Interstitial fluid collection and constituent measurement

• US 20030233055A1
• Filed: 03/06/2003
• Published: 12/18/2003
• Est. Priority Date: 10/13/1993
• Status: Active Grant

• Current Assignee: Integ Incorporated (Johnson & Johnson)
• Original Assignee: Integ Incorporated (Johnson & Johnson)
• Inventors: Knudson, Mark B., Erickson, Brian J., Hilgers, Michael E., Shapland, J. Edward, Hendrickson, Tracy A., Solomon, Frank A.
• Granted Patent: US 7,001,343 B2
• Time in Patent Office: Days
• 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 a sample of body fluid, said method-comprising:

urging a sampler against a patient'"'"'s skin, said sampler including a penetration member sized to penetrate the patient'"'"'s skin into but not substantially through a dermal layer upon placement of said sampler against said skin;

drawing a sample of said fluid along said penetration member and out of said skin;

testing said sample for desired constituents.

2. A method according to claim 1 wherein said sample is tested by passing light through said sample and measuring an absorption of predetermined wavelengths.

3. A method according to claim 1 wherein said sample is tested electro-chemically.

4. A method according to claim 1 wherein said sample is tested colormetrically.

5. A method according to claim 1 wherein said sample is tested by attenuated total reflectance.

6. A method according to claim 1 wherein said penetration member is a needle selected to have a size smaller than 28 gauge.

7. A method according to claim 1 comprising compressing against said skin in a region surrounding said penetration member during placement of said sampler against said skin.

8. A method according to claim 1 comprising drying said fluid prior to said testing.

9. A method according to claim 1 comprising retaining said fluid on a membrane for said testing.

10. An apparatus for obtaining a sample of body fluid, said apparatus comprising a penetration member with a fluid pathway for fluid to flow at least partially along the length of said member, said member sized to penetrate at least into the dermal layer of a patient'"'"'s skin for a sample of said fluid to flow along said pathway.

11. An apparatus according to claim 10 comprising a membrane in close proximity to an end of said penetration for said sample to flow from said fluid pathway and be deposited on said membrane.

12. An apparatus according to claim 11 wherein said membrane is formed of a microporous material.

13. An apparatus according to claim 12 wherein said membrane is accessible for drying prior to testing of constituents deposited on said membrane.

14. An apparatus according to claim 10 comprising a base member, a needle disposed within said base member and having a penetration end protruding beyond a lower surface of said base member and having an opposite end.

15. An apparatus according to claim 14 further comprising means for compressing said skin in a region surrounding said needle upon penetration of said needle into said skin.

16. An apparatus according to claim 14 wherein said needle is sized to penetrate into but not through a dermal layer of said skin.

17. An apparatus according to claim 14 further comprising a membrane disposed against said opposite end for depositing said sample on said membrane.

18. An apparatus according to claim 14 wherein said needle is selected to have a size smaller than 28 gauge.

19. An apparatus for obtaining a sample of body fluid, said apparatus comprising:

a penetration member with a fluid pathway for fluid to flow at least partially along a length of said member, said member sized to penetrate at least into the dermal layer of skin, said having means to admit and retain a body fluid located residing in the dermal layer into said passageway; and

means for controlling the depth of the penetration of said conduit so that said conduit penetrates into the dermal layer of skin but not through the dermal layer.

20. An apparatus according to claim 19 wherein the constituent is glucose and said member includes at least a section composed of a material which is transparent to a light source including infrared light having a wavelength absorbable by glucose.

21. An apparatus according to claim 19 wherein said member is a conduit having a passageway and wherein said conduit includes a proximal and distal end and said admitting means includes means for applying a negative pressure to said proximal end of the conduit such that body fluid located adjacent said distal end of the conduit is drawn up into said passageway of the conduit.

22. An apparatus according to claim 19 wherein said admitting means includes means for compressing the skin adjacent the member such that body fluid located adjacent said conduit is forced up into said passageway of the conduit.

23. An apparatus for obtaining a sample of body fluid contained in the skin for determining a level of a constituent in the body fluid, said apparatus comprising:

a conduit defining a passageway and sized to penetrate into the skin wherein body fluid contained in the skin is admitted and retained in said passageway, said conduit including at least a section composed of a material which is transparent to a testing light of known intensity having a wavelength absorbable by the constituent

24. A method for determining a level of a constituent in a body fluid, said method comprising:

inserting a conduit into the skin;

collecting body fluid located within the skin in said conduit;

directing a light source through the constituent retained in said conduit to determine the level of a constituent in the body fluid.

25. A method according to claim 24 wherein the constituent is glucose and said light source includes infrared-light having a wavelength absorbable by glucose.

26. A method according to claim 24 wherein said step of directing the light includes measuring the amount of infrared light absorbed by the constituent in the body fluid as the light is directed through the conduit to determine the concentration of the constituent in the body fluid.

27. A method for determining a level of a constituent in a body fluid, said method comprising:

inserting a conduit into the dermal layer of skin but not through the dermal layer;

passing a sample of said body fluid located within the dermal layer into said conduit;

evaporating the liquid from said conduit so that only the constituent remains on the walls of the conduit; and

directing a light source through the constituent retained in said conduit to determine the level of a constituent in the body fluid.

28. A method according to claim 27 wherein said light source includes light having a wavelength absorbable by the constituent and said step of directing the light source through the constituent includes measuring the amount of light absorbed by the constituent to determine the concentration of the constituent in the body fluid.

29. A method for collecting a sample of body fluid, said method comprising:

selecting a penetrating member having a length sized to partially extend into the dermal layer of skin and having a fluid pathway for fluid to flow at least partially along a length of said member further sized to collect said fluid upon insertion of said member into said skin and without substantial pain upon insertion;

inserting said penetrating member into said skin and;

drawing said fluid along said fluid pathway.

30. A method according to claim 29 further comprising compressing skin adjacent said member to urge said fluid along said fluid pathway.