title: Using human extra-cortical local field potentials to control a switch.
abstract: Individuals with profound paralysis and mutism require a communication channel. Traditional assistive technology devices eventually fail, especially in the case of amyotrophic lateral sclerosis (ALS) subjects who gradually become totally locked-in. A direct brain-to-computer interface that provides switch functions can provide a direct communication channel to the external world. Electroencephalographic (EEG) signals recorded from scalp electrodes are significantly degraded due to skull and scalp attenuation and ambient noise. The present system using conductive skull screws allows more reliable access to cortical local field potentials (LFPs) without entering the brain itself. We describe an almost locked-in human subject with ALS who activated a switch using online time domain detection techniques. Frequency domain analysis of his LFP activity demonstrates this to be an alternative method of detecting switch activation intentions. With this brain communicator system it is reasonable to expect that locked-in, but cognitively intact, humans will always be able to communicate.
authors.affiliation: Neural Signals Inc., 3688 Clearview Avenue, Atlanta, GA 30340, USA. phlkennedy@neuralsignals.com
authors.forename: Philip
authors.initials: P
authors.lastname: Kennedy
authors.forename: Dinal
authors.initials: D
authors.lastname: Andreasen
authors.forename: Princewill
authors.initials: P
authors.lastname: Ehirim
authors.forename: Brandon
authors.initials: B
authors.lastname: King
authors.forename: Todd
authors.initials: T
authors.lastname: Kirby
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
authors.forename: Melody
authors.initials: M
authors.lastname: Moore
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology* / Q000534:rehabilitation*; D002540:Cerebral Cortex / Q000503:physiopathology*; D003143:Communication Devices for People with Disabilities; D004569:Electroencephalography / Q000379:methods*; D005071:Evoked Potentials; D005528:Foot / Q000503:physiopathology; D006801:Humans; D018482:Muscle, Skeletal / Q000503:physiopathology; D014584:User-Computer Interface