Relationship between power law coefficients and major blood constituents affecting whole blood viscosity

The present work concerns a quantitative analysis of parameters that affect apparent blood viscosity at different low shear rates, i.e, between 1 s-1 and, 100 s-1. Viscosity profile of a large number of blood samples from thromboembolic stroke cases and age and sex matched healthy controls were studied which confirmed non-Newtonian power law behaviour of blood. The power law coefficients, n and k, which are unique to each blood sample, were related with blood viscosity parameters in the form of a mathematical equation by performing non-linear regression analysis. It was possible to calculate n and k of power law model by supplying the values of major blood constituents in the equation obtained for stroke and controls. The calculation of n and k of a blood sample using the equation obtained, provided a quick information on its apparent viscosity values at any given shear rate without viscometry. The calculated and the experimental viscosity were found in good agreement within a permissible error range. The relation obtained between power law coefficients and major blood constituents in the present investigation would give a quantification of different blood viscosity parameters contributing to the resistance to flow of blood. Such an analysis may be considered as a scientific basis for the study of blood fluidity in different disease conditions.