Whole-blood viscosity, as determined by plasma viscosity, haematocrit, and shear¹

Issue title: Proceedings of the Fourth International Congress of Biorheology. Jikei University School of Medicine, Tokyo, Japan, 27 July – 1 August 1981. Dedicated to Alex Silberberg

Guest editors: Alfred L. Copley

Article type: Research Article

Authors: Whittington, R.B.^a | Harkness, J.^b

Affiliations: [a] Bioengineering Unit, University of Liverpool, England | [b] Musgrove Park Hospital, Taunton, Somerset, England

Note: [1] Paper prepared at the 4th International Congress of Biorheology, Tokyo, 1981.

Note: [] Accepted by: Editor S. Oka

Abstract: The viscometers used were: (a) a proprietary rotational coaxial-cylinder instrument; and (b) a Harkness capillary-tube viscometer. In (a), the mean shear-rate is selected by the choice of rotational speed. In (b), the wall shear-stress is selected by the choice of driving-pressure. If the Viscosity is varied, the mean shear-rate varies, at constant wall shear-stress. The present paper attempts to show how, in principle, a complete family of “constant-rate” (rotational) curves can be computer-plotted from two suitably-spaced capillary-tube measurements. The reverse process, involving the correction of “playback” errors, is touched upon. A variable “Einstein coefficient” is derived from the principal parameters in the computer solution; and the basic problems of compatibility in “rates of shear” are discussed.

Keywords: Viscosity, haematocrit, shear

DOI: 10.3233/BIR-1982-191-220

Journal: Biorheology, vol. 19, no. 1-2, pp. 175-184, 1982