Systems and methods for the determination of the aggregation rate of red blood cells. More specifically, the subject technology is used to determine the aggregation rate of red blood cells, and other parameters related to these, such as viscosity, deformability, elasticity, density, in the field of in vitro medical analyses, using optical systems after or during vibration for red blood cell disruption and redistribution. Once the detected light variation stops decreasing (e.g., a minimum is reached), complete disruption is accomplished for evaluation of the blood sample.