DocumentCode :
923007
Title :
Control strategies for integration of electric motor assist and functional electrical stimulation in paraplegic cycling: utility for exercise testing and mobile cycling
Author :
Hunt, Kenneth J. ; Stone, Barry ; Negård, Nils-Otto ; Schauer, Thomas ; Fraser, Matthew H. ; Cathcart, Andrew J. ; Ferrario, Chiara ; Ward, Susan A. ; Grant, Stan
Author_Institution :
Dept. of Mech. Eng., Univ. of Glasgow, UK
Volume :
12
Issue :
1
fYear :
2004
fDate :
3/1/2004 12:00:00 AM
Firstpage :
89
Lastpage :
101
Abstract :
Aim: The aim of this study was to investigate feedback control strategies for integration of electric motor assist and functional electrical stimulation (FES) for paraplegic cycling, with particular focus on development of a testbed for exercise testing in FES cycling, in which both cycling cadence and workrate are simultaneously well controlled and contemporary physiological measures of exercise performance derived. A second aim was to investigate the possible benefits of the approach for mobile, recreational cycling. Methods: A recumbent tricycle with an auxiliary electric motor is used, which is adapted for paraplegic users, and instrumented for stimulation control. We propose a novel integrated control strategy which simultaneously provides feedback control of leg power output (via automatic adjustment of stimulation intensity) and cycling cadence (via electric motor control). Both loops are designed using system identification and analytical (model-based) feedback design methods. Ventilatory and pulmonary gas exchange response profiles are derived using a portable system for real-time breath-by-breath acquisition. Results: We provide indicative results from one paraplegic subject in which a series of feedback-control tests illustrate accurate control of cycling cadence, leg power control, and external disturbance rejection. We also provide physiological response profiles from a submaximal exercise step test and a maximal incremental exercise test, as facilitated by the control strategy. Conclusion: The integrated control strategy is effective in facilitating exercise testing under conditions of well-controlled cadence and power output. Our control approach significantly extends the achievable workrate range and enhances exercise-test sensitivity for FES cycling, thus allowing a more stringent characterization of physiological response profiles and estimation of key parameters of aerobic function. We further conclude that the control approach can significantly i- - mprove the overall performance of mobile recreational cycling.
Keywords :
bioelectric phenomena; biomechanics; handicapped aids; medical control systems; neuromuscular stimulation; patient rehabilitation; pneumodynamics; aerobic function; analytical feedback design methods; cycling cadence; electric motor assist; exercise testing; external disturbance rejection; feed back control strategies; functional electrical stimulation; leg power output; maximal incremental exercise test; mobile cycling; mobile recreational cycling; paraplegic cycling; physiological measures; physiological response profiles; pulmonary gas exchange; real-time breath-by-breath acquisition; recumbent tricycle; submaximal exercise step test; system identification; ventilatory gas exchange; workrate; Automatic control; Centralized control; Electric motors; Electric variables measurement; Feedback control; Instruments; Leg; Neuromuscular stimulation; Particle measurements; Testing; Algorithms; Bicycling; Electric Stimulation Therapy; Energy Transfer; Exercise Test; Feedback; Humans; Leg; Male; Models, Biological; Paraplegia; Respiratory Function Tests; Systems Integration;
fLanguage :
English
Journal_Title :
Neural Systems and Rehabilitation Engineering, IEEE Transactions on
Publisher :
ieee
ISSN :
1534-4320
Type :
jour
DOI :
10.1109/TNSRE.2003.819955
Filename :
1273527
Link To Document :
بازگشت