System and method for particles measurement

Patent metadata

Field	Value
Publication number	US-11781965-B2
Application number	US-201816652653-A
Country	US
Kind code	B2
Filing date	Oct 25, 2018
Priority date	Oct 26, 2017
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

An optical system for particle size and concentration analysis, includes: at least one laser that produces an illuminating beam; a focusing lens that focuses the illuminating beam on particles that move relative to the illuminating beam at known or pre-defined angles to the illuminating beam through the focal region of the focusing lens; and at least two forward-looking detectors, that detect interactions of particles with the illuminating beam in the focal region of the focusing lens. The focusing lens is a cylindrical lens that forms a focal region that is: (i) narrow in the direction of relative motion between the particles and the illuminating beam, and (ii) wide in a direction perpendicular to a plane defined by an optical axis of the system and the direction of relative motion between the particles and the illuminating beam. Each of the two forward-looking detectors is comprised of two segmented linear arrays of detectors.

First claim

What is claimed is:

1. An optical system for particle detection configured to operate in a Dual Path mode, the optical system comprising:
(a) an optical source for generating an illuminating beam in a propagating direction;
(b) a flow cell positioned in a particle detection region, the flow cell comprising a fluid flow inlet and a fluid flow outlet, the flow cell configured for receiving the illuminating beam and for passing a fluid flow having one or more particles into the fluid flow inlet, along a flow direction through the illuminating beam, and out the fluid flow outlet;
(c) a first optical element that receives said illuminating beam from said optical source and focuses said illuminating beam on the one or more particles in the fluid flow at a focal region of the first optical element;
(d) a beam splitter for transmitting at least a portion of the illuminating beam in the propagating direction;
(e) a reflective surface configured to reflect at least a portion of the illuminating beam after interacting with said one or more particles in said particle detection region, thereby generating a reflected beam in a reflected direction, wherein said beam splitter directs at least a portion of the reflected beam to first and second forward-looking detectors; and
(f) the first and second forward-looking detectors each configured to detect light that has interacted with the one or more particles in both a first interaction in the propagating direction and a second interaction in the reflected direction, wherein:
(1) the first interaction produces light transmitted, scattered, or both, forward of the one or more particles along the propagating direction upon interaction of the one or more particles and the illuminating beam, and
(2) the second interaction produces light transmitted, scattered, or both, forward of the particles along the reflected direction upon interaction of the one or more particles and the reflected beam,

wherein each of the first and second forward-looking detectors comprises a segmented linear detector array; wherein the first detector is configured to detect light from a first region of the flow cell thereby generating a first signal, and the second detector is configured to detect light from a second region of the flow cell positioned down stream of said first region along said flow direction, thereby generating a second signal; and
(g) an analyzer for receiving the first signal from the first detector and the second signal from the second forward looking detector; wherein the analyzer generates a differential signal from the first signal and the second signal characteristic of the particles.

2. The optical system of claim 1 , wherein said illuminating beam comprises a Gaussian beam, a structured non-Gaussian beam, or a structured dark beam.

3. The optical system of claim 2 , wherein said optical source comprises a laser and a phase element for generating said illuminating beam comprising a structured non-Gaussian beam, a dark beam, or a structured dark beam.

4. The optical system of claim 1 , wherein said reflective surface comprises a mirror.

5. The optical system of claim 1 , wherein said first optical element comprises a beam shaping optical system for generating an anamorphic beam from said illuminating beam which is provided to the particle detection region.

6. The optical system of claim 1 , wherein said first optical element comprises a cylindrical lens.

7. The optical system of claim 1 , further comprising a second optical element for receiving and focusing said reflected beam on said one or more particles in said particle detection region at a focal region of the second optical element.

8. The optical system of claim 7 , wherein the focal region of the first optical element and the focal region of the second optical element are overlapping.

9. The optical system of claim 7 , wherein said second optical element comprises a cylindrical lens.

10. The optical system of claim 1 , wherein said analyzer analyzes said differential signals in a time domain.

11. The optical system of claim 1 , wherein said analyzer counts said one or more particles based on said differential signals or characterizes the size of said particles based on said differential signals.

12. The optical system of claim 1 , wherein said analyzer comprises a pattern matching unit, to perform a pattern matching of (i) an array of synthetically generated potential interactions, with (ii) the differential signals.

13. The optical system of claim 1 , wherein said analyzer compares each differential signal with a pre-generated library of known signals corresponding to particles to determine if each differential signal corresponds to a particle detection event or laser noise.

14. The optical system of claim 1 , wherein each differential signal is converted to a frequency domain using a Fourier transformation or a fast Fourier transformation by said analyzer.

15. The optical system of claim 12 , wherein the pattern matching is performed using a convolution of the differential signal against a bank of variable delay and variable width matched filters according to equation (1):
y k ( t )= x ( b )* h k ( t )  (1)

wherein x(t) is the differential signal; h k (t) is a specific matching filter normalized to unit energy; and y k (t) is an output signal.

16. The optical system of claim 15 , wherein a mean sensor response is represented by equation (2):

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Assignees

• Particle Measuring Syst

Inventors

• Karasikov Nir
• Weinstein Ori
• Shwartz Shoam
• Moghaddam Mehran Vahdani
• Dubin Uri

Classifications

• G01N15/1434 Primary

  Optical arrangements · CPC title

• G01N15/1459 Primary

  the analysis being performed on a sample stream · CPC title

• G01N2015/1075

  Physics · mapped topic

• G01N2015/1486

  Counting the particles · CPC title

• G01N2015/1493

  Particle size · CPC title