Position detection

• US 20040207385A1
• Filed: 01/09/2004
• Published: 10/21/2004
• Est. Priority Date: 07/09/2001
• Status: Active Grant

• Current Assignee: TecPharma Licensing AG (Ypsomed Holding AG)
• Original Assignee: TecPharma Licensing AG (Ypsomed Holding AG)
• Inventors: Krieftewirth, Michael, Yeandel, Julian, Steffen, Beat, Gafner, Simone
• Granted Patent: US 7,138,806 B2
• Time in Patent Office: Days
• US Class Current: 324/76.11
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: A61M 5/3155 by rotational movement of dose setting member, e.g. during setting or filling of a syringe
• CPC Class Codes: A61M 5/31556 Accuracy improving means
• CPC Class Codes: G01D 5/2412 by varying overlap
• CPC Class Codes: H02P 6/16 Circuit arrangements for detecting position

Abstract

The invention relates to a device for detecting the position of a rotor relative to a stator, wherein at least one electrode is arranged on the rotor and at least one electrode is arranged on the stator, such that the electrodes at least partially overlap in at least one rotational position of the rotor relative to the stator, and encompasses a method for measuring the rotational position of a rotor comprising at least one rotor electrode relative to a stator comprising at least one stator electrode, wherein the rotational position is detected using a capacitive coupling between the rotor electrode and the stator electrode.

Claims

1. A device for detecting the position of a rotor relative to a stator, wherein at least one electrode is arranged on said rotor and at least one electrode is arranged on said stator, such that said electrodes at least partially overlap in at least one position of the rotor relative to the stator.

2. The device as set forth in claim 1, wherein at least two electrodes are arranged on the stator.

3. The device as set forth in claim 1, wherein at least one reference capacitor is provided.

4. The device as set forth in claim 3, wherein said reference capacitor is formed by at least one rotor electrode and at least one stator electrode.

5. The device as set forth in claim 3, wherein the reference capacitor is connected to at least one stator electrode.

6. The device as set forth in claim 1, wherein one of a voltmeter and comparator is operably coupled to the at least one electrode on the rotor and at least one of the at least one electrode on the stator and a reference capacitor.

7. The device as set forth in claim 1, wherein two, three, four or more electrodes are provided one of the rotor and the stator.

8. The device as set forth in claim 7, wherein at least some of the rotor and stator electrodes have different geometries with respect to each other.

9. The device as set forth in claim 7, wherein at least some of the rotor and stator electrodes have different surfaces with respect to each other.

10. The device as set forth in claim 1, wherein the at least one electrode on the rotor and the at least one electrode on the stator comprises an annular portion of the rotor and stator respectively.

11. The device as set forth in claim 10, wherein at least one electrode is provided on the rotor and stator, said electrode opposing the annular portion.

12. The device as set forth in claim 1, wherein the at least one electrode on the rotor and the at least one electrode on the stator comprises a partially annular area of the rotor and stator respectively.

13. The device as set forth in claim 1, wherein the at least one electrode on the rotor and the at least one electrode on the stator are arranged such that, when the rotor is turned by a predetermined angle relative to the stator, the polarity of the electrodes can be reversed.

14. The device as set forth in claim 1, further comprising at least one locking position of the rotor relative to the stator.

15. The device as set forth in claim 14, further comprising two locking positions of the rotor relative to the stator, wherein the rotational angle between the two locking positions is sufficiently large that the polarity of at least one of the at least one electrode on the rotor and the at least one electrode on the stator can be reversed.

21. The device as set forth in claim 1, wherein at least one electrode is made of conductive plastic.

22. The device as set forth in claim 1, wherein the device is one of an infusion apparatus or an injection apparatus.

16. A device for detecting the axial shift of a shifting element using a measuring device which can detect the position of the shifting element.

17. The device as set forth in claim 16, wherein said measuring device is a pressure or force sensor.

18. The device as set forth in claim 16, wherein the measuring device is one or more slip rings or a variable resistor comprising a tapped electrode.

19. The device as set forth in claim 16, wherein the measuring device comprises at least one electrode in which the capacitive coupling to a counter electrode can be changed by shifting.

20. The device as set forth in claim 16, wherein a lock for the shifting element is provided in at least one position.

23. A method for measuring the rotational position of a rotor comprising at least one electrode relative to a stator comprising at least one electrode, wherein said rotational position is detected using a capacitive coupling between the rotor electrode and the stator electrode.

24. The method as set forth in claim 23, wherein the degree of capacitive coupling between the rotor electrode and the stator electrode is ascertained by measuring the voltage.

25. The method as set forth in claim 23, wherein the degree of capacitive coupling between the rotor electrode and the stator electrode is ascertained by measuring the current.

26. The method as set forth in claim 23, wherein a peak value is detected in order to obtain a binary measuring signal.

27. The method as set forth in claim 23, wherein errors are recognized on the basis of the measured values.

28. The method as set forth in claim 23, wherein errors are recognized and corrected on the basis of the measured values.

29. An injection device comprising relatively positionable elements and means for providing sensing characteristics, wherein a change in provided sensing characteristics reflects the relative position of the relatively positionable elements.

30. The injection device according to claim 29, wherein the sensing characteristics are electrical.

31. The injection device according to claim 29, wherein the sensing characteristics are magnetic.

32. An injection device comprising an axially shifting element and another element which is fixed relative to the axially shifting element, wherein the axially shifting element and another element are capacitively coupled, wherein the relative position of the axially shifting element and the another element can be determined on the basis of the change in capacity.

33. An injection device comprising an axially shifting element and another element which is fixed relative to the axially shifting element, wherein the axially shifting element and another element carry electrodes, wherein the relative position of the axially shifting element and the another element can be determined on the basis of the relative position of the electrodes.

34. An injection device comprising relatively positionable elements, wherein the relatively positionable elements are capacitively coupled, and wherein the relative position of the relatively positionable elements can be determined on the basis of the change in capacity.