Infusion device and driving mechanism and process for same with actuator for multiple infusion uses

• US 20050024175A1
• Filed: 08/23/2004
• Published: 02/03/2005
• Est. Priority Date: 12/26/2002
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Gray, John, Lorenzen, Eric, Bosley, Robert W.
• Granted Patent: US 6,945,760 B2
• Time in Patent Office: Days
• US Class Current: 335/220
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: F04B 17/042 the solenoid motor being separated from the fluid flow
• CPC Class Codes: F04B 17/046 the fluid flowing through the moving part of the motor
• CPC Class Codes: F04B 35/045 using solenoids

Abstract

A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. The armature may be configured with a reduced diameter by including a coil cup for supporting the coil including a shelf portion defining at least a portion of a pole surface of the coil cup.

Claims

1. A coil cup composed of a magnetizable material, the coil cup comprising:

a generally annular inner wall having one end defining an inner pole surface of the coil cup;

a generally annular outer wall having a first inner diameter and a first outer diameter, the outer wall having a generally annular shelf portion extending from the outer wall towards the inner wall, the shelf portion having a second inner diameter and a second outer diameter, the second inner diameter being smaller than the first inner diameter, the shelf portion having a second end defined by the second inner and outer diameters, the second end defining at least a portion of an outer pole surface of the coil cup; and

a generally annular interior between the inner and outer walls, the annular interior containing a coil.

2. A coil cup according to claim 1, wherein the generally annular shelf portion extends partially over the coil.

3. A coil cup according to claim 1, wherein the generally annular shelf portion extends over a portion of the generally annular interior.

4. A coil cup according to claim 1, wherein the generally annular shelf portion includes a surface facing away from the generally annular interior.

5. A coil cup according to claim 1, further comprising an generally annular lip extending from extending from the inner wall towards the outer wall.

6. A coil cup according to claim 5, wherein the generally annular lip includes a surface facing away from the generally annular interior.

7. A coil cup according to claim 5, wherein the generally annular lip is configured to increase the inner pole surface of the coil cup.

8. A coil cup according to claim 5, wherein the generally annular lip is configured to increase an electromagnetic flux between the inner pole surface of the coil cup and the outer pole surface of the coil cup.

9. A coil cup according to claim 5, wherein an inner edge of at least one of the generally annular shelf and the generally annular lip is angled.

10. A coil cup according to claim 5, wherein inner edges of the generally annular shelf and the generally annular lip are configured to minimize a straight surface area of the inner pole surface of the coil cup and the outer pole surface of the coil cup.

11. A coil cup according to claim 5, wherein inner edges of the generally annular shelf and the generally annular lip are configured to reduce electromagnetic flux between the inner pole surface of the coil cup and the outer pole surface of the coil cup.

12. A coil cup according to claim 5, wherein inner edges of the generally annular shelf and the generally annular lip are configured to reduce a gap between the inner pole surface of the coil cup and the outer pole surface of the coil cup.

13. A coil cup according to claim 9, wherein an angle of at least one of the inner edge of the generally annular shelf and the inner edge of the generally annular lip is between ten degrees and twenty degrees.

14. A coil cup according to claim 9, wherein an angle of at least one of the inner edge of the generally annular shelf and the inner edge of the generally annular lip is between approximately ten degrees and twenty degrees.

15. A coil cup according to claim 5, wherein the generally annular shelf and the generally annular lip form a unitary body with the coil cup.

16. A coil cup according to claim 5, wherein the generally annular shelf and the generally annular lip are formed separately from the coil cup.

17. A coil cup according to claim 5, wherein the generally annular shelf is formed separately from the coil cup.

18. A coil cup according to claim 5, wherein the generally annular lip is formed separately from the coil cup.

19. A coil cup composed of a magnetizable material, the coil cup comprising:

a generally annular inner wall having one end defining an inner pole surface of the coil cup;

a generally annular outer wall having a first inner diameter and a first outer diameter, at least one of the first inner diameter and the first outer diameter defining at least a portion of an outer pole surface of the coil cup; and

a generally annular lip extending from extending from the inner wall towards the outer wall,

wherein the generally annular inner wall and the generally annular outer wall define a generally annular interior, and

wherein the generally annular interior contains a coil.

20. A coil cup according to claim 19, wherein the generally annular lip includes a surface facing away from the generally annular interior.

21. A coil cup according to claim 19, wherein the generally annular lip is configured to increase the inner pole surface of the coil cup.

22. A coil cup according to claim 19, wherein the generally annular lip is configured to increase an electromagnetic flux between the inner pole surface of the coil cup and the outer pole surface of the coil cup.

23. A coil cup according to claim 19, wherein an inner edge of the generally annular lip is angled.

24. A coil cup according to claim 19, wherein an inner edge of the generally annular lip is configured to minimize a straight surface area of the inner pole surface of the coil cup and the outer pole surface of the coil cup.

25. A coil cup according to claim 19, wherein an inner edge of the generally annular lip is configured to reduce electromagnetic flux between the inner pole surface of the coil cup and the outer pole surface of the coil cup.

26. A coil cup according to claim 19, wherein an inner edge of the generally annular lip is configured to reduce a gap between the inner pole surface of the coil cup and the outer pole surface of the coil cup.

27. A coil cup according to claim 23, wherein an angle of the inner edge of the generally annular lip is between ten degrees and twenty degrees.

28. A coil cup according to claim 23, wherein an angle of the inner edge of the generally annular lip is between approximately ten degrees and twenty degrees.

29. A coil cup according to claim 19, wherein the generally annular lip forms a unitary body with the coil cup.

30. A coil cup according to claim 19, wherein the generally annular lip is formed separately from the coil cup.

31. A coil cup according to claim 19, wherein the generally annular lip extends partially over the coil.

32. A coil cup according to claim 19, wherein the generally annular lip extends over a portion of the generally annular interior.

33. A driving mechanism for an infusion device, the driving mechanism comprising:

a coil arranged to be selectively energized;

a piston moveable in a piston channel in response to energizing the coil, for conveying an infusion media;

a coil cup composed of a magnetizable material, the coil cup comprising;

a generally annular inner wall having one end defining an inner pole surface of the coil cup;

a generally annular outer wall having a first inner diameter and a first outer diameter, the outer wall having a generally annular shelf portion extending from the outer wall towards the inner wall, the shelf portion having a second inner diameter and a second outer diameter, the second inner diameter being smaller than the first inner diameter, the shelf portion having a second end defined by the second inner and outer diameters, the second end defining at least a portion of an outer pole surface of the coil cup; and

a generally annular interior between the inner and outer walls, the annular interior containing a coil.

34. A drive mechanism according to claim 33, wherein the generally annular shelf portion extends partially over the coil.

35. A drive mechanism according to claim 33, wherein the generally annular shelf portion extends over a portion of the generally annular interior.

36. A drive mechanism for an infusion device, the drive mechanism comprising:

a coil arranged to be selectively energized;

a piston moveable in a piston channel in response to energizing the coil, for conveying an infusion media;

a coil cup composed of a magnetizable material, the coil cup comprising;

a generally annular inner wall having one end defining an inner pole surface of the coil cup;

a generally annular outer wall having a first inner diameter and a first outer diameter, at least one of the first inner diameter and the first outer diameter defining at least a portion of an outer pole surface of the coil cup; and

a generally annular lip extending from extending from the inner wall towards the outer wall,

wherein the generally annular inner wall and the generally annular outer wall define a generally annular interior, and

wherein the generally annular interior contains a coil.

37. A drive mechanism according to claim 36, wherein the generally annular lip extends partially over the coil.

38. A drive mechanism according to claim 36, wherein the generally annular lip extends over a portion of the generally annular interior.