Patent ID: 8634072

Claim:
A method for analyzing particles, comprising: a) providing a sample space for particles, the sample space having a volume, b) illuminating at least one of the particles, c) detecting selected scattered light, which is scattered only from particles located within a region of the sample space, said region having a volume which is smaller than the volume of the sample space, i) wherein the detecting step includes passing said scattered light through an aperture means which allows selected scattered light, which is scattered generally only from particles located within said region to be received by at least one detecting means, ii) wherein the aperture means is located in a plane which is optically conjugate to a plane in said region of the sample space by transfer of light through an optical means, iii) wherein said aperture means and said optical means are designed for providing at least one of the group consisting of 1) selecting scattered light from generally one particle of interest which resides within a plurality of particles and rejecting scattered light from generally other particles of interest which are concurrently in said sample space, 2) lower coincidence counts of particles of interest, and 3) acceptable coincidence counts of particles of interest at higher particle concentration, and d) analyzing the scattered light detected in step (c) to derive information about the particles.