• 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 the Ergonomics Society of Korea
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• v.33 no.5
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• pp.395-405
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• 2014

Objective: The aim of this study is to investigate 1) somatotopic arrangement of the second and third fingers in SI area 2) difference of neural activation in the SI area produced by stimulation with different frequencies 3) correlation between the intensity of tactile perception by different stimulus intensity and the level of brain activation measurable by means of fMRI. Background: Somatosensory cortex can obtain the information of environmental stimuli about "where" (e.g., on the left palm), "what" (e.g., a book or a dog), and "how" (e.g., scrub gently or scrub roughly) to organism. However, compared to visual sense, the neural mechanism underlying the processing of specific electrotactile stimulus is still unknown. Method: 10 right-handed subjects participated in this study. Non-painful electrotactile stimuli were delivered to two different finger tips of right hand. Functional brain images were collected from 3.0T MRI using the single-shot EPI method. The scanning parameters were as follows: TR and TE were 3000, 35ms, respectively, flip angle 60, FOV $24{\times}24cm$, matrix size $64{\times}64$, slice thickness 4mm (no gap). SPM5 was used to analyze the fMRI data. Results: Significant activations produced by the stimulation were found in the SI, SII, the subcentral gyrus, the precentral gyrus, and the insula. In all participants, statistically significant activation was observed in the contralateral SI area and the bilateral SII areas by the stimulation on the fingers but ipsilaterally dominant. The SI area representing the second finger generally located in the more lateral and inferior side than that of the third finger across all the subjects. But no difference in brain area was found for the stimulation of the fingers by different frequencies. And two typical patterns were observed on the relationship between the perceived psychological intensity and the amount of voxels in the primary sensory cortex during the stimulation. Conclusion: It was possible to discriminate the representation sites in the SI by electrotactile stimulation of digit2 and digit3. But we could not find the differences of the brain areas according to different stimulation frequencies from 3 to 300Hz. Application: The results of the study can provide a deeper understanding of somatosensory cortex and offer the information for tactile display for blinds.

• 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 KOSOMBE Conference
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• v.1992 no.05
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• pp.198-202
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• 1992

In this paper, we have performed an experiment to obtain an optimized electric stimulation condition on the tip or a ringer skin. The desired parameters for stimulation of the finger tip skin are waveforms, frequency, stimulation intensity, duty cycle. As a result, when the finger skin was stimulated with monophasic, biphasic, and differntial phasic, the most appropriate condition was 200 to 250[Hz] in frequency, 10 to 25[%] in duty cycle. Burst type pulse was more sensitive effect than that of continuous pulse methode.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2004.11a
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• pp.33-33
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• 2004