• Title, Summary, Keyword: Brain mapping

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Neuronal Spike Train Decoding Methods for the Brain-Machine Interface Using Nonlinear Mapping (비선형매핑 기반 뇌-기계 인터페이스를 위한 신경신호 spike train 디코딩 방법)

  • Kim, Kyunn-Hwan;Kim, Sung-Shin;Kim, Sung-June
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.7
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    • pp.468-474
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    • 2005
  • Brain-machine interface (BMI) based on neuronal spike trains is regarded as one of the most promising means to restore basic body functions of severely paralyzed patients. The spike train decoding algorithm, which extracts underlying information of neuronal signals, is essential for the BMI. Previous studies report that a linear filter is effective for this purpose and there is no noteworthy gain from the use of nonlinear mapping algorithms, in spite of the fact that neuronal encoding process is obviously nonlinear. We designed several decoding algorithms based on the linear filter, and two nonlinear mapping algorithms using multilayer perceptron (MLP) and support vector machine regression (SVR), and show that the nonlinear algorithms are superior in general. The MLP often showed unsatisfactory performance especially when it is carelessly trained. The nonlinear SVR showed the highest performance. This may be due to the superiority of the SVR in training and generalization. The advantage of using nonlinear algorithms were more profound for the cases when there are false-positive/negative errors in spike trains.

Advances in Functional Connectomics in Neuroscience : A Focus on Post-Traumatic Stress Disorder (뇌과학 분야 기능적 연결체학의 발전 : 외상후스트레스장애를 중심으로)

  • Park, Shinwon;Jeong, Hyeonseok S.;Lyoo, In Kyoon
    • Korean Journal of Biological Psychiatry
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    • v.22 no.3
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    • pp.101-108
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    • 2015
  • Recent breakthroughs in functional neuroimaging techniques have launched the quest of mapping the connections of the human brain, otherwise known as the human connectome. Imaging connectomics is an umbrella term that refers to the neuroimaging techniques used to generate these maps, which recently has enabled comprehensive brain mapping of network connectivity combined with graph theoretic methods. In this review, we present an overview of the key concepts in functional connectomics. Furthermore, we discuss articles that applied task-based and/or resting-state functional magnetic resonance imaging to examine network deficits in post-traumatic stress disorder (PTSD). These studies have provided important insights regarding the etiology of PTSD, as well as the overall organization of the brain network. Advances in functional connectomics are expected to provide insight into the pathophysiology and the development of biomarkers for diagnosis and treatment of PTSD.

Reduced Regional Cerebral Blood Flow in Patients with Traumatic Brain Injury Who Had No Structural Abnormalities on Magnetic Resonance Imaging : A Quantitative Evaluation of Tc-99m-ECD SPECT Findings (정상 MRI 소견을 보이는 외상성 뇌손상 환자에서 국소뇌혈류량의 이상)

  • Kim, Nam-Hee;Chung, Young-Ki
    • Korean Journal of Biological Psychiatry
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    • v.9 no.2
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    • pp.152-158
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    • 2002
  • Background & Purpose:Neuropsychological disorders after traumatic brain injury(TBI) are poorly correlated with structural lesions detected by structural neuroimaging techniques such as computed tomography(CT) scan or magnetic resonance imaging(MRI). It is well known that patients with TBI have cognitive and behavioral disorders even in the absence of structural lesions of the brain. This study investigated whether there are abnormalities of regional cerebral blood flow(rCBF) in TBI patients without structural abnormality on MRI, using technetium 99m ethyl cysteinate dimer(Tc-99m-ECD) single photon emission computed tomography(SPECT) scans. Materials and Methods:Twenty-eight TBI patients without structural abnormality on MRI(mild, n=13/moderate, n=9/severe, n=6) and fifteen normal controls were scanned by SPECT. A voxel-based analysis using statistical parametric mapping(SPM) was performed to compare the patients with the normal controls. Results:rCBF was reduced in the right uncus and the right lateral orbitofrontal gyrus in the TBI patients. However, no increase of rCBF was noted in the patients in comparison to the normal controls. Conclusions:These results suggest that the TBI patients, even in the absence of structural lesion of the brain, may have dysfunction of the brain, particularly of the orbitofrontal and anterior pole of the temporal cortex. They also suggest that SPECT can be a useful method to identify brain dysfunctions in combination with structural brain imaging and neuropsychological tests.

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Usefulness of applying Macro for Brain SPECT Processing (Brain SPECT Processing에 있어서 Macro Program 사용의 유용성)

  • Kim, Gye-Hwan;Lee, Hong-Jae;Kim, Jin-Eui;Kim, Hyeon-Joo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.1
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    • pp.35-39
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    • 2009
  • Purpose: Diagnostic and functional imaging softwares in Nuclear Medicine have been developed significantly. But, there are some limitations which like take a lot of time. In this article, we introduced that the basic concept of macro to help understanding macro and its application to Brain SPECT processing. We adopted macro software to SPM processing and PACS verify processing of Brain SPECT processing. Materials and Methods: In Brain SPECT, we choose SPM processing and two PACS works which have large portion of a work. SPM is the software package to analyze neuroimaging data. And purpose of SPM is quantitative analysis between groups. Results are made by complicated process such as realignment, normalization, smoothing and mapping. We made this process to be more simple by using macro program. After sending image to PACS, we directly input coordinates of mouse using simple macro program for processes of color mapping, adjustment of gray scale, copy, cut and match. So we compared time for making result by hand with making result by macro program. Finally, we got results by applying times to number of studies in 2007. Results: In 2007, the number of SPM studies were 115 and the number of PACS studies were 834 according to Diamox study. It was taken 10 to 15 minutes for SPM work by hand according to expertness and 5 minutes and a half was uniformly needed using Macro. After applying needed time to the number of studies, we calculated an average time per a year. When using SPM work by hand according to expertness, 1150 to 1725 minutes (19 to 29 hours) were needed and 632 seconds (11 hours) were needed for using Macro. When using PACS work by hand, 2 to 3 minutes were needed and for using Macro, 45 seconds were needed. After applying theses time to the number of studies, when working by hand, 1668 to 2502 minutes (28 to 42 hours) were needed and for using Macro, 625 minutes (10 hours) were needed. Following by these results, it was shown that 1043 to 1877 (17 to 31 hours were saved. Therefore, we could save 45 to 63% for SPM, 62 to 75% for PACS work and 55 to 70% for total brain SPECT processing in 2007. Conclusions: On the basis of the number of studies, there was significant time saved when we applied Macro to brain SPECT processing and also it was shown that even though work is taken a little time, there is a possibility to save lots of time according to the number of studies. It gives time on technologist's side which makes radiological technologist more concentrate for patients and reduce probability of mistake. Appling Macro to brain SPECT processing helps for both of radiological technologists and patients and contribute to improve quality of hospital service.

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The acupuncture mechanism related brain in Medline and the journal of Korean acupuncture & moxibustion (PubMed와 대한침구학회지(大韓針灸學會誌) 논문(論文) 검색(檢索)을 통(通)한 침요법(鍼療法)과 뇌(腦)와의 관계(關係)에 대한 연구동향(硏究動向) 고찰(考察))

  • Kim, Hoo-Dong;Koh, Hyung-Kyun;Kim, Chang-Hwan
    • Journal of Acupuncture Research
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    • v.18 no.4
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    • pp.188-200
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    • 2001
  • Background and Objetive : Acupuncture is a valuable method of oriental medicine with broad application in many disease. It is based on the experiences of traditional oriental medicine as well as on experimentally proven biological (biochemical and neurophysiological) effects. Acupuncture theory has been explained by the meridian system that is thought to be linked with particular organs. However, in western medicine it is held that many disorders are either controlled or affected by the brain. Material and Method : In order to review the studies concerned with the mechanism related brain, we have referred to the Pubmed site and the Journal of Korean acupuncture and moxibustion Result and Conculsion : Among the 12 studies in the Journal of Korean acupuncture and moxibustion, 8 papers related neurotransmitters were done by experimental study, 4 papers related brain mapping were done by clinical study. Among the 8 studies related brain mapping in the Pubmed site, 6 clinical studies using functional magnetic resonance imaging(fMRI) were done and I clinical study using single-photon emission computed tomography(SPECT) was done, I paper was review article. By the above result, it would be needed further research on the acupuncture mechanism related brain using SPECT, fMRI, positron emission tomography(PET) etc.

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3-D Manipulation of Brain Atlas

  • Paik, Chul-Hwa;Kim, Won-Ky
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.233-234
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    • 1995
  • Tri-planar interpolation of the orthogonal digital brain Atlas is proposed to achieve a higher resolution of a volume-metric atlas. With these expanded dataset, the brain mapping will be accomplished with fewer registration errors.

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비선형 상관차원 분석을 통한 EEG 뇌파신호 특성 추출

  • Kang, Kun;Lee, Hyoung
    • Journal of Information Technology Applications and Management
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    • v.9 no.4
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    • pp.165-177
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    • 2002
  • For measuring EEG with the international 10-20 electrode system on 16 channels, and to analyze the interrelationship between the original signals and the changed signals after the stimulation, we use the scent of lavender which stimulates the olfactory sense. Moreover, the effect of the scent stimulation to the brain is analyzed. The purpose of this analysis is to apply these results to the computerized mapping of the brain signals and to find possible ways of specifying the source of the brain signals through various medical applications.

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Nano-Resolution Connectomics Using Large-Volume Electron Microscopy

  • Kim, Gyu Hyun;Gim, Ja Won;Lee, Kea Joo
    • Applied Microscopy
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    • v.46 no.4
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    • pp.171-175
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    • 2016
  • A distinctive neuronal network in the brain is believed to make us unique individuals. Electron microscopy is a valuable tool for examining ultrastructural characteristics of neurons, synapses, and subcellular organelles. A recent technological breakthrough in volume electron microscopy allows large-scale circuit reconstruction of the nervous system with unprecedented detail. Serial-section electron microscopy-previously the domain of specialists-became automated with the advent of innovative systems such as the focused ion beam and serial block-face scanning electron microscopes and the automated tape-collecting ultramicrotome. Further advances in microscopic design and instrumentation are also available, which allow the reconstruction of unprecedentedly large volumes of brain tissue at high speed. The recent introduction of correlative light and electron microscopy will help to identify specific neural circuits associated with behavioral characteristics and revolutionize our understanding of how the brain works.

Brain MRI Template-Driven Medical Images Mapping Method Based on Semantic Features for Ischemic Stroke (허혈성 뇌졸중을 위한 뇌 자기공명영상의 의미적 특징 기반 템플릿 중심 의료 영상 매핑 기법)

  • Park, Ye-Seul;Lee, Meeyeon;Lee, Jung-Won
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.2
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    • pp.69-78
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    • 2016
  • Ischemic stroke is a disease that the brain tissues cannot function by reducing blood flow due to thrombosis or embolisms. Due to the nature of the disease, it is most important to identify the status of cerebral vessel and the medical images are necessarily used for its diagnosis. Among many indicators, brain MRI is most widely utilized because experts can effectively obtain the semantic information such as cerebral anatomy aiding the diagnosis with it. However, in case of emergency diseases like ischemic stroke, even though a intelligent system is required for supporting the prompt diagnosis and treatment, the current systems have some difficulties to provide the information of medical images intuitively. In other words, as the current systems have managed the medical images based on the basic meta-data such as image name, ID and so on, they cannot consider semantic information inherent in medical images. Therefore, in this paper, to provide core information like cerebral anatomy contained in brain MRI, we suggest a template-driven medical images mapping method. The key idea of the method is defining the mapping characteristics between anatomic feature and representative images by using template images that can be representative of the whole brain MRI image set and revealing the semantic relations that only medical experts can check between images. With our method, it will be possible to manage the medical images based on semantic.