Methods to study rheological properties of blood during clotting.

In vitro rheological studies on clotting of fibrinogen solution, plasma and blood are reviewed. Multiple viscoelastorecorder (MVER) and viscoelastorecorder (VER) were developed for determining the dynamic rigidity modulus (G') and loss modulus (G") during clotting. The effect of some parameters on clotting and the properties of fibrin clot are discussed. The parameters include measuring frequency, measuring shear strain and surface coating of measuring cell. The change of dynamic rigidity during clotting was compared between normal plasma and plasma from patient with Glanzmann's disease. By detecting the stress at the higher harmonic frequency, the non-linear terms of G' and G" were determined.