• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.24-27
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• 2003

This paper discusses practical strategies for transition from a pinching to a power grasping, where a multi-fingered hand mounted on a robotic arm envelops a cylindrical object on a table. When the manipulation system grasps a cylindrical object like a pen on a desk, a complete enveloping is not impossible in the initial configuration. The system firstly pinches the object only with two or three fingers and then grasp it with fingers and a palm after regrasping. In this pinching-grasping transition maneuver, human unconsciously selects proper strategy according to some conditions including object dimensions and initial pinching positions. In this paper we therefore develop six possible strategies for this pinching-grasping transition and then investigate their performances for some objects with various dimensions and various grasping positions, using numerical simulations. Based on their results, effective strategies are implemented by using a hand-arm system.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1014-1020
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• 2011

This presents a motion and force estimation system of human fingers by using an Electromyography (EMG) sensor module and a data glove system to be proposed in this paper. Both EMG sensor module and data glove system are developed in such a way to minimize the number of hardware filters in acquiring the signals as well as to reduce their sizes for the wearable. Since the onset of EMG precedes the onset of actual finger movement by dozens to hundreds milliseconds, we show that it is possible to predict the pattern of finger movement before actual movement by using the suggested system. Also, we are to suggest how to estimate the grasping force of hand based on the relationship between RMS taken EMG signal and the applied load. Finally we show the effectiveness of the suggested estimation system through several experiments.

• Smart Media Journal
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• v.8 no.4
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• pp.53-57
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• 2019

In this paper, we propose a flex sensor-based data glove to track the movements of human fingers for virtual reality education. By putting flex sensors and utilizing an accelerometer, this data glove allows people to enjoy applications for virtual reality (VR) or augmented reality (AR). With the maximum and minimum values of the flex sensor at each finger joint, it determines an angle corresponding to the bending value of the flex sensor. It tracks the movements of fingers and hand gestures with respect to the angle values at finger joints. In order to prove the effectiveness of the proposed data glove, we implemented a VR classroom application.

• Journal of the Ergonomics Society of Korea
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• v.28 no.2
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• pp.27-34
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• 2009

The purpose of this study was to evaluate aging (young and old), gender (male and female), and handle shape effects on grip force, finger force, and subjective comfort. Four handle shapes of A, D, I, and V were implemented by a multi-finger force measurement (MFFM) system which was developed to measure every finger force with different grip spans. Forty young (20 males and 20 females) and forty old (20 males and 20 females) subjects participated in twelve gripping tasks and rated their comfort for all handles using a 5-point scale. Grip forces were calculating by summation of all four forces of the index, middle, ring and little fingers. Results showed that young males (283.2N) had larger gripping force than old males (235.6N), while young females (151.4N) had lower force than old females (153.6N). Young subjects exerted the largest gripping force with D-shape due to large contribution of the index and middle fingers and the smallest with A-shape; however, old subjects exerted the largest with I-shape and the smallest with V-shape due to small contribution of the ring and little fingers. As expected, the middle finger had the largest finger force and the little finger had the smallest. The fraction of contribution of index and ring fingers to grip force differed among age groups. Interestingly, young subjects provided larger index finger force than ring finger force, whereas old subjects showed that larger ring finger forces than index finger force in the griping tasks. In the relationship between performance and subjective comfort, I-shape exerting the largest grip force had less comfort than D-shape producing the second largest grip force. The findings of this study can provide guidelines on designing hand tool handle to obtain better performance as well as users' comfort.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.5
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• pp.516-523
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• 2012

Stroke patients should exercise for the rehabilitation of their fingers, because they can't use their hand and fingers. The moving direction of thumb of five fingers is different that of four fingers (force finger, middle finger, ring finger, little finger). The thumb rehabilitation robot for rehabilitation exercise must be included a force control system, because robot can injure thumb by applying too much force. In this paper, the rectangular-type thumb rehabilitation robot was developed for stroke patient's thumb rehabilitation exercise of the flexibility rehabilitation exercise. The characteristic test of the developed rectangular-type thumb rehabilitation robot was carried out with normal men in their twenties. As a result, it is thought that the robot can be used for the flexibility rehabilitation exercise of stroke patient's thumb.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.5 no.1
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• pp.143-154
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• 1998

Background : There have been very few studies conducted on the number and type of microorganisms that remain on the ring finger after handwashing. This study was performed to investigate whether there were changes and differences in the type and number of microorganisms on the ring finger before and after handwashing. Method : The subjects of the study were 15 MICU and SICU staff nurses who were wearing rings. I swabbed two different fingers of the same hand with cotton balls. One finger which had a ring and the other with no ring. I swabbed the fingers of each subject three times(before handwashing, after handwashing with soap, and after handwashing with bethadine solution). After storing them for 48 hours in an incubator, I sent them to the laboratory and recorded the culture results. Results : There was no difference in the type of microorganism, but a major difference in the number of the microorganisms that existed on the finger ring. The results showed that there were much more microorganisms on the ring fingers than on the fingers that did not have rings both before and after handwashing. This tendency was consistent regardless of the handwashing agent. I therefore recommend that all nursing staff who work in general nursing units, as well as nurses who work in the ICU, remove their rings when taking care of the patients.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.83-95
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• 2014

Hand posture recognition is an important technique to enable a natural and familiar interface in HCI(human computer interaction) field. In this paper, we introduce a hand posture recognition method by using a depth camera. Moreover, the hand posture recognition method is incorporated with MPEG-U based advanced user interaction (AUI) interface system, which can provide a natural interface with a variety of devices. The proposed method initially detects positions and lengths of all fingers opened and then it recognizes hand posture from pose of one or two hands and the number of fingers folded when user takes a gesture representing a pattern of AUI data format specified in the MPEG-U part 2. The AUI interface system represents user's hand posture as compliant MPEG-U schema structure. Experimental results show performance of the hand posture recognition and it is verified that the AUI interface system is compatible with the MPEG-U standard.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.995-998
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• 2002

In this paper, we present a fast algorithm for hand gesture recognition of a human from an image by using the directivity information of the fingers. To implement a fast recognition system, we applied the morphological shape decomposition. A proposed gesture recognition algorithm has been tested on the 300 ${\times}$ 256 digital images. Our experiments using image acquired image camera have shown that the proposed hand gesture recognition algorithm is effective.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.192-197
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• 2012

This paper describes the control of the hand fixing system attached to the finger rehabilitation robot for the rehabilitation exercise of patient's fingers. The finger rehabilitation robot is used to exercise the finger rehabilitation, and a patient's hand is safely fixed using the hand fixing system. In this paper, the hand fixing system was controlled with PD gains to fix a palm of the hand, and the characteristic test for the hand fixing system was carried out to sense the fixed hand movement of the front and the rear, that of the left and the right, and that of the upper. It is thought that the hand fixing system could safely fix the hand, and the movement of the fixed hand could be perceived using the five-axis force/moment sensor attached to the hand fixing system.

• Archives of Plastic Surgery
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• v.39 no.5
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• pp.483-488
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• 2012

Background Pediatric hand burns are a difficult problem because they lead to serious hand deformities with functional impairment due to rapid growth during childhood. Therefore, adequate management is required beginning in the acute stage. Our study aims to establish surgical guidelines for a primary full-thickness skin graft (FTSG) in pediatric hand burns, based on long-term observation periods and existing studies. Methods From January 2000 to May 2011, 210 patients underwent primary FTSG. We retrospectively studied the clinical course and treatment outcomes based on the patients' medical records. The patients' demographics, age, sex, injury site of the fingers, presence of web space involvement, the incidence of postoperative late deformities, and the duration of revision were critically analyzed. Results The mean age of the patients was 24.4 months (range, 8 to 94 months), consisting of 141 males and 69 females. The overall observation period was 6.9 years (range, 1 to 11 years) on average. At the time of the burn, 56 cases were to a single finger, 73 to two fingers, 45 to three fingers, and 22 to more than three. Among these cases, 70 were burns that included a web space (33.3%). During the observation, 25 cases underwent corrective operations with an average period of 40.6 months. Conclusions In the volar area, primary full-thickness skin grafting can be a good indication for an isolated injured finger, excluding the web spaces, and injuries of less than three fingers including the web spaces. Also, in the dorsal area, full-thickness skin grafting can be a good indication. However, if the donor site is insufficient and the wound is large, split-thickness skin grafting can be considered.