• 한국전자파학회논문지
• /
• 제29권7호
• /
• pp.508-514
• /
• 2018

뇌전도는 뇌 활동 시 발생하는 뇌 세포 간 상호작용으로 생성된 전기적 활동이며, 손동작 시 뇌 활동으로 인해 뇌전도가 발생한다. 본 연구에서는 16채널 뇌전도 측정 장비를 이용하여 손동작 전과 좌 혹은 우 손동작 시 발생되는 뇌전도를 측정하였으며, 측정된 데이터는 지도 학습 모델인 서포트 벡터 머신으로 분류하며, 서포트 벡터 머신의 학습 시간을 단축 위해 동작관련 정보 손실을 최소화하고, 뇌전도 정보를 축약할 수 있는 필터링을 통한 특징 추출과 벡터 차원 축소 기법을 제안한다. 분류 결과, 전두엽 부위의 전극에서 손동작 전 상태-손동작사이에서 평균 72.7 %의 정확도로 분류되었다.

• 한국정밀공학회지
• /
• 제22권1호
• /
• pp.183-192
• /
• 2005

This study compared cerebral lateralization index based on the area of neural activation with that based on the intensity of neural activation. For this purpose, 8 right-handed male college students (the mean age - 23.5 years) and 10 right-handed male college students (the mean age - 25.1 years) participated respectively in researches on visuospatial and verbal task brain function. Functional brain images were taken from 3T MRI using the single-shot EPI method. The result of measuring cerebral lateralization index based on the area of neural activation suggested that the right hemisphere is dominant in visuospatial tasks and the left one is in verbal tasks. However, the dominance is not sufficient to locate the exact part of the brain for these tasks. When cerebral lateralization index was computed based on the intensity of neural activation, it was derived that the area of cerebral lateralization closely related to visuospatial tasks is the superior parietal lobe, and the area of cerebral lateralization closely related to verbal tasks is the inferior and middle frontal lobes. Thus, cerebral lateralization index by area based on the intensity of neural activation as proposed by this study can determine the dominance of the cerebrum by area, so is helpful for accurate and quantitative determination of cerebral lateralization.

• 한국산학기술학회논문지
• /
• 제10권10호
• /
• pp.2985-2989
• /
• 2009

본 논문에서는 학습집중력을 향상시킬 수 있는 시트를 제작하였다. 학습집중력의 향상을 입증하기위하여 인체 내에 존재하고 있는 조영제를 이용하여 공간적 시간적 해상도가 뛰어나고 비침습적으로 뇌기능을 측정할 수 있는 기능적 자기공명영상을 획득하여 분석을 한 결과 기억작용과 관련 있는 전두엽 부근의 뇌혈류량의 활성화를 확인할 수 있었고 뇌파 측정 분석 결과 절대알파파와 절대베타파의 비율에서 유의할 만한 변화를 확인하였다. 기능적 자기공명영상은 뇌의 생리기능적 역할을 규명, 의학적으로 수술 전후 장애를 방지하고 예방하는데 활용되고 있으며 뇌신경망의 가시화로 학습집중력 향상 시트등과 같이 뇌와 관련된 제품을 개발하는데 많은 연구가 이루어질 것이다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권23호
• /
• pp.10319-10323
• /
• 2015

Background: The incidence rate of brain tumors has increased more than 40% in the past 20 years, especially in adults. We aimed to study the clinical and pathological findings of central nervous system (CNS) tumor patients and to evaluate their 5 year survival rates. Materials and Methods: The archives of all patients with CNS tumors in 6 health care centers in Yazd, Iran, from 2006 to 2013, were studied. Patients data were extracted using a checklist which included age, sex, date of reference and diagnosis, date of death, clinical signs, radiography findings, pathology report, size and location of tumor, patient treatment and grade of tumor. Results: A total of 306 patient records were studied in the 8 year period. The most prevalent type of tumor was astrocytoma (n=113, 36.9%). The frequency of almost all tumor types was statistically higher in male patients (p=0.025). In most cases surgery with radiotherapy was the treatment of choice (49.3%). The most frequent symptom reported was headache (in 60.8% of patients) followed by convulsions (15.7%). Most of the tumors were located in the right hemisphere (46.1%) and the frontal and parietal lobe (26% and 12%, respectively). Radiography findings displayed edema with a nonhomogeneous lesion in majority of the patients (87%). The survival fraction of the patients with malignant tumors decreased over time (0.807 in the first year and 0.358 at the end of the $5^{th}$ year). Conclusions: Astrocytoma was the more common CNS tumor with male predominance. Overall survival rates of malignant tumors decreased over time and this was in relation with tumor grade.

• Journal of Korean Neurosurgical Society
• /
• 제30권3호
• /
• pp.371-375
• /
• 2001

Intracranial hemorrhage due to preeclampsia in the postpartum woman is rarely documented. Generally, the incidence of stroke is increased during pregnancy and early postpartum. Preeclampsia is considered a main cause of both nonhemorrhagic and hemorrhagic stroke. We present a 32-year-old woman who had intracranial hemorrhage at 5 days postpartum. At admission, her consciousness was semicomatose with elevated blood pressure. Computerized tomography revealed intracranial hemorrhage on right frontal lobe. Additional angiography did not reveal abnormal vascular lesion. Emergency craniectomy with hematoma removal was done. However, the patient showed no recovery and died 2 weeks later. We conclude that postpartum care of preeclampsia is important to prevent intraparenchymal hemorrhage. Relative high risk of stroke during the postpartum period suggests a causal roles for the large decrease in blood volume or the rapid changes in hormonal status that follow a live birth or stillbirth, perhaps by means of hemodynamics, coagulative, or vessel wall changes.

• Journal of Korean Neurosurgical Society
• /
• 제30권3호
• /
• pp.366-370
• /
• 2001

Objective : The authors present three cases of brain tumors in which epidural hematomas(EDHs) were developed postoperatively in the remote areas from craniotomy sites. The preventive tactics as well as possible mechanisms of development of remote EDH are discussed. Material and Methods : The magnetic resonance imagings of three patients revealed a left lateral ventricular mass located just aside of foramen Monro in a 27-year-old male, a large cystic mass in the temporal lobe in a 35-year-old male, and a partially calcified pineal mass in a 27-year-old male patient. The surgical removals of these tumors were performed without any noticeable events during surgery via left frontal transcortical transventricular approach for lateral ventricular tumor, left temporal craniotomy for cystic temporal tumor, and right occipital transtentorial approach for pineal tumor. Results : Postoperative EDHs remote from the sites of craniotomy were detected by the immediate postoperative computerized tomographic scans. We obtained good outcomes without any morbidity in all three patients with emergent evacuation of the hematoma. The pathologic diagnoses were lateral ventricular ependymoastrocytoma, temporal craniopharyngioma and mixed germinoma of the pineal region. Conclusion : It is postulated that a sudden reduction of intracranial pressure(ICP) at the time of tumor removal may strip the dura from the inner table of the skull to cause EDH from the remote site of craniotomy. Gradual reduction of ICP with slow drainage of cerebrospinal fluid before tumor removal as well as lowering the head position of patient during surgery might be helpful for preventing this unusual complication.

• Journal of Korean Neurosurgical Society
• /
• 제37권4호
• /
• pp.268-271
• /
• 2005

Objective: This study is undertaken to review the characteristics, risk factors and the surgical outcomes in long term follow-up of brain abscesses. Methods: We had reviewed medical records and radiological findings in patients with brain abscess who underwent operations in our hospital from January 1992 to June 2003. Results: Observed 11 cases were comprised of 8 men and 3 women with 42 years old average age ranging from 17 to 66. Lesions were located at frontal lobe in 5 cases, parietal in 4 cases, temporal in 1 case, and occipital in 1 case. The mean follow-up period was 23.8 months and ranged from 5 to 33 months. The microbial sources of infection had been found in 5 cases (45%). The organisms were identified by using the microbial culture obtained from the excisional biopsy. We had applied all cases with surgical excision. Empirical antibiotic treatment started soon after diagnosis in all cases. The mortality and morbidity of surgical excision were low. Nine patients were neurologically improved. One patient had died after the operation due to acute respiratory distress syndrome (ARDS). Conclusion: The single and large abscess located in an accessible lesion is a good candidate for surgical excision because of it's low morbidity, mortality, and favorable outcome after surgical excision. Further study is required to compare the surgical excision with other treatment modalities of brain abscess.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제8권2호
• /
• pp.217-231
• /
• 1997

본 연구에서는 ADHD의 원인론에 대한 다양한 신경학적 이론들을 살펴본 후, ADHD 진단에 널리 사용되는 신경심리학적 평가방법들에 대한 국내, 외 연구결과들을 고찰하였다. ADHD 아동들이 여러 주의력 검사상에서 일관성있게 경계력, 지속적 주의력, 주의산만성, 주의력의 분할과 조절에 문제를 보이고 있고, 실행 능력과 작동기억외에 연합기억에서도 어려움을 보이는 것으로 나타났다. 이러한 신경심리학적 검사결과는 ADHD 아동이 전두엽외에 망상활성체계 등 두뇌의 여러 부위를 포함하는 신경망에 장애가 있을 가능성을 시사해주는 것으로 생각된다. 그러나 국내에서 ADHD 아동들에게 널리 사용되고 있는 신경심리검사들은 대부분 외국에서 제작된 것이므로, ADHD 아동들의 수행결과를 보다 정확하게 비교하고 해석하기 위해서는 ADHD와 정상 아동, 그리고 기타 소아정신과장애 아동들을 대상으로 그러한 신경심리검사들에 대한 연령별 규준 확립과 타당도 검증을 위한 한국 표준화연구가 조만간 이루어져야 하겠다.

• 한국소음진동공학회논문집
• /
• 제21권4호
• /
• pp.307-314
• /
• 2011

This study was focused on the influence of soundscape provided to the interior landscape on the improvement of occupants' sound environment. When soundscape was provided to occupants together with the interior landscape rather than simply providing interior landscape, the occupants' satisfaction seemed to be improved. The most preferred sound source among the three sound sources was considered as the sound of the grasshopper. When both of the interior landscape and the landscape substances was provided, the adjectives with the average difference of more than 1 are "Vicissitudinous", "Elegant" and "Cheerful". When the interior landscape and the sound source were provided, such adjectives as "Vicissitudinous", "Complex" and "Cheerful" are extracted. When all the variables were provided, such adjectives as "Vicissitudinous", "Abundant" and "Cheerful" seem to show the difference of more than 1. Regarding "Vicissitudinous", it was possible to know that the average difference of more than 1.5 was the biggest. Regarding the relative values of the ${\alpha}$ wave and the ${\beta}$ wave for each part, it seemed that the highest ${\alpha}$ wave was generated on the left parietal lobe of P3, while the lowest ${\beta}$ wave was generated on the left and right frontal lobes of Fp1 and Fp2. According to this study, it was shown that the soundscape and the interior landscape seemed to influence the improvement of the occupants' sound environment.

• 제어로봇시스템학회논문지
• /
• 제21권1호
• /
• pp.59-64
• /
• 2015

In this paper, we found the usefulness of the deep belief network (DBN) in the fields of brain-computer interface (BCI), especially in relation to imagined speech. In recent years, the growth of interest in the BCI field has led to the development of a number of useful applications, such as robot control, game interfaces, exoskeleton limbs, and so on. However, while imagined speech, which could be used for communication or military purpose devices, is one of the most exciting BCI applications, there are some problems in implementing the system. In the previous paper, we already handled some of the issues of imagined speech when using the International Phonetic Alphabet (IPA), although it required complementation for multi class classification problems. In view of this point, this paper could provide a suitable solution for vowel classification for imagined speech. We used the DBN algorithm, which is known as a deep learning algorithm for multi-class vowel classification, and selected four vowel pronunciations:, /a/, /i/, /o/, /u/ from IPA. For the experiment, we obtained the required 32 channel raw electroencephalogram (EEG) data from three male subjects, and electrodes were placed on the scalp of the frontal lobe and both temporal lobes which are related to thinking and verbal function. Eigenvalues of the covariance matrix of the EEG data were used as the feature vector of each vowel. In the analysis, we provided the classification results of the back propagation artificial neural network (BP-ANN) for making a comparison with DBN. As a result, the classification results from the BP-ANN were 52.04%, and the DBN was 87.96%. This means the DBN showed 35.92% better classification results in multi class imagined speech classification. In addition, the DBN spent much less time in whole computation time. In conclusion, the DBN algorithm is efficient in BCI system implementation.