심장병 진단을 위한 실시간 디지탈 감산 조영 영상기법의 개발

민병구,이태수,Min, Byoung-Goo,Lee, Tae-Soo 대한전자공학회 1989 전자공학회논문지 Vol. No.

본 연구에서는 심장의 박동영상을 방사선 투시법으로 관찰하여 심장질환을 진단하기 위한 실시간 처리 심장 디지탈 감산 조영 영상기법(cardiac digital subtraction angiography)을 개발하여 임상실험을 시행하였다. 평균 1초에 1번의 심장박동에 따른 주변부위의 운동에 의한 오차의 영향을 감소하면서, 좌심실 박동상을 32프레임까지 실시간으로 감산 처리하는 고속기억(512X512 해상도와 256 gray level) 및 고속 데이타링크 시스템과 프로세서를 개발하였다. 기억된 영상을 컴퓨터에 입력하고, 심장의 경계면을 Dynamic Programming을 사용하여 검출하고, 부피를 구하여 심장의 박동에 따른 최대부피(ESV)와 박동후 최소부피(ESV), 최대와 최소부피의 비율(EF)로서 표시되는 심박출계수 등 심장의 좌심실기능을 나타내는 생리계수를 영상으로 부터 구하는 알고리듬을 개발해서 임상실험을 시행하였다. We have designed a real-time Cardiac digital substraction angiography system (C-DSA) and tested the system for the diagnosis of Cardiac patients. The system was developed by interfacing a radiographic angiography system to a computerized motional image analysis system. This new cardiac DSA can perform the real time processing of averaging and subtraction of the 32 image frames to measure the volume changes of the left ventricle after elimination of motional artrifacts, caused by the heart contraction of beats per minute in average. Each frame has a resolution of 512 x 512 pixels and 256 gray levels. Two image data with maximal and minimal volume were moved to the interfaced IBM PC computer system by high speed computer link line for computation of the heart's contraction parameters. First, the boundary of the left ventricule was detected using a dynamic programming of the gray levels, and its volume was computered to determine the parameters, such as the maximal volume of end-diastolic volume (EDV), the minimal volume of end systolic volume (ESV), and ejection fraction (EF).

이중 박동형 생명구조장치의 혈류, 혈압, 박동성의 분석

최성욱,민병구,Choi, Seong-Wook,Min, Byoung-Goo 대한의용생체공학회 2007 의공학회지 Vol.28 No.5

Previous trials for development of a pulsatile-Extracorporeal Life Support had some defects such as insufficient blood flow, high pressure at its membrane oxygenator and the high risk of blood cell damage. To solve those problems of previous pulsatile-ECLSs, we suggest dual pulsatile blood pump structure for the new pulsatile-ECLS. Two pulsatile pumps areconnected in a parallel manner and this new structure raises the inflow capacity and efficiency and it decreases the high blood pressure at membrane oxygenator. In in-vitro experiments, The Energy Equivalent Pressure Increment(EEP inc.) was 10%, and it showed that its pulsatilty was $5{\sim}10$ times higher than other commercial ECLS In in-vivo experiments, we had applied a new pulsatile-ECLS to 30 Kg pigs and a new pulsatile-ECLS couldsupport high blood flow and pulsatility above 2 L/min, 10% EEP inc.

심전도의 재분극상에서의 활동전임의 추정

강훈,민병구,최계근,Kang, Hoon,Min, Byoung-Goo,Choi, Keh-Kun 대한전자공학회 1983 전자공학회지 Vol.20 No.6

심전도는 심장근육세포와 홍분세포들의 활동전위의 전파에 따른 전파에 의해 발생한다. 활동전위의 재분극상은 임상적 요인에 매우 민감하다. 따라서. 역심전도에 관한 본 논문에서는, 디지탈 신호 추정방법으로 심전도의 재분극상에서의 일정활동전위(uniform action potential)를 추정하는 방법을 연구하였다. 추정된 정상인의 활동전위는 임상적 자료와 비슷한 재분극상을 보였다. The body surface ECG(electrocardiogram) is produced by the electric fields caused by the propagation of action potentials within the myocardial cells. The repolarization phase of the action potential is very sensitive to factors of clinical importance. Therefore, in this paper of the inverse electrocardiography, we studied a method of estimating the uniform action potentials during repolarization phase from the body surface ECG using digital signal identification techniques. The estimated action potential of a normal was similar to that of clinical data in the repolarization phase.

사이드 홀을 가진 케뉼라에 관한 수치해석적 연구

박중열,박찬영,민병구,Park Joong Yull,Park Chan Young,Min Byoung Goo 대한의용생체공학회 2004 의공학회지 Vol.25 No.6

혈액이 케뉼라를 통과할 때 생리적인 범위를 벋어나는 기계적인 하중이나 전단응력을 받게 되며, 그 결과로 용혈의 발생기전이 되는 ADP(Adenosine Diphospate)를 증가 시키게 된다. 저자는 수치해석적인 방법을 이용하여 사이드 홀을 가진 케뉼라의 3차원 유동을 해석하였다. 연구의 대상이 되는 케뉼라는 환자의 대퇴정맥에 삽입되어 혈액을 배출하는 배액 케뉼라이다. 이러한 배액 케뉼라는 배출 성능을 높이기 위해 일반적으로 사이드 홀을 장착한다. 4개, 12개, 20개인 사이드 홀을 가진 케뉼라에 대하여 경우에 대하여, 각각 엇갈림 배열, 직렬 배열. 변형된 직렬배열을 적용하여, 총 9가지 서로 다른 모델을 시뮬레이션 해보았으며 이것을 사이드 홀이 없는 케뉼라와 더불어 비교하였다. 유량, 벽면전단응력(Wail Shear Stress. WSS), 전단율(Shear Rate. SR) 값을 구하여 분석하므로 사이드 홀의 영향을 알아보았다. 연구를 통하여 사이드 홀의 개수와 배열이 모두 혈류 역학적인 변수들에 영향을 주는 것을 확인하였다. 유량이 사이드 홀의 개수에 비례하지 않는 것을 확인 하였고 사이드 홀의 개수가 많을 수로 평균 전단율을 줄이는 것을 확인 하였다. Insertion of cannulae into vessels may disturb the blood flow doing non-physiological load and stress on blood cells such that ADP may increase and result in hemolysis. Authors used the computational method to simulate the 3-dimensional blood flow inside of the cannula using numerical method. We limited the research to within the drainage cannulae with side holes inserted through the human vein. In this paper, 9 different cannulae with side holes categorized by the number of side holes of 4, 12, and 20, and also categorized by the array type of side holes of staggered array, in-line array, and alternative in-line array were studied and compared to the cannula with no side holes by using CFD analysis. We evaluated the flow rate, the wall shear stress, and the shear rate and compared them with one another to estimate the effect of the side holes. The flow rate is not proportional to the number of the side holes. However, larger number of side holes can reduce the mean shear rate. Both the number and the array type of side holes play an important role on the fluid dynamics of the blood flow in cannulae.

폴리우레탄 인공혈관을 위한 extracellular matrix 기질상의 내피세포이식

이윤신,박동국,민병구,Lee, Yoon-Shin,Park, Dong-Kook,Min, Byoung-Goo 대한의용생체공학회 1991 의공학회지 Vol.12 No.3

Many experiments about endothelial cell seeding on artificial vessels were studied and conducted For this one or a combination of the extramatrix was used for the underlying matrix. But we used the whole ECM(extracellular matrix) that made excreated from flbroblasl. In thls study, we obtained human adult omental microvascular endothelium by collagenase digestion and used polyurthane sheets in order to make a new artificial vessel material. We cultured fibroblast on the polyurethane and gelatin - coated polyurethane. After confluent ingrowth we treated the polyure thane with triton in order to destroy the cytoskeleton and nucleus. We observed the preformed extra cellular matrix on the ployurethane and cultured the isolated microvascular endothelium. We also ok served the growth of microvascular endothelium on the polyurethane and gelatin. We conclude that the use of the whole ECM is promising fair as a new underying substrate for endothelial cell seeding on artificial vessels.

고분자 표면의 혈관내피세포 부착력에 관한 연구

최진욱,유규하,민병구,Choi, Jin-Wook,Ryu, Gyu-Ha,Min, Byoung-Goo 대한의용생체공학회 1990 의공학회지 Vol.11 No.1

To improve antithrombogenicity of polymer that used in vascular graft and artificial organs, seeding of human endothelial cells on the polyurethane was studied. Human endothelial cells were ismlated from human umbilical veins, using type I collagenase, and identified with goat anti vWF antibodies. Human endothilial cell seeding was tried upon the polyurethane which has good mechanical property and resists stresses. The hydrophobic polyurethane surface was changed hydrophilic by corona discharf:e treatment. Surface hydrophilicity was measured with Wilhemly plate method and the goniometer. To evaluate matrix protein adsorption, fibronectin adsorption test was done. To eveluate cell adhesion, human endothelial cell attachment forces were measured rising a perfusion chamber of , ism diamter. Less cells were detached from the hydrophilically treated polyurethane. This showed that corona discharge on the polyurethane could improve matrix adsorption and endothelial cell attachment.

간 조직 감쇄 계수의 초음파 영상

송인찬,곽철은,민병구,Song, In-Chan,Kwack, Cheol-Eun,Min, Byoung-Goo 대한의용생체공학회 1990 의공학회지 Vol.11 No.2

As a part of the study on ultrasonic tissue characterization, conventional ultrasonic imaging system is interfaced to the personal computer to acquire raw ultrasonic signal. One approach for tissue charaterization is performed using the attenuation map to the conventional images and the resulting attenuation map images are compared and inspected inside the region of interest from the viewpoint of pattern analysis. Currently, these methods are applied and modified to effectively find out the differences between the normal control and the patients with liver cirrhosis.

Relation Between Multidimensional Linear Interpolation and Fuzzy Reasoning

Kyong-Sik Om(엄경식),Byoung-Goo Min(민병구) 한국지능시스템학회 1996 한국지능시스템학회논문지 Vol.6 No.4

인공심장의 연구개발현황

박찬영(Chan Young Park),민병구(Byoung Goo Min) Korean Society for Precision Engineering 2000 한국정밀공학회지 Vol.17 No.11

Relation between Multidimensional Linear Interpolation and Regularization Networks

Kyong-Sik Om(엄경식),Byoung-Goo Min(민병구) 한국지능시스템학회 1997 한국지능시스템학회논문지 Vol.7 No.3