First Demonstration of Functional Task Performance Using a Sonomyographic Prosthesis: A Case Study.

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Prosthetics

Background:

• Ultrasound-based sonomyography has previously shown potential for classifying hand grasps in offline settings.
• Real-time control of upper limb prostheses remains a significant challenge for individuals with limb absence.

Purpose of the Study:

• To demonstrate the first real-time prosthetic hand control using sonomyography for functional tasks.
• To evaluate the feasibility of sonomyography for controlling upper limb prostheses in real-world applications.

Main Methods:

• An individual with congenital bilateral limb absence was fitted with sockets containing ultrasound transducers.
• A linear discriminant analysis classifier was trained to recognize muscle contractions for rest, tripod grasp, and index finger point.
• The classifier controlled a prosthetic hand mounted to the socket for functional tasks.

Main Results:

• The participant successfully completed functional tasks requiring different hand grasps using real-time sonomyographic control.
• Control was maintained across a broad range of arm positions.
• The system demonstrated robustness, with successful repetitions over 3 hours and after simulated donning/doffing without retraining.

Conclusions:

• Sonomyography is a feasible method for real-time control of upper limb prostheses.
• This technology offers a promising pathway for improving the functionality of prosthetic devices.
• The study supports the potential of sonomyography for real-world prosthetic applications.