• Title/Summary/Keyword: Neurophysiological

Search Result 153, Processing Time 0.031 seconds

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

  • Chang, D.B.;Kim, G.H.;Cho, W.R.;Lee, G.K.;Kang, I.T.;Ko, H.W.
    • Proceedings of the KIEE Conference
    • /
    • 1995.07b
    • /
    • pp.950-952
    • /
    • 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.

  • PDF

Mirror Neuron System and Stroke Rehabilitation (미러뉴런시스템과 뇌졸중 재활)

  • Kim, Sik-Hyun
    • PNF and Movement
    • /
    • v.7 no.4
    • /
    • pp.45-53
    • /
    • 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.

  • PDF

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

  • Kang, Chul-Hoo;Oh, Jung Hwan;Song, Sook Keun;Kang, Sa-Yoon
    • Annals of Clinical Neurophysiology
    • /
    • v.17 no.2
    • /
    • pp.73-75
    • /
    • 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
    • /
    • v.17 no.4
    • /
    • pp.241-251
    • /
    • 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
    • Proceedings of the PSK Conference
    • /
    • 2003.10b
    • /
    • pp.179.3-179.3
    • /
    • 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).

  • PDF

Electric Therapy System Based on Discontinuous Conduction Mode Boost Circuit

  • Chen, Wenhui;Lee, Hyesoo;Jung, Heokyung
    • Journal of information and communication convergence engineering
    • /
    • v.18 no.4
    • /
    • pp.245-253
    • /
    • 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
    • /
    • v.21 no.2
    • /
    • pp.173-178
    • /
    • 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
    • /
    • v.66 no.2
    • /
    • pp.211-218
    • /
    • 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.

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

  • Cheun, Jae-Kyu;Kim, Sae-Yune;Bae, Jung-In
    • The Korean Journal of Pain
    • /
    • v.5 no.2
    • /
    • pp.213-220
    • /
    • 1992
  • The sciatic nerves of anesthetized rabbits were exposed and stimulated by a nerve stimulator in order to observe the myoneural response. These rabbits were divided into three groups and respectively injected with morphine (Group 1), meperidine(Group 2) and pentazocine (Group 3). The sciatic nerves were stimulated periodically and gait changes were observed to see the myoneural activity after the injections. When the distal part of the sciatic nerves were stimulated by the nerve stimulator after the respective drug injections, the normal muscle twitch responses were observed in all the progressional stages of Group 1. However, in Group 2 and 3, the muscle twitch responses decreased gradually, finally disappearing after approximately 10 minutes in these two groups. Complete motor paralysis continued for about 60 minutes. The muscle reactions returned to normal approximately 90 minutes after injection. Specimens drug-injected tissues were severed 4 hours, 24 hours and 1 week after injection respectively. These tissue were investigated under light as well as electron microscopy. The tissue revealed rare to moderate vacuolizations scattered in the axons of the myelinated and unmyelinated nerves of some of the specimens; however, there were no significant pathologic lesions. These results provide evidence that neurophysiologically, meperidine and pentazocine have a local anesthetic-like effect such as motor paralysis, but morphine does not. In addition, the results indicated that neurohistologically, the three narcotics have no significant toxic effects on the nerve tissue.

  • PDF

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
    • /
    • v.61 no.3
    • /
    • pp.363-375
    • /
    • 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.