Developing a blood-mimicking fluid for particle image velocimetry with silicone vascular models
Date of Award
Master of Engineering Science
A new blood-mimicking fluid (BMF) has been developed which enables the study of flow in vascular models using particle image velocimetry (PIV).
PIV is a valuable engineering technique used to obtain accurate flow-related in formation, such as velocity and shear stress, in order to gain a better understanding of the hemodynamics related to the initiation and progression of vascular disease. In PIV, flow models are perfused with a fluid seeded with tiny particles. The distance traveled by particles over a specific time is measured, by correlating consecutive im ages from high resolution cameras, and used to determine fluid velocity. A major difficulty in PIV that affects measurement accuracy is the deflection and distortion of light passing through the model and the fluid, due to the difference in the refractive index (n) between the two materials. The problem can be eliminated by using a fluid with a refractive index matching that of the model. Such fluids are not commonly available, especially for vascular research where the fluid should also have a viscosity similar to human blood (4.4 ± 0.5 cP).
In this work, a new blood mimicking fluid (BMF) composed of varying relative concentrations of water, glycerol, and sodium iodide, has been developed to accom modate commonly used modeling materials such as silicone elastomers. The fluid exhibits a refractive index ranging between, but not limited to, 1.40 and 1.43 and a viscosity ranging between 4.16-4.69 cP. A mixture suitable for use with our silicone vascular models (Sylgard 184; n — 1.414) was produced by using relative concentra tions (% by weight) of 47.38% water, 36.94% glycerol and 15.68% sodium iodide, with resulting viscosity of 4.31 ± 0.03 cP and refractive index of 1.4140 ± 0.0001.
This BMF enables PIV studies in vascular models of materials with various re fractive indices while maintaining a suitable viscosity with respect to blood. Results demonstrating the possible range of refractive index and viscosity will be presented, as well as demonstrative digital particle images from flow in a carotid artery bifurcation flow model.
Yousif, Majid Yacoub, "Developing a blood-mimicking fluid for particle image velocimetry with silicone vascular models" (2009). Digitized Theses. 3924.