Hollow microneedle patch

• US 20020006355A1
• Filed: 06/11/2001
• Published: 01/17/2002
• Est. Priority Date: 07/11/2000
• Status: Active Grant

• Current Assignee: Bayer Corporation (Bayer AG)
• Original Assignee: Bayer Corporation (Bayer AG)
• Inventors: Whitson, Robert C.
• Granted Patent: US 6,603,987 B2
• Time in Patent Office: Days
• US Class Current: 422/56
• CPC Class Codes: A61B 5/14514 using means for aiding extraction of interstitial fluid, e.g. microneedles or suction
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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
• CPC Class Codes: A61B 5/150755 Blood sample preparation for further analysis, e.g. by separating blood components or by mixing
• CPC Class Codes: A61B 5/150969 Low-profile devices which resemble patches or plasters, e.g. also allowing collection of blood samples for testing
• CPC Class Codes: A61B 5/150984 Microneedles or microblades
• CPC Class Codes: A61B 5/15142 Devices intended for single use, i.e. disposable
• CPC Class Codes: A61B 5/15186 Devices loaded with a single lancet, i.e. a single lancet with or without a casing is loaded into a reusable drive device and then discarded after use; drive devices reloadable for multiple use
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2037/003 having a lumen
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: G01N 33/528 Atypical element structures, e.g. gloves, rods, tampons, toilet paper

Abstract

A test strip is provided for use in the determination of the concentration of an a chemical in blood. The test strip comprises a plurality of microneedles and a test area. Each microneedle is adapted to puncture skin and to draw blood. The test area is in fluid communication with the microneedles. The test area contains a reagent adapted to produce a reaction indicative of the concentration of the chemical in blood.

Claims

1. A test strip for use in the determination of the concentration of an a chemical in blood, comprising:

a plurality of microneedles, each microneedle being adapted to puncture skin and to draw blood; and

a test area in fluid communication with the microneedles, the test area containing a reagent being adapted to produce a reaction indicative of the concentration of a chemical in blood.

2. The test strip of claim 1 wherein the reagent is adapted to produce a colorimetric reaction.

3. The test strip of claim 2 in combination with a colorimetric sensor.

4. The test strip of claim 1 wherein the reagent is adapted to produce an electrochemical reaction, the test strip further comprising a pair of electrodes coupled to the test area.

5. The test strip of claim 4 in combination with a sensor being adapted to measure a change in current across the electrodes.

6. The test strip of claim 1 wherein the chemical is glucose.

7. The test strip of claim 6 in combination with a sensor adapted to measure the concentration of glucose in the blood.

8. The test strip of claim 1 further comprising an adhesive disposed on the test area, the adhesive being adapted to adhere the test strip to skin.

9. The test strip of claim 1 wherein each microneedle has a length of at least about 0.005 inch.

10. The test strip of claim 1 wherein each microneedle is hollow.

11. The test strip of claim 1 wherein each microneedle has a generally cylindrical wall and a collection point, the collection point being adapted to receive blood and to direct blood to the test area, the cylindrical wall at the collection point being downwardly slanted in a direction moving radially away from the center of the microneedle.

12. The test strip of claim 1 wherein each microneedle has a generally cylindrical wall and a collection point, the collection point being adapted to receive blood and to direct blood to the test area, the cylindrical wall at the collection point being upwardly sloping in a direction moving radially away from the center of the microneedle.

13. The test strip of claim 1 wherein each microneedle has a collection point disposed at an angle relative to a longitudinal axis of the microneedle, the collection point being adapted to receive blood and to direct blood to the test area.

14. The test strip of claim 13 whereon the angle is about ninety degrees.

15. The test strip of claim 1 wherein the plurality of microneedles is a twenty by twenty microneedle array.

16. A blood chemical monitoring system for monitoring the concentration of chemical in blood, the system comprising:

a test chamber having a top and a bottom, the test chamber containing a reagent;

an array of hollow microneedles, each of the hollow microneedles being adapted to draw blood, each of the microneedles containing an inlet and an outlet, said inlet being adapted to puncture skin, the outlet being in fluid communication with the test chamber; and

a sensor for determining the concentration of a chemical in the blood.

17. The system of claim 16 wherein the reagent is adapted to produce a calorimetric reaction and the sensor is a calorimetric sensor.

18. The system of claim 16 wherein the bottom of the test chamber is transparent.

19. The system of claim 16 wherein the test chamber includes a pair of electrodes and the reagent is adapted to produce an electrochemical reaction, the sensor being adapted to measure a change in current across the electrodes.

20. The system of claim 16 wherein the chemical is glucose.

21. The system of claim 16 further comprising an adhesive disposed on the top of the test chamber, the adhesive being adapted to adhere the test chamber to skin.

22. The test strip of claim 16 wherein each hollow microneedle has a length of at least about 0.005 inch.

23. The test strip of claim 16 wherein each hollow microneedle has a generally cylindrical wall, the cylindrical wall at the inlet being downwardly slanted in a direction moving radially away from the center of the microneedle.

24. The test strip of claim 16 wherein each microneedle has a generally cylindrical wall, the cylindrical wall at the inlet being upwardly sloping in a direction moving radially away from the center of the microneedle at the collection point.

25. The test strip of claim 16 wherein the inlet of each microneedle is disposed at an angle relative to a longitudinal axis of the microneedle.

26. The test strip of claim 25 wherein the angle is about ninety degrees.

27. The test strip of claim 16 wherein the array of hollow microneedles is a twenty by twenty hollow microneedle array.

28. A method for determining a concentration of a chemical in blood with a microneedle patch, the microneedle patch including a plurality of microneedles and a test chamber in fluid communication with the microneedles, the method comprising:

puncturing skin with at least some of the plurality of microneedles to a depth above a first layer of nerves in the skin; and

collecting a sample of blood through at least some of the plurality of microneedles in the test chamber.

29. The method of claim 28 further comprising mixing the samples of blood in the test chamber and a reagent disposed in the chamber to produce a reaction.

30. The method of claim 29 wherein the reaction is a calorimetric reaction.

31. The method of claim 30 wherein the reaction is an electrochemical reaction.

32. The method of claim 30 further comprising producing a signal indicative of the concentration of a chemical in the blood.

33. The method of claim 32 wherein the signal is a change in color.

34. The method of claim 32 wherein signal is an electrical signal.

35. The method of claim 32 further comprising measuring the signal produced by the reaction of the regent and a chemical in the samples of blood.

36. The method of claim 28 wherein the chemical is glucose.

37. The method of claim 28 wherein the depth is about 0.005 inch.

38. The method of claim 28 further comprising adhering the microneedle patch to skin.

39. The method of claim 28 wherein collecting a sample of blood though at least some of the plurality of microneedles further comprises moving the blood though at least some of the plurality of microneedles by capillary action.

40. A method for determining the concentration of a chemical in blood comprising:

assembling a plurality of microneedles on patch having a test chamber;

pressing the patch onto skin wherein at least some of the microneedles puncture the skin to a depth above a first nerve layer;

collecting a sample of blood through at least some of the plurality of microneedles in the test chamber.

41. The method of claim 40 further comprising mixing the samples of blood in the test chamber and a reagent disposed in the chamber to produce a reaction.

42. The method of claim 41 wherein the reaction is a colorimetric reaction.

43. The method of claim 41 wherein the reaction is an electrochemical reaction.

44. The method of claim 41 further comprising producing a signal indicative of the concentration of a chemical in the blood.

45. The method of claim 44 wherein the signal is a change in color.

46. The method of claim 44 wherein signal is an electrical signal.

47. The method of claim 44 further comprising measuring the signal produced by the reaction of the regent and a chemical in the samples of blood.

48. The method of claim 40 wherein the chemical is glucose.

49. The method of claim 40 wherein the depth is about 0.005 inch.

50. The method of claim 40 further comprising adhering the microneedle patch to skin.

51. The method of claim 40 wherein collecting a sample of blood though at least some of the plurality of microneedles further comprises moving the blood though at least some of the plurality of microneedles by capillary action.