Process and apparatus for counting biological particles

Claim 1

A process for the instantaneous counting of the various particles in suspension in a sample of blood and for determining the hematocrit and average red blood cell volume, comprising the steps of: placing two samples successively into the trajectory of a light beam emerging from an optical system converging on a focal plane powered by a source of coherent and monochromatic light, one of said samples being a blood sample in which the red blood cells have been spherized and the other of which being a blood sample in which the red blood cells have been hemolyzed; detecting and measuring the luminous flux diffracted by the particles at said focal plane between the angles formed with the initial direction of the light beam: s1 (1.5 to 2.5) ( lambda / pi (ad)) and s2 (3 to 5)s1, and s''1 0.5 lambda / pi (ad) and s''2 3 s''1, where lambda is the wavelength of the light used, ad is the average diameter of the particles being analyzed and s1, s2, s''1, and s''2 are expressed in radians; and transforming said detected and measured luminous fluxes into electrical signals, correcting to eliminate known sources of error and displaying the results for the number of platelets, the number of white cells, the number of red cells, the hematocrit and the average red blood cell volume.

Claim 7

An apparatus for the instantaneous counting of the various particles in suspension in a sample of blood and for determining the hematocrit and average red cell volume, comprising: a. a source of coherent monochromatic light; b. a convergent optical system mounted in front of said source; c. at least one cell which serves as a receptacle for the blood to be analyzed, said cell being placed on the trajectory of the light beam; d. a screen placed in the focal plane of the optical system and containing at least two windows whose internal edges and external edges correspond to the diffraction angles which are essentially equal respectively to the following: s1 (1.5 to 2.5) ( lambda / pi (ad)) and s2 (3 to 5)s1, (1) and s''1 (0.5 lambda / pi (ad)) and s''2 3s''1, (2) where lambda is the wavelength of the light used, ad is the averate diameter of the particles being analyzed, and s1, s2, s''1, and s''2 are expressed in radians; e. means for measuring the diffracted light fluxes which pass through said windows; and f. means for transforming the fluxes into electrical signals characteristic of each type of particle and for displaying directly the results thereof.

Claim 8

An apparatus for the instantaneous counting of the various particles in suspension in a sample of blood and for determining the hematocrit and average red cell volume, comprising: a. a source of coherent monochromatic light; b. a convergent optical system mounted in front of said source; c. at least one cell which serves as a receptacle for the blood to be analyzed, said cell being placed on the trajectory of the light beam; d. a screen placed in the focal plane of the optical system and containing at least two windows whose internal edges and external edges correspond to the diffraction angles which are essentially equal respectively to the following: s1 (1.5 to 2.5) ( lambda / pi (ad)) and s2 (3 to 5)s1, (1) and s''1 (0.5 lambda / pi (ad)) and s''2 3s''1, (2) where lambda is the wavelength of the light used, ad is the averate diameter of the particles being analyzed, and s1, s2, s''1, and s''2 are expressed in radians; e. means for measuring the diffracted light fluxes which pass through said windows; and f. means for transforming the fluxes into electrical signals characteristic of each type of particle and for displaying directly the results thereof.