Method For Providing A One Piece Header Assembly Over Molded To An Implantable Medical Device
The present invention is directed to a header assembly attachable to a medical device for the purpose of connecting its output terminals to at least one lead, the lead terminating at a target organ or portion of the body intending to be assisted. A number of leads are connectable to the header, including single and coaxial leads. The header assembly may be molded directly to the medical device or performed and then attached to the device casing, either by mechanical fastener and/or chemical adhesive.
1 . A method for connecting an implantable medical device to a conductor terminating at a body organ intended to be assisted by the medical device, comprising the steps of:
a) providing the medical device having a housing containing control circuitry, at least one electrical energy storage device and at least a first and second feedthrough wires extending from the control circuitry through a wall of the housing to first and second distal ends located outside the housing;
b) connecting the first and second distal ends of the first and second feedthrough wires to respective first and second terminals, wherein the terminals includes first and second lead openings aligned in a first co-axial relationship; and
c) molding a body of polymeric material secured to the wall of the housing with the body having a bore communicating from outside the body to the first co-axial first and second lead openings of the terminals.
2 . The method of claim 1 including providing the housing having third and fourth feedthrough wires extending from the control circuitry and through the wall of the housing to respective third and fourth terminals having third and fourth lead openings aligned in a second co-axial relationship along a second bore communicating from outside the body to the third and fourth terminals.
3 . The method of claim 1 including providing the wall of the housing having anchors encased by the polymeric material to secure the body to the housing.
4 . The method of claim 1 wherein the wall of the housing is a lid.
5 . The method of claim 1 including providing the housing for the medical device comprising mating first and second clam shell housing portions closed by a lid.
6 . The method of claim 1 including providing the first and second terminals having first and second apertures.
7 . The method of claim 6 including inserting a lead of the conductor into the bore of the body and into the first and second lead openings of the first and second terminals aligned in the first co-axial relationship and then threading a threaded member into the first and second apertures of the respective first and second terminals to retain the lead in place.
8 . The method of claim 6 including providing the body having first and second passageways in communication with first and second apertures in the respective first and second terminals.
9 . The method of claim 1 including providing the bore having an annular channel supporting an O-ring for sealing about a lead of the conductor received in the first and second terminals.
10 . The method of claim 1 including selecting the electrical energy storage device from a battery and a capacitor.
11 . The method of claim 1 including selecting the medical device from the group consisting of hearing assist device, neurostimulator, cardiac pacemaker, drug pump and cardiac defibrillator.
12 . The method of claim 1 including selecting the first and second terminals from the group consisting of a terminal block, a sleeve, a ring-shaped member supporting a coil spring and a ring shaped member supporting at least one leaf spring.