Can Iterative Learning Control be used in the Re-education of Upper Limb Function, Mediated by Functional Electrical Stimulation (FES)?

Abstract

Introduction There is a body of clinical evidence to support the use of FES to improve motor control (De Kroon et al. 2002) and theoretical support from neurophysiology (Burridge & Ladouceur 2001) and motor learning research (Schmidt & Lee 1999). Iterative learning control has its origins in the control of processes that repetitively perform a task with a view to improving accuracy. The classic example is the area of trajectory following in robotics but can it be usefully applied to neurological rehabilitation? Method To answer this question, the ability of 10 patients to track a 2 D pattern using a robot arm, over a number of trials is being tested. We are designing an algorithm to control FES of appropriate muscles in terms of timing and amplitude to improve tracking. Subsequently the stimulation will be reduced to encourage optimal voluntary contribution to the task. To achieve this, a model is being created using unimpaired subjects to identify activation patterns with respect to joint positions. This will inform when we need to apply stimulation (although we expect patients to differ due to spasticity). In the initial phase surface EMGs have been collected from triceps, biceps, anterior deltoid, upper, middle and lower trapezius and pectoralis major during 9 reaching tasks. The EMG data will identify which muscles to control, be used in the controller, and to compare differences between stroke and unimpaired subjects. The next phase involves collecting data using the robot both with and without stimulation and then applying different control algorithms. Results Surface EMG results and analysis from 10 unimpaired subjects will be presented. Preliminary analysis on EMGs from 8 subjects shows evidence that reciprocal inhibition of upper trapezius occurs during maximum reach. If successful the concept could be used for other neurological conditions such as cerebral palsy and incomplete spinal injury. References Burridge, J. H. & Ladouceur, M. 2001, "Clinical and therapeutic applications of neuromuscular stimulation: A review of current use and speculation into future developments", Neuromodulation, vol. 4, no. 4, pp. 147-154. De Kroon, J. R., van der Lee, J. H., Izerman, M. J., & Lankhorst, G. J. 2002, "Therapeutic electrical stimulation to improve motor control and functional abilities of the upper extremity after stroke: a systematic review", Clinical Rehabilitation, vol. 16, pp. 350-360. Schmidt, R. A. & Lee, T. D. 1999, Motor control and learning a behavioural emphasis. 3rd Edition Human Kinetics Part 3 Motor Learning.

More information

Identifiers

ORCID for A.M. Hughes: orcid.org/0000-0002-3958-8206

ORCID for P.L. Lewin: orcid.org/0000-0002-3299-2556

ORCID for E. Rogers: orcid.org/0000-0003-0179-9398

Catalogue record

Export record