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Gait Event Detection with Proprioceptive Force Sensing in a Powered Knee_Ankle Prosthesis Validation over Walking Speeds and Slopes.pdf (1.41 MB)
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Gait Event Detection with Proprioceptive Force Sensing in a Powered Knee-Ankle Prosthesis: Validation over Walking Speeds and Slopes

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posted on 2023-02-23, 18:38 authored by Emily KellerEmily Keller, Curt Laubscher, Robert GreggRobert Gregg

Many powered prosthetic devices use load cells to detect ground interaction forces and gait events. These sensors introduce additional weight and cost in the device. Recent proprioceptive actuators enable an algebraic relationship be?tween actuator torques and ground contact forces. This paper presents a proprioceptive force sensing paradigm which esti?mates ground reaction forces as a solution to detect gait events without a load cell. A floating body dynamic model is obtained with constraints at the center of pressure representing foot-ground interaction. Constraint forces are derived to estimate ground reaction forces and subsequently timing of gait events. A treadmill experiment is conducted with a powered knee-ankle prosthesis used by an able-bodied subject walking at various speeds and slopes. Results show accurate gait event timing, with pooled data showing heel strike detection lagging by only 6.7 ± 7.2 ms and toe off detection leading by 30.4 ± 11.0 ms compared to values obtained from the load cell. These results establish proof of concept for predicting gait events without a load cell in powered prostheses with proprioceptive actuators. 

Funding

Controlling Locomotion over Continuously Varying Activities for Agile Powered Prosthetic Legs

Eunice Kennedy Shriver National Institute of Child Health and Human Development

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CAREER: Recovering and Enhancing Natural Locomotion in Changing Conditions with Powered Lower-Limb Prostheses and Orthoses

Directorate for Engineering

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History

Email Address of Submitting Author

egkeller@umich.edu

Submitting Author's Institution

University of Michigan

Submitting Author's Country

  • United States of America

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