• Journal of Biomedical Engineering Research
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• v.44 no.1
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• pp.33-40
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• 2023

Transcutaneous auricular vagus nerve stimulation (taVNS) is known to be effective in improving symptoms of numerous diseases such as depression and epilepsy by increasing vagus nerve activity through electrical stimulation. The purpose of this study is to investigate the effect of vagus nerve stimulation on the activity of autonomic nervous system and the changes in postprandial blood glucose levels. Seven healthy adults participated in a non-invasive transcutaneous auricular vagus nerve stimulation experiment. taVNS (25 Hz, 200 ㎲, biphasic pulse) was applied to the cymba concha (taVNS group) or the earlobe (Sham-taVNS group) of the left ear. As autonomic nervous system signals, skin conductance level, skin temperature, and heart rate were recorded during the application of taVNS. Postprandial blood glucose changes due to food intake were recorded at 5 min intervals for 25 minutes after taVNS or sham-taVNS. The taVNS showed a significantly lower skin conductance level than the shamtaVNS (p < 0.05). The increase rate of postprandial blood glucose was significantly lower in the taVNS than in the sham-taVNS (p < 0.05). These results showed that taVNS reduced the activity of the sympathetic nerve system and alleviated early rise in postprandial blood glucose. Although further studies in diabetic patients are needed, this study suggest that taVNS has a potential for clinical use to improve postprandial blood glucose.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.291-296
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• 1998

In the experiment carried out on 20 college students, recorded were frontal, temporal and occipital EEG, skin conductance response, skin conductance level, heart rate and respiration rate during listening to two music fragments with different affective valences and white noise administered immediately after negative visual stimulation. Analysis of physiological patterns observed during the experiment suggests that affective auditory stimulation with music is able to selectively modulate autonomic and cortical activity evoked by preceding aversive visual stimulation and to restore initial baseline levels. On other hand, physiological responses to white noise, which does not possess emotion-eliciting capabilities, evokes response typical for orienting reaction after the onset of a stimulus and is rapidly followed by habituation. Observed responses to white noise were similar to those specific to attention only and had no evidence for any emotion-related processes. Interpretation of the obtained data is considered in terms of the role of emotional and orienting significance of stimuli, dependence of effects on the background physiological activation level and time courses of attention and emotion processes. Physiological parameters are summarized with regard to their potential utility in differentiation of psychological processes induced by auditory stimuli.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.11
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• pp.126-128
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• 1991

Skin conductance level(SCL) was measured in 51 paralytic subjects. The measurements are made on the back of the second metacarpal according to the Zhang's method. Physical constitution is classified based on the Lee's physical constitution theory. The following tendencies were observed. In paralytic examinees, SCL of micro-positive physical constitution is generally higher than that of micro-negative and macro-negative physical constitution. And as Setting old, SCL is slightly decreased.

• Journal of Sasang Constitutional Medicine
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• v.4 no.1
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• pp.187-192
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• 1992

Skin conductance level (SCL) is used to analyze the individual differences in pathological states. The points of measurement were on the back of the second metacarpals, according to the Zhang's biological whole body medical treatment method. SCL was measured in 38 healthy men and women and in 98 patients in lung, liver, stomach, kidney, and paralysis. The classification of the physical constitution was done to them with respect to Lee's physical constitution theory. The following tendencies were observed. 1. SCL in patients group is lower than that in healthy group. 2. In healthy group, SCL in micro-positive physical constitution is higher than those of micro-negative and macro-negative physical constitution. 3. In patients group, SCL in micro-positive physical constitution is lower than those of micro-negative and macro-negative physical constitution vice versa.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.107-113
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• 2002

We examined the psychophysiological effects of navigation in a virtual reality (VR). Subjects were exposed to the VR, and required to detect specific objects. Ten electrophysiological signals were recorded before, during, and after navigation in the VR. Six questionnaires on the VR experience were acquired from 45 healthy subjects. There were significant changes between the VR period and the pre-VR control period in several psychophysiological measurements. During the VR period, eye blink, skin conductance level, and alpha frequency of EEG were decreased but gamma wave were increased. Physiological changes associated with cybersickness included increased heart rate, eye blink, skin conductance response, and gamma wave and decreased photoplethysmogram and skin temperature. These results suggest an attentional change during VR navigation and activation of the autonomic nervous system for cybersickness. These findings would enhance our understanding for the psychophysiological changes during VR navigation and cybersickness.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.18-22
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• 2010

The purpose of this study was to investigated correlation between personal aggression and skin conductance level during watching attack image. Twenty three male ($21.4\pm1.8$ years) college students participated in this experiment. A personal aggression of each subject measured by questionnaire. The experimental procedure consisted of four phases, i.e., rest state (15 min), control image 1 (2 min. 14 sec), aggression image (50 sec), and control image 2 (2 min. 14 sec). Control image 1 and 2 consisted of sea, mountain, and valley scenary. Aggression image used scenes of the violence movie. Skin Conductance Level (SCL) of electrothermal activity was measured during watching the images. The SCL was greater during aggression image than during control image 1 and 2. A negative correlation was found between aggressive personality and change rate of SCL during watching aggression image compared to control image 1. This results suggests that aggression image was accompanied by the higher activation of Sympathetic Nervous System (SNS). Also, the higher aggression scores, an increasing rate of SNS activation was become smaller during watching aggression image.

• Science of Emotion and Sensibility
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• v.7 no.3
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• pp.27-35
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• 2004

This study has investigated a psychological status of optimal and pleasant driving condition by measuring various physiological signals using SCR(skin conductance response), PPG(peripheral plethysmograph), SKT(skin temperature) and HR(heart rate). The physiological response was measured during various simulated driving conditions. We developed a hardware and algorithm to measure and analyze the physiological response. The physiological signals has reflected the level of driver's tension or relaxation as well as the heart rate. The emotional responses of drivers were also measured and analyzed in this experiment. The result of the study can be used to design a system to enhance the driver's emotional satisfaction as well as to monitor the driver's safety and health condition.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.271-274
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• 1997

Skin temperatures, heart rates and skin conductance levels were tested in order to extract the biological characteristics of the physical constitutional types in according to the Lee's 4 type physical constitutional theory. The subjects of this experiment were 14 ; 5 Macro-Negative subjects, 5 Micro-Negative subjects, 3 Micro-Positive subjects and 1 Macro-Positive subject. All subjects were stimulated with 2.5Hz 30V peak-peak pulses for 2 minutes. As the results, in normal prestimulation state the skin temperatures of the trunk in Micro-Positive and Macro-Positive subjects were higher than those of Macro-Negative and Micro-Negative subjects. In Macro-Negative subjects the reflected skin temperature of lever was the highest in the anterior trunk. In Micro-Negative subjects the reflected skin temperature of kidney was the highest in the trunk. In Micro-Positive subjects the reflected skin temperature of stomach was the highest in the trunk. In Macro-Positive subject the reflected skin temperature of lung was the highest in the trunk. In transient poststimulation state, heart rate was decreased in 7 cases among of 10 Macro-Negative and Micro-Negative subjects, but it was iscreased in 3 cases among of 4 Micro-Positive and Macro-Positive subjects. And the hand temperature was increased in 8 cases among of 10 Macro-Negative and Micro-Negative subjects, but it was decreased in 3 cases among of 4 Micro-Positive and Macro-Positive subjects.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.269-273
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• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.

• Journal of Biomedical Engineering Research
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• v.22 no.3
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• pp.275-283
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• 2001

This study was performed to extract and analyze the biosignals to find the relationship between the level of anesthesia and the variations of physiological parameters during epidural anesthesia. Seven male and twenty female patients(ages from 45 to 70 years old) were participated for the experiment, and ECGs, PPGs, SKTs, SCRs were obtained during anesthesia. As results, the HF/LF ratios of HRV were decreased after the injection anesthetics. For skin temperatures, values measured from the palm was reduced and the temperatures from four channels, measured from armpit through the right side of the body, were increased. SCRs were decreased for all channels after the injection of anesthetics. However the heart rate and PPGs showed no significant changes. It was concluded that the injection of anesthetics result the changes in biosignals, and it could be explained by the degree of the sympathetic and/or parasympathetic nerve activities. Results of this study could provide the valuable information for the estimation of level for the spinal and general anesthesia, and could be extended to the development of a system which could quantify the level of anesthesia.