Non-constant pressure infusion pump

• US 6,620,151 B2
• Filed: 03/01/2001
• Issued: 09/16/2003
• Est. Priority Date: 03/01/2001
• Status: Expired due to Term

• Current Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories)
• Inventors: Blischak, Brian, Daglow, Terry, Hooper, Sandra Marie, Wigness, Bruce David, Erickson, John H.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Fristoe, Jr., John K
• Application Number:
  US09/796,969
• Publication Number:
  US 20020156464A1
• Time in Patent Office: 929 Days
• Field of Search: 604/890.1, 604/891.1, 604/892.1, 604/65, 604/66, 604/67, 604/207, 604/245, 604/246, 604/247, 604/248, 604/249
• US Class Current: 604/891.1
• 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 of controlling infusate output from an implantable infusion device for a prescribed dose period, the device having a collapsible infusate chamber, an energy source to collapse the chamber, and an outlet flow path extending between the chamber and a device outlet, wherein the outlet flow path includes a restrictor and a valve to selectively and at least partially occlude the outlet flow path, comprising the steps of:

actuating the valve so as to effect a change in an occluded state of the outlet flow path;

measuring a transient pressure profile across the valve; and

assessing a rate of change of the pressure profile during the actuating step wherein the step of assessing can reveal an undesired flow restriction upstream of the valve based on a rate of change of a measured pressure profile.

2. A method of controlling infusate output from an implantable infusion device for a prescribed dose period, the device having a collapsible infusate chamber, an energy source to collapse the chamber, and an outlet flow path extending between the chamber and a device outlet, wherein the outlet flow path includes a restrictor and a valve to selectively and at least partially occlude the outlet flow path, comprising the steps of:

actuating the valve so as to effect a change in an occluded state of the outlet flow path;

measuring a transient pressure profile across the valve; and

assessing a rate of change of the pressure profile during the actuating step, wherein the step of assessing can reveal an undesired flow restriction downstream of the valve based on a rate of change of a measured pressure profile.

3. A method of controlling infusate output from an implantable infusion device for a prescribed dose period, the device having a collapsible infusate chamber, an energy source to collapse the chamber, and an outlet flow path extending between the chamber and a device outlet, wherein the outlet flow path includes a restrictor and a valve to selectively and at least partially occlude the outlet flow path, comprising the steps of:

actuating the valve so as to effect a change in an occluded state of the outlet flow path;

measuring a transient pressure profile across the valve; and

assessing a rate of change of the pressure profile during the actuating step, wherein the step of assessing can reveal a valve malfunction.

4. A method of controlling infusate output from an implantable infusion device for a prescribed dose period, the device having a collapsible infusate chamber, an energy source to collapse the chamber, and an outlet flow path extending between the chamber and a device outlet, wherein the outlet flow path includes a restrictor and a valve to selectively and at least partially occlude the outlet flow path, comprising the steps of:

actuating the valve so as to effect a change in an occluded state of the outlet flow path;

measuring a transient pressure profile across the valve; and

assessing a rate of change of the pressure profile during the actuating step, wherein the step of assessing can reveal changes in infusate delivery caused by changes in certain properties of the infusate based on a rate of change of a measured pressure profile, the certain properties being of the group of;

physical, chemical, therapeutic, and pharmacological.

5. A method of controlling infusate output from an implantable infusion device for a prescribed dose period, the device having a collapsible inflisate chamber, an energy source to collapse the chamber, and an outlet flow path extending between the chamber and a device outlet, wherein the outlet flow path includes a restrictor and a valve to selectively and at least partially occlude the outlet flow path, comprising the steps of:

actuating the valve so as to effect a change in an occluded state of the outlet flow path;

measuring a transient pressure profile across the valve; and

assessing a rate of change of the pressure profile during the actuating step, wherein the step of assessing can reveal a catheter malfunction.

6. A method of controlling infusate output from an implantable infusion device for at least one prescribed dose period, the device having a collapsible infusate chamber, an energy source to collapse the chamber, and an outlet flow path extending between the chamber and a device outlet, wherein the outlet flow path includes a restrictor and a valve to selectively and at least partially occlude the outlet flow path, comprising the steps of:

dividing the prescribed dose period into a plurality of unit dose periods, wherein each unit dose period is defined by an open-close cycle of the valve;

measuring a pressure differential;

modifying an operational timing of the open-close cycle of the valve, in accordance with the measured pressure differential, so as to maintain a unit dose for each unit dose period;

actuating the valve so as to effect a change in an occluded state of the outlet flow path;

measuring a transient pressure profile across the valve; and

assessing a rate of change of a measured pressure profile at or about said actuating step.

7. A method in accordance with claim 6, wherein a plurality of prescribed dose periods define a flow period, and further comprising the step of dividing the flow period into the plurality of prescribed dose periods.

8. A method in accordance with claim 6, wherein the operational timing that is subject to regulation by the controller is a duty cycle of the open-close cycle of the valve.

9. A method in accordance with claim 6, further comprising the step of measuring an infusate temperature, wherein the step of modifying is effected also in accordance with a measured temperature.

10. A method in accordance with claim 6, wherein the infusion device is adapted to communicate with a controller external to the patient, and further comprising the step of transmitting a signal to the controller, wherein the signal is representative of the measured infusate pressure differential.

11. A method in accordance with claim 6, wherein the infusion device is adapted to communicate with a controller external to the patient, and further comprising the step of transmitting a signal to the controller, wherein the signal corresponds to the measured pressure profile.