Comparison of control strategies for an EMG controlled orthotic exoskeleton for the hand

• Published in: 2004 IEEE International Conference on Robotics and Automation Vol. 2; pp. 1622 - 1627 Vol.2
• Main Authors: DiCicco, M., Lucas, L., Matsuoka, Y.
• Format: Conference Proceeding
• Language: English
• Published: Piscataway NJ IEEE 2004
• Subjects: Applied sciences; Computer science; control theory; systems; Control system synthesis; Control theory. Systems; Design engineering; Electric variables control; Electromyography; Exact sciences and technology; Exoskeletons; Fasteners; Feedback; Fingers; Muscles; Orthotics; Signal restoration; Dexterity; Control synthesis; Electromyography; Skeleton; Arm; Hand; Deformable body
• ISBN: 9780780382329; 0780382323
• ISSN: 1050-4729
• DOI: 10.1109/ROBOT.2004.1308056

To restore dexterity to paralyzed hands, we have designed and constructed a lightweight, low-profile orthotic exoskeleton controlled by the user's residual electromyography (EMG) signals. In this paper, we compared several simple strategies to control the orthotic device for a quadriplegic (C5/C6) subject. When contralateral arm control was employed, we found that a simple on/off strategy allowed for faster interaction with objects, while variable control provided more controlled interactions, especially with deformable objects. Furthermore, we designed a control strategy that allowed for a natural reaching and pinching sequence without the use of the contralateral arm. We validated that the EMG signal from the ipsilateral biceps could be used to develop an extremely reliable natural reaching and pinching algorithm. This evaluation showed that different control strategies may be appropriate for different situations, and further investigation on the natural algorithm is crucial.