the dura-mater due to the decrease in intracranial pressure and the outflow of cerebrospinal fluid. Since the brain is composed of soft tissue, this shift is exacerbated when the surgeon must perform an excision, sometimes involving volumes exceeding 100 cm³ in the case of tumor surgery. In the field of clinical imaging, intraoperative photos or videos of brain surgeries are common but rarely used in conjunction with computer vision approaches.
During neurosurgery, Magnetic Resonance Imaging (MRI) are considered before the operation to allow planification and neuro-navigation, but do not take into account the brain shift that can be up to 2 cm.
In order to find the correspondence between intra-operative images and MRIs, we aim to perform a non-rigid registration. Intra-operative images are in 2D, while MRIs are in 3D, so in order to have data of the same dimensions, we project the MRI onto a plane that approximately represents the camera's position in the real world.
From images showing the brain surface in these two different modalities, we set up a pipeline, shown in Figure 9 to pre-process them and extract features in order to perform registration. The three elements that can be found in both intraoperative images and preoperative MRI (without contrast agent and with gadolinium injection) are vessels, sulci, and gyri.
In order to segment these elements in the intraoperative image, we have planed to train a U-Net, a convolutional network that works well with few data and is suitable for medical applications 37. The training will incorporate constraints giving advantage to the anatomical accuracy into the cost function, such as ClDice 38. In order to train this model, we are currently building a dataset containing image/segmentation pairs with around ten classes, which is more than what is commonly done. We have currently segmented 65 images manually, requiring around 4 hours per image. Each image will be double-checked by healthcare experts.
To segment the MRIs, we first process them with HD-BET (brain extraction tool) and then Freesurfer in order to extract the brain and to better remove the dura mater, which may still be present after preprocessing with skullstrip tools. This also allows us to normalize the voxel values. Then we display the MRI in 3DSlicer's 3D view, we manually position a camera in a view similar to the camera in the real world, and we generate an image representing the brain surface from the T1 MRI without contrast agent, and another with the same viewpoint from the T1 MRI with gadolinium. This step requires human intervention, but could be automated using a FLAIR image to determine the position of the tumor and therefore deduce the position of the craniotomy and the surgeon. In the MRI images, the vessels are extracted by thresholding, while the gyri and sulci are segmented manually.
Using these segmented images, we will now perform a non-rigid registration in order to find the correspondence between the T1 MRI and the real brain during the operation.
In addition, we plan to publish a dataset containing the images and manual segmentations, as well as a section of the MRI corresponding to the craniotomy, over the upcoming year.
An internal communication on this "Action exploratoire" was published this year.
The image illustrates the process for brain surface image creation and surgical planning. It involves using deep learning (U-Net) for automated segmentation of intraoperative images into vessels, gyri, and sulci. MRI scans (T1 and T1CE) are used to extract regions of interest and perform vessel, gyri, and sulci segmentation. These segmentations are combined to compute non-rigid registration and estimate brain surface deformation. Style transfer is applied to create a detailed brain surface image for surgical planning. Data augmentation is used to improve segmentation accuracy.
8.1.3 Style Transfer application to better guiding of brain surgery
Participants: Emilie Ouraou, Paul André, François Bailly, François Bonnetblanc, Ronan Le Guillou, Emmanuel Mandonnet [Neurosurgery Dpt APHP, Paris], Sam Ng [Neurosurgery Dpt Montpellier Hospital], Hugues Duffau [Neurosurgery Dpt Montpellier Hospital].
Before neurosurgery, a pre-operatory MRI is acquired to allow the surgeon to plan the surgery. However, because of brain deformations called brain-shift occurring at the start and during surgery, these MRIs do not precisely represent what the surgeon will encounter during the operation. The main objective of this project is to help surgery planning by providing a more accurate view of the brain's configuration. Our main concern is the blood vessels, since we want the surgeon to be able to clearly identify the regions where extra caution is required. Indeed, the surgeon has to be very careful not to cut any big blood vessel trying to access the tumor, but currently they can only be seen pre-operatively by extracting 2D slices from the 3D MRI.
For a start, we want to link the pre-operative MRI with the intra-operative view (obtained via intra-operatory images), initially without considering brain-shift. The goal is to transform the MRI into a realistic visual representation corresponding to the cerebral surface where surgery is going to take place, using style transfer. To do so, we seek to translate segmented images back into realistic intra-operative images using generative models, namely Pix2pix and CycleGAN. Both are derivatives of the Generative Adversarial Network model types, but while Pix2pix uses paired data (combinations of images and its associated segmentation, which limits the number of available data due to the scarcity of segmentations available), CycleGAN works with unpaired data (images and segmentations do not need to be from the same patient). On the other hand, Pix2pix is often more respectful of the structures represented.
Our first step focuses on intra-operative images. We manually segment these images and train a generative model to learn the transformation from segmentation maps back into real images. The main novelty of this work lies in the number of classes chosen: while the literature generally considers three classes (background, parenchyma and vessels), we chose to also include gyri and sulci, believing it should improve the precision of our model.
This step will also be useful to train an automatic segmentation model. Due to the scarcity of segmented data and the time burden of manually labeling each image (around four hours per image), segmented data are rare and thus training datasets are limited. However, our style transfer model could be applied to generate realistic-looking images from synthetic segmentations, in order to artificially increase to amount of data at disposal to train an automatic segmentation model.
The next step is to segment the pre-operative MRIs and use those segmentations in the style transfer network, attempting to convert MRI segmentations into photorealistic intra-operative images. This new representation could help non-expert surgeons better visualize MRI data and improve surgery planning. In future steps, we could also generate augmented-reality images which would, for example, display deep vessels not currently visible to the surgeon but which require special attention.
Figure 10 presents examples of the style transfer currently achieved.
The image depicts a flowchart of a style transfer model for medical imaging, specifically for brain scans. It involves different stages and components (input images and manual segmentation, generative Models)
8.2 Movement analysis, detection and modeling
Our team develops tools and methods to understand and model movement in order to improve function assistance.
8.2.1 Optimal estimation of forearm muscle activations evoked by implanted electrical stimulation in complete quadriplegia
Participants: Maggioni Valentin, Schegg Pierre, Guiho Thomas, Faraud Baptiste, Azevedo Christine, Bailly François.
Muscle activity assessment is crucial to understand both natural and evoked human movements. The most common method to measure it is through surface electromyography (EMG). However, this method presents significant caveats, such as cross-talk from adjacent muscles, or its inability to detect deep-muscles’ contractions. A possible solution to address these limitations is multimodal estimation, through the use of a musculoskeletal (MSK) model leveraging kinematic and EMG data. In particular, it is possible to formulate an optimal estimation problem to blend these quantities and estimate the activation of the model’s muscles.
This work aims to apply this approach to a hand model developed in the context of functional electrical stimulation (FES) of arms’ nerves to restore hand movements in individuals with complete quadriplegia via implanted epineural electrodes, to accurately estimate the muscle activation of FES-induced hands movements.
This study combines kinematic and EMG data from the AGILIS and AGILISTIM experimental protocols in a single optimal estimation problem that was adapted specifically for the context of FES-induced hand movements, by considering different objective functions and simulation parameters depending on whether the radial or median nerve is stimulated. The objective functions that permit to exploit both kinematic and EMG data simultaneously mathematically takes the form of a cost function to be minimized and expressed as:
Where and are the number of muscles and joints of the musculoskeletal model respectively, and are the muscle activation derived from the EMG measurements and estimated by the optimal estimation problem respectively, and are the joint kinematics measured experimentally and estimated by the optimal estimation problem respectively, and are the weight associated with the activation and kinematic terms respectively.
The kinematic data was obtained through markerless motion capture using webcams and the Mediapipe API. The pipeline used to convert the webcam video feed into usable kinematic data was developed between 2024 and 2025 and is described in a paper that was published in Sensors (15). A graph of the experimental setup used to obtain kinematic and EMG data in the AGILIS and AGILISTIM experimental setup, as well as the max position and muscle recruitment measured for specific articulations and muscles for two stimulation configurations are shown in Fig. 11. Additionally, EMOK, a software made to ease the usage of the motion capture method was developed and uploaded on the BIL software database.
To ensure a correct estimation, a musculoskeletal hand model was developed based on an open-source literature model and personalized for quadriplegic individuals. This includes a simplification of the model by removing all muscles innervated by the ulnar nerve, which is not stimulated by an implant and an adaptation of the passive forces at each finger articulation, which are personalized to each individual based on kinematic measurements.
The optimal estimation method, combined with the personalized hand musculoskeletal model allowed us to estimate the muscle activation of deep muscle for some of the AGILISTIM measurements, and some of the first results of this work were presented in a scientific conference (“Congrès de la société de Biomécanique 2025”) and published in the conference paper 16. Some of the estimated muscle activation from an AGILISTIM measurement are shown Figure 12. More measurements from both the AGILIS and AGILISTIM experimental protocols, as well as measurements from the Clinical Trial 2 of the AI-HAND European project will additionally be studied with this method as part of future works.
The image illustrates the setup for analyzing hand movement and muscle activity using cameras and surface electromyography (eMG). Diagrams depict the kinematics of wrist, thumb, and finger movements, along with muscle recruitment data for various forearm muscles. The bar graphs detail maximum joint positions and muscle activity levels during different hand tasks. A labeled diagram of the hand's muscles is also included, identifying key muscles involved in these actions.
Bar graph of the mean forearm muscle activation obtained with the optimal control problem solution and the measured values.
8.2.2 Evaluation of muscle recruitment: Decomposition of Evoked Electromyographic Signals
Participants: Olivier Rossel, Maria Fernanda Paes Leme, Thomas Guiho, François Bailly, Christine Azevedo.
The image illustrates a scientific study of neural stimulation and muscle electrical activity recording. Panel A illustrates the neural stimulation setup, with electrodes placed on the nerve and EMG recordings obtained from muscles of the hand and forearm. Panel B displays electromyography (EMG) signals from three distinct muscles. Panel C shows muscle recruitment levels (in percentage) for two stimulation configurations. Panel D displays the corresponding recorded EMG signals for these two stimulation configurations where the resulting EMG is a waited sum of EMG components, whose amplitudes are proportional to the muscle recruitment. Panel E summarizes the underlying hypothesis and analysis framework (in text and equation) : the recorded signals are assumed to be linear combinations of EMG components with amplitudes proportional to the muscle recruitment levels. The objective is to identify the contributing EMG components and their activation levels. The method consist in semi–non-negative matrix factorization approach applied to records.
This project addresses the challenge of estimating muscle recruitment levels through the analysis of evoked electromyographic (EMG) signals. These signals, recorded using surface electrodes, are inherently complex due to the superposition of activities originating from multiple muscles (Fig. 13). The recorded EMG signal contains information related both to the recruitment level and to the specific combination of EMG components associated with each muscle. In this work, we assume that the observed signal can be modeled as a linear combination of individual muscle EMG components, weighted by their respective recruitment levels (Fig. 13.E).
This direct modeling approach enables the generation of synthetic EMG signal databases, which are used as benchmark data to quantitatively evaluate the performance and efficiency of the proposed signal decomposition methods.
The image displays three panels related to electromyography (EMG) signal analysis. Panel A shows the synthetic EMG benchmark signal and the corresponding estimated signal (black and colored traces, respectively). Panel B presents the results obtained using the standard non-negative matrix factorization (SNNMF), including the extracted signal waveforms and their associated activation patterns (histograms) for the different stimulation configurations. Panel C shows the results of the modified SNNMF. As in Panel B, the extracted waveforms and their corresponding activation patterns are displayed, but with improved signal separation and activation estimates that more closely match the benchmark data.
The Standard Non-Negative Matrix Factorization (SNNMF) approach was evaluated and demonstrated satisfactory decomposition performance. However, as illustrated in Fig. 14.B, the initial factorization may generate artifacts in the estimation ( columns may represent mixtures of several EMG contribution, with excessive energy, lines may be correlated, reflecting a dependency between estimated recruitments, columns may be correlated, reflecting a dependency between estimated waves).
These limitations compromise the physiological interpretation of the results, particularly with respect to accurately distinguishing individual muscle contributions.
The proposed method, developed during a M1 internship, is based on a reformulation of the classical SNNMF, where the decomposition is obtained by minimizing an enriched cost function. In addition to the reconstruction error term, regularization terms have been added to penalize the energy of the matrix and reduce correlations between the columns of and between the rows of , thus ensuring greater independence of the extracted components. The optimization of this regularized cost function led to the derivation of new analytical expressions for the gradients, which were then used to define the update rules.
These modified approaches show promising results on synthetic benchmark data, as illustrated in Fig. 14. Quantitative evaluation using these synthetic benchmarks further demonstrates their effectiveness. Promising results were also obtained on real EMG recordings. Overall, the proposed methods show strong potential for real-time muscle recruitment analysis.
8.2.3 Processing of complex surface EMG signals - AI-Hand project
Participants: Hamdi Amani, Maggioni Valentin, Guiho Thomas, Guiraud David [Neurinnov].
Analysis of the electrical signals generated by muscles (EMGs) in response to neural stimulation makes it possible to evaluate the selectivity of the stimulation and thus estimate its potential in terms of functional rehabilitation. These EMGs, which are mainly captured by electrodes placed on the surface of the skin in human, contain rich but complex information. The relative distance of the electrodes from the target muscles alters the accuracy of the measurements and often leads to the recording of activity from several muscles (composite EMGs). The decomposition of these signals is an important challenge that must enable: i. the correct monitoring of the target muscles, ii. deciding on the selectivity of the stimulation parameters investigated, and iii. identifying the most selective parameters. To address this issue, time-frequency analysis work based on the Meyer wavelet transform has been undertaken in recent years within the team. The objective of this project was to further this work by:
- Comparing the performance of Meyer wavelets with other wavelet families;
- Facilitating the analysis of composite EMG signals through the automation of wavelet decomposition.
To achieve this, existing MATLAB scripts—based on Meyer wavelets—were refined to improve the processing of a dataset from a clinical trial investigating the impact of arm nerve stimulation on restoring wrist and hand function in four quadriplegic individuals.
8.2.4 Optimal Control Framework for Personalized FES-cycling in Individuals with Spinal Cord Injury
Participants: Coelho-Magalhães Tiago, Azevedo Christine, Bailly François.
We introduce an optimal control framework to enhance Functional Electrical Stimulation (FES)-cycling for individuals with spinal cord injury. The work integrated a stimulation-aware muscle model, calibrated using experimental data from an SCI participant, and demonstrated the feasibility of tracking a 42 rpm cadence and a 20 W power target through optimized pulse-duration control of six muscles 23. The approach achieved an average power output of 17.53 ± 7.87 W and a velocity of 4.09 ± 0.36 rad/s (Fig. 15), highlighting the potential of using trajectory optimization to improve the personalization and effectiveness of FES-cycling protocols 25.
The image contains three polar plots showing optimized stimulation patterns, crank angular velocity and power output.
8.2.5 Optimized Stimulation Patterns for FES-assisted Cycling Using an Experimentally Identified Physiological Muscle Model
Participants: Coelho-Magalhães Tiago, Azevedo Christine, Bailly François.
This work presents a numerical-optimal-control–compliant muscle model accounting for electrically evoked contractions and its application to FES-assisted cycling. The model incorporates calcium–troponin complex dynamics to more accurately reproduce the nonlinear force response of muscle under electrical stimulation, and it is calibrated using subject-specific isometric torque data collected from an individual with spinal cord injury. The individualized muscle parameters are identified through a trajectory optimization procedure implemented with Bioptim, ensuring compatibility with gradient-based optimal control. Using the calibrated model, predictive simulations of FES-driven pedaling are performed in which stimulation pulse duration are optimized to achieve a target cadence and power output (Fig. 16). Results demonstrate coordinated agonist–antagonist activation patterns and realistic pedaling dynamics, highlighting the potential of using optimal control for improving FES cycling performance and contributing toward more effective, personalized rehabilitation strategies.
The image depicts a study on FES-assisted cycling with four sub-figures. (a) Shows the musculoskeletal model used in the study. (b) Features a polar plot of an optimized stimulation patterns over a 360-degree cycle. (c) Displays a polar plot of crank angular velocity over a cycle. (d) Presents a polar plor of power output measured in watts across the cycle. The plots use various colors and lines to indicate different data sets and stages of movement.
8.2.6 Numerical-Optimal-Control-Compliant Muscle Model for Electrically Evoked Contractions
Participants: Coelho-Magalhães Tiago, Azevedo Christine, Bailly François.
A published study adapted an existing physiological muscle model—designed to predict force generation in response to electrical stimulation—to make it compatible with gradient-based numerical optimal control (13). The activation dynamics was reformulated to allow stimulation sequences that vary over time, enabling the simulation of more complex FES-assisted movements. Model parameters were identified using electrically evoked isometric torque data from three individuals with spinal cord injury. Using an optimal control framework, the work demonstrated accurate prediction of knee torque and the feasibility of optimizing stimulation patterns in simulation (Fig. 17). This proof of concept highlights the potential of physiological muscle model–based control to personalize and improve functional electrical stimulation strategies.
The image depicts an overview of the methodology used in the paper cited in this section (equations, methodology and an illustration of the musculoskeletal model used in the study.)
8.2.7 Musculotendon Parameters of the Human Upper Limb: a Scoping Review and Dataset Aggregation
Participants: Schegg Pierre, Maggioni Valentin, Faraud Baptiste, Bailly François.
We conducted a PRISMA-ScR-compliant scoping review of musculotendon parameters for 50 upper limb muscles, aggregating data from 107 studies and 3,742 participants. The database covers seven parameters, reported across 50 muscles, with physiological cross sectional area documented in all 50 muscles, maximal isometric force in 19 muscles, optimal fiber length in 49, fiber length in 48, pennation angle in all 50, tendon slack length in 40, and contraction velocity in one. We provide statistical values of parameters for each muscle, alongside interactive visualization tools. To facilitate data exploration, we developed a dedicated website for visualization and navigation, complemented by open-source software offering advanced filtering and visualization capabilities. The study also discusses biaises and gaps in the litterature and makes recommendations on how to address them. We anticipate that this research and the accompanying tools will serve the biomechanical modeling community by providing both an initial guess for musculoskeletal model calibration and a validation tool. Early results of the study were orally presented at the 50ème Congrès de la Société de Biomécanique by Pierre Schegg and the full length article was submitted to Sports Medicine. In conjunction with this review, we developed open-source software to visualize and filter the musculotendon parameter data. This tool facilitated the analysis and discussion in our article and is designed to be the primary interface for researchers engaging with the database. The software is published on GitLab for open access. Additionally, we created a companion website that displays the data in a browser-accessible format without the filtering options available in the software. The website is a more accessible option since it can be viewed through a browser while the software requires a python environment to be set up.
8.2.8 Upper-limb Musculoskelatal Model Calibration
Participants: Schegg Pierre, Bailly François.
This research focuses on musculoskeletal model calibration and personalization. We investigated the use of static optimization techniques applied to pre-recorded kinematic and electromyographic (EMG) data to calibrate musculotendon parameters of the model. Specifically, we examined how the quantity of input data influences calibration accuracy. We proposed a method to reduce the amount of experimental data needed to accurately identify musculotendon parameters of the model, which led to a poster presentation at the 20th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering (Barcelona, Spain) 27. Additionally, we are exploring the statistical and physical characteristics of recorded motion that contribute to effective calibration. This preliminary work is conducted in the context of the B-IRD ANR grant (PI François Bailly) and will be further developed next year with the beginning of Kloé Bonnet's PhD thesis in late 2025.
8.2.9 Optimization of Bicycle Designs
Participants: Otmani Sabrina, Murray Andrew [Dayton University, OH, USA], Azevedo Christine, Bailly François.
This year marks a milestone for this project in which we work towards the improvement of FES-assisted pedaling performance for people with spinal cord injury (SCI). Our approach, which consists in optimizing the bicycle structural design to maximize the power throughput at the crank at constant speed, led to two journal publications this year.
The first article (18) explores the customization and optimization of three distinct bicycle drive mechanisms (Fig. 18), leveraging an individual’s biomechanical data to maximize pedaling power throughput. Our approach utilizes torque/velocity/position relationships of the hip and the knee, so that the kinematics of the optimized designs allow the user to pedal with maximized joint torques and thus, enhance the power produced at the crank. The method is applied to the cases of two users with significantly distinct anthropometries, showing noticeable changes in the drive mechanisms and demonstrating its effectiveness for personalizing bicycle designs. The study highlights the importance of considering individual biomechanical factors, showing that even slight variations in design can lead to changes in the cycling kinematics, resulting in improved performance. Simulation results also show increased mean power throughput for more complex drive mechanisms compared to a classical one, regardless of the user profile. This suggests that such designs should be capable of accommodating a range of cyclists, from recreational users to high-performance athletes, as well as individuals and athletes with motor impairments. These findings highlight the potential of biomechanically-informed, personalized bicycle drive mechanisms. Such systems can optimize pedaling efficiency and enhance performance across diverse user groups.
The second article (17) presents a novel crank-pedal mechanism designed to optimize pedal-path kinematics. The goal of the design is to maximize power throughput by utilizing torque-generating capabilities produced by individual riders. The dimensions of the design are determined through an optimization algorithm that modifies the crank length, pedal shape, and frame geometry. The optimization uses the joint position, velocity, and torque relationships of a user (Fig. 19). As such, the solver can take advantage of musculoskeletal motions that generate sustained large torques. The approach is tested in simulation with data from two user profiles, demonstrating similarities and variations that morphologies can produce in the design. In both cases, the optimized designs with the new crank-pedal mechanism improved the mean crank power during a crank revolution by approximately 15% compared to a traditional personalized bicycle. These results suggest that altering the dimensions of a bike using biomechanical data in the design process could have a significant impact on the pedaling performance of individuals, ranging from everyday users to athletes and individuals with motor impairments.
The image contains three diagrams illustrating how the human lower limb in interaction with the bicycle is mathematically modeled (angles, dimensions, relationships).
The image shows how the solver leverages the muscular capacities of the users by overlaying the optimized trajectories (hip and knee joints) with colormaps of the muscular capacities.
8.2.10 Scoping review on the use of optimal control in FES
Participants: Bailly François, Begon Mickael [Université de Montréal, Canada], Co Kevin [Université de Montréal, Canada], Moissonet Florent [Université de Genève, Switzerland].
Following the PRISMA guidelines, a search was conducted up to February 2024 using the combined keywords “FES”, “optimal control” or “fatigue” across five databases (Medline, Embase, CINAHL Complete, Web of Science, and ProQuest Dissertations Theses Citation Index) 12. Inclusion criteria included the use of optimal control with FES for healthy individuals and those with neuromuscular disorders. Among the 44 included studies, half were in silico and half in vivo, involving 87 participants, predominantly healthy young men. Twelve different motor tasks were investigated, with a focus on single-joint lower-limb movements. These studies principally used simple FES models, modulating pulse width or intensity to track joint-angle.
Optimal control-driven FES can deliver precise motions and reduce fatigue. Yet clinical adoption is slowed down by the lack of consensus about modeling, inconvenient model identification protocol and limited validation. Additional barriers include insufficient open- science practices, computational performance reporting and the availability of customizable commercial hardware. Comparative FES model studies and longitudinal trials with large cohorts, among other efforts, are required to improve the technology readiness level. Such advances would help clinical adoption and improve patient outcomes.
8.3 Motor functions assistance
8.3.1 AI-Hand project: Restoring upper-limb functions in individuals with tetraplegia
The AI-Hand European project (EIC pathfinder), focuses on the development of an active implantable medical device (AIMD) for neural stimulation - supported by Neurinnov company - to restore wrist and hand function in individuals with tetraplegia 28. In this framework, the project is divided into two successive phases, a phase dedicated to the development/refinement of the approach that will immediately be followed by a clinical phase by 2026 (first implantation in people with tetraplegia). The CAMIN team, tasked with coordinating the project, focuses on two key aspects: 1) in-depth study of user stimulation control strategies and 2) support for the development of the implanted solution (by directly managing trials through preclinical testing and being an integral part of clinical trials). Regarding preclinical trials, progress for 2025 is mainly focused on finalizing the processing of previous experiments in human 22, 11 the processing of biological signals and samples collected during acute (PLASTICISTIM) and chronic (AI-Hand) experiments on pigs conducted in 2024.
CT1 non invasive clinical trial
Participants: Azevedo Christine, François Bailly, Baptiste Faraud.
The first non-invasive Clinical Trial 1 (CT1) was dedicated to assessing the usability of various piloting modalities future implant users will have access to in the medical device developed by NEURINNOV. During this trial, CAMIN was in charge of analyzing the capacity of participants with upper limb paralysis to use the piloting modalities to modulate a command. 10 participants were recruited (USSAP Perpignan Rehabilitation Center). An experimental platform was developed to allow the users to interact with the serious game TARGETTRACK via the control modalities developed by NEURINNOV (see Fig. 20). As described in the "New Platform" section, two games were available: the first one consisted in a simple gauge. The “+/-” inputs turn the needle to the right or left until it reaches the dotted area. The second game consisted in driving the position of a moving character in a cluttered environment with the “+/-“ control inputs to avoid collisions, reflecting the capacity of the user to interact dynamically with the control modalities (joystick or voice control).
A person in a wheelchair (the participant) is seated at the center of a desk, with two other people seated on either side. On the desk, there is one laptop and a main screen, both displaying similar information: a clear pathway surrounded by blue vertical columns. A UFO is displayed on the clear pathway. Photos of the two modalities (joystick and module of the voice control are also displayed)
Acute animal experiments - PLASTICISTIM project
Participants: Baum Jonathan, Guiho Thomas, Azevedo Christine, Chamot-Nonin Manon [Neurinnov], Guiraud David [Neurinnov].
The PLASTICISTIM project complements AI-Hand by exploring, as a proof of concept, the combined use of peripheral nerve stimulation (PNS) and spinal cord stimulation (SCS) to restore motor function after spinal cord injury. While PNS enables direct motor activation, SCS has been shown to facilitate/strengthen degraded voluntary commands and support progressive motor recovery, suggesting a potentially synergistic effect. In June–July 2024, the project investigated the combination of transcutaneous SCS (t-SCS) with epineural PNS in three pigs. Sessions of sole PNS stimulation were performed before and after combining PNS with t-SCS using state of the art stimulation devices —Neurinnov’s benchtop stimulator connected to CorTec’s epineural cuff electrodes on one side (PNS) and Pajunk’s Stim2go stimulator on the other side (t-SCS). Muscular responses were assessed via custom implanted EMG needles.
EMG data processing began in early 2025, with an initial focus on PNS-evoked signals to assess the reliability of the PNS stimulation chain but also to evaluate the short-term effect of tSCS on PNS responses by comparing PNS-evoked muscular responses before and after tSCS. First only pure EMG signals — i.e. noise-free signals — were processed to compute recruitment curves reflecting muscles activation following progressive increases in stimulation intensity (Fig. 21). In parallel with this work, a source separation algorithm is currently implemented to enable the processing of all data — regardless of the different sources of noise (measurement or physiological noise).
The image is in two parts. A top subfigure and a bottom subfigure. The top subfigure shows graphs of electromyography (EMG) signals from four different muscles obtained for increasing stimulation intensities: FDS, FCR, PT, and ECR. The top four graphs display voltage (U) versus time (ms) for each muscle, with multiple signal traces in different colors — one trace for every stimulation intensity. The bottom subfigure shows graph plotting the stimulation intensity (I) in microamperes (µA) against the amplitude of the EMG signals (output voltage - U) in millivolts (mV), showing the response of each muscle to varying stimulation intensities. The colors red, blue, green, and purple represent FDS, FCR, PT, and ECR respectively.
At the end of these acute experiments, stimulated and non-stimulated (control) nerves were harvested for histological purposes. Three features conditioning the impact of stimulation on nerves were investigated: 1) global morphometric structure of the nerve using Hematoxylin-eosin staining; 2) identification and distribution of motor fibers within the nerve via anti-ChAT immunostaining; and 3) characterization of fiber diameter with toluidine blue staining — myelin sheath thickness — (Fig. 22).
The image shows three microscopic views of a tissue sample. These views are corresponding to cross-sectional sections of one of the stimulated peripheral nerves The first, stained with hematoxylin-eosin, displays a cellular structure with pink and red hues (the fascicles). The second, labeled ChAT, shows a more subdued view with brownish spots indicating enzyme activity specific to motor neurons (enabling identification of the positioning of these motor neurons). The third, stained with toluidin blue, highlights the tissue in various tones of blue, showing detailed cellular and structural elements. Among these details, the thickness of the myelin sheath surrounding these neurons is of particular interest.
The rationale behind these histological studies is to enable comparison of the 3D distribution of injected currents (so called configurations of current) with the actual architecture of the stimulated nerve in order to better understand the evoked muscle responses (24). This comparative study, made possible by the collection of stimulated nerve samples — and therefore restricted to animal testing — provides a rare opportunity to better understand the links between stimulation, nerve architecture, and muscle response. With this in mind, a reconstruction of the relative position of the electrode around the nerve and a comparison with the recruitment curves obtained by stimulation is currently underway (Fig. 23).
The image consists of two main parts: a radar chart on the left and a histological section on the right. The radar chart shows six axes labeled STR1 to STR6 - each of these corresponding to a specific stimulation configuration with a single active side parametered as Cathode turning progressively around the nerve - starting from the first active site as cathode STR1 to the sixth contact as cathode STR6 (justifying the radar representation), each with values ranging from 0 to 1. This scores corresponds to normalized muscles activity (normalized by the maximum amplitude of the corresponding EMG) and compares activation of four diffrent muscles: FDS (blue), FCR (orange), PT (yellow), and ECR (purple). The right side features a labeled microscopic image corresponding to the cross-section of the correspondig nerve, highlighting specific regions with preferential muscle activation: FCR, PT, ECR, and FDS, with boundaries marked by black and red lines. The labeled regions correspond to the parameters in the radar chart. The image depicts cellular structures within a designated area (mainly fascicular anatomy and motor neurons location).
Chronic animal experiments - AI-Hand project
Participants: Guiho Thomas, Baum Jonathan, Azevedo Christine, Chamot-Nonin Manon [Neurinnov], Bechet Matthieu [Neurinnov], Demarcq Milan [Neurinnov], Guiraud David [Neurinnov], Degeorge Benjamin [Clinique Saint-Jean], Tessier Jacques [Clinique Saint-Jean], Hertel Frank [CH Luxembourg].
Chronic animal experiments were performed in two animals (for 28 and 35 days) from September to October 2024. The protocol supporting the conduct of these experiments was prepared, refined and validated by Inria and Neurinnov in consultation with Medical Doctors (Neurosurgeon and orthopedic surgeons).
These chronic experiments tested the first version of the integrated system developed by NEURINNOV in collaboration with CorTec. The implantation procedure involved four main steps (exposure of arm nerves, creation of a subcutaneous pocket for the Implanted Pulse Generator - IPG, tunneling of the cables, and placement of the electrodes around two nerves). The animals were then anesthetized once a week to test the connection and the proper functioning of the implant. Ultrasound was used to locate the IPG, and additional tests were conducted to assess both electrodes' impedances and Radio-Frequency communication. Stimulation and chronic follow-up sessions were also performed on a weekly basis. EMG signals and videos were thus acquired during these stimulation sessions on anesthetized animals. The chronic experiments were deemed successful as the stimulation delivered by the AIMD induced reproducible muscle responses on both animals.
Both the device and surrounding tissues (nerve, skin, fibrotic tissue) were collected during the explantation procedure. Implanted part of the device were sent back to Neurinnov and Cortec for in-depth technical assessment while biological samples were intended for histological analysis focusing on fascicles, motor neurons, and axon diameters identification.
The last few months of 2025 were devoted to data formatting and development/adaptation of signal processing algorithms in order to complete EMG analyses in the first half of 2026.
8.3.2 Correcting the Gait in Real-Time for Children with Cerebral Palsy
Participants: Graffagnino Gabriel, Gasq David, Patte Karine [Institut Saint-Pierre], Sijobert Benoît, Azevedo Christine.
Gabriel’s thesis, funded by an INRIA-INSERM grant, focuses on pathological gait in children with cerebral palsy (CP).
CP is the most prevalent motor disorder in childhood and often results in gait abnormalities that hinder mobility and diminish quality of life. Functional electrical stimulation (FES) has demonstrated potential in enhancing gait in individuals in this population 29, however, its practical implementation remains complex, as it requires monitoring various gait parameters and delivering personalized stimulation to different muscles in order to correct various gait impairments. Recent advancements in real-time motion capture (MOCAP) and wearable sensors now enable the development of closed-loop, multi-channel FES systems.
In this context, we developed a real-time, event-triggered multi-channel stimulation protocol during treadmill walking, and assessed the feasibility and responsiveness of it 26. The stimulation was triggered by specific gait events (heel strike, knee flexion, ankle dorsiflexion) detected through the MOCAP system and administered via a multichannel electrical stimulator. We emulated the real-time kinematic acquisition seen in children with CP using data already acquired to assess the technical feasibility. We reported different technical outcomes including the latency between gait event detection and triggering function calling in the algorithm, and the latency between this function call and the start message sent to the stimulator. The results confirm the viability of the system, laying the groundwork for future clinical application in the rehabilitation of children with CP (Fig. 24).
The image illustrates a process for detecting gait events and triggering stimulation. It begins with motion capture (a), showing a person walking on a treadmill monitored by cameras. The captured data is analyzed to detect gait events (b), represented by a graph of knee flexion over time. This information is processed by a triggering algorithm (c), which, upon detecting a gait event (T1), initiates a function call (T2), leading to the sending of a start message (T3) to a stimulation trigger device. The process involves complete tracking of a walking individual's movement, data analysis, decision-making through an algorithm, and triggering of a specific action.
An important contribution this year was also to analyze complementary biomarkers of gait in children with cerebral palsy to insist on their complementarity 14.
8.3.3 Systematic review to explore assistive devices designed to improve upper-limb movements
Participants: Charlotte Le Goff, Pauline Coignard [Association Approche], Charles Fattal [Centre Bouffard Vercelli USSAP], Azevedo Christine.
Among people with disabilities resulting from chronic illnesses, accidents, or aging, upper limb (UL) motor impairments are particularly common and hinder independence in activities of daily living (ADL). Assistive technology devices offer promising solutions, but their diversity and level of maturity remain variable. In the context of PEPR O2R ASSISTMOV project, we carried a systematic review to explore assistive devices designed to improve UL movement in people with disabilities, in a functional assistance context. A systematic search was conducted according to PRISMA guidelines, with rigorous study selection. Several databases were searched, including PubMed, Pascal, IEEExplore, and EBSCO. The inclusion criteria were as follows: a study of an UL assistive device used in ADLs or whose concept was transposable to this use, and published in English. Forty-five studies were selected, the majority published after 2010, and involving single testing sessions. Of these, 46.7 involved patients with chronic stroke, with a particular focus on distal deficits (hand, wrist, fingers). The most frequently studied devices are mechatronic exoskeletons and gripping gloves. Although numerous prototypes have been developed, few are currently available on the market, limiting their accessibility for users. We concluded that existing technologies offer benefits in terms of functional autonomy and quality of life, but still face constraints related to ergonomics, cost, and portability. Assistive devices for daily living activities represent a promising but still limited technological field. This review highlights the importance of user-centered development and the need to strengthen the methodological robustness of future studies to prioritize innovative, modular, and accessible solutions 21.
8.3.4 Grasping intention estimator
Participants: Moullet Etienne [INRIA WILLOW], Azevedo Christine, Bailly François, Justin Carpentier [INRIA WILLOW].
We have developed i-GRIP, a framework that decodes grasp intention - specifically target object and grasp type - from natural upper-limb kinematics during reaching within a known scene containing multiple candidate objects. We have investigated its real-time operation and user adaptation when deployed as a grasp-assistance control interface in an immersive virtual reality (VR) environment (Figs. 25 and 26). Two control modes were compared: natural control, in which the virtual hand directly mirrored the user’s hand motion, and assisted control, in which finger motion was delegated to i-GRIP predictions while hand position remained user-driven. Twenty-two healthy participants performed 3,300 grasping trials (3,244 retained for analysis). The VR environment demonstrated ecological validity, as movements produced under natural control exhibited completion durations comparable to those reported in physical-world settings. Under assisted control, task success remained high (93–96%), despite longer and less smooth movements compared to natural control. Mixed-effects analyses revealed robust learning effects across trials, with increasing odds of task success and progressive reductions in movement duration and velocity peaks.
The image shows a person wearing a VR headset, seated in a chair with their arm extended. They are interacting with a virtual reality environment. In the VR scene, there are several household items on a table, including a carton of milk, a bottle of mustard, a bottle of dish soap, and a jar of tomato sauce. A virtual arm is reaching towards these items. There is also a button labeled "start experiment" on the table. The person appears to be participating in an experiment within the VR setting.
The image contains six sub-images labeled (A) through (F): (A) A 3D model of a virtual hand with a central positional marker on the palm. (B) A virtual reality scene showing a table with various objects including a sphere, bottles, and a box. Instructions and status are displayed on a screen. (C) Similar as the scene (B), but when a button is pressed with the virtual hand, the ghost outline of another hand appears and performs a grasping action to be reproduced by the participant. (D) In the same virtual scene, a completion feedback is given to the participant when the task has been performed successfully by highlighting the hand in green color. (E) In the same virtual scene, a failure feedback is given to the participant when the task has been performed wrongly by highlighting the hand in red color. (F) In a similar virtual scene, a yellow overlay is placed on the object being targetted by the virtual hand and depending on the approach trajectory of the hand,grasping strategies are chosen (whether pinch or palmar grasp) to control the opening and closing of the hand.
9 Bilateral contracts and grants with industry
9.1 Neurinnov
Participants: Jonathan Baum, Thomas Guiho, David Guiraud [Neurinnov], Christine Azevedo.
NEURINNOV startup finances half of the PhD thesis salary of Jonathan Baum (from December 2023 - PLASTICISTIM Project).
A convention was signed with Neurinnov for David Guiraud to join the team as a collaborator.
10 Partnerships and cooperations
10.1 International initiatives
10.1.1 Inria associate team not involved in an IIL or an international program
GOIABA
Participants: Christine Azevedo, François Bailly, Tiago Coelho Magalhães, Sabrina Otmani, Ronan Le Guillou, Charles Fattal, Henrique Resende [UFMG].
-
Title:
Optimization of Hybrid Mechatronic Devices for Rehabilitation
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Duration:
2023 -> 2025
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Coordinator:
Christine Azevedo
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Partners:
- Universidade Federal de Minas Gerais Belo Horizonte (Brésil)
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Inria contact:
Christine Azevedo Coste
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Summary:
Our teams are involved in research projects that combines mechatronic systems and functional electrical stimulation (FES). FES allows to restore muscle contraction in paralyzed limbs. The use of FES in interaction with an instrumented tricycle for instance allows people with spinal cord injuries to pedal. FES can also be combined with orthoses, in particular for the upper limb to take advantage of the two solutions. Our aim is to develop a collaboration to optimize the outcomes of hybrid mechatronic devices in the context of functional rehabilitation.
ACER
Participants: François Bailly, Valentin Maggioni, Pierre Schegg, Pierre Puchaud [INRIA AUCTUS], Mickael Begon [Université de Montréal].
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Title:
Model-based control of functional electrical stimulation
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Duration:
2025–>
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Coordinator:
François Bailly
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Partners:
- Mickael Begon, Université de Montréal, Montréal, Canada
- Pierre Puchaud, INRIA Auctus
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Inria contact:
François Bailly
-
Summary:
Our aim is to use musculoskeletal simulations combined with numerical optimization to propose tailored and optimized model-based stimulation patterns in an automatized manner. The bottlenecks of a real-time multi-scale FES musculoskeletal model are: i) the cumulative effect of past stimulations that creates time dependency, ii) FES model requires a much finer time grid integration than musculoskeletal models, iii) both FES and musculoskeletal model needs to be personalized to each patient. The joint effort will be put into developing models and algorithms that will i) simulate the interaction of the FES with musculoskeletal systems in real-time, and ii) control it to achieve desired biomechanical tasks. The first requirement consists in elaborating FES-stimulated musculoskeletal models-compatible with an optimization framework (differentiability, smoothness), without sacrificing their accuracy. Existing models’ compatibility with gradient-based optimization frameworks is impeded by their formulation (if/else statements, infinite summations). Then, fast algorithms able to compute online the stimulation parameters are needed to reach model-based real-time control of FES. Both our teams need such a software platform; hence we propose to joint research effort through the ACER associate team.
10.1.2 Visits of international scientists
Other international visits to the team
Eve Charbonneau
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Status
Postdoc
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Institution of origin:
Université de Sherbrooke
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Country:
Canada
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Dates:
09/2025 -> 03/2026
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Context of the visit:
Collaboration with François Bailly
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Mobility program/type of mobility:
Research stay
10.1.3 Visits to international teams
Research stays abroad
Valentin Maggioni
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Visited institution:
Université de Montréal
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Country:
Canada
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Dates:
09/2025
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Context of the visit:
Associate Team ACER
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Mobility program/type of mobility:
Research stay
Pierre Schegg
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Visited institution:
Université de Montréal
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Country:
Canada
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Dates:
09/2025
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Context of the visit:
Associate Team ACER
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Mobility program/type of mobility:
Research stay
Tiago Magalhaes
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Visited institution:
Universidade Federal de Minas Gerais
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Country:
Brésil
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Dates:
06/2025 and 09/2025
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Context of the visit:
Associate Team GOIABA
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Mobility program/type of mobility:
Research stay
10.1.4 Horizon Europe
AI-HAND
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Title:
Advanced Intelligent stimulation device: HAND movement restoration
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Duration:
From August 1, 2023 to January 31, 2027
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Partners:
- INSTITUT NATIONAL DE RECHERCHE EN INFORMATIQUE ET AUTOMATIQUE (INRIA), France
- CORTEC GMBH (CORTEC), Germany
- ALBERT-LUDWIGS-UNIVERSITAET FREIBURG (UFR), Germany
- NEURINNOV, France
- UNION SANITAIRE ET SOCIALE POUR L'ACCOMPAGNEMENT ET LA PREVENTION (USSAP), France
- CENTRE NATIONAL DE REEDUCATION FONCTIONNELLE ET DE READAPTATION, Luxembourg
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Inria contact:
Christine Azevedo
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Coordinator:
Christine Azevedo
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Summary:
Very advanced stimulation paradigms applied to peripheral nervous system (PNS) have been studied for years even decades among which the 3D current distribution through multi-contact epineural electrodes. Non-rectangular stimulus waveforms are also of strong interest to provide more efficient or fiber type selective stimulation. However none were implemented in an Active Implanted Medical Device and thus almost none validated through clinical trials. One of the reasons is the high complexity of the needed analogue front-end and its safe control by a microcontroller or a digital system. AI-HAND project aims at developing a breakthrough, ASIC based technology, together with a specific self adapting epineural multi contact electrode to provide such an AIMD. The demonstration of the clinical relevance of such an approach will be achieved through a first-in-man proof of concept aiming at the restoration of hand movements in persons with complete quadriplegia. It means that a full innovative device should be developed and validated in animals, but the real added value will be supported by the clinical trial; indeed, no animal model exists while the clinical needs is clearly stated by clinicians and patients. Thus this project will innovate concerning both the technology and the therapeutic approach with a minimally invasive concept. Indeed, spatial selectivity allows to stimulate nerves selectively targeting muscles through 3D currents shaping instead of implanting one electrode per muscle. The technology clearly addresses generic issues so that the paradigms and the innovative technology can be further used to stimulate the central nervous system (spinal cord and brain) and, on a long-term basis, may drastically open therapeutics for medical needs that are still unmet.
10.2 National initiatives
INRIA-INSERM Phd thesis grant (2023-26)
- Coordinator: Christine Azevedo (INRIA).
- We obtained a grant to finance the PhD thesis of Gabriel Graffagnino between CAMIN and INSERM Tonic team (CHU Toulouse) in collaboration with Institut Saint Pierre (Palavas).
ARC FOUNDATION for Research Against Cancer (2022-2025)
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Coordinator: François Bonnetblanc (INRIA), (collaboration with Pr Hugues Duffau (CHU Montpellier) and Pr Emmanuel Mandonnet (APHP)). Guiding brain tumor surgery in real time using electrophysiology
During the resection of brain tumors, the neuro-surgeons have substantial imaging data allowing them to plan their gesture upstream. However, during the actual surgical gesture, in real time, this imaging becomes ineffective due to the deformation of the brain (so called brain shift). It is then possible to use direct electrical stimulation of the brain in an awake patient who cooperates with the neurosurgeon to determine the functional areas and those which are not. When patients are under general anesthesia this possibility no longer exists. We have planned to use the electrophysiology evoked by the DES of the brain during brain surgery to diagnose and determine the location the tumor and the anatomical connectivity on-line in order to guide the surgery in awake patients or under general anesthesia. This work needs to go beyond the proof of concept we have already performed, and necessitates addressing and solving some methodological challenges. At a fundamental level, this will also help to better understand the electrophysiological effect of DES in order to optimize its use.
AEx noCNN (2024-27)
- Coordinators : François Bailly and François Bonnetblanc (INRIA).
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No-brain-shift and Comprehensive Neurosurgical Navigation using computer vision, funded by INRIA's Action Exploratoire program.
Preoperative MRI is central to preparing for tumor resection in the brain. Throughout the operation, it serves as a reference point for the surgeon to guide their actions using neuronavigation, a technology that allows the surgeon’s tools used in the operating room to be represented in this MRI. However, during the operation, the brain loses its initial shape, distorting this representation. In collaboration with neurosurgeons, we are working to model this phenomenon in real time in order to correct neuronavigation and better guide surgical procedures. More specifically, using computer vision and deep learning, the objective of the noCNN project is to (i) accurately, automatically and continuously reconstruct the volume of the brain exposed by craniotomy during neurosurgeries and (ii) reposition this volume deformed by the decrease in intracranial pressure and resection in standard imaging (MRI).
PEPR O2R ASSISTMOV
- Coordinators : François Bailly and Christine Azevedo.
- The integrated PI3 project “ASSISTMOV”, made up of a multidisciplinary team in engineering and Social Sciences and Humanities (SSH), targets the use case of assistive robotics for movement support for people with disabilities. Through the development of a range of exoskeletons (for both lower and upper limbs), the project aims to deliver a disruptive technology enabling smooth interaction that is robust across a wide variety of environments and uses (from rehabilitation to everyday life). The project finances the PhDs of Charlotte Le Goff (Association Approche) and Amina Ferrad (INRIA).
Handitech Lab Inria (HLI)
- Coordinators: Christine Azevedo and Roger Pissard-Gibollet (INRIA).
- Developing technological solutions for and with people with handicap. INRIA cross-cutting action.
ANR B-IRD (2024-28)
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Coordinator: François Bailly (INRIA).
Biomechanically-Informed Rehabilitation Devices : Fast and reliable biomechanical methods dedicated to assistive technologies.
Grasp-Again Project Maturation Société d’Accélération du Transfert de Technologies (SATT) (2024-25)
- Coordinators: David Gasq (CHU de Toulouse), Ronan Le Guillou (INRIA), Christine Azevedo (INRIA).
- In cooperation with Toulouse Tech Transfer (SATT of Toulouse), the know-how acquired through the Prehens-Stroke and Grasp-Again clinical research protocols on the usage and developement of a grasping assistance neuroprosthesis was officialy commited as intellectual property as an e-Soleau enveloppe. Furthermore, through a "Project Maturation" dedicated funding, the Digital Medical Hub (DMH) and Aguila Technologies were contracted to investigate market access considerations and future potential roadmaps.
ANR JCJC AT-Reach (2025-29)
- Coordinator: Thomas Guiho (INRIA).
-
Title: Computational models to optimize functional rehabilitation of upper-limb functions: Relevance of pairing peripheral nerve and spinal cord stimulations.
Bilateral loss of upper-limb functions after complete cervical Spinal Cord Injury (SCI) dramatically impacts people ability to live independently. Although, considerable progress has been made in the field of Spinal Cord Stimulation (SCS) for rehabilitation of motor functions in recent years, the most significant results are still achieved through long-lasting clinical trials combining SCS with task-specific physical exercises. Alongside these studies, recent clinical trials reported promising outcomes after performing peripheral nerve stimulation (PNS) with implanted electrodes which immediately restores functional – albeit coarse – movements of the upper limb. The AT-REACH proposal aims at paving the way to the next generation of clinical protocols by investigating the added-value of pairing PNS with SCS. The AT-REACH multimodal approach will call for research beyond state-of-the-art and test these hypotheses via the conception of biomimetic computational models supported by animal experiments in order to 1- elucidate SCS mechanisms of action and 2- improve knowledge on spinal cord neural networks in intact and neurologically impaired conditions. Progress is expected at the crossroads of engineering, neuroscience and rehabilitation medicine.
11 Dissemination
Participants: Christine Azevedo, Thomas Guiho, François Bailly, François Bonnetblanc, Olivier Rossel, Charles Fattal, Ronan Le Guillou, Pierre Schegg, Gabriel Graffagnino, Valentin Maggioni, Jonathan Baum.
11.1 Promoting scientific activities
11.1.1 Scientific events: organization
General chair, scientific chair
- Thomas Guiho was chairman of the "Signal Processing 2" session at IEEE EMBC 2026 conference.
Member of the organizing committees
- Thomas Guiho and Giulia Petrarulo organized a webinar presenting pre-clinical results in the frame of the AI-Hand european Project (Project aiming at restoring hand and wrist functions in people with complete tetraplegia by using direct electrical stimulation on arms' nerves)
11.1.2 Scientific events: selection
International conferences
- François Bailly was reviewer for IEEE IROS 2025, ACC 2026, IFESS 2025, IGS 2025.
- Thomas Guiho was reviewer for the 47th Annual International Conference of the IEEE Engineering in Medecine and Biology society (IEEE EMBC 2025).
- Olivier Rossel was reviewer for the 47th Annual International Conference of the IEEE Engineering in Medecine and Biology society (IEEE 2025).
- Pierre Schegg reviewed 1 article for the IEEE International Conference on Robotics and Automation (ICRA) 2026.
11.1.3 Journal
Member of the editorial boards
- Christine Azevedo is member of editorial boards of Frontiers in Neurology and Frontiers in Neuroscience and associate editor for Institute of Electrical and Electronics Engineers Robotics and Automation Letters (IEEE RA-L)
- Christine Azevedo is editor of a special issue "Advancing Assistive Technology for People with Disabilities: Insights and Innovations from the Cybathlon 2024" for Journal of NeuroEngineering and Rehabilitation.
Reviewer - reviewing activities
- Christine Azevedo was reviewer for IEEE TNSRE (Transactions on neural systems and rehabilitation engineering), Journal of NeuroEngineering and Rehabilitation.
- Pierre Schegg reviewed 1 article for the IEEE Transactions on Neural Systems and Rehabilitation Engineering (TNSRE) journal.
- François Bonnetblanc was reviewer for Communications Biology, Scientific Reports, Clinical Neurophysiology.
- François Bailly was reviewer for IEEE Transactions on Neural Systems & Rehabilitation Engineering, Scientific Data, AIMS Neuroscience, Medical & Biological Engineering & Computing.
- Olivier Rossel was reviewer for Journal of Neural Engineering, BioMedical Engineering OnLine, Medical & Biological Engineering & Computing.
- Olivier Rossel was qualified for IOP Trusted Reviewer status by Journal of Neural Engineering
11.1.4 Invited talks
- Gabriel Graffagnino FES Vienna 2025 - Real-time gait event detection using motion capture to control an electrical stimulator: Proof-of-concept - September 15th to 18th 2025
- François Bonnetblanc : The BCI & Neurotechnology Spring School, keynote speaker 2025, link(Participants from 140 countries joined the Spring School; More than 90,000 people attended the live sessions; Over 550,000 views were recorded across the 10 days of the event; 140 lectures were delivered)
- François Bailly was an invited speaker at the Inria-Brasil Workshop on Digital Health, online, April 2025. link
- Christine Azevedo was an invited speaker at the Inria-Brasil Workshop on Digital Health, online, April 2025. link
- Christine Azevedo and Roger Pissard-Gibollet (SED Grenoble) presented HumanLab HLI actions during GDR Robotic seminar on Making robotics accessible to a non-expert audience (May 2025).
- Christine Azevedo presented her activities on science dissemination towards children during GDR Robotic seminar on Making robotics accessible to a non-expert audience (May 2025).
- Christine Azevedo and Roger Pissard-Gibollet (SED Grenoble) presented HumanLab HLI actions during INRIA scientific Days "Handicap" in Paris (June 2025).
- Christine Azevedo presented AGILIS and AI-Hand projects actions during Program INRIA Quadrant annual meeting in Paris (June 2025).
- Christine Azevedo presented AGILIS and AI-Hand projects at Kerpape Rehabilitiation Center (Rennes) (June 2025).
- Christine Azevedo and Charles Fattal presented Ai-Hand and Freewheels projects at a fundraising evening organized by the USSAP endowment fund in Perpignan (November 2025).
- Christine Azevedo presented HumanLab HLI actions during European Week SEEPH "Handicap" in Rocquencourt (November 2025).
- Christine Azevedo presented HumanLab HLI actions in Saclay INRIA Center (October 2025).
- Christine Azevedo presented HumanLab HLI during a webinar for INRIA Alumni association (November 2025).
- Christine Azevedo and Charles Fattal presented AGILIS and AGILISTIM projects during the USSAP annual day in Narbonne (November 2025).
- François Bailly was an invited speaker at the workshop “Barriers and Facilitators in FES Cycling: Bridging Clinical Insights and Technological Advances”, Rehabweek 2025, Chicago, USA. link
- François Bailly was an invited speaker at the "Journées Nationales de la Recherche en Robotique" 2025, Rennes, France, link
- Thomas Guiho was invited to give a talk on "Functional central and peripheral neural stimulation for rehabilitation" at Grenoble Neurotechschool 2025 in Aussois.
11.1.5 Leadership within the scientific community
- Christine Azevedo is member of the International Functional Electrical Stimulation Society (IFESS) society board.
11.1.6 Scientific expertise
- Christine Azevedo is member of Program INRIA Quadrant (PIQ) expert committee.
- François Bonnetblanc belongs to the college of experts for the European Science Foundation and makes regular expertise for this institution.
- Christine Azevedo is a member of the National Scientific Advisory Board of the Robotics Research Group (GdR 3072).
11.1.7 Research administration
- Christine Azevedo and Roger Pissard-Gibollet (SED Grenoble) coordinate the HanditechLab Inria.
- Thomas Guiho is responsible for the “Neuroprostheses” teaching unit (Université de Montpellier, Dpt EEA). This unit is an option common to all the masters of the Information and Communication Technologies (ICT) for health training package.
- Jonathan Baum managed Inria Montpellier PhD seminars (with Anne Bernard from LEMON Inria team)
- Ronan Le Guillou was a member of the organization commitee for the 6-7 November 2025 meeting in Montpellier of the Inria Thematic Network (Réseau Thématique) on Prototyping.
- Ronan Le Guillou is a member of the organization commitee for the 20-21 January 2026 meeting in Lyon of the Inria Thematic Network (Réseau Thématique) named LLM4Prod and intended to help merge the experiences of the various Inria centers in developing and proposing Large Language Models (LLM) for the various needs of Inria agents.
- François Bonnetblanc co-supervised with Christophe Botella the local comittee for sustainable development.
11.2 Teaching - Supervision - Juries - Educational and pedagogical outreach
11.2.1 Teaching
- Gabriel Graffagnino Sensory supplementation (1.5h) - Neuroprosthetics Teaching Unit, SNS Master 2, University of Montpellier - Introduction to Electronics (12h) - MEA3, Polytech Montpellier - Logic Systems Programming (36h) - MEA3, Polytech Montpellier - Signal Processing (18h) - MEA3, Polytech Montpellier
- Pierre Schegg Licence STAPS, Montpellier University, France : “Movement and Performance Analysis”, 8h, Licence Mention Education et Motricité - 16h, Licence Mention Entraînement sportif - 8h, Licence Mention Management du Sport.
- Pierre Schegg Master 2 ICT for Health, Montpellier University, France, Neuroprosthesis option: “Introduction to signal processing and Brain Computer Interfaces”, 3h - “Introduction to biomechanics”, 3h - “Introduction to Control Theory”, 3h - “Lab: Signal Processing with Python”, 6h.
- Master ICT for Health, Neuroprotheses option: Charles Fattal, “Neuroprosthesis and motor support strategies after spinal cord injuries”, 3h, M2, Montpellier University, France
- Master ICT for Health, Neuroprotheses option: Olivier Rossel, “Modeling of the peripheral nervous system”, 3h, M1, Montpellier University, France
- Master ICT for Health, Neuroprotheses option: Ronan Le Guillou, “Control basics and signal processing”, 3h, M1, Montpellier University, France
- Master ICT for Health, Neuroprotheses option: Valentin Maggioni, “Biomaterials and biocompatibility” and "Signal processing of neural signals", 22h, M2, Montpellier University, France
- Master Biologie Santé, Module Approches Bioniques Program Integrated Pathophysiology Charles Fattal, 3h, M2, Montpellier University, France
- Master Cognitive and integrated neuroscience, "Sensorimotor Deficiencies and palliative strategies teaching unit": Thomas Guiho, “Implantable neuroprosthesis for motor rehabilitation”, 4.5h, M2, Paul Sabatier University, Toulouse, France
- State diploma of “hearing aid professional”: Jonathan Baum, “office automation”, 33h, 1st year, audiocampus, Montpellier University, France
- Pierre Schegg Master 2 Robotics, Montpellier University, France: “Perception for Robotics”, 30h.
11.2.2 Supervision
PhDs
- PhD in progress : Gabriel Graffagnino (2023-...) , " Apport des nouvelles technologies numériques dans la rééducation pédiatrique : stimulation électrique fonctionnelle, réalité virtuelle et robotique d’assistance dans la rééducation de la marche chez l’enfant atteint de paralysie cérébrale", Inria-INSERM-Institut St Pierre, supervised by Christine Azevedo, Benoît Sijobert, Karinne Patte and David Gasq.
- PhD in progress : Valentin Maggioni (2023-...), "Développement d'un simulateur neuromusculosquelettique du membre supérieur sous stimulation électrique fonctionnelle", University of Montpellier-Inria, supervised by François Bailly and Christine Azevedo.
- PhD in progress : Jonathan Baum (2023-...), "Precise neural stimulation and underlying electrophysiological mechanisms", University of Montpellier-Inria-NEURINNOV, supervised by Thomas Guiho, David Guiraud and Christine Azevedo.
- PhD in progress : Paul André (October 2024-...), "Navigation neurochirurgicale exhaustive et sans décalage de cerveau grâce à la vision par ordinateur", Inria, supervised by François Bailly and François Bonnetblanc.
- PhD in progress : Charlotte Le Goff (2024-...) , "Étude des besoins et des usages pour l’assistance robotique aux mouvements humains, développement et mise en place d’un exosquelette pour les personnes en situation de handicap", PEPR O2R ASSiSTMOV, supervised by Charles Fattal, Christine Azevedo.
- PhD in progress : Amina Ferrad (2025-2028) "Advancing Grasp for people with upper limb paralysis: a shared control approach between the user and the assistive device", Inria, supervised by François Bailly and Christine Azevedo.
-
PhD in progress : Kloé Bonnet (2025-2028) "Robot-based identification of upper-limb muscle parameters in humans", Inria, supervised by François Bailly and Christine Azevedo.
- PhD completed : Clotilde Turpin (2022-2025), "Electrophysiologie des potentiels évoqués par la stimulation électrique du cerveau: vers un guidage intra-opératoire des gestes neurochirurgicaux ?", Inria, supervised by François Bonnetblanc.
INTERNSHIPS
- Christine Azevedo supervised Lise Roulliaux during her 1-month engineering internship in orthopedics on the INKREDABLE project (HanditechLab–INRIA).
- Christine Azevedo-Coste and Pierre Schegg supervized 1 BTS student for a 8 week internship on the theme Modifying a pneumatic glove to assist grasping of a tetraplegic patient.
- Pierre Schegg supervized 1 Master 1 student for 7 weeks on the theme Musculoskeletal modeling and simulation of healthy and post-stroke participants: comparing electromyography and kinematic data from the U-Limb dataset.
- Valentin Maggioni and Thomas Guiho supervised Amani Hamdi's internship (last year of engineering degree) from April 2025 to August 2025 on the topic: "Utilisation d'ondelettes pour le traitement des signaux musculaires évoqués par une stimulation électrique du nerf périphérique chez l'homme".
- Jonathan Baum and Thomas Guiho supervised Mahoua Safiatou Kone's internship (Master 1) from April 2025 to July 2025 on the topic: "Analyse de coupes histologiques du nerf périphérique chez le cochon: Révéler l’architecture du nerf pour faciliter l’évolution des modèles computationnels de stimulation neurale"
- Christine Azevedo-Coste and Thomas Guiho supervised Saouda Padavia's internship (Master 1) from June 2025 to August 2025 on the topic "Évaluation et étude comparative des orthèses et exosquelettes d'assistance à la préhension".
- Olivier Rossel and François Bailly supervised Maria Fernanda Paes Leme internship (Master 1) from May 2025 to August 2025 on the topic "Evaluation of muscle recruitment: Decomposition of Evoked Electromyographic Signals".
- Olivier Rossel supervised Ali Boukhsibi (Master 1) from June 2025 to July 2025 on the topic "Analyse et modélisation de l’artefact de stimulation en enregistrement électrophysiologique".
11.2.3 Juries
- Christine Azevedo was president for the PhD thesis defense of Mathieu Celerier "Interaction Homme-Robot Physique Soutenue: Des Mouvements Inspirés de l'Humain au Contrôle Sûr, Adaptable et Précis vers une Industrie centrée sur l'Humain." Montpellier University, December 16th, 2025.
- Christine Azevedo was president for the PhD thesis defense of Abdelwaheb Hafs "Commande prédictive par jeux différentiels pour l'assistance intuitive du mouvement lors d'une interaction humain-robot." Paris-Saclay University, December 8th, 2025.
- Christine Azevedo was reviewer for the PhD thesis defense of Edouard Ferrand "Interfaçage d'une prothèse bidirectionnelle chez la souris." Paris Saclays University, October 7th, 2025.
- Gabriel Graffagnino Master's internship defense - SNS Master 1, University of Montpellier
- Gabriel Graffagnino, Jonathan Baum, Olivier Rossel and Pierre Schegg were members of the juries assessing the work performed by ICT for health Master’s students during their 2-month projects in immersion in public laboratories or private companies.
- François Bailly was member of the jury for the selection of a maître de conférence for the Université de Montpellier (section 74)
11.2.4 Educational and pedagogical outreach
- Gabriel Graffagnino participated in the finals for the Occitanie region of "My Thesis in 180 seconds" (MT180) in March 28th 2025
- Thomas Guiho participated in a round table discussion on ethics in digital health at the University of Montpellier in December 2025.
- Jonathan Baum welcomed a 1 week internship of an 8th grade children this year
11.3 Popularization
11.3.1 Productions (articles, videos, podcasts, serious games, ...)
- The latest video capsule retracing the life of the AGILIS and AGILISTIM projects is now online video
- G Graffagnino participated in "Dance your PhD" - video
- The Ai-Hand project was presented in a television report on the program MAG SANTÉ, broadcast on France TV on May 5, 2025.
- Christine Azevedo gave an interview to CORTEC, a partner company of AI-Hand, sharing insights into the project. Two videos are available online on their website. video
- Thomas Guiho participated in a “Lab Santé” round table discussion organized by the newspaper “midi libre” on the theme:“Moving differently thanks to technology”
- Thomas Guiho participated in a webinar on November 25 to share feedback on Chiche! interventions.
11.3.2 Participation in Live events
CHICHE program
- Thomas Guiho is the Montpellier referent for the "1 Chercheur, 1 Classe : Chiche!" programme.
- Thomas Guiho spoke to students 2 second-year classes at Lycée Notre Dame de la Merci in Montpellier on January 15th, 2025 as part of the "1 Chercheur, 1 Classe : Chiche!" program.
- Thomas Guiho spoke to students 4 second-year classes at Lycée Philippe de Girard in Avignon on January 31th, 2025 as part of the "1 Chercheur, 1 Classe : Chiche!" program.
- Gabriel Graffagnino and Thomas Guiho spoke to students in 4 second-year classes at Lycée Joseph Joffre in Montpellier on February 6th, 2025 as part of the "1 Chercheur, 1 Classe : Chiche!" program.
- Clotilde Turpin, Gabriel Graffagnino and Thomas Guiho spoke to students in 14 second-year classes at Lycée Jean Vilar in Villeneuve-lès-Avignon on April 7th, 2025 as part of the "1 Chercheur, 1 Classe : Chiche!" program.
- François Bonnetblanc and Thomas Guiho spoke to students in 6 second-year classes at Lycée Déodat de Severac in Ceret on December 9th, 2025 as part of the "1 Chercheur, 1 Classe : Chiche!" program.
Other interventions
- Thomas Guiho helped supply the prizes for the winners of the Olympiad in Mathematics.
- Christine Azevedo participated in a mediation/outreach activity around the project “Sport, Brain and Nutrition”, in collaboration with Lycée Françoise Combes in Montpellier and Genopolys. The project aimed to introduce a second-year class to the research being carried out in these fields, as well as to careers in research. This involved a 1-hour classroom session followed by participation in the students’ final presentations in May over the course of a morning.
- Christine Azevedo gave introduction to programming interventions using Thymio Robot (4 sessions of 1,5 hour) in two 6th-grade classes at Collège Léon Cordas.
- François Bailly gave introduction to programming interventions using Thymio Robot (half a day) in two 6th-grade classes at Collège Léon Cordas, Montpellier.
11.3.3 Others science outreach relevant activities
- Ten team members participated in the 3-day hackathon FABRIKARIUM organized by the HumanLab Saint Pierre (LINK).
- Jonathan Baum, Baptiste Faraud and Gabriel Graffagnino presented live demonstrations of EMG recordings for interactions at "Nuit méditerranéenne des chercheuses 2025" - Mediterranean Researchers' Night MEDNIGHT - September 26th 2026.
12 Scientific production
12.1 Major publications
- 1 articleActivating effective functional hand movements in individuals with complete tetraplegia through neural stimulation.Scientific Reports121December 2022, 16189HALDOI
- 2 articleNumerical-Optimal-Control-Compliant Muscle Model for Electrically Evoked Contractions.IEEE Transactions on Medical Robotics and Bionics2025. In press. HAL
- 3 articleNew Stimulation Device to Drive Multiple Transverse Intrafascicular Electrodes and Achieve Highly Selective and Rich Neural Responses.Sensors21October 2021, #7219HALDOI
- 4 articleBioptim, a Python Framework for Musculoskeletal Optimal Control in Biomechanics.IEEE Transactions on Systems, Man, and Cybernetics: Systems531January 2023, 321-332HALDOI
- 5 articleA phantom axon setup for validating models of action potential recordings.Medical and Biological Engineering and Computing1042016, 671-678HALDOI
- 6 articleSelective neural electrical stimulation restores hand and forearm movements in individuals with complete tetraplegia.Journal of NeuroEngineering and Rehabilitation171May 2020, 66-78HALDOI
- 7 articleCombining Functional Electrical Stimulation (FES) to Elicit Hand Movements and a Mechanical Orthosis to Passively Maintain Wrist and Fingers Position in Individuals With Tetraplegia: A Feasibility Test.IEEE Transactions on Medical Robotics and Bionics2024, 1-1HALDOI
- 8 articleGold standard for estimation of propagation velocity from axono- or cortico-cortical evoked potentials? A case study.Clinical Neurophysiology179November 2025, 2111370HALDOI
- 9 articleInfluence of myelo-architectures on direct cortical response evoked by electrical stimulation.Clinical NeurophysiologyDecember 2025, 2111488HALDOI
- 10 articleShapes of direct cortical responses vs. short-range axono-cortical evoked potentials: The effects of direct electrical stimulation applied to the human brain.Clinical NeurophysiologyNovember 2024HALDOI
12.2 Publications of the year
International journals
National journals
International peer-reviewed conferences
Conferences without proceedings
Scientific book chapters
Reports & preprints
Other scientific publications
12.3 Cited publications
- 37 inproceedingsU-Net: Convolutional Networks for Biomedical Image Segmentation.Medical Image Computing and Computer-Assisted Intervention -- MICCAI 2015ChamSpringer International Publishing2015, 234--241back to text
- 38 inproceedingsclDice - a Novel Topology-Preserving Loss Function for Tubular Structure Segmentation.2021 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)IEEEJune 2021, 16555–16564URL: http://dx.doi.org/10.1109/CVPR46437.2021.01629DOIback to text
- 39 articleShapes of direct cortical responses vs. short-range axono-cortical evoked potentials: The effects of direct electrical stimulation applied to the human brain.Clinical NeurophysiologyNovember 2024HALDOIback to textback to text