• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.71-76
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• 2008

Introduction: In this study, we compared sleep structure, EEG characteristic of pediatric obstructive sleep apnea (OSA) and normal controls which were matched in sex and age. Methods: Fifteen children (male：female=4：11) who complained snoring and were suspected to have sleep apnea and their age and sex matched normal controls (male：female=5：10) have been done nocturnal polysomnography (NPSG). Sleep parameters, sleep apnea variables and relative spectral components of EEG from NPSG have been compared between both groups. Results: Pediatric OSA group were distinguished from normal controls in terms of apnea index, respiratory disturbance index and nadir of oxyhemoglobulin desaturation. Pediatric OSA group showed increased percent of sleep stage 1, decreased rapid eye movement sleep percent and increased delta power in O1 EEG channel. However other sleep parameters and spectral powers were not different between two groups. Conclusion: In pediatric OSA group, sleep structure parameter disruption may be not prominent as the previous studies for adult OSA group because of including mild OSA data in diagnostic criteria. In addition, EEG changes might not be distinct due to low arousal index compared to adult OSA patients. We can observe general characteristics and particularity of pediatric OSA through this study.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.2
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• pp.63-69
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• 2019

In this study, bispectrum analysis method introduced to reduce variability of SEF(spectral edge frequency) and MF(median frequency), which are the anesthetic depth indexes extracted by EEG spectral analysis. Bispectrum analysis is an analytical method that can confirm the nonlinearity of EEG. Signal measurement and analysis in the surgical environment should take into consideration various external artifact factors. Bispectrum analysis can confirm the presence of externally introduced artifacts, thereby effectively eliminating artifacts that affect the EEG signal. By applying bispectrum parameters, real-time variability of the anesthetic depth parameters SEF, MF could be reduced. Elimination of variability makes it possible to use SEF, MF as a real-time index during surgery.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.1211-1212
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• 2003

본 연구에서는 감성 변화가 빈번하게 일어나는 오라인 포커 게임을 대상으로 EEG를 이용하여 게임 중 발생 할 수 있는 감성 변화를 알아내고자 하는 연구를 수행하였다. 포커 게임에서 나타날 수 있는 사용자의 감성과 행동을 Task Analysis를 이용하여 구분하였고 전두엽 표면 뇌파를 측정하여 Neural Network 및 통계적 처리를 이용하여 분석하였다. 이후 분석될 뇌파에서 인간의 감성상태를 구분할 수 있는 Index를 찾아내었다. 향후 ECG를 추가적으로 연구하여 감성상태를 더 정확하게 파악하는 연구가 진행될 것이다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.121-124
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• 2001

Using ordors with the different concentration of essential oils, e studied the effect of a pleasant olfactory stimulation on physiological responses. we examined psychological response, mental task and changes in cardiac, immunity and EEG in responses to 150times solution (feel easily) and 500times solution (feel with difficulty) which of essential oil (called PCK) were diluted in propylene glycol, and neutral (water). The 150times solution that was felt pleasant produced significant differences (p<0.05) in relative power change of beta activity in the left frontal region (Fp1, F3, F7) of the brain, and heart rate (HR) deceleration after mental task. these results are consistent with substantial research that has documented cardiac and EEG responses to pleasant stimuli. What is more, 150times solution increased the concentration of s-IgA know as an index of immunity.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.1
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• pp.55-58
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• 2012

By using EEG and HRV, subjects were estimated on their psychological and physiological reaction when reading psychrometric chart in 7 point century font, in an environmental test room in the condition of temperature 25[$^{\circ}C$], relative humidity 50[RH%], air current speed 0.02[m/sec], giving variation in illuminance to 0.1, 300, 600, 1000, 1300 and 1600[lux]. As a result, it was at 1300[lux] that absolute ${\alpha}$ wave, SMR, SDNN were most vitalized, and also both sides ${\alpha}$ wave asymmetry index, SEF50, HRT, stress and fatigue degree were at the lowest. It was found that a certain illuminance which minimizes psychological stress and fatigue degree while enhancing concentration and task achievement stably does exist.

• Journal of Magnetics
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• v.16 no.3
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• pp.259-262
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• 2011

Compared to acupuncture, the pulsed magnetic field (PMF) stimulus is a useful tool for treatment of many physical conditions and health maintenance due to its advantages as a noninvasive and nontoxic medical treatment. The purpose of this study was to investigate the effect of PMF stimulus direction at PC9 on the alpha activity of electroencephalogram (EEG) and vascular aging calculated from photoplethysmograph (PPG). It can be concluded that the direction of PMF stimulus affects the increase of alpha activity of EEG and PPG, indicating the vascular stiffness and the sclerosis level of blood vessels weakly relevant to the direction of PMF stimulus.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2801-2803
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• 2003

This paper describes a technique for human sensibility evaluation using personality-group templates of EEG(electroencephalogram). 10-channel EEGs of 5 extroverts and 5 introverts are collected in comfortable seat, uncomfortable seat and relaxed state. After preprocessing of EEG, the linear predictor coefficients are extracted and used as feature parameters. A neural network based sensibility classifier is designed and the output of the neural network is assumed as the sensibility index. Multiple templates of two personality-groups are stored and the most similar template can be selected by the proposed method. The proposed method showed the better performance than our previous results which have used ungrouped templates.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.2
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• pp.163-173
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• 2013

PURPOSE: This study determined the effect of balance control therapy in the brain activation. METHODS: Twenty-two college students who showed decrease of muscle strength in O-ring test were as participants in this study. And the subjects were randomly divided into experimental group (n=13) and control group (n=9). Measurement device is portable EEG (Nihonkhoden, Japan). Examinations used twenty electrodes attached to the head to capture electrical brain signals during 5 minutes with brain activated states such as the awaked state and the data were compared between the two groups. RESULTS: After treatment by balance control therapy, P3 (p<.025) and P4 areas (p<.025) showed a significantly lower ST index in the experimental group than the control group, The variation of ST index in P4 area (p<.025) was decreased in the experimental group but was increased in the control group. CONCLUSION: These results showed that the balance control therapy was helpful to change the brain activation such as the stress (ST) index at the sensory area in the college students.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.2
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• pp.305-316
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• 2021

In this study, the effect of wearing functional compression pants is verified using a lower-limb wearable robot through a bio-signal analysis and subjective fit evaluation. First, the compression area to be applied to the functional compression pants is derived using the quad method for nine men in their 20s. Subsequently, functional compression pants are prepared, and changes in Electroencephalogram (EEG) and Electrocardiogram (ECG) signals when wearing the functional compression and normal regular pants inside a wearable robot are measured. The EEG and ECG signals are measured with eyes closed and open. Results indicate that the Relative alpha (RA) and Relative gamma wave (RG) of the EEG signal differ significantly, resulting in increased stability and reduced anxiety and stress when wearing the functional compression pants. Furthermore, the ECG analysis results indicate statistically significant differences in the Low frequency (LF)/High frequency (HF) index, which reflect the overall balance of the autonomic nervous system and can be interpreted as feeling comfortable and balanced when wearing the functional compression pants. Moreover, subjective sense is discovered to be effective in assessing wear fit, ease of movement, skin friction, and wear comfort when wearing the functional compression pants.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.144-152
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• 2016

Carotid-artery stenosis may reduce cerebral perfusion, and affect cerebral neuronal activities. We examined the question of whether the recovery of cerebral-perfusion reserve after carotid-artery stenting (CAS) can affect the EEG power-spectrum. Nineteen candidates for CAS were initially recruited. Subtraction imaging of single photon emissary computerized tomography (SPECT) and an electroencephalogram (EEG) were taken twice, before and 1 month after CAS. At each time point, the EEGs were recorded before and after injection of acetazolamide (pre-ACZ EEG and post-ACZ EEG). Finally, 7 patients were enrolled after exclusion of incomplete studies. We obtained the spectral ratio (SR) of each hemisphere. SR was defined as the divided value of the power-spectrum sum of fast activities by that of slow activities. The power-spectrum values between hemispheres were compared using the inter-hemispheric index of spectral ratio (IHISR), and we examined the correlation between the power-spectrum and the cerebral-perfusion reserve. Cerebral-perfusion reserve improved after CAS on the stent side in 6 of 7 patients. In 3 patients with unilateral carotid-artery stenosis, CAS increased SR on the pre-ACZ EEGs, and IHISR on the post-ACZ EEGs. The increases of SR and IHISR were concordant with the increment of cerebral-perfusion reserve. In contrast, the results in the other patients with bilateral stenosis showed complex patterns. The SR of pre-ACZ EEGs and IHISR of post-ACZ EEGs may be useful electrophysiological markers for the blood-flow reserve after CAS in patients with unilateral carotid-artery stenosis, but not in those with bilateral stenosis.