Fig. 3

Constraint of platelet acceleration directly modulates [Ca²⁺]_c flux. A–F Color maps showing velocity (U m s⁻¹) and strain rate (\(\dot{\gamma}\) s⁻¹) distributions within an x,y plane 50 μm from the microchannel floor (derived from CFD modelling of blood flow; Q = 200 μL/min) for θ_e = 60°, 40°, 20° (constant exit θ = 80°). White lines show predicted platelet trajectories (2 μm particles) (see “Methods”). G Predicted change in U for T14 as a function of θ_e. H Predicted strain rate profiles for T14 as a function of θ_e. I Predicted shear stress profiles for T14 as a function of θ_e. J Coordinate system showing predicted change in trajectory T14 as a function of θ_e and 10 μm Ø subsampling regions of interest (ROI) as a function of position within the microfluidic. K Ca²⁺ sampling along T14 as a function of θ_e for 10 μm Ø ROIs defined as: Baseline—− 3 mm upstream of stenosis apex center-point; Acc1—at start of flow acceleration zone; Acc2—mid-acceleration zone; Acc3—end of flow acceleration zone (θ_e = 20° [N = 3 experiments]; θ_e = 40° [N = 5 experiments]; θ_e = 60° [N = 5 experiments]; θ_e = 80° [N = 8 experiments]). L Platelet aggregation at stenosis apex as a function of θ_e. Curves shown are [Agonist] vs. response Variable slope (four parameters) least squares fit + 95% CI. Dots represent individual data sets from N = 5 independent experiments