• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.487-496
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• 2001

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$k\Omega$ and 5mA. respectively. and it could Produce DC, sine wavers. or Pulse waves. Eve movements of 20 normal subjects by galvanic stimulation were analyzed using a commercial videooculogragh. During stimulating with DC for 30 sec. we recorded the response of eye movement with current intensity of 0.75. 1 2, and 3 mA. Nystagmus occurred to all the subjects when the galvanic stimulus intensity was larger than 2 mA. Average SPV(slow Phase eye movement velocity) and the number of nystagmus increased from 7.1 to 4.8 deg/sec and from 17 to 48, respectively, when the stimulus current increased from 0.75 to 3 mA. 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 .

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.3
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• pp.189-198
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• 2003

Videooculography (VOG) is one of the eye-movement measurement methods used for objective evaluation of vestibule -ocular reflex. A key feature of VOG is to estimate accurately the center of pupil and ocular torsion with being less influenced by the upper eyelid droop, eyelashes, corneal reflection, and eye blinks. Especially, it Is important to find the accurate center of the pupil in 3-D VOG because the inaccurate pupil center causes significant errors on measuring torsional eye movement. A new algorithm was proposed to find the center of pupil which is a little influenced by factors mentioned above. In this study, real time three-dimensional VOG which can measure horizontal, vortical, torsional eye movements, and the diameter of pupil was implemented using the proposed method.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2741-2744
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• 2003

본 연구에서는 전기 전정 자극(GVS, Galvanic vestibular stimulation)이 일측 전정 기능 소실 환자에게서 정상인과 어떠한 특이성을 보이는가에 대하여 관찰하였다. 실험대상은 14 명(남:5, 여:9)의 일측 전정 기능 소실 환자(경와우절제술 12 례, 전정신경 절제술 2 례)로 자극 방법은 bipolar 로 하여 전류 세기를 1mA에서 3mA 까지 달리하며 실험하였다. GVS 에 대한 반응은 영상 안진기(VOG, Videooculograrh)를 이용하여 관찰하였다. 정상 기능이 있는 측면으로의 자극에 대해서는 정상인과 동일한 반응을 보였으나 일측 전정 기능 소실(unilateral loss)을 갖는 환자의 경우 병변이 있는 쪽에 음의 자극, 없는 쪽에 양의 자극을 가하였을 경우에는 대상자 모두에게서 어떠한 안진 반응도 일어나지 않았다. 자극 후 안진의 경우 정상인은 일반적으로 나타나지 않으나 피검자들에게서는 나타나는 특성을 보였다.