title: Biopotentials as command and feedback signals in functional electrical stimulation systems.
abstract: Today Functional Electrical Stimulation (FES) is available as a clinical tool in muscle activation used for picking up objects, for standing and walking, for controlling bladder emptying, and for breathing. Despite substantial progress in development and new knowledge, many challenges remain to be resolved to provide a more efficient functionality of FES systems. The most important task of these challenges is to improve control of the activated muscles through open loop or feedback systems. Command and feedback signals can be extracted from biopotentials recorded from muscles (Electromyogram, EMG), nerves (Electroneurogram, ENG), and the brain (Electroencephalogram (EEG) or individual cells). This paper reviews work in which EMG, ENG, and EEG signals in humans have been used as command and feedback signals in systems using electrical stimulation of motor nerves to restore movements after an injury to the Central Nervous System (CNS). It is concluded that the technology is ready to push for more substantial clinical FES investigations in applying muscle and nerve signals. Brain-computer interface systems hold great prospects, but require further development of faster and clinically more acceptable technologies.
authors.affiliation: Center for Sensory-Motor Interaction, Aalborg University, Fredrik Bajers Vej 7D-3, DK-9220 Aalborg, Denmark. ts@smi.auc.dk
authors.forename: Thomas
authors.initials: T
authors.lastname: Sinkjaer
authors.forename: Morten
authors.initials: M
authors.lastname: Haugland
authors.forename: Andreas
authors.initials: A
authors.lastname: Inmann
authors.forename: Morten
authors.initials: M
authors.lastname: Hansen
authors.forename: Kim D
authors.initials: KD
authors.lastname: Nielsen
mesh_terms: D000200:Action Potentials; D000465:Algorithms; D002493:Central Nervous System Diseases / Q000534:rehabilitation; D004599:Electric Stimulation Therapy / Q000379:methods*; D004568:Electrodiagnosis / Q000379:methods; D004569:Electroencephalography / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D005246:Feedback; D005534:Foot Diseases / Q000503:physiopathology; D020233:Gait Disorders, Neurologic / Q000534:rehabilitation; D006225:Hand / Q000503:physiopathology; D006801:Humans; D016571:Neural Networks, Computer; D010525:Peripheral Nerves / Q000503:physiopathology; D011782:Quadriplegia / Q000534:rehabilitation; D012815:Signal Processing, Computer-Assisted