• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.07a
• /
• pp.490-493
• /
• 2011

최근 사용자와 컴퓨터간의 상호작용이 가능한 사용자 인터페이스(UI, User Interface)에 대한 연구가 활발히 진행되고 있다. 이중 키보드나 마우스, 리모컨과 같은 별도의 입력장치가 없이 뇌의 활동으로부터 발생하는 생체신호를 이용하여 사용자의 생각만으로 컴퓨터와 커뮤니케이션을 할 수 있는 뇌만으로 컴퓨터와 커(BCI, Brain-Computer Interface) 시스템이 각광을 받고 있다. 본 연구에서는 뇌의 생체신호로는 뇌전도도(EEG, Electroencephalogram)를 사용하였으며, 이를 통하여 P300 speller 실험을 수행하였다. P300 speller 실험을 통하여 발생된 뇌전도도를 취합하여 P300(사건 관련 전위(ERP, Event-related potential)에서 자극 제시 약 300msec 후에 정점에 달하는 정파)을 분석하였다.

• The Korean Society of Law and Medicine
• /
• v.21 no.2
• /
• pp.209-244
• /
• 2020

TMS and tDCS are non-invasive devices that treat the diseases of patients or individual users, and manage or improve their health by applying stimulation to a brain through magnetism and electricity. The effect and safety of these devices have proved to be valid in several diseases, but research in this area is still much going on. Despite increasing cases of their application, legislations directly regulating TMS and tDCS are hard to find. Legal regulation regarding TMS and tDCS in the United States, Germany and Japan reveals that while TMS has been approved as a medical device with a moderate risk, tDCS has not yet earned approval as a medical device. However, the recent FDA guidance, European MDR changes, recalls in the US, and relevant legal provisions of Germany and Japan, as well as recommendations from expert groups all show signs of tDCS growing closer to getting approved as a medical device. Of course, safety and efficacy of tDCS can still be regulated as a general product instead of as a medical device. Considering multiple potential impacts on a human brain, however, the need for independent regulation is urgent. South Korea also lacks legal provisions explicitly regulating TMS and tDCS, but they fall into the category of the grade 3 medical devices according to the notifications of the Korean Ministry of Food and Drug Safety. And safety and efficacy of TMS are to be evaluated in compliance with the US FDA guidance. But no specific guidelines exist for tDCS yet. Given that tDCS devices are used in some hospitals in reality, and also at home by individual buyers, such a regulatory gap must quickly be addressed. In a longer term, legal system needs to be in place capable of independently regulating non-invasive brain stimulating devices.

• Investigative Magnetic Resonance Imaging
• /
• v.10 no.1
• /
• pp.26-31
• /
• 2006

Purpose : To evaluate the effect of global scaling analysis on brain activation for sensory and motor functional MR imaging study. Materials and methods : Four normal subjects without abnormal neurological history were included. Arm extension-flexion movement was used for motor function and 1KHz pure tone stimulation was used for auditory function. Functional magnetic resonance imaging was performed at 3T MRI (GE, Milwaukee, USA) using BOLD-EPI technique and SPM2 was employed for data analysis. On data analysis, the brain activation images were obtained with and without global scaling by fixing other parameters such as motion correction and realignment. Results : The difference in brain activation between no scaling and global scaling was not large in case of right upper extremity movement (p<0.000001). For auditory test, brain activation with global scaling showed larger activation than that of without global scaling (p<0.05). Conclusion : A caution must be taken into account when analyzing functional imaging data with global scaling especially for functional study of small local BOLD signal change.

• 재활복지
• /
• v.18 no.4
• /
• pp.237-255
• /
• 2014

Idiopathic Parkinson disease(IPD) is an neurodegenerative disease caused by the loss of dopamine cells in the substantia nigra, a region of midbrain. Its major symptoms are muscular rigidity, bradykinesia, resting tremor, and postural instability. An estimated 70~90% of patients with IPD also have hypokinetic dysarthria. Subthalamic nucleus deep brain stimulation (STN-DBS) has been reported to be successful in relieving the core motor symptoms of IPD in the advanced stages of the disease. However, data on the effects of STN-DBS on speech performance are inconsistent. A medline literature search was done to retrieve articles published from 1987 to 2012. The results were narrowed down to focus on speech performance under STN-DBS based perceptual, acoustic, and/or aerodynamic analyses. Among the 32 publications which dealt with speech performance after STN-DBS indicated improvement(42%), deterioration(29%), mixed results(26%), or no change(3%). The most favorite method was found to be based upon acoustic analysis by using a vowel prolongation and Unified Parkinson's Disease Rating Scale(UPDRS). For the purpose of verifying the effect of the STN-DBS, speech evaluation should be undertaken on all speech components such as articulation, resonance, phonation, respiration, and prosody by using a contextual speech task.

• Investigative Magnetic Resonance Imaging
• /
• v.9 no.1
• /
• pp.43-49
• /
• 2005

A few studies have shown that the function of fusiform face area is selectively involved in the perception of faces including a race difference. We investigated the neural substrates of the face-selective region called fusiform face area in the ventral occipital-temporal cortex and same-race memory superiority in the fusiform face area by the event-related fMRI. In our fMRI study, subjects (Oriental-Korean) performed the implicit distinction of the race while they consciously made familiar-judgments, regardless of whether they considered a face as Oriental-Korean or European-American. For race distinction as an implicit task, the fusiform face areas (FFA) and the right parahippocampal gyrus had a greater response to the presentation of Oriental-Korean faces than for the European-American faces, but in the conscious race distinction between Oriental-Korean and European-American faces, there was no significant difference observed in the FFA. These results suggest that different activation in the fusiform regions and right parahippocampal gyrus resulting from superiority of same-race memory could have implicitly taken place by the physiological processes of face recognition.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.23 no.2
• /
• pp.13-19
• /
• 2019

Purpose Tc-99m HMPAO is widely used radiopharmaceutical for brain perfusion SPECT. Tc-99m HMPAO is chemically unstable and is liable to show deterioration of labeling efficiency due to high incidence of secondary Tc-99m HMPAO complex, free pertechnetate and reduced-hydrolyzed Tc-99m. In this study, we investigated whether sialogogues administration could reduce the impurities of Tc-99m HMPAO. Materials and Methods In thirty subjects(20 male and 10 female, age range 19~89 years, mean age $60.7{\pm}14.5years$), brain perfusion SPECT were performed at basal and citric acid stimulation states consecutively after injection of 555 MBq of Tc-99m HMPAO. In the salivary glands, the uptake coefficient was calculated using Siemens processing program. Statistical comparison between before and after the citric acid stimulation performed paired t-test. P value less than 0.05 was regarded as statistically significant. Results Salivary glands uptake was $12900{\pm}3101$ counts in basal and $10677{\pm}2742$ counts in citric acid stimulation states. Unnecessary impurities in the body is much decreased after citric acid administration(t=10.78, P<0.05). The image quality was much improved after administration of citric acid and the regional cerebral perfusion was clearly from demarcated the background. Conclusion The impurity is distributed throughout the body particularly in the salivary glands and nasal mucosa when Tc-99m HMPAO brain perfusion SPECT is performed. If this impurities is not removed, the quality of the image may deteriorate, resulting in errors in visual evaluation. The use of sialogogues could be helpful for decreasing unnecessary impurities in the body.

• Proceedings of the Korean Society for Cognitive Science Conference
• /
• 2006.06a
• /
• pp.47-51
• /
• 2006

본 실험은 한국어 심성어휘집의 표상 정보가 음운정보로 이루어져 있는지, 철자정보로 이루어져 있는지 알아보기 위해 실시되었다. 실험자극은 한국어의 2음절 단어 중 음운변화(자음동화)를 겪는 단어(예: 국민)를 사용하였으며, 각 조건은 철자이웃이 크며 음운 이웃이 큰 단어 조건(O+P+), 철자이웃이 크고 음운이웃은 작은 단어 조건(O+P-), 철자이웃은 작고 음운이웃이 큰 단어 조건(O-P+), 철자이웃과 음운이웃 모두가 작은 조건(O-P-)이었다 실험 1에서 어휘판단 과제를 실시한 결과, 음운이웃 크기와 철자이웃 크기간의 상호작용이 나타났다. 실험2는 동일한 실험자극을 사용한 fMRI 연구를 수행하였다. 실험2 결과 음운처리에 관련된 뇌영역의 활성화가 나타났다. 본 연구결과는 한국어의 경우 심성어휘집이 음운정보로 이루어져 있음을 시사한다.

• Proceedings of the KSMRM Conference
• /
• 2003.10a
• /
• pp.94-94
• /
• 2003

목적： 기능적 자기공명영상과 확산텐서영상기법을 이용하여 전음성 난청과 감각신경성 난청에서의 뇌활성화 양상 그리고 청신경경로상의 차이점을 비교 연구하고자 하였다. 대상 및 방법： 전음성 난청군 (n=4)과 감각신경성 난청군(n=5) 그리고 정상군(n=5)에서의 기능적 자기 공명영상과 확산텐서영상을 획득하였다. 기능적 자기공명영상의 경우 1.5T Siemens MR scanner에서 BOLD 기법을 이용하여 500 Hz 순음 청각자극에 대한 뇌활성화 영역을 검출하였고 영상촬영시 발생하는 기계적 소음을 차폐하기 위한 청각자극기를 특별히 제작하여 사용하였다. 뇌백질신경로를 영상화하는 확산텐서영상은 3.0T GE whole body MR scanner를 사용하였으며 미세한 확산운동을 검출하기 위해 초고속 영상기법인 EPI 기법을 사용하였다. 영상의 화질을 높이기 위해 공간적으로 25개의 다른 방향으로 확산경사자장을 가하였다. 청신경로의 비등방성 영상, 신경로 방향 영상등을 구현하기 위해 획득한 확산영상들에 대한 영상 후처리과정을 시행하였다.

• Proceedings of the Optical Society of Korea Conference
• /
• 2008.02a
• /
• pp.455-456
• /
• 2008

근적외선 분광법(Near-infrared spectroscopy, NIRS)은 대뇌피질에서의 혈류변화(oxy-, deoxyhemoglobin의 농도변화)를 비침습적으로 측정할 수 있는 방법이다. 본 논문에서는 향후 뇌-컴퓨터 접속기술(Brain computer interface)에 적용하기위한 초기 연구단계로, 쥐의 수염을 자극시 활성화되는 대뇌수염피질 영역에서의 혈류변화 및 전기신호를 동시에 측정하고 두 신호의 패턴을 분석한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.04a
• /
• pp.226-229
• /
• 2014

편측무시는 뇌졸중 환자에게서 나타나는 지각 손상중의 하나로 말초 운동 및 감각 신경의 손상과 상관없이 손상된 대뇌반구의 반대편의 공간과 신체의 지각이 감소된 상태로 양방향에서 동시에 주어지는 자극에 대해서 한쪽 자극만을 지각하며 뇌손상 반대편의 신체 움직임의 인식 부족과, 무시된 공간쪽으로의 적은 눈 움직임을 보인다. 이와 같은 편측무시를 측정하는 기존 방법으로는 Albert Test, Line bisection Test, Star Cancellation Test 등이 있다. 하지만, 기존 편측무시 평가 방식에는 여러 가지 단점들이 발생한다. 항상 새로운 평가용지가 필요, 검사시간이 오래 소모되고, 모든 작업을 수작업으로 진행, 종이로 데이터를 관리, 수작업이므로 인력낭비 발생한다. 따라서 본 논문에서는 이러한 아날로그 방식에서 나오는 문제점들을 누구나 사용하고 있는 스마트 디바이스를 이용해 디지털방식으로 전환하여 기존의 비효율적이던 방식을 개선시키고자 평가시스템을 개발하고자 한다.