Pulse edge measurement for determining particle dimensional characteristics

摘要

Method and apparatus for analyzing pulses from optical devices such as flow cytometers to generate indicators of particle dimensional attributes, such as size and shape, as well as orientations in a flow stream of non-spherical particles. Particles are conveyed through a beam of electromagnetic radiation and a photodetector responds to radiation resulting from interaction of the particle with the beam to output a resultant signal in the form of a pulse as a particle enters and passes through the beam. Pulse edge width between two threshold values, preferably established as constant fractions of peak pulse amplitude, is measured as an indication of a particle dimensional attribute.