• Archives of Plastic Surgery
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• 제36권2호
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• pp.153-160
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• 2009

Purpose: The heterodigital or homodigital artery island flap is a popular method of reconstruction for finger defects. Sometimes, digital artery island flap has some disadvantages such as postoperative flap edema, congestion, and partial necrosis of the flap margin. However, we could decrease these disadvantages by means of venous superdrainage. The aim of this study is to report usefulness and postoperative results of venous supercharging digital artery island flaps for finger reconstruction. Methods: From March of 2005 to March of 2008, a total of eight patients with soft tissue defects of the finger underwent venous supercharging digital island flap transfer. Briefly, the flap is harvested along with dorsal vein that is then anastomosed to a recipient vein in an end - to - end fashion, after flap transfer and insetting. Using this technique, eight patients were operated on, ranging in age 23 to 52 years. Results: All the flaps survived with a success rate of 100 percent, thus fully satisfying the reconstructive requirements. No postoperative flap congestion was recognized, obviating the need to take any measures for venous engorgement, such as suture removal. Among 8 cases, it was possible to make an long - term and follow - up observation more than 6 months. In these cases, the fact that light touches and temperature sensations can be detected in all the flaps. Cold intolerance and hyperesthesia were not seen in our series. Conclusion: Providing good harmony with conventional methods and microsurgery, inclusion of a vein with the heterodigital and homodigital artery island flap allows a more reliable and safer reconstructive choice for finger defects. The venous supercharged island flap is a reliable flap with a consistent arterial structure, and with its augmented venous drainage, it is more reliable, providing single - stage reconstruction of adjacent finger defects, including the fingertip.

• 디지털융복합연구
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• 제11권7호
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• pp.157-163
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• 2013

본 논문에서는 손가락 마디 추정을 이용한 비전 및 깊이 정보 기반 손 인터페이스 방법을 제안한다. 먼저 비주얼 영상 및 깊이 정보 영상을 매핑한 후 왼손과 오른손의 영역의 레이블링 및 윤곽선 잡음 보정 후 각 손 영역에 대하여 손 중심점 및 회전각을 구현한다. 그리고 손 중심점에서 일정간격의 원을 확장하여 손 경계 교차점의 중간 지점을 계산하여 손가락 끝점과 마디를 추정하여 사용자의 손가락 동작을 인식한다. 본 방법을 실험한 결과 손의 회전 및 손가락 시작점 및 끝점을 정확하게 추정하여 다양한 손동작 인식 및 제어가 가능함을 보였다. 왼손과 오른손을 사용하여 다양한 손 포즈에 대해 실험한 결과, 본 논문의 제안 방법은 평균 90% 이상의 정확도로 초당 25프레임 이상의 처리 성능을 보였다. 제안 방법은 컴퓨터간의 HCI 제어, 게임, 교육 등의 비접촉식 인터페이스 응용분야에 적용될 수 있다.

• 한국간호교육학회지
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• 제12권2호
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• pp.265-271
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• 2006

Purpose: To analyze the newly developed vacuum assisted auto-lancing technique applied to the forearm for the purpose of obtaining an adequate blood sample for glucose test with minimal pain. Methods: Visual and facial pain measures were introduced to compare lancing pain between the forearm and fingertip in 58 normal females. Sampled blood volumes were accurately measured by computer scanning technique. Results: Visual pain measure demonstrated significant pain reduction effect of the forearm sampling compared with the traditional fingertip sampling, which was also consistent with facial pain measure results. Blood volume more than $0.5{\mu}L$, enough for blood glucose testing with modern glucometers, was collected in 399(86%) of 464 forearm samples. Conclusions: Capillary blood sampling could be performed with minimal pain on the forearm by the newly developed vacuum assisted auto-lancing technique. With some resampling when necessary, the forearm sampling seemed very useful, considering almost no pain felt by the patients.

• Archives of Plastic Surgery
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• 제45권1호
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• pp.58-61
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• 2018

Background Venous anastomosis is an important component of digital replantation, but is not always feasible, as some cases require external bleeding to treat venous congestion in the replanted tissue. In the present study, we evaluated the relationship between the number of vein anastomoses and the survival rate of Tamai zone I replantations. Methods A retrospective review was performed of all patients who underwent replantation of a fingertip amputation between 2014 and 2016. Patient charts were reviewed for demographic information, the mechanism of injury, the number of venous anastomoses, and the use of anticoagulation, external bleeding, and/or leeches. The cohort was divided into 3 groups depending on the number of venous anastomoses: no veins (group 1), a single vein (group 2), and 2 or more veins (group 3). Survival rates and external bleeding rates were analyzed across the groups. Results The review identified 143 fingertip replantations among 134 patients. The overall survival rate was 94% (135 of 143). Failures were due equally to venous complications (n=4, 50%) and to arterial complications (n=4, 50%). Our analysis did not identify any correlation between the number of veins anastomosed and the replant survival rate (P=0.689). However, a greater number of anastomoses was associated with a significantly lower frequency of external bleeding (P=0.017). Conclusions The number of venous anastomoses was not correlated with the survival rate. However, a greater number of venous anastomoses was associated with a decreased need for external bleeding, corresponding to a significant decrease in the need for postoperative monitoring and leech therapy.

• Transactions on Control, Automation and Systems Engineering
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• 제4권1호
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• pp.2-8
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• 2002

This paper discusses haptic display for grasping a virtual object by two fingers. Much research has been done on fundamental analysis for stability of haptic display. But it is difficult to apply the results immediately to grasping situations by two fingers, since the studies usually deal with a single device and a single object and the fingertip force in grasping situations has two components, internal and external components. The conventional methods, which specify the coupling impedance at each contact point separately, have no other alternative but to specify the impedance for the sum of the internal and external components. So even if only the impedance for the external force should be changed, the impedance for the internal force is also changed at the same time. In this paper, a new method, in which the coupling impedance is specified separately for the internal and external forces, is proposed and the stability of the proposed method is discussed using passivity analysis for 1 -DOF(Degree-Of-Freedom) system. Finally, some experiments are performed to study the effects of the proposed method.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 1부
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• pp.1143-1148
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• 2006

사용자 친화형 유저 인터페이스 구현을 위해 인간의 손 형상을 실시간으로 인식하는 연구의 중요성이 부각되고 있다. 그러나 인간의 손은 자유도가 크기 때문에 손 형상을 정확히 인식하기란 매우 어렵고 또한 피부색과 유사한 색을 가지는 복잡한 배경에서는 더욱 곤란하다. 본 논문에서는 별도의 센서를 부착하지 않고 카메라를 사용하여 피부색 정보에 의한 손 형상을 분할한 후 손가락 끝 점을 찾는다. 찾은 손가락 끝점을 이용하여 방향을 탐지하는 알고리즘에 대해 기술한다. 이 방법은 템플리트 매칭을 이용하여 손가락 끝 점을 탐색한 후 찾은 손 가락 끝 점과 손목의 중심을 이용하여 전, 후, 좌, 우 방향을 탐지한다. 제안하는 방법을 이용하여 3D가상현실 공간에서의 Navigation에 응용하였으며, 실험결과 전진, 후진 및 좌측, 우측의 방향전환도 매우 좋은 결과를 보였다. 또한 본 논문에서 제안하는 방법은 마우스, 키보드, 조이스틱 등의 조작 없이 전, 후, 좌, 우 방향전환을 사용자가 직관적으로 지시함으로써 보다 자연스러운 인간과 컴퓨터의 상호작용을 제공할 수 있을 것이다.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 1부
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• pp.1037-1043
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• 2006

본 논문에서는 유비쿼터스 컴퓨팅 오피스 환경에서 가장 직관적인 HCI 수단인 손 제스처를 사용하여 대형 스크린 상의 응용 프로그램들을 쉽게 제어할 수 있는 시스템을 제안한다. 손 제스처는 손 영역의 정보, 손 중심점의 위치 변화값과 손가락 형상을 이용하여 시스템 제어에 필요한 종류들을 미리 정의해 둔다. 먼저 효율적으로 손 영역 획득을 위해 적외선 카메라를 사용하여 연속된 영상을 획득한다. 획득된 영상 프레임으로부터 구조적 템플레이트 매칭 방법을 사용하여 손의 중심(centroid) 및 손가락끝(fingertip)을 검출한다. 인식과정에서는 양손의 Euclidean distance와 손가락 형상 정보를 이용하여 미리 정의된 제스처와 비교하여 인식을 행한다. 본 논문에서 제안한 비전 기반 hand gesture 제어 시스템은 인간과 컴퓨터의 상호작용을 이해하는데 많은 이점을 제공할 수 있다. 실험 결과를 통해 본 논문에서 제안한 방법의 효율성을 입증한다.

• ETRI Journal
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• 제29권3호
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• pp.305-310
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• 2007

If a virtual object in a virtual environment represented by a stereo vision system could be touched by a user with some tactile feeling on his/her fingertip, the sense of reality would be heightened. To create a visual impression as if the user were directly pointing to a desired point on a virtual object with his/her own finger, we need to align virtual space coordinates and physical space coordinates. Also, if there is no tactile feeling when the user touches a virtual object, the virtual object would seem to be a ghost. Therefore, a haptic interface device is required to give some tactile sensation to the user. We have constructed such a human-computer interaction system in the form of a simple virtual reality game using a stereo vision system, a vibro-tactile device module, and two position/orientation sensors.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1764-1769
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• 1991

Recently, dexterous mechanical hands have become of interest in the field of robotics. In this paper, a new symbolic C-Y notation is proposed for the kinematic modeling, and we solve the kinematics of a simplified model of POSTECH Hand 1, which is a 5 fingered, 20 degrees of freedom anthropomorphic hand. POSTECH Hand I is designed to have distinctive kinematic structure and the kinematic analysis of the hand is carried out using C-Y notation. To prove the feasibility of C-Y notation, D-H notation is also applied to the POSTECH Hand 1. In the inverse kinematic analysis, we neglect the fingertip geometry and assume the point contact with 3 degrees of freedom constraints. The configurations which optimize manipulability index[2] was obtained based on the simulation experiments on the SUN-4 graphic workstation using SUNPhigs graphic software.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.185-190
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• 1993

The POSTECH Hand adopting coupled tendon driven technique with planar two fingers is developed. The hand is designed to emulate principal motions of the human hand which has two and three joints respectively. Its kinematic parameters are determined through a parameter optimizing technique to aim at improving the isotropy of fingertip motions with new criterion functions of design. For the control of the hand, tension and torque control algorithms are developed. Based on the virtual stiffness concept, we develop the stiffness control method of a grasped object with redundant finger mechnism and investigate experimentally.