Sampling devices and methods utilizing biased capillary action

• US 20040122339A1
• Filed: 12/10/2003
• Published: 06/24/2004
• Est. Priority Date: 12/24/2002
• Status: Abandoned Application

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Roe, Steven N.
• Application Number:
  US10/732,615
• Publication Number:
  US 20040122339A1
• Time in Patent Office: Days
• US Class Current: 600/573
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150358 Strips for collecting blood, e.g. absorbent optical reagent test strips G01N21/8483; chemical reagent test strips G01N33/4875, G01N33/52

Abstract

A device is constructed so as to define a capillary channel that draws a body fluid form a proximal portion of the capillary channel toward a distal portion. A counterbore defining a “ledge” not substantially normal to the center line of channel causes the meniscus of body fluid to be “biased” into a non-radially-symmetric shape. In one example, the bias draws the body fluid toward a testing element that is set into a groove in the main body of the device. In another example, hydrophilic and/or hydrophobic regions are created on or in device to produce the biasing effect. In certain configurations, device requires less blood to be drawn into the capillary channel for a successful test than if the biasing effect were not created.

Claims

1. A device comprising a main body that defines a capillary channel, wherein:

said capillary channel is dimensioned to draw a body fluid into said capillary channel by capillary action;

said body fluid defines a meniscus when said body fluid is drawn into said capillary channel; and

said capillary channel is constructed to tend to bias said meniscus in a radially asymmetric manner when said body fluid is drawn into said capillary channel.

2. The device of claim 1 wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

3. The device of claim 2 wherein said testing element comprises a test strip.

4. The device of claim 3 wherein said test strip comprises a membrane.

5. The device of claim 3 wherein said test strip is mounted in a groove defined in said device.

6. A device for sampling body fluid, comprising a main body that defines a capillary channel, wherein:

said capillary channel is dimensioned to draw a body fluid into said capillary channel by capillary action;

said body fluid defines a meniscus when said body fluid is drawn into said capillary channel; and

said capillary channel has a relatively hydrophilic portion tending to bias said meniscus in a radially asymmetric manner when said body fluid is drawn into said capillary channel.

7. The device of claim 6 wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

8. The device of claim 7 wherein said testing element comprises a test strip.

9. The device of claim 8 wherein said test strip comprises a membrane.

10. The device of claim 8 wherein said test strip is mounted in a groove defined in said device.

11. A fluid sampling device comprising a capillary tube defining a capillary channel adapted to contain fluid defining a meniscus, the capillary channel further adapted to impart a radially asymmetric bias to the meniscus of the fluid when the fluid is within the capillary channel.

12. The device of claim 11, the capillary channel having an angled counterbore adapted to impart the radially asymmetric bias to the meniscus of the fluid when the fluid is within the capillary channel.

13. The device of claim 12, wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

14. The device of claim 13, wherein said testing element comprises a test strip.

15. The device of claim 14, wherein said test strip comprises a membrane.

16. The device of claim 14, wherein said test strip is mounted in a groove defined in said device.

17. The device of claim 11, the capillary channel having a hydrophilic region adapted to impart the radially asymmetric bias to the meniscus of the fluid when the fluid is within the capillary channel.

18. The device of claim 17, wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

19. The device of claim 18, wherein said testing element comprises a test strip.

20. The device of claim 19, wherein said test strip comprises a membrane.

21. The device of claim 19, wherein said test strip is mounted in a groove defined in said device.

22. A device, comprising:

a body defining a capillary channel having a first region and a second region and a proximal portion and a distal portion;

the first region having a first capillary attraction to a fluid when the fluid flows in the capillary channel from the proximate portion toward the distal portion;

the second region having a second capillary attraction to the fluid when the fluid flows in the capillary channel from the proximate portion toward the distal portion; and

the first capillary attraction being stronger than the second capillary attraction sufficiently to bias the flow of the fluid within the capillary channel toward the first region when the fluid flows in the capillary channel from the proximate portion toward the distal portion.

23. The device of claim 22 wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

24. The device of claim 23, wherein said testing element comprises a test strip.

25. The device of claim 24, wherein said test strip comprises a membrane.

26. The device of claim 24, wherein said test strip is mounted in a groove defined in said device.

27. A fluid sampling device comprising body means defining capillary channel means, wherein the capillary channel means includes means for biasing the meniscus of fluid within the capillary channel means.

28. The device of claim 27, wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

29. The device of claim 28, wherein said testing element comprises a test strip.

30. The device of claim 29, wherein said test strip comprises a membrane.

31. The device of claim 29, wherein said test strip is mounted in a groove defined in said device.

32. A device for sampling body fluid, comprising:

a body defining a capillary channel; and

a lancet disposed within said capillary channel and defining a space between said lancet and said body;

said lancet being selectively advancable and retractable;

said capillary channel being dimensioned to draw a body fluid into said space through capillary action;

said body fluid defining a meniscus when said body fluid is drawn into said space; and

said capillary channel, or said lancet, or both, being dimensioned to tend to bias said meniscus in a radially asymmetric manner when said body fluid is drawn into said space.

33. The device of claim 32, wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

34. The device of claim 33, wherein said testing element comprises a test strip.

35. The device of claim 34, wherein said test strip comprises a membrane.

36. The device of claim 34, wherein said test strip is mounted in a groove defined in said device.

37. A device for sampling body fluid, comprising:

a body defining a capillary channel; and

a lancet disposed within said capillary channel and defining a space between said lancet and said body;

said lancet being selectively advancable and retractable;

said capillary channel being dimensioned to draw a body fluid into the space through capillary action;

said body fluid defining a meniscus when said body fluid is drawn into the space; and

said capillary channel, or said lancet, or both, having a relatively hydrophilic portion tending to bias said meniscus toward said hydrophilic portion when said body fluid is drawn into the space.

38. The device of claim 37, wherein said bias tends to bias said fluid toward a testing element in spatial communication with said fluid.

39. The device of claim 38, wherein said testing element comprises a test strip.

40. The device of claim 39, wherein said test strip comprises a membrane.

41. The device of claim 39, wherein said test strip is mounted in a groove defined in said device.