• 한국소음진동공학회논문집
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• 제26권6_spc호
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• pp.680-686
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• 2016

In an optical disc archive system, disc insertion process is an important part. Furthermore, dynamic analysis with the contact area between multi-bent leaf spring and a disc should be considered because the contact area is moved when the disc is inserted into the cartridge. In this paper, a finite element model of disc insertion was constructed based on dynamic characteristics, vertical stiffness, and dynamic response. The disc insertion model was validated with the experimental results. To identify the dynamic response of the disc induced by the changed contact area, applied force to the disc and the stiffness of the multi-bent leaf spring were analyzed. As the results, the factors which cause the failure of the disc insertion were investigated.

• 한국CDE학회논문집
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• 제20권3호
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• pp.263-268
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• 2015

Due to an increased sitting time in work, lumbar disc disease is one of the most frequent diseases in modern days, and this occasionally requires surgery for treatment. Endoscopic disc surgery, one of the common disc surgeries, requires a process of inserting a guide needle to the target disc for which the insertion path is manually planned by drawing lines on the patient's skin while monitoring the fluoroscopic view of the lumbar. Such procedure inevitably exposes both surgeon and patient to the fluoroscopy radiation emitted from the c-arm for a long time. To reduce the radiation exposure time, this study proposes a computer assisted method of calculating the 3D guide needle path by using 2D c-arm images of the disc in 3 different angles. Additionally, a method of the guide robot control based on the 3D needle path was developed by implementing the Hand-eye Calibration method to calculate the transformation matrix between the c-arm and robot base coordinate systems. The proposed system was then tested for its accuracy.

• Journal of Korean Neurosurgical Society
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• 제46권3호
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• pp.261-264
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• 2009

Vascular injury during lumbar disc surgery is a rare but potentially life-threatening complication. It has been managed by open vascular surgical repair. With recent technologic advance, endovascular treatment became one of effective treatment modalities. We present a case of a 32-year-old woman who suffered with common iliac artery injury during lumbar disc surgery that was treated successfully by endovascular repair with temporary balloon occlusion and subsequent insertion of a covered stent. Temporary balloon occlusion for 1.5 hours could stop bleeding, but growing pseudoaneurysm was identified at the injury site during the following 13 days. It seems that the temporary balloon occlusion can stall bleeding from arterial injury for considerable time duration, but cannot be a single treatment modality and requires subsequent insertion of a covered stent.

• Journal of Oral Medicine and Pain
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• 제38권2호
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• pp.149-159
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• 2013

이 연구의 목적은 측두하악관절장애와 외측 익돌근의 수평적 형태 간의 연관성을 조사하는 것이다. 이를 위해 10대에서 50대까지 연령군별로 각 남녀 15명씩 임의로 선정한 총 150명의 측두하악관절장애 환자에서 자기공명영상의 수평면 및 시상면상에서 나타난 외측 익돌근 및 측두하악관절의 형태적 특성을 조사하였다. 조사한 해부학적 특성은 외측 익돌근의 최대폭경, 수평 부착각도, 관절원판의 위치, 과두의 변형여부, 관절 삼출액 여부 등이며, 또한 전이부의 통증여부, 과두 주변의 압통 유무와 같은 임상적 소견이 포함되었다. 이들 해부학적 특성 및 임상적 소견의 상호 간 관련성을 분석한 결과, 비정복성 관절원판 변위를 가진 경우 외측 익돌근의 부착각도가 유의하게 높았으며 전이부에 통증이 있는 경우에는 최대 폭경이 유의하게 큰 것으로 나타났다. 뿐만 아니라 연령이 낮을수록 부착각도가 유의하게 높았으며 남성에서 최대 폭경이 더 큰 것으로 나타났다. 위의 결과를 통해 외측 익돌근 수평 부착각도가 관절원판 변위와 유의한 관련성이 있으며 전이부의 통증이 최대 폭경을 증가시키는 것으로 생각된다. 결론적으로 외측 익돌근의 높은 수평 부착각도가 관절원판 변위 발생의 중요한 해부학적 기여요인이 될 수 있으며, 측두하악관절의 통증은 외측 익돌근의 활성에 영향을 줄 수 있을 것으로 추정된다.

• 한국컴퓨터정보학회논문지
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• 제22권12호
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• pp.125-130
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• 2017

Screw insertion surgery is frequently required among surgical procedures. Especially, very careful attention should be paid to the insertion of screw in the operation of the cervical vertebra. Therefore, there is a need for a guide that allows the surgeon to reliably and promptly perform treatment by calculating the desired insertion angle and length for screw insertion. In this study, the center and direction of the pedicle were calculated through 3D modeling and 3D vector numerical analysis using the CT or MRI image of the patient for the safe operation of the guide, and based on this, After that, we will implement surgical guide based on this.

• 한국정밀공학회지
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• 제24권8호통권197호
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• pp.122-129
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• 2007

To evaluate the effect of artificial disc implantation and fusion on the biomechanics of adjacent motion segment, a nonlinear three-dimensional finite element model of whole lumbar spine (L1-S1) was developed. Biomechanical analysis was performed for two different types of artificial disc, ProDisc and SB $Charit{\acute{e}}$ III model, inserted at L4-L5 level and these results were also compared with fusion case. Angular motion of vertebral body, forces on the spinal ligaments and facet joint under sagittal plane loading with a compressive preload of 150 N at a nonlinear three-dimensional finite element model of Ll-S1 were compared. The implant did not significantly alter the kinematics of the motion segment adjacent to the instrumented level. However, $Charit{\acute{e}}$ III model tend to decrease its motion on the adjacent levels, especially in extension motion. Contrast to motion and ligament force changes, facet contact forces were increased in the adjacent levels as well as implanted level for constrained instantaneous center of rotation model, i.e. ProDisc model.

• Journal of Korean Neurosurgical Society
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• 제61권4호
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• pp.530-536
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• 2018

We present two cases of unexpected postoperative intractable cervicalgia due to over-sized implant insertion during simple anterior cervical decompression and fusion (ACDF) or artificial disc replacement (ADR). These patients experienced severe cervicalgia mostly related to their neck motion even after standard cervical operations. In both cases, the restored disc heights after the operations were prominently greater than the preoperative disc heights. The patients had not responded to any of the conservative treatments, and unloading of these excessively distracted segments through ultimate revision surgery led to dramatic pain relief. This report emphasizes the increase in distractional forces that takes place after a standard ACDF or ADR, as well as the importance of a proper sized implant. It also includes the reviews of other biomechanical or clinical reports dealing with this issue, thereby cautioning the surgeons not to disregard these factors, which might have an adverse effect in patients with cervicalgia even after radiographically successful cervical procedures.

• Journal of Korean Neurosurgical Society
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• 제40권2호
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• pp.79-83
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• 2006

Objective : The purpose of this study was to describe a surgical technique of axillary approach of percutaneous endoscopic interlaminar discectomy for L5-S1 disc herniation and its preliminary results. Methods : From July 2002 to September 2003, 101 patients with lumbar radiculopathy due to L5-S1 disc herniation, who were treated by percutaneous interlaminar endoscopic discectomy, were retrospectively reviewed. There were 57 males and 44 females with a mean age of 44.8 years [range, 18 to 62 years]. The surgery consisted of needle insertion into the epidural space via the interlaminar space, sequential dilatation, and endoscopic discectomy through the axillary area of the S1 root. Results : The mean follow-up period was 14.5 months and the average surgical time was 41 min. According to the modified Macnab criteria, 44 patients [43.6%] had excellent outcomes, 49 [48.5%] had good results and only 8 [78%] had fair or poor outcomes. Four patients had a revision microdiscectomy due to incomplete removal of disc fragment. There were no major complications related to this surgical approach. Conclusion : Axillary approach of percutaneous endoscopic interlaminar discectomy is safe and effective procedure for the treatment of L5-Sl disc herniation. It combines the advantages of MED and conventional percutaneous endoscopic discectomy.

• The Korean Journal of Pain
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• 제12권2호
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• pp.258-262
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• 1999

Sacral meningeal cyst is usually asymtomatic, but may be responsible for sciatic pain syndromes and other clinical symptoms. Sacral meningeal cyst might be suspected when definite explanation for the clinical symptom, such as herniation of the intervertebral disc or spinal stenosis is not found. Plain films and CT may suggest the presence of sacral meningeal cyst, but MR is the current imaging study of choice. Evaluation of the correlation between the symptom and the cyst is as important as detection of it. We have experienced a case of sacral meningeal cyst detected during caudal epidural block. The patient complained of low back pain radiating to thigh. Plain films and lumbar spine CT showed no remarkable finding except disc bulging. During caudal epidural needle insertion, there was leakage of clear CSF, and intrasacral cystic shadow was visualized by dye injection. MR confirmed sacral meningeal cyst.

• 한방재활의학과학회지
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• 제27권2호
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• pp.39-54
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• 2017

Objectives This study aimed to search the Chinese literature on acupotomy for lumbar disc herniation and to analyze their methodologies. Methods Using 4 Chinese databases (CBM [www.sinomed.ac.cn], CNKI [www.cnki.net], WANFANG [www.wanfangdata.com], and WEIPU [www.cqvip.com]), we searched for clinical trials conducted in China over the past 10 years on acupotomy for lumbar disc herniation. The search terms used were "(腰椎椎間板脫出症 or 椎間板脫出症 or 椎間板脫出) and (针刀or 针刀松解术)" and we selected only meta-analyses that were published before December 2016. From among these meta-analyses, we excluded duplicates and selected the remaining 36 randomized controlled trials (RCTs) for our final analysis. Results The largest numbers of acupotomy papers were published in 2008 and 2013 (8 papers each). The average number of subjects was 120; the most common treatment method used for the control group was standard acupuncture (in 11 papers), and the most common concurrent treatment in the treatment group was massage (in 10 papers). The most common site of needle insertion was between the spinous processes, or at less than 0.5 cm on either side of the spinous processes (in 24 papers). The most common site of adhesion lysis was at the transverse process (in 24 papers). Two studies were blinded, and the mean Jadad score was 1.17. Conclusions A large number of RCTs on the use of acupotomy for lumbar disc herniation are conducted every year in China, and the procedure has been shown to be very effective, with few adverse effects. However, the average quality of the studies was not very high. Based on our study, we expect several high-quality clinical trials on acupotomy to be conducted in Korea in the future.