Evaluation of a Desktop 3D Printed Rigid Refractive-Indexed-Matched Flow Phantom for PIV Measurements on Cerebral Aneurysms

• Published in: Cardiovascular engineering and technology Vol. 11; no. 1; pp. 14 - 23
• Main Authors: Ho, W. H., Tshimanga, I. J., Ngoepe, M. N., Jermy, M. C., Geoghegan, P. H.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-02-2020; Springer Nature B.V
• Subjects: 3-D printers; Algorithms; Biomedical Engineering and Bioengineering; Biomedical materials; Biomedicine; Cardiology; Casting; Computational fluid dynamics; Computer simulation; Engineering; Experimentation; Flow visualization; Geometric accuracy; Image quality; Investment casting; Lithography; Measurement methods; Model accuracy; Optical flow (image analysis); Optical properties; Original; Original Article; Particle image velocimetry; Photopolymers; Post-production processing; Refractivity; Thiocyanates; Three dimensional flow; Three dimensional models; Three dimensional printing; Visualization; Cerebral aneurysm; Flow phantom; experimentation; Particle image velocimetry; Haemodynamics; Additive manufacturing; PIV; Bio-fluids; Refractive-matched; 3D printing; Experimental fluid dynamics; In vitro experimentation
• ISSN: 1869-408X; 1869-4098
• DOI: 10.1007/s13239-019-00444-z

Purpose
Fabrication of a suitable flow model or phantom is critical to the study of biomedical fluid dynamics using optical flow visualization and measurement methods. The main difficulties arise from the optical properties of the model material, accuracy of the geometry and ease of fabrication.
Methods
Conventionally an investment casting method has been used, but recently advancements in additive manufacturing techniques such as 3D printing have allowed the flow model to be printed directly with minimal post-processing steps. This study presents results of an investigation into the feasibility of fabrication of such models suitable for particle image velocimetry (PIV) using a common 3D printing Stereolithography process and photopolymer resin.
Results
An idealised geometry of a cerebral aneurysm was printed to demonstrate its applicability for PIV experimentation. The material was shown to have a refractive index of 1.51, which can be refractive matched with a mixture of de-ionised water with ammonium thiocyanate (NH
4
SCN). The images were of a quality that after applying common PIV pre-processing techniques and a PIV cross-correlation algorithm, the results produced were consistent within the aneurysm when compared to previous studies.
Conclusions
This study presents an alternative low-cost option for 3D printing of a flow phantom suitable for flow visualization simulations. The use of 3D printed flow phantoms reduces the complexity, time and effort required compared to conventional investment casting methods by removing the necessity of a multi-part process required with investment casting techniques.