Optical detection system with polarizing beamsplitter

• US 7,471,394 B2
• Filed: 12/30/2004
• Issued: 12/30/2008
• Est. Priority Date: 08/02/2000
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Padmanabhan, Aravind, Fritz, Bernard S.
• Primary Examiner(s): Chowdhury; Tarifur
• Assistant Examiner(s): COOK, JONATHON
• Application Number:
  US11/027,134
• Publication Number:
  US 20050118723A1
• Time in Patent Office: 1,461 Days
• Field of Search: 356/39, 356/436, 356/327, 356/339, 356/340, 356/365, 356/343, 356/243.2, 436/63, 436/10, 435/7.24
• US Class Current: 356/365
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150213 Venting means
• CPC Class Codes: A61B 5/150221 Valves
• CPC Class Codes: A61B 5/150343 Collection vessels for collecting blood samples from the skin surface, e.g. test tubes, cuvettes sampling from within body cavities A61B5/150015, A61B5/150045
• CPC Class Codes: A61B 5/150351 Caps, stoppers or lids for sealing or closing a blood collection vessel or container, e.g. a test-tube or syringe barrel caps for bottles or containers in general B65D41/00
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G01F 1/7086 using optical detecting arrangements
• CPC Class Codes: G01N 15/1404 Handling flow, e.g. hydrodynamic focusing
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream
• CPC Class Codes: G01N 2015/016 White blood cells
• CPC Class Codes: G01N 2015/1486 Counting the particles

Abstract

An optical detection system for use in flow cytometry or the like, which includes a polarizing beamsplitter 820 such as a Wollaston prism. A light source provides an input light beam to a flow stream, wherein the input light beam has a polarization direction. The particles in the flow stream may produce an output light beam that includes a polarized component and a depolarized component. The polarizing beamsplitter receives the output light beam, and provides a polarized light beam and a depolarized light beam to a pair of detectors. The pair of detectors provide a first output signal that corresponds to the polarized light beam and a second output signal that corresponds to the depolarized light beam. A controller or processor may use the first output signal and the second output signal to help identify/classify particles and/or particle characteristics in the flow stream.

Claims

1. A cytometer for analyzing predetermined characteristics of biological particles within a flow stream, the cytometer comprising:

a removable flow cytometry cartridge for receiving a sample fluid including biological particles and for hydrodynamic focusing the biological particles into a single file arrangement through an interrogation channel within the removable cartridge, the removable cartridge having a first sidewall with a first optically transparent window in optical communication with the interrogation channel, and a second sidewall opposite to the first sidewall with a second optically transparent window in optical communication with the interrogation channel;

a housing for removably receiving the removable flow cytometry cartridge, the housing including;

a light source for providing an input light beam to the interrogation channel through the first optically transparent window of the removable flow cytometry cartridge, the input light beam having a polarization direction;

a polarizing beamsplitter for receiving an output light beam from the interrogation channel through the second optically transparent window of the removable flow cytometry cartridge, and for providing a polarized light beam and a depolarized light beam, wherein the polarized light beam and the depolarized light beam form an angle therebetween of less than 90 degrees; and

light receiving means for receiving the polarized light beam and the depolarized light beam, and for providing a first output signal that corresponds to the polarized light beam and a second output signal that corresponds to the depolarized light beam.

2. The cytometer of claim 1 wherein the output light beam includes scattered light, and the polarizing beamsplitter receives a portion of the output light beam that is scattered in a direction that is about 90 degrees offset relative to the input light beam.

3. The cytometer of claim 2 wherein the polarizing beamsplitter includes a Wollaston prism.

4. The cytometer of claim 1 wherein the angle formed between the polarized light beam and the depolarized light beam is less than 20 degrees.

5. The cytometer of claim 1 wherein the angle formed between the polarized light beam and the depolarized light beam is less than 10 degrees.

6. The cytometer of claim 1 wherein the polarizing beamsplitter is a polarizing beamsplitter cube.

7. The cytometer of claim 1 wherein the polarizing beamsplitter is a polarizing beamsplitter film.

8. The cytometer of claim 1 wherein the light receiving means includes a pair of photodetectors.

9. The cytometer of claim 1 wherein the input light beam is polarized, and the polarized light beam has the same polarization as the input light beam.

10. The cytometer of claim 9 wherein the depolarized light beam has a polarization that is orthogonal to the polarization of the input light beam.

11. The cytometer of claim 1, further comprising processing means, the processing means using the first output signal and the second output signal to help classify the biological particles, wherein the biological particles include white blood cells.

12. The cytometer of claim 11, wherein the white blood cells include eosinophils.

13. The cytometer of claim 1, wherein the removable cartridge further includes a micro lens situated in optical communication with the first optically transparent window.

14. The cytometer of claim 1, wherein the removable cartridge further includes a micro lens situated in optical communication with the second optically transparent window.

15. A method for analyzing predetermined characteristics of biological particles within a flow stream within a fluidic cartridge that is removable received by a housing, the method comprising:

inserting the fluidic cartridge into the housing;

hydrodynamic focusing the biological particles into a single file arrangement through an interrogation channel within the fluidic cartridge;

providing an input light beam from one or more light sources of the housing to the interrogation channel of the fluidic cartridge through a micro lens situated on the fluidic cartridge adjacent to a first side of the interrogation channel, the input light beam being provided at an angle of incidence of less than 90 degrees relative to the interrogation channel, the input light beam having a polarization direction;

receiving an output light beam from a second opposing side of the interrogation channel by a polarizing beamsplitter, the polarizing beamsplitter producing a polarized light beam and a depolarized light beam, wherein the polarized light beam and the depolarized light beam form an angle therebetween of less than 90 degrees;

detecting the polarized light beam and the depolarized light beam, and providing a first output signal that corresponds to the polarized light beam and a second output signal that corresponds to the depolarized light beam; and

removing the fluidic cartridge from the housing.

16. The method of claim 15 wherein the output light beam that is provided to the polarizing beamsplitter is scattered about 90 degrees relative to the input light beam by the flow stream.

17. The method of claim 15 wherein the angle formed between the polarized light beam and the depolarized light beam is less than 20 degrees.

18. The method of claim 15 wherein the angle formed between the polarized light beam and the depolarized light beam is less than 10 degrees.

19. The method of claim 15 wherein the polarizing beamsplitter is a polarizing beamsplitter cube.

20. The method of claim 15 wherein the polarizing beamsplitter is a polarizing beamsplitter film.

21. The method of claim 15 wherein the polarizing beamsplitter includes a Wollaston prism.

22. The method of claim 15 wherein the polarized light beam and the depolarized light beam are detected using a pair of photodetectors.

23. The method of claim 15 wherein the polarized light beam has the same polarization as the input light beam.

24. The method of claim 15 wherein the depolarized light beam has a polarization that is orthogonal to the polarization of the input light beam.

25. An optical detection system for analyzing predetermined characteristics of biological particles in a flow stream, the optical detection system comprising:

a removable cartridge for receiving a sample fluid including biological particles and for hydrodynamic focusing the biological particles into a single file arrangement through an interrogation channel of the removable cartridge, the removable cartridge having a first sidewall with a first optically transparent window in optical communication with the interrogation channel, and a second sidewall opposite to the first sidewall with a second optically transparent window in optical communication with the interrogation channel;

a housing for removably receiving the removable cartridge, the housing including;

a light source for providing an input light beam to the interrogation channel through the first optically transparent window of the removable cartridge, the input light beam having in incident angle relative to the interrogation channel and a polarization direction;

a polarizing beamsplitter configured to receive an output light beam from the interrogation channel through the second optically transparent window of the removable cartridge, the output light beam exiting about 90 degrees relative to the incident angle of the input light beam, the polarizing beamsplitter providing a polarized light beam and a depolarized light beam, wherein the polarized light beam and the depolarized light beam form an angle therebetween of less than 90 degrees;

the second optically transparent window of the removable cartridge having a filter for at least partially filtering out the input light beam from exiting with the output light beam; and

light receiving means for receiving the polarized light beam and the depolarized light beam, and for providing a first output signal that corresponds to the polarized light beam and a second output signal that corresponds to the depolarized light beam.

26. The optical detection system of claim 25 wherein the polarized light beam has the same polarization as the input light beam.

27. The optical detection system of claim 26 wherein the depolarized light beam has a polarization that is orthogonal to the polarization of the input light beam.

28. The optical detection system of claim 25, wherein the first optically transparent window of the removable cartridge includes a micro lens for receiving the input light beam.

29. The optical detection system of claim 25, wherein the second optically transparent window of the removable cartridge includes a micro lens for modifying the output light beam.

30. The optical detection system of claim 28, wherein the second optically transparent window of the removable cartridge includes a micro lens for modifying the output light beam.