Test strip for measuring analyte concentration over a broad range of sample volume
First Claim
1. A test strip, suitable for determining the concentration of an analvte in a body fluid, which comprises:
- a cover sheet, having an elongated window cut through it;
a lamellar membrane adjacent to the cover sheet, extending across and into the window and containing a reagent that reacts with the analyte to produce a color change;
a porous sheet in fluid communication with the membrane, having a pillow portion and a compressed portion, the pillow portion being substantially aligned with the window; 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 to the membrane, and analyte in the fluid can react with the reagent to produce a color change visible through the window.
8 Assignments
0 Petitions
Accused Products
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.
52 Citations
24 Claims
-
1. A test strip, suitable for determining the concentration of an analvte in a body fluid, which comprises:
-
a cover sheet, having an elongated window cut through it;
a lamellar membrane adjacent to the cover sheet, extending across and into the window and containing a reagent that reacts with the analyte to produce a color change;
a porous sheet in fluid communication with the membrane, having a pillow portion and a compressed portion, the pillow portion being substantially aligned with the window; 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 to the membrane, and analyte in the fluid can react with the reagent to produce a color change visible through the window. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 19, 20)
-
-
16. The test strip of claim I wherein the porous sheet contains polypropylene glycol in an amount effective as a surfactant to improve wicking of fluid by the porous sheet.
-
18. A test strip, suitable 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 incompressible 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 to the membrane, and analyte in the fluid can react with the reagent to produce a color change visible through the window.
-
-
21. 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 adhesivecoated 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. - View Dependent Claims (22, 23, 24)
-
Specification