http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Abdul I. Barakat (검색결과 6 건)
- 무료
- 기관 내 무료
- 유료
-
The assessment of the performance of drug-eluting stent using computational fluid dynamics
서태원,Abdul I. Barakat 한국유변학회 2009 Korea-Australia rheology journal Vol.21 No.4
Numerical investigations have been conducted on the assessment of the performance of drug-eluting stent. Computational fluid dynamics is applied to investigate the flow disturbances and drug distributions released from the stent in the immediate vicinity of the given idealized stent in the protrusion into the flow domain. Our simulations have revealed the drug concentration in the flow field due to the presence of a drug-eluting stent within an arterial segment. Wall shear stress increases with Reynolds number for a given stent diameter, while it increases with stent diameter for a given Reynolds number. The drug concentration is dependent on both Reynolds number and stent geometry. In pulsatile flow, the minimum drug concentration in the zone of inter-wire spacing occurs at the maximum acceleration of the inlet flow while the maximum drug concentration gains at the maximum deceleration of the inlet flow. These results provide an understanding of the flow physics in the vicinity of drug-eluting stents and suggest strategies for optimal performance of drug-eluting stent to minimize flow disturbance.
-
-
The assessment of the performance of drug-eluting stent using computational fluid dynamics
Seo, Tae-Won,Barakat, Abdul I. The Korean Society of Rheology 2009 Korea-Australia rheology journal Vol.21 No.4
Numerical investigations have been conducted on the assessment of the performance of drug-eluting stent. Computational fluid dynamics is applied to investigate the flow disturbances and drug distributions released from the stent in the immediate vicinity of the given idealized stent in the protrusion into the flow domain. Our simulations have revealed the drug concentration in the flow field due to the presence of a drug-eluting stent within an arterial segment. Wall shear stress increases with Reynolds number for a given stent diameter, while it increases with stent diameter for a given Reynolds number. The drug concentration is dependent on both Reynolds number and stent geometry. In pulsatile flow, the minimum drug concentration in the zone of inter-wire spacing occurs at the maximum acceleration of the inlet flow while the maximum drug concentration gains at the maximum deceleration of the inlet flow. These results provide an understanding of the flow physics in the vicinity of drug-eluting stents and suggest strategies for optimal performance of drug-eluting stent to minimize flow disturbance.
-
여러 형상을 고려한 약물분출 스텐트의 성능에 대한 수치해석적 연구
서태원(Taewon Seo),Abdul I. Barakat 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.6
본 연구는 내피세포 표면에 약물방출 스텐트에서 방출되는 약물의 농도와 약물분출 스텐트의 형상과 설계가 스텐트 주위 유동특성에 어떤 영향을 미치는지를 조사하기 위해 전산유체역학을 이용하여 연구를 수행하였다. 본 연구에서는 이상적으로 가정된 세 종류의 스텐트 모델과 임상결과를 거쳐 상용화 되고 있는 세 종류의 스텐트 모델에 대하여 전산수치해석을 수행하였다. 본 연구의 목적은 스텐트의 성능을 정량적으로 평가할 수 있는 스텐트 영향 지수의 개념을 소개하고, 성능을 비교하는 것이다. 비교 결과, 연구된 세 종류의 상용 스텐트 모델 중 수치 모사에 적용된 모든 레이놀즈 수에 대하여 BX Velocity 스텐트의 스텐트 영향 지수가 가장 낮게 나타났다. 그러나 여섯 종류의 스텐트 모델 가운데에서는 전산 수치 모사에 적용된 모든 유동조건하에서 Spiral 스텐트의 스텐트 영향 지수가 가장 낮고 성능 역시 가장 좋은 것으로 나타났다. In this study, we performed computational fluid dynamic simulations to explore how the detailed design of drug-eluting stents affects both the flow field in the vicinity of the stent as well as the concentration of the eluted drug at the endothelial cell surface. Simulations were performed on three idealized stent geometries we developed and on geometries approximating three commercial stents,: Medtronic’s Aurora stent, Cordis’s BX Velocity stent, and Boston Scientific’s Wallstent. An important contribution of the present study is the introduction of the stent effectiveness index (EI), which provides a quantitative assessment of stent performance and an objective basis for comparing the performance of different stents. Among the three commercial stents studied, our simulations have revealed that the BX Velocity stent is associated with the lowest in-stent EI values for the range of flowReynolds numbers studied (200 ≤ Re ≤ 800). In addition to commercial stent designs, we investigated the EI in three idealized stents and determined that a spiral stent provides excellent performance (low EI) under all flow conditions investigated.
-
서태원(Taewon Seo),Abdul I. Barakat 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10
In this study, we performed computational fluid dynamic simulations to explore how the detailed design of drugeluting stents affects both the flow field in the vicinity of the stent as well as the concentration of the eluted drug at the endothelial cell surface. Simulations were performed on three idealized stent geometries we developed and approximating three commercial stents, Medtronics Aurora stent, Cordis BX Velocity stent, and Boston Scientifics Wallstent. An important contribution of the present study is the introduction of the stent effectiveness index (SEI) which provides a quantitative assessment of stent performance and an objective basis for comparing the performance of different stents. Among the three commercial stents studied, our simulations have revealed that the BX Velocity stent is associated with the lowest in-stent SEI values for the range of flow Reynolds numbers studied (200≤Re≤800). In addition to commercial stent designs, we investigated the SEI in three idealized stents and determined that a spiral stent provides excellent performance (low SEI) under all flow conditions investigated.
-
Drug-Eluting Stent Design is a Determinant of Drug Concentration at the Endothelial Cell Surface
Seo, Taewon,Lafont, Antoine,Choi, Sun-Young,Barakat, Abdul I. Springer-Verlag 2016 Annals of biomedical engineering Vol.44 No.2
<P>Although drug-eluting stents (DES) have greatly reduced arterial restenosis, there are persistent concerns about stent thrombosis. DES thrombosis is attributable to retarded vascular re-endothelialization due to both stent-induced flow disturbance and the inhibition by the eluted drug of endothelial cell proliferation and migration. The present computational study aims to determine the effect of DES design on both stent-induced flow disturbance and the concentration of eluted drug at the arterial luminal surface. To this end, we consider three closed-cell stent designs that resemble certain commercial stents as well as three 'idealized' stents that provide insight into the impact of specific characteristics of stent design. To objectively compare the different stents, we introduce the Stent Penalty Index (SPI), a dimensionless quantity whose value increases with both the extent of flow disturbance and luminal drug concentration. Our results show that among the three closed-cell designs studied, wide cell designs lead to lower SPI and are thus expected to have a less adverse effect on vascular re-endothelialization. For the idealized stent designs, a spiral stent provides favorable SPI values, whereas an intertwined ring stent leads to an elevated SPI. The present findings shed light onto the effect of stent design on the concentration of the eluted drug at the arterial luminal surface, an important consideration in the assessment of DES performance.</P>
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
