Method and system for withdrawing body fluid

• US 9,414,774 B2
• Filed: 10/09/2006
• Issued: 08/16/2016
• Est. Priority Date: 04/10/2004
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Korner, Stephan, Jaeggi, Rainer, Griss, Patrick, Sarofim, Emad, Calasso, Irio Guiseppe
• Primary Examiner(s): Szmal, Brian
• Assistant Examiner(s): NGUYEN, HUONG Q
• Application Number:
  US11/539,675
• Publication Number:
  US 20070118051A1
• Time in Patent Office: 3,599 Days
• Field of Search: 600/583, 600/584, 600/573, 606/181, 606/182, 606/183
• US Class Current: 1/1
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• 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 5/150358 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 5/150816 by tactile feedback, e.g. vibration
• CPC Class Codes: A61B 5/150954 Means for the detection of operative contact with patient, e.g. by temperature sensitive sensor
• 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 5/157 Devices characterised by integrated means for measuring characteristics of blood

Abstract

A system and method for carrying out the withdrawal of body fluid with as little body fluid as possible visible to the user at the end of the process. The present invention provides a pressure piece for exerting pressure on a body part. The pressure piece is moved relative to a support for the body part, and in the final phase of fluid withdrawal, the compressive or resistive force of the pressure piece on the body part is reduced in order to avoid the escape of body fluid from the puncture site. The support results in a defined positioning of the body part that rests against it for the lancing process, whereas the relative movement of the pressure piece enables an additional increase in pressure and thus an improved collection of fluid.

Claims

1. A method of using an analytical instrument for withdrawing blood from a body part, comprising:

moving a pressure piece relative to a support which contacts the body part to exert pressure on the body part with the pressure piece;

inserting a lancing member into the body part, wherein the lancing member includes a capillary to collect blood;

withdrawing blood through the capillary with a collecting unit;

using the analytical instrument to reduce the compressive force of the pressure piece on the body part to avoid forming a drop of blood on the skin surface of the body part.

2. The method of claim 1, wherein the reducing the compressive force takes place in the final phase of fluid withdrawal.

3. The method of claim 1, wherein the lancing member is removed from the body part during or after the pressure reduction.

4. The method of claim 1, further comprising pressing the body part against the pressure piece, wherein the pressure piece is moved towards the support against a resisting force.

5. The method of claim 1, wherein a positioning drive moves the pressure piece towards or away from the body part.

6. The method of claim 1, wherein the compressive force of the pressure piece is lowered by relaxing a pretensioning element comprising a pretensioned spring acting against the pressure piece.

7. The method of claim 1, wherein the compressive force of the pressure piece is regulated by a force element.

8. The method of claim 1, wherein the pressure piece is moved away from the body part at the end of fluid withdrawal.

9. The method of claim 1, wherein the pressure piece is retracted through an opening of the support into a position that is screened from contact by the body part in order to reduce the pressure.

10. The method of claim 1, wherein the pressure piece delimits a free puncture area for the lancing member.

11. The method of claim 1, wherein the compressive force exerted by the pressure piece is controlled as a function of the amount, rate, or duration of fluid withdrawal.

12. A method of using an analytical instrument for withdrawing blood from a body part, comprising:

moving a pressure piece relative to a support which contacts the body part to exert pressure on the body part with the pressure piece;

inserting a lancing member into the body part to create a puncture;

withdrawing blood with a collecting unit;

controlling the compressive force exerted by the pressure piece on the body part for a defined withdrawal of blood and thereafter using the analytical instrument to reduce the compressive force exerted by the pressure piece in a permanent manner without increase; and

then

moving the lancing member away from the body part with substantially no blood being visible on the skin surface near the puncture.

13. The method of claim 12, wherein the control occurs by one of a user-defined presetting for the withdrawal duration, a detection of the collected volume, or of the actual flow rate of the body fluid.

14. The method of claim 12, further comprising generating a release signal to activate the lancing process when the pressure piece reaches a preset position or when the support is touched.

15. The method of claim 12, further comprising generating a release signal to activate the lancing process when the pressure piece or the support is in a stop position.

16. The method of claim 12, wherein the lancing member is inserted to a defined lancing depth into the body part and then is retracted into a collecting position at a smaller lancing depth.

17. The method of claim 12, further comprising coupling a detection unit with the collecting unit to analyse the body fluid.

18. The method of claim 12, further comprising transporting the body fluid by a capillary transport channel of the collecting unit.

19. The method of claim 12, further comprising selecting the pressure piece from a plurality of different pressure pieces, wherein the method is adapted to the anatomy of the body part.

20. The method of claim 12, further comprising bulging or stretching the body part in a puncture area under the pressure of the pressure piece.

21. A system for withdrawing blood from a body part, comprising:

a pressure piece configured to apply pressure to a body part and having an actuator operably connected thereto;

a lancing member configured for insertion into the body part and including a capillary to collect blood;

a support configured to contact the body part;

a collecting unit to withdraw blood; and

the pressure piece being movable relative to the support in order to exert pressure on the body part, wherein the actuator is configured to reduce the compressive force of the pressure piece in a permanent manner without increase after removing an amount of blood, whereby substantially no blood is visible on a skin surface near a puncture created by the lancing member after the lancing member is retracted from the body part.

22. The system of claim 21, wherein the lancing member is formed on the collecting unit.

23. The system of claim 21, wherein the pressure piece is configured to be moved towards the support against a restoring force of the actuator by pressing the body part against the pressure piece.

24. The system of claim 21, wherein the actuator comprises a pretensioning element that further comprises a spring resting under pretension against the pressure piece.

25. The system of claim 21, wherein the actuator comprises a movable support to relax the pretensioning element.

26. The system of claim 21, wherein the actuator comprises a curve-controlled positioning drive for the movement of the pressure piece.

27. The system of claim 21, wherein the support comprises a positioning surface to which to apply the body part, the positioning surface being provided with an opening for the passage of the pressure piece.

28. The system of claim 21, wherein the pressure piece is formed as a ring and the lancing member is configured to be lanced through an opening in the ring into the body part.

29. The system of claim 21, wherein the pressure piece is formed by at least one bar configured to press down on the body part linearly or by a strut configured to press down on the body part in a punctiform manner.

30. The system of claim 21, wherein the pressure piece is elastically deformable.

31. The system of claim 21, further comprising a signal generator that is activated when a preset position is reached or when the support or the pressure piece is touched or reaches a stop position in order to generate a release signal for the activation of the lancing member.

32. The system of claim 21, wherein the collecting unit is operatively connected with a detection unit configured to analyze the body fluid.

33. The system of claim 21, wherein the collecting unit comprises a capillary transport channel to transport the body fluid.

34. A method of withdrawing blood from a body part with a device of the type having a housing, a lancing opening formed in the housing and which defines a support for the body part, a lancing member which is extendable through the lancing opening during operation of the device, and a movable pressure piece positioned adjacent the opening, the method comprising:

arranging the pressure piece such that it can be contacted from outside of the housing by a body part;

exerting pressure on the pressure piece with the body part during which the pressure piece moves and provides a resistive force against the body part;

after beginning the step of exerting pressure on the pressure piece with the body part, inserting the lancing member into the body part to a lancing depth;

withdrawing blood from the body part;

retracting the pressure piece inside of the housing; and

removing the body part from the lancing device after the step of retracting the pressure piece within the opening, wherein substantially no blood is visible on the skin surface near the puncture created by the lancing member.

35. The method of claim 34, further comprising, after the inserting step, partially retracting the lancing member to a collecting position in which the tip of the lancing member is positioned at or below a skin surface.

36. The method of claim 35, further comprising completely retracting the lancing member from the body part.

37. The method of claim 34, further comprising contacting the support with the body part.

38. The method of claim 37, further comprising triggering the inserting of the lancing member when the body part contacts the support.

39. The method of claim 34, further comprising regulating the amount of the resistive force provided by the pressure piece against the body part as a function of the quantity of body fluid withdrawn, rate of body fluid withdrawal, or duration of body fluid withdrawal.

40. The method of claim 39, wherein the body part is in contact with the support and the pressure piece during the regulating of the amount of resistive force provided by the pressure piece.

41. The method of claim 34, further comprising providing the pressure piece in the form of a ring.

42. The method of claim 34, wherein the pressure piece initially extends from the lancing opening.

43. The method of claim 34, wherein the resistive force provided by the pressure piece against the body part is reduced as the withdrawal of body fluid proceeds.

44. The method of claim 43, wherein the reduction in the resistive force provided by the pressure piece concludes with the pressure piece being removed from contact with the body part, whereby a tactile signal is provided to the user that the body fluid withdrawal is complete.

45. The method of claim 43, wherein the reduction in the resistive force is gradual.