US Patent 7217937 Automatic identification of suspended particles

The present invention relates to the automatic analysis and identification of different species of particles in a liquid sample using both fluorescent tagging and magnification techniques. A light source at a first wavelength is used to induce the tagged particles to emit light at a second wavelength, while the image thereof is captured on a pixel array of a digital camera. A second camera can be used to capture an image of the particles illuminated at the first wavelength, which is separated from the second wavelength by an optical filter. Alternatively, a second light source emitting pulses of light at the second wavelength, which alternate with the first light source.