Guzmán, A.M., Escobar, E.A., and Amon, C.H., "Fluid Dynamics Characteristics in a 3-D Model of an Intravascular Oxygenator without Balloon Pulsations", Invited Presentation, 2001 ASME International Mechanical Engineering Congress and Exposition - IMECE 2001, New York, NY, 2001.

The Intravenous Membrane Oxygenator (IMO) device shown in figure 1(a) is an intravascular oxygenator under development at the University of Pittsburgh Medical Center (UPMC) with the purpose of providing temporary relief to patients with the Acute Respiratory Distress Syndrome (ARDS) [1,2]. The idealized intravascular artificial lung (IIVAL) has been developed at the UPMC with the purpose of determining flow and O2 and CO2 exchange characteristics, and mass transfer correlations for a theoretical model of the IMO [4]. The IIVAL is a device composed of a non-permeable elastic balloon, which inflates and deflates to a given frequency and amplitude, and hundreds of fibers located longitudinally around the balloon as shown in figure 1(b). The balloon and fibers are positioned within a plastic transparent tube -the mock vena cava. In-vitro experiments and numerical simulations of the transport process of blood and oxygen occurring in the IMO and IIVAL devices have been carried out with the objective of getting a better understanding of the flow and mass transfer characteristics of both devices [1-3, 5-10]. This article reports the fluid dynamics characteristics obtained with computational models of the IIVAL device using the spectral element method. An initial 3D computational model is used to determine the global flow pattern; then, 3 reduced 3D models are used to study the effect on the fluid dynamics characteristics of the number of fibers and their geometrical positioning within the mock vena cava. Simulations are performed under stationary balloon conditions up to a Reynolds number (based on the mean velocity and diameter of the mock vena cava) of 480.