• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2753-2758
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• 2003

Tactile sensation is essential for many manipulation and exploration tasks not only in a real environment but also in a virtual environment. In this paper, we discuss a conceptual design of an integrated tactile display system. The system comprises two parts: a 2 DOF force feedback device for kinesthetic display and a tactile feedback device for displaying the normal stimulation to skin and the skin slip/stretch. Psychophysical experiments measure the effects of fingerpad selection, the direction of finger movements and the texture width on tactile sensitivity. We also investigate characteristics of lateral finger movement while subjects perceive different textures. From the experimental results, the principal parameters for designing a tactile display are suggested. A tactile display device is implemented using eight piezoelectric bimorphs and a linear actuator, and is attached to a 2 DOF translational force feedback device to simultaneously simulate texture and stiffness of the object.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1589-1590
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• 2011

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2010.05a
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• pp.48-54
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• 2010

INTRODUCTION Interaction between temporal events at the millisecond level is important for visual and tactile interaction. OBJECT The aim of the present study is to identify any neural signature, as reflected in event-related potentials (ERP), for the integrative processes when the two sensory modalities are stimulated in synchrony as opposed to when they are stimulated separately. METHOD The basic strategy was to compare ERP signals obtained with simultaneous visual and tactile stimulation with a linear summation of ERP patterns obtained with each modality stimulated separately. Condition were presented, paired with various stimulus-onset-asynchronies (SOA) ranging from - 300 ms (tactile-first) to 300 ms (visual-first), and in trials where only one modality was stimulated alone. RESULT A positive deviation was located in observed ERP at C4 electrode (contralateral to the stimulated hand) at 200-400 ms, in comparison to the predicted ERP. The deviation was present at all SOAs other than -300ms (tactile-first) and 300 ms (visual-first). There was also a positive deviation at occipital leads at the 50-ms SOA (visual-first) trials. DISCUSSION It suggested that neural signatures of cross-modal integration occur within a limited time-window. The deviations were specifically localized at the contralateral somatosensory and visual cortices, indicating that the integration happens at or before the level of the primary cortices.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.91-94
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• 1997

Objective of this stuey was to find the corrdlation between emotiona changes and the parameters of HRV spectrum evoked by tactile stimualtion. Twenty-one subjects were useds and five different types of materials, dry cottn, wet cotton, paper, sandpaper, and vinyl were applied to the left hand of each subject as a tactile stimulation. The results showed that HF/LF(ratio of high to low frequency amplitude calculated from power spectrum of HRV) decreased as the subject experienced the unpleasant emotion caused by wet cotton and sandpaper. On the othr hand, when the subject experienced the comfort, HF/LF increased. It was concluded that the proprsed methods can be applied to evaluate the characteristic changes in the autonomic nervous system which regulates the human emotion in the psychological aspects.

• The Journal of Korea Robotics Society
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• v.16 no.1
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• pp.12-16
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• 2021

Attempts are being made to provide various tactile feedbacks to user. In particular, a variety of soft actuators are being inserted into the tactile feedback device to give a more flexible, soft and strong stimulation. In this study, a basic study was performed to utilize a hydraulically amplified self-healing electrostatic (HASEL) actuator as a tactile feedback actuator. The HASEL actuator showed great displacement and force with a simple circuit configuration. In particular, by making the actuator in a circular shape, the angle was reduced and the electrode was arranged in a ring shape to maximize the displacement of the central part. As a result, the HASEL actuator showed a displacement difference according to the input waveform. In addition, in order to use it safely as an actuator for tactile feedback, we covered the surface with silicone and confirmed that the actuator works well. Using these actuators, it will be possible to manufacture a lightweight, portable tactile feedback device.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.7 no.1
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• pp.23-27
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• 2009

Purpose : The purpose of this study was to examine the effects of different medium frequency currents on afferent fibers. Methods : Thirty healthy volunteers who had no known history of neurological disorders were equally assigned to one of three groups; 2500Hz, 4000Hz, and control and each group was applied to the left wrist in palmer cutaneous branch of radial nerve by different medium frequency currents for 15 min. We measured the changes of thresholds for tactile, two-point discrimination, and thresholds for pain. Results : The results showed that the medium frequency currents stimulation increased thresholds for tactile, two-point discrimination, and thresholds for pain. However, there is no statistically significant difference between group 2500Hz and group 4000Hz. Conclusion : This may explain thresholds for tactile, two-point discrimination, and thresholds for pain plain medium frequency currents stimulation inhibits the excitability of afferent fibers, but the effect of the frequency difference within medium frequency currents is not demonstrated.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.145-150
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• 2005

This paper presents an Electrotactile Display System (ETCS). One of the most important human sensory systems for human computer interaction is the sense of touch, which can be displayed to human through tactile output devices. To realize the sense of touch, electrotactile display produces controlled, localized touch sensation on the skin by passing small electric current. In electrotactile stimulation, the mechanoreceptors in the skin may be stimulated individually in order to display the sense of vibration, touch, itch, tingle, pressure etc. on the finger, palm, arm or any suitable location of the body by using appropriate electrodes and waveforms. We developed an ETCS and investigated effectiveness of the proposed system in terms of the perception of roughness of a surface by stimulating the palmar side of hand with different waveforms and the perception of direction and location information through forearm. Positive and negative pulse trains were tested with different current intensities and electrode switching times on the forearm or finger of the user with an electrode-embedded armband in order to investigate how subjects recognize displayed patterns and directions of stimulation.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.8
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• pp.783-789
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• 2007

In this paper, firstly, we propose a generating method of the 3-D obstacle map using ultrasonic sensors. Secondly, we try to find the necessary stimulation conditions of compact tactile display device for effective transfer of obstacle information. The final goal of this research is the development of a walking guide system for the blind to walk safely. The walking guide system consists of a guide vehicle for the obstacle detection and a tactile display device for the transfer of the obstacle information. The guide vehicle, located in front of the walking blind, detects the obstacle using ultrasonic sensors. The processed information makes an obstacle map and transmits safe path and emergency situation to the blind by the tactile display. The tactile display device, located in the handle which is connected with the guide vehicle by cane, offers the processed obstacle information such as position, size, moving, shape of obstacle and safe path, etc. The concept of a walking guide system with tactile display is introduced, and experiments of 3-D obstacle detection and tactile perception are carried out and analyzed.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.5
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• pp.445-450
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• 2005

In this paper, we suggest an integrated tactile display system that provides kinesthetic force, pressure distribution, vibration and slip/stretch. The system consists of two parts: a 2 DOF force feedback device for kinesthetic display and a tactile feedback device for displaying the normal stimulation to the skin and the skin slip/stretch. Psychophysical experiments measure the effects of fingerpad selection, the direction of finger movements and the texture width on tactile sensitivity. We also investigate the characteristics of lateral finger movement while subjects perceive different textures. From the experimental results, the principal parameters for designing a tactile display are suggested. A tactile display device, using eight piezoelectric bimorphs and a linear actuator, Is implemented and attached to a 2 DOF translational force feedback device to simultaneously simulate the texture and stiffness of the object. As a result, we find out that the capability of the suggested device is sufficient to display physical quantities to display the texture.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.199-215
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• 2020

The purpose of this study is to understand dogs for their happy lives. Experiment and survey were conducted to find out the effects of sensory stimulation on dogs emotions. Sensory were divided into visual, auditory, olfactory, tactile, complex and emotions were measured by the rate of deep sleep, feed intake, and heart rate. Research has shown that complex stimulation (walking) is the most positive stimulation for dog's emotions, but visual stimulation and auditory stimulation do not act as stimuli that positively change usual state of dog's emotions. Olfactory stimuli is the second best stimulation. Since olfactory stimulation is effective in maintaining a calm state without large deviation in the dog's state, it can be used as a method for relieving the dog's stress in exceptional situations when complex stimulation is not possible. On the other hand, tactile stimulation, bath, is a negative sensory stimulus that causes hypersomnia and binge eating for most dogs.