Method of manufacturing an implantable lead

Abstract

An implantable lead body for a medical device with improved conductor lumens separates and insulates conductors while permitting access to the conductors through the implantable lead outer surface. The implantable lead comprises a lead body, a stylet lumen, at least one conductor lumen, and at least one axial slit in the lead body. The lead body has a proximal end, a distal end, an internal portion, and an external portion. The stylet lumen is formed in the internal portion. The conductor lumen is formed in the internal portion and positioned near an outer surface of the internal portion such that there is only a web between the conductor lumen and the outer surface of the internal portion. The axial slit is formed in the lead body distal end between the conductor lumen and the outer surface of the internal portion.

1 . A method of constructing an implantable lead body comprising:
 extruding an internal portion of the lead body, such that the internal portion includes at least one conductor lumen that extends between a proximal end and a distal end of the internal portion and is located near a periphery of the internal portion;   fitting the internal portion into a generally tubular external portion of the lead body;   attaching a distal coupling to a distal terminal end of a conductor of the lead body, such that the distal terminal end of the conductor is contained within a first coupling region of the distal coupling and a second coupling region of the distal coupling extends distally from the distal terminal end of the contained distal terminal end of the conductor, the second coupling region defining an isolation space of the distal coupling and being located adjacent to the first coupling region;   forming an axial slit through the internal portion of the lead body, in order to create a path from an exterior surface of the lead body to the conductor lumen of the fitted internal portion;   positioning the conductor within the conductor lumen of the internal portion of the lead body, such that the first and second coupling portions of the attached distal coupling are contained within the conductor lumen and a third coupling region of the attached distal coupling extends through the axial slit of the internal portion to the exterior surface of the lead body, the third coupling region being located adjacent to the isolation space defined by the second coupling region of the distal coupling, on a side thereof that is opposite the first coupling region of the distal coupling;   placing the third coupling region of the attached distal coupling, which extends through the axial slit of the internal portion of the lead body, within a slot of a contact, the contact being carried on the lead body in proximity to the distal end of the internal portion; and   welding the placed third coupling region of the attached distal coupling to the contact.   
     
     
         2 . The method of  claim 1 , further comprising:
 attaching a proximal coupling to a proximal end of the conductor; and   welding the attached proximal coupling to another contact that is carried on the lead body in proximity to the proximal end of the internal portion of the lead body.   
     
     
         3 . The method of  claim 1 , wherein the contact is generally annular in shape and extends around the internal portion of the lead body. 
     
     
         4 . The method of  claim 1 , wherein the internal portion of the lead body is extruded to further include a stylet lumen that extends between the proximal end and the distal end of the internal portion and alongside the conductor lumen. 
     
     
         5 . The method of  claim 4 , further comprising forming a proximal flare on the proximal end of the internal portion of the lead body, the proximal flare surrounding an opening into the stylet lumen, in order to facilitate insertion of a stylet into the stylet lumen, and the proximal flare sealing the conductor lumen at a proximal end thereof. 
     
     
         6 . The method of  claim 1 , further comprising bending the attached distal coupling, prior to placing the third coupling region thereof within the slot of the contact. 
     
     
         7 . The method of  claim 1 , further comprising deforming a diameter of the third coupling region of the attached distal coupling, prior to placing the third coupling region within the slot of the contact. 
     
     
         8 . The method of  claim 1 , wherein:
 the isolation space defined by the second coupling region of the attached distal coupling is a void, and the void extends through the third coupling region of the attached distal coupling; and   welding the placed third coupling region of the attached distal coupling seals the void.   
     
     
         9 . The method of  claim 1 , wherein the isolation space defined by the second coupling region of the attached distal coupling includes a fill material.