A Physics-based Virtual Reality Environment to Quantify Functional Performance of Upper-limb Prostheses.

Area of Science:

• Biomedical Engineering
• Rehabilitation Robotics
• Human-Computer Interaction

Background:

• Upper-limb prosthesis usability is hindered by complex hand-object interactions in daily activities.
• Functional evaluation is crucial for optimizing prosthesis design and performance tuning.
• Existing evaluation methods may lack quantitative metrics for real-time feedback.

Purpose of the Study:

• To implement a low-cost, physics-based virtual reality environment (VRE) for human-in-the-loop optimization of upper-limb prostheses.
• To quantitatively assess user performance in grasping and manipulation tasks using movement kinematics and interaction forces.
• To validate the VRE through a preliminary experiment involving object transfer tasks with a simulated prosthetic hand.

Main Methods:

• Development of a physics-based virtual reality environment (VRE) simulating diverse object grasping and manipulation tasks.
• Quantitative assessment of user performance via movement kinematics and interaction forces within the VRE.
• Preliminary experiment with four able-bodied subjects using a simulated myoelectric prosthetic hand and controlled wrist motion limitations.

Main Results:

• The VRE successfully simulated object transfer tasks with a prosthetic hand, enabling quantitative performance assessment.
• Task completion time remained consistent across different wrist motion conditions.
• Limited wrist pronation increased shoulder compensatory motion; challenging object orientation increased torso compensatory motion.

Conclusions:

• The developed VRE provides a viable, low-cost platform for quantitative functional evaluation and human-in-the-loop optimization of upper-limb prostheses.
• Understanding compensatory movements is essential for designing more intuitive and effective prosthetic devices.
• The VRE can inform future prosthetic design by highlighting the impact of device constraints on user movement strategies.