Implantable medical pump with pressure sensor

• US 9,737,657 B2
• Filed: 06/03/2010
• Issued: 08/22/2017
• Est. Priority Date: 06/03/2010
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Miesel, Keith A., Haase, James M., Paidosh, Chris J., Janzig, Darren A., Denison, Timothy J.
• Primary Examiner(s): VU, QUYNH-NHU HOANG
• Application Number:
  US12/793,457
• Publication Number:
  US 20110301575A1
• Time in Patent Office: 2,637 Days
• Field of Search: 600485, 6048901, 6048911, 604 65- 67, 604502, 604503
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 39/0208 Subcutaneous access sites for injecting or removing fluids transcutaneous access sites A61M39/0247; implantable infusion devices A61M5/14276
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: G01L 15/00 Devices or apparatus for measuring two or more fluid pressure values simultaneously
• CPC Class Codes: G01L 19/0023 for flowthrough systems having a flexible pressure transmitting element
• CPC Class Codes: G01L 19/0069 from the sensor to its support
• CPC Class Codes: G01L 19/086 for remote indication
• CPC Class Codes: G01L 19/143 Two part housings
• CPC Class Codes: G01L 19/148 Details about the circuit board integration, e.g. integrated with the diaphragm surface or encapsulation
• CPC Class Codes: G01L 19/149 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 Class Codes: G01L 9/0072 using variations in capacitance

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.

Claims

1. An implantable medical device (IMD) comprising:

one or more electrical components within the IMD;

a fluid enclosure wall partially defining a fluid enclosure configured to accommodate a fluid within the IMD, wherein;

the fluid enclosure wall defines a channel opening, and

the IMD is configured to deliver the fluid out of the IMD; and

a pressure sensor comprising an operative surface that comprises a sensor housing configured to mate to the fluid enclosure wall, wherein;

the operative surface is configured to partially define the fluid enclosure and occlude the channel opening when the sensor housing is mated to the fluid enclosure wall, and

occlusion of the channel opening by the pressure sensor separates the fluid from the one or more electrical components.

2. The IMD of claim 1, wherein

the sensor housing is configured to be attached to a portion of the fluid enclosure wall defining the channel opening.

3. The IMD of claim 2, wherein the operative surface further comprises:

a diaphragm mounted to the sensor housing and configured to deflect in response to a pressure of the fluid.

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

5. The IMD of claim 4, wherein the pressure sensor is configured to self-align to the channel opening such that an electrical connection is made between the pressure sensor and at least one electrical component of the IMD by positioning at least one electrical contact of the pressure sensor in proximity to at least one electrical contact of the at least one electrical component of the IMD.

6. The IMD of claim 4, wherein the pressure sensor is shaped to self-align in a predetermined rotational orientation within the channel opening.

7. The IMD of claim 4, wherein the pressure sensor comprises a non-circular shape.

8. The IMD of claim 7, wherein the non-circular shape comprises a tear-drop shape.

9. The IMD of claim 4, wherein the pressure sensor comprises at least one of one or more notches and one or more protrusions configured to self-align the pressure sensor to the channel opening.

10. The IMD of claim 1, wherein the fluid enclosure wall is defined in at least a portion of a bulkhead that houses the one or more electrical components of the IMD.

11. The IMD of claim 1, further comprising a reservoir different than the fluid enclosure and configured to retain the fluid, and wherein the fluid enclosure is a fluid channel configured to direct fluid flow through the IMD and direct fluid flow at least one of to the reservoir or from the reservoir.

12. The IMD of claim 1, wherein the fluid enclosure is a reservoir configured to retain the fluid.

13. The IMD of claim 1, further comprising a reservoir configured to retain the fluid and a refill port configured to receive fluid into the IMD, and wherein the fluid enclosure is a portion of a receptacle positioned for receiving fluid as a fluid path between the reservoir and the refill port within the IMD.

14. The IMD of claim 1, wherein the fluid enclosure is configured to direct fluid from a medical pump to a catheter outlet.

15. The IMD of claim 1, wherein a surface of the fluid enclosure wall in contact with the fluid and the operative surface of the pressure sensor are formed of a corrosion resistant material.

16. The IMD of claim 15, wherein the surface of the fluid enclosure wall in contact with the fluid and the operative surface of the pressure sensor are formed of a bio-compatible material.

17. The IMD of claim 1, wherein a surface of the fluid enclosure wall in contact with the fluid and the operative surface of the pressure sensor are formed of Grade 9 titanium alloy.

18. The IMD of claim 1, wherein:

the pressure sensor is a capacitive pressure sensor;

the pressure sensor comprises a diaphragm configured as a first capacitive plate of the capacitive pressure sensor and a portion of the operative surface; and

the pressure sensor comprises a metal film configured as a second capacitive plate of the capacitive pressure sensor.

19. The IMD of claim 18, wherein the metal film configured as a second capacitive plate of the capacitive pressure sensor is arranged to be substantially rigid.

20. The IMD of claim 19, wherein the metal film is formed upon a substantially rigid insulator.

21. The IMD of claim 1, wherein at least a portion of the operative surface of the pressure sensor extends into the fluid enclosure.

22. A method comprising:

accommodating a fluid within a fluid enclosure of an implantable medical device (IMD), wherein;

the fluid enclosure is partially defined by a fluid enclosure wall;

the fluid enclosure wall defines a channel opening;

the IMD comprises one or more electrical components within the IMD; and

the IMD is configured to deliver the fluid out of the IMD; and

detecting a pressure of the fluid with a pressure sensor comprising an operative surface that comprises a sensor housing configured to mate to the fluid enclosure wall, wherein;

the operative surface is configured to partially define the fluid enclosure and occlude the channel opening when the sensor housing is mated to the fluid enclosure; and

occlusion of the channel opening by the pressure sensor separates the fluid from the one or more electrical components.

23. The method of claim 22, wherein detecting the pressure of the fluid includes detecting the pressure with the operative surface that includes a sensor housing configured to be secured to the opening defined by the fluid enclosure wall.

24. The method of claim 23, wherein detecting the pressure of the fluid comprises detecting the pressure with an operative surface that includes a diaphragm mounted to the sensor housing and configured to deflect in response to the pressure of the fluid.

25. The method of claim 22, further comprising:

occluding the channel opening defined by the fluid enclosure wall with the pressure sensor according to a self-aligning shape of the pressure sensor.

26. The method of claim 22, wherein detecting the pressure of the fluid comprises detecting the pressure of the fluid accommodated within a reservoir of the IMD.

27. The method of claim 22, wherein detecting the pressure of the fluid comprises detecting the pressure of the fluid accommodated within a portion of a receptacle for receiving fluid within the IMD.

28. The method of claim 22, wherein detecting the pressure of the fluid comprises detecting the pressure of the fluid accommodated within a fluid conduit of the IMD.

29. The method of claim 22, wherein detecting the pressure of the fluid comprises measuring a change in capacitance between a first capacitive plate and a second capacitive plate of the pressure sensor.

30. A device comprising:

a bulkhead that defines a first portion of a fluid enclosure configured to accommodate a fluid; and

a pressure sensor configured of a size and a shape to self-align in a predetermined rotational orientation within a channel opening defined by the bulkhead and occlude the channel opening.

31. The IMD of claim 30, wherein the pressure sensor is configured to self-align to the channel opening such that an electrical connection is made between the pressure sensor and at least one electrical component of the device by positioning at least one electrical contact of the pressure sensor in proximity to at least one electrical contact of the at least one electrical component of the device.

32. The IMD of claim 30, wherein the pressure sensor comprises a non-circular shape.

33. The IMD of claim 30, wherein the pressure sensor comprises at least one of one or more notches and one or more protrusions configured to self-align the pressure sensor to the channel opening.

34. An implantable medical device (IMD) comprising:

a fluid enclosure wall partially defining a fluid enclosure configured to accomodate a fluid within the IMD; and

a pressure sensor comprising an operative surface configured to partially define the fluid enclosure and occlude a channel opening defined by the fluid enclosure wall, wherein;

the pressure sensor is sized and shaped to self-align to the channel opening defined by the fluid enclosure wall, and

the pressure sensor is configured to self-align to the channel opening such that an electrical connection is made between the pressure sensor and at least one electrical component of the IMD by positioning at least one electrical contact of the pressure sensor in proximity to at least one electrical contact of the at least one electrical component of the IMD.