• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권4호
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• pp.327-336
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• 2021

In this paper, we will introduce the image processing methods for the remote pupillary light reflex measurement using the video taken by a general smartphone camera without a special device such as an infrared camera. We propose an algorithm for estimate the size of the pupil that changes with light using image data analysis without a learning process. In addition, we will introduce the results of visualizing the change in the pupil size by removing noise from the recorded data of the pupil size measured for each frame of the video. We expect that this study will contribute to the construction of an objective indicator for remote pupillary light reflex measurement in the situation where non-face-to-face communication has become common due to COVID-19 and the demand for remote diagnosis is increasing.

• 한국멀티미디어학회논문지
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• 제24권5호
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• pp.642-650
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• 2021

Strabismus is one of the most common disease that might be associated with vision impairment. Especially in infants and children, it is critical to detect strabismus at an early age because uncorrected strabismus may go on to develop amblyopia. To this end, ophthalmologists usually perform the Hirschberg test, which observes corneal light reflex (CLR) to determine the presence and type of strabismus. However, this test is usually done manually in a hospital, which might be difficult for patients who live in a remote area with poor medical access. To address this issue, we propose an automatic strabismus screening method that calculates the CLR ratio to determine the presence of strabismus based on image processing. In particular, the method first employs a pre-trained face detection model and a 68 facial landmarks detector to extract the eye region image. The data points located in the limbus are then collected, and the least square method is applied to obtain the center coordinates of the iris. Finally, the coordinate of the reflective light point center within the iris is extracted and used to calculate the CLR ratio with the coordinate of iris edges. Experimental results with several images demonstrate that the proposed method can be a promising solution to provide strabismus screening for patients who cannot visit hospitals.

• Journal of Korean Neurosurgical Society
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• 제40권1호
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• pp.11-15
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• 2006

Objective : Acute cerebral infarction is often accompanied by transtentorial herniation which can be fatal. The aim of this study is to determine the timing of surgical intervention and prognostic factors in patients who present with acute cerebral infarction. Methods : We reviewed retrospectively 23 patients with acute cerebral infarction, who received decompressive craniectomy or conservative treatment from January 2002 to December 2004. We divided patients into two groups according to the treatment modalities [Group 1 : conservative treatment, Group 2 : decompressive craniectomy]. In all patients, the outcome was quantified with Glasgow Outcome Scale and Barthel Index. Results : Of the 23 patients, 11 underwent decompressive craniectomy. With decompressive craniectomy at the time of loss of pupillary light reflex, we were able to prevent death secondary to severe brain edema in all cases. Preoperative Glasgow Coma Scale and loss of pupillary light reflex were significant to the clinical outcome statistically. With conservative treatment, 9 of the 12 patients died secondary to transtentorial herniation. The clinical outcomes of remaining 3 patients were poor. Conclusion : This study confirms the value of life-saving procedure of decompressive craniectomy after acute cerebral infarction. We propose that the loss of pupillary light reflex should be considered one of the most important factors to determine the timing of the decompressive craniectomy.

• 한국안광학회지
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• 제3권1호
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• pp.201-207
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• 1998

눈의 cornea, crystalline의 reflection pattern을 알기 위해 matrix를 이용하여 image의 위치, size를 이론적으로 계산하였고, 3개의 light source와 reflex camera를 이용하여 reflection pattern를 측정할 수 있는 system을 만들었다. 단일 광원을 이용하여 retina에서 반사 pattern으로부터 눈의 원시 및 근시 등을 측정하였고, 2개의 광원을 이용한 reflection pattern으로부터 cornea, crystalline의 curvature를 측정하였다.

• 한국수산과학회지
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• 제12권2호
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• pp.79-86
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• 1979

빛이 어류의 행동에 미치는 영향을 조사하기 위하여 잉어, Cyprinus carpio에 광척극을 가한 실험을 낮과 밤에 각각 실시한 결과를 요약하면 다음과 같다. 1. 잉어의 분포율은 본 실험에 사용한 제한된 수조내에서 U자형과 거의 같은 구간분포경향을 보였다. 2. 빛의 세기가 어떤 적정치보다 더 강하거나 약할 때 어류가 광원으로부터 멀리 떨어진 곳에 모였기 때문에 잉어의 적정수중조도가 발견되었다. 3. 수중조도에 대한 집어율곡선의 최대치로부터 잉어의 집어율이 낮과 밤에 차이가 있었다. 4. 잉어의 집어율이 최대인 평균수중조도는 낮에 $3.813lux(2.99\~4.761\;lux)$였고, 밤에는 $6.292lux(5.0\~7.89\;lux)$였다. 5. 잉어의 집어율은 반사집어율과 평형집어율의 두가지 형태로 나타났다. 6. 반사집어율은 광원을 점등한 직후에 나타났으며, 시간에 따라 변화를 보였고, 평형집어율은 거의 균일하였다.

• Journal of Preventive Medicine and Public Health
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• 제30권3호
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• pp.599-608
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• 1997

6명의 20대 여성을 대상으로 VDT작업으로 인한 조절반응 및 동공대광반사의 작업부과에 따른 변화와 다른 사무작업을 부과할 때와의 차이를 보았다. 그 결과 다음과 같은 결과를 얻었다. 1. VDT작업에서 작업부과 시간이 증가함에 따라 조절 수축속도가 감소했으며 1시간의 휴식시간 후에는 현저하게 증가했고 다시 작업을 부과함에 따라 감소하는 경향을 보였다. 조절 수축속도의 변화보다는 뚜렷하지 않지만 이완속도도 VDT작업부과에 따라 감소되고 휴식에 의한 회복되는 경향을 보였다. 2. 일반 사무작업과 근거리 사무작업에서는 조절 수축속도에서 VDT작업부과때와 같은 반응은 보이지 않았으며, 근거리 사무작업에서 이완속도가 작업부과에 따라 감소하였으나 휴식 후 회복되지 않았다. 3. 동공대광반사에서 최초동공직경, 최초동공면적은 VDT작업에서만 작업시간의 증가에 따라 유의한 감소를 보였는데 휴식 후 회복되지 않았다. 이러한 결과는 조절 수축속도의 변화, 조절 이완속도, 동공직경과 면적의 변화가 VDT작업의 특성을 연구하는데 사용될 가능성을 보여주며, 이를 위해서 연구대상이 개인차, 생체리듬, 감정적 자극 등을 보정한 연구가 필요하다고 생각된다.

• Journal of the Optical Society of Korea
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• 제17권3호
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• pp.249-254
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• 2013

In ophthalmology, a pupillometer, a device to measure the diameter of the pupil of the eye, can provide information on the function of the autonomic nervous system. The current pupillometers on the market are either too large to be a handheld instrument, or relatively expensive. In this study, a pupillometer based on a smartphone was designed. Both white and infrared LEDs and a 3M pixel camera of a smartphone were applied for the visual stimuli to an eye and for the acquisition of the eye images, respectively. Contrary to the existing method of pupil measurement that usually observe the variation of pupil diameter, the proposed algorithm in this study was applied to calculate the constriction ratio of the pupillary area in response to pupillary light reflex. The results showed that the constriction ratio of the pupillary area were all in the normal range (above 4.0) from the sixteen healthy participants. It is believed that the approach to pupil measurement used in this study is suitable for a mobile interface, and this system can be applied to clinical research, home-use healthcare, and distributed to some areas which suffer from problems like a lack of medical support.

• The Korean Journal of Physiology and Pharmacology
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• 제12권3호
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• pp.89-94
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• 2008

In order to reproduce chronic cerebral hypoperfusion as it occurs in human aging and Alzheimer's disease, we introduced permanent, bilateral occlusion of the common carotid arteries (BCCAO) in rats (Farkas et al, 2007). Here, we induced BCCAO in two different rat strains in order to determine whether there was a strain difference in the pathogenic response to BCCAO. Male Wistar and Sprague-Dawley (SD) rats (250-270 g) were subjected to BCCAO for three weeks. Kluver-Barrera and cresyl violet staining were used to evaluate white matter and gray matter damage, respectively. Wistar rats had a considerably higher mortality rate (four of 14 rats) as compared to SD rats (one of 15 rats) following BCCAO. Complete loss of pupillary light reflex occurred in all Wistar rats that survived, but loss of pupillary light reflex did not occur at all in SD rats. Moreover, BCCAO induced marked vacuolation in the optic tract of Wistar rats as compared to SD rats. In contrast, SD rats showed fewer CA1 hippocampal neurons than Wistar rats following BCCAO. These results suggest that the neuropathological process induced by BCCAO takes place in a region-specific pattern that varies according to the strain of rat involved.

• 대한수의학회지
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• 제59권2호
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• pp.109-111
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• 2019

A 10-year-old intact female Jindo dog was presented with a 1-week history of conjunctival redness and ocular discharge in the left eye. There was an absence of menace response, dazzle reflex, and direct pupillary light reflex. Slit-lamp biomicroscopy revealed corneal edema, ciliary flush, and aqueous flare. Intraocular pressure was 68 mmHg. Based on the information available, a diagnosis of glaucoma and uveitis was made. Subsequent histopathologic examination showed the glaucoma was produced by the effects of goniodysgenesis, posterior synechia, and pigment dispersion in the trabecular meshwork. This is the first report of primary glaucoma caused by goniodysgenesis in Jindo dogs.

• 대한한의학회지
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• 제20권1호
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• pp.106-112
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• 1999

The purpose of this study is to investigate the effects of Bee Venom Herb-Acupuncture on the jaw opening reflex evoked by tooth pulp stimulation. Rats were anesthetized with thiopental sodium given intraperitoneally in an initial dose of 80mg/kg. Maintenance doses of 5mg/kg thiopental sodium were given through a cannular in the femoral vein as required to maintain light anesthesia. To apply noxious stimuli, a pair of enameled wires were inserted into the tooth pulp of the lower incisor. The effects of conditioning stimuli were estimated as an indicator of the degree of suppression of the digastric muscle electromyogram(dEMG) in the jaw opening reflex. Bee Venom Herb- Acupuncture(0.2% solution 0.1ml/rat) was injected to Hapgok(LI4) loci. In addition, Normal Saline (0.1ml/rat) was injected to Hapgok loci so as to compare the degree of suppression elicited from Bee-Venom. By administration of Bee Venom Herb-Acupuncture, the amplitude of dEMG was maximally suppressed to $67.5{\pm}3.38%$ ipsilaterally, 73.33{\pm}8.00%$ contralaterally. Generally, the dEMG activities caused by electrical stimulation were gradually suppressed during the stimulation and maximal suppressive effect showed at 15min after its onset. However the dEMG activities by Be Venom Herb-Acupuncture were immediately suppressed after its onset and the suppressive effect continued for a long time compared to electrical stimulation. In conclusion, Bee Venom Herb-Acupuncture may have a different mechanism of analgesia from that of electro-acupuncture and contribute to the modulation of pain analgesia.