Control Scheme for Independent Thumb Motion in a Myoelectrically Controlled Hand Prosthesis

摘要

This study presents a three control degrees of freedom myoelectric control scheme that employs an independent signal for thumb flexion intended to allow for multiple gripping patterns. This scheme is designed to work with an adaptive grasp prosthesis designed in a parallel study. The control scheme is designed and employed using LabVIEW 8.2~R. Human subject testing is conducted to evaluate functionality, perceived ease of learning, and perceived ease of control for both genders. Testing indicated that independent control of thumb flexion and generating DC motor drive signals for multiple grips was possible (success rate >=83%). A visual analog scale score of 9.28/10 indicated that the system and the program user interface were very easy to learn. A visual analog scale score of 6.3/10 indicated that the system was fairly easy to control. A marginally significant difference (p = 0.057) was observed between genders, where females perceived the system to be easier to control than males.