Pneumatic Relaxation Oscillator with Passive Components for Continuous Toes Movement

Area of Science:

• Biomedical Engineering
• Robotics
• Rehabilitation Technology

Background:

• Continuous passive motion (CPM) aids recovery from ankle injuries by improving circulation.
• Soft robotic devices are preferred for foot applications due to adaptability.
• Conventional pneumatic soft robots are power-intensive due to solenoid valves.

Purpose of the Study:

• To introduce a novel, low-power pneumatic oscillator for toe CPM.
• To demonstrate a passive pneumatic system for continuous toe movement.
• To evaluate the performance of the developed toe CPM device.

Main Methods:

• Implemented a relaxation oscillator using pneumatic RC filters and a soft actuator.
• Verified pneumatic RC filter characteristics and oscillation using pressure measurements.
• Tested the toe CPM device on a participant, measuring toe bending angle and torque.

Main Results:

• Pneumatic RC circuit exhibited low-pass and oscillation characteristics as expected.
• The toe CPM device achieved a bending angle of 15°–30°.
• A flexing torque of 1.5 Nm was recorded within a 15-second period.

Conclusions:

• The developed passive pneumatic oscillator offers an energy-efficient solution for toe CPM.
• This technology reduces power requirements and user dependency compared to existing methods.
• The device shows potential for enhancing rehabilitation and recovery for ankle injuries.