EMG feedback improves grasping of compliant objects using a myoelectric prosthesis

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Human-Computer Interaction

Background:

• Closing the control loop in myoelectric prostheses via artificial somatosensory feedback is crucial but challenging.
• Redundant sensory information from hearing or vision can limit feedback effectiveness.
• Electromyography (EMG) feedback offers intrinsic, non-invasive signal information unavailable through other senses.

Purpose of the Study:

• To investigate the efficacy of EMG feedback in myoelectric prosthesis force control.
• To compare performance with and without EMG feedback when grasping compliant objects of varying stiffness.
• To assess EMG feedback's utility despite the presence of incidental sensory cues.

Main Methods:

• 10 able-bodied participants and 1 individual with transradial amputation used a myoelectric prosthesis.
• Participants grasped compliant objects with different stiffness values.
• Performance was evaluated with and without EMG feedback, comparing task success rate and completion time.

Main Results:

• EMG feedback significantly increased task success rates across all stiffness levels.
• No significant difference in completion time was observed between feedback conditions.
• Participants demonstrated smoother control signals and more consistent commands with EMG feedback.

Conclusions:

• EMG feedback effectively enhances myoelectric prosthesis control, particularly in challenging scenarios.
• The study supports the utility of intrinsic EMG feedback for closing the prosthesis control loop.
• EMG feedback improves accuracy and control consistency, even when incidental cues are present.