Abstract:
A surgical instrument includes a shaft having a proximal end and a distal end and end effector coupled to the distal end of the shaft. An electrical transmission conduit extends along the shaft from the proximal end to the distal end and is configured to deliver electrical energy to energize the end effector. A connector assembly electrically couples the electrical transmission conduit to the end effector, and the end effector is pivotably coupled to the connector assembly. In another aspect, a surgical instrument includes a pin, an electrically conductive connector including a contact portion and an attachment, the contact portion surrounding the pin. An electrical conduit is electrically coupled to the attachment of the connector. An electrically conductive jaw including an aperture is pivotable around the contact portion, and the contact portion electrically contacts the jaw at the aperture of the jaw.

Description:
[0001]    This application is a divisional application of U.S. patent application Ser. No. 14/209,043, filed on Mar. 13, 2014, which claims the benefit of U.S. Provisional Application No. 61/803,046, filed on Mar. 18, 2013, each of which is incorporated by reference herein in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    Aspects of the present disclosure relate to a surgical instrument for a teleoperated (robotic) surgical system. Further aspects relate to a drive element for a surgical instrument and an electrical connection for a surgical instrument. 
       INTRODUCTION 
       [0003]    Some minimally invasive surgical techniques are performed remotely through the use of teleoperated (robotically-controlled) surgical instruments (which may also be referred to as tools). In teleoperated surgical systems, surgeons manipulate input devices at a surgeon console, and those inputs are passed to a patient side cart that interfaces with one or more teleoperated surgical instruments. Based on the surgeon&#39;s inputs at the surgeon console, the one or more teleoperated surgical instruments are actuated at the patient side cart to operate on the patient, thereby creating a master-slave control relationship between the surgeon console and the surgical instrument(s) at the patient side cart. 
         [0004]    Teleoperated surgical systems may have multiple arms to which surgical instruments may be coupled. The surgical instruments include end effectors used to perform surgical procedures. An end effector may be actuated by a drive element. Further, when the end effector is energized, such as for a cauterization procedure, the surgical instrument includes an electrical connection to provide electrical energy to the end effector. It is desirable to provide drive elements and electrical connections with enhanced durability while also performing their respective functions within the small space of a surgical instrument. 
       SUMMARY 
       [0005]    Exemplary embodiments of the present disclosure may solve one or more of the above-mentioned problems and/or may demonstrate one or more of the above-mentioned desirable features. Other features and/or advantages may become apparent from the description that follows. 
         [0006]    In accordance with at least one exemplary embodiment, a surgical instrument comprises a shaft, an end effector connected to the shaft, and a push/pull drive element. The push/pull drive element comprises a head that extends perpendicular to a push/pull direction of the push/pull element. The head of the push/pull drive element may have end portions each having a cross-section that differs from a cross-section of a main portion of the head between the end portions. 
         [0007]    In accordance with at least one exemplary embodiment, a surgical instrument may comprise a shaft, an end effector connected to the shaft, and a push/pull drive element. The push/pull drive element may include an engagement portion and an end portion connected to an end of the engagement portion. The engagement portion may be in contact with the end effector to actuate the end effector. The engagement portion may have a first width and the end portion may have a second width, wherein the second width is greater than the first width. 
         [0008]    In accordance with at least one exemplary embodiment, a surgical instrument may comprise a shaft, an end effector connected to the shaft, at least one conduit to provide energy to the end effector, and a connector. The connector may electrically connect the at least one conduit to the end effector. The end effector may be in sliding contact with a portion of the connector. 
         [0009]    Additional objects, features, and/or advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present disclosure and/or claims. At least some of these objects and advantages may be realized and attained by the elements and combinations particularly pointed out in the appended claims. 
         [0010]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claims; rather the claims should be entitled to their full breadth of scope, including equivalents. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The present disclosure can be understood from the following detailed description, either alone or together with the accompanying drawings. The drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more exemplary embodiments of the present teachings and together with the description serve to explain certain principles and operation. 
           [0012]      FIG. 1  is a top view of an exemplary embodiment of a surgical instrument including a force transmission mechanism. 
           [0013]      FIG. 2  is a partial perspective view of an exemplary embodiment of a surgical instrument having an end effector. 
           [0014]      FIG. 3  is an exploded view of the surgical instrument of  FIG. 2 . 
           [0015]      FIG. 4  is a side view of the end effector of  FIG. 2 , along line  4 - 4  of  FIG. 2 , the end effector being in a closed position. 
           [0016]      FIG. 5  is a view of the end effector of  FIG. 4  in an open position. 
           [0017]      FIG. 6  is a cut-away view of an exemplary embodiment of a clevis of a surgical instrument in accordance with the present disclosure. 
           [0018]      FIG. 7  is a cross-section view along line  7 - 7  of  FIG. 4  but with an exemplary embodiment of a clevis also shown. 
           [0019]      FIG. 8  is a cross-sectional view along line  8 - 8  of  FIG. 5  but with an exemplary embodiment of a clevis also shown. 
           [0020]      FIG. 9  is a cut-away view of an exemplary embodiment of a clevis and an end of a projection of a drive element located within a groove of the clevis. 
           [0021]      FIG. 10  is a partial perspective view of an exemplary embodiment of a push/pull drive element. 
           [0022]      FIG. 11  is an exploded view of the push/pull drive element of  FIG. 10 . 
           [0023]      FIG. 12  is an end view of the push/pull drive element of  FIG. 10 . 
           [0024]      FIG. 13  is an end view of another exemplary embodiment of a push/pull drive element. 
           [0025]      FIG. 14  is a partial cut-away view of an exemplary embodiment of a surgical instrument clevis and a push/pull drive element. 
           [0026]      FIG. 15  is a partial cut-away view of an exemplary embodiment of a clevis and an end of a projection of a push/pull drive element. 
           [0027]      FIG. 16  is a partial cut-away view of an exemplary embodiment of a non-energized surgical instrument. 
           [0028]      FIG. 17  is a cut-away view of an exemplary embodiment of a surgical instrument clevis and a push/pull drive element. 
           [0029]      FIG. 18  is a partial side cut-away view of an exemplary embodiment of a surgical instrument. 
           [0030]      FIG. 19  is a partial side cut-away view of the surgical instrument of  FIG. 18  with a jaw removed. 
           [0031]      FIG. 20  is a perspective view of an exemplary embodiment of a connector assembly. 
           [0032]      FIG. 21  is an exploded view of the connector assembly of  FIG. 20 . 
           [0033]      FIG. 22  is a perspective view of an exemplary embodiment of a connection portion of a connector assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Exemplary embodiments discussed herein regard a surgical instrument for a teleoperated surgical system. The surgical instrument may be relatively simple and inexpensive to manufacture, while providing a robust configuration resulting in a relatively durable instrument able to perform multiple functions within a relatively compact design. 
         [0035]    This description and the accompanying drawings that illustrate exemplary embodiments should not be taken as limiting. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the scope of this description and the invention as claimed, including equivalents. In some instances, well-known structures and techniques have not been shown or described in detail so as not to obscure the disclosure. Like numbers in two or more figures represent the same or similar elements. Furthermore, elements and their associated features that are described in detail with reference to one embodiment may, whenever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment. 
         [0036]    For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages, or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about,” to the extent they are not already so modified. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. 
         [0037]    It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items. 
         [0038]    This description&#39;s terminology is not intended to limit the present disclosure or claims. For example, spatially relative terms—such as “beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like—may be used to describe one element&#39;s or feature&#39;s relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e., locations) and orientations (i.e., rotational placements) of a device in use or operation in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be “above” or “over” the other elements or features. Thus, the exemplary term “below” can encompass both positions and orientations of above and below. A device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
         [0039]    Teleoperated surgery generally involves the use of a manipulator that has multiple manipulator arms. One or more of the manipulator arms often support a surgical instrument. One or more of the manipulator arms may be used to support a surgical image capture device, such as an endoscope (which may be any of a variety of structures such as a laparoscope, an arthroscope, a hysteroscope, or the like), or, optionally, some other imaging modality (such as ultrasound, fluoroscopy, magnetic resonance imaging, or the like). Typically, the manipulator arms will support at least two surgical tools corresponding to the two hands of a surgeon and one image capture device. Such teleoperated surgical systems are described in U.S. Pat. No. 8,545,515 entitled “Curved Cannula Surgical System,” issued on Oct. 1, 2013, which is hereby incorporated by reference in its entirety. 
         [0040]    Turning to  FIG. 1 , a side view of an exemplary embodiment of a surgical instrument  100  for a teleoperated surgical system is shown. Surgical instrument  100  may include a force transmission mechanism  110 , a shaft  122  connected to force transmission mechanism  110  at a proximal end  123  of shaft  122 , and an end effector  120  connected to a distal end  124  of shaft  122 . Shaft  122  may be flexible. According to an exemplary embodiment, shaft  122  may have a diameter ranging from about 3 mm to about 15 mm. According to another exemplary embodiment, the diameter of shaft  122  may range, for example, from about 5 mm to about 8 mm. Surgical instrument  100  may include one or more members to translate force between force transmission mechanism  110  and end effector  120 . For instance, one or more drive element(s)  126  may connect force transmission mechanism  110  to end effector  120  to provide actuation forces to end effector  120 , such as by extending through an interior of shaft  122 . By utilizing drive element(s)  126 , force transmission mechanism  110  may actuate end effector  120  to, for example, control a wrist mechanism (not shown in  FIG. 1 ) of instrument  100  and/or to control a jaw of end effector  120  (or other moveable part). Further, because end effector  120  may be fixed to shaft  122 , force translated from force translation mechanism  110  to end effector  120  may in turn be translated to shaft  122 , such as when force translation mechanism  110  actuates end effector  120  in a rolling motion. Drive element(s)  126  may be in the form of tension elements, such as when force transmission mechanism  110  is a pull-pull mechanism, or one or more drive element rods or push rods, such as when force transmission mechanism  110  is a push-pull mechanism, as described in U.S. Pat. No. 8,545,515. 
         [0041]    Force transmission mechanism  110  may include one or more components to engage with a patient side cart of a teleoperated surgical system to translate a force provided by patient side cart to surgical instrument  100 . According to an exemplary embodiment, force transmission mechanism  110  may include one or more interface disks  112 ,  114  that engage with a manipulator of a patient side cart, as described in U.S. Pat. No. 8,545,515. Thus, interface disks  112 ,  114  utilize actuation forces from a manipulator to actuate instrument  100 . For instance, first disk  112  may be configured to provide a rolling motion to shaft  122  and provide a roll DOF for end effector  120 , while second disk  114  may operate a jaw mechanism of end effector  120  to open and close. The force transmission mechanism may include other interface disks that actuate various other functionalities of a surgical instrument, as those having ordinary skill in the art are familiar with. 
         [0042]    Turning to  FIG. 2 , an exemplary embodiment of a surgical instrument  200  for a teleoperated surgical system is shown that includes a shaft  202 , clevis  204 , and an end effector  206 . According to an exemplary embodiment, surgical instrument  200  may include a wrist that couples the clevis  204  to the shaft  202 , or surgical instrument  200  may be a non-wristed instrument. If surgical instrument  200  lacks a wrist, end effector  206  may be directly connected to clevis  204  and clevis  204  may be directly connected to shaft  202 . As shown in  FIG. 3 , which is an exploded view of the exemplary embodiment of  FIG. 2 , end effector  206  may include a first jaw  220  and a second jaw  230 . First jaw  220  may include a grip portion  222 , a connection aperture  224 , and an actuation aperture  226 . Similarly, second jaw  230  may include a grip portion  232 , a connection aperture  234 , and an actuation aperture  236 . 
         [0043]    According to an exemplary embodiment, connection apertures  224 ,  234  may be used to connect jaws  220 ,  230  to clevis  304 , which is in turn connected to shaft  202 . For instance, as shown in the exemplary embodiment of  FIGS. 2 and 3 , a rivet or pin  208  may be inserted through connection apertures  224 ,  234  and through an aperture  205  in clevis  204  to connect jaws  220 ,  230  to clevis  204 . Pin  208  may also serve as an axis of rotation about which jaws  220 ,  230  rotate when end effector  206  is actuated to open and close jaws  220 ,  230 , which will be described below. 
         [0044]    Surgical instrument  200  may include a mechanism to actuate end effector  206 , such as to open and close jaws  220 ,  230 . As shown in the exemplary embodiment of  FIG. 3 , surgical instrument may include a drive element  210  connected to end effector  206 . A proximal end (not shown) of drive element  210  may be connected to a manipulator (not shown) of a teleoperated surgical system that provides motive force to drive element  210 . For instance, drive element  210  may be a push/pull drive element rod that is pushed or pulled along direction  213  in  FIG. 3  by a motive force provided by the manipulator to actuate end effector  206 . 
         [0045]    A distal end  215  of drive element  210  may be connected to end effector  206  to translate the motive force from the manipulator to the jaws  220 ,  230 . According to an exemplary embodiment, distal end  215  of drive element  210  may include a first projection  212  connected to jaw  220  and a second projection  214  connected to jaw  230 . For instance, jaw  220  may include an actuation aperture  226  that first projection  212  is inserted into and jaw  230  may include an actuation aperture  236  that second projection  214  is inserted into. Actuation apertures  226 ,  236  may be in form of, for example, elongated slots, such as rectangular or oval slots that projections  212 ,  214  may be inserted into. Thus, as drive element  210  is pushed or pulled along direction  213  in  FIG. 3 , projections  212 ,  214  may slide within actuation apertures  226 ,  236 , causing jaws  220 ,  230  to pivot about pin  208 . 
         [0046]    Turning to  FIG. 4 , a side view of end effector  206  is shown along line  4 - 4  in  FIG. 2  but without clevis  204  and pin  208 . In the exemplary embodiment of  FIG. 4 , the jaws  220 ,  230  of end effector  206  are in a closed state. Although drive element  210  is not shown in  FIG. 4 , second projection  214  is shown within actuation slot  236  of jaw  230 . When drive element  210  is pushed in direction  217  in  FIG. 4 , second projection  214  is forced upwards. Consequently, jaws  220 ,  230  rotate and pivot about pin (not shown) located in connection aperture  234  in direction  219  in  FIG. 5 , causing jaws  220 ,  230  to separate and open. 
         [0047]    Surgical instrument  200  may include one or more features to assist with the movement of drive element  210  during actuation of end effector  206 , such as between the closed and open states shown in the exemplary embodiments of  FIGS. 4 and 5 , respectively. According to an exemplary embodiment, clevis  204  may include one or more features to assist with the movement of drive element  210 . Turning to  FIG. 6 , a cut away view of an exemplary embodiment of clevis  204  is provided. Clevis  204  includes a sidewall  246  that forms an outer surface of clevis  246  and in  FIG. 6  a portion of sidewall  246  has been removed to show internal features of clevis  204 . Clevis  204  may include a lumen  244  for passage of drive element  210  through clevis  204  and an aperture  205  for a pin  208  to connect jaws  220 ,  230  of an end effector  206 , as discussed above in regard to the exemplary embodiment of  FIG. 3 . According to an exemplary embodiment, clevis  204  may include other lumens for other components, such as, for example, conduits to provide energy to end effector  206  (e.g., electrical wires) and/or additional actuation components (e.g., an actuation element for an additional degree of freedom for surgical instrument or for a component, such as a knife). 
         [0048]    To assist with the movement of drive element  210 , clevis  204  may include one or more features to interact with the projections  212 ,  214  of drive element  210 . For instance, clevis  204  may include a groove  240  in the sidewall  246 , as shown in the exemplary embodiment of  FIG. 6 . According to an exemplary embodiment, groove  240  may have a finite depth and a bottom surface  245 , as shown in  FIG. 6 . However, the configuration of groove  240  is not limited to such a geometry and groove  240  may instead be provided as a slot (not shown) that passes completely through sidewall  246  of clevis  204 . One or more projections  212 ,  214  of drive element  210  may be configured to extend into groove  240  so that when drive element  210  is moved to actuate end effector  206 , groove  240  supports a projection  212 ,  214 . In other words, one or more projections  212 ,  214  of drive element  210  may have a length sufficient to extend through jaws  220 ,  230  (such as through actuation apertures  226 ,  236 ) and into groove  240  in sidewall  246 . 
         [0049]    Turning to  FIG. 7 , a cross-section view is shown along line  7 - 7  of  FIG. 4  is shown but with clevis  204  also provided.  FIG. 8  depicts a cross-sectional view along line  8 - 8  of  FIG. 5  but with clevis also provided. As shown in the exemplary embodiment of  FIG. 7 , clevis  204  may include two grooves  240 ; one for each projection  212 ,  214  of drive element  210 . In addition, grooves  240  may be opposed to one another, as shown in  FIG. 7 . Because projections  212 ,  214  of drive element  210  are placed within grooves  240 , when drive element  210  is moved to actuate an end effector  206  (e.g., by moving drive element  210  in and out of the page of  FIG. 7 ), grooves  240  support and/or guide the movement of projections  212 ,  214  and thus drive element  210 . For instance, at least one of sidewalls  241 ,  243  of groove  240  may contact projections  212 ,  214  as drive element  210  is moved and projections  212 ,  214  slide back and forth within groove  240 . According to an exemplary embodiment, a bottom surface  245  of groove  240  may be in contact with projections  212 ,  214  to support projections  212 ,  214 , either alternatively or in addition to contact with one or more sidewalls  241 ,  243 . Turning to  FIG. 9 , a cut-away view of an exemplary embodiment of clevis  204  is shown, which is similar to the view of  FIG. 6 , except that the end of projection  212  is shown within groove  240 . As shown in the exemplary embodiment of  FIG. 9 , projection  212  may contact sidewalls  241 ,  243  of groove  240 , such as at contact portions  248 , so that projection  212  is supported by groove  240 . Because projections  212 ,  214  have a substantially circular cross section, even at the ends of projections  212 ,  214  that fit within grooves  240 , contact portions  248  may be characterized by contact between a circle and a planar surface. For instance, contact portions  248  may be a substantially tangential contact portion between projections  212 ,  214  and sidewalls  214 ,  243  of groove  240 . In other words, contact portions  248  may have a shape of line or a point. Thus, all of the stress transmitted between projections  212 ,  214  and sidewalls  241 ,  243  is concentrated to relatively small areas. 
         [0050]    When drive element  210  is moved to actuate an end effector  206  to open and close jaws  220 ,  230 , portions of jaws  220 ,  230  may move apart from one another. This is also demonstrated in  FIGS. 7 and 8 . In  FIG. 7 , jaws  220 ,  230  are in a closed position, as shown in the exemplary embodiment of  FIG. 4 . In  FIG. 8 , jaws  220 ,  230  have been moved to an open position due to the movement of drive element  210 , as shown in the exemplary embodiment of  FIG. 5 . In particular, the proximal ends of jaws  220 ,  230  may move in different directions when jaws  220 ,  230  move to an open position, as shown in the exemplary embodiment of  FIG. 5 . This is also demonstrated in  FIG. 8 , which shows that the end of jaw  220  has moved in direction  250  relative to  FIG. 7  and that the end of jaw  230  has moved in direction  252  relative to  FIG. 7 . 
         [0051]    Because of the motions of jaws  220 ,  230  in respective directions  250 ,  252 , a torque is exerted upon drive element  210  in direction  254  shown in the exemplary embodiment of  FIG. 8 . Torque in direction  254  causes drive element  210  to twist, resulting in projection  212  exerting force against sidewall  243  of one groove  240  and projection  214  exerting force against sidewall  241  of another groove  240 . Further, due to the geometry of contact portions  248  between projections  212 ,  214  and sidewalls  241 ,  243  of grooves  240 , such as line or point contact, the force exerted between projections  212 ,  214  and sidewalls  241 ,  243  is limited to small areas. As a result, grooves  240  may permanently deform and/or wear as projections  212 ,  214  slide back and forth within grooves  240  and press against sidewalls  241 ,  243 . According to an exemplary embodiment, jaws  220 ,  230  may move in opposite directions to directions  250 ,  252  shown in the exemplary embodiment of  FIG. 8  when jaws  220 ,  230  are actuated to a closed position, which may result in a torque and twisting motion in a direction opposite to direction  254  in  FIG. 8 . 
         [0052]    According to an exemplary embodiment, clevis  204  may be made from a non-metallic material. For instance, clevis  204  may be made of a plastic, such as, for example polyether ether ketone (PEEK), including glass filled PEEK. When clevis  204  is made of a non-metallic material, for example, a plastic material, permanent deformation and/or wear may occur on the surfaces of grooves  240 , such as sidewalls  241 ,  243 . In addition, forces between projections  212 ,  214  and sidewalls  241 ,  241  may even be sufficient for projections to pop out of grooves  240  when drive element  210  is twisted in direction  254 , particularly when sidewalls  241 ,  243  have become worn. 
         [0053]    In view of these considerations, it may be desirable to provide a surgical instrument with enhanced durability. In particular, it may be desirable to provide a surgical instrument with one or more features to support and/or guide the movement of a drive element for an end effector that have enhanced durability, such as by enhancing the distribution of force between the drive element and another component of the surgical instrument. 
         [0054]    Turning to  FIG. 10 , a perspective view of an exemplary embodiment of a push/pull drive element  300  is shown. Push/pull drive element  300  may be, for example, a push rod, a wire, a cable, or other structure known by one of ordinary skill in the art for use as a push/pull drive element. For instance, push/pull drive element may be an element with sufficient columnar compressibility to transmit an axial pushing force applied to the push/pull drive element. Push/pull drive element  300  may be used according to the same functions as drive element  210  described above for the exemplary embodiments of  FIGS. 2-9 . As shown in  FIG. 10 , push/pull drive element  300  may include a shaft  302  connected to a head  304 . Head  304  may include, for example, a cross shaft  309  and end portions  306 , as shown in  FIG. 11 . Cross shaft  309  may also be referred to, for example, as a main portion of head  304 . Head  304  may be formed from separate pieces, such as cross shaft  309  and end portions  306 , as shown in the exemplary embodiment of  FIGS. 10 and 11 , or head  304  may be provided with a single piece construction by providing cross shaft  309  and end portions  306  as a single piece. According to an exemplary embodiment, portions of push/pull drive element  300 , such as shaft  302  and cross shaft  309  and end portions  306 , may be made of a metal. For example, portions of push/pull drive element  300  may be made of a wear resistant stainless steel alloy, such as Nitronic® 60. 
         [0055]    According to an exemplary embodiment, push/pull drive element  300  may include an insulative material  308 , such as when push/pull drive element  300  is used in a surgical instrument is energized, as will be discussed below. Insulative material  308  may be a material that minimizes arcing and electrical conductivity, such as, for example, a plastic material. As shown in the exemplary embodiment of  FIG. 10 , insulative material  308  may be provided on at least a portion of cross shaft  309  and shaft  302 . For instance, insulative material  308  may be provided on at least one of cross shaft  309  and shaft  302  by overmolding the insulative material  308 . 
         [0056]    According to an exemplary embodiment, cross shaft  309  includes engagement portions  310  that engage with portions of an end effector when push/pull drive element  300  is moved to actuate the end effector. For instance, engagement portions  310  may be configured to engage actuation apertures  226 ,  236  of jaws  220 ,  230  of end effector  206 , as described above in the exemplary embodiments of  FIGS. 2-5 , to actuate end effector  206  when push/pull drive element  300  is moved. According to an exemplary embodiment, engagement portions  310  may have a circular cross-section, like projections  212 ,  214  of the exemplary embodiments of  FIGS. 2-8 . Further, engagement portions  310  of cross shaft  309  may have a diameter  311  (see  FIG. 11 ) substantially the same as diameter  247  of projections  212 ,  214  (see  FIG. 9 ). However, the diameter  311  of engagement portions  310  need not be substantially the same diameter  247  of projections  212 ,  214 , but instead may be different. For instance, the diameter  311  of engagement portions  310  may be smaller than the diameter  247  of projections  212 ,  214 , according to an exemplary embodiment. 
         [0057]    According to an exemplary embodiment, engagement portions  310  may have a non-circular cross-section. For instance, a cross-sectional shape of engagement portions  310  may include one or more flat surface portions (not shown). One or more flat surface portions may be provided to increase the contact area between engagement portions  310  and actuation apertures  226 ,  236  of jaws  220 ,  230 , such as to increase the distribution of forces exerted between engagement portions  310  and jaws  220 ,  230 . According to an exemplary embodiment, actuation apertures  226 ,  236  of jaws  220 ,  230  may have a different shape than the shape shown in the exemplary embodiment of  FIGS. 2 and 3 . For instance, actuation apertures  226 ,  236  may be curved, instead of being straight as shown in  FIGS. 2 and 3 . For example, actuation apertures  226 ,  236  may be curved so that actuation apertures  226 ,  236  are either convex or concave in shape relative to connection apertures  224 ,  234  in the exemplary embodiment of  FIG. 3 . 
         [0058]    End portions  306  of push/pull drive element  300  may be configured to enhance the distribution of forces between end portions  306  and other components of a surgical instrument, such as a clevis. As shown in the exemplary embodiment of  FIGS. 10 and 11 , end portions  306  may be larger than engagement portions  310  of cross shaft  309 . For instance, engagement portions  310  may have a diameter or width  311 , while end portions  306  may have a width  313  or  315  that is larger than the width  311  of engagement portions  310 . If dimensions  313 ,  315  of end portions  306  are not equal or substantially equal, the width of end portions  306  may be the larger of dimensions  313 ,  315 , according to an exemplary embodiment. For instance, when dimension  315  of end portion  306  is larger than dimension  313 , dimension  315  is the width of end portions and is also larger than the width  311  of engagement portions  310 . According to an exemplary embodiment, a ratio of dimension  315  to diameter  311  is greater than 1. For example, a ratio of dimension  315  to diameter  311  ranges from, for example, about 1.1 to about 1.3. According to an exemplary embodiment, dimension  315  may have a length of, for example, about 0.075 inches while diameter  311  is, for example, about 0.061 inches. 
         [0059]    End portions  306  of push/pull drive element  300  may have a cross-section with various shapes. As shown in the exemplary embodiments of  FIGS. 10 and 11 , end portions  306  may have a rectangular shape. As shown in the exemplary embodiment of  FIG. 12 , end portions  306  may have a square shape. According to another exemplary embodiment, an end portion  320  may have an oval shape, as shown in  FIG. 13 . The oval shape may include flat surfaces  322 ,  324  and rounded ends  323 , as shown in the exemplary embodiment of  FIG. 13 . However, the cross-sectional shape of end portions of a push/pull drive element is not limited to the exemplary embodiments of  FIGS. 10-13  and other shapes may be utilized. 
         [0060]    According to an exemplary embodiment, a cross-sectional shape of an end portion of a push/pull drive element includes one or more flat surface portions. As shown in the exemplary embodiments of  FIGS. 11 and 12 , end portions  306  may include flat surface portions  317 ,  319 . Further, an end portion  320  having an oval shape or other non-rectangular or non-square shape may have flat surface portions  322 ,  324 , as shown in the exemplary embodiment of  FIG. 13 . According to an exemplary embodiment, flat surface portions may be opposite to one another and substantially in planes that are parallel to the elongated direction of the groove  240  of the clevis, as shown in the exemplary embodiments of  FIGS. 11-13 . 
         [0061]    By providing end portions  306  with a cross-section that is enlarged relative to that of the cross shaft  309 , providing end portions  306  having a shape described above, and/or providing end portions  306  having at least one flat surface portion in a plane parallel to the elongated direction of the groove  240  of the clevis, a contact area between end portions  306  and a clevis of a surgical instrument may be increased. This in turn may enhance the distribution of forces between end portions  306  and the clevis. 
         [0062]    Turning to  FIG. 14 , a cut away view of a clevis  330  is provided to show internal features of clevis  330 , including groove  340  formed in a sidewall  336  of clevis  330 . Clevis  330  may further include an aperture  335  for a pin (not shown) to connect the jaws of an end effector and groove  340  may include sidewalls  341 ,  343 . As shown in the exemplary embodiment of  FIG. 14 , an end portion  306  of a push/pull drive element  300  may be placed within groove  340  so that groove  340  supports and/or guides end portion  306  as push/pull drive element  300  moves back and forth to actuate an end effector. In particular, the one or more surface portions of end portion  306  may be in contact with one or more surfaces of groove  340 . Turning to  FIG. 15 , which is side view of clevis  340  and push/pull drive element  300 , with an end portion  306  of push/pull drive element  300  located within groove  340 , surface portions  317 ,  319  of end portion  306  may engage one or both of sidewalls  341 ,  343  of groove  340  via contact portions  350 . According to an exemplary embodiment, surface portions  317 ,  319  may be flat. Because end portion  306  has one or more surface portions  317 ,  319 , contact portions  350  between end portion  306  and sidewalls  341 ,  343  of groove  340  are not limited to point contacts or approximately tangential contacts, as discussed above in regard to the exemplary embodiment of  FIG. 9 , but instead provide relatively large contact areas over which the forces exerted between end portion  306  and groove  340  may be distributed. As a result, the forces are not concentrated to a small area, which may lead to permanent deformation and/or increased wear rates. Further, end portions  306  of push/pull drive element  300  have enhanced resistance to the forces exerted when push/pull drive element  300  actuates an end effector and is subjected to twisting, as described above in regard to the exemplary embodiment of  FIGS. 7 and 8 . 
         [0063]    As described above with regard to the exemplary embodiments of  FIGS. 10-14 , push/pull drive element  300  may include an insulative material  308 , particularly when push/pull drive element  300  is used in an energized surgical instrument. However, the exemplary embodiments described herein are not limited to energized surgical instruments and a push/pull drive element may be used in a non-energized surgical instrument. Turning to  FIG. 16 , a cut-away view of a non-energized surgical instrument  400  is shown. Surgical instrument  400  may include a shaft  402 , clevis  404 , end effector  406 , and a push/pull drive element  410 . End effector  406  may include jaws  420 ,  430  that may be connected to clevis  404  by a pin  408  inserted through an aperture  405 . Push/pull drive element  410  may be configured according to the exemplary embodiments of  FIGS. 10-15  except that push/pull drive element  410  does not include insulative material  308  because surgical instrument  400  is not energized. As shown in  FIG. 17 , which shows a cut-away view of clevis  404 , push/pull drive element  410  may include a shaft  412 , one or more engagement portions  414  (such as, for example, engagement portions  414  provided by a cross shaft, as discussed above in regard to  FIG. 11 ), and one or more end portions  416 . End portion  416  may be inserted within a groove  440  of clevis  404 , as discussed above in regard to the exemplary embodiments of  FIGS. 10-15 , so that end portion  416  is guided and/or supported when push/pull drive element  410  moves back and forth to actuate end effector  406 . 
         [0064]    Due to the shape and size of end portions of a push/pull drive element as described in the exemplary embodiments of  FIGS. 10-17 , the amount of contact area between the end portions and a clevis groove is significantly increased. Thus, the end portions may advantageously enhance the distribution of force exerted between the end portions and grooves of a clevis. As a result, end portions of a push/pull drive element may counteract torque and a twisting motion applied to the push/pull drive element during actuation of an end effector, which may otherwise lead to deformation or wear of the clevis groove or the push/pull drive element popping out of the clevis groove. In particular, end portions of a push/pull drive element may minimize or reduce permanent deformation or wear of a groove of a clevis made of a non-metallic material, such as a plastic. 
         [0065]    When a surgical instrument is energized, an electrical connection is provided between an end effector of the surgical instrument and one or more conduits providing electrical energy to the end effector. However, due to movements of the end effector, providing and maintaining a connection between the one or more conduits and the end effector may be difficult. Further, due to the small size of a surgical instrument and the limited about of space within a surgical instrument, the level of difficultly of providing a connection that is functional and durable is relatively high. For instance, an outer diameter of a surgical instrument may be, for example, approximately 5 mm. 
         [0066]    Turning to  FIG. 18 , an exemplary embodiment of a surgical instrument  500  is shown that includes jaws  502 ,  504  connected via a pin  508 , a clevis  506 , and a push/pull drive element  510 . Push/pull drive element  510  may be configured according to the exemplary embodiments of  FIGS. 10-17 . According to an exemplary embodiment, surgical instrument  500  may further include a connector assembly  530  to connect one or more conduits  520 ,  522  to jaws  502 ,  504 . Conduits  520 ,  522  may provide energy to jaws  502 ,  504 , such as, for example electrical energy, to energize jaws  502 ,  504 .  FIG. 19  shows surgical instrument  500  with jaw  504  removed so that components of surgical instrument  500  may be more easily viewed, such as connector assembly  530 . Surgical instrument  500  may further include a shaft (not shown) connected to clevis  506  and covering conduits  520 ,  522 . 
         [0067]    When jaws  502 ,  504  are actuated, jaws  502 ,  504  move relative to other components of surgical instrument  500 . For instance, jaws  502 ,  504  may pivot in direction  540  relative to pin  508 , as shown in the exemplary embodiments of  FIGS. 18 and 19 . Due to the movement of jaws  502 ,  504 , providing a connection between conduits  520 ,  522  and jaws  502 ,  504  can be challenging. For instance, if conduits  520 ,  522  are directly connected to jaws  502 ,  504 , at least a portion of conduits  520 ,  522  may move when jaws  502 ,  504  move, which may lead to challenges in providing a durable connection between jaws  502 ,  504  and conduits. 
         [0068]    Turning to  FIG. 20 , an exemplary embodiment of a connector assembly  530  is shown, which includes a body  531 . Connector assembly  530  may provide a connection between one or more conduits  520 ,  522  and an end effector, such as jaws  502 ,  504 , so that energy (e.g., electrical energy) may be provided from the one or more conduits  520 ,  522  to the end effector. Thus, connector assembly  530  may provide an electrical connection between one or more conduits  520 ,  522  and an end effector, according to an exemplary embodiment. According to an exemplary embodiment, body  531  may be made of an insulative material, such as an electrically insulative material. For example, body  531  may be made of a plastic, such as, for example, a polyphthalamide (PPA) (e.g., Amadei®, which is sold by Solvay Advanced Polymers, L.L.C.). Body  531  may be used, for instance, to provide a structural support for a connection between one or more conduits  520 ,  522  and jaws  502 ,  504  while substantially insulating components of surgical instrument  500  from the energy connected between the one or more conduits  520 ,  522  and jaws  502 ,  504 . As shown in the exemplary embodiment of  FIG. 20 , body  531  may be approximately U-shaped and include a first leg  532  and a second leg  534 . Further, legs  532 ,  534  may be separated by a gap  536 , as shown in the exemplary embodiment of  FIG. 20 . Gap  536  may, for example, provide space for movement of push/pull drive element  510  within body  531 , as shown in the exemplary embodiment of  FIG. 19 , such as when push/pull drive element  510  is moved to actuate jaws  502 ,  504 . Body  531  may further include a lumen  538  that pin  508  may be inserted through, as shown in the exemplary embodiment of  FIGS. 18 and 19 . 
         [0069]    According to an exemplary embodiment, legs  532 ,  534  of body may include a structure to receive conduits  520 ,  522 . For instance, leg  534  may include a cavity  533  to receive conduit  520 , as shown in the exemplary embodiment of  FIG. 20 . Cavity  533  may be open, as shown in the exemplary embodiment of  FIG. 20 , or cavity may be at least partially covered. Conduit  520  may be received in cavity  533  by, for example, inserting conduit  520  through an aperture  535  in leg  534 . Leg  532  may be configured according to any of the above exemplary embodiments discussed for leg  534 . 
         [0070]    As shown in  FIG. 21 , which is an exploded view of the exemplary embodiment of connector assembly  530  of  FIG. 20 , connector assembly  530  may further include one or more connector portions  550 . According to an exemplary embodiment, connector assembly  530  may include a connector portion  550  for each conduit. For instance, connector assembly  530  may include a connector portion  550  for each of conduits  520 ,  522 , as shown in  FIG. 21 . Connector portions  550  may be attached to body  531 . As shown in the exemplary embodiment of  FIG. 21 , connector portions  550  may be fit over protuberances  537 . Connector portions  550  may have a shape corresponding to the shape of protuberances  537 . Further, connector portions  550  may be press fit to protuberances  537 , according to an exemplary embodiment. According to an exemplary embodiment, protuberances  537  may connect to clevis  506  to attach connector assembly  530  and clevis  506 . 
         [0071]    Connector portions  550  may include one or more structures to attach a conduit. Turning to  FIG. 22 , which depicts an exemplary embodiment of conduit  520  attached to connector portion  550 , connector portion  550  may include a first attachment  552  to connect connector portion  550  to conduit  520 . Connector  550  may further include a second attachment  553 , as shown in the exemplary embodiments of  FIGS. 21 and 22 . For instance, when conduit  520  includes more than one component, such as an outer insulative cover  523  and a conductor  521 , as shown in the exemplary embodiment of  FIG. 22 , first attachment  552  may connect to insulative cover  523  while second attachment  553  connects to an exposed portion of conductor  521 . Thus, first attachment  552  may be provided, for example, to assist with maintaining a position of conductor  520  relative to connector portion  550 , while second attachment  553  is provided to form an electrically conductive contact between connector portion  550  and conduit  520 , particularly conductor  521 . Attachments  552 ,  553  may be attached to conduit  520  via a mechanical connection, such as, for example, crimping attachments  552 ,  553  to conduit  520 , via a bond, such as solder (e.g., soldering attachment  553  to conductor  521 ), or other joining method known to one of ordinary skill in the art. Conduit  522  may be connected to connector portion  550  in the same way, according to an exemplary embodiment. 
         [0072]    Connector portions  550  may further include one or more structures to contact a portion of an end effector. For instance, connector portions  550  may include a contact portion  554  to contact at least one of jaws  502 ,  504 . Contact portion  554  may contact at least one of jaws  502 ,  504  via sliding contact, according to an exemplary embodiment. For instance, as shown in the exemplary embodiment of  FIG. 18 , jaw  504  may include an aperture  505  so that jaw  504  may be fit over contact portion  554 . Further, aperture  505  may be structured to have a shape and size corresponding to contact portion  554  so that the portion of jaw  504  forming aperture  505  is in contact with contact portion  554 . For instance, contact portions  554  may have a split ring shape, as shown in the exemplary embodiments of  FIGS. 19, 21, and 22 . Thus, when jaw  504  moves, such as by pivoting in direction  540  relative to pin  508 , jaw  504  remains in contact with contact portion  554 . Jaw  502  may be configured according to the exemplary embodiments of jaw  504  to also form a sliding contact with a contact portion  554  of a connector assembly  530 . By configuring contact portions  554  of connectors  530  to contact jaws  502 ,  504  via sliding contact, a connection, such as an electrical connection, may be provided between conduits  520 ,  522  and jaws  502 ,  504  that is advantageously durable while permitting movement of jaws  502 ,  504  and providing energy to jaws  502 ,  504  from conduits  502 ,  504 . 
         [0073]    According to an exemplary embodiment, connectors  530  may be configured so that jaws  502 ,  504  move independently of contact portions  554 . For instance, when jaws  502 ,  504  move, such as when jaws  502 ,  504  are actuated to pivot in direction  540  about pin  508 , as shown in the exemplary embodiment of  FIGS. 18 and 19 , contact portion  554  remains substantially stationary as jaw  504  slides over contact portion  554 . As a result, conduits  520 ,  522  connected to connectors  530  may also remain substantially stationary as jaws  502 ,  504 , which may advantageously minimize or reduce wear or deformation of conduits  520 ,  522  and connections between conduits  520 ,  522  and connectors  530 . Further, conduits  520 ,  522  are not directly connected to jaws  502 ,  504  because connectors  530  form connections between conduits  520 ,  522  and jaws  502 ,  504 . 
         [0074]    According to an exemplary embodiment, a contact portion  554  may be connected to the one or more attachment(s)  552 ,  553  of connector portions  550  by a bridge  556 , as shown in the exemplary embodiment of  FIG. 22 . According to an exemplary embodiment, connector portions  550  may have a single piece construction. For instance, the one or more attachment(s)  552 ,  553 , contact portion  554 , and bridge  556  may be formed from a single piece, although the exemplary embodiments of connector portions  550  described herein are not limited to a single piece construction. 
         [0075]    According to an exemplary embodiment, connection portions  550  may be made of a conductive material, such as an electrically conductive material, so that energy provided by conduits  520 ,  522  may be provided to jaws  502 ,  504  via connector portions  550 . For example, connection portions  550  may be made of a metal, such as, for example, a stainless steel. 
         [0076]    By providing a surgical instrument with a push/pull drive element according to the exemplary embodiments described herein, a connection may be advantageously provided between the push/pull drive element and a component of the surgical instrument that has enhanced durability while permitting push/pull drive element to move and actuate an end effector of the surgical instrument. Further, by providing a connector that permits sliding contact and/or independent movement between an end effector and the connector, a connection may be advantageously provided between one or more conduits and the end effector that is durable, while permitting movement of the end effector and providing energy to the end effector from the one or more conduit(s). 
         [0077]    Further modifications and alternative embodiments will be apparent to those of ordinary skill in the art in view of the disclosure herein. For example, the systems and the methods may include additional components or steps that were omitted from the diagrams and description for clarity of operation. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the present teachings. It is to be understood that the various embodiments shown and described herein are to be taken as exemplary. Elements and materials, and arrangements of those elements and materials, may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the present teachings may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of the description herein. Changes may be made in the elements described herein without departing from the spirit and scope of the present teachings and following claims. 
         [0078]    It is to be understood that the particular examples and embodiments set forth herein are nonlimiting, and modifications to structure, dimensions, materials, and methodologies may be made without departing from the scope of the present disclosure and claims, including equivalents. 
         [0079]    Other embodiments in accordance with the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the present disclosure and claims. It is intended that the specification and examples be considered as exemplary only, with the claims being entitled to their full scope and breadth, including equivalents.