Comparison of the 20-Gauge Conventional Vitrectomy Technique with the 23-Gauge Releasable Suture Vitrectomy Technique

김인근,이수정,박정민 대한안과학회 2013 Korean Journal of Ophthalmology Vol.27 No.1

Purpose: To compare the efficacy of the transconjunctival releasable suture technique for pars plana vitrectomy using 23-gauge (23G) instruments versus the conventional 20-gauge (20G) technique. Methods: A retrospective and interventional case series was consecutively performed for 199 eyes of the 192 patients that were a part of this study. Clinical data were reviewed retrospectively regarding the operation time, preoperative and postoperative intraocular pressure, visual acuity and astigmatism for 54 consecutive patients who received a 23G releasable suture vitrectomy and for 98 consecutive patients who received a 20G conventional vitrectomy during the period between April 2007 and September 2010. Results: Mean operation time based on the operation record was 88.5 ± 20.1 minutes in the 23G releasable suture vitrectomy group and 102.1 ± 23.1 minutes in the 20G conventional vitrectomy group, respectively (p = 0.01). The last best-corrected visual acuity (BCVA) was significantly better than the preoperative BCVA in both patient groups (p = 0.01, p = 0.01). The 23G releasable suture group showed less surgically induced astigmatism than the 20G conventional vitrectomy group. Vitreous bleeding was observed to be in 6 eyes (5.9%) in the 23G group, and in 8 eyes (8.2%) in the 20G group. In addition, ocular hypertension was noted to be in 3 eyes (3.0%) in the 23G group, and 6 eyes (6.1%) in the 20G group. No serious complications such as postoperative hypotony or endophthalmitis were observed in either group. Conclusions: The 23G releasable suture technique is as effective as the 20G conventional technique and offers several advantages.

한국의 과학기술 어디까지 왔나-자기부상열차

김인근,Kim, In-Geun 한국과학기술단체총연합회 1994 과학과 기술 Vol.27 No.11

눈물점 폐쇄에서 눈물점성형술과 Pigtail Probe를 이용한 실리콘관삽입술의 효과

김인근,김상수,In Geun Kim,MD,Sang Soo Kim,MD 대한안과학회 2012 대한안과학회지 Vol.53 No.9

Purpose: To assess the surgical results of a punctoplasty with insertion of a silicone tube using a pigtail probe for the management of acquired punctal obstruction. Methods: The medical records of 61 patients who underwent an operation for the management of punctual obstruction were reviewed. After punctal dilation, fluorescein dye disappearance test was performed to evaluate its efficacy. In the case of no functional delay after punctal dilation, three-snip punctoplasty with a silicone tube using a pigtail probe was performed. In the case of a functional delay, three-snip punctoplasty with a silicone tube into the nasolacrimal duct was performed. Results: The surgical success over 1 year was 39.1% in patients who underwent only three-snip punctoplasty, 79.2% in patients who underwent a three-snip punctoplasty with a silicone tube insertion into the nasolacrimal duct, and 85.7% in patients who underwent a three-snip punctoplasty with canalicular intubation using a pigtail probe. Conclusions: The use of a pigtail probe for canalicular intubation together with a three-snip punctoplasty is useful to prevent the recurrence of punctal obstruction. J Korean Ophthalmol Soc 2012;53(9):1219-1225

자기부상열차 개발을 위한 시스템 엔지니어링기술

김인근,유문환,Kim, In-Geun,Yu, Mun-Hwan 재료연구소 1997 機械와 材料 Vol.9 No.2

자기부상열차 개발현황과 추진전략

김인근,유문환,Kim, In-Geun,Yu, Mun-Hwan 재료연구소 1991 機械와 材料 Vol.3 No.2

A Study on the Stable Sensorless Control of BLDC Motor Inside Auxiliary Air Compressor

김인근,홍현석,고성철,오예준,주경진,이주 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

Pantograph must be correctly attached to catenary to continuously supply stable power to railway vehicle, and the device used here is Auxiliary Air Compressor (ACM). The existing ACM used the DC motor that included commutator and brush. Since maintenance and repair by mechanical friction are essential for the DC motor, BLDC motor studies have been conducted to improve this. A three-phase BLDC motor does 120° two-phase commutation through hall sensors in general. However, since hall sensor is vulnerable to heat and can run only when all three sensors work normally, sensorless control method has been studied to solve this. Using back EMF Zero Crossing Point (ZCP) detection method, this paper will introduce a stable switching sensing method that has a noncommutation area in a low speed zone.

인도네시아 자동차 시장에 대한 한국의 수출경쟁력 분석

김인근,김성룡 한국국제상학회 2022 國際商學 Vol.37 No.2

본 연구는 인도네시아 자동차 시장 현황을 다각도로 조사하고 한국의 수출경쟁력을 무역특화지수(TSI), 시장비교우위지수(MCA) 등의 국제교역 분석지수를 이용해 인도네시아 시장 내 주요 경쟁국인 일본, 태국과 비교 분석하고 있다. 인도네시아 자동차 시장은 첫째 내수 비중이 높고, 둘째 다목적차량이 주종을 이루며, 셋째 일본 브랜드의 점유율이 높고, 넷째 외산 수입 부품에 많이 의존하는 것으로 조사되었다. 한국과 인도네시아 사이의 자동차 산업 수출입 동향을 무역특화지수를 이용하여 분석한 결과 대다수 한국산 제품이 양(+)의 값을 가져 한국이 강하게 수출특화 되어있음을 확인하였다. 인도네시아 시장에서 주요 경쟁 상대인 일본, 태국과의 국제경쟁력 비교에는 시장비교우위지수를 활용하였다. 그 결과 일본과 태국은 인도네시아 자동차 시장에서 장기간 강력한 국제경쟁력을 유지한 품목이 다수 확인되었으나, 반면 한국은 전무한 것으로 나타나 향후 한국이 인도네시아 자동차 시장에서 경쟁력 확보를 위해서는 새로운 시장진출 전략이 필요함을 확인하였다.

혈관빛간섭단층촬영을 이용한 정상인과 당뇨망막병증 환자에서의 망막중심오목 무혈관부위 분석

김인근,이주은 대한안과학회 2017 대한안과학회지 Vol.58 No.8

Purpose: To evaluate the effectiveness of optical coherence tomography angiography (OCTA) in investigating changes in the area of the foveal avascular zone (FAZ) in patients with diabetic retinopathy (DR) and normal subjects. Methods: Eighty-five eyes of 50 DR patients and 50 eyes of 25 normal subjects were included. OCTA images of the FAZ were acquired using the split-spectrum amplitude decorrelation angiography algorithm of Optovue Avanti RTVue XR OCT. Patients were divided into three groups according to DR severity: mild-to-moderate non-proliferative diabetic retinopathy (NPDR) group, severe NPDR group, and proliferative DR group. The area of the FAZ was measured using built-in software and was compared between the patients and normal subjects and among the three groups. Results: The area of the FAZ in patients with diabetic retinopathy (0.46 mm2) was significantly larger than that in normal subjects (0.30 mm2, p = 0.001). A significant difference was observed depending on DR severity: 0.40 mm2 in the mild-to-moderate NPDR group, 0.45 mm² in the severe NPDR group, and 0.53 mm2 in the PDR group (p = 0.03). Correlation between area of the foveal avascular zone and visual acuity showed a tendency toward reduction in visual acuity (p = 0.002). Conclusions: OCTA effectively detected changes in the FAZ area in DR patients. OCTA has the potential to be used for noninvasive quantification and monitoring of the FAZ. 목적: 당뇨망막병증 환자를 대상으로 혈관빛간섭단층촬영을 이용하여 망막중심오목 무혈관부위를 측정하고 정상 대조군과 비교하여 혈관빛간섭단층촬영의 임상적 유용성에 대해 알아보고자 하였다. 대상과 방법: 당뇨망막병증 50명 85안과 정상 대조군 25명 50안을 비교 대상으로 하였다. Optovue Avanti RTVue XR optical coherence tomography를 이용하여 망막중심오목 무혈관부위의 혈관 영상을 얻은 후 면적측정 기능을 이용하여 망막중심오목 무혈관부위의 면적을 측정하고, 정상인과 당뇨망막병증 환자에서의 차이, 당뇨망막병증의 진행정도에 따른 차이를 비교하였다. 당뇨망막병증 환자는 진행 정도에 따라 경도-중등도 비증식당뇨망막병증, 심한 비증식당뇨망막병증, 그리고 증식성당뇨망막병증으로 나누어 비교하였다. 결과: 당뇨망막병증 환자의 망막중심오목 무혈관부위(0.46 mm2)는 정상 대조군(0.30 mm2)에 비해 의미 있게 넓게 측정되었다(p=0.001). 망막중심오목 무혈관부위를 당뇨망막병증의 정도에 따라 비교했을 때 세 군 간의 의미 있는 차이를 보였다(경도-중등도비증식당뇨망막병증; 0.40 mm2, 심한 비증식당뇨망막병증; 0.45 mm2, 증식성당뇨망막병증; 0.53 mm2, p=0.03). FAZ의 면적과 최대교정시력과의 연관성을 조사하였을 때 FAZ가 넓어질수록 시력이 떨어지는 음의 상관관계를 보였다(p=0.002). 결론: 혈관빛간섭단층촬영은 당뇨망막병증 환자에서 망막중심오목 무혈관부위를 비침습적으로 측정하고 이를 정량화할 수 있어, 당뇨망막병증의 경과 관찰에 유용하게 활용할 수 있을 것으로 사료된다.

기질적 안질환이 있는 소아 및 청소년에서의 사시 발생에 영향을 주는 인자

김인근,김상현,이수정,In Geun Kim,Sang Hyun Kim,Soo Jung Lee 대한안과학회 2011 대한안과학회지 Vol.52 No.6

Purpose: To evaluate risk factors associated with the development of strabismus in children with organic ocular diseases. Methods: The authors reviewed the medical records of 143 patients diagnosed with organic ocular disease between the ages of six months and 19 years from March 2000 through September 2009. The distributions of etiology, age, visual acuity and visual acuity difference between both eyes at onset of visual loss, spherical equivalent difference between both eyes, duration of visual loss, and nystagmus were analyzed to determine relationships with the development of strabismus. Results: Of 143 patients, strabismus developed in 41 children (28.7%). The causative diseases were congenital cataract (73.2%), developmental cataract (7.3%), uncorrected aphakia (7.3%), retinal detachment (4.9%), lens subluxation (2.4%), optic nerve disorder (2.4%), and corneal opacity (2.4%). The incidence of strabismus increased significantly in the cases of congenital disease, those ≤ five years of the age at onset of visual loss, those with ≤ 20/200 visual acuity, and those with large interocular spherical equivalent difference. There was no relationship between incidence of strabismus and visual acuity difference between both eyes. However, the incidence of strabismus increased significantly when the visual acuity difference was more than three Snellen lines in congenital ocular disease. Conclusions: When ocular disease is congenital, an increased risk of onset of strabismus should be considered when the age at onset of visual loss is less than five years, when visual acuity is below 20/200, and when there is a large spherical equivalent difference between both eyes. J Korean Ophthalmol Soc 2011;52(6):721-725

고환종양 : 위험인자와 생존률의 분석 Analysis of Risk Factors and Survival Rate 12년간의 경험 Experience of 12 years

김인근,류현열 고신대학교 의학부 2005 高神大學校 醫學部 論文集 Vol.20 No.1

Backgroud: This study reviewed clinical characteristics and prognostic factors in testicular germ cell turmor in adults. Materials and Methods: This investigation reviewed the records of 22 patients with testicular germ cell tumors managed at Kosin Hospital between July 1990 and June 2002. Patients were followed regularly to determine clinical outcome with tumor markers, chest X-ray and abdominal CT. mean follow-up was 5.65 years ranging from 5 months to 158 months. Results: Painless testicular enlargements (91%) was the most common presenting symptom and histry of cryptorchidism was noted in 1 patient. Among 11 seminoma patients, 5 were stage Ⅰ, 5 were stage Ⅱ, and Ⅰ was Ⅲ, and among 11 nonseminomatous germ cell tumor (NSGCT) patients, 2 were stage Ⅰ, 6 were stage Ⅱ, 2 were stage Ⅲ and Ⅰ was Ⅳ, of the 5 patients with stange Ⅰ seminoma, there was no recurrance who recived retroperitoneal low dose radiation therapy after orchiectomy. And one patient had elevated level of serum β-hCG at initial presentation, but no relapse. Among 5 patients with stage Ⅰ and Ⅱ NSGCT under surveillance after radical orchiectomy, serum AFP or HCG elevations were observed in 1 seminoma and 4 NSGCT (2 mixed cell tumors and 2 yolk sac tumors), and one patient expired for brain metastasis despite of salvage chemotherapy. Five stage Ⅰ seminoma patients were treated radiotherapis and stage Ⅱ, Ⅲ, Ⅳ patients treated BEP (bleomycin and etoposide and cispatin) chemotherapies. One choricaricinoma patient expried in 5 months. The overall survival rate in total 22 patients was 86.4% at the median follow up of 5.65 years. Conclusions: In this study, we had only 22 cases of testicular tumor, but could follow-up them up to 12 years. Most patients showed excellent survival, and it was not related with initial pathologic presentations or the clinical stage. So the authors suggest the need for further investigation about the new therapeutic modalities of more potent and less toxic.