SYSTEM FOR WITHDRAWING SMALL AMOUNTS OF BODY FLUID

• US 20110257559A1
• Filed: 06/30/2011
• Published: 10/20/2011
• Est. Priority Date: 07/20/2001
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Koelker, Harl-Heinz, Hein, Heinz-Michael, Deck, Frank, Effenhauser, Carlo
• Granted Patent: US 8,388,552 B2
• Time in Patent Office: Days
• US Class Current: 600/583
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• 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 5/150282 for piercing elements, e.g. blade, lancet, canula, needle
• 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 5/150419 comprising means for capillary action
• CPC Class Codes: A61B 5/15045 comprising means for capillary action
• 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 5/15113 Manually triggered, i.e. the triggering requires a deliberate action by the user such as pressing a drive button
• CPC Class Codes: A61B 5/15115 Driving means for propelling the piercing element to pierce the skin, e.g. comprising mechanisms based on shape memory alloys, magnetism, solenoids, piezoelectric effect, biased elements, resilient elements, vacuum or compressed fluids
• 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: Y10T 29/49826 Assembling or joining

Abstract

A system is provided for withdrawing small amounts of body fluid from an animal or human. The system includes a holder and a disposable lancing unit attached to the holder. The lancing unit also includes an open capillary channel for transporting the body fluid and piercing the skin.

Claims

1. System for withdrawing small amounts of body fluid, comprising:

a drive unit which has a holder which is moved from a first position into a second position when the drive unit is activated; and

a disposable lancing unit having an elongate capillary structure and a needle with a distal end for piercing skin, the capillary structure having a longitudinal extension with at least one capillary channel for transporting body fluid, wherein the at least one capillary structure is open to the outside from at least the distal end to at least an upper end of the needle that is above the skin during piercing so that the capillary channel is vented when the body fluid is drawn into the capillary channel.

2. System as claimed in claim 1, in which the disposable lancing unit has a holding area.

3. System as claimed in claim 2, in which the holding area has a detection zone for detecting one or several analytes, the detection zone being arranged such that the detection zone can take up the body fluid from the capillary structure.

4. System as claimed in claim 2, in which the capillary structure and holding area are integrally connected together.

5. System as claimed in claim 4, in which the holding area and capillary structure are integrally manufactured from a single piece of material.

6. System as claimed in claim 2, in which the holding area and capillary structure are manufactured from a semiconductor.

7. System as claimed in claim 1, in which the drive unit moves the disposable lancing unit in such a manner that the disposable lancing unit remains in the second position for a collection time period and, subsequently, the disposable lancing unit is moved into a position in which the distal end of the capillary structure is outside the skin.

8. System as claimed in claim 1, in which the drive unit moves the disposable lancing unit in such a manner that after reaching the second position the disposable lancing unit is moved back into a collecting position in which a section of the capillary structure located in the skin is shorter than in the second position.

9. System as claimed in claim 1, in which the area of the capillary structure that is open to the outside has a channel shape.

10. System as claimed in claim 9, in which the channel-shaped area has an essentially V-shaped cross-section.

11. System as claimed in claim 1, in which the length of the capillary structure is in the range from 0.3 to 3 mm and the cross-section of the capillary structure is in the range from 0.03 to 0.8 mm.

12. A system, comprising:

a disposable lancing unit including

a lancing tip with a sharpened end configured to pierce a surface of skin,

a detection zone containing a reagent configured to detect analyte in body fluid from the skin, and

a capillary groove in the disposable lancing unit extending uncovered along at least a length of the lancing tip, wherein the capillary groove has adequate wettability to transport the body fluid via capillary action to the detection zone; and

a drive mechanism configured to actuate the disposable lancing unit to pierce the surface of the skin, the drive mechanism being configured to hold the disposable lancing unit at an extended position where the capillary groove extends from below the surface of the skin to above the surface of the skin to promote venting during uptake of the body fluid.

13. The system of claim 12, wherein:

the capillary groove has an aspect ratio from 2 to 5; and

the capillary groove has a wetting angle of less than 90°

.

14. The system of claim 12, wherein the drive mechanism is configured to partially retract the lancing unit in the skin so that the capillary groove remains in part in the skin to promote pooling of the body fluid.

15. A method, comprising:

piercing skin with a lancing unit by actuating a drive unit;

collecting body fluid with an uncovered capillary groove of the lancing unit, wherein said collecting the body fluid includes venting the capillary groove by positioning the lancing unit with the drive unit so that the capillary groove extends from below the surface of the skin to above the surface of the skin; and

transporting the body fluid in the open capillary groove via capillary action to a detection zone of the lancing unit.

16. The method of claim 15, further comprising:

said collecting the body fluid includes allowing the capillary groove to reside within the incision in the skin for a collection period.

17. The method of claim 15, further comprising:

retracting partially the lancing unit in the incision so that the capillary groove remains in part in the incision to promote pooling of the body fluid in the incision.

18. The method of claim 15, wherein the lancing unit remains at a maximum penetration depth into the skin during said collecting.

19. The method of claim 15, wherein the body fluid is drawn from both the surface of the skin and below the surface of the skin during said collecting.

20. The method of claim 15, further comprising:

detecting analyte in the body fluid in the detection zone.