MAGNETIC POWERED LANCING DRIVE

• US 20100069943A1
• Filed: 09/16/2008
• Published: 03/18/2010
• Est. Priority Date: 09/16/2008
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Roe, Steven N.
• Granted Patent: US 8,118,824 B2
• Time in Patent Office: Days
• US Class Current: 606/181
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150167 Adjustable piercing speed of skin piercing element, e.g. blade, needle, lancet or canula, for example with varying spring force or pneumatic drive
• CPC Class Codes: A61B 5/150183 Depth adjustment mechanism using end caps mounted at the distal end of the sampling device, i.e. the end-caps are adjustably positioned relative to the piercing device housing for example by rotating or screwing
• CPC Class Codes: A61B 5/150412 Pointed piercing elements, e.g. needles, lancets for piercing the skin blade-like piercing elements A61B5/150442
• 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 5/15123 comprising magnets or solenoids
• 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

Abstract

A self-powered lancing drive system and lancing technique uses permanent magnets to initially store the potential energy that is converted to kinetic energy for extending a lancet during lancing. This self-powered lancing drive system is a pure permanent magnet drive that is highly reliable under numerous operating conditions. Permanent magnets can produce stronger magnetic fields at smaller sizes as compared to electromagnets. In one form, the lancing system has a drive permanent magnet that is kept fixed or stationary while the lancet magnet travels along the firing path. With the drive magnet being stationary, the lancet experiences fewer fluctuations in the magnetic field. The lancet vibrates less and is driven straighter into the tissue. In another form, a retraction magnet is positioned at the end of the firing path of the lancet, near the tissue, to enhance retraction of the lancet. In another form, a mechanical structure keeps the magnets in close proximity so that the strength of the magnetic propulsion force is maintained. The mechanical structure in one example is a crank mechanism that confines magnet movement to a circular path. The crank mechanism provides a smooth lancing profile as well as facilitates adjustments to the lancing profile.

Claims

1. An apparatus, comprising:

a lancet for forming an incision in tissue;

a crank operatively coupled to the lancet, the crank being configured to rotate about an axis; and

one or more magnets configured to rotate the crank about the axis for actuating the lancet to form the incision.

2. The apparatus of claim 1, further comprising:

the one or more magnets being permanent magnets.

3. The apparatus of claim 1, further comprising:

the one or magnets including

a crank magnet coupled to the crank, and

a drive magnet positioned to drive the crank magnet.

4. The apparatus of claim 3, further comprising:

means for changing polarities between the drive magnet and the crank magnet.

5. The apparatus of claim 4, further comprising:

the means for changing the polarities including at least one of the crank magnet and the drive magnet being moveable to change the polarities between the crank magnet and the drive magnet.

6. The apparatus of claim 5, further comprising:

the means for changing the polarities including a knob coupled to the drive magnet to rotate the drive magnet.

7. The apparatus of claim 5, further comprising:

the drive magnet being configured to move in a linear fashion.

8. The apparatus of claim 4, further comprising:

a trigger positioned to hold the crank stationary as the polarities between the crank magnet and the drive magnet are changed to cock the lancet.

9. The apparatus of claim 4, further comprising:

a second crank magnet coupled to the crank for facilitating contactless cocking of the lancet.

10. The apparatus of claim 9, further comprising:

both of the crank magnets having ends with the same polarity facing the drive magnet.

11. The apparatus of claim 9, further comprising:

at least one trigger positioned to hold the crank.

12. The apparatus of claim 1, further comprising:

the one or magnets including

a first crank magnet attached to the crank,

a second crank magnet attached to the crank,

a drive magnet oriented to repel the first crank magnet and attract the second crank magnet, and

the crank and drive magnets being permanent magnets;

a trigger positioned to hold the crank in a cocked state where the first crank magnet and the drive magnet are at least in close proximity;

a lancet carrier to which the lancet is secured;

a lancet guide defining a guide channel in which the lancet carrier is disposed; and

a connecting rod connecting the lancet carrier to the crank.

13. The apparatus of claim 1, further comprising:

a lancet carrier to which the lancet is secured;

a lancet guide defining a guide channel in which the lancet carrier is disposed;

a connecting rod connecting the lancet carrier to the crank;

the one or more magnets being permanent magnets;

the one or magnets including

a first crank magnet attached to the crank,

a second crank magnet attached to the crank, and

a drive magnet rotatable relative to the first and second crank magnets;

a first trigger positioned to hold the crank in a first cocked position where the drive magnet is oriented to create a first repulsive force with the first magnet; and

a second trigger positioned to hold the crank in a second cocked position where the drive magnet is oriented to create a second repulsive force with the second magnet.

14. A method, comprising:

releasing a lancet magnet coupled to a lancet from a cocked state where a repulsive magnetic field exists between the lancet magnet and a drive magnet, wherein the drive magnet and the lancet magnet are permanent magnets; and

after releasing lancet the lancet magnet, keeping the drive magnet stationary while the lancet travels along a firing path into tissue.

15. The method of claim 14, further comprising:

retracting the lancet from the tissue; and

keeping the drive magnet stationary at least until the lancet is withdrawn from the tissue.

16. The method of claim 14, further comprising:

placing the lancet magnet in the cocked state by moving the drive magnet and/or the lancet magnet to create the repulsive magnetic field between the lancet magnet and the drive magnet.

17. The method of claim 16, further comprising:

wherein the lancet magnet is attached to a lancet carrier to which the lancet is secured; and

wherein said placing the lancet magnet in the cocked state includes moving the lancet carrier towards the drive magnet with the ends of the drive magnet and the lancet magnet having the same polarity facing each other.

18. The method of claim 16, further comprising:

wherein the lancet magnet is attached to a crank; and

wherein said placing the lancet magnet in the cocked state includes moving the lancet magnet towards the drive magnet by rotating the crank with the ends of the drive magnet and the lancet magnet having the same polarity facing each other.

19. The method of claim 16, further comprising:

wherein said placing the lancet magnet in the cocked state includes rotating the drive magnet so that the ends of the drive magnet and the lancet magnet have the same polarity facing each other.

20. The method of claim 19, further comprising:

wherein the lancet magnet is attached to a crank that is coupled to the lancet; and

rotating the crank due to the repulsive magnetic field during said keeping the drive magnet stationary.

21. The method of claim 19, further comprising:

wherein the lancet magnet is attached to a lancet carrier that is coupled to the lancet; and

moving the lancet carrier in a linear direction due to the repulsive magnetic field during said keeping the drive magnet stationary.

22. The method of claim 16, further comprising:

wherein said placing the lancet magnet in the cocked state includes moving the drive magnet in a linear direction so that the ends of the drive magnet and the lancet magnet have the same polarity facing each other.

23. The method of claim 14, further comprising:

firing the lancet magnet with an electromagnet before said releasing the lancet magnet.

24. A method, comprising:

placing a lancet magnet in a cocked state by moving a drive magnet and/or the lancet magnet to create a repulsive magnetic force between the lancet magnet and the drive magnet;

wherein the drive magnet and the lancet magnet are permanent magnets;

wherein the lancet magnet is coupled to a lancet;

holding the lancet magnet in the cocked state with a trigger; and

firing the lancet by actuating the trigger to release the lancet magnet.

25. The method of claim 24, further comprising:

wherein the lancet magnet is attached to a crank; and

wherein said placing the lancet magnet in the cocked state includes rotating the crank so that the lancet magnet is facing the drive magnet.

26. The method of claim 25, further comprising:

wherein said placing the lancet magnet in the cocked state includes rotating the drive magnet so that the ends of the drive magnet and the lancet magnet have the same polarity facing each other.

27. The method of claim 24, further comprising:

wherein said firing the lancet includes rotating the crank due to the repulsive magnetic field.

28. The method of claim 24, further comprising:

wherein said placing the lancet magnet in the cocked state includes rotating the drive magnet so that the ends of the drive magnet and the lancet magnet have the same polarity facing each other.

29. The method of claim 24, further comprising:

wherein said placing the lancet magnet in the cocked state includes moving the drive magnet in a linear direction so that the ends of the drive magnet and the lancet magnet have the same polarity facing each other.

30. The method of claim 24, further comprising:

retracting the lancet; and

engaging the trigger to hold the lancet magnet in place during said retracting the lancet.

31. The method of claim 24, further comprising:

wherein the lancet magnet is attached to a crank and a second lancet magnet is attached to the crank;

retracting the lancet by rotating the crank due to a magnetic attractive force between the second lancet magnet and the drive magnet; and

engaging a second trigger to hold the lancet magnet in place during said retracting the lancet.

32. The method of claim 24, further comprising:

wherein the lancet carrier moves along a linear firing path; and

retracting the lancet through a repulsive magnetic force between the lancet magnet and a retraction magnet that is positioned at the end of the linear firing path opposite the drive magnet.

33. An apparatus, comprising:

a lancet;

a lancet magnet coupled to the lancet, the lancet magnet being a permanent magnet, the lancet magnet being moveable to fire the lancet;

a drive magnet to move the lancet magnet, the drive magnet being a permanent magnet; and

means for holding the lancet magnet stationary while the polarities of the lancet magnet and the drive magnet facing one another are made the same.

34. The apparatus of claim 33, further comprising:

the means for holding the lancet magnet stationary includes a trigger.

35. The apparatus of claim 33, further comprising:

the drive magnet being rotatable relative to the lancet magnet to change the polarities.

36. The apparatus of claim 33, further comprising:

the drive magnet being linearly moveable relative to the lancet magnet to change the polarities.

37. The apparatus of claim 33, further comprising:

a lancet carrier that couples the lancet to the lancet magnet.

38. The apparatus of claim 33, further comprising:

a crank to which the lancet magnet is secured; and

a connecting rod coupling the crank to the lancet.

39. The apparatus of claim 33, further comprising:

an electromagnet positioned proximal the drive magnet.

40. The apparatus of claim 33, further comprising:

the lancet magnet being movable along a firing path when the lancet is fired; and

a retraction magnet being positioned at the end of the firing path proximal tissue, the retraction magnet being oriented to repulse the lancet magnet.

41. The apparatus of claim 40, further comprising:

the retraction magnet being moveable to adjust penetration depth of the lancet.