Attachment apparatus and method for an implantable medical device employing ultrasonic energy

• US 5,897,578 A
• Filed: 08/27/1998
• Issued: 04/27/1999
• Est. Priority Date: 08/01/1997
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kelley, James F., Haeg, Daniel C., Wiklund, Craig L.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US09/140,499
• Time in Patent Office: 243 Days
• Field of Search: 607/36-38
• US Class Current: 607/36
• CPC Class Codes: A61N 1/3752 Details of casing-lead connections
• CPC Class Codes: Y10T 29/49925 Inward deformation of aperture or hollow body wall

Abstract

A method and apparatus for attaching a pre-formed header module, e.g. a connector header module or an electrode bearing header module, etc., to a hermetically sealed enclosure of the implantable medical device, typically including electronic integrated circuits, batteries, electromechanical pumps, or the like, are disclosed. A plurality of upstanding tabs that are fixed to the hermetically sealed enclosure, e.g. to the enclosure attachment surface, extend into a like plurality of tab channels formed in the header module housing. The upstanding tab(s) are inserted into the respective tab channel(s) during seating of the module and enclosure attachment surfaces and effects an initial alignment of the header module with the hermetically sealed enclosure. Each attachment tab has a retention feature formed on or in the tab that is designed to accommodate the flow of the thermoplastic material during the application of ultrasonic energy in the region of the tab channel and to cooperate with the solidified mass of thermoplastic material. During application of the ultrasonic energy, the thermoplastic material melts and flows into the remaining space of the tab channel and encapsulate the attachment tab including the retention feature. Upon termination of the ultrasonic energy, the thermoplastic housing material cools and solidifies and forms a continuous mass that encapsulates the surface of the attachment tab and the retention feature.

Claims

1. An implantable medical device comprising a hermetically sealed enclosure, a header module formed of a thermoplastic material, and a mechanism for attaching the hermetically sealed enclosure to the header module, the mechanism comprising:

at least one upstanding attachment tab having a lower portion connected to a predetermined location disposed on a first upper mating surface of the enclosure, a free upper end of the at least one upstanding attachment tab extending upwardly in a predetermined location away from the first upper mating surface;

at least one tab channel disposed in the header module and extending upwardly in respect of a second lower mating surface of the header module, the at least one channel being sized to receive the at least one upstanding attachment tab therein when at least portions of the first upper mating surface and the second lower mating surfaces engage and are aligned in respect of one another, at least portions of the first and second mating surfaces being configured and shaped to matingly fit against one another;

at least one pleat formed in the at least one upstanding attachment tab, the tab being disposed in the tab channel; and

header module solidified thermoplastic material surrounding the at least one pleat and connecting the at least one pleat to the header module, wherein the solidified thermoplastic material originates from melted portions of the header module corresponding to the at least one pleat.

2. An implantable medical device comprising a hermetically sealed enclosure, a header module formed of a thermoplastic material, and a mechanism for attaching the hermetically sealed enclosure to the header module, the mechanism comprising:

a plurality of upstanding attachment tabs, each tab having a lower portion connected to a predetermined location disposed on a first upper mating surface of the enclosure, a free upper end of each attachment tab extending in corresponding predetermined directions away from the first upper mating surface;

a plurality of tab channels disposed in the header module extending away from a second lower mating surface of the header module, the channels being sized to receive corresponding ones of the plurality of upstanding attachment tabs therein when at least portions of the first mating surface and the second mating surfaces engage and are aligned in respect of one another, at least portions of the first and second mating surfaces being configured and shaped to matingly fit against one another;

a plurality of pleats, wherein at least one pleat is formed in each of the plurality of upstanding attachment tabs, the tabs being disposed in the tab channels; and

header module solidified thermoplastic material surrounding the tabs and connecting the tabs to the header modules, wherein the solidified thermoplastic material originates from melted portions of the header module corresponding to the tabs.