Abstract:
A surgical instrument suitable for preparing an intervertebral disc space includes an outer sleeve, an instrument head, an inner shaft, a handle, a universal joint, a coupling member, and a drive mechanism. The outer sleeve includes a proximal end, a distal end and a longitudinal axis. The instrument head defines a longitudinal axis and is disposed at the distal end of the outer shaft. The inner shaft is slidably disposed within the outer sleeve and includes a proximal end, a distal end and a longitudinal axis coaxially aligned with the longitudinal axis of the outer sleeve. The drive mechanism is coupled between the outer sleeve and the inner shaft and actuates the outer sleeve axially relative to the inner shaft, thereby setting an angle of the longitudinal axis of the instrument head in relation to the longitudinal axis of the inner shaft.

Description:
FIELD 
       [0001]    The present disclosure relates to a surgical instrument, and more particularly to a surgical insertion instrument having an articulating wrist. 
       BACKGROUND 
       [0002]    This section provides background information related to the present disclosure and is not necessarily prior art. 
         [0003]    Instruments and tools are used during surgical procedures for various purposes, including providing access to a surgical site, inserting or providing materials to the surgical site, and attaching or otherwise assembling certain components at the surgical site. In some situations, it may be necessary or desirable to insert the surgical instrument into small or constrained space, or enter the surgical site from a predetermined direction, or access a predetermined location in the surgical site, or provide a portion of the surgical instrument with various manners of movement (e.g., translation, rotation, angulation, etc.) at the surgical site. For example, during some surgical procedures it may be desirable to access or otherwise approach the surgical site from a lateral direction in order to avoid a portion of the anatomy or to enter another portion of the anatomy. 
         [0004]    While known surgical instruments have proven to be acceptable for their intended purposes, a continuous need for improvement in the relevant art remains. In this regard, it would be desirable to provide a surgical instrument that allows, or otherwise makes it easier, for a surgeon to access the surgical site and/or use and manipulate the surgical instrument at the surgical site. 
       SUMMARY 
       [0005]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0006]    According to one aspect of the present disclosure, a surgical instrument suitable for preparing an intervertebral disc space is provided. The surgical instrument includes an outer sleeve, an instrument head, an inner shaft, a handle, a universal joint, a coupling member, and a drive mechanism. The outer sleeve includes a proximal end, a distal end and a longitudinal axis. The instrument head defines a longitudinal axis and is disposed at the distal end of the outer shaft. The inner shaft is slidably disposed within the outer sleeve and includes a proximal end, a distal end and a longitudinal axis coaxially aligned with the longitudinal axis of the outer sleeve. The handle is coupled to the proximal end of the inner shaft. The universal joint includes one end coupled to the distal end of the inner shaft and another end coupled to the instrument head. The coupling member includes one end pivotably coupled between the distal end of the outer sleeve and another end pivotably coupled to a retainer. The drive mechanism is coupled between the outer sleeve and the inner shaft and actuates the outer sleeve axially relative to the inner shaft, thereby setting an angle of the longitudinal axis of the instrument head in relation to the longitudinal axis of the inner shaft. 
         [0007]    In some configurations, the instrument head includes one of a hexagonal head, a screw driver, and a drill bit. 
         [0008]    In some configurations, the universal joint includes an annular groove and the retainer includes an aperture. The surgical instrument further includes a hinge member disposed within the aperture and the annular groove. 
         [0009]    In some configurations, the drive mechanism includes a first drive mechanism coupled to the inner shaft and a second drive mechanism coupled to the outer shaft. 
         [0010]    In some configurations, the surgical instrument includes a handle member. 
         [0011]    In some configurations, the first drive mechanism is rotatable in relation to the handle member and the second drive mechanism, and the second drive mechanism is rotatable in relation to the handle member and the first drive mechanism. 
         [0012]    In some configurations, the outer sleeve includes a first threaded portion and the second drive mechanism includes a second threaded portion threadingly engaged with the first threaded portion. 
         [0013]    In some configurations, the outer sleeve includes a retaining feature extending from a proximal end to a distal end along the longitudinal axis. 
         [0014]    In some configurations, a portion of the handle assembly slidably engages the retaining feature. 
         [0015]    According to another aspect of the present disclosure, a surgical instrument is provided. The surgical instrument includes an outer sleeve, an inner shaft, a universal joint, a retainer, and a coupler. The outer sleeve includes a proximal end, a distal end, and a longitudinal axis extending between the proximal and distal ends. The inner shaft is rotatably and translatably disposed within the outer sleeve. The universal joint is pivotally coupled to the inner shaft. The retainer is configured to rotatably support the universal joint. The coupler includes a proximal end pivotally coupled to the outer sleeve and a distal end pivotally coupled to the retainer. 
         [0016]    According to yet another aspect of the present disclosure, a method of operating a surgical instrument is provided. The surgical instrument includes an outer sleeve extending along a first axis, an inner shaft supported by the outer sleeve for rotation about the first axis, and a drive member extending along a second axis. The method includes rotating the inner shaft about the first axis to rotate the drive member about the second axis. The method also includes translating the outer sleeve along the first axis to angulate the second axis relative to the first axis. 
         [0017]    In some configurations, the surgical instrument includes an activation member threadably engaged to the outer sleeve. 
         [0018]    In some configurations, translating the outer sleeve along the first axis includes threading the activation member relative to the outer sleeve. 
         [0019]    In some configurations, the surgical instrument includes an implant coupled to at least one of the inner shaft and the outer sleeve, and the method includes inserting the surgical instrument through an incision in an anterior posterior direction. The method can also include inserting the implant into an intervertebral disc space in a medial lateral direction. 
         [0020]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0021]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0022]      FIG. 1A  is a perspective view of an insertion instrument with an articulating wrist in a first position in accordance with the principles of the present disclosure; 
           [0023]      FIG. 1B  is a perspective view of the insertion instrument with an articulating wrist of  FIG. 1 , the insertion instrument shown in a second position; 
           [0024]      FIG. 2  is an exploded view of the insertion instrument with an articulating wrist of  FIG. 1 ; 
           [0025]      FIG. 3  is a cross-sectional view of a portion of the insertion instrument with an articulating wrist of  FIG. 1  taken along the line  3 - 3 ; 
           [0026]      FIG. 4  is a cross-sectional view of a portion of the insertion instrument with an articulating wrist of  FIG. 1  taken along the line  4 - 4   
           [0027]      FIG. 5  is a perspective view of a portion of the insertion instrument with an articulating wrist of  FIG. 1 , with a portion of the insertion instrument removed for clarity; 
           [0028]      FIG. 6  is a cross-sectional view of a portion of the insertion instrument with an articulating wrist of  FIG. 1  taken along the line  3 - 3 . 
           [0029]      FIG. 7A  is an environmental view of the insertion instrument with an articulating wrist of  FIG. 1  in a first mode of operation; and 
           [0030]      FIG. 7B  is an environmental view of the insertion instrument with an articulating wrist of  FIG. 1  in a second mode of operation. 
       
    
    
       [0031]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0032]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0033]    Referring to  FIG. 1A , an insertion instrument  10  with an articulating wrist constructed in accordance with the principles of the present teachings is illustrated. According to one exemplary use, the insertion instrument  10  may be used to insert an implant during a surgical procedure. Specifically, in some configurations, the insertion instrument  10  may be used to insert a spinal implant  12  into a portion of a spine  14  ( FIGS. 7A and 7B ), including into an intervertebral space  15  between adjacent vertebrae  17 . It will be appreciated, however, that the insertion instrument  10  may have various uses within the scope of the present disclosure. For example, as will be discussed in more detail below, the insertion instrument  10  may be used for drilling or otherwise forming an aperture, driving a fastener, assembling a multi-component implant, or other similar uses. 
         [0034]    With particular reference to  FIGS. 1A, 1B and 6 , the insertion instrument  10  includes an articulation assembly  16  and a handle assembly  18 . As will be explained in more detail below, the articulation assembly  16  may be drivingly engaged with the handle assembly, such that manipulation (e.g., rotation) of a portion of the handle assembly  18  can cause a portion of the articulation assembly  16 , and thus the implant  12 , to move (e.g., rotate, translate, angulate, etc.). 
         [0035]    As illustrated in  FIG. 2 , the articulation assembly  16  can include an outer sleeve  20 , an inner sleeve or shaft  22 , a universal joint  24 , a coupler  26 , and a retainer  28 . The outer sleeve  20  includes, or otherwise extends from and between a proximal end  30  and a distal end  32  along a first longitudinal axis A 1 . In this regard, as illustrated in  FIGS. 3 and 6 , the outer sleeve  20  includes a bore  34  extending longitudinally from and between the proximal and distal ends  30 ,  32  of the outer sleeve  20 . The proximal end  30  of the outer sleeve  20  can include a threaded portion  36  and an anti-rotation feature  38 . As illustrated in  FIGS. 2 and 6 , the threaded portion  36  can be an outer threaded portion  36 . The anti-rotation feature  38  can include a channel or groove formed in an outer surface  42  of the outer sleeve  20  between the proximal end  30  and the threaded portion  36 . In this regard, the anti-rotation feature  38  can extend from a proximal end  44  to a distal end  46  along the first longitudinal axis A 1 . As will be explained in more detail below, the distance along the first longitudinal axis A 1 , between the proximal end  44  and the distal end  46  of the anti-rotation feature  38 , can define a maximum travel distance of the outer sleeve  20  relative to the inner shaft  22  along the first longitudinal axis A 1 . 
         [0036]    As illustrated in  FIG. 2 , the distal end  32  of the outer sleeve  20  can include a first pivot feature or hinge  50 . The hinge  50  can be an aperture formed in the outer sleeve  20 , and a pin member  52 . As will be explained in more detail below, in an assembled configuration, the hinge  50  can pivotally couple the outer sleeve  20  to the coupler  26 . As illustrated, the distal end  32  of the outer sleeve  20  can also include a cut-away or recessed portion  51 , such that the distal end  32  of the outer sleeve  20  defines a portion of a cylinder (e.g., a semi-cylindrical construct). 
         [0037]    With further reference to  FIG. 2 , the shaft  22  includes, or otherwise extends from and between a proximal end  53  and a distal end  54  along a second longitudinal axis A 2 . In an assembled configuration, the shaft  22  can be rotatably and translatably disposed within the bore  34  of the outer sleeve  20 , such that the second longitudinal axis A 2  is parallel to the first longitudinal axis A 1 . In this regard, the shaft  22  is configured to rotate within the outer sleeve  20  about the second longitudinal axis A 2 , and translate within the outer sleeve  20  along the second longitudinal axis A 2 . 
         [0038]    The shaft  22  can include a first retaining feature or groove  56  disposed near the proximal end  53 , a hinge mechanism or yoke  58  disposed near the distal end  54 , and a retaining feature or reduced diameter portion  60  disposed between the proximal and distal ends  53 ,  54 . As will be explained in more detail, below, in the assembled configuration the groove  56  can secure the shaft  22  to the handle assembly  18 , and the hinge mechanism  58  can be pivotally coupled to the universal joint  24 . In this regard, the hinge mechanism  58  can define a first pivot axis P 1  of the universal joint  24 . As will be explained in more detail below, the reduced diameter portion  60  can help to secure the shaft  22  within the outer sleeve  20 , and/or further define the maximum travel distance of the outer sleeve  20  relative to the inner sleeve  22  along the first longitudinal axis A 1 . In this regard, with reference to  FIGS. 3 and 4 , the pin  52  can create or otherwise define a reduced diameter portion of the bore  34  of the outer sleeve  20  that is substantially equal to, or slightly greater than, an outer diameter of the reduced diameter portion  60  of the shaft  22 . Accordingly, the shaft  22  is at least partially supported for rotation and translation by the pin  52 . 
         [0039]    As illustrated in  FIG. 2 , the universal joint  24  can include a spider or cross-piece  64  and a hinge mechanism or yoke  66 . The hinge mechanism  66  can define a second pivot axis P 2  of the universal joint  24 . The second pivot axis P 2  is perpendicular to the first pivot axis P 1 . In this regard, in the assembled configuration, the hinge mechanism  58  of the shaft  22  can be pivotally coupled to the cross-piece  64  for pivotal rotation about the first pivot axis P 1 , and the hinge mechanism  66  of the universal joint  24  can be pivotally coupled to the cross-piece  64  for pivotal rotation about the second pivot axis P 2 . 
         [0040]    With reference to  FIGS. 2 and 3 , the hinge mechanism  66  may further include an instrument head or driving feature  70  and a retaining feature  72 . The driving feature  70  and the second pivot axis P 2  may be disposed at opposite ends of the hinge mechanism  66 . As illustrated in  FIG. 2 , the driving feature  70  can include a hex head or other similar feature that can drivingly engage, or otherwise mate with, the implant  12 . In this regard, it will also be appreciated that the driving feature  70  may include, or otherwise be configured to mate with, other surgical tools or implants, such as drill bits, fasteners, pins, and other similar components. The retaining feature  72  can be disposed between the second pivot axis P 2  and the driving feature  70 . As illustrated in at least  FIG. 2 , in some configurations, the retaining feature  72  can include an annular groove or channel. As will be explained in more detail below, in the assembled configuration, the retaining feature  72  can help to rotatably secure the hinge mechanism  66  within the retainer  28 . 
         [0041]    The coupler  26  can extend from a proximal end  78  to a distal end  80 . In some configurations, the coupler  26  may include or otherwise define a portion of a cylinder extending from and between the proximal and distal ends  78 ,  80 . In this regard, in the assembled configuration, the coupler  26  may mate with, or otherwise be received by, the recessed portion  51  of the outer sleeve, such that the distal end  32  of the outer sleeve  20  and the coupler  26  collectively define a substantially cylindrical construct. 
         [0042]    The proximal end  78  of the coupler  26  includes a first pivot or hinge feature  82 , and the distal end  80  includes a second pivot or hinge feature  84 . As illustrated in  FIG. 2 , in some configurations, the first and second hinge features  82 ,  84  can each include a pair of aligned apertures. In the assembled configuration, the first hinge feature  82  can be pivotally coupled to the outer sleeve  20 , and the second hinge feature  84  can be pivotally coupled to the retainer  28 . In this regard, in the assembled configuration, the pin  52  can be rotatably received by at least one of the first hinge feature  82  and the hinge  50  of the outer sleeve  20 , such that the coupler  26  is pivotally coupled to the outer sleeve  20 , as described above. 
         [0043]    The retainer  28  includes, or otherwise extends from and between a proximal end  88  and a distal end  90  along a third longitudinal axis A 3 . In this regard, as illustrated in  FIG. 3 , the retainer  28  includes a bore  92  extending longitudinally from and between the proximal and distal ends  88 ,  90 . The bore  92  is sized and shaped to receive a portion of the hinge mechanism  66  (e.g., the driving feature  70 ) for rotation therein. The proximal end  88  of the retainer  28  can include a second pivot feature or hinge  94  that is substantially similar to the first pivot feature or hinge  50  formed in the outer sleeve  20 . In this regard, the hinge  94  can include an aperture formed in the retainer  28 , and a pin  98 . As illustrated in  FIG. 3 , the pin  98  and the pin  52  may define parallel pivot axes P 3 , P 4 , respectively. In the assembled configuration, the pin  98  can be rotatably received by at least one of the second hinge feature  84  of the coupler  26  and the hinge  94  of the retainer  28 , such that the retainer  28  is pivotally coupled to the coupler  26 . In this regard, as illustrated in  FIG. 3 , the pin  98  can be received within the retaining feature  72  of the hinge mechanism  66 , such that the pin  98  can allow the hinge mechanism  66  to rotate within the bore  92  about the third longitudinal axis A 3 , and can prevent the hinge mechanism  66  from translating within the bore  92  in a direction parallel to the third longitudinal axis A 3 . In this regard, as illustrated in  FIG. 4 , in the assembled configuration, the pin  98  can be slidably received within the groove  72 . 
         [0044]    As illustrated in  FIG. 2 , the proximal end  88  of the retainer  28  can also include a cut-away or recessed portion  100 , such that the proximal end  88  of the retainer  28  defines a portion of a cylinder (e.g., a semi-cylindrical construct). In this regard, in the assembled configuration, the coupler  26  may mate with, or otherwise be received by, the recessed portion  100  of the retainer  28 , such that the coupler  26  and the proximal end  88  of the retainer  28  collectively define a substantially cylindrical construct. 
         [0045]    With reference to  FIGS. 1, 2 and 6 , the handle assembly  18  includes a handle  104 , a first drive or actuation mechanism  106 , and a second drive or actuation mechanism  108 . As will be explained in more detail below, the first and second actuation mechanisms  106 ,  108  can be rotatably coupled to the handle  104  and configured to drive or actuate the shaft  22  and the outer sleeve  20 , respectively, and cause the hinge mechanism  66  to rotate about the third longitudinal axis A 3 , and/or to cause the hinge mechanism  66  and third longitudinal axis A 3  to angulate relative to the first longitudinal axis A 1 . 
         [0046]    The handle  104  includes, or otherwise extends from and between a proximal end  112  and a distal end  114  along a fourth longitudinal axis A 4 . In this regard, as illustrated in  FIG. 6  the handle  104  includes a bore  116  extending longitudinally from and between the proximal and distal ends  112 ,  114  of the handle  104 . The bore  116  can be sized and shaped to rotatably receive the outer sleeve  20 , the inner shaft  22 , and the first and second actuation mechanisms  106 ,  108  at the proximal and distal ends  112 ,  114 , respectively, of the handle  104 . 
         [0047]    As illustrated in  FIG. 6 , the first actuation mechanism  106  is coupled to the shaft  22  and rotatably received within the bore  116  of the handle  104 . In this regard, in the assembled configuration the shaft  22  may be coupled to the first actuation mechanism  106  with a set screw  118 , for example, such that rotation of the first actuation mechanism  106  causes the rotation of the shaft  22  about the second longitudinal axis A 2 , and in turn, rotation of the hinge mechanism  66  and the drive feature  70  about the third longitudinal axis A 3 . 
         [0048]    With continued reference to  FIG. 6 , the second actuation mechanism  108  is coupled to the outer sleeve  20  and rotatably received within the bore  116  of the handle  104 . In this regard, the second actuation mechanism  108  may include an internally threaded portion  122  configured to engage the threaded portion  36  of the outer sleeve  20 . Accordingly, and as will be explained in more detail below, in the assembled configuration, rotation of the second actuation mechanism  108  relative to the handle  104  can cause the threaded portion  122  of the second actuation mechanism  108  to threadably engage the threaded portion  36  of the outer sleeve, and in turn, cause the outer sleeve  20  to translate within the bore  116  and along the first longitudinal axis A 1 . 
         [0049]    With continued reference to the figures, operation of the insertion instrument  10  will now be described in more detail. In a first mode of operation, a surgeon may choose to rotate the driving feature  70 , or the implant  12  coupled thereto, for example, about the third longitudinal axis A 3 . In this regard, in the first mode of operation, the surgeon may rotate the first actuation mechanism  106  relative to the handle  104  about the fourth longitudinal axis A 4 , to cause the shaft  22  and the driving feature  70 , coupled thereto in the manner described above, to rotate about the second and third longitudinal axes A 2 , A 3 , respectively. Accordingly, the driving feature  70  and/or the implant  12  may rotate from a first position ( FIG. 1A ) to a second position ( FIG. 1B ) about the third longitudinal axis A 3 . 
         [0050]    With reference to  FIGS. 7A and 7B , in an exemplary surgical procedure, the first mode of operation may include creating an incision  102  in a patient to provide access to a surgical site  104  from a first direction. For example, the incision  102  may be aligned with the patient&#39;s spine  14 , and provide access to the patient&#39;s spine  14  from an anterior-posterior direction. Accordingly, the implant  12  may be inserted into the incision in the anterior-posterior direction while the instrument  10  is in the first position ( FIG. 7A ). 
         [0051]    In a second mode of operation, the surgeon may choose to angulate the third longitudinal axis A 3  or the driving feature  70  relative to the second longitudinal axis A 2  of the shaft  22 . The second mode of operation can occur before, after, or concurrently with the first mode of operation. Specifically, the surgeon may rotate the second actuation mechanism  108  relative to the handle  104  about the fourth longitudinal axis A 4 . As the surgeon rotates the second actuation mechanism  108 , the threaded portion  122  of the second actuation mechanism  108  will threadably engage the threaded portion  36  of the outer sleeve  20 . In this regard, the handle assembly  18  may further include at least one second anti-rotation feature or pin  126 . In the assembled configuration, the pin  126  will engage the anti-rotation feature  38  formed in the outer sleeve  20  to prevent the outer sleeve from rotating relative to the handle  104 . As the outer sleeve  20  threadably engages the second actuation mechanism  108 , the outer sleeve will translate relative to the handle  104 , and thus the shaft  22 , along the first longitudinal axis A 1 . As the outer sleeve  20  translates along the first longitudinal axis A 1 , the coupler  26  will restrain the distance between the hinge  94  of the retainer  28  and the hinge  50  of the outer sleeve  20 , while the pin  98  and the retaining feature  72  of the hinge mechanism  66  can prevent the retainer  28  from translating relative to the hinge mechanism  66  along the third longitudinal axis A 3 . Accordingly, as the outer sleeve  20  translates along the first longitudinal axis A 1 , the hinge mechanism  66  is forced to pivot about the first and/or second pivot axes P 1 , P 2 , thus allowing the third longitudinal axis A 3  to angulate relative to the first longitudinal axis A 1  from the first position ( FIG. 7A ) to the second position ( FIG. 7B ). As illustrated in  FIGS. 7A and 7B , the first longitudinal axis A 1  may remain in the same position in both the first and second modes of operation. 
         [0052]    In an exemplary surgical procedure, the second mode of operation may include directing or otherwise moving the driving feature  70  and/or the implant  12  in a second direction transverse to the first direction. For example, as illustrated in  FIGS. 7A and 7B , in a spinal surgery procedure, the surgeon may direct the driving feature  70  and/or the implant  12  into the surgical site  104 , such as the intervertebral disc space  15  of the spine  14  for example, in a medial-lateral direction, while a portion of the instrument  10  extends through the incision  102  in the anterior-posterior direction. Accordingly, as illustrated in  FIG. 7B , the implant  12  may be inserted into the intervertebral disc space  15  while the outer sleeve  20  remains in the first position ( FIG. 7A ). 
         [0053]    The adjustability (e.g., rotation) of the driving feature  70  about the third longitudinal axis A 3 , and the adjustability of the third longitudinal axis (e.g., angulation) relative to the first longitudinal axis A 1  can allow the surgeon to move the driving feature  70  and/or the implant  12  into a plurality of positions. As such, the adjustability of the driving feature  70  and/or the implant  12  can allow the surgeon to access the surgical site  104  from various directions and in various configurations to perform a variety of procedures at the surgical site  104 . 
         [0054]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. 
         [0055]    Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
         [0056]    The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0057]    When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0058]    Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
         [0059]    Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.