Infusion device and driving mechanism for same

• US 20040225281A1
• Filed: 06/15/2004
• Published: 11/11/2004
• Est. Priority Date: 09/07/2001
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Gray, John, Lorenzen, Eric, Bosley, Robert
• Granted Patent: US 7,396,353 B2
• Time in Patent Office: Days
• US Class Current: 604/890.1
• CPC Class Codes: A61M 2205/8212 with means or measures taken for minimising energy consumption
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/16877 Adjusting flow; Devices for setting a flow rate

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. The piston channel provides a passage for communication of infusion medium to an outlet chamber located at one end of the piston channel. 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. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium. As the piston is moved to its forward position, the piston chamber volume is reduced and pressure within the piston chamber increases to a point where the pressure moves the valve member into an open position. When the valve member is in the open position, medium from the piston chamber is discharged into an outlet chamber located on the opposite side of the coil relative to the armature. An outlet is provided in flow communication with the outlet chamber, for discharging infusion medium from the outlet chamber.

Claims

1-5. -5. (Canceled)

6. A drive mechanism for delivery of infusion medium comprising:

an inlet for receiving infusion medium;

an outlet for discharging infusion medium;

a channel through which infusion medium is communicated between the inlet and the outlet;

a piston moveable between an quiescent position and a forward position to drive infusion medium from the piston channel toward the outlet;

a valve member facing a first end of the channel, the valve member being moveable between closed and open positions to open and close the first end of the channel in conjunction with movement of the piston between quiescent and forward positions; and

a valve seat located adjacent the end of the channel that faces the valve member for contacting the valve member when the valve member is in closed position;

the valve member including at least one generally rigid stop surface for contacting the valve seat upon the valve member being in a closed position, the valve member further including a generally compliant portion extending toward the valve seat, beyond the generally rigid stop surface for contacting the valve seat when the valve member is in a closed position,

wherein the valve seat includes at least one projecting surface arranged to contact the at least one stop surface, upon the valve member being in the closed position.

7. A drive mechanism as recited in claim 6, wherein the valve seat further includes at least one recessed surface for contacting the compliant portion of the valve member, upon the valve member being in the closed position.

8. A drive mechanism as recited in claim 7, wherein the recessed and projecting surfaces of the valve seat are configured relative to the compliant portion of the valve member and the stop surface of the valve member, such that the compliant portion of the valve member contacts the recessed surface of the valve seat upon the stop surface of the valve member contacting the projecting surface of the valve seat.

9. A drive mechanism as recited in claim 7, wherein the recessed and projecting surfaces of the valve seat are configured relative to the compliant portion of the valve member and the stop surface of the valve member, such that the compliant portion of the valve member contacts the recessed surface of the valve seat prior to the stop surface of the valve member contacting the projecting surface of the valve seat.

10. A drive mechanism for delivery of infusion medium comprising:

an inlet for receiving infusion medium;

an outlet for discharging infusion medium;

a channel through which infusion medium is communicated between the inlet and the outlet;

a piston moveable between an quiescent position and a forward position to drive infusion medium from the piston channel toward the outlet;

a valve member facing a first end of the channel, the valve member being moveable between closed and open positions to open and close the first end of the channel in conjunction with movement of the piston between quiescent and forward positions; and

a valve seat located adjacent the end of the channel that faces the valve member for contacting the valve member when the valve member is in closed position;

the valve member including at least one generally rigid stop surface for contacting the valve seat upon the valve member being in a closed position, the valve member further including a generally compliant portion extending toward the valve seat, beyond the generally rigid stop surface for contacting the valve seat when the valve member is in a closed position,

wherein the valve seat includes at least one projecting surface arranged to contact the compliant portion of the valve member, upon the valve member being in the closed position.

11. A drive mechanism as recited in claim 10, wherein the projecting portion of the valve seat is configured relative to the compliant portion of the valve member and the stop surface of the valve member, such that the projecting portion of the valve seat contacts the compliant portion of the valve member upon the stop surface of the valve member making contact with the valve seat.

12. A drive mechanism as recited in claim 10, wherein the projecting portion of the valve seat is configured relative to the compliant portion of the valve member and the stop surface of the valve member, such that the projecting portion of the valve seat contacts the compliant portion of the valve member prior to the stop surface of the valve member making contact with the valve seat.

13-16. -16. (Canceled)

17. A drive mechanism for delivery of infusion medium comprising:

an inlet for receiving infusion medium;

an outlet for discharging infusion medium;

a channel through which infusion medium is communicated between the inlet and the outlet;

a piston moveable between an quiescent position and a forward position to drive infusion medium from the piston channel toward the outlet,

a valve member facing a first end of the channel, the valve member being moveable between closed and open positions to open and close the first end of the channel in conjunction with movement of the piston between quiescent and forward positions; and

a valve seat located adjacent the end of the channel that faces the valve member for contacting the valve member when the valve member is in closed position, the valve seat including a generally rigid surface and at least one compliant member;

the valve member including at least one generally rigid stop surface for contacting the generally rigid surface of the valve seat upon the valve member being in a closed position, the valve member further including at least one projection arranged to contact the at least one compliant member of the valve seat, upon the valve member being in the closed position.

18. A drive mechanism as recited in claim 17, wherein the at least one compliant member comprises at least one annular member composed of a compliant material and located to surround the valve end of the central channel.

19. A drive mechanism as recited in claim 18, wherein the at least one projection on the valve member comprises at least one annular projection arranged to contact the annular compliant member when the valve member is in the closed position.

20. A drive mechanism as recited in claim 17, wherein the projection and stop surface on the valve member are configured relative to the compliant member and generally rigid surface of the valve member, such that the projection on the valve member contacts the compliant member of the valve seat upon the stop surface of the valve member contacting the generally rigid surface of the valve seat.

21. A drive mechanism as recited in claim 17, wherein the projection and stop surface on the valve member are configured relative to the compliant member and generally rigid surface of the valve member, such that the projection on the valve member contacts the compliant member of the valve seat prior to the stop surface of the valve member contacting the generally rigid surface of the valve seat.