• Proceedings of the KTCVS Conference
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• 1995.10a
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• pp.44-44
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• 1995

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.45-51
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• 2007

Background: Although echocardiography is usually used for quantitative assessment of left ventricular function, the recently developed 16-slice multidetector computed tomography (MDCT) is not only capable of evaluating the coronary arteries but also left ventricular function. Therefore, the objective of our study was to compare the values of left ventricular function quantified by MDCT to those by echocardiography for evaluation of its regards to clinical applications. Material and Method: From 49 patients who underwent MDCT in our hospital from November 1, 2003 to January 31, 2005, we enrolled 20 patients who underwent echocardiography during the same period for this study. Left ventricular end-diastolic volume index (LVEDVI), left ventricular end-systolic volume index (LVESVI), stroke volume index (SVI), left ventricular mass index (LVMI), and ejection fraction (EF) were analyzed. Result: Average LVEDVI ($80.86{\pm}34.69mL$ for MDCT vs $60.23{\pm}29.06mL$ for Echocardiography, p<0.01), average LVESVI ($37.96{\pm}24.52mL$ for MDCT vs $25.68{\pm}16.57mL$ for Echocardiography, p<0.01), average SVI ($42.90{\pm}15.86mL$ for MDCT vs $34.54{\pm}17.94mL$ for Echocardiography, p<0.01), average LVMI ($72.14{\pm}25.35mL$ for MDCT vs $130.35{\pm}53.10mL$ for Echocardiography, p<0.01), and average EF ($55.63{\pm}12.91mL$ for MOCT vs $59.95{\pm}12.75ml$ for Echocardiography, p<0.05) showed significant difference between both groups. Average LVEDVI, average LVESVI, and average SVI were higher in MDCT, and average LVMI and average EF were higher in echocardiogram. Comparing correlation for each parameters between both groups, LVEDVI $(r^2=0.74,\;p<0.0001)$, LVESVI $(r^2=0.69,\;p<0.0001)$ and SVI $(r^2=0.55,\;p<0.0001)$ showed high relevance, LVMI $(r^2=0.84,\;p<0.0001)$ showed very high relevance, and $EF (r^2=0.45,\;p=0.0002)$ showed relatively high relevance. Conclusion: Quantitative assessment of left ventricular volume and function using 16-slice MDCT showed high relevance compared with echocardiography, therefore may be a feasible assessment method. However, because the average of each parameters showed significant difference, the absolute values between both studies may not be appropriate for clinical applications. Furthermore, considering the future development of MDCT, we expect to be able to easily evaluate the assessment of coronary artery stenosis along with left ventricular function in coronary artery disease patients.

• Journal of Chest Surgery
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• v.34 no.2
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• pp.118-124
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• 2001

배경: 승모판막재건술이 승모판막치환술보다 술후 좌심실기능이 보다 향상될 수 있으며 또한 수술사망율과 인공판막에 관련된 합병즈인 혈전색전증, 심내막염 및 항응고제사용에 따른 출혈빈도는 낮다고 하였다. 방법: 1996년 1월부터 2000년 5월까지 승모판막폐쇄부전으로 진단된 환자 87례를 대상으로 재건술군 59례, 치환술군 28례로 나누어 비교분석하였다. 결과: 술전 환자들의 NYHA 기능분류, 흉부 X-선상 심흉곽의 비, 심초음파상 좌심실박출계수는 두 군간에 유의한 차이가 없었다. 원인질환은 양군에서 퇴행성 병변이 가장 많았다. 체외순환시간은 재건술군에서 유의하게 길었으나 수술사망은 양군에서 없었다. 술후 NYHA 기능분류, 흉부 X-선상 심흉곽의 비는 향상되었으나 두 군간에 차이가 없었으며 술후 좌심실박출계수는 두 군에서 감소되었으나 유의한 차이는 없었다. 결론: 이상의 결과로 승모판막폐쇄부전에 대하여 재건술이 치환술처럼 비교적 안전하게 시행될 수 있는 술식으로 사료된다.

• The Korean Journal of Nuclear Medicine
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• v.37 no.3
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• pp.153-161
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• 2003

Purpose: Recently the occurrence of dipyridamole stress-induced short term stunning was proven and it is reported that Bland Altman analysis by repeated acquisition Tl-201 gated myocardial SPECT (gSPECT) revealed the 95% limit of agreement for LVEF was 10.3 %. The purpose of this study was to investigate the clinical value of dipyridamole induced transient LV dysfunction on Tl-201 gSPECT. Materials and Methods: Total 93 patients were included and coronary angiography was peformed in all patients less than 2 month from gSPECT. The patients with myocardial infarction were excluded. All patients underwent both dipyridamole stress and 4-h redistribution Tl-201 gSPECT. Forty nine patients of total 93 showed normal coronary arteries (Group 1) and the remaining 44 patients had coronary artery disease (Group 2). We compared LV EF, EDV and ESV during post-stress and 4-h redistribution period calculated by gSPECT using quantitative gated SPECT software and the incidence of dipyridamole induced transient LV dysfunction between group 1 and 2. The criteria for transient LV dysfunction was defined more decrease ${\geq}11%$ of LVEF during post-stress than 4-h redistribution according to previous reported Bland Altman analysis. Results: During post-stress and 4-h redistribution average of 3.1% increment in LVEF, 6.6% increment in LVEDV and 0.7% decrement in LVESV were shown after stress in Group 1, whereas 4.1% decrement, 9.7% increment and 7.2% increment in Group 2 respectively. Dipyridamole induced transient LV dysfunction was only detected in group 2 (18.2%) and not in group 1. It was more frequently observed in triple vessel disease and left main disease (31.8%, N=22) than one and two vessel disease (4.5%, N=22). Conclusion: As with Tc-99m myocardial agent post-stress LV dysfunction was observed in dipyridamole Tl-201 gSPECT. It was only detected in CAD and more frequently occurred in multivessel disease. Thus this finding seems to provide additional information in the diagnosis of coronary artery disease and prediction of prognosis.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.387-392
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• 1995

전기 유압식 좌심실 보조장치에서 모터 전류 파형을 정보로 하여 작동기의 이완기 속도를 조절함으로써 좌심방으로부터 유입되는 혈류량을 조절하는 알고리즘을 개발하였다. 좌심실 보조장치(Left Ventricular Assist Device, LVAD)는 허혈성 심장질환 등으로 좌심실 의 혈액 박출 기능이 저하된 환자에게 시술하여 정상 상태의 심박출량을 유지할 수 있도록 하는 보조 혈액 박출 기능이이다. 전기 유압식 좌심실 보조장치에서는 혈액의 유입이 능동 적으로 이루어지므로, 좌심방 함몰로 인한 심근 손상 및 외부 공기 유입으로 인한 색전증을 방지하기 위해 유입혈류량을 현재 좌심방내의 상태에 따라 적절히 조절해 주어야 한다. 좌 심방 내의 혈액량 정도는 혈액을 유입해 내는 작동기의 이완기 동작 시에 소모되는 에너지 크기에 반영되고, 작동기를 구동하는 모터에 들어가는 전류의 크기는 작동기에 공급되는 에 너지에 비례하므로, 이전류 파형의 정보들을 통해 좌심방내의 상태를 추정해 볼 수 있다. 본 논문에서는 퍼지로직을 적용하여 모터 전류 파형의 정보들을 통해 좌심방 내의 상태를 추정 해 볼 수 있다. 본 논문에서는 퍼지로직을 적용하여 모터 전류 파형의 이상 유무를 판단한 뒤 에에 따라 작동기의 이완기 속도를 조절하는 알고리즘을 개발하여 모의순환장치 실험을 통해 그 실효성을 검증한 결과를 정리하였다.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.867-874
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• 1996

This study was designed to assess the left ventricular peak systolic pressure/end-systolic volume (PSP/ESV) ratio in predicting symptomatic improvement with valve replacement in patients with aortic regurgitation and enlarged left von'lrlcular volume. We studied 21 patients (15 men and 6 women aged 15 to 60 years) with moderate or severe aortic regur- gitation, no other cardiovascular abnormalities and left ventricular end-systolic volume over 60 m11m2. In this group we assessed the preoperative variables which routinely were measured at cardiac catheterlzation to predict symptomatic improvement with valve replacement. Six months after operation, symptoms were alleviated in 13 patients(62%), and unchanged in 8()8%). By multivariate analysis, the PSP/ESV rati was a strong predictor for functional class 6 months after surgery(p=0.005) and also for change- in functional class prior to an operation to 6 months postoperatively(p=0.0)2). By 6 months after receiving valve replacement, all patients with a ratio over 1. 71 mmHglml/m'were in functional class I or II , in contrast, of those with a ratio < 1.71 mmHg/ml/m2, 40% were in functional class III. The PSP/ESV ratio may help to predict which patients with aortic regurgitation and enlarged left ven- tricular end-systolic volume will have symptomatic improvement with valve replacement.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.670-672
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• 2000

본 논문에서는 단일광자방출 전산화단층촬영영상 (SPECT)을 이용하여 좌심실의 내.외벽의 운동을 분리하여 추적하는 방법을 제시한다. 좌심실의 운동은 크게 평행이동, 회전이동, 비강체 변형으로 나뉘어 분석된다. 운동 추적을 위해 사용된 역동적 변형 솔리드는 물체중심 변동 좌표계로써 특징점들의 모드형태벡터를 사용하고, 좌심실 역동성을 유한요소방법에 의해 시뮬레이션한다. 또한, 변형 모델에 대해 묵시적으로 표준화된 parameterization을 하지 않고, 의료영상으로부터 얻은 자료값을 직접 이용하기 위해 노드간 보간함수로써 3차원 가우시안 함수를 사용한다. 그리하여 보다 자연스러운 방식으로 연속적으로 변화하는 좌심실의 운동을 추적할 수 있다. 이러한 분리된 내.외벽 운동 분석은 운동 기능에 이상이 있는 심질환 분석을 보다 효과적으로 도울 수 있다.

• Journal of the korean veterinary medical association
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• v.41 no.12
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• pp.1142-1147
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• 2005

생명체 안에는 정맥혈과 동맥혈이라는 두 가지 종류의 혈액이 흐른다. 여기에는 신체 내 세 가지 기관이 관여하는데, 간은 영양과 성장의 임무를 심장은 생명의 원동력을 뇌는 인지와 이성을 담당한다. 영양과 성장은 간에서 형성되는 '정맥혈'을 통해 형성되고 생명의 원동력은 심장에서 형성되는 '동맥혈'을 통해 전신으로 퍼진다. 이 혈액들은 심장으로 다시 돌아오지 않고 온 몸에 퍼져 소비된다. 혈액은 심장이 이완될 때 심장 안으로 빨아들여진다. 심장은 혈액을 펌프질하는 기능이 없으며 동맥이 그 스스로가 '박동성'을 가지고 혈액을 밀어낸다. 좌심실에서 정맥혈과 프네우마(Pneuma)가 섞이게 되는데 심장 오른쪽 심실과 심방의 정맥혈은 좌심실과 우심실 사이 중격(심실중격, interventricularseptum)의 작은 구멍을 통해 좌심실로 이동한다.

• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.269-278
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• 2020

The purpose of this study was to investigate the effect of left ventricular diastolic function on exercise capacity in hypertensive patients with obesity compared to the obese group. Adults who visited a general hospital in Gyeonggi-do from 2016 to 2019(man: 308, women: 192) were divided into 4 groups according to hypertension and obesity. In the hypertensive obesity group(IV), the A wave and E/E' wave were significantly higher than the normotensive obesity group(II), and the E' wave was significantly lower(respectively p<0.001). The group IV had significantly lower METS(metabolic equivalents) and exercise duration than the group II(respectively p<0.001). In group IV, E/A ratio was positively correlated with METS(p=0.025) and exercise duration(p=0.026). In contrast, E/E' wave in these groups showed a negative correlation with the exercise duration(p=0.046).

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.761-766
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• 2023

In this paper, TI was measured to classify the presence or absence of mild left ventricular diastolic dysfunction. Of the total 306 data, 206 were used as training data and 100 were used as test data, and the machine learning models used for classification used SVM and KNN. As a result, it was confirmed that SVM showed relatively higher accuracy than KNN and was more useful in diagnosing the presence of left ventricular diastolic dysfunction. In future research, it is expected that classification performance can be further improved by adding various indicators that evaluate not only TI but also cardiac function and securing more data. Furthermore, it is expected to be used as basic data to predict and classify other diseases and solve the problem of insufficient medical manpower compared to the increasing number of tests.