On the viscoelasticity of anticoagulated whole human blood in steady shear as tested by rheogoniometric measurements of normal forces

Abstract

Observations of normal stress were made on whole blood, with hematocrits ranging from 40 to 48 per cent, anticoagulated with EDT A, from six healthy, adult human subjects. Two methods were used in connection with the Weissenberg Rheogoniometer. One technique employs a readout system, while the other concerns visual macroscopic observations. In these measurements, the blood was subjected to rotational testing using a cone and plate geometry at shear rates from 0.001 to 1.0 × 10⁻² sec⁻¹. No positive normal stress at a minimum sensitivity of 1 was found in a study on the presence of normal forces in non-clotted whole blood from healthy human subjects. The negative findings are discussed in relation to concepts by Weissenberg, and to findings of an elastic component in whole blood, recently reported by other authors and subsequently found by us in mutual studies with other investigators.