Titre
Evaluation of controllers for augmentative hip exoskeletons and their effects on metabolic cost of walking: explicit versus implicit synchronization.
Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Auteur(s)
Manzoori, A.R.
Auteure/Auteur
Malatesta, D.
Auteure/Auteur
Primavesi, J.
Auteure/Auteur
Ijspeert, A.
Auteure/Auteur
Bouri, M.
Auteure/Auteur
Liens vers les personnes
Liens vers les unités
ISSN
2296-4185
Statut éditorial
Publié
Date de publication
2024
Volume
12
Première page
1324587
Peer-reviewed
Oui
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: epublish
Publication Status: epublish
Résumé
Background: Efficient gait assistance by augmentative exoskeletons depends on reliable control strategies. While numerous control methods and their effects on the metabolic cost of walking have been explored in the literature, the use of different exoskeletons and dissimilar protocols limit direct comparisons. In this article, we present and compare two controllers for hip exoskeletons with different synchronization paradigms. Methods: The implicit-synchronization-based approach, termed the Simple Reflex Controller (SRC), determines the assistance as a function of the relative loading of the feet, resulting in an emerging torque profile continuously assisting extension during stance and flexion during swing. On the other hand, the Hip-Phase-based Torque profile controller (HPT) uses explicit synchronization and estimates the gait cycle percentage based on the hip angle, applying a predefined torque profile consisting of two shorter bursts of assistance during stance and swing. We tested the controllers with 23 naïve healthy participants walking on a treadmill at 4 km ⋅ h <sup>-1</sup> , without any substantial familiarization. Results: Both controllers significantly reduced the metabolic rate compared to walking with the exoskeleton in passive mode, by 18.0% (SRC, p < 0.001) and 11.6% (HPT, p < 0.001). However, only the SRC led to a significant reduction compared to walking without the exoskeleton (8.8%, p = 0.004). The SRC also provided more mechanical power and led to bigger changes in the hip joint kinematics and walking cadence. Our analysis of mechanical powers based on a whole-body analysis suggested a reduce in ankle push-off under this controller. There was a strong correlation (Pearson's r = 0.778, p < 0.001) between the metabolic savings achieved by each participant with the two controllers. Conclusion: The extended assistance duration provided by the implicitly synchronized SRC enabled greater metabolic reductions compared to the more targeted assistance of the explicitly synchronized HPT. Despite the different assistance profiles and metabolic outcomes, the correlation between the metabolic reductions with the two controllers suggests a difference in individual responsiveness to assistance, prompting more investigations to explore the person-specific factors affecting assistance receptivity.
PID Serval
serval:BIB_4FF098941408
PMID
Open Access
Oui
Date de création
2024-04-02T07:33:56.397Z
Date de création dans IRIS
2025-05-20T14:58:34Z
Fichier(s)![Vignette d'image]()
En cours de chargement...
Nom
38532879_BIB_4FF098941408.pdf
Version du manuscrit
published
Licence
https://creativecommons.org/licenses/by/4.0
Taille
2.44 MB
Format
Adobe PDF
PID Serval
serval:BIB_4FF098941408.P001
URN
urn:nbn:ch:serval-BIB_4FF0989414088
Somme de contrôle
(MD5):5f1abc1ea3af0b169425fb23860b18e5