Automatically counting leucocytes of different types - by recognition of diffraction image produced in laser beam

摘要

Automatic differential counting of leucocytes in a blood sample consists of conducting the individual cells of the blood sample continuously and successively through the beam of a laser and of analysing the diffraction pattern of each cell by photoelectric receivers. In one variant, parallel laser light is used and the Fraunhofer diffraction pattern of the cells is analysed. Alternatively, the laser beam is focused and the cells pas through the focal point. Each different type if leucocyte is found to produce different, characteristic diffraction pattern; this feature is used to enable the cells to be automatically counted, thus obviating the necessity for laborious counting through a microscope.