Abstract:
A connector assembly for a medical device includes at least one contact assembly, and each of the at least one contact assembly includes a mounting member, a first contact clip and a second contact clip. A method for assembling the connector assembly includes mounting the first contact clip to one of a first pair of opposing mounting sidewalls, on a first side of a shoulder of the mounting member, and mounting a second contact clip to one of a second pair of opposing mounting sidewalls of the mounting member, on a second side of the shoulder. The mounting member includes a bore, to receive axial insertion of a medical electrical lead connector therein, and the first and second pairs of opposing mounting sidewalls extend about the bore, such that opposing curved legs of each of the mounted connector clips bend into and out from the bore.

Description:
TECHNICAL FIELD 
       [0001]    The present invention pertains to medical device and more particularly to medical device connector assemblies and contact assemblies thereof. 
       BACKGROUND 
       [0002]    A host of medical devices include electrical connector assemblies for coupling with a type of medical electrical lead connector that is formed along a proximal portion of the lead and includes a plurality of connector elements disposed along a length thereof. These connector assemblies typically include a plurality of electrical contacts positioned within a bore of what is typically called a device connector module, or header, at locations corresponding to the connector elements of the lead connector, in order to mate with the corresponding connector elements when the connector is fully inserted within the bore. Some device connector assemblies further include sealing elements located between the electrical contacts to mate with insulative spacers located between the connector elements of the lead connector, and thereby provide electrical isolation between each mating contact and connector element. Although a variety of contact assemblies for such connector assemblies are known in the art, there is still a need for new contact assembly designs that provide for stable electrical connection without increasing a bulk, complexity or cost of the connector assemblies. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    The following drawings are illustrative of particular embodiments of the present invention and therefore do not limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements. 
           [0004]      FIG. 1A  is perspective view of a portion of an exemplary medical system that may include embodiments of the present invention. 
           [0005]      FIG. 1B  is a perspective view of a pair of connector assemblies from the system show in  FIG. 1A , according to an exemplary embodiment of the present invention. 
           [0006]      FIG. 2  is a perspective view of a contact assembly, according to some embodiments of the present invention. 
           [0007]      FIG. 3  is an exploded perspective view of the contact assembly of  FIG. 2 , according to some embodiments of the present invention. 
           [0008]      FIGS. 4A-C  are cross-sections of a component of the contact assembly shown in  FIG. 3 , along  FIG. 3  section lines C-C, D-D, and B-B, respectively. 
           [0009]      FIG. 5  is a cross-section of another component of the contact assembly shown in  FIGS. 2 and 3 , along section line E-E of  FIG. 3 . 
           [0010]      FIG. 6  is a plan view of a contact clip, according to some embodiments of the present invention. 
           [0011]      FIG. 7  is a longitudinal cross-section along a portion of the one of the connector assemblies shown in  FIG. 1B , according to some embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    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 of the present invention. 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 invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized. 
         [0013]      FIG. 1A  is perspective view of a portion of an exemplary medical system that may include embodiments of the present invention.  FIG. 1A  illustrates the medical system including a medical device  10  and a medical electrical lead  100 ; a connector  130  of lead  100  is shown terminating a proximal end thereof and including a plurality of connector elements  131  spaced apart along a length of connector  130  by a plurality of interposed insulative spacers. Materials, components and construction methods for lead connectors, such as connector  130 , are well known to those skilled in the art.  FIG. 1A  further illustrates device  10  including a housing  11  and a connector module  12  mounted thereto; module  12  includes a pair of bores  121  formed by connector assemblies  120 , which are contained within module  12  and are shown in  FIG. 1B . 
         [0014]      FIG. 1B  is a perspective view of connector assemblies  120 , according to an exemplary embodiment of the present invention.  FIG. 1B  illustrates each connector assembly  120  including a plurality of contact assemblies  122 ,  129  spaced apart from one another, by a plurality of seal members  124 , along a length of bore  121 . According to the illustrated embodiment, contact assembly  129  is a set screw-type contact known to those skilled in the art. A location of each contact assembly  122 ,  129  corresponds to a location of each connector element  131  of lead connector  130  to provide electrical coupling between the corresponding connector element  131  and circuitry contained within housing  11 , when connector  130  is fully inserted into either of bores  121 ; and interspersed seal members  124  provide electrical isolation between the couplings. An additional sealing member  124 ′ is shown located at an entry to each bore; sealing members  124 ′ may prevent an ingress of bodily fluids into bore  121 , for example, if device  10  is an implantable device. Those skilled in the art will appreciate that module  12 , for example, formed from either silicone or polyurethane, or a combination thereof, may be molded around connector assemblies  120  and includes passages or wire-ways for routing of lead wires from contact assemblies  122  to corresponding feedthrough ports which extend through housing  11 ; if device  10  is implantable, the feedthrough ports are hermetically sealed. Connector assemblies  120 , as a whole, will be discussed in greater detail, below, in conjunction with  FIG. 7 . 
         [0015]      FIG. 2  is a perspective view of one of contact assemblies  122 , according to some embodiments of the present invention.  FIG. 2  illustrates contact assembly  122  including a bore  221 , which forms a portion of bore  121  ( FIGS. 1A-B ), and contact surfaces  20  protruding into bore  221 . According to some embodiments, when lead connector  130  is inserted within one of bores  121  formed by connector assemblies  120 , such that one of lead connector elements  131  is aligned with contact surfaces  20  within bore  221 , surfaces  20  make electrical contact with the aligned connector element  131 .  FIG. 2  further illustrates contact assembly  122  including two members  243 ,  244 , embodiments of which are described in greater detail in conjunction with  FIGS. 3-5 ; the members are called a cup member  243  and a mounting member  244  in the following description. 
         [0016]      FIG. 3  is an exploded perspective view of contact assembly  122 , according to some embodiments of the present invention.  FIG. 3  illustrates contact surfaces  20  located along first and second legs  311 ,  312  of a first contact clip  31  and along first and second legs  321 ,  322  of a second contact clip  32 . According to the illustrated embodiment, a sidewall of mounting member  244 , that extends about bore  221 , includes first and second mounting sidewalls  33 ,  35 , which each provide for the mounting, or attachment of a corresponding contact clip  31 ,  32 , such that contact surfaces  20  thereof protrude into bore  221 . With further reference to  FIG. 3 , it may be appreciated that each of mounting sidewalls  33 ,  35  only extend about a portion of a perimeter of bore  221  to allow for legs  311 ,  312  and  321 ,  322  to extend into bore  221 , and that sidewalls  33 ,  35  are axially offset from one another, that is, offset from one another along a longitudinal axis of member  244 . With reference to  FIGS. 4A-B , which are cross-section views of component  244 , without clips  31 ,  32 , through lines C-C and D-D of  FIG. 3 , it may further be appreciated that the portions of the perimeter of bore  221  about which sidewalls  33 ,  35  extend are offset, about the perimeter, from one another by approximately ninety degrees. It should be noted that although bore  221  has a round cross-section, so that the perimeter thereof defines a circumference of the bore, embodiments of the present invention are not limited to including bores having round cross-sections. 
         [0017]    With further reference to  FIG. 3 , the sidewall of mounting member  244  includes a shoulder  34  located between first and second mounting sidewalls  33 ,  35 ; shoulder  34  may stabilize the mounting of first and second contact clips  31 ,  32  with respect to one another, when clips  31 ,  32  are attached to mounting sidewalls  33 ,  35 , respectively. Although  FIG. 3  illustrates a preferred embodiment in which shoulder  34  extends about an entirety of the perimeter of bore  221 , it should be noted that an extent of shoulder  34  can be more limited, according to alternate embodiments, for example, as shown by the shading bounded by dashed lines in  FIGS. 4A-B .  FIG. 3  further illustrates another shoulder  36  axially offset from shoulder  34  and located alongside second mounting sidewall  35 . According to the illustrated embodiment, shoulder  36  extends about the entirety of the perimeter of bore  221  and, with reference to  FIG. 4C , which is a cross-section view through section line B-B of  FIG. 3 , shoulder  36  extends axially away from second mounting sidewall  35  to surround a counter-bore  421  of mounting member  244 . Like shoulder  34 , as previously described, shoulder  36 , according to alternate embodiments, can extend about only a portion of the perimeter of bore  221 . Shoulder  36  may serve to further stabilize the mounting of second clip  32 , and the extent of shoulder  36  which surrounds counter-bore  421  can interlock with an adjacent member of connector assembly  120 , as will be described below in conjunction with  FIG. 7 . 
         [0018]    FIGS.  3  and  4 A-C further illustrate a first opposing sidewall  330 , opposite first mounting sidewall  33 , and a second opposing sidewall  350 , opposite second mounting sidewall  35 . With particular reference to  FIGS. 4A-B , it may be appreciated that first and second opposing sidewalls  330 ,  350  extend about portions of the perimeter of bore  221  which are offset from the corresponding mounting sidewalls  33 ,  35  by approximately 180 degrees. According to the illustrated embodiment, first and second opposing sidewalls  330 ,  350  and first and second mounting sidewalls  33 ,  35 , respectively, are symmetric; such symmetry may be advantageous for ease, or flexibility of assembly, since opposing sidewalls  330 ,  350  can serve as alternative mounting sidewalls for contact clips  31 ,  32 . According to some embodiments, first and second opposing sidewalls  330 ,  350  interface with contact clip legs  311 ,  312  and  321 ,  322 , in proximity to contact clip terminal ends  310 ,  313  and  320 ,  323 , respectively, in order to pre-load clips  31 ,  32 , respectively. Pre-loading will be described in greater detail, below, in conjunction with  FIG. 6 . 
         [0019]      FIG. 5  is a cross-section view through cup member  243  of contact assembly  122 , along section line E-E shown in  FIG. 3 .  FIGS. 3 and 5  illustrate cup member  243  including a sidewall  50  surrounding bore  221  and two counter-bores  521 ,  721  extending on either side of bore  221 . According to the illustrated embodiment, when cup member  243  is assembled together with mounting member  244 , that has clips  31 ,  32  attached thereto, for example, as shown in  FIGS. 2 and 7 , clips  31 ,  32  are contained in counter-bore  521 , and an inner surface  54  of sidewall  50  surrounding counter-bore  521  fits snugly about shoulder  34  of mounting member  244 . The extent of sidewall  50  that surrounds counter-bore  721  can interlock with an adjacent member of connector assembly  120 , as will be described below in conjunction with  FIG. 7 . 
         [0020]      FIG. 6  is a plan view of either of clips  31 ,  32 .  FIG. 6  illustrates clip  31 / 32  including a joining portion  65 ; joining portion  65  is shown extending between first and second legs  311 / 321 ,  312 / 322 , being curved about a circumference of a circle having a diameter D, and spanning a segment of the circle that has a central angle A.  FIG. 6  further illustrates each leg  311 / 321 ,  312 / 322  bending inward, toward one another, and then outward away from one another; the inward bending, or curvature, of each leg  311 / 321 ,  312 / 322  extends about a circumference of a circle having a radius R 1 , and spans a segment of the circle that has a central angle B 1 , and the outward bending, or curvature, of each extends about a circumference of a circle having a radius R 2 , and spans a segment of the circle that has a central angle B 2 . With reference back to  FIG. 3 , it may be appreciated that joining portion  65  of each clip  31 ,  32  rests on, and approximately spans the corresponding mounting sidewall  33 ,  34 , that the inward bending of legs  311 / 321 ,  312 / 322  results in the protrusion of contact surfaces  20  into bore  221 , and that the outward bending of legs  311 / 321 ,  312 / 322  keeps terminal ends  310 / 320 ,  313 / 323  located outside bore  221 , as well as facilitating a rather easy assembly of clips  31 / 32  onto the sidewall of mounting member  244 . According to preferred embodiments of the present invention, clip  31 / 32  is formed from a wire having a round cross-section, although any cross-sectional geometry may be employed by alternate embodiments. 
         [0021]      FIG. 6  further illustrates a relaxed gap G between a peak of the outward bending of leg  311 / 321  and a peak of the outward bending of leg  312 / 322 . According to the illustrated embodiment, these peaks form opposing contact surfaces  20  and gap G is opened up by insertion of a lead connector, for example, connector  130  ( FIG. 1A ) therebetween; a spring force of clips  31 / 32  applies an appropriate contact pressure of contact surfaces  20  against the corresponding connector element  131  positioned within bore  221  of the corresponding contact assembly  122 . As mentioned above, opposing sidewalls  330 ,  350 , opposite mounting sidewalls  33 ,  35 , according to some embodiments of the present invention, provide an interface for pre-loading of clips  31 ,  32 . Sidewall  330 / 350  can pre-load clip  31 / 32  by spreading opposing legs  311 / 321 ,  312 / 322  further apart from one another and holding a gap between therebetween which is wider than relaxed gap G. Such pre-loading may decrease an axial force required to insert a connector into a connector assembly that includes contact assemblies  122 , for example, connector  130  into connector assembly  120 . 
         [0022]    According to an exemplary embodiment of the present invention, for connector elements, for example, elements  131  of connector  130  ( FIG. 1A ), which have an outer diameter between approximately 0.044 inch and approximately 0.052 inch, and in which clips  31 / 32  are not pre-loaded: relaxed gap G is between approximately 0.041 inch and approximately 0.043 inch; diameter D of the circle defining joining portion  65  is between approximately 0.069 inch and approximately 0.071 inch, and central angle A of the segment of the circle defining joining portion  65  is between approximately 82 degrees and approximately 85 degrees; radius R 1  of the circle defining the inward bending of legs  311 / 321 ,  312 / 322  is between approximately 0.004 inch and approximately 0.006 inch, and the central angle B 1  of the segment of the circle defining the inward bending is between approximately 67 degrees and approximately 70 degrees; and radius R 2  of the circle defining the outward bending of legs  311 / 321 ,  312 / 322  is between approximately 0.059 inch and approximately 0.061 inch, and the central angle B 2  of the segment of the circle defining the outward bending is between approximately 44 degrees and approximately 46 degrees. An outer diameter of mounting sidewall  33 / 35 , and optionally opposing sidewall  330 / 350 , is between approximately 0.069 inch and approximately 0.071 inch for a line-to-ling fit of clip  31 / 32  thereon, according to the exemplary embodiment; and an inner diameter of sidewall  33 / 35  and  330 / 350  may be approximately 0.056 inch for the exemplary embodiment. Those skilled in the art will understand that these exemplary dimensions may be modified according to various diameters of connector elements  131  and/or if pre-loading is desired. 
         [0023]      FIG. 7  is a longitudinal cross-section along a portion of connector assembly  120  ( FIG. 1B ), according to some embodiments of the present invention.  FIG. 7  illustrates a lead wire  72  coupled to each of contact assemblies  122 ; as previously described, a module, for example, module  12  ( FIG. 1A ), which contains connector assembly  120 , may include wire-ways providing for the routing of each of lead wires  72  to the corresponding feedthrough port. According to an exemplary embodiment of the present invention, each of clips  31 ,  32 , mounting member  244  and cup member  243  are formed from MP35N alloy; alternative conductive materials from which these components may be formed include, without limitation, stainless steel, titanium, tantalum and platinum-iridium. Thus, according to the illustrated embodiment, a fit of cup member  243  over mounting member  244  and clips  31 ,  32 , being mounted thereon, provides intimate contact therebetween for electrical coupling so that lead wires  72 , being coupled to cup member  243 , power clips  31 ,  32 ; alternately, lead wires  72  may be coupled to mounting member  244 . With reference back to  FIG. 2 , in conjunction with  FIG. 7 , it will be appreciated that an outer diameter of cup member sidewall  50  is approximately equal to an outer diameter of mounting member shoulder  36 ; as previously described, an inner surface  54  of cup member sidewall  50  ( FIG. 5 ) fits snugly about mounting member shoulder  34 , and an interface, or seam  253  between sidewall  50  and shoulder  36  may be laser or resistance spot welded to secure members  243 ,  244  together. 
         [0024]    According to some alternate embodiments, one or both of members  243 ,  244  are formed from a non-conductive material, for example, a hard plastic or ceramic. If one of members  243 ,  244  is non-conductive, lead wires  72  may be coupled to the other of members  243 ,  244 , or directly to contact clips  31 ,  32 , in order to power clips  31 ,  32 . If neither of members  243 ,  244  is conductive, lead wires  72  may be coupled directly to each of clips  31 ,  32 , for example, via a wire-way formed through one of members  243 ,  244 . 
         [0025]      FIG. 7  further illustrates seal members  124  including internally-projecting sealing rings  74 , for mating with insulative spacers disposed between connector elements  131  of connector  130  ( FIG. 1A ), and an interlocking of each seal member  124  with adjacent contact assemblies  120 . As previously described, mounting member shoulder  36  extends to provide for the interlocking, as does cup member sidewall  50 . The illustrated interlocking features of connector assembly  120  are described in greater detail in commonly-assigned U.S. Pat. No. 6,895,276, salient portions of which are hereby incorporated by reference. 
         [0026]    In the foregoing detailed description, the invention has been described with reference to specific embodiments. 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. For example, although embodiments of a contact assembly presented herein include a pair of contact clips, for example, clips  31 ,  32 , to make common electrical contact with a single lead connector element, for example, one of elements  131 , each clip of the pair of contact clips may be isolated from one another within the contact assembly, for example, via mounting member  244  being formed from a non-conductive material, and individually coupled to independent lead wires for electrical coupling of two independent lead connector elements having been inserted within the contact assembly.