• 한국기계가공학회지
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• 제21권2호
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• pp.116-122
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• 2022

This study proposed a method of testing the stability when selecting gears to reduce the weight of a 3-DOF wrist mechanism for a pick-and-place 3-DOF parallel robot with an increased workspace by using an additional straight axis at its top. We performed SolidWorks^® modeling- and ANSYS^®-based structural analysis of a pinion gear, which is most vulnerable to the force from a 3-DOF wrist mechanism, to lighten the robot weight for performing various tasks. When the initial analysis results considerably differed from the theoretical values calculated in advance, we checked and identified the errors in the contact conditions or input values. Ultimately, it is believed that the methodology presented in this paper will help in mitigating errors during analysis and determine the accurate values for a lightweight 3-DOF wrist mechanism for a parallel robot with an expanded workspace.

• Clinical Pain
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• 제20권1호
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• pp.15-19
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• 2021

There are many wrist and hand diseases in which ultrasound can help in the diagnosis and treatment. Because many small structures are located, identifying anatomical locations and pathways is especially important. In De Quervain's syndrome, it is necessary to find tendon lesions located in the first compartment of the wrist. If injection therapy is required, administer the regimen accurately within the tendon sheath through ultrasound. In carpal tunnel syndrome, there are several methods to diagnose a disease by measuring cross-sectional area of the median nerve. Ultrasound has the advantage of administering injection therapy without damaging the nerve. Intersection syndrome can be diagnosed by observing swelling and hypoechoic appearances at the point where the tendons of the first compartment cross over the second compartment of the wrist. Ultrasound-guided injection is also safe and efficient. If there is a trigger finger lesion, the most representative findings is to observe a nodular hypoechoic thickening of the involved A1 pulley. When injection therapy is performed, it is effective to administer medication between pulley and flexor tendons as much as possible to reduce pressure on the attached structures.

• 대한정형외과스포츠의학회지
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• 제11권1호
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• pp.17-23
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• 2012

완관절 관절경은 최근 들어 적응증이 확대되면서 여러 질환의 진단과 치료에 유용하게 사용되고 있다. 본 종설에서는 완관절 관절경에 대하여 전통적인 적응증뿐만 아니라 최근에 소개된 적응증을 문헌 고찰을 통해 알아보기로 하겠다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.909-914
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• 1987

In this paper a pneumatic vibratory wrist with PWM controller is developed for robotic assembly. Since the vibration characteristics are critical to assembly performance, they are investigated both theoretically and experimentally. The results show that within a wide range of conditions the wrist vibration can be effectively used for precision assembly.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.528-532
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• 1991

Having very small linear displacement, piezoelectric actuators have been restricted in robotic application as positioning devices. In this paper, a mechanical amplifier was developed to enhance the displacement of piezoelectric actuator and the corresponding driving circuit was designed. This equipment was integrated as a robotic wrist having 2 D.O.F micropositioning capability. Each joint was analysed in mechanical and dynamic view points. Experimental result showed that this device has Some hysteresis but could be used as vibratory robotic wrist with relatively high frequency. For more fine positioning control, a closed loop approach must be taken into account.

• Archives of Reconstructive Microsurgery
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• 제20권2호
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• pp.121-125
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• 2011

Simple ganglions are most common benign tumor of the hand and wrist. However, cystic adventitial disease is an uncommon vascular anomaly first described in 1947 in the external iliac artery. It usually involves the popliteal artery, although other arteries and veins may also be involved. Radial artery adventitial cysts are found directly within the adventitia, whereas the more common wrist ganglions may extrinsically compress or adhere to the artery walls. The diagnosis is rarely made before surgery because of their similar appearance and location. The authors report a rare case of a 46-year old woman with mucoid adventitial cyst of the radial artery in the wrist.

• 대한통합의학회지
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• 제3권2호
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• pp.1-8
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• 2015

Purpose: This study was conducted to know the evidence case to assessment about literatures of extensor carpi radialis therapeutic strategy of tennis elbow about dysfunction wrist extension with anatomy, biomechanic and function. Method: Patient was received the physical therapy program with medication for two weeks. Physical therapy program consists of strengthening exercise, stretching exercise and extracopereal shock wave therapy. Results: Patients could do computer and house works at three weeks significant with improved pain. The amounts used repetitive muscle was reduced slowly over a period of a day or two days for wrist moving. Wrist flexor strengthening exercise and could reduced the wrist extensor injury. Conclusion: Clinicians certainly realized biomechanic effects and anatomy of extensor carpiradialis and elbow joint.

• 한국안전학회지
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• 제21권3호
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• pp.122-126
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• 2006

This study investigated effect of arm posture, wrist motion repetition and external load on perceived discomfort through an experiment. Eleven female college students participated in the experiment, where shoulder, elbow and wrist motion, wrist motion repetition, and external load were used as independent variables. The results showed that only external load had a significant effect on perceived discomfort. The perceived discomfort linearly increased with external load. Based on the results of this and the previous study for males, it was concluded that effect of external load on perceived discomfort was larger than that of other posture and motion repetition related variables. This implies that effect of external load is the most important factor considered in the first place when assessing postural load.

• 대한인간공학회지
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• 제29권3호
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• pp.337-345
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• 2010

The purpose of this study was to investigate the effects of sleep/wake behavior for shiftwork in air traffic controllers (ATCs) using wrist actigraph for ten workers on a continuous full-day three-team three-shift system of forward rotation including on-duty and off-duty periods. The wrist actigraph data were recorded for three days (one shift cycle) for each subject. The mean activity counts during an on-duty period progressively increased from the night, the swing, to the morning shifts. The doze length during on-duty periods showed decreases in the morning and swing shifts as compared to the night shift. Total sleep time (TST) and sleep efficiency (SE) during off-duty periods increased in the morning-1 and swing-night shift compared to the morning-2 shift. Finally, I discussed the role of doze-taking during the burden on night shift ATCs.

• 대한인간공학회지
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• 제16권1호
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• pp.73-83
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• 1997

It is improtant to get accurate information about the grip strength for designing ergonomic grips and handles. It has been known that the excessive and repetitive use of grip force and unnatural posture of the wrist may cause cumulative trauma disorders (CTDs) such as carpal tunnel syndrome, tendrome, tendonitis, DeQuervan's disease, etc. In this paper we have measured the grip strength for sitting and standing posture for Korean adults ; 114 males and 105 females aged from the 20's to above the 50's. And this paper performed statistical analysis for deriving characteristics between grip strength and anthropometric data. The results are as follows ; (1) The maximum grip strength posture is exerted under standing posture with the elbow in full extension (180 .deg. ) for both males and females (2) There is significant difference among posture, sex and right and/or left handedness (3) Grip strength decreases with age for male, but it traces an inverted U curve for female (4) Grip strength has corre- lations with the age, weight, height, BSA, forearm length, hand length, thickness of wrist, circumference of wrist, and breadth of wrist for males.