• Archives of Reconstructive Microsurgery
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• v.23 no.1
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• pp.29-32
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• 2014

Few articles have been written about the flexor tendon sheath ganglion in the finger, especially, between A1 pulley and A2 pulley. We report on rare cases of flexor tendon sheath ganglion with one symptomatic and two asymptomatic. All masses were evaluated using real-time ultrasonography and well-defined anechoic cystic lesions with posterior enhancement were observed. A 17-year-old female had a small mass at the 4th metacarpophalageal joint of her right hand, with pain and triggering. The patient underwent simple excision and a ganglion measuring $1.0{\times}0.8$ cm in size was derived from Camper's chiasm, between A1 pulley and A2 pulley. In two asymptomatic cases, ganglia measuring less than 0.5 cm in size observed. Based on our experience, real-time ultrasonography would be an excellent diagnostic modality in determining the treatment method in flexor tendon sheath ganglia, and surgical excision is recommended in symptomatic, especially triggering patients.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.124-129
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• 1992

The goal of the proposed Intelligent Assisting System - IAS is to assist human operators in an intelligent way, while leaving decision and goal planning instances for the human. To realize the IAS the very important issue of manipulation skill identification and analysis has to be solved, which then is stored in a Skill Data Base. Using this data base the IAS is able to perform complex manipulations on the motion control level and to assist the human operator flexibly. We propose a model for manipulation skill based on the dynamics of the grip transformation matrix, which describes the dynamic transformation between object space and finger joint space. Interaction with a virtual world simulator allows the calculation and feedback of appropriate forces through controlled actuators of the sensor glove with 10 degrees-of-freedom. To solve the sensor glove calibration problem, we learn the nonlinear calibration mapping by an artificial neural network(ANN). In this paper we also describe the experimental system setup of the skill acquisition and transfer system as a first approach to the IAS. Some simple manipulation examples and simulation results show the feasibility of the proposed manipulation skill model.

• Archives of Plastic Surgery
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• v.45 no.4
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• pp.363-366
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• 2018

Background Camptodactyly refers to permanent flexion contracture at the proximal interphalangeal joint. Most cases are limited to fifth-finger involvement. Although common, the treatment of camptodactyly is controversial. Many published studies have emphasized conservative treatment, while others have described surgical procedures. The problem with this deformity is that it presents in several forms, which means that there is no single model for effective treatment. The aim of this paper is to present the difficulties encountered with this condition and the management thereof on an individual basis. Methods This is a case series of 14 patients (nine males, five females) who underwent surgical treatment. The results were classified using the method from Mayo Clinic as excellent, good, fair, and poor. Results Fourteen patients with 15 fingers underwent surgery, and the results achieved were as follows: excellent, 0; good, 1; fair, 6; poor, 8. The treatment of camptodactyly still remains controversial, and hence proper planning individualized to each patient is needed to achieve the maximal improvement with realistic goals. Conclusions Although we performed individualised surgery, our careful follow-up was not able to identify any method as superior over another with respect to gain in extension and loss of flexion. We therefore propose that the extensor mechanism should not be disturbed during surgery to treat camptodactyly cases.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.1
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• pp.99-104
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• 2009

This article describes the analysis of stable grasping for multi-fingered robot. An analysis method of stable grasping, which is based on the three-dimensional acceleration convex polytope, is proposed. This method is derived from combining dynamic equations governing object motion and robot motion, force relationship and acceleration relationship between robot fingers and object's gravity center through contact condition, and constraint equations for satisfying no-slip conditions at every contact points. After mapping no-slip condition to torque space, we derived intersected region of given torque bounds and the mapped region in torque space so that the intersected region in torque space guarantees no excessive torque as well as no-slip at the contact points. The intersected region in torque space is mapped to an acceleration convex polytope corresponding to the maximum acceleration boundaries which can be exerted by the robot fingers under the given individual bounds of each joints torque and without causing slip at the contacts. As will be shown through the analysis and examples, the stable grasping depends on the joint driving torque limits, the posture and the mass of robot fingers, the configuration and the mass of an object, the grasp position, the friction coefficients between the object surface and finger end-effectors.

• The Journal of Korea Robotics Society
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• v.10 no.4
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• pp.179-185
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• 2015

The versatility of a human hand is what the researchers eager to mimic. As one of the attempt, the redundant degree of freedom in the human hand is considered. However, in the force domain the redundant joint causes a control issue. To solve this problem, the force control method for a redundant robotic hand which is similar to the human is proposed. First, the redundancy of the human hand is analyzed. Then, to resolve the redundancy in force domain, the artificial minimum energy point is specified and the restoring force is used to control the configuration of the finger other than the force in a null space. Finally, the method is verified experimentally with a commercial robot hand, called Allegro Hand with a force/torque sensor.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.2
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• pp.88-94
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• 2016

In this paper, we describe a new approch to control method of a four joints-robot gripper for the purpose of parts assemblying. The robot gripper is specifically modeled by using a 3D CAD program (ANSYS), considering artificial grippers, and then the proposed control method is illustrated through the dynamic simulation tool (Adams). Each gripper finger is individually controlled to be located at the optimal positions where the maximal joint torque can be calculated. To verified the effectiveness of the proposed control method, we proposed two cases for the reference position of gripper. By comparing the control performance of two method, the performance of the proposed control method was verified.

• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.273-276
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• 2009

A 54-year-old man experienced injury to the second finger of his left hand due to damage from a paintball gun shot 8 years prior, and the metacarpo-phalangeal joint was amputated. He gradually developed mechanical allodynia and burning pain, and there were trophic changes of the thenar muscle and he reported coldness on his left hand and forearm. A neuroma was found on the left second common digital nerve and was removed, but his symptoms continued despite various conservative treatments including a morphine infusion pump on his left arm. We therefore attempted median nerve stimulation to treat the chronic pain. The procedure was performed in two stages. The first procedure involved exposure of the median nerve on the mid-humerus level and placing of the electrode. The trial stimulation lasted for 7 days and the patient's symptoms improved. The second procedure involved implantation of a pulse generator on the left subclavian area. The mechanical allodynia and pain relief score, based on the visual analogue scale, decreased from 9 before surgery to 4 after surgery. The patient's activity improved markedly, but trophic changes and vasomotor symptom recovered only moderately. In conclusion, median nerve stimulation can improve chronic pain from complex regional pain syndrome type II.

• Journal of Korea Game Society
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• v.12 no.5
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• pp.79-88
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• 2012

In this paper, we present a real-time hand pose recognition method to provide an intuitive user interface through hand poses or movements without a keyboard and a mouse. For this, the areas of right and left hands are segmented from the depth camera image, and noise removal is performed. Then, the rotation angle and the centroid point of each hand area are calculated. Subsequently, a circle is expanded at regular intervals from a centroid point of the hand to detect joint points and end points of the finger by obtaining the midway points of the hand boundary crossing. Lastly, the matching between the hand information calculated previously and the hand model of previous frame is performed, and the hand model is recognized to update the hand model for the next frame. This method enables users to predict the hidden fingers through the hand model information of the previous frame using temporal coherence in consecutive frames. As a result of the experiment on various hand poses with the hidden fingers using both hands, the accuracy showed over 95% and the performance indicated over 32 fps. The proposed method can be used as a contactless input interface in presentation, advertisement, education, and game applications.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.131-139
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• 2008

Purpose: Lipomatous tumor occurred in hand is very rare. There is a broad spectrum of lipomatous tumors including lipomas, variants of lipomas, lipomatosis, liposarcomas and so on. We report the clinical features of 11 cases of lipomatous tumor which occurred in hand. Materials and Methods: Between 1992 and 2008, 11 cases were histologically diagnosed as lipomatous tumor in hand. We reviewed all medical records and clinical photographs retrospectively and ascertained recurrence by telephone interview. Results: Eight cases were ordinary lipomas. Three cases were angiolipoma, fibrolipoma and atypical lipoma respectively. Four cases occurred in finger, two cases in thenar area, two cases in hypothenar area, one case in palm, two cases in wrist. All cases were situated on volar surface. All patients complained of palpable masses. One patient with subungal angiolipoma felt pain. There was no neurologic sign or vascular symptom preoperatively. In one case, postoperative complication (hypoesthesia in $5^{th}$ finger) was developed. There was no local recurrence. Conclusion: In our study, lipomatous tumors occurred in hand did not recur. Patients mainly complained of feeling of lump. Pain was uncommon symptom. Postoperative complication was rare if operation was performed carefully.

• Journal of Korea Foresty Energy
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• v.20 no.1
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• pp.73-80
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• 2001

This study was carried out to investigate the strength and technical feasibility of arch type laminated lumber from the domestic small lumbers(Pinus densiflora S. et Z. and Larix kampferi Catt.). Arch type lumbers manufactured with different compositions of laminae. It was designed to improve the strength and stiffness. Strength S. rt Z. U;timate load Carr. laminated lumbers were higher than that of the Pinus densiflora S. et Z. Ultimate load of 7-ply laminated lumbers were 2 times higher than the 5-ply laminated lumbers. The strength of finger jointed lumbers were found to be about 15.8% less than that of the no joint lumber. One solution for this problem is to use veneer as face lamina. The veneer laminated lumbers was considerably greater than that of the non-veneer laminated lumbers. It was suggested that this small lumber may be a candidate for high valued product member to provide the proper combination of laminae.