Evaluation of blood plasma coagulation dynamics by speckle analysis.

Analysis of speckle dynamics is frequently used to study the motion of scattered objects or liquids. By assessing the increase in contrast on the speckle field produced by a blood plasma sample, illuminated by a laser during a coagulation test, as well as the slowing down of speckle fluctuations, we measured the time required for blood plasma coagulation in vitro and evidence the process dynamics. Then, we compared this noninvasive method with a mechanical viscosity-based detection system classically used in hematology laboratories; our results show good correlation and could provide more information about the blood clotting process.