• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.115-123
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• 2017

This paper presents the design and the control performance of a novel dynamic compliant-arm support with parallel elastic actuators that was developed to assist with the daily living activities of those whose arms are compromised by muscular disease or the aging process. The parallel elastic-arm support consists of a compliant mechanism with combined passive and active components for human interaction and to reach the user's desired positions. The achievement of these tasks requires impedance control, which can change the virtual stiffness, damping coefficients, and equilibrium points of the system; however, the desired-position tracking by the impedance control is limited when the end-effector weight varies according to the equipping of diverse objects. A prompt algorithm regarding weight calibration and friction compensation is adopted to overcome this problem. A result comparison shows that, by accurately assessing the desired workspace, the proposed algorithm is more effective for the accomplishment of the desired activities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5364-5371
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• 2015

The purpose of the study is to prevent pain and malfunction of the hand by correcting the angle of holding a smartphone. Subjects comprised of 21 healthy students. This research was conducted from April 21 2014 to April 27 2014. The three groups were as follows: first group included 7 students who held the phone at an angle of 90 degrees without a sling, and second group included 7 students who held the smartphone at an angle of 90 degrees with a sling; and the third group included 7 students who held the smartphone at an angle of 120 degrees with a sling. VAS was measured through the Finkelstein Test. Also, pain rating and muscle strength were assessed four times 30 minutes before and after the experiment for one and a half hour with pinch grip, dynamometer, and visual analogue scale. Smartphone was used. In all of the measurements, period showed a significant difference (p<.05) between both sides and a significant difference was not found between the group. In the time ${\times}$ group, pain score and grip strength were significantly different in the right side only (p<.05). According to the results of this experiment, providing support to the hand helps to increase the hand function by reducing the stress.