• 제목/요약/키워드: Finger

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경량 의수용 SMA 구동식 생체모방 손가락 모듈 (SMA-driven Biomimetic Finger Module for Lightweight Hand Prosthesis)

  • 정성윤;문인혁
    • 제어로봇시스템학회논문지
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    • 제18권2호
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    • pp.69-75
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    • 2012
  • This paper proposes a biomimetic finger module to be used in a lightweight hand prosthesis. The finger module consists of finger skeleton and an actuator module driven by SMA (Shape Memory Alloy). The prototype finger module can perform flexion and extension motions; finger flexion is driven by a contraction force of SMA, but it is extended by an elastic force of an extension spring inserted into the finger skeleton. The finger motions are controlled by feedback of electric resistance of SMA because the finger module has no sensors to measure length and angle. Total weight of a prototype finger module is 30g. In experiments the finger motions and finger grip force are tested and compared with simulation results when a constant contraction force of SMA is given. The experimental results show that the proposed SMA-driven finger module is feasible to the lightweight hand prosthesis.

A constant tendon moment arms finger model in the sagittal plane

  • Lee, K.H.
    • 대한인간공학회:학술대회논문집
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    • 대한인간공학회 1992년도 추계학술대회논문집
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    • pp.46-53
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    • 1992
  • Finger movements in the sagittal plane mainly consist of flexion and extension about the metacarpophalangeal(MCP) and proximal interphalangeal(PIP) joints. A kinematic finger model was developed with the assumption of constant tendon moment arms. Equations of static equilibrium were derived for the finger model using the principle of virtual work. Equations of static equilibrium for the finger model were indeterminate since only three equations were available for five unknown variables(forces). The number of variables was reduced based on information on muscular activities in finger movements. Then the amounts of forces which muscles exerted to maintain static equilibrium against external loads were computed from the equilibrium equations. The muscular forces were expressed mathematically as functions of finger positions, tendon moment arms, lengths of phalanges, and the magnitude and direction of external load. The external finger strength were computed using the equations of muscular forces and anatomical data. Experiments were performed to measure finger strengths. Measurements were taken in combinations of four finger positions and four directions of force exertions. Validation of the finger models and of procedure to estimate finger strengths was done by comparing the results of computations and experiments. Significang differences were found between the predicted and measured finger strengths. However, the trends of finger strengths with respect to finger positions were similar inboth the predicted and measured. These findings indicate that the finger model and the procedure to predict finger strengths were correctly developed.

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한국인을 위한 장갑 패턴 고찰 (2) - 장갑 원형 설계를 중심으로 - (A Study on the Pattern-making for Korean Glove - Focusing on Pattern-making for Glove -)

  • 류경옥
    • 복식문화연구
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    • 제17권6호
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    • pp.981-991
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    • 2009
  • The purpose of this study was to develop the pattern-making for Korean glove. To develop the pattern-making for glove this study comprehensive list of candidate hand data was reviewed and the manufacturers(career over th 15 years) were interviewed on the method of glove. The results of regression analysis(hand data) were as follows (unit: cm): wrist thumb tip length = middle finger length + 3.22, hand bread = 1.25 $\times$ middle finger length + 2.18, middle finger breadth at dist = 0.23 $\times$ index finger circumference + 0.4, maximum hand circumference = 3.15 $\times$ index finger circumference + 4.13, middle finger circumference = 0.91 $\times$ index finger circumference + 0.47, maximum hand thickness = 0.69 $\times$ index finger circumference -0.02. Hand measurements for glove pattern-making were developed: There were palmar hand length, hand circumference, index finger circumference and middle finger length.

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손가락 누르기 속력에 따른 Enslaving 효과 (Enslaving Effects on Finger Pressing Speed)

  • 우병훈
    • 한국운동역학회지
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    • 제17권3호
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    • pp.217-224
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    • 2007
  • This study was to investigate the effects of enslaving on finger-tip force of other fingers on finger pressing speed. We hypothesized that the effects depend on finger pressing speed, and the fingers proximity and are larger for fingers that are closer to each other. Six healthy, right-handed subjects(age: $27.1{\pm}4.3yr$, height: $175.4{\pm}7.2cm$, weight $71.3{\pm}5.8kg$) participated in the experiment. Each finger showed no significant on task finger speed. In the tasks with two neighboring fingers (e.g. middle and ring finger tasks), the index and middle fingers showed larger forces than the other neighboring fingers. During the index and little finger tasks, the enslaving force magnitude decreased with distance to the task finger (i.e. index finger enslaving force was the smallest during the little finger task).

Effect of Adhesives and Finger Pitches on Bending Creep Performances of Finger-Jointed Woods

  • Park, Han-Min;Oh, Seong-Won;Byeon, Hee-Seop
    • Journal of the Korean Wood Science and Technology
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    • 제33권5호통권133호
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    • pp.57-65
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    • 2005
  • Following our previous reports for finger-jointed woods with various finger profiles studied for the efficient use of small diameter logs and woods containing various defects, twelve types of finger-jointed woods glued with three kinds of adhesives and with two sizes of finger pitches were made with sitka spruce and red pine. The effects of the adhesives and finger pitches on bending creep performances of finger-jointed woods were investigated. The shape of creep curves differed among the used adhesives and finger pitches of finger-jointed woods for both tested species. Their creep curves showed a linear behavior beyond about one hour, and the N values fitted to power law increased with increasing finger pitches. The initial deformation increased with increasing finger pitches, regardless of the tested species and kinds of adhesives, whereas the effect of finger pitches on the creep deformation was not clear. For finger-jointed woods glued with polyvinyl acetate (PVAc) resin, creep failure occurred in 106 hours after the load was applied. And the difference of the creep compliance between finger-jointed woods glued with resorcinol-phenol formaldehyde (RPF) resin and aqueous vinyl urethane (AVU) resin was small. The ratios for creep performances of finger-jointed woods glued with RPF resin and AVU resin versus solid wood were higher in creep deformation than initial deformation for both species, and the difference between both adhesives was not found. The relative creep decreased with increasing finger pitches, and the marked differences was not found between RPF resin and AVU resin.

Effect of Finger Profile on Static Bending Strength Performance of Finger-Jointed Wood

  • Park, Han-Min;Lee, Gyun-Pil;Kong, Tae-Suk;Ryu, Hyun-Soo;Byeon, Hee-Seop
    • Journal of the Korean Wood Science and Technology
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    • 제32권6호
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    • pp.57-66
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    • 2004
  • To study the efficient usage of small diameter logs and woods containing defects such as knots, slope of the grain and decay, six types of finger-jointed woods with various finger profiles were made of poplar, pine and oak with different density. We investigated the effect of finger profile on static bending strength performances of finger-jointed woods. The efficiency of bending MOE, MOR and deflection showed the highest value in poplar finger-jointed wood with the lowest density of three species, and the lowest value in oak finger-jointed wood with the highest density of three species. The values markedly decreased with increasing finger pitch for finger-jointed wood glued with polyvinyl acetate (PVAc) resin for all tested species, whereas for the finger-jointed wood glued with resorcinol-phenol formaldehyde (RPF) resin, the influence of finger pitch on the efficiency of MOE was not found in all tested species, and those on the efficiency of MOR and deflection indicated the same trend as finger-jointed wood glued with PVAc resin in the case of pine and oak finger-jointed wood with higher densities. It was found that the values tended to decrease with increasing density of species on the whole and the desirable finger pitches were L (6.8 mm) for poplar, M (4.4 mm) for pine and S (3.5 mm) for oak in a view of economy. For finger-jointed wood glued with PVAc resin, the fitness between a tip and a root width of a pair of fingers δ of 0.5 mm indicated the highest efficiency of MOE for all species. And, the influence of δ on MOR was only found in oak finger-jointed wood glued with RPF resin and the desirable δ value for oak was 0.1 mm. However, it was found that the influence of δ on the strength performance was very small.

3축 힘센서를 이용한 두 손가락 힘측정장치 개발 (Development of Force Measuring System using Three-axis Force Sensor for Measuring Two-finger Force)

  • 김현민;윤정원;신희석;김갑순
    • 제어로봇시스템학회논문지
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    • 제16권9호
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    • pp.876-882
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    • 2010
  • Stroke patients can't use their hands because of the paralysis their fingers. Their fingers are recovered by rehabilitating training, and the rehabilitating extent can be judged by measuring the pressing force to be contacted with two fingers (thumb and first finger, thumb and middle finger, thumb and ring finger, thumb and little finger). But, at present, the grasping finger force of two-finger can't be accurately measured, because there is not a proper finger-force measuring system. Therefore, doctors can't correctly judge the rehabilitating extent. So, the finger-force measuring system which can measure the grasping force of two-finger must be developed. In this paper, the finger-force measuring system with a three-axis force sensor which can measure the pressing force was developed. The three-axis force sensor was designed and fabricated, and the force measuring device was designed and manufactured using DSP (Digital Signal Processing). Also, the grasping force test of men was performed using the developed finger-force measuring system, it was confirmed that the grasping forces of men were different according to grasping methods.

단축 힘센서를 이용한 두 손가락 잡기 힘측정장치 개발 및 특성평가 (Development of Two-Finger Force Measuring System to Measure Two-Finger Gripping Force and Its Characteristic Evaluation)

  • 김현민;신희석;윤정원;김갑순
    • 센서학회지
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    • 제20권3호
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    • pp.172-177
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    • 2011
  • Finger patients can't use their hands because of the paralysis their fingers. Their fingers are recovered by rehabilitating training, and the rehabilitating extent can be judged by measuring the pressing force to be contacted with two fingers(thumb and first finger, thumb and middle finger, thumb and ring finger, thumb and little finger). At present, most hospitals have used a thin plastic-plate for measuring the two-finger grasping force, and we can only judge that they can grasp the plate with their two-finger through it, because the plate can't measure the two-finger grasping force. But, recently, the force measuring system for measuring two-finger grasping force was developed using three-axis force sensor, but it is very expensive, because it has a three-axis force sensor. In this paper, two-finger force measuring system with a one-axis force sensor which can measure two-finger grasping force was developed. The one-axis force sensor was designed and fabricated, and the force measuring device was designed and manufactured using DSP(Digital Signal Processing). Also, the grasping force test of men was performed using the developed two-finger force measuring system, it was confirmed that the grasping forces of men were different according to grasping methods, and the system can be used for measuring two-finger grasping force.

모바일 환경에서 실시간 지문인식을 위한 웹 서비스 시스템 구현 (The Implementation of Web Services System for Realtime Finger Recognition in Mobile Environments)

  • 고유정;김윤중
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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    • pp.483-487
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    • 2006
  • 본 논문에서는 PDA에서 지문 이미지를 전송하여 실시간으로 인식할 수 있는 지문인식 웹 서비스 시스템을 구현하였다. 지문인식 웹 서비스 시스템은 지문이미지를 수신 받아 인식결과를 XML 형태로 반환함으로써 무선인터넷을 이용하는 PDA뿐만 아니라 유선 인터넷을 이용한 클라이언트에게도 동일한 서비스를 제공하였다. 본 시스템은 모바일 클라이언트와 지문인식 웹 서비스 제공자로 구성된다. 모바일 클라이언트는 채취된 지문 이미지를 DIME(Direct Internet Message Encapsulation)을 이용하여 지문인식 웹 서비스 제공자를 요청함으로써 저장 공간이 제약적인 PDA에 대용량의 지문 데이터베이스를 설치할 필요 없이 지문인식 결과를 받아 올 수 있다. 지문인식 웹 서비스 제공자는 지문 이미지를 수신 받아 지문인식시스템을 호출하여 인식을 수행한 후 인식결과를 반환하는 서비스를 제공한다.

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수지 첨부 및 수장부 연부 조직 결손에서 시행한 외측 중위 수지 피판술 (The Lateral Middle Phalangeal Finger Flap for Pulp and Palmar Defects of the Finger)

  • 정덕환;이재훈
    • Archives of Reconstructive Microsurgery
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    • 제15권1호
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    • pp.33-37
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    • 2006
  • Purpose: The aim of this study was to evaluate the efficacy of lateral middle phalangeal finger flap for pulp and palmar defect of the finger. Materials and methods: We performed the lateral middle phalangeal finger flap in thumb pulp defect 4 cases and the palmar defect of other finger 3 cases. Mean age was 38(25-53) years old and there were male 6 cases and female 1 case. Sensate flap was performed in 4 cases of thumb pulp defects. Mean follow-up period was 14(7-22) months. Results: All flaps were survived. Mean static two-pint discrimination of sensate flap 4 cases was 8(6-10) mm. The sensation of donor finger tip was normal in all cases. Limitation of range of motion of the donor fingers was absent. Patients complained of transient cold intolerance 1 month after surgery but didn't complain of that in all cases at last follow-up. Conclusions: The advantages of the lateral middle phalangeal finger flap are the preservation of the ipsilateral palmar digital nerve, good sensory reconstruction of the fingertip, well maintained donor finger mobility with minimal exposure of the extensor tendon, cosmetically good appearances of donor finger, and easy raising as a large flap. So we suggest that this flap is versatile for reconstructing of relatively large pulp defect of the thumb and the palmar defects involving the joint of finger.

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