Ultrasonically welded, staked or swaged components in an implantable medical device

• US 20030040780A1
• Filed: 07/19/2002
• Published: 02/27/2003
• Est. Priority Date: 08/01/1997
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kelley, James F., Haeg, Daniel C., Wiklund, Craig L.
• Granted Patent: US 7,187,974 B2
• Time in Patent Office: Days
• US Class Current: 607/36
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers

Abstract

The present invention generally relates to an improved implantable medical device (IMD) and more particularly to an ultrasonically weld perforated lid for an IMD to form a hermetic seal between the IMD and the perforated lid. Appropriately configured perforated lids retain one or more components within a cavity or port formed in a part of an IMD. Such lids preferably secure a pierceable resilient grommet, septum or other resilient member in a cavity or port. When an adjustment instrument, a pull tool or a syringe is temporarily inserted therethrough and later extracted, the resilient member heals (i.e., seals and/or reseals). Preferably, the resilient member abuts a mechanical stop and is compressed slightly during assembly and ultrasonic welding of the lid. The resilient member preferably has a lateral dimension like the cavity or port so that when the lid compresses the resilient member it expands slightly and contacts the interior cavity surfaces thus improving the seal.

Claims

6-1. An implantable medical device according to claim 1, wherein the periphery of the perforated lid has a flash-reducing cut out feature.

17. A method of ultrasonically welding a modular lid over a cavity in a connector module of an implantable medical device, comprising the steps of:

inserting a resilient member into a cavity of a header module of an IMD, wherein the cavity has a depth and a geometric shaped opening at the exterior surface of the IMD and wherein the resilient member engages interior structure of said cavity so that a portion of the resilient member is approximately at the same elevation as an adjacent exterior surface of the IMD;

aligning a perforated lid, having a shape corresponding to the geometric shaped opening, over the cavity of the connector module of an IMD;

compressing the resilient member with an articulated ultrasonic horn member so that the exterior surface of the perforated lid is at approximately the same elevation as the exterior surface of the IMD; and

energizing the ultrasonic horn member for a predetermined period of time so that an ultrasonic weld bonds the perforated lid to the connector module thereby ultrasonically welding the periphery of said perforated lid to the periphery of said opening.

18. A method according to claim 17, further comprising an initial step of inserting a setscrew assembly into the cavity.

19. A method according to claim 17, further comprising the step of applying a medical grade adhesive to the periphery of the perforated lid or the periphery of the opening prior to performing the step of compressing the resilient member.

20. A method according to claim 17, wherein the IMD is a one of:

an implantable drug pump, a cardioverter defibrillator, an implantable data logging, an implantable nerve stimulator, an implantable muscle stimulator.

21. A method according to claim 17, wherein said resilient member is a pierceable grommet member.

22. A method according to claim 17, wherein said resilient member is a septum member and the IMD is a drug pump.

23. An implantable medical device having a thermoplastic portion and wherein said thermoplastic portion has an aperture formed therein, said thermoplastic portion comprising:

a port formed in the thermoplastic portion defining a surface opening coupled to an interior cavity portion;

a resilient member firmly disposed—

without use of an adhesive or a mechanical fastener—

within the interior portion and adjacent the surface opening;

a thermoplastic washer member abutting the resilient member, having a shape corresponding to the shape of the opening and wherein the periphery of the thermoplastic washer member is ultrasonically welded to the periphery of the opening.