Enhanced interstitial fluid collection

• US 6,203,504 B1
• Filed: 03/03/1999
• Issued: 03/20/2001
• Est. Priority Date: 09/08/1995
• Status: Expired due to Term

• Current Assignee: Integ Incorporated (Johnson & Johnson)
• Original Assignee: Integ Incorporated (Johnson & Johnson)
• Inventors: Hoegh, Thomas B., Erickson, Brian J., Hilgers, Michael E., Latterell, Scott T., Brinda, Paul D., Shoup, Michael J.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): WINGOOD, PAMELA LYNN
• Application Number:
  US09/262,146
• Time in Patent Office: 748 Days
• Field of Search: 600/573, 600/576, 600/577, 600/578, 600/583, 600/584, 606/181, 606/182
• US Class Current: 600/576
• 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 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157 disposable multilayered or laminated electrodes G01N27/307; details of handling chemical test elements G01N33/4875
• 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
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150068 by tissue compression, e.g. with specially designed surface of device contacting the skin area to be pierced
• CPC Class Codes: A61B 5/150114 by tissue compression, e.g. with specially designed surface of device contacting the skin area to be pierced
• 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 5/150389 Hollow piercing elements, e.g. canulas, needles, for piercing the skin
• CPC Class Codes: A61B 5/150503 Single-ended needles hollow piercing element tip design A61B5/150396, needle sets for catheters A61M25/06, needles for bringing media into the body A61M5/32
• CPC Class Codes: A61B 5/15109 Fully automatically triggered, i.e. the triggering does not require a deliberate action by the user, e.g. by contact with the patient's skin
• CPC Class Codes: A61B 5/15113 Manually triggered, i.e. the triggering requires a deliberate action by the user such as pressing a drive button
• CPC Class Codes: A61B 5/15117 comprising biased elements, resilient elements or a spring, e.g. a helical spring, leaf spring, or elastic strap
• CPC Class Codes: A61B 5/1519 comprising driving means, e.g. a spring, for propelling the piercing unit
• CPC Class Codes: A61B 5/15194 fully automatically retracted, i.e. the retraction does not require a deliberate action by the user, e.g. by terminating the contact with the patient's skin
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood

Abstract

A sampling apparatus for interstitial fluid includes a pressure ring surrounding a collection needle. The pressure ring and needle are movable relative to one another for the ring to first engage a patient'"'"'s skin surface prior to insertion of the needle.

Claims

1. A method of inserting a needle into a skin layer, the needle having a distal end, a first pressure surface being movable along a path parallel to an axis of the needle, the method comprising:

biasing a first pressure surface so that the distal end of the needle is recessed behind the pressure surface; and

pressing the first pressure surface against the skin layer with a force sufficient to form a pressurized zone of interstitial fluid opposing the needle and to cause the needle to extend past the first pressure surface and into the skin layer.

2. The method of claim 1 wherein pressing the first pressure surface against the skin layer with a force sufficient to extend the needle past the first pressure surface and into, but not through, the skin layer.

3. The method of claim 2 wherein a second pressure surface is spaced axially from the distal end of the needle, the method further comprising pressing the second pressure surface against the skin layer.

4. The method of claim 3 wherein pressing the second pressure surface against the skin layer increases the pressure at the pressurized zone of interstitial fluid that is formed by the first pressure surface.

5. The method of claim 3 further comprising biasing the second pressure surface, thereby urging the needle outwardly of the first pressure surface.

6. The method of claim 5 wherein the first pressure surface is biased with a spring preloaded with a force of about 3 lbs. and with a spring constant of about 4 lbs. per inch.

7. The method of claim 5 wherein the second pressure surface is biased with a spring preloaded with a force of about 1 lbs. and with a spring constant of about 2 lbs. per inch.

8. The method of claim 1 further comprising collecting interstitial fluid.

9. The method of claim 8 further comprising deposing at least a portion of the collected interstitial fluid on a membrane.

10. The method of claim 8 further comprising determining the level of glucose in the interstitial fluid.

11. The method of claim 10 wherein causing the needle to extend past the first pressure surface and into the skin layer includes creating a hole in the skin layer, the method further comprising:

withdrawing the needle from the skin layer; and

drawing fluid from the hole.

12. The method of claim 11 further comprising relaxing pressure caused by the first pressure surface.

13. The method of claim 11 wherein the fluid is interstitial fluid.

14. The method of claim 13 wherein the needle extends into, but not through, the skin layer.

15. The method of claim 14 wherein the needle defines a fluid path and the fluid is drawn through the fluid path.

16. A method of inserting a needle into a skin layer, the needle having a distal end, a first pressure surface being movable along a path parallel to an axis of the needle, and a second pressure surface is spaced axially from the distal end of the needle, the method comprising:

biasing a first pressure surface so that the distal end of the needle is recessed behind the pressure surface;

pressing the first pressure surface against the skin layer with a force sufficient to form a pressurized zone of interstitial fluid opposing the needle and to cause the needle to extend past the first pressure surface and into the skin layer;

pressing the first pressure surface against the skin layer with a force sufficient to extend the needle past the first pressure surface and into, but not through, the skin layer;

biasing the second pressure surface, thereby urging the needle outwardly of the first pressure surface

pressing the second pressure surface against the skin layer;

collecting interstitial fluid; and

determining the level of glucose in the interstitial fluid.