• Archives of Plastic Surgery
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• v.36 no.1
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• pp.84-88
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• 2009

Purpose: Compression of the ulnar nerve in the ulnar tunnel is a relatively uncommon condition. Many authors have described several etiologies of ulnar nerve compression. We experienced two cases of ulnar nerve compression in the ulnar tunnel due to an anomalous pulsatile S - shaped ulnar artery. Methods: Case 1: A 51 - year - old man was referred with numbness and paroxysmal tingling sensation along the volar side of the ring and little fingers of his right hand for 6 months. When exploration, the ulnar artery was pulsatile S - shaped and was impinging on the ulnar nerve. To decompress the ulnar nerve, the tortuous ulnar artery was mobilized and translocated radially onto the adjacent fibrous tissue. Case 2: A 41 - year - old man was referred with tingling sensation on the 4 th, 5 th finger of the right hand for 4 months. Sensory nerve conduction velocities of the ulnar nerve was delayed. Preoperative 3D angio CT scan showed an anomalous S - shaped ulnar artery. Same operation was done. Results: The postoperative course was uneventful. After decompression, paroxysmal tingling sensation decreased to less than 1 minute per episode, occurring 1 - 2 times a day. After 4 months, they had no more episodes of numbness and tingling sensation. Examination demonstrated good sensation to pinprick and touch on the ulnar aspect of the hand. Conclusion: We report two cases of ulnar nerve compressive neuropathy that was caused by an anomalous pulsatile S - shaped ulnar artery in the ulnar tunnel. Although this is an unusual cause of ulnar nerve compression, the symptoms will not spontaneously resolve. The prompt relief of compressive neuropathic symptoms following the translocation of the impinging ulnar artery from the affected ulnar nerve onto adjacent tissue proved that the ulnar nerve compression is due to the anomalous vessel.

• Journal of Biomedical Engineering Research
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• v.40 no.6
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• pp.242-249
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• 2019

Forearm electromyography (EMG) generated by wrist movements has been widely used to develop an electrical prosthetic hand, but EMG generated by finger movements has been rarely used even though 20% of amputees lose fingers. The goal of this study is to improve the classification performance of different finger movements using a deep learning algorithm, and thereby contributing to the development of a high-performance finger-based prosthetic hand. Ten participants took part in this study, and they performed seven different finger movements forty times each (thumb, index, middle, ring, little, fist and rest) during which EMG was measured from the back of the right hand using four bipolar electrodes. We extracted mean absolute value (MAV), root mean square (RMS), and mean (MEAN) from the measured EMGs for each trial as features, and a 5x5-fold cross-validation was performed to estimate the classification performance of seven different finger movements. A long short-term memory (LSTM) model was used as a classifier, and linear discriminant analysis (LDA) that is a widely used classifier in previous studies was also used for comparison. The best performance of the LSTM model (sensitivity: 91.46 ± 6.72%; specificity: 91.27 ± 4.18%; accuracy: 91.26 ± 4.09%) significantly outperformed that of LDA (sensitivity: 84.55 ± 9.61%; specificity: 84.02 ± 6.00%; accuracy: 84.00 ± 5.87%). Our result demonstrates the feasibility of a deep learning algorithm (LSTM) to improve the performance of classifying different finger movements using EMG.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.2
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• pp.13-18
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• 2005

The ulnar nerve extends down the arm, across the elbow, and into the hand. It provides sensation to the little and ring fingers and activates many of the small muscles in the hand. The determination of peripheral nerve conduction velocity is an important part of ulnar nerve evaluation. The electrodiagnostic value as neurophysiologic investigative procedure has been known for many years but normal value of digital nerve was not reported in Korea. The purpose of this investigation was to measure the digital nerve conduction velocity of ulnar nerve for obtain clinically useful reference value and compare difference in each fingers and then compare with the other countries. 71 normal Korean volunteers (age, 19-65 years; 142 hands) examined who has no history of peripheral neuropathy, diabetic mellitus, chronic renal failure, endocrine disorders, anti-cancer medicine, anti-tubercle medicine, alcoholism, trauma, radiculopathy. Nicolet Viking II (EMG machine) was use for detected conduction velocity and amplitude of digital nerves in ulnar nerve. Data analysis was performed using SPSS. Descriptive analysis was used for obtain mean and standard deviation and independent t-test was used to compare with ring and little finger. Conduction velocity of the right ring finger was 57.44m/sec and little finger was 55.32msec. The left ring finger was 55.55msec and little finger was 54.11msec. Amplitude of the right ring finger was $30.28{\mu}V$ and little finger was $48.36{\mu}V$. The left ring finger was $30.67{\mu}V$ and little finger was $52.76{\mu}V$. There were significantly difference between ring and little in amplitude (p<.05) but there were no statistically difference between conduction velocity of ring and little finger (p>.05). The amplitude of little finger are greater than ring finger. The present results revealed that electodiagnosis can easily perform in little finger for digital nerve of ulnar nerve study.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.33-42
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• 2014

Hand-signal is an effective communication means in the situation where voice cannot be used for expression especially for soldiers. Vision-based approaches using cameras as input devices are widely suggested in the literature. However, these approaches are not suitable for soldiers that have unseen visions in many cases. in addition, existing special-glove approaches utilize the information of fingers only. Thus, they are still lack for soldiers' hand-signal recognition that involves not only finger motions, but also additional information such as the rotation of a hand. In this paper, we have designed and implemented a new recognition system for six military hand-signal motions, i. e., 'ready', 'move', quick move', 'crawl', 'stop', and 'lying-down'. For this purpose, we have proposed a finger-recognition method and motion-recognition methods. The finger-recognition method discriminate how much each finger is bended, i. e., 'completely flattened', 'slightly flattened', 'slightly bended', and 'completely bended'. The motion-recognition algorithms are based on the characterization of each hand-signal motion in terms of the three axes. Through repetitive experiments, our system have shown 91.2% of correct recognition.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.1-16
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• 1996

This study was conducted at an automobile assembly line located in Kyonggi-do, Korea from January 16 to February 28, 1995. The purposes of this study were to assess worker exposures to hand-arm vibration and the performance of gloves for reduction of vibration. The exposure to vibration was measured using to the ISO 5349(1986) method. Vibration acceleration and frequency spectra for each tool were determined on-line replicating actual working conditions and analyzed together with exposure time for evaluating individual worker exposure. Eight pneumatic hand tools, 60 workers exposured to hand-arm vibration, and three pairs of gloves were involved in this study. Results are summarized as follows. 1. Dominant frequencies of vibration for all tools(n=8) measured in this study ranged from 250 Hz to 800 Hz. 2. There was no significant correleration between dominant frequencies and free running speed (p>0.05). 3. Total predicted exposure times of using impact, hammer type did not exceed 40 minutes, but metal finish task, using grinder and sander exceeded 40 minutes. Total exposure time affected significantly the frequency-weighted, 4 hr equivalent acceleration. 4. Predicted prevalence and observed exposure period data were compared in workers(n=60), according to ISO 5349. In this results, 23(50.0 %) and 24(48.07 %) persons exceeded the mean latency periods for vibration-induced white finger(VWF) at 10 % (n=46) and 50 % (n=52) standards, respectively. On the basis of ISO equation, mean latent periods for VWF were 3.23, 4.72 years at 10 %, 50 % standards, respectively. 5. Reduction of vibration by gloves was evaluated. Since impact pneumatic tools produced low frequency vibrations, conventional gloves did not provide any protection. Gloves A and C amplify somewhat the signal at frequency below 400 Hz; the attenuation increases progressively by frequency to reach 18 dB ($7.94{\times}10^{-6}m/s^2$) at 1,000 Hz, slightly worsening Glove B did not provide any protection and made the situation slightly worse. However, since they make the hands warm, the occurrence of vibration-induced white fingers may be reduced.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.19-23
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• 2024

Patients with amputations of both hands need prosthetic hands that serve both cosmetic and functional purposes, and research on prosthetic hands using electromyography of remaining muscles is active, but there is still the problem of high cost. In this study, an artificial prosthetic hand was manufactured and its performance was evaluated using low-cost parts and software such as a surface electromyography sensor, machine learning software Edge Impulse, Arduino Nano 33 BLE, and 3D printing. Using signals acquired with surface electromyography sensors and subjected to digital signal processing through Edge Impulse, the flexing movement signals of each finger were transmitted to the fingers of the prosthetic hand model through training to determine the type of finger movement using machine learning. When the digital signal processing conditions were set to a notch filter of 60 Hz, a bandpass filter of 10-300 Hz, and a sampling frequency of 1,000 Hz, the accuracy of machine learning was the highest at 82.1%. The possibility of being confused between each finger flexion movement was highest for the ring finger, with a 44.7% chance of being confused with the movement of the index finger. More research is needed to successfully develop a low-cost prosthetic hand.

• Archives of design research
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• v.19 no.1 s.63
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• pp.293-302
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• 2006

clay cups with handles made in studios in Korea and the United States were selected and analyzed. The shape of cup were fixed to ensure proper comparison between handle size of the cup and position. The variable factors were the thickness of the handle, the number of fingers required to hold the cup, the relationship between the handle's shape and the position of its attachment to the cup, the effect of the handle's setter, the change in shape of the handle's thickness, and the relationship between the cup's weight center and handle. Preference test were designed and tested to the users, and the results were analyzed. The results showed that to make a comfortable handle, it is important to incorporate the shape of the resting hand in the design of the handle. Specifically, the design should be such that the cup can be held comfortably. This is possible if the weight of the cup is spread evenly when several fingers are inside the handle's curve and if such factors as the hand size, the curve of the fingers, and the position that best controls the cup's weight center are carefully considered. At this time, if there is a setter for the thumb, a cup of the same weight can be lifted more lightly. In the design of such a cup, the oval line is drawn by extending the cup's handle toward the direction of the cup's body. If the cup's weight center is located on the oval line, the cup's handle may be said to be effective. In such a case, the nearer the handle is to the cup's body weight center, the less power is needed to lift the cup efficiently. Our test results can be applied as a powerful tools in design and manufacturing cups with handle in terms of artistry and functionality.

• The Journal of Korea Robotics Society
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• v.12 no.3
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• pp.270-278
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• 2017

The electrical muscle stimulator (EMS) based human machine interface (HMI) free to mechanical constraint and muscle fatigue problems are proposed for force feedback in a virtual reality. The device was designed to provide force feedback up to 4.8 N and 2.6 N each to the thumb and forefingers. The main objective of the HMI is to make unnecessary mechanical structures to attach on the hand or fingers. It employs custom EMSs and an interface arranged in the forearm. In this work, major muscle groups such as extensor pollicis brevis (EPB), extensor indicis proprius (EIP), flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) are selected for efficient force feedback and controlled individually. For this, a human muscular-skeletal analysis was performed and verified. The validity of the proposed multi-channel EMS based HMI was evaluated thorough various experiments with ten human subjects, interacting with a virtual environment.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.873-878
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• 2015

A finger exoskeleton actuated by ionic polymer metal composite (IPMC) actuators has been developed. In order to evaluate performance of cylindrical grasping of finger exoskeletons, they were equipped with a hand dummy, which is composed of four fingers. The finger dummy has three joints that can be actuated by bending the IPMC actuators. A four finger grasping motion was analyzed using cameras, and cylindrical grasping motion was accomplished within two minutes after applying a 4 volt direct voltage to the IPMC actuators. A pull out test was also performed to evaluate the cylindrical grasping force of the finger exoskeletons actuated by the IPMC actuators. Each finger generated about 2 N of holding force when grasping the cylinder which had a diameter of 50 mm.

• Archives of Reconstructive Microsurgery
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• v.10 no.1
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• pp.7-11
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• 2001

Purpose : To evaluate the neurologic abnormalities in the donor limb after contralateral C7 transfer in brachial plexus injury. Materials and Methods : From August 1996 to December 1999, five patients with brachial plexus injury were treated with contralateral C7 nerve root transfer. The average follow up was 16 months(range, 5 to 36 months). The clinical findings were assessed using the British Medical Research Council Grading System, and also measured grip power, pinch power of hand and two point discrimination of the fingers. Results : We had no difference in shoulder abduction and elbow flexion after contralateral C7 transfer. The grip and pinch strength were recovered within 4weeks. Sensory loss occurred in all patients and was noted to be more severe on index and middle finger. Four patients recovered within 2 weeks, one continued till one year. Subjective numbness and pain on percussion minimally persisted until last follow-up. Conclusion : The division of the C7 nerve root resulted in minimal and temporary functional deficit in the donor upper limb.