• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.8
• /
• pp.1471-1477
• /
• 2006

Electrocorticogram (ECoG) was recorded in one young adult suffering from medically refractory partial seizures a few weeks before resection. ECoG of intractable focal epilepsy was analyzed usins AR model, wavelet analysis and cross-correlation analysis. The cross-correlation of the epileptic discharges was calculated between the electrodes in every unit of time, to get the phase shift. A contour map of the phase shift and the sequential two-dimensional phase shift maps were utilized to localize the epileptic foci and to study their propagation process. More than two epileptogenic foci were localized and two kinds of propagating process were shown. These investigations suggest that epileptic phenomena can be caused by at least two kinds of mechanisms in one patient.

• Science of Emotion and Sensibility
• /
• v.22 no.3
• /
• pp.21-34
• /
• 2019

This study was an examination of the relevance and clinical significance of electroencephalographic (EEG) indexes (e.g., mental/physical stress and attention) and indexes of heart rate variability (HRV) with regard to cognitive function and physiological health conditions in elderly people. A device was used to record two-channel EEGs of the frontal lobe and a one-channel ECG simultaneously. Subjects were 76 people average aged 73. The significant findings are as follows: First, subjects whose intrinsic alpha rhythm had high amplitude, regardless of peak, showed higher resistance to mental stress and lower physical stress than did subjects with low-amplitutde intrinsic alpha rhythm. Second, HRV, SDNN, and RMSSD indexes showed strong positive correlations between the two groups of subjects regardless of the division of groups. Third, the alpha asymmetry of the left and right sides of the brain in subjects with low-amplitude intrinsic alpha rhythm was larger, and the delta/alpha ratio (reflecting physical stress) and theta/sensorimotor rhythm (SMR) ratio (showing the decline in attention) were bigger. Fourth, the subjects in whom intrinsic alpha rhythm peak occurred during slow rhythm had a higher theta/SMR ratio than did subjects whose peak occurred during fast rhythm, which was related to a steeper decline in attention. Therefore, the presence or absence of intrinsic alpha rhythm peak and amplitude on quantitative EEG may be an index reflecting the cognitive function and physiological health of elderly people.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 1998.11a
• /
• pp.158-162
• /
• 1998

향에 의해 유발되는 감성에 대한 중추신경계 및 자율신경계의 반응의 변화를 측정하기 위해 안정시키는 향과 각성시키는 향을 사용하여 주관적 평가와 동시에 시행하였다. 안정시키는 향으로 1% Lavendar 향을 사용하였고, 각성시키는 향으로 0.8% Jasmin 향을 사용하였으며, 안정상태를 향자극 전후에 측정하여 대조군으로 사용하였다. 중추신경계의 지표로 뇌파측정을 하였고 뇌파의 전극은 international 10-20 system에서 4 채널을 사용하였으며, 자율신경계의 지표로는 심전도, heart rate, 피부저항, 피부온도를 기록하였다. 뇌파의 분석은 Fast Fourier Transform analysis의 power spectra로 하였고, 그 frequency bands는 theta(4-8Hz), alpha(8-l3Hz), beta(14-30Hz)로 하였다 또한 심전도를 이용하여 심전도 상의 연속적인 R-R peak간 시간간격을 시계열 데이터로 재구성한 Heart rate variability 분석도 하였다. HRV 분석을 보다 정확히 할 수 있도록 호흡이 심전도에 미치는 영향을 제거하기 위하여 호흡을 분당 20회로 일정하게 하였다 생체신호 측정과 동시에 실시한 주관적 검사에서 lavendar 향은 친숙하게, jasmin 향은 활기차고 상쾌하고 유쾌하게 평가되었다. 뇌파 분석에서 lavendar 향을 주었을 때 theta의 증가 양상을 보였으며, Jasmin 향을 주었을 때는 모든 채널에서 beta 파의 증가 양상을 보였다. 또한 HRV 분석 결과 부교삼신경의 활동성이 부각되는 HF/LF의 값이 lavendar에서는 대조 자극보다 높게 나타났으며, jasmin에서는 대조자극보다 낮은 값이 나타나는 경향을 보였다. 결론적으로 안정과 각성의 후각 자극으로 인한 감성의 변화를 뇌파와 자율신경계 등의 생체지표로 관찰할 수 있었다.정하는 감성요인의 차이를 알 수 있었으며 또한 essential oil에서는 성별 차이가 없는데 반해 페르몬 향의 경우 성별의 차이를 나타내었다.. 방법을 타액과 혈청내 testosterone 농도 측정에 응용하여 RIA의 결과와 비교하여 본 바 상관관계가 타액에서 r=0.969, 혈청에서 r=0.990으로 두 결과가 잘 일치하였다. 본 실험에서 측정된 한국인 여성의 타액내 testosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to have been "Japanese Letter Jobcheso." Therefore, the purpose of this study is to loo

• Clinical and Experimental Pediatrics
• /
• v.51 no.1
• /
• pp.62-66
• /
• 2008

Purpose : In addition to epileptic seizures (ES), a variety of physiologic, organic and psychogenic disorders can manifest as paroxysmal behavioral events. Paroxysmal nonepileptic events (PNEs) are quite encountered in infants, young children, and adolescents. In a substantial proportion of cases, a careful history and examination will elucidate their nature. However, in other cases, it is necessary to differentiate PNEs from ES by video-electroencephalographic (EEG) monitoring. We report our experiences with PNEs in a group of children and adolescents who underwent video-EEG monitoring. Methods : From September, 2004 to June, 2006, one hundred thirty patients were monitored in the Pediatric Epilepsy Monitoring Units of Korea University Guro and Ansan hospitals. Their hospital charts were reviewed and video records of these events were analyzed. We observed all patients after video-EEG monitoring for more than 3 months. Results : Typical spells occurred during monitoring in 33 patients, not associated with a seizure pattern on EEG recordings. Two patients were diagnosed as frontal lobe epilepsy on basis of typical semiology and clinical characteristics, so 31 patients were documented to have PNEs finally. The mean age of patients was $7.2{\pm}5.8\;years$. The male to female ratio was 15 (48.4%) to 16 (51.6%). Among 31 patients, fifteen patients had associated disorders such as epilepsy, developmental delay, cerebral palsy, gastric ulcer, attention deficit hyperactivity disorder or depressive disorder. Somatoform disorder and factitious disorder was frequently seen in children more than 5 years old (P<0.05). Psychogenic disorder was more frequent in female (n=6) than in male (n=2) but there was no statistical significance (P>0.05). Conclusion : Our study suggests that video-EEG monitoring is an important diagnostic tool in the evaluation of paroxysmal behavioral events. With correct diagnosis of the PNEs, several unnecessary treatment could be avoided.

• Journal of KIISE
• /
• v.44 no.9
• /
• pp.887-892
• /
• 2017

Brain-computer interface (BCI) is a technology that controls computer and transmits intention by measuring and analyzing electroencephalogram (EEG) signals generated in multi-channel during mental work. At this time, optimal EEG channel selection is necessary not only for convenience and speed of BCI but also for improvement in accuracy. The optimal channel is obtained by removing duplicate(redundant) channels or noisy channels. This paper propose a dual filter-based channel selection method to select the optimal EEG channel. The proposed method first removes duplicate channels using Spearman's rank correlation to eliminate redundancy between channels. Then, using F score, the relevance between channels and class labels is obtained, and only the top m channels are then selected. The proposed method can provide good classification accuracy by using features obtained from channels that are associated with class labels and have no duplicates. The proposed channel selection method greatly reduces the number of channels required while improving the average classification accuracy.

• Korean Journal of Biological Psychiatry
• /
• v.12 no.2
• /
• pp.123-135
• /
• 2005

Objectives:EEG coherence could imply the connectivity between two different areas of the brain, which is known to be important in the pathophysiology of bipolar I disorder(BPD I) and schizophrenia. The authors investigated EEG coherence in patients with BPD I and schizophrenia to examine the connectivity of the neural circuit. Methods:EEGs were recorded in 15 schizophrenia and 14 bipolar disorder patients, and 14 age-matched normal control subjects from 16 electrodes with linked-ear reference. Spectral parameters and coherence were calculated for the alpha bandwidth(8-13Hz) by a multi-channel autoregressive model using 20 artifact-free 2-seconds epochs and the differences were compared among three groups by two different statistical methods;F-test and Kruskal-Wallis test. Furthermore, when there were significant differences among three groups, Scheffe's multiple comparison tests were provided and Jonckheere-Terpstra tests for the ordered alternative were given. Results:In the intra-hemispheric comparison, left frontal coherence was increased in order of control, BPD I and schizophrenia. In the inter-hemispheric comparison, 1) inter-prefrontal coherence in BPD I was signifi- cantly higher than in normal controls, and 2) inter-prefrontal coherence in schizophrenia was significantly lower than in controls. Conclusion:These results suggest that 1) both schizophrenia and BPD I are diseases having the abnormality of neural circuit connectivity in both frontal and prefrontal lobes, and 2) the abnormality is more severe in schizophrenia than in BPD I. Furthermore, the data support that a common pathogenetic process may reside in both schizophrenia and BPD I.

• The Journal of Korean society of community based occupational therapy
• /
• v.8 no.2
• /
• pp.29-37
• /
• 2018

Objective : Sleep disorder caused by stress or disease to elderly currently. We tried to make clear constant exercise according to exercise intensity would have effect on sleep disorder in elderly using EEG and melatonin. Methods : Thirty subjects were over 65 years old who lived a senior facility in some parts. They were able to communicate and understand the purpose of the study. They also expressed their intension to participate actively in experiment. They should have alert consciousness and orientation about time, place, and people. Sleep disorder was assessed via below 6 hr total sleep time and Pittsburge Sleep Quality Index, which was satisfied with both of criterion at the same time. Exercises composed of low intensity walking, moderate aerobic exercise, and high intensity resistance strength. We used QEEG 8-System (LAXTHA Inc. KOREA) to check wave type and Polysomnograpy (Compumedics, Australia) to test quality of sleep. and Histologic features were observed by TTC (triphenyltetrazolium chloride) staining and H & E (Hematoxylin & Eosin) staining. Results : There was a significant sleep index and change of melatonin after aerobic exercise. There was a significant SOL, S1, S2, and SWS in aerobic exercise, but there was a significant SWS in walking and resistance strength. There was a significant change of delta wave especially in frontal and temporal region between exercises. Conclusion : They had different effects according to type of exercise, when elderly who have chemical, behavioral change of circadian rhythms did exercise consistently. Aerobic exercise had more effect on sleep disorder than other exercise. Therefore, we may supply proper exercise to elderly and high quality of life.

• Journal of Biomedical Engineering Research
• /
• v.20 no.1
• /
• pp.81-90
• /
• 1999

This paper describes an EEG(electroencephalogram) software for two-channel cerebral function monitoring system to detect the cerebral ischemia. In the software, two-channel bipolar analog EEG signals are digitized and from the signals various EEG parameters are extracted and displayed on a monitor in real-time. Digitized EEG signal is transformed by FFT(Fast Fourier transform) and represented as CSA(compressed spectral array) and DSA(density spectral array). Additional 5 parameters, such as alpha ratio, percent delta, spectral edge frequency, total power, and difference in total power, are estimated using the FFT spectra. All of these are effectively merged in a monitor and displayed in real-time. Through animal experiments and clinical trials on men, the software is modified and enhanced. Since the software provides raw EEG, CSA, DSA, simultaneously with additional 5 parameters in a monitor, it is possible to observe patients multilaterally. For easy comparison of patient's status, reference patterns of CSA, DSA can be captured and displayed on top of the monitor. And user can mark events of surgical operation and patient's conditions on the software, this allow him jump to the points of events directly, when reviewing the recorded EEG file afterwards. Other functions, such as forward/backward jump, gain control, file management are equipped and these are operated by simple mouse click. Clinical tests in a university hospital show that the software responds accurately according to the conditions of patients and medical doctors can use the software easily.

• Korean Journal of Biological Psychiatry
• /
• v.20 no.4
• /
• pp.166-178
• /
• 2013

Objectives Alteration of epigenetic effects of testosterone during early development was suggested as an ancillary mechanism for the genesis of schizophrenia. EEG coherence was thought to be a marker for cerebral laterality of which important determinant was testosterone during early development. We studied sex-related differences of EEG coherences between patients with schizophrenia and controls to examine the sex effects in the genesis of schizophrenia. Methods EEG was recorded in 35 patients with schizophrenia and 46 healthy controls in the eyes closed resting state. Pair-wise EEG coherences were calculated over delta, theta, alpha, beta and gamma frequency bands. To examine the differences of EEG coherence according to sex in each group, ANCOVA was performed using Statistical Analysis system (SAS, Ver 9.3) and R (Ver 2.15.2). Results Healthy control males showed more increased right intrahemispheric coherences than healthy control females in delta, theta, alpha and beta frequency bands. In patients with schizophrenia, this male dominant pattern in right intrahemispheric coherences was attenuated especially in alpha and beta bands. Healthy control females showed more increased interhemispheric coherences than healthy control males in delta, theta, beta and gamma frequency bands. In patients with schizophrenia, these female dominant patterns in interhemispheric coherences were attenuated especially in delta, theta, and beta bands, which were commonly observed in frontal to central areas. Conclusion Sex differences in resting EEG coherences were attenuated in schizophrenia patients. These results imply that sex-related aberrant cerebral lateralization might exist in patients with schizophrenia, which are partly due to sex hormones via epigenetic mechanisms.

• Journal of Yeungnam Medical Science
• /
• v.24 no.2
• /
• pp.107-118
• /
• 2007

Background : It is well known that non-rapid eye movement(NREM) sleep activates the occurrence of interictal epileptiform discharges(IED) in many epileptic syndromes. We performed this study to assess the effect of NREM sleep on IED in epileptic patients with organic brain lesions. Materials and Methods : We analyzed awake and sleep electroencephalopathy(EEG) recorded simultaneously after partial sleep deprivation in 50 patients. We calculated the awake and sleep spike index (ASI and SSI, spikes/epoch), and the percentage increase of ASI and SSI during sleep. Results : In the 50 patients, the IEDs were recorded exclusively during the awake state in 1 (2%) patient, and during the sleep state in 13(26%) patients. The SSI was higher in 44 (88%) patients, and the ASI was higher in 5 (10%) patients. The mean ASI and the SSI in patients with organic brain lesions were $0.058{\pm}0.121$ and $0.148{\pm}0.187$, and it was $0.081{\pm}0.150$ and $0.174{\pm}0.226$ in patients without organic brain lesions. There were significant increases in the spike index (P<0.05) during NREM sleep in both groups (n=36), but no significant difference in the percent increase of spike index (P>0.05). Conclusion : The IEDs were activated significantly during NREM sleep both in patients with and without organic brain lesions, but there were no differences in the degree of activation in both groups. The activating effect of NREM sleep was not correlated with clinical factors such as, frequent nocturnal seizures, frequent generalized tonic clonic seizures, type of epilepsy and taking anticonvulsants. We conclude that the routine EEG used to evaluate epileptiform discharges in epileptic patients should include sleep recordings after partial sleep deprivation.