Infusion medium delivery device and method with drive device for driving plunger in reservoir

• US 20080097326A1
• Filed: 10/27/2006
• Published: 04/24/2008
• Est. Priority Date: 08/23/2006
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Moberg, Sheldon B., Kavazov, Julian D., Chong, Colin A., Hanson, Ian B., Hudak, Philip J., Griffin, Christopher G., Mounce, R. Paul, Bente, Paul F.
• Granted Patent: US 7,905,868 B2
• Time in Patent Office: Days
• US Class Current: 604/155
• CPC Class Codes: A61M 2005/14268 with a reusable and a disposable component
• CPC Class Codes: A61M 2005/14573 with a replaceable reservoir for quick connection/disconnection with a driving system
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 2205/103 rotating
• CPC Class Codes: A61M 2205/58 Means for facilitating use, e.g. by people with impaired vision
• CPC Class Codes: A61M 2205/6054 Magnetic identification systems
• CPC Class Codes: A61M 5/1413 Modular systems comprising interconnecting elements
• CPC Class Codes: A61M 5/14236 Screw, impeller or centrifugal type pumps
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/14526 the piston being actuated by fluid pressure
• CPC Class Codes: A61M 5/1456 with a replaceable reservoir comprising a piston rod to be moved into the reservoir, e.g. the piston rod is part of the removable reservoir
• CPC Class Codes: A61M 5/5086 for indicating if defective, used, tampered with or unsterile
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A delivery device includes a durable housing portion and a separable disposable portion that selectively engage and disengage from each other. The disposable housing portion secures to the patient-user and may be disposed of after it has been in use for a prescribed period. Components that normally come into contact with a patient-user or with infusion medium are supported by the disposable housing portion, while the durable housing portion supports other components such as electronics and a drive device. A reservoir is supported by the disposable housing portion and has a moveable plunger that operatively couples to the drive device, when the disposable and durable housing portions are engaged.

Claims

1. A delivery device for delivering an infusion medium to a user, the device comprising:

a disposable housing portion adapted to be secured to a user;

a durable housing portion configured to be selectively engaged with and disengaged from the disposable housing portion to allow disposal of the disposable housing portion without disposing of the durable housing portion;

a reservoir supported by the disposable housing portion, the reservoir having an interior for containing a fluidic medium and a plunger moveable within the interior of the reservoir along an axial direction of the reservoir, the plunger having a threaded channel;

a rotatable shaft disposed at least partially within the reservoir interior, along the axial direction of the reservoir, the rotatable shaft extending through the threaded channel of the plunger and having a threaded portion operatively engaged with the threaded channel of the plunger, wherein rotation of the rotatable shaft causes the plunger to move along the length of the threaded portion of the rotatable shaft to vary the interior volume of the reservoir; and

a drive device supported by the durable housing portion in a position to operatively connect to the rotatable shaft, to selectively rotate the rotatable shaft, when the disposable and durable housing portions are engaged.

2. A delivery device according to claim 1, further comprising at least one seal arranged between the rotatable shaft and the plunger, to inhibit the passage of the fluidic medium F through the central channel of the plunger.

3. A delivery device according to claim 2, wherein the at least one seal comprises at least one layer of sealing material disposed over the rotatable shaft.

4. A delivery device according to claim 2, wherein the at least one seal comprises a plurality of o-ring seals disposed around the rotatable shaft.

5. A delivery device according to claim 1, wherein:

the durable housing portion has an enclosed interior volume containing the drive device;

the rotatable shaft has a connection end; and

the drive device operatively connects to the connection end of the rotatable shaft through a drive linkage that extends through an aperture in the durable housing portion.

6. A delivery device according to claim 5, wherein:

the drive linkage includes a connection end for connecting to the connection end of the rotatable shaft; and

the connection end of the drive linkage and the connection end of the rotatable shaft have mating shapes that mate together and allow transfer of rotational motion from the drive linkage to the rotatable shaft, when the disposable and durable housing portions are engaged.

7. A delivery device according to claim 5, further comprising a seal adjacent the aperture in the durable housing portion, to seal the aperture through which the drive linkage extends.

8. A delivery device according to claim 1, further comprising electrical control circuitry contained in the durable housing portion, wherein the electrical control circuitry controls the delivery of infusion medium from the reservoir to the user when the durable housing portion and the disposable housing portion are engaged.

9. A delivery device according to claim 1, wherein the disposable housing portion comprises a base portion having a bottom surface and an adhesive material on the bottom surface for securing the disposable housing portion to the skin of the user.

10. A delivery device according to claim 1, wherein the reservoir includes a septum that may be pierced by a hollow needle for providing a fluid flow path from the interior of the reservoir to the hollow needle.

11. A delivery device according to claim 1, further comprising an anti-rotation structure to inhibit the plunger from rotating within the reservoir.

12. A delivery device according to claim 11, wherein the reservoir has an interior surface and wherein the anti-rotation structure comprises at least one projection extending from one of the plunger and the interior surface of the reservoir and at least one channel provided in the other one of the plunger and the interior surface of the reservoir, wherein the at least one projection is configured to extend at least partially into the at least one channel.

13. A delivery device according to claim 1, wherein the plunger has an outer peripheral surface and at least one seal arranged around the outer peripheral surface, for inhibiting the passage of infusion medium between the outer peripheral surface of the plunger and an interior surface of the reservoir.

14. A delivery device according to claim 5, wherein the drive device comprises:

an escapement wheel supported for rotation, the escapement wheel having a plurality of teeth, the escapement wheel being operatively connected to rotate the drive linkage with rotation of the escapement wheel;

a drive pawl supported for linear movement between a start position and an end position and having a drive surface arranged to engage a tooth of the escapement wheel and rotate the escapement wheel in a first direction as the drive pawl moves between the start and end positions; and

an actuator operatively connected to the drive pawl, for selectively moving the drive pawl from the start position to the end position.

15. A method of making a delivery device for delivering an infusion medium to a user, the method comprising:

providing a first housing portion adapted to be secured to a user;

providing a second housing portion configured to be selectively engaged with and disengaged from the first housing portion to allow disposal of the first housing portion without disposing of the second housing portion;

supporting a reservoir on the first housing portion, the reservoir having an interior for containing a fluidic medium;

arranging a plunger within the interior of the reservoir and moveable relative to the reservoir along an axial direction of the reservoir, the plunger having a threaded channel;

arranging a rotatable shaft at least partially within the reservoir interior, along the axial direction of the reservoir, extending the rotatable shaft through the threaded channel of the plunger, and operatively engaging a threaded portion of the rotatable shaft with the threaded channel of the plunger, wherein rotation of the rotatable shaft relative to the plunger causes the plunger to move along the length of the threaded portion of the rotatable shaft to vary the interior volume of the reservoir; and

supporting a drive device on the second housing portion in a position to operatively connect to the rotatable shaft, to selectively rotate the rotatable shaft, when the first and second housing portions are engaged.

16. A method according to claim 15, the method further comprising arranging at least one seal between the rotatable shaft and the plunger, to inhibit the passage of the fluidic medium through the central channel of the plunger.

17. A method according to claim 16, wherein arranging at least one seal comprises providing at least one layer of sealing material over the rotatable shaft.

18. A method according to claim 16, wherein arranging at least one seal comprises providing a plurality of o-ring seals disposed around the rotatable shaft.

19. A method according to claim 15, wherein:

the second housing portion has an enclosed interior volume containing the drive device;

the rotatable shaft has a connection end; and

the method further comprises extending a drive linkage through an aperture in the second housing portion to a position to operatively connect to the connection end of the rotatable shaft when the first and second housing portions are engaged; and

coupling the drive linkage with the drive device, for transmitting drive force from the drive device to the rotatable drive shaft when the first and second housing portions are engaged.

20. A method according to claim 19, further comprising:

providing the drive linkage with a connection end for connecting to the connection end of the rotatable shaft; and

providing the connection end of the drive linkage and the connection end of the rotatable shaft with mating shapes that mate together and allow transfer of rotational motion from the drive linkage to the rotatable shaft, when the first and second housing portions are engaged.

21. A method according to claim 19, further comprising arranging a seal adjacent the aperture in the durable housing portion, to seal the aperture through which the drive linkage extends.

22. A method according to claim 15, further comprising supporting electrical control circuitry on the second housing portion, wherein the electrical control circuitry controls the delivery of infusion medium from the reservoir to the user when the first housing portion and the second housing portion are engaged.

23. A method according to claim 15, wherein providing a first housing portion comprises providing a base portion having a bottom surface and an adhesive material on the bottom surface for securing the base to the skin of the user.

24. A method according to claim 15, further comprising supporting a septum that may be pierced by a hollow needle for providing a fluid flow path from the interior of the reservoir to the hollow needle.

25. A method according to claim 15, further comprising providing an anti-rotation structure to inhibit the plunger from rotating within the reservoir.

26. A method according to claim 15, wherein the reservoir has an interior surface and wherein providing the anti-rotation structure comprises providing at least one projection extending from one of the plunger and the interior surface of the reservoir and providing at least one channel in the other one of the plunger and the interior surface of the reservoir, wherein the at least one projection is configured to extend at least partially into the at least one channel.

27. A method according to claim 15, further comprising arranging at least one seal around an outer peripheral surface of the plunger, for inhibiting the passage of infusion medium between the outer peripheral surface of the plunger and an interior surface of the reservoir.

28. A method according to claim 15, wherein supporting a drive device comprises:

supporting an escapement wheel for rotation, the escapement wheel having a plurality of teeth, the escapement wheel being operatively connected to rotate the drive linkage with rotation of the escapement wheel;

supporting a drive pawl for linear movement between a start position and an end position and having a drive surface arranged to engage a tooth of the escapement wheel and rotate the escapement wheel in a first direction as the drive pawl moves between the start and end positions; and

operatively connecting an actuator to the drive pawl, for selectively moving the drive pawl from the start position to the end position.