Realtime optical method and system for detecting and classifying biological and non-biological particles
AssigneeHamilton Associates, Inc.
InventorDavid B. Silcott
Life of this patent
Estimating the term…
Abstract
Methods, apparatuses, and systems for detecting and classifying individual airborne biological and non-biological particles, in real time, based on particle size and polarized elastic scatter. Auto-fluorescence content may also be used along with particle size and polarized elastic scatter for further orthogonal classification. With polarized elastic scattering, the degree of linear or circular depolarization produced from particle morphology, refractive index, internal asymmetric structures and molecular optical activity can be used for classifying individual airborne particles. Alternatively, circular intensity differential scattering (CIDS) or linear intensity differential scattering (LIDS) can be used to discriminate individual particles.
Claims25
A method of detecting and classifying single airborne particles, said method comprising:
- (a) directing an airborne sample having a plurality of airborne particles into an optical sensing zone of an optical detector, the airborne sample being taken from an environment surrounding the optical detector;
- (b) illuminating a single airborne particle in the optical sensing zone with a first polarized light beam;
- (c) detecting elastic light scatter resulting from the illumination of the single airborne particle with the first polarized light beam;
- (d) determining, using the detected elastic light scatter resulting from the illumination of the single airborne particle with the first polarized light beam, each of the following:
- (i) a size of the single airborne particle;
- and,
- (ii) a first value for the single airborne particle wherein the first value is one of a depolarization value for the single airborne particle and an intensity differential elastic scattering value for the single airborne particle;
- and,
- (e) determining at least one characteristic of the single airborne particle based on the size of the single airborne particle and the first value for the single airborne particle.
A method of detecting and classifying single airborne particles, said method comprising:
- (a) using a vacuum source to pull an airborne sample having a plurality of airborne particles into an optical sensing zone of an optical detector from an environment surrounding the optical detector;
- (b) illuminating a single airborne particle in the optical sensing zone with a horizontally polarized light beam;
- (c) illuminating the single airborne particle in the optical sensing zone with a vertically polarized light beam, wherein the vertically polarized light beam illuminates the single airborne particle before or after the horizontally polarized light beam illuminates the single airborne particle;
- (d) detecting elastic light scatter resulting from the illumination of the single airborne particle with the horizontally polarized light beam and the vertically polarized light beam;
- and,
- (e) prior to the detecting step of paragraph (d), passing elastic light scatter resulting from the illumination of the single airborne particle with the horizontally polarized light beam through a horizontal polarization filter.
A single airborne particle optical analyzer for detecting and classifying single airborne particles, said single airborne particle optical analyzer comprising:
- (a) an optical sensing zone;
- (b) a vacuum source for pulling an airborne sample having a plurality of airborne particles into an optical sensing zone of an optical detector from an environment in which the optical sensing zone is located;
- (c) means for illuminating a single airborne particle in the optical sensing zone with at least one polarized light beam;
- (d) a light detector for detecting elastic light scatter resulting from the illumination of the single airborne particle;
- (e) a processor for determining, using the detected elastic light scatter resulting from the illumination of the single airborne particle, each of the following:
- (i) a size of the single airborne particle;
- and,
- (ii) a first value for the single airborne particle wherein the first value is one of a depolarization value for the single airborne particle and an intensity differential elastic scattering value for the single airborne particle;
- and,
- (f) the processor further being configured to determine at least one characteristic of the single airborne particle based on the size of the single airborne particle and the first value for the single airborne particle.
A method of detecting and classifying single airborne particles, said method comprising:
- (a) directing an airborne sample having a plurality of airborne particles into an optical sensing zone of an optical detector, the airborne sample being taken from an environment surrounding the optical detector;
- (b) illuminating a single airborne particle in the optical sensing zone with a first polarized light beam;
- (c) determining from the illumination of the single airborne particle with the first polarized light beam, each of the following:
- (i) particle auto-fluorescence;
- and,
- (ii) a first value for the single airborne particle wherein the first value is a depolarization value for the single airborne particle;
- and,
- (d) determining at least one characteristic of the single airborne particle based on particle auto-fluorescence and the first value for the single airborne particle.
Dependencies are inferred from the claim text.