Method and apparatus for detecting microorganisms within a liquid product in a sealed vial

• US 5,164,597 A
• Filed: 05/06/1991
• Issued: 11/17/1992
• Est. Priority Date: 09/29/1989
• Status: Expired due to Fees

• Current Assignee: University Of Kentucky Research Foundation (University of Kentucky)
• Original Assignee: University Of Kentucky Research Foundation (University of Kentucky)
• Inventors: Lodder, Robert A.
• Primary Examiner(s): FIELDS, CAROLYN
• Application Number:
  US07/696,354
• Time in Patent Office: 561 Days
• Field of Search: 250/341, 250/574, 250/228, 250/343, 356/337, 356/338, 356/341, 356/343
• US Class Current: 250/341.8
• CPC Class Codes: C12M 41/36 of biomass, e.g. colony counters or by turbidity measurements electrooptical investigation of individual particles G01N15/14, flow cytometers G01N15/1404
• CPC Class Codes: G01N 2021/4709 Backscatter
• CPC Class Codes: G01N 2021/4742 comprising optical fibres
• CPC Class Codes: G01N 21/51 inside a container, e.g. in an ampoule G01N21/53 takes precedence
• CPC Class Codes: G01N 21/9027 in containers after filling
• CPC Class Codes: G01N 2201/065 Integrating spheres

Abstract

An apparatus and method are provided for the noninvasive and nondestructive detection of microorganisms within a liquid product contained within a sealed vial. The apparatus includes a near-IR light source that produces both incident and reference beams having a wavelength between 800 and 2500 nm and, more preferably, 1100 and 1360 nm. The apparatus also includes an integrating sphere having incident and reference beam ports and a sample window opposite the incident beam port. A detector is mounted in the integrating sphere substantially adjacent the sample window. A substantially U-shaped mirror is provided to hold the vial. The U-shaped mirror is of a size substantially corresponding to the diameter of the vial. In operation, the incident beam is directed through a sample window so as to enter the vial adjacent a sidewall of the mirror. In this way the U-shaped mirror reflects the incident beam so that it passes through the vial three times before returning to the detector. A computer analyzes the resulting signals from the detector.

Claims

1. An apparatus for the noninvasive and non destructive detection of a microorganism with a liquid product contained within a vial, comprising:

a light source for producing an incident beam;

means for directing said incident beam through said vial and liquid product;

means for reflecting said incident beam through said vial and liquid product;

means for detecting the reflected incident beam and light scattered by any microorganisms present in said liquid product; and

means for analyzing said incident beam and light scattered by any microorganism that is detected.

2. The apparatus set forth in claim 1 wherein said light source produces an incident beam having a wavelength between 800 and 2500 nm.

3. The apparatus set forth in claim 1, wherein said light source produces an incident beam having a wavelength between 1100 and 1360 nm.

4. The apparatus set forth in claim 1, wherein said light source also produces a reference beam that is directed to said detecting means so as to compensate for noise and source intensity variations.

5. The apparatus set forth in claim 1, further including an integrating sphere for collecting scattered light and directing said scattered light toward said detecting means.

6. The apparatus set forth in claim 5, wherein said integrating sphere includes an incident beam port and a sample window opposite said incident beam port through which said incident beam is directed at said vial and said liquid product.

7. The apparatus set forth in claim 6, wherein said detecting means is mounted within said integrating sphere adjacent said sample window.

8. The apparatus set forth in claim 7, wherein said integrating sphere further includes a reference beam port.

9. The apparatus set forth in claim 8, wherein said reflecting means comprises a substantially U-shaped mirror.

10. The apparatus set forth in claim 9, wherein said sample window of said integrating sphere is positioned along the open end of said substantially U-shaped mirror.

11. The apparatus set forth in claim 10, wherein said sample window positioned along the open end of said substantially U-shaped mirror is also adjacent a sidewall of said substantially U-shaped mirror.

12. A method for the noninvasive and nondestructive detection of a microorganism within a liquid product contained with a vial, comprising the steps of:

placing the vial adjacent a mirror;

directing an incident beam of light into said vial and liquid product;

detecting said incident beam of light as well as light scattered by any microorganism present in the liquid product following reflection by said mirror; and

analyzing said incident beam and light scattered by any microorganism that is detected.

13. The method set forth in claim 12, wherein said mirror is substantially U-shaped and has a cavity sized to receive said vial.

14. The method set forth in claim 13, wherein said incident beam is directed into said vial through an open end of said substantially U-shaped mirror adjacent a sidewall of said mirror.

15. The method set forth in claim 12, including reflecting said incident beam through said vial and liquid product at least twice before detecting.

16. The method set forth in claim 12, including reflecting said incident beam through said vial and liquid product at least three times before detecting.

17. The method set forth in claim 12, including steps of identifying multiple discrete scanning planes through said vial and liquid product and directing said incident beam through said multiple discrete scanning planes in order to detect a microorganism in said liquid product.

18. The method set forth in claim 12, including providing a reference beam to compensate for noise and source-intensity variations.

19. The method set forth in claim 12, wherein said incident beam has a wavelength between 1100 and 1360 nm.