Comparing the Attentional Demands and Functional Outcomes in People With Transradial Amputation

Description

Pattern recognition controller (PRC) systems for upper limb prostheses are a replacement to conventional direct controller (DC) systems. For decades, two-site DC has been the primary method for controlling upper limb myoelectric prosthetic devices. The DC method involves recording surface electromyography (EMG) at two ‘control sites’, ideally an antagonistic muscle pair in the residual limb. Alternatively, PRC is an emerging approach to myoelectric control that can potentially address the key limitations of DC. PRC uses pattern classifiers to discern intended motions based on EMG signals recorded from multiple sites on the residual limb. PRC combines EMG signals captured from multiple electromyography sensors on the residual limb to determine control intent and subsequently translate that intent to the wrist and hand/terminal device unit, while DC relies on signal level from two sensors, with the dominant signal being translated into a movement intention to control the prosthesis. The PRC technique avoids the need to isolate muscle activations and non-intuitive triggers. PRC offers a potentially more natural and intuitive way to operate along a greater range of motion, as well as perform a larger number of hand grasps when compared to DC – particularly during tasks that are complex and require rapid switching between actions of the wrist and/or terminal device. PRC also allows the user to recalibrate control at any time, better accommodating day-to-day variations in socket fit and positioning of the electrodes over the targeted muscle sites. While both systems have been commercially available for more than a decade or more, there is lack of comparative evidence to inform clinical decisions and guide policy. The current trial will investigate potential functional advantages and disadvantages of PRC compared to DC.