Multi-polar feedthrough array for analog communication with implantable medical device circuitry

• US 20060009813A1
• Filed: 07/12/2004
• Published: 01/12/2006
• Est. Priority Date: 07/12/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Knowles, Shawn D., Taylor, William J., Olson, John C.
• Granted Patent: US 7,210,966 B2
• Time in Patent Office: Days
• US Class Current: 607/36
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: H01G 4/35 Feed-through capacitors or anti-noise capacitors
• CPC Class Codes: H01R 13/7197 with filters integral with or fitted onto contacts, e.g. tubular filters
• CPC Class Codes: H01R 2201/12 for medicine and surgery

Abstract

According to one aspect of the invention, an improved multi-polar feedthrough array employs a particular metallic ferrule material for improved dimensional stability during initial fabrication and sustained hermetic operation. According to the invention, the IMD enclosure consists of grade 2 titanium and the ferrule material comprises grade 4 titanium or grade 5 titanium. In one form of the invention, the multi-polar feedthrough assembly comprises a filtered feedthrough array (e.g., employing capacitive filters coupled to the electrically conductive pins or serpentine conductors of the array). According to another aspect of the invention, the improved multi-polar feedthrough array incorporates additional pins, thus further increasing the footprint of the array, and the additional pins provide analog electrical communication between operative circuitry inside an IMD and analog components external to the IMD.

Claims

1. A multi-polar array for an implantable medical device, comprising

A titanium ferrule surrounding the outer periphery of the array and adapted to mechanically couple to a corresponding inner periphery of a titanium surface of an implantable medical device, said ferrule having a plurality of conductive pin-receiving bores formed through a major surface thereof, and wherein said ferrule consists of one of grade 4 titanium and grade 5 titanium;

A plurality of electrically insulative members sealingly disposed within each said plurality of bores and wherein each of said members is adapted to receive; and

a plurality of conductive feedthrough pins, each said pin disposed within one of said plurality of electrically insulative members.

2. A multi-polar array according to claim 1, wherein the plurality of pin-receiving bores comprises at least four bores.

3. A multi-polar array according to claim 1, wherein the plurality of pin-receiving bores comprises at least six bores.

4. A multi-polar array according to claim 1, wherein the plurality of pin-receiving bores comprises at least eight bores.

5. A multi-polar array according to claim 4, wherein the plurality of pin-receiving bores are arranged in one of a linear array or a staggered set of bores.

6. A multi-polar array according to claim 1, wherein the titanium surface of the implantable medical device consists of grade 2 titanium.

7. A multi-polar array according to claim 1, wherein the plurality of electrically insulative members comprises at least one of:

a polysilicon material, a glass material, an amorphous material, a ceramic material.

8. A multi-polar array according to claim 1, wherein at least one of the plurality of conductive feedthrough pins comprises one of:

a titanium material, a tantalum material, a niobium material, a platinum material, or an alloy of any of the foregoing materials.

9. A multi-polar array according to claim 1, further comprising a plurality of capacitive elements adapted to reduce or eliminate electromagnetic interference from a like plurality of the conductive feedthrough pins, effectively disposed proximate each of said like plurality of the conductive feedthrough pins.

10. A multi-polar array according to claim 9, wherein the plurality of conductive feedthrough pins exceeds the plurality of capacitive elements by at least one, so that an analog and/or digital signal coupled to a non-capacitively filtered feedthrough pin substantially completely conducts via said pin.

11. A multi-polar array according to claim 10, further comprising a spacer element disposed proximate the non-capacitively filtered feedthrough pin.

12. A multi-polar array according to claim 11, wherein said spacer element includes a feature abutting a portion of the non-capacitively filtered feedthrough pin, said feature comprising one of:

a bore, a slot, an edge surface, a wedge-shaped cut-out.

13. A multi-polar array according to claim 11, wherein said spacer element comprises at least one of:

a resin-based material, a polymer-based material, an alumina material, a polysilicon material, a glass material, an amorphous material, a ceramic material.

14. A multi-polar array according to claim 10, wherein the non-capacitively filtered feedthrough pin is electrically coupled to operative circuitry of the implantable medical device communication.

15. A method of manufacturing a feedthrough assembly adapted to be fitted into an opening of a grade 2 titanium substrate, the method comprising:

providing an electrically conductive multi-polar ferrule having a peripheral ferrule wall adapted to be fitted into a corresponding opening grade 2 titanium substrate opening, said multi-polar ferrule consisting of one of;

grade 4 titanium and grade 5 titanium; and

hermetically sealing a corresponding substrate edge to the peripheral ferrule wall.

16. A method according to claim 15, further comprising:

placing a capacitive filter array around at least one of a plurality of conductive elements disposed within said ferrule.

17. A method according to claim 16, further comprising:

coupling analog/digital circuitry to at least one of said plurality of conductive elements disposed within said ferrule, wherein said at least one comprises an non-capacitively filtered conductive element.

18. A method according to claim 15, further comprising prior to hermetically sealing the substrate edge, placing a relatively high temperature brazing alloy on an upper portion of an electrically insulative member and outer surface of the insulator to the ferrule sealingly surrounding an intermediate portion of the conductive elements abutting a like plurality of discrete ferrule bores and feedthrough pins;

and

applying heat to melt the brazing alloy.