Method for selectively combining multiple membranes for assembly into test strips

• US 7,129,038 B2
• Filed: 06/21/2002
• Issued: 10/31/2006
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson), LifeScan IP Holdings, LLC
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Gopalan, Ramanan, Messamer, Jon Michael, Sharma, Manoj
• Primary Examiner(s): Chin, Christopher L.
• Application Number:
  US10/177,542
• Publication Number:
  US 20030235858A1
• Time in Patent Office: 1,593 Days
• Field of Search: None
• US Class Current: 435/4
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

A method for selectively combining multiple membranes for assembly into test strips (such as visual blood glucose test strips with side-by-side membranes). The method includes first measuring a plurality of color parameters (e.g., L*, a* and b*color parameters) associated with membrane samples from at least two membrane lots. Next, response characteristics (e.g., blood glucose response levels) are simulated for a speculative test strip that includes, for purposes of the simulation, combined multiple membranes tentatively selected from the at least two membrane lots. The simulated response characteristics are based on the measured plurality of color parameters of the tentative selection of combined multiple membranes. Optionally, the simulated response characteristics can also be based on simulated color parameters of the tentative selection of combined multiple membranes. Subsequently, assembly of the at least two membrane lots into a test strip with combined membranes is contingent on acceptable simulated response characteristics. Any suitable color parameters can be employed. The method can be used to selectively combine two or more membranes based on any number of color parameters. The assembled test strips can be used to measure glucose, cholesterol, proteins, ketones, phenylalanine or enzymes in blood, urine, saliva or other biological fluid, as well as sample fluid characteristics (e.g., pH and alkalinity).

Claims

1. A method for selectively combining multiple membranes for assembly into test strips comprising:

measuring a plurality of color parameters associated with membrane samples from at least a first lot of membranes and a second lot of membranes;

simulating response characteristics of a speculative test strip that includes, for purposes of simulating the response characteristics, combined multiple membranes tentatively selected from the at least first lot of membranes and second lot of membranes, the simulated response characteristics being based on the measured plurality of color parameters of the tentative selection of combined multiple membranes,

wherein the simulated response characteristics are also based on simulated color response data and are obtained utilizing an experimentally-derived multivariate mixed model equation of the form;

R=Yβ

+Zγ

+e

 

where;

R is an N×

1 vector of color parameter responses;

β

is a b×

1 vector of fixed effect coefficients;

Y is an N×

b matrix of independent covariates;

γ

is a g×

1 vector of random effect coefficients;

Z is an N×

g matrix of random effects; and

e is a N×

l vector of residual errors; and

assembling the at least first and second lot of membranes from which the combined multiple membranes were tentatively selected into a test strip with combined membranes, the assembly contingent on an assessment of acceptable test strip clinical accuracy based on the simulated response characteristics.

2. The method of claim 1, wherein the simulating step further includes estimating the variances of the simulated response characteristics and adjusting the variances for user-related visual effects.

3. The method of claim 1, wherein the assembling step includes assembly contingent on an assessment of acceptable test strip clinical accuracy based on the simulated response characteristics as determined by comparison of the simulated response characteristics to a specification indicative of test strip of acceptable clinical accuracy.

4. The method of claim 1, wherein the assembling step includes assembly contingent on an assessment of acceptable test strip clinical accuracy based on the simulated response characteristics as determined using a Clarke'"'"'s Error Grid analysis.

5. The method of claim 1, wherein the measuring step measures L*, a* and b*color parameters of the L*a*b*color space of the Commission Internationale de L'"'"'Eclairage.

6. The method of claim 1, wherein the measuring step is accomplished using a chromameter.

7. The method of claim 1, wherein the measuring step is accomplished using a spectrophotometer.

8. The method of claim 1, wherein the measuring step measures X, Y and Z color parameters of the XYZ tristimulus space.

9. The method of claim 1, wherein the measuring step measures Y, x and y values of the Yxy color space.

10. The method of claim 1, wherein the measuring step measures L, C and h values of the L*C*h color space Commission Internationale de L'"'"'Eclairage.

11. The method of claim 1, wherein the measuring step measures HL, a and b values of the Hunter Lab color system.

12. The method of claim 1, wherein the measuring step includes measuring a plurality of color parameters on membrane samples that have been reacted with an analyte.

13. A method for selectively combining multiple membranes for assembly into visual test strips, the visual test strips for use in determination of analyte concentration in a biological fluid, the method comprising:

measuring L*, a* and b*color parameters, Commission of the Internationale de L'"'"'Eclairage, associated with membrane samples from at least a first lot of membranes and a second lot of membranes;

obtaining simulated color parameters associated with the membrane samples selected from at least the first lot of membranes and the second lot of membranes;

simulating response characteristics of a speculative test strip that includes, for purposes of simulating the response characteristics, combined multiple membranes tentatively selected from the at least first lot of membranes and second lot of membranes, the simulated response characteristics being based on the measured plurality of color parameters and the simulated color parameters of the tentative selection of combined multiple membranes,

wherein the simulated response characteristics are also based on simulated color response data and are obtained utilizing an experimentally-derived multivariate mixed model equation of the form;

R=Yβ

+Zγ

+e

 

where;

R is an N×

1 vector of color parameter responses;

β

is a b×

1 vector of fixed effect coefficients;

Y is an N×

b matrix of independent covariates;

γ

is a g×

1 vector of random effect coefficients;

Z is an N×

g matrix of random effects; and

e is a N×

l vector of residual errors; and

assembling the at least first and second lot of membranes into a test strip with combined membranes contingent on an assessment of acceptable test strip clinical accuracy based on the simulated response characteristics.

14. The method of claim 13, wherein the simulating step further includes estimating the variances of the simulated response characteristics and adjusting the variances for user-related visual effects.

15. The method of claim 13, wherein the assembling step includes assembly contingent on an assessment of acceptable test strip clinical accuracy based on the simulated response characteristics as determined by comparison of the simulated response characteristics to a specification indicative of a test strip of acceptable clinical accuracy.

16. The method of claim 13, wherein the assembling step includes assembly contingent on an assessment of acceptable test strip clinical accuracy based on the simulated response characteristics as determined using a Clarke'"'"'s Error Grid analysis.