Pneumatic Quasi-Passive Actuation for Soft Assistive Lower Limbs Exoskeleton

Area of Science:

• Robotics
• Biomechanics
• Assistive Technology

Background:

• Growing interest in soft wearable robots for mobility enhancement and rehabilitation.
• Usability, comfort, and acceptance are key factors for widespread adoption of assistive devices.
• The XoSoft EU project developed a modular soft lower-limb exoskeleton for individuals with low mobility.

Purpose of the Study:

• To present the bio-inspired design of a soft, modular exoskeleton for lower limb assistance.
• To evaluate the performance and feasibility of a novel pneumatic quasi-passive actuation system.
• To assess the energetic outcomes and human-exoskeleton interaction during walking in healthy subjects.

Main Methods:

• Development of a modular, reconfigurable soft exoskeleton prototype.
• Implementation of pneumatic quasi-passive actuation modulating assistance from an elastic belt.
• Evaluation of energetic outcomes and gait kinematics on healthy subjects during walking.

Main Results:

• The exoskeleton provided significant power assistance: 26.6% (hip), 9.3% (knee), and 12.6% (ankle) overall power ratio (Λ).
• Maximum released power supplied was 113.6% (hip), 93.2% (knee), and 150.8% (ankle).
• Analysis of human-exoskeleton interaction revealed task-based biological power assistance and gait kinematics variations.

Conclusions:

• The developed soft, modular exoskeleton is feasible for lower limb assistance.
• Pneumatic quasi-passive actuation effectively modulates assistance for enhanced mobility.
• The device shows potential for improving autonomy and rehabilitation in individuals with mobility impairments.