Somatosensory evoked potentials elicited by air-puff stimuli generated by a new high-speed air control system

Sharp-fronted air-puffs (a rise-time of 1 msec) generated by the new high-speed air control system were used for eliciting SEPs. This system employs a rotating disk driven by a synchronous electric motor for high-speed control of air flow from a compressed air source. The air-puff is reproducible and its pressure wave form can be varied. SEPs to air-puffs or electrical stimulations of the right hand recorded from the contralateral parietal scalp had similar wave forms, but SEPs to air-puffs showed longer latencies (1-4 msec) and smaller amplitudes than those to electrical stimuli. The amplitude of early components in air-puff SEPs was on average 30% of that in electrical SEPs, but later components reached up to about 90%.