• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.4
• /
• pp.65-70
• /
• 2020

While the demand for robots in the manufacturing industry has dramatically increased, the industrial robots' functionality is mainly determined by the effector attached to the end of their arms. They need a flexible gripping system that can act as a human hand and easily grasp a variety of objects, which requires resilient sensors. This study clarifies the electrical output characteristics of elastic tactile sensors according to contact terminals because the output characteristics of the tactile sensors vary greatly, depending on the contact material and the method of contact with the conductive wire. Our research considers the Three Roll Mill and Paste Mixer as the dispersion medium, and a nickel- and gold-plated brass electrode as the contact terminal.

• Proceedings of the KOSOMBE Conference
• /
• v.1996 no.11
• /
• pp.243-246
• /
• 1996

This study was peformed to characterize the physiological signal prior to develop an algorithm which quantifies EEGs evoked by tactile stimulation. The experiment was devised with four experimental conditions, which were control and two levels of pressures in tactile sensation. Twenty subjects were used to obtain EEGs while applying tactile stimulation using two types of textiles, soft towel and sand paper, to the right hand of each subject. EEGs were acquired for 20 seconds, and each trial was repeated five times randomly at the different levels of stimulus intensities. The index, $S_{n}$, was obtained by calculating the ratio of energy distribution in the time-frequency plot for each scored psychological state of the subject. The results showed that dominant aspects of the EEG signals have their maximal frequencies concentrated at a lower ranges for the resting and pleasant state, while the spectral energies were distributed to higher frequency ranges when subjects experience an unpleasant emotion.

• The Journal of Korean Physical Therapy
• /
• v.24 no.5
• /
• pp.291-299
• /
• 2012

Purpose: This study examined the improved sensory, hand function, postural balance and activities of daily living (ADL) through somatosensory stimulation, such as the facilitation of functional reaching and tactile, proprioceptive stimulus of the upper limb (UL) and hand. Methods: Seventeen stroke patients having problems with motor and somatosensory deficits were selected in Bobath Memorial Hospital adult rehabilitation center. The patients were divided into two groups; the sensorimotor deficit group (SMDG) and motor deficit group (MDG). Somatosensory stimulation on the UL, physical therapy and occupational therapy were carried out three times a week over a six week these treatments were performed in both group period. To compare each group, the following assessment tools were used: such as tactile detection thresholds (TDT), two point discrimination on the affected side (TPDas), unaffected side (TPDus) stereognosis (ST) manual function test, hand function on the affected side (HFas) and unaffected side (HFus), Postural Assessment Scale for Stroke (PASS) and Korean version Modified Barthel Index (K-MBI). Results: In the SMDG, somatosensory stimulation on the UL was statistically important for TDT, TPDas, TPDus (except for the thener), ST, hand function on HFas, on HFus, PASS length of displacement with foam (LDFSEO), and K-MBI. In the MDG, somatosensory stimulation on the UL was important for TDT, TPDas, TPDus (except index finger) length of displacement with the eyes open, LDFSEO, HFas, HFus, PASS and K-MBI. In addition, there was a significant difference in the PASS between SMDG and MDG. Conclusion: Somatosensory stimulation on the UL affects the sensory, hand function, postural control and ADLs performance.

• Science of Emotion and Sensibility
• /
• v.14 no.4
• /
• pp.537-544
• /
• 2011

Tactile acuity was assessed in groups of control, blind, deaf, and blind caused by complication to investigate the effective tactile stimuli on tactile sensory substitution studies when tactile display is applied to persons with sensory loss of vision or hearing. Two-point discrimination and grating resolution were assessed by compass and JVP dome, respectively, in the hand, arm, neck, lumbar, and knee. In two-point discrimination by compass, control group showed the highest sensitivity in fingers among assessed body areas but did not show any significant difference between male and female. Blind group and deaf group compared to control group did not show any significant difference in fingers but showed lower sensitivity in arm and knee. In grating resolution by JVP dome, control group did not show any significant difference among five fingers as well as between male and female. Blind group showed higher sensitivity in five fingers compared to control group, but deaf group did not show any significant difference from control group. Blind caused by complication group showed lower sensitivity in two-point discrimination and grating resolution compared to control group and blind group. These results suggest that the body area and method of tactile stimulation, and difference in tactile acuity depending on underlying disease of sensory loss should be considered when tactile display is applied for sensory substitution.

• Archives of Reconstructive Microsurgery
• /
• v.21 no.1
• /
• pp.76-80
• /
• 2012

Various soft tissue defects can be occurred in the hand. In determining the most suitable means of reconstruction a defect, the benefit of the reconstruction has to outweigh the risk of donor morbidity. Flap selection will be based on the size of the defect, the requirements for sensibility, the surgeon's comfort level, and the patient profile such as gender, age, or systemic disease. The hand is the most important tactile sensory organ, hence sensory restoration is critical. Neurosensory free flaps can provide sensibility, vascularity, and soft tissue coverage to an injured hand. This paper will discuss free flaps which can be used for soft tissue reconstruction of the hand.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 1998.11a
• /
• pp.225-229
• /
• 1998

The purpose of the current study was comparative analysis of autonomic and electrocortical responses to passive and active touch of the tektites with different subjective emotional preference. Perspective goal of the project is development of a template for classification of tactile stimuli according to subjective comfort and associated physiological manifestations. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and B10PAC 100 systems with AcqKnowledge III software. Frontal, parietal and occipital EEG (relative power spectrum /percents/ of EEG bands - delta, theta, slow and fast alpha, low and fast beta), and autonomic variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, rise time and number of SCRs) were analyzed for rest baseline and stimulation conditions. Analysis of the overall pattern of reaction indicated that autonomic response to tactile stimulation was manifested in a form of moderate HR acceleration, RSP increase, RSA decrease (lowered vagal tone), decreased n and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand) were featured by short-term alpha-blocking, slightly reduced theta and significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome. Nevertheless, development of sufficiently sensitive .and reliable template for classification of emotional responses to tactile stimulation based on physiological response pattern may require more extensive empirical database.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.04a
• /
• pp.259-262
• /
• 2003

Fabric hand is ultimately a subjective response to physical stimuli, but there are clearly practical advantage in the development and commercial trading of textile fabrics to be gained from the replacement of the traditional subjective tactile assessment by an objective measurement evaluation method. Moreover, the reliable objective measurement method for warp knitted fabrics have not developed yet, despite their increasing importance. (omitted)

• Korean Journal of Computational Design and Engineering
• /
• v.21 no.1
• /
• pp.42-50
• /
• 2016

Traditional tactile controls that include push buttons and rotary switches may cause significant visual and biomechanical distractions if they are located away from the driver's line of sight and hand position, for example, on the central console. Gestural controls, as an alternative to traditional controls, are natural and can reduce visual distractions; however, their types and numbers are limited and have no feedback. To overcome the problems, a driver interface combining gestures and visual feedback with a head-up display has been proposed recently. In this paper, we investigated the effect of this type of interface in terms of driving performance measures. Human-in-the-loop experiments were conducted using a driving simulator with the traditional tactile and the new gesture-based interfaces. The experimental results showed that the new interface caused less visual distractions, better gap control between ego and target vehicles, and better recognition of road conditions comparing to the traditional one.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.40 no.2
• /
• pp.305-314
• /
• 2016

This paper investigated the applicable possibility of PTT and wool staple fibers to the air vortex system as high quality yarns for a high emotional and comfort garment. It was found that the tactile hand of vortex yarn knitted fabrics was harsher than ring and compact yarns knitted fabrics. It was observed that formability and sewability of air vortex yarn knitted fabrics seemed worse than ring and compact yarns due to low tensile and compressional resilience and high bending and shear hysteresis of air vortex yarn knitted fabrics. It revealed that wicking and drying rates of air vortex yarn knitted fabric were better than ring and compact yarns; in addition, the heat keepability of vortex yarn knitted fabric was higher than ring and compact yarns due to low thermal conductivity and max heat flow rate ($Q_{max}$). Any difference of thermal shrinkage between air vortex and ring yarn knitted fabrics was not shown, but pilling characteristic of air vortex yarn knitted fabric was superior. However, it was shown that wicking, drying, thermal property and pilling characteristics of air vortex yarn knitted fabric were superior due to air vortex yarn structure with parallel fibers in the core part and periodical and fasciated twists in the sheath part of the yarns.

• Journal of the Ergonomics Society of Korea
• /
• v.18 no.3
• /
• pp.1-12
• /
• 1999

This study investigated human operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, the effects of three mechanical parameters consisting vibrotactile stimulations, i.e., vibration frequency, pulse-width modulation duty cycle, and number of contactors, on differential thresholds were examined at five different loci of the hand. It was observed that differential threshold varies with vibration frequency and number of active contactors. Differential sensitivity was the greatest at the vibration frequency of 120 Hz. The differential sensitivity was not found to be affected by loci on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. It should be noted that the conclusions from this study generally correspond to those from the previous study on the absolute sensitivity. which means that tactile sensitivity to vibrotactile stimulations can be controlled with a systematic and consistent passion for emulating normal everyday contact on human hands in teleoperation and virtual reality applications.