Test strip for measuring analyte concentration over a broad range of sample volume

• US 6,986,869 B2
• Filed: 03/28/2002
• Issued: 01/17/2006
• Est. Priority Date: 08/28/1989
• Status: Expired due to Fees

• Current Assignee: Cilag Gmbh International (Johnson & Johnson), LifeScan IP Holdings, LLC
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Tuohy, Deborah P., Dubowik, John M.
• Primary Examiner(s): Gitomer, Ralph
• Application Number:
  US10/113,066
• Publication Number:
  US 20020106711A1
• Time in Patent Office: 1,391 Days
• Field of Search: 422/56, 422/57, 435/14
• US Class Current: 422/422
• CPC Class Codes: C12Q 1/54 involving glucose or galactose
• CPC Class Codes: G01N 33/48 Biological material, e.g. blood, urine G01N33/02, G01N33/26, G01N33/44, G01N33/46 take precedence; Haemocytometers counting blood corpuscules distributed over a surface by scanning the surface G06M11/02
• CPC Class Codes: G01N 33/521 Single-layer analytical elements
• CPC Class Codes: G01N 33/523 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/54386 Analytical elements
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

A test strip for determining the concentration of an analyte in a body fluid includes a membrane in fluid communication with a porous layer. The membrane and the porous layer are divided into compressed portions, which restrict the capillary flow of the body fluid, and uncompressed portions. The uncompressed portions are adapted to absorb and retain body fluids in excess of the amount required for operation of the test strip. The test strip may be constructed with an internal relief chamber to accommodate the uncompressed portions. A method of making the test strip by pressure and/or heat sealing individual components on a shaping die is also provided.

Claims

1. A test strip, for detecting an analyte in a body fluid, comprising:

a cover sheet having an elongated window cut through it;

a lamellar membrane adjacent to the cover sheet, extending across the window and containing a reagent that reacts with the analyte to produce a color change;

a relatively imcompressible center plate, adjacent to the membrane and having a central portion cut out of it to form an internal relief chamber, into which a portion of the membrane protrudes, the relief chamber being substantially aligned with the window;

a porous sheet adjoining the center plate, in fluid communication with the membrane, and having a pillow portion that extends into the relief chamber; and

a backing sheet adjoining the porous sheet and having a sample port cut through it;

whereby fluid introduced into the sample port can flow through the porous sheet to the membrane, and analyte in the fluid can react with the reagent to produce a color change visible through the window.

2. The test strip of claim 1 wherein the surfaces of the center plate and cover sheet that adjoin the membrane comprise solid thermoplastics which penetrate the membrane, creating a seal and fastening the center plate and cover sheet to the membrane.

3. The test strip of claim 1 wherein the surfaces of the backing sheet and center plate that adjoin the porous sheet comprise solid thermoplastics, which penetrate the pores of the porous sheet, creating a seal and fastening the backing sheet and center plate to the absorbent sheet.