Method of preventing short sampling of a capillary or wicking fill device

• US 7,131,342 B2
• Filed: 04/03/2003
• Issued: 11/07/2006
• Est. Priority Date: 03/27/2000
• Status: Expired due to Fees

• Current Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Hodges, Alastair McIndoe
• Primary Examiner(s): NOLAND, THOMAS
• Application Number:
  US10/408,189
• Publication Number:
  US 20030167862A1
• Time in Patent Office: 1,314 Days
• Field of Search: 738/647.2, 738/63, 738/649.1, 73/645.6, 738/648.1, 7386483-86485, 7386401-86402, 738/645.1, 204/556, 204/403, 295/95, 436/180, 422 55- 58, 422/68.1, 422/69, 422/50, 422/101, 422/102, 435/14, 600/584, 604/584
• US Class Current: 73/864.72
• CPC Class Codes: A61B 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157 disposable multilayered or laminated electrodes G01N27/307; details of handling chemical test elements G01N33/4875
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/069 Absorbents; Gels to retain a fluid
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/0887 Laminated structure
• CPC Class Codes: B01L 2300/165 Specific details about hydrophobic, oleophobic surfaces
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

The current invention provides a device, and a method for using the device, for ensuring that a capillary or wicking fill device is fully filled. In particular this invention is directed to, but not limited to, use with capillary or wicking action filled electrochemical sensors suitable for use in analyzing blood or interstitial fluids.

Claims

1. A method for ensuring that a sensing device is substantially filled with a sample of fluid comprising:

providing a device for sampling a fluid, comprising a pre-chamber having an interior surface and a first volume, the pre-chamber being capable of exerting a first capillary force, the device further comprising a sensing chamber in fluid communication with the pre-chamber, the sensing chamber comprising electrodes and having an interior surface and a second volume, the sensing chamber being capable of exerting a second capillary force, wherein the first volume is not less than the second volume, and wherein a differential exists between the capillary forces, the differential being sufficient to cause flow of fluid from the pre-chamber to substantially fill the sensing chamber;

contacting the device with the fluid for a sufficient period of time to allow the fluid to enter the pre-chamber in a volume equal to or greater than the second volume;

and allowing the sample to flow from the pre-chamber to the sensing chamber, such that the sensing chamber is substantially filled, wherein at least one of the pre-chamber and the sensing chamber further comprises a mesh material, wherein the mesh material contributes to the capillary force of at least one of the pre-chamber and the sensing chamber.

2. The method of claim 1, wherein both the pre-chamber and the sensing chamber comprise a mesh material.

3. The method of claim 2, wherein the mesh material of the pre-chamber comprises a first mesh size, and the mesh material of the sensing chamber comprises a second mesh size, wherein the second mesh size is smaller than the first mesh size.

4. The method of claim 1, wherein the mesh material comprises a material is selected from the group consisting of polyolefin, polyester, polytetrafluoroethylene, cellulose, polystyrene, polycarbonate, polysulfone and mixtures thereof.

5. A method for ensuring that a sensing device is substantially filled with a sample of fluid comprising:

providing a device for sampling a fluid, comprising a pre-chamber having an interior surface and a first volume, the pre-chamber being capable of exerting a first capillary force, the device further comprising a sensing chamber in fluid communication with the pre-chamber, the sensing chamber comprising electrodes and having an interior surface and a second volume, the sensing chamber being capable of exerting a second capillary force, wherein the first volume is not less than the second volume, and wherein a differential exists between the capillary forces, the differential being sufficient to cause flow of fluid from the pre-chamber to substantially fill the sensing chamber;

contacting the device with the fluid for a sufficient period of time to allow the fluid to enter the pre-chamber in a volume equal to or greater than the second volume;

and allowing the sample to flow from the pre-chamber to the sensing chamber, such that the sensing chamber is substantially filled, wherein at least one of the pre-chamber and the sensing chamber comprise a fibrous filling material, wherein the filling material contributes to the capillary force of at least one of the pre-chamber and the sensing chamber.

6. The method of claim 5, wherein both the pre-chamber and the sensing chamber comprise a fibrous filling material.

7. The method of claim 5, wherein the fibrous filling material comprises a material selected from the group consisting of polyolefin, polyester, polytetrafluoroethylene, cellulose, polystyrene, polycarbonate, and polysulfone.

8. The method of claim 5, wherein the fibrous filling material comprises a nonwoven or melt blown polymer.

9. A method for ensuring that a sensing device is substantially filled with a sample of fluid comprising:

providing a device for sampling a fluid, comprising a pre-chamber having an interior surface and a first volume, the pre-chamber being capable of exerting a first capillary force, the device further comprising a sensing chamber in fluid communication with the pre-chamber, the sensing chamber comprising electrodes and having an interior surface and a second volume, the sensing chamber being capable of exerting a second capillary force, wherein the first volume is not less than the second volume, and wherein a differential exists between the capillary forces, the differential being sufficient to cause flow of fluid from the pre-chamber to substantially fill the sensing chamber;

contacting the device with the fluid for a sufficient period of time to allow the fluid to enter the pre-chamber in a volume equal to or greater than the second volume;

and allowing the sample to flow from the pre-chamber to the sensing chamber, such that the sensing chamber is substantially filled, wherein at least one of the pre-chamber and the sensing chamber comprise a powder, wherein the powder contributes to the capillary force of at least one of the pre-chamber and the sensing chamber.

10. The method of claim 9, wherein both the pre-chamber and the sensing chamber comprise a powder.

11. The method of claim 9, wherein the powder is insoluble in the sample.

12. The method of claim 9, wherein the powder is soluble in the sample.

13. The method of claim 9, wherein the powder comprises a material selected from the group consisting of microcrystalline cellulose, soluble salts, insoluble salts, and sucrose.

14. A method for ensuring that a sensing device is substantially filled with a sample of fluid comprising:

providing a device for sampling a fluid, comprising a pre-chamber having an interior surface and a first volume, the pre-chamber being capable of exerting a first capillary force, the device further comprising a sensing chamber in fluid communication with the pre-chamber, the sensing chamber comprising electrodes and having an interior surface and a second volume, the sensing chamber being capable of exerting a second capillary force, wherein the first volume is not less than the second volume, and wherein a differential exists between the capillary forces, the differential being sufficient to cause flow of fluid from the pre-chamber to substantially fill the sensing chamber;

contacting the device with the fluid for a sufficient period of time to allow the fluid to enter the pre-chamber in a volume equal to or greater than the second volume;

and allowing the sample to flow from the pre-chamber to the sensing chamber, such that the sensing chamber is substantially filled, wherein the pre-chamber comprises at least one material, which may be the same or different, selected from the group consisting of a mesh material, a fibrous filling material, a porous material, and a powder, and wherein the sensing chamber comprises at least one material, which may be the same or different, selected from the group consisting of a mesh material, a fibrous filling material, a porous material, and a powder.

15. The method of claim 14, further comprising the step of:

detecting a condition wherein the pre-chamber contains a volume of fluid sufficient to substantially fill the sensing chamber.

16. The method of claim 14, further comprising the step of:

determining a presence or an absence of an analyte in the sample.

17. The method of claim 16, wherein the determining step comprises conducting a quantitative measurement of the analyte.

18. The method of claim 16, wherein the analyte comprises a substance selected from the group consisting of lactate, cholesterol, enzymes, nucleic acids, lipids, polysaccharides, and metabolites.

19. The method of claim 16, wherein the analyte comprises glucose.

20. The method of claim 16, wherein the determining step comprises an electrochemical measurement.

21. The method of claim 16, wherein the sample comprises a biological fluid.

22. The method of claim 21, wherein the biological fluid comprises a body fluid of an animal or a plant.

23. The method of claim 22, wherein the body fluid is selected from the group consisting of interstitial fluid, blood, tears, expectorate, saliva, urine, semen, vomitus, sputum, fruit juice, vegetable juice, plant sap, and nectar.

24. The method of claim 21, wherein the biological fluid comprises a food product.

25. The method of claim 16, wherein the sample comprises a non-biological fluid.

26. The method of claim 25, wherein the non-biological fluid comprises a water-based solution.

27. The method according to claim 16, the sensing chamber further comprising a chemical for use in the sensing chamber.

28. The method according to claim 27, the chemical further comprising a reagent capable of undergoing a redox reaction with an analyte or a reaction product of the analyte.

29. The method according to claim 14, wherein at least one of the electrodes has a layer that comprises a noble metal.

30. The method according to claim 29, wherein at least one of the electrode layers is selected from the group consisting of palladium, platinum, and silver.

31. The method according to claim 14, wherein at least one of the electrodes has a layer that comprises a sputter coated metal deposit.

32. The method according to claim 14, wherein the electrodes are spaced apart by a distance of 600 microns or less.

33. The method according to claim 14, wherein the electrodes are spaced apart by a distance of 400 microns or less.

34. The method according to claim 14, wherein the electrodes are spaced apart by a distance of 200 microns or less.

35. A method for ensuring that a sensing device is substantially filled with a sample of fluid comprising:

providing a device for sampling a fluid, comprising a pre-chamber having an interior surface and a first volume, the pre-chamber being capable of exerting a first capillary force, the device further comprising a sensing chamber in fluid communication with the pre-chamber, the sensing chamber having an interior surface and a second volume, the sensing chamber being capable of exerting a second capillary force, wherein the first volume is not less than the second volume, and wherein a differential exists between the capillary forces, the differential being sufficient to cause flow of fluid from the pre-chamber to substantially fill the sensing chamber, wherein both the pre-chamber and the sensing chamber comprise a mesh material, the mesh material of the pre-chamber comprising a first mesh size, and the mesh material of the sensing chamber comprising a second mesh size, wherein the second mesh size is smaller than the first mesh size;

contacting the device with the fluid for a sufficient period of time to allow the fluid to enter the pre-chamber in a volume equal to or greater than the second volume;

and allowing the sample to flow from the pre-chamber to the sensing chamber, such that the sensing chamber is substantially filled and wherein the mesh material contributes to the capillary force of at least one of the pre-chamber and the sensing chamber.

36. A method for ensuring that a sensing device is substantially filled with a sample of fluid comprising:

providing a device for sampling a fluid, comprising a pre-chamber having an interior surface and a first volume, the pre-chamber being capable of exerting a first capillary force, the device further comprising a sensing chamber in fluid communication with the pre-chamber, the sensing chamber having an interior surface and a second volume, the sensing chamber being capable of exerting a second capillary force, wherein the first volume is not less than the second volume, and wherein a differential exists between the capillary forces, the differential being sufficient to cause flow of fluid from the pre-chamber to substantially fill the sensing chamber;

contacting the device with the fluid for a sufficient period of time to allow the fluid to enter the pre-chamber in a volume equal to or greater than the second volume;

and allowing the sample to flow from the pre-chamber to the sensing chamber, such that the sensing chamber is substantially filled, wherein at least one of the pre-chamber and the sensing chamber comprise a powder, wherein the powder is soluble in the sample and contributes to the capillary force of at least one of the pre-chamber and the sensing chamber.

37. A method for ensuring that a sensing device is substantially filled with a sample of fluid comprising:

providing a device for sampling a fluid, comprising a pre-chamber having an interior surface and a first volume, the pre-chamber being capable of exerting a first capillary force, the device further comprising a sensing chamber in fluid communication with the pre-chamber, the sensing chamber having an interior surface and a second volume, the sensing chamber being capable of exerting a second capillary force, wherein the first volume is not less than the second volume, and wherein a differential exists between the capillary forces, the differential being sufficient to cause flow of fluid from the pre-chamber to substantially fill the sensing chamber;

contacting the device with the fluid for a sufficient period of time to allow the fluid to enter the pre-chamber in a volume equal to or greater than the second volume;

allowing the sample to flow from the pre-chamber to the sensing chamber, such that the sensing chamber is substantially filled, wherein the pre-chamber comprises at least one material, which may be the same or different, selected from the group consisting of a mesh material, a fibrous filling material, a porous material, and a powder, and wherein the sensing chamber comprises at least one material, which may be the same or different, selected from the group consisting of a mesh material, a fibrous filling material, a porous material, and a powder; and

detecting a condition wherein the pre-chamber contains a volume of fluid sufficient to substantially fill the sensing chamber.