Hermetically sealed feedthrough connector using shape memory alloy for implantable medical device

• Main Authors: Imani, Ray, Nason, Clyde K
• Format: Patent
• Language: English
• Published: 24.12.2002

The present invention relates generally to an electrical connector used with an implantable medical device, such as a pacemaker, for stimulating selected body tissue for connecting an implantable electrical lead to the electrical circuits within a hermetically sealed housing of the medical device. More particularly, the present invention relates to a feedthrough connector assembly which employs shape memory alloy components for ease of manufacture and for assuring a hermetically sealed engagement with the electrical lead. A feedthrough connector for an implantable medical device includes a hermetically sealed housing containing an electrical circuit and a tubular barrel with an open end and a closed end defining a tubular channel that protrudes into the sealed housing while maintaining the seal of the housing. The inside of the tubular channel is open to the outside of the sealed housing through the open end and the tubular barrel also has a plurality of circumferentially spaced openings extending between an outer peripheral surface and the tubular channel. An electrical contact assembly electrically in common with the electrical circuit within the housing serves to make electrical contact with an electrical lead axially inserted into the open end of the tubular channel. The electrical contact assembly includes a plurality of contact members received in and projecting radially through a plurality of circumferentially spaced openings and a sleeve member of shape memory alloy freely overlies the contact members when in a first deformed-shape configuration but engage the contact members and the outer peripheral surface of the tubular barrel when in a second memory-shaped configuration, urging the contact members into mechanical, electrical, and hermetically sealed engagement with the electrical lead. The tubular channel may include a plurality of conductive cylindrical portions coaxial with the axis of the tubular barrel, the dimensions of the diameter of the successive cylindrical portions progressively decreasing from the open end to the closed end.