Medical Lead Termination Sleeve for Implantable Medical Devices

• US 20100179627A1
• Filed: 01/11/2010
• Published: 07/15/2010
• Est. Priority Date: 01/09/2009
• Status: Active Grant

• Current Assignee: Cyberonics, Inc
• Original Assignee: Cyberonics, Inc
• Inventors: Floyd, Jared, Genau, Christopher, Leyde, Kent W.
• Granted Patent: US 8,588,933 B2
• Time in Patent Office: Days
• US Class Current: 607/116
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: H01R 2201/12 for medicine and surgery
• CPC Class Codes: H01R 4/20 using a crimping sleeve H01R4/01 takes precedence
• CPC Class Codes: Y10T 29/49218 with deforming

Abstract

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.

Claims

1. An implantable medical device comprising:

an electrical lead wire comprising an inner conductive core and an outer insulating protective 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 into which the electrical lead wire is inserted;

a sealed distal end;

a first portion that sealingly engages the insulating cover encapsulating the electrical lead, thereby defining an inner volume extending between the first portion and the distal end of the hollow elongate body, the first portion being disposed proximate to the proximal end of the hollow elongate body; and

a second portion that conductively engages the inner conductive core of the electrical lead wire at the distal portion of the electrical lead wire; and

an electrode that is electrically and physically coupled to the termination sleeve.

2. The implantable medical device of claim 1, wherein the outer insulating protective cover at the distal portion of the electrical lead wire that conductively engages the termination sleeve is removed to expose the inner conductive core.

3. 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.

4. The implantable medical device of claim 3, wherein the inner conductive core of the electrical lead wire comprises a nickel cobalt alloy.

5. The implantable medical device of claim 3, wherein the electrode and termination sleeve comprise a platinum iridium alloy.

6. 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.

7. The implantable medical device of claim 6, wherein the distal electrode array is a linear array.

8. The implantable medical device of claim 7, wherein each termination sleeve in the at least one electrode array is aligned with a longitudinal axis of the electrode array.

9. The implantable medical device of claim 7, wherein each termination sleeve in the at least one electrode array is aligned perpendicular with a longitudinal axis of the electrode array.

10. The implantable medical device of claim 7, 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.

11. The implantable medical device of claim 1, wherein the electrode comprises a stimulation electrode.

12. The implantable medical device of claim 1, wherein the electrode comprises a monitoring electrode.

13. The implantable medical device of claim 1, wherein the electrical lead wire has a diameter of about 0.003 inches.

14. 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.

15. A medical lead and electrode connection comprising:

(a) a medical lead wire including an outer insulating jacket and an inner conductor formed of a first conductive material selected for its conductive and mechanical properties;

(b) an electrode formed of a second conductive material selected for its conductive, corrosion resistant, and biocompatible properties; and

(c) a closed end termination sleeve being electrically and physically coupled to the electrode, the closed end termination sleeve also being formed of the second conductive material, the closed ended termination sleeve surrounding a distal end of the medical lead wire to achieve both;

(i) a seal between the insulating jacket and the termination sleeve, the seal isolating an inner volume extending between the closed end of the termination sleeve and the seal; and

(ii) an electrical connection between the termination sleeve and the inner conductor of the medical lead wire, the electrical connection being disposed within the inner volume.

16. A method for using an electrically conductive termination sleeve, comprising:

removing an outer insulating layer from a distal portion of an electrical lead wire, thereby exposing an inner conductive core;

inserting a distal end of the electrical lead wire into the termination sleeve, such that a portion of the electrical lead wire still covered by the outer insulating layer is disposed within the termination sleeve adjacent to a proximal end of the termination sleeve; and

mechanically modifying the termination sleeve such that the proximal end of the modified portion of the sleeve sealingly engages the outer insulating layer of the electrical lead wire; and

the distal end of the modified portion of the sleeve conductively engages the exposed inner conductive core at the distal portion of the electrical lead wire.

17. The method of claim 16, wherein the step of modifying the termination sleeve comprises mechanically modifying a contiguous portion of the termination sleeve, a length of the contiguous portion being sufficient to extend between a first location overlaying a portion of the electrical lead wire still covered by the outer insulating layer and a second location overlaying the exposed inner conductive core at the distal portion of the electrical lead wire, such that at the first location the termination sleeve sealingly engages the outer insulating layer of the electrical lead wire and at the second location the termination sleeve conductively engages the exposed inner conductive core at the distal portion of the electrical lead wire.

18. The method of claim 16, wherein the step of modifying the termination sleeve comprises the steps of:

mechanically modifying the termination sleeve at a first location adjacent the proximal end of the termination sleeve, such that at the first location the termination sleeve sealingly engages the outer insulating layer of the electrical lead wire; and

mechanically modifying the termination sleeve at a second location, such that at the second location the termination sleeve conductively engages the exposed inner conductive core at the distal portion of the electrical lead wire.

19. The method of claim 16, wherein the termination sleeve has a closed distal end, such that the step of mechanically modifying the termination sleeve to sealingly engage the outer insulating layer of the electrical lead wire forms a seal, isolating an inner volume of the termination sleeve extending between the seal and the closed distal end of the termination sleeve.

20. The method of claim 16, further comprising the step of physically and electrically coupling the termination sleeve to an electrode.

21. The method of claim 20, wherein the step of physically and electrically coupling the termination sleeve to the electrode comprises the step of laser spot welding the termination sleeve to the electrode.

22. The method of claim 20, further comprising the steps of:

utilizing an electrical lead wire whose inner conductive core comprises a first conductive material selected based on its conductive and fatigue resistant mechanical properties;

utilizing a termination sleeve comprising a second conductive material selected based on its conductive, corrosion resistant, and biocompatible properties, and

utilizing an electrode comprising the second conductive material.

23. A method for using an electrically conductive termination sleeve, comprising the steps of:

inserting a distal end of the electrical lead wire into the termination sleeve, such that the distal end of the electrical lead wire is covered by the outer insulating layer;

mechanically modifying the termination sleeve at a first location adjacent the proximal end of the termination sleeve, such that at the first location the termination sleeve sealingly engages the outer insulating layer of the electrical lead wire; and

mechanically modifying the termination sleeve at a second location, such that at the second location the termination sleeve displaces the outer insulating layer and conductively engages the exposed inner conductive core at the distal portion of the electrical lead wire.