• 대한의용생체공학회:의공학회지
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• 제17권2호
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• pp.179-188
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• 1996

A clinically oriented 32-channel electroencephalogram (EEG) and evoked potential (EP) mapping system has been developed EEG and EP signals acquired from 32-channel electrodes attached on the heroid surface are amplified by a pre-amplifier which is separated from main amplifier and is located near the patient to reduce signal attenuation and noise contamination between electrodes and the amplifier. The amplified signals are further amplified by a main amplifier where various filtering and gain contr61 are achieved An automatic artifact rejection scheme is employed using neural network-based EEG and artifact classifier, by which examination time is substantially reduce4 The continuously measured EEG sigrlals are used for spectral mapping, and auditory and visual evoked potentials measured in synchronous to the auditory and visual stimuli are used for temporal evoked potential mapping. A user-friendly graphical interface based on the Microsoft Window 3.1 is developed for the operation of the system. Statistical databases for comparisons of group and individual are included to support a statistically-based diagnosis.

• 수면정신생리
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• 제4권1호
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• pp.96-106
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• 1997

The clinical validity of a korean EEG and EP mapping system(Neuronics) was evaluated with schizophrenic patients(n=20), normal controls(n=19), and 10 patients with central nervous system disease(8 patients with cerebrovascular accident, 1 patient with brain mass, and 1 patient with periodic paralysis). In the normal control group, the pattern of resting computerized EEG with eyes closed showed normal parieto-occipital dominance of alpha wave. Compared with normal controls, schizophrenic patients had more delta activity in the frontal region, and less alpha activity especially in the parieto-occipital region. In most cases patients with cortical organic lesions(n=5) revealed increased delta and theta activity and decreased alpha activity on the lesion areas. These findings were compatible with their MRI and clinical findings. However in the cases of subcortical lesions(n=5) EEG showed various findings which suggest diverse influences of subcortical abnormalities on cortical activities. The P300 of schizophrenic group was smaller and more delayed than those of normal controls. These results are generally compatible with the previous studies using other EEG and EP mapping systems consequenty and suggest that the this EEG and EP mapping system(Neuronics) has clinical validity.

• The Journal of Korean Physical Therapy
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• 제27권3호
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• pp.135-139
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• 2015

Purpose: The aim of this study was to compare EEG topographical maps in patients with chronic stroke after action observation physical training. Methods: Ten subjects were recruited from a medical hospital. Participants observed the action of transferring a small block from one box to another for 6 sessions of 1 minute each, and then performed the observed action for 3 minutes, 6 times. An EEG-based brain mapping system with 32 scalp sites was used to determine cortical reorganization in the regions of interest (ROIs) during observation of movement. The EEG-based brain mapping was comparison in within-group before and after training. ROIs included the primary sensorimotor cortex, premotor cortex, superior parietal lobule, inferior parietal lobule, superior temporal lobe, and visual cortex. EEG data were analyzed with an average log ratio in order to control the variability of the absolute mu power. The mu power log ratio was in within-group comparison with paired t-tests. Results: Participants showed activation prior to the intervention in all of the cerebral cortex, whereas the inferior frontal gyrus, superior frontal gyrus, precentral gyrus, and inferior parietal cortex were selectively activated after the training. There were no differences in mu power between each session. Conclusion: These findings suggest that action observation physical training contributes to attaining brain reorganization and improving brain functionality, as part of rehabilitation and intervention programs.

• 대한의용생체공학회:의공학회지
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• 제16권2호
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• pp.157-166
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• 1995

The Electroencephalogram (EEG) and evoked potential (EP) t;ave widely been used for study of brain functions. The EEG and EP signals acquired from multi-channel electrodes placed on the head surface are often interfered by other relatively large physiological signals such as electromyogram (EMG) or electroculogram (EOG). Since these artifact-affected EEG signals degrade EEG mapping, the removal of the artifact-affected EEGs is one of the key elements in neuro-functional mapping. Conventionally this task has been carried out by human experts spending lots of examination time. In this paper a neural-network based classification is proposed to replace or to reduce human expert's efforts and time. From experiments, the neural-network based classification performs as good as human experts : variation of decisions between the neural network and human expert appears even smaller than that between human experts.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 춘계학술대회
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• pp.75-78
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• 1994

To represent the overall potential distribution on the entire scalp it is necessary to interpolate between sampled EEG(electroencephalogram) values, we describe a method to interpolate between scalp recorded EEG data which obtained from electrodes irregularly disposed on the scalp, using polynomial interpolation. This method can analyze the variance of source temporally or spatially and present continuous distributed topographic mapping of the EEG records. In the result, we obtained the overall potentials distribution on the entire scalp from the EEG records of a patient which was known to epilepsy.

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.31-36
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• 1988

A personal computer-based brain map is described which will display a gray scale maps showing the distribution of signals derived from the electrical activity of the brain such as EEG or EP This topographic brain mapping system has a flexibility which describe the electrode number and placement mapping onto any shaped space and generate a brain maps by incoorporated the data acquisition and processing software with conventional EEG machine.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 추계학술대회
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• pp.81-84
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• 1994

A clinically oriented EEG and EP mapping system was developed with user-friendly interface and easy interactive operations. The system was based on the graphical user interface developed with C/C++ and Software Development Kit (SDK) operated under Microsoft Windows 3.1. Continuous acquisition for the EEG signal and burst mode acquisition for EEG signal syncronized to the external stimuli arc implemented with real time display. A neural network based automatic artifact discrimation is developed and implemented with which examination time can be reduced by a factor of 3 or more. Several bands of spectral maps and spectrums arc displayed for EEG diagnosis. Amplitude maps of EP signal at specified times by operator are displayed together with cine mode of EP maps for dynamic study. Source localization and other statistical signal processing are also included.

• 대한의생명과학회지
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• 제5권2호
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• pp.167-179
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• 1999

냉동생물학 연구분야 중 동면의 기전은 미래의 우주과학과 저온생물학이 풀어야 될 중요한 과제로서, 박쥐를 비롯한 동면동물을 사용하는 응용과학에서 가장 주목을 받아 오고 있다. 동면동물의 동면돌입 현상이 체온하강과 함께 뇌 전도상 전간발작 (epileptic seizure)을 유도시킨다는 가설을 검증하기 위하여 여러 가지 박쥐를 포함하는 동면동물을 대상으로 박쥐의 정상 동면돌입과정과 전간발작유발인자인 tetrahydrocannabinol (THC), pentylenetetrazol (metrazol), intermittent light stimulation (ILS)이 박쥐의 체온 (Tb), 심박률 (HR), 뇌전도 (EEG), 뇌영상 (brain mapping) 등에 미치는 영향을 관찰하여 다음과 같은 결과를 얻었다. 정상 동면돌입과정에 있어서는 안주애기박쥐는 1∼2개의 고평부를 형성하지만 대체로 2시 간 후에 동면에 안정 (심박률 15회/분)되었고 작은갈색박쥐는 2시간 30분에 동면온도에서 안정되었다. THC는 햄스터의 체온을 감소시켰고, pentylenetetrazol (metrazol)의 유의한 체온하강효과는 볼 수 없었으나, ILS는 긴가락박쥐, 쇠박쥐의 체온과 심박률을 하강시켰으며, 문둥이박쥐는 정상적으로 동면돌입시 뇌전도상 epileptic seizure시 나타나는 뇌파 (3 spikes and wave/sec)를 나타내었으며, 사람의 경우 ILS 자극 (Intensity 4∼8, 20 flashes/sec)을 받은 9명 중 1명에서 epileptic seizure시의 EEG상의 뇌영상 (brain map) (우측 후두엽의 일부만이 활성)으로 추측되는 소견을 볼 수 있었다. 이상의 실험결과는, 북부 온대지방의 동면동물인 박쥐와 햄스터의 경우 동면돌입과 체온하강 및 전간발작과 상당한 관련성이 있음을 암시한다고 사료된다.

• 수면정신생리
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• 제16권1호
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• pp.16-21
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• 2009

In accordance with the development of EEG and polysomnography in the field of sleep research, the sleep onset period (SOP) between wakefulness and sleep has been considered an important part for understanding the physiology of sleep. SOP in the transition from wakefulness to sleep is a gradual process integrating various viewpoints such as behavior, EEG, physiology and subjective report. Particularly, based on understanding of EEG changes during sleep, SOP has been regarded as a pattern of topographical change in specific frequency and specific state in EEG. Studies on quantitative EEG (qEEG) and event-related potential (ERP) have suggested that SOP shows the changes of functional coordination at the specific cortical areas in qEEG and the changes of regular patterns in response to environmental stimulation in ERP. The development of sleep EEG and topographic mapping of EEG is expected to integrate various viewpoints of SOP and clarify the neurophysiologic mechanism of SOP further.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.370-373
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• 1997

We are exposed to the various external stimuli input from the environment, which cause emotional changes based on the characteristics of the stimuli. Unfortunately there are no quantitative results on relationship between human sensibility and the characteristics of physiological signals. The objective of this study was to quantify EEG signals evoked by auditory stimulation based on the assumption that the analysis of the variability on the characteristics of the EEG waveform may provide the significant information regarding changes in psychological states of the subject. The experiment was devised with seven experimental conditions, which are control and six different types of auditory stimulation. Six subjects were used to obtain EEGs while introducing auditory stimulation. Wavelet transformation was employed to analyze the EEG signals. The results showed that the reconstructed signals at the decomposition level revealed the different energy value on the EEG signal. Also, general patterns of EEG signals in rest state compare with negative and positive stimulus were found. This study could be extended to establish an algorithm which distinguishes psychophysiological states of the subjects exposed to the auditory stimulation.