107 research outputs found
Assessing Balance During Gait with a Lower Limb Exoskeleton
No full textMaintaining balance is a critical aspect of human gait, especially for individuals with balance deficiencies. Accurate assessment and monitoring of balance are essential to reduce the risk of falls and improve mobility outcomes. Individuals with balance impairments tend to adopt larger step widths, resulting in increased mediolateral center of mass displacement with increased step-to-step variability. We aim to establish a quantitative metric that can accurately detect balance deficiencies, potentially improving the safety and effectiveness of lower limb exoskeletons. Using the linear inverted pendulum model, we estimated the mediolateral center of mass displacement in three healthy subjects walking with narrow, normal, and wide step widths. Our analysis demonstrates the importance of mediolateral center of mass displacement for assessing balance and stability during walking showing the significant differences in this metric with varying step widths. By leveraging this metric, we aim to enhance the balance assistance with lower limb exoskeletons.BIOROBSCI-STI-M
Towards Predictive Control of Trunk Internal Loads: Modeling Musculotendon Loads and Predicting Muscle Excitations
No full textLow back pain is prevalent among industrial workers due to heavy lifting and poor posture, causing significant back injuries globally and affecting health and productivity. Existing back-support exoskeletons (BSEs) lack closed-loop control for musculotendon unit (MTU) or joint loads. This study proposes a framework for closed-loop control of L5/S1 joint loads, featuring a simplified BSE dynamics model, a muscle excitation predictor (MEP), and a nonlinear model predictive control (NMPC) algorithm. The simplified model matches the neuromusculoskeletal model with a correlation %0.98, and the MEP has a prediction accuracy of 0.86 ± 0.06. Future work will develop the MPC algorithm to finalize the control framework
Predictive Control for Bio-Protective Robotic Exoskeletons: Closed-Loop Control of Internal Body Forces
No full textThe current exoskeleton and exosuit controllers lack direct control over biological tissue parameters such as muscle force and joint torques. This paper presents a predictive framework for controlling biological Musculotendon Unit (MTU) loads using exoskeletons. It introduces novel closed-form combined human-exoskeleton ordinary differential equation (ODE) models for simulating hopping and walking motions, which are utilized in the nonlinear model Predictive Controller (NMPC) of this framework. Through simulations, the framework demonstrates its capability to maintain MTU force below predefined thresholds. Future work aims to achieve real-time control of MTU load and joint torques during dynamic activities. The proposed framework, with the integration of NMPC, holds promise for enhancing the integration of exoskeleton technology in diverse applications, offering potential improvements in assistive and rehabilitative fields
Comunicación y educación en la sociedad de la información nuevos lenguajes y conciencia crítica
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Optimal Lower Limb Exoskeleton Assistance in Walking Predicted by Musculoskeletal Simulation
No full textBreakthroughs in assistive exoskeletons have occurred in the recent decade; both active and passive devices that provide partial joint moments in the lower limbs have reduced metabolic costs during walking by assisting muscle action. Musculoskeletal simulation is highly useful in describing the interaction between assistive moments, muscle-tendon mechanics, and walking energetics. In this study, we computed optimal assistive moments in ankle plantarflexion and hip flexion that produce minimal muscle activations during walking, described the muscle energetics, and estimated the potential reduction in metabolic cost. We described with analyses of muscle-tendon mechanics and motor control how reductions in muscle activation do not always result in metabolic cost savings.</p
Robotic-Aided Training and Assessment of Upper Limb Muscle Coordination Following Stroke
No full textTechnology-aided interventions and assessments are at the base of personalized motor rehabilitation after stroke. In the AVANCER trial, the effects of a novel personalized neurotech intervention were assessed by using an instrumented Fugl-Meyer (FM) evaluation pre and post interventions. The activity of 9 muscles in the affected and unaffected side of 12 severe chronic stroke patients was acquired during the FM test. Spinal maps showed specific topographical organization for different movements, and a sensitivity to upper limb impairments and recovery after stroke. The number of muscle synergies did not reflect the level of impairment or recovery in severe chronic stroke patients. These tools measure motor performance and nervous system status, enhancing understanding of stroke recovery.UPHUMME
User Involvement During the Development of the T-GRIP Thumb Exoskeleton
No full textT-GRIP is an innovative robotic hand exoskeleton that supports the lateral pinch grip by actuating the thumb flexion and extension. To gain insight into the user requirements to further develop the T-GRIP prototype, focus groups with potential end users, consisting of patients and healthcare professionals were conducted. Findings gave insight into problems participants encounter in daily live, assistance that is needed, preferences regarding the development of the hardware and control of T-GRIP and valuable information to develop the business case model. Human centered design empowers potential end users to have a substantial role in the product design. Focus groups are an impactful qualitative method to discover what users expect from a device.</p
Resisted and Endurance High Intensity Interval Training for Combat Preparedness
No full textBACKGROUND: Studies support the use of new training models based on low volume and high intensity in athletes, especially in soldier populations, showing greater physical improvements than conventional and classic approaches. We conducted this study to analyze the psychophysiological response of soldiers in two different high intensity interval training protocols (HIIT), resisted (RHIIT) and endurance (EHIIT), in order to determine which HIIT elicits a psychophysiological response similar to that in actual theaters of operation.
METHODS: We recruited 21 professional soldiers from the Spanish Army. HIIT protocols were conducted in accordance with actual military scenarios, performed at 36–38°C.
RESULTS: Both protocols, RHIIT and EHIIT, produced a significant increase in blood lactate (1.6 ± 0.3 to 6.4 ± 4.8 and 1.7 ± 0.6 to 11.2 ± 5.0, respectively), rate of perceived exertion, heart rate, and lower limb explosive strength; skin temperature and bodyweight presented significant decreases. Only EHIIT presented a significant increase on cortical arousal (35.9 ± 2.1 to 37.3 ± 2.8) and isometric hand-grip strength, achieving similar psychophysiological response as in previous simulated combat studies.
DISCUSSION: Both endurance and resisted high interval intensity training protocols produced a significant increase in the psychophysiological response of soldiers. EHIIT presented more similarities with actual combat situations.Tornero-Aguilera, Jose Grancisco-b66391e5-077f-4885-a969-f96d2a550cf2-0Clemente Suárez, Vicente Javier-0000-0002-2397-2801-60
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