Hollow microneedle patch

• US 6,603,987 B2
• Filed: 06/11/2001
• Issued: 08/05/2003
• Est. Priority Date: 07/11/2000
• Status: Expired due to Fees

• Current Assignee: Bayer Corporation (Bayer AG)
• Original Assignee: Bayer Corporation (Bayer AG)
• Inventors: Whitson, Robert C.
• Primary Examiner(s): Jeffery, John A.
• Application Number:
  US09/877,519
• Publication Number:
  US 20020006355A1
• Time in Patent Office: 785 Days
• Field of Search: 600/345, 600/347, 600/316, 600/317, 600/322, 600/341, 600/365, 600/367, 600/368, 600/583, 604/19-22, 604/506, 604/46, 604/272, 604/274, 604/307, 604/27, 422/56, 422/58, 422/82.05, 436/169
• US Class Current: 600/345
• 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, each microneedle having 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; 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 the plurality of microneedles is a twenty by twenty microneedle array.

12. 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, each microneedle having 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; and

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

13. The system of claim 12 wherein the reagent is adapted to produce a colorimetric reaction and the sensor is a colorimetric sensor.

14. The system of claim 12 wherein the bottom of the test chamber is transparent.

15. The system of claim 12 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.

16. The system of claim 12 wherein the chemical is glucose.

17. The system of claim 12 futher comprising an adhesive disposed on the top of the test chamber, the adhesive being adapted to adhere the test chamber to skin.

18. The system of claim 12 wherein each hollow microneedle has a length of at least about 0.005 inch.

19. The system of claim 12 wherein the array of hollow microneedles is a twenty by twenty hollow microneedle array.