A proof-of-principle study published in the Journal of Neuroengineering and Rehabilitation reports on the first successful integration of a noninvasive electroencephalogram (EEG)-based brain computer interface (BCI) with a noninvasive Food & Drug Administration (FDA)-approved functional electrical stimulation (FES) system that enables the direct brain control of foot dorsiflexion in able-bodied individuals. The study has implications for the neuro-rehabilitation of individuals with lower-limb paralysis due to neurological injury, according to the team of researchers from the University of California – Irvine (UCI).
Photograph of the experimental setup courtesy of the study authors and the Journal of Neuroengineering and Rehabilitation.
Five able-bodied subjects underwent computer-cued epochs of repetitive foot dorsiflexion and idling while their EEG signals were recorded via an EEG cap and sent to a bioamplifier and then to the BCI computer for analysis. The computer then sends commands to an FES device by means of the micro-controller unit (MCU). The FES device then stimulates the tibialis anterior (TA) muscle of the foot, thereby causing contralateral dorsiflexion.
The epochs of BCI-FES mediated foot dorsiflexion were highly correlated with the epochs of voluntary foot dorsiflexion. In addition, all subjects achieved a 100 percent BCI-FES response (no omissions), and one subject had a single false alarm.
The results suggest that a modified BCI-FES system may offer a therapy for the neuro-rehabilitation of individuals with lower-limb paralysis or foot drop due to neurological injury such as stroke, spinal cord injury, or traumatic brain injury, offering an alternative to current physiotherapy techniques that may provide only a limited degree of motor function recovery in these individuals, according to the researchers.
