Parametric control in pulsed light sterilization of packages and their contents

• US 5,925,885 A
• Filed: 05/01/1997
• Issued: 07/20/1999
• Est. Priority Date: 05/22/1996
• Status: Expired due to Term

• Current Assignee: Tesla Inc.
• Original Assignee: Purepulse Technologies, Inc.
• Inventors: Lierman, James C., Lander, Donald, Dunn, Joseph E., Clark, Reginald Wayne
• Primary Examiner(s): Berman, Jack I.
• Application Number:
  US08/846,102
• Time in Patent Office: 810 Days
• Field of Search: 250/492.1, 250/455.11, 422/24
• US Class Current: 250/492.1
• CPC Class Codes: A23L 3/26 by irradiation without heating
• CPC Class Codes: A23L 3/28 with ultraviolet light
• CPC Class Codes: A61L 12/06 Radiation, e.g. ultraviolet or microwaves
• CPC Class Codes: A61L 12/063 Ultraviolet radiation
• CPC Class Codes: A61L 12/08 using chemical substances
• CPC Class Codes: A61L 12/086 Container, accessories or devices therefor
• CPC Class Codes: A61L 2/08 Radiation
• CPC Class Codes: A61L 2/081 Gamma radiation
• CPC Class Codes: A61L 2/24 Apparatus using programmed or automatic operation
• CPC Class Codes: A61L 2202/14 Means for controlling sterilisation processes, data processing, presentation and storage means, e.g. sensors, controllers, programs
• CPC Class Codes: B65B 25/008 packaging of contact lenses
• CPC Class Codes: B65B 55/02 Sterilising, e.g. of complete packages
• CPC Class Codes: B65B 55/16 by irradiation

Abstract

An approach for sterilizing microorganisms at a target object employs a flashlamp system including means for generating pulses of light, and for deactivating microorganisms within the target object by illuminating the target object with the pulses of light having been generated; a photo-sensitive detector positioned so as to receive a portion of each of the pulses of light as a measure of an amount of light illuminating the target object, for generating an output signal in response thereto; and a control system, coupled to the flashlamp system and the photo-sensitive detector, for determining, in response to the output signal, whether the pulses of light are sufficient to effect a prescribed level of deactivation of microorganisms in the target object. In accordance with this approach sterilizing microorganisms involves steps of generating a pulse of light; deactivating microorganisms at the target object by directing the pulse of light having been generated at the target object; receiving a portion of the pulse of light as a measure of an amount of the pulse of light illuminating the target object; generating an output signal in response to the receiving of the portion of the pulse of light; and determining; in response to the generating of the output signal, whether the pulse of light is sufficient to effect a prescribed level of deactivation of microorganisms in the target object.

Claims

1. An apparatus for sterilizing microorganisms at a target object comprising:

container enveloping the target object, wherein the container transmits light in a spectrum of from between 180 nm and 300 nm;

a flashlamp system for generating high-intensity, short-duration pulses of polychromatic light in a broad spectrum, and for deactivating microorganisms within the target object by illuminating the container with the pulses of light having been generated;

a photo-sensitive detector, positioned so as to receive a portion of each of the pulses of light as a measure of an amount of light illuminating the target object, for generating an output signal in response thereto; and

a control system, coupled to the flashlamp system and the photo-sensitive detector, for determining, in response to the output signal, whether the pulses of light are sufficient to effect a prescribed level of deactivation of microorganisms in the target object.

2. The apparatus of claim 1 wherein the control system further comprises means for monitoring another output signal indicative of a pulse parameter and for further determining whether, in response to the other output signal, the pulse parameter is sufficient to generate pulses of light that effect a prescribed level of deactivation of microorganisms in the target object.

3. The apparatus of claim 2 wherein the control system further comprises:

monitor and control circuitry; and

a computer including software.

4. The apparatus of claim 2 wherein said control system comprises means for monitoring the other output signal, wherein the other output signal is indicative of a pulse parameter selected from a group of pulse parameters consisting of current, voltage, peak current, current waveshape, peak voltage and voltage waveshape.

5. The apparatus of claim 1 wherein said photosensitive detector generates said output signal, wherein said output signal is indicative of a photo parameter selected from a group of photo parameters consisting of total fluence-per-flash, fluence-per-flash, total energy over time, and energy within a preselected bandwidth over time.

6. The apparatus of claim 5 wherein said control system comprises:

monitor and control circuitry; and

a computer including software.

7. The apparatus of claim 1 wherein said control system includes means for determining, in response to the output signal, whether the pulses of light are of at least a prescribed fluence per flash.

8. The apparatus of claim 1 wherein said control system includes means for determining, in response to the output signal, whether the pulses of light are of at least a prescribed fluence per flash within a prescribed frequency band.

9. The apparatus of claim 1 wherein said means for deactivating includes means for achieving a sterility assurance level of at least 10^-6.

10. The apparatus of claim 1 wherein said means for deactivating includes means for achieving a sterility assurance level of at least 10^-3.

11. The apparatus of claim 1 wherein said flashlamp system includes a reflector at least partially surrounding a flashlamp bulb and said target object for reflecting the pulses of light toward the target object and for reflecting at least a portion of light transmitted through the target object back toward the target object.

12. The apparatus of claim 1 further comprising:

a reflector positioned proximate to the flashlamp for reflecting the pulses of light toward the target object.

13. The apparatus of claim 12 further comprising:

a hole located in said reflector and in which the photosensitive device is positioned.

14. The apparatus of claim 1 further comprising:

a port coupled to the container including means through which the product within the container can be withdrawn.

15. The apparatus of claim 1 wherein said container contains a transmissive product that transmits more than about one percent of light at a wavelength of 260 nm.

16. A method for sterilizing microorganisms in a target object comprising:

generating a high-intensity, short-duration pulse of polychromatic light in a broad spectrum;

deactivating microorganisms at the target object by directing the pulse of light having been generated at a container enveloping the target object, the container transmitting light in a spectrum of from between 180 nm and 300 nm;

receiving a portion of the pulse of light as a measure of an amount of the pulse of light illuminating the target object;

generating an output signal in response to the receiving of the portion of the pulse of light; and

determining, in response to the generating of the output signal, whether the pulse of light is sufficient to effect a prescribed level of deactivation of microorganisms in the target object.

17. The method of claim 16 wherein said determining whether the pulses of light are sufficient includes determining whether the pulses of light are of at least a prescribed fluence per flash.

18. The method of claim 16 wherein said determining whether the pulses of light are sufficient includes determining whether the pulses contain at least a prescribed spectral content.

19. The method of claim 16 wherein said deactivating includes achieving a sterility assurance level of at least 10^-6.

20. The method of claim 16 wherein said deactivating includes achieving a sterility assurance level of at least 10^-3.

21. The method of claim 16 further comprising:

reflecting at least a portion of each pulse of light toward the target object.

22. An apparatus for sterilizing microorganisms within a container comprising:

the container enveloping a product, wherein the container transmits light in a spectrum of from between 180 nm and 300 nm;

a flashlamp system for generating high-intensity, short-duration pulses of polychromatic light in a broad spectrum, for directing the pulses of polychromatic light at the container and for deactivating microorganisms within the container by illuminating the container with the pulses of light having been generated;

a photo-sensitive detector, positioned so as to receive a portion of each of the pulses of light as a measure of an amount of light illuminating the product, and for generating an output signal in response thereto; and

a control system, coupled to the flashlamp system and the photo-sensitive detector, for determining, in response to the output signal, whether the pulses of light are sufficient to effect a prescribed level of deactivation of microorganisms in the container.

23. The apparatus of claim 22 wherein the control system further comprises means for monitoring another output signal indicative of a pulse parameter and for further determining whether, in response to the other output signal, the pulse parameter is sufficient to generate pulses of light that effect a prescribed level of deactivation of microorganisms within the container.

24. The apparatus of claim 23 wherein the control system further comprises:

monitor and control circuitry; and

a computer including software.

25. The apparatus of claim 23 wherein said control system comprises means for monitoring the other output signal, wherein the other output signal is indicative of a pulse parameter selected from a group of pulse parameters consisting of current, voltage, peak current, current waveshape, peak voltage and voltage waveshape.

26. The apparatus of claim 22 wherein said photosensitive detector generates said output signal, wherein said output signal is indicative of a photo parameter selected from a group of photo parameters consisting of total fluence-per-flash, fluence-per-flash, total energy over time, and energy within a preselected bandwidth over time.

27. The apparatus of claim 26 wherein said control system comprises:

monitor and control circuitry; and

a computer including software.

28. The apparatus of claim 22 wherein said control system includes means for determining, in response to the output signal, whether the pulses of light are of at least a prescribed fluence per flash.

29. The apparatus of claim 22 wherein said means for deactivating includes means for achieving a sterility assurance level of at least 10^-6.

30. The apparatus of claim 22 wherein said means for deactivating includes means for achieving a sterility assurance level of at least 10^-3.

31. The apparatus of claim 22 wherein said flashlamp system includes a reflector at least partially surrounding a flashlamp bulb and said container for reflecting the pulses of light toward the container and for reflecting at least a portion of light transmitted through the container back toward the container.

32. The apparatus of claim 23 further comprising:

a reflector positioned proximate to the flashlamp for reflecting the pulses of light toward the container.

33. The apparatus of claim 32 further comprising:

a hole located in said reflector and in which the photosensitive device is positioned.

34. The apparatus of claim 22 further comprising:

a port coupled to the container including means through which the product within the container can be withdrawn.

35. The apparatus of claim 22 wherein said container contains a transmissive product that transmits more than about one percent of light at a wavelength of 260 nm.

36. A method for sterilizing microorganisms within a container comprising:

generating a high-intensity, short-duration pulse of polychromatic light in a broad spectrum;

deactivating microorganisms within the container by directing the pulse of light having been generated at the container enveloping a product, the container transmitting light in a spectrum of from between 180 nm and 300 nm;

receiving a portion of the pulse of light as a measure of an amount of the pulse of light illuminating the product;

generating an output signal in response to the receiving of the portion of the pulse of light; and

determining, in response to the generating of the output signal, whether the pulse of light is sufficient to effect a prescribed level of deactivation of microorganisms in the container.

37. The method of claim 36 wherein said determining whether the pulses of light are sufficient includes determining whether the pulses of light are of at least a prescribed fluence per flash.

38. The method of claim 36 wherein said determining whether the pulses of light are sufficient includes determining whether the pulses contain at least a prescribed spectral content.

39. The method of claim 36 wherein said deactivating includes achieving a sterility assurance level of at least 10^-6.

40. The method of claim 36 wherein said deactivating includes achieving a sterility assurance level of at least 10^-3.

41. The method of claim 36 further comprising:

reflecting at least a portion of each pulse of light toward the container.