Symbitron ‒ BioRob ‐ EPFL

Project Description

Symbitron: Symbiotic man-machine interactions in wearable exoskeletons to enhance mobility for paraplegics

2013-10-01 to 2018-03-31 (ongoing project)

The goal of Symbitron is to enable individuals with paraplegia to regain mobility with a novel lower-limb exoskeleton and a bio-inspired controller. BioRob’s role is to develop and test a neuromuscular controller that can produce various walking gaits with resemblance to human kinematics, kinetics, and muscle activations with few sensors and no pre-defined reference patterns.

Neuromuscular Controller

For real world function, wearable devices to assist gait should be highly responsive to both the user and the environment. Users should also be able to interact with the device in an intuitive manner. This positive shared control between machine and human is especially important for individuals with spinal cord injuries, where active recruitment of their own neuromuscular system could promote motor recovery. Here we demonstrate the capability of a biologically-inspired neuromuscular controller (NMC) and its use in assisting the gait of SCI test pilots.

The NMC was based on a sagittal plane neuromechanical simulation developed by Hartmut Geyer, which generates walking by activating simulated muscle reflex loops stimulated by few sensory imputs. Only the foot contact states and joint angles are needed to activate the simulated reflex loops of the Hill-type muscle models. The stance reflexes loop provides weight bearing support during the stance phase, and the swing reflexes allow the leg to flex and swing freely. The muscle forces generated from the virtual muscle dynamics combine to produce knee and hip torque commands to the gait trainer. The advantages of this controller over other approaches include robustness, modularity, and adaptability. In particular, the controller does not require filtering of its inputs (as with myoelectric control), can be decomposed into relevant modules (e.g. only knee or hip control), and can generate walking at different speeds and on different terrains in simulation.

For implementation on hardware, we developed a NMC Simulink library with control modules that allowed for tailoring to specific exoskeleton devices. So far we have tested the NMC on three different devices. The ankle module was tested on powered ankle exoskeleton Achilles, and the knee and hip modules were tested with gait trainer LOPES (both devices are from UTwente). We are currently testing the ankle and knee module on our new wearable exoskeleton. To provide subject-specific control for the SCI subjects, the NMC modules were designed to provide asymmetric control between the right and left legs, between extension and flexion, and among different muscles.

Tests with Human Subjects

We evaluated our controller with both healthy and paraplegic subjects. The modular nature of our controller enables us to test it on several different types of lower limb assistive devices. We evaluated subjects’ walking kinematics and kinetics, muscle activation levels, and metabolic power when possible.

Ankle Control

We tested the ankle module of the neuromuscular controller with a powered ankle exoskeleton (UTwente’s Achilles) on healthy subjects and paraplegic test plots with some mobility. For the healthy subjects, we evaluated the mechanics and energetics of walking with such a device and controller. This controller was designed to mimic human reflex patterns during locomotion, which we hypothesized would lead to lower energetic costs compared to walking with the added mass of the device only. Preliminary tests found that healthy-like gait patterns remained intact, and metabolic costs were reduced compared to the transparent mode of the device. Muscle activity of the tibialis anterior and soleus were also reduced with the assistive push-off. Please see Dzeladini et al. 2016 under Publications for more information.

Knee and Hip Control

We evaluated the neuromuscular controller on a lower-limb knee and hip robotic gait trainer (UTwente’s LOPES) with seven pilots with paraplegia (four complete, two incomplete) and one healthy subject. We determined that the NMC could enable normal-like walking gait kinematics at various walking speeds. We found that SCI pilots could walk at a range of normal walking speeds– from 0.6 m/s to 1.4 m/s. Despite a few differences between NMC-produced torques and healthy biological torques, the SCI joint kinematics were similar to healthy kinematics. With few sensors and no predefined gait patterns for multiple speeds or different subjects, the NMC could produce various walking patterns based on subject interaction with the environment. Please see Wu et al. 2017 under publications for more information.

WE1: Ankle and Knee Control

Our consortium partners at Delft and UTwente have developed a new ankle and knee wearable exoskeleton. Tests of the NMC with this device on paraplegic pilots are currently ongoing at the Fondazione Santa Lucia, another one of our consortium partners. Since this exoskeleton only actuates the ankle and knee, these pilots already have some volitional control of their hip joint.

WE2: Lower Limb Control (ankle, knee, hip)

Tests of the full lower limb exoskeleton and neurmuscular controller will be conducted in early 2018. These tests will involve paraplegic pilots who do not have volitional control of their hip joints.

Media

S08_LNMC_Symbitron_Video.mp4

Symbitron_WE1_promo_video.mp4Promotion video for WE1 (knee and ankle actuation) in zero impedance mode

Student Projects

Related student projects:

S. Berger. Energy consumption optimization and stumbling corrective response for bipedal walking gait.

F. Dzeladini. Implementation of a human feedback-based locomotion and its control by means of a feedforward component inspired by central pattern generators

A. di Russo. Biomechanical analysis of slow walking and stepping behavior in healthy subjects on treadmill

Researchers

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Auke J. Ijspeert, Florin Dzeladini, Amy R. Wu

Publications

Electrically tunable giant Nernst effect in two-dimensional van der Waals heterostructures

G. Pasquale; Z. Sun; G. Migliato Marega; K. Watanabe; T. Taniguchi et al.

Nature Nanotechnology. 2024-07-02. DOI : 10.1038/s41565-024-01717-y.

Project Description

Neuromuscular Controller

Tests with Human Subjects

Ankle Control

Knee and Hip Control

WE1: Ankle and Knee Control

WE2: Lower Limb Control (ankle, knee, hip)

Media

Student Projects

Researchers

Publications

Electrically tunable giant Nernst effect in two-dimensional van der Waals heterostructures

Les fumées des trains à vapeur, un débordement industriel et professionnel (France, Grande-Bretagne, années 1860-1930)

Infectious disease spread in connected communities

Diving into the heterogeneity of the visual system

Impact of Mitofusin 2 in the Nucleus Accumbens on motivated behavior and underlying neurobiological mechanisms

Politique du logement à Genève. Revenu des ménages, loyers et prix des logements

How to support students to develop coaching and peer teaching skills

Analysis of a DC Data Center Power Supply with Series-Connected Active and Passive Rectifiers

Medium Voltage Power Electronics Research: Challenges and Opportunities

Numerical study of optical transmission in silver plasmonic square nanohole and its to windows

Alex’s Vision in Functional Quantum Matter

Training a Filter-Based Model of the Cochlea in the Context of Pre-Trained Acoustic Models

Electrodeposition of polyaniline on reduced graphene oxide/cotton yarn with tunable electrochemical performance for flexible textile supercapacitors

Milestones in tumor vascularization and its therapeutic targeting

MXene Inks for High-Throughput Printing of Electronics

Quantification of Native Lignin Structural Features with Gel-Phase 2D-HSQC0 Reveals Lignin Structural Changes During Extraction

Direct high-temperature growth of GaN on Si using trimethylaluminum preflow enabling vertically-conducting heterostructures

Anisotropic Adaptive Finite Elements for a p-Laplacian Problem

Overview of fast particle experiments in the first MAST Upgrade experimental campaigns

Nanocluster Aerosols from Ozone-Human Chemistry Are Dominated by Squalene-Ozone Reactions

Realization of an atomic quantum Hall system in four dimensions

Highly dispersed nanomaterials in polymer matrix via aerosol-jet-based multi-material 3D printing

Developments and applications of the OPTIMADE API for materials discovery, design, and data exchange

Simulations of primary and secondary ice production during an Arctic mixed-phase cloud case from the Ny-Ålesund Aerosol Cloud Experiment (NASCENT) campaign

Single-cell epigenomic reconstruction of developmental trajectories from pluripotency in human neural organoid systems

Permanently magnetized elastomer rotating actuator using traveling waves

Safe Schedule Verification for Urban Air Mobility Networks With Node Closures

A mmWave Low Complexity and Low-Cost Super Wideband Dual-Polarized Aperture Coupled Antenna for 5G Applications

Assessing the Charge Carrier Dynamics at Hybrid Interfaces of Organic Photoanodes for Solar Fuels

Unraveling ice multiplication in winter orographic clouds via in-situ observations, remote sensing and modeling

Joint host-pathogen genomic analysis identifies hepatitis B virus mutations associated with human NTCP and HLA class I variation

The Complete CEERS Early Universe Galaxy Sample: A Surprisingly Slow Evolution of the Space Density of Bright Galaxies at z ∼ 8.5-14.5

Enhancing Efficiency of Industrially-Compatible Monolithic Perovskite/Silicon Tandem Solar Cells with Dually-Mixed Self-Assembled Monolayers

The interplay between white adipose tissue, adipokines, and structural gray matter changes

Effects of Photon Recycling and Luminescent Coupling in All-Perovskite Tandem Solar Cells Assessed by Full Opto-electronic Simulation

Sparse autoregressive neural networks for classical spin systems

Tool Developments in the OpenMC Code: Correlated Sampling and Transient Fission Matrix Approach Coupled to OpenFOAM

The high flux nano-X-ray diffraction, fluorescence and imaging beamline ID27 for science under extreme conditions on the ESRF Extremely Brilliant Source

Study of impurity C transport and plasma rotation in negative triangularity on the TCV tokamak

Multi-Frequency Tracking via Group-Sparse Optimal Transport

Revealing the Mechanism Underlying 3D-AFM Imaging of Suspended Structures by Experiments and Simulations

Microkinetic Molecular Volcano Plots for Enhanced Catalyst Selectivity and Activity Predictions

Fast refacing of MR images with a generative neural network lowers re-identification risk and preserves volumetric consistency

Exciton migration in two-dimensional materials

Strengthening of edge prism dislocations in Mg-Zn by cross-core diffusion

Improving the photoelectrocatalytic efficiency of CuWO4 through molybdenum for tungsten substitution and coupling with BiVO4

Stabilization versus competing de-metalation, trans-metalation and (cyclo)-dehydrogenation of Pd porphyrins at a copper surface

Influence of Si3N4 fillers and pyrolysis profile on the microstructure of additively manufactured silicon carbonitride ceramics derived from polyvinylsilazane

Intermediate complexity atmospheric modeling in complex terrain: is it right?

Hierarchical Protofilament Intertwining Rules the Formation of Mixed-Curvature Amyloid Polymorphs

Triarylamine Trisamide Interfacial Modulation for Perovskite Photovoltaics

The autism susceptibility kinase, TAOK2, phosphorylates eEF2 and modulates translation

Value Estimation versus Effort Mobilization: A General Dissociation between Ventromedial and Dorsomedial Prefrontal Cortex

Mesh-based topology, shape and sizing optimization of ribbed plates

Plasmoid drift and first wall heat deposition during ITER H-mode dual-SPIs in JOREK simulations

Contrasting Views of the Electric Double Layer in Electrochemical CO2 Reduction: Continuum Models vs Molecular Dynamics

DTT toroidal field conductor samples test in Sultan: DC and AC characterization

Measuring and shaping the nutritional environment via food sales logs: case studies of campus-wide food choice and a call to action

Development of Ti-Zr-Mn based AB 2 type metal hydrides alloys for an 865 bar two-stage hydrogen compressor

Estimation of the bar stress based on crack width measurements in reinforced concrete structures

Reactivity of Cyanobacteria Metabolites with Ozone: Multicompound Competition Kinetics

Transdiagnostic markers across the psychosis continuum: a systematic review and meta-analysis of resting state fMRI studies

The Current State of the OBI DICT Project: A Bilingual e-Dictionary of Oracle-Bone Inscriptions with AI Image Recognition

Convalescent human plasma candidate reference materials protect against Crimean-Congo haemorrhagic fever virus (CCHFV) challenge in an A129 mouse model

Using Negative Control Populations to Assess Unmeasured Confounding and Direct Effects

Machine learning-aided generative molecular design

Subwavelength imaging using a solid-immersion diffractive optical processor

Succinct ordering and aggregation constraints in algebraic array theories

Carbazole Treated Waterproof Perovskite Films with Improved Solar Cell Performance