• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.851-856
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• 2015

This study aimed to develop a sensory feedback system which could measure force and temperature for the user of myoelectric prosthetic hands. The Sensory measurement module consisted of a force sensing resistor to measure forces and non-contact infrared temperature sensor. These sensors were attached on the fingertips of the myoelectric prosthetic hand. The module was validated by using standard weights corresponding to external force and a Peltier module. Sensory transmission module consisted of four vibration motors. Eight vibration patterns were generated by combining motion of each vibration motor and were dependent on kinds and/or magnitude. The module was verified by using standard weigts and water at varying temperatures. There were correlations of force and temperature between the sensory measurement module and standard weight and water. Additionally, exact vibration patterns were generated, indicating the efficacy of the sensory feedback system for the myoelectric prosthetic hand.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.4
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• pp.125-137
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• 2021

PURPOSE: The growing number of people exposed to a static sitting posture has resulted in an increase in people with a poor posture out of the optimally aligned posture because of the low awareness of a correct sitting posture. Learning the correct sitting posture by applying sensory feedback is essential because a poor posture has negative consequences for the spine. Therefore, this study examined the effects of the sensory feedback types on learning correct sitting posture. METHODS: Thirty-six healthy adult males were assigned to a visual feedback group, a tactile feedback group, and a visuotactile feedback group to learn the correct sitting posture by applying sensory feedback. The spine angle, muscle activity, and muscle thickness were measured in the sitting position using retro-reflexive markers, electromyography, and ultrasound immediately after, five minutes, and 10 minutes after intervention. RESULTS: The intervention time was significantly shorter in the visuotactile feedback group than the visual feedback group (p < .05). Compared to the pre-intervention, the repositioning error angles of the thoracic and lumbar vertebrae of all groups were reduced significantly immediately after intervention and after five minutes. After 10 minutes, there was a significant difference in the thoracic and lumbar repositioning error angles of the tactile feedback group and the visuotactile feedback group (p < .05). No significant difference was noted at any time compared to the pre-intervention in all groups (p > .05). CONCLUSION: The use of tactile and visuotactile feedback in intervention to correct the sitting posture is proposed.

• Journal of the Ergonomics Society of Korea
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• v.16 no.2
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• pp.83-100
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• 1997

The Human Sensory Feedback Laboratory, park of the Armstrong Laboratory at Wright-Patterson Air Force Base, Ohio, is involved in the development and evaluation of systems that provide sensory feedback to the human operator in telerobotic and virtual environment applications. Specific projects underway in the laboratory are primarily concerned with the information provided by force and vibrotactile feedback to the operator in dextrous manipulation tasks. Four specific research projects are described in the present report. These include : 1) experiments evaluating a 30-element fingertip display, which employs a titanium-nickel shape memory alloy actuator design to provide vibrotactile feedback about object shape and surface texture ; 2) of a fingertip force-feedback display for 3-dimensional information about object shape and suface texture ; 3) use of a force- feedback joystic to provide "force tunnel" information in pilot pursuit tracking tasks ; and 4) evaluations of a 7 degree-of-freedom exoskeleton used to control a robotic arm. Both basic and applied research questions are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1994-1999
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• 2003

This paper discusses dynamic characteristics of motion of a pair of multi-degrees of freedom robot fingers executing grasp of a rigid object and controlling its orientation with the aid of rolling contacts. In particular, the discussions are focused on a problem of gain-tuning of sensory feedback signals proposed from the viewpoint of sensorymotor coordination, which consist of a feedforward term, a feedback term for controlling rotational moment of the object, and another term for controlling its rotational angle. It is found through computer simulations of the overall fingersobject dynamics subject to rolling contact constraints that some dynamic characteristics of torque-angular velocity relation may play an important role likely as reported by experimental results in muscle physiology and therefore selection of damping gains in angular velocity feedback depending on the guess of object mass is crucial. Finally, a guidance of gain-tuning in each feedback term is suggested and its validity is discussed by various computer simulations.

• Journal of Korea Multimedia Society
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• v.21 no.7
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• pp.802-812
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• 2018

Recently, there are several active and vibrant studies on Realistic Media that try to provide the immersion and the presence by adding sensory effects to video. Because existing sensory effects on Realistic Media are produced through experts and automation programs on sensory effects, there is a limit to fill up the gap of user satisfaction which comes from the diversity of cybernauts. In this paper, we propose a method to improve the satisfaction with sensory effects by collecting and analyzing user's response information, and applying the result to the attributes of sensory effects. The proposed method allows you to produce the Sensory Effect Metadata effectively by analyzing users' biometric data and subjective satisfaction with realistic media experience, measuring the weighted value to revise the effects, and applying to the attribute of sensory effect. The experimental result shows that the proposed method improves the satisfaction with realistic content by generating the revised Sensory Effect Metadata in response to user's experiential feedback information.

• Physical Therapy Korea
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• v.27 no.2
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• pp.126-132
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• 2020

Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a co-contraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.3
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• pp.39-45
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• 2015

PURPOSE: The purpose of this study was to investigate the effect of weight shift training with electrical sensory simulation feedback on quiet standing balance in hemiplegic stroke patients. METHODS: 30 stroke patients were equally allocated at random to an experimental group or a control group. Patients in both two groups underwent comprehensive rehabilitation physical therapy for 30 minutes per day for 5 days per week for 4 weeks. Members of the experimental group received additional weight shift training with electrical sensory simulation feedback was conducted for 15 minutes after 30 minute sessions, whereas members of the control group underwent additional leftward/rightward weight shift training by themselves after 30 minutes per day for four weeks. COP (center of pressure) path lengths, COP velocities, and foot forces were measured before and immediately after the 4-week training period in both groups and results were compared. RESULTS: COP path lengths significantly decreased by 3% after training in the experimental group and this was significantly greater than that observed in the control group (p<0.05). In both groups, foot forces of affected sides showed significant increases after intervention, whereas foot forces of unaffected sides showed significant decreases (p<0.05). No significant difference was observed between the two groups with respect to these changes. CONCLUSION: Weight shift training using electrical sensory simulation feedback has a positive effect on quiet standing balance in hemiplegic stroke.

• Journal of the HCI Society of Korea
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• v.11 no.3
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• pp.23-30
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• 2016

The landscape of the current fitness trackers is not only limited to the aerobic exercises but also the weight training is comparatively excluded. Recently, a few weight training fitness tracker was released, human-computer interaction was not well designed due to the lack of considering the context. Because body movement would be intense while doing exercises, having exercise performers hold or operate a device makes a negative experience. As the wearable device is always inseparable to body, it could provide effective feedback because holding or operating a device is not necessary. Therefore, this study aims to make the exercise performers feel a natural feedback through the wearable device to do effective exercises. As a result, this study identified three findings. First, the information which exercise performers most needed was 'during exercise.' and the most necessary information for exercise performers through wearable device's sensory feedback was about 'pace control' with counting and motivation. Second, the order of the most preferred presentation type of sensory feedback was auditory feedback, haptic feedback and visual feedback. Third, the satisfaction, utility, usefulness score of sensory feedback as same as the personal trainer's feedback. In conclusion, this study illustrated the feedback design implications using a wearable device while doing weight training and the possibilities that wearable device could be substitute for personal trainer.

• Journal of Drive and Control
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• v.18 no.4
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• pp.77-83
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• 2021

With the progress in virtual reality technology, various virtual objects can be displayed using head-mounted displays (HMD). However, force feedback sensations such as pushing against a virtual object are not possible with an HMD only. Focusing on force feedback, desktop-type devices are generally used, but the user cannot move in a virtual space because such devices are fixed on a desk. With a wearable force feedback device, users can move around while experiencing force feedback. Therefore, the authors have developed a wearable force feedback device using a magnetorheological fluid clutch and pneumatic rubber artificial muscle, aiming at presenting the elasticity, friction, and viscosity of an object. To date, we have developed a wearable four-degree-of-freedom (4-DOF) force feedback device and have quantitatively evaluated that it can present commanded elastic, frictional, and viscous forces to the end effector. However, sensory evaluation with a human has not been performed. In this paper, therefore, we conduct a sensory evaluation of the proposed method. In the experiment, frictional and viscous forces are rendered in a virtual space using a 4-DOF force feedback device. Subjects are asked to answer questions on a 1- to 7-point scale, from 1 (not at all) to 4 (neither) to 7 (strongly). The Wilcoxon signed rank test was used for all data, and answer 4 (neither) was used as compared standard data. The experimental results confirmed that the user could feel the presence or absence of viscous and frictional forces. However, the magnitude of those forces was not sensed correctly.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.442-448
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• 2014

Purpose: The objective of this study is to evaluate the effect of neuro-feedback training and transcutaneous electrical nerve stimulation (TENS) on stress, quantitative sensory threshold and pain in patients suffering from tension type headache. Methods: 22 participants who passed the preliminary evaluation were enrolled in the study and 11 participants were randomly assigned to each group. The control group (n=11) was subject to the TENS treatment of which was composed of a 20-minute session for 5 times a week during 4 weeks, and the experimental group (n=11) was subject to both neuro feedback training and TENS treatment for 10 minutes a day and 5 days a week during 4 weeks. The Perceived Stress Scale (PSS) was used to measure a level of stress and the quantitative sensory testing (QST) was used for the measurement of cold pain threshold (CPT) and heat pain threshold (HPT); A degree of pain was evaluated through the headache impact test-6 (HIT-6). Results: In comparision of all dependent variables between the control and subject groups, there were significant differences in stress, quantitative sensory threshold and pain after the treatment (p<0.05), and the experimental group showed significant differences in stress, CPT, HPT and pain (p<0.05) and the control group showed only a significant difference in HPT (p<0.05). Conclusion: Findings of this study demonstrate that the concomitant administration of the TENS treatment and neuro feedback training is effective on alleviation of stress, quantitative sensory threshold and pain in patients with tension type headache.