Physical Disturbance Rejection Methods in Myokinetic Control of Prosthetic Limbs.

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Prosthetics

Background:

• Myokinetic control interfaces for limb prosthetics use implanted magnets and external sensors to translate muscle displacement into motor commands.
• Clinical translation requires addressing external disturbances, such as unintended sensor-magnet displacement, which can impair interface function.

Purpose of the Study:

• To develop and evaluate methods for rejecting physical disturbances affecting myokinetic control interfaces.
• To ensure the reliable and accurate functioning of magnetic tracking in prosthetic limb control.

Main Methods:

• Proposed three disturbance rejection strategies: numerical realignment and two differential measurement techniques.
• Simulated and physically validated these methods using a forearm model mimicking upper limb prostheses.
• Evaluated one method in a first-in-human implementation of the myokinetic interface.

Main Results:

• All proposed methods effectively rejected physical disturbances.
• Achieved median localization errors below 10% of the displacement caused by voluntary muscle contraction.

Conclusions:

• The optimal disturbance rejection method is application-dependent, requiring careful consideration of various factors.
• Findings offer valuable insights for myokinetic interface development and other remote magnetic tracking applications in biomedicine.