Non-constant pressure infusion pump

• US 7,338,464 B2
• Filed: 07/25/2003
• Issued: 03/04/2008
• Est. Priority Date: 03/01/2001
• Status: Expired due to Fees

• Current Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Blischak, Brian, Hooper, Sandra M., Wigness, Bruce D., Erickson, John H., Daglow, Terry
• Primary Examiner(s): DeSanto; Matthew F.
• Application Number:
  US10/626,902
• Publication Number:
  US 20040153029A1
• Time in Patent Office: 1,684 Days
• Field of Search: 604/890.1, 604/891.1, 604/892.1, 604 65- 67, 604/207, 604245-249
• US Class Current: 604/65
• CPC Class Codes: A61M 2005/14264 with means for compensating influence from the environment
• CPC Class Codes: A61M 2005/14506 mechanically driven, e.g. spring or clockwork
• CPC Class Codes: A61M 2205/33 Controlling, regulating or measuring
• CPC Class Codes: A61M 2205/3372 Temperature compensation
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28

Abstract

The present invention relates to an implantable infusion pump having a refillable infusate reservoir in fluid communication with a delivery site via a flow path. This flow path includes a flow resistance. The infusion pump includes a sensing device(s), positioned relative to the flow path, to provide data regarding a flow rate along the flow path. The infusion pump effects a division of a total flow period into at least a plurality of unit dose periods, each unit dose period effecting delivery of a unit dose of infusate. The cumulative effect of delivering the total number of unit dose periods is the delivery of a desired dose over the total flow period. The present invention permits a reservoir pressure to vary over any portion of total flow period but effects a constant-pressure state over each unit dose cycle.

Claims

1. A method for infusing a fluid in a living body, said method comprising:

providing a reservoir, a flow restrictor, and a valve in an implantable drug pump device;

transiently storing fluid infusate in said reservoir for transmission to a delivery site after the implantable drug pump device has been implanted in a patient;

limiting a flow rate of the fluid infusate using said flow restrictor disposed in a fluid path between said reservoir and said delivery site;

determining transient pressure differentials relative to said flow restrictor by a controller component of the implantable drug pump;

determining whether an occlusion is present in the flow path using the transient pressure differentials, the transient pressure differentials being determined when the controller component closes a valve to interrupt flow of the fluid infusate from the implantable drug pump device;

determining a location of an occlusion when an occlusion is detected using the transient pressure differentials;

controlling said valve disposed in said fluid path between said reservoir and said delivery site to control infusate output from said reservoir to said delivery site as a function of said transient pressure differentials across said flow restrictor, wherein the controlling said valve automatically responds to a detection of a partial occlusion by altering a unit dose period for delivery of the fluid infusate;

communicating a signal, from implantable drug pump device to an external device, that is indicative of an amount of occlusion detected by the controller; and

communicating a signal, from implantable drug pump device to an external device, that is indicative of a location of the occlusion.

2. The method of claim 1, wherein controlling said valve comprises:

subdividing a flow period into smaller unit dose periods over which a pressure differential across said flow restrictor is likely to remain constant and controlling said valve to deliver a total dose of said infusate through a series of said unit dose periods.

3. The method of claim 2, wherein said unit dose periods are selected at least in part to reduce battery consumption.

4. The method of claim 2, wherein said unit dose periods are selected so that an open/close rate of said valve is pharmacologically insignificant.

5. The method of claim 1, further comprising:

determining a rate at which a pressure differential across said flow restrictor changes.

6. The method of claim 5, wherein controlling said valve comprises:

altering timing of a period of said valve being opened as a function of said rate at which a pressure differential across said flow restrictor changes.

7. The method of claim 1, further comprising:

providing an alert with respect to overfilling of said reservoir using a pressure differential across said flow restrictor.

8. The method of claim 1, further comprising:

providing an alert with respect to depletion of said reservoir using a pressure differential across said flow restrictor.

9. The method of claim 1, further comprising:

determining a temperature of said infusate, wherein controlling said valve comprises controlling infusate output from said reservoir as a function of said temperature of said infusate.