System and method for particles measurement

Patent metadata

Field	Value
Publication number	US-12399102-B2
Application number	US-202318448563-A
Country	US
Kind code	B2
Filing date	Aug 11, 2023
Priority date	Oct 26, 2017
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

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, the optical system comprising:
(a) a flow cell for flowing a fluid containing particles along a flow direction;
(b) an optical source for generating a beam of electromagnetic radiation in a propagating direction;
(c) a beam shaping optical system positioned to receive the beam of electromagnetic radiation; the beam shaping optical system for generating an anamorphic beam comprising a top hat beam and for directing at least a portion of the top hat beam through the flow cell;
(d) first and second forward-looking detectors each configured to detect light that has interacted with the one or more particles in the flow cell, 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;
(e) 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 one or more particles.

2. The optical system of claim 1 , wherein:
interaction of the top hat beam and the one or more particles produces light transmitted, scattered, or both, along the propagating direction; wherein at least a portion of said light transmitted, scattered, or both, along the propagating direction is detected by the first forward-looking detector and the second forward-looking detector.

3. The optical system of claim 1 , wherein said optical source comprises a laser and the beam shaping system comprising a diffractive element for generating said anamorphic beam.

4. The optical system of claim 1 , wherein the anamorphic beam comprising said top hat beam is characterized by different optical powers in more than one spatial dimension.

5. The optical system of claim 1 , wherein the anamorphic beam comprising said top hat beam is characterized by different optical powers in two spatial dimensions corresponding to a cross-sectional area of the flow cell.

6. The optical system of claim 1 , wherein the anamorphic beam passes through the flow cell once.

7. The optical system of claim 1 , wherein the anamorphic beam is directed to interact with the first and second regions of the flow cell twice.

8. The optical system of claim 1 , wherein the anamorphic beam is directed to interact with the first and second regions of the flow cell more than twice.

9. The optical system of claim 1 , wherein the first and second forward-looking detectors comprise one or more segmented linear detector arrays.

10. The optical system of claim 1 , wherein the first and second forward-looking detectors together comprise a segmented linear detector array.

11. The optical system of claim 1 , wherein the differential signal is the difference between the first signal and the second signal.

12. The optical system of claim 1 , wherein the analyzer generates a summation signal from the first signal and second signal characteristic of the particles, wherein the summation signal is the sum of the first signal and the second signal.

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

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

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

16. 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.

17. 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.

18. 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.

19. The optical system of claim 16 , 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.

20. The optical system of claim 19 , 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

• G01N2015/1027

  Determining speed or velocity of a particle · CPC title

• G01N2015/1493

  Particle size · CPC title

• G01N2015/1486

  Counting the particles · CPC title

• G01N15/1459 Primary

  the analysis being performed on a sample stream · CPC title

• G01N2015/0053

  in liquids, e.g. trouble · CPC title