• Journal of Korea Multimedia Society
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• v.8 no.4
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• pp.492-501
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• 2005

In this paper, we proposed the new segmentation method of optic nerve head and optic cub to consider the depth of optic nerve head on stereo fundus image. We analyzed the error factor of stereo matching on stereo fundus image, and compensated them. For robust extraction of optic nerve head and optic cub, we proposed the modified active contour model to consider the 3D depth of optic nerve head. As experiment result to various stereo fundus images, we confirmed that proposed method can segment optic nerve head and optic cup effectively.

• Biomolecules & Therapeutics
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• v.3 no.2
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• pp.149-153
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• 1995

Nitric oxide (NO) has been regarded as one of the neurotransmitters of nonadrenergic, noncholinergic (NANC) nerve stimulation in rabbit corpus cavernosum, rat gastric fundus and human intestine. PIANO (photo-induced adequate nitric oxide) is a very useful tool to investige the role of NO in various smooth muscles where NO is a mediator. The present study was undertaken to compare the physiological responses of the rat gastric smooth muscle in response to NANC nerve stimulation and to PIANO. Photolysis of L-NAME, D-NAME and streptozotocin (572) by UV light in the bathing medium caused relaxation of rat gastric fungus that contracted with carbachol, but was resistant to tetrodotoxin (TTX, 1 $\mu$M). Electrical stimulation (20 V, 2~32 Hz, 0.2 msec, 10s) of the gastric fundus, in the presence of atropine and guanethidine, induced frequency-dependent, TTX-sensitive relaxation. Sodium nitroprusside (1 nM-10 $\mu$M), a NO donor, mimicked the relaxations observed after NANC-stimulation or PIANO. Furthermore, PIANO caused UV light exposure time-dependent increase of CGMP in rat gastric fungus strips. These results provide another evidence indirectly that NO is one of the mediators of the NANC inhibitory nerve stimulation in the rat gastric fundus.

• Journal of Biomedical Engineering Research
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• v.16 no.2
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• pp.121-128
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• 1995

Information about retinal blood vessels can be used in grading disease severity or as part of the process of automated diagnosis of diseases with ocular menifestations. In this paper, we address the problem of detecting retinal blood vessels and optic disk (papilla) in eye-fundus images. We introduce an algorithm for feature extraction based on Fuzzy Clustering algorithm (fuzzy c-means). A method of finding the optic disk (papilla) is proposed in the eye-fundus images. Additionally, the inrormations such as position and area of the optic disk are extracted. The results are compared to those obtained from other methods. The automatic detection of retinal blood vessels and optic disk in the eye-rundus images could help physicians in diagnosing ocular diseases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.636-638
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• 2022

This paper is a study to apply CNN(Convolution Neural Network) to fundus images for identifying glaucoma. Fundus images are evaluated in the field of medical diagnosis detection, which are diagnosing of blood vessels and nerve tissues, retina damage, various cardiovascular diseases and dementia. For the experiment, using normal image set and glaucoma image set, two types of image set are classifed by using AlexNet. The result performs that glaucoma with abnormalities are activated and characterized in feature map.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.317-324
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• 2010

We elucidated the distribution of interstitial cells of Cajal (ICC) in human stomach, using cryosection and $c-Kit$ immunohistochemistry to identify $c-Kit$ positive ICC. Before $c-Kit$ staining, we routinely used hematoxylin and eosin (HE) staining to identify every structure of human stomach, from mucosa to longitudinal muscle. HE staining revealed that the fundus greater curvature (GC) had prominent oblique muscle layer, and $c-Kit$ immunostaining $c-Kit$ positive ICC cells were found to have typical morphology of dense fusiform cell body with multiple processes protruding from the central cell body. In particular, we could observe dense processes and ramifications of ICC in myenteric area and longitudinal muscle layer of corpus GC. Interestingly, $c-Kit$ positive ICC-like cells which had morphology very similar to ICC were found in gastric mucosa. We could not find any significant difference in the distribution of ICC between fundus and corpus, except for submucosa where the density of ICC was much higher in gastric fundus than corpus. Furthermore, there was no significant difference in the density of ICC between each area of fundus and corpus, except for muscularis mucosa. Finally, we also found similar distribution of ICC in normal and cancerous tissue obtained from a patient who underwent pancreotomy and gastrectomy. In conclusion, ICC was found ubiquitously in human stomach and the density of ICC was significantly lower in the muscularis mucosa of both fundus/corpus and higher in the submucosa of gastric fundus than corpus.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1160-1165
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• 2018

Purpose: To evaluate the availability of ultra-wide field fundus photography based on eye steering technique to diagnose retinal breaks in patients with symptomatic posterior vitreous detachment (PVD). Methods: The medical records of patients with symptomatic PVD were reviewed. Retinal breaks were independently identified using four eye steering capture images of ultra-wide field fundus photographs. The sensitivity and specificity of eye steering capture imaging for diagnosing retinal breaks were calculated. Results: A total of 94 eyes of 94 patients were included. Using fundus examination after pupil dilatation, retinal breaks were diagnosed in 42 (45%) eyes. The sensitivity of the eye steering capture imaging was 98% (95% confidence interval [CI]: 88-100%), and the specificity was 98% (95% CI: 90-100%). Of the 58 retinal tears, 28 (97%) involving the superior quadrant, 10 (100%) involving the inferior quadrant, 6 (100%) involving the nasal quadrant, and 13 (100%) involving the temporal quadrant were identified using eye steering capture images. Conclusions: Ultra-wide field fundus photography based on eye steering technique was useful for diagnosing retinal breaks in patients with symptomatic PVD. However, eye steering photography could not adequately replace the fundus examination after pupil dilatation in all cases.

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.91-97
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• 2003

The Propose of this paper is hierarchical detection method for the optic disc in fundus image. We detected the optic disc boundary by using the Prior information. It is based on the anatomical knowledge of fundus which are the vessel information. the image complexity. and etc. The whole method can be divided into three stages . First, we selected the region of interest(ROI) which included optic disc region. This is used to calculate location and size of the optic disc which are prior knowledge to simplify image preprocessing. And then. we divided the fundus image into numberous regions with watershed algorithm and detected intial boundary of the optic disc by reducing the number of the separated regions in ROI. Finally, we have searching the defective parts of boundary as a result of serious vessel interference in order to detect the accurate boundary of optic disc and we have removing and interpolating them.

• Journal of Veterinary Clinics
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• v.30 no.1
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• pp.27-31
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• 2013

We investigated the effects of Ponciri Fructus (PF) and Aurantii Fructus Immaturus (AI) on the cicular and longitudinal smooth muscle of rat gastric fundus. Methanol extracts of PF (PFM) and AI (AIM), water-fractions (PFW, AIW) and chloroform-fractions (PFC, AIC) of the extracts induced relaxation in the rat fundic circular muscle pre-contracted by U46619. All extracts showed relaxation without significant differences among the extracts. In the longitudinal smooth muscle, PFM and its water fraction, PFW, showed multiphasic effects, fast relaxation and rebound contraction followed by lasting relaxation. AIM and AIW showed diphasic effects, transient contraction followed by lasting relaxation. However, PFC and AIC induced only relaxation in the rat fundic longitudinal muscle contracted by U46619. PFM showed significantly more effective relaxation compared with PFW, AIM and AIW. Hesperidin, flavonoids known as common constituent of PF and AI and it's an aglycon, hesperetin, induced relaxation in both fundic circular and longitudinal smooth muscle pre-contracted by U46619. Poncirin, known as flavonoid content of PF showed also induced relaxation in the both circular and longitudinal smooth muscle pre-contracted by U46619. These results suggest that both PF and AI has relaxing effects on the gastric fundus smooth muscle and its effects might be caused by their flavonoids constituents.

• Biomedical Science Letters
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• v.15 no.1
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• pp.25-29
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• 2009

The changes on the regional distributions and frequencies of somatostatin-immunoreactive (IR) cells in the fundus and pylorus of the stomach of osteoporotic Sprague-Dawley rats induced by ovariectomy were studied by immunohistochemical methods. The experimental animals were divided into two groups, one for non-ovariectomized group (Sham) and the other for ovariectomized group (OVX). Samples were collected from the fundus and pylorus regions at the 10 th week after ovariectomy or sham-operation. Somatostatin-IR cells were observed in both regions of the stomach regardless of ovariectomy. Most of these IR cells in the mucosa of the fundus or pylorus were generally spherical or spindle in shape (open type cell) while cells found in the gastric gland regions were round in shape (close type cell). Significantly lower number (P<0.01) of somatostatin-IR cells were detected in OVX as compared with Sham in the fundus and pylorus. In the present study, the density of somatostatin in the stomach was markedly decreased. Therefore, these changes in density of somatostatin-IR cells detected in this study may support the speculation that the development of gastrointestinal symptoms in osteoporosis such as impairments of calcium and some lipids, frequently encountered in patients with postmenopausal osteoporosis because the changes in gastrointestinal endocrine density would reflect the change in the capacity of producing these hormones and regulating gut motility and digestion.

• Journal of Korean Medical Science
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• v.33 no.43
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• pp.239.1-239.12
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• 2018

Background: We described a novel multi-step retinal fundus image reading system for providing high-quality large data for machine learning algorithms, and assessed the grader variability in the large-scale dataset generated with this system. Methods: A 5-step retinal fundus image reading tool was developed that rates image quality, presence of abnormality, findings with location information, diagnoses, and clinical significance. Each image was evaluated by 3 different graders. Agreements among graders for each decision were evaluated. Results: The 234,242 readings of 79,458 images were collected from 55 licensed ophthalmologists during 6 months. The 34,364 images were graded as abnormal by at-least one rater. Of these, all three raters agreed in 46.6% in abnormality, while 69.9% of the images were rated as abnormal by two or more raters. Agreement rate of at-least two raters on a certain finding was 26.7%-65.2%, and complete agreement rate of all-three raters was 5.7%-43.3%. As for diagnoses, agreement of at-least two raters was 35.6%-65.6%, and complete agreement rate was 11.0%-40.0%. Agreement of findings and diagnoses were higher when restricted to images with prior complete agreement on abnormality. Retinal/glaucoma specialists showed higher agreements on findings and diagnoses of their corresponding subspecialties. Conclusion: This novel reading tool for retinal fundus images generated a large-scale dataset with high level of information, which can be utilized in future development of machine learning-based algorithms for automated identification of abnormal conditions and clinical decision supporting system. These results emphasize the importance of addressing grader variability in algorithm developments.