LAUSR

It is essential to formulate a refractive index (RI)-matched fluid to use in silicone phantom models for particle image velocimetry (PIV) experiments. In this work, an extensive effort to develop a non-Newtonian human milk-mimicking fluid (HMMF) with different concentrations of sodium iodide (NaI), glycerol (Gly), xanthan gum (XG), and distilled water (DW) is conducted. Measurements of RI and density are fitted onto a linear empirical expression relating to the NaI and Gly concentration. The Cross model was utilized to find the nonlinear viscosity model of raw human milk. HMMF solution is generated from a multi-constrained optimization. The matched HMMF, suitable for use in the lactating human breast phantom with bifurcated ductal structures, is achieved with composition of 15.69% NaI, 30.27% Gly, 54.02% water and 0.02% XG by weight percentage resulting in a non-Newtonian viscosity matched with that of human milk.