Medical lead termination sleeve for implantable medical devices
View Patent ↗A wire and electrode combination suitable for use with implanted medical devices, and a method for coupling the wire and electrode to achieve a robust electrical connection suitable for use with such medical devices are disclosed. The apparatus employs a wire that is optimized for strength, an electrode optimized for biocompatibility, and a termination sleeve with a closed distal end for coupling the wire to the electrode, while eliminating the potential for galvanic corrosion, enhancing weld quality, and facilitating manufacture of the apparatus. The method involves compressing the sleeve to engage the wire at two locations, where contact between the sleeve and wire at the first location seals the interior of the sleeve, and contact between the sleeve and wire at the second location electrically couples the wire to the sleeve. The sleeve, which is easier to manipulate than the wire, is then spot welded to the electrode.
1. An implantable medical device comprising:
an electrical lead wire comprising an inner conductive core and an outer insulating cover;
an electrically conductive termination sleeve configured to engage the electrical lead wire, the termination sleeve comprising a hollow elongate body formed from an electrically conductive material, the hollow elongate body including:
an open proximal end in which a portion of the electrical lead wire is received;
a sealed distal end;
a first portion that sealingly engages the outer insulating cover encapsulating the electrical lead; and
a second portion that conductively engages the inner conductive core of the electrical lead wire, said second portion being located along the hollow elongate body between the first portion and the distal end; and
an electrode that is electrically and physically coupled to the termination sleeve, whereby said electrode is electrically coupled to the electrical lead wire via the termination sleeve,
wherein the termination sleeve comprises a substantially cylindrical body, wherein the first portion of the termination sleeve is crimped to engage the outer insulating cover, and the second portion of the termination sleeve is crimped to engage the electrical lead wire.
2. The implantable medical device of claim 1 , wherein the inner conductive core of the electrical lead wire comprises a first material, and the electrode and the termination sleeve comprise a second material, the first material having been selected for its ability to resist bending fatigue and its conductive properties, and the second material having been selected for its conductive properties, its corrosion resistance properties, and its biocompatible properties.
3. The implantable medical device of claim 2 , wherein the inner conductive core of the electrical lead wire comprises a nickel cobalt alloy.
4. The implantable medical device of claim 2 , wherein the electrode and termination sleeve comprise a platinum iridium alloy.
5. The implantable medical device of claim 1 , wherein the implantable medical device further comprises at least one additional electrical lead wire, termination sleeve, and electrode in combination, such that the implantable medical device comprises at least one electrode array.
6. The implantable medical device of claim 5 , wherein the at least one electrode array is a linear array.
7. The implantable medical device of claim 6 , wherein each termination sleeve in the at least one electrode array is aligned with a longitudinal axis of the electrode array.
8. The implantable medical device of claim 6 , wherein each termination sleeve in the at least one electrode array is aligned perpendicular with a longitudinal axis of the electrode array.
9. The implantable medical device of claim 6 , wherein each termination sleeve in the at least one electrode array is disposed at an angle relative to a longitudinal axis of the electrode array.
10. The implantable medical device of claim 1 , wherein the electrode comprises a stimulation electrode.
11. The implantable medical device of claim 1 , wherein the electrode comprises a monitoring electrode.
12. The implantable medical device of claim 1 , wherein the electrical lead wire has a diameter of about 0.003 inches.
13. The implantable medical device of claim 1 , wherein the implantable medical device comprises a proximal connector for an implantable medical lead comprising a plurality of electrical lead wires, termination sleeves and electrodes in combination.
14. The implantable medical device of claim 1 , wherein the first portion of the termination sleeve is disposed proximate to the proximal end of the hollow elongate body.