System for withdrawing small amounts of body fluid

• US 8,821,413 B2
• Filed: 02/20/2013
• Issued: 09/02/2014
• Est. Priority Date: 07/20/2001
• Status: Expired due to Fees

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Effenhauser, Carlo, Hein, Heinz-Michael, Koelker, Karl-Heinz, Deck, Frank
• Primary Examiner(s): SZMAL, BRIAN SCOTT
• Application Number:
  US13/771,307
• Publication Number:
  US 20130158373A1
• Time in Patent Office: 559 Days
• Field of Search: 600573-584, 604264-274, 604/46, 604/157, 606181-183, 436/180, 436/146, 436/148, 436/169, 436/177, 422 99-101, 137/828, 137/803, 137/833, 385/17, 385/18
• US Class Current: 600/584
• 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. A system, comprising:

a disposable lancing unit having a needle with a distal end for piercing a surface of skin, wherein the needle has at least one capillary structure that is open to the outside from at least the distal end to at least an upper end of the needle;

a drive unit configured to hold the distal end of the needle below the surface of the skin and the upper end above the surface of the skin during fluid collection; and

wherein the capillary structure is configured to transport body fluid solely via capillary action.

2. The system of claim 1, in which the disposable lancing unit has a holding area.

3. The system of claim 2, in which the holding area has a detection zone for detecting one or several analytes, the detection zone being arranged for taking up body fluid from the capillary structure.

4. The system of claim 3, wherein the detection zone includes a reagent for detecting the analytes in the body fluid.

5. The system of claim 2, in which the capillary structure and holding area are integrally connected together.

6. The system of claim 2, in which the holding area and capillary structure are integrally manufactured from a single piece of material.

7. The system of claim 2, in which the holding area and capillary structure are manufactured from a semiconductor.

8. The system of claim 1, wherein the drive unit is configured to partially retract the lancing unit in the skin so that the capillary structure remains in part in the skin to promote pooling of body fluid.

9. The system of 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.

10. The system of claim 1, wherein:

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

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

.

11. A method, comprising:

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

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

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

12. The method of claim 11, further comprising:

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

13. The method of claim 11, further comprising:

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

14. The method of claim 11, wherein the lancing unit remains at a maximum penetration depth into the skin during said collecting.

15. The method of claim 11, wherein the body fluid is drawn from both the surface of the skin and below the surface of the skin during said collecting.

16. The method of claim 11, further comprising:

detecting analyte in the body fluid in the detection zone.

17. A method of manufacturing a disposable lancing unit, comprising:

creating an open capillary groove in a surface of a holding area from a distal end of a lancing tip to a holding area, the capillary groove being configured to draw body fluid solely via capillary action;

leaving the open capillary groove uncovered along the entire length of the lancing tip; and

applying a detection zone over the capillary groove at the holding area.

18. The method of claim 17, further comprising applying a window over the detection zone.

19. The method of claim 17, wherein said applying includes applying a reagent over the holding area.