Methods and apparatus for lancet actuation

• US 7,175,642 B2
• Filed: 09/05/2002
• Issued: 02/13/2007
• Est. Priority Date: 04/19/2002
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Pelikan Technologies, Inc.
• Inventors: Boecker, Dirk, Alden, Don, Freeman, Dominique M., Briggs, Barry Dean, Leonard, Jon Hewitt
• Primary Examiner(s): Hayes; Michael J.
• Assistant Examiner(s): NGUYEN, VI X
• Application Number:
  US10/237,262
• Publication Number:
  US 20040049219A1
• Time in Patent Office: 1,622 Days
• Field of Search: 606/167, 606/172, 606/181, 606/182, 606/183, 600/573, 600/576, 600577-579, 600/583
• US Class Current: 606/181
• CPC Class Codes: A61B 17/32093 for skin incisions
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• 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 5/150083 by vibration, e.g. ultrasound
• CPC Class Codes: A61B 5/150099 by negative pressure, other than vacuum extraction into a syringe by pulling on the piston rod or into pre-evacuated tubes
• CPC Class Codes: A61B 5/150152 by an adequate mechanical impact on the puncturing location
• 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 5/15019 Depth adjustment mechanism using movable stops located inside the piercing device housing and limiting the travel of the drive mechanism mechanisms using distal end caps A61B5/150183, mechanisms at the piercing element carrier proximal end A61B5/150198
• CPC Class Codes: A61B 5/150213 Venting means
• CPC Class Codes: A61B 5/150221 Valves
• CPC Class Codes: A61B 5/150229 Pumps for assisting the blood sampling
• 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 5/150412 Pointed piercing elements, e.g. needles, lancets for piercing the skin blade-like piercing elements A61B5/150442
• CPC Class Codes: A61B 5/150435 Specific design of proximal end
• 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 5/150572 Pierceable protectors, e.g. shields, caps, sleeves or films, e.g. for hygienic purposes
• CPC Class Codes: A61B 5/150809 by audible feedback
• CPC Class Codes: A61B 5/150824 by visual feedback
• CPC Class Codes: A61B 5/150832 : by topography of the surface, e.g. Braille, embossed printing
• CPC Class Codes: A61B 5/15087 : short range, e.g. between console and disposable using implanted devices A61B5/150877
• CPC Class Codes: A61B 5/150916 : by blocking components, e.g. piston, driving device or fluid passageway
• 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 5/151 : Devices specially adapted for taking samples of capillary blood, e.g. by lancets , needles or blades
• CPC Class Codes: A61B 5/15111 : Semi-automatically triggered, e.g. at the end of the cocking procedure, for instance by biasing the main drive spring or when reaching sufficient contact pressure, the piercing device is automatically triggered without any deliberate action by the user
• 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 5/15123 : comprising magnets or solenoids
• CPC Class Codes: A61B 5/15146 : Devices loaded with multiple lancets simultaneously, e.g. for serial firing without reloading, for example by use of stocking means. multiple simultaneous cutting or piercing A61B5/150977
• CPC Class Codes: A61B 5/15151 : Each piercing element being stocked in a separate isolated compartment
• CPC Class Codes: A61B 5/15163 : Characterized by propelling the piercing element in an axial direction relative to the disc
• CPC Class Codes: A61B 5/15169 : Characterized by a rolled strip
• CPC Class Codes: A61B 5/15171 : Characterized by propelling the piercing element perpendicular to the direction of movement of the strip
• CPC Class Codes: A61B 5/15174 : Piercing elements stocked in the form of a stack or pile
• CPC Class Codes: A61B 5/15176 : Stocking means comprising cap, cover, sheath or protection for aseptic stocking
• CPC Class Codes: A61B 5/15184 : Piercing device comprising a separate compartment or unit for used piercing elements separate compartments for used piercing elements in stocking means A61B5/15178
• 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 5/1519 : 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: B01L 2200/10 : Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2300/0663 : Whole sensors
• CPC Class Codes: B01L 2300/18 : Means for temperature control
• CPC Class Codes: B01L 3/5027 : by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: G01N 33/4905 : Determining clotting time of blood by chemical methods G01N33/86, C12Q1/54
• CPC Class Codes: G01N 33/557 : using kinetic measurement, i.e. time rate of progress of an antigen-antibody interaction

Abstract

A lancet driver is provided wherein the driver exerts a driving force on a lancet during a lancing cycle and is used on a tissue site. The driver comprises of a drive force generator for advancing the lancet along a path into the tissue site, and a sensor configured to detect lancet position along said path during the lancing cycle.

Claims

1. A lancet driver configured to exert a driving force on a lancet used at a tissue site during a lancing cycle, said device comprising:

a voice-coil, drive force generator;

a processor coupled to the drive force generator capable of changing the direction and magnitude of force exerted on the lancet during the lancing cycle; and

a lancet position sensor coupled to the processor, the position sensor configured to detect lancet position during the lancing cycle and relay to the position sensor at least one of, skin penetrating performance or a skin penetrating setting of the lancet through the skin, the drive force generator using the at least one of skin penetrating performance or a skin penetrating setting of the lancet through the skin from the process to actuate the lancet to penetrate to a depth in the tissue site and pause for a controlled dwell time while in the tissue site, the dwell time sufficient to draw body fluid into a wound channel created by the lancet.

2. The device of claim 1 wherein said voice coil comprises a cylindrical coil encircling a movable magnet.

3. The device of claim 1 wherein said voice coil comprises a linear flat coil.

4. The device of claim 1 wherein said drive force generator comprises a rotary voice coil drive force generator.

5. The device of claim 1 wherein said drive force generator comprises a linear voice coil drive force generator.

6. The device of claim 1 wherein the drive force generator comprises a magnetic source that produces a controllable magnetic field in a magnetically active region adjacent the magnetic source;

a moveable member at least partially disposed in the magnetically active region, said member moved by the controllable magnetic field to actuate said lancet.

7. The device of claim 1 wherein said drive force generator uses electricity to create a controllable electromagnetic field for actuating said lancet.

8. The device of claim 1 further comprising a human interface on a housing of said driver and providing at least one output selected from:

stick number, lancets remaining, time, alarm, profile information, force in last stick, or last stick time.

9. The device of claim 1 further comprising a human interface on a housing, said interface selected from:

an LED, an LED digit display, or an LCD display.

10. The device of claim 1 further comprising an input device on a housing, said input device selected from:

one or more pushbuttons, a touch pad independent of the display device, or a touch sensitive screen on the LCD display.

11. The device of claim 1 wherein said drive force generator uses electricity and is configured to hold said lancet in the tissue site at a fixed position when electric current is turned off, allowing for unlimited dwell time in the tissue site.

12. The device of claim 1 wherein said drive force generator holds said lancet at a fixed position against tenting force from said tissue site without contacting a mechanical stop.

13. The device of claim 1 wherein said drive force generator has a movable member and a drive coil creating a magnetic field wherein the drive coil magnetically attracts the movable member, said drive coil configured to only partially encircle said movable member.

14. The device of claim 1 a mechanical damper disposed to minimize oscillation of the lancet in the tissue site when the lancet reaches an end point of its penetration stroke into said tissue site.

15. The device of claim 1 a lancet coupler for removably coupling the lancet to said drive force generator.

16. The device of claim 1 wherein said housing and all elements therein have a combined weight of less than about 0.5 lbs.

17. The device of claim 1 wherein the sensor comprises an incremental encoder.

18. The device of claim 1 wherein the sensor comprises a linear optical incremental encoder.

19. The device of claim 1 wherein the sensor comprises a rotary optical incremental encoder.

20. The device of claim 1 wherein the sensor comprises a capacitive incremental encoder.

21. The device of claim 1 wherein the sensor comprises an optical encoder and an optical encoder flag secured to the movable member.

22. The device of claim 1 wherein average lancet velocity into the tissue site differs from average lancet velocity leaving the tissue site.

23. The device of claim 1 wherein said force generator is configured to achieve a withdrawal stroke of the lancet at a lancet velocity of 0.5 meters per second to less than about 0.02 meter per second.

24. The device of claim 1 wherein said force generator is configured to achieve a penetration stroke of the lancet at a lancet velocity between about 0.8 and 20.0 meter per second.

25. The device of claim 1 further comprising a cartridge coupled to the drive force generator, said cartridge containing a plurality of lancets.

26. The device of claim 1 further comprising a processor coupled to the drive force generator for signaling said generator to change the direction and magnitude of force exerted on the lancet during the lancing cycle, said sensor communicating with said processor.

27. The device of claim 26 wherein said processor determines relative position and velocity of the lancet based on relative position measurements of the lancet with respect to time.

28. The device of claim 26 further comprising memory for storage and retrieval of a set of alternative lancing profiles which the processor uses to modulate the drive force generator.

29. The device of claim 26 wherein the processor modulates the lancet driver by comparing an actual profile of the lancet to the profile and maintaining a preset error limit between the actual profile and the profile.

30. The device of claim 26 wherein the processor optimizes said phases of a lancet velocity profile based on information entered by a user of the lancing device.

31. The device of claim 26 wherein the processor calculates an appropriate lancet diameter and geometry to collect a blood volume required by a user.

32. The device of claim 26 wherein said processor has logic for learning and recording characteristics of said tissue site to optimize control of lancet velocity and lancet position in a manner that minimizes pain to the patient while drawing body fluid for sampling.

33. The device of claim 1 wherein a processor actuates said drive force generator to drive the lancet at velocities in time that follow a selectable lancing velocity profile said selectable lancing velocity profile is selected from a set of alternative lancing velocity profiles having characteristic phases for lancet advancement and retraction.

34. The device of claim 33 wherein the lancing velocity profile is selectable by a user of the lancing device.

35. The device of claim 33 wherein said lancing velocity profile provides a lancet withdrawal velocity sufficiently slow to allow blood flowing from punctured blood vessels to flow into a wound channel in the tissue site created by the lancet, to follow the lancet out of the wound channel, and flow to a skin surface.

36. The device of claim 33 wherein said velocity profile includes a lancet deceleration phase, after said lancet penetrates said tissue site and prior to withdrawal from said tissue site, wherein said lancet velocity follows a programmable deceleration profile having said lancet stopping in the tissue site without a sudden hard stop.

37. The device of claim 33 wherein the lancing velocity profile is selected by the lancing device based on optimization of lancing parameters from information obtained in previous lancing events.

38. The device of claim 37 wherein said processor optimizes said velocity profile for subsequent lancing based upon success of obtaining a blood sample from said user in previous lancing events.

39. The device of claim 37 wherein said processor optimizes said velocity profile for subsequent lancing based upon blood volume obtained from said user in previous lancing events.

40. The device of claim 37 wherein said processor optimizes said velocity profile for subsequent lancing based upon elastic tenting associated with skin deformation in previous lancing events.

41. The device of claim 37 wherein said lancet penetrating to a depth in the tissue site based on impedance measurements from a distal portion of the lancet in said tissue site.