• 한국동물학회지
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• 제33권3호
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• pp.247-254
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• 1990

GABA antagonist 를 닭의 열린 눈과 닫힌 눈에 차례로 주입한 후 monocular head와 eye optokinetic nystagmus을 관찰하고 코일 기록에 의해서 연구하였다. 주입전 이 visuomotor reflex를 일으키는데 있어서 닭은 N-T 자극에 대해서 보다 T-N 자극에 대해서 더욱 효과적인 OKN을 나타냈다. 열린눈에 주입한 GABA antagonist는 head와 eye OKN의 감소 또는 소멸을 일으키며, GABA antagonist를 닫힌 눈속에 주입했을 때는 head와 eye OKN은 증가 되었다. 이와 같이 GABA antagonist는 monocular OKN의 N-T 성분을 억제하는데 GABAergic 메카니즘이 관련되고 있다는 것을 지시함으로써 head와 eye OKN의 방향적 불균형성을 제거하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.33-35
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• 2005

We propose an eye gaze tracking system under natural head movements. The system consists of one CCD camera and two front-surface mirrors. The mirrors rotate to follow head movements in order to keep the eye within the view of the camera. However, the mirror controller cannot guarantee the fast head movements, because the frame rate is generally 30Hz. To overcome this problem, we applied Kalman predictor to estimate next eye position from the current eye image. In the results, our system allows the subjects head to move 50cm horizontally and 40cm vertically, with the speed about 10cm/sec and 6cm/sec, respectively. And spatial gaze resolutions are about 4.5 degree and 4.5 degree, respectively, and the gaze estimation accuracy is 92% under natural head movements.

• The Korean Journal of Physiology
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• 제22권1호
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• pp.79-88
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• 1988

The effect of cervical proprioceptors on the control of eye movement and body posture was examined in unanesthetized labyrinthine intact and bilateral labyrinthectomized cats. Cervico-ocular reflex(COR) was elicited by stimulation of the cervical proprioceptors by means of sinusoidal rotation of head or body in the darkness. The following results were obtained: 1) In labyrinthine intact cats, sinusoidal rotation of the whole body elicited compensatory eye movement(vestibulo-ocular reflex: VOR); the direction of eye movement was opposite to the direction of head rotation. 2) Anticompensatory eye movement was observed by sinusoidal rotation of the body with head fixed in labyrinthine intact cats; the direction of eye movement was the same as the direction of head rotation. 3) Compensatory eye movement was observed by sinusoidal rotation of the head with body fixed or sinusoidal rotation of the body with head fixed in both acute and chronic bilateral labyrinthectomized cats. These results suggest that the cervical proprioceptors are important in the control of ocular movement and posture in the bilateral labyrintectomized cats, although they are questionable in labyrinthine intact cats.

• 대한인간공학회지
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• 제19권1호
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• pp.77-90
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• 2000

The aim of this study is to develop and evaluate an efficient camera calibration method for vision-based head tracking. Tracking head movements is important in the design of an eye-controlled human/computer interface. A vision-based head tracking system was proposed to allow the user's head movements in the design of the eye-controlled human/computer interface. We proposed an efficient camera calibration method to track the 3D position and orientation of the user's head accurately. We also evaluated the performance of the proposed method. The experimental error analysis results showed that the proposed method can provide more accurate and stable pose (i.e. position and orientation) of the camera than the conventional direct linear transformation method which has been used in camera calibration. The results of this study can be applied to the tracking head movements related to the eye-controlled human/computer interface and the virtual reality technology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.1087-1104
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• 2015

An eye location based head posture recognition method is proposed in this paper. First, face is detected using skin color method, and eyebrow and eye areas are located based on gray gradient in face. Next, pupil circles are determined using edge detection circle method. Finally, head postures are recognized based on eye location information. The proposed method has high recognition precision and is robust for facial expressions and different head postures, and can be used in mouse operation. The experimental results reveal the validity of proposed method.

• Annals of Clinical Neurophysiology
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• 제1권2호
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• pp.173-181
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• 1999

Eye movements serve vision by placing the image of an object on the fovea of each retina, and by preventing slippage of images on the retina. The brain employs two modes of ocular motor control, fast eye movements (saccades) and smooth eye movements. Saccades bring the fovea to a target, and smooth eye movements prevent retinal image slip. Smooth eye movements comprise smooth pursuit, the optokinetic reflex, the vestibulo-ocular reflex (VOR), vergence, and fixation. Saccades achieve rapid refixation of targets that fall on the extrafoveal retina by moving the eyes at peak velocities that can exceed $700^{\circ}/s$. Various brain lesions can affect saccadic latency, velocity, or accuracy. Smooth pursuit maintains fixation of a slowly moving target. The pursuit system responds to slippage of an image near the fovea in order to accelerate the eyes to a velocity that matches that of the target. When smooth eye movements velocity fails to match target velocity, catch-up saccades are used to compensate for limited smooth pursuit velocities. The VOR subserves vision by generating conjugate eye movements that are equal and opposite to head movements. If the VOR gain (the ratio of eye velocity to head velocity) is too high or too low, the target image is off the fovea, and head motion causes oscillopsia, an illusory to-and-fro movement of the environment.

• 감성과학
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• 제17권2호
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• pp.91-100
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• 2014

본 연구에서는 P300 문자입력기의 물리적 특성에 해당하는 문자판의 시각도와 사용자의 개인적 특성에 해당하는 시선응시 방법이 P300 문자입력기의 정확도에 미치는 영향을 검증하였다. 문자판의 시각도는 사용자와 문자판 간의 거리로 조작하였으며, 60 cm 집단과 100 cm 집단, 150 cm 집단으로 구성하였다. 시선응시방법은 세 조건으로 반복측정하였다. 머리 조건은 머리를 움직여서 시선을 두는 조건이었으며, 눈동자 조건은 머리는 고정한 채 눈동자를 움직여서 시선을 두는 조건이었고, 시선고정 조건은 시선을 문자입력기의 중앙에 고정시킨 조건이었다. 이요인설계에 의한 실험결과, 문자입력의 정확도가 시선응시방법에 따라 유의한 차이가 있었다. 머리 조건의 정확도가 눈동자 조건의 정확도 보다 높았으며, 눈동자 조건의 정확도가 시선고정 조건의 정확도 보다 높았다. 그러나 문자판의 시각도와 상호작용효과는 모두 유의하지 않았다. 시선응시방법에 따라 목표문자의 P300 진폭을 측정한 결과, 머리조건의 P300이 눈동자 조건의 P300보다 더 컸다. 머리조건과 눈동자 조건 간에는 오류분포에서 큰 차이가 없었지만, 시선고정 조건은 나머지 두 조건과 큰 차이를 보였다. 머리조건과 눈동자 조건에서는 오류가 주로 목표문자와 인접한 문자에서 나타난 반면, 시선고정 조건은 오류가 상대적으로 넓게 분포하였으며, 문자판의 중심에서 멀리 떨어져 있는 문자들에서 오류가 많이 발생하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.663-668
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• 2003

This paper presents a new observation system which is useful to observe the scene of the remote controlled robot vision. This system is composed of a motionless camera and head motion detector with a motion sensor. The motionless camera has a fish eye lens and is for observing a hemisphere space. The head motion detector has a motion sensor is for defining an arbitrary subspace of the hemisphere space from fish eye lens. Thus processing the angular information from the motion sensor appropriately, the direction of face is estimated. However, since the fisheye image is distorted, it is unclear image. The partial domain of a fish eye image is selected by head motion, and this is converted to perspective image. However, since this conversion enlarges the original image spatially and is based on discrete data, crevice is generated in the converted image. To solve this problem, interpolation based on an intensity of the image is performed for the crevice in the converted image (space problem). This paper provides the experimental results of the proposed observation system with the head motion detector and perspective image conversion using the proposed conversion and interpolation methods, and the adequacy and improving point of the proposed techniques are discussed.

• 제어로봇시스템학회논문지
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• 제16권1호
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• pp.90-95
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• 2010

This paper describes the development of integrated head and eye tracker system. Vision based head tracker is performed and it has 7mm error in 300mm translation. The epi-polar method and point matching are used for determining a position of head and rotational degree. High brightness LEDs are installed on helmet and the installed pattern is very important to match the points of stereo system. Eye tracker also uses LED for constant illumination. A Position of gazed object(3m distance) is determined by pupil tracking and eye tracker has 1~5 pixel error. Integration of result data of each tracking system is important. RS-232C communication is applied to integrated system and triggering signal is used for synchronization.

• 제어로봇시스템학회논문지
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• 제15권3호
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• pp.265-272
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• 2009

In this paper, a simple optical method that uses an infrared(IR) cut filter is proposed to minimize variation of eye image by external infrared(IR) sources in a video based head mounted eye tracking system that is used in the field of sports. For this, the IR cut filter is attached to a head mount of the eye tracking system, and the camera with an IR LED is located between the IR cut filter and eye. In this structure, external IR is blocked by the IR cut filter, and the IR intensity on the eye can be controlled by the IR LED. Therefore, the illumination condition of the camera to capture the eye can be stable without being affected by external IR illuminations. To verify the proposed idea, variation of the eye image and intensity of the IR with/without the IR cut filter is measured under various illumination conditions. The measured data show that the IR cut filter method can block external IR effectively, and complex pupil detection algorithms can be replaced by a simple binarized method.