• Title/Summary/Keyword: 각막 반사

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Placement of an Intraocular Silicone Prosthesis with Evisceration in a Dog with Refractory Glaucoma (난치성 녹내장을 지닌 개에서 안구내용제거술을 통한 안구 내 실리콘 보철물 적용 1례)

  • Kim, Kyung-Hee;Kim, Joon-Young;Choi, Young-Min;Lee, Jong-Hoon;Park, Chang-Hee;Lee, Jung-Ha;Lee, Young-Sun;Jeong, Soon-Wuk
    • Journal of Veterinary Clinics
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    • v.27 no.5
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    • pp.610-613
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    • 2010
  • An 8-year-old male dog weighing 7.9 kg was referred to us for evaluation of exophthalmos and corneal edema of the left eye, on which cataract surgery had been performed 3 years prior. On ophthalmic examination, the left eye showed an extremely high intraocular pressure (47 mmHg), with no menace response, dazzle reflex, or pupillary light reflex. The dog was treated with systemic and topical glaucoma medications. After treatment, corneal edema decreased but IOP did not return to within acceptable limits. Seventeen months later, the dog presented with hyphema, episcleral congestion, and corneal edema attributable to accidental trauma. The owner wished to maintain an attractive ocular appearance, and an intraocular silicone prosthesis (ISP) was thus inserted after the evisceration. Three months postoperatively, a corneal ulcer was detected, but this resolved successfully after prescription of appropriate medication. One year after surgery, no complications related to surgery were evident.

Development of Videooculograph for Vestibular Function Test (전정 기능 평가를 위한 영상 안구 운동 측정 시스템의 개발)

  • 김수찬;남기창;이원선;김덕원
    • 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.

시선인식을 이용한 지능형 휠체어 시스템

  • Kim, Tae-Ui;Lee, Sang-Yoon;Kwon, Kyung-Su;Park, Se-Hyun
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2009.05a
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    • pp.88-92
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    • 2009
  • 본 논문에서는 시선인식을 이용한 지능형 휠체어 시스템에 대해 설명한다. 지능형 휠체어는 초음파센서를 이용하여 전동휠체어가 장애물을 감지하여 회피할 수 있게 하고, 조이스틱을 움직이기 힘든 중증 장애인을 위해 시선인식 및 추적을 이용하여 전동휠체어를 움직일 수 있게 하는 인터페이스를 제안한다. 지능형 휠체어는 시선인식 및 추적 모듈, 사용자 인터페이스, 장애물 회피 모듈, 모터 제어 모듈, 초음파 센서 모듈로 구성된다. 시선인식 및 추적 모듈은 적외선 카메라와 두개의 광원으로 사용자 눈의 각막 표면에 두 개의 반사점을 생성하고, 중심점을 구한 뒤, 동공의 중심점과 두 반사점의 중심을 이용하여 시선 추적을 한다. 시선이 응시하는 곳의 명령어를 사용자 인터페이스를 통해서 하달 받고, 모터 제어 모듈은 하달된 명령과 센서들에 의해 반환된 장애물과의 거리 정보로 모터제어보드에 연결되어 있는 두 개의 좌우 모터들을 조종한다. 센서 모듈은 전등휠체어가 움직이는 동안에 주기적으로 센서들로부터 거리 값을 반환 받아 벽 또는 장애물을 감지하여 장애물 회피 모듈에 의해 장애물을 우회 하도록 움직인다. 제안된 방법의 인터페이스는 실험을 통해 시선을 이용하여 지능형 휠체어에 명령을 하달하고 지능형 휠체어가 임의로 설치된 장애물을 효과적으로 감지하고 보다 정확하게 장애물을 회피 할 수 있음을 보였다.

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Gaze Recognition Interface Development for Smart Wheelchair (지능형 휠체어를 위한 시선 인식 인터페이스 개발)

  • Park, S.H.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.5 no.1
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    • pp.103-110
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    • 2011
  • In this paper, we propose a gaze recognition interface for smart wheelchair. The gaze recognition interface is a user interface which recognize the commands using the gaze recognition and avoid the detected obstacles by sensing the distance through range sensors on the way to driving. Smart wheelchair is composed of gaze recognition and tracking module, user interface module, obstacle detector, motor control module, and range sensor module. The interface in this paper uses a camera with built-in infra red filter and 2 LED light sources to see what direction the pupils turn to and can send command codes to control the system, thus it doesn't need any correction process per each person. The results of the experiment showed that the proposed interface can control the system exactly by recognizing user's gaze direction.

The Measurements of the Photoreflection Pattern for Cornea and Crystalline (각막과 수정체의 Photoreflection Pattern 측정기구 개발)

  • Kim, YongGeun;Park, Dong-Hwa
    • Journal of Korean Ophthalmic Optics Society
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    • v.3 no.1
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    • pp.201-207
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    • 1998
  • It was theoretically calculated the image position and size using matrix to obtain the reflection pattern for eye's cornea and crystalline, and made system to measure the reflection pattern by three light sources and a reflex camera. Hyperopia and myopia were measured by reflect pattern using single light source at retina, and cornea and curvature of crystalline were measured by the reflection pattern using double light sources.

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A Study on Fast Iris Detection for Iris Recognition in Mobile Phone (휴대폰에서의 홍채인식을 위한 고속 홍채검출에 관한 연구)

  • Park Hyun-Ae;Park Kang-Ryoung
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.2 s.308
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    • pp.19-29
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    • 2006
  • As the security of personal information is becoming more important in mobile phones, we are starting to apply iris recognition technology to these devices. In conventional iris recognition, magnified iris images are required. For that, it has been necessary to use large magnified zoom & focus lens camera to capture images, but due to the requirement about low size and cost of mobile phones, the zoom & focus lens are difficult to be used. However, with rapid developments and multimedia convergence trends in mobile phones, more and more companies have built mega-pixel cameras into their mobile phones. These devices make it possible to capture a magnified iris image without zoom & focus lens. Although facial images are captured far away from the user using a mega-pixel camera, the captured iris region possesses sufficient pixel information for iris recognition. However, in this case, the eye region should be detected for accurate iris recognition in facial images. So, we propose a new fast iris detection method, which is appropriate for mobile phones based on corneal specular reflection. To detect specular reflection robustly, we propose the theoretical background of estimating the size and brightness of specular reflection based on eye, camera and illuminator models. In addition, we use the successive On/Off scheme of the illuminator to detect the optical/motion blurring and sunlight effect on input image. Experimental results show that total processing time(detecting iris region) is on average 65ms on a Samsung SCH-S2300 (with 150MHz ARM 9 CPU) mobile phone. The rate of correct iris detection is 99% (about indoor images) and 98.5% (about outdoor images).

A Study on Eyes Region Detection on a Mobile Phone (휴대폰에서 눈 영역 검출 연구)

  • Park, Hyun-Ae;Park, Kang-Ryoung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2005.05a
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    • pp.789-792
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    • 2005
  • 최근 급격히 발전한 휴대폰은 다양한 기능을 가지고 있다. 그 중 디지털 카메라의 기능을 겸비한 휴대폰은 디지털 카메라의 판매량을 앞서고 있고, 메가픽셀의 고화소 디카폰의 개발로 대중화가 더욱 가속화되고 있다. 카메라폰을 응용한 연구분야로는 생체인식기술을 적용할 수 있으며, 본 논문은 제약이 많은 휴대폰 환경에서 홍채인식기술을 적용하기 위한 휴대폰 카메라로 취득된 얼굴영상에서의 눈 영역을 검출하는 방법을 제안한다. 얼굴영상에서 눈은 피부나 머리카락보다 빛에 대한 반사율이 높아 각막에 specular reflection이 생기게 되고, 동공은 눈의 다른 지역에 비해 흑화소가 많다는 특징을 가지고 있다. 이러한 두 가지 특징을 이용하여 동공 후보 영역을 선정하였고, 선정된 이진영상에서 수평 프로파일과 수직 프로파일을 적용하여 동공 후보 영역을 줄이면서 동공의 중심 위치를 검출한다. 본 연구는 휴대폰 환경을 고려하였기 때문에 최소한의 메모리 사용과 적은 연산량을 목표로 하여 눈의 위치를 검출 한다. 실험 결과, 입력 영상 내에 일정크기의 동공영역이 존재할 경우 높은 눈 영역 추출 성공률을 보이며, 본 연구에서 제안한 알고리즘을 실제 휴대폰에서 수행한 결과 평균571.6ms의 시간이 소요됨을 알 수 있었다.

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Study on the Fine Structure of Retina of Anterior Lateral Eyes in Pardosa astrigera L. Koch (Aranea: Lycosidae) (별늑대거미 (Pardosa astrigera L. Koch) 전측안(前側眼) 망막(綱膜)의 미세구조(微細構造)에 관한 연구)

  • Jeong, Moon-Jin;Moon, Myung-Jin
    • Applied Microscopy
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    • v.24 no.3
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    • pp.1-9
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    • 1994
  • Pardosa astrigera possessed eight eyes arranged in three rows on the frontal carapace. A pair of small anterior lateral eyes (ALE) flanked each side by an anterior median eyes (AME) lay along the anterior margin that was situated on the anterior row of clypeus. The anterior lateral eye was composed of cornea, vitreous body, and retina. Cornea was made up mainly of exocuticle lining the cuticle. Lens in anterior lateral eye was biconvex type which bulged into the cavity of the eyecup. Outer and inner central region of lens were approximately spherical with radius of curvature $5.6{\mu}m$ and $12.5{\mu}m$, respectly. Vitreous body formed a layer between the cuticular lens and retina. They formed biconcave shape. Retina of the anterior lateral eyes was composed of three types of cells: visual cells, glia cells, and pigment cells. The visual cells were unipolar neuron, as were the receptor of the posterior lateral eye. But cell body was unique to the anterior lateral eyes. They were giant cell, relatively a few in number, and under the layer of vitreous bodies. Each visual cell healed rhabdomeres for a short stretch beneath the cell body. Rhabdomes were irregulary pattern in retina and electron dense pigment granules scattered between the rhabdomes. Glia cell situated at the cell body of visual cell and glia cell process reached to rhabdomere portion. Below the rhabdome, tapetum were about $30{\mu}m$ distance from lens, which composed of 4-5 layers. It was about $25{\mu}m$ length that intermediate segment of distal portion of visual cell. Electron dense pigment granules between the intermediate segment were observed.

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Ultrastructure of the Eyes of Menemerus fulvus (Araneae: Salticidae) (흰수염깡충거미(Menemerus fulvus) (거미목, 깡충거미과)시각기의 미세구조)

  • 김주필;권중균
    • The Korean Journal of Soil Zoology
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    • v.5 no.2
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    • pp.101-112
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    • 2000
  • Spiders usually have poor vision but not the jumping spiders. Their eight eyes are located on its distinctive box-shaped head and relatively well developed. The Spiders were fixated with 3% glutaraldehyde and thin section was performed with ultra-microtome. The specimens were observed with light microscopy, transmission and scanning electron microscopy. Eye area of jumping spider is competed of three rows. The first eye row comprise four eyes. Among them, two anterior median eyes are the largest and two anterior lateral eyes are relatively small. The former are main-eyes and have excellent vision. The second row, which has the two smallest eyes, is located about midway between the first and third rows. The third row is about half-way back on the thorax and eyed of which are middle size. To investigate ultrastructure of salticid spiders'eye, Menemerus fulvus was chosen. All of Menemerus fuvus's eyes are composed of cornea, lens, vitreous body and retina in histologically. Cornea layer, linked to exocuticle of exoskeleton. is regular layer structure without any cell tripe. Lenses are biconvex type. Retinas comprise well developed microvilli-shape rhabdomeres, unpigmented supporting cells, and pigmented cell. Retinas of anterior median eyes are surrounded by circular cylinder-shaped vitreous body, photoreceptor, i.e. rhabdomeres, of it is irregularly arranged compared to the other eyes.

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A Study on Eye Detection by Using Adaboost for Iris Recognition in Mobile Environments (Adaboost를 이용한 모바일 환경에서의 홍채인식을 위한 눈 검출에 관한 연구)

  • Park, Kang-Ryoung;Park, Sung-Hyo;Cho, Dal-Ho
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.45 no.4
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    • pp.1-11
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    • 2008
  • In this paper, we propose the new eye detection method by using adaboost (adaptive boosting) method. Also, to reduce the false alarm rate which identifies the non-eye region as genuine eye that is the Problems of previous method using conventional adaboost, we proposed the post processing methods which used the cornea specular reflection and determined the optimized ratio of eye detecting box. Based on detected eye region by using adaboost, we performed the double circular edge detector for localizing a pupil and an iris region at the same time. Experimental results showed that the accuracy of eye detection was about 98% and the processing time was less than 1 second in mobile device.