Development and Pre-Clinical Validation of Tendon Driven 2 Degree-of-Freedom Powered Ankle-Foot Orthosis for...

Area of Science:

• Rehabilitation Engineering
• Biomechatronics
• Robotics

Background:

• Powered Ankle-Foot Orthoses (PAFO) are crucial for mobility rehabilitation, especially for the elderly.
• Existing 2-degree-of-freedom PAFOs using pneumatic artificial muscles (PAMs) have limited control capacity due to low cutoff frequencies.
• There is a need for PAFOs with improved actuation and control for effective gait assistance.

Purpose of the Study:

• To develop a novel tendon-driven PAFO with enhanced control capabilities.
• To investigate the efficacy of a heuristic-based algorithm for human-in-the-loop optimization in improving walking stability.
• To address the limitations of low cutoff frequencies in PAM-actuated PAFOs.

Main Methods:

• Development of a tendon-driven actuation system using cables and a motor for higher cutoff frequencies.
• Implementation of a heuristic-based algorithm for human-in-the-loop optimization, focusing on antagonistic muscle activity.
• Pre-clinical experiments to evaluate walking stability using Gaussian ellipsoid metrics.

Main Results:

• The developed tendon-driven PAFO demonstrated higher cutoff frequencies compared to PAM-based systems.
• The heuristic-based algorithm showed potential in enhancing walking stability.
• Pre-clinical experiments validated the feasibility of the proposed approach for gait rehabilitation.

Conclusions:

• A novel tendon-driven PAFO offers improved actuation and control for ankle rehabilitation.
• The human-in-the-loop optimization algorithm shows promise for enhancing gait stability in individuals with mobility impairments.
• This technology has the potential to advance rehabilitation robotics and improve patient outcomes.