Medical lead termination sleeve for implantable medical devices

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.

What is claimed is: 
     
         1 . A method of assembling a medical device lead, the method comprising:
 providing a sleeve comprising an axial sleeve length and an internal hollow portion communicating with a sleeve opening, wherein the sleeve further includes a first portion and a second portion each disposed along the axial sleeve length of the sleeve, and a third portion disposed between the first portion and the second portion, the third portion defining a third portion sleeve outer dimension about a sleeve axis;   positioning a lead wire within the sleeve, wherein the lead wire includes a lead wire end supporting a conductor and a cover and the positioning disposes the conductor and the cover within the internal hollow portion of the sleeve;   deforming the sleeve at the first portion to sealingly engage the cover; and   deforming the sleeve at the second portion to engage the conductor, wherein at least one of the first portion and the second portion defines a deformed sleeve outer dimension of the sleeve about the sleeve axis, the deformed sleeve outer dimension being less than the third portion sleeve outer dimension.   
     
     
         2 . The method of  claim 1 , wherein the conductor includes at least one wire, and wherein deforming the sleeve at the second portion comprises mechanically deforming the sleeve at the second portion to engage the at least one wire. 
     
     
         3 . The method of  claim 1 , wherein the conductor includes a plurality of wires, and wherein deforming the sleeve at the second portion comprises mechanically deforming the sleeve at the second portion to engage at least one wire of the plurality of wires. 
     
     
         4 . The method of  claim 1 , wherein the hollow portion defines an inner volume, and wherein deforming the sleeve at the first portion provides a seal between the inner volume and the sleeve opening. 
     
     
         5 . The method of  claim 1 , wherein the conductor comprises a nickel cobalt alloy. 
     
     
         6 . The method of  claim 1 , wherein the sleeve comprises a platinum iridium alloy. 
     
     
         7 . The method of  claim 1 , wherein the conductor is a drawn filled tube composite. 
     
     
         8 . The method of  claim 1 , wherein the conductor is a drawn filled tube (DFT) wire. 
     
     
         9 . The method of  claim 1 , wherein:
 deforming the sleeve at the first portion comprises crimping the first portion; and   deforming the sleeve at the second portion comprises crimping the second portion.   
     
     
         10 . The method of  claim 1 , wherein engagements between the lead wire and the sleeve are devoid of welds. 
     
     
         11 . The method of  claim 1 , further comprising:
 providing a conductive engagement within the sleeve at the second portion, wherein the conductive engagement is contained within a sealed portion of the internal hollow portion.   
     
     
         12 . A method of assembling an electrode assembly, the method comprising:
 providing a sleeve comprising an axial sleeve length and an internal hollow portion communicating with a sleeve opening, wherein the sleeve further includes a first portion and a second portion each disposed along the axial sleeve length of the sleeve, and a third portion disposed between the first portion and the second portion, the third portion defining a third portion sleeve outer dimension about a sleeve axis;   coupling, using the sleeve, an electrode to a lead wire, wherein the lead wire includes a lead wire end supporting a conductor and a cover, wherein the conductor and the cover are disposed within the internal hollow portion of the sleeve;   deforming the sleeve at the first portion to sealingly engage the cover; and   deforming the sleeve at the second portion to engage the sleeve with the conductor, wherein at least one of the first portion and the second portion defines a deformed sleeve outer dimension of the sleeve about the sleeve axis, the deformed sleeve outer dimension being less than the third portion sleeve outer dimension.   
     
     
         13 . The method of  claim 12 , wherein the conductor is a drawn filled tube composite. 
     
     
         14 . The method of  claim 12 , wherein the conductor is a drawn filled tube (DFT) wire. 
     
     
         15 . The method of  claim 12 , wherein:
 deforming the sleeve at the first portion comprises crimping the first portion; and   deforming the sleeve at the second portion comprises crimping the second portion.   
     
     
         16 . The method of  claim 12 , wherein the electrode and the sleeve comprise a same material. 
     
     
         17 . The method of  claim 12 , wherein engagements between the lead wire and the sleeve are devoid of welds. 
     
     
         18 . The method of  claim 12 , further comprising:
 providing a conductive engagement within the sleeve at the second portion, wherein the conductive engagement is contained within a sealed portion of the internal hollow portion.   
     
     
         19 . A method of assembling a medical device lead, the method comprising:
 providing a sleeve comprising an axial sleeve length and an internal hollow portion communicating with a sleeve opening, wherein the sleeve further includes a first portion and a second portion each disposed along the axial sleeve length of the sleeve;   positioning a lead wire within the sleeve, wherein the lead wire includes a lead end supporting a conductor and a cover, wherein the cover defines a cover outer diameter and the conductor defines a conductor outer diameter, the cover outer diameter being greater than the conductor outer diameter, and wherein the positioning disposes the conductor and the cover within the internal hollow portion of the sleeve with the first portion aligned with the cover and the second portion aligned with the conductor;   deforming the sleeve such that the internal hollow portion transitions from a pre-deformation state to a post-deformation state, wherein the pre-deformation state includes a uniform pre-deformation inner diameter extending along the axial sleeve length from the first portion to the second portion, and the internal hollow portion in the post-deformation state has a plurality of post-deformation inner diameters extending along the axial sleeve length from the first portion to the second portion, and   wherein at least a portion of the sleeve in the post-deformation state is in contact with the conductor.   
     
     
         20 . The method of  claim 19 , wherein the conductor comprises at least one of a nickel cobalt alloy, a drawn filled tube composite, and a drawn filled tube (DFT) wire. 
     
     
         21 . The method of  claim 19 , wherein the sleeve comprises a platinum iridium alloy.