Patent EP-2669678-A1 (EP)
Inventor: POHER VINCENT
IPC: G01N15/14
Filed: 2013-05-31
Abstract: The method comprises: introducing a liquid (12) in a fluid chamber (14); illuminating the fluid chamber via an excitation light beam (18) emitted by a light source (16), where the light beam extends through the fluid chamber in a longitudinal direction (X); acquiring an image of a matrix photodetector; and calculating an indicator characterizing the variation of the speed or particle agglomeration from the acquired image. In the acquiring step, the photodetector is arranged at a distance of less than 1 cm from the fluid chamber in the longitudinal direction. The method comprises: introducing a liquid (12) in a fluid chamber (14); illuminating the fluid chamber via an excitation light beam (18) emitted by a light source (16), where the light beam extends through the fluid chamber in a longitudinal direction (X); acquiring an image of a matrix photodetector, where the image is formed by a radiation transmitted by the fluid chamber; and calculating an indicator characterizing the variation of the speed or particle agglomeration from the acquired image. In the acquiring step, the photodetector is arranged at a distance of less than 1 cm from the fluid chamber in the longitudinal direction. The light beam has a surface area of 25 mm 2> according to a plane perpendicular to the longitudinal direction, where the plane is arranged in contact with the fluid chamber. The light beam directly illuminates the fluid chamber, and the images are directly formed by the radiation transmitted by the fluid chamber enlightened in the absence of an enlargement optics placed between the fluid chamber and the photodetector. The image transmission is acquired sequentially at different temporal moments in the step of acquisition. A first calculated indicator is an indicator of correlation ready to characterize the variation of the speed of the particles at the step of calculation. The indicator of correlation is representative of the correlation between the two image transmissions acquired at moments or the correlation for a predetermined area image transmission. The liquid comprises an analyte. The method further comprises mixing the liquid with a reagent to support the deceleration of the particles, where the reagent supports the deceleration of the blood particles via a coagulation of blood; determining coagulation of the blood particles and/or a time of coagulation from the first calculated indicator between a moment origin and a moment to which the first calculated indicator takes a predetermined value; and estimating the quantity of the analyte in the liquid in function of a second calculated indicator. The light source is a temporally coherent light source such as laser. The first indicator is calculated from correlation images defining a space correlation between the image transmissions or a predetermined area of the images correlation. The correlation images are determined by an equation as given in the specification. The first indicator is calculated using an equation as given in the specification. The second calculated indicator is an indicator for each acquired images at the step of calculation, where the second indicator is representative of the intensity of the pixels of images in a predetermined area of images. The particle agglomeration is determined from the second calculated indicator and given when the second indicator exceeds a predetermined threshold or exceeds an indicator of reference obtained by the images realized in a reference area. The reagent comprises an antibody. Relative information with the blood type is given from the particle agglomeration. The fluid chamber comprises multiple channels for circulating the fluid. The indicator is calculated for each of the channels at the step of calculation. An independent claim is included for a system for characterizing a speed distribution and clotting of particles in a liquid.