Affiliations: Unité de Biorhéologie, Département de Biophysique, Université Paris, 6 CHU Pitié-Salpêtrière 91, bd de l’Hopital, 75013 Paris, France
Abstract: Some results on the use of viscometry in clinical hemorheology investigation are presented. First, viscometric quantities used in Couette viscometry such as shear rate, shear stress and apparent viscosity are defined. Then, are given details on the two modes of measurement: steady state and unsteady state flow modes. In the former, shear-thinning rheograms are presented and related data processing is indicated. In the latter, transient rheograms and hysteresis loops are shown and indices of viscoelasticity and thixotropy are defined. Corresponding rheological behaviors are linked to blood structure which is modified by shear stresses. Examples of viscometric data are given for suspensions of artificially modified RBC in the cases of: (i) modifications of RBC aggregation, (ii) modifications of RBC shape and RBC deformability. Finally, clinical applications of viscometry on pathological bloods are given in the cases of insulino-dependent diabetes, Raynaud phenomenon and ischemic cardiopathy with normal coronarography.
