전기자극과 VOG(Videooculograph)를 이용한 정상인의 전정 안반사 측정

Abstract

In this study, a galvanic stimulator providing bipolar mode controlled by a PIC(peripheral interface controller) was constructed to evaluate vestibular function. The maximum load and maximum current intensity of the constant current source were 3㏀ and 5㎃, respectively, and it could produce DC, sine waves, or pulse waves. Eye movements of 20 normal subjects by galvanic stimulation were analyzed using a commercial videooculograph. During stimulation with DC for 30 sec, we recorded the response of eye movement with current intensity of 0.75, 1, 2, and 3㎃. Nystagmus occurred to all the subjects when the galvanic stimulus intensity was larger than 2㎃. Average SPV(slow phase eye movement velocity) and the number of nystagmus increased from 1.1 to 4.8 deg/sec and from 17 to 48, respectively, when the stumulus current increased from 0.75 to 3㎃. All the fast eye movement of the nystagmus were the direction of the negative electrode. The asymmetry which means the difference between right- and left-eye movements decreased when the stimulus intensity increased. It is expected that this study would be useful in evaluating vestibular function and in studying basic physiology mechanism of vestibular ocular reflex by galvanic stimulus.