Myoelectric Control System and Task-Specific Characteristics Affect Voluntary Use of Simultaneous Control

• Published in: IEEE transactions on neural systems and rehabilitation engineering 2016-01, Vol.24 (1), p.109-116
• Main Authors: Smith, Lauren H., Kuiken, Todd A., Hargrove, Levi J.
• Format: Article
• Language: English
• Subjects: Algorithms; Auditoriums; Complexity theory; Control systems; Electromyography; Electromyography - methods; Feedback, Physiological - physiology; Female; Fitts' Law; Humans; intramuscular electromyography; Male; Mathematical analysis; Movement - physiology; Movements; Muscle Contraction - physiology; Muscle, Skeletal - physiology; Muscles; Myoelectric control; Myoelectricity; Postural Balance - physiology; Proportional control; Prostheses; prosthesis control; Rehabilitation; Renovation & restoration; School environment; School safety; Sequential control; Stability; Strategy; Task Performance and Analysis; Tasks; User-Computer Interface; Velocity; Velocity control; Volition - physiology; Wrist; Young Adult
• ISSN: 1534-4320; 1558-0210
• DOI: 10.1109/TNSRE.2015.2410755

Clinically available myoelectric control does not enable simultaneous proportional control of prosthetic degrees of freedom. Multiple studies have proposed systems that provide simultaneous control, though few have investigated whether subjects voluntarily use simultaneous control or how they implement it. Additionally, few studies have explicitly evaluated the effect of providing proportional velocity control. The objective of this study was to evaluate factors influencing when and how subjects use simultaneous myoelectric control, including the ability to proportionally control the velocity and the required task precision. Five able-bodied subjects used simultaneous myoelectric control systems with and without proportional velocity control in a virtual Fitts' Law task. Though subjects used simultaneous control to a substantial degree when proportional velocity control was present, they used very little simultaneous control when using constant-velocity control. Furthermore, use of simultaneous control varied significantly with target distance and width, reflecting a strategy of using simultaneous control for gross cursor positioning and sequential control for fine corrective movements. These results provide insight into how users take advantage of simultaneous control and highlight the need for real-time evaluation of simultaneous control algorithms, as the potential benefit of providing simultaneous control may be affected by other characteristics of the myoelectric control system.