Medical electrical lead joints and methods of manufacture

Abstract

A joint between an insulative sidewall of a medical electrical lead subassembly and an underlying fluoropolymer layer includes an interfacial layer. A first section of the interfacial layer is bonded to the fluoropolymer layer and is formed by a thermoplastic fluoropolymer; a second section of the interfacial layer extends adjacent the first section and is bonded to the insulative sidewall. The insulative sidewall, of the subassembly, and the second section, of the interfacial layer, are each formed from a material that is not a fluoropolymer. A recess is formed in the first section of the interfacial layer and the second section of the interfacial layer extends within the recess.

1 . A medical electrical lead, comprising:
 an elongate conductor;   an inner insulative layer surrounding the conductor, the inner insulative layer formed from a first material;   a subassembly including an insulative sidewall formed from a second material and a conductive member mounted about the insulative sidewall, and the conductive member including an exposed electrical contact surface; and   a joint between the inner insulative layer and the insulative sidewall of the subassembly, the joint formed by an interfacial layer extending between an outer surface of the inner insulative layer and an inner surface of the insulative sidewall, the interfacial layer comprising:
 a first section formed from a third material bonded the outer surface of the inner insulative layer; and 
 a second section formed from a fourth material and being bonded to the inner surface of the insulative sidewall of the subassembly; and 
 wherein one of the first and second materials comprises a fluoropolymer and the other does not; wherein one of the third and fourth materials comprises a fluoropolymer; and wherein the one of the third and fourth materials comprising a fluoropolymer is bonded to the one of the first and second materials which comprises a fluoropolymer; and 
 wherein the first section includes an outer surface facing the inner surface of the insulative sidewall, and at least one recess formed in the outer surface of the first section and the second section extends adjacent the first section and within the at least one recess. 
   
     
     
         2 . The lead of  claim 1 , wherein the inner insulative layer comprises a tubular member, the conductor being slideable therein. 
     
     
         3 . The lead of  claim 1 , wherein the conductive member comprises a connector contact. 
     
     
         4 . The lead of  claim 1 , wherein the exposed electrical contact surface of the conductive sidewall of the subassembly comprises an electrode. 
     
     
         5 . The lead of  claim 1 , wherein the second material and the fourth material are substantially the same. 
     
     
         6 . The lead of  claim 1 , wherein the fourth material forming the second section of the interfacial layer comprises an adhesive. 
     
     
         7 . The lead of  claim 1 , wherein the recess comprises at least one groove of the first section of the interfacial layer comprises a plurality of recesses. 
     
     
         8 . The lead of  claim 1 , wherein the recess comprises at least one groove of the first section of the interfacial layer extends along a helical path 
     
     
         9 . A method for manufacturing a joint in a medical electrical lead, the joint being between an inner surface of an insulative sidewall of the lead and an outer surface of a fluoropolymer layer, the subassembly comprising a conductive member mounted about the insulative sidewall, and the conductive member including an exposed electrical contact surface; the method comprising:
 thermally bonding a thermoplastic fluoropolymer layer to the outer surface of the fluoropolymer layer;   assembling another material layer over the outer surface of the fluoropolymer layer and adjacent to the thermoplastic fluoropolymer layer; and   adhesively bonding the other material layer to the inner surface of the insulative sidewall of the subassembly;   wherein the other material layer and the insulative sidewall of the subassembly are formed from a material that does not comprise a fluoropolymer.   
     
     
         10 . The method of  claim 9 , wherein:
 the fluoropolymer layer and the other material layer are tubular; and   assembling the other material layer over the outer surface of the fluoropolymer layer comprises inserting the tubular fluoropolymer layer into a lumen of the tubular other material layer such that an edge of the other material layer abuts an edge of the thermally bonded thermoplastic fluoropolymer layer.   
     
     
         11 . The method of  claim 9 , wherein the fluoropolymer layer and the thermoplastic fluoropolymer layer are tubular and further comprising:
 inserting the tubular fluoropolymer layer into a lumen of the tubular thermoplastic fluoropolymer layer, prior to thermally bonding; and   assembling a temporary containment member about the tubular thermoplastic fluoropolymer layer and the tubular fluoropolymer layer, prior to thermally bonding.   
     
     
         12 . The method of  claim 9 , further comprising:
 forming at least one recess in an outer surface of the thermally bonded thermoplastic fluoropolymer layer; and   wherein assembling the other material layer over the outer surface of the fluoropolymer layer and adjacent to the thermoplastic fluoropolymer layer comprises placing the other material layer within the at least one recess.   
     
     
         13 . The method of  claim 9 , further comprising:
 forming at least one recess in an outer surface of the thermoplastic fluoropolymer layer in conjunction with thermally bonding the thermoplastic fluoropolymer layer; and   wherein assembling the other material layer over the outer surface of the fluoropolymer layer and adjacent to the thermoplastic fluoropolymer layer comprises placing the other material layer within the at least one recess.   
     
     
         14 . The method of  claim 9 , further comprising:
 forming at least one recess in an outer surface of the thermoplastic fluoropolymer layer; and   wherein the other material layer comprises an adhesive; and   assembling the other material layer over the outer surface of the fluoropolymer layer and adjacent to the thermoplastic fluoropolymer layer comprises injecting the adhesive into the at least one recess.