Interstitial fluid collection and constituent measurement

• US 6,602,205 B1
• Filed: 06/26/2000
• Issued: 08/05/2003
• Est. Priority Date: 10/13/1993
• Status: Expired due to Fees

• Current Assignee: Integ Incorporated (Johnson & Johnson)
• Original Assignee: Integ Incorporated (Johnson & Johnson)
• Inventors: Shapland, J. Edward, Hendrickson, Tracy A., Solomon, Frank A., Knudson, Mark B., Erickson, Brian J., Hilgers, Michael E.
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): WINGOOD, PAMELA LYNN
• Application Number:
  US09/604,018
• Time in Patent Office: 1,135 Days
• Field of Search: 600/365, 600/573-584, 600/309, 600/319, 606/181-185, 606/188
• US Class Current: 600/573
• CPC Class Codes: A61B 10/0045 Devices for taking samples of body liquids devices for taking blood samples A61B5/15
• CPC Class Codes: A61B 2010/008 Interstitial fluid
• 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 5/1455 using optical sensors, e.g. spectral photometrical oximeters

Abstract

An apparatus and method is disclosed for obtaining and measuring constituents in a sample of body fluid. The apparatus includes a member which is sized to penetrate into at least the dermal layer of skin to collect a sample of body fluid located within the dermal layer.

Claims

1. A method for testing the glucose level in a patient having skin laden with interstitial fluid, the method comprising:

providing a testing apparatus comprising a needle;

penetrating the needle into, but not through, the skin;

extracting interstitial fluid from the skin,

transporting the interstitial fluid directly from the patient to within the test apparatus; and

testing the glucose level of the interstitial fluid within the test apparatus.

2. The method of claim 1 wherein the extracting of interstitial fluid from skin is performed without extracting a substantial portion of blood.

3. The method of claim 1 wherein transporting the interstitial fluid comprises inserting a tube into the skin.

4. The method of claim 3 wherein the transporting of the interstitial fluid comprises transporting the interstitial fluid through the tube with a capillary action.

5. The method of claim 2 wherein the transporting of the interstitial fluid comprises applying a negative pressure to assist the flow of the interstitial fluid into the tube.

6. The method of claim 1 wherein the transporting of the interstitial fluid comprises transporting the interstitial fluid to a membrane within the test apparatus and said testing is performed at the membrane.

7. The method of claim 1 wherein the testing of the glucose level in the interstitial fluid comprises spectrophotometric analysis.

8. The method of claim 7 wherein spectrophotometric analysis comprises:

exposing the interstitial fluid to spectral radiation, the spectral radiation including a predetermined wavelength of light; and

determining whether the interstitial fluid absorbs the predetermined wavelength of light from the spectral radiation.

9. The method of claim 8 wherein the predetermined wavelength of light is in the infrared portion of the spectral radiation.

10. The method of claim 8 wherein the interstitial fluid is retained within the capillary tube when exposed to the spectral radiation.

11. The method of claim 1 wherein the testing of the glucose level in the interstitial fluid comprises electrochemical testing.

12. The method of claim 11 wherein the electrochemical testing comprises placing electrodes in electrical communication with the interstitial fluid.

13. The method of claim 1 wherein the testing of the glucose level in the interstitial fluid comprises colorimetric testing.

14. The method of claim 13 wherein the colorimetric testing comprises exposing the interstitial fluid to a chemical wherein the chemical changes color when exposed to glucose.