• 한국통신학회논문지
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• 제22권1호
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• pp.81-88
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• 1997

Wavelength tunable, narrowbandwidth wvelength filters in compound semiconductor have been modeled, fabricated, and characterized. In order to obtain a narrow bandpass characteristics at 1.55.$\mu$m, a highly asymmertrical directional coupler structure composed of a strongly guided ridge waveguide and a weakly guided strip-loaded waveguide was used. The optimized filter structure modeling has been obtained by using the spectral index method, effective index method, and the coupled mode theory. Operation at a center wavelength a 1.537.mu.m with a bandwidth of 1.8nm and transfer efficiency of 50-70% is experimentally achieved. For the purpose of center wavelength tuning, the carrier injection in p-n diode structure has been theoretically investigated. It has been found that the tuning range of nanometer can be easily obtained by moderate amount carrier injection. We also found that the bandwidth becomes broad as the center wavelength tuning increases.

• 대한음성언어의학회:학술대회논문집
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• 대한음성언어학회 2017년도 제46차 춘계학술대회
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• pp.4-5
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• 2017

• The Korean Journal of Pain
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• 제28권1호
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• pp.52-56
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• 2015

Painful periarticular calcification most commonly occurs within the rotator cuff of the shoulder and rarely around the elbow, hip, foot, and neck. As acute inflammatory reaction develops, severe pain, exquisite tenderness, local swelling, and limitation of motion with pain occur. In case of calcific tendinitis of the shoulder, it can be easily diagnosed according to the symptoms and with x-ray. However, in lesions of the hip, as it is a rare location and usually involves pain in the posterolateral aspect of the thigh, which can simulate radicular pain from a lumbar intervertebral disc, it could be difficult to diagnose. Hence, physicians usually focus on lumbar lesions; therefore, misdiagnosis is common and leads to a delayed management. Here, we report the case of a 30-year-old female patient with calcific tendinitis of the rectus femoris that was successfully managed with ultrasound-guided steroid injection. This study offers knowledge about the rectus femoris calcification.

• Clinics in Shoulder and Elbow
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• 제22권4호
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• pp.210-215
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• 2019

Background: This study was undertaken to evaluate early clinical outcomes of ultrasound-guided suprascapular nerve block (SSNB) using a proximal approach, as compared with subacromial steroid injection (SA). Methods: This retrospective study included a consecutive series of 40 patients of SSNB and 20 patients receiving SA, from August 2017 to August 2018. The visual analogue scale (VAS), American Shoulder Elbow Surgeon's score (ASES), University of California, Los Angeles score (UCLA), the 36 health survey questionnaire mental component summary (SF36-MCS), physical component summary (PCS), and range of motion (forward elevation, external rotation, and internal rotation) were assessed for clinical evaluations. Results: Compared with the baseline, VAS, and ranges of motion in the SSNB group significantly improved at the 4-week follow-up (VAS scores improved from $6.7{\pm}1.6$ to $4.3{\pm}2.4$, p<0.001; all ranges of motion p<0.05), while other variables showed no statistically significant differences. All clinical variables were significantly improved in the SA group (p<0.05). However, all clinical scores at the 4-week follow-up showed no significant difference between groups. Conclusions: Ultrasound-guided SSNB using proximal approach provides significant pain relief at 4-weeks after treatment, with statistically significant difference when compared with SA, suggesting that SSNB using proximal approach is a potentially useful option in managing shoulder pain. However, in the current study, it was less effective in improving shoulder function and health-related quality of life, compared with SA.

• 대한정형외과학회지
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• 제55권5호
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• pp.418-425
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• 2020

목적: 무릎 내측 구획 골관절염 환자에서 초음파 유도하 무릎 관절강내 경 반월상 연골 주사를 소개하고 그 임상적 결과를 분석하고자 하였다. 대상 및 방법: 2019년 3월부터 2019년 7월까지 3개월 이상 무릎 통증이 지속되었던 무릎 내측 구획 골관절염 환자 중 초음파 유도하 경 반월상 연골 주사를 시행한 36명의 환자에 대해서 후향적으로 분석하였다. 초음파 유도하 척추 바늘을 이용하여 무릎 관절강내 내측 구획에 corticosteroid와 국소마취제를 주사하였다. 시술 전, 1주, 4주, 8주째 신체진찰을 하였고 numeric pain rating scale (NRS), Lequesne index, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) 점수를 측정하였다. 시간에 따른 NRS, Lequesne index, WOMAC 점수를 분석하였으며 상당한 호전이 있었던 환자들의 비율을 분석하였다. 또한 내측 구획 골관절염의 단계에 따른 NRS, Lequesne index, 상당한 호전이 있었던 환자들의 비율을 분석하였다. 결과: 시술 전과 비교하여 1주, 4주, 8주째 NRS와 Lequesne index는 감소하였고 8주째까지 통증 감소 효과는 차이 없이 지속되었다. 상당한 호전이 있었던 환자들의 비율은 1주, 4주, 8주째 각각 50.0%, 47.2%, 52.8%였으며 8주째까지 통증 감소 효과는 차이없이 지속되었다. 시술 전과 비교하여 1주, 4주, 8주째 WOMAC 점수는 감소하였고 8주째까지 차이 없이 감소가 지속되었다. 골관절염 1, 2단계 환자들에서 상당한 호전이 있었던 환자들의 비율이 골관절염 3, 4단계 환자들보다 1주, 4주, 8주째 유의하게 많았다(p<0.05). 결론: 무릎 내측 구획 골관절염 환자에서 초음파 유도하 무릎 관절강내 경 반월상 연골 주사는 평균 8주 이상의 통증 감소 및 기능 개선 효과를 보였다. 특히 내측 구획 골관절염 1, 2단계 환자에서는 통증 감소 효과가 더 컸다.

• 대한영상의학회지
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• 제82권3호
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• pp.589-599
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• 2021

목적 대퇴동맥을 통한 시술 후 발생한 의인성 가성동맥류에 대한 초음파 유도하 경피적 트롬빈 주입 치료의 성공률과 합병증 발생률, 치료의 실패에 관련된 요인 등을 분석해 보고자 한다. 대상과 방법 2009년 3월부터 2019년 6월까지 대퇴동맥에 발생한 의인성 가성동맥류에 대하여 영상의학과에서 초음파 유도하 경피적 트롬빈 주입 치료를 받은 30명의 환자들을 후향적으로 분석하였다. 대퇴동맥의 가성동맥류는 초음파 또는 전산화단층촬영을 사용하여 진단하였으며, 환자와 병변의 특성에 대하여 분석하였다. 결과 환자들의 평균 나이는 67.8세였으며, 가성동맥류의 평균 직경은 20.88 mm (5~40 mm)였다. 첫 치료에서 20명의 환자에서 완전한 혈전형성을 보였으며(66.6%), 10명의 환자에서 부분적 혈전형성을 보였다(33.3%). 혈소판 수가 낮은 환자(< 130 k/µL)에서 부분적 혈전형성의 가능성이 유의하게 높았다. 모든 환자에서 시술 관련 합병증은 보이지 않았다. 결론 대퇴동맥의 의인성 가성동맥류에 대한 초음파 유도하 트롬빈 주입 치료는 안전하고 효과적인 우선적 치료 방법이다.

• The Korean Journal of Pain
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• 제36권1호
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• pp.98-105
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• 2023

Background: Ultrasound-guided first sacral transforaminal epidural steroid injection (S1 TFESI) is a useful and easily applicable alternative to fluoroscopy or computed tomography (CT) in lumbosacral radiculopathy. When a needle approach is used, poor visualization of the needle tip reduces the accuracy of the procedure, increasing its difficulty. This study aimed to improve ultrasound-guided S1 TFESI by evaluating radiological S1 posterior foramen data obtained using three-dimensional CT (3D-CT). Methods: Axial 3D-CT images of the pelvis were retrospectively analyzed. The radiological measurements obtained from the images included 1st posterior sacral foramen depth (S1D, mm), 1st posterior sacral foramen width (S1W, mm), the angle of the 1st posterior sacral foramen (S1A, °), and 1st posterior sacral foramen distance (S1ds, mm). The relationship between the demographic factors and measured values were then analyzed. Results: A total of 632 patients (287 male and 345 female) were examined. The mean S1D values for males and females were 11.9 ± 1.9 mm and 10.6 ± 1.8 mm, respectively (P < 0.001); the mean S1A 28.2 ± 4.8° and 30.1 ± 4.9°, respectively (P < 0.001); and the mean S1ds, 24.1 ± 2.9 mm and 22.9 ± 2.6 mm, respectively (P < 0.001); however, the mean S1W values were not significantly different. Height was the only significant predictor of S1D (β = 0.318, P = 0.004). Conclusions: Ultrasound-guided S1 TFESI performance and safety may be improved with adjustment of needle insertion depth congruent with the patient's height.

• 대한기관식도과학회지
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• 제19권1호
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• pp.19-24
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• 2013

Objective The objective was to evaluate changes in swallow safety and dietary status after the transcutaneous injection of botulinum toxin into the upper esophageal sphincter in a series of outpatients with dysphagia. Methods Patients who were at risk for aspiration and who had an unsuccessful trial of swallowing therapy were admitted to the study. All patients showed significant pooling of fluids in the pyriform sinus. All patients were treated in the office; none had previous esophageal dilatation. The upper border of the cricoid cartilage was identified using standard electromyogram procedures and botulinum toxin was injected. Outcomes were assessed using the penetration-aspiration scale, NIH swallowiwng safety score, patients' short-term and long-term subjective impressions of their ability to swallow, and change in dietary status. Results Ten patients underwent an instrumental evaluation of swallowing function. Of the 10 patients, 9 showed an overall improvement in their ability to take an oral diet safely. The penetration-aspiration scale, NIH swallowiwng safety score, patients' short-term and long-term subjective impressions of their ability to swallow, and change in dietary status were significantly improved after office-based botox injection. Conclusion Office-based EMG guided botox injection to the cricopharyngeus muscle is a simple, safe, and effective tool for dysphagia patients. Injection of Botox in the office should be considered when the dysphagia pattern is aspiration after swallow.

• Clinics in Shoulder and Elbow
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• 제24권3호
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• pp.166-171
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• 2021

Background: This study aims to compare the clinical outcomes of steroid injections during the rehabilitation period after arthroscopic rotator cuff repair (ACRC). Methods: Among patients who underwent ARCR, 117 patients who met the inclusion and exclusion criteria were enrolled. Pain and range of motion (ROM) recovery at the 3-, 6-, and 24-month follow-up visits and functional outcome at the 24-month follow-up were compared between 45 patients who received ultrasound-guided subacromial steroid injection at postoperative week 4 or 6 and 72 patients who did not. Functional outcome was assessed using the American Shoulder and Elbow Surgeons (ASES) score and Constant score. Healing of the repaired tendon and retear were observed at the 6-month follow-up via magnetic resonance imaging (MRI) or computed tomography (CT) arthrography. Results: At the 3-month follow-up, the steroid injection group showed lower visual analog scale scores than the control group (p<0.05) and showed faster recovery of forward flexion and internal rotation (p<0.05). From the 6-month follow-up, the two groups did not show differences in pain and ROM, and the ASES score and Constant score also did not significantly differ at the 24-month follow-up. The two groups did not differ in retear rate as determined by MRI or CT arthrography at the 6-month follow-up. Conclusions: This study demonstrated that ultrasound-guided subacromial steroid injection at 4 or 6 weeks after ARCR leads to quick pain reduction and ROM recovery until 3 months after surgery. Therefore, subacromial steroid injection is speculated to be an effective and relatively safe method to assist rehabilitation.

• The Korean Journal of Pain
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• 제23권2호
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• pp.137-141
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• 2010

Background: Facet joint have been implicated as a source of chronic low back pain. Radiofrequency denervation has demonstrated the most solid evidence. To increase safety and efficacy of treatment, computed tomography (CT) guidance injection has been used in several disease. The purpose of this study was to evaluate the efficacy of CT-guided radiofrequency rhizotomy in the treatment of facet joint pain. Methods: A total of 40 patients were randomized to undergo radiofrequency facet joint denervation under CT guidance or C-arm guidance. All patients were examined visual analogue scale (VAS) score before treatment, 1 month, and 3 months after treatment. Results: The VAS in both groups showed significant improvement over the 1-month interval. No significant difference in the VAS score among the group was observed. Conclusions: In this study there was no significant difference between CT guidance lumbar rhizotomy and C-arm guidance lumbar rhizotomy. Therefore CT-guided radiofrequency denervation of the lumbar facet joint was a minimally invasive technique that appears effective.