Abstract:
In one embodiment, a surgical instrument comprises a handle assembly. The handle assembly comprises a first translatable member defining a notch, a lockout lever comprising a cam surface and a detent, a closure trigger, a jaw position sensor in a first state, and a translatable cam operatively coupled to the closure trigger. The detent of the lockout lever is configured to engage the notch of the first translatable member. In response to actuation of the closure trigger, the translatable cam is configured to slidably interface with the cam surface of the lockout lever to: (i) disengage the detent of the lockout lever from the notch of the first translatable member, and (ii) actuate the jaw position sensor to a second state.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 14/075,839, entitled ELECTROSURGICAL DEVICES, filed Nov. 8, 2013, now U.S. Patent Application Publication No. 2015/0133921, the entire disclosure of which is hereby incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    The present disclosure is related generally to electrosurgical devices with various mechanisms for clamping and treating tissue. In particular, the present disclosure is related to electrosurgical devices with various mechanisms for controlling a curved end effector. 
         [0003]    While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims. 
       SUMMARY 
       [0004]    In various embodiments, a surgical instrument is disclosed. In one embodiment, the surgical instrument comprises a handle assembly. The handle assembly comprises a first translatable member defining a notch, a lockout lever comprising a cam surface and a detent, a closure trigger, a jaw position sensor in a first state, and a translatable cam operatively coupled to the closure trigger. The detent of the lockout lever is configured to engage the notch of the first translatable member. In response to actuation of the closure trigger, the translatable cam is configured to slidably interface with the cam surface of the lockout lever to: (i) disengage the detent of the lockout lever from the notch of the first translatable member, and (ii) actuate the jaw position sensor to a second state. 
         [0005]    In various embodiments, a surgical instrument is disclosed. In one embodiment, the surgical instrument comprises a handle assembly. The handle assembly comprises a jaw position sensor in a first state, a lockout lever comprising a cam surface, a closure trigger, and a translatable cam operatively coupled to the closure trigger. In response to actuation of the closure trigger, the translatable cam is configured to interface with the cam surface of the lockout lever to actuate the jaw position sensor to a second state. 
         [0006]    In various embodiments, a surgical instrument is disclosed. In one embodiment, the surgical instrument comprises a handle assembly. The handle assembly comprises a first translatable member defining a notch, a lockout lever comprising a cam surface and a detent, a closure trigger, and a translatable cam operatively coupled to the closure trigger. The detent of the lockout lever is configured to engage the notch of the first translatable member. In response to actuation of the closure trigger, the translatable cam is configured to interface with the cam surface of the lockout lever to disengage the detent of the lockout lever from the notch of the first translatable member. 
     
    
     
       DRAWINGS 
         [0007]    The novel features of the embodiments described herein are set forth with particularity in the appended claims. The embodiments, however, both as to organization and methods of operation may be better understood by reference to the following description, taken in conjunction with the accompanying drawings as follows. 
           [0008]      FIG. 1  illustrates one embodiment of an electrosurgical instrument. 
           [0009]      FIG. 2  illustrates a side-perspective of the electrosurgical instrument of  FIG. 1 . 
           [0010]      FIG. 3  illustrates a side-view of the electrosurgical instrument of  FIG. 1 . 
           [0011]      FIG. 4  illustrates a perspective view of the electrosurgical instrument of  FIG. 1  with a left handle housing removed. 
           [0012]      FIG. 5  illustrates an exploded view of the electrosurgical instrument of  FIG. 1 . 
           [0013]      FIG. 6  illustrates a side view of the electrosurgical instrument  FIG. 1  comprising a jaw closure system in the handle assembly. 
           [0014]      FIG. 7  illustrates the electrosurgical instrument of  FIG. 6  with the jaw closure system in a partially-closed position. 
           [0015]      FIG. 8  illustrates a firing mechanism lock-bar interfaced with cutting member firing mechanism. 
           [0016]      FIG. 9  illustrates a closure trigger rotated sufficiently to disengage a lock bar from a rack unlock block. 
           [0017]      FIG. 10  illustrates the firing mechanism lock-bar of  FIG. 8  in an unlocked position. 
           [0018]      FIG. 11  illustrates one embodiment of a jaw position sensor. 
           [0019]      FIG. 12  illustrates one embodiment of a jaw position sensor comprising an adjustment screw lock spring. 
           [0020]      FIG. 13  illustrates one embodiment of a jaw position sensor. 
           [0021]      FIG. 14  illustrates one embodiment of a jaw position sensor mounted in a handle assembly. 
           [0022]      FIG. 15  illustrates one embodiment of the electrosurgical instrument of  FIG. 4  with the closure trigger fully actuated. 
           [0023]      FIG. 16  illustrates the electrosurgical instrument of  FIG. 4  with a closure trigger lock engaged. 
           [0024]      FIG. 17  illustrates the electrosurgical instrument of  FIG. 16  with a firing trigger in an actuated position. 
           [0025]      FIG. 18  illustrates one embodiment of a yoke of a jaw closure system coupled to a return stroke dampener. 
           [0026]      FIG. 19  illustrates one embodiment of return stroke dampener. 
           [0027]      FIG. 20A  illustrates the interface between a yoke and a return stroke dampener when the jaws of an end effector are in a closed position. 
           [0028]      FIG. 20B  illustrates the interface between the yoke and the return stroke dampener when the jaws of the end effector transition to an open position. 
           [0029]      FIG. 21  illustrates the electrosurgical instrument of  FIG. 4  with the closure trigger lock released and the closure trigger in a released position. 
           [0030]      FIG. 22  illustrates one embodiment of a rack spring washer. 
           [0031]      FIG. 23  illustrates one embodiment of a jaw closure spring stop. 
           [0032]      FIG. 24  illustrates one embodiment of an electrical energy system comprising an energy button, a source cable, and a return cable. 
           [0033]      FIG. 25  illustrates one embodiment of an electrosurgical instrument comprising a pre-compressed jaw closure spring. 
           [0034]      FIG. 26  illustrates one embodiment of an electrosurgical instrument comprising a top-mounted knife firing gear and rack. 
           [0035]      FIGS. 27A and 27B  illustrate one embodiment of an electrosurgical end effector comprising a curved shape. 
           [0036]      FIG. 28  illustrates one embodiment of the electrosurgical end effector of  FIGS. 27A-27B  comprising an off-set jaw closure actuator. 
           [0037]      FIG. 29  illustrates one embodiment of an electrosurgical end effector comprising a first jaw member and a second jaw member having a smooth taper, curved shape. 
           [0038]      FIG. 30  illustrates one embodiment of the electrosurgical end effector of  FIG. 29  in a closed position. 
           [0039]      FIG. 31  illustrates one embodiment of a lower jaw of the electrosurgical end effector of  FIGS. 29-30  comprising a curved longitudinal cutting member slot. 
           [0040]      FIG. 32  shows a graph illustrating the mechanical advantage of the closure trigger at various trigger angles. 
           [0041]      FIGS. 33  shows a graph illustrating force delivered by the jaws when no tissue is located within the jaws. 
           [0042]      FIG. 34  shows a graph illustrating force delivered by the jaws when a tissue section is located within the jaws. 
           [0043]      FIG. 35  shows a graph illustrating the dampener effect on a return load provided by a return stroke dampener. 
       
    
    
     DESCRIPTION 
       [0044]    This application is related to U.S. patent application Ser. No. 14/075,863, entitled ELECTROSURGICAL DEVICES, filed Nov. 8, 2013, now U.S. Patent Application Publication No. 2015/0133915, the entire disclosure of which is hereby incorporated by reference herein. 
         [0045]    In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols and reference characters typically identify similar components throughout the several views, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented here. 
         [0046]    The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive. 
         [0047]    It is further understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The following-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims. 
         [0048]    Before explaining the various embodiments of the surgical devices with close quarter articulation features in detail, it should be noted that the various embodiments disclosed herein are not limited in their application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. Rather, the disclosed embodiments may be positioned or incorporated in other embodiments, variations and modifications thereof, and may be practiced or carried out in various ways. Accordingly, embodiments of the surgical devices with close quarter articulation features disclosed herein are illustrative in nature and are not meant to limit the scope or application thereof. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the embodiments for the convenience of the reader and are not to limit the scope thereof. In addition, it should be understood that any one or more of the disclosed embodiments, expressions of embodiments, and/or examples thereof, can be combined with any one or more of the other disclosed embodiments, expressions of embodiments, and/or examples thereof, without limitation. 
         [0049]    Also, in the following description, it is to be understood that terms such as front, back, inside, outside, top, bottom and the like are words of convenience and are not to be construed as limiting terms. Terminology used herein is not meant to be limiting insofar as devices described herein, or portions thereof, may be attached or utilized in other orientations. The various embodiments will be described in more detail with reference to the drawings. 
         [0050]    Turning now to the figures,  FIG. 1  illustrates one embodiment of an electrosurgical instrument  2 . The electrosurgical instrument  2  comprises a two-trigger clamp and cut mechanism. The electrosurgical instrument  2  comprises a handle assembly  4 , a shaft assembly  12  coupled to a distal end of the handle assembly  4 , and an end effector  10  coupled to the distal end of the shaft assembly  12 . The handle assembly  4  is configured as a pistol grip and comprises left and right handle housing shrouds  6   a,    6   b,  a closure trigger  8 , a pistol-grip handle  14 , a firing trigger  16 , an energy button  18 , and a rotatable shaft knob  20 . An electrical cable  21  enters the handle assembly  4  at a proximal end. 
         [0051]    The shaft assembly  12  comprises a jaw actuator, a cutting member actuator, and an outer sheath  23 . The jaw actuator is operatively coupled to the closure trigger  8  of the handle assembly  4 . In some embodiments, the outer sheath  23  comprises the jaw actuator. The cutting member actuator is operatively coupled to the firing trigger  14  of the handle assembly  4 . The outer sheath  23  comprises one or more contact electrodes on the distal end configured to interface with the end effector  10 . The one or more contact electrodes are operatively coupled to the energy button  18  and an energy source (not shown). 
         [0052]    The energy source may be suitable for therapeutic tissue treatment, tissue cauterization/sealing, as well as sub-therapeutic treatment and measurement. The energy button  18  controls the delivery of energy to the electrode. A detailed explanation of each of these control elements is provided herein below. As used throughout this disclosure, a button refers to a switch mechanism for controlling some aspect of a machine or a process. The buttons may be made out of a hard material such as usually plastic or metal. The surface may be formed or shaped to accommodate the human finger or hand, so as to be easily depressed or pushed. Buttons can be most often biased switches, though even many un-biased buttons (due to their physical nature) require a spring to return to their un-pushed state. Terms for the “pushing” of the button, may include press, depress, mash, and punch. 
         [0053]    In some embodiments, an end effector  10  is coupled to the distal end of the shaft assembly  12 . The end effector  10  comprises a first jaw member  22   a  and a second jaw member  22   b.  The first jaw member  22   a  is pivotably coupled to the second jaw member  22   b.  The first jaw member  22   a  is pivotally moveable with respect to the second jaw member  22   b  to grasp tissue therebetween. In some embodiments, the second jaw member  22   b  is fixed. In other embodiments, the first jaw member  22   a  and the second jaw member  22   b  are pivotally movable. The end effector  10  comprises at least one electrode  92 . The electrode  92  is configured to delivery energy. Energy delivered by the electrode  92  may comprise, for example, radiofrequency (RF) energy, sub-therapeutic RF energy, ultrasonic energy, and/or other suitable forms of energy. In some embodiments, a cutting member (not shown) is receivable within a longitudinal slot defined by the first jaw member  22   a  and/or the second jaw member  22   b.  The cutting member is configured to cut tissue grasped between the first jaw member  22   a  and the second jaw member  22   b.  In some embodiments, the cutting member comprises an electrode for delivering energy, such as, for example, RF and/or ultrasonic energy. 
         [0054]      FIG. 2  illustrates a side perspective view of the electrosurgical instrument  2  illustrated in  FIG. 1 .  FIG. 2  illustrates the right handle housing  6   b.  The energy button  18  extends through the handle assembly  4  and is accessible on both sides of the handle assembly  4 . The closure trigger  8 , the firing trigger  14 , and the energy button  18  comprise an ergonomic design. In some embodiments, the handle assembly  14  is thinner near the energy button  18  to allow ease of access to the energy button  18  by a clinician. In some embodiments, the energy button  18  is disposed on either the left handle housing  6   a  or the right handle housing  6   b.    FIG. 3  illustrates a side view of the electrosurgical instrument  2  and the right handle housing  6   b.    
         [0055]      FIG. 4  illustrates one embodiment of the surgical instrument  2  of  FIG. 1  with the left handle housing  6   a  removed. The handle assembly  4  comprises a plurality of components for actuating the surgical instrument  2 , such as, for example, mechanisms for affecting closure of the jaws  22   a,    22   b  of the end effector  10 , deploying a cutting member within the end effector  10 , and/or delivering energy to the electrode  92  coupled to the end effector  10 . A closure trigger  8  is configured to transition the jaws  22   a,    22   b  from an open position to a closed position. The closure trigger  8  is connected to a clamp arm  24 . The clamp arm  24  couples the closure trigger  8  to a yoke  26 . When the closure trigger  8  is actuated towards the pistol grip handle  14 , the yoke  26  moves proximally and compresses a clamp spring  28 . Compression of the clamp spring  28  retracts a jaw actuator, such as, for example, the outer sheath  23 , to transition the first jaw member  22   a  of the end effector  10  from an open position to a closed position. In the illustrated embodiment, the clamp spring  28  comprises an uncompressed spring. In some embodiments, a partially pre-compressed spring may be used (see  FIG. 25 ). 
         [0056]    A firing trigger  16  is configured to deploy a cutting member within the end effector  10 . The firing trigger  16  is operatively coupled to a compound gear  42 . The compound gear  42  interfaces with a rack  44 . The rack  44  is coupled to a firing actuator (not shown). When the firing trigger  16  is actuated, the compound gear  42  rotates and moves the rack  44  distally. The distal movement of the rack  44  causes distal movement of the firing actuator and deployment of the cutting member within the end effector  10 . The cutting member is deployed from the proximal end of the end effector  10  to the distal end. In one embodiment, the firing trigger  16  comprises a high pivot to provide a linear feel during actuation of the firing trigger  16 . The linear feel provides increased control and comfort to a clinician actuating the firing trigger  16 . 
         [0057]    In some embodiments, the rack  44  comprises a lock mechanism. In the illustrated embodiment, the rack  44  comprises a rack unlock block  40 . The rack unlock block  40  interfaces with a lock arm  38  to prevent actuation of the cutting member firing switch  16  prior to actuation of the closure trigger  8 . When the closure trigger  8  is in an open position, the lock arm  38  interfaces with the rack unlock block  40  to lock the rack  44  and prevent actuation of the firing trigger  16 . When the closure trigger  8  is actuated, the yoke  26  raises the lock arm  38  away from the rack unlock block  40 . When the closure trigger  8  is sufficiently actuated, corresponding to the jaws  22   a,    22   b  of the end effector  10  being in a sufficiently closed position to prevent the cutting member from existing a slot in the jaws  22   a,    22   b,  the lock arm  38  is decoupled from the rack unlock block  40 , allowing actuation of the firing trigger  16 . 
         [0058]      FIG. 5  illustrates an exploded view of the electrosurgical instrument  2 . As shown in  FIG. 5 , the handle assembly  4  comprises a left handle housing  6   a  and a right handle housing  6   b.  The handle assembly  4  comprises a closure trigger  8 , a firing trigger  16 , and an energy button  18 . A clamp arm  24  is coupled to the jaw closure trigger  8  and a yoke  26  by a plurality of pins  52 . A mil max connector  53  is located at a proximal end of the handle assembly  4  to couple to an energy source (not shown). Although the illustrated embodiments comprise a surgical instrument  2  coupled to an external energy source, those skilled in the art will recognize that the energy source and/or one or more drive circuits may be located within the handle assembly  4 . For example, in one embodiments, a battery and a RF generation circuit may be mounted in the handle assembly  4  and coupled to the energy button  18 . In some embodiments, a jaw position sensor  34  is mounted in the handle assembly  4  to indicate when the jaws  22   a,    22   b  of the end effector  10  have closed beyond a predetermined position. A screw lock spring  36  is mounted to the jaw position sensor  34  to prevent accidental adjustment of the jaw position sensor  34 . A control board  48  is mounted in the handle assembly  4 . 
         [0059]      FIG. 6  illustrates a side perspective of the handle assembly  4  comprising a jaw closure mechanism in the handle assembly  4 . The closure trigger  8  is illustrated in an initial position corresponding to an open position of the jaws  22   a,    22   b.  In operation, a clinician actuates the closure trigger  8  to transition the jaws  22   a,    22   b  to a closed position.  FIG. 7  illustrates the closure trigger  8  in a partially actuated position. As shown in  FIG. 7 , as the closure trigger  8  is rotated proximally towards the pistol-grip handle  14 , the clamp arm  24  moves the yoke  26  in a proximal direction to compress the clamp spring  28 . Compression of the clamp spring  28  causes the jaws  22   a,    22   b  to transition to a closed position and applies a force to tissue grasped between the jaws  22   a,    22   b.  For example, in some embodiments, the closure trigger  8  position illustrated in  FIG. 7  corresponds to a full closure of the jaws  22   a,    22   b.  Additional actuation of the closure trigger  8  increases the force applied by the jaws  22   a,    22   b  to a tissue section grasped therebetween. In other embodiments, full closure of the jaws  22   a,    22   b  occurs when the closure trigger  8  is fully actuated. A hole  19  in the closure trigger  8  allows the closure trigger  8  to be actuated without interfering with the energy button  18 . In some embodiments, the hole  19  is covered by the left and right handle housings  6   a,    6   b.    
         [0060]      FIG. 8  illustrates a firing trigger lock mechanism  33 . A lock arm  38  interfaces with a rack unlock block  40  to prevent actuation of the firing trigger  16  prior to closure of the jaws  22   a,    22   b.  The firing trigger lock mechanism  33  is unlocked through actuation of the closure trigger  8 . The yoke  26  is coupled to an unlock bar  41 . When the yoke  26  is moved distally through actuation of the closure trigger  8 , the lock bar  41  lifts the lock arm  38  vertically away from the rack unlock block  40 . When the lock arm  38  has been lifted a sufficient distance, the rack  44  is allowed to move distally and the firing trigger  16  is actuatable to deploy the cutting member within the end effector  10 .  FIGS. 9 and 10  illustrate the handle assembly  4  of the surgical instrument  2  with the jaw clamping trigger  8  sufficiently compressed to release the lock arm  38  from the rack unlock block  40 . As can be seen in  FIG. 9 , the lock arm  38  is lifted a sufficient distance to allow actuation of the firing trigger  16  prior to full rotation of the closure trigger  8 . The firing trigger  16  is unlocked when the jaws  22   a,    22   b  are sufficiently closed such that the cutting member cannot skip out of a slot formed in the end effector  10 . For example, in some embodiments, the lock arm  38  is released when the closure trigger  8  is compressed about 8 degrees, corresponding to jaw opening of about 2.5 degrees. In other embodiments, the lock arm  38  may be released at a lower or higher degree of rotation of the closure trigger  8 . 
         [0061]    In some embodiments, a lock spring  64  is coupled to the lock arm  38  to apply a biasing force to the lock arm  38 . The biasing force biases the lock arm  38  towards the rack unlock block  40  and maintains the lock arm  38  in contact with the rack unlock block  40  until the closure trigger  8  has been sufficiently actuated. When the closure trigger  8  is released and the yoke  26  returns to a rest position, the lock spring  64  biases the lock arm  38  back into a locked configuration with the rack unlock block  40 . 
         [0062]      FIG. 10  illustrates the lock arm  38  in an unlocked position. In the unlocked position, a clinician may actuate the firing trigger  16  to drive the rack  44  distally and deploy the cutting member within the end effector  10 . In some embodiments, a jaw position sensor  34  is configured to indicate when the jaws  22   a,    22   b  are sufficiently closed to allow deployment of the cutting member. In some embodiments, the jaw position sensor  34  comprises a bypass switch. In other embodiments, other types of switches may be used, such as, for example, normally open, normally closed, and/or other switch types. 
         [0063]      FIG. 11  illustrates one embodiment of a jaw position sensor  34 . The jaw position sensor  34  comprises an adjustable contact  77 . The adjustable contact  77  is mechanically adjustable to adjust the jaw sense activation point of the jaw position sensor  34 . The contact  77  is adjusted by rotating a screw  76  coupled to the jaw position sensor  34 . Rotation of the screw  76  increases or decreases (depending on the direction of rotation) the necessary height of the lock arm  38 , corresponding to a specific rotation of the closure trigger  8 , required to activate the jaw position sensor  34 . In some embodiments, such as the embodiment illustrated in  FIG. 12 , a screw lock spring  36  is coupled to the screw  76  to prevent accidental adjustment of the contact  77 . In order to adjust the contact  77  in the embodiment illustrated in  FIG. 12 , the screw lock spring  36  must be depressed prior to rotation of the screw  76 . The screw lock spring  36  is released after adjustment of the screw  76  to lock the screw  76  in place. In some embodiments, the screw  76  comprises a locking thread. Activation of the jaw position sensor  34  may correspond to, for example, a distance of about 0.01 inches between the first jaw  22   a  and the second jaw  22   b.    
         [0064]      FIG. 13  illustrates one embodiment of a jaw position sensor  134 . The jaw position sensor  134  comprises a switch  170 . When the contact  177  of the switch  170  is depressed by the lock bar  41 , an electrical connection within the switch  170  is opened. The break in the electrical connection of the switch  170  is detected by a two-position connection header  172 . The connection header  172  is coupled to, for example, a control board  38 . A connected receptacle  174  couples the connection header  172  to the handle assembly  4 .  FIG. 14  illustrates the jaw sensor  34  mounted in the handle assembly  4 . The handle assembly  4  comprises a plurality of access holes  79  to allow a clinician to depress the screw lock spring  36  and to rotate the screw  76  to adjust the contact  77 . 
         [0065]      FIG. 15  illustrates one embodiment of the handle assembly  4  with the closure trigger  8  fully actuated. When the closure trigger  8  is fully actuated, the yoke  26  compresses the clamp spring  28  to a maximum compression, corresponding to a maximum force applied by the jaws  22   a,    22   b.  In some embodiments, the jaws  22   a,    22   b  may be configured to maintain a minimal spacing therebetween to prevent damage to components of the surgical instrument  2  and/or the tissue section. In other embodiments, the maximum compression of the clamp spring  28  corresponds to a fully closed position of the jaws  22   a,    22   b.  In some embodiments, full actuation of the closure trigger  8  corresponds to a rotation of about 30 degrees. When the closure trigger  8  is fully rotated against the pistol-grip handle  14 , a closure trigger lock  46  is engaged to maintain the closure trigger  8  in a rotated position and therefore maintain the jaws  22   a,    22   b  in a closed position. As shown in  FIG. 15 , the hole  19  in the closure trigger  8  allows the closure trigger  8  to be fully rotated against the pistol-grip handle  14  without interfering with the energy button  18 . Once the trigger lock  46  has been engaged, the clinician may release the closure trigger  8  and the trigger lock  46  maintains the closure trigger  8  in a closed position, as illustrated in  FIG. 16 . 
         [0066]    As shown in  FIG. 16 , the trigger lock  46  maintains the closure trigger  8  in a less than fully retracted position to prevent damage to components of the surgical instrument  2  due to over application of force to the jaws  22   a,    22   b.  The trigger lock  46  maintains the closure trigger  8  in a sufficiently rotated position to release the lock arm  38  from the rack unlock block  40  and to engage the jaw position sensor  34 . For example, in the illustrated embodiment, the trigger lock  46  maintains the closure trigger  8  at a rotation of about  28  degrees. With the closure trigger  8  in a locked position, the clinician may actuate the firing trigger  16  to deploy the cutting member within the end effector  10 . In some embodiments, the clinician may actuate the energy button  18  to deliver energy to a tissue section grasped between the jaws  22   a,    22   b  prior to or simultaneously with, deployment of the cutting member. 
         [0067]    In various embodiments, the closure trigger  8  provides a mechanical advantage in transferring force from the closure trigger  8  to the jaws  22   a,    22   b.    FIG. 32  is a chart  700  illustrating the mechanical advantage  704  of the closure trigger  8  at various trigger angles  702 . As shown in  FIG. 32 , as the angle of the closure trigger  8  increases, for example, by actuating the closure trigger  8  towards the pistol-grip handle  14 , the mechanical advantage  704  delivered by the clamp spring  28  to the jaws  22   a,    22   b  increases.  FIGS. 33 and 34  illustrate the force provided by the jaws  22   a,    22   b  as the closure trigger  8  is rotated towards the pistol-grip handle  14 .  FIG. 33  illustrates force  806  delivered by the jaws  22   a,    22   b  when no tissue is located within the jaws  22   a,    22   b.    FIG. 34  illustrates the force  906  delivered by the jaws  22   a,    22   b  when a tissue of about 3 mm thickness is located between the jaws  22   a,    22   b.    
         [0068]    As illustrated in  FIG. 16 , the firing trigger  16  is coupled to a compound gear  42  interfaced with a rack  44 . The rack  44  is mechanically coupled to a firing actuator (not shown) configured to deploy the cutting member distally within the end effector  10 . Rotation of the firing trigger  16  proximally towards the handle assembly  4  causes the rack  44  to advance distally within the handle assembly  4  and drive the cutting member within the end effector  10 .  FIG. 17  illustrates the handle assembly  4  with the firing trigger  16  in an actuated position. The compound gear  42  has advanced the rack  44  distally, corresponding to the cutting member being located at a distal most position within the end effector  10 . Advancement of the rack  44  in a distal direction compresses a spring washer  58 . When the clinician releases the firing trigger  16 , the spring washer forces the rack  44  in a proximal direction, withdrawing the cutting member from the end effector  10 . The firing trigger  16  comprises a mechanical advantage that adjusts the force applied by the cutting member with respect to the force applied to the firing trigger  16 . For example, in one embodiment, the firing trigger  16  comprises a mechanical advantage of 0.6, such that one pound of force applied to the firing trigger  16  corresponds to 0.6 pounds of force applied by the cutting member to a tissue section grasped within the end effector  10 . In some embodiments, the firing trigger  16  comprises a maximum rotation corresponding to the cutting member being located at a distal-most portion of the end effector  10 . For example, the firing trigger  16  may rotate about nineteen degrees to fully deploy the cutting member within the end effector  10 . In some embodiments, the handle assembly  4  comprises a rack-biasing spring  47  configured to bias the rack in an proximal position. The closure trigger lock  46  is released to open the jaws  22   a,    22   b  and release tissue grasped therein. 
         [0069]      FIG. 18  illustrates one embodiment of a return stroke dampener  32  coupled to the yoke  26  to reduce the force of the return stroke of the clamp spring  28 . The return stroke dampener  32  dampens the return stroke of the yoke  26  when the closure trigger  8  is released.  FIG. 19  illustrates one embodiment of a return stroke dampener  32 .  FIGS. 20A and 20B  illustrate an interface between the yoke  26  and the return stroke dampener  32 . The return stroke dampener  32  comprises a toggle arm  78  and a dampening spring  76 . The yoke  26  comprises a dampener interface pin  79 . When the yoke  26  moves distally, for example, when the jaws  22   a,    22   b  are released and the closure trigger  8  returns to an unactuated position, the interface pin  79  forces the toggle arm  78  down, compressing the dampening spring  76  and reducing the load from the closure spring  28  on the closure trigger  8 . Once the interface pin  79  pushes the toggle arm  78  close to over center, the load on the yoke pin  79  goes almost to zero such that the dampener effect is eliminated for the remainder of the stroke. The return stroke dampener  32  reduces the force of the closure spring  28  when the closure trigger  8  is released from an actuated position. 
         [0070]      FIG. 35  is a chart illustrating the dampener effect on a return load provided by a return stroke dampener  32 . The chart  1000  illustrates the trigger angle  1002  of the closure trigger  8  plotted against the force  1004  applied to the closure trigger  8 . As can be seen in  FIG. 35 , the force applied by the jaws  22   a,    22   b  increases to a maximum point at about 18 degrees of rotation of the clamp trigger  8 . The dampening force decreases as the clamp trigger  8  is released and the dampener toggle  78  crosses over a center point. 
         [0071]      FIG. 21  illustrates the handle assembly  4  after the closure trigger  8  has been released and the jaws  22   a,    22   b  have assumed an open position. The closure trigger  8  has returned to an unactuated position with respect to the pistol-grip handle  14 . The clamp spring  28  and the rack  44  have returned to their respective starting positions. The return stroke dampener  32  is fully compressed when the clamp spring  28  is in a rest position.  FIG. 22  illustrates one embodiment of a spring washer  158  configured to interface with a rack spring  59  when the rack  44  is advanced in a distal direction. The spring washer  158  and the rack spring  59  cause the rack  44  to move proximally if the firing trigger  16  is released.  FIG. 23  illustrates one embodiment of a spring stop  162 . The spring stop  162  is coupled to the proximal end of the clamp spring  28 . 
         [0072]      FIG. 24  illustrates one embodiment of an electrical energy system  80  mounted within the handle assembly  4 . An energy button  18  is configured to deliver energy to an electrode  92  coupled to the end effector  10 . The energy button  18  is coupled to a plurality of power activation wires  82 . When the energy button  18  is depressed, a circuit is completed allowing delivery of energy to the electrode  92 . A source path  84  couples an electrical contact mounted on the distal end of the outer tube  23  of the shaft assembly  12 . In some embodiments, the source path comprises the outer tube  23 . Alternatively, in some embodiments, the source path comprises a solid or stranded conductor housed within the outer tube  23 . A return path  85  acts as a return for bipolar RF energy delivered to the electrode. For monopolar RF energy, the return path may comprise a grounding electrode coupled to a patient. In some embodiments, the power activation wires  82  are coupled to a generator. The control board  48  is further coupled to the jaw position switch  34  and the generator. The generator may prevent delivery of energy to the electrode  92  unless the jaw position sensor  34  indicates that the jaws  22   a,    22   b  are in a sufficiently closed position. 
         [0073]      FIG. 25  illustrates one embodiment of an electrosurgical instrument  202  comprising a pre-compressed closure spring  228 . The pre-compressed closure spring  228  comprises a closure spring having a certain pre-compression before actuation of the closure trigger  8 . The pre-compressed closure spring  228  requires a clinician to apply less force to a closure trigger  8  to generate the same amount of force at the jaws  22   a,    22   b  when compared to an un-compressed spring. The pre-compressed spring  228  may further provide a shorter stroke for compressing the jaws  22   a,    22   b  to the same closure or force level as an uncompressed spring. The electrosurgical instrument  204  is otherwise similar to the electrosurgical instrument  4  discussed with respect to  FIGS. 1-24 . For example, closure of an end effector coupled to the surgical instrument  202  is affected by actuating a closure trigger  8  to move a yoke  226  proximally to compress the pre-compressed spring  228  and transition the jaws  22   a,    22   b  from an open position to a closed position. 
         [0074]      FIG. 26  illustrates one embodiment of surgical instrument  302  comprising a handle assembly  304  having a top-mounted compound gear  342  and rack  344 . The firing trigger  316  is coupled to the compound gear  342  by a plurality of teeth  343 . Actuation of the firing trigger  316  advances the rack  344  in a distal direction. The rack  344  is coupled to a firing actuator (not illustrated) which advances a cutting member distally within an end effector coupled to the shaft  312 . The surgical instrument  302  is otherwise similar to the electrosurgical instrument  4  illustrated in  FIGS. 1-24 . For example, closure of the jaws of an end effector coupled to the shaft assembly  312  is affected by actuating a closure trigger  8  coupled to a yoke  326  to compress a closure spring  328 . 
         [0075]      FIGS. 27A and 27B  illustrate one embodiment of an electrosurgical end effector  410  comprising a curved shape. The end effector  410  comprises a first jaw member  422   a  and a second jaw member  422   b.  The first jaw member  422   a  is pivotally coupled by a pivot pin  479  to the second jaw member. The electrosurgical end effector  410  is configured to be coupled to an electrosurgical instrument, such as, for example, the electrosurgical instrument  2  illustrated in  FIGS. 1-24 . In some embodiments, the first jaw member  422   a  and the second jaw member  422   b  are smoothly tapered with the proximal portion of the jaw members  422   a,    422   b  being the widest portion and the distal end of the jaw members  422   a,    422   b  being the narrowest portion of the jaw members  422   a,    422   b.  The smooth taper comprises a taper in a plane of curvature of the end effector  410  and parallel to a central axis of the shaft  412 . For example, in some embodiments, the distal portion of the end effector  410  may comprise approximately 25% to 50% of the proximal width of the end effector  410 , such as, for example, 33%. The smooth taper provides better dissection while maintaining a wide electrode through most of the end effector  410  for better sealing. The first jaw member  422   a  and the second jaw member  422   b  are curved along a longitudinal axis of the end effector  410 . The curve of the end effector  410  comprises a radius of curvature. The radius of curvature may comprise, for example, a radius of about 1.000″ to about 4.000″. 
         [0076]    The taper and curvature of the end effector  410  increase visibility of the tip  491 . The taper compensates for the loss of force on the tissue on more proximal locations of the end effector  410  providing a more constant pressure on the tissue. The smooth transitions along the longitudinal axis of the end effector  410  and the taper distribute deflection along the length of the end effector  410  and reduce stress concentration allowing greater loads to be applied by the end effector  410 . The reduced stresses and deflection permit the end effector  410  to be lengthened beyond non-curved, non-tapered end effectors. For example, in some embodiments, the end effector  410  comprises a length of approximately 23 mm. 
         [0077]    In some embodiments, the end effector  410  comprises an offset pivot  486 . The offset pivot  486  comprises a pivot point offset from the longitudinal axis of the shaft  412  and the end effector  410 . The offset pivot enables the use of a linkage-style closure mechanism. The link pin  488  and offset pivot  486  provides precise control of the movement of the first jaw member  422   a.    FIG. 28  illustrates one embodiment of an end effector  510  comprising an offset pivot  586  coupled to an offset actuator. The offset actuator comprises a single asymmetric lever arm  590  coupled to the first jaw member  522   a.  The asymmetric lever arm  590  provides additional material around the pivot  586  when compared to a traditional two lever arm end effector. 
         [0078]      FIG. 29  illustrates one embodiment of an end effector  610  comprising an offset pivot  686  and an asymmetric lever arm  690  coupled to a shaft  612 . The end effector  610  comprises a first jaw member  622   a  and a second jaw member  622   b.  The first jaw member  622   a  is pivotally moveable with respect to the second jaw member  622   b.  The second jaw member  622   b  is fixed. The first and second jaw members  622   a,    622   b  comprises a curved shape having a radius of curvature with respect to a longitudinal axis of a shaft  612 . The first jaw member  622   a  and the second jaw member  622   b  comprise a smooth taper from the proximal end to the distal end. The distal tip  690  comprises a width less than the width of the proximal section of the end effector  610 . For example, in some embodiments, the distal tip comprises a width of about 25% to about 50% of the width of the proximal section of the end effector  610 . The end effector  610  is illustrated in an open position in  FIG. 29 . In some embodiments, movement of the first jaw member  622   a  with respect to the second jaw member  622   b  is accomplished by a linked connection between the asymmetric lever arm  690  and an outer sheath  623  of the shaft  612 . A low friction bushing  698 , such as, for example, a lubricious metal or plastic, comprises a sliding interface between the asymmetric lever arm  690  and the outer sheath  623 . The low friction bushing  698  is disposed between an outer diameter of the asymmetric lever arm  690  and an inner diameter of the shaft  612 .  FIG. 30  illustrates the end effector  610  of  FIG. 29  in a closed position. As shown in  FIG. 30 , the end effector  610  is transitioned to a closed position by moving the asymmetric lever arm  690  proximally. Proximal movement of the asymmetric lever arm  690  may be affected by, for example, actuating a closure trigger  8  of a handle assembly  4  coupled to the end effector  610  by the shaft  612 . 
         [0079]    In some embodiments, an electrode  692  is coupled to the second jaw member  622   b.  The electrode  692  is adhered to the second jaw member  622   b  by an adhesive, such as, for example, a silicon or epoxy adhesive. The electrode  692  is selectively coated with a ceramic coating that provides electrical insulation to prevent shorting between the electrode  692  and the second jaw member  622   b.  In some embodiments, the ceramic coating and adhesive comprise a thermal conductivity of about 0.5 W/(mK) to about 2.0 W/(mK). The electrode  692  contacts a source electrode on the distal end of the outer tube  623  when the first jaw member  622   a  is rotated into a closed position with respect to the second jaw member  622   b.  Placement of the contact electrode on the outer shaft  623  ensures a good connection between the electrode  692  and an energy source. In some embodiments, the first jaw member  622   a  and/or the second jaw member  622   b  define a cutting member slot.  FIG. 31  illustrates one embodiment of the second jaw member  622   b  comprising a cutting member slot  696 . The proximal end of the cutting member slot  696  begins in a plane through a central axis of the shaft  612 . The cutting member slot  696  biases to a first side of the central axis of the shaft  612  then crosses the central axis to a location biased to the opposite side of the central axis at the distal-most portion of the cutting member slot  696 . The cutting member slot  696  shape maximizes the radius of the cutting member slot  696  reducing the bending load on the cutting member  695 . The geometry of the cutting member slot  696  maintains a nearly equivalent electrode  692  width on both sides of the cutting member slot  696 . In some embodiments, the curvature of the cutting member slot  696  is substantially equal to the curvature of the end effector  610 , which is substantially equal to the curvature of the anatomy being transected. In some embodiments, a radius of curvature of the cutting member slot  696  varies from about 2.000″ to about 4.000″ over the length of the cutting member slot  696 . In some embodiments, the cutting member slot  696  is biased to either the first side and/or the second side of the central axis of the shaft  612  by a distance of greater than 0.000″ to a maximum of about 0.065″. 
         [0080]    While the examples herein are described mainly in the context of electrosurgical instruments, it should be understood that the teachings herein may be readily applied to a variety of other types of medical instruments. By way of example only, the teachings herein may be readily applied to tissue graspers, tissue retrieval pouch deploying instruments, surgical staplers, ultrasonic surgical instruments, etc. It should also be understood that the teachings herein may be readily applied to any of the instruments described in any of the references cited herein, such that the teachings herein may be readily combined with the teachings of any of the references cited herein in numerous ways. Other types of instruments into which the teachings herein may be incorporated will be apparent to those of ordinary skill in the art. 
         [0081]    It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 
         [0082]    The disclosed embodiments have application in conventional endoscopic and open surgical instrumentation as well as application in robotic-assisted surgery. 
         [0083]    Embodiments of the devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. Embodiments may, in either or both cases, be reconditioned for reuse after at least one use. Reconditioning may include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, embodiments of the device may be disassembled, and any number of the particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, embodiments of the device may be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device may utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. 
         [0084]    By way of example only, embodiments described herein may be processed before surgery. First, a new or used instrument may be obtained and if necessary cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam. 
         [0085]    It is worthy to note that any reference to “one aspect,” “an aspect,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in one embodiment,” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same aspect. 
         [0086]    One skilled in the art will recognize that the herein described components (e.g., operations), devices, objects, and the discussion accompanying them are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific exemplars set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components (e.g., operations), devices, and objects should not be taken limiting. 
         [0087]    With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations are not expressly set forth herein for sake of clarity. 
         [0088]    The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected,” or “operably coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable,” to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components, and/or wirelessly interactable, and/or wirelessly interacting components, and/or logically interacting, and/or logically interactable components. 
         [0089]    Some aspects may be described using the expression “coupled” and “connected” along with their derivatives. It should be understood that these terms are not intended as synonyms for each other. For example, some aspects may be described using the term “connected” to indicate that two or more elements are in direct physical or electrical contact with each other. In another example, some aspects may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, also may mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. 
         [0090]    In some instances, one or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. 
         [0091]    While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true scope of the subject matter described herein. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. 
         [0092]    In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” 
         [0093]    With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flows are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. 
         [0094]    In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more embodiments were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope. 
         [0095]    Various aspects of the subject matter described herein are set out in the following numbered clauses: 
         [0096]    1. A surgical instrument comprising: a handle; a shaft assembly extending distally from the handle; an end effector coupled to a distal end of the shaft assembly, wherein the end effector comprises: a jaw assembly having a proximal end and a distal end, the jaw assembly comprising: a moveable jaw member; and a fixed jaw member, wherein the moveable jaw member is pivotably moveable between an open position and a closed position with respect to the fixed jaw member; wherein in the closed position, the jaw assembly defines a radius of curvature and a smooth taper from the proximal end to the distal end. 
         [0097]    2. The surgical instrument of clause 1, wherein the distal end of the jaw assembly defines a width of between about 25% to about 50% of a width of a proximal end of the jaw assembly. 
         [0098]    3. The surgical instrument of clause 2, wherein the smooth taper is configured to provide nearly constant pressure from a proximal end to a distal end of the jaw assembly. 
         [0099]    4. The surgical instrument of clause 1, wherein the radius of curvature is about 1.000″ to about 4.000″. 
         [0100]    5. The surgical instrument of clause 1, comprising a cutting member longitudinally deployable within a longitudinal curved slot defined by the jaw assembly, wherein the longitudinal curved slot comprises a proximal portion substantially in-line with a central axis of the shaft assembly, and wherein the longitudinal curved slot substantially follows the radius of curvature of the jaw assembly. 
         [0101]    6. The surgical instrument of clause 5, wherein a central portion of the longitudinal curved slot is offset on a first side of the central axis of the shaft assembly by a distance of greater than 0.000″ to about 0.065″. 
         [0102]    7. The surgical instrument of clause 6, wherein a distal portion of the longitudinal curved slot is offset on a second side of the central axis of the shaft assembly by a distance of greater than 0.000″ to about 0.065″. 
         [0103]    8. The surgical instrument of clause 7, wherein the radius of curvature varies from about 2.000″ to about 4.000″. 
         [0104]    9. The surgical instrument of clause 1, comprising a lever arm asymmetrically coupled to the moveable jaw member on a first side of a central axis of the shaft assembly, wherein the lever arm is configured to pivot the moveable jaw member from an open position to a closed position. 
         [0105]    10. The surgical instrument of clause 9, wherein a pivot connection between the moveable jaw member and the fixed jaw member is offset to the first side of the axis of the shaft assembly. 
         [0106]    11. The surgical instrument of clause 10, wherein the pivot connection comprises a pinned link-slider. 
         [0107]    12. The surgical instrument of clause 9, wherein the lever arm extends longitudinally through the shaft assembly, and wherein a lubricous bushing is located between an outer diameter of the lever arm and an inner diameter of the shaft assembly. 
         [0108]    13. The surgical instrument of clause 12, wherein the lubricous bushing comprises a plastic material. 
         [0109]    14. The surgical instrument of clause 12, wherein the lubricous bushing comprises a dissimilar metal material. 
         [0110]    15. The surgical instrument of clause 1, comprising an electrode disposed on the fixed jaw member, wherein the electrode is configured to deliver an electrosurgical radiofrequency (RF) signal. 
         [0111]    16. The surgical instrument of clause 15, comprising a ceramic coating disposed on the electrode to electrically isolate the electrode from the fixed jaw member. 
         [0112]    17. The surgical instrument of clause 16, wherein the ceramic coating comprises one of aluminum oxide or zirconium oxide. 
         [0113]    18. The surgical instrument of clause 15, wherein the electrode is coupled to the fixed jaw member by an adhesive. 
         [0114]    19. The surgical instrument of clause 18, wherein a thermal conductivity of the adhesive is approximately 0.5 W/(mK) to 2.0 W/(mK). 
         [0115]    20. A surgical end effector, comprising: a jaw assembly having a proximal end and a distal end, the jaw assembly comprising: a moveable jaw member; a fixed jaw member; and a pivot connection coupling the moveable jaw member and the fixed jaw member, wherein the moveable jaw member is pivotably moveable between an open position and a closed position with respect to the fixed jaw member; wherein, in the closed position, the jaw assembly defines a radius of curvature and a smooth taper from the proximal end to the distal end. 
         [0116]    21. The surgical end effector of clause 20, comprising a lever arm asymmetrically coupled to the first jaw member on a first side of a central axis of the jaw assembly, wherein the lever arm is configured to pivot the moveable jaw member from the open position to the closed position. 
         [0117]    22. The surgical end effector of clause 21, wherein the pivot connection between the moveable jaw member and the fixed jaw member is offset to the first side of the axis of the jaw assembly. 
         [0118]    23. The surgical end effector of clause 22, wherein the pivot connection comprises a pinned link-slider. 
         [0119]    24. The surgical end effector of clause 21, comprising a lubricous bushing, wherein the lubricous bushing is configured to be located between an outer diameter of the lever arm and an inner diameter of an outer shaft when the end effector is coupled to a surgical instrument. 
         [0120]    25. The surgical end effector of clause 24, wherein the lubricous bushing comprises a plastic material. 
         [0121]    26. The surgical end effector of clause 24, wherein the lubricous bushing comprises a dissimilar metal material. 
         [0122]    27. A surgical instrument comprising: a handle; a shaft assembly extending distally from the handle, the shaft assembly comprising a lever arm extending distally therethrough; an end effector coupled to a distal end of the shaft assembly, wherein the end effector comprises: a jaw assembly having a proximal end and a distal end, the jaw assembly comprising: a moveable jaw member; and a fixed jaw member, wherein the moveable jaw member is pivotably moveable between an open position and a closed position with respect to the fixed jaw member, wherein the lever arm is asymmetrically coupled to the moveable jaw member on a first side of a central axis of the shaft assembly, and wherein a pivot connection between the moveable jaw member and the fixed jaw member is offset to the first side of the central axis of the shaft assembly; wherein in the closed position, the jaw assembly defines a radius of curvature and a smooth taper from the proximal end to the distal end. 
         [0123]    28. A surgical instrument comprising: a handle assembly comprising: a closure trigger defining an energy button hole; an energy button located within the energy button hole; a firing trigger; and a shaft assembly coupled to the handle assembly, the shaft assembly comprising: an outer tube; a closure actuator operatively coupled to the closure trigger; and a firing actuator operatively coupled to the firing trigger; and an end effector coupled to a distal end of the shaft assembly, the end effector comprising: a jaw assembly having a proximal end and a distal end, the jaw assembly comprising: a first jaw member; a second jaw member, wherein the first and second jaw members define a longitudinal slot, wherein the closure actuator is coupled to the first jaw member to pivotally move the first jaw member from an open position to a closed position relative to the second jaw member; and a cutting member deployable within the longitudinal slot, wherein the cutting member is coupled to the firing actuator to advance the cutting member distally within the longitudinal slot. 
         [0124]    29. The surgical instrument of clause 28, wherein the handle assembly comprises: a compound gear coupled to the firing trigger, the compound gear comprising a high pivot; and a rack coupled to the firing actuator and operably coupled to the compound gear, wherein the compound gear is configured to rotate upon actuation of the firing trigger to advance the rack and firing actuator distally to deploy the cutting member distally within the end effector. 
         [0125]    30. The surgical instrument of clause 29, wherein the firing actuator comprises a pull tube. 
         [0126]    31. The surgical instrument of clause 29, wherein the handle assembly comprises a firing lock configured to prevent actuation of the firing trigger prior to closure of the jaw assembly, wherein the closure trigger is configured to release the firing lock when the closure trigger is in a predetermined closure position, and wherein release of the firing lock allows actuation of the firing trigger. 
         [0127]    32. The surgical instrument of clause 31, wherein the handle assembly comprises a cutting member return spring stop comprising a crimp and a washer. 
         [0128]    33. The surgical instrument of clause 28, wherein the closure trigger comprises a yoke interfaced with a closure spring, wherein the closure spring is coupled to the closure actuator, wherein actuation of the closure trigger slides the yoke proximally to compress the closure spring, and wherein compression of the closure spring moves the closure actuator proximally to rotate the first jaw member into a closed position. 
         [0129]    34. The surgical instrument of clause 33, wherein the jaw closure spring comprises a pre-compressed spring. 
         [0130]    35. The surgical instrument of clause 28, wherein the closure actuator comprises a lever arm asymmetrically coupled to the first jaw member, and wherein the jaw assembly comprises an offset pivot. 
         [0131]    36. The surgical instrument of clause 28, wherein the shaft assembly comprises an electrical contact disposed on the outer tube and the end effector comprises an electrode, wherein the electrical contact is configured electrically couple the electrode to an energy source when the jaw assembly is in a closed position. 
         [0132]    37. The surgical instrument of clause 1, wherein in the closed position, the jaw assembly defines a radius of curvature and a smooth taper from the proximal end to the distal end. 
         [0133]    38. A surgical instrument comprising: a handle assembly comprising: a closure trigger defining an energy button hole; an energy button located within the energy button hole; and a firing trigger; a shaft assembly coupled to the handle assembly, the shaft assembly comprising: an outer tube; a closure actuator operatively coupled to the closure trigger; and a firing actuator operatively coupled to the firing trigger; and an end effector coupled to a distal end of the shaft assembly, the end effector comprising: a jaw assembly having a proximal end and a distal end, the jaw assembly comprising: a moveable jaw member; a fixed jaw member, wherein the moveable jaw member is pivotably moveable between an open position and a closed position with respect to the fixed jaw member, and wherein in the closed position, the jaw assembly defines a radius of curvature; and a cutting member deployable within the curved slot, wherein the cutting member is coupled to the firing actuator to advance the cutting member distally within the curved slot. 
         [0134]    39. The surgical instrument of clause 38, wherein the handle assembly comprises: a compound gear coupled to the firing trigger, the compound gear comprising a high pivot; and a rack coupled to the firing actuator and operably coupled to the compound gear, wherein the compound gear is configured to rotate upon actuation of the firing trigger to advance the rack and firing actuator distally to deploy the cutting member distally within the end effector. 
         [0135]    40. The surgical instrument of clause 38, wherein the firing actuator comprises a pull tube. 
         [0136]    41. The surgical instrument of clause 40, wherein the handle assembly comprises a firing lock configured to prevent actuation of the firing trigger prior to closure of the jaw assembly, wherein the closure trigger is configured to release the firing lock when the closure trigger is in a predetermined closure position, and wherein release of the firing lock allows actuation of the firing trigger. 
         [0137]    42. The surgical instrument of clause 41, wherein the handle assembly comprises a cutting member return spring stop comprising a crimp and a washer. 
         [0138]    43. The surgical instrument of clause 38, wherein the closure trigger comprises a yoke interfaced with a closure spring, wherein the closure spring is coupled to the closure actuator, wherein actuation of the closure trigger slides the yoke proximally to compress the closure spring, and wherein compression of the closure spring moves the closure actuator proximally to rotate the first jaw member into a closed position. 
         [0139]    44. The surgical instrument of clause 43, wherein the jaw closure spring comprises a pre-compressed spring. 
         [0140]    45. The surgical instrument of clause 38, wherein the shaft assembly comprises an electrical contact disposed on the outer tube and the end effector comprises an electrode, wherein the electrical contact is configured electrically couple to the end effector when the jaw assembly is in a closed position. 
         [0141]    46. The surgical instrument of clause 38, wherein in the closed position the jaw assembly comprising smooth taper from the proximal end to the distal end. 
         [0142]    47. A surgical instrument comprising: a handle assembly comprising: a closure trigger defining an energy button hole; an energy button located within the energy button hole; and a firing trigger; a shaft assembly coupled to the handle assembly, the shaft assembly comprising: an outer tube; a closure actuator operatively coupled to the closure trigger; and a firing actuator operatively coupled to the firing trigger; and an end effector coupled to a distal end of the shaft assembly, the end effector comprising: a jaw assembly having a proximal end and a distal end, the jaw assembly comprising: a moveable jaw member; and a fixed jaw member, wherein the moveable jaw member is pivotably moveable between an open position and a closed position with respect to the fixed jaw member, wherein the closure actuator is asymmetrically coupled to the moveable jaw member on a first side of a central axis of the shaft assembly, and wherein a pivot connection between the moveable jaw member and the fixed jaw member is offset to the first side of the central axis of the shaft assembly; wherein in the closed position, the jaw assembly defines a radius of curvature and a smooth taper from the proximal end to the distal end.