Cardiac lead welding

Abstract

An implantable lead may have a distal assembly including a coupler, a terminal pin and a conductive member rotatably secured to both the coupler and the terminal pin. The conductive member may be a fine-wire, multiple-filar coil. The conductive member may be welded to the coupler and/or the terminal pin by welding through banded portions formed within the distal and proximal ends, respectively, of the conductive member.

1 . An implantable lead comprising:
 a flexible body extending between a proximal end and a distal end;   a connector assembly secured to the proximal end for coupling the lead to an implantable medical device, the connector assembly including a terminal pin rotatable relative to the body;   a conductor member rotatably disposed longitudinally within the body and coupled to the terminal pin, the conductor member comprising a multiple filar coil having a distal region, a proximal region and a banded portion formed within the distal region of the multiple filar coil; and   a distal assembly coupled to the distal end of the body and including:
 a housing having a distal region and a proximal region, the proximal region fixedly coupled to the distal end of the body; 
 a coupler rotatably disposed within the housing, the coupler having a proximal end and a distal end; and 
 a helical electrode fixedly secured to the distal end of the coupler, the banded portion of the conductor member fixedly secured to the proximal end of the coupler; 
 wherein the terminal pin is rotatably engaged with the coupler via the conductor member such that rotation of the terminal pin causes the coupler and the helical electrode to rotate and therefore translate relative to the housing. 
   
     
     
         2 . The implantable lead of  claim 1 , wherein the banded portion of the conductive member is welded to the proximal end of the coupler. 
     
     
         3 . The implantable lead of  claim 1 , wherein the banded portion extends radially at least substantially around the distal end of the conductive member. 
     
     
         4 . The implantable lead of  claim 1 , wherein the banded portion comprises two or more distinct banded regions within the distal end of the conductive member. 
     
     
         5 . The implantable lead of  claim 4 , wherein the banded portion of the conductive member is secured to the proximal end of the coupler by welding through at least one of the two or more distinct banded regions. 
     
     
         6 . The implantable lead of  claim 1 , wherein the conductive member further comprises a second banded portion formed within the proximal region of the conductive member. 
     
     
         7 . The implantable lead of  claim 6 , wherein the second banded portion of the conductive member is welded to the terminal pin. 
     
     
         8 . A method of assembling an extendable/retractable active fixation lead having a coupler and a conductive member secured to the coupler, the conductive member having a distal region and a proximal region, the coupler including a proximal portion configured to accommodate the distal region of the conductive member, the method comprising:
 subjecting the distal region of the conductive member to heat and pressure to form a banded portion;   disposing the banded portion of the conductive member about the proximal portion of the coupler; and   welding the banded portion of the conductive member to the coupler.   
     
     
         9 . The method of  claim 8 , wherein subjecting the distal region of the conductive member to heat and pressure comprises subjecting the distal region of the conductive member to laser energy while applying an axial compressive force. 
     
     
         10 . The method of  claim 8 , wherein the conductive member comprises a multiple filar coil. 
     
     
         11 . The method of  claim 10 , wherein subjecting the distal region of the conductive member to heat and pressure comprises banding together a plurality of adjacent filars. 
     
     
         12 . The method of  claim 11 , wherein welding the banded portion to the metal structure comprises welding through the plurality of adjacent filars banded together. 
     
     
         13 . The method of  claim 8 , the lead further comprising a terminal pin, the method further comprising steps of:
 melting and compressing the proximal region of the conductive member;   re-solidifying the proximal region of the conductive member to form a second banded portion;   disposing the second banded portion about the terminal pin; and   welding the second banded portion to the terminal pin.   
     
     
         14 . The method of  claim 8 , further comprising steps of:
 attaching a fixation helix to the coupler to form an assembly; and   disposing the assembly within a lead body.   
     
     
         15 . A method of assembling an implantable lead comprising a coupler, a terminal pin and a conductive member extending between the coupler and the terminal pin, the conductive member comprising a multiple filar coil having a distal region and a proximal region, the method comprising:
 melting and compressing the distal region of the multiple filar coil;   re-solidifying the distal region of the multiple filar coil to form a banded portion;   disposing the banded portion proximate the coupler;   welding the banded portion to the coupler;   melting and compressing the proximal region of the multiple filar coil;   re-solidifying the proximal region of the multiple filar coil to form a second banded portion;   disposing the second banded portion proximate the terminal pin; and   welding the second banded portion to the terminal pin.   
     
     
         16 . The method of  claim 15 , wherein the coupler comprises a shaft portion configured to fit within the distal region of the multiple filar coil, and the method further comprises fitting the distal region of the multiple filar coil over the shaft portion prior to welding the banded portion to the coupler. 
     
     
         17 . The method of  claim 15 , wherein the coupler is configured to accommodate the distal region of the multiple filar coil within the coupler, and the method further comprises fitting the distal region of the multiple filar coil within the coupler prior to welding the coupler to the banded portion. 
     
     
         18 . The method of  claim 15 , wherein the terminal pin is configured to extend within the proximal region of the multiple filar coil, and the method further comprises fitting the proximal region of the multiple filar coil over the terminal pin prior to welding the banded portion to the terminal pin. 
     
     
         19 . The method of  claim 15 , wherein the terminal pin is configured to accommodate the proximal region of the multiple filar coil within the terminal pin, and the method further comprises fitting the proximal region of the multiple filar coil within the terminal pin prior to welding the terminal pin to the banded portion. 
     
     
         20 . The method of  claim 16 , further comprising disposing the coupler and attached conductive member within a lead body.