Title :
Closed-loop recruitment and frequency modulation of antagonistic muscles during co-activation in FNS
Author :
Lan, Ning ; Crago, Patrick E. ; Chizeck, Howard J.
Author_Institution :
Dept. of Biomed. & Syst. Eng., Case Western Reserve Univ., Cleveland, OH, USA
Abstract :
Coactivation of electrically antagonistic muscles provides resistance to external disturbances and continuity of bidirectional activation. A closed-loop controller for simultaneous pulse-width (PW) and stimulus-period (SP) modulation during cocontraction of antagonists has been developed. This PW+SP controller consists of a modified proportional-plus-integral (PI) control law and an SP modulation algorithm that modulates the stimulus frequency of the antagonists in a push-pull manner. The control algorithm is evaluated for the control of joint position and load transition using a cat hindlimb. Faster net force production in the desired direction and improved performance were achieved when compared with the PI controller with PW modulation alone.<>
Keywords :
biocontrol; closed loop systems; muscle; neurophysiology; patient treatment; cat hindlimb; closed-loop controller; closed-loop recruitment; electrically antagonistic muscles; frequency modulation; joint position; load transition; muscles coactivation; pulse-width modulation; stimulus-period modulation;
Conference_Titel :
Engineering in Medicine and Biology Society, 1988. Proceedings of the Annual International Conference of the IEEE
Conference_Location :
New Orleans, LA, USA
Print_ISBN :
0-7803-0785-2
DOI :
10.1109/IEMBS.1988.94656
