Method of making a test strip for determining analyte concentration over a broad range of sample volumes

• US 6,949,221 B2
• Filed: 03/28/2002
• Issued: 09/27/2005
• Est. Priority Date: 08/28/1989
• Status: Expired due to Fees

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Kiser, Ernest J., Tuohy, Deborah P., Dubowik, John M.
• Primary Examiner(s): GITOMER, RALPH J
• Application Number:
  US10/113,063
• Publication Number:
  US 20020106710A1
• Time in Patent Office: 1,279 Days
• Field of Search: 422/56, 422/57, 435/14
• US Class Current: 156/60
• 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 method of making a test strip for determining the concentration of an analyte in a body fluid, which comprises:

assembling as a sealable package;

a cover sheet having an elongated window cut in it;

a lamellar membrane which extends across the window, has a sealable coating and contains a reagent that reacts with the analyte to produce a color change;

an adhesive-coated porous sheet, and a backing sheet which contacts the adhesive and has through it a sample port;

positioning the sealable package between a substantially flat plate and a shaping die that defines an elongated groove having a length about equal to the length of the window, such that the groove and the window are in alignment; and

applying the die to the sealable package with sufficient pressure to compress portions of the porous layer that are located on opposite sides of the groove and to bond the cover sheet to the membrane and the porous sheet to the backing sheet.

2. The method of claim 1 which further comprises venting the porous layer by removing a part of the sealable package adjacent to an end of the groove.

3. The method of claim 1 in which the sealable package and sealable coating are heat sealable.

4. The method of claim 3 wherein the die is applied to the heat-sealable package with a pressure in the range of about 340 to about 1400 kPa. at a temperature in the range of about 65°

C. to about 110°

C.