Medical devices that pump blood should do so without damaging the blood. Damage may be either homolysis or thrombosis, which are both life-threatening conditions. To aid those responsible for medical device approval, we seek to develop methods to measure local stress states in benchmark constriction-flow geometries that lead to blood damage. For example, we seek improvements in flow-field imaging, flow birefringence imaging, and model fluids that replicate non-Newtonian blood rheology and that contain suitable probes.