• 한국콘텐츠학회논문지
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• 제6권12호
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• pp.96-104
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• 2006

본 연구에서는, 심전도 송수신 장치의 개발을 위한 지그비(Zigbee) 기반 무선 센서 모듈과 PDA(Personal Digital Assistant)의 데이터 전송률과 전력 소비에 대하여 분석 하였다. 데이터 전송률은 패킷(Packet) 구조에 의존적이며, 패킷을 2개의 심전도 데이터와 1개의 3축 가속도 벡터로 구성하였을 때, 초당 300 샘플의 전송률을 나타내었다. 두 개의 AAA 전지를 직렬로 연결하여, 센서 모듈의 동작 시간은 평균적으로 28시간 이었다. PDA의 전력 소비는 화면의 ON/OFF 여부와 시리얼 포트의 사용 여부 및 패턴에 의존적임을 알 수 있었다. 이러한 응용에서, PDA 동작 시간은 평균적으로 5시간 정도임을 확인하였으며, 이때, PDA는 논 블로킹 모드로 시리얼 포트로부터 전송된 데이터를 수신 한다. 결론적으로, 본 연구에서 개발된 장치를 24 시간 홀터(Holter) 심전계로 응용할 경우, 센서 모듈의 전력 소비와 전송 속도에는 문제가 없었으나, PDA는 전력 소모율에 문제가 있으며 이는 해결되어야할 과제이다.

• 전자공학회논문지
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• 제49권10호
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• pp.202-208
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• 2012

태아심박의 모니터링은 태아의 안녕을 평가하기 위해 중요한 정보이다. 비관혈적인 태아심전도는 산모의 복부 신호로부터 추출될 수 있다. 따라서 산모 복부의 혼합 신호로부터 태아심전도를 추출하기 위해 많은 유망한 신호처리 방법들이 개발되어 왔다. 그러나 비관혈적인 태아심전도는 안정적인 신호 측정법이 부족하고 신호처리 방법의 어려움으로 여전히 임상에서 널리 적용되지 못하고 있다. 태아심전도를 추출하는 신호처리 결과는 가우시안 백색잡음에 의해 신호대잡음비가 낮아질 수 있다. 본 논문에서는 태아심전도에서 시간에 따라 변하는 백색잡음 신호를 제거하여 신호대잡음비를 높이기 위한 방법으로 시변 칼만 평활기를 제안하였고 그 가능성을 확인하였다. Wiener 과정을 시스템 모델로 설정하고 백색잡음 크기에 따라 공분산 행렬을 수정하였으며, 이를 통해 칼만 이득을 변화시켜 평활화 정도를 가변시킬 수 있도록 설계하였다. 5채널 태아심전도 모델을 이용하여 백색잡음의 크기에 따른 최적 공분산 행렬 값을 구하였고, 모의실험을 통해 제안된 방법의 가능성을 확인할 수 있었다.

• 한국한의학연구원논문집
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• 제14권1호
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• pp.85-89
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• 2008

This study is to investigate cardiotonic effect of acupuncture on heart rate variability(HRV) analyzed by a nonlinear way(DFA, Detrended Fluctuation Analysis). It was designed as a randomized, single-blind, waiting list-controlled, cross-over study. We assessed heart rate and R-R intervals in Circadian electrocardiography with a Holter monitoring device for twelve hospitalized participants. The compatible analytical program, Zymed, was used for generating the signals of R-R intervals from 24 hour-ECG. In DFA analysis, we produced DFA alpha 1, alpha 2 parameters according to the process of Cygwin module of Linux server. We tested if there was any difference between HRV parameters using SPSS, a statistical package. There was no difference between acupuncture and no treatment group in DFA alpha 2 parameter {95% Confidence Interval (-)0.058 - 0.037, P = .565}. Two group all showed large intra-individual variations. Consequently, acupuncture treatment did not modulate the complexity of HRV in a DFA analysis. This study can be a rationale for acupuncture's properties on cardiovascular and autonomic systems.

• Clinical and Experimental Pediatrics
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• 제56권7호
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• pp.308-311
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• 2013

In this report, we present a pediatric case of severe symptomatic hypermagnesemia resulting from the use of magnesium oxide as a laxative in a child undergoing continuous cyclic peritoneal dialysis for end-stage renal disease. The patient showed abnormal electrocardiography (ECG) findings, such as tall T waves, a widened QRS complex, and irregular conduction, which were initially misdiagnosed as hyperkalemia; later, the correct diagnosis of hypermagnesemia was obtained. Emergent hemodialysis successfully returned the serum magnesium concentration to normal without complications. When abnormal ECG changes are detected in patients with renal failure, hypermagnesemia should be considered.

• Neonatal Medicine
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• 제16권2호
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• pp.239-243
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• 2009

다소성 심방 빈맥은 신생아에서 드물게 발생하며 진단하기에 어려워 심방 조동으로 오인되기도 한다. 치료가 어려우나 생후 1년 안에 자연적으로 사라지는 경우도 있다. 불규칙한 심방 빈맥을 가진 신생아에게 직접 제작한 경식도 전극을 이용한 심전도를 시행하여 다소성 심방 빈맥을 진단하였다. Propranolol은 치료에 효과적이지 않았으나 digoxin과 sotalol 투여 후 환자는 점차 동리듬으로 회복되었다. 신생아에서 경식도 전극을 이용하여 다소성 심방 빈맥을 진단하였던 1례를 보고한다.

• 대한임상검사과학회지
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• 제38권2호
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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.

• International Journal of Arrhythmia
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• 제19권3호
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• pp.285-339
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• 2018

Catheter ablation of atrial fibrillation (AF) is one of the most complex interventional electrophysiological procedures. The success of AF ablation is based in large part on freedom from AF recurrence based on electrocardiography (ECG) monitoring. Arrhythmia monitoring can be performed with the use of noncontinuous or continuous ECG monitoring tools. AF ablation is an invasive procedure that entails risks, most of which are present during the acute procedural period. However, complications can also occur in the weeks or months following ablation. Recognizing common symptoms after AF ablation and distinguishing those that require urgent evaluation and referral to an electrophysiologist is an important part of follow-up after AF ablation. This section reviews the complications associated with catheter ablation procedures performed to treat AF. The types and incidence of complications are presented, their mechanisms are explored, and the optimal approach to prevention and treatment is discussed. Finally, surgical and hybrid AF ablation technology and the indications for concomitant open or closed surgical ablation of AF, stand-alone and hybrid surgical ablation of AF are covered in this section.

• Journal of Yeungnam Medical Science
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• 제31권2호
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• pp.94-98
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• 2014

Background: We analyzed the changes in QT dispersion (QTd) in children with Kawasaki disease (KD), and determined the presence of repolarization abnormality in these children even in the absence of coronary artery abnormalities. Methods: Ninety-one children with KD and 20 healthy controls were enrolled in this retrospective study. Serial echocardiographic and electrocardiographic (ECG) measurements in the beginning of treatment, 2nd month and 6th month after the diagnosis were compared. Fifty-one of 91 children had at least 2 serial ECG data. The number of patients who had 3 consecutive ECG data was 23. Results: Among the 67 KD patients with no coronary artery changes, the consecutive mean QTd values were 41.86 ms, 37.84 ms, and 25.47 ms, respectively (26 ms for controls). In the analysis of changes among KD patients without coronary artery abnormalities, QTd showed a significant decrease with time (p=0.01). Especially, the 1st month and the 6th month QTd values were significantly different (p=0.028). The mean QTd values in KD patients with coronary artery changes were significantly higher than those in KD patients with no coronary artery changes at each time (1st, 2nd, and 6th month exam). Conclusion: QTd is significantly increased in children during the early stage of KD. Repolarization abnormality may exist during the acute stage of KD, regardless of the echocardiographic changes.

• 한국의료질향상학회지
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• 제20권1호
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• pp.12-24
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• 2014

Objectives: The aim of this study was to explore whether emergency bell could shorten door to electrocardiograms (ECG) time in chest pain patients presenting to emergency department (ED) by self-transport. Methods: This was a planned 6-month before-and-after interventional study design. We set up the emergency bell in walk-in patients' waiting room. Prior to the change, patients were triaged before an ECG was obtained. In new process, as soon as patient with chest pain push the emergency bell, emergency physicians examined patient and prioritized performing ECG. We analyzed door to electrocardiograms (DTE) times for patients with chest pain and ST segment elevation myocardial infarction (STEMI) patients between two periods. Results: During the enrollment period, a total of 63 patients called emergency bell. The median DTE time was 6 min (interquartile range: 3.0 - 9.0) and 82.5% received an ECG within 10 minutes, and only three patients were STEMI. DTE time in patient with chest pain was not different between two periods (p=0.980). Before intervention period, 15 walk-in patients admitted in ED for STEMI and 53.8% of STEMI patients received an ECG within 10 minutes. After intervention period, total 19 walk-in patients admitted in ED for STEMI. Of these, 89.5% met the time requirement. Conclusion: Because a small portion of patients with chest pain activated the emergency bell, new strategy for promotion of emergency bell must be needed.

• 전기학회논문지
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• 제63권9호
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• pp.1294-1299
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• 2014

The emotion is deeply affected by human behavior and cognitive process, so it is important to do research about the emotion. However, the emotion is ambiguous to clarify because of different ways of life pattern depending on each individual characteristics. To solve this problem, we use not only physiological signal for objective analysis but also hybrid unsupervised-supervised learning classifier for automatic emotion detection. The hybrid emotion classifier is composed of K-means, genetic algorithm and support vector machine. We acquire four different kinds of physiological signal including electroencephalography(EEG), electrocardiography(ECG), galvanic skin response(GSR) and skin temperature(SKT) as well as we use 15 features extracted to be used for hybrid emotion classifier. As a result, hybrid emotion classifier(80.6%) shows better performance than SVM(31.3%).