• Korean Circulation Journal
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• 제53권9호
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• pp.621-631
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• 2023

Background and Objectives: The morphology-voltage-P-wave duration (MVP) electrocardiography (ECG) risk score is a newly defined scoring system that has recently been used for atrial fibrillation (AF) prediction. The aim of this study was to evaluate the ability of the MVP ECG risk score to predict AF in patients with an implantable cardioverter defibrillator (ICD) and heart failure with reduced ejection fraction in long-term follow-up. Methods: The study used a single-center, and retrospective design. The study included 328 patients who underwent ICD implantation in our hospital between January 2010 and April 2021, diagnosed with heart failure. The patients were divided into low, intermediate and high-risk categories according to the MVP ECG risk scores. The long-term development of atrial fibrillation was compared among these 3 groups. Results: The low-risk group included 191 patients, the intermediate-risk group 114 patients, and the high-risk group 23 patients. The long-term AF development rate was 12.0% in the low-risk group, 21.9% in the intermediate risk group, and 78.3% in the high-risk group. Patients in the high-risk group were found to have 5.2 times higher rates of long-term AF occurrence compared to low-risk group. Conclusions: The MVP ECG risk score, which is an inexpensive, simple and easily accessible tool, was found to be a significant predictor of the development of AF in the long-term follow-up of patients with an ICD with heart failure with reduced ejection fraction. This risk score may be used to identify patients who require close follow-up for development and management of AF.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.395-398
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• 1997

Human pulse represents the physical characteristics of heart and cardiovascular system. Therefore, malfunctions and errors of heart and cardiovascular system can be determined by using an automatic diagnosis system that can detect the pulse signal. Not only will the computerised system preclude the possibilities of observational errors by giving an accurate measurement with great stability, but minimize the possibilities of misinterpretation by using an automated diagnostic logic. A new combinational fiber-optic sensor, which has a detecting part and a transmitting part was used to acquire radial pulse signal noninvasively. The development of P-5 transducer makes it possible to obtain more effective detection and obvious display of pulse signals in the aspect of reliability. Using P-5 transducer in the field of plethysomography and MAC- JIN, one of our diagnoses in Korean traditional medicine, it is expected that we can ontain quantitative and valuable information or the diagnosis of human pulses.

• 기본간호학회지
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• 제2권2호
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• pp.229-237
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• 1995

The purpose of this study is to define requisite content of physiology for nursing education. This study classifies the subjects of physiology into 15 areas. The areas are cell and cell membrane, body fluid, nervous system, special sense, muscular system, blood, cardiovascular system, respiratory system, urinary system, digestive system, energy metabolism, body temperature, immune system, endocrine system, and reproductive system. Each subject area is further classified into subarea, resulting in a total of 194 subarea. The importance of each subarea is measured with a 3-point scale using a questionnaire. The subjects of this study were full-time professors teaching nursing in Korean universities. The analysis of the data collected from 68 respondents is as follows. 1. The areas of physiology necessary for nursing education in the order of importance are : body fluid, blood, endocrine, immune system, body temperature, urinary system, respiratory system, digestive system, reproductive system, energy metabolism, nervous system, cardiovascular system, cell and cell membrane, muscular system, and special sense. 2. Depending on the specific areas of nursing(such as pediatric nursing, maternity nursing), the importance of each physiology area may differ. For instance, the most important area for maternity nursing is reproductive physiology, whereas one for the psychiatric nursing is neuro-physiology. 3. The importance of each physiology area does not determine the importance of its subarea. For example, while the importance of cell and cell membrane was relatively very low across the respondents from different areas of nursing science, the importance of such subarea as osmosis, diffusion, and filteration reported by most respondents were high.

• 대한한방내과학회지
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• 제27권1호
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• pp.265-275
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• 2006

Objectives : Electrical acupoint stimulation(EAS) has been used to treat motor dysfunction of stroke patients with reportedly effective results. The purpose of this study is to evaluate the efficacy of the EAS with different frequencies in treating motor dysfunction of ischemic stroke patients. Methods : The subject of this study were forty-two ischemic stroke patients with motor dysfunction in Kyunghee oriental medicine hospital who were hospitalized for one week to one month from onset. They were treated with 2Hz or 120Hz EAS for two weeks, and motor evoked potentials(MEP) were measured before and after EAS treatment. To compare the effect of 2Hz EAS with 120Hz, the number of patients who showed MEP responses after two weeks among those who had no previous response was checked. Also measured were latency, central motor conduction time(CMCT), amplitude of MEP before and after EAS treatment. Results : After two weeks of treatment, 4 out of 15 patients(27%) in the 2Hz EAS group and lout of 19 patients(5%) in the 120Hz group showed potential responses. Yet there was no significant difference between the two groups. When MEP data of the affected side between the 2Hz group and the 120Hz group was compared, the former showed more significant improvement than the latter in latency, CMCT and amplitude(P=0.040, 0.019,0.021). When the proportion of the affected side and unaffected side in MEP data was examined, the 2Hz group showed improvement on only latency and CMCT with significant differences(P=0.040, 0.014). Conclusions : These results show that EAS with low frequency is more helpful for motor recovery after ischemic stroke than that with high frequency. This suggests that low frequency EAS activates the central motor conduction system better than high frequency EAS.

• 제어로봇시스템학회논문지
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• 제10권12호
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• pp.1164-1171
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• 2004

A new multi-scale simulation model is proposed to analyze heart mechanics. Electrophysiology of a cardiac cell is numerically approximated using the previous model of human ventricular myocyte. The ion transports across cell membrane initiated by action potential induce an excitation-contraction mechanism in the cell via cross bridge dynamics. Negroni and Lascano model (NL model) is employed to calculate the tension of cross bridge which is closely related to the ion dynamics in cytoplasm. To convert the tension on cell level into contraction force of cardiac muscle, we introduce a simple geometric model of ventricle with a thin-walled hemispheric shape. It is assumed that cardiac tissue is composed of a set of cardiac myocytes and its orientation on the hemispheric surface of ventricle remains constant everywhere in the domain. Application of Laplace law to the ventricle model enables us to determine the ventricular pressure that induces blood circulation in a body. A lumped parameter model with 7 compartments is utilized to describe the systemic circulation interacting with the cardiac cell mechanism via NL model and Laplace law. Numerical simulation shows that the ion transports in cell level eventually generate blood hemodynamics on system level via cross bridge dynamics and Laplace law. Computational results using the present multi-scale model are well compared with the existing ones. Especially it is shown that the typical characteristics of heart mechanics, such as pressure volume relation, stroke volume and ejection fraction, can be generated by the present multi-scale cardiovascular model, covering from cardiac cells to circulation system.

• 대한한방내과학회지
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• 제39권4호
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• pp.624-636
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• 2018

Objectives: The purpose of this study was to investigate the cardioprotective effect of the potent antioxidant properties of Scrophulariae Radix (SR) aqueous extracts by examining pressure overload (PO) heart failure (HF) induced by transverse aortic constriction (TAC) of C57BL/6 mice. Methods: SR (500, 250, 125 mg/kg) and resveratrol (10 mg/kg) were administered orally once a day for 14 days, after the TAC operation. Changes in mortality, the body and heart weights, histopathology of the heart, and antioxidant defense system of the heart were analyzed. Results: After the TAC operation, increases were observed in mortality, heart weights, left ventricular hypertrophy, and lytic and focal fibrotic histological change, and destruction of the heart antioxidant defense system. However, the HF signs showed dose-dependent inhibition following 14 days of continuous oral treatment with SR. A SR dose of 125 mg/kg gave a similar inhibition to that obtained with resveratrol at 10 mg/kg. Conclusions: Oral administration of SR beneficially improves PO-induced HF following TAC surgery by increasing the activity of the heart antioxidant defense system. The overall effect of SR at 125 mg/kg is similar to the effect of resveratrol at 10 mg/kg. However, more detailed mechanistic studies should be performed by screening of the biologically active compounds in SR.

• 대한한의학회지
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• 제18권1호
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• pp.299-315
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• 1997

The present experiments were designed to investigate the effects of Samsaengyeum. water extracts on the Cardiovascular System in the Experimental Animals. Thus, the changes of blood pressure and heart rate were measured after oral administration. Measurement of Mortality rate was observed for measuring the effect of Samsaengyeum water extract Samsaengyeum water extract against pulmonary thromboembolism induced by collagen the mixture(0.1me/10g, 2mg/kg B.W) plus serotonin(5mg/kg B.W) in mouse. The effect of Samsaengyeiim water extract was examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as followings. 1. Samsaengyeum dropped the blood pressure in spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 4. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug reduced the fibrinogen lyses time and increased the lyses area of rat. 8. Samsaengyeum reduced fibrinogen lyses time of rat in vitro assay. According to the above mentioned results, Samsaengyeum increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug inhibited the platelet aggregation.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.80-85
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• 1996

The various function of the cardiovascular system(CVS) and the dynamic characteristics on each part of human body can be acquired in the electric analog circuit model. According to the performed outcome by other researchers, viscos resistance, flow inertia, and vascular compliance in the CVS are analogous to resister, inductor, and capacitor in electric circuit, so the CVS models were represented by the electric circuit models. these approaches were to propose the suitable models interest part of body and to simulate the various characteristics on the CVS. In this paper, the electric circuit model considering the characteristics of morphologic structure is represented, the parameter values of model is sotted up, and the dynamic characteristics of the the CVS is simulated using VisSim, one of the simulation tools. The observed simulation results are similar to the cardiovascular functions of nomal adults who have no heart failure. Besides, the simulation is operated to observe the pathophysiological abnomal symptoms(for example, bleeding within a certain period). The controller by baroreceptor, which is one of controllers to control the CVS, is appended in the model. and the dynamic response characteristics and the procedure to return normal state is observed in simulation when the bleeding last within a certain period.

• 한국컴퓨터정보학회논문지
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• 제27권12호
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• pp.267-275
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• 2022

이 논문은 대기오염의 심장병에 대한 위험도를 예측하기 위하여 Keras를 활용한 Deep Neural Network Model 시스템을 제안하였다. 연구 데이터로 서울열린데이터광장의 서울시 기간별 시간평균 대기환경 데이터 18,000개의 데이터 셋을 분석하여, 심장병 질병에 미치는 영향에 대한 정보를 얻을 수 있었다. 이 모델은 각각 8개의 노드를 가진 3개의 은닉층, Sigmoid, Binary_crossentropy, Adam과 Accuracy를 사용했을 때 88.92%의 높은 정확도를 얻을 수 있었다. 이 시스템은 각 지역별 대기오염에 따른 심장병 질병 위험도를 예측하여 유용한 질병 예방의 지표로 활용 가능하다고 사료되고, 대기오염과 미세먼지의 각 성분이 유해질환에 미치는 영향에 대한 데이터만 존재한다면 어떠한 호흡기 질환이든 위험도 예측 결과를 알 수 있다는 것에 의미가 있다. 이 시스템을 더욱 발전시킨다면, 마스크 및 공기정화제품 생산기업에게 유용한 정보를 제공하여 기업의 기술개발에 도움이 될 수 있다고 사료된다.

• Journal of Chest Surgery
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• 제40권8호
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• pp.546-551
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• 2007

배경: 관상동맥 우회술에서 요골동맥 이식편의 사용이 증가하는 추세이나 혈관조영술을 이용한 요골동맥의 개통률 분석은 내흉동맥이나 복재정맥에 비해 적다. 대상 및 방법: 요골동맥을 이용한 관상동맥 우회술 후 2001년 1월부터 2006년 6월 사이에 재입원하여 혈관조영술을 시행받은 132명의 환자를 대상으로 하였다. 남자 92명, 여자 40명이었으며 수술 후 평균 32개월($2{\sim}110$개월)에 혈관조영술을 시행하였다. 수술 전 관상동맥 병소의 분포는 1혈관 질환이 7명, 2혈관 질환이 38명, 3혈관 질환이 87명이었으며 좌 주관상동맥 질환 46명이 포함되어 있었다. 인공심폐기를 사용한 경우(on-pump)가 58명, 인공심페기를 사용하지 않은 경우(off-pump)가 74명이었다. 결과: 관상동맥 조영술 결과 이식혈관의 평균 개통률은 91.2% (376/412)였으며 on pump군과 off pump군 사이의 개통률에 대한 통계학적 차이는 없었다(p=0.125). 수술 전 관상동맥 협착의 정도에 따른 요골동맥의 개통은 90% 이상의 협착이 있던 110개소 중 완전 개통을 보인 곳이 98개소(89%), 폐쇄된 경우가 8개소(7.3%)였으며, 90% 이하의 협착이 있던 76개소의 경우는 완전 개통이 60개소(78.9%), 폐쇄된 경우가 9개소(11.8%)로 나타나 수술 전 관상동맥에 90% 이상 협착이 있었던 군이 90% 미만의 협착이 있었던 군보다 높은 경향을 보였다(p=0.057). 폐쇄된 요골동맥 이식편의 관상동맥 문합 부위는 좌전하행지가 7군데 중1개소(14.2%), 대각지가 40군데 중 1개소(2.5%), 회선지가 96군데 중 6개소(6.2%), 우 관상동맥이 43군데 중 9개소(20.9%)로 우 관상동맥의 개통률이 가장 저조하였다(p=0.027). 요골동맥 근위부 문합방법에 따른 요골동맥이식편의 개통률은 3군간에 차이가 없었다(p=0.078). 결론: 요골동맥은 관상동맥 우회술에서 중기 혈관 조영술 상 만족할 만한 이식편이라 생각하지만 우 관상동맥에 이식하거나, 90% 이하의 관상동맥 협착에 이식시 개통률이 저조하였다. 인공심폐기의 사용 유무나 근위부 문합방법에 따른 개통률의 차이는 없었다.