Two-dimensional optical imaging methods and systems for particle detection

An optical particle analyzer comprising:

• an optical source for generating a beam of electromagnetic radiation;
• a flow chamber for flowing a fluid containing particles along a flow direction and through the beam of electromagnetic radiation, thereby generating scattered or emitted electromagnetic radiation from a single particle in said fluid;
• an optical collection system for collecting and directing at least a portion of the scattered or emitted electromagnetic radiation from said single particle onto a plurality of detector elements of an array of a two-dimensional detector, wherein at least a portion of the detector elements of the array generate output signals corresponding to intensities of the scattered or emitted electromagnetic radiation;
• and
• a processor operationally connected to the two-dimensional detector capable of identifying and analyzing a particle detection signature for said single particle comprising a pattern of a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element;
• wherein the threshold value for each detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element;
• wherein said particle detection signature comprises a longitudinal component corresponding to a distribution of intensities of said scattered or emitted electromagnetic radiation along said flow direction;
• said longitudinal component comprising 2 or more directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction.

A method of distinguishing a single particle scattering event from other electromagnetic radiation generation or detection processes in an optical particle analyzer, said method comprising the steps of:

• providing a fluid flow having said particle to said optical particle analyzer, said fluid flow having a flow direction;
• exposing said fluid flow to a beam of electromagnetic radiation, wherein interaction between said single particle and said beam generates scattered or emitted electromagnetic radiation from said single particle;
• directing at least a portion of said scattered or emitted electromagnetic radiation onto a plurality of detector elements provided in an array of a two-dimensional detector of said optical particle analyzer;
• detecting at least a portion of said scattered or emitted electromagnetic radiation directed onto said plurality of detector elements, wherein at least a portion of said detector elements of said array generate output signals corresponding to intensities of said scattered or emitted electromagnetic radiation from said single particle;
• measuring output signals for at least a portion of said detector elements of said array;
• and
• sensing a particle detection event upon identification of a particle detection signature for said single particle comprising a pattern of a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element;
• wherein the threshold value for each detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element;
• wherein said particle detection signature comprises a longitudinal component corresponding to a distribution of intensities of said scattered or emitted electromagnetic radiation along said flow direction;
• said longitudinal component comprising 2 or more directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction;
• thereby distinguishing said single particle scattering event from other electromagnetic radiation generation or detection processes in said optical particle analyzer.

A method for detecting a single particle in a fluid flow, said method comprising the steps:

• providing said fluid flow having said single particle, said fluid flow having a flow direction;
• exposing said fluid flow to a beam of electromagnetic radiation, wherein interaction between said single particle and said beam generates scattered or emitted electromagnetic radiation from said single particle;
• directing at least a portion of said scattered or emitted electromagnetic radiation onto a plurality of detector elements provided in an array of a two-dimensional detector;
• detecting at least a portion of said scattered or emitted electromagnetic radiation, wherein at least a portion of said detector elements of said array generate output signals corresponding to intensities of said scattered or emitted electromagnetic radiation from said single particle;
• measuring output signals for at least a portion of said detector elements of said array;
• identifying a particle detection signature for said single particle comprising a pattern of a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element;
• wherein the threshold value for each detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element;
• wherein said particle detection signature comprises a longitudinal component corresponding to a distribution of intensities of said scattered or emitted electromagnetic radiation along said flow direction;
• said longitudinal component comprising 2 or more directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction;
• determining a subset of said detector elements of said array, said subset comprising a plurality of detector elements receiving scattered or emitted electromagnetic radiation from said single particle, wherein each detector element of said subset has an output signal greater than or equal to said threshold value for a given detector element;
• transmitting to a processor only the output signals of said subset;
• and
• analyzing the output signals transmitted to said processor, thereby detecting said single particle.

A method for detecting a single particle in a fluid flow, said method comprising the steps:

• providing said fluid flow having said single particle, said fluid flow having a flow direction;
• exposing said fluid flow to a beam of electromagnetic radiation, wherein interaction between said single particle and said beam generates scattered or emitted electromagnetic radiation from said single particle;
• directing at least a portion of said scattered or emitted electromagnetic radiation onto a plurality of detector elements provided in an array of a two-dimensional detector;
• detecting at least a portion of the scattered or emitted electromagnetic radiation directed onto said plurality of detector elements, wherein at least a portion of said detector elements of said array generate output signals corresponding to intensities of said scattered or emitted electromagnetic radiation from said single particle;
• measuring output signals for at least a portion of said detector elements of said array;
• identifying a particle detection signature for said single particle comprising a pattern of a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element;
• wherein the threshold value for each detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element;
• wherein said particle detection signature comprises a longitudinal component corresponding to a distribution of intensities of said scattered or emitted electromagnetic radiation along said flow direction;
• said longitudinal component comprising 2 or more directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction;
• generating a plurality of detection frames, wherein each detection frame comprises a plurality of said output signals of said detector elements for a given time interval;
• combining a plurality of detection frames having output signals corresponding to detected intensities of said scattered or emitted electromagnetic radiation to generate a composite image of a particle detection event for said single particle;
• analyzing said composite image, thereby detecting said single particle.

A method for detecting a single particle in a fluid flow, said method comprising the steps:

• providing said fluid flow having said single particle, said fluid flow having a flow direction;
• exposing said fluid flow to a beam of electromagnetic radiation, wherein interaction between said single particle and said beam generates scattered or emitted electromagnetic radiation from said single particle;
• directing at least a portion of said scattered or emitted electromagnetic radiation onto a plurality of detector elements provided in an array of a two-dimensional detector;
• detecting at least a portion of said scattered or emitted electromagnetic radiation directed onto said plurality of detector elements, wherein at least a portion of said detector elements of said array generate output signals corresponding to intensities of said scattered or emitted electromagnetic radiation from said single particle;
• measuring output signals for at least a portion of said detector elements of said array;
• identifying a particle detection signature for said single particle comprising a pattern of a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element;
• wherein the threshold value for each detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element;
• wherein said particle detection signature comprises a longitudinal component corresponding to a distribution of intensities of said scattered or emitted electromagnetic radiation along said flow direction;
• said longitudinal component comprising 2 or more directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction;
• detecting at least a portion of said scattered or emitted electromagnetic radiation using a sub-array of said two-dimensional detector, wherein at least a portion of said detector elements of said sub-array generate output signals corresponding to intensities of said scattered or emitted electromagnetic radiation from said single particle;
• transmitting to a processor only output signals of said detector elements corresponding to said sub-array or a portion thereof;
• and
• analyzing the output signals transmitted to said processor, thereby detecting said single particle.

A method for detecting a single particle in a fluid flow, said method comprising the steps:

• providing said fluid flow having said single particle, said fluid flow having a flow direction;
• exposing said fluid flow to a beam of electromagnetic radiation, wherein interaction between said single particle and said beam generates scattered or emitted electromagnetic radiation from said single particle;
• directing at least a portion of said scattered or emitted electromagnetic radiation onto a plurality of detector elements provided in an array of a two-dimensional detector;
• detecting at least a portion of said scattered or emitted electromagnetic radiation directed onto said plurality of detector elements, wherein at least a portion of said detector elements of said array generate output signals corresponding to intensities of said scattered or emitted electromagnetic radiation from said single particle;
• measuring output signals for at least a portion of said detector elements of said array;
• identifying a particle detection signature for said single particle comprising a pattern of a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element;
• wherein the threshold value for each detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element;
• wherein said particle detection signature comprises a longitudinal component corresponding to a distribution of intensities of said scattered or emitted electromagnetic radiation along said flow direction;
• said longitudinal component comprising 2 or more directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction;
• detecting at least a portion of said scattered or emitted electromagnetic radiation using a sub-array of said two-dimensional detector, wherein at least a portion of said detector elements of said sub-array generate output signals corresponding to intensities of said scattered or emitted electromagnetic radiation;
• determining a subset of said detector elements of said sub-array, said subset comprising a plurality of detector elements, wherein each detector element of said subset has an output signal greater than or equal to said threshold value for a given detector element;
• transmitting to a processor only the output signals of said subset;
• and
• analyzing the output signals transmitted to said processor, thereby detecting said single particle.