Hybrid orthosis system with a variable hip coupling mechanism.

Area of Science:

• Biomechanics and Rehabilitation Engineering
• Assistive Technology Development
• Robotics and Control Systems

Background:

• Existing reciprocating gait orthoses (RGOs) feature fixed 1:1 hip flexion/extension coupling ratios (FECR).
• These fixed ratios limit stride length and gait speed in individuals with paraplegia.
• There is a need for advanced RGOs with adaptable hip joint mechanics.

Purpose of the Study:

• To develop a novel hip reciprocating mechanism for hybrid orthosis systems capable of variable hip FECR.
• To enhance gait restoration and mobility for individuals with paraplegia.

Main Methods:

• Designed a hydraulic hip reciprocating mechanism utilizing solenoid valves for controlled coupling between hip joint cylinders.
• Implemented a continuous variable hip coupling system through pulsed valve actuation.
• Investigated piston velocity dependence on pulse width and frequency.
• Addressed internal hydraulic losses within the cylinders.
• Developed a dual-layer feedback control system using a fuzzy inference system and supervisory rules for gait event detection.

Main Results:

• Demonstrated that piston velocity is inversely proportional to pulse width and dependent on pulsing frequency.
• Identified primary internal losses occurring within the hydraulic cylinders.
• Established a foundation for advanced gait event detection and control.

Conclusions:

• The developed variable hip FECR mechanism offers a promising advancement over fixed-ratio RGOs.
• This innovation has the potential to significantly improve gait parameters and functional mobility for paraplegic individuals.
• Further research and development in feedback control systems will optimize performance.