Feedthrough connector for implantable medical device

• US 4,934,366 A
• Filed: 09/19/1989
• Issued: 06/19/1990
• Est. Priority Date: 09/01/1988
• Status: Expired due to Term

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories), Siemens-Elema AB (Siemens AG)
• Original Assignee: Siemens Pacesetter, Inc. (Abbott Laboratories)
• Inventors: Truex, Buehl E., Stutz, William H. Jr.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): GETZOW, SCOTT M
• Application Number:
  US07/409,202
• Time in Patent Office: 273 Days
• Field of Search: 128/419 P, 128/784, 128/785, 128/786, 439/353, 439/668, 439/669, 439/840
• US Class Current: 607/37
• CPC Class Codes: A61N 1/3752 Details of casing-lead connections
• CPC Class Codes: H01R 13/41 by frictional grip in grommet, panel or base

Abstract

A feedthrough connector for an implantable medical device, combines the connector function with the feedthrough function and eliminates the need for the cast epoxy connector previously used on such devices. The feedthrough connector includes a barrel assembly having open and closed ends. The open end of the assembly has an opening for receiving a slidably inserted electrical lead. The barrel assembly includes cylindrical metal conductive portions separated by cylindrical ceramic insulating portions. Spring contacts are mounted on the inside of the metal portions and are adapted to make electrical contact with the appropriate contacts of an electrical lead when the lead is inserted into the connector. The outer side of the metal portions are electrically connected to the appropriate electrical circuit within the housing, and the open end of the barrel assembly is bonded (welded) to the device housing so that the inside of the device can be hermetically sealed. Releasable lead gripping means are included as part of the barrel assembly to detachably lock and seal the electrical lead in its inserted position inside of the connector.

Claims

1. An implantable medical device comprising:

a hermetically sealed housing;

an electrical circuit within said housing;

An electrical connector within said housing comprising;

a tubular barrel assembly having an open end and a closed end, and a barrel axis passing through the open end and closed end, said open end being, attached to an exposed surface of said housing, said closed end being internal to said housing, the tubular barrel assembly creating a tubular channel that protrudes into the sealed housing, but does not break the seal of said housing, the inside of said tubular channel being open to the outside of said sealed housing through said open end, the tubular channel further comprising a plurality of conductive cylindrical portions coaxial with the barrel axis, the dimension of the diameter of successive cylindrical portions progressively decreasing from the open end to the closed end,

means for making electrical contact between selected cylindrical portions of said tubular channel and said electrical circuit, and

locking means for detachably locking and gripping an electrical lead axially inserted into the open end of said tubular channel in electrical contact with selected cylindrical portions of said tubular channel, said locking means being actuable with less than 360 degrees of relative rotation between said lead and said tubular barrel assembly.

2. The implantable medical device of claim 1 wherein said hermetically sealed housing shall not exhibit a leak rate of greater than 2×

10E-8 atmcc/sec.

3. The implantable medical device of claim 1 wherein said hermetically sealed housing comprises a pacemaker, and said electrical lead comprises a pacemaker lead adapted to connect the pacemaker to a desired tissue location.

4. The implantable medical device of claim 1 wherein said locking means is actuable with substantially no relative rotation between said electrical lead and said tubular barrel assembly.

5. The implantable medical device of claim 1 wherein successive ones of the plurality of conductive cylindrical portions are separated by an insulating nonconductive cylindrical portion.

6. The implantable medical device of claim 5 wherein successive conductive cylindrical portions of said barrel assembly are spaced apart and overlap at their respective adjacent ends, thereby defining a region of overlap therebetween, the insulating nonconductive cylindrical portions being disposed throughout the region of overlap between successive conductive cylindrical portions, said ends of said conductive cylindrical portions being thereby held in a spaced-apart nontouching and electrically isolated relationship by said insulating nonconductive cylindrical portions.

7. The implantable medical device of claim 5 wherein said means for making electrical contact comprises:

a canted coil spring positioned on the inside of said selected cylindrical portions so as to make electrical contact therewith in a multiplicity of locations; and

wire means for making electrical contact with the outside of said selected cylindrical portions and said electrical circuit.

8. The implantable medical device of claim 1, wherein said locking means comprises:

engaging means on the inside of said tubular channel;

a cam and cam follower each having a hollow essentially tubular coaxial portion having a diameter that allows said electrical lead to pass therethrough, said cam rotatable between first and second positions, the cam having detent means being received by the engaging means for preventing axial translation of the cam, the cam follower engaging the cam such that as the cam is rotated from the first to the second position, the cam follower moves away from the cam in an axial direction; and

gripping means for engaging the cam follower and for gripping said electrical conductor whenever the cam is rotated from the first to the second position and for releasing said electrical lead whenever the cam is rotated from the second to the first position.

9. The implantable medical device of claim 8, wherein the engaging means comprises an annular groove and the detent means comprises at least one lobe protruding from an outer surface of the cam, said at least one lobe adapted to be received within the annular groove to confine the cam to rotational motion when the at least one lobe is received within the groove.

10. The implantable medical device of claim 9, comprising:

pin means extending radially from an inside surface of said tubular channel; and

groove means extending in an axial direction on an outer surface of the cam follower for engaging the pin means for confining the cam follower to translational motion in an axial direction.

11. The implantable medical device of claim 9, wherein the cam and cam follower each have corresponding matching and engaging curvilinear portions and flat land portions, such that during rotation of the cam from the first to the second position, the cam follower engages the cam initially along the respective curvilinear portions and then along the respective flat land portions, whereby when the cam and cam follower are engaged along their respective flat land portions the cam and cam follower remain in a relatively locked position.

12. The implantable medical device of claim 11, wherein the at least one lobe comprises a pair of opposite and outwardly facing lobes.

13. The implantable medical device of claim 1, wherein the locking means further comprises:

cam follower means movable axially inward toward the closed end of the tubular barrel assembly in response to rotation of the cam follower means from a first to a second position; and

gripping means for engaging the cam follower means and for gripping said electrical connector, whenever the cam follower means is rotated from the first to the second position.

14. The implantable medical device of claim 13, wherein when the cam follower means is in the second position, the cam follower means is in a locked condition.

15. The implantable medical device of claim 1 wherein said locking means comprises engaging means on the inside of said tubular channel that mate with matching engaging means on said electrical lead whenever a proximal end of said electrical lead is inserted into the open end of said tubular channel.

16. The implantable medical device of claim 15 wherein said engaging means of said tubular channel and said electrical lead become lockably engaged so as to prevent removal of said electrical lead from said tubular channel whenever said electrical lead is rotated relative to said tubular channel a fraction of a turn.

17. An implantable medical device comprising:

a hermetically sealed housing;

an electrical circuit within said housing;

a connector within said housing comprising;

an electrical tubular barrel assembly having an open end and a closed end, said open end being attached to an exposed surface of said housing, said closed end being internal to said housing, the tubular barrel assembly creating a tubular channel that protrudes into the sealed housing, but does not break the seal of said housing, the inside of said tubular channel being open to the outside of said sealed housing through said open end,

means for making electrical contact between a selected first portion of the inside of said tubular channel and said electrical circuit, and

locking means for detachably locking and gripping an electrical lead inserted into the open end of said tubular channel comprising;

engaging means on the inside of said tubular channel;

a cam and cam follower each having a hollow essentially tubular coaxial portion having a diameter that allows said electrical lead to pass therethrough, said cam rotatable between first and second positions, the cam having detent means being received by the engaging means for preventing axial translation of the cam, the cam follower engaging the cam such that as the cam is rotated from the first to the second position, the cam follower moves away from the cam in an axial direction; and

gripping means for engaging the cam follower and for gripping said electrical connector whenever the cam is rotated from the first to the second position and for releasing said electrical lead whenever the cam is rotated from the second to the first position.

21. The implantable medical device of claim 17 wherein the diameter of the first groove is larger than the diameter of the second groove, and wherein the locking ring comprises a radially compressible collet, said collet having a first inside diameter that allows said electrical lead to slidably pass therethrough when the shoulder of the collet is received within said first groove, and wherein said collet has a second inside diameter that lockably grips said electrical lead when the shoulder of the collet is received within the second groove.

18. An implantable medical device comprising:

a hermetically sealed housing;

an electrical circuit within said housing;

a connector within said housing comprising;

a tubular barrel assembly having an open end and a closed end, said open end being attached to an exposed surface of said housing, said closed end being internal to said housing, the tubular barrel assembly creating a tubular channel that protrudes into the sealed housing, but does not break the seal of said housing, the inside of said tubular channel being open to the outside of said sealed housing through said open end,

means for making electrical contact between a selected first portion of the inside of said tubular channel and said electrical circuit, and

locking means for detachably locking and gripping an electrical lead inserted into the open end of said tubular channel comprising;

first and second spaced-apart engaging means on the inside of said tubular channel;

a locking ring having a plurality of detent bumps, said locking ring having an inside diameter that allows said electrical lead to fit therethrough, and an outside diameter that allows said ring to be slidably inserted into the open end of said tubular channel, at least one detent bump of the locking ring being received by either said first or second engaging means depending upon the depth to which the locking ring is inserted into the tubular channel;

gripping means for gripping said electrical lead whenever said at least one detent bump is received by said first engaging means, and for releasing said electrical lead whenever said at least one detent bump is received by said second engaging means.

19. The implantable medical device of claim 18 wherein said first and second engaging means comprise first and second circumferential grooves on the inside of said tubular channel near the open end thereof;

and wherein said at least one detent bump of said locking ring snaps into either said first or second groove depending upon the depth to which the locking ring is pushed into the tubular channel.

20. The implantable medical device of claim 19 wherein the tubular channel of the barrel assembly further includes stop means positioned near said first second circumferential grooves, and wherein said gripping means is held captive between said stop means and said locking ring, said gripping means comprising an annular section of resilient material, having an inside diameter that allows said electrical lead to pass therethrough when said resilient material is not subjected to axial compression, and further wherein said resilient material is placed under axial compression when said at least one detent bump is received within said second groove, said axial compression causing the resilient material to bulge inwardly into the tubular channel, thereby reducing the inside diameter of said annular resilient section, sufficiently to firmly grip the electrical lead thereby preventing axial movement thereof.

22. An internal connector for use with a sealed implantable medical device comprising:

lead receiving means for slidably receiving a connecting end of an electrical lead, said lead receiving means defining an open channel within said medical device, the open channel having an open end for receiving the electrical lead, and a closed end that is not open to an inner sealed portion of said medical device, the connecting end of said electrical lead being slidably received within said open channel without breaking the seal of said medical device, the open channel comprising a plurality of spacedapart successively and axially disposed electrically conductive channel segments for making electrical contact with respective portions of an electrical lead inserted within the internal connector, the channel segments being cylindrical, the diameter of successive channel segments progressively decreasing from the open end to the closed end; and

electrical feedthrough means for making electrical contact between the sealed inner portion of said medical device and the non-sealed open channel of said lead receiving means.

23. The connector of claim 22 wherein said feedthrough means comprises means for making electrical contact with at least one of said electrically conductive channel segments.

24. The connector of claim 23 wherein said means for making electrical contact includes multiple contact spring means positioned around the inside circumference of at least one of said electrically conductive channel segments for making electrical contact with a multiplicity of locations within said at least one electrically conductive channel segment, and electrical conductor means for making electrical contact with at least one location on the outside of said at least one electrically conductive channel segment.

25. The connector of claim 23 wherein said lead receiving means further includes at least one cylindrical channel segment separating said electrically conductive channel segments thereby electrically isolating them one from the other.

26. The connector of claim 25 wherein said cylindrical channel segment comprises a ceramic segment that is hermetically bonded to the adjoining electrically conductive channel segments.

27. An internal connector for use with a hermetically sealed implantable device comprising:

lead receiving means for slidably receiving a connecting end of an electrical lead, said lead receiving means defining an open channel within said device that is not open to an inner sealed portion of the device;

electrical feedthrough means for making electrical contact between the sealed inner portion of said device and a portion of the nonsealed open channel of said lead receiving means; and

releasable lead gripping means for detachably locking the electrical lead in an inserted position inside of said lead receiving means for sealing the open channel to prevent fluids from entering therein comprising;

lead locking means slidably received within said internal connector;

means for engaging said lead locking means in first and second positions; and

collar means within said lead receiving means and coupled to said lead locking means for providing a first diameter collar when said lead locking means is engaged in the first position, and for providing a second diameter collar when said lead locking means is engaged in the second position, said first diameter collar having a first inside diameter that allows said electrical lead to slidably pass therethrough, and said second diameter collar having an inside diameter that is smaller than the diameter of said electrical lead, the second diameter collar thereby pinching said electrical lead and preventing further axial movement thereof.

28. The internal connector of claim 27 wherein said collar means comprises an annular section within said lead receiving means that assumes said first diameter when said annular section is not placed under axial compression, and that assumes said second diameter when said annular section is placed under axial compression.

29. The internal connector of claim 28 wherein said annular section is held captive between said lead locking means and a stop element within said lead receiving means when said lead locking means is in said first position, and wherein said annular section is axially compressed between the stop element and the lead locking means when said lead locking means is in said second position.

30. A method of making electrical contact between the connecting end of an implantable electrical lead and the electrical circuits within a sealed housing of an implantable medical device without sacrificing the integrity of the seal of the implantable medical device, said method comprising the steps of:

(a) forming an indented channel in said housing, said channel having an open end at the surface of said housing for slidably receiving the connecting end of said electrical lead, said channel further having a closed end inside of said housing for preserving the integrity of the seal of said housing, said channel having a plurality of conductive coaxial cylindrical portions, the diameter of successive cylindrical portions decreasing from the open end to the closed end, and said channel also having at least one of the cylindrical portions thereof made from an electrically conductive material that is electrically isolated from the remainder of said housing, said electrically conductive portion having a front side that is accessible through the open indented channel, and a back side that is accessible from within the sealed housing;

(b) sliding the connecting end of said electrical lead into said channel such that at least one electrode on the connecting end of said lead is in electrical contact with said at least one electrically conductive portion of said indented channel;

(c) electrically connecting the back side of the electrically conductive portion of the indented channel to the electrical circuits within the sealed housing; and

(d) sealing the indented channel to prevent entry of body fluids therein.

31. The method of claim 30 wherein step (d) of sealing the indented channel further includes the step of detachably locking the electrical lead within said indented channel.

32. The method of claim 31 wherein the step of detachably locking the electrical lead within said channel comprises gripping the electrical lead with a collar having a shrinking diameter.