Please download the dossier by clicking on the dossier button x
×

Method and system for counting particles in a laminar flow with an imaging device

  • US 8,798,338 B2
  • Filed: 01/09/2006
  • Issued: 08/05/2014
  • Est. Priority Date: 01/09/2006
  • Status: Active Grant
First Claim
Patent Images

1. A method of enumerating particles in a flow wherein the flow is monitored by an imaging system including an imaging device having a focal plane that images an illuminated cross-section of the flow, the method comprising the steps of:

  • (a) imaging one or more frames with the imaging device;

    (b) making a preliminary estimate of particle density, using a default counting algorithm, based upon an imaged frame;

    (c) determining into which of two or more predetermined categories of density the particle density of the imaged frame falls;

    (d) adjusting at least one of the following elements according to the determined density category—

    the counting algorithm;

    a parameter of the imaging system; and

    /orthe flow speed; and

    (e) enumerating particles in the flow after making the adjustment of step (d);

    wherein the adjusting step adjusts the counting algorithm by selecting between counting algorithms designed to operate at different particle density categories;

    wherein the counting algorithms comprise a Lower Particle Density Algorithm and a High Particle Density Algorithm; and

    wherein the Lower Particle Density Algorithm implements the steps of—

    differencing two successive image frames;

    flagging groups of pixels above a predetermined threshold of intensity;

    counting flagged groups as particles; and

    correcting counts for spatial confusion.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×