US 6,489,133 B2Granted

Apparatus for determinating the concentration of glucose in whole blood

AssigneeLifeScan, Inc.

InventorsRoger Phillips, Geoffery McGarraugh, Franklin A. Jurik, Raymond D. Underwood

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method for determining the presence of an analyte in a fluid is described along with various components of an apparatus specifically designed to carry out the method. The method involves taking a reflectance reading from one surface of an inert porous matrix impregnated with a reagent that will interact with the analyte to produce a light-absorbing reaction product when the fluid being analyzed is applied to another surface and migrates through the matrix to the surface being read. Reflectance measurements are made at two separate wavelengths in order to eliminate interferences, and a timing circuit is triggered by an initial decrease in reflectance by the wetting of the surface whose reflectance is being measured by the fluid which passes through the inert matrix. Repeatability is insured by a normalization technique performed on the light source before each reading, and an alignment method operated on the reagent strip prior to emplacement on the apparatus. The method and apparatus are particularly suitable for the measurement of flucose levels in blood without requiring separation of red blood cells from serum or plasma.

Claims11

Dependent claims

An apparatus for measuring the concentration of glucose in a sample of whole blood, which comprises:

(a) a chamber for removably accepting a test strip that includes a porous matrix pad which
(1) has a first major surface for accepting the sample and a reflective second major surface opposite to the first surface,
(2) allows a portion of the sample to travel through the pad from the first surface toward the second surface, and
(3) is impregnated with a reagent that reacts with glucose to cause a change in the reflectance at the second surface;
(b) means for illuminating the second surface of the pad in the chamber;
(c) means for monitoring intensity of light reflected from the second surface of the pad in the chamber;
(d) means for taking a sequence of reflectance readings from the second surface of said matrix at specified time intervals upon detecting a predetermined drop in reflectance sufficient to indicate that said sample has reached said first surface;
and
(e) means for calculating said glucose concentration in said sample from one of said reflectance readings upon detection of a suitably stable endpoint, without having determined the time at which sample was initially applied to the matrix pad.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/784,993Filed 15 Feb 2001 · division
Priority: 13 Aug 1986
Published: US 2001/0019831 A16 Sep 2001
Granted: 3 Dec 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification21 codes

G01N 21/8483
Systems specially adapted for particular applications: investigating reagent band
C12Q 1/54
Measuring or testing processes involving enzymes, nucleic acids or microorganisms ; Compositions therefor; Processes of preparing such…
G01N 33/52
Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing: use of…
G01N 33/521
Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including…:…

Family

Application06/896,418Parent of this continuation-in-part · filed 13 Aug 1986
Application07/819,431Parent of this division · filed 10 Jan 1992
Application08/006,859Parent of this division · filed 21 Jan 1993
Application08/148,055Parent of this continuation · filed 5 Nov 1993
Application08/408,064Parent of this continuation · filed 21 Mar 1995
Application08/691,154Parent of this continuation · filed 1 Aug 1996
Application08/941,868Parent of this continuation · filed 30 Sep 1997
Application08/965,745Parent of this continuation · filed 7 Nov 1997
Application07/187,602Parent of this division · filed 28 Apr 1998
Application09/323,442Parent of this division · filed 28 May 1999
US 2001/0019831 A1Pre-grant publication · published 6 Sep 2001
US 6,268,162 B1Parent of this division
Application09/323,442Parent of this continuation
US 5,968,760 AParent of this continuation
US 5,843,692 AParent of this continuation
US 5,563,042 AParent of this continuation
US 5,426,032 AParent of this continuation
Application08/148,055Parent of this division
US 5,179,005 AParent of this division
Application07/187,602Parent of this continuation-in-part
US 4,935,346 AParent of this continuation-in-part
US 6,489,133 B2This patent

From the US filing history. Foreign family members aren’t listed.