the following detailed description is exemplary in nature and is not intended to limit the scope , applicability , or configuration of the invention in any way . rather , the following description provides practical illustrations for implementing exemplary embodiments . examples of constructions , materials , dimensions , and manufacturing processes are provided for selected elements , and all other elements employ that which is known to those of skill in the field of the disclosure . those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized . fig1 is a plan view of an exemplary medical electrical lead 100 that may include embodiments of the present invention . fig1 illustrates lead 100 including an outer insulation sidewall 110 that extends between a proximal portion 116 and a distal portion 117 ; proximal portion 116 includes electrical contact surfaces 12 , 14 and 15 , which are shown mounted on connector legs of proximal portion 116 ; and distal portion 117 includes electrode surfaces 120 , 140 and 151 . dashed lines in fig1 schematically illustrate conductors 220 , 240 and 250 which extend within outer insulation sidewall 110 to couple each of electrode surfaces 120 , 140 , 151 to a corresponding contact surface 12 , 14 , 15 . thus , lead 100 is a tripolar lead that may provide pacing and sensing , via electrode surfaces 120 and 140 , and defibrillation , via electrode surface 151 . according to some preferred embodiments , conductor 220 is formed as a coil to provide torque transfer between proximal portion 116 and distal portion and to electrically couple electrode surface 120 to contact surface 12 , and conductors 240 , 250 are each formed as a cable to electrically couple electrode surfaces 140 , 150 to contact surfaces 14 , 15 , respectively . according to embodiments described herein , electrode surface 151 is a first portion of an electrode component 150 , and a second portion of electrode component 150 extends within outer insulative sidewall 110 for coupling with conductor 250 . it should be noted that either or both of the components including electrode surfaces 120 and 140 may also include portions which are coupled to the corresponding conductors 220 , 240 in a manner similar to embodiments described herein . two exemplary lead configurations , or arrangements of conductors 220 , 240 , 250 will be described herein ( a first in conjunction with fig2 b - c and 3 , and a second in conjunction with fig5 ), but any suitable arrangement of conductors 220 , 240 , 250 , within outer insulation sidewall 110 , is within the scope of the present invention . furthermore , it should be noted , that embodiments are not limited to inclusion in tripolar pacing and defibrillation leads , like lead 100 , and lead 100 is only an exemplary type of lead used for the purpose of illustration . fig2 a is a perspective view of a coupling component 225 , according to some embodiments , which may be incorporated into lead 100 to form the coupling between conductor 250 and the aforementioned second portion of electrode component 150 . fig2 a illustrates coupling component 225 , which is formed from a slug of conductive material , including a first side 211 , a second side 212 , which extends opposite first side 211 , a third side , which extends between first and second sides 211 , 212 , and a fourth side 214 , which also extends between first and second sides 211 , 212 , opposite third side 213 . fig2 a further illustrates component 225 including a continuous bulk 25 of the slug of conductive material , which defines third side 213 , and first and second arms 21 , 22 , each of which extend over a length l , from continuous bulk 25 to fourth side 214 ; each arm 21 , 22 is shown having a width w , which is defined between first and second sides 211 , 212 . according to the illustrated embodiment , a space g between first and second arms 21 , 22 of component 225 is intended to receive a length of an elongate conductor , for crimping between the arms , for example , conductor 250 , as shown in fig2 b - c . although fig2 a shows length l being approximately the same for both arms 21 , 22 , it should be noted that , according to alternate embodiments , arms 21 , 22 extend over different lengths ; the differing lengths may facilitate an overlapping of arms 21 , 22 when conductor is crimped therebetween , according to these alternate embodiments . fig2 b - c are each a perspective view of a portion of lead 100 , generally coinciding with section line a - a of fig1 , wherein outer insulation sidewall 110 is cut away to show alternative couplings between electrode component 150 and conductor 250 , via coupling component 225 . fig2 b - c illustrate conductor 250 extending between an inner insulation sidewall 210 and outer insulation sidewall 110 , and coupling component 225 also located between sidewalls 210 , 110 to receive a length of conductor 250 , between arms 21 , 22 , for a crimp joint , and to receive a second portion 152 of electrode component 150 over a surface 20 thereof for a weld joint . although not shown , it should be appreciated that conductor 220 , which couples electrode surface 120 to contact surface 12 ( fig1 ), extends within inner insulation sidewall 210 . conductor 240 is also not shown , for the purpose of clarity in the illustration of the coupling ; but , it should be appreciated that conductor 240 also extends between inner insulation sidewall 210 and outer insulation sidewall 110 to couple electrode surface 140 to contact surface 14 . dashed lines in fig2 b - c illustrate an optional extension of conductor 250 beneath first portion 151 of electrode component 150 , beyond the crimped junction with component 225 , for example , to another junction with electrode component 150 , at an opposite end thereof , according to some embodiments . according to the embodiments of fig2 b - c , a length of conductor 250 , about which arms 21 , 22 are crimped , extends along width w of arms 21 , 22 and , generally , in a direction of a longitudinal axis 11 of lead 100 . conductor 250 may include a 1 × 19 cable configured from a plurality of wire strands , for example , formed from mp35n alloy , which is known to those skilled in the art ; a cross - section view of conductor 250 including such a cable is shown in fig2 d . silver cored mp35n may also be employed . this present invention is even more important in this context as silver has lower melting point . the conductor wires may alternatively can be cable or solid conductors such as ta or ag cored mp35n . fig2 d illustrates cable 290 surrounded by an insulative jacket 295 , for example , formed from a fluoropolymer , such as ptfe or etfe ; a portion of jacket 295 is removed from about cable 290 , along the length of conductor 250 which is crimped between arms 21 , 22 , either prior to , or during the formation of the crimp . fig2 d further illustrates cable 290 made up of a plurality of wire strands 209 , for example , each having a diameter between approximately 0 . 0005 inch and approximately 0 . 005 inch ; strands 210 may be stranded with a pitch between approximately 0 . 3 inch and 0 . 6 inch . another exemplary cable , that may form conductor 250 , is known as a 7 × 7 cable , which includes seven cabled bundles of seven wire strands , and is described in commonly - assigned u . s . pat . no . 5 , 760 , 341 , which is hereby incorporated by reference . according to some embodiments , width w of arms is at least approximately 0 . 02 inch , and , if a diameter of conductor 250 is approximately 0 . 006 inch ( with insulative jacket 295 removed for the coupling ), the space g between arms 21 , 22 is approximately 0 . 008 inch and a length l over which arms 21 , 22 extend is at least approximately 0 . 01 inch . a length of arms 21 , 22 may be such that ends of arms do not overlap when the arms are crimped about the conductor , for example , by confronting crimp heads that indent arms 21 , 22 on either side of conductor 250 ; but , according to alternate embodiments , for example , as will be describe below in conjunction with fig3 , a length of arms 21 , 22 is such that one of arms overlaps the other when crimped . with further reference to fig2 a - c , a surface 20 of component 225 , which faces outer insulation sidewall 110 , is intended to receive an overlapping of second portion 152 of electrode component 150 , for welding thereto , for example , via a solid state yag type laser , known to those skilled in the art . fig2 a illustrates surface 20 of component 225 including a first part 201 , which extends over continuous bulk 25 , and a second part 202 , which extends over first arm 21 ; a spot weld joint between second portion 152 of electrode component 150 and component 225 is preferably located along first part 201 of surface 20 so that a maximum thickness of conductive material , which is present in continuous bulk 25 , as opposed to in arm 21 , is available to maximize the weld pool for the joint . locating the weld on first part 201 of surface 20 also helps to offset the weld joint from the crimp joint formed between arms 21 , 22 and conductor 250 , so that the formation of the two joints are less likely to compromise one another , while still allowing the entire coupling , between electrode component 150 and conductor 250 , to reside beneath outer insulation sidewall 110 . according to embodiments illustrated by fig2 b , second portion 152 of electrode component 150 extends , over first part 201 of surface 20 of component 225 , in a direction transverse to the direction of longitudinal axis 11 ; while , according to embodiments illustrated by fig2 c , second portion 152 extends , over first part 201 of surface 20 , in the general direction of longitudinal axis 11 , similar to the extent of the crimped portion of conductor 250 . suitable materials from which all , or at least second portion 152 of electrode component 150 may be formed include , without limitation , platinum - iridium alloy , tantalum , tantalum alloys , platinum - iridium clad tantalum and platinum - iridium clad tantalum alloys . corresponding suitable materials from which component 225 may be formed , in order to accommodate laser welding between bulk 25 and second portion 152 of component 225 , include , without limitation , platinum - iridium alloy , tantalum , tantalum alloys , titanium and titanium alloys . according to some preferred embodiments , if space g and length l of arms 21 , 22 are dimensioned as described above , for conductor 250 as described above , and electrode component 150 is formed by a multi - filar coil , as illustrated , and each filar of the coil has a diameter between approximately 0 . 005 inch and approximately 0 . 01 inch , a thickness of bulk 25 ( between surface 20 and an opposite surface 20 ′) is between approximately 0 . 014 inch and approximately 0 . 02 inch , and an approximate area of first part 201 of surface 20 is the product of width w , which ranges from approximately 0 . 02 inch to approximately 0 . 06 inch , and a depth d , which ranges from approximately 0 . 01 inch to approximately 0 . 02 inch ( fig2 a ). dimensions may correspondingly be reduced if smaller conductor cables are used . according to some alternate embodiments , electrode component 150 is a coil formed from a single filar , or wire , for example , having a diameter of between approximately 0 . 005 inch and approximately 0 . 01 inch . the single or multiple filars forming electrode component 150 , according to some preferred embodiments , are formed from flattened , or ribbon , wire , rather than round wire ; a cross - section of the flattened , or ribbon , wire may be defined by a width that is between approximately 0 . 005 inch and approximately 0 . 013 inch and a thickness , or height , that is between approximately 0 . 002 inch and approximately 0 . 005 inch . fig3 is a perspective view of a portion of lead 100 ( fig1 ), generally coinciding with section line a - a of fig1 , wherein outer insulation sidewall 110 is cut away to show a conductive coupling , according to yet further embodiments . fig3 illustrates an alternative orientation of both component 225 and the length of conductor 250 , which is crimped between arms 21 , 22 of component 225 . according to the illustrated embodiment , conductor 250 is wound about inner insulation sidewall 210 , and component 225 is oriented such that length l of arms 21 , 22 extends generally in the direction of longitudinal axis 11 and the length of conductor 250 , which is crimped between arms 21 , 22 , extends in the general direction of the winding of conductor 250 , which is transverse to longitudinal axis 11 . although conductor 240 ( fig1 ) is not shown in fig3 , for the purpose of clarity in the illustration of the coupling , it should be appreciated that conductor 240 may also be wound about inner insulation sidewall 210 , alongside conductor 250 , and extends beneath electrode surface 151 , being routed to a coupling with electrode surface 140 ( fig1 ). fig3 further illustrates arm 21 overlapping arm 22 in the crimp about conductor 250 , for example , having been formed by bending , either as an alternative to , or in addition to indenting , as described above . fig4 a is a perspective view of a coupling component 325 , according to some alternate embodiments , which may be employed , as a substitute for component 225 , in the embodiments illustrated by fig2 b - c and 3 . it should be noted that suitable materials and dimensions for coupling component 325 may be the same as previously described for component 225 . fig4 a illustrates coupling component 325 including the four sides 211 , 212 , 213 , 214 , the two arms 21 , 22 , and the continuous bulk 25 , as previously described , such that component 325 has the same general form as component 225 . fig4 a further illustrates a surface 30 of component 325 including a first portion 301 , which extends over continuous bulk 25 , a second portion 302 , which extends over arm 21 , and a groove 315 , which is formed in first part 301 of surface 30 and extends orthogonally with respect to length l over which arms 21 , 22 extend . according to the illustrated embodiment , groove 315 is located to receive one or both filars of second portion 152 of electrode component 150 , so as to provide a positively identified position for second portion 152 , for repeatability of welding , from one coupling to the next ; and , according to some embodiments , groove 315 may be sized to be a friction fit about second portion 152 , to further hold portion 152 in place for welding . dashed lines in fig4 a illustrate multiple alternate and / or additional locations and orientations for grooves , according to alternate embodiments of component 325 . according to some alternate embodiments , component 325 includes an additional groove , which extends alongside groove 315 , so that each filar of second portion 152 of electrode component 150 can extend in an independent corresponding groove . according to some further alternate embodiments , component 325 includes one or more grooves that extend at an angle less than 90 degrees with respect to length l over which arms 21 , 22 extend . in order to make embodiments of component 325 less sensitive to orientation , and thereby increase manufacturing flexibility , a duplicate groove or set of grooves may be formed in a first part 301 ″ of a surface 30 ″ of component 325 , which surface 30 ″ is opposite surface 30 . fig4 b is a perspective view of a coupling component 425 , according to yet further alternate embodiments , which may also be employed , as a substitute for component 225 , in the embodiments illustrated by fig2 b - c and 3 . it should be noted that suitable materials and dimensions for coupling component 425 may be the same as previously described for component 225 . fig4 b illustrates coupling component 425 including the four sides 211 , 212 , 213 , 214 and the continuous bulk 25 , as previously described for component 225 ; in contrast to component 225 , a first arm 41 of component 425 includes a terminal end 411 that extends toward a second arm 42 of component 425 , and second arm 42 includes a terminal end 412 that extends toward first arm 41 . fig4 b further illustrates each of terminal ends 411 , 412 including an interlocking feature , so that arms 41 , 42 mate together when crimped about a conductor , for example , conductor 250 , as illustrated in fig5 . like coupling components 225 and 325 , component 425 includes continuous bulk 25 defining third side 213 and from which arms 41 and 42 extend ; a surface 40 of coupling component includes a first part 401 , which extends over continuous bulk 25 , and a second part 402 , which extends over first arm 41 . according to the illustrated embodiment , and similar to the previously described embodiments , a spot weld joint between second portion 152 of electrode component 150 and component 425 is preferably located along first part 401 of surface 40 so that a maximum thickness of conductive material , which is present in continuous bulk 25 , as opposed to in arm 41 , is available to maximize the weld pool for the joint ; such a joint is illustrated in fig5 . fig5 is a cross - section through medical electrical lead 100 , at section line a - a of fig1 , showing a conductive coupling within an alternative insulative sidewall configuration , according to some alternate embodiments . fig5 illustrates an inner insulative sidewall 510 of lead 100 being integral with outer insulative sidewall 110 in a multi - lumen tube configuration , wherein sidewalls 110 and 510 together form a first lumen 501 , in which conductor 220 extends , a second lumen 502 , in which conductor 240 extends , and a third lumen 503 , in which conductor 250 extends . fig5 further illustrates , a conductive coupling between conductor 250 and electrode component 150 located in third lumen 503 ; the illustrated coupling is formed by interlocking arms 41 , 42 of coupling component 425 crimped about a length of conductor 250 and by a weld joint formed between second portion 152 of electrode component 150 and continuous bulk 25 of coupling component 425 . in the foregoing detailed description , specific embodiments have been described . however , it may be appreciated that various modifications and changes can be made without departing from the scope of the invention as set forth in the appended claims .
the present invention is configured to provide an offset weld and crimp in a coupling component that can be located entirely within a lumen of a lead body . this end is accomplished by providing an asymmetric coupling component is provided with a crimp recess , for example a groove or a bore extending along one side of the component and a thickened portion offset laterally from the groove or bore and having a welding surface displaced laterally from the groove or bore . while the embodiments illustrated herein are those employing a crimping groove , for purposes of understanding the invention it should be understood that a bore may be substituted . in preferred embodiments , the crimp recess is used to receive a stranded or cabled conductor within the lead body and the offset portion is used to attach to one or more filars of an electrode coil by welding thereto .