Non-contact scanning using a magneto-resistive sensor

• US 20060161112A1
• Filed: 01/06/2006
• Published: 07/20/2006
• Est. Priority Date: 07/09/2003
• Status: Active Grant

• Current Assignee: Ypsomed AG (Ypsomed Holding AG)
• Original Assignee: TecPharma Licensing AG (Ypsomed Holding AG)
• Inventors: Steffen, Beat
• Granted Patent: US 7,511,480 B2
• Time in Patent Office: Days
• US Class Current: 604/188
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/6054 Magnetic identification systems
• CPC Class Codes: A61M 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: A61M 5/31535 Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose
• CPC Class Codes: A61M 5/31546 Electrically operated dose setting, e.g. input via touch screen or plus/minus buttons
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31556 Accuracy improving means
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: G01D 2205/772 Sawtooth profiles
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06

Abstract

A device for administering a fluid product includes a measuring assembly for measuring a position between spaced apart elements of the apparatus that can be moved relative to each other. The measuring assembly includes at least one magneto-resistive sensor that is fixed to a first element, such as a casing, and is arranged opposite at least a second element, such as a sleeve, which can be moved relative to said first element. A magnetic device co-operates with the at least one sensor and is formed by a permanent magnet on the first element and a magnetized second element including a magnetic surface profile or including of a number of alternately arranged, different magnetic pole areas.

Claims

1. A fluid administration device comprising a measuring assembly for measuring a position between spaced apart elements of said device, said measuring assembly comprising:

at least one magneto-resistive sensor, said magneto-resistive sensor being fixedly connected to a casing of said device and being arranged opposite a sleeve of said device, said sleeve being movable relative to said casing and being spaced apart from said casing;

a first permanent magnet fixedly arranged relative to said casing; and

at least one second permanent magnet including a predetermined surface profile, said at least one second permanent magnet being fixedly attached to said sleeve, wherein said magneto-resistive sensor is spaced apart from said surface profile.

2. The fluid administration device as claimed in claim 1, wherein said second permanent magnet includes a plurality of magnetically polarized areas on the surface profile arranged with alternating polarities.

3. The fluid administration device as claimed in claim 2, wherein said first permanent magnet on the casing is a rod magnet.

4. The fluid administration device as claimed in claim 1, wherein said first permanent magnet is arranged on the magneto-resistive sensor.

5. The fluid administration device as claimed in claim 1, wherein said second permanent magnet is ferromagnetic.

6. The fluid administration device as claimed in claim 1, wherein said surface profile includes at least two periodically alternating height levels.

7. The fluid administration device as claimed in claim 6, wherein the surface profile comprises at least one reference height level that differs from the periodically alternating height levels.

8. The fluid administration device as claimed in claim 1, wherein said second permanent magnet is a magnetic strip or ring.

9. The fluid administration device as claimed in claim 2, wherein said second permanent magnet includes at least one magnetic reference pole area that differs in polarity from the plurality of magnetically polarized areas.

10. The fluid administration device as claimed in claim 1, wherein the sleeve is a sliding element that can be shifted in the longitudinal direction of the administration device relative to the casing.

11. The fluid administration device as claimed in claim 1, wherein the sleeve is a rotational element that can be rotated around the longitudinal axis of the administration device relative to the casing.

12. The fluid administration device as claimed in claim 2, wherein discrete setting positions of the sleeve are determinable based on the alternately arranged magnetic pole areas on the surface profile.

13. The fluid administration device as claimed in claim 1, wherein said at least one second permanent magnet includes a plurality of magnetic strips arranged along the longitudinal axis of the sleeve at circumferential positions thereon.

14. The fluid administration device as claimed in claim 13, wherein said circumferential positions of the plurality of magnetic strips correspond to discrete rotational positions of the sleeve.

15. A method for measuring a position between spaced apart elements of a fluid administration device, comprising the steps of:

measuring with a magneto-resistive sensor a change in resistance generated between a casing of the fluid administration device and a sleeve of said fluid administration device when the casing and the sleeve are moved relative to each other thereby causing alteration of a magnetic field of a first permanent magnet fixedly arranged relative to said casing wherein the distance between the first permanent magnet and a surface profile of a second permanent magnet fixedly attached to said sleeve is changed;

detecting a path distance travelled during said movement based on the change in resistance; and

correlating the path distance with a reference position thereby ascertaining a position of the sleeve with respect to the casing.

16. The method as set forth in claim 15, wherein the distance between the surface of the first permanent magnet and the surface profile of the second permanent magnet changes when the elements are moved relative to each other due to height variations in the surface profile.

17. The method as set forth in claim 15, wherein detecting the path distance travelled comprises detecting movement direction of the sleeve around the longitudinal axis of the administration device.

18. The method as set forth in claim 15, wherein detecting the path distance travelled comprises detecting movement of the sleeve in the longitudinal direction of the administration device.

19. The method as set forth in claim 15, wherein the second permanent magnet is ferromagnetic and is magnetised by the movement of the sleeve and the casing relative to each other.

20. The method as set forth in claim 15, wherein correlating the path distance with the reference position comprises ascertaining discrete setting positions of the sleeve.

21. The method as set forth in claim 15, further comprising measuring a locking position of a locking means of the administration device.

22. A method for measuring a position between spaced apart elements of a fluid administration device, comprising the steps of:

measuring with a magneto-resistive sensor a change in resistance generated between a casing of the fluid administration device and a sleeve of said fluid administration device when the casing and the sleeve are moved relative to each other thereby causing alteration of a magnetic field of a first permanent magnet fixedly arranged relative to said casing wherein a surface profile of a second permanent magnet fixedly attached to said sleeve including a plurality of magnetically polarized areas arranged with alternating polarities is moved relative to said first permanent magnet;

detecting a path distance travelled during said movement based on the magnetic filed alteration; and

correlating the path distance with a reference position thereby ascertaining a position of the sleeve with respect to the casing.

23. The method as set forth in claim 22, wherein detecting the path distance travelled comprises detecting movement direction of the sleeve around the longitudinal axis of the administration device.

24. The method as set forth in claim 22, wherein correlating the path distance with the reference position comprises ascertaining discrete setting positions of the sleeve.

25. The method as set forth in claim 22, further comprising measuring a locking position of a locking means of the administration device.