Purpose -The purpose of this paper is to use rapid prototyping technology, in this case fused deposition modeling (FDM), to manufacture 2D and 3D particle image velocimetry (PIV) compatible patient-specific airway models. Design/methodology/approach -This research has been performed through a case study where patient-specific airway geometry was used to manufacture a PIV compatible model. The sacrificial kernel of the airways was printed in waterworkse which is a support material used by Stratasys Maxum FDM devices. Transparent silicone with known refractive index was vacuum casted around the kernel and after curing out, the kernel was removed by washing out in sodium hydroxide. Findings -The resulting PIV model was tested in an experimental PIV setup to check the PIV compatibility. The results showed that the model performs quite well when the refractive index (RI) of the silicone and the fluid are matched. Research limitations/implications -Drawbacks such as the surface roughness, due to the size of the printing layers, and the yellowing of the silicone, due to the wash out of the kernel, need to be overcome. Originality/value -The paper presents the manufacturing process for making complex thick walled patient-specific PIV models starting from a strong workable sacrificial kernel. This removable kernel is obtained by switching the building and the support materials of the FDM machine. In this way, the kernel was printed in support material while the building material was used to support the kernel during printing. The model was tested in a PIV setup and the results show that the airway model is suitable for performing particle image velocimetry.

as a M.Sc. in 2008. In his master thesis he studied the mitral valve leakage in a simplified atrium geometry. He is since 2009 active as a PhD student at the University College Ghent, Belgium in collaboration with Ghent University, Belgium. His current research interests include respiratory flow visualization on patient specific airways and particle image velocimetry.

Today, hemodialysis is a common therapy to treat people with severe chronic kidney disease. This therapy strongly relies upon the vascular access that connects the patient’s circulation to the artificial kidney and which is obtained by surgically creating an arteriovenous fistula in the arm. However, due to the high flows involved at the venous side and elevated venous pressures, the functioning of venous valves in the arm is significantly disturbed, which too often bring about serious dysfunctions or complications in the patient [1–2]. To this end, research is done to improve the outcome of vascular access in patients on hemodialysis therapy by means of computational modeling [3]. One crucial challenge, however, is experimental validation of these computer models, preferably by using Particle Image Velocimetry (PIV) for simulations of flow fields. Yet, the task of modeling the venous valve is daunting because this valve functions at very low physiological pressure differences. Moreover, PIV requires an experimental model to be fully transparent. In this study, we propose an innovative design of a PIV-compatible venous valve model which has the ability to function at minimal pressure differences and which is able to generate valuable PIV data.

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An experimental and numerical platform was developed to investigate the fluidodynamics in human airways. A pre operative patient specific geometry was used to create an identical experimental and numerical model. The experimental results obtained from Particle Image Velocimetry (PIV) measurements were compared to Computational Fluid Dynamics (CFD) simulations under stationary and pulsatile flow regimes. Together these results constitute the first step in predicting the clinical outcome of patients after lung surgeries such as Lung Volume Reduction.