Ultra-lightweight robotic hip exoskeleton with anti-phase torque symmetry for enhanced walking efficiency

Area of Science:

• Robotics
• Biomechanics
• Gerontology

Background:

• Human gait relies heavily on hip joint power generation.
• Symmetrical hip torques are crucial for efficient walking.
• Existing exoskeletons often lack optimal assistance-to-weight/size ratios.

Purpose of the Study:

• To develop a compact, lightweight hip exoskeleton for gait assistance.
• To leverage hip joint mechanics for efficient power delivery.
• To evaluate the exoskeleton's effectiveness in improving elderly participants' mobility and strength.

Main Methods:

• Designed a single-actuator hip exoskeleton focusing on sagittal plane hip motion.
• Implemented an adaptive delayed output feedback controller for consistent performance.
• Conducted a 4-week outdoor walking program with elderly participants, measuring gait, balance, and muscle strength.
• Performed metabolic cost analysis on young adults using the exoskeleton.

Main Results:

• Elderly participants showed significant improvements in walking speed (10-15%) and mobility tests (18-25%).
• Ankle muscle strength increased substantially (dorsiflexion 75%, plantar flexion 46%).
• Young adults experienced a 13.6% reduction in metabolic cost of walking.

Conclusions:

• The single-actuator hip exoskeleton provides effective gait assistance with a compact and lightweight design.
• The device demonstrates potential for widespread application in enhancing mobility and reducing metabolic effort.
• This novel approach optimizes the assistance-to-weight/size ratio for robotic gait support.