Prosthetic command signals following targeted hyper-reinnervation nerve transfer surgery

Area of Science:

• Biomedical Engineering
• Reconstructive Surgery
• Neuroprosthetics

Background:

• High-level upper-limb amputations present challenges in controlling multi-degree-of-freedom prostheses due to limited myoelectric control signals.
• Existing prosthetic control methods often lack the intuitive, simultaneous multi-joint operation desired by users.

Purpose of the Study:

• To develop a novel method for enhanced control of myoelectric upper-limb prostheses.
• To enable simultaneous control of multiple prosthetic degrees-of-freedom through increased myoelectric signal availability.

Main Methods:

• A surgical procedure involving the transfer of residual nerves to innervate spare muscles in or near the residual limb.
• Development of a prosthetic system capable of utilizing the additional myoelectric signals generated by reinnervated muscles.
• Fitting and evaluation of the system on patients with high-level upper-limb amputations (shoulder disarticulation and transhumeral).

Main Results:

• Successful implementation of the nerve transfer and prosthetic fitting in two amputees.
• Demonstrated simultaneous control of multiple prosthetic joints (e.g., hand, elbow, humeral rotator) using the novel system.
• Significant increase in functional range-of-motion and ability to perform previously impossible tasks, such as object retrieval.

Conclusions:

• The described surgical and prosthetic approach provides a more natural and intuitive control paradigm for upper-limb prostheses.
• This method significantly enhances the functional capabilities and range-of-motion for individuals with high-level upper-limb loss.
• Nerve transfers to spare muscles offer a promising strategy for improving myoelectric prosthetic control.