Up-Care: an Upper Limb Portable Cable Assistive Recovery Exoskeleton for Elbow Movement Assistance.

Area of Science:

• Rehabilitation Engineering
• Robotics
• Biomechanics

Background:

• Upper limb paralysis is a common challenge for stroke survivors, impacting daily activities and independence.
• Existing powered assistive exoskeletons face challenges in weight, portability, and accessibility for widespread patient use.

Purpose of the Study:

• To introduce the Upper limb Portable Cable Assistive Recovery Exoskeleton (UPCARE), a novel lightweight and portable robotic exoskeleton designed for elbow movement assistance.
• To present the design, fabrication, and preliminary testing of the UPCARE system.

Main Methods:

• UPCARE utilizes a brushless DC motor with a two-stage planetary gearbox and a dual-pulley cable system.
• High-strength additive manufacturing materials and 3D printing were employed to reduce actuator weight and enhance design modularity.
• The system's total mass is 4.75 kg, with only 0.62 kg worn by the user.

Main Results:

• The 3D-printed actuator design achieved a 52% weight reduction compared to conventional transmissions.
• Preliminary testing showed accurate elbow position tracking up to 90 degrees.
• The device generated an average elbow joint torque of 18.9 Nm, indicating a high torque-to-weight ratio.

Conclusions:

• UPCARE is a lightweight, portable exoskeleton suitable for assistive rehabilitation, particularly for stroke survivors.
• The device effectively supports elbow flexion/extension, with potential to aid stroke survivors in regaining independence.
• The innovative design demonstrates the feasibility of using additive manufacturing for accessible and modular assistive robotic devices.