Assistive acting movement therapy devices with pneumatic rotary-type soft actuators

Area of Science:

• Robotics
• Biomedical Engineering
• Rehabilitation Technology

Background:

• Safe human-robot interaction requires inherent compliance and assistive behavior, especially in rehabilitation robots interacting with sensitive individuals.
• Novel soft fluidic actuators, specifically rotary elastic chambers (REC actuators), enable the development of compact, lightweight, and cost-effective therapeutic devices.

Purpose of the Study:

• To describe the modular design and control strategies for new assistive robotic devices for upper and lower extremity movement therapy.
• To demonstrate gentle treatment through inherent compliance and back-drivability of pneumatic REC actuators, enabling force estimation without expensive sensors.
• To integrate a special safety concept with control algorithms for enhanced safeness and error handling in pneumatic actuator systems.

Main Methods:

• Development of modular robotic devices utilizing novel soft fluidic actuators (REC actuators).
• Implementation of active model-based gravity compensation using separated robot and patient extremity models for assistive control.
• Integration of a safety concept with control algorithms to manage system errors and emergency situations.
• Design of a user-friendly interface for intuitive device operation.

Main Results:

• Pneumatic REC actuators facilitate gentle treatment and allow interaction force estimation without costly sensors.
• Active gravity compensation enables effective assistive control for patient movement therapy.
• Prototypes demonstrated comfort and effectiveness through background control routines during extensive testing with healthy individuals.
• The knee/hip movement therapy device is currently undergoing clinical trials.

Conclusions:

• Novel soft fluidic actuators (REC actuators) are suitable for developing safe, cost-effective, and compliant rehabilitation robotic devices.
• The described modular design, control strategies, and safety concepts contribute to advanced assistive movement therapy.
• Clinical trials indicate the potential of these devices for widespread application in orthopedic and trauma rehabilitation.