title: Shear viscosity and nonlinear behavior of whole blood under large amplitude oscillatory shear.
abstract: We investigated experimentally the rheological behavior of whole human blood subjected to large amplitude oscillatory shear under strain control to assess its nonlinear viscoelastic response. In these rheological tests, the shear stress response presented higher harmonic contributions, revealing the nonlinear behavior of human blood that is associated with changes in its internal microstructure. For the rheological conditions investigated, intra-cycle strain-stiffening and intra-cycle shear-thinning behavior of the human blood samples were observed and quantified based on the Lissajous-Bowditch plots. The results demonstrated that the dissipative nature of whole blood is more intense than its elastic component. We also assessed the effect of adding EDTA anticoagulant on the shear viscosity of whole blood subjected to steady shear flow. We found that the use of anticoagulant in appropriate concentrations did not influence the shear viscosity and that blood samples without anticoagulant preserved their rheological characteristics approximately for up to 8 minutes before coagulation became significant.
authors.affiliation: Departamento de Engenharia Química, CEFT, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal.
authors.forename: P C
authors.initials: PC
authors.lastname: Sousa
authors.affiliation: Departamento de Engenharia Química, CEFT, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Carneiro
authors.affiliation: Departamento de Neurocirurgia, Hospital S. João, Porto, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Vaz
authors.affiliation: Departamento de Neurocirurgia, Hospital S. João, Porto, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Cerejo
authors.affiliation: Departamento de Engenharia Mecânica, CEFT, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal.
authors.forename: F T
authors.initials: FT
authors.lastname: Pinho
authors.affiliation: Departamento de Engenharia Química, CEFT, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal.
authors.forename: M A
authors.initials: MA
authors.lastname: Alves
authors.affiliation: James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow, UK.
authors.forename: M S N
authors.initials: MS
authors.lastname: Oliveira
mesh_terms: D001775:Blood Circulation; D001777:Blood Coagulation; D005260:Female; D018056:Hemorheology; D006801:Humans; D008297:Male; D017711:Nonlinear Dynamics; D033081:Shear Strength; D013314:Stress, Mechanical; D014783:Viscosity
keywords: Whole blood rheology; anticoagulant effect; large amplitude oscillatory shear (LAOS); shear viscosity