Independent pro-supination control in transradial myoelectric prostheses
University of New Brunswick
This research investigated simultaneous control of the wrist and hand function by designing a new prosthetic socket interface and augmenting the available control input from the prosthesis user. The primary focus was to determine if a viable control input could be acquired from the user’s forearm rotation (pronation and supination) alongside surface EMG signals that drive hand function. These inputs could then be used to control two degrees of freedom simultaneously. A novel design for a transradial prosthesis is presented in this thesis, that allowed for independent control of a wrist rotation unit and a single degree of freedom prosthetic hand. The functionality of this prosthesis was evaluated by a prosthesis user who performed the Box and Blocks test and a clothespin relocation task. Outcome measures included time to complete a task, number of blocks moved, and analysis of kinematic angles using a motion capture system. Comparisons were made between the new prosthesis, the user’s current prosthesis, and a benchmark group of 13 able-bodied subjects. Results indicated a decrease in compensatory motions of the trunk, head, and shoulder angles in certain activities, but an increase in time to complete the task with the new design. Feedback from the prosthesis user favoured the functionality provided by the wrist rotator and associated control strategy.