The effect of rotational stirring on the suspension stability of human blood

Article type: Research Article

Authors: Barbee, James^{; *}

Affiliations: Department of Chemical Engineering, California Institute of Technology, Pasadena, California 91109

Note: [*] Present address: Department of Chemical Engineering, Iowa State University, Ames, Iowa 50010.

Abstract: The complete study of the rheological properties of human blood requires the use of a capillary viscometer. In a capillary viscometer, the blood in the feed reservoir must be continuously stirred in order to prevent sedimentation. The density difference between the plasma and the red cell that causes the red cells to settle in stationary blood may cause a radial concentration gradient when the blood is stirred with a rotating stirring bar. The radial concentration distribution of red cells in a healthy human blood sample contained in a capillary viscometer feed reservoir and stirred by a magnetic stirring bar rotating on the bottom of the reservoir was investigated. The results indicate that centrifugal stirring can be used to agitate blood (and attain complete mixing and rouleaux breakup) in the feed reservoir of a capillary viscometer. This is accomplished at a fairly low rotational speed; plasma denaturation due to continuous production of fresh blood–air interface is negligible.

DOI: 10.3233/BIR-1973-10305

Journal: Biorheology, vol. 10, no. 3, pp. 321-323, 1973