Portail des publications scientifiques IMT Mines Alès
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Experimental Data-Driven Angular Velocity Control for a Soft Pneumatic Wrist Exoskeleton for Motion Assistance in Rehabilitation
No full textInternational audienceSoft robotic devices have proven to be highly effective in supporting stroke patients by offering adaptive, gentle, and precise assistance for rehabilitation and mobility improvement. Their inherent flexibility and compliance make them ideal for promoting recovery in individuals with neurological impairments. This paper presents a methodology for utilizing experimental data to develop a control model for a pneumatic soft robotic wrist exoskeleton. The exoskeleton is equipped with capacitive-type flexible sensors to measure angular displacement and employs a proportional-integral (PI) controller to regulate wrist flexion and extension movements. To establish reliable control parameters, a linear dynamic state-space model for the wrist exoskeleton is derived from experimental data. The system identification method enabled the development of state-space models that closely matched the experimental system with minimal error. A simulation model of angular velocity control is created in MATLAB/Simulink, incorporating the estimated state-space model and PI controller. This simulation is used to fine-tune the PI parameters, which are then programmed into a microcontroller to control the soft robotic wrist exoskeleton. Experimental results demonstrated angular velocity tracking with average errors of 0.18-0.26 deg/sec across different configurations and velocity commands, validating the effectiveness of the system identification approach and simulation-based tuning in reducing manual tuning efforts while achieving precise control of the required angular velocities
Carbon dioxide sorption in earthen plasters and its impact on Indoor Air Quality
No full textInternational audienceRaw earth-based materials play a significant role in creating comfortable indoor environments, particularly due to the presence of clay minerals, which can interact with indoor air constituents such as moisture and provide passive regulation. This study explores the interactions between raw earth plasters and carbon dioxide (CO) in indoor air, with a focus on their potential role in passive CO regulation, particularly in densely occupied or poorly ventilated spaces. Experiments were conducted using an emission chamber with continuous CO monitoring to assess: (i) the influence of humidity on sorption processes, (ii) sorption differences between two types of earth materials and a plasterboard, and (iii) the effect of plaster thickness. Results show that raw earth plasters effectively adsorb CO, with higher adsorption under high humidity. Furthermore, CO diffusion occurs within the plaster, leading to greater adsorption with increased plaster thickness. Key coefficients, adsorption and desorption rate constants (, ) and the material/air partition coefficient (), were determined. Using these coefficients, simulations were performed to predict the impact of earthen plasters on CO concentrations in a typical bedroom. Simulations predict that earth plasters can reduce CO levels, with a modest, yet measurable, 8% reduction overnight compared to a room without plasters
Développement d’un pipeline de création de jumeaux numériques pour l’optimisation des protocoles de dosimétrie en médecine nucléaire
No full textNational audienceAbdollahi et al., 2024 (1) définissent les Jumeaux Numériques (JN) comme des ” répliques virtuelles d’objets, de systèmes ou de processus ayant pour objectif de simuler le comportement et la performance de l’original à des fins d’analyse et/ou d’optimisation ”. Ils permettent de mener des études numériques dans un cadre proche de la réalité clinique, entièrement maîtrisé et paramétrable, tout en limitant les coûts et les risques pour le patient.Garcia et al., 2015 (2) ont initié une approche précurseur en médecine nucléaire avec leur logiciel TestDose pour la modélisation des acquisitions et de la dosimétrie. Cette étude s’en inspire pour proposer un pipeline pour créer un JN basé sur des données patient, destiné à l’étude et l’optimisation des protocoles de dosimétrie en médecine nucléaire
Improving Optical Cable Safety with Advanced Flame-Retardant Formulations
No full textInternational audienc
Enhancing Methane Emissions Management in Nigeria’s Oil and Gas Sectors: A Comprehensive Policy and Strategic Framework
No full textInternational audienceThis report examines the institutional framework for methane emissions reduction in Nigeria, with a particular focus on the Niger Delta region. Methane emissions in this area primarily stem from oil and gas extraction activities, including gas flaring and fugitive emissions. As one of the world’s largest methane emitters, Nigeria owes much of its output to the Niger Delta’s extensive oil extraction infrastructure. However, inconsistencies between local assessments and satellite data expose significant gaps in methane emission reporting, hindering accurate quantification and the implementation of effective mitigation strategies. Methane emissions in the Niger Delta have severe environmental and public health consequences, degrading air quality and exacerbating climate change. Despite the urgency, limited monitoring and reporting mechanisms constrain efforts to assess and address emissions comprehensively. Studies suggest that capturing flared gas could not only mitigate environmental harm but also provide economic and public health benefits. Nigeria has initiated steps to curb methane emissions, such as the 2018 Short-Lived Climate Pollutants Action Plan, which aims to end routine gas flaring by 2030. However, progress has been slow due to infrastructure deficiencies and enforcement challenges, underscoring the need for a stronger institutional framework. Addressing these barriers requires a coordinated effort among stakeholders, including government bodies, funding organizations, research institutions, and local communities. This report outlines actionable strategies for reducing methane emissions, emphasizing the importance of stringent regulations, advanced monitoring systems, and incentives for cleaner technologies. It also proposes national and global policy recommendations that define clear objectives and foster collaboration among stakeholders. By prioritizing transparency, education, and community involvement, Nigeria can establish a cohesive framework to tackle methane emissions effectively, promoting environmental sustainability and driving economic growth
Impact of amputation level on gait disorders in transfemoral and transtibial amputees
No full textInternational audienceQuestion: how does the level of lower limb amputation affect spatiotemporal gait asymmetry and cautious gait criteria to inform tailored rehabilitation interventions?Design: a retrospective study analyzing gait patterns in individuals with unilateral lower limb amputations.Participants: 49 amputees (22 (45%) transtibial, 27 (55%) transfemoral) compared to 30 healthy controls, evaluated between January 2018 and June 2023. INTERVENTION PARTICIPANTS: performed a spontaneous walking speed test on a pressure mat (Zebris® FDM 2 & 3 System, 100 Hz, v 1.18.44, GmbH, Isny, Germany) after completing rehabilitation.Outcome measures: gait symmetry and cautious gait were assessed using spatio-temporal parameters, center of pressure (CoP) displacement, and foot segment forces.Results: increased asymmetry was observed in stance phase duration, step length, stance duration, and walking speed (95 % CI 0.398-0.658) depending on the level of amputation. Transfemoral amputees showed significant increases in step width (95 % CI 0.201-0.512), double support phase (95% CI 0.000-0.150), and medio-lateral CoP displacement (95% CI 0.039-0.326). The increased asymmetry in spatio-temporal parameters suggests different compensation strategies between transfemoral and transtibial levels. These differences highlight the importance of the rehabilitation paradigm in managing asymmetry and its underlying compensations during locomotor activities.Conclusion: the level of amputation significantly impacts gait asymmetry and cautious gait parameters. Transfemoral amputees exhibit more pronounced cautious gait characteristics, likely due to the need for greater stabilization. These findings underscore the importance of personalized rehabilitation to address specific compensations and gait abnormalities based on amputation level
Underwater HNS Release: Modeling Gas Behavior
No full textInternational audienceThe maritime transportation of Hazardous and Noxious Substances (HNS) continues to grow, posing significant risks to the marine environment and human health. In the event of an accidental release, these substances can create severe hazards, including toxic gas clouds, fires, and potential explosions. While existing models are effective for simulating conventional hydrocarbon spills, they lack the capability to accurately represent the complex behavior of volatile HNS released at sea. As part of the MANIFESTS-Genius European project, research has been conducted to advance knowledge in this area. A new module has been developed to simulate underwater gas releases, aiming to evaluate the quantity of gas dissolution as a gas plume rises through the water column from sources such as underwater pipelines or shipwrecks. By accurately modeling this process, it becomes possible to predict the characteristics of the gas cloud that may form at the surface. The module consists of a Python-based bubble rising and dissolution tracker. Its outputs can be used as standalone data or integrated into the OSERIT Lagrangian transport model, which is currently employed by the Belgian coastguard and member states of the Bonn Agreement. This integration enhances OSERIT's predictive capabilities for underwater gaseous releases by determining the initial distribution of HNS between the water column and the atmosphere. Consequently, this improvement strengthens decision-support tools used by responders to manage HNS-related incidents at sea. In this communication, we will present the processes implemented in the module, and how they have been validated using experimental data produced in the framework of the project
Maximizing healthcare security outcomes through AI/ML multi-label classification approach on IoHT devices
No full textInternational audience[Purpose]The Internet of Health Things (IoHT) is a precise adaptation of the Internet of Things (IoT) in the health domain that allows medical objects to be embedded with electronic and networking capabilities for real-time medical data exchange. Their increased adoption comes at the expense of widening cyberattack surfaces and other unintended cybersecurity consequences that require sophistication to address. This paper aims to employ AI and ML techniques to strengthen cybersecurity practices in the healthcare sector.[Methods]For our methods, we used a streamlined and adapted ML pipeline on the Edith Cowan University (ECU) IoHT; a dataset developed primarily for the analysis and evaluation of network traffic. Furthermore, we compared several approaches employed in anomaly detection in IoHT environment and converged with four classification AI/ML techniques of Gradient Boosting (GB), Decision Trees (DT), Random Forest (RF) and Multi-Layer Perceptron (MLP).[Results]A comprehensive comparative analysis is conducted based on key performance metrics such as accuracy, precision, recall, and F1-score. The results showed impressive classification accuracy of more than 90% in classifying ARP spoofing, DoS, Nmap port scan and smurf attack types. Experimental results demonstrate that each algorithm exhibits unique strengths in different aspects of IoHT security.[Conclusions]In conclusion, the findings of this study provide valuable insights into selecting appropriate AI algorithms for specific IoHT security requirements, contributing to the development of more resilient and effective security mechanisms in healthcare systems leveraging IoHT technologies
Intérêt de l’ajout d’un traitement de thérapie miroir en réalité augmentée à une prise en charge conventionnelle dans le Syndrome Douloureux Régional Complexe (SDRC) du membre supérieur : étude en Single Case Experimental Design (SCED)
No full textInternational audienc
A Proof-of-Concept Digital Twin for Real-Time Simulation: Leveraging a Model-Based Systems Engineering Approach
No full textInternational audienceThis paper presents a proof-of-concept digital twin designed to enhance industrial process monitoring and maintenance through real-time and bidirectional communication. The integrated approach combines a physical twin—constructed using LEGO © Spike Prime kits and multiple Raspberry Pi 4 microcontrollers—with a digital twin modeled in FlexSim discrete-event simulation software package. Data is continuously synchronized via the MQTT protocol, allowing the digital twin to accurately mirror key operational parameters such as object sorting status, conveyor speed, and splitter position. The system leverages Model-Based Systems Engineering (MBSE) techniques, implemented with Capella and the Arcadia methodology, to support a robust design and integration of physical and digital components. Experimental scenarios, including normal operation and simulated malfunctions, demonstrate the system’s ability to trigger corrective actions and provide valuable insights for predictive maintenance. The results confirm that such a modular digital twin approach can improve real-time simulation, fault detection, and operational efficiency in industrial applications