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

• US 20060056998A1
• Filed: 08/31/2005
• Published: 03/16/2006
• 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 7,762,793 B2
• Time in Patent Office: Days
• US Class Current: 417/413.100
• 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

1-38. -38. (canceled)

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

a coil arranged to be selectively energized;

an armature moveable in response to energizing the coil, the armature having a first pair of pole surfaces;

a piston moveable in conjunction with the armature in response to energizing the coil, wherein the piston is moveable in a piston channel for conveying an infusion media;

a coil housing containing the coil, the coil housing composed of a magnetizable material and providing a second pair of pole surfaces in a magnetic flux path with the first pair of pole surfaces when the coil is energized;

wherein the armature comprises an armature body having a cavity and a magnetic material located within the cavity.

40. A drive mechanism as recited in claim 39, wherein the armature body is composed of a material having a lower magnetic permeability relative to the magnetic material.

41. A drive mechanism as recited in claim 40, wherein the armature body is composed of at least one of titanium, stainless steel, biocompatible plastic, ceramic or glass.

42. A drive mechanism as recited in claim 40, wherein the armature body is composed of a non-ferritic stainless steel.

43. A drive mechanism as recited in claim 39, wherein the magnetic material comprises at least one of a ferrous material and an S44700 stainless steel material.

44. A drive mechanism as recited in claim 39, further comprising a cover provided over the cavity of the armature body, to cover the magnetic material located within the cavity.

45. A drive mechanism as recited in claim 44, wherein the cover comprises a foil material.

46. A drive mechanism as recited in claim 39, further comprising a cover for inhibiting the magnetic material from contacting infusion media.

47. A drive mechanism as recited in claim 39, wherein the magnetic material located within the cavity completes a flux path when the coil is energized.

48. A drive mechanism as recited in claim 47, further comprising a cover for inhibiting the magnetic material from contacting infusion media when the coil is energized.

49. A drive mechanism as recited in claim 48, wherein the cover comprises a foil material.

50. A drive mechanism as recited in claim 39, wherein the first pole surfaces face the same direction.

51. A method for making a drive mechanism for an infusion device, the method comprising:

arranging a coil to be selectively energized;

supporting an armature for movement in response to energizing the coil, the armature having an armature body and a first pair of pole surfaces;

supporting a piston in a piston channel for movement in conjunction with the armature in response to energizing the coil, to convey an infusion media;

containing the coil in a coil housing composed of a magnetizable material;

arranging the coil cup such that a second pair of pole surfaces on the coil cup are in a magnetic flux path with the first pair of pole surfaces when the coil is energized;

supporting a magnetic material within a cavity in the armature body for completing the flux path when the coil is energized.

52. A method as recited in claim 51, wherein supporting an armature comprises supporting an armature having an armature body composed of a material having a lower magnetic permeability relative to the magnetic material.

53. A method as recited in claim 51, wherein supporting an armature comprises supporting an armature having an armature body composed of at least one of titanium, stainless steel, biocompatible plastic, ceramic or glass.

54. A method as recited in claim 51, wherein supporting an armature comprises supporting an armature having an armature body composed of a non-ferritic stainless steel.

55. A method as recited in claim 51, wherein supporting a magnetic material comprises supporting at least one of a ferrous material and an S44700 stainless steel material.

56. A method as recited in claim 51, further comprising covering the magnetic material with a cover provided over the cavity of the armature body.

57. A method as recited in claim 51, further comprising covering the magnetic material with a foil disposed over the cavity of the armature body.

58. A method as recited in claim 51, further comprising covering the magnetic material with a cover that inhibits the magnetic material from contacting infusion media.

59. A drive mechanism as recited in claim 51, wherein supporting an armature comprises supporting an armature with the first pole surfaces facing the same direction.