The Design of the Dummy Arm: A Verification Tool for Arm Exoskeleton Development

Area of Science:

• Biomedical Engineering
• Rehabilitation Engineering
• Human-Machine Interaction

Background:

• Motorized arm supports need precise compensation for arm weight and joint impedance.
• Estimating these human arm parameters in vivo is challenging and subjective evaluations are unreliable.

Purpose of the Study:

• To design and verify a cost-effective dummy arm that replicates human arm anthropometrics, mass, center of mass, and passive joint impedance.
• To provide a tool for the development and verification of motorized arm supports, such as the Duchenne ARm ORthosis (DAROR).

Main Methods:

• A dummy arm was designed with adjustable segment masses, degrees of freedom, and the ability to replicate passive elbow joint impedance (eJimp).
• The dummy arm's anthropometrics, range of motion, mass, center of mass, and eJimp torque-angle profiles were verified against human arm data.
• Segment masses, centers of mass, and eJimp were tuned to match a target population.

Main Results:

• The dummy arm successfully replicated human arm range of motion, mass, and center of mass.
• The dummy arm demonstrated the ability to replicate various eJimp torque-angle profiles.
• The design allows for tuning to match specific populations, proving valuable for DAROR development.

Conclusions:

• The developed dummy arm is a simple, cost-effective tool for verifying and developing motorized arm supports.
• This tool aids in optimizing design specifications for future arm-assistive devices.
• It provides practical insights for the application of assistive technologies for individuals with arm muscle weakness.