Connector assembly for an implantable medical device and process for making

Abstract

A connector circuit assembly for use in an implantable medical device, and a method of making the assembly that includes a core portion formed of a thermoplastic material using either an injection molding process or a machining process. This core portion is adapted to be fitted with at least one electrically-conductive circuit component such as a connector member, a set-screw block, or a conductive jumper member. In one embodiment of the invention, the core portion includes multiple receptacles or other spaces that are adapted to be loaded with the various circuit components. The core assembly is positioned into a second-shot mold assembly, and a second thermoplastic material is injected into the mold so that the second thermoplastic material extends over and adheres to the core portion and the circuit component.

1 . A method of fabricating a modular header for providing electrical connections between an array of feed-through pins extending through a wall of a hermetically sealed enclosure of an implantable medical device and lead connector receptacles within a modular header assembled to said device comprising:
 (a) providing a pre-formed molded header module having paths therein to accept and incorporate a set of flexible conductors and connector blocks associated with lead connector receptacles;   (b) providing a separate set of intermediate conjoined flexible conductors each having a free end and a fixed end, wherein the fixed ends of the flexible conductors are connected to a common element and assembling said set of conductors into said paths in said pre-formed molded header module attaching the free ends thereof to corresponding connector blocks provided in said molded header module;   (c) performing an over-molding operation to incorporate and hermetically seal said conductors into said header structure;   (d) removing said common element to provide an array of spaced connectors configured and positioned to match and mate with said array of feed-through pins when said header is assembled to a compatible corresponding hermetically sealed enclosure;   (e) assembling said header module to said hermetically sealed enclosure and connecting said flexible conductors to said feed-through pins; and   (f) backfilling any open interface volume between said header module and said hermetically sealed enclosure after connecting said flexible conductors to said feed-through pins.   
     
     
         2 . A method of fabricating a modular header as in  claim 1  including testing the integrity of the connectors traversing said header prior to assembling said header on a corresponding hermetically sealed enclosure of an implantable medical device. 
     
     
         3 . A method of fabricating a modular header as in  claim 1  wherein said flexible conductors are wrapped around said feed-through pins and welded thereto. 
     
     
         4 . A method as in  claim 1  wherein said paths in said pre-formed molded header include recessed channels. 
     
     
         5 . A modular header for making electrical connections between an array of feed-through pins extending through a wall of a hermetically sealed enclosure of an implantable medical device and lead connector receptacles within said modular header, said device comprising:
 (a) a pre-formed molded header module having paths therein to accept and incorporate a set of flexible conductors and connector blocks;   (b) a separate set of intermediate flexible conductors each having a free end assembled into said paths in said pre-formed molded header module, said free ends being attached to corresponding connector blocks located in said molded header module;   (c) a layer of over molding incorporating and sealing said conductors into said header structure; and   (d) wherein said flexible conductors each have an end opposite the free end provided with a connecting device designed to connect with a feed-through pin in a corresponding hermetically sealed medical device enclosure and wherein one or more of said flexible conductors wrap around said pre-formed molded header module.   
     
     
         6 . A modular header as in  claim 5  wherein said header includes recessed conductor channels. 
     
     
         7 . A modular header as in  claim 5  wherein said flexible conductors connect to connector receptacles located on a common side of said pre-formed molded header module. 
     
     
         8 . A modular header as in  claim 7  wherein said lead connector receptacles are arranged in a row in spaced alignment. 
     
     
         9 . A modular header as in  claim 5  wherein said header is connected with a hermetically sealed enclosure of an implantable medical device and wherein said flexible conductors match and are connected to a corresponding array of feed-through pins protruding from said enclosure wherein said connections are located in a recess provided in said modular header and wherein said recess is backfilled with a medical grade polymer. 
     
     
         10 . A method of making a connector assembly for providing electrical connections between a feed-through pattern of an implantable medical device and lead receptacles within a connector assembly coupled to said device comprising:
 (a) providing a core portion having channel guides therein to accept and incorporate a circuit member and set-screw blocks associated with lead receptacles;   (b) providing a circuit member comprising joined deformable conductive finger elements each having a free end and a joined end, wherein the joined ends of the deformable conductive finger elements are mechanically and electrically connected via conductive traces, and coupling said circuit member into said channel guides in said core portion attaching the free ends thereof to corresponding set-screw blocks provided in said core portion;   (c) performing an over-molding operation to encapsulate said conductive finger elements in said connector assembly;   (d) cutting away said conductive traces to provide connector pads positioned to connect with said feedthrough pattern when said connector assembly is coupled to a compatible corresponding implantable medical device;   (e) assembling said connector assembly to said implantable medical device and connecting said deformable conductive finger elements to said feedthrough pattern; and   (f) overlaying medical adhesive on the connections between said connector assembly and said implantable medical device after connecting said deformable conductive finger elements to said feedthrough pattern.   
     
     
         11 . A method of making a connector assembly as in  claim 10 , including testing the integrity of the connectors traversing said connector assembly prior to coupling said connector assembly to a corresponding implantable medical device. 
     
     
         12 . A method of making a connector assembly as in  claim 10 , wherein said deformable conductive finger elements are connected to said feedthrough pattern and welded thereto. 
     
     
         13 . A method as in  claim 10 , wherein said channel guides in said core portion comprise recessed channels. 
     
     
         14 . A connector assembly for making electrical connections between a feedthrough pattern of an implantable medical device and lead receptacles within said connector assembly, said device comprising:
 (a) a core portion having channel guides therein to accept and incorporate a circuit member and set-screw blocks;   (b) said circuit member comprising deformable conductive finger elements each having a free end assembled into said channel guides in said core portion, said free ends being coupled to corresponding set-screw blocks located in said connector assembly;   (c) a second shot of overmolding encapsulating said finger elements in said connector assembly; and   (d) wherein said deformable conductive finger elements each have an end opposite the free end provided with a connector pad designed to connect with a feedthrough pattern in a corresponding implantable medical device and wherein one or more of said deformable conductive finger elements wrap around said core portion.   
     
     
         15 . A connector assembly as in  claim 14 , wherein said connector assembly comprises recessed channel guides. 
     
     
         16 . A connector assembly as in  claim 14 , wherein said deformable conductive finger elements connect to lead receptacles located on a common side of said core portion. 
     
     
         17 . A connector assembly as in  claim 16 , wherein said lead receptacles are arranged in a row in spaced alignment. 
     
     
         18 . A connector assembly as in  claim 14 , wherein said connector assembly is coupled to an implantable medical device and wherein said deformable conductive finger elements match and are connected to a corresponding feedthrough pattern on said implantable medical device, wherein said connections are located in a recess provided in said connector assembly and wherein said recess is overlaid with a medical adhesive. 
     
     
         19 . An apparatus, comprising:
 a pre-molded header that is biocompatible and that defines a first channel and a second channel, the pre-molded header including a first terminal in electrical communication with a first lead terminal of the pre-molded header;   a flex harness conformed to the pre-molded header, the flex harness including a first conductor including a first connection terminal and a second conductor including a second connection terminal, the first and second conductors being physically coupled by a common harness portion, the flex harness including a pre-formed alignment such that the first conductor is disposed in the first channel and the second conductor is disposed in the second channel, with the first conductor defining a conductive path between the first terminal and the first connection terminal; and   an over-molded layer that is biocompatible and disposed over the pre-molded header and the flex harness such that the first conductor and the second conductor are disposed between the pre-molded header and the over-molding layer.   
     
     
         20 . The apparatus of  claim 19 , wherein a conductive path extends between the first connection terminal and the first lead terminal internal to the pre-molded header. 
     
     
         21 . The apparatus of  claim 19 , further comprising an implantable device including a first pin and a second pin, with the first connection terminal crimped to the first pin, and the second connection terminal crimped to the second pin. 
     
     
         22 . The apparatus of  claim 21 , wherein the first connection terminal is welded to the first pin and the second connection terminal is welded to the second pin. 
     
     
         23 . The apparatus of  claim 21 , wherein the pre-molded header and the first over-molded layer define a backfill recess, with the first connection terminal and the second connection terminal being disposed the in the backfill recess, and further comprising backfill disposed in the backfill recess. 
     
     
         24 . The apparatus of  claim 21 , further comprising a first lead coupled to the first lead terminal. 
     
     
         25 . The apparatus of  claim 24 , wherein the first lead terminal is female, and the first lead include a male terminal which is disposed at least partially in the first lead terminal. 
     
     
         26 . The apparatus of  claim 19 , wherein the terminal is a first connection terminal is a first spade terminal and the second connection terminal is a second spade terminal. 
     
     
         27 . The apparatus of  claim 26 , wherein the first spade terminal and the second spade terminal each include stainless steel. 
     
     
         28 . The apparatus of  claim 26 , wherein the first spade terminal and the second spade terminal each are substantially planar and are coplanar. 
     
     
         29 . An apparatus, comprising:
 a pre-molded header that is biocompatible and that defines a plurality of lead terminals in a row, the pre-molded header defining an exterior surface with a first terminal in electrical communication with a first lead terminal of the plurality of lead terminals, and with a second terminal in electrical communication with a second lead terminal of the plurality of lead terminals;   a harness coupled to the pre-molded header, the harness including a first conductor including a first connection terminal and a second conductor including a second connection terminal, the first and second conductors being physically coupled by a common harness portion, the harness including a pre-formed alignment such that the first conductor is aligned to the first terminal and the second conductor is aligned to the second terminal, with the first conductor defining a conductive path between the first terminal and the first connection terminal; and   an over-molded layer that is biocompatible and disposed over the pre-molded header and the harness such that the first conductor and the second conductor are disposed between the pre-molded header and the over-molding layer.   
     
     
         30 . The apparatus of  claim 29 , wherein the first terminal includes a block connection. 
     
     
         31 . The apparatus of  claim 29 , wherein the common harness portion is a removable common harness portion adapted to be removed from the first conductor and to be removed from the second conductor. 
     
     
         32 . An apparatus, comprising:
 a pre-molded header that is biocompatible and that defines a first channel and a second channel, the pre-molded header including a first terminal in electrical communication with a first lead terminal of the pre-molded header;   a flex harness conformed to the pre-molded header, the flex harness including a first conductor including a first connection terminal and a second conductor including a second connection terminal, the first and second conductors being physically coupled by a common harness portion, the flex harness including a pre-formed alignment such that the first conductor is disposed in the first channel and the second conductor is disposed in the second channel, with the first conductor defining a conductive path between the first terminal and the first connection terminal; and   an over-molded layer that is biocompatible and disposed over the pre-molded header and the flex harness such that the first conductor and the second conductor are disposed between the pre-molded header and the over-molding layer.   
     
     
         33 . The apparatus of  claim 32 , wherein a conductive path extends between the first terminal and the first lead terminal internal to the pre-molded header. 
     
     
         34 . The apparatus of  claim 32 , wherein the common harness portion is a removable common harness portion adapted to be removed from the first conductor and to be removed from the second conductor. 
     
     
         35 . A method, comprising:
 molding a biocompatible material over an internal conductor to define a pre-molded header that includes a first channel, a second channel and a lead terminal to receive a lead, the internal conductor electrically coupling the lead terminal to a first terminal;   pre-forming a flex conductor harness including a first conductor that includes a first connection terminal and a second conductor that includes a second connection terminal, with the first conductor and the second conductor coupled at a common portion such that the first conductor is pre-formed to conform, in alignment, to the first channel, and the second conductor is pre-formed to conform, in alignment, to the second channel;   wrapping the flex conductor harness around the pre-molded header such that a first conductor of the flex conductor harness is disposed in the first channel and a second conductor of the flex conductor harness is disposed in the second channel;   electrically coupling the first conductor to the first terminal; and   over-molding at a first pressure an over-molded layer of biocompatible material over the first terminal, the first conductor and the second conductor, with the first connection terminal and the second connection terminal being exposed through an opening in the over-molded layer.   
     
     
         36 . The method of  claim 35 , further comprising:
 wrapping the first connection terminal around a first pin of an implantable device; wrapping the second connection terminal around a second pin of the implantable device; and   welding the first terminal to the first pin and the second connection terminal to the second pin by automatically adjusting a welding machine between a first welding position and a second welding position along a single axis.   
     
     
         37 . The method of  claim 36 , further comprising backfilling, under a second pressure which is lower than the first pressure, a recess defined by the implantable device, the pre-molded header, and the over-molded layer, and containing the first connection terminal and the second connection terminal. 
     
     
         38 . The method of  claim 36 , further comprising laser welding the first connection terminal to the first pin and laser welding the second connection terminal to the second pin. 
     
     
         39 . The method of  claim 38 , further comprising adjusting a laser welder along a single axis to weld the first connection terminal to the first pin and to weld the second connection terminal to the second pin. 
     
     
         40 . The method of  claim 38 , further comprising implanting the implantable device without further coating the implantable device. 
     
     
         41 . An apparatus, comprising:
 means for electrically and physically coupling a first lead terminal to a first terminal; means for coupling to a pin of an implantable device and for electrically coup the pin to the first terminal; and   an over-molded layer that is biocompatible and disposed over the means for electrically and physically coupling a first lead terminal to a first terminal and the means for coupling to a pin of an implantable device.   
     
     
         42 . The apparatus of  claim 41 , wherein the means for electrically and physically coupling a first lead terminal to a first terminal include a pre-molded header that is biocompatible and that defines a first channel and a second channel, the pre-molded header including a first terminal in electrical communication with a first lead terminal of the pre-molded header. 
     
     
         43 . The apparatus of  claim 42 , wherein the means for coupling to a pin of an implantable device include a flex harness that is biocompatible, one-piece and includes a first conductor with a first connection terminal and a second conductor with a second connection terminal, with the first conductor and the second conductor being physically interconnected by a common harness portion, the flex harness conformed to the pre-molded header such that the first conductor is disposed in the first channel and the second conductor is disposed in the second channel. 
     
     
         44 . An apparatus, comprising:
 a core portion that is biocompatible and that defines a first channel guide and a second channel guide, the core portion including a first set-screw block in electrical communication with a first lead receptacle of the core portion;   a circuit member conformed to the core portion, the circuit member including a first conductive finger element comprising a first connector pad and a second conductive finger element comprising a second connector pad, the first and second conductive finger elements being mechanically connected via conductive traces, the circuit member comprising a pre-formed alignment such that the first conductive finger element is disposed in the first channel guide and the second conductive finger element is disposed in the second channel guide, wherein the first conductive finger element defines a conductive path between the first terminal and the first connector pad; and   an overmolded layer that is biocompatible and disposed over the core portion and the circuit member such that the first conductive finger element and the second conductive finger element are disposed between the core portion and the overmolded layer.   
     
     
         45 . The apparatus of  claim 44 , wherein a conductive path extends between the first set-screw block and the first lead receptacle internal to the core portion. 
     
     
         46 . The apparatus of  claim 44 , further comprising an implantable device including a first connector and a second connector, with the first connector pad soldered or welded to the first connector, and the second connector pad soldered or welded to the second connector. 
     
     
         47 . The apparatus of  claim 46 , wherein the first connector pad is welded to the first connector and the second connector pad is welded to the second connector. 
     
     
         48 . The apparatus of  claim 46 , wherein the core portion and the overmolded layer define a recess, with the first connector pad and the second connector pad being disposed the in the recess, and further comprising medical adhesive disposed in the recess. 
     
     
         49 . The apparatus of  claim 46 , further comprising a first medical electrical lead coupled to the first lead receptacle. 
     
     
         50 . The apparatus of  claim 49 , wherein the first lead receptacle is female, and the first medical electrical lead comprises a male pin or ring which is disposed at least partially in the first lead receptacle. 
     
     
         51 . The apparatus of  claim 44 , wherein the first connector pad is a first spade connector and the second connector pad is a second spade connector. 
     
     
         52 . The apparatus of  claim 51 , wherein the first spade connector and the second spade connector each comprise stainless steel. 
     
     
         53 . The apparatus of  claim 51 , wherein the first spade connector and the second spade connector each are substantially planar and are coplanar. 
     
     
         54 . An apparatus, comprising:
 a core portion that is biocompatible and that defines a plurality of lead receptacles in a row, the core portion defining an exterior surface with a first set-screw block in electrical communication with a first lead receptacle of the plurality of lead receptacles, and with a second set-screw block in electrical communication with a second lead receptacle of the plurality of lead receptacles;   a circuit member coupled to the core portion, the circuit member comprising a first conductive finger element including a first connector pad and a second conductive finger element comprising a second connector pad, the first and second conductive finger elements being mechanically connected via conductive traces, the circuit member comprising a pre-formed alignment such that the first conductive finger element is aligned to the first set-screw block and the second conductive finger element is aligned to the second set-screw block, with the first conductive finger element defining a conductive path between the first set-screw block and the first connector pad; and   an overmolded layer that is biocompatible and disposed over the core portion and the circuit member such that the first conductive finger element and the second conductive finger element are disposed between the core portion and the overmolded layer.   
     
     
         55 . The apparatus of  claim 54 , wherein the first set-screw block comprises a block connection. 
     
     
         56 . The apparatus of  claim 54 , wherein the conductive traces are removable conductive traces adapted to be removed from the first conductive finger element and to be removed from the second conductive finger element. 
     
     
         57 . An apparatus, comprising:
 a core portion that is biocompatible and that defines a first channel guide and a second channel guide, the core portion comprising a first set-screw block in electrical communication with a first lead receptacle of the core portion;   a circuit member conformed to the core portion, the circuit member comprising a first conductive finger element comprising a first connector pad and a second conductive finger element comprising a second connector pad, the first and second conductive finger elements being mechanically connected via conductive traces, the circuit member comprising a pre-formed alignment such that the first conductive finger element is disposed in the first channel guide and the second conductive finger element is disposed in the second channel guide, with the first conductive finger element defining a conductive path between the first set-screw block and the first connector pad; and   an overmolded layer that is biocompatible and is disposed over the core portion and the circuit member such that the first conductive finger element and the second conductive finger element are disposed between the core portion and the overmolded.   
     
     
         58 . The apparatus of  claim 57 , wherein a conductive path extends between the first set-screw block and the first lead receptacle internal to the core portion. 
     
     
         59 . The apparatus of  claim 57 , wherein the conductive traces are removable conductive traces adapted to be removed from the first conductive finger element and to be removed from the second conductive finger element. 
     
     
         60 . A method, comprising:
 molding a biocompatible material over a jumper to define a core portion that includes a first channel guide, a second channel guide, and a lead receptacle to receive a medical electrical lead, the jumper electrically coupling the lead receptacle to a first set-screw block;   pre-forming a circuit member comprising a first conductive finger element that comprises a first connector pad and a second conductive finger element that includes a second connector pad, wherein the first conductive finger element and the second conductive finger element are coupled via conductive traces such that the first conductive finger element is pre-formed to conform, in alignment, to the first channel guide, and the second conductive finger element is pre-formed to conform, in alignment, to the second channel guide;   wrapping the circuit member around the core portion such that a first conductive finger element of the circuit member is disposed in the first channel guide and a second conductive finger element of the circuit member is disposed in the second channel guide;   electrically coupling the first conductive finger element to the first set-screw block; and   overmolding at a first pressure an overmolded layer of biocompatible material over the first set-screw block, the first conductive finger element, and the second conductive finger element, wherein the first connector pad and the second connector pad are exposed through an opening in the overmolded layer.   
     
     
         61 . The method of  claim 60 , further comprising:
 wrapping the first connector pad around a first connector of an implantable device; wrapping the second connector pad around a second connector of the implantable device; and   welding the first connector pad to the first connector and the second connector pad to the second connector by automatically adjusting a welding machine between a first welding position and a second welding position along a single axis.   
     
     
         62 . The method of  claim 61 , further comprising backfilling, under a second pressure which is lower than the first pressure, a recess defined by the implantable device, the core portion, and the overmolded layer, and comprising the first connector pad and the second connector pad. 
     
     
         63 . The method of  claim 61 , further comprising laser welding the first connector pad to the first connector and laser welding the second connector pad to the second connector. 
     
     
         64 . The method of  claim 63 , further comprising adjusting a laser welder along a single axis to weld the first connector pad to the first connector and to weld the second connector pad to the second connector. 
     
     
         65 . The method of  claim 63 , further comprising implanting the implantable device without further coating the implantable device. 
     
     
         66 . An apparatus, comprising:
 means for electrically and physically coupling a first lead receptacle to a first set-screw block;   means for coupling to a connector of an implantable device and for electrically coupling the connector to the first set-screw block; and   an overmolded layer that is biocompatible and disposed over the means for electrically and physically coupling a first lead receptacle to a first set-screw block, and the means for coupling to a connector of an implantable device.   
     
     
         67 . The apparatus of  claim 66 , wherein the means for electrically and physically coupling a first lead receptacle to a first set-screw block comprises a core portion that is biocompatible and that defines a first channel guide and a second channel guide, the core portion including a first set-screw block in electrical communication with a first lead receptacle of the core portion. 
     
     
         68 . The apparatus of  claim 67 , wherein the means for coupling to a connector of an implantable device comprises a circuit member that is biocompatible, one-piece, and that comprises a first conductive finger element with a first connector pad and a second conductive finger element with a second connector pad, wherein the first conductive finger element and the second conductive finger element are physically interconnected by conductive traces, the circuit member conformed to the core portion such that the first conductive finger element is disposed in the first channel guide and the second conductive finger element is disposed in the second channel guide.