Improved Myoelectric Prosthesis Control Using Targeted Reinnervation Surgery: A Case Series

Abstract

Targeted Reinnervation is a surgical technique developed to increase the number of myoelectric input sites available to control an upper-limb prosthesis. Because signals from the nerves related to specific movements are used to control those missing degrees-of-freedom, the control of a prosthesis using this procedure is more physiologically appropriate compared to conventional control. This procedure has successfully been performed on three people with a shoulder disarticulation level amputation and three people with a transhumeral level amputation. Performance on timed tests, including the box-and-blocks test and clothespin test, has increased two to six times. Options for new control strategies are discussed.

Recent Trends in EMG-Based Control Methods for Assistive Robots

“…Targeted muscle reinnervation (TMR) is a surgical procedure which is developed to increase the number of psychologically appropriate control inputs available for use with a prosthetic device [42]. A surgical procedure is used to transfer the motor neurons of the residual limb to a remaining set of muscles.…”

“…For a transhumeral amputee, the goal is to transfer the median and distal radial nerves to target muscle segments creating hand open and close signals. For the shoulder/humeral neck disarticulated amputees all four brachial plexus nerves are transferred to the target muscles [42]. It should be noted that for cases with left shoulder disarticulation the interference of electrocardiogram (ECG) causes an effect to the TMR EMG signals [42].…”

“…For the shoulder/humeral neck disarticulated amputees all four brachial plexus nerves are transferred to the target muscles [42]. It should be noted that for cases with left shoulder disarticulation the interference of electrocardiogram (ECG) causes an effect to the TMR EMG signals [42]. This could be eliminated using a second-order high pass filter with 60Hz cutoff frequency, which results in 80% elimination of the ECG signals and 20% elimination of the EMG signals producing an improved law signal-to-noise ratio output.…”

“…The control algorithm of the system is comprised of proportional controlling of velocity according to the amplitude of the EMG signal. Table 2 shows summary of information of TMR subjects in the experiment [42].…”

Performance Evaluation Methods for Assistive Robotic Technology

“…The performance measures include joint angle, joint torque, and power consumption. However, several research institutions have conducted end-user evaluations, including RIC [67,57], Northwestern University [67,57], Massachusetts Institute of Technology [4,5], and Hong Kong Polytechnic University [58].…”