Protective feedthrough

• US 5,759,197 A
• Filed: 10/30/1995
• Issued: 06/02/1998
• Est. Priority Date: 10/04/1994
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Sawchuk, Robert T., Ruben, David, Galvin, Jeff, Simmons, Bill, Seifried, Lynn M.
• Primary Examiner(s): Lacyk, John P.
• Assistant Examiner(s): HUANG, STEPHEN D
• Application Number:
  US08/550,273
• Time in Patent Office: 946 Days
• Field of Search: 607/36-38, 174/50.61, 361/302, 333/158, 333/182-185
• US Class Current: 607/36
• CPC Class Codes: A61N 1/3754 Feedthroughs

Abstract

A feedthrough configuration for a hermetically sealed implantable medical device includes a metal case having an aperture and a feedthrough in the aperture which includes a ferrule sealed in the aperture, a pin extending through the ferrule and the aperture, an insulating material supporting the pin within the ferrule and an electrically conductive block spaced from the ferrule and in electrical connection with the pin. A device for electrical or electromagnetic protection can be connected to a peripheral upstanding portion of the ferrule and a peripheral skirt portion of the block. This arrangement of feedthrough elements can be particularly useful if the protective device is a chip capacitor which typically has a flat-sided configuration that can bridge the space between the ferrule and the block and be connected at one end to the block and at the other end to the ferrule.

Claims

1. A hermetically sealed implantable medical device, comprising:

(a) a metal case having an interior surface and an exterior surface and an aperture extending between the interior and exterior surfaces; and

(b) a feedthrough disposed in the case aperture, comprising;

(1) an electrically conductive ferrule disposed in the case aperture and in sealing engagement therewith, the ferrule having a first outer peripheral surface upstanding from one of the case surfaces;

(2) an electrically conductive pin extending through the ferrule and the aperture such that the pin has a first end projecting from the exterior surface of the case and a second end projecting from the interior surface of the case;

(3) an insulating material supporting the pin within the ferrule and in sealing engagement with the ferrule and with the pin;

(4) a preformed electrically conductive block spaced from the ferrule and in electrical connection with the pin, the block having a second outer peripheral surface substantially in alignment with the first outer peripheral surface of the ferrule, wherein the conductive block is spaced from the ferrule by the insulating material; and

(5) a device for electrical or electromagnetic protection electrically connected at and mounted to a first point on the first outer peripheral surface of the ferrule and electrically connected at and mounted to a second point on the second outer peripheral surface of the block.

2. A medical device according to claim 1 wherein the electrically conductive block has a flat top surface.

3. A medical device according to claim 2 also comprising an electrical circuit spaced apart from the conductive block and a conductor extending from the electrical circuit and electrically connected to the top of the conductive block.

4. A medical device according to claim 1 wherein the device for electrical or electromagnetic protection comprises a capacitor.

5. A hermetically sealed implantable medical device, comprising:

(a) a metal case having an interior surface and an exterior surface and an aperture extending between the interior and exterior surfaces; and

(b) a feedthrough in the case aperture comprising;

(1) an electrically conductive ferrule at the case aperture in sealing engagement with the case, the ferrule having a having a first outer peripheral surface upstanding from one of the case surfaces;

(2) an electrically conductive pin extending through the ferrule and the aperture such that the pin has a first end projecting from the exterior surface of the case and a second end projecting from the interior surface of the case;

(3) an insulating material supporting the pin within the ferrule and in sealing engagement with the ferrule and with the pin;

(4) a preformed electrically conductive block spaced from the ferrule and in electrical connection with the pin, the block having a second outer peripheral surface substantially in alignment with the first outer peripheral surface of the ferrule,

(5) a first device for electrical or electromagnetic protection electrically connected at and mounted to a first point on the first outer peripheral surface of the ferrule and electrically connected at and mounted to a second point on the second outer peripheral surface of the block, and;

(6) a second device for electrical or electromagnetic protection electrically connected at and mounted to a third point on the first outer peripheral surface of the ferrule and electrically connected at and mounted to a fourth point on the second outer peripheral surface of the block, the third and fourth points being disposed on opposite sides of the ferrule and block, respectively, from those of the first and second points.

6. A medical device according to claim 5, wherein the feedthrough is one of an array of similar feedthroughs, the array defining a linear axis, the first and second electrical and electromagnetic protection devices being disposed at locations offset from the linear axis.

7. A hermetically sealed implantable medical device, comprising:

(a) a metal case having an interior surface and an exterior surface and an aperture extending between the interior and exterior surfaces;

(b) a feedthrough in the case aperture comprising;

(1) an electrically conductive ferrule at the case aperture in sealing engagement with the case;

(2) an electrically conductive pin extending through the ferrule and the aperture such that the pin has a first end projecting from the exterior surface of the case and a second end projecting from the interior surface of the case;

(3) an insulating material supporting the pin within the ferrule and in sealing engagement with the ferrule and with the pin;

(4) a preformed electrically conductive block spaced from the ferrule by the insulating material, the block being in electrical connection with the pin; and

(5) a device for electrical or electromagnetic protection having a first end and a second end and a flat portion therebetween which bridges across the spaced block and ferrule, the electrical or electromagnetic protection device being electrically connected at the first end to the ferrule and electrically connected at the second end to the block.

8. A medical device according to claim 7 wherein the conductive block is spaced from the ferrule by the insulating material.

9. A medical device according to claim 7 wherein the electrically conductive block has a flat top surface.

10. A medical device according to claim 9 also comprising an electrical circuit spaced apart from the conductive block and a conductor extending from the electrical circuit and electrically connected to the top of the conductive block.

11. A medical device according to claim 7, wherein the feedthrough is one of an array of similar feedthroughs, the array defining a linear axis, the electrical and electromagnetic protection devices being disposed at locations offset from the linear axis.

12. A medical device according to claim 7, wherein the device for electrical or electromagnetic protection comprises a chip capacitor.