• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.617-620
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• 2007

최근 건강에 대한 관심이 높아지면서 의료 분야를 지원하는 애플리케이션 개발이 활발히 이루어지고 있다. 심장의 상태를 곡선으로 나타내는 ECG 를 기반으로 심장병의 유무를 발견하는 애플리케이션은 의료 분야 애플리케이션의 좋은 예라고 할 수 있다. ECG 만으로 질환을 판단하는 것은 제약이 있어, 이를 극복하기 위해 MCG 혹은 가상심장과 같은 다른 자원을 활용하는 것은 좋은 방법이다. 이와 같은 통합 시스템을 지원하려면 각 도메인에 대한 지식이 정의되어야 한다. 이에 본 연구에서는 ECG 와 심장계 질환에 대한 지식을 온톨로지를 이용하여 구축하고 ECG 를 통해 질환을 발견할 수 있는 추론 시스템을 제안하고 프로토타입 시스템을 개발한다.

• Korean Journal of Radiology
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• v.24 no.4
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• pp.284-293
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• 2023

Objective: To validate a simplified ordinal scoring method, referred to as modified length-based grading, for assessing coronary artery calcium (CAC) severity on non-electrocardiogram (ECG)-gated chest computed tomography (CT). Materials and Methods: This retrospective study enrolled 120 patients (mean age ± standard deviation [SD], 63.1 ± 14.5 years; male, 64) who underwent both non-ECG-gated chest CT and ECG-gated cardiac CT between January 2011 and December 2021. Six radiologists independently assessed CAC severity on chest CT using two scoring methods (visual assessment and modified length-based grading) and categorized the results as none, mild, moderate, or severe. The CAC category on cardiac CT assessed using the Agatston score was used as the reference standard. Agreement among the six observers for CAC category classification was assessed using Fleiss kappa statistics. Agreement between CAC categories on chest CT obtained using either method and the Agatston score categories on cardiac CT was assessed using Cohen's kappa. The time taken to evaluate CAC grading was compared between the observers and two grading methods. Results: For differentiation of the four CAC categories, interobserver agreement was moderate for visual assessment (Fleiss kappa, 0.553 [95% confidence interval {CI}: 0.496-0.610]) and good for modified length-based grading (Fleiss kappa, 0.695 [95% CI: 0.636-0.754]). The modified length-based grading demonstrated better agreement with the reference standard categorization with cardiac CT than visual assessment (Cohen's kappa, 0.565 [95% CI: 0.511-0.619 for visual assessment vs. 0.695 [95% CI: 0.638-0.752] for modified length-based grading). The overall time for evaluating CAC grading was slightly shorter in visual assessment (mean ± SD, 41.8 ± 38.9 s) than in modified length-based grading (43.5 ± 33.2 s) (P < 0.001). Conclusion: The modified length-based grading worked well for evaluating CAC on non-ECG-gated chest CT with better interobserver agreement and agreement with cardiac CT than visual assessment.

• Science of Emotion and Sensibility
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• v.11 no.3
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• pp.419-426
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• 2008

In order to develop "textile electrode - sensing clothing" which is a sort of smart clothing to measure electric activities of heart, we propose possible ways to develop textile electrode and design of sensing clothing, ultimately aiming to develop "ECG sensing clothing for lifestyle monitoring". Conventional sensors for measuring typical electric activities of heart keep certain distance between measuring electrodes to measure signals for electric activities of heart, but these sensors often cause inappropriate factors (e.g. motional artifacts, inconvenience of use, etc) for monitoring natural cardiac activities in our daily life. In addition, most of textile electrodes have made it difficult to collect data due to high impedance and unstable contact between skin and electrodes. To overcome these questions, we minimized distance between electrodes and skin to maximize convenience of use. And in order to complement contact between skin electrodes, we modified textile electrode's form and developed ways to design clothing. As a result, we could find out clinical significance by investigating possible associations of clinical electrocardiogram (ECG) with variation of distance between electrodes, and could also demonstrate clinically significant associations between textile electrode developed herein and clothing.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.11
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• pp.495-501
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• 2006

Diagnostics of unborn baby is mainly aimed at prediction and detection of occurrence of intrauterine hypoxia. Consequences resulting from fetal hypoxia appear in its heart activity. In this study, we have developed a new non-invasive system for fetal hypoxia diagnosis which provides systolic time interval(STI) parameters on the basis of analysis of electrical and mechanical heart activity together. For this we have worked on 1) the proper lead system for the acquisition of abdominal ECG, 2) the independent component analysis based signal processing and fetal ECG separation, 3) the development of a hardware which consists of an abdominal ECG amplifying module and an ultrasound module and 4) the detection of characteristic points of FECG and Doppler signal and the extraction of diagnostic parameters. The developed system was evaluated by the clinical experiments in which 33 subjects were participated. The acquired STI by the system were distributed within the ranges from the well-established invasive results of other researchers. From this, we can conclude that the developed non-invasive fetal hypoxia diagnosis system is useful.

• The Korean Journal of Emergency Medical Services
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• v.25 no.1
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• pp.235-241
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• 2021

Cardiogenic syncope occurs due to arrhythmia (bradycardia and tachycardia) or decreased cardiac output, and if proper treatment is not provided, it can lead to acute sudden death. A detailed medical history and physical examinations are required to determine the cause of syncope, and clinical approaches, including 12-lead ECG, are important. The 12-lead ECG does not have a chest lead in the posterior wall of the left ventricle; therefore, ECG of the isolated posterior wall myocardial infarction caused by left circumflex artery occlusion is not observed with ST elevation. Therefore, the significantly higher appearance of ST depression and R waves than S waves from V1 to V3 of the chest lead must be interpreted meaningfully. Isolated posterior wall myocardial infarction is small in the area of myocardial necrosis, and tension is increased in the necrotic area due to the contraction of the normal myocardial muscle, which can cause ventricular wall rupture. Therefore, it is necessary to additionally check Beck's triad, such as jugular venous distension and decreased heart sound, in patients with low blood pressure with an isolated posterior wall myocardial infarction on 12-lead ECG in patients with syncope.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.135-140
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• 2006

Magnetocardiography (MCG) is the measurement and analysis of the magnetic component of the electro-magnetic field of the human heart, usually conducted externally, using extremely sensitive devices such as a Superconducting Quantum Interference Device (SQUID). MCG is a totally noninvasive method, it uses neither radiation nor ultrasonics. The magnetic activity of the heart is registered from outside the thorax. MCG has a very high sensitivity and a high spatial resolution for very a small, local myocardial current. In comparison to the electrical signals measured by an ECG, the magnetic signal does not disturb the boundaries of tissues with different electrical properties. MCG measures the myocardial function rather than describing the morphology. MCG is a relatively new technique that promises good spatial resolution and extremely high temporal resolution, thus complementing other heart activity measurement techniques such as Electrocardiography (ECG). The clinical uses of MCG are in detecting various cardiac disorders including myocardial infarction, ventricular hypertrophy, ventricular conduction defects, Wolff-Parkinson-White (WPW) syndrome, sudden cardiac death and fetal magnetocardiography. Magnetocardiography may be used alone or together with electrcardiography for the measurement of spontaneous or overloaded activity and for research or clinical purposes.

• Clinical and Experimental Pediatrics
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• v.53 no.5
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• pp.644-647
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• 2010

Purpose: To evaluate myocardial conductivity to understand cardiac involvement in patients with mitochondrial disease. Methods: We performed retrospective study on fifty-seven nonspecific mitochondrial encephalopathy patients with no clinical cardiac manifestations. The patients were diagnosed with mitochondrial respiratory chain complex defects through biochemical enzyme assays of muscle tissue. We performed standard 12-lead electrocardiography (ECG) on all patients. Results: ECG abnormalities were observed in 30 patients (52.6%). Prolongation of the QTc interval (>440 ms) was seen in 19 patients (33.3%), widening of the corrected QRS interval in 15 (26.3%), and bundle branch block in four (7.0%). Atrioventricular block, premature atrial contraction and premature ventricular contraction were seen in two patients each (3.5%) and Wolff-Parkinson-White syndrome in one patient (1.8%). Conclusion: Given this finding, we recommend active screening with ECG in patients with mitochondrial disease even in patients without obvious cardiac manifestation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.467-472
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• 2005

ECG signals are recorded for diagnostic purposes in many clinical situations. Also, In order to permit good clinical interpretation, data is needed at high resolutions and sampling rates. Therefore In this paper, we designed to compression structure using multiple wavelet basis function(SWBF) and compared to single wavelet basis function(SWBF) and discrete cosine transform(DCT). For experience objectivity, Simulation was performed using the arrhythmia data with sampling frequency 360Hz, resolution lIbit at MIT-BIH database. An estimate of performance estimate evaluate the reconstruction error. Consequently compression structure using MWBF has high performance result.

• Parasites, Hosts and Diseases
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• v.46 no.4
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• pp.223-227
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• 2008

Changes in selected blood and serum components and electrocardiography (ECG) were investigated in 20 adults (13 females and 7 males) of water buffaloes suffering from severe theileriosis. The age of all animals used in this study ranged 1.5-5yr. Theileriosis was diagnosed by observation of parasites in the peripheral blood and the presence of schizonts in lymphocytes that were provided from swollen lymph nodes. Statistically significant decreases were observed in the means of RBC, WBC, and packed cell volume (PCV) in blood of infected animals. The means levels of sodium, calcium, phosphorus, and potassium of infected animals were lower than healthy animals, but only the decrease of potassium was significant. The mean serum activities of aspartate transferase and alanine aminotransfrase were significantly higher than in un infected animals. Three cases had atrial premature beat, 2 cases had sinus tachycardia, 2 had sinus arrhythmia, and 1 had first degree of atrioventricular block in ECG. The present study showed that T. annulata infection in cattle is associated with hematological and biochemical, and ECG changes.

• The Journal of the Korean life insurance medical association
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• v.32 no.1
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• pp.15-20
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• 2013

The exercise ECG test is a well-established, inexpensive, and non-invasive procedure for answering important clinical questions related to heart problems. The heart disease is directly led to mortality and serious issue to insurance medicine. Here is some evidence for interpretation of exercise ECG test results can determine prognosis of the heart disease.