Apparatus for optical detection of bio-contaminants by comparing intensities of filtered light at two predetermined wavelengths

• US 10,451,552 B2
• Filed: 09/01/2017
• Issued: 10/22/2019
• Est. Priority Date: 02/26/2013
• Status: Active Grant

• Current Assignee: Steris Inc (Steris Corporation)
• Original Assignee: Steris Inc (Steris Corporation)
• Inventors: Rochette, Daniel, Gallant, Pascal, Mermut, Ozge, Baribeau, Francois, Noiseux, Isabelle, Gosselin, Isabelle
• Primary Examiner(s): Xu, Xiaoyun R
• Application Number:
  US15/693,779
• Publication Number:
  US 20180024060A1
• Time in Patent Office: 781 Days
• Field of Search: None
• CPC Class Codes: A61L 2/28 Devices for testing the effectiveness or completeness of sterilisation, e.g. indicators which change colour apparatus involving enzymes or microorganisms C12M1/34; methods involving enzymes or microorganisms C12Q1/00
• CPC Class Codes: A61L 2202/24 Medical instruments, e.g. endoscopes, catheters, sharps
• CPC Class Codes: G01N 2021/6417 Spectrofluorimetric devices
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers
• CPC Class Codes: G01N 2201/068 Optics, miscellaneous
• CPC Class Codes: G01N 2201/0697 Pulsed lasers
• CPC Class Codes: G01N 2201/10 Scanning
• CPC Class Codes: G01N 2201/105 Purely optical scan

Abstract

A method for optical detection of residual soil on articles (such as medical instruments and equipment), after completion of a washing or a rinsing operation by a washer. A soil detection system provides an indication of soil on the articles by detecting luminescent radiation emanating from the soil in the presence of ambient light.

Claims

1. A soil detection system for detecting presence of soil on an article, the soil detection system comprising:

a scanning unit for scanning the article treated with a fluorescent agent bound to soil present on the article, the fluorescent agent emitting fluorescent light at a fluorescence wavelength, said scanning unit including;

a light source for producing incident light on the article, the incident light having an excitation wavelength for producing the fluorescent light at the fluorescence wavelength,

a light filter for filtering the light emanating from said article at the fluorescence wavelength and a second predetermined wavelength,

a light detector for detecting the filtered light emanating from said article and generating light data corresponding thereto, said light emanating from said article including ambient light reflected by the article and light emitted by exciting the fluorescent agent bound to the soil, and

a control unit for receiving the light data generated by the detector to determine the presence of soil on the article by spectrally discriminating between the fluorescent light and the ambient light reflections based upon a measure of saturation of light intensities of combined fluorescent light and ambient light at the fluorescence wavelength relative to light intensities of ambient light at the second predetermined wavelength.

2. A soil detection system according to claim 1, wherein the light source for producing incident light comprises a device able to emit a monochromatic electromagnetic field in an ambient light environment.

3. A soil detection system according to claim 2, wherein the light source is a laser diode that predominantly emits laser light at a blue excitation wavelength of 488 nm.

4. A soil detection system according to claim 1, wherein the fluorescent agent is fluorescein, which has a maximum excitation wavelength of about 490 nm, and which, once excited, emits the fluorescent light at a fluorescence wavelength of about 513 nm.

5. A soil detection system according to claim 1, wherein the second predetermined wavelength is a red light wavelength.

6. A soil detection system according to claim 1, wherein the control unit is programmed to spectrally discriminate between soil fluorescence indicating the presence of soil and specular ambient light reflections.

7. A soil detection system according to claim 1, wherein the control unit is programmed to spectrally discriminate between the fluorescent light and the ambient light reflections based upon the measure of saturation of light intensities such that a range of the measure of saturation is enclosed between zero and one, such that a value of saturation close to zero is indicative of presence of specular ambient light reflections, whereas a value close to one is indicative of the presence of soil.

8. A soil detection system according to claim 1, wherein the light emanating from said article comprises ambient light reflections that include both green light at the fluorescence wavelength and red light at the second predetermined wavelength, wherein the light filter filters out all but the red light and the green light, which are detected by the light detector.

9. A soil detection system according to claim 8, wherein the light data received by the control unit comprises a green light waveform indicative of intensity of the green light detected by the light detector and a red light waveform indicative of intensity of the red light detected by the light detector.