DEVICE AND METHOD FOR DETECTING AND/OR CHARACTERIZING FLUID-BORNE PARTICLES

• US 20190331601A1
• Filed: 05/09/2017
• Published: 10/31/2019
• Est. Priority Date: 06/20/2016
• Status: Active Grant

• Current Assignee: Plair S.A.
• Original Assignee: Plair S.A.
• Inventors: Kiselev, Denis, Kiseleva, Svetlana
• Granted Patent: US 11,204,322 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 15/1434 Optical arrangements
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream
• CPC Class Codes: G01N 2015/1006 for cytology
• CPC Class Codes: G01N 2015/1027 Determining speed or velocity of a particle
• CPC Class Codes: G01N 2021/4761 Mirror arrangements, e.g. in IR range
• CPC Class Codes: G01N 2021/6421 Measuring at two or more wavelengths
• CPC Class Codes: G01N 21/6402 Atomic fluorescence; Laser induced fluorescence
• CPC Class Codes: G01N 21/6408 with measurement of decay time, time resolved fluorescence
• CPC Class Codes: G01N 21/6445 Measuring fluorescence polarisation
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 2201/0697 Pulsed lasers

Abstract

Measurement device for the detection and/or characterization of fluid-borne particles (9), the measurement device comprising means (1, 10) for producing a flow of fluid along a fluid flow path, a laser (2) positioned for emitting pulses of laser light polarized in a first direction of polarization, in a measurement volume of the fluid flow path, each pulse having a pulse duration, means (3) for directing pulses of laser light polarized in a second direction of polarization in the measurement volume, wherein the second direction of polarization is different from the first direction of polarization, a first optical spectrometer for capturing fluorescent light emitted by individual fluid-borne particles (9) in the measurement volume and measuring intensity of the captured fluorescent light at at least one determined wavelength at a sampling rate of at least three samples per pulse duration, wherein the means (3) for directing are configured such that they direct a pulse of laser light polarized in the second direction of polarization in the measurement volume each time a pulse of laser light emitted by the laser (2) and polarized in the first direction has crossed the measurement volume, the time delay between the moment of crossing the measurement volume by the pulse emitted by the laser and the moment of crossing the measurement volume by the pulse directed by the means (3) for directing is longer than the pulse duration and shorter than a travel time of the fluid in the measurement volume. Measurement method for the detection and/or characterization of fluid-borne particles (9) using the measurement device of the invention.

Claims

1. Measurement device for the detection and/or characterization of fluid-borne particles (9), the measurement device comprising:

means (1, 10) for producing a flow of fluid along a fluid flow path;

a laser (2) positioned for emitting pulses of laser light polarized in a first direction of polarization, in a measurement volume of the fluid flow path, each of said pulses having a pulse duration;

means (3) for directing pulses of laser light polarized in a second direction of polarization in said measurement volume, wherein said second direction of polarization is different from said first direction of polarization,

a first optical spectrometer for capturing fluorescent light emitted by individual fluid-borne particles (9) in said measurement volume and measuring intensity of said captured fluorescent light at at least one determined wavelength at a sampling rate of at least three samples per said pulse duration;

wherein said means (3) for directing are configured such that they direct a pulse of laser light polarized in said second direction of polarization in said measurement volume each time a pulse of laser light emitted by said laser (2) and polarized in said first direction has crossed said measurement volume, the time delay between the moment of crossing said measurement volume by said pulse emitted by said laser (2) and the moment of crossing said measurement volume by said pulse directed by said means (3) for directing is longer than said pulse duration and shorter than a travel time of the fluid in said measurement volume.

2. Measurement device according to claim 1, wherein said second direction of polarization is perpendicular to said first direction of polarization.

3. Measurement device according to claim 1 or 2, wherein said means for producing a flow of fluid is a nozzle (1) for producing a laminar flow of air with a flow path beyond the nozzle (1).

4. Measurement device according to claim 1 or 2, wherein said means for producing a flow of fluid comprises a transparent tube (10) for producing a flow of liquid with a flow path along said tube (10).

5. Measurement device according to one of the preceding claims, wherein said means for directing are a passive optical system (3) configured for collecting pulses of laser light emitted by said laser (2) after they have crossed said measurement volume and redirecting them towards said measurement volume again, and for rotating the polarization of the light of said pulses from said first direction of polarization to said second direction of polarization before redirected pulses reach said measurement volume again.

6. Measurement device according to one of the preceding claims, wherein said means (3) for directing are passive optical elements (30, 31, 32), comprising:

a first optical mirror (31) located opposite said laser (2) on the other side of said measurement volume for reflecting pulses of laser light emitted by said laser (2) after they have crossed said measurement volume;

a second optical mirror (32) for reflecting pulses of laser light reflected by said first optical mirror (31) and directing them in said measurement volume;

an optical wave plate (30) for rotating the direction of polarization of the laser light of said pulses by 90°

, said optical wave plate (30) being located on the path of laser pulses, either between said measurement volume and said first optical mirror (31), or between said first optical mirror (31) and said second optical mirror (32), or between said second optical mirror (32) and said measurement volume.

7. Measurement device according to one of the preceding claims, wherein said first optical spectrometer (4) is configured to measure intensity of said collected fluorescent light at three different wavelengths.

8. Measurement device according to one of the preceding claims, wherein said first optical spectrometer (4) is configured for sampling said collected fluorescent light at a sampling frequency greater or equal to 500 MSPS (Mega samples per second).

9. Measurement device according to the preceding claim, wherein said first optical spectrometer (4) is configured for sampling said collected fluorescent light at a sampling frequency greater or equal to 1 GSPS (Giga samples per second).

10. Measurement device according to one of the preceding claims, further comprising:

a second optical spectrometer (5) for capturing fluorescent light emitted by individual fluid-borne particles (9) in said measurement volume and determining the optical spectrum of said captured fluorescent light over a broad frequency range.

11. Measurement device according to one of the preceding claims, further comprising:

an element adapted to guide all light coupled from a larger diameter side to a lower diameter side by effect of total internal reflection, and having at least one of the structure comprised in the group of a reflective objective lens (60) with infinite back-focal length conjugated with an optical lens (61), a reflective objective lens (60) with infinite back-focal length conjugated with parabolic reflector (62), or reflective objective lens (60) with infinite back-focal length conjugated with an optical taper (63).

14. Measurement method according to claim 11 or 12, wherein said fluid is air.

15. Measurement method according to claim 11 or 12, wherein said fluid is a liquid.

16. Measurement method according to one of claims 11 to 14, wherein the step of directing comprises collecting said pulse of laser light polarized in a first direction of polarization after it crossed said measurement volume and redirecting it towards said measurement volume again, and rotating the polarization of the light of said pulse of laser light polarized in a first direction from said first direction of polarization to said second direction of polarization before said pulse reaches said measurement volume again.

17. Measurement method according to one of claims 11 to 15, wherein said step of directing comprises:

reflecting said pulse of laser light polarized in a first direction of polarization after it crossed said measurement volume with a first optical mirror (31);

reflecting said pulse of laser light reflected by said first optical mirror (31) and directing it in said measurement volume with a second optical mirror (32);

rotating the direction of polarization of the laser light of the pulse by 90°

with an optical wave plate (30) located on the path of the pulse of laser light, either between said measurement volume and said first optical mirror (31), or between said first optical mirror (31) and said second optical mirror (32), or between said second optical mirror (32) and said measurement volume.

18. Measurement method according to one of claims 11 to 16, wherein said first optical spectrometer (4) is configured to measure intensity of said captured fluorescent light at three different wavelengths.

19. Measurement method according to one of claims 11 to 17, wherein said first optical spectrometer (4) is configured for sampling said captured fluorescent light at a sampling frequency greater or equal to 500 MSPS (Mega samples per second).

20. Measurement device according to the preceding claim, wherein said first optical spectrometer (4) is configured for sampling said captured fluorescent light at a sampling frequency greater or equal to 1 GSPS (Giga samples per second).

21. Measurement method according to one of claims 11 to 19, wherein the steps of capturing and measuring further comprise determining the optical spectrum of said fluorescent light over a broad frequency range.

12. Measurement method for the detection and/or characterization of fluid-borne particles (9), the measurement method comprising the steps of:

producing a flow of fluid along a fluid flow path,

emitting a pulse of laser light polarized in a first direction of polarization, in a measurement volume of the fluid flow path, said pulse having a pulse duration,

collecting fluorescent light emitted by individual fluid-borne particles (9) in said measurement volume when hit by said pulse of laser light polarized in said first direction of polarization and filtered by a linear polarizer, and measuring an intensity of said collected fluorescent light, filtered with a linear polarizer, at at least one determined wavelength at a sampling rate of at least three samples per fluorescence decay duration,

directing a pulse of laser light polarized in a second direction of polarization in said measurement volume, wherein said second direction of polarization is different from said first direction of polarization, such that the time delay between the moment of crossing said measurement volume by said pulse of laser light polarized in said first direction of polarization and the moment of crossing said measurement volume by said pulse of laser light polarized in said second direction of polarization is longer than said pulse duration and shorter than a travel time of the fluid in said measurement volume,

capturing fluorescent light emitted by individual fluid-borne particles (9) in said measurement volume when hit by said pulse of laser light polarized in said second direction of polarization and filtered by a linear polarizer, and measuring an intensity of said captured fluorescent light, filtered with a linear polarizer, at said at least one determined wavelength at a sampling rate of at least three samples per said pulse duration.

13. Measurement method according to the preceding claim, wherein said second direction of polarization is perpendicular to said first direction of polarization.