• 제목/요약/키워드: Neurophysiological

검색결과 151건 처리시간 0.024초

잡음이 혼입된 패턴인식을 위한 신경망의 설계 (Design of a Neural Network for Recognizing Noised Patterns)

  • 장두봉;김경하;조원래;이건기;강익태;고한우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 B
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    • pp.950-952
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    • 1995
  • In this paper, a novel method which can recognize noised patterns by using a neural network is proposed. Patern recognition is processed by two networks and the processing mechanism is partially based on the results of neurophysiological studies. Synaptic activitoes of combining neurons between layers are implemented by spatial filters which approximate receptive fields of the modelled optic nerve cells.

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미러뉴런시스템과 뇌졸중 재활 (Mirror Neuron System and Stroke Rehabilitation)

  • 김식현
    • PNF and Movement
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    • 제7권4호
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    • pp.45-53
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    • 2009
  • Purpose : The purpose of this article was to review the literature on mirror neuron system with reference to its functional diversity in stroke rehabilitation.. Method : This review outlines scientific findings regarding different neurophysiological properties in mirror neurons, and discusses their involvement in process of stroke rehabilitation. Result & Conclusions : Mirror neurons were first discovered in macaque monkey. These neurons, like most neurons in F5 areas in premotor cortex, fired when an individual performs an action, as well as when he/she observes a similar action done by another individual, although originally fired only during action execution. Mirror neurons form a network for motor planning and initiating of motor action. Thus, in stroke rehabilitation based on the mirror neuron-action observation, motor imagery, observation with intent to imitate and imitation-may help activate mirror neuron system for improved outcome of physical therapy. These studies provide a scientific theoretical basis and discuss for the use of mirror neuron system as a complement to clinical physical therapy in stroke rehabilitation.

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길랑-바레 증후군에서 발생한 Takotsubo 심근병 (Takotsubo Cardiomyopathy Associated with Guillain-Barré Syndrome)

  • 강철후;오정환;송숙근;강사윤
    • Annals of Clinical Neurophysiology
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    • 제17권2호
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    • pp.73-75
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    • 2015
  • A 69-year-old woman presented with a progressive limb weakness. Both clinical and neurophysiological findings were consistent with diagnosis of Guillain-$Barr{\acute{e}}$ syndrome (GBS). Two days after admission, the patient suffered from an acute coronary syndrome without stenosis at coronary arteriography. Echocardiography revealed left ventricular inferior wall and apical akinesia and decreased ejection fraction. A diagnosis of Takotsubo cardiomyopathy was then made. Left ventricular dysfunction and electrocardiography normalized within one month. Takotsubo cardiomyopathy can be developed as a complication of GBS.

Characteristics of electroencephalogram signatures in sedated patients induced by various anesthetic agents

  • Choi, Byung-Moon
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제17권4호
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    • pp.241-251
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    • 2017
  • Devices that monitor the depth of hypnosis based on the electroencephalogram (EEG) have long been commercialized, and clinicians use these to titrate the dosage of hypnotic agents. However, these have not yet been accepted as standard monitoring devices for anesthesiology. The primary reason is that the use of these monitoring devices does not completely prevent awareness during surgery, and the development of these devices has not taken into account the neurophysiological mechanisms of hypnotic agents, thus making it possible to show different levels of unconsciousness in the same brain status. An alternative is to monitor EEGs that are not signal processed with numerical values presented by these monitoring devices. Several studies have reported that power spectral analysis alone can distinguish the effects of different hypnotic agents on consciousness changes. This paper introduces the basic concept of power spectral analysis and introduces the EEG characteristics of various hypnotic agents that are used in sedation.

Studies Toward the Total Synthesis of Perhydrohistrionicotoxin

  • Ko, Hyo-Jin;Lee, Tae-Ho;Kim, Shin-Ae;Kim, Sang-Hee
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.179.3-179.3
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    • 2003
  • Natural histrionicotoxin, a substance isolated from the skins of the "arrow poison frog" and its fully hydrogenated derivative, perhydrohistrionicotoxin (pHTX), have been the subject of synthetic investigation because of their important neurophysiological activity and a unique framework. In this work, we could obtained the appropriately functionalized spiropiperidine compound as a formal precursor of perhydrohistrionicotoxin. An important feature of this synthesis is the creation of a stereogenic center by using Ireland-Claisen Rearrangement, and Ring-Closing Metathesis (RCM).sis (RCM).

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Electric Therapy System Based on Discontinuous Conduction Mode Boost Circuit

  • Chen, Wenhui;Lee, Hyesoo;Jung, Heokyung
    • Journal of information and communication convergence engineering
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    • 제18권4호
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    • pp.245-253
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    • 2020
  • The human body and nervous system transmit information through electric charges. After the electric charge transmits information to the brain, we can feel pain, numbness, comfort, and other feelings. Electric therapy is currently used widely in clinical practice because the field of examination is more representative of electrocardiogram, and in the field of treatment is more representative of electrotherapy. In this study, we design a system for neurophysiological therapy and conduct parameter calculation and model selection for the components of the system. The system is based on a discontinuous conduction mode (DCM) boost circuit, and controlled and regulated by a single-chip microcomputer. The system does not only have a low cost but also fully considers the safety of use, convenience of the human-computer interface, adjustment sensitivity, and waveform diversity in the design. In future, it will have strong implications in the field of electrotherapy.

Tooth hypersensitivity associated with paresthesia after inferior alveolar nerve injury: case report and related neurophysiology

  • You, Tae Min
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제21권2호
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    • pp.173-178
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    • 2021
  • Inferior alveolar nerve (IAN) injury is usually caused by stretching or crushing of the neurovascular structures and postoperative intra-alveolar hematoma or edema after dental procedures. This results in paresthesia in the ipsilateral chin, lip (vermilion border, skin, and mucosa), and labial or buccal alveolar mucosa of the mandibular anterior teeth. However, there are no reports of sensory alterations in the teeth, especially tooth hypersensitivity, after IAN injury. I report a case in which paresthesia of the lower lip and hypersensitivity of the lower anterior teeth occurred simultaneously after the removal of the third molar that was located close to the IAN. In addition, I discuss the reasons for the different sensory changes between the tooth and chin (skin) after nerve injury from a neurophysiological point of view. Since the dental pulp and periodontal apparatus are highly innervated by the inferior alveolar sensory neurons, it seems necessary to pay attention to the changes in tooth sensitivity if IAN injury occurs during dental procedures.

Pediatric Nondysraphic Intramedullary Lipoma : Report of Two Cases and Review of the Literature

  • Jong Seok Lee;Young Mi Kim;Soo Ahn Chae;Seung-Ki Kim;Ji Hoon Phi
    • Journal of Korean Neurosurgical Society
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    • 제66권2호
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    • pp.211-218
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    • 2023
  • Pediatric nondysraphic intramedullary lipoma is very rare, and only limited cases have been reported. In the present case, we present two infant patients with these pathologies who were surgically treated. Previous literature on 20 patients with these diseases who had undergone surgical treatments was analyzed. Surgical treatment should be considered in most symptomatic patients, and laminoplastic laminotomy and internal debulking of the lipoma under intraoperative neurophysiological monitoring are mostly recommended.

가토의 좌골신경에 Morphine, Meperidine, Pentazocine을 주사한 후 미세형태학적 및 신경생리학적 변화 (Ultrastructural and Neurophysiological Changes Observed Following Injection of Morphine, Meperidine and Pentazocine in the Sciatic Nerves of Rabbits)

  • 전재규;김세연;배정인
    • The Korean Journal of Pain
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    • 제5권2호
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    • pp.213-220
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    • 1992
  • Morphine, meperidine 및 pentazocine을 가토의 좌골신경에 주입한 후 마약제의 신경차단 유무와 약제 주입 후 4시간, 24시간 및 1주에 좌골 신경을 절취하여 신경조직학적 변화를 관찰하였다. 좌골신경에 약제를 주입한 후 신경자극에 의한 반응과 뒷다리 운동을 관찰한 결과, morphine군은 신경차단 효과가 없었고 meperidine군과 pentazocine군은 약제주입 5분 후부터 근육이완이 시작되어 10분 후부터 근육수축이 나타나지 않았으며 뒷다리에 마비증상은 약제주입 60분 후부터 부분적으로 회복되기 시작하여 90분 후에는 정상으로 회복되는 양상의 신경차단 효과가 있었다. 광학 현미경적 소견으로는 모두 4시간부터 1주까지의 표본에 특기할만한 변화가 없었으며, 전자 현미경적 소견에서 morphine군은 1주 후 소견에서 유수신경섬유와 무수신경섬유에 경미한 수포양을 보였다. Meperidine군은 4시간 후 소견으로 유수신경섬유의 축삭돌기에 경미한 수포양이 있었고 무수신경의 마이엘린화되는 소견이 있었으며, 24시간 후 유수신경섬유에 경미한 수포양이 있었고 무수신경섬유가 정상으로 되었으며 1주 후 특기할 만한 변화가 없었다. Pentazocine군은 약제주입 4시간 후 유수신경섬유에 경미한 수포양을 보였으며 24시간 후 유수신경 섬유와 무수신경섬유에 중등도의 수포양이 나타났으며 1주 후 경미한 수포양을 나타내었다. 주입된 약제중 morphine이 가장 수포양이 적었으며 pentazocine이 심한 변화를 나타내었고, 전단계 쥐 실험에서 나타났던 meperidine주입 1주 후의 심한 신경조직 손상은 본 실험에서 나타나지 않았다.

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Intraoperative Neurophysiological Monitoring : A Review of Techniques Used for Brain Tumor Surgery in Children

  • Kim, Keewon;Cho, Charles;Bang, Moon-suk;Shin, Hyung-ik;Phi, Ji-Hoon;Kim, Seung-Ki
    • Journal of Korean Neurosurgical Society
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    • 제61권3호
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    • pp.363-375
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    • 2018
  • Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal age-adjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.