• 대한기계학회논문집A
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• 제26권2호
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• pp.314-321
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• 2002

An endoscope is usually inserted into the human body for the inspection of the gullet, stomach, and large intestine (colon) and this may cause discomfort to patients and damage to tissues during diagnostic or therapeutic procedures. This situation necessitates a self-propelling endoscope. There are many kinds of mechanism to move in a rigid pipe. However, these methods are difficult to apply directly to the endoscope. The main reason is that human intestine cannot be considered as a uniform, straight, and rigid pipe. This paper proposes a flexible loop wheel mechanism, which is adaptable to the human intestine. This mechanism is designed and fabricated by a simple modeling, and tested by an experiment. Finally, the actuator is inserted into the pig colon.

• Journal of Korean Neurosurgical Society
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• 제45권2호
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• pp.67-73
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• 2009

Objective : Although endoscopic procedures for lumbar disc diseases have improved greatly, the postoperative outcomes for high grade inferior migrated discs are not satisfactory. Because of anatomic limitations, a rigid endoscope cannot reach all lesions effectively. The purpose of this study was to determine the feasibility of endoscopic transforaminal suprapedicular approach to high grade inferior-migrated lumbar disc herniations. Methods : Between May 2006 and March 2008, a suprapedicular approach was performed in 53 patients with high grade inferior-migrated lumbar disc herniations using a rigid endoscope and a semi-rigid flexible curved probe. One-to-four hours after surgery, the presence of remnant discs was checked with MRI. The outcomes were evaluated with the visual analogue scale (VAS) score and the Oswestry Disability Index (ODI) one week after surgery. Results : The L2-3 level was involved in 2 patients and the L3-4 level was involved in 14 patients, while the L4-5 level was involved in 39 patients. There were single piece-type in 34 cases and a multiple piece-type in 19 cases. Satisfactory results were obtained in all cases. The mean preoperative VAS for leg pain was $9.32{\pm}0.43$ points (range, 7-10 points), whereas the mean ODI was $79.82{\pm}4.53$ points (range, 68-92 points). At the last follow-up examination, the mean postoperative VAS for leg pain was $1.78{\pm}0.71$ points and the mean postoperative ODI improved to $15.27{\pm}3.82$ points. Conclusion : A high grade inferior migrated lumbar disc is difficult to remove sufficiently by posterolateral endoscopic lumbar dscectomy using a rigid endoscope. However, a satisfactory result can be obtained by applying a transforaminal suprapedicular approach with a flexible semi-rigid curved probe.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 추계학술대회 논문집
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• pp.279-280
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• 2007

• Journal of Mechanical Science and Technology
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• 제20권7호
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• pp.1012-1018
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• 2006

Diagnosis and treatment using the conventional flexible endoscope in gastro-intestinal tract are very common since advanced and instrumented endoscopes allow diagnosis and treatment by introducing the human body through natural orifices. However, the operation of endoscope is very labor intensive work and gives patients some pains. As an alternative, therefore, the capsule endoscope is developed for the diagnosis of digestive organs. Although the capsule endoscope has conveniences for diagnosis, it is passively moved by the peristaltic waves of gastro-intestinal tract and thus has some limitations for doctor to get the image of the organ and to diagnose more thoroughly. As a solution of these problems, various locomotive mechanisms for capsule endoscopes are introduced. In our proposed mechanism, the capsule-type microrobot has synchronized multiple legs that are actuated by a linear actuator and two mobile cylinders inside of the capsule. For the feasibility test of the proposed microrobot, a series of in-vitro experiments using small intestine without incision were carried out. From the experimental results, our proposed microrobot can advance along the 3D curved and sloped path with the velocity of about $3.29\sim6.26mm/sec$ and $35.1\sim66.7%$ of theoretical velocity. Finally, the proposed locomotive mechanism can be not only applicable to micro capsule endoscopes but also effective to advance inside of gastro-intestinal tract.

• 한국임상수의학회지
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• 제28권6호
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• pp.555-561
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• 2011

본 연구에서는 중 소형견에서 1개의 복강경 통로를 통한 내시경적 담낭 제거술을 실시함으로써, 개에서 최소 침습적 수술로 담낭 절제술을 실시할 수 있는 방법을 확립하기 위하여 실시하였다. 실험 동물로 총 3마리의 수컷 비글견 ($10.3{\pm}0.62$ kg)을 이용하였으며 배꼽 주위에 하나의 절개창을 만든 후 단일 통로 내시경 시스템을 장착하였다. 이 시스템을 통해 내시경과 Maryland 복강경용 겸자로 담낭을 견인, 제거하였다. 3마리 모두 성공적으로 담낭 절제술을 실시하였으며, 수술 후 감염과 같은 합병증은 발생하지 않았다. 또한 술전, 술후를 비교한 혈액, 혈청 검사상에서도 특이적인 소견은 관찰되지 않았다. 술후 7일 후에 이루어진 부검 소견에서도 출혈 및 담즙의 유출 및 복막염 등과 같은 부작용은 관찰되지 않았다. 따라서 본 연구를 통해, 단일 통로를 이용한 내시경 유도하 담낭 절제술은 중소형견에서 실시할 수 있는 복강 수술 방법 중 최소한의 절개를 통해 비침습적으로 이루어질 수 있는 유용한 수술 방법이라 할 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.854-857
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• 2001

At present, colonoscopy is performed by means of quite long and flexible endoscopes and controlled manually. Although the flexibility of the distal tip allows the endoscope to follow the tortuous path of the colon, the insertion of the endoscope requires the endoscopist to exert forces on and to perform rotations of the proximal end; these actions cause discomfort to the patient. Though self-propelling colonoscopic systems has been suggested to overcome these problems, it is difficult to pass through highly curved regions of the intestine. In this paper, we introduce a steering mechanism for a self-propelling coloinlscope, the smart capsule, which has three actuator units. The mechanism is designed not only to move forward and backward but also to pass through the curved regions. We derived the governing equations of this mechanism. Active movements and motion control are developed.

• 한국광학회지
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• 제33권6호
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• pp.295-302
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• 2022

FHD급 고해상도 연성 내시경을 설계하기 위한 wedge prism 적용 방법을 연구하였다. 기존의 연성 내시경 광학계의 경우, 넓은 피사계 심도 범위에서 동일한 결상 성능을 얻기 위해 F 넘버를 크게 가져가거나 액체 렌즈를 적용하였다. 하지만 이는 추가적인 light guide와 기구물을 필요로 하여 광학계의 직경이 커진다는 문제점이 있다. 이를 해결하기 위해, 연성 내시경 광학계에 2매의 wedge prism을 적용하여 각 물체거리별로 상거리를 조절하였다. 먼저 설계한 내시경 광학계에 2매의 wedge prism을 대칭으로 배치하고, 각 물체거리별로 목표 결상 성능을 만족하는 상거리 값을 도출하였다. 그 다음, 상거리를 조절하기 위한 wedge prism 디센터 값을 도출하였다. 이 두 가지 데이터를 조합하여, 각 물체거리에서 목표 결상 성능을 만족하는 wedge prism 디센터 값을 다중구성으로 적용하였다. Wedge prism을 적용한 최적 설계 결과, 100 mm-7 mm의 전체 피사계 심도 범위에서, 분해능 178 cycles/mm에 대한 변조전달함수 20% 이상의 목표 결상 성능을 만족하였다.

• Current Optics and Photonics
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• 제7권6호
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• pp.755-760
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• 2023

In this paper, an illumination optical system that can mitigate the saturation phenomenon in the center of an image (caused by the typical flexible-endoscope illumination system using LEDs with Lambertian light distribution) is designed. When an LED with Lambertian light distribution is used as a light source, the amount of light in the center of the endoscopic illumination system is relatively high, compared to the periphery, causing saturation in the image. Since this phenomenon causes difficulty in detecting the patient's lesion, it is necessary to find a lighting-system design that can alleviate the saturation phenomenon. Therefore, in this paper a lighting system with bat-wing light distribution, which can lower the intensity at the center and secure the maximum amount of light at the maximum light distribution angle, is designed. In addition, to check the performance of the designed lighting system, a simulation of illumination and luminance is conducted for a system using a common aspherical lens with otherwise the same components. As a result, it is confirmed that the lighting system designed in this paper effectively reduces the luminance value at the center and secures more luminance values at the periphery than the familiar lighting system.

• Clinical Endoscopy
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• 제51권6호
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• pp.552-557
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• 2018

Although colonoscopy was originally a diagnostic imaging procedure, it has now expanded to include an increasing range of therapeutic interventions. These procedures require precise maneuvers of instruments, execution of force, efficient transmission of force from the operator to the point of application, and sufficient dexterity in the mobilization of endoscopic surgical instruments. The conventional endoscope is not designed to support technically demanding endoscopic procedures. In case of colonoscopy, the tortuous anatomy of the colon makes inserting, moving, and orientating the endoscope difficult. Exerting excessive pressure can cause looping of the endoscope, pain to the patient, and even perforation of the colon. To mitigate the technical constraints, numerous technically enhanced systems have been developed to enable better control of instruments and precise delivery of force in the execution of surgical tasks such as apposing, grasping, traction, counter-traction, and cutting of tissues. Among the recent developments are highly dexterous robotic master and slave systems, computer-assisted or robotically enhanced conventional endoscopes, and autonomously driven locomotion devices that can effortlessly traverse the colon. Developments in endoscopic instrumentations have overcome technical barriers and opened new horizons for further advancements in therapeutic interventions. This review describes examples of some of these systems in the context of their applications to advanced therapeutic colonoscopy.

• 대한두경부종양학회지
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• 제28권2호
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• pp.114-117
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• 2012

Background and Objectives : To assure the surgical completeness of the gasless endoscopic thyroidectomy via single incision axillary approach using flexible videoscope which provide wide angle and working space, we compared single incision axillary approach and axillo-areolar approach by means of clinical, surgical outcomes. Materials and Methods : From March 2011 to July 2012, 24 patients who had underwent endoscopic thyroidectomy via transaxillary approach were enrolled. Of total, 17 patients underwent single incision axillary approach(group I) and the other 7 underwent axillo-areolar approach(group II). Results : Patient demographics, surgical indications were similar between the two groups. The operating time(group I 144.6min, group II 153.6 min ; p=.29), blood loss(group I : 55.4cc, group II : 35.7cc : p=.64), hospital stay(group I : 4.2days, group II : 4.4 days ; p=.65) were similar in the two groups. Overall, two patients in group I(2/17, 11.8%) experienced postoperative complications, including one hematoma and one seroma. Due to narrow working space, one patient was change to axillo-areolar approach during single incision axillary approach with $30^{\circ}$ rigid endoscope. Conclusion：Single incision axillary approach is safe and effective similar to other endoscopic thyroidectomy methods using flexible videoscope. Different with $30^{\circ}$ rigid endoscope, 10-mm flexible videoscope can put inside the axillary inicision site in different axis with endoscopic instruments. This difference in endoscopic axis help to prevent crash with endoscopic instrument.