The key of pocket dissection in transaxillary dual-plane breast augmentation : how to control inferior malposition of smooth implants : 매끄러운 보형물의 아래쪽 이동을 줄이는 방법

오요한 인제대학교 일반대학원 2022 국내석사

목적: 유방확대술 후 보형물의 아래쪽 이동은 재수술의 두번째로 흔한 이유다. 본 논문에서는 깊은 가슴근막 표층의 연속성을 보존하여 보형물의 아래쪽 이동을 방 지하기 위해, 겨드랑이를 통한 유방 확대술시 이중 평면 보형물방의 새로운 개념을 소개하고자 한다. 방법: 2017년 1월부터 2019년 12월까지 실시한 겨드랑이를 통한 내시경적 유방 확대술을 시행받은 환자에 대해 후향적으로 검토하였다. 수술은 내시경 하에 박리 를 진행하였으며, 대흉근의 기시점 분리 동안, 깊은 가슴근막의 표층을 보존하였고, 보형물방을 만든 뒤 실리콘 젤 보형물을 삽입하였다. 수술 후 합병증에 대한 자료 는 후향적으로 검토하였다. 결과: 총 251명의 환자가 수술을 받았고, 평균 추적 관찰 기간은 20.6개월이었다. 합병증 발생 건수는 총 28건(11.2%)이었으며, 재수술이 2건이었다. 총 3명 (1.2%)의 보형물 위치 이상 환자 중에서 1명(0.4%)이 가벼운 양측 바닥판 기형 을 보였다. 결론: 겨드랑이를 통한 유방 확대술시 내시경을 통한 정밀한 보형물방 박리를 통하 여 깊은 가슴근막의 표층 파괴를 방지함으로, 유방밑선에서 온전한 연속성을 가진 근막 시스템을 만들어 보형물의 아래쪽 이동을 방지할 수 있다. Background: Inferior implant malposition after breast augmentation is the second most common reason for revision operation. This article introduces the new concept of dual-plane pocket formation in transaxillary breast augmentation to prevent inferior implant malposition by preserving the continuity of the superficial layer of the deep pectoralis fascia. Methods: Patients who underwent transaxillary endoscopic breast augmentation performed from January of 2017 to December of 2019 were retrospectively reviewed. With the aid of the endoscope, dissection proceeded. During pectoralis muscle origin detachment, the superficial layer of deep pectoralis fascia was preserved. After making pocket, silicone gel implants were inserted. Retrospective chart review was done to collect data on the postoperative complications. Results: A total of 251 patients were performed and the mean follow-up time was 20.6 months. In a total of 28 cases of complications (11.2%), there were 2 cases of reoperations. In a total of three patients (1.2%) of implant malposition, one patient (0.4%) developed mild bilateral bottoming-out deformity. Conclusions: Meticulous dissection by endoscopy could avoid destruction of the superficial layer of the deep pectoralis fascia during pocket dissection and produce an intact fascial system with its own continuity at the IMF. A wellcontrolled envelope over the implant and supporting structure underneath it are important in breast augmentation to prevent inferior implant malposition.

Ultrathin label-free endoscope with microscopic spatial resolution

Munkyu Kang 고려대학교 대학원 2023 국내박사

The endoscope is a thin imaging device that allows minimally invasive investigation of areas where conventional microscopes cannot reach, such as inside curved passages or deep within light-scattering tissue. Recent advances have focused on improving the spatial resolution to the microscopy level, which led to the development of endomicroscopy. Microscopic imaging modalities such as confocal microscopy, multiphoton microscopy, and optical coherent tomography have been integrated with endoscopy to implement endomicroscopy. Endomicroscopy uses several types of optical fibers as imaging probes. Single-mode fiber is widely used in optical communications since it is thin and has low dispersion. However, since only one piece of information is transmitted at a time, the scanner must be attached at the distal end for imaging. This makes the endoscope unit bulky and fragile. Coherent imaging fiber bundle is another widely used image guiding medium. In the form of combining several optical fibers into one, it can deliver an object image like camera pixels. However, it is mainly used for fluorescence imaging due to back-reflection noise generated at the tip of the probe. Also, when performing high-resolution imaging, pixelation artifact occurs due to empty spaces between cores. Multimode fiber also enables high-resolution imaging because it supports a high numerical aperture and many orthogonal modes. However, due to mode mixing and dispersion, the object's information passing through the fiber appears as a distorted speckle pattern. To obtain images with multimode fibers, the way to characterize the fiber have been developed, such as transmission matrix measurements and phase conjugation. However, when bending and twisting of the fiber occurs, the fiber has to be re-calibrated, making it work only as a rigid-mode endoscope. Throughout this thesis, I introduce the development of a flexible reflection-mode ultra-thin microscopic endoscope system. A bundle fiber was used as a probe, and high-contrast and high-resolution images were obtained by removing back-reflection noise generated from the probe through single-core illumination. First, we eliminated the back-reflection noise by focusing light on each core of the bundle fiber to illuminate the object and measuring the object's information with the other cores. The characteristics of the probe were analyzed by measuring the transmission matrix of the bundled fiber, and a high-resolution image with high contrast was obtained by removing the pixelation artifacts inherently occurring when using the bundled fiber. Subsequently, we analyzed the measured sample electric field according to the Fresnel approximation and developed an algorithm to find the complex phase retardations of bundled fibers in situ. As a result, microscopic images were obtained through a fully-flexible endoscope using an ultra-thin probe. Even when there are bending and twisting in the fiber during data measurement, a clear image can be obtained by correcting the motion artifact. In addition to the development of endomicroscopes, I conducted the 3-dimensional (3D) imaging of macroscopic objects. The 3D information of the object behind the scattering layer was reconstructed by selecting the depth through time-gated measurements. Also, we present a low-coherence interferometric imaging system designed for 3D imaging of a macroscopic object through a narrow passage. We introduced a method of spatial frequency multiplexing to improve measurement speed by eliminating mechanical depth scanning of 3D information. This led to the minimization of motion artifacts and restoration of an accurate 3D shape.

Comparison on the efficacy of automated endoscope reprocessors : orthophthalaldehyde vs. PHMB/DBAC

김선영 고려대학교 대학원 2011 국내석사

Background: With the increase in the use of endoscopes for diagnostic and also for therapeutic purposes, the importance of reprocessing has become a top priority to minimize spread of infection through endoscopes. Endoscopes are classified as semicritical item and thus high-level disinfection is required. To standardize and improve the disinfection efficacy, automated endoscopes reprocessors (AERs) have been developed and are being widely used. Recently, a novel endoscope processor, COOLENDO (APEX Korea, Seoul, Korea) has been released on market in Korea. The aim of this study is to compare the efficacy of two ultrasonographic cleaning incorporated AERs (COOLENDO and OER-A). Materials and Methods: Endoscope reprocessing was first performed with 40 endoscopes as a pilot study in order to calculate the sample size. Based on the result of the pilot study, random sampling was done on 86 endoscopes. Samples were taken from the tip of insertion tube with swab wetted with normal saline and also after rinsing the working channel with 30mL of normal saline which was later filtered through a membrane filter of 0.22um in size and then incubated onto blood agar plate. The presence of any cultured organism, including H.pylori, was assessed. Results: The culture-positive rate at the tip of insertion tube and working channel was 0% and 2.33% for COOLENDO and 4.65% and 0% for OER-A. The reprocessing efficacy of COOLENDO was non-inferior to that of OER-A (p = 0.032, C.I. -0.042 to 0.042). Conclusions: The reprocessing efficacy of COOLENDO was non-inferior to that of OER-A.

VGA급 캡슐형 내시경을 위한 영상 신호 비압축 실시간 전송

박희준 경북대학교 대학원 2005 국내박사

In order to overcome the weakness of CIF capsule endoscope and furnish doctors a high quality image for accurate diagnosis or therapy, a VGA capsule endoscope system was proposed and implemented in this paper. For transmission of VGA digital image, the new encoding and transmission method without compression was proposed. The bandwidth of encoded image signal is limited by a simple pulse shaping circuit which can be loaded within the miniaturized capsule, and this bandwidth-limited signal is transmitted to external receiver using BFSK modulation. Finally, the transmitted signal is demodulated and restored in receiver part, and reconstructed so that the endoscopes' images can be displayed in the personal computer. Using the proposed method, a VGA capsule endoscope which has the data rate of 20 Mbps was implemented. The capsule which has the shape of cylinder is composed of a VGA image sensor, a CPLD module for signal encoding, a transmitter with a pulse shaping circuit, a transmitting antenna, a optical lens, and a battery. The external device for receiving the images transmitted by the capsule consists of a RF receiver with a receiving antenna, a pulse shaping circuit for restoration of pulse signal, a CPLD module for signal decoding, a data acquisition board, and a personal computer with a display unit. The CPLD encoder in the capsule adds a specified bit stream to original image data, and this encoded data is transmitted using the asynchronous BFSK method. The received signal is restored to original pulse train using a pulse shaping circuit. And the pulse train is separated into the synchronization code and endoscopes' image data by the CPLD decoder. Then, the processed data is transmitted to the data acquisition board for the reconstruction of endoscopes' images. The frequency for transmitting data was selected as 1.2 GHz considering the attenuation due to the human body and the size of transmitting antenna. The output power was -6 dBm with reference to the international regulation for maximum permeable exposure. In order to confirm the operation of the implemented VGA capsule endoscope, several fundamental test and experiment for data transmission was accomplished. Through the results, it was verified that the implemented capsule could have the enough efficiency and operation performance. From the in-vivo experiment using an animal, it was confirmed that the implemented VGA capsule endoscope can transmit the high-quality VGA image at the rate of 1.4 frames per second. The encoding method for transmitting images without compression proposed in this paper has three advantages. Firstly, this encoding method doesn't increase the transmission data and doesn't use any compression method, but the implemented capsule can transmit the image data in real-time using a simple timing control method. Secondly, the high frequency component in the abrupt transition of pulse signal is blocked using a pulse shaping circuit, but no loss of information is occurred when the transmitted signal is reconstructed in the pulse shaping circuit of an external receiver. Finally, since this method uses a simple circuit with a miniaturized analog device, the easy implementation in a capsule endoscope system is possible as simple hybrid form. The VGA capsule endoscope implemented in this paper can transmit the higher quality images in real-time than CIF capsule. Therefore, it is expected that the proposed method for high data rate transmission of VGA image signal can be applied to various biomedical fields for more accurate diagnosis and therapy.

Hardware Prototyping and Algorithm Development for Endoscopic Vision Systems

Zhou, Yaxuan University of Washington ProQuest Dissertations & 2022 해외박사(DDOD)

Medical endoscopy is a key technology of (semi)surface-based imaging of human organ for diagnosis in medical screening, surgical guidance in minimally invasive surgery or tele-surgery and cancer surveillance in re-examinations. The significant role of endoscope in these applications has been strengthened over the last few decades by efforts in the following directions. Firstly, build new endoscope hardware system that functions better to acquire desired images. Secondly, construct auxiliary system to assist usage of endoscope. Thirdly, develop computational tools for automated processing and understanding of endoscope images, and furthermore, for guidance of computer-aided interventions. Based on these three directions, this thesis presents our research works that result in hardware and software prototypes in efforts to advance the technology of medical endoscopy. Innovative hardware prototypes in this thesis were designed based on the scanning fiber endoscope invented in Human Photonics Lab, University of Washington. Chapter 2 reports an innovative endoscope system nirSFE (near-infrared scanning fiber endoscope) for dental imaging, which has the advantages of easier operation due to flexible and miniature scope as well as more sensitive detection of dental decay due to deeper penetration of near-infrared light into the tooth. Chapter 3 further presents an AR-based auxiliary system for visualization and guidance for nirSFE, which can potentially be used for computer-aided support system both during training and during procedure time. Besides hardware prototyping, computational tools were also developed to lay the groundwork for 3D endoscopy in computer-assisted diagnosis and surgery and even tele-surgery in the foreseeable future. Due to limitations in the early-stage SFE hardware prototype, the software tools in this thesis were designed and tested on commercial endoscopes for easy generalization to any available endoscope system in the clinics. Chapter 4 presents a toolset for synthesis of endoscope videos and evaluation of 3D reconstruction pipeline. Chapter 5 reports the improvement on a 3D reconstruction pipeline to generate a textured 3D surface model of patient bladder using clinical videos acquired by flexible cystoscope, which enables computer-assisted diagnosis and surgery. Lastly, Chapter 6 presents a scope localization pipeline based on efficient image retrieval and camera pose recovery, which, along with the reconstructed 3D model of human organ are the two key components for tele-surgery.

Development of a High-Performance Electromagnetic Actuation System for Multi-functional Capsule Endoscope Applications

황만콩 전남대학교 2021 국내박사

무선 캡슐 내시경 (Wireless Capsule Endoscope, WCE)은 약 20년 전 처음 개발되어 수동형 캡슐내시경으로 상용화되어 의료현장에서 활용되고 있는 기술이다. 이후 능동조향이 가능한 캡슐내시경이 제안되었으나, 이동성능 및 제어성능에 대한 문제점, 그리고 영상진단 이외의 다양한 부가 기능이 가능한 캡슐내시경 개발 등, 로봇형태의 캡슐로 의료적 파급효과를 극대화하기 위한 더 많은 연구가 요구되고 있다. 본 논문에서는 이러한 문제점을 해결하고 능동구동이 가능한 다기능 캡슐내시경의 새로운 모델을 제시하기 위해, 캡슐내시경의 제어성능 향상을 위한 다기능 고성능 전자기구동시스템과 다기능 캡슐내시경의 연구 및 개발내용을 다룬다. 특히, 작업 공간을 극대화하기 위해 새로운 전자기 구동시스템 구조를 제안하였고, 구동성능 및 전자기장 세기를 향상시키기 위한 새로운 제어 알고리즘을 개발하였으며, 캡슐내시경의 의료현장에서 활용성을 확대하기 위한 방법으로, 카메라를 통한 영상진단 이외에, 생검, 약물전달이 가능한 다기능 캡슐내시경을 개발하였다. 첫번째, 위장진단을 목적으로 위장관 내에서 캡슐내시경의 유연한 동작을 구현하기 위해 전자기장의 독립제어기법을 개발하였다. 8개의 공심형 전자석을 이용하여, Maxwell 코일 및 Helmholtz 코일 구조로 구성된 전자기구동시스템은 내부 공간을 최대화하고 그에 따른 외경이 최소화되도록 설계되어 최적화하였다. 캡슐 내시경의 제어성과 불충분한 힘의 중대한 문제는 자기장 중첩 특성 및 선형독립특성을 이용한 새로운 제어 방법을 통해 해결하였다. 제안된 시스템은 기존 시스템에 비해 적은 수의 코일을 사용하지만, 로봇의 위치에 관계없이 강한 전자기력을 발생하여, 캡슐내시경의3 차원 운동을 구현할 수 있다. 방향독립 제어동작 (Orientation-Independent-Drive; OID) 은 이전 연구결과와 차별되는 모션으로, 수평 정렬 및 횡방향 이동과 같은 동작을 구현할 수 있게 되어, 보다 효율적으로 위장관을 스캔할 수 있는 방법으로, in-vitro 및 in-vivo 실험을 통해 성능을 검증하였다. 두번째로, 수치기반 최적화 프로그램을 통해 기존 방법이 가지고 있던 캡슐내시경의 자화값 포화 문제를 해결하고, 전자기구동시스템의 구동 정확성과 자기장세기 제어 성능을 개선하여, 이전의 연구결과와 비교하여 최대 자기장 및 자기장 기울기 세기가 향상되는 결과를 얻었다. 개발된 방법은 시뮬레이션을 통해 특성화되고 검증되었으며, 개선된 성능과 효과는 실험을 통해서 검증하였다. 마지막으로, 본 연구를 통해 개발된 전자기구동시스템 및 제어 방법을 이용하여 다기능 캡슐내시경을 개발하였다. 전자기 구동 원리 및 화학 반응을 기반으로 하는 약물전달캡슐내시경 및 타투잉용 캡슐내시경을 설계 및 제작하였고, 실험을 통해 성능을 검증하였다. 제안된 방법은 소량의 시약으로 고압의 추진력을 발생할 수 있는 방법으로, 성능이 향상된 전자기 구동시스템의 높은 자기력과 사용 가능한 유연한 동작을 통해, 제안된 약물전달 및 타투잉 메커니즘을 구현할 수 있었다. 연구결과들은 최소침습 및 비침습을 주로 하는 현대 의료로봇기술 중 소화기 진단 및 치료의 새로운 영역을 개척하는데 필요한 핵심적인 기술들로, 유효성에 대한 체계적 검증을 통해, 향후 의료기기 상용화 및 고도화된 시스템으로 실제 의료현장에 활용되는 파급효과를 가질 것으로 기대한다. Wireless Capsule Endoscope (WCE) has emerged for two decades, and many commercial devices have been deployed in clinical; however, ever-challenges such as mobility, controllability and functionality need to be conquered to improve the performance and utility of the current version. This dissertation addresses these challenges by focusing on the development of a high-performance Electromagnetic Actuation (EMA) system and multifunctional capsule endoscopes. A new electromagnet configuration is developed to maximize the working space and novel control algorithms are proposed to improve the mobility and magnetic field strength. Multifunctional robots are also developed and demonstrated to extend the utility of the current diagnostic capsule endoscope. First, a new hardware system applied independent control method to enable flexible motions of capsule robot for gastrointestinal diagnosis is presented. The configuration of the system was designed to have a large inner workspace and an optimized outer dimension. The critical problems of low force and controllability of the capsule were solved through a new control methodology using superposition property of magnetic fields. Compared to the other systems using electromagnets, the developed system uses fewer electromagnets, but can produce a high magnetic field and propulsion force with three-dimensional locomotion. Orientation-Independent-Drive (OID) motions were proposed and demonstrated for flexible motions to scan and perform functions. Second, a novel numerical optimization programming-based control method is proposed to address the saturation problem of conventional control methods and improve the control performance in terms of both accuracy and strength of redundant EMA systems. Performance comparisons between the developed method and conventional control approaches have shown a significant increase in the maximum magnetic and gradient fields. The proposed methodology is characterized and validated through simulations and experiments. Experiments have been conducted to verify the performance and effectiveness of the proposed strategy. Finally, multifunctional capsule endoscopes are developed for the application of the proposed EMA system. Drug delivery and tattooing capsule endoscopes using chemical reaction-based thrust are designed and tested. Chemical reaction can generate high thrust force with a small volume of reagent. Thanks to the high magnetic force and available flexible motions of the proposed EMA system, these mechanisms can be realized, and their performances show the potential applications for minimally invasive therapy in the digestive system.

Design of Orientation Change Module and Angle Calibration Using Neural Network

Park, Jong Gu 연세대학교 일반대학원 2015 국내석사

Endoscope is instrument which can watch inside of something. For medical purpose, it can watch inside of hollow organs or human cavity without surgery. Using steering mechanism make endoscope possible to move around anatomic structures that gives various vision with different angle of view which is not possible with conventional endoscope. And it is very useful when surgeon try to find tumor metastases or performing surgery in cavities. Moreover, it have been widely used in minimally invasive surgery (MIS) which reduces patient`s pain and recovery period. According to the research about depth perception, observing objects from different sides is possible to diminish the possibility of mistakes when we interpret two-dimensional (2D) images to three-dimensional (3D) position of target.Therefore, endoscope needs to be steerable to take picture of targets in different sides. Development of technology has reduced diameter of endoscope from 12mm to 5mm and made its structure more flexible, and also it has been resulted in improvement of image quality and widen viewing angle. Also steerable mechanism for endoscope has been developed for last 20 years. However, it still have problem to be improved. Conventional steering mechanisms use push-pull mechanism with rotation joint and wire. But, movements of endoscope are restricted because of working circumstance and its structural drawbacks. Cavity acts like fulcrum make movement of endoscope restricted. And based on medical device safety reports collected by the FDA from 1985 to 2009, the most commonly reported mechanism failures are cable malfunction because of usage of rotation joint and wire. Also the most common medical issues associated with endoscopes include bowel perforations due to stiffness of scopes resulted in its own structures. In this paper, mechanism using three spring is suggested. It controls its orientation by adjusting length of each spring. It uses flexible spring so that it has less stiffness on lateral direction and more durable structure than conventional mechanism. Uncertainty because of flexible materials Also orientation control algorithm using neural network is suggested and it is validated through experiment. 내시경은 몸 속의 여러 기관을 카메라를 통하여 들여다 볼 수 있는 기구로, 암이나 종양과 같은 질환을 조기에 발견할 수 있는 의료 기구이다. 또한 환자의 통증과 회복기간을 최소화 시킬 수 있는 복강경 수술 시, 수술 기구와 장기의 위치를 확인하는 중요한 역할을 한다. 내시경 시술을 할 때, 다양한 각도에서 영상을 찍는 것은 중요하다. Depth Perceptron에 관련된 조사 결과에 따르면 2D 화면으로부터 3D 위치정보를 알아 낼 경우, 다양한 각도에서 대상을 관찰 할 경우 실수를 줄일 수 있으며, 종양, 전이와 같은 질환을 좀 더 정확하게 진단할 수 있다. 따라서 작은 곡률반경을 갖으며, 모든 방향으로 크게 휠 수 있는 조향 메커니즘이 필요하며, 이를 통하여 다양한 각도에서 장기의 상태나 수술장비의 위치를 확인하는 것이 필요하다. 기술의 발달로 인하여 지난 20년간 내시경의 지름은 12mm에서 5mm까지 줄어들었으며, 사진의 품질도 향상되었다. 하지만 현재 사용 되는 내시경은 구조적인 문제로 인하여 그 움직임이 제한적이다. 그 결과 다양한 각도에서 장기나 수술 도구의 위치를 파악하는 것이 불가능 하다. 기존 내시경의 경우, 끝단의 조향 메커니즘은 회전 조인트와 케이블의 장력을 이용한 tendon-driven 메커니즘을 사용한다. 하지만 FDA에서 조사한 의료기기 안전 보고서에 따르면 케이블이나 회전 조인트로 인해 생기는 cable malfunction이 고장의 주된 이유이다. 조작성과 내구도는 트레이드오프 관계로, 수 밀리미터 단위로 작게 만들 경우 자유도를 제한하지 않으면 부서지기 쉽고, 내구성을 키우면 자유도가 제한된다. 또한 케이블로 회전 조인트를 움직이기 때문에 메커니즘의 강도가 크며, 이로 인해 장기가 천공되는 문제가 발생한다. 본 연구에서는 내구성이 높고 장기에 손상을 최소화 할 수 있는 내시경 메커니즘을 제안한다. 기존 내시경들의 내구성 문제는 회전 조인트와 케이블 사용으로 인해 야기되었기 때문에, 이를 극복하기 위하여 유연한 링크를 사용하여 메커니즘을 설계한다. 또한 내시경의 자세 제어를 위해 링크 길이의 변화가 있어야 하므로 이를 위해 Helical 구조를 갖는 링크를 적용한다. 이와 같은 이유로, 본 연구에서 제안한 메커니 즘은 스프링을 이용한 구조로 구성된다. 3개의 스프링을 활용하여 각 스프링의 길이 차이를 통해 내시경 끝 단의 모듈의 자세를 제어하도록 설계한다. 유연한 링크를 사용하기 때문에 내구성이 높고, 장기에 끝단이 닿아도 유연한 링크의 탄성으로 인해 자극이 기존의 내시경에 비해 상대적으로 작다. 메커니즘 구조상 생기는 마찰력, 스프링의 비선형성, 제작 시 생기는 오차 등 비선형적인 요소들이 외부 요인으로 작용하며 이는 불확실성이 높은 요소들로 평가된다. 불확실성이 높은 시스템에 대한 강건한 제어 시스템을 설계하기 위하여, 인공 신경망 구조를 이용하여 본 연구에서 제안한 내시경의 끝단 자세 제어 알고리즘을 구성한다. 제안된 내시경 메커니즘은 모델링을 통한 기구학적 해석을 수행하고 실제 시스템을 제작하여 실험을 통해 그 효용성을 평가한다. 해석 결과 및 실험 결과에 대한 고찰을 통해 해당 시스템의 학술적 의미를 확인한다.

Development of a Modular Capsule Endoscope: Separation and Assembly mechanism

이진우 전남대학교 2021 국내석사

With the development of wireless capsule endoscope technology, more and more functional capsule endoscopes have been developed, such as targeted drug delivery, pH detection in the digestive tract, etc. Complex functions mean that the demand for capsule size is increasing Larger, but due to the limitation of the size of the digestive tract itself, the size of the capsules swallowed by the patient is limited and cannot meet the size of the multifunctional capsule, which makes the multifunctional capsule endoscope unreachable. This article introduces a controllable modular capsule endoscope based on the electromagnetic actuation (EMA) system. The capsule endoscope is divided into a driving capsule and a functional capsule. Capsules with different functions are swallowed in sequence and then controlled by the EMA system to carry out recombination, transportation and separation in the stomach of a large space to solve the problem of multi-functional capsule endoscopes. The recombination and separation function utilizes the characteristic that the direction of soft magnetization can be changed. The above actions can be completed by adding a soft magnet to the capsule and the precise control of the magnetic field by the EMA system. 무선 캡슐 내시경 기술이 발달하면서 표적 약물 전달, 소화관 내 pH 검출 등 기능성 캡슐 내시경이 개발되는 사례가 늘고 있다. 복합기능은 캡슐 크기에 대한 수요가 커진다는 뜻이지만 소화관 자체의 크기에 한계가 있어 환자가 삼킨 캡슐의 크기가 제한돼 다기능 캡슐 내시경을 맞출 수 없다. 이 자료에는 전자파 작동(EMA) 시스템에 기초한 제어 가능한 모듈식 캡슐 내시경이 소개되어 있다. 캡슐내시경은 구동 캡슐과 기능 캡슐로 나뉩니다. 기능이 다른 캡슐을 순차적으로 삼킨 뒤 EMA 시스템으로 제어해 넓은 공간의 위에서 재조합, 이송, 분리를 수행해 다기능 캡슐 내시경 문제를 해결한다. 재조합 및 분리 기능은 연자화 방향이 변경될 수 있는 특성을 활용한다. 위의 조치는 캡슐에 부드러운 자석을 추가하고 EMA 시스템에 의한 자기장의 정밀한 제어를 통해 수행할 수 있습니다.

Evaluation of Cap assisted Endoscopic Retrograde Cholangiopancreatography in Patients with Altered Anatomy

Ho Seok Ki 전남대학교 대학원 2010 국내석사

Background : Endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging in patients with altered gastrointestinal anatomy. I retrospectively evaluated the usefullness and safety of ERCP using a cap assisted forward-viewing endoscope for bile duct manipulations in such patients. Patients and Methods : In 76 patients with a Billorth II gastretomy (n=66), Roux-en-Y total gastrectomy(n=4), abnormally located papilla of Vater in duodenal bulb (n=3), hepaticoduodenostomy (n=2), or Braun anastomosis (n=1), ERCP (125 procedures ) was performed with a cap assisted forward-viewing endoscope. Result : The success rate of access to the papilla of Vater was 96.0% (120/125). In cases of sucessful access, selective cannulation of the bile duct was achieved in 97.5%(117/120) of patients. Therapeutic interventions including stone extraction (n=51), sphinterotomy (n=48), stent placement (n=41), nasobiliary drainage (n=20), endoscopic papillary balloon dilatation (n=7), mechanical lithotripsy (n=15) were performed successfully. Clinically important complications such as perforation, pancreatitis or bleeding, occurred in 9.4%(11/117) of procedures, serious complications were not encountered in the patients. Conclusion : ERCP with a cap assisted forward-viewing endoscope was useful in both diagnostic and therapeutic purpose in patients with altered anantomy. It enables easy access to the papilla of Vater and successful selective cannulation in such patients.

Long-term Outcomes of Laterally Spreading Tumors after Endoscopic Resection with a Positive Lateral Margin

Park Eun Young 부산대학교 2018 국내석사

Background: Diagnosis and resection of laterally spreading tumors (LSTs) is difficult and incomplete resection of tumor can cause local recurrence and interval cancer. However, the long-term outcomes of endoscopically resected LSTs with positive lateral margins have not been elucidated. We evaluated the long-term outcomes and risk factors of local recurrence after endoscopic resection of LSTs with positive lateral margins. Methods: We retrospectively analyzed the clinicopathologic and endoscopic features of 363 LSTs of 324 patients with positive lateral margins after endoscopic resection from 2011 to 2015. One hundred seventy-six tumors of 156 patients underwent follow-up colonoscopy. Results: The local recurrence rate was 6.3% (11/176) with a median follow-up period of 19.5 months. In univariate analysis, local recurrence rate was higher when piecemeal resection was performed (72.7% vs. 29.7%, p=0.001) and when tumors was not performed adjuvant thermal ablation (27.3% vs. 1.2%, p=0.002). The size, location, macroscopic type, resection method, and histology of tumor was not significantly different. In multivariable analysis, local recurrence was associated with piecemeal resection (odds ratio [OR], 6.85; confidence interval [CI], 1.34-35.03; p=0.021) and inversely associated with adjuvant thermal ablation (OR, 0.033; CI, 0.002-0.45; p=0.011). At the first surveillance examination, recurrence was noted in 9/11 LSTs (81.8%) and histology of the recurrent tumor was adenoma in 10/11 (90.9%); these were treated endoscopically. One recurrent lesion was adenocarcinoma with deep submucosal invasion; this patient underwent right hemicolectomy. Conclusions: Patients with positive lateral margins have favorable long-term outcomes after endoscopic resection.