Disposable electronic diagnostic instrument

• US 5,728,352 A
• Filed: 05/12/1995
• Issued: 03/17/1998
• Est. Priority Date: 11/14/1994
• Status: Expired due to Term

• Current Assignee: PA Consulting Group Limited
• Original Assignee: Advanced Care Products, Ltd., PA Consulting Group Limited
• Inventors: Delahanty, Francis T., Strahs, Kenneth R., Moorman, Michael, Conner, Timothy J., Poto, Edward M., Wieck, Henry
• Primary Examiner(s): Pyon, Harold Y.
• Application Number:
  US08/440,278
• Time in Patent Office: 1,040 Days
• Field of Search: 422/55-58, 422/61, 422/68.1, 422/82.05, 436/46, 436/63, 436/95, 436/166, 436/169, 435/14, 435/805, 435/808, 435/810
• US Class Current: 422/82.05
• 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 21/8483 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
• CPC Class Codes: G01N 33/92 involving lipids, e.g. cholesterol , lipoproteins, or their receptors steroid hormones G01N33/743
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/808 Optical sensing apparatus
• CPC Class Codes: Y10S 435/81 Packaged device or kit
• CPC Class Codes: Y10T 436/112499 with sample on test slide
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

The invention relates to a disposable electronic diagnostic instrument designed for use in an Over-the-Counter (OTC) cholesterol test kit for measuring cholesterol levels of blood. The instrument is designed and calibrated specifically for use with diagnostic test strips supplied with the OTC cholesterol test kit.

Claims

1. An electronic instrument for measuring reflectance of a test surface which comprises an instrument housing, said housing comprising a testing area wherein said testing area defines a planar surface;

a test reading aperture;

a light source positioned to emit radiation towards said test area, said light source having a longitudinal light emitting axis substantially perpendicular to said planar surface; and

a photodetector positioned to detect radiation reflected by said test area, said photodetector having a longitudinal light detecting axis substantially perpendicular to said planar surface, and said instrument having a keying guide defining a location at which a chemical test strip is placed;

a test strip;

a sensor switch located adjacent said keying guide and contacted by said strip in response to said strip being inserted into said guide; and

a control circuit, said switch connected to said control circuit for activation of said instrument by providing power to said instrument in order to operate said instrument, wherein said instrument measures the change in reflectance of said strip in response to a test solution being applied to said strip, and wherein said keying guides include at least one lateral edge guide for engaging a lateral edge of strip and an angled fore guide for engaging an angled fore edge of said strip.

2. The electronic instrument according to claim 1 said light source comprises a light emitting diode, and said detector comprises a silicon photodiode.

3. The electronic instrument according to claim 1 having no optical components between said light source and said photodetector.

4. The electronic instrument according to claim 1 wherein a flare screen is positioned between said light source and said photodetector extending substantially perpendicular to said planar surface.

5. The electronic instrument according to claim 1 wherein an optical filter, having bandpass characteristics matching the desired detection wavelengths, is mounted over said light source and photodetector.

6. The electronic instrument according to claim 1 wherein said angled fore guide being positioned off-center with respect to said strip, such that said angled fore edge of said strip can properly engage said angled fore guide only when said strip is properly positioned in said instrument housing.

7. The electronic instrument according to claim 1 wherein said instrument further comprises;

a. a display mounted on said instrument for displaying prompt icons to instruct the user concerning use of the instrument and results of reflectance measurement;

b. a light source positioned to emit radiation towards said strip and a photodetector positioned to detect radiation reflected by said strip;

c. a control circuit comprising means for controlling the operation of said light source, analyzing the output signal of said photodetector, and controlling the operation of said display.