• Title/Summary/Keyword: 단엽식

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Nonlinear Analysis of the Monoleaflet Polymer Valve According to Shape of Supporting Members (지지대 형상에 따른 단엽식 고분자 판막의 비선형 해석)

  • 한근조;안성찬;심재준;김성윤
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.748-751
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    • 2001
  • Monoleaflet polymer artificial heart valve was known to show remarkable improvement in antithrombosis and pressure drop compared with other type of artificial valve. In this investigation monoleaflet the vertical and horizontal deflection pattern of polymer heart valve with three types of supporting members straight member, and two curved members was analysed using the large deformation nonlinear finite element method.

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Nonlinear Analysis of the Monoleaflet Polymer Valve according to Shape of Supporting Members (지지대 형상에 따른 단엽식 고분자 판막의 비선형 해석)

  • 한근조;안성찬;심재준;김성윤
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.3
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    • pp.120-124
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    • 2003
  • Monoleaflet polymer artificial heart valve was known to show remarkable improvement in antithrombosis and pressure drop compared with other type of artificial valve. In this investigation of monoleaflet heart valve the vertical and horizontal deflection pattern of polymer heart valve with three types of supporting members, straight member and two curved members were analysed using the large deformation nonlinear finite element method.

A Study on the Location of Supporting Members in Monoleaflet Polymer Valve to Minimize Stress and Deformation (응력과 변형을 최소화하기 위한 단엽식 고분자 판막의 지지대 위치에 관한 연구)

  • Lee Seong Wook;Shim Jae Joon;Han Dong Seop;Han Geun Jo;Kim Tae Hyung
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.2
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    • pp.156-163
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    • 2005
  • A monoleaflet polymer artificial heart valve showed the remarkable improvement in pressure drop compared with other types of artificial valve. So, in this study we designed a monoleaflet polymer artificial valve with two supporting members to minimize the deformation and bending stress of the valve with respect to the variation of the gap between two supporting members using nonlinear contact analysis. The marginal valve thickness was also predicted in accordance with the relationship between the thickness and horizontal displacement in order to prevent the dislocation of the valve tip from the frame wall.

Finite Element Analysis of the Monoleaflet Polymer to Minimize Stress and Displacement (응력 및 변위를 최소화하기 위한 단엽식 고분자 판막의 유한 요소 해석)

  • 한근조;안성찬
    • Journal of Biomedical Engineering Research
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    • v.17 no.1
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    • pp.85-92
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    • 1996
  • A monoleaflet polymer artificial heart valve which showed the remarkable improvement in pressure drop compared with other types of artificial valve was designed to minimize the deflection in vertical direction and the displacement of the valve tip in horizontal direction obtained by using finite element method as the location of the supporting members of the valve frame changed stress distribution change was also studied on each model generated by changing the distance between the frame and supporting members. It was found that by using the valve tip horizontal displacement the minimum valve thickness could be obtained in order to prevent the gap between the valve tip and the frame wall.

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In Vitro Test of a Monoleaflet Polymer Valve (단엽식 고분자판막의 모의순환실험)

  • Kim, S.H.;Kim, W.K.;Chang, B.C.;Cho, B.K.
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.05
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    • pp.51-53
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    • 1993
  • We have developed a monoleaflet polymer valve in order to be used as an inlet valve of the ventricular assist device, because it could help to improve the fluid dynamic characteristics in the ventricle. Mean systolic transvalvular pressure drops were measured for the monoleaflet polymer valve and their results were compared wi th that of the mechanical valve.

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Hemodynamic Evaluation of Monoleaflet Polymer Valve (단엽식 고분자판막의 혈역학적 성능평가)

  • 김상현;장병철
    • Journal of Biomedical Engineering Research
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    • v.16 no.1
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    • pp.61-66
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    • 1995
  • We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane. To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medicals prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volllme and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate.

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Design of the monoleaflet polymer valve to minimize stress and displacement (응력 및 변위를 최소화하기 위한 단엽식 고분자 판막의 설계)

  • Han, G.J.;Kim, S.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.11
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    • pp.99-103
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    • 1993
  • A monoleaflet polymer artificial heart valve which showed the remarkable improvement in pressure drop compared with other types of artificial valve was designed to decrease the deflection in vertical direction and the displacement or the valve tip in horizontal direction. Stress distribution change was studied as the location of the supporting members or the valve frame changed. And it was found that using the valve tip horizontal displacement the minimum valve thickness could be obtained in order to prevent the gap between the valve tip and the frame wall.

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Animal Experiment and Blood Biocompatibility Study of Polymer Valve (고분자판막의 동물실험 및 생체내 혈액적합성 연구)

  • 김상현;홍유선
    • Journal of Chest Surgery
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    • v.30 no.4
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    • pp.357-362
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    • 1997
  • In vivo testings of the monoleaflet polymer valve were performed in seven dogs to prove its blood biocompatibility. The monoleaflet polymer valve used in this study was developed for short-term usage n the ventricular assist device. The frame and leaflet of the polymer valve were made of polyurethane. The inter-aortic valved conduit were implanted in four dogs and the ventriculo-atrial valved conduit was implanted in one dog. The ventricular assist devices with polymer valve were implanted in two dogs. The longest survival was 20 days. Main causes of death were bleeding and infection. To examine the blood compatibility, each blood sample was collected and RBC, WBC, hematocrit, hemoglobin, platelet and lactic acid dehydrogenase were analyzed. These studies thus far demonstrated that, with further development, a reliable and inexpensive polymer valve will be used in the ventricular assist device as short term usage.

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