Event-based control for sit-to-stand transition using a wearable exoskeleton.

Area of Science:

• Rehabilitation Engineering
• Biomechanics
• Control Systems

Background:

• Sit-to-stand (STS) transition is a fundamental functional movement crucial for lower limb rehabilitation.
• Assisting patients from wheelchair to higher functional levels necessitates effective STS transition strategies.
• Existing methods may lack adaptability and comprehensive support during the transition.

Purpose of the Study:

• To propose a mixed stiffness-damping control adaptation for optimizing the sit-to-stand transition.
• To ensure stability, constant velocity, and equal user participation during the STS movement.
• To explore the integration of muscle stimulation for comprehensive patient assistance.

Main Methods:

• Development of a hybrid control model combining stiffness and damping elements.
• Implementation of control strategies to manage initiation, execution, and final stabilization of the STS transition.
• Consideration of joint movement assistance and muscle stimulation for enhanced support.

Main Results:

• The proposed control model facilitates reaching the goal position with constant velocity.
• The combined control ensures stability and equilibrium throughout the sit-to-stand movement.
• The model allows for equal participation from the user in achieving the transition.

Conclusions:

• The mixed stiffness-damping control adaptation offers an effective solution for sit-to-stand transitions in rehabilitation.
• Integration with muscle stimulation presents a pathway for complete assistance, particularly for paraplegic patients.
• This approach supports patient independence and functional recovery by ensuring stable upright posture maintenance.