• Annals of Clinical Neurophysiology
• /
• 제10권1호
• /
• pp.1-12
• /
• 2008

Intraoperative neuromonitoring (INM) is well known to be useful method to reduce intraoperative complications during the surgery of nervous system lesions. Evoked potentials are most commonly used among the electrophysiological tests. Brainstem auditory evoked potentials are for detecting the problems along the auditory pathways including the eighth cranial nerve and brainstem. Somatosensory evoked potentials are applied for preventing the spinal cord lesions. The INM is affected by many factors. In order to perform an optimal INM, the confounding factors including technical, anesthetical, and individual factors should be kept well under control. INM has frequent electrophysiologic changes during the surgery and it might be helpful to keep one's eyes on which monitoring modalities are reluctant to change during each operation. The skillful monitoring and timely interpretation of electrophysiologic changes can drive the patient to be undergone surgery, even in high surgical risk group.

• 대한의용생체공학회:의공학회지
• /
• 제36권5호
• /
• pp.198-203
• /
• 2015

The purpose of the study is to examine the effects of pacemaker location on cardiac pumping efficacy theoretically. We used a three-dimensional finite element cardiac electromechanical model of canine ventricles with models of the circulatory system. Electrical activation time for normal sinus rhythm and artificial pacing in apex, left ventricular free wall, and right ventricular free wall were obtained from electrophysiological model. We applied the electrical activation time maps to the mechanical contraction model and obtained cardiac mechanical responses such as myocardial contractile ATP consumption, stroke work, stroke volume, ejection fraction, and etc. Among three artificial pacing methods, left ventricle pacing showed best performance in ventricular pumping efficacy.

• Journal of Korean Neurosurgical Society
• /
• 제48권3호
• /
• pp.298-300
• /
• 2010

Authors describe a patient who developed a myelopathy associated with Guillain-Barr$\'{e}$ syndrome and cervical myelopathy. We provide radiological evidence of non-compressive herniated cervical intervertebral disc with cord signal changes and show the clinical and electrophysiological result of coexisting Guillain-Barr$\'{e}$ syndrome and cervical myelopathy. We tried to introduce and review the case of Guillain-Barr$\'{e}$ syndrome which was combined with cervical myelopathy to let us recollect the presumptive cause.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2007년도 춘계학술발표대회
• /
• pp.558-559
• /
• 2007

The detection of neural spike activity is a technical challenge that is very important for studying many types of brain function. On temporal recordings of firing events or interspike interval series of neural signal, spike pattern correspond to action will be repeated in the presence of background noise and they need to be detected to develop higher applications. We will introduce new method to find these patterns in raw multitrial data and is tested on surrogate data sets with the main target to get meaningful analysis of electrophysiological data from microelectrode arrays (MEA).

• Journal of Chest Surgery
• /
• 제48권6호
• /
• pp.429-431
• /
• 2015

Congenital pericardial defects (CPDs) are infrequent anomalies that are usually asymptomatic and are discovered incidentally during unrelated interventions. Here we report the case of a CPD with herniation of an enlarged left atrial appendage identified during total thoracoscopic ablation (TTA) for persistent atrial fibrillation (AF). The persistent AF was successfully treated with a hybrid procedure, in which TTA was followed by an electrophysiological study.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
• /
• pp.549-552
• /
• 2003

The electrical current generated by heart creates not only electric potential but also a magnetic field. We have observed electrophysiological phenomena of the heart by measuring tangential components of magnetocardiogram(MCG) using 61 channel superconducting quantum interference device(SQUD) system. In this paper, we developed a new analysis method, which is based on the theory of electromagnetic field. We show some differences of the current direction between the normal MCG and the abnormal(ischemic heart disease) MCG.

• 수면정신생리
• /
• 제2권1호
• /
• pp.91-96
• /
• 1995

A 24-year-old woman complained of recurrent episodes of hypersomnia lasting on the average about 15 days with mild mood alternation such as depression and irritability. During interepisode interval, she was free of any symptoms. Depending on the absence of excessive eating and hypersexuality, she was clinically diagnosed as recurrent monosymptomatic hypersomnia or the incomplete form of Kleine-Levin syndrome. When nocturnal polysomnography and multiple sleep latency test were performed 10 days after her recovery from a hypersomnic episode, reduced slow wave sleep % and pathologic daytime sleepiness were still noted. The authors suggest that the clinical recovery in recurrent monosymptomatic hypersomnia precede electrophysiological normalization by several days.

• Annals of Clinical Neurophysiology
• /
• 제7권1호
• /
• pp.55-57
• /
• 2005

Two different unusual cases of acute sciatic neuropathy are described. They appeared to have been caused by complications from a procedure performed on a patient in the lithotomy position, and an uncertain etiology associated with either a previous femur fracture or a recent blunt trauma to the buttock. Comprehensive histories of weakness, with radiographic or electrophysiological studies, or even exploratory surgery are important in order to understand the etiologies of the sciatic neuropathies.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1665-1668
• /
• 2008

Arrhythmia causes sudden cardiac death. In the past, there were medical limitations in finding the cause of arrhythmia. As an alternative solution for research of arrhythmia, there have been studies to find the causes of arrhythmia by producing a virtual heart model. Medically, arrhythmia has two main causes: abnormal occurrence of action potential and abnormal conduction of action potential. Based on these, the tachycardia, which is one of the arrhythmia, was manifested and the phenomenon of ventricular fibrillation was numerically analyzed in this study. For this purpose, an electrophysiological model of ventricular cells was implemented, which was subsequently applied to the reaction-diffusion partial differential equation to interpret the macroscopic conduction phenomenon in two-dimensional tissues. The ventricular fibrillation refers to a condition where several irregular waves occur in cardiac tissue, whose generation mechanism is pathologically related to the cardiac tissue.

• Clinical and Experimental Pediatrics
• /
• 제57권1호
• /
• pp.1-18
• /
• 2014

Channelopathies are a heterogeneous group of disorders resulting from the dysfunction of ion channels located in the membranes of all cells and many cellular organelles. These include diseases of the nervous system (e.g., generalized epilepsy with febrile seizures plus, familial hemiplegic migraine, episodic ataxia, and hyperkalemic and hypokalemic periodic paralysis), the cardiovascular system (e.g., long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia), the respiratory system (e.g., cystic fibrosis), the endocrine system (e.g., neonatal diabetes mellitus, familial hyperinsulinemic hypoglycemia, thyrotoxic hypokalemic periodic paralysis, and familial hyperaldosteronism), the urinary system (e.g., Bartter syndrome, nephrogenic diabetes insipidus, autosomal-dominant polycystic kidney disease, and hypomagnesemia with secondary hypocalcemia), and the immune system (e.g., myasthenia gravis, neuromyelitis optica, Isaac syndrome, and anti-NMDA [N-methyl-D-aspartate] receptor encephalitis). The field of channelopathies is expanding rapidly, as is the utility of molecular-genetic and electrophysiological studies. This review provides a brief overview and update of channelopathies, with a focus on recent advances in the pathophysiological mechanisms that may help clinicians better understand, diagnose, and develop treatments for these diseases.