Concentric electrodes for producing acupuncture-like anesthetic effects

Abstract

We designed concentric electrodes composed of a center electrode and an outer ring electrode. Electrical stimulation with two sets of such electrodes for 15 min as conditioning stimuli was given to the left hand of 35 adult subjects to induce acupuncture-like anesthetic effects. The effects immediately after the conditioning were compared between stimulation through a pair of center electrodes alone at 3 Hz (conditioning 1) and simultaneous stimulation of 3 Hz through a pair of center electrodes and 100 Hz through a pair of outer ring electrodes (conditioning 2). In conditioning 2, modulating effects of 100 Hz stimuli through a pair of outer ring electrodes made it possible to increase the voltage strength of 3 Hz stimuli through a pair of center electrodes with maintaining the minimum perception of pricking sensation. In both conditioning procedures, muscle twitching was not accompanied. It was found that the respective stimulating current thresholds for faint touch sensation and also for pricking sensation at the right forearm could be elevated significantly more by conditioning 2 (1.54 and 1.40 times) than by conditioning 1 (1.20 and 1.14 times).