Determination of Position of Injection Needle

• US 20090088662A1
• Filed: 03/20/2007
• Published: 04/02/2009
• Est. Priority Date: 03/20/2006
• Status: Active Grant

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Larsen, Andre
• Granted Patent: US 9,008,764 B2
• Time in Patent Office: Days
• US Class Current: 600/547
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/16836 by sensing tissue properties at the infusion site, e.g. for detecting infiltration detecting tissue temperature for diagnostic purposes A61M39/0247
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/427 Locating point where body is to be pierced, e.g. vein location means using ultrasonic waves, injection site templates
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion

Abstract

The present invention relates to a method for detecting contact between an injection needle of a medication delivery device and a body of a patient. The method comprises the step of generating a contact signal in response to closure of an electrical signal path comprising an exterior surface part of the injection needle, an exterior surface part of a handle of the medication delivery device and at least part of the body of the patient. The present invention further relates to a method for determining the position of insertion of the injection needle, and to the insertion depth of the injection needle.

Claims

1. A medication delivery device comprising

a needle receiving portion adapted to receive an injection needle having an electrically conducting exterior surface part, the needle receiving portion being adapted to galvanically or capacitively connect to the electrically conducting exterior surface part of the injection needle,

an electrically conducting exterior surface part forming part of a handle of the medication delivery device, the electrically conducting exterior surface part of the handle forming an integral part of the medication delivery device, and

a sensing arrangement arranged between the needle receiving portion and the electrically conducting exterior surface part forming part of the handle.

2. A medication delivery device according to claim 1, wherein the sensing arrangement comprises an electrical circuit adapted to measure an impedance value of an object closing an exterior signal path between the electrically conducting surface part of an injection needle galvanically connected to the needle receiving portion and the electrically conducting exterior surface part forming part of the handle.

3. A medication delivery device according to claim 2, further comprising signaling means adapted to provide a signal to a user of the medication delivery device in response to a measured impedance value.

4. A medication delivery device according to claim 3, wherein the signaling means comprises acoustical signaling means and/or visual signaling means.

5. A medication delivery device according to claim 2, further comprising an electrical circuit for generating and providing a time varying electric signal to the needle receiving portion or to the electrically conducting exterior surface part forming part of the handle.

6. A medication delivery device according to claim 5, wherein the time varying electrical signal has a frequency of at least 5 kHz, such as at least 50 kHz, such as at least 100 kHz.

7. A medication delivery device according to claim 5, wherein the time varying electrical signal has an amplitude value in the range 50-500 mV.

8. A medication delivery device according to claim 1, wherein the needle receiving portion is adapted to detachably retain the injection needle in a fixed position relative to the medication delivery device.

9. A medication delivery device adapted to determine the type of tissue into which a tip of an injection needle of the medication delivery device has been inserted, the medication delivery device comprising:

means for determining a value of an electrical signal of a closed electrical signal path comprising an exterior surface part of the injection needle, an exterior surface part of a handle of the medication delivery device and at least part of the body of the patient, the exterior surface part of the handle forming an integral part of the medication delivery device,

means for determining which of a number of predetermined ranges of values the determined value falls within, and

means for generating an information signal to the user of the medication delivery device in accordance therewith.

10. A medication delivery device according to claim 9, wherein the generated information signal comprises an alarm signal, the alarm signal being generated if the determined value falls within a predetermined range of values associated with the tip of the injection needle being inserted into muscular tissue.

11. A medication delivery device according to claim 9, wherein the generated information signal comprises a clearing signal, the clearance signal being generated if the determined value falls within a predetermined range of values associated with the tip of the injection needle being inserted into subcutis tissue.

12. A medication delivery device according to claim 9, wherein the number of predetermined ranges of values comprises a first, a second and a third predetermined range.

13. A medication delivery device according to claim 12, wherein the first predetermined range comprises expected values associated with a first area of injection on the body, and wherein the second predetermined range comprises expected values associated with a second area of injection on the body, and wherein the third predetermined range comprises expected values associated with a third area of injection on the body.

14. A medication delivery device according to claim 13, wherein the first, the second and the third area of injection on the body are associated with the thigh, the stomach and a buttock, respectively.

15. A medication delivery device according to claim 9, wherein the determined value of the electrical signal comprises an amplitude value of a time varying electrical signal.

16. A medication delivery device according to claim 15, wherein the frequency of the time varying signal is at least 5 kHz.

17. A method according to claim 15, wherein the time varying signal comprises a plurality of time varying signals of different frequencies.

18. A method for determining the type of tissue into which a tip of an injection needle of a medication delivery device has been inserted, the method comprising:

inserting the injection needle of the medication delivery device into the body tissue,

determining a value of an electrical signal of a closed electrical signal path comprising an exterior surface part of the injection needle, an exterior surface part of a handle of the medication delivery device and at least part of the body of the patient, the exterior surface part of the handle forming an integral part of the medication delivery device,

determining which of a number of predetermined ranges of values the determined value falls within, and

generating an information signal to the user of the medication delivery device in accordance therewith.

19. A method according to claim 18, wherein the generated information signal comprises an alarm signal, the alarm signal being generated if the determined value falls within a predetermined range of values associated with the tip of the injection needle being inserted into muscular tissue.

20. A method according to claim 18, wherein the generated information signal comprises a clearing signal, the clearance signal being generated if the determined value falls within a predetermined range of values associated with the tip of the injection needle being inserted into subcutis tissue.

21. A method according to claim 18, wherein the number of predetermined ranges of values comprises a first, a second and a third predetermined range.

22. A method according to claim 21, wherein the first predetermined range comprises expected values associated with a first area of injection on the body, and wherein the second predetermined range comprises expected values associated with a second area of injection on the body, and wherein the third predetermined range comprises expected values associated with a third area of injection on the body.

23. A method according to claim 22, wherein the first, the second and the third area of injection on the body are associated with the thigh, the stomach and a buttock, respectively.

24. A method according to claim 18, wherein the determined value of the electrical signal comprises an amplitude value of a time varying electrical signal.

25. A method according to claim 24, wherein the frequency of the time varying signal is at least 5 kHz.

26. A method according to claim 24, wherein the time varying signal comprises a plurality of time varying signals of different frequencies.

27. A method for detecting contact between an injection needle of a medication delivery device and a body of a patient, the method comprising generating a contact signal in response to closure of an electrical signal path comprising an exterior surface part of the injection needle, an exterior surface part of an integrated handle of the medication delivery device and at least part of the body of the patient.

28. A method according to claim 27, wherein the contact signal is generated in response to a measurement of a value of an electrical signal of the electrical signal path comprising the exterior surface part of the injection needle, the exterior surface part of the integrated handle of the medication delivery device and at least part of the body of the patient.

29. A method according to claim 28, wherein the measured value of the electrical signal comprises an amplitude value of the electrical signal.

30. A method according to claim 28, wherein the value of the electrical signal is measured in response to applying a time varying electrical signal to the injection needle.

31. A method according to claim 30, wherein the time varying electrical signal has a frequency of at least 5 kHz.

32. A method according to claim 30, wherein the time varying electrical signal has an amplitude value in the range 50-500 mV.