Patient-driven loop control for hand function restoration in a non-invasive functional electrical stimulation system.
OBJECTIVE
In this study, a patient-driven loop control in a non-invasive functional electrical stimulation (FES) system was designed to restore hand function of stroke patients with their residual capabilities.


METHODS
With this patient-driven loop control, patients use the electromyographic (EMG) signals from their voluntary controlled muscles in affected limbs to adjust stimulus parameters of the system. A special designed FES system generated electrical stimuli to excite the paralyzed muscles through surface electrodes on the basis of the control command from the residual myoelectric signals. EMG signals were also served as the trigger and the adjustment of stimulus parameters and thereby adding versatility of the FES system. Four stroke patients were recruited in the experiment to validate our system.


RESULTS
The experimental results showed that hemiplegics could successfully control the system to restore their lost hand functions with the strategy of patient-driven loop control (the average estimated success rate was 77.5% with the tasks of cylindrical grasp and lateral pinch); and further, they would benefit by using the residual capabilities to regain their hand functions from the viewpoints of rehabilitation and psychology.


CONCLUSIONS
According to the experiment results, this patient-driven loop control can be beneficial for hemiplegics to restore their hand functions such as cylindrical grasp and lateral pinch. The control strategy of this study has the potential to be employed not only in the FES system but also in other assistive devices.
Chiou
Ying-Han
YH
Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, R.O.C.
Luh
Jer-Junn
JJ
Chen
Shih-Ching
SC
Chen
Yu-Luen
YL
Lai
Jin-Shin
JS
Kuo
Te-Son
TS
D000328:Adult; D016022:Case-Control Studies; D004599:Electric Stimulation Therapy / Q000295:instrumentation* / Q000379:methods; D004576:Electromyography; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006429:Hemiplegia / Q000209:etiology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D010865:Pilot Projects; D020521:Stroke / Q000150:complications