Publications by authors named "F Sergi"

Human-in-the-loop (HIL) optimization is a control paradigm used for tuning the control parameters of human-interacting devices while accounting for variability among individuals. A limitation of state-of-the-art HIL optimization algorithms such as Bayesian Optimization (BO) is that they assume that the relationship between control parameters and user response does not change over time. BO can be modified to account for the dynamics of the user response by implementing time into the kernel function, a method known as Dynamic Bayesian Optimization (DBO).

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Objective: to establish whether torque pulses ap-plied by an exoskeleton to the hip and knee joint modulate propulsion mechanics and whether changes in propulsion me-chanics are sustained after exposure to torque pulses under user-driven treadmill control.

Methods: we applied twelve for-mulations of torque pulses consecutively over 300 strides to 22 healthy participants, and quantified the evolution of four outcome measures - gait speed (GS), hip extension (HE), trailing limb angle (TLA), normalized propulsive impulse (NPI) - before, during, and immediately after training.

Results: Metrics of propulsion mechanics significantly changed both during and after training.

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: The treatment of displaced intra-articular calcaneal fractures (DIACF) is debated. This study compares open reduction and internal fixation (ORIF) with minimally invasive osteosynthesis (MIOS). : We conducted a retrospective study on 70 patients with DIACF treated between January 2018 and September 2022, divided into ORIF ( = 50) and MIOS ( = 20) groups.

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Multiple mechanisms of motor learning contribute to the response of individuals to robot-aided gait training, including error-based learning and use-dependent learning. Previous models described either of these mechanisms, but not both, and their relevance to gait training is unknown. In this paper, we establish the validity of existing models to describe the response of healthy individuals to robot-aided training of propulsion via a robotic exoskeleton, and propose a new model that accounts for both use-dependent and error-based learning.

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Methodological constraints have hindered direct measurement of reticulospinal tract (RST) function. The RST is thought to contribute to the increase in the amplitude of a long latency response (LLR), a stereotypical response evoked in stretched muscles, that arises when participants are asked to "resist" a perturbation. Thus, functional magnetic resonance imaging (fMRI) during robot-evoked LLRs under different task goals may be a method to measure motor-related RST function.

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