Spectrophotometer arrangement with multi-detector readhead

• US 5,477,326 A
• Filed: 06/30/1994
• Issued: 12/19/1995
• Est. Priority Date: 06/30/1994
• Status: Expired due to Term

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Bayer Corporation (Bayer AG)
• Inventors: Dosmann, Andrew J.
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US08/269,363
• Time in Patent Office: 537 Days
• Field of Search: 356/402, 356/405, 356/406, 356/407, 356/409, 356/414, 356/416, 356/419, 356/425, 250/226, 257/80, 257/84, 257/88, 257/89, 257/440
• US Class Current: 356/406
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/78 producing a change of colour
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04

Abstract

A photometer readhead is used to measure concentrations within a test sample of preselected color-developed analytes having different characteristic absorption bands. The photometer readhead comprises an artificial light source for illuminating the test sample, a plurality of light-emitting diodes for detecting light transmitted through or reflected from the test sample, and a housing assembly for enclosing and supporting the plurality of light-emitting diodes. The plurality of light-emitting diodes have spectral responses encompassing respective ones of the different characteristic absorption bands of the preselected color-developed analytes. The plurality of light-emitting diodes preferably include a first light-emitting diode having a spectral response in red portion of the visible light spectrum; a second light-emitting diode having a spectral response in the blue portion of the visible light spectrum, a third light-emitting diode having a spectral response in the green portion of the visible light spectrum, and a fourth light-emitting diode having a spectral response in the infrared light spectrum.

Claims

1. A spectrophotometer arrangement, comprising:

a biological test sample containing unknown concentrations of preselected color-developed analytes having different characteristic absorption bands;

an artificial light source for illuminating the biological test sample;

a plurality of light-emitting diodes for detecting light from the biological test sample, said plurality of light-emitting diodes having spectral responses encompassing respective ones of the different characteristic absorption bands of the preselected color-developed analytes; and

a housing assembly for supporting said plurality of light-emitting diodes, wherein said housing assembly includes a base and said plurality of light-emitting diodes are mounted to said base, and wherein said housing assembly includes a window disposed opposite said base and a side wall bridging said base and said window such that said plurality of light-emitting diodes are enclosed within said housing assembly.

2. The photometer readhead of claim 1, wherein said plurality of light-emitting diodes are disposed on an opposite side of the test sample relative to said artificial light source so that said plurality of light-emitting diodes detect a portion of light transmitted through the test sample.

3. The photometer readhead of claim 2, wherein said artificial light source, the test sample, and said plurality of light-emitting diodes are disposed in line with each other.

4. The photometer readhead of claim 1, wherein said plurality of light-emitting diodes are disposed on the same side of the test sample as said artificial light source so that said plurality of light-emitting diodes detect a portion of light reflected from the test sample.

5. The photometer readhead of claim 4, wherein said plurality of light-emitting diodes are disposed at a scattering angle of approximately 45 degrees as measured between a line representing a direction of travel of light from said artificial light source to the test sample and a line representing a direction of travel of the reflected light portion from the test sample to said plurality of light-emitting diodes.

6. The photometer readhead of claim 1, wherein said artificial light source is selected from the group consisting of an incandescent lamp, a halogen lamp, a fluorescent lamp, and a plurality of light-emitting diodes.

7. The photometer readhead of claim 1, wherein said plurality of light-emitting diodes include a first light-emitting diode having a spectral response in the red portion of the visible light spectrum, a second light-emitting diode having a spectral response in the blue portion of the visible light spectrum, and a third light-emitting diode having a spectral response in the green portion of the visible light spectrum.

8. The photometer readhead of claim 7, wherein said plurality of light-emitting diodes include a fourth light-emitting diode having a spectral response in the infrared light spectrum.

9. The photometer readhead of claim 1, wherein said base includes a printed circuit board.

10. A spectrophotometer arrangement, comprising:

a biological test sample containing unknown concentrations of preselected color-developed analytes having different characteristic absorption bands;

an artificial light source for illuminating the biological test sample; and

a detector assembly for detecting light from the biological test sample, said detector assembly including a plurality of light-emitting diodes having spectral responses encompassing respective ones of the different characteristic absorption bands of the preselected color-developed analytes, said plurality of light-emitting diodes including a pair of light-emitting diodes having respective spectral responses in different portions of the visible light spectrum such that said respective spectral responses are substantially non-overlapping;

wherein said detector assembly includes a housing for enclosing and supporting said plurality of light-emitting diodes and wherein said housing includes a base and said plurality of light-emitting diodes are mounted to said base, and wherein said housing includes a window disposed opposite said base and a side wall bridging said base and said window such that said plurality of light-emitting diodes are enclosed within said housing; and

wherein said plurality of light-emitting diodes are disposed at a scattering angle of approximately 45 degrees as measured between a line representing a direction of travel of light from said artificial light source to the test sample and a line representing a direction of travel of the reflected light portion from the test sample to said plurality of light-emitting diodes.

11. The photometer readhead of claim 10, wherein a first of said pair of light-emitting diodes has a spectral response in the red portion of the visible light spectrum and a second of said pair of light-emitting diodes has a spectral response in the blue portion of the visible light spectrum, and wherein said plurality of light-emitting diodes includes a third light-emitting diode having a spectral response in the green portion of the visible light spectrum.

12. The photometer readhead of claim 11, wherein said plurality of light-emitting diodes include a fourth light-emitting diode having a spectral response in the infrared light spectrum.

13. The photometer readhead of claim 10, wherein said base includes a printed circuit board.

14. The photometer readhead of claim 10, wherein said artificial light source is selected from the group consisting of an incandescent lamp, a halogen lamp, a fluorescent lamp, and a plurality of light-emitting diodes.