Dispensing Fluid from an Infusion Pump System

• US 20090198186A1
• Filed: 04/13/2009
• Published: 08/06/2009
• Est. Priority Date: 09/26/2005
• Status: Active Grant

• Current Assignee: Insulet Corporation
• Original Assignee: M2 Group Holdings Inc (Bigfoot Biomedical, Inc.)
• Inventors: Wenger, Mitchell, Kirschen, Todd, Mernoe, Morten, Causey, James
• Granted Patent: US 7,938,803 B2
• Time in Patent Office: Days
• US Class Current: 604/151
• CPC Class Codes: A61M 2005/14506 mechanically driven, e.g. spring or clockwork
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• CPC Class Codes: A61M 2205/8212 with means or measures taken for minimising energy consumption
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/1454 spring-actuated, e.g. by a clockwork
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump

Abstract

Some embodiments of an infusion pump device may include a drive system that accurately and incrementally dispenses fluid from the pump device in a controlled manner. Particular embodiments of the drive system may include a rotational motor that is coupled to a string member, which is used to adjust a pawl relative to a ratchet body. In such circumstances, the drive system can provide a reliable and compact infusion pump device that accurately dispenses the desired volume of fluid.

Claims

1. A medical infusion pump system, comprising:

a pump device having a drive system to cause dispensation of a medicine, the drive system including;

a pawl that is adjustable relative to a ratchet body, the pawl engaging one or more teeth of the ratchet body to incrementally advance the ratchet body;

a string member coupled to the pawl, the string member being arranged in a loop around two or more guide structures; and

a rotational motor coupled to the string member so that rotation by the motor causes the string member to adjust the pawl relative to the ratchet body.

2. The medical infusion pump system of claim 1, further comprising a removable controller device that is mechanically and electrically connectable to the pump device.

3. The medical infusion pump system of claim 2, wherein removable controller device comprises a user interface that provides information to a user when the controller device is connected to the pump device.

4. The medical infusion pump system of claim 2, wherein the pump device further comprises a housing that defines a cavity to receive a medicine cartridge, the pump device housing defining at least one portion that mates with the removable controller device.

5. The medical infusion pump system of claim 2, wherein removable controller device controls the rotational motor to alternate between rotation in a first rotational direction and rotation in a second rotational direction.

6. The medical infusion pump system of claim 1, wherein the string member that is coupled to the motor comprises braided filaments capable of enduring repeated twisting cycles of the string member.

7. The medical infusion pump system of claim 6, wherein the string member comprises braided filaments that are braided around a centrally disposed thin wire.

8. The medical infusion pump system of claim 7, wherein the braided filaments of the string member generate a tension force to adjust the pawl when the string member is twisted by the one or more rotations of the rotational motor.

9. The medical infusion pump system of claim 1, wherein the pawl is adjustable from a reset position to a forward position to incrementally advance the ratchet body.

10. The medical infusion pump system of claim 9, wherein the drive system further includes a bias member coupled to the pawl to drive the pawl toward the forward position and incrementally advance the ratchet body.

11. The medical infusion pump system of claim 10, wherein the drive system further includes a flexible piston rod that is advanced in a longitudinal direction by an incremental distance in response the incremental advancement of the ratchet body.

12. The medical infusion pump system of claim 10, wherein the string member is twisted by the one or more rotations of the rotational motor and thereby urges the pawl member toward the reset position.

13. The medical infusion pump system of claim 12, wherein the loop is shortened in length when the string member is twisted by the one or more rotations of the rotational motor.

14. The medical infusion pump system of claim 1, wherein the pawl comprises a pivotable body and the ratchet body comprises a ratchet wheel.

15. The medical infusion pump system of claim 1, wherein at least one of the guide structures is fixedly positioned relative to the rotational motor.

16. The medical infusion pump system of claim 15, wherein at least one of the guide structures is fixedly positioned relative to the pawl.

17. The medical infusion pump system of claim 1, wherein one or more rotations by the motor causes the string member to apply a tension force to the pawl.

18. The medical infusion pump system of claim 17, wherein one or more rotations by the motor causes a portion of the string member between the rotational motor and the guide structures to be twisted.

19. The medical infusion pump system of claim 1, wherein the string member comprises a flexible member capable of transmitting a tension force.

20. The medical infusion pump system of claim 19, wherein the flexible member is selected from the group consisting of a braided filament structure, a monofilament string structure, and a tape structure.