Particle aggregation monitoring by speckle size measurement; application to blood platelets aggregation.

We report on a new method based on speckle size analysis and devoted to particle aggregation measurements. The experimental measurements give the speckle size variation during a salt aggregation process of polystyrene microspheres. The measurements are taken at a fixed monomer concentration, varying the salt concentration. Moreover, we applied this technique to follow blood platelet aggregation, usually monitored with a visible light transmittance photometer (aggregometer). Aggregation process was induced by ADP (adenosine diphosphate) addition, then we measured the speckle size variation versus time at two different ADP concentrations.