Flow visualization study of a novel respiratory assist catheter.
Flow visualization study of a novel respiratory assist catheter.
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新型呼吸辅助导管的流量可视化研究。
DOI：
10.1111/j.1525-1594.2009.00751.x
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发表时间：
2009
影响因子：
2.4
通讯作者：
Federspiel,WilliamJ
中科院分区：
文献类型：
--
作者：
Budilarto,StephanusG;Frankowski,BrianJ;Hattler,BrackG;Federspiel,WilliamJ
呼吸辅助使用静脉导管可能是急性和急性上慢性肺衰竭患者的潜在治疗方法。一个重要的设计限制是呼吸导管的尺寸，需要新的策略来减小尺寸，同时保持足够的气体交换。我们的团队目前正在开发一种经皮呼吸辅助导管（PRAC），它使用一束旋转的中空纤维膜，随着纤维束旋转速率的增加，可以增强二氧化碳的去除和二氧化碳的供应。本研究采用粒子图像测速技术（PIV）分析了PRAC旋转纤维束周围的流体流动模式和速度场。该研究的目的是评估随着纤维束旋转增加而发生的气体交换增强的背景下的旋转流动模式。一个PRAC原型被放置在一个1 - in。专为PIV研究设计的体外流动环的内径测试部分。PRAC的转速在500 ~ 7000 rpm之间变化，用PIV测量了主流面（r‐θ）和次流面（r‐z）的速度场。二次流表现出时变的非相干涡，与Taylor数（Ta）对应的转速（2200 < Ta < 31000）所期望的经典Taylor涡一致。在一次流动中，切向速度在纤维束和血管壁附近呈现小于½mm的边界层。在7000转/分的转速下，与泰勒涡相关的剪应力估计约为11达因/厘米2，比初级流动边界层的剪应力小10倍以上。
Respiratory assist using intravenous catheters may be a potential therapy for patients with acute and acute‐on‐chronic lung failure. An important design constraint is respiratory catheter size, and new strategies are needed that enable size reduction while maintaining adequate gas exchange. Our group is currently developing a percutaneous respiratory assist catheter (PRAC) that uses a rotating bundle of hollow fiber membranes to enhance CO2removal and O2supply with increasing bundle rotation rate. In this study, particle image velocimetry (PIV) was used to analyze the fluid flow patterns and velocity fields surrounding the rotating fiber bundle of the PRAC. The goal of the study was to assess the rotational flow patterns within the context of the gas exchange enhancement that occurs with increasing fiber bundle rotation. A PRAC prototype was placed in a 1‐in. internal diameter test section of an in vitro flow loop designed specifically for PIV studies. The rotation rate of the PRAC was varied between 500 and 7000 rpm, and PIV was used to determine the velocity fields in the primary (r‐θ) and secondary (r‐z) flow planes. The secondary flow exhibited time‐varying and incoherent vortices that were consistent with the classical Taylor vortices expected for Taylor numbers (Ta) corresponding to the rotation speeds studied (2200 < Ta < 31 000). In the primary flow, the tangential velocity exhibited boundary layers of less than ½ mm adjacent to the fiber bundle and vessel wall. The estimated shear stress associated with the Taylor vortices was approximately 11 dyne/cm2at 7000 rpm and was over 10 times smaller than the shear stress in the primary flow boundary layers.