Implantable medical pump with pressure sensor

Patent metadata

Field	Value
Publication number	US-11426514-B2
Application number	US-201916565013-A
Country	US
Kind code	B2
Filing date	Sep 9, 2019
Priority date	Jun 3, 2010
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

The disclosure is directed to a pressure sensor of an implantable medical device. The pressure sensor may utilize detect fluid pressure based on a changing capacitance between two capacitive elements. The pressure sensor may define at least a portion of a fluid enclosure of the IMD. In one example, the pressure sensor has a self-aligning housing shape that occludes an opening in the pump bulkhead of the IMD. An operative surface of the pressure and the portion of the fluid enclosure may be formed of a corrosion resistant and/or biocompatible material. A first capacitive element of the pressure sensor may be a metal alloy diaphragm that deflects in response to external fluid pressure. A second capacitive element of the pressure sensor may be a metal coating on a rigid insulator sealed from the fluid by the diaphragm and a housing of the sensor.

First claim

The invention claimed is:

1. An implantable medical device (IMD) comprising:
a housing;
one or more electrical components within the housing;
a fluid enclosure wall within the housing and partially defining a fluid enclosure and defining an opening, wherein the fluid enclosure is configured to accommodate a fluid; and
a pressure sensor within the housing, the pressure sensor comprising an operative surface configured to mate to the fluid enclosure wall, the operative surface occluding the opening to partially define the fluid enclosure and separate the fluid from the one or more electrical components, wherein the one or more electrical components are configured to detect, based on a signal from the pressure sensor, a beyond threshold fluid pressure during refill of the IMD with the fluid.

2. The IMD of claim 1 , wherein the beyond threshold fluid pressure is indicative of at least one of IMD damage or overflow of the fluid out of the housing.

3. The IMD of claim 1 , further comprising a memory configured to store a threshold fluid pressure value, wherein the one or more electrical components are configured to detect the beyond threshold fluid pressure by comparing a fluid pressure represented by the signal from the pressure sensor to the threshold fluid pressure value stored in memory.

4. The IMD of claim 1 , wherein the operative surface of the pressure sensor is configured to monitor a pressure of a refill port of the IMD.

5. The IMD of claim 1 , wherein the operative surface of the pressure sensor is configured to partially define the fluid enclosure at a position adjacent to a refill port of the IMD.

6. The IMD of claim 1 , wherein the operative surface of the pressure sensor is configured to partially define the fluid enclosure, the fluid enclosure defining part of a fluid channel between a refill port of the IMD and a reservoir of the IMD configured to store the fluid.

7. The IMD of claim 1 , wherein the fluid enclosure is configured to create a reservoir to store the fluid.

8. The IMD of claim 1 , further comprising a telemetry circuit configured to transmit data from the IMD to an external device.

9. The IMD of claim 8 , wherein the one or more electrical components comprise processing circuitry configured to control, in response to detecting the beyond threshold fluid pressure, the telemetry circuit to transmit the data to the external device, wherein the data is representative of an alert indicative of the beyond threshold fluid pressure.

10. The IMD of claim 1 , wherein the pressure sensor is sized and shaped to self-align in a predetermined rotational orientation to the opening defined by the fluid enclosure wall.

11. The IMD of claim 1 , wherein:
the pressure sensor includes a capacitive pressure sensor;
the operative surface comprises a diaphragm mounted to a sensor housing, the diaphragm configured as a first capacitive plate of the capacitive pressure sensor and configured to deflect in response to a pressure of the fluid; and
the pressure sensor comprises a metal film configured as a second capacitive plate of the capacitive pressure sensor.

12. The IMD of claim 1 , further comprising the fluid, wherein the fluid comprises a therapeutic agent.

13. A method comprising:
controlling a pump of an implantable medical device (IMD) to deliver a fluid out of the IMD, wherein the IMD comprises:
a housing;
one or more electrical components within the housing;
a fluid enclosure wall within the housing and partially defining a fluid enclosure and defining an opening, wherein the fluid enclosure is configured to accommodate the fluid; and
a pressure sensor within the housing, the pressure sensor comprising an operative surface configured to mate to the fluid enclosure wall, the operative surface occluding the opening to partially define the fluid enclosure and separate the fluid from the one or more electrical components; and

detecting, with the one or more electrical components and based on a signal from the pressure sensor, a beyond threshold fluid pressure during refill of the IMD with the fluid.

14. The method of claim 13 , wherein the beyond threshold fluid pressure is indicative of at least one of IMD damage or overflow of the fluid out of the housing.

15. The method of claim 13 , wherein the beyond threshold fluid pressure is indicative of a blockage located in a catheter connected to the IMD.

16. The method of claim 13 , wherein determining the beyond threshold fluid pressure comprises determining the beyond threshold fluid pressure using the operative surface of the pressure sensor, wherein the operative surface monitors a pressure of a refill port of the IMD.

17. The method of claim 13 , wherein determining the beyond threshold fluid pressure comprises determining the beyond threshold fluid pressure using the operative surface of the pressure sensor, wherein the operative surface partially defines the fluid enclosure at a position adjacent to a refill port of the IMD.

18. The method of claim 13 , wherein determining the beyond threshold fluid pressure comprises determining the beyond threshold fluid pressure using the operative surface of the pressure sensor, wherein the operative surface partially defines the fluid enclosure that is part of a fluid channel between a refill port of the IMD and a reservoir of the IMD configured to store the fluid.

19. The method of claim 13 , wherein determining the beyond threshold fluid pressure comprises determining the beyond threshold fluid pressure using the operative surface of the pressure sensor, wherein the operative surface partially defines the fluid enclosure that creates a reservoir configured to store the fluid.

20. The method of claim 13 , further comprising controlling a telemetry circuit of the IMD to transmit, to an external device, data representative of an alert indicative of the beyond threshold fluid pressure.

21. The method of claim 20 , further comprising presenting, via a user interface of the external device, the alert indicative of the beyond threshold fluid pressure to a user, wherein the user interface is configured to provide the alert as at least one of a visual alert or an audible alert.

22. The method of claim 13 , wherein the fluid comprises a therapeutic agent.

23. A system comprising:
an implantable medical device (IMD) configured to connect with a catheter and deliver fluid to a patient via the catheter, wherein the IMD comprises:
a housing;
one or more electrical components within the housing;
a fluid enclosure wall within the housing and partially defining a fluid enclosure and defining an opening, wherein the fluid enclosure is configured to accommodate the fluid;
a pressure sensor within the housing, the pressure sensor comprising an operative surface configured to mate to the fluid enclosure wall, the operative surface occluding the opening to partially define the fluid enclosure and separate the fluid from the one or more electrical components, wherein the one or more electrical components are configured to detect, based on a signal from the pressure sensor, a beyond threshold fluid pressure during refill of the IMD with the fluid; and
telemetry circuitry configured to transmit data representative of the beyond threshold fluid pressure; and

an external device comprising a user interface, wherein the external device is configured to:
receive, from the IMD, the data representative of the beyond threshold fluid pressure; and
present, via the user inte

Assignees

• Medtronic Inc

Inventors

• Miesel Keith A
• Haase James M
• Paidosh Chris J
• Janzig Darren A
• Denison Timothy J

Classifications

• G01L19/086

  for remote indication · CPC title

• A61M2205/3317

  Electromagnetic, inductive or dielectric measuring means · CPC title

• G01L19/0069

  from the sensor to its support · CPC title

• G01L19/149

  of immersion sensor, e.g. where the sensor is immersed in the measuring medium or for in vivo measurements, e.g. by using catheter tips · CPC title

• G01L15/00

  Devices or apparatus for measuring two or more fluid pressure values simultaneously · CPC title