• Title/Summary/Keyword: Eyeball

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Development of Retinal Prosthesis Module for Fully Implantable Retinal Prosthesis (완전삽입형 인공망막 구현을 위한 인공망막모듈 개발)

  • Lee, Kang-Wook;Kaiho, Yoshiyuki;Fukushima, Takafumi;Tanaka, Tetsu;Koyanagi, Mitsumasa
    • Journal of Biomedical Engineering Research
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    • v.31 no.4
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    • pp.292-301
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    • 2010
  • To restore visual sensation of blind patients, we have proposed a fully implantable retinal prosthesis comprising an three dimensionally (3D) stacked retinal chip for transforming optical signal to electrical signal, a flexible cable with stimulus electrode array for stimulating retina cells, and coupling coils for power transmission. The 3D stacked retinal chip is consisted of several LSI chips such as photodetector, signal processing circuit, and stimulus current generator. They are vertically stacked and electrically connected using 3D integration technology. Our retinal prosthesis has a small size and lightweight with high resolution, therefore it could increase the patients` quality of life (QOL). For realizing the fully implantable retinal prosthesis, we developed a retinal prosthesis module comprising a retinal prosthesis chip and a flexible cable with stimulus electrode array for generating optimal stimulus current. In this study, we used a 2D retinal chip as a prototype retinal prosthesis chip. We fabricated the polymide-based flexible cable of $20{\mu}m$ thickness where 16 channels Pt stimulus electrode array was formed in the cable. Pt electrode has an impedance of $9.9k{\Omega}$ at 400Hz frequency. The retinal prosthesis chip was mounted on the flexible cable by an epoxy and electrically connected by Au wire. The retinal prosthesis chip was cappted by a silicone to pretect from corrosive environments in an eyeball. Then, the fabricated retinal prosthesis module was implanted into an eyeball of a rabbit. We successfully recorded electrically evoked potential (EEP) elicited from the rabbit brain by the current stimulation supplied from the implanted retinal prosthesis module. EEP amplitude was increased linearly with illumination intensity and irradiation time of incident light. The retinal prosthesis chip was well functioned after implanting into the eyeball of the rabbit.

Anthropometric analysis of the eyeball exposure area in Koreans

  • Park, Ki Soo;Ka, Soon Il;Park, Dae Hwan
    • Archives of Plastic Surgery
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    • v.47 no.1
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    • pp.9-14
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    • 2020
  • Background Eyelids vary in morphology and structure depending on age, sex, and race. Usually, one-dimensional measurements are used to evaluate blepharoplasty outcomes. However, in recent years, three- or four- directional enlargements of the eyelid have been used for blepharoplasty in Asian patients, and the outcomes of techniques such as lateral canthoplasty or canthotomy and medial epicanthoplasty with increased scleral area cannot be analyzed using marginal reflex distance 1 or the area of corneal exposure. Therefore, we describe the use of a measurement method based on the eyeball exposure area (EEA). Methods To obtain normal EEA values by age and sex, 320 individuals were recruited. The participants were divided into eight age groups (n=40 in each group: female subjects, n=20; male subjects, n=20): 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-89 years. The EEA value was obtained by dividing the exposed area by the total eyeball area. The normal EEA values and differences in EEA according to age and sex were calculated. Results The mean EEA values for male and female subjects were 66.86% ±9.20% and 71.48%±10.48%, respectively. In each age group, the EEA values of females were higher than those of males. EEA decreased significantly with age in both male and female subjects (P<0.05). Conclusions We determined normal EEA values according to age and sex. EEA can be used as an indicator of the outcome of blepharoplasty.

Case Report: Miller Fisher Syndrome (한방치료로 호전된 Miller Fisher 증후군 환자 증례보고)

  • Ryu, Ju-young;Lee, Kang-wook;Cho, Min-kyoung;Cho, Hyun-kyoung;Yoo, Ho-ryong;Seol, In-chan;Kim, Yoon-sik
    • The Journal of Internal Korean Medicine
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    • v.37 no.4
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    • pp.661-668
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    • 2016
  • Objectives: To describe the effect of traditional Korean medicine and treatment on Miller Fisher syndrome (MFS).Methods: A 54-year-old woman diagnosed with MFS presented with eyeball dysfunction, diplopia, vertigo, right facial palsy, and back dysesthesia. The patient had been treated with immunoglobulin for 21 d, but her symptoms failed to improve. Thus, herbal medicine, acupuncture, electropuncture, pharmacopuncture, and moxibustion were added. Length of eyeball movement, distance that the patient recognize double images in the eyes and Visual Analogue Scale (VAS) are measures for the syndrome.Results: The symptoms of the patient considerably improved, with the return of eyeball movement to normal and disappearance of diplopia.Conclusions: The results suggest that Korean medicine may be an effective therapy for MFS.

Clinical Implementation of an Eye Fixing and Monitoring System with Head Mount Display (Head Mount Display (HMD)를 이용한 안구의 고정 및 감시장치의 임상사용 가능성 확인)

  • Ko, Young-Eun;Park, Seoung-HO;Yi, Byong-Yong;Ahn, Seung-Do;Lim, Sang-Wook;Lee, Sang-Wook;Shin, Seong-Soo;Kim, Jong-Hoon;Choi, Eun-Kyung;Noh, Young-Ju
    • Progress in Medical Physics
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    • v.18 no.1
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    • pp.1-6
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    • 2007
  • A system to non-invasively fix and monitor eye by a head mounted display (HMD) with a CCD camera for stereotactic radiotherapy (SRS) of uveal melanoma has been developed and implemented clinically. The eye fixing and monitoring system consists of a HMD showing patient a screen for fixing eyeball, a CCD camera monitoring patient's eyeball, and an immobilization mask. At flrst, patient's head was immobilized with a mask. Then, patient was Instructed to wear HMD, to which CCD camera was attached, on the mask and see the given reference point on its screen. While patient stared at the given point in order to fix eyeball, the camera monitored Its motion. Four volunteers and one patient of uveal melanoma for SRS came into this study. For the volunteers, setup errors and the motion of eyeball were analyzed. For the patient, CT scans were peformed, with patient's wearing HMD and fixing the eye to the given point. To treat patient under the same condition, daily CT scans were also peformed before every treatment and the motion of lens was compared to the planning CT Setup errors for four volunteers were within 1mm and the motion of eyeball was fixed within the clinically acceptable ranges. For the patient with uveal melanoma, the motion of lens was fixed within 2mm from daily CT scans. An eye fixing and monitoring system allowed Immobilizing patient as well as monitoring eyeball and was successfully implemented in the treatment of uveal melanoma for SRS.

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The evaluation of lens absorbed dose according to the Optimold for whole brain radiation therapy (전뇌 방사선치료 시 Optimold에 따른 수정체의 흡수선량 평가)

  • Yang, Yong Mo;Park, Byoung Suk;Ahn, Jong Ho;Song, Ki Won
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.1
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    • pp.77-81
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    • 2014
  • Purpose : In the current whole brain Radiation Therapy, Optimold was used to immobilize the head. However, skin dose was increased about 22% due to the scattering radiation by the Optimold. Since the minimum dose causing cataracts was 2 Gy, it could be seen that the effects were large especially on the lens. Therefore, in the whole brain Radiation Therapy, it was to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part. Materials and Methods : In order to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part, the Optimold mask was made ??up to 5mm bolus on the part of the eye lens in the human model phantom (Anderson Rando Phantom, USA). In the practice treatment, to measure the lens dose, the simulation therapy was processed by placing the GafChromic EBT3 film under bolus, and after the treatment plan was set up through the treatment planning system (Pinnacle, PHILIPS, USA), the treatments were measured repeatedly three times in the same way. After removing the Optimold mask in the eyeball part, it was measured in the same way as above. After scanning the film and measuring the dose by using the Digital Flatbed Scanner (Expression 10000XL, EPSON, USA), the doses were compared and evaluated according to the presence of Optimold mask in the eyeball part. Results : When there was the Optimold mask in the eyeball part, it was measured at $10.2cGy{\pm}1.5$ in the simulation therapy, and at $24.8cGy{\pm}2.7$ in the treatment, and when the Optimold mask was removed in the eye part, it was measured at $12.9cGy{\pm}2.2$ in the simulation therapy, and at $17.6cGy{\pm}1.5$ in the treatment. Conclusion : In case of removing the Optimold mask in the eyeball part, the dose was increased approximately 3 cGy in the simulation therapy and was reduced approximately 7 cGy in the treatment in comparison to the case that the Optimold mask was not removed. During the whole treatment, since the lens absorbed dose was reduced about 27%, the chance to cause cataracts and side effects was considered to be reduced due to decrease of the absorbed dose to the eye lens which had the high sensitivity on the radiation.

Pediatric Radiation Examination by Development of Bismuth Shield Research on Radiation Exposure (비스무스 차폐체 개발을 통한 소아 방사선검사의 피폭에 관한 연구)

  • Hoon Kim;Yong-Keun Kim;Joon-Nyeon Kim;Seung-Hyun Wi;Eun-Kyung Park;Myung-Jun Chae;Bu-Gil Baek;Eun-Hye Kim;Cheong-Hwan Lim
    • Journal of radiological science and technology
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    • v.47 no.3
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    • pp.205-211
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    • 2024
  • Currently, with the development of technologies, X-ray examinations for medical examinations at hospital is increasing. This study was conducted to help reduce radiation exposure by measuring the exposure dose received by pediatric patients and the spatial dose of the X-ray room. Dosimeters were installed in the eyeball, thyroid gland, breast, gonads and 4 directions at a distance of 30 cm, 40 cm, 50 cm from the phantom. The dose was measured ten times each, before, and after the application of the bismuth shield under the examination conditions of the head, chest, and abdomen of pediatric patients. Under the condition of head examination, when a shielding was applied, the dose reduction rate was 68.58% for the eyeball, 72.88% for the thyroid, 84.2% for the breast, and 72.36% for the gonad. The chest examination showed reductions of 19.56% eyeball, 56.98% thyroid, 1.21% breast, and 0.68% gonad. The abdominal examination showed reduction rates of 2.6% eyeball, 10.67% thyroid, 19.85% breast, and 82.02% gonad. Spatial dose decreased by 62.25% at 30 cm, 61.16% at 40 cm, and 68.68% at 50 cm. When the bismuth shield was applied, there was a decrease in dose across all examinations, as well as a reduction in spatial dose. Continued research on the use of bismuth shields will help radiological technologists achieve their goal of dose reduction.

The Centering of the Invariant Feature for the Unfocused Input Character using a Spherical Domain System

  • Seo, Choon-Weon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.9
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    • pp.14-22
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    • 2015
  • TIn this paper, a centering method for an unfocused input character using the spherical domain system and the centering character to use the shift invariant feature for the recognition system is proposed. A system for recognition is implemented using the centroid method with coordinate average values, and the results of an above 78.14% average differential ratio for the character features were obtained. It is possible to extract the shift invariant feature using spherical transformation similar to the human eyeball. The proposed method, which is feature extraction using spherical coordinate transform and transformed extracted data, makes it possible to move the character to the center position of the input plane. Both digital and optical technologies are mixed using a spherical coordinate similar to the 3 dimensional human eyeball for the 2 dimensional plane format. In this paper, a centering character feature using the spherical domain is proposed for character recognition, and possibilities for the recognized possible character shape as well as calculating the differential ratio of the centered character using a centroid method are suggested.

Eyeball deviation by orbital mucocele after midface sinus injury

  • Oh, Se Young;Choi, Ji Seon;Lim, Jin Soo;Kim, Min Cheol
    • Archives of Craniofacial Surgery
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    • v.21 no.1
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    • pp.53-57
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    • 2020
  • A mucocele is an epithelium-lined, mucus-filled cavity in the paranasal sinuses. Mucocele may develop due to scarring and obstruction of the sinus ostium caused by midface sinus trauma, such as orbital bone fracture or endoscopic sinus surgery. The authors report two cases of orbital mucocele as complications following midface sinus injury (endoscopic sinus surgery in one case, and orbital fracture repair in the other). In both cases, imaging studies showed a large orbital mucocele accompanied by bony erosion and orbital wall remodeling, compressing the ocular muscle. Using an open approach, the lesion was excised and marsupialized. The symptoms resolved, and the postoperative eyeball position was normal. Orbital mucocele may cause serious complications such as ocular symptoms, orbital cellulitis, osteomyelitis, and the formation of an abscess with the potential to invade the brain. Therefore, surgeons should consider the possibility of mucocele as a late complication of surgery and initiate an immediate work-up and surgical treatment if needed.

THE MICROBIOLOGICAL ASSAY OF TRYPTOPHAN IN RED PORGY, PAGROSOMUS MAJOR (미생물정량법에 의한 참돔중의 Tryptophan의 정량)

  • KIM Chang Yang;LEE Hyun Ki
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.1 no.2
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    • pp.81-86
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    • 1968
  • A porgy was divided into eight parts. After drying at low temperature and pulberizing it, the sample was hydrolyzed by $Ba(OH)_2{\cdot}8H_2O\;at\;120^{\circ}C$, under the pressure of $1\;kg/cm^2$ for 8 hours. Tryptophan was determined by means of microbiological assay, using Lactoba-cillus arabinosus 17-5. The result of experiments was as follows: The content of nitrogen of eight parts of the body amounted $12.55\%$ in muscle being the highest of all, $11.49\%$ in heart, $11.31\%$ in eyeball, $11.22\%$ in liver, $11.06\%$ in intestine, $8.75\%$ in head, $7.81\%$ in gill, and $6.02\%$ in fin which was the lowest of the parts tested. The content of tryptophan per 1 gram nitrogen was 11.79mg in liver, which was the highest of all, 10.11mg in heart, 9.76mg in eyeball, 8.77mg in intestine, 6.28mg in muscle, 5.72mg in head, 4.03mg in gill 2.64mg in fin, and in that order.

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Femtosecond laser induced shock generation and its application (펨토초 레이저 유발 shock 형성 및 그 응용)

  • Jeoung, Sae Chae;Lee, Heung Soon;Sidhu, M.S.;Moon, Heh-Young
    • Laser Solutions
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    • v.17 no.4
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    • pp.1-6
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    • 2014
  • Femtosecond laser induced shock generation in water and vitreous humor of enucleated porcine eyeball was investigated. When focusing the femtosecond laser into the liquid mediums, the acoustic waves with a frequency of about 15.6kHz could be observed by using wide-band microphone. The amplitude of the acoustic signals from water has attained a maximum under a laser power of about 5mW. Further increment of the power results in a decrement of the acoustic signals due to nonlinear optical process including filamentation of laser beam. We have further investigated the effect of femtosecond laser induced acoustic waves by applying the laser pulse into enucleated porcine eyeball. The comparative studies on both healthy and diseased eyeballs led us propose that the femtosecond laser pulses could be utilized as a novel tools for treatment of partially detached retina layers from their choroid structures.

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