Fast Device Discovery for Remote Device Management in Lighting Control Networks

( Sang Il Choi ),( Sang Hun Lee ),( Seok Joo Koh ),( Sang Kyu Lim ),( In Su Kim ),( Tae Gyu Kang ) 한국정보처리학회 2015 Journal of information processing systems Vol.11 No.1

The Remote Device Management (RDM) protocol is used to manage the devices in the lighting control networks. RDM provides bi-directional communications between a controller and many lighting devices over the DMX512-A network. In RDM, using a simple binary search scheme, which is based on the 48-bit unique ID (UID) of each device, discovers the lighting devices. However, the existing binary search scheme tends to require a large delay in the device discovery process. In this paper, we propose a novel partition-based discovery scheme for fast device discovery in RDM. In the proposed scheme, all devices are divided into several partitions as per the device UID, and the controller performs device discovery for each partition by configuring a response timer that each device will use. From numerical simulations, we can see that there is an optimal number of partitions to minimize the device discovery time for a given number of devices in the proposed scheme, and also that the proposed partition-based scheme can reduce the device discovery time, as compared to the existing binary search scheme.

Secure Patient Safety and Improve Exposure Defense during Mobile CT Examination for Device Development

Sung-Kun Bae(배성근),Sung Yeong Lee(이성영),Jae Min Lee(이재민) 대한CT영상기술학회 2019 대한CT영상기술학회지 Vol.21 No.1

목적: Mobile CT 를 이용한 두뇌부 검사 시 무의식 및 불안정한 환자의 검사 시 자세 및 낙상의 위험으로부터 보조할 수 있는 Device를 개발함으로써 환자의 안전과 영상의 질 향상에 도움을 주고, 보조 device의 적용에 따른 편의성 및 유용성을 평가하는데 목적이 있다. 대상 및 방법: CT장치는 두부 전용 8채널 Mobile 장치인 CereTomTM NL-3000를 사용하였고, 남자 60명, 여자 40명 총 100명을 대상으로 본원에서 제작한 보조 device를 임상에 적용하여 반복 촬영 횟수, 시술 시간의 변화 및 선량 평가를 하였고, 신경외과 전문의, 방사선사, 간호사를 대상으로 보조 device의 사용으로 인한 정성적 평가를 5점 척도로 항목을 평가하였다. 결과: 보조 device 적용 전ㆍ후 반복 촬영 회수 결과 Brain CT 8.3%, Head Angiography(perfusion) 8.0% 감소, 검사시간 변화는 Brain CT 70%, Head Angiography(perfusion) 60% 감소하였고, 선량 비교는 Brain CT 33.3%, Head Angiography(perfusion) 40% 감소하였고, 정성적 평가는 정확도 4.62, 효율성 4.55, 만족도 4.68, 편리성 4.55점으로 평균은 4.60의 점수로 평가되었다. 결론: 본 연구는 수술 중, 후의 무의식 상태의 Mobile CT검사 중 낙상 위험으로부터 환자를 보호하고, 정확한 검사 자세의 보정과 화질 개선을 위한 보조 device를 자체 제작 하였다. 위 결과에서처럼 device 적용 시 불안정한 환자 검사에서 안전을 확보할 수 있었으며, 반복 촬영 횟수, 검사시간, 선량 평가에 도움이 되었고, 만족도 조사 결과에서처럼 효율성과 만족도 그리고 편리성이 높게 평가되었다. 그러므로 보조 device 적용은 무의식 상태의 환자 검사에 많은 도움을 줄 수 있음을 알 수 있다. Purpose: The mobile CT by using brain examination is to improve patient safety and image quality by developing a device development that can assist from posture and falling risk during unconscious and unstable patients. The purpose of this study is application by self-production assistive device to evaluate convenience and usefulness of. Materials & Methods: CereTomTM NL-3000 (Neurologica, Danvers, MA, USA) was used as an 8 channel mobile device for brain only, A total of 100 patients (60 males and 40 females) were enrolled in this study to evaluate the number of repeated shots, changes in procedure time and dose rate. the qualitative evaluation by the application of assistive device to the neurosurgeon, Radiogical technologist and nurse were evaluated as the 5 - point scale item. Results: Brain CT and head angiography (perfusion) as the number of repeated shot was decreased by 8.3% and 8.0%, respectively. scan time was decreased by 70% and 60%, respectively. dose comparison was decreased by 33.3% and 40%, respectively.The qualitative evaluation was 4.62 for accuracy, 4.55 for efficiency, 4.68 for satisfaction, and 4.55 for convenience. The average was 4.60. Conclusions: The purpose of this study is to protect patients from falling during mobile CT scan during unconscious condition, and to assist in correcting patient position and improving image quality by self-production assistive device development. As shown in the above results, safety was ensured in unstable patient test when applied, and efficiency, satisfaction, and convenience were evaluated to be high as in the satisfaction survey results. Therefore, it can be seen that the application of assistive devices can be very helpful for unconscious patient examination.

Mobile Device Selection Model in terms of Contents Sharing

Hyun Joo Lee(이현주),Jin Ki Kim(김진기) 한국경영과학회 2014 한국경영과학회 학술대회논문집 Vol.2014 No.5

The growing use of mobile devices means that users can share their digital contents with other users. In mobile device selection various characteristics are considered and developed for their needs. Various field of studies on the mobile devices dealt with prices, designs, services and functions have been done. In particular, the concept of content sharing is important in selecting a mobile device. This study starts with the assumption of that users’ selection of their mobile devices is based on the three perspectives: the economic perspective for device price and device service plan, the device perspective for device design and device function, and the content sharing within in the same product line and among other mobile device users. This study aims at exploring the mobile device selection in terms of contents sharing. Utilizing the characteristics of the mobile device selection in views of three perspectives could be efficient for mobile device selection and find out how effective to lead mobile device selection on contents sharing. Based on survey data, this study is trying to verify the hypotheses of the study. The results of this study could contribute academically to show how critical factors to select of mobile devices and to propose how critical factors to related in the mobile device industry practically.

Mobile Device Selection Model in terms of Contents Sharing

Hyun Joo Lee(이현주),Jin Ki Kim(김진기) 대한산업공학회 2014 대한산업공학회 춘계학술대회논문집 Vol.2014 No.5

The growing use of mobile devices means that users can share their digital contents with other users. In mobile device selection various characteristics are considered and developed for their needs. Various field of studies on the mobile devices dealt with prices, designs, services and functions have been done. In particular, the concept of content sharing is important in selecting a mobile device. This study starts with the assumption of that users’ selection of their mobile devices is based on the three perspectives: the economic perspective for device price and device service plan, the device perspective for device design and device function, and the content sharing within in the same product line and among other mobile device users. This study aims at exploring the mobile device selection in terms of contents sharing. Utilizing the characteristics of the mobile device selection in views of three perspectives could be efficient for mobile device selection and find out how effective to lead mobile device selection on contents sharing. Based on survey data, this study is trying to verify the hypotheses of the study. The results of this study could contribute academically to show how critical factors to select of mobile devices and to propose how critical factors to related in the mobile device industry practically.

융복합 의료제품 규제를 위한 의약품과 의료기기 정의규정의 개정 필요성과 그 방향

오승한 서울대학교 법학연구소 2022 경제규제와 법 Vol.15 No.2

Recently, drug-device combinations, such as ‘a drug eluting stents’ and ‘transdermal patches’, become more important and are growing as efficient alternatives of traditional therapies. The combination products are defined as the products, which are composed of two or more of the traditional medicinal products, drug, device, and biologic. All combination products, however, consists of at least two distinct constituents, unlike other traditional medicinal products. In the current premarket allowance pathway for the drugs and devices, it is unclear whether the combination products are regulated as drugs or devices. Although publicizing the guidelines and the regulatory notices for the handling process of ‘the market application for combination products’, the Ministry of Food and Drug Safety (MFDS), actually, has no authority of making criteria to allocate them into the drug, the medical device, or the biologic pathway. None of laws regulates the definition of combination products and the standard to classify them, which are answer for what kinds of requirements are required to get market allowance. The most problematic hurdles in designing the appropriate regulation pathway for combination products are the definitions of a drug (including a biological product) and a device, which are stipulated in separate legislations, the Pharmaceutical Affairs Act (PAA) and the Medical Devices Act (MDA), respectively. The current PAA specifically defines ‘the drugs’ with exception of device and MDA also specifies ‘the devices’ as distinct from drugs. As a result, in the current Korean medical statutes, the definitions of drug and device are mutually exclusive; therefore, PAA should be applied to only the drug portion of the product, and MDA device law also should be applied to only the medical device. For this reason, whether the combination products composed of both drug(biologic) and medical device should be regulated as a drug, a biologic or a device, sometimes, has not been decided and delayed. In order to remove this regulation gap, the amendment of the definition articles for drug and device in PAA and MDA is not avoidable. 최근 의료산업 현장에서는 전통적인 의약품과 의료기기(의약외품)를 결합하여 기존 치료제보다 편의성은 물론 유효성⋅안전성 측면에서 더 나은 효과를 가진 의료제품이 등장하고 있고, 이것을 융복합 의료제품이라고 호칭한다. 융복합 의료제품은 의약품과 의료기기(의약외품)가 결합되어 각각의 구성부분이 모두 치료⋅처지⋅진단 등의 기능을 수행한다. 그런데 융복합 의료제품은 ‘의약품’과 ‘의료기기(의약외품)’를 중심으로 완전히 분리된 시판허가 기준과 규제절차를 운영하고 있는 현재의 의료제품 규제체제 안에서 양자 어느 곳에서도 속할 수가 없어서, 적용될 시판 검증기준과 규제절차 등이 불분명한 상황에 처해 있다. 식품의약품안전처는 현재 자체 내규에 불과한 민원규정, 민원인 안내서 등을 통해서, 최소한도로 융복합 의료제품의 인⋅허가 신청절차 및 규제절차, 인⋅허가 요건 등을 안내하고 있으나, 그 근거가 불명확하고 충분하지 않다. 따라서 상위법에 명확한 규제근거와 규제절차 등을 제정하여 융복합 의료제품에 대한 규제절차를 설정할 필요가 있는데, 이를 위해 의약품과 의료기기(의약외품)를 완전히 독립적이고 철저히 분리되는 상품으로만 간주하여 양자의 양립가능성을 전혀 인정하지 않고 있는 현행 약사법과 의료기기법의 ‘의약품’ 및 ‘의료기기(의약외품)’에 대한 정의규정의 개정이 필요하다. 이를 통해, 의약품과 결합된 의료기기가 사실상 의료기기로 인정될 수 없고, 의약품도 될 수가 없어서 어느 한 곳에도 속하지 못하는 규제공백을 해결할 필요가 있다.

Conceptual Framework for Mobile Device Product Line Security based on Internet of Thing

Regin Joy Conejar,Haeng-Kon Kim 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.7

Numerous technology devices have been propelled to explore the prospects of mobile devices. There is a growing demand to transform the existing PC-based software systems to mobile device platforms since mobile devices are low-cost compared for a PC, and their affordance, usability, and user-friendliness are such that they can theoretically counterpart or even replace traditional computer technology and mobile devices perform well using a lesser amount of memory than PC-based systems. Mobile device product lines are promising approaches for deriving and delivering custom-made applications to devices. In this paper, a conceptual framework for the mobile device product line is designed to create a strategic concept on how the mobile device delivers its application towards its users. It is designed to construct an interaction within the mobile application to its user devices. Mobile Device Product Line Security is a new concept, which appears with the Internet of Things (IoT) application in industry. This technology applied in production systems provides many benefits like better transparency or real-time information. This approach proposes a conceptual framework for IoT application in Production Systems Security. The aim of this framework is helping enterprises to identify the main elements to apply IoT in Mobile Device Product Line Security Systems.

흉부 X-Ray 검사실에서 Auto Voice Device의 유용성과 방사선사의 편의성에 관한 고찰

정인아(In-A Jung),이동희(Dong-Hee Lee),이민우(Min-Woo Lee),김순배(Sun-Bae Kim) 대한영상의학기술학회 2012 대한영상의학기술학회 논문지 Vol.2012 No.-

목적: 음성안내가 많은 흉부 X-ray 검사실에서 사용할 Auto voice device를 제작하여 장비의 유용성과 이에 따른 방사선사의 업무 편의성에 대해 알아보고자 하였다. 대상 및 방법: 2012년 01월 09일 부터 02월 24일에 걸쳐 방사선사 87명에게 검사방법과 장비사용법이 담긴 동영상을 보여준 후 연구목적과 취지를 설명하고 협조를 요청하여 설문 지를 배부하여 분석하였다. 방사선사의 일반적 특성은 성별은 남성이 58명(67.7%)으로 9 명(33.3%)인 여성의 약 2배이고, 평균연령은 36(35.89±7.90)세이며, 근무기간은 13(13.41±7.54)년, 검사건수는 300~399건이 41명(28.7%)으로 가장 많은 비중을 차지했 다. 조사결과 분석은 방사선사의 검사에 대한 일반적 견해와 개선사항과 장비의 질에 대한 견해를 파악하기 위해 빈도와 백분율을 산출하고, 검사장비도입의 효과 및 효능의 통계적 처리는 SPSS를 이용하여 일원배치 분산분석(ANOVA)을 하였다. 결과: 설문조사 결과 연령과 근무기간에 따른 Auto voice device의 유용성은 유의확률이 0.05 이상으로 모두 통계적으로 유의하지 않아 상관관계가 적은 것으로 나타났다. 그러나 검사건수에 따른 검사자의 피로도 감소는 유의확률 0.000 (p<0.01)으로 매우 유의한 결과를 얻었고, 검사건수에 따른 업무의 편의성도 유의확률 0.001 (p<0.01)으로 매우 유의하다는 결과가 나왔다. 결론: Auto voice device를 사용함으로써 업무의 편의성 증가와 목의 피로도 감소는 매우 높은 평가를 얻었다. 하지만 장비를 조작하는 시간이 추가됨에 따라서 전체적인 검사시간은 단축되지 않았고, 호흡조절도 장비를 사용하는 것과 육성을 사용하는 것을 비교하였을 때크게 다르지 않았다. 향후 개선사항들을 토대로 장비의 음질 개선과 언어의 다양화, 자막기 능을 추가하여 현재 장비의 업그레이드를 진행 중이며, 더 발전된 Auto voice device로 방사선사의 업무에 보다 더 효율을 줄 것으로 기대한다. Purpose: This study investigated usefulness of the device and its work convenience for radiologic technologist by making auto voice device used at chest X-ray lab where many voice guidance is made. Materials and Methods: The subjects are 87 radiologic technologists and they were asked to see video clip where how to use the device and method of applying to examination was introduced during the period from Jan. 9, 2012 to Feb. 24, 2012. Since then, study purpose was explained to ask for cooperation. For general characteristics of the subjects, the gender is 58 males (67.7%); 29 females (33.3%) - male is double female. Average age is 36 (35.89±7.90). Working period is 13 (13.41±7.54) years. As for number of examination by radiologic technologist, 41 radiologic technologists (28.7%) did 300-399 cases each person. To show general opinion of the subjects about examination, and opinion about improvements and quality of device, percentage was used. Effect and efficiency of using Auto voice device was analyzed using ANOVA through statistical processing by SPSS. Results: For reduction of fatigue in radiologic technologist s throat according to number of examination, p-value 0.000 (p<0.01) - this is very significant result. For work convenience according to number of examination, p-value 0.000 (p<0.01) -this is also very significant result. Conclusion: Using auto voice device brought increase of work convenience and reduction of fatigue in throat. But whole time for examination was not saved because maneuvering device requires additional time. In controlling breathing, there is no much difference between using device and human voice. It is expected that if auto voice device is improved in sound quality, variety in provided language etc. through this study results, this device would be more useful for work of radiologic technologists in the future.

Ergonomic Design of Necklace Type Wearable Device

Jinsil Lee,Kimin Ban,Jaeho Choe,Eui S. Jung 대한인간공학회 2017 大韓人間工學會誌 Vol.36 No.4

Objective: This study aims to identify important physical design variables in designing a necklace type wearable device, and to present design guidelines to maximize comfort that a user feels upon wearing the device. Background: Interests in fitness culture and personal health are on the rise recently. In such a situation, demand for necklace type wearable devices is projected to increase a lot, as the devices enable users to use their hands freely and to enjoy various contents through connection with mobile devices. However, the necklace type wearable device’s comfort was assessed to have the lowest comfort in a running situation, where human body moves up and down and left and right more than other devices wearable on other human body parts. Therefore, the usability of a necklace type wearable device was low. In this regard, studies on identification of the variables affecting user comfort upon wearing a necklace type wearable device and on physical design direction maximizing comfort and usability are needed. Method: A pretest and a main test were carried out to draw the direction of necklace type wearable device design. In the pretest, wearing evaluation on the diverse types of devices released in the market was conducted to draw physical design variables of the devices affecting comfort. Furthermore, variables significantly affecting the comfort of a device were selected through an analysis of variance (ANOVA). In the main test, anthropometry was performed, and information on anthropometric items corresponding to the design variables selected in the pretest was acquired. Based on the pretest results and the anthropometric information in the main test, the present study produced design guidelines maximizing the comfort of a necklace type wearable device with regard to major design variables upon dynamic tasks. Results: According to the pretest results, the variables having effects on comfort were the angle of side points, width, and height. Due to interactions between variables, those need to be simultaneously considered upon designing a device. Upon dynamic tasks, the angle of side points and width of a device was designed to be smaller than mean angle of the trapezius muscle and neck width, and thus attachment to human body was high. As height was designed to be larger than mean neck front and rear point width, comfort was higher due to feeling of stability. Conclusion: Because user sensitivity to comfort was high at human body’s inflection points, a device needs to be designed for users not to feel high pressure on specific body parts with the device fitting human body shape well. A design considering user’s situation is also required in further studies.

제품 연동의 인터페이스 디자인을 위한 상호작용 블루프린트 제안

송지원 인제대학교 디자인연구소 2019 Journal of Integrated Design Research (JIDR) Vol.18 No.3

Background : Interface design and user experience of device association have become important issues. Although many researchers have discussed interface design factors, user mental models, and technological solutions for wireless device connection, design tools for multi-device experience and interface have not studied enough. The lack of design tools is one of the major challenges standing in the way of advanced user experience of connecting devices. In this paper, I propose a design tool, an interface design blueprint framework, in order to help designers design and review the overall user-device interaction for the procedure of wireless device association. Methods : This study has been conducted via understanding device association interaction and suggesting the blueprint framework iteratively. First, user-device interaction with regard to wireless network connection has been studied from references. Second, the initial components of the blueprint have been drawn up from reference to the Service Blueprint framework. Third, I studied the features of device association interaction, applying the components toward diagramming the interaction of three selected cases, and the framework has been updated to reflect the found features. Fourth, the blueprint framework has been evaluated by a design workshop in which designers used the diagram to anticipate user experience and design device interfaces. Finally, the improved interface design blueprint has been suggested as a design tool for visualizing the overall user-device interaction of device connections. Result : The proposed interface design blueprint diagrams a user and device interaction following an association procedure. The device interaction is presented in forestage and backstage so that the framework helps designers efficiently review not only visible interaction but also invisible interaction. The arrows between a user and devices present the interaction flow. The framework also helps designers review the user interface in detail with displayed visual interface and user action for all related devices. Conclusion : The proposed interface design blueprint framework efficiently visualizes the complex interaction of a user and connecting devices in order to help designers preview the user experience and iterate the interface design in the early stages of design. 연구배경: 제품들 간의 무선 결합이 빈번해 짐에 따라 이를 위한 인터페이스 디자인과 사용자 경험이 중요한 문제가 되고 있다. 제품 연동의 인터페이스를 위한 디자인 요인, 사용자 멘탈 모델, 기술적 제안들이 활발하게 논의되고 있는 데에 비하여 실제 인터페이스 디자인 과정에서 효율적으로 사용자 상호작용을 예측하고 검토할 수 있도록 도울 디자인 도구에 대한 연구는 부족한 상황이며, 이러한 도구의 부족은 인터페이스 디자인의 혁신을 어렵게 하는 중요한 요인으로 지적되고 있다. 이에 본 연구에서는 무선 제품들의 결합을 초기 설정하는 연동 과정에 대하여 전체적인 사용자-기기 상호작용을 시각화할 수 있는 프레임워크를 개발하여 효율적인 인터페이스 디자인과 검토를 돕는 도구로 제시하고자 한다. 연구방법: 본 연구는 제품 연동 상호작용과 시각화에 대한 이해와 해결안인 상호작용 블루프린트 프레임워크의 제시를 반복하는 과정을 통해 수행되었다. 첫째, 무선 연동의 과정에서 발생하는 사용자-기기 상호작용의 특성을 이해하고, 둘째, 서비스 블루프린트의 체계를 참고하여 제품 연동 상호작용의 컴포넌트들을 도출하고 초기 프레임워크를 제시하였으며, 셋째, 3건의 사례에 컴포넌트들을 적용하는 과정을 통하여 제품 연동 상호작용의 특징을 이해하고 이를 반영하도록 프레임워크를 구체화하였다. 넷째, 워크숍을 통하여 사용자-기기 간 상호작용을 예측하고 디자인하는 과정에서 프레임워크의 유용성을 평가하고 개선 요구사항을 이해하여, 최종적으로 기기 연동 상호작용의 인터페이스 디자인을 위한 상호작용 블루프린트 프레임워크를 제안하였다. 연구결과: 제안된 상호작용 블루프린트 프레임워크는 무선 연동의 프로세스를 따라 사용자와 기기들 간의 상호작용을 다이어그램으로 나타내며, 가시적 상호작용과 비가시적 상호작용을 전방영역과 후방영역으로 나누어 디자이너의 효율적 검토를 돕는다. 상호작용의 흐름과 프로세스에 따른 순차적 진행을 논리적으로 검토할 수 있도록 제시되었으며, 제품들의 시각적 인터페이스 및 사용자 인풋을 자세히 나타내어 인터페이스 디자인을 제안하고 검토할 수 있는 도구로 제시되었다. 결론: 본 연구는 제품들을 무선 결합하는 과정에서 여러 기기와 사용자 사이에서 발생하게 되는 복잡한 상호작용을 전체적으로 파악할 수 있도록 도식화하는 프레임워크를 디자인 도구로 제안하였으며, 이를 통해 디자이너들이 사용자-기기 상호작용을 효율적으로 검토하고 디자인을 향상하도록 도울 수 있다.

비만 환자를 대상으로 한 가상대장 내시경 검사에서 Device 사용의 유용성 평가

최성민(Seong min Choi),김영남(Yeong nam Kim),김정훈(Jeong hoon Kim),김상현(Sang hyeong Kim) 대한CT영상기술학회 2011 대한CT영상기술학회지 Vol.13 No.1

목 적 비만 환자에 대하여 CTC 검사를 시행할 경우 그렇지 않은 환자에 비하여 Prone position을 취하였을 때, 환자 본인의 하 복부 비만 부위로 인해 배가 눌려 S상 결장 부위의 장 팽창이 상대적으로 부족함을 보인다. 이러한 이유로 검사 시 환자의 hip joint 부위와 가슴 부위에 device를 사용하여 하복부에 직접적인 압박이 가해 지지 않도록 하여 device를 사용하지 않았을 때에 비하여 S상 결장 부위의 장 팽창의 용이함을 2D axial 영상과 재구성된 3D 이미지에서 대장 내 지름을 측정 비교하여 Device 사용의 유용성을 알아보고자 하였다. 대상 및 방법 2009년 12월 과 2010년 1월 서울 아산병원 입원 또는 외래를 통한 Virture colonoscophy 검사자 중 체중과 신장을 이용한 체질량 지수를 구하여 그 중 비만도가 높은 환자를 대상으로 검사 하였다. 총 195명의 환자를 검사 했으며 그 중 남자 15명, 여자 15명을 대상으로 하였다. prone position 검사 시 device를 사용하지 않았을 때와 device를 사용하였을 때 복부 전체를 두번 scan 하였다. scan 후 평가는 S상 결장의 확장 정도를 PACS 상에서 measure program을 사용하여 size를 측정하여 넓어진 정도를 비교하였다. 결 과 Device를 사용하지 않은 남자와 여자 15명 모두 대장의 직경이 평균 3.1 cm의 팽창을 보였으며, 동일 환자에 대하여 device를 사용 하면서 검사한 경우에는 남자 15명의 경우 평균 4.3 cm으로 측정, 사용하지 않았을 때 보다 평균 1.2 cm 더 넓어져 38%의 증가를 가져왔으며, 여자 15명의 경우 평균 4.2 cm으로 평균 1.1cm 더 넓어져 35%의 증가를 가져왔다. 결 론 S상 결장은 전체 대장암 중에서 그 차지하는 비중이 두 번째로 높은 호발 부위이다. 이러한 부위가 충분히 확장이 되지 않을 경우 1 cm 이하의 병변은 구별해 내기가 쉽지가 않다. 따라서 비만 환자의 경우 device를 환자의 hip joint와 가슴 부위에 사용하여 복부가 눌리지 않게 해줌으로서 상대적으로 체중으로 눌렸을 때에 비하여 S상 결장부위가 더 많이 확장시키는 결과를 보여 주기 때문에 device를 사용하는 것이 더 효율적이라 하겠다. Ⅰ. Purpose In a CTC examinations, Obesity patients especailly show less distension than thin patients adapting Prone position, because abdomen is pressed by a own redoubling obesity parts. so distension of sigmoid colon is relatively insufficient. For this reason, in CTC exam, we use the device both hip joint and thoracic portion not to push direct pressure. our purpose is to show usefulness of distension in sigmoid colon comparing CTC using device with CTC using not device. and we measure a diameter of colon and compare with 2D axial image and 3D. finally, we reveal utility of using device in CTC. Ⅱ. Materials and Methods target: inpatients and outpatients who are tried virtual colonoscopy from December, 2009 to January, 2010 in Asan Medical Center. measure: we calculate body mass index of total 195patients based on weight and height and select high level of 30patients(male: 15, Female: 15). method: twice scan in entire abdominal region using device versus not using device adapting prone position. evaluation: compare an expansion degree of sigmoid colon on PACS as we measured using measure program. Ⅲ. Results 15 men and women patients who don’t use device show the colon distension of average 3.1cm, but in same 15 men patients who use device show the colon distension of average 4.3 cm(increase +1.2 cm) and in same 15 women patients who utilize device show the colon distension of average 4.2 cm(increase +1.1 cm). Ⅳ. Conclusion Sigmoid colon is part to well occur colon cancer where is known for the second high portion. If distension doesn’t work enough in these part, region of less than 1cm can’t have distinguished it. Therefore, for obesity patients, to put device in hip joint and thoracic portion can help to prevent to push abdominal portion in prone position. as a result, device can help to distent sigmoid colon very efficiently.