Development of 3-D Printed Optically Clear Rigid Anatomical Vessels for Particle Image Velocimetry Analysis in Cardiovascular Flow

Abstract

In recent years, blood flow analysis of diseased arterial mock vessels using particle image velocimetry (PIV) has been hampered by the inability to fabricate optically clear anatomical vessel models that realistically replicate the complex morphology of arterial vessels and provide highly resolved flow images of flow tracer particles. The aim of the present work is to introduce an approach for producing optically clear rigid anatomical models that are suitable for PIV analysis using a common 3-D SLA inkjet printing process (using a Formlabs Form 2 3-D printer) and stock clear resin (RS-F2-GPCL-04). By matching the index of refraction (IOR) of the working fluid to the stock clear resin material, and by printing the part in a 45-degree print orientation, a clear anatomical model that allows clear visualization of flow tracer particles can be produced which yields highly resolved flow images for PIV analyses. However, a 45-degree print orientation increases the need for post processing due to an increased amount of printed support material. During post processing, the part must be wet sanded in several steps and surface finished with Novus Plastic Polish 3 Step System to achieve the final surface finish needed to yield high quality flow images. The fabrication methodology of the clear anatomical models is described in detail.

A Review on Novel Channel Materials for Particle Image Velocimetry Measurements—Usability of Hydrogels in Cardiovascular Applications

“…IOR matching was not implemented [ 14 ]. Another study was performed by Stanley et al [ 15 ]. The group produced optically clear anatomical vessel models by 3D printing with a rigid resin.…”

“…The group produced optically clear anatomical vessel models by 3D printing with a rigid resin. Stanley et al [ 15 ] matched the IOR of the fluid to that of the resin material by utilizing a fluid mixture composed of sodium iodide, glycerol, and distilled water. The IOR of the resin was 1.5304 [ 15 ].…”

“…Stanley et al [ 15 ] matched the IOR of the fluid to that of the resin material by utilizing a fluid mixture composed of sodium iodide, glycerol, and distilled water. The IOR of the resin was 1.5304 [ 15 ]. The limitations were the stiffness of the model and the postprocess of the inner and outer vessel.…”

“…Current studies have shown substantial limitations in PIV utilization for cardiovascular applications, as the previously discussed studies by ONG et al [ 14 ], STANLEY et al [ 15 ], and Franzetti et al [ 16 ] underline. For the channel materials, polymethylmethacrylate (PMMA) [ 17 ], resin [ 15 ], and silicone [ 14 , 18 , 19 ] have been used. This has made it almost impossible to simulate natural blood vessels.…”

“…Compliance refers to the extensibility of a blood vessel in a radial direction triggered by a physiological pressure load (diastole/systole) [ 20 ]. Mixtures of water with glycerin, sodium iodide, and xanthan gum have been used for blood replacement fluids [ 14 , 15 , 18 , 19 , 21 ]. By changing the chemical composition of these solvents, IOR matching can be adapted precisely.…”