• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.125-130
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• 1989

In the present study, we described a test to explore the function of optokinetic system which subjected to a full visual field stimulation using two different stimulus images patterns. Our results were interesting in a point of view that the stimulation image pattern had non- neglisible influence on the optokinetic response and that in a bidimensionnel image such as the randomly distributed spots images pattern the linearity of system was assured upto the stimulus velocity of about 50 deg/sec for normal subject. As for measuring human optokinetic after nystagmus, the regular stripes pattern was rather desirable than the randomly distributed spots pattern in this study.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.247-254
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• 1990

Chicken monocular head and eye optokinetic nystagmus (OKN) were observed by coil recordings after intravitreal administration of GABA antagonists (picrotoxin and bicuculline) into the opened and closed eye. Before injection of drugs the chicken displayed an OKN for T-N stimulation being more efficient in evoking this visuomotor reflex than for N-T stimulation. The injection of GABA antagonist into the opened eye provoked a decrease or disappearance of the head and eye OKN. On the other hand, the injection of GABA antagonist into the closed eye, the head and eye OKN augmented. Thus, GABA antagonist abolished the directional asymmetry of the head and eye OKN, indicating the involvement of GABAergic mechanisms in the inhibition of the N-T component of the monocular OKN.

• Therapeutic Science for Rehabilitation
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• v.5 no.2
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• pp.81-92
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• 2016

Objective: This study aim is to identify whether 30minutes optokinetic stimulation(OKS) with smooth pursuit eye movement can alleviate chronic hemispatial neglect. Methods: We applied optokinetic stimulation with smooth pursuit eye movement to 2 chronic hemispatial neglect patients. experimental duration was total 4weeks - 1week baseline, 2weeks OKS intervention, 1week 2nd. baseline. The intervention was 10 OKS sessions (30min each, 1session daily, from Monday to Friday) over a period of 2weeks. The neglect test carried out 3 times a week every other day. The OKS was provided on the screen when patient sat in front of the screen(13.5 inch). The OKS video that the 24 yellow squares moving coherently from the right to the left side. Patients were instructed to perform smooth pursuit eye movement without head and neck movement. Results: As a result of the OKS for 2weeks, the degree of neglect trends to decrease on both 2 cases compared to baseline A. The degree of the neglect of subject 1 tended to increase the at the baseline A. In contrast, the subject 2 showed that tendency that the degree of the neglect declined additionally at the baseline A. Conclusions: We identified that 30 minutes optokinetic stimulation with sooth pursuit eye movement is effective intervention method for chronic hemispatial neglect.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.237-242
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• 1999

The nature of the interactions between the vestibular and autonomic systems is complex and has not been fully defined. Vestibuloocular reflex induced by sinusoidal rotation and activity of the autonomic nerves in the heart were measured to investigate the interactions between the vestibular system and the autonomic nervous system in healthy adults. Eye movement induced by sinusoidal rotation of the whole body or optokinetic stimulation at 0.04 Hz was analyzed in gain, phase, and symmetry. EKG was measured during vestibular stimulation and analyzed in heart rate variability including mean R-R interval, standard deviation (SD) and coefficient of variance (CV) of R-R interval, and power spectrum of low frequency region (LF) and high frequency region (HF). Gain of eye movement was 0.65${\pm}$0.03 by ratatory stimulation, 0.70${\pm}$0.02 in optokinetic stimulation, 0.08${\pm}$0.02 in visual suppression, and 0.84${\pm}$0.04 in visual enhancement. In R-R interval, resting condition (control) was 0.82${\pm}$0.03 sec, and visual suppression showed significant increase and visual enhancement did significant decrease compared with control (p<0.01).CV was 0.06${\pm}$0.02 in control and visual enhancement increased significantly (p<0.05). In LF/HF control was 1.40${\pm}$0.23, which was not different from rotatory or optokinetic stimulation. But visual suppression decreased LF/HF significantly and visual enhancement increased significantly compared with control (p<0.01). These results suggest that degree of gain corresponds with LF/HF and increased gain in visual enhancement is deeply related to the activity of sympathetic nerves.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.133-140
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• 1990

In monocular vision, bead and eye optokinetic nystagmus (OKN) display directionnal asymmetry, in lower vertebrates such as chickens, T-N stimulation being more efficient in evoking this visuomotor reflex than N-T stimulation. The N-T component of monocular OKN is significantly weaker in chickens. Coil recordings and observation showed that in adult chickens, prolonged monocular visual deprivation by unilateral eyelid suture provoked significant and progressive increase of the N-T component in chickens. This plasticity phenomenon involved the eye and head OKN in chickens. The administration of THIP, a GABA agonist, abolished reversibly the increase of the N-T component in chickens. This fact suggests that the GABAergic system could be involved in determining this plasticity phenomenon observed in adult lower vertebrates.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.628-631
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• 2000

A new control method for precision robust speed control of a PMSM(Permanent Magnet Synchronous Motor) using load torque observer is presented. With this system we can obtain more reliable eye moving singal(nystagmus) Until now rotating chair system which is called 2D-optokinetic stimulator is used to make dizzincess. However an inclined rotating chair system witch is 3D-optokinetic stimulator is needed to obtain the precise dizziness data. This 3D-optokinetic sitimulator include unbalanced load aused by unbalanced center of mass. For this case new compensation method is considered to obtain robust speed control using load torque observer. To reduce the effect of this disturbance we can use dead-beat observer which has high gain. The application of the load torque observer is published in [1] for position control. A problem of using speed information such as amplifying effect of noise is reduce by moving average process. The experimental results are depicted in this paper to show the effect of this proposed algorithm.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.157-162
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• 1997

The purpose of this study was to develop a sinusoidal rotatory chair systim for evaluating the vestibular function in patients suffered from vertigo with vestibualr disorders. The sinusoidal rotatory chair system is composed of a rotatory chair systim and softwares. Maximum velocity of the rotatiry chair was upto 60 degree per second and frequency range was 0.01 to 0.64 Hz. To evaluate the vestibular function in vertigo patients, vestibuloocular reflex was measured by sinusoidal rotation of the whole body about vertical axis in the darkness, and optokinetic nystagmus, visual vestibuloocular reflex , and visual supression test were also performed. Eye movement was measured by means of a electronystgmograph amplifier through Ag-AgCI surface electrodes. Gain, phase, and symmetry were obtained from analysis of the eye movement ineuced by vestibular or visual stimulation. In healthy adults, sinusoidal rotation of the shole body produced nystagmus, of which gain was directly proportional to the velocity of stimulation. The gain of visual vestibuloocular reflex or optokinetic nystagmus, and it was suppressed markedly by visual suppression test. These results suggest that the sinusoieal rotatory chair systim which was developed by this study can evaluate the vestibular function quantitatively, also this system is very useful to diagnose and to dstimate the vestibualr function during recovery from vertigo

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.1-11
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• 1996

The SR 95531, a GABA antagonist was microinjected into either the pretectum nuclei (nucleus Superficialis Synencephali nSS) or the nBOR (nucleus Ectomammilaris nEM) of chickens. Monocular optokinetic nystagmus (01(N) was reorded by the search coil technique before and after unilateral intracerebral drug administration. Unilateral microinjections of SR 95531 into either the nSS or nEM induce a reversible increase of gain in OKN directed by contralateral eye for both directions of stimulation. The administration into the nSS increased directional asymmetry by increasing the T~ component velocity gain more strongly than the N-T component velocity gain. On the other hand, the unilateral administration of the drug into the nEM suppressed the diretional O1(N asymmetry by increasing the N-T component velocity gain more strongly than the T-N component velocity gain. The nSS seems especially involved in monocular OKN in response to a T-N stimulation, while the nEM seems more involved in the OKN response to N-T stimulation. These results indicate that the drug suppresses GABAergic inhibition at the mesencephalic level. The increase in gain of OKN directed by the ipsilateral eye to microinjeded nuclei could account for the strong interactions existing between these two mesencephalic structures responsible for horizontal OKN.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.3-6
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• 1999

The study was performed to evaluate the sense of equilibrium by means of rotary chair system in middle school girls with dance learning. Control of equilibrium, which is the most important function in dancing, is maintained by vestibular, visual, and proprioceptive inputs. Experimental groups were divided into trained group with dance (experimental group, 13~14 ys, n=15) and untrained group (control group, 13~14 ys, n=15). experimental group was trained by programmed dancing for 12 weeks, 45 min/day and 5 day/week. Gain of eye movement was measured for vestibulocular reflex (VOR), visual vestibular stimulation (VVOR), optokinetic stimulation(OKN), and visual fixation (VFX). The gain of eye movement at higher than 0.08 hz was significant decrease in experimental group, and VVOR showed the similar fashion to VOR. The gain in OKN and VFX was not significant difference between experimental and control groups. These results suggest that programmed training of dancing improves control of balance by adaptation of the vestibular function, and rotary chair system would be useful to evaluate the sense of equilibrium ability.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.6
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• pp.524-530
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• 2002

A control of the body posture and movement is maintained by the vestibular system, vision, and proprioceptors. Afferent signals from those receptors are transmitted to the vestibular nuclear complex, and the efferent signals from the vestibular nuclear complex control the eye movement and skeletal muscle contract. The postural disturbance caused by loss of the vestibular function results in nausea, vomiting, vertigo and loss of craving for life. The purpose of this study is to develop a off-vertical rotatory system for evaluating the function of semicircular canals and otolith organs, selectively, and visual stimulation system for- stimulation with horizontal, vortical and 3D patterns. The Off-vortical axis rotator is composed of a comportable chair, a DC servo-motor with reducer and a tilting table controlled by PMSM. And a double feedback loop system containing a velocity feedback loop and a position feedback loop is applied to the servo controlled rotatory chair system. Horizontal, vertical, and 3D patterns of the visual stimulation for applying head mounted display are developed. And wireless portable systems for optokinetic stimulation and recording system of the eye movement is also constructed. The gain, phase, and symmetry is obtained from analysis of the eye movement induced by vestibular and visual stimulation. Detailed data were described.