• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.3
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• pp.284-290
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• 2012

In this research, a new type of haptic master device using electrorheological(ER) fluid for minimally invasive surgery(MIS) is devised and control performance of the proposed haptic master is evaluated. The proposed haptic master consists of ER bi-directional clutch/brake for 2 DOF rotational motion(X, Y) using gimbal structure and ER brake on the gripper for 1 DOF rotational motion (Z). Using Bingham characteristic of ER fluid and geometrical constraints, principal design variables of the haptic master are determined. Then, the generation of torque of the proposed master is experimentally evaluated as a function of applied field of voltage. A sliding mode controller which is robust to uncertainties is then designed and empirically realized. It has been demonstrated via experiment that the proposed haptic master associated with the controller can be effectively applied to MIS in real field conditions.

• Journal of Chest Surgery
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• v.53 no.5
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• pp.313-316
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• 2020

Esophageal perforation after endoscopic ultrasound-guided fine-needle aspiration for mediastinal staging is a rare but severe complication. We report 2 cases of patients with esophageal perforation who were treated using video-assisted thoracoscopic surgery in combination with esophageal stenting. Through these cases, the feasibility of minimally invasive thoracic surgery was evaluated.

• Korean Journal of Head & Neck Oncology
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• v.31 no.2
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• pp.1-5
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• 2015

The role of transoral robotic surgery in the treatment of upper aerodigestive tract tumor has expanded in recent. Since the approval of the da Vinci system, the number of transoral robotic surgery has increased significantly. The main indications of transoral robotic surgery are tumors of oropharynx, hypopharynx, and larynxs. Transoral robotic surgery is a minimally invasive surgical approach that offers surgical access to the laryngopharynx without the morbidity of open surgeries while achieving excellent oncologic and functional outcomes. The appropriate application of transoral robotic surgery is still being investigated and previous studies supports transoral robotic surgery as a viable option in the management of upper aerodigestive tract tumor.

• Journal of Chest Surgery
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• v.48 no.2
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• pp.126-128
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• 2015

A 75-year-old woman who had previously undergone a double valve replacement was admitted to Asan Medical Center because of severe bioprosthetic mitral valve dysfunction and tricuspid regurgitation. Under hypothermic fibrillatory arrest without aortic cross-clamping, minimally invasive mitral and tricuspid valve surgery was performed via a right minithoracotomy.

• Journal of Chest Surgery
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• v.51 no.5
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• pp.363-366
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• 2018

One of the complications of permanent pacemaker implantation is unintended phrenic nerve stimulation. A 15-year-old boy with a permanent pacemaker presented with chest discomfort due to synchronous chest wall contraction with pacing beats. Even after reprogramming of the pacemaker, diaphragmatic stimulation persisted. Therefore, we performed thoracoscopic phrenic nerve insulation using a Gore-Tex patch to insulate the phrenic nerve from the wire. A minimally invasive approach using a thoracoscope is a feasible option for retractable phrenic nerve stimulation after pacemaker implantation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.9
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• pp.65-70
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• 2015

Minimal line length enables low-cost construction of the transmission lines and low-loss transportation of electric power. This paper presents a derivation to determine the coordinate and length of the straight line that minimally connects two perpendicular lines x-axis and y-axis via a specific point, using the optimization technique. The author shows a formula to obtain the minimal length, which is represented by the cube root of the coordinate given by the specific point. Case studies have been also discussed to prove the optimal solutions derived by the proposed formula.

• Journal of Chest Surgery
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• v.44 no.4
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• pp.288-291
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• 2011

Postoperative coronary arterial spasm is a rare but potentially fatal complication. A 51-year-old male patient with a history of a reactive ergonovine stress test coronary angiogram developed refractory coronary artery spasm after undergoing minimally invasive direct coronary artery bypass grafting of the left anterior descending coronary artery. The patient was successfully managed with rapid implementation of intra-aortic balloon-pump counter pulsation and extracorporeal membrane oxygenation.

• Journal of Chest Surgery
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• v.34 no.5
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• pp.399-402
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• 2001

최근 심폐기를 사용하지 않는 최소침습성 직접 관상동맥우회술(MIDCAB procedure)은 심장수술 분야에서 급속도로 발전을 거듭하고 있다. 금번 저자들은 전에 만들어 준 좌전하행지 이식편이 막혀 관상동맥 재수술을 필요로 하였으나 좌내 유동맥의 혈류량의 불충분하였다고 생각되었다. 1례에서 최소 침습 수기를 통한 액와-관상동맥 우회술을 시행하여 만족스러운 결과를 얻었기에 문헌고찰과 함께 보고하고자 한다.

• Smart Structures and Systems
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• v.11 no.3
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• pp.283-297
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• 2013

An innovative cage for spinal fusion surgery is presented within this work. The cage utilizes shape memory alloy for its hinge actuation. Because of the use of SMA, a smaller incision is needed which makes the cage deployment minimally invasive. In the development of the cage, a model for predicting the torsional behavior of SMAs was developed and verified experimentally. The prototype design of the cage was developed and manufactured. The prototype was subjected to static tests per ASTM specifications. The cage survived all of the tests, alluding to its safety within the body.

• The Korean Journal of Pain
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• v.28 no.4
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• pp.275-279
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• 2015

Facet joint synovial cysts are usually associated with osteoarthritis of the adjacent facet joint and/or spondylolisthesis. In between the conservative and operative ends of the treatment spectrum lie minimally invasive techniques such as cyst rupture using epiduroscopy. In this report, we describe an 82-year-old male patient presenting with low back pain radiating to his lower left extremity and associated paresthesia. Magnetic resonance imaging of the lumbar spine revealed a synovial cyst at left L4/5 facet joint. Using epiduroscopy, the cyst was mechanically ruptured by popping it with the tip of the scope. The patient remained symptom-free at his successive visits until 12 months after the procedure, and was opened for desired follow up.