Test strip qualification system

• US 6,835,570 B2
• Filed: 11/12/2003
• Issued: 12/28/2004
• Est. Priority Date: 03/14/2002
• Status: Expired due to Term

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Patel, Harshad
• Primary Examiner(s): WALLENHORST, MAUREEN
• Application Number:
  US10/712,679
• Publication Number:
  US 20040096980A1
• Time in Patent Office: 412 Days
• Field of Search: 436/8, 436/63, 436/69, 436/180, 422/73, 422/100, 435/13, 600/368, 600/369, 73/644.1, 702/19, 702/31, 702/32
• US Class Current: 436/8
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G01N 33/86 involving blood coagulating time or factors, or their receptors
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

In connection with a fluidic medical diagnostic device that permits measurement of the coagulation time of blood, software, methods and associated devices for quality control are provided. The fluidic device preferably includes a test strip with one end having a sample port for introducing a sample and a bladder at the other end for drawing the sample to a measurement area. A channel carries sample from the sample port to an assay measurement area and first and second control measurement areas. Preferably a stop junction, between the measurement areas and bladder, halts the sample flow for measurement. If results from measurements taken for each control fall within a predetermined zone or defined limits, the assay measurement is qualified. If not, an error is registered and the test strip is counted as unfit.

Claims

1. A method of test strip qualification comprising:

providing a test strip comprising an assay reaction area, a first control reaction area and a second control reaction area;

obtaining prothrombin (PT) results for each reaction area; and

comparing results from said first control reaction area to control qualification criteria comprising an upper limit and a lower limit, wherein said upper limit is dependent upon assay reaction area PT results at or below about a 2.0 International Normalized Ratio (INR) and is independent of assay reaction area PT results at or above about a 2.0 INR, wherein said test strip is qualified if said results fall below within said lower limit and said upper limit.

2. The method of claim 1, wherein said lower limit comprises a value independent of assay reaction PT results.

3. The method of claim 2, wherein said lower limit is about 0.60 INR.

4. The method of claim 1, wherein said upper limit is a line function when said assay reaction area PT results are at or above about a 2.0 INR.

5. The method of claim 4, wherein said line function is expressed as y=mx+b, wherein y represents INR results obtained for said first control reaction area, x represents INR results obtained for said assay reaction area, m≈

0.50 and b≈

0.91 for said upper limit.

6. The method of claim 1, further comprising outputting a message to a user indicating test strip qualification.

11. A system programmed to operate according to a method selected from the test strip qualification methods of claim 1, 7, or 9.

12. A computer-readable medium embodying a program to direct a system to perform a method selected from the test strip qualification methods of claim 1, 7 or 9.

13. A computer-readable medium containing data representing sample results, wherein said data is made by a method selected from the test strip qualification methods of claim 1, 7 or 9.

7. A method of test strip qualification comprising:

providing a test strip comprising an assay reaction area, a first control reaction area and a second control reaction area;

obtaining prothrombin (PT) results for each reaction area; and

comparing results from said second control reaction area to control qualification criteria comprising an upper limit and a lower limit, wherein said upper limit is dependent upon assay reaction area PT results and wherein said lower limit comprises first and second portions dependent upon assay reaction area PT results, wherein said second portion drops-off from said first portion, wherein said test strip is qualified if said results fall within said upper limit and said lower limit.

8. The method of claim 7, further comprising outputting a message to a user indicating test strip qualification.

9. A method of test strip qualification comprising:

providing a test strip comprising an assay reaction area, a first control reaction area and a second control reaction area;

obtaining prothrombin (PT) results for each of said reaction areas; and

comparing results from said first control reaction area to control qualification criteria comprising a first upper limit and a first lower limit, wherein said upper limit is dependent upon assay reaction area PT results at or below about a 2.0 International Normalized Ratio (INR) and is independent of assay reaction area PT results at or above about a 2.0 INR, wherein said test strip is qualified if said results fall below within first said first lower limit and said first upper limit; and

comparing results from said second control reaction area to control qualification criteria comprising a second upper first, wherein said second upper first is dependent upon assay reaction area PT results and wherein said second limit comprises first and second portions dependent upon assay reaction area PT results, wherein said second portion drops-off from said first portion, wherein said test strip is qualified if said results fall within said upper limit and said lower limit;

wherein said test strip is qualified if said results from said first control reaction area fall within said first upper limit and said first lower limit and if said results from said second control reaction area fall within said second upper limit and said second lower limit.

10. The method of claim 9, further comprising outputting a message to a user indicating test strip qualification.