Blood fluid characteristics analysis instrument

• US 5,995,236 A
• Filed: 04/13/1998
• Issued: 11/30/1999
• Est. Priority Date: 04/13/1998
• Status: Expired due to Term

• Current Assignee: Trividia Health, Inc. (Sinocare, Inc.)
• Original Assignee: MIT Development Corp (Sinocare, Inc.)
• Inventors: Roth, G. Thomas, Paolini, Gregory P.
• Primary Examiner(s): Kim, Robert H.
• Assistant Examiner(s): MERLINO, AMANDA H
• Application Number:
  US09/059,082
• Time in Patent Office: 596 Days
• Field of Search: 356/445-448, 356/39-42
• US Class Current: 356/445
• CPC Class Codes: G01N 21/47 Scattering, i.e. diffuse reflection G01N21/25, G01N21/41 take precedence G01N21/55 takes precedence
• 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

An apparatus for enhancing the analysis of light reflected from a blood exposed reagent is described. Light from sources, such as LED'"'"'s, is used to detect the levels of glucose and fructosamine in the blood exposed reagent. A special optical arrangement is used ot obtain optical signals indicative of the optically sensitive chemicals in the reagent. The optical beams from respective LED'"'"'s are directed at a common surface of an optical element used to redirect the light onto the reagent and reflect portions onto a reference detector. A main detector is strategically located adjacent a surface of the optical element to detect reflections from the reagent. A control circuit is described with which the light from the LED light sources can be held at substantially constant levels despite factors tending to cause light level changes.

Claims

1. A diagnostic apparatus for generating a signal indicative of the levels of predetermined first and second chemicals in a body fluid sample using respectively different reagent strips with reagents which undergo a color change when exposed to a fluid sample, comprising:

a housing having a surface for receiving reagent strips and having an optical aperture through which an optical beam from inside the housing can illuminate the reagent on a strip;

an optical beam generating structure positioned inside the housing and producing said optical beam through said optical aperture with light from a reagent strip being reflected back through said aperture for detection;

said structure further including;

an optical element having a front surface, an upper surface, a bottom surface and a back located inclined reflecting surface extending at a reflecting angle relative to said front surface, said upper surface being juxtaposed with respect to said aperture;

first and second spaced apart light beam generators producing respectively first and second optical beams along first and second beam axes, each of said beam axes being oriented at first and second angles relative to a normal to said front surface of the optical element to cause a reflection therefrom along reference axes and to cause a refraction into the optical element towards its reflecting surface for reflection thereby to the aperture;

a reference detector positioned so that reflections along the reference axes are incident on the reference detector and produce a signal indicative thereof; and

a main detector juxtaposed with respect to said bottom surface of the optical element and located in front of said inclined reflecting surface to detect reflections passing through said optical element from a reagent strip aligned with said aperture along a straight line of sight with said reagent strip.

2. The apparatus as claimed in claim 1 wherein said inclined reflecting surface is an internal surface of said optical element.

3. The apparatus as claimed in claim 1 wherein said optical structure further includes a base plate and a cover plate adapted to intermesh with each other to form an optically sealed enclosure;

said optical enclosure including first and second channels respectively containing said first and second light beam generators and their respective optical beams.