• Archives of Reconstructive Microsurgery
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• v.10 no.2
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• pp.99-104
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• 2001

Purpose : Loss of sensibility over the finger tip resents a grave deficit and is an indication for sensible soft tissue reconstruction. This paper was performed to assess the long term results obtained by nerovascular island flap. Material and Methods : We performed neurovascular island graft for defective sensibility of finger tip loss in 94 cases since 1979 to 2000. The recipient sites were the thumb pulp defect in 79 cases, the amputated thumb in 9 cases, the amputated index in 4 cases, and the velar aspect of interphalangeal joint of thumb in 2 cases. The donor flaps were obtained from the radial side of ring finger in 63 cases, the ulnar side of the ring finger in 21 cases, and the ulnar side of the middle finger in 10 cases. A mean follow-up period was 5.7 years. Results : The flap quality was well vascularized and survived in 89 cases. The two-point discrimination was average 8.7mm. Because of scar contracture, the range of motion of the donor finger was decreased 3.5% of the normal finger in the distal interphalangeal joint, 8,2% in the proximal interphalangeal joint. A phenomenon of double sensibility occurred in 66 cases. Conclusion : This technique was excellent both aesthetically and functionally as a reconstruction of the Loss of fingertip.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.4
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• pp.9-15
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• 2012

This paper presents application of a new tactile slippage sensation algorithm in robot hand control system. The optical three-axis tactile sensor is a type of tactile sensor capable of defining normal and shear forces simultaneously. The tactile sensor is mounted on fingertip of robotic hand. Shear force distribution is used to define slippage sensation in the robot hand system. Based on tactile slippage analysis, a new control algorithm was proposed. To improve performance during object handling motions, analysis of slippage direction is conducted. The control algorithm is classified into two phases: grasp-move-release and grasp-twist motions. Detailed explanations of the control algorithm based on the existing robot arm control system are presented. The experiment is conducted using a bottle cap, and the results reveal good performance of the proposed control algorithm to accomplish the proposed object handling motions.

• Archives of Plastic Surgery
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• v.33 no.5
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• pp.652-654
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• 2006

Beau first described transverse depressions of the fingernails after an acute febrile illness in 1846. It was the result of the temporary arrest of nail matrix formation. The transient interference of nail growth rate is usually induced by disability caused by severe systemic disease. Such as Raynaud disease, myocardial infarction, pulmonary embolism, acute renal failure, psoriasis and dysmenorrhea were reported to be the cause of Beau's line. The trauma caused either in a hand or in a forearm was also reported to be the cause of Beau's line. We experienced patients with Beau's line, two cases secondary to fingertip injury and one case due to fracture in radius. They had Beau's lines in all fingers of traumatized hand and nails of opposite hand were normal. During the follow-up, the growth rate of traumatized fingernails were normal and there was no complication.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.214-221
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• 2007

This paper presents a myoelectric hand prosthesis(MHP) with two degree of freedom(2-DOF), which consists of a mechanical hand, a surface myoelectric sensor(SMES) for measuring myoelectric signal, a control system and a charging battery. The actuation for the 2-DOF hand functions such as grasping and wrist rotation was performed by two DC-motors, and controlled by myoelectric signal measured from the residual forearm muscle. The grip force of the MHP was automatically changed by a mechanical automatic speed reducer mounted on the hand. The skin interface of SMES was composed of the electrodes using the SUS440 metal in order to endure a wet condition due to the sweat. The sensor was embedded with a amplifier and a filter circuit for rejecting the offset voltage caused by power line noises. The control system was composed of the grip force sensor, the slip sensor, and the two controllers. The two controllers were made of a RISC-type microprocessor, and its software was executed on a real-time kernel. The control system used Force Sensing Resistors, FSR, as slip pick-ups at the fingertip of a thumb and the grip force information was obtained from a strain-gauge on the lever of the MHP. The experimental results were showed that the proposed control system is feasible for the MHP.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1808-1813
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• 2005

In this paper, we present the finger tip tactile sensor which can detect contact normal force as well as slip. The developed sensor is made of two different materials, such as polyvinylidene fluoride(PVDF) that is known as piezoelectric polymer and pressure variable resistor ink. In order to detect slip to surface of object, a PVDF strip is arranged along the normal direction in the robot finger tip and the thumb tip. The surface electrode of the PVDF strip is fabricated using silk-screening technique with silver paste. Also a thin flexible force sensor is fabricated in the form of a matrix using pressure variable resistor ink in order to sense the static force. The developed tactile sensor is physically flexible and it can be deformed three-dimensionally to any shape so that it can be placed on anywhere on the curved surface. In addition, we developed a tactile sensing system by miniaturizing the charge amplifier, in order to amplify the small signal from the sensor, and the fast signal processing unit. The sensor system is evaluated experimentally and its effectiveness is validated.

• Journal of Computational Design and Engineering
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• v.2 no.1
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• pp.26-37
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• 2015

A lot of researchers have been investigating interactive portable projection systems such as a mini-projector. In addition, in exhibition halls and museums, there is a trend toward using interactive projection systems to make viewing more exciting and impressive. They can also be applied in the field of art, for example, in creating shadow plays. The key idea of the interactive portable projection systems is to recognize the user's gesture in real-time. In this paper, a vision-based shadow gesture recognition method is proposed for interactive projection systems. The gesture recognition method is based on the screen image obtained by a single web camera. The method separates only the shadow area by combining the binary image with an input image using a learning algorithm that isolates the background from the input image. The region of interest is recognized with labeling the shadow of separated regions, and then hand shadows are isolated using the defect, convex hull, and moment of each region. To distinguish hand gestures, Hu's invariant moment method is used. An optical flow algorithm is used for tracking the fingertip. Using this method, a few interactive applications are developed, which are presented in this paper.

• The Journal of Korean Medical History
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• v.26 no.2
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• pp.63-74
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• 2013

Objective : In Donguibogam(東醫寶鑑), like a slow pulse with irregular intervals(結脈), an abrupt pulse(促脈) and a slow and weak pulse with regular intervals(代脈), an uneven pulse is written as a kind of arrhythmia. Such a recognition differs from the present one. In this study, I try to seize the meaning and deliberate whether those expressions are appropriate. Method : 1. Collect and compare the materials of the above four pulses among documentary records of feeling the pulse for diagnosis. 2. Grasp the aspect and trend of changes. 3. Reason whether records in Donguibogam(東醫寶鑑) are proper or not. Result & Conclusions : Donguibogam(東醫寶鑑) written "like a slow pulse with irregular intervals(結脈), an abrupt pulse(促脈) and a slow and weak pulse with regular intervals(代脈), an uneven pulse is written as a kind of arrhythmia". It is not 'an uneven pulse' is written about irregularity of pulse, but 'an uneven pulse' is written about irregularity of the sense able to be felt on the fingertip.

• Archives of Plastic Surgery
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• v.40 no.2
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• pp.129-133
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• 2013

Background A pneumatic tourniquet is generally used to achieve a bloodless operation field in hand surgery. However, this has changed with tumescent solution-based wide-awake surgery. This study is a preliminary prospective case series study to elaborate the formula and indications of the tumescent technique in hand surgery without a tourniquet. Methods Seven patients (age range, 4 months to 37 years) underwent hand or upper extremity surgery for conditions such as nerve palsy, electric burn defect, fingertip injury, contracture, constriction ring syndrome, or acrosyndactyly. A "one-per-mil" tumescent solution (epinephrine 1:1,000,000+20 mg lidocaine/50 mL saline) was used to create a bloodless operating field without a tourniquet. Observation was performed to document the amount of solution injected, the operation field clarity, and the postoperative pain. Results The "one per mil" epinephrine solution showed an effective hemostatic effect. The tumescent technique resulted in an almost bloodless operation field in the tendon and in the constriction ring syndrome surgeries, minimal bleeding in the flap and contracture release surgeries, and acceptable bleeding in acrosyndactyly surgery. The amount of solution injected ranged from 5.3 to 60 mL. No patient expressed significant postoperative pain. Flap surgeries showed mixed results. One flap was lost, while the others survived. Conclusions Epinephrine 1:1,000,000 in saline solution is a potential replacement for a tourniquet in hand surgery. Further studies are needed to delineate its safety for flap survival.

• Archives of Reconstructive Microsurgery
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• v.15 no.1
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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.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.5
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• pp.404-414
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• 2000

This paper addresses the development of a 3-fingered humanoid robot hand system and a real-time grasp synthesis of multifingered robot hands to find grasp configurations which satisfy the force closure condition of arbitrary shaped objects. We propose a fast and efficient grasp synthesis algorithm for planar polygonal objects, which yields the contact locations on a given polygonal object to obtain a force closure grasp by the multifingered robot hand. For an optimum grasp and real-time computation, we develop the preference and the hibernation process and assign physical constraints of the humanoid hand to the motion of each finger. The preferences consist of each sublayer reflecting the primitive preference similar to the conditional behaviors of humans for given objectives and their arrangements are adjusted by the heuristics inspired from human's grasping behaviors. The proposed method reduces the computational time significantly at the sacrifice of global optimality, and enables the grasp posture to be changable within two-finger and three-finger grasps. The performance of the presented algorithm is evaluated via simulation studies to obtain the force-closure grasps of polygonal objects with fingertip grasps. The architecture suggested is verified through experimental implementation to our robot hand system by solving the 2- or 3-finger grasp synthesis.