Figure 4.

Estimation of shear rate and velocity in the bleed chip using numerical modeling. Computational fluid dynamics model of the bleed chip was solved using COMSOL to generate surface plots of velocity (a) and shear rate (b) in the bleed chip at initial steady state conditions. (a) Surface plot of velocity in the bleed chip at steady state conditions. White arrows indicate the direction of flow in the device. Blood is modeled as a non-Newtonian power law fluid and the Navier-Stokes equation is solved using COMSOL to compute the velocity and shear rate in the bleed chip at steady state conditions. (b) Wall shear rate increases from 1000 s⁻¹ in the main channel to 9000 s⁻¹ on pillar surfaces and then decreases to 1000 s⁻¹ distal to the pillars in the bleeding channel.