• 대한의용생체공학회:의공학회지
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• 제30권4호
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• pp.306-310
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• 2009

The purpose of this study is to observe the change in gamma-band cortical activities (GBAs) due to task difficulty. Event-related potential and gamma-band activity were investigated using electroencephalograms recorded during auditory oddball tasks with two difficulty levels. For more difficult task, the amplitude of P300 decreased and the peak latency of P300 was delayed significantly compared to easier task. The induced GBA decreased considerably during the P300 latency period and the peak latency of the induced GBA was delayed for more difficult task. The results imply that the difficulty-related change in cortical information processing may be implemented as a change in the strength of local neuronal association.

• 대한불안의학회지
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• 제6권2호
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• pp.102-108
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• 2010

Objective : Although studies have explored responses to fear had been assessed using various psychophysiological methods, results have been inconsistent. The present study examined psychophysiological responses in healthy subjects after viewing fear stimuli in a video clip for set up future fear related psychophysiological studies. Methods : We monitored three psychophysiological variables (electroencephalography, skin temperature, and heart rate variability) in adults who watched either a control stimulus movie clip or a fear-inducing movie clip. Results : In 16 healthy adults, theta activity decreased significantly after the fear stimulus as compared to the normal stimulus. However the participants showed no differences in heart rate variability or skin temperature between the fear and normal control stimulus situations. Conclusion : In the limbic area, theta activity corresponds with information processing, integration into previous memories and long-term potentiation. In this study, we suggest decreased theta activity represents amygdalo-hippocampal activity, associated with fear, short-term memory, and memory extinction in the healthy adults. Further studies are needed to evaluate the interaction of fear, memory, and the pathophysiology of anxiety disorder in patient with anxiety disorders.

• Journal of Communications and Networks
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• 제17권4호
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• pp.419-427
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• 2015

There have been increases in the elderly population worldwide, and this has been accompanied by rapid growth in the health-care market, as there is an ongoing need to monitor the health of individuals. Wireless body area networks (WBANs) consist of wireless sensors attached on or inside the human body to monitor vital health-related problems, e.g., electrocardiograms (ECGs), electroencephalograms (EEGs), and electronystagmograms (ENGs). With WBANs, patients' vital signs are recorded by each sensor and sent to a coordinator. However, because of obstructions by the human body, sensors cannot always send the data to the coordinator, requiring them to transmit at higher power. Therefore, we need to consider the lifetime of the sensors given their required transmit power. In the IEEE 802.15.6 standard, the transmission topology functions as a one-hop star plus one topology. In order to obtain a high throughput, we reduce the transmit power of the sensors and maintain equity for all sensors. We propose the multiple-hop transmission for WBANs based on the IEEE 802.15.6 carrier-sense multiple-access with collision avoidance (CSMA/CA) protocol. We calculate the throughput and variance of the transmit power by performing simulations, and we discuss the results obtained using the proposed theorems.

• The Korean Journal of Physiology and Pharmacology
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• 제23권2호
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• pp.131-139
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• 2019

Manually reviewing electroencephalograms (EEGs) is labor-intensive and demands automated seizure detection systems. To construct an efficient and robust event detector for experimental seizures from continuous EEG monitoring, we combined spectral analysis and deep neural networks. A deep neural network was trained to discriminate periodograms of 5-sec EEG segments from annotated convulsive seizures and the pre- and post-EEG segments. To use the entire EEG for training, a second network was trained with non-seizure EEGs that were misclassified as seizures by the first network. By sequentially applying the dual deep neural networks and simple pre- and post-processing, our autodetector identified all seizure events in 4,272 h of test EEG traces, with only 6 false positive events, corresponding to 100% sensitivity and 98% positive predictive value. Moreover, with pre-processing to reduce the computational burden, scanning and classifying 8,977 h of training and test EEG datasets took only 2.28 h with a personal computer. These results demonstrate that combining a basic feature extractor with dual deep neural networks and rule-based pre- and post-processing can detect convulsive seizures with great accuracy and low computational burden, highlighting the feasibility of our automated seizure detection algorithm.

• 국제물리치료학회지
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• 제10권1호
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• pp.1687-1694
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• 2019

Background: Although cranial electrotherapy stimulation (CES) is reported to have positive effects on mental functions such as depression and sleep improvement, detailed studies regarding awakening, attention and concentration among brain waves reflecting brain activity are lacking. Objective: To examine the effects of cranial electrotherapy stimulation (CES) on various electroencephalograms (EEGs) reflecting brain activities. Design: Randomized controlled clinical trial (single blind) Methods: This study selected 30 healthy adult women in their 20s who volunteered for this experiment. A total of 30 subjects were randomly assigned to three groups (Sham group, 0.5 Hz CES group, and 100 Hz CES group). EEGs were measured before and after the single CES, and the results were compared and analyzed. Results: The relative theta, alpha, and gamma waves indicated no significant differences in the interaction effects between time and group. The relative fast alpha wave only showed significant differences in the interaction effects between time and group in P4. The relative slow beta wave only indicated statistically significant differences in the interaction effects between time and group in T3 and T4. The relative mid and fast beta waves showed statistically significant differences in the interaction effects between time and group in all areas. Conclusions: These results suggest that a CES of 0.5 Hz awakens consciousness and has a positive influence on brain activity, while a CES of 100 Hz has a positive influence on thinking activity accompanying mental load during concentrating on one subject.

• 생명과학회지
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• 제22권2호
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• pp.192-199
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• 2012

본 연구는 라벤더(Lavandula angustifolia)향이 뇌기능에 미치는 효능을 객관적인 관점에서 살펴보고자 함에 의의를 두고 뇌파 변화를 살펴보았다. 신체적으로 건강한 20대 여자 성인(28명)을 대상으로 검증된 수면장애 조사를 통하여 수면질을 조사하여 수면에 문제를 가진 대상자를 선별하고 라벤더 향기요법을 실행하여 뇌파의 변화를 분석하였다. 뇌파 전극은 10-20 국제법에 의하여 전부두(F3, F4), 측두부(T3, T4), 후두부(O1, O2), 두정부(P3, P4)에 부착하였다. 향기요법을 시행하기 전 3분, 시행 중 3분, 그리고 시행 후 3분씩 나누어서 뇌파 검사를 시행하였다. 라벤더향은 수면질이 좋은 사람(15명)에서 후두부와 두정부에서 알파파를 감소시키고, 전두부에서는 세타파와 후두부에서 베타파를 증가시켰다. 그러나 수면질이 나쁜 사람(13명)에서는 대뇌 모든 영역에서 수면 입면파인 세타파만을 증가시키는 효능이 나타났다. 따라서 라벤더향은 수면질이 나쁜 사람에게 수면을 유도하는 긍정적인 뇌기능 효능이 있음을 확인하였다.

• Clinical and Experimental Pediatrics
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• 제54권9호
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• pp.380-384
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• 2011

Purpose: To investigate the efficacy of topiramate monotherapy in West syndrome prospectively. Methods: The study population included 28 patients (15 male and 13 female children aged 2 to 18 months) diagnosed with West syndrome. After a 2-week baseline period for documentation of the frequency of spasms, topiramate was initiated at 2 mg/kg/day. The dose was increased by 2 mg/kg every week to a maximum of 12 mg/kg/day. Clinical assessment was based on the parents' report and a neurological examination every 2 weeks for the first 2 months of treatment. The baseline electroencephalograms (EEGs) were compared with the post-treatment EEGs at 2 weeks and 1 month. Results: West syndrome was considered to be cryptogenic in 7 of the 28 patients and symptomatic in 21 patients. After treatment, 11 patients (39%) became spasm-free, 6 (21%) had more than 50% spasms-reduction, 3 (11%) showed less than 50% reduction, and 8 (29%) did not respond. The effective daily dose for achieving more than 50% reduction in spasm frequency, including becoming spasm-free, was found to be $5.8{\pm}1.1$ mg/kg/day. Nine patients (32%) showed complete disappearance of spasms and hypsarrhythmia, and 11 (39%) showed improved EEG results. Despite adverse events (4 instances of irritability, 3 of drowsiness, and 1 of decreased feeding), no patients discontinued the medication. Conclusion: Topiramate monotherapy seems to be effective and well tolerated as a first line therapy for West syndrome and is not associated with serious adverse effects.

• PNF and Movement
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• 제14권3호
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• pp.209-217
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• 2016

Purpose: Treatments using a mirror neuron system, such as 3D virtual reality therapy, are used in stroke rehabilitation, but they need to be constructed according to a detailed procedure. The aims of this study were to analyze electroencephalograms (EEG) during relaxation and action while observing first person perspective (1AE) and third person perspective (3AE) videos of the right hand for 20's. Methods: Thirty participants (Male=4, Female=26) were recruited for this study. Participants were selected by a vividness of movement imagery questionnaire (VMIQ). EEG was measured during relaxxation and during action with 1AE and 3AE videos, focusing on the supination and pronation actions of participants' right hands. An absolute mu rhythm, a relatively high alpha power, and a relative beta power were identified. In each group, one-way repeated measures ANOVA was used for statistical analysis. Results: Measurement of absolute mu rhythms was significantly suppressed for both 1AE and 3AE compared with relaxation in C3 and C4 regions. High alpha wave measurements were significantly suppressed for both 1AE and 3AE in all regions, while beta wave measurements were significantly increased only for 3AE in F3 and F4 regions. Conclusion: Based on this study, we suggest that the mirror neuron system is activated during actions accompanied by action observation, especially actions with 3AE video observation, which can be a great therapeutic mathod in stroke rehabilitation.

• Clinical and Experimental Pediatrics
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• 제50권7호
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• pp.694-697
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• 2007

발작성 운동이상증(Paroxysmal kinesigenic dyskinesia, PKD)은 경련성 발작과 구분해야 하는 드문 신경질환으로써 1940년에 Mount와 Reback에 의해 발작성 무도무위증(paroxysmal dystonic choreoathetosis)란 용어로 처음 보고되었으며 1967년 Kertesz에 의해 처음으로 발작성 운동이상증(Dyskinesia)으로 명명 되어졌다. PKD는 아동기에서 성인기 초에 호발하며 가족성 우성 유전으로도 나타날 수 있고 chromosome 16p11.2-q12.1, 16q13-q22.1, 2q32-36과 관계 있다는 보고가 있다. 증상은 대부분 수 초 이내 멈추나 드물게 5분 이상 지속되는 경우도 있다. 증상 발현 전에 감각 이상 등의 전구 증상이 동반되는 경우가 있으며 의식소실은 동반되지 않는다. 치료는 carbamazepne, phenytoin, valproic acid, clonazepam 등의 항경련제를 투여하는데 일부에서는 oxycarbazepine이나 levodopa를 투여하기도 한다. 저자들은 한 가족의 세명의 형제에서 나타난 발작성 이상운동증을 경험하고 항경련제(Oxcarbamazepine or Carbamazepine)를 통한 좋은 치료성적을 거두었기에 보고하는 바이다.

• Journal of Ginseng Research
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• 제34권4호
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• pp.304-313
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• 2010

This study was undertaken to discover the effects and possible mechanisms of the effect of red ginseng extract (RGE) on spontaneous sleep. The effects of a low dose (10 mg/kg) and a high dose (200 mg/kg) of RGE were compared in rats. After recovery from a surgical operation enabling electroencephalograms recordings, rats were administered RGE orally. RGE was administered orally for 1 day or once per day for 5 days in either 10 or 200 mg/kg doses. Polygraphic signs were recorded for 12 h after oral administration of RGE. Both treatment with a large dose (200 mg/kg) of RGE for one day and treatment with either a large or a small dose for 5 days reduced the number of sleep.wake cycles. Daily treatment with RGE (either 10 or 200 mg/kg) for 5 days augmented NREM and total sleep, but reduced wakefulness. Delta wave activity recorded during non-REM (NREM) sleep and REM sleep was increased after one treatment with RGE (either 10 or 200 mg/kg). Delta wave activity during NREM was enhanced after daily treatment with RGE (either 10 or 200 mg/kg) for 5 days. Both alpha and beta subunits of the $\gamma$-aminobutyric acid $(GABA)_A$ receptor were significantly over-expressed in the hypothalamus of the RGE-treated groups. Moreover, the expression of glutamic acid decarboxylase was also increased in the hypothalamus. These results demonstrate that RGE may regulate spontaneous sleep via $GABA_A$ergic systems.