Device And Method For Contact Free Absolute Position Determination

• US 20090076460A1
• Filed: 09/22/2006
• Published: 03/19/2009
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Munchow, Bodo von, Nielsen, Preben
• Granted Patent: US 8,638,108 B2
• Time in Patent Office: Days
• US Class Current: 604/207
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: G01D 5/204 by influencing the mutual induction between two or more coils G01D5/22 takes precedence
• CPC Class Codes: G01D 5/2403 by moving plates, not forming part of the capacitor itself, e.g. shields

Abstract

The present invention relates to a contact free arrangement for determining an absolute position of a member adapted for setting an amount of medicament to be injected from a medication delivery device, or adapted for determining an amount of medicament injected from a medication delivery device. The arrangement according to the present invention comprises at least one track of reflector means, at least one emitter means, and at least one receiver means. The at least one emitter means and the at least one receiver means are adapted to electrically couple to a number of the reflector means. The electrical coupling may be capacitive or inductive. In addition, the present invention relates to a medication delivery device or a syringe having such arrangement.

Claims

1. A contact free arrangement in a medication delivery device for determining an absolute position of a first member moveably mounted relative to a second member, the first member being restricted for movement between a first end position and a second end position, the arrangement comprising:

at least one track of reflector means associated with the first member,

at least one emitter means associated with the second member, the at least one emitter means being adapted to electrically couple to a number of the reflector means, and

at least one receiver means associated with the second member, the at least one receiver means being adapted to electrically couple to a number of the reflector means,

wherein the first member is arranged relative to the second member in such a manner that there is provided an unambiguously determinable electrical parameter to each respective position of the first member relative to the second member.

2. The arrangement according to claim 1, wherein at least part of the at least one track of reflector means forms a helical, circular or linear path.

3. The arrangement according to claim 2 comprising a single track of reflector means.

4. The arrangement according to claim 3, wherein the single track of reflector means comprises a helical-shaped row of electrically conducting members arranged on the first member of the medication delivery device, and wherein the dimensions of the electrically conducting members forming the track varies monotonically along an axial direction of the row.

5. The arrangement according to claim 1, comprising a first and a second track of reflector means, the first and second tracks of reflector means being arranged in a substantially parallel manner.

6. The arrangement according to claim 5, wherein the first track of reflector means comprises a helical-shaped row of electrically conducting members arranged on the first member of the medication delivery device, the electrically conducting members of the first track defining a first period, and wherein the second track of reflector means comprises a helical-shaped row of electrically conducting members arranged on the first member of the medication delivery device, the electrically conducting members of the second track defining a second period, the first period being different from the second period.

7. The arrangement according to claim 1, wherein the at least one emitter is/are arranged on a non-rotatably mounted part of the medication delivery device.

8. The arrangement according to claim 1, wherein the at least one receiver is/are arranged on a non-rotatably mounted part of the medication delivery device.

9. The arrangement according to claim 5, wherein the first and second tracks of reflector means each comprises an essentially unbroken path of an electrically conducting material, each of said first and second essentially unbroken paths of electrically conducting material having a width which varies along an axial direction of the track.

10. The arrangement according to claim 1, wherein the at least one emitter and a number of the reflector means form a capacitor in combination.

11. The arrangement according to claim 1, wherein the at least one receiver and a number of the reflector means form a capacitor in combination.

12. The arrangement according to claim 1, wherein the at least one emitter and a number of the reflector means are adapted to couple in an inductive manner.

13. The arrangement according to claim 1, wherein the at least one receiver and a number of the reflector means are adapted to couple in an inductive manner.

14. The arrangement according to claim 12, wherein the at least one emitter and the at east one receiver comprise a coil adapted for generating and receiving a magnetic field, respectively.

15. The arrangement according to claim 12, wherein a number of the reflector means are configured so as to support eddy currents induced by the emitters.

16. The arrangement according to claim 1, comprising, for each track of reflector means, two emitter means and one receiver means.

17. The arrangement according to claim 16, wherein, for each track of reflector means, the two emitter means and the one receiver means are arranged along a substantially straight line, and wherein the one receiver means is arranged between the two emitter means.

18. The arrangement according to claim 1, further comprising processor means for processing a signal or signals from the at least one receiver means, and generator means for generating a signal or signals and providing such signal(s) to the at least one emitter means.

19. A medication delivery device or a syringe comprising the arrangement according to claim 1.

27. The arrangement according to claim 1, wherein the unambiguously determinable electrical parameter is a capacitance.

20. A contact free method for determining an absolute position of a first member moveably mounted relative to a second member in a medication delivery device, the first member being restricted for movement between a first end position and a second end position, the method comprising:

providing at least one track of reflector means associated with the first member,

providing an electrical signal to at least one emitter means associated with the second member, the at least one emitter means being electrically coupled to a number of the reflector means, and

receiving an electrical signal from at least one receiver means associated with the second member, the at least one receiver means being electrically coupled to a number of the reflector means,

wherein the first member is arranged relative to the second member in such a manner that there is provided an unambiguously determinable electrical parameter to each respective position of the first member relative to the second member.

21. The method according to claim 20, wherein a first electrical signal is provided to a first emitter, and wherein a second electrical signal is provided to a second emitter, the first and second electrical signals being approximately 180 degrees out of phase.

22. The method according to claim 21, wherein the electrical signals provided to the first and second emitters oscillate with a frequency within the range 50 kHz-150 kHz.

23. The method according to claim 21, wherein the frequency of the first electrical signal is different than the frequency of the second electrical signal.

24. The method according to claim 23, wherein the frequency of the second electrical signal is shifted 8-10% relative to the frequency of the first electrical signal.

25. The method according to claim 20, wherein the unambiguously determinable electrical parameter is a capacitance.

26. The method according to claim 22, wherein the electrical signals provided to the first and second emitters oscillate with a frequency within the range of 90 kHz-110 kHz.