Assisting Forearm Function in Children With Movement Disorders via A Soft Wearable Robot With Equilibrium-Point...

Area of Science:

• Robotics
• Biomedical Engineering
• Human-Robot Interaction

Background:

• Soft wearable robots offer a promising solution for assisting individuals with movement impairments.
• Challenges exist in developing effective feedback control for soft robots due to their complex, nonlinear behavior.
• Existing control strategies often struggle to seamlessly integrate human intent with robotic assistance.

Purpose of the Study:

• To design, fabricate, and implement a control architecture for a soft wearable robot assisting forearm supination and pronation.
• To introduce a bio-inspired equilibrium-point control scheme integrating proprioceptive and exteroceptive feedback for enhanced human-robot interaction.
• To evaluate the effectiveness of the proposed controller in reducing user effort during dynamic tasks.

Main Methods:

• Developed a soft wearable robot with an antagonistic pair of pneumatic helical actuators for pronation and supination.
• Implemented an equilibrium-point control scheme inspired by motor control theory, directly linking muscle activation signals to actuator valve behavior.
• Recruited seven pediatric participants with movement disorders to perform dynamic trajectory tracking tasks with a haptic manipulandum under different system dynamics (spring-dominant and inertia-dominant).

Main Results:

• The soft wearable robot, utilizing the proposed control scheme, reduced user effort by an average of 14%.
• The controller effectively integrated user muscle activation signals to modulate robotic assistance.
• No significant increase in task error was observed with the active assistance.

Conclusions:

• Demonstrated the practical feasibility of an equilibrium-point volitional controller for soft wearable robots.
• The developed system offers a foundational approach for creating versatile, low-cost soft wearable robots for assistive applications.
• This technology has the potential to significantly amplify the independence of individuals with movement impairments.