• Proceedings of the KOSOMBE Conference
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• v.1991 no.11
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• pp.70-74
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• 1991

좌심실보조기의 임상응용범위를 넓히기 위해서 개심술을 하지 않고 좌심실보조기를 적용할 수 있도록 캐뉼라형 좌심실보조기를 이용한 보조순환 실험을 하였다. 좌심실 보조기는 모터의 회전력이 PVC 벨로우즈를 수측, 팽창시키는 전기유압식으로 구동되며 환자는 양쪽 대퇴동맥을 통하여 보조순환을 받도록 되어 있다. 두차례의 동물실험을 통하여 대퇴동맥을 통한 보조 순환방식의 가능성 및 그 효과에 대해서 관찰하였다. 첫 실험은 12kg 개를 이용하여 셀딩거 방법으로 뮬린형 카테터를 디퇴동맥으로 삽입히여, 캐뉼라형 보조순환방법의 가능성을 확인하였고, 두번째 동물실험에서는 내경 4.8 mm의 PVC 카테터를 이용하여 좌심방에 유입카테터를 연결하고 대동맥에 유출카테터를 연결하여 보조순환에 의한 대동맥압의 변화와 혈류량의 변화를 관찰하였다. 보조순환동안 개의 동맥압을 100mmHg로 유지할 수 있었으며, 좌심실내압이 감소하는 것을 관찰할 수 있었다.

• Journal of Chest Surgery
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• v.40 no.7 s.276
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• pp.512-516
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• 2007

A mechanical circulatory support system is a life-saving option for treating acute severe respiratory failure or cardiac failure. There are currently a few types of assist devices and the Twin-Pulse Life Support (T-PLS) system is a kind of pulsatile pump. We report here on three patients with severe life threatening cardiopulmonary dysfunction who had the T-PLS system used as an assist device. The indications for applying the T-PLS system were continuing respiratory or cardiac failure in spite of maximal ventilatory and inotropic support. There were two patients with acute respiratory failure due to infection and one patient with cardiac failure due to acute myocarditis. One respiratory failure patient and one cardiac failure patient survived after applying the T-PLS system for 3 days and 5 days, respectively. The T-PLS system is useful as an assist device and it should be considered before multi-organ failure occurs.

• Journal of Chest Surgery
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• v.42 no.5
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• pp.604-609
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• 2009

Background: Recently, percutaneous cardiopulmonary support (PCPS) has been widely used to rescue patients in cardiogenic shock or cardiac arrest. However, patients with cardiopulmonary bypass (CPB) weaning failure during open heart surgery still have very poor outcomes after PCPS. We investigated clinical results and prognostic factors for patients who underwent PCPS during open heart surgery. Material and Method: From January 2005 to December 2008, 10 patients with CPB weaning failure during open heart surgery underwent PCPS using the CAPIOX emergency bypass system ($EBS^{(R)}$, Terumo Inc, Tokyo, Japan). We retrospectively reviewed the medical records of those 10 patients. Result: The average age of the patients was $60.2{\pm}16.5$ years (range, $19{\sim}77$ years). The mean supporting time was $48.7{\pm}64.7$ hours (range, $4{\sim}210$ hours). Of the 10 patients, 6(60%) were successfully weaned from the PCPS While 5 (50%) were able to be discharged from the hospital. Complications were noted in 5 patients (50%). In univariate analysis, long aortic cross clamp time during surgery, mediastinal bleeding during PCPS and high level of Troponin-I before PCPS were significant risk factors. All of the discharged patients are still surviving $34{\pm}8.6$ months (range, $23{\sim}48$ months) post-operatively. Conclusion: The use of PCPS for CPB weaning failure during open heart surgery can improve the prognosis. More experience and additional clinical studies are necessary to improve survival and decrease complications.

• Journal of Chest Surgery
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• v.43 no.1
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• pp.20-24
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• 2010

Background: Fulminant myocarditis is a rare, but life threatening condition. Its prognosis is related with proper management in the acute phase. A cardiopulmonary support device can be very useful in this phase. We report on our experiences with managing acute fulminant myocarditis with a cardiopulmonary support (CPS) device. Material and Method: We reviewed retrospectively 9 patients who had a CPS device used for their fulminant myocarditis between September, 2006 and October, 2008. A Capiox emergency bypass system (Terumo Inc, Tokyo, Japan) was percutaneously inserted in all the patients. Upon implantation, all the patients were in cardiogenic shock because of ventricular arrhythmia or severe left ventricular dysfunction. The mean left ventricular ejection fraction (EF) was $20{\pm}6%$ according to transthoracic echocardiography. Result: 3 patients died despite CPS. The CPS was bridged to a transplanted heart in one patient. The rest were successfully explanted after a mean time of $107{\pm}70$ hours of running. The mean EF after discharge was $56{\pm}7%$ without dilated cardiomyopathy. Conclusion: Fulminant myocarditis can be fatal, but its prognosis is excellent if these patients receive proper, timely treatment. A cardiopulmonary support device can be very useful in this acute period. However, the implantation and management protocol of cardiopulmonary support are not yet settled. Further study is necessary to lower the complications of cardiopulmonary support for patients with fulminant myocarditis.

• Journal of Chest Surgery
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• v.37 no.12
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• pp.1003-1009
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• 2004

Mechanical circulatory support (MCS) has been used for myocardium failure, but moreover, it may be essential for the life support in cardiac arrest or cardiogenic shock. Many commercial devices can be used effectively for the long-term support. However, there are some limitations in the aspects of the cost and technical support by production company. Short-term support with centrifugal type has been reported numerously with the purpose of bridging to heart transplantation or recovery. We successfully treated 5 patitents who were in the status of cardiogenic shock (n=3) or arrest (n=2) with the technique of extracorporeal life support system (ECLS) or left ventricular assist device (LVAD) using the centrifugal type pump. The MCS were performed emergently (n=2) under cardiac arrest caused by ischemic heart disease, and urgently (n=3) under cardiogenic shock with ischemic heart disease (n=1) or acute fulminant viral myocarditis (n=2). All patients were weaned from MCS. Complications related to the use of MCS were bleeding and acute renal failure, but there were no major complications related to femoral cannulations. Mechanical circulatory support may be essential for the life support and rescue in cardiac arrest or cardiogenic shock.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.250-251
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• 2017

본 논문에서는 ZVT 인터리브드 양방향 LDC의 순환전류 손실 저감을 위한 스위칭 주파수 변조 기법을 제안하였다. 제안된 컨버터 회로는 ZVT 동작을 수행하기 위해 보조 인덕터 전류가 부하 전류보다 커야하는 조건이 필요하다. 하지만 부하전류 변화에도 불구하고 보조 인덕터 순환전류는 변하지 않고 같은 값을 유지하는 문제점이 있다. 따라서 부하 전류가 감소함에 따라 도통 손실이 발생하여 컨버터의 효율이 감소한다. 이러한 문제점을 해결하기 위해 부하 전류와 시비율에 따른 최적의 주파수 값을 적용하여 보조 인덕터 순환 전류의 크기를 변화시켰다. 따라서 도통 손실을 저감시켰고 컨버터의 전반적인 효율이 증가함을 확인하였다. 본 논문에서 제안된 기법은 실험을 통해 검증되었다.

• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.399-402
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• 2006

Stent thrombosis is a rare complication after percutaneous coronary intervention (PCI), but it might be related to fatal outcomes. We report a case of patient who suffered from acute myocardial infarction complicated with cardiogenic shock and ventricular tachycardia caused by stent thrombosis and successfully resuscitated by percutaneous cardiopulmonary bypass support.

• 순환기질환의공학회:학술대회논문집
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• 2004.11a
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• pp.19-20
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• 2004

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.298-302
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• 2010

Extracorporeal circulation support system is a device for repiratory and heart failure treatment, and there have been many trials for development and clinical application in the world. These devices need to be careful while using is air embolism. Air embolism can be a lethal complication of surgical procedures during which venous pressure at the site of surgery is sub-atmospheric or air is forced under pressure into a body cavity or using extracorporeal circulation support system. To solve the problem, we developed the air detector using relative dielectric constant change. In experiments with a mock circulation system, the proposed system showed a signal difference depending on the amount of air in the tube.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.570-575
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• 1996

1단계 확률론적 안전성 평가 (Level 1 Probabilistic Safety Assessment, PSA)를 수행할 때 나타나는 보조계통 고장 수목간의 순환 논리는 사고 경위 정량화를 위하여 해결되어야만 한다. 기존의 PSA에서는 이를 위하여 별도의 고장 수목을 다시 작성하였으나, 이 방법을 사용하기 위하여서는 보조계통 간의 관계를 검토하여야 하며, 이에 따른 별도의 고장 수목을 작성하여야 하는 등 추가적인 작업이 요구된다. 또한 기존 방법은 일부 최소 단절군이 생성되지 않는 약점을 갖고 있다. 이에 따라 한국원자력연구소에서는 해석적으로 순환 논리를 푸는 방법을 개발하였으며, 이를 PSA용 코드인 KIRAP 코드에 구축하였다. 이에 따라 기존 방법의 약점을 극복하고 고장 수목간의 순환 논리를 자동으로 풀 수 있게 되었다. 본 논문에서는 개발된 해석적 방법을 설명하며, 또한 이 방법을 실제 PSA에 적용하며 나타난 여러 현상에 대하여 살펴본다.