Attachment apparatus and method for an implantable medical device

• US 5,851,221 A
• Filed: 08/01/1997
• Issued: 12/22/1998
• Est. Priority Date: 12/05/1996
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Schulhauser, Randal C., Gonzalez, Frank, Zart, Bryan, Rieder, Eric M.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US08/905,093
• Time in Patent Office: 508 Days
• Field of Search: 607/1, 607/2, 607/9, 607/38
• US Class Current: 607/93
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers

Abstract

An implantable medical device of the type formed of a hermetically sealed enclosure attached on a enclosure attachment surface thereof to a module attachment surface of a pre-formed header module is disclosed. The pre-formed header module is attached to the enclosure attachment surface through use of a retention structure extending away from the enclosure surface into proximity with a portion of the pre-formed header module when the enclosure and module attachment surfaces are aligned with respect to one another. The retention structure comprises a bendable member that is bent from an initial position allowing the pre-formed header module to be seated with respect to the hermetically sealed enclosure to a retention position making an attachment against a bend engaging portion of the pre-formed header module. The bendable member is the free end portion of an attachment tab having a tab base attached at a predetermined location of the hermetically sealed enclosure such that the upstanding attachment tab extends in a predetermined direction away from the enclosure surface and the free end of the attachment tab is bendable laterally with respect to the predetermined direction against the bend engaging portion. Adhesive is then applied to the retention mechanism and the space between the enclosure attachment surface and the module attachment surface.

Claims

1. A method of making an implantable medical device, comprising the steps of:

providing an hermetically sealed enclosure having an enclosure attachment surface disposed thereon;

providing a pre-formed module having a module attachment surface disposed thereon;

forming a retention structure extending away from the enclosure attachment surface into proximity with a portion of the pre-formed header module when the enclosure attachment surface and the module attachment surface of the pre-formed header module are aligned with respect to one another, the retention structure comprising a bendable member that may be bent from an initial position to allow the pre-formed header module to be seated with respect to the hermetically sealed enclosure in a retention position;

forming a bend engaging portion of the pre-formed header module;

aligning and firmly seating the module attachment surface against the enclosure attachment surface such that bendable member of the retention structure extending away from the enclosure surface is brought into proximity with the bend engaging portion of the pre-formed header module; and

applying a bending force to the bendable member to bend it into engagement with the bend engaging portion of the pre-formed header module to attach the pre-formed header module attachment surface to the enclosure attachment surface.

2. The method of claim 1, wherein the retention structure forming step further comprises:

forming an upstanding attachment tab extending from a tab base to a tab free end which constitutes the bendable member; and

attaching the tab base at a predetermined location of the hermetically sealed enclosure such that the upstanding attachment tab extends in a predetermined direction away from the enclosure surface and at least a portion of the tab free end is bendable laterally with respect to the predetermined direction.

3. The method of claim 2, wherein the step of forming the bend engaging portion further comprises:

providing a tab channel in the pre-formed header module oriented to receive the upstanding attachment tab when the enclosure attachment surface and the module attachment surface are aligned in respect of one another;

providing an access window extending across the tab channel from a surface of the housing to provide access to the upstanding attachment tab received in the tab channel of the pre-formed header module to define an intersecting edge of the bend engaging portion, wherein the step of applying bending force further comprises applying a bending force to the region of the upstanding attachment tab in the tab channel to bend at least a portion of the tab free end over the intersecting edge of the access window.

4. The method of claim 3, further comprising the steps of:

applying adhesive through the access window to flow into the tab channel; and

filling the access window with a sealing material.

5. The method of claim 3, wherein the intersecting access window comprises a cross-bore that extends laterally with respect to the tab channel and the bending force applying step further comprises:

applying a bending force through the access window against the portion of the upstanding attachment tab free end within the window to bend it over the laterally extending intersecting window.

6. The method of claim 5, further comprising the steps of:

applying adhesive through the cross-bore to flow into the tab channel; and

filling the access window with a sealing material.

7. The method of claim 3, wherein:

the attachment tab forming step further comprises forming a pair of upstanding attachment tabs extending from each end of the tab base, each attachment tab terminating at its tab free end with a bendable member;

the tab base attaching step further comprises attaching the tab base at a predetermined location of the enclosure attachment surface such that the upstanding attachment tabs extend in predetermined directions away from the enclosure surface;

the tab channel providing step further comprises providing a pair of spaced apart tab channels in the pre-formed header module oriented to receive the upstanding attachment tabs when the enclosure attachment surface and the module attachment surface are aligned in contact with one another;

the access window providing step further comprises providing an access window extending across each of the tab channels to provide access to the upstanding attachment tab received in each tab channel of the pre-formed header module and defining an intersecting edge window in each case;

the aligning and firmly seating step further comprises aligning the module attachment surface with the enclosure attachment surface such that the upstanding attachment tabs are received in the respective tab channels of the pre-formed header module;

the bending force applying step further comprises applying a bending force to each bendable member of each attachment tab in the access window to bend it over the intersecting edge of the access window.

8. The method of claim 7, further comprising the steps of:

applying adhesive through each access window to flow into each tab channel; and

filling each access window with a sealing material.

9. The method of claim 1, wherein:

the step of forming a retention structure further comprises attaching a plurality of attachment tabs at a respective plurality of predetermined locations of the hermetically sealed enclosure, each attachment tab extending in a predetermined direction away from the enclosure surface to a tab free end which constitutes the bendable member that is bendable laterally at an angle with respect to the predetermined direction;

the step of forming a bend engaging portion of the pre-formed header module further comprises forming a like plurality of bend engaging portions in the pre-formed header module;

the plurality of bendable members of the plurality of attachment tabs extending away from the enclosure surface being brought into proximity with the respective bend engaging portions of the pre-formed header module in the step of aligning and firmly seating the module attachment surface against the enclosure attachment surface; and

the step of applying a bending force comprises applying the bending force to each bendable member to bend it into engagement with a respective proximate bend engaging portion of the pre-formed header module to attach the pre-formed header module attachment surface to the enclosure attachment surface.

10. The method of claim 9, wherein:

the step of forming a like plurality of bend engaging portions of the pre-formed header module further comprises;

forming a like plurality of spaced apart tab channels in the pre-formed header module oriented to receive the upstanding attachment tabs and the bendable members thereof when the enclosure attachment surface and the module attachment surface are aligned in respect of one another; and

forming one of the like plurality of bend engaging portions of the pre-formed header module in each of the tab channels; and

the step of applying a bending force comprises applying the bending force to each bendable member within each tab channel to bend it into engagement with a respective proximate bend engaging portion to attach the pre-formed header module attachment surface to the enclosure attachment surface.

11. The method of claim 10, further comprising the step of:

providing an access window extending across each of the tab channels to provide access to the upstanding attachment tab received in each tab channel of the pre-formed header module and defining an intersecting edge window for each bend engaging portion; and

the bending force applying step further comprises;

applying a bending force to each bendable member of each attachment tab in the access window to bend it over the intersecting edge of the access window, a pair of spaced apart and parallel tab channels in the pre-formed header module being oriented to receive the upstanding attachment tabs when the enclosure attachment surface and the module attachment surface are aligned in respect of one another.

12. The method of claim 11, further comprising the steps of:

applying adhesive through each access window to flow into each tab channel; and

filling each access window with a sealing material.

13. An implantable medical device having an hermetically sealed enclosure attached to a pre-formed header module, the device comprising:

a retention structure extending away from the enclosure attachment surface into proximity with a portion of the pre-formed header module when the enclosure attachment surface and a module attachment surface of the pre-formed header module are aligned with respect to one another, the retention structure comprising a bendable member that may be bent from an initial position allowing the pre-formed header module to be seated with respect to the hermetically sealed enclosure to a retention position;

a bend engaging portion of the pre-formed header module over which the bendable member may be bent upon alignment and firmly seating of the module attachment surface against the enclosure attachment surface whereby the bendable member of the retention structure extending away from the enclosure surface is brought into proximity with the bend engaging portion of the pre-formed header module; and

a bend formed in the bendable member bending it into engagement with the bend engaging portion of the pre-formed header module to attach the pre-formed header module attachment surface to the enclosure attachment surface.

14. The mechanism of claim 13, wherein the retention structure further comprises:

at least one upstanding attachment tab attached at a tab base to said hermetically sealed enclosure and extending to a tab free end forming the bendable member such that the upstanding attachment tab extends in a predetermined direction away from the enclosure surface and at least a portion of the tab free end is bendable laterally with respect to the predetermined direction.

15. The mechanism of claim 14, wherein the bend engaging portion further comprises:

at least one tab channel in the pre-formed header module, the tab channel being oriented to receive the upstanding attachment tab when the enclosure attachment surface and the module attachment surface are aligned in respect of one another;

an access window extending across the tab channel from a surface of the housing to provide access to the upstanding attachment tab received in the tab channel of the pre-formed header module and defining an intersecting edge of the bend engaging portion;

wherein the bend in the bendable member is formed by applying a bending force to the tab free end in the tab channel to bend at least a portion thereof over the intersecting edge of the access window.

16. The mechanism of claim 15, further comprising:

a layer of adhesive applied through the access window into the tab channel; and

a sealing material applied into and filling the access window.

17. The mechanism of claim 15, wherein the intersecting window extends laterally with respect to the tab channel such that the bending force applied through the access window against the portion of the upstanding attachment tab within the window causes the bend to extend over the laterally extending intersecting window.

18. The mechanism of claim 17, further comprising:

a layer of adhesive applied through the access window into the tab channel; and

a sealing material applied into and filling the access window.

19. The mechanism of claim 13, wherein the retention structure further comprises:

a pair of upstanding attachment tabs each having a tab free end extending from a common tab base attached to said hermetically sealed enclosure, the tab free ends constituting a respective pair of spaced apart bendable members such that the upstanding attachment tabs extend in predetermined directions away from the enclosure surface and at least a portion of the tab free ends are bendable at an angle with respect to the predetermined direction.

20. The mechanism of claim 19, wherein the bend engaging portions each further comprise:

a tab channel in the pre-formed header module, the tab channel being oriented to receive an upstanding attachment tab when the enclosure attachment surface and the module attachment surface are aligned in respect of one another;

an access window extending across the tab channel from a surface of the housing to provide access to the upstanding attachment tab received in the tab channel of the pre-formed header module and defining an intersecting edge of the bend engaging portion;

wherein the bend in the bendable member is formed by applying a bending force to the free end of the upstanding attachment tab in the tab channel to bend it over the intersecting edge of the access window.

21. The mechanism of claim 20, further comprising:

a layer of adhesive applied through the access window into the tab channel; and

a sealing material applied into and filling the access window.

22. The mechanism of claim 20, wherein each intersecting window extends laterally with respect to the respective tab channel such that the bending force applied through the access window against the portion of the upstanding attachment tab free end within the access window causes the bend to extend at least over a portion of the intersecting edge of the access window.

23. The mechanism of claim 22, further comprising:

a layer of adhesive applied through the access window into the tab channel; and

a sealing material applied into and filling the access window.

24. The mechanism of claim 13, wherein the retention structure further comprises:

a plurality of upstanding attachment tabs each attached at a tab base to said hermetically sealed enclosure and extending in predetermined directions away from the enclosure surface, the tab free ends of the attachment tabs forming a plurality of spaced apart bendable members that are bendable laterally with respect to the predetermined directions.

25. The mechanism of claim 24, wherein the bend engaging portions each further comprise:

a tab channel in the pre-formed header module, the tab channel being oriented to receive an upstanding attachment tab when the enclosure attachment surface and the module attachment surface are aligned in respect of one another;

an access window extending across the tab channel from a surface of the housing to provide access to the upstanding attachment tab received in the tab channel of the pre-formed header module and defining an intersecting edge of the bend engaging portion;

wherein the bend in the bendable member is formed by applying a bending force to the tab free end in the tab channel to bend at least a portion thereof over the intersecting edge of the access window.

26. The mechanism of claim 25, further comprising:

a layer of adhesive applied through the access window into the tab channel; and

a sealing material applied into and filling the access window.

27. The mechanism of claim 25, wherein the intersecting window extends laterally in respect of the tab channel such that the bending force applied through the access window against the portion of the upstanding attachment tab free end within the access window causes the bend to extend over at least a portion of the laterally extending intersecting window.

28. An implantable medical device comprising an hermetically sealed enclosure having an enclosure attachment surface disposed thereon, a pre-formed header module formed of an insulating material and having a module attachment surface disposed thereon, the device comprising:

attachment tab means for extending an upstanding attachment tab in a predetermined direction away from the enclosure attachment surface;

means for defining a tab channel in the pre-formed header module extending away from the module attachment surface and oriented to receive an upstanding attachment tab therein when the enclosure attachment surface and the module attachment surface are seated and aligned with respect to one another;

means for defining an access window extending laterally across the tab channel from a further surface of the pre-formed header module that defines an intersecting edge of the tab channel and exposes a free end portion of the attachment tab within the window extending across the tab channel when the enclosure attachment surface and the module attachment surface are seated and aligned with respect to one another;

wherein the free end portion of the attachment tab is formed with a laterally extending bend thereof over the intersecting edge and into the laterally extending access window so that the attachment tab resists being withdrawn from the tab channel when a separation force is applied to separate the pre-formed header module from the hermetically sealed enclosure.