An experimental approach to study the red blood cell dynamics in a capillary tube by biospeckle laser

In this study we investigated the human red blood cell (RBC) dynamics by means of biospeckle laser analysis. Blood samples from healthy donors were introduced in a 0.8 mm internal diameter capillary tube, and illuminated with a He-Ne laser in order to obtain the biospeckle pattern from both side and for- ward scattered light. Experiments were carried out for di erent concentrations of red blood cells in plasma, from 25% to 50%. Biospeckle parameters such as Correlation Coe cient and Inertia Moment, were calculated for di erent fre- quency bandwidths in order to assess their sensitivity and versatility. A lter based on the Discrete Wavelet Transform was used to decompose the registered sample activity. A relation between Inertia Moment and the RBCs to plasma volume ratio was observed. The Correlation Index that measures the level of correlation of biospeckle images was de ned and analyzed. This work inquires in a technique that is suitable for the development of novel non-invasive optical tools for clinical diagnosis in vascular pathologies.