Patent ID: 8174697

Claim:
A method of detecting a particle, said method comprising the steps of: providing said particle suspended within a fluid flowing in a flow direction through a flow cell; passing a beam of electromagnetic radiation having a cross sectional profile having a major axis and a minor axis through said fluid, wherein an angle between said major axis and said flow direction is non-orthogonal, and wherein said particle interacts with said beam thereby generating scattered or emitted electromagnetic radiation; collecting at least a portion of said scattered or emitted electromagnetic radiation using a system of optics, wherein said system of optics has an optical axis positioned non-orthogonal to said major axis; imaging at least a portion of said scattered or emitted electromagnetic radiation collected by said system of optics onto a two-dimensional detector, wherein said two-dimensional detector is positioned non-orthogonal to said optical axis of said system of optics; detecting at least a portion of said scattered or emitted electromagnetic radiation imaged on said two-dimensional detector, thereby generating a plurality of output signals corresponding to intensities of said scattered or emitted electromagnetic radiation detected by said two-dimensional detector; and analyzing at least a portion of said plurality of output signals using one or more techniques selected from the group consisting of time delay integration, image threshold analysis, image shape analysis, pulse height analysis, and pulse width analysis, thereby detecting said particles.