Patent Publication Number: US-10779845-B2

Title: Ultrasonic surgical instruments with distally positioned transducers

Description:
PRIORITY 
     This application is a divisional application under 35 U.S.C. § 121, of U.S. patent application Ser. No. 13/538,601, filed on Jun. 29, 2012, entitled “Ultrasonic Surgical Instruments With Distally Positioned Transducers,” now U.S. Publication No. 2014/0005702, the contents of which is hereby incorporated by reference in their entirety. 
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is related to the following, U.S. patent applications which were filed on Jun. 29, 2012, which are incorporated herein by reference in their entirety:
     U.S. application Ser. No. 13/539,096, entitled “Haptic Feedback Devices for Surgical Robot,” now U.S. Pat. No. 9,198,714;   U.S. application Ser. No. 13/539,110 entitled “Lockout Mechanism for Use with Robotic Electrosurgical Device,” now U.S. Pat. No. 9,326,788;   U.S. application Ser. No. 13/539,117, entitled “Closed Feedback Control for Electrosurgical Device,” now U.S. Pat. No. 9,226,767;   U.S. application Ser. No. 13/538,588, entitled “Surgical Instruments with Articulating Shafts,” now U.S. Pat. No. 9,393,037;   U.S. application Ser. No. 13/538,700, entitled “Surgical Instruments with Articulating Shafts,” now U.S. Pat. No. 9,408,622;   U.S. application Ser. No. 13/538,711, entitled “Ultrasonic Surgical Instruments with Distally Positioned Jaw Assemblies,” now U.S. Pat. No. 9,351,754;   U.S. application Ser. No. 13/538,720, entitled “Surgical Instruments with Articulating Shafts,” now U.S. Patent Publication No. 2014/0005705;   U.S. application Ser. No. 13/538,733, entitled “Ultrasonic Surgical Instruments with Control Mechanisms,” now U.S. Patent Publication No. 2014/0005681; and   U.S. application Ser. No. 13/539,122, entitled “Surgical Instruments With Fluid Management System” now U.S. Pat. No. 9,283,045.   

    
    
     BACKGROUND 
     Various embodiments are directed to surgical instruments including ultrasonic instruments with distally positioned transducers. 
     Ultrasonic surgical devices, such as ultrasonic scalpels, are used in many applications in surgical procedures by virtue of their unique performance characteristics. Depending upon specific device configurations and operational parameters, ultrasonic surgical devices can provide substantially simultaneous transection of tissue and homeostasis by coagulation, desirably minimizing patient trauma. An ultrasonic surgical device comprises a proximally-positioned ultrasonic transducer and an instrument coupled to the ultrasonic transducer having a distally-mounted end effector comprising an ultrasonic blade to cut and seal tissue. The end effector is typically coupled either to a handle and/or a robotic surgical implement via a shaft. The blade is acoustically coupled to the transducer via a waveguide extending through the shaft. Ultrasonic surgical devices of this nature can be configured for open surgical use, laparoscopic, or endoscopic surgical procedures including robotic-assisted procedures. 
     Ultrasonic energy cuts and coagulates tissue using temperatures lower than those used in electrosurgical procedures. Vibrating at high frequencies (e.g., 55,500 times per second), the ultrasonic blade denatures protein in the tissue to form a sticky coagulum. Pressure exerted on tissue by the blade surface collapses blood vessels and allows the coagulum to form a hemostatic seal. A surgeon can control the cutting speed and coagulation by the force applied to the tissue by the end effector, the time over which the force is applied and the selected excursion level of the end effector. 
     With respect to both ultrasonic and electrosurgical devices, it is often desirable for clinicians to articulate a distal portion of the instrument shaft in order to direct the application of ultrasonic and/or RF energy. Bringing about and controlling such articulation, however, is often a considerable challenge. 
    
    
     
       DRAWINGS 
       The features of the various embodiments are set forth with particularity in the appended claims. The various embodiments, however, both as to organization and methods of operation, together with advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings as follows: 
         FIG. 1  illustrates one embodiment of a surgical system including a surgical instrument and an ultrasonic generator. 
         FIG. 2  illustrates one embodiment of the surgical instrument shown in  FIG. 1 . 
         FIG. 3  illustrates one embodiment of an ultrasonic end effector. 
         FIG. 4  illustrates another embodiment of an ultrasonic end effector. 
         FIG. 5  illustrates an exploded view of one embodiment of the surgical instrument shown in  FIG. 1 . 
         FIG. 6  illustrates a cut-away view of one embodiment of the surgical instrument shown in  FIG. 1 . 
         FIG. 7  illustrates various internal components of one embodiment of the surgical instrument shown in  FIG. 1   
         FIG. 8  illustrates a top view of one embodiment of a surgical system including a surgical instrument and an ultrasonic generator. 
         FIG. 9  illustrates one embodiment of a rotation assembly included in one example embodiment of the surgical instrument of  FIG. 1 . 
         FIG. 10  illustrates one embodiment of a surgical system including a surgical instrument having a single element end effector. 
         FIG. 11  illustrates a block diagram of one embodiment of a robotic surgical system. 
         FIG. 12  illustrates one embodiment of a robotic arm cart. 
         FIG. 13  illustrates one embodiment of the robotic manipulator of the robotic arm cart of  FIG. 12 . 
         FIG. 14  illustrates one embodiment of a robotic arm cart having an alternative set-up joint structure. 
         FIG. 15  illustrates one embodiment of a controller that may be used in conjunction with a robotic arm cart, such as the robotic arm carts of  FIGS. 11-14 . 
         FIG. 16  illustrates one embodiment of an ultrasonic surgical instrument adapted for use with a robotic system. 
         FIG. 25  illustrates one embodiment of an electrosurgical instrument adapted for use with a robotic system. 
         FIG. 17  illustrates one embodiment of an instrument drive assembly that may be coupled to a surgical manipulators to receive and control the surgical instrument shown in  FIG. 16 . 
         FIG. 18  illustrates another view of the instrument drive assembly embodiment of  FIG. 26  including the surgical instrument of  FIG. 16 . 
         FIG. 28  illustrates another view of the instrument drive assembly embodiment of  FIG. 26  including the electrosurgical instrument of  FIG. 25 . 
         FIGS. 19-21  illustrate additional views of the adapter portion of the instrument drive assembly embodiment of  FIG. 26 . 
         FIGS. 22-24  illustrate one embodiment of the instrument mounting portion of  FIG. 16  showing components for translating motion of the driven elements into motion of the surgical instrument. 
         FIGS. 25-27  illustrate an alternate embodiment of the instrument mounting portion of  FIG. 16  showing an alternate example mechanism for translating rotation of the driven elements into rotational motion about the axis of the shaft and an alternate example mechanism for generating reciprocating translation of one or more members along the axis of the shaft. 
         FIGS. 28-32  illustrate an alternate embodiment of the instrument mounting portion  FIG. 16  showing another alternate example mechanism for translating rotation of the driven elements into rotational motion about the axis of the shaft. 
         FIGS. 33-36A  illustrate an alternate embodiment of the instrument mounting portion showing an alternate example mechanism for differential translation of members along the axis of the shaft (e.g., for articulation). 
         FIGS. 36B-36C  illustrate one embodiment of a tool mounting portion comprising internal power and energy sources. 
         FIG. 37  illustrates one embodiment of an articulatable surgical instrument comprising a distally positioned ultrasonic transducer assembly. 
         FIG. 38  illustrates one embodiment of the shaft and end effector of  FIG. 37  used in conjunction with an instrument mounting portion of a robotic surgical system. 
         FIG. 39  illustrates a cut-away view of one embodiment of the shaft and end effector of  FIGS. 37-38 . 
         FIGS. 40-40A  illustrate one embodiment for driving differential translation of the control members of  FIG. 39  in conjunction with a manual instrument, such as the instrument of  FIGS. 37-38 . 
         FIG. 41  illustrates a cut-away view of one embodiment of the ultrasonic transducer assembly of  FIGS. 37-38 . 
         FIG. 42  illustrates one embodiment of the ultrasonic transducer assembly and clamp arm of  FIGS. 37-38  arranged as part of a four-bar linkage. 
         FIG. 43  illustrates a side view of one embodiment of the ultrasonic transducer assembly and clamp arm, arranged as illustrated in  FIG. 42 , coupled to the distal shaft portion, and in an open position. 
         FIG. 44  illustrates a side view of one embodiment of the ultrasonic transducer assembly and clamp arm of  FIGS. 37-38 , arranged as illustrated in  FIG. 42 , coupled to the distal shaft portion and in a closed position. 
         FIGS. 45-46  illustrate side views of one embodiment of the ultrasonic transducer assembly and clamp arm of  FIGS. 37-38 , arranged as illustrated in  FIG. 42 , including proximal portions of the shaft. 
         FIGS. 47-48  illustrate one embodiment of an end effector having an alternately shaped ultrasonic blade and clamp arm. 
         FIG. 49  illustrates one embodiment of another end effector comprising a flexible ultrasonic transducer assembly. 
         FIG. 50  shows one embodiment of a manual surgical instrument having a transducer assembly extending proximally from the articulation joint. 
         FIG. 51  illustrates a close up of the transducer assembly, distal shaft portion, articulation joint and end effector arranged as illustrated in  FIG. 50 . 
         FIG. 52  illustrates one embodiment of the articulation joint with the distal shaft portion and proximal shaft portion removed to show one example embodiment for articulating the shaft and actuating the haw member. 
         FIG. 53  illustrates one embodiment of a manual surgical instrument comprising a shaft having an articulatable, rotatable end effector. 
         FIG. 54  illustrates one embodiment of the articulation lever of the instrument of  FIG. 53  coupled to control members. 
         FIG. 55  illustrates one embodiment of the instrument showing a keyed connection between the end effector rotation dial and the central shaft member. 
         FIG. 56  illustrates one embodiment of the shaft of  FIG. 53  focusing on the articulation joint. 
         FIG. 57  illustrates one embodiment of the central shaft member made of hinged mechanical components. 
         FIG. 58  illustrates one embodiment of the shaft of  FIG. 53  comprising a distal shaft portion and a proximal shaft portion. 
         FIG. 59  illustrates one embodiment of the shaft of and end effector of  FIG. 53  illustrating a coupling between the inner shaft member and the clamp arm. 
         FIGS. 60-61  illustrate a control mechanism for a surgical instrument in which articulation and rotation of the end effector  1312  are motorized. 
         FIGS. 62-63  illustrate one embodiment of a shaft that may be utilized with any of the various surgical instruments described herein. 
         FIG. 64  illustrates one embodiment of a shaft that may be articulated utilizing a cable and pulley mechanism. 
         FIG. 65  illustrates one embodiment of the shaft of  FIG. 64  showing additional details of how the distal shaft portion may be articulated. 
         FIG. 66  illustrates one embodiment of an end effector that may be utilized with any of the various instruments and/or shafts described herein. 
         FIG. 67  illustrates one embodiment of the shaft of  FIG. 64  coupled to an alternate pulley-driven end effector. 
         FIG. 68  illustrates one embodiment of the end effector. 
     
    
    
     DESCRIPTION 
     Example embodiments described herein are directed to articulating ultrasonic surgical instruments, shafts thereof, and methods of using the same. In various example embodiments, an ultrasonic instrument comprises a distally positioned end effector comprising an ultrasonic blade. The ultrasonic blade may be driven by a distally positioned ultrasonic transducer assembly. A shaft of the instrument may comprise proximal and distal shaft members pivotably coupled to one another at an articulation joint. The end effector may be coupled to a distal portion of the distal shaft member such that the end effector (and at least a portion of the distal shaft member) are articulatable about a longitudinal axis of the shaft. To facilitate articulation, the distally positioned ultrasonic transducer assembly may be positioned partially or completely distal from the articulation joint. In this way, the ultrasonic blade may be acoustically coupled to the ultrasonic transducer assembly such that neither the ultrasonic blade itself nor any intermediate waveguide spans the articulation joint. 
     Reference will now be made in detail to several embodiments, including embodiments showing example implementations of manual and robotic surgical instruments with end effectors comprising ultrasonic and/or electrosurgical elements. Wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict example embodiments of the disclosed surgical instruments and/or methods of use for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative example embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein. 
       FIG. 1  is a right side view of one embodiment of an ultrasonic surgical instrument  10 . In the illustrated embodiment, the ultrasonic surgical instrument  10  may be employed in various surgical procedures including endoscopic or traditional open surgical procedures. In one example embodiment, the ultrasonic surgical instrument  10  comprises a handle assembly  12 , an elongated shaft assembly  14 , and an ultrasonic transducer  16 . The handle assembly  12  comprises a trigger assembly  24 , a distal rotation assembly  13 , and a switch assembly  28 . The elongated shaft assembly  14  comprises an end effector assembly  26 , which comprises elements to dissect tissue or mutually grasp, cut, and coagulate vessels and/or tissue, and actuating elements to actuate the end effector assembly  26 . The handle assembly  12  is adapted to receive the ultrasonic transducer  16  at the proximal end. The ultrasonic transducer  16  is mechanically engaged to the elongated shaft assembly  14  and portions of the end effector assembly  26 . The ultrasonic transducer  16  is electrically coupled to a generator  20  via a cable  22 . Although the majority of the drawings depict a multiple end effector assembly  26  for use in connection with laparoscopic surgical procedures, the ultrasonic surgical instrument  10  may be employed in more traditional open surgical procedures and in other embodiments, may be configured for use in endoscopic procedures. For the purposes herein, the ultrasonic surgical instrument  10  is described in terms of an endoscopic instrument; however, it is contemplated that an open and/or laparoscopic version of the ultrasonic surgical instrument  10  also may include the same or similar operating components and features as described herein. 
     In various embodiments, the generator  20  comprises several functional elements, such as modules and/or blocks. Different functional elements or modules may be configured for driving different kinds of surgical devices. For example, an ultrasonic generator module  21  may drive an ultrasonic device, such as the ultrasonic surgical instrument  10 . In some example embodiments, the generator  20  also comprises an electrosurgery/RF generator module  23  for driving an electrosurgical device (or an electrosurgical embodiment of the ultrasonic surgical instrument  10 ). In the example embodiment illustrated in  FIG. 1 , the generator  20  includes a control system  25  integral with the generator  20 , and a foot switch  29  connected to the generator via a cable  27 . The generator  20  may also comprise a triggering mechanism for activating a surgical instrument, such as the instrument  10 . The triggering mechanism may include a power switch (not shown) as well as a foot switch  29 . When activated by the foot switch  29 , the generator  20  may provide energy to drive the acoustic assembly of the surgical instrument  10  and to drive the end effector  18  at a predetermined excursion level. The generator  20  drives or excites the acoustic assembly at any suitable resonant frequency of the acoustic assembly and/or derives the therapeutic/sub-therapeutic electromagnetic/RF energy. As shown in  FIG. 1 , according to various embodiments, the ultrasonic generator module  21  and/or the electrosurgery/RF generator module  23  may be located external to the generator  21  (shown in phantom as ultrasonic generator module  21 ′ and electrosurgery/RF generator module  23 ′). 
     In one embodiment, the electrosurgical/RF generator module  23  may be implemented as an electrosurgery unit (ESU) capable of supplying power sufficient to perform bipolar electrosurgery using radio frequency (RF) energy. In one embodiment, the ESU can be a bipolar ERBE ICC 350 sold by ERBE USA, Inc. of Marietta, Ga. In bipolar electrosurgery applications, as previously discussed, a surgical instrument having an active electrode and a return electrode can be utilized, wherein the active electrode and the return electrode can be positioned against, or adjacent to, the tissue to be treated such that current can flow from the active electrode to the return electrode through the tissue. Accordingly, the electrosurgical/RF module  23  generator may be configured for therapeutic purposes by applying electrical energy to the tissue T sufficient for treating the tissue (e.g., cauterization). 
     In one embodiment, the electrosurgical/RF generator module  23  may be configured to deliver a subtherapeutic RF signal to implement a tissue impedance measurement module. In one embodiment, the electrosurgical/RF generator module  23  comprises a bipolar radio frequency generator as described in more detail below. In one embodiment, the electrosurgical/RF generator module  23  may be configured to monitor electrical impedance Z, of tissue T and to control the characteristics of time and power level based on the tissue T by way of a return electrode provided on a clamp member of the end effector assembly  26 . Accordingly, the electrosurgical/RF generator module  23  may be configured for subtherapeutic purposes for measuring the impedance or other electrical characteristics of the tissue T. Techniques and circuit configurations for measuring the impedance or other electrical characteristics of tissue T are discussed in more detail in commonly assigned U.S. Patent Publication No. 2011/0015631, titled “Electrosurgical Generator for Ultrasonic Surgical Instrument,” the disclosure of which is herein incorporated by reference in its entirety. 
     A suitable ultrasonic generator module  21  may be configured to functionally operate in a manner similar to the GEN300 sold by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio as is disclosed in one or more of the following U.S. patents, all of which are incorporated by reference herein: U.S. Pat. No. 6,480,796 (Method for Improving the Start Up of an Ultrasonic System Under Zero Load Conditions); U.S. Pat. No. 6,537,291 (Method for Detecting Blade Breakage Using Rate and/or Impedance Information); U.S. Pat. No. 6,662,127 (Method for Detecting Presence of a Blade in an Ultrasonic System); U.S. Pat. No. 6,977,495 (Detection Circuitry for Surgical Handpiece System); U.S. Pat. No. 7,077,853 (Method for Calculating Transducer Capacitance to Determine Transducer Temperature); U.S. Pat. No. 7,179,271 (Method for Driving an Ultrasonic System to Improve Acquisition of Blade Resonance Frequency at Startup); and U.S. Pat. No. 7,273,483 (Apparatus and Method for Alerting Generator Function in an Ultrasonic Surgical System). 
     It will be appreciated that in various embodiments, the generator  20  may be configured to operate in several modes. In one mode, the generator  20  may be configured such that the ultrasonic generator module  21  and the electrosurgical/RF generator module  23  may be operated independently. 
     For example, the ultrasonic generator module  21  may be activated to apply ultrasonic energy to the end effector assembly  26  and subsequently, either therapeutic or sub-therapeutic RF energy may be applied to the end effector assembly  26  by the electrosurgical/RF generator module  23 . As previously discussed, the sub-therapeutic electrosurgical/RF energy may be applied to tissue clamped between claim elements of the end effector assembly  26  to measure tissue impedance to control the activation, or modify the activation, of the ultrasonic generator module  21 . Tissue impedance feedback from the application of the sub-therapeutic energy also may be employed to activate a therapeutic level of the electrosurgical/RF generator module  23  to seal the tissue (e.g., vessel) clamped between claim elements of the end effector assembly  26 . 
     In another embodiment, the ultrasonic generator module  21  and the electrosurgical/RF generator module  23  may be activated simultaneously. In one example, the ultrasonic generator module  21  is simultaneously activated with a sub-therapeutic RF energy level to measure tissue impedance simultaneously while the ultrasonic blade of the end effector assembly  26  cuts and coagulates the tissue (or vessel) clamped between the clamp elements of the end effector assembly  26 . Such feedback may be employed, for example, to modify the drive output of the ultrasonic generator module  21 . In another example, the ultrasonic generator module  21  may be driven simultaneously with electrosurgical/RF generator module  23  such that the ultrasonic blade portion of the end effector assembly  26  is employed for cutting the damaged tissue while the electrosurgical/RF energy is applied to electrode portions of the end effector clamp assembly  26  for sealing the tissue (or vessel). 
     When the generator  20  is activated via the triggering mechanism, electrical energy is continuously applied by the generator  20  to a transducer stack or assembly of the acoustic assembly. In another embodiment, electrical energy is intermittently applied (e.g., pulsed) by the generator  20 . A phase-locked loop in the control system of the generator  20  may monitor feedback from the acoustic assembly. The phase lock loop adjusts the frequency of the electrical energy sent by the generator  20  to match the resonant frequency of the selected longitudinal mode of vibration of the acoustic assembly. In addition, a second feedback loop in the control system  25  maintains the electrical current supplied to the acoustic assembly at a pre-selected constant level in order to achieve substantially constant excursion at the end effector  18  of the acoustic assembly. In yet another embodiment, a third feedback loop in the control system  25  monitors impedance between electrodes located in the end effector assembly  26 . Although  FIGS. 1-9  show a manually operated ultrasonic surgical instrument, it will be appreciated that ultrasonic surgical instruments may also be used in robotic applications, for example, as described herein as well as combinations of manual and robotic applications. 
     In ultrasonic operation mode, the electrical signal supplied to the acoustic assembly may cause the distal end of the end effector  18 , to vibrate longitudinally in the range of, for example, approximately 20 kHz to 250 kHz. According to various embodiments, the blade  22  may vibrate in the range of about 54 kHz to 56 kHz, for example, at about 55.5 kHz. In other embodiments, the blade  22  may vibrate at other frequencies including, for example, about 31 kHz or about 80 kHz. The excursion of the vibrations at the blade can be controlled by, for example, controlling the amplitude of the electrical signal applied to the transducer assembly of the acoustic assembly by the generator  20 . As noted above, the triggering mechanism of the generator  20  allows a user to activate the generator  20  so that electrical energy may be continuously or intermittently supplied to the acoustic assembly. The generator  20  also has a power line for insertion in an electro-surgical unit or conventional electrical outlet. It is contemplated that the generator  20  can also be powered by a direct current (DC) source, such as a battery. The generator  20  can comprise any suitable generator, such as Model No. GEN04, and/or Model No. GEN11 available from Ethicon Endo-Surgery, Inc. 
       FIG. 2  is a left perspective view of one example embodiment of the ultrasonic surgical instrument  10  showing the handle assembly  12 , the distal rotation assembly  13 , the elongated shaft assembly  14 , and the end effector assembly  26 . In the illustrated embodiment the elongated shaft assembly  14  comprises a distal end  52  dimensioned to mechanically engage the end effector assembly  26  and a proximal end  50  that mechanically engages the handle assembly  12  and the distal rotation assembly  13 . The proximal end  50  of the elongated shaft assembly  14  is received within the handle assembly  12  and the distal rotation assembly  13 . More details relating to the connections between the elongated shaft assembly  14 , the handle assembly  12 , and the distal rotation assembly  13  are provided in the description of  FIGS. 5 and 7 . 
     In the illustrated embodiment, the trigger assembly  24  comprises a trigger  32  that operates in conjunction with a fixed handle  34 . The fixed handle  34  and the trigger  32  are ergonomically formed and adapted to interface comfortably with the user. The fixed handle  34  is integrally associated with the handle assembly  12 . The trigger  32  is pivotally movable relative to the fixed handle  34  as explained in more detail below with respect to the operation of the ultrasonic surgical instrument  10 . The trigger  32  is pivotally movable in direction  33 A toward the fixed handle  34  when the user applies a squeezing force against the trigger  32 . A spring element  98  ( FIG. 5 ) causes the trigger  32  to pivotally move in direction  33 B when the user releases the squeezing force against the trigger  32 . 
     In one example embodiment, the trigger  32  comprises an elongated trigger hook  36 , which defines an aperture  38  between the elongated trigger hook  36  and the trigger  32 . The aperture  38  is suitably sized to receive one or multiple fingers of the user therethrough. The trigger  32  also may comprise a resilient portion  32   a  molded over the trigger  32  substrate. The resilient portion  32   a  is formed to provide a more comfortable contact surface for control of the trigger  32  in outward direction  33 B. In one example embodiment, the resilient portion  32   a  may also be provided over a portion of the elongated trigger hook  36  as shown, for example, in  FIG. 2 . The proximal surface of the elongated trigger hook  32  remains uncoated or coated with a non-resilient substrate to enable the user to easily slide their fingers in and out of the aperture  38 . In another embodiment, the geometry of the trigger forms a fully closed loop which defines an aperture suitably sized to receive one or multiple fingers of the user therethrough. The fully closed loop trigger also may comprise a resilient portion molded over the trigger substrate. 
     In one example embodiment, the fixed handle  34  comprises a proximal contact surface  40  and a grip anchor or saddle surface  42 . The saddle surface  42  rests on the web where the thumb and the index finger are joined on the hand. The proximal contact surface  40  has a pistol grip contour that receives the palm of the hand in a normal pistol grip with no rings or apertures. The profile curve of the proximal contact surface  40  may be contoured to accommodate or receive the palm of the hand. A stabilization tail  44  is located towards a more proximal portion of the handle assembly  12 . The stabilization tail  44  may be in contact with the uppermost web portion of the hand located between the thumb and the index finger to stabilize the handle assembly  12  and make the handle assembly  12  more controllable. 
     In one example embodiment, the switch assembly  28  may comprise a toggle switch  30 . The toggle switch  30  may be implemented as a single component with a central pivot  304  located within inside the handle assembly  12  to eliminate the possibility of simultaneous activation. In one example embodiment, the toggle switch  30  comprises a first projecting knob  30   a  and a second projecting knob  30   b  to set the power setting of the ultrasonic transducer  16  between a minimum power level (e.g., MIN) and a maximum power level (e.g., MAX). In another embodiment, the rocker switch may pivot between a standard setting and a special setting. The special setting may allow one or more special programs to be implemented by the device. The toggle switch  30  rotates about the central pivot as the first projecting knob  30   a  and the second projecting knob  30   b  are actuated. The one or more projecting knobs  30   a ,  30   b  are coupled to one or more arms that move through a small arc and cause electrical contacts to close or open an electric circuit to electrically energize or de-energize the ultrasonic transducer  16  in accordance with the activation of the first or second projecting knobs  30   a ,  30   b . The toggle switch  30  is coupled to the generator  20  to control the activation of the ultrasonic transducer  16 . The toggle switch  30  comprises one or more electrical power setting switches to activate the ultrasonic transducer  16  to set one or more power settings for the ultrasonic transducer  16 . The forces required to activate the toggle switch  30  are directed substantially toward the saddle point  42 , thus avoiding any tendency of the instrument to rotate in the hand when the toggle switch  30  is activated. 
     In one example embodiment, the first and second projecting knobs  30   a ,  30   b  are located on the distal end of the handle assembly  12  such that they can be easily accessible by the user to activate the power with minimal, or substantially no, repositioning of the hand grip, making it suitable to maintain control and keep attention focused on the surgical site (e.g., a monitor in a laparoscopic procedure) while activating the toggle switch  30 . The projecting knobs  30   a ,  30   b  may be configured to wrap around the side of the handle assembly  12  to some extent to be more easily accessible by variable finger lengths and to allow greater freedom of access to activation in awkward positions or for shorter fingers. 
     In the illustrated embodiment, the first projecting knob  30   a  comprises a plurality of tactile elements  30   c , e.g., textured projections or “bumps” in the illustrated embodiment, to allow the user to differentiate the first projecting knob  30   a  from the second projecting knob  30   b . It will be appreciated by those skilled in the art that several ergonomic features may be incorporated into the handle assembly  12 . Such ergonomic features are described in U.S. Pat. App. Pub. No. 2009/0105750 entitled “Ergonomic Surgical Instruments”, now U.S. Pat. No. 8,623,027, which is incorporated by reference herein in its entirety. 
     In one example embodiment, the toggle switch  30  may be operated by the hand of the user. The user may easily access the first and second projecting knobs  30   a ,  30   b  at any point while also avoiding inadvertent or unintentional activation at any time. The toggle switch  30  may readily operated with a finger to control the power to the ultrasonic assembly  16  and/or to the ultrasonic assembly  16 . For example, the index finger may be employed to activate the first contact portion  30   a  to turn on the ultrasonic assembly  16  to a maximum (MAX) power level. The index finger may be employed to activate the second contact portion  30   b  to turn on the ultrasonic assembly  16  to a minimum (MIN) power level. In another embodiment, the rocker switch may pivot the instrument  10  between a standard setting and a special setting. The special setting may allow one or more special programs to be implemented by the instrument  10 . The toggle switch  30  may be operated without the user having to look at the first or second projecting knob  30   a ,  30   b . For example, the first projecting knob  30   a  or the second projecting knob  30   b  may comprise a texture or projections to tactilely differentiate between the first and second projecting knobs  30   a ,  30   b  without looking. 
     In one example embodiment, the distal rotation assembly  13  is rotatable without limitation in either direction about a longitudinal axis “T.” The distal rotation assembly  13  is mechanically engaged to the elongated shaft assembly  14 . The distal rotation assembly  13  is located on a distal end of the handle assembly  12 . The distal rotation assembly  13  comprises a cylindrical hub  46  and a rotation knob  48  formed over the hub  46 . The hub  46  mechanically engages the elongated shaft assembly  14 . The rotation knob  48  may comprise fluted polymeric features and may be engaged by a finger (e.g., an index finger) to rotate the elongated shaft assembly  14 . The hub  46  may comprise a material molded over the primary structure to form the rotation knob  48 . The rotation knob  48  may be overmolded over the hub  46 . The hub  46  comprises an end cap portion  46   a  that is exposed at the distal end. The end cap portion  46   a  of the hub  46  may contact the surface of a trocar during laparoscopic procedures. The hub  46  may be formed of a hard durable plastic such as polycarbonate to alleviate any friction that may occur between the end cap portion  46   a  and the trocar. The rotation knob  48  may comprise “scallops” or flutes formed of raised ribs  48   a  and concave portions  48   b  located between the ribs  48   a  to provide a more precise rotational grip. In one example embodiment, the rotation knob  48  may comprise a plurality of flutes (e.g., three or more flutes). In other embodiments, any suitable number of flutes may be employed. The rotation knob  48  may be formed of a softer polymeric material overmolded onto the hard plastic material. For example, the rotation knob  48  may be formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. This softer overmolded material may provide a greater grip and more precise control of the movement of the rotation knob  48 . It will be appreciated that any materials that provide adequate resistance to sterilization, are biocompatible, and provide adequate frictional resistance to surgical gloves may be employed to form the rotation knob  48 . 
     In one example embodiment, the handle assembly  12  is formed from two (2) housing portions or shrouds comprising a first portion  12   a  and a second portion  12   b . From the perspective of a user viewing the handle assembly  12  from the distal end towards the proximal end, the first portion  12   a  is considered the right portion and the second portion  12   b  is considered the left portion. Each of the first and second portions  12   a ,  12   b  includes a plurality of interfaces  69  ( FIG. 7 ) dimensioned to mechanically align and engage each another to form the handle assembly  12  and enclosing the internal working components thereof. The fixed handle  34 , which is integrally associated with the handle assembly  12 , takes shape upon the assembly of the first and second portions  12   a  and  12   b  of the handle assembly  12 . A plurality of additional interfaces (not shown) may be disposed at various points around the periphery of the first and second portions  12   a  and  12   b  of the handle assembly  12  for ultrasonic welding purposes, e.g., energy direction/deflection points. The first and second portions  12   a  and  12   b  (as well as the other components described below) may be assembled together in any fashion known in the art. For example, alignment pins, snap-like interfaces, tongue and groove interfaces, locking tabs, adhesive ports, may all be utilized either alone or in combination for assembly purposes. 
     In one example embodiment, the elongated shaft assembly  14  comprises a proximal end  50  adapted to mechanically engage the handle assembly  12  and the distal rotation assembly  13 ; and a distal end  52  adapted to mechanically engage the end effector assembly  26 . The elongated shaft assembly  14  comprises an outer tubular sheath  56  and a reciprocating tubular actuating member  58  located within the outer tubular sheath  56 . The proximal end of the tubular reciprocating tubular actuating member  58  is mechanically engaged to the trigger  32  of the handle assembly  12  to move in either direction  60 A or  60 B in response to the actuation and/or release of the trigger  32 . The pivotably moveable trigger  32  may generate reciprocating motion along the longitudinal axis “T.” Such motion may be used, for example, to actuate the jaws or clamping mechanism of the end effector assembly  26 . A series of linkages translate the pivotal rotation of the trigger  32  to axial movement of a yoke coupled to an actuation mechanism, which controls the opening and closing of the jaws of the clamping mechanism of the end effector assembly  26 . The distal end of the tubular reciprocating tubular actuating member  58  is mechanically engaged to the end effector assembly  26 . In the illustrated embodiment, the distal end of the tubular reciprocating tubular actuating member  58  is mechanically engaged to a clamp arm assembly  64 , which is pivotable about a pivot point  70 , to open and close the clamp arm assembly  64  in response to the actuation and/or release of the trigger  32 . For example, in the illustrated embodiment, the clamp arm assembly  64  is movable in direction  62 A from an open position to a closed position about a pivot point  70  when the trigger  32  is squeezed in direction  33 A. The clamp arm assembly  64  is movable in direction  62 B from a closed position to an open position about the pivot point  70  when the trigger  32  is released or outwardly contacted in direction  33 B. 
     In one example embodiment, the end effector assembly  26  is attached at the distal end  52  of the elongated shaft assembly  14  and includes a clamp arm assembly  64  and a blade  66 . The jaws of the clamping mechanism of the end effector assembly  26  are formed by clamp arm assembly  64  and the blade  66 . The blade  66  is ultrasonically actuatable and is acoustically coupled to the ultrasonic transducer  16 . The trigger  32  on the handle assembly  12  is ultimately connected to a drive assembly, which together, mechanically cooperate to effect movement of the clamp arm assembly  64 . Squeezing the trigger  32  in direction  33 A moves the clamp arm assembly  64  in direction  62 A from an open position, wherein the clamp arm assembly  64  and the blade  66  are disposed in a spaced relation relative to one another, to a clamped or closed position, wherein the clamp arm assembly  64  and the blade  66  cooperate to grasp tissue therebetween. The clamp arm assembly  64  may comprise a clamp pad (not shown) to engage tissue between the blade  66  and the clamp arm  64 . Releasing the trigger  32  in direction  33 B moves the clamp arm assembly  64  in direction  62 B from a closed relationship, to an open position, wherein the clamp arm assembly  64  and the blade  66  are disposed in a spaced relation relative to one another. 
     The proximal portion of the handle assembly  12  comprises a proximal opening  68  to receive the distal end of the ultrasonic assembly  16 . The ultrasonic assembly  16  is inserted in the proximal opening  68  and is mechanically engaged to the elongated shaft assembly  14 . 
     In one example embodiment, the elongated trigger hook  36  portion of the trigger  32  provides a longer trigger lever with a shorter span and rotation travel. The longer lever of the elongated trigger hook  36  allows the user to employ multiple fingers within the aperture  38  to operate the elongated trigger hook  36  and cause the trigger  32  to pivot in direction  33 B to open the jaws of the end effector assembly  26 . For example, the user may insert three fingers (e.g., the middle, ring, and little fingers) in the aperture  38 . Multiple fingers allows the surgeon to exert higher input forces on the trigger  32  and the elongated trigger hook  326  to activate the end effector assembly  26 . The shorter span and rotation travel creates a more comfortable grip when closing or squeezing the trigger  32  in direction  33 A or when opening the trigger  32  in the outward opening motion in direction  33 B lessening the need to extend the fingers further outward. This substantially lessens hand fatigue and strain associated with the outward opening motion of the trigger  32  in direction  33 B. The outward opening motion of the trigger may be spring-assisted by spring element  98  ( FIG. 5 ) to help alleviate fatigue. The opening spring force is sufficient to assist the ease of opening, but not strong enough to adversely impact the tactile feedback of tissue tension during spreading dissection. 
     For example, during a surgical procedure, the index finger may be used to control the rotation of the elongated shaft assembly  14  to locate the jaws of the end effector assembly  26  in a suitable orientation. The middle and/or the other lower fingers may be used to squeeze the trigger  32  and grasp tissue within the jaws. Once the jaws are located in the desired position and the jaws are clamped against the tissue, the index finger can be used to activate the toggle switch  30  to adjust the power level of the ultrasonic transducer  16  to treat the tissue. Once the tissue has been treated, the user may release the trigger  32  by pushing outwardly in the distal direction against the elongated trigger hook  36  with the middle and/or lower fingers to open the jaws of the end effector assembly  26 . This basic procedure may be performed without the user having to adjust their grip of the handle assembly  12 . 
       FIGS. 3-4  illustrate the connection of the elongated shaft assembly  14  relative to the end effector assembly  26 . As previously described, in the illustrated embodiment, the end effector assembly  26  comprises a clamp arm assembly  64  and a blade  66  to form the jaws of the clamping mechanism. The blade  66  may be an ultrasonically actuatable blade acoustically coupled to the ultrasonic transducer  16 . The trigger  32  is mechanically connected to a drive assembly. Together, the trigger  32  and the drive assembly mechanically cooperate to move the clamp arm assembly  64  to an open position in direction  62 A wherein the clamp arm assembly  64  and the blade  66  are disposed in spaced relation relative to one another, to a clamped or closed position in direction  62 B wherein the clamp arm assembly  64  and the blade  66  cooperate to grasp tissue therebetween. The clamp arm assembly  64  may comprise a clamp pad (not shown) to engage tissue between the blade  66  and the clamp arm  64 . The distal end of the tubular reciprocating tubular actuating member  58  is mechanically engaged to the end effector assembly  26 . In the illustrated embodiment, the distal end of the tubular reciprocating tubular actuating member  58  is mechanically engaged to the clamp arm assembly  64 , which is pivotable about the pivot point  70 , to open and close the clamp arm assembly  64  in response to the actuation and/or release of the trigger  32 . For example, in the illustrated embodiment, the clamp arm assembly  64  is movable from an open position to a closed position in direction  62 B about a pivot point  70  when the trigger  32  is squeezed in direction  33 A. The clamp arm assembly  64  is movable from a closed position to an open position in direction  62 A about the pivot point  70  when the trigger  32  is released or outwardly contacted in direction  33 B. 
     As previously discussed, the clamp arm assembly  64  may comprise electrodes electrically coupled to the electrosurgical/RF generator module  23  to receive therapeutic and/or sub-therapeutic energy, where the electrosurgical/RF energy may be applied to the electrodes either simultaneously or non simultaneously with the ultrasonic energy being applied to the blade  66 . Such energy activations may be applied in any suitable combinations to achieve a desired tissue effect in cooperation with an algorithm or other control logic. 
       FIG. 5  is an exploded view of the ultrasonic surgical instrument  10  shown in  FIG. 2 . In the illustrated embodiment, the exploded view shows the internal elements of the handle assembly  12 , the handle assembly  12 , the distal rotation assembly  13 , the switch assembly  28 , and the elongated shaft assembly  14 . In the illustrated embodiment, the first and second portions  12   a ,  12   b  mate to form the handle assembly  12 . The first and second portions  12   a ,  12   b  each comprises a plurality of interfaces  69  dimensioned to mechanically align and engage one another to form the handle assembly  12  and enclose the internal working components of the ultrasonic surgical instrument  10 . The rotation knob  48  is mechanically engaged to the outer tubular sheath  56  so that it may be rotated in circular direction  54  up to 360°. The outer tubular sheath  56  is located over the reciprocating tubular actuating member  58 , which is mechanically engaged to and retained within the handle assembly  12  via a plurality of coupling elements  72 . The coupling elements  72  may comprise an O-ring  72   a , a tube collar cap  72   b , a distal washer  72   c , a proximal washer  72   d , and a thread tube collar  72   e . The reciprocating tubular actuating member  58  is located within a reciprocating yoke  84 , which is retained between the first and second portions  12   a ,  12   b  of the handle assembly  12 . The yoke  84  is part of a reciprocating yoke assembly  88 . A series of linkages translate the pivotal rotation of the elongated trigger hook  32  to the axial movement of the reciprocating yoke  84 , which controls the opening and closing of the jaws of the clamping mechanism of the end effector assembly  26  at the distal end of the ultrasonic surgical instrument  10 . In one example embodiment, a four-link design provides mechanical advantage in a relatively short rotation span, for example. 
     In one example embodiment, an ultrasonic transmission waveguide  78  is disposed inside the reciprocating tubular actuating member  58 . The distal end  52  of the ultrasonic transmission waveguide  78  is acoustically coupled (e.g., directly or indirectly mechanically coupled) to the blade  66  and the proximal end  50  of the ultrasonic transmission waveguide  78  is received within the handle assembly  12 . The proximal end  50  of the ultrasonic transmission waveguide  78  is adapted to acoustically couple to the distal end of the ultrasonic transducer  16  as discussed in more detail below. The ultrasonic transmission waveguide  78  is isolated from the other elements of the elongated shaft assembly  14  by a protective sheath  80  and a plurality of isolation elements  82 , such as silicone rings. The outer tubular sheath  56 , the reciprocating tubular actuating member  58 , and the ultrasonic transmission waveguide  78  are mechanically engaged by a pin  74 . The switch assembly  28  comprises the toggle switch  30  and electrical elements  86   a,b  to electrically energize the ultrasonic transducer  16  in accordance with the activation of the first or second projecting knobs  30   a ,  30   b.    
     In one example embodiment, the outer tubular sheath  56  isolates the user or the patient from the ultrasonic vibrations of the ultrasonic transmission waveguide  78 . The outer tubular sheath  56  generally includes a hub  76 . The outer tubular sheath  56  is threaded onto the distal end of the handle assembly  12 . The ultrasonic transmission waveguide  78  extends through the opening of the outer tubular sheath  56  and the isolation elements  82  isolate the ultrasonic transmission waveguide  78  from the outer tubular sheath  56 . The outer tubular sheath  56  may be attached to the waveguide  78  with the pin  74 . The hole to receive the pin  74  in the waveguide  78  may occur nominally at a displacement node. The waveguide  78  may screw or snap into the hand piece handle assembly  12  by a stud. Flat portions on the hub  76  may allow the assembly to be torqued to a required level. In one example embodiment, the hub  76  portion of the outer tubular sheath  56  is preferably constructed from plastic and the tubular elongated portion of the outer tubular sheath  56  is fabricated from stainless steel. Alternatively, the ultrasonic transmission waveguide  78  may comprise polymeric material surrounding it to isolate it from outside contact. 
     In one example embodiment, the distal end of the ultrasonic transmission waveguide  78  may be coupled to the proximal end of the blade  66  by an internal threaded connection, preferably at or near an antinode. It is contemplated that the blade  66  may be attached to the ultrasonic transmission waveguide  78  by any suitable means, such as a welded joint or the like. Although the blade  66  may be detachable from the ultrasonic transmission waveguide  78 , it is also contemplated that the single element end effector (e.g., the blade  66 ) and the ultrasonic transmission waveguide  78  may be formed as a single unitary piece. 
     In one example embodiment, the trigger  32  is coupled to a linkage mechanism to translate the rotational motion of the trigger  32  in directions  33 A and  33 B to the linear motion of the reciprocating tubular actuating member  58  in corresponding directions  60 A and  60 B. The trigger  32  comprises a first set of flanges  97  with openings formed therein to receive a first yoke pin  94   a . The first yoke pin  94   a  is also located through a set of openings formed at the distal end of the yoke  84 . The trigger  32  also comprises a second set of flanges  96  to receive a first end  92   a  of a link  92 . A trigger pin  90  is received in openings formed in the link  92  and the second set of flanges  96 . The trigger pin  90  is received in the openings formed in the link  92  and the second set of flanges  96  and is adapted to couple to the first and second portions  12   a ,  12   b  of the handle assembly  12  to form a trigger pivot point for the trigger  32 . A second end  92   b  of the link  92  is received in a slot  93  formed in a proximal end of the yoke  84  and is retained therein by a second yoke pin  94   b . As the trigger  32  is pivotally rotated about the pivot point  190  formed by the trigger pin  90 , the yoke translates horizontally along longitudinal axis “T” in a direction indicated by arrows  60 A,B. 
       FIG. 8  illustrates one example embodiment of an ultrasonic surgical instrument  10 . In the illustrated embodiment, a cross-sectional view of the ultrasonic transducer  16  is shown within a partial cutaway view of the handle assembly  12 . One example embodiment of the ultrasonic surgical instrument  10  comprises the ultrasonic signal generator  20  coupled to the ultrasonic transducer  16 , comprising a hand piece housing  99 , and an ultrasonically actuatable single or multiple element end effector assembly  26 . As previously discussed, the end effector assembly  26  comprises the ultrasonically actuatable blade  66  and the clamp arm  64 . The ultrasonic transducer  16 , which is known as a “Langevin stack”, generally includes a transduction portion  100 , a first resonator portion or end-bell  102 , and a second resonator portion or fore-bell  104 , and ancillary components. The total construction of these components is a resonator. The ultrasonic transducer  16  is preferably an integral number of one-half system wavelengths (nλ/2; where “n” is any positive integer; e.g., n=1, 2, 3 . . . ) in length as will be described in more detail later. An acoustic assembly  106  includes the ultrasonic transducer  16 , a nose cone  108 , a velocity transformer  118 , and a surface  110 . 
     In one example embodiment, the distal end of the end-bell  102  is connected to the proximal end of the transduction portion  100 , and the proximal end of the fore-bell  104  is connected to the distal end of the transduction portion  100 . The fore-bell  104  and the end-bell  102  have a length determined by a number of variables, including the thickness of the transduction portion  100 , the density and modulus of elasticity of the material used to manufacture the end-bell  102  and the fore-bell  22 , and the resonant frequency of the ultrasonic transducer  16 . The fore-bell  104  may be tapered inwardly from its proximal end to its distal end to amplify the ultrasonic vibration amplitude as the velocity transformer  118 , or alternately may have no amplification. A suitable vibrational frequency range may be about 20 Hz to 32 kHz and a well-suited vibrational frequency range may be about 30-10 kHz. A suitable operational vibrational frequency may be approximately 55.5 kHz, for example. 
     In one example embodiment, the piezoelectric elements  112  may be fabricated from any suitable material, such as, for example, lead zirconate-titanate, lead meta-niobate, lead titanate, barium titanate, or other piezoelectric ceramic material. Each of positive electrodes  114 , negative electrodes  116 , and the piezoelectric elements  112  has a bore extending through the center. The positive and negative electrodes  114  and  116  are electrically coupled to wires  120  and  122 , respectively. The wires  120  and  122  are encased within the cable  22  and electrically connectable to the ultrasonic signal generator  20 . 
     The ultrasonic transducer  16  of the acoustic assembly  106  converts the electrical signal from the ultrasonic signal generator  20  into mechanical energy that results in primarily a standing acoustic wave of longitudinal vibratory motion of the ultrasonic transducer  16  and the blade  66  portion of the end effector assembly  26  at ultrasonic frequencies. In another embodiment, the vibratory motion of the ultrasonic transducer may act in a different direction. For example, the vibratory motion may comprise a local longitudinal component of a more complicated motion of the tip of the elongated shaft assembly  14 . A suitable generator is available as model number GEN11, from Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. When the acoustic assembly  106  is energized, a vibratory motion standing wave is generated through the acoustic assembly  106 . The ultrasonic surgical instrument  10  is designed to operate at a resonance such that an acoustic standing wave pattern of predetermined amplitude is produced. The amplitude of the vibratory motion at any point along the acoustic assembly  106  depends upon the location along the acoustic assembly  106  at which the vibratory motion is measured. A minimum or zero crossing in the vibratory motion standing wave is generally referred to as a node (i.e., where motion is minimal), and a local absolute value maximum or peak in the standing wave is generally referred to as an anti-node (e.g., where local motion is maximal). The distance between an anti-node and its nearest node is one-quarter wavelength (λ/4). 
     The wires  120  and  122  transmit an electrical signal from the ultrasonic signal generator  20  to the positive electrodes  114  and the negative electrodes  116 . The piezoelectric elements  112  are energized by the electrical signal supplied from the ultrasonic signal generator  20  in response to an actuator  224 , such as a foot switch, for example, to produce an acoustic standing wave in the acoustic assembly  106 . The electrical signal causes disturbances in the piezoelectric elements  112  in the form of repeated small displacements resulting in large alternating compression and tension forces within the material. The repeated small displacements cause the piezoelectric elements  112  to expand and contract in a continuous manner along the axis of the voltage gradient, producing longitudinal waves of ultrasonic energy. The ultrasonic energy is transmitted through the acoustic assembly  106  to the blade  66  portion of the end effector assembly  26  via a transmission component or an ultrasonic transmission waveguide portion  78  of the elongated shaft assembly  14 . 
     In one example embodiment, in order for the acoustic assembly  106  to deliver energy to the blade  66  portion of the end effector assembly  26 , all components of the acoustic assembly  106  must be acoustically coupled to the blade  66 . The distal end of the ultrasonic transducer  16  may be acoustically coupled at the surface  110  to the proximal end of the ultrasonic transmission waveguide  78  by a threaded connection such as a stud  124 . 
     In one example embodiment, the components of the acoustic assembly  106  are preferably acoustically tuned such that the length of any assembly is an integral number of one-half wavelengths (nλ/2), where the wavelength λ is the wavelength of a pre-selected or operating longitudinal vibration drive frequency f d  of the acoustic assembly  106 . It is also contemplated that the acoustic assembly  106  may incorporate any suitable arrangement of acoustic elements. 
     In one example embodiment, the blade  66  may have a length substantially equal to an integral multiple of one-half system wavelengths (nλ/2). A distal end of the blade  66  may be disposed near an antinode in order to provide the maximum longitudinal excursion of the distal end. When the transducer assembly is energized, the distal end of the blade  66  may be configured to move in the range of, for example, approximately 10 to 500 microns peak-to-peak, and preferably in the range of about 30 to 64 microns at a predetermined vibrational frequency of 55 kHz, for example. 
     In one example embodiment, the blade  66  may be coupled to the ultrasonic transmission waveguide  78 . The blade  66  and the ultrasonic transmission waveguide  78  as illustrated are formed as a single unit construction from a material suitable for transmission of ultrasonic energy. Examples of such materials include Ti6A14V (an alloy of Titanium including Aluminum and Vanadium), Aluminum, Stainless Steel, or other suitable materials. Alternately, the blade  66  may be separable (and of differing composition) from the ultrasonic transmission waveguide  78 , and coupled by, for example, a stud, weld, glue, quick connect, or other suitable known methods. The length of the ultrasonic transmission waveguide  78  may be substantially equal to an integral number of one-half wavelengths (nλ/2), for example. The ultrasonic transmission waveguide  78  may be preferably fabricated from a solid core shaft constructed out of material suitable to propagate ultrasonic energy efficiently, such as the titanium alloy discussed above (i.e., Ti6A14V) or any suitable aluminum alloy, or other alloys, for example. 
     In one example embodiment, the ultrasonic transmission waveguide  78  comprises a longitudinally projecting attachment post at a proximal end to couple to the surface  110  of the ultrasonic transmission waveguide  78  by a threaded connection such as the stud  124 . The ultrasonic transmission waveguide  78  may include a plurality of stabilizing silicone rings or compliant supports  82  ( FIG. 5 ) positioned at a plurality of nodes. The silicone rings  82  dampen undesirable vibration and isolate the ultrasonic energy from an outer protective sheath  80  (FIG.  5 ) assuring the flow of ultrasonic energy in a longitudinal direction to the distal end of the blade  66  with maximum efficiency. 
       FIG. 9  illustrates one example embodiment of the proximal rotation assembly  128 . In the illustrated embodiment, the proximal rotation assembly  128  comprises the proximal rotation knob  134  inserted over the cylindrical hub  135 . The proximal rotation knob  134  comprises a plurality of radial projections  138  that are received in corresponding slots  130  formed on a proximal end of the cylindrical hub  135 . The proximal rotation knob  134  defines an opening  142  to receive the distal end of the ultrasonic transducer  16 . The radial projections  138  are formed of a soft polymeric material and define a diameter that is undersized relative to the outside diameter of the ultrasonic transducer  16  to create a friction interference fit when the distal end of the ultrasonic transducer  16 . The polymeric radial projections  138  protrude radially into the opening  142  to form “gripper” ribs that firmly grip the exterior housing of the ultrasonic transducer  16 . Therefore, the proximal rotation knob  134  securely grips the ultrasonic transducer  16 . 
     The distal end of the cylindrical hub  135  comprises a circumferential lip  132  and a circumferential bearing surface  140 . The circumferential lip engages a groove formed in the housing  12  and the circumferential bearing surface  140  engages the housing  12 . Thus, the cylindrical hub  135  is mechanically retained within the two housing portions (not shown) of the housing  12 . The circumferential lip  132  of the cylindrical hub  135  is located or “trapped” between the first and second housing portions  12   a ,  12   b  and is free to rotate in place within the groove. The circumferential bearing surface  140  bears against interior portions of the housing to assist proper rotation. Thus, the cylindrical hub  135  is free to rotate in place within the housing. The user engages the flutes  136  formed on the proximal rotation knob  134  with either the finger or the thumb to rotate the cylindrical hub  135  within the housing  12 . 
     In one example embodiment, the cylindrical hub  135  may be formed of a durable plastic such as polycarbonate. In one example embodiment, the cylindrical hub  135  may be formed of a siliconized polycarbonate material. In one example embodiment, the proximal rotation knob  134  may be formed of pliable, resilient, flexible polymeric materials including Versaflex® TPE alloys made by GLS Corporation, for example. The proximal rotation knob  134  may be formed of elastomeric materials, thermoplastic rubber known as Santoprene®, other thermoplastic vulcanizates (TPVs), or elastomers, for example. The embodiments, however, are not limited in this context. 
       FIG. 10  illustrates one example embodiment of a surgical system  200  including a surgical instrument  210  having single element end effector  278 . The system  200  may include a transducer assembly  216  coupled to the end effector  278  and a sheath  256  positioned around the proximal portions of the end effector  278  as shown. The transducer assembly  216  and end effector  278  may operate in a manner similar to that of the transducer assembly  16  and end effector  18  described above to produce ultrasonic energy that may be transmitted to tissue via blade  226 . 
     Over the years, a variety of minimally invasive robotic (or “telesurgical”) systems have been developed to increase surgical dexterity as well as to permit a surgeon to operate on a patient in an intuitive manner. Robotic surgical systems can be used with many different types of surgical instruments including, for example, ultrasonic instruments, as described herein. Example robotic systems include those manufactured by Intuitive Surgical, Inc., of Sunnyvale, Calif., U.S.A. Such systems, as well as robotic systems from other manufacturers, are disclosed in the following U.S. patents which are each herein incorporated by reference in their respective entirety: U.S. Pat. No. 5,792,135, entitled “Articulated Surgical Instrument For Performing Minimally Invasive Surgery With Enhanced Dexterity and Sensitivity”, U.S. Pat. No. 6,231,565, entitled “Robotic Arm DLUs For Performing Surgical Tasks”, U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool With Ultrasound Cauterizing and Cutting Instrument”, U.S. Pat. No. 6,364,888, entitled “Alignment of Master and Slave In a Minimally Invasive Surgical Apparatus”, U.S. Pat. No. 7,524,320, entitled “Mechanical Actuator Interface System For Robotic Surgical Tools”, U.S. Pat. No. 7,691,098, entitled Platform Link Wrist Mechanism”, U.S. Pat. No. 7,806,891, entitled “Repositioning and Reorientation of Master/Slave Relationship in Minimally Invasive Telesurgery”, and U.S. Pat. No. 7,824,401, entitled “Surgical Tool With Writed Monopolar Electrosurgical End Effectors”. Many of such systems, however, have in the past been unable to generate the magnitude of forces required to effectively cut and fasten tissue. 
       FIGS. 11-26  illustrate example embodiments of robotic surgical systems. In some embodiments, the disclosed robotic surgical systems may utilize the ultrasonic or electrosurgical instruments described herein. Those skilled in the art will appreciate that the illustrated robotic surgical systems are not limited to only those instruments described herein, and may utilize any compatible surgical instruments. Those skilled in the art will further appreciate that while various embodiments described herein may be used with the described robotic surgical systems, the disclosure is not so limited, and may be used with any compatible robotic surgical system. 
       FIGS. 11-16  illustrate the structure and operation of several example robotic surgical systems and components thereof.  FIG. 11  shows a block diagram of an example robotic surgical system  500 . The system  500  comprises at least one controller  508  and at least one arm cart  510 . The arm cart  510  may be mechanically coupled to one or more robotic manipulators or arms, indicated by box  512 . Each of the robotic arms  512  may comprise one or more surgical instruments  514  for performing various surgical tasks on a patient  504 . Operation of the arm cart  510 , including the arms  512  and instruments  514  may be directed by a clinician  502  from a controller  508 . In some embodiments, a second controller  508 ′, operated by a second clinician  502 ′ may also direct operation of the arm cart  510  in conjunction with the first clinician  502 ′. For example, each of the clinicians  502 ,  502 ′ may control different arms  512  of the cart or, in some cases, complete control of the arm cart  510  may be passed between the clinicians  502 ,  502 ′. In some embodiments, additional arm carts (not shown) may be utilized on the patient  504 . These additional arm carts may be controlled by one or more of the controllers  508 ,  508 ′. The arm cart(s)  510  and controllers  508 ,  508 ′ may be in communication with one another via a communications link  516 , which may be any suitable type of wired or wireless communications link carrying any suitable type of signal (e.g., electrical, optical, infrared, etc.) according to any suitable communications protocol. Example implementations of robotic surgical systems, such as the system  500 , are disclosed in U.S. Pat. No. 7,524,320 which has been herein incorporated by reference. Thus, various details of such devices will not be described in detail herein beyond that which may be necessary to understand various embodiments of the claimed device. 
       FIG. 12  shows one example embodiment of a robotic arm cart  520 . The robotic arm cart  520  is configured to actuate a plurality of surgical instruments or instruments, generally designated as  522  within a work envelope  527 . Various robotic surgery systems and methods employing master controller and robotic arm cart arrangements are disclosed in U.S. Pat. No. 6,132,368, entitled “Multi-Component Telepresence System and Method”, the full disclosure of which is incorporated herein by reference. In various forms, the robotic arm cart  520  includes a base  524  from which, in the illustrated embodiment, three surgical instruments  522  are supported. In various forms, the surgical instruments  522  are each supported by a series of manually articulatable linkages, generally referred to as set-up joints  526 , and a robotic manipulator  528 . These structures are herein illustrated with protective covers extending over much of the robotic linkage. These protective covers may be optional, and may be limited in size or entirely eliminated in some embodiments to minimize the inertia that is encountered by the servo mechanisms used to manipulate such devices, to limit the volume of moving components so as to avoid collisions, and to limit the overall weight of the cart  520 . Cart  520  will generally have dimensions suitable for transporting the cart  520  between operating rooms. The cart  520  may be configured to typically fit through standard operating room doors and onto standard hospital elevators. In various forms, the cart  520  would preferably have a weight and include a wheel (or other transportation) system that allows the cart  520  to be positioned adjacent an operating table by a single attendant. 
       FIG. 13  shows one example embodiment of the robotic manipulator  528  of the robotic arm cart  520 . In the example shown in  FIG. 13 , the robotic manipulators  528  may include a linkage  530  that constrains movement of the surgical instrument  522 . In various embodiments, linkage  530  includes rigid links coupled together by rotational joints in a parallelogram arrangement so that the surgical instrument  522  rotates around a point in space  532 , as more fully described in issued U.S. Pat. No. 5,817,084, the full disclosure of which is herein incorporated by reference. The parallelogram arrangement constrains rotation to pivoting about an axis  534   a , sometimes called the pitch axis. The links supporting the parallelogram linkage are pivotally mounted to set-up joints  526  ( FIG. 12 ) so that the surgical instrument  522  further rotates about an axis  534   b , sometimes called the yaw axis. The pitch and yaw axes  534   a ,  534   b  intersect at the remote center  536 , which is aligned along a shaft  538  of the surgical instrument  522 . The surgical instrument  522  may have further degrees of driven freedom as supported by manipulator  540 , including sliding motion of the surgical instrument  522  along the longitudinal instrument axis “LT-LT”. As the surgical instrument  522  slides along the instrument axis LT-LT relative to manipulator  540  (arrow  534   c ), remote center  536  remains fixed relative to base  542  of manipulator  540 . Hence, the entire manipulator  540  is generally moved to re-position remote center  536 . Linkage  530  of manipulator  540  is driven by a series of motors  544 . These motors  544  actively move linkage  530  in response to commands from a processor of a control system. As will be discussed in further detail below, motors  544  are also employed to manipulate the surgical instrument  522 . 
       FIG. 14  shows one example embodiment of a robotic arm cart  520 ′ having an alternative set-up joint structure. In this example embodiment, a surgical instrument  522  is supported by an alternative manipulator structure  528 ′ between two tissue manipulation instruments. Those of ordinary skill in the art will appreciate that various embodiments of the claimed device may incorporate a wide variety of alternative robotic structures, including those described in U.S. Pat. No. 5,878,193, the full disclosure of which is incorporated herein by reference. Additionally, while the data communication between a robotic component and the processor of the robotic surgical system is primarily described herein with reference to communication between the surgical instrument  522  and the controller, it should be understood that similar communication may take place between circuitry of a manipulator, a set-up joint, an endoscope or other image capture device, or the like, and the processor of the robotic surgical system for component compatibility verification, component-type identification, component calibration (such as off-set or the like) communication, confirmation of coupling of the component to the robotic surgical system, or the like. 
       FIG. 15  shows one example embodiment of a controller  518  that may be used in conjunction with a robotic arm cart, such as the robotic arm carts  520 ,  520 ′ depicted in  FIGS. 12-14 . The controller  518  generally includes master controllers (generally represented as  519  in  FIG. 15 ) which are grasped by the clinician and manipulated in space while the clinician views the procedure via a stereo display  521 . A surgeon feed back meter  515  may be viewed via the display  521  and provide the surgeon with a visual indication of the amount of force being applied to the cutting instrument or dynamic clamping member. The master controllers  519  generally comprise manual input devices which preferably move with multiple degrees of freedom, and which often further have a handle or trigger for actuating instruments (for example, for closing grasping saws, applying an electrical potential to an electrode, or the like). 
       FIG. 16  shows one example embodiment of an ultrasonic surgical instrument  522  adapted for use with a robotic surgical system. For example, the surgical instrument  522  may be coupled to one of the surgical manipulators  528 ,  528 ′ described hereinabove. As can be seen in  FIG. 16 , the surgical instrument  522  comprises a surgical end effector  548  that comprises an ultrasonic blade  550  and clamp arm  552 , which may be coupled to an elongated shaft assembly  554  that, in some embodiments, may comprise an articulation joint  556 .  FIG. 17  shows one example embodiment of an instrument drive assembly  546  that may be coupled to one of the surgical manipulators  528 ,  528 ′ to receive and control the surgical instrument  522 . The instrument drive assembly  546  may also be operatively coupled to the controller  518  to receive inputs from the clinician for controlling the instrument  522 . For example, actuation (e.g., opening and closing) of the clamp arm  552 , actuation (e.g., opening and closing) of the jaws  551 A,  551 B, actuation of the ultrasonic blade  550 , extension of the knife  555  and actuation of the energy delivery surfaces  553 A,  553 B, etc. may be controlled through the instrument drive assembly  546  based on inputs from the clinician provided through the controller  518 . The surgical instrument  522  is operably coupled to the manipulator by an instrument mounting portion, generally designated as  558 . The surgical instruments  522  further include an interface  560  which mechanically and electrically couples the instrument mounting portion  558  to the manipulator. 
       FIG. 18  shows another view of the instrument drive assembly of  FIG. 17  including the ultrasonic surgical instrument  522 . The instrument mounting portion  558  includes an instrument mounting plate  562  that operably supports a plurality of (four are shown in  FIG. 17 ) rotatable body portions, driven discs or elements  564 , that each include a pair of pins  566  that extend from a surface of the driven element  564 . One pin  566  is closer to an axis of rotation of each driven elements  564  than the other pin  566  on the same driven element  564 , which helps to ensure positive angular alignment of the driven element  564 . The driven elements  564  and pints  566  may be positioned on an adapter side  567  of the instrument mounting plate  562 . 
     Interface  560  also includes an adaptor portion  568  that is configured to mountingly engage the mounting plate  562  as will be further discussed below. The adaptor portion  568  may include an array of electrical connecting pins  570 , which may be coupled to a memory structure by a circuit board within the instrument mounting portion  558 . While interface  560  is described herein with reference to mechanical, electrical, and magnetic coupling elements, it should be understood that a wide variety of telemetry modalities might be used, including infrared, inductive coupling, or the like. 
       FIGS. 19-21  show additional views of the adapter portion  568  of the instrument drive assembly  546  of  FIG. 17 . The adapter portion  568  generally includes an instrument side  572  and a holder side  574  ( FIG. 19 ). In various embodiments, a plurality of rotatable bodies  576  are mounted to a floating plate  578  which has a limited range of movement relative to the surrounding adaptor structure normal to the major surfaces of the adaptor  568 . Axial movement of the floating plate  578  helps decouple the rotatable bodies  576  from the instrument mounting portion  558  when the levers  580  along the sides of the instrument mounting portion housing  582  are actuated (See  FIG. 16 ) Other mechanisms/arrangements may be employed for releasably coupling the instrument mounting portion  558  to the adaptor  568 . In at least one form, rotatable bodies  576  are resiliently mounted to floating plate  578  by resilient radial members which extend into a circumferential indentation about the rotatable bodies  576 . The rotatable bodies  576  can move axially relative to plate  578  by deflection of these resilient structures. When disposed in a first axial position (toward instrument side  572 ) the rotatable bodies  576  are free to rotate without angular limitation. However, as the rotatable bodies  576  move axially toward instrument side  572 , tabs  584  (extending radially from the rotatable bodies  576 ) laterally engage detents on the floating plates so as to limit angular rotation of the rotatable bodies  576  about their axes. This limited rotation can be used to help drivingly engage the rotatable bodies  576  with drive pins  586  of a corresponding instrument holder portion  588  of the robotic system, as the drive pins  586  will push the rotatable bodies  576  into the limited rotation position until the pins  586  are aligned with (and slide into) openings  590 . 
     Openings  590  on the instrument side  572  and openings  590  on the holder side  574  of rotatable bodies  576  are configured to accurately align the driven elements  564  ( FIGS. 18, 28 ) of the instrument mounting portion  558  with the drive elements  592  of the instrument holder  588 . As described above regarding inner and outer pins  566  of driven elements  564 , the openings  590  are at differing distances from the axis of rotation on their respective rotatable bodies  576  so as to ensure that the alignment is not 33 degrees from its intended position. Additionally, each of the openings  590  may be slightly radially elongated so as to fittingly receive the pins  566  in the circumferential orientation. This allows the pins  566  to slide radially within the openings  590  and accommodate some axial misalignment between the instrument  522  and instrument holder  588 , while minimizing any angular misalignment and backlash between the drive and driven elements. Openings  590  on the instrument side  572  may be offset by about 90 degrees from the openings  590  (shown in broken lines) on the holder side  574 , as can be seen most clearly in  FIG. 21 . 
     Various embodiments may further include an array of electrical connector pins  570  located on holder side  574  of adaptor  568 , and the instrument side  572  of the adaptor  568  may include slots  594  ( FIG. 21 ) for receiving a pin array (not shown) from the instrument mounting portion  558 . In addition to transmitting electrical signals between the surgical instrument  522 ,  523  and the instrument holder  588 , at least some of these electrical connections may be coupled to an adaptor memory device  596  ( FIG. 20 ) by a circuit board of the adaptor  568 . 
     A detachable latch arrangement  598  may be employed to releasably affix the adaptor  568  to the instrument holder  588 . As used herein, the term “instrument drive assembly” when used in the context of the robotic system, at least encompasses various embodiments of the adapter  568  and instrument holder  588  and which has been generally designated as  546  in  FIG. 17 . For example, as can be seen in  FIG. 17 , the instrument holder  588  may include a first latch pin arrangement  600  that is sized to be received in corresponding clevis slots  602  provided in the adaptor  568 . In addition, the instrument holder  588  may further have second latch pins  604  that are sized to be retained in corresponding latch devises  602  in the adaptor  568 . See  FIG. 20 . In at least one form, a latch assembly  608  is movably supported on the adapter  568  and is biasable between a first latched position wherein the latch pins  600  are retained within their respective latch clevis  602  and an unlatched position wherein the second latch pins  604  may be into or removed from the latch devises  602 . A spring or springs (not shown) are employed to bias the latch assembly into the latched position. A lip on the instrument side  572  of adaptor  568  may slidably receive laterally extending tabs of instrument mounting housing  582 . 
     As described the driven elements  564  may be aligned with the drive elements  592  of the instrument holder  588  such that rotational motion of the drive elements  592  causes corresponding rotational motion of the driven elements  564 . The rotation of the drive elements  592  and driven elements  564  may be electronically controlled, for example, via the robotic arm  512 , in response to instructions received from the clinician  502  via a controller  508 . The instrument mounting portion  558  may translate rotation of the driven elements  564  into motion of the surgical instrument  522 ,  523 . 
       FIGS. 22-24  show one example embodiment of the instrument mounting portion  558  showing components for translating motion of the driven elements  564  into motion of the surgical instrument  522 .  FIGS. 22-24  show the instrument mounting portion with a shaft  538  having a surgical end effector  610  at a distal end thereof. The end effector  610  may be any suitable type of end effector for performing a surgical task on a patient. For example, the end effector may be configured to provide ultrasonic energy to tissue at a surgical site. The shaft  538  may be rotatably coupled to the instrument mounting portion  558  and secured by a top shaft holder  646  and a bottom shaft holder  648  at a coupler  650  of the shaft  538 . 
     In one example embodiment, the instrument mounting portion  558  comprises a mechanism for translating rotation of the various driven elements  564  into rotation of the shaft  538 , differential translation of members along the axis of the shaft (e.g., for articulation), and reciprocating translation of one or more members along the axis of the shaft  538  (e.g., for extending and retracting tissue cutting elements such as  555 , overtubes and/or other components). In one example embodiment, the rotatable bodies  612  (e.g., rotatable spools) are coupled to the driven elements  564 . The rotatable bodies  612  may be formed integrally with the driven elements  564 . In some embodiments, the rotatable bodies  612  may be formed separately from the driven elements  564  provided that the rotatable bodies  612  and the driven elements  564  are fixedly coupled such that driving the driven elements  564  causes rotation of the rotatable bodies  612 . Each of the rotatable bodies  612  is coupled to a gear train or gear mechanism to provide shaft articulation and rotation and clamp jaw open/close and knife actuation. 
     In one example embodiment, the instrument mounting portion  558  comprises a mechanism for causing differential translation of two or more members along the axis of the shaft  538 . In the example provided in  FIGS. 22-24 , this motion is used to manipulate articulation joint  556 . In the illustrated embodiment, for example, the instrument mounting portion  558  comprises a rack and pinion gearing mechanism to provide the differential translation and thus the shaft articulation functionality. In one example embodiment, the rack and pinion gearing mechanism comprises a first pinion gear  614  coupled to a rotatable body  612  such that rotation of the corresponding driven element  564  causes the first pinion gear  614  to rotate. A bearing  616  is coupled to the rotatable body  612  and is provided between the driven element  564  and the first pinion gear  614 . The first pinion gear  614  is meshed to a first rack gear  618  to convert the rotational motion of the first pinion gear  614  into linear motion of the first rack gear  618  to control the articulation of the articulation section  556  of the shaft assembly  538  in a left direction  620 L. The first rack gear  618  is attached to a first articulation band  622  ( FIG. 22 ) such that linear motion of the first rack gear  618  in a distal direction causes the articulation section  556  of the shaft assembly  538  to articulate in the left direction  620 L. A second pinion gear  626  is coupled to another rotatable body  612  such that rotation of the corresponding driven element  564  causes the second pinion gear  626  to rotate. A bearing  616  is coupled to the rotatable body  612  and is provided between the driven element  564  and the second pinion gear  626 . The second pinion gear  626  is meshed to a second rack gear  628  to convert the rotational motion of the second pinion gear  626  into linear motion of the second rack gear  628  to control the articulation of the articulation section  556  in a right direction  620 R. The second rack gear  628  is attached to a second articulation band  624  ( FIG. 23 ) such that linear motion of the second rack gear  628  in a distal direction causes the articulation section  556  of the shaft assembly  538  to articulate in the right direction  620 R. Additional bearings may be provided between the rotatable bodies and the corresponding gears. Any suitable bearings may be provided to support and stabilize the mounting and reduce rotary friction of shaft and gears, for example. 
     In one example embodiment, the instrument mounting portion  558  further comprises a mechanism for translating rotation of the driven elements  564  into rotational motion about the axis of the shaft  538 . For example, the rotational motion may be rotation of the shaft  538  itself. In the illustrated embodiment, a first spiral worm gear  630  coupled to a rotatable body  612  and a second spiral worm gear  632  coupled to the shaft assembly  538 . A bearing  616  ( FIG. 17 ) is coupled to a rotatable body  612  and is provided between a driven element  564  and the first spiral worm gear  630 . The first spiral worm gear  630  is meshed to the second spiral worm gear  632 , which may be coupled to the shaft assembly  538  and/or to another component of the instrument  522 ,  523  for which longitudinal rotation is desired. Rotation may be caused in a clockwise (CW) and counter-clockwise (CCW) direction based on the rotational direction of the first and second spiral worm gears  630 ,  632 . Accordingly, rotation of the first spiral worm gear  630  about a first axis is converted to rotation of the second spiral worm gear  632  about a second axis, which is orthogonal to the first axis. As shown in  FIGS. 22-23 , for example, a CW rotation of the second spiral worm gear  632  results in a CW rotation of the shaft assembly  538  in the direction indicated by 634CW. A CCW rotation of the second spiral worm gear  632  results in a CCW rotation of the shaft assembly  538  in the direction indicated by 634CCW. Additional bearings may be provided between the rotatable bodies and the corresponding gears. Any suitable bearings may be provided to support and stabilize the mounting and reduce rotary friction of shaft and gears, for example. 
     In one example embodiment, the instrument mounting portion  558  comprises a mechanism for generating reciprocating translation of one or more members along the axis of the shaft  538 . Such translation may be used, for example to drive a tissue cutting element, such as  555 , drive an overtube for closure and/or articulation of the end effector  610 , etc. In the illustrated embodiment, for example, a rack and pinion gearing mechanism may provide the reciprocating translation. A first gear  636  is coupled to a rotatable body  612  such that rotation of the corresponding driven element  564  causes the first gear  636  to rotate in a first direction. A second gear  638  is free to rotate about a post  640  formed in the instrument mounting plate  562 . The first gear  636  is meshed to the second gear  638  such that the second gear  638  rotates in a direction that is opposite of the first gear  636 . In one example embodiment, the second gear  638  is a pinion gear meshed to a rack gear  642 , which moves in a liner direction. The rack gear  642  is coupled to a translating block  644 , which may translate distally and proximally with the rack gear  642 . The translation block  644  may be coupled to any suitable component of the shaft assembly  538  and/or the end effector  610  so as to provide reciprocating longitudinal motion. For example, the translation block  644  may be mechanically coupled to the tissue cutting element  555  of the RF surgical device  523 . In some embodiments, the translation block  644  may be coupled to an overtube, or other component of the end effector  610  or shaft  538 . 
       FIGS. 25-27  illustrate an alternate embodiment of the instrument mounting portion  558  showing an alternate example mechanism for translating rotation of the driven elements  564  into rotational motion about the axis of the shaft  538  and an alternate example mechanism for generating reciprocating translation of one or more members along the axis of the shaft  538 . Referring now to the alternate rotational mechanism, a first spiral worm gear  652  is coupled to a second spiral worm gear  654 , which is coupled to a third spiral worm gear  656 . Such an arrangement may be provided for various reasons including maintaining compatibility with existing robotic systems  500  and/or where space may be limited. The first spiral worm gear  652  is coupled to a rotatable body  612 . The third spiral worm gear  656  is meshed with a fourth spiral worm gear  658  coupled to the shaft assembly  538 . A bearing  760  is coupled to a rotatable body  612  and is provided between a driven element  564  and the first spiral worm gear  738 . Another bearing  760  is coupled to a rotatable body  612  and is provided between a driven element  564  and the third spiral worm gear  652 . The third spiral worm gear  652  is meshed to the fourth spiral worm gear  658 , which may be coupled to the shaft assembly  538  and/or to another component of the instrument  522  for which longitudinal rotation is desired. Rotation may be caused in a CW and a CCW direction based on the rotational direction of the spiral worm gears  656 ,  658 . Accordingly, rotation of the third spiral worm gear  656  about a first axis is converted to rotation of the fourth spiral worm gear  658  about a second axis, which is orthogonal to the first axis. As shown in  FIGS. 26 and 27 , for example, the fourth spiral worm gear  658  is coupled to the shaft  538 , and a CW rotation of the fourth spiral worm gear  658  results in a CW rotation of the shaft assembly  538  in the direction indicated by 634CW. A CCW rotation of the fourth spiral worm gear  658  results in a CCW rotation of the shaft assembly  538  in the direction indicated by 634CCW. Additional bearings may be provided between the rotatable bodies and the corresponding gears. Any suitable bearings may be provided to support and stabilize the mounting and reduce rotary friction of shaft and gears, for example. 
     Referring now to the alternate example mechanism for generating reciprocating translation of one or more members along the axis of the shaft  538 , the instrument mounting portion  558  comprises a rack and pinion gearing mechanism to provide reciprocating translation along the axis of the shaft  538  (e.g., translation of a tissue cutting element  555  of the RF surgical device  523 ). In one example embodiment, a third pinion gear  660  is coupled to a rotatable body  612  such that rotation of the corresponding driven element  564  causes the third pinion gear  660  to rotate in a first direction. The third pinion gear  660  is meshed to a rack gear  662 , which moves in a linear direction. The rack gear  662  is coupled to a translating block  664 . The translating block  664  may be coupled to a component of the device  522 ,  523 , such as, for example, the tissue cutting element  555  of the RF surgical device and/or an overtube or other component which is desired to be translated longitudinally. 
       FIGS. 28-32  illustrate an alternate embodiment of the instrument mounting portion  558  showing another alternate example mechanism for translating rotation of the driven elements  564  into rotational motion about the axis of the shaft  538 . In  FIGS. 28-32 , the shaft  538  is coupled to the remainder of the mounting portion  558  via a coupler  676  and a bushing  678 . A first gear  666  coupled to a rotatable body  612 , a fixed post  668  comprising first and second openings  672 , first and second rotatable pins  674  coupled to the shaft assembly, and a cable  670  (or rope). The cable is wrapped around the rotatable body  612 . One end of the cable  670  is located through a top opening  672  of the fixed post  668  and fixedly coupled to a top rotatable pin  674 . Another end of the cable  670  is located through a bottom opening  672  of the fixed post  668  and fixedly coupled to a bottom rotating pin  674 . Such an arrangement is provided for various reasons including maintaining compatibility with existing robotic systems  500  and/or where space may be limited. Accordingly, rotation of the rotatable body  612  causes the rotation about the shaft assembly  538  in a CW and a CCW direction based on the rotational direction of the rotatable body  612  (e.g., rotation of the shaft  538  itself). Accordingly, rotation of the rotatable body  612  about a first axis is converted to rotation of the shaft assembly  538  about a second axis, which is orthogonal to the first axis. As shown in  FIGS. 28-29 , for example, a CW rotation of the rotatable body  612  results in a CW rotation of the shaft assembly  538  in the direction indicated by 634CW. A CCW rotation of the rotatable body  612  results in a CCW rotation of the shaft assembly  538  in the direction indicated by 634CCW. Additional bearings may be provided between the rotatable bodies and the corresponding gears. Any suitable bearings may be provided to support and stabilize the mounting and reduce rotary friction of shaft and gears, for example. 
       FIGS. 33-36A  illustrate an alternate embodiment of the instrument mounting portion  558  showing an alternate example mechanism for differential translation of members along the axis of the shaft  538  (e.g., for articulation). For example, as illustrated in  FIGS. 33-36A , the instrument mounting portion  558  comprises a double cam mechanism  680  to provide the shaft articulation functionality. In one example embodiment, the double cam mechanism  680  comprises first and second cam portions  680 A,  680 B. First and second follower arms  682 ,  684  are pivotally coupled to corresponding pivot spools  686 . As the rotatable body  612  coupled to the double cam mechanism  680  rotates, the first cam portion  680 A acts on the first follower arm  682  and the second cam portion  680 B acts on the second follower arm  684 . As the cam mechanism  680  rotates the follower arms  682 ,  684  pivot about the pivot spools  686 . The first follower arm  682  may be attached to a first member that is to be differentially translated (e.g., the first articulation band  622 ). The second follower arm  684  is attached to a second member that is to be differentially translated (e.g., the second articulation band  624 ). As the top cam portion  680 A acts on the first follower arm  682 , the first and second members are differentially translated. In the example embodiment where the first and second members are the respective articulation bands  622  and  624 , the shaft assembly  538  articulates in a left direction  620 L. As the bottom cam portion  680 B acts of the second follower arm  684 , the shaft assembly  538  articulates in a right direction  620 R. In some example embodiments, two separate bushings  688 ,  690  are mounted beneath the respective first and second follower arms  682 ,  684  to allow the rotation of the shaft without affecting the articulating positions of the first and second follower arms  682 ,  684 . For articulation motion, these bushings reciprocate with the first and second follower arms  682 ,  684  without affecting the rotary position of the jaw  902 .  FIG. 36A  shows the bushings  688 ,  690  and the dual cam assembly  680 , including the first and second cam portions  680 B,  680 B, with the first and second follower arms  682 ,  684  removed to provide a more detailed and clearer view. 
     In various embodiments, the instrument mounting portion  558  may additionally comprise internal energy sources for driving electronics and provided desired ultrasonic and/or RF frequency signals to surgical tools.  FIGS. 36B-36C  illustrate one embodiment of a tool mounting portion  558 ′ comprising internal power and energy sources. For example, surgical instruments (e.g., instrument  522 ) mounted utilizing the tool mounting portion  558 ′ need not be wired to an external generator or other power source. Instead, the functionality of the generator  20  described herein may be implemented on board the mounting portion  558 . 
     As illustrated in  FIGS. 36B-36C , the instrument mounting portion  558 ′ may comprise a distal portion  702 . The distal portion  702  may comprise various mechanisms for coupling rotation of drive elements  592  to end effectors of the various surgical instruments  522 , for example, as described herein above. Proximal of the distal portion  702 , the instrument mounting portion  558 ′ comprises an internal direct current (DC) energy source and an internal drive and control circuit  704 . In the illustrated embodiment, the energy source comprises a first and second battery  706 ,  708 . In other respects, the tool mounting portion  558 ′ is similar to the various embodiments of the tool mounting portion  558  described herein above. The control circuit  704  may operate in a manner similar to that described above with respect to generator  20 . For example, the control circuit  704  may provide an ultrasonic and/or electrosurgical drive signal in a manner similar to that described above with respect to generator  20 . 
       FIG. 37  illustrates one embodiment of an articulatable surgical instrument  1000  comprising a distally positioned ultrasonic transducer assembly  1012 . An end effector  1014  of the instrument  1000  comprises an ultrasonic blade  1018  and a clamp arm  1016 . The end effector  1014  is coupled to a distal end of a shaft  1004 . The shaft  1004  extends along a longitudinal axis  1002  and comprises a distal shaft member  1007  and a proximal shaft member  1009 . For example, the end effector  1014  may be coupled to a distal portion of the distal shaft member  1007 . The distal and proximal shaft members  1007 ,  1009  are pivotably coupled to one another at an articulation joint  1010 . For example, the distal and proximal shaft members  1007 ,  1009  may be coupled to pivot about an axis  1006  that is perpendicular to the longitudinal axis  1002 . Potential directions of articulation are indicated by arrow  1008 . 
     In  FIG. 37 , a proximal end of the shaft  1009  is coupled to a handle  1001 . The handle  1001  may comprise various controls for controlling the operation of the shaft  1009  and end effector  1014  including, for example, trigger  1022  and buttons  1024 . These features may operate in a manner similar to that of trigger  24  and buttons  28  described herein above. In some embodiments, the handle  1001  may comprise one or more electric or other motors to assist the clinician in operation of the shaft  1007 ,  1009  and end effector  1014 . Examples of such handles are provided in U.S. Pat. No. 7,845,537, which is incorporated herein by reference in its entirety.  FIG. 38  illustrates one embodiment of the shaft  1004  and end effector  1014  used in conjunction with an instrument mounting portion  1020  of a robotic surgical system. For example, the shaft  1004 , end effector  1014  and instrument mounting portion  1020  may be used in conjunction with the robotic surgical system  500  described herein above. 
       FIG. 39  illustrates a cut-away view of one embodiment of the shaft  1004  and end effector  1014 . As illustrated, the distal and proximal shaft portions  1007 ,  1009  may comprise respective devises  1026 ,  1028  joined by a pin  1030  to form the articulation joint  1010 . In various embodiments, the pin  1030  is substantially parallel to the axis  1006  ( FIGS. 37-38 ). Also, although the articulation joint  1010  is illustrated in  FIG. 39  as being implemented with devises  1026 ,  1028  and a pin  1030 , it will be appreciated that any suitable type of pivotable joint mechanism may be used.  FIG. 39  also illustrates a clamp arm control member  1044  that may be coupled to one or more components of the end effector  1014 , as described herein, to bring about opening and closure of the clamp arm  1016 . A power wire  1038  may be coupled to the ultrasonic transducer assembly  1012 , and specifically to an ultrasonic transducer  1040  thereof, so as to connect the ultrasonic transducer assembly  1012  to a generator, such as the generator  20  described herein. 
     In various embodiments, articulation of the distal shaft member  1007  and end effector  1014  may be brought about utilizing translating articulation control members  1032 ,  1034 . The control members  1032 ,  1034  may be substantially opposite the longitudinal axis  1002  from one another. Distal portions of the control members  1032 ,  1034  may be coupled to either the end effector  1014  or the distal shaft member  1007 . For example, the control members  1032 ,  1034  are illustrated in  FIG. 39  to be coupled to the distal shaft member  1007  by pegs  1046 ,  1048 . The control members  1032 ,  1034  extend proximally past the articulation joint  1010  and through the proximal shaft portion  1009 . 
     The control members  1032 ,  1034  may be differentially translated to cause articulation of the end effector  1014  and distal shaft portion  1007 . For example, proximal translation of the control member  1034  may cause the distal shaft member  1007  and end effector  1014  to pivot towards the control member  1034 , as shown in  FIG. 39  and indicated by arrow  1041 . Similarly, proximal translation of the control member  1032  may cause the distal shaft member  1007  and end effector  1014  to pivot towards the control member  1032  in a manner opposite to that shown in  FIG. 39 . In various embodiments, proximal translation of one control member  1032 ,  1034  may occur in conjunction with distal translation of the opposite control member, for example, to provide slack in the opposite control member  1032 ,  1034  so as to facilitate articulation. 
     Differential translation of the control members  1032 ,  1034  may be brought about in any suitable manner. For example, when used in conjunction with a robotic surgical system, differential translation of the control members  1032 ,  1034  may be initiated utilizing any of the devices and methods described herein above with respect to  FIGS. 22-36C .  FIGS. 40-40A  illustrate one embodiment for driving differential translation of the control members  1032 ,  1034  in conjunction with a manual instrument, such as  1000 .  FIG. 40  shows the instrument  1000  including an articulation assembly  1050  including an articulation lever  1052 . Referring now to  FIG. 40A , the articulation lever  1052  is coupled to a spindle gear  1058 . Each of the control members  1032 ,  1034  may define respective proximal rack gears  1054 ,  1056  interfacing with the spindle gear  1058 . Rotation of the articulation lever  1052  and spindle gear  1058  in a first direction, indicated by arrow  1060 , may cause distal translation of control member  1032  and proximal translation of control member  1034 . Rotation of the articulation lever  1052  in the opposite direction, indicated by arrow  1062 , may cause distal translation of control member  1034  and proximal translation of control member  1032 . 
       FIG. 41  illustrates a cut-away view of one embodiment of the ultrasonic transducer assembly  1012 . As illustrated, the assembly  1012  comprises an outer housing  1064  enclosing the ultrasonic transducer  1040 . The transducer may be in electrical communication with a generator via power cable  1038 , as described herein. At a distal portion, the ultrasonic transducer  1040  is acoustically coupled to the ultrasonic blade  1018 . The transducer  1040  may be secured within the housing  1064  by washers  1070 , which may be made from silicone or another suitable material. In certain embodiments, the housing  1064  defines proximal ( 1066 ) and distal ( 1068 ) hinge portions, which may be utilized, as described herein, to couple the assembly  1012  to a clamp arm member, for example, as described herein. 
       FIG. 42  illustrates one embodiment of the ultrasonic transducer assembly  1012  and clamp arm  1016  arranged as part of a four-bar linkage. The clamp arm  1016  may comprise a clamp pad  1076  positioned to contact the ultrasonic blade  1018  when the clamp arm  1016  is in the closed position. The clamp arm  1016  may further comprise a proximal member  1078  pivotably coupled to the transducer assembly  1012  at pivot point  1072 . The pivot point  1072  may be any suitable type of mechanical pivot and may, for example, comprise a pin, as shown. The proximal member  1078  may extend further proximally from the pivot point  1072  and, at or near a proximal end, may be pivotably coupled to a linkage member  1074  at a pivot point  1075 . Similarly, a proximal portion of the ultrasonic transducer assembly  1012  may be pivotably coupled to a linkage member  1076  at pivot point  1077 . The linkage members  1074 ,  1076  may be pivotably coupled to one another, and to the clamp arm control member  1044 , at a pivot point  1080 . Proximal and distal translation of the clamp arm control member  1044  may transition the clamp arm  1016  and ultrasonic blade  1018  between open and closed positions, as described herein. 
     In the example embodiment shown in  FIG. 42 , the clamp arm  1016  comprises a second proximal member  1078 ′ such that the proximal members  1078 ,  1078 ′ straddle the ultrasonic transducer assembly  1012  and be pivotably coupled to a second linkage member  1074 ′. Similarly, a second linkage member  1076 ′ may be pivotably coupled to the ultrasonic transducer assembly  1012  in a manner similar to that of linkage member  1078 . All of the linkage members  1074 ,  1074 ′,  1078 ,  1078 ′ may be pivotably coupled to one another at pivot point  1080 . In various embodiments, pivot point  1075  may comprise a bar  1082  extending between proximal member/linkage member  1078 / 1074  and proximal member/linkage member  1078 ′/ 1074 ′. A similar bar  1084  may be positioned at pivot point  1080 . 
       FIG. 43  illustrates a side view of one embodiment of the ultrasonic transducer assembly  1012  and clamp arm  1016 , arranged as illustrated in  FIG. 42 , coupled to the distal shaft portion  1007  and in an open position. As illustrated in  FIG. 43 , the distal shaft portion  1007  comprises a clevis arm  1086  that is pivotably coupled to the ultrasonic transducer assembly  1012  and clamp arm  1016  at the pivot point  1072  such that the ultrasonic transducer assembly  1012 , the clamp arm  1016  and the clevis arm  1086  are all pivotable relative to one another. In some embodiments, a second clevis arm (not shown) is present on an opposite side of the ultrasonic transducer assembly  1012  and clamp arm  1016 . As illustrated, the clamp arm control member  1044  is translated distally in the direction indicated by arrow  1088 . This pushes the linkage members  1074 ,  1076  apart and, in turn, causes the clamp arm  1016  and blade  1018  (e.g., coupled to the assembly  1012 ) to pivot away from one another about the pivot point  1072  to the position shown. 
       FIG. 44  illustrates a side view of one embodiment of the ultrasonic transducer assembly  1012  and clamp arm  1016 , arranged as illustrated in  FIG. 42 , coupled to the distal shaft portion  1007  and in a closed position. In  FIG. 44 , the clamp arm control member  1044  has been pulled proximally in the direction of arrow  1090 . This pulls linkage members  1074 ,  1076 , moving the pivot points  1075 ,  1077  towards one another in the directions indicated by arrows  1092 ,  1094 . Similarly, the blade  1018  and clamp arm  1016  are pivoted about the pivot point  1072  towards one another in the direction of arrows  1096 ,  1098  to the closed position illustrated. Distal and proximal translation of the clamp arm control member  1044  may be brought about in any suitable manner. For example, in a handheld instrument, the clamp arm control member  1044  may be distally and proximally translated in manner similar to that described above with respect to the tubular actuating member  58 . Also, for example, in a robotic instrument, the clamp arm control member  1044  may be distally and proximally translated in a manner similar to that described herein above with respect to  FIGS. 22-36C . 
       FIGS. 45 and 46  illustrate side views of one embodiment of the ultrasonic transducer assembly and clamp arm of  FIGS. 37-38 , arranged as illustrated in  FIG. 42 , including proximal portions of the shaft  1004 . In  FIG. 45 , the blade  1018  and clamp arm  1016  are shown in the closed position, similar to  FIG. 44 . Proximal shaft portion  1009  is shown extending from a trocar  1100 . The distal shaft portion  1007  and end effector  1014  are shown articulated about the articulation joint  1010  in the direction indicated by arrows  1102 . The clamp arm control member  1044  is pulled proximally, as indicated by arrow  1090  and is shown bent around the articulation joint  1010 . In  FIG. 46 , the blade  1018  and clamp arm  1016  are shown in the open position, similar to  FIG. 43 . The clamp arm control member  1044  is pushed distally, as indicated by  1088  and, again, is bent about the articulation joint  1010 . In the embodiments shown in  FIGS. 37-46 , and in various embodiments described herein, the ultrasonic blade and clamp arm may take any suitable shape or shapes. For example,  FIGS. 47-48  illustrate one embodiment of an end effector  1014 ′ having an alternately shaped ultrasonic blade  1018 ′ and clamp arm  1016 ′. 
       FIG. 49  illustrates one embodiment of another end effector  1014 ″ comprising a flexible ultrasonic transducer assembly  1012 ′. The ultrasonic transducer assembly  1012 ′ comprises a distal transducer portion  1103  and a proximal transducer portion  1104  coupled by a bendable intermediate portion  1106 . The proximal transducer portion  1104  may be coupled to a proximal transducer bracket  1108 . For example, the transducer portion  1104  may be coupled to the bracket  1108  utilizing various disks  1070  that may be positioned at nodes of the transducer. The bracket  1108  may be pivotably coupled to the linkage member  1074  at pivot point  1080 . The distal transducer portion  1103  may be coupled to a distal bracket  1110 , again, for example, utilizing disks  1070  at transducer nodes. The distal bracket  1110  may be pivotably coupled to the clamp arm  1016  and the clevis arm  1086  at the pivot point  1072 . In various embodiments, the bendable intermediate portion  1106  may have a transverse area that is smaller than that of the distal transducer portion  1103  and proximal transducer portion  1104 . Also, in some embodiments, the intermediate portion  1106  may be made of a different material than the distal and proximal transducer portions  1103 ,  1104 . For example, the distal and proximal transducer portions  1103 ,  1104  may be made from piezoelectric elements (such as elements  112  described herein above). The bendable intermediate portion  1106  may be made from any suitable flexible material that conducts ultrasonic energy including, for example, titanium, a titanium alloy, nitanol, etc. It will be appreciated that the ultrasonic transducer assembly  1012 ′ is illustrated in  FIG. 49  without any outer housing so as to more clearly illustrate the embodiment. In use, the ultrasonic transducer assembly  1012  may be utilized with a housing such as the housing  1064  described herein above with respect to  FIG. 41 . 
     In use, the bendable intermediate transducer portion  1106  may serve a function similar to that of the pivot point  1077 . For example, when the clamp arm control member  1044  is pushed distally, the bendable intermediate transducer portion  1106  may bend, pushing the blade  1018  and clamp arm  1016  into an open position, shown in  FIG. 49 . When the clamp arm control member  1044  is pulled proximally, the bendable intermediate transducer portion  1106  may be more straightened, pulling the blade  1018  and clamp arm  1016  into a closed position. 
     In some example embodiments, the ultrasonic transducer assembly may be positioned in the shaft such that a proximal end of the transducer assembly extends proximally from the articulation joint. This may serve to minimize a distance between the articulation and a distal tip of the ultrasonic blade.  FIG. 50  shows one embodiment of a manual surgical instrument  1200  having a transducer assembly  1012  extending proximally from the articulation joint  1010 . It can be seen that a distance  1204  between a distal-most point of the ultrasonic blade  1018  and the articulation joint  1010  is less than it would be if all of the ultrasonic transducer assembly  1012  were distal of the articulation joint. Although the instrument  1200  shown in  FIG. 50  is a manual instrument, it will be appreciated that the shaft  1004  and end effector  1014  in the configuration illustrated in  FIG. 50  may also be used with a robotic surgical system, such as the system  500  described herein. 
       FIG. 51  illustrates a close up of the transducer assembly  1012 , distal shaft portion  1007 , articulation joint  1010  and end effector  1014  arranged as illustrated in  FIG. 50 .  FIG. 52  illustrates one embodiment of the articulation joint  1010  with the distal shaft portion  1007  and proximal shaft portion  1009  removed to show one example embodiment for articulating the shaft  1004  and actuating the haw member  1016 . In  FIG. 52 , articulation control members  1210 ,  1212  are coupled to a pulley  1206 . The pulley, in turn, may be coupled to the distal shaft portion  1007 , for example, at the articulation joint  1010  such that rotation of the pulley  1206  causes corresponding pivoting of the distal shaft portion  1007  and end effector  1014 . Proximal translation of the control member  1212  may rotate the pulley  1206  clockwise (in the configuration shown in  FIG. 52 ), thereby articulating the end effector  1014  towards the control member  1212 , as shown in  FIG. 52 . Similarly, proximal translation of the control member  1210  may rotate the pulley  1206  counter clockwise (in the configuration shown in  FIG. 52 ), thereby articulating the end effector  1014  towards the control member  1210 , the opposite of what is shown in  FIG. 52 . 
     Clamp arm control member  1044  may extend through a channel  1208  in the pulley  1206 . As illustrated, the clamp arm  1016  is configured to be pivotably coupled to a distal plate  1215  at a pivot point  1214 . The clamp arm control member  1044  is coupled to the clamp arm  1016  at a point  1216  offset from the pivot point  1214 , such that distal and proximal translation of the clamp arm control member  1044  opens and closes the clamp arm  1016 . The plate  1215 , for example, may be coupled to the distal shaft portion  1007  (not shown in  FIG. 52 ), the transducer assembly  1012  or any other suitable component. In some embodiments, the clamp arm  1016  is pivotably coupled directly to the distal shaft portion  1007  and/or the transducer assembly  1012 . 
     The articulation control members  1210 ,  1212  may be differentially translated to articulate the distal shaft portion  1007  and end effector  1014 . Differential articulation of the control members  1210 ,  1212  may be actuated in any suitable manner. For example, in a manual surgical instrument, the control members  1210 ,  1212  may be differentially translated utilizing an articulation lever  1052  and spindle gear  1058  as illustrated in  FIG. 40A . Also, in robotic surgical instruments, the control members  1210 ,  1212  may be differentially translated, for example, utilizing any of the mechanisms described above with respect to  FIGS. 22-36C . The clamp arm control member  1044  may be driven in various ways including, for example, all of the additional ways described herein. 
     In some embodiments, a surgical instrument has an end effector that is rotatable independent of the shaft. For example, the shaft itself may rotate and articulate at an articulation joint. Additionally, the end effector may rotate independent of the shaft including, for example, while the shaft is articulated. This may effectively increase the spatial range of the end effector.  FIG. 53  illustrates one embodiment of a manual surgical instrument  1300  comprising a shaft  1303  having an articulatable, rotatable end effector  1312 . Although the shaft  1303  is illustrated for use with a manual surgical instrument comprising a handle  1302 , it will be appreciated that a similar shaft may be utilized with a robotic surgical system, such as those described herein. 
     The shaft  1303  comprises an articulation joint  1010  that may be articulated utilizing articulation lever  1052 , for example, as indicated by arrow  1306 . A rotation knob  1314  may rotate the shaft  1303 , for example, as the rotation knob  48  rotates the shaft assembly  14  described herein above. End effector rotation dial  1304  may rotate the end effector, for example, as indicated by arrow  1310 .  FIG. 54  illustrates a cut-away view of one embodiment of the instrument  1300  and shaft  1303 .  FIG. 54  illustrates one embodiment of the articulation lever  1052  coupled to control members  1032 ,  1034 , for example, as described above with respect to  FIGS. 39, 40 and 40A . A central shaft member  1316  may extend through the shaft  1303  and be coupled at a distal end to the end effector  1312  (e.g., the ultrasonic blade  1018  and clamp arm  1016 ). A proximal end of the central shaft member  1316  may be coupled to the end effector rotation dial  1304  such that rotation of the dial causes rotation of the central shaft member  1316  and corresponding rotation of the end effector  1312 . 
     The central shaft member  1316  may be made of any suitable material according to any suitable construction. For example, in some embodiments, the central shaft member  1316  may be solid (or hollow for enclosing wires and other components). The central shaft member  1316  may be made from a flexible material, such as a surgical grade rubber, a flexible metal such as titanium, nitinol, etc. In this way, the central shaft member  1316  may bend when the shaft  1303  is articulated at the articulation joint  1010 . Rotation of the central shaft member  1316  may still be translated to the end effector  1312  across the articulation joint  1010 . 
     In some embodiments, the central shaft member  1316 , in addition to rotating the end effector  1312 , may also actuate the clamp arm  1016 . For example, the central shaft member  1316  may actuate the clamp arm  1016  by translating distally and proximally, for example, in response to actuation of the trigger  1022 .  FIG. 52 , described above, illustrates one embodiment of a clamp arm  1016  that may be opened and closed with distal and proximal motion. An additional embodiment is described below with respect to  FIG. 59 . 
     In embodiments where the central shaft member  1316  actuates the clamp arm  1016 , it may be desirable to avoid translating distal and/or proximal motion of the central shaft member  1316  to the dial  1304 .  FIG. 55  illustrates one embodiment of the instrument  1300  showing a keyed connection between the end effector rotation dial  1304  and the central shaft member  1316 . A proximal portion of the central shaft member  1316  may be coupled to a collar  1324  defining a slot  1326 . The dial  1304  may be coupled to shaft  1320  positioned within the collar  1324 . The shaft  1320  defines a key or spline  1322  positioned to fit within the slot  1326 . In this way, rotation of the dial  1304  may cause corresponding rotation of the central shaft member  1316 , but distal and proximal translation of the central shaft member  1316  may not be communicated to the dial  1304 .  FIG. 55  also illustrates one example method of passing an electrical drive signal to the transducer assembly  1012 . For example, a drive cable  1318  may be coupled to a slip ring  1324 . The slip ring  1324 , in turn, may be coupled to a distal drive cable  1330  ( FIG. 56 ) that may extend through the shaft  1303 , for example, through the central shaft member  1316 .  FIG. 56  illustrates one embodiment of the shaft  1303  focusing on the articulation joint  1010 . In the embodiment shown in  FIG. 56 , it may not be necessary for the entirety of the central shaft member  1316  to be bendable. Instead, as illustrated in  FIG. 56 , the central shaft member  1316  comprises a bendable section  1332  aligned with the articulation joint  1010  of the shaft  1303 . 
     The bendable section  1332  may be implemented in any suitable manner. For example, the bendable section  1332  may be constructed from a flexible material such as, for example, surgical grader rubber or a bendable metal such as, for example, titanium, nitinol, etc. Also, in some embodiments, the bendable section  1332  may be made of hinged mechanical components. For example,  FIG. 57  illustrates one embodiment of the central shaft member  1316  made of hinged mechanical components. As illustrated in  FIG. 57 , the central shaft member  1316  comprises a distal member  1340  pivotably coupled to a central member  1342 . The distal ( 1340 ) and central ( 1342 ) members may pivot relative to one another in the direction indicated by arrow  1346 . The central member  1342  may also be pivotably coupled to a proximal member  1344 . The central ( 1342 ) and proximal ( 1344 ) members may pivot relative to one another in the direction indicated by arrow  1348 . For example, the pivoting direction of members  1344 ,  1342  may be substantially perpendicular to the pivoting direction of the members  1342 ,  1340 . In this way, the central shaft member  1316  may provide rotating torque to the end effector  1312  while pivoting with the articulation joint  1010  at bendable section  1332 . 
     Referring back to  FIG. 56 , the articulation joint  1010  is illustrated as a continuous, flexible portion  1350  of the shaft  1303 . Various other configurations may be used. For example,  FIG. 58  illustrates one embodiment of the shaft  1303  comprising a distal shaft portion  1356  and a proximal shaft portion  1358 . The respective shaft portions  1356 ,  1358  may be pivotably coupled, for example, to an intermediate shaft portion  1360 , at pivot points  1352 ,  1354 , respectively. The articulation joint  1010 , in the configuration shown in  FIG. 58 , may be articulated as described herein above, for example, with respect to  FIGS. 39, 40 and 40A . 
       FIG. 59  illustrates one embodiment of the shaft  1303  and end effector  1312  illustrating a coupling between the central shaft member  1316  and the clamp arm  1016 . In  FIG. 59 , the central shaft member  1316  is illustrated as a solid (or hollow) member that is bendable and/or has a bendable portion at articulation joint  1010 . In  FIG. 59 , portions of the distal ( 1356 ) and proximal ( 1358 ) shaft portions are omitted to show the operation of the central shaft member  1316 . For example, the central shaft member  1316  may extend around the ultrasonic transducer assembly  1012  and transducer  1040  and be pivotably coupled to the clamp arm  1016  at pivot point  1366 . The clam arm  1016  may also be pivotably coupled to the distal shaft portion  1356  at pivot point  1364 . Pivot points  1364 ,  1366  may be offset from one another relative to the longitudinal axis  1002 . When the central shaft portion  1316  is pushed distally, it may push the clamp arm  1016  distally at pivot point  1366 . As pivot point  1364  may remain stationary, the clamp arm  1364  may pivot to an open position. Pulling the central shaft portion  1316  proximally may pull the clamp arm  1016  back to the closed position shown in  FIG. 59 . As illustrated, when the central shaft portion  1316  is translated distally and proximally, the transducer assembly  1012  and blade  1018  may also be translated distally and proximally. 
     Although the instrument  1300  is described herein as a manual instrument, it will be appreciated that the shaft  1303  in the various described embodiments may be utilized in a robotic surgical instrument as well. For example, differential translation of the control members  1032 ,  1034 , rotation of the shaft  1303  and rotation of the central shaft member  1316  may be brought about as described herein above with respect to  FIGS. 22-36C . Similarly, the shaft  1303  may be utilized in a manual instrument where articulation and rotation of the end effector  1312  is motorized.  FIGS. 60-61  illustrate a control mechanism for a surgical instrument  1300 ′ in which articulation and rotation of the end effector  1312  are motorized. The instrument  1300 ′ comprises a handle  1302 ′ that may comprise electric motors and mechanisms, for example, similar to the motors and mechanisms described herein with respect to  FIGS. 22-36C . An articulation knob  1370  may be moved in the directions of arrow  1375  to articulate the end effector  1312  about articulation joint  1010  and/or may be rotated in the directions indicated by arrow  1372  to rotate the end effector  1312  (e.g., by rotating the central shaft member  1316 ). 
       FIGS. 62-63  illustrate one embodiment of a shaft  1400  that may be utilized with various surgical instruments described herein. The shaft  1400  may comprise a two-direction articulation joint  1402  that may be articulated in multiple directions, as indicated by arrows  1410  and  1412 . The shaft  1400  may comprise a proximal shaft member  1404  pivotably coupled to a joint member  1408  such that the proximal shaft member  1404  is pivotable relative to the joint member  1408  in the direction of arrow  1412 . The joint member  1408  may also be pivotably coupled to a distal shaft member  1406  such that the distal shaft member  1406  is pivotable relative to the joint member  1408  in the direction of arrow  1410 . The pivotably couplings between the respective members  1404 ,  1406 ,  1408  may be of any suitable type including, for example, pin and clevis couplings. 
     Referring now to  FIG. 63 , the articulation joint  1402  may be actuated by a series of control members. Control members  1414 ,  1412  may be coupled to the joint member  1408  and may extend proximally through the proximal shaft member  1404 . Differential translation of the control members  1414 ,  1412  may cause the end effector  1411  to pivot away from the longitudinal axis  1002  in the directions of the arrow  1412 . For example, proximal translation of the control member  1412  (e.g., accompanied by distal translation of the control member  1414 ) may pull the end effector  1411 , distal shaft member  1406  and joint member  1408  away from the longitudinal axis  1002  and towards the control member  1412 . Similarly, proximal translation of the control member  1414  (e.g., accompanied by distal translation of the control member  1412 ) may pull the end effector  1411 , distal shaft member  1406  and joint member  1408  away from the longitudinal axis  1002  and towards the control member  1414 . 
     Additional control members  1416 ,  1418  may be coupled to the distal shaft member  1406 . Differential translation of the control members  1416  may cause the distal shaft member  1406  and end effector  1411  to pivot in the directions of the arrow  1410 . For example, proximal translation of the control member  1416  (e.g., accompanied by distal translation of the control member  1418 ) may pull the end effector  1411  and distal shaft member  1406  away from the longitudinal axis  1002  and towards the control member  1416 . Similarly, proximal translation of the control member  1418  (e.g., accompanied by distal translation of the control member  1416 ) may pull the end effector  1411  and distal shaft member  1406  away from the longitudinal axis  1002  and towards the control member  1418 . Drive signal wires for driving the ultrasonic transducer assembly  1012  may pass through the proximal shaft member  1404 , joint member  1408  and distal shaft member  1406 . 
     Differential translation of the respective control members  1412 ,  1414 ,  1416 ,  1418  may be implemented in any suitable manner. For example, in a manual instrument, differential translation of the control members  1412 ,  1414 ,  1416 ,  1418  may be implemented in the manner described above with respect to  FIGS. 39, 40 and 40A . In a robotic instrument, any method or mechanism may be used including, for example, those described above with respect to  FIGS. 22-36C . 
       FIG. 64  illustrates one embodiment of a shaft  1600  that may be articulated utilizing a cable and pulley mechanism. The shaft  1600  may be utilized with any of the various surgical instruments described herein. The shaft  1600  comprises a proximal shaft member  1602  and a distal shaft member  1614  coupled at an articulation joint  1615 . An end effector  1617  may be coupled to a distal portion of the distal shaft member  1614 . The end effector  1615 , as illustrated in  FIG. 64  may comprise an ultrasonic blade  1018 , ultrasonic transducer assembly  1012 , clamp arm  1016  and linkage members  1608 ,  1610  arranged in a four-bar linkage configuration similar to that described herein with respect to end effector  1014  shown at  FIGS. 42-46 . For example, the end effector  1617  may be pivotably coupled to the distal shaft member  1614  at clevis arms  1615 . Clamp arm control member  1624  may be coupled to the linkage members  1608 ,  1610  to open and close the clamp arm member  1016 , as described above. The shaft  1600  may be rotated, as indicated by arrow  1604 . In contrast to the end effector  1014 , the end effector  1617  may only comprise a single linkage member  1608  and a single linkage member  1610 , as illustrated. It will be appreciated that the ultrasonic transducer assembly  1012  is illustrated in  FIG. 64  without any outer housing so as to more clearly illustrate the embodiment. In use, the ultrasonic transducer assembly  1012  may be utilized with a housing such as the housing  1064  described herein above with respect to  FIG. 41 . 
       FIG. 65  illustrates one embodiment of the shaft  1600  showing additional details of how the distal shaft portion  1614  (and end effector  1617  not shown in  FIG. 65 ) may be articulated. For example, control members  1620 ,  1622  may extend through the proximal shaft member  1602  and around a pulley  1618  coupled to the distal shaft member  1614 . For example, rotation of the pulley  1618  about the axis  1615  ( FIG. 64 ) may cause pivoting of the distal shaft portion  1614 . The pulley  1618  may be rotated by differential translation of the control members  1620 ,  1622 , thereby bringing about articulation of the distal shaft portion  1614  and end effector  1617  in the direction of the arrow  1606 .  FIG. 64  shows an alternate position  1601  of the end effector  1617  and distal shaft member  1615  articulated in a first direction relative to the longitudinal axis  1002 . It will be appreciated, however, that the end effector  1617  and distal shaft member  1615  may be articulated in multiple directions about articulation axis  1619  ( FIG. 64 ). 
     The control members  1620 ,  1622  and clamp arm control member  1624  may be actuated in any suitable manner. For example, the control members  1620 ,  1622  may be differentially translated to articulate the end effector  1617  and distal shaft member  1615 . In use with a manual instrument, the control members  1620 ,  1622  may be differentially translated, for example, as described herein above with respect to  FIGS. 39, 40 and 40A . In use with a robotic instrument, the control members  1620 ,  1622  may be differentially translated, for example, utilizing any of the mechanisms described above with respect to  FIGS. 22-36C . In a manual instrument, the clamp arm control member  1624  may be mechanically coupled to an instrument trigger, such as tubular actuating member  58  is coupled to trigger  22  described above. In a robotic instrument, the clamp arm control member  1624  may be actuated, for example, utilizing any of the mechanisms described above with respect to  FIGS. 22-36C . 
       FIG. 66  illustrates one embodiment of an end effector  1700  that may be utilized with any of the various instruments and/or shafts described herein. The end effector  1700  may facilitate separate actuation of the clamp arm  1016  and ultrasonic blade  1018 . The end effector  1700  may operate similar to the four-bar linkage end effector  1014  described herein above. Instead of the linkage members  1705 ,  1707  being coupled to a single clamp arm control member  1044  ( FIG. 42 ), each of the linkage members  1705 ,  1707  may be coupled to distinct control members  1702 ,  1704 . For example, linkage member  1705  may be coupled to a clamp arm control member  1702  while linkage member  1707  may be coupled to a blade control member  1704 . Proximal ends of the linkage member  1705 ,  1707  may ride within slots  1706 ,  1708  defined by the shaft  1710  (or a distal portion thereof). For example, linkage members  1705 ,  1076  may comprise respective pegs  1712 ,  1714  that ride within the slots  1706 ,  1708 . In some embodiment, linkage members  1705 ,  1707  may be singular (similar to linkage members  1608 ,  1610 , or may be double linkage members (similar to linkage members  1074 ,  1074 ′ and  1076 ,  1076 ′). 
     Distal and proximal translation of the clamp arm control member  1702  may cause the clamp arm  1016  to pivot about the pivot point  1072 . For example, proximal translation of the clamp arm control member  1702  may pull the linkage member  1705  and proximal portion  1078  of the clamp arm  1016  proximally, tending to pivot the clamp arm  1016  about the pivot point  1072  in the direction indicated by arrow  1716 . Distal translation of the clamp arm control member  1702  may push the linkage member  1705  and proximal portion  1078  of the clamp arm member  1078  distally (shown at  1724 ) tending to pivot the clamp arm  1016  about the pivot point  1072  in the direction indicated by arrow  1718 . Similarly, distal and proximal translation of the blade control member  1704  may cause the blade  1018  to pivot about the pivot point  1072 . Proximal translation of the blade control member  1704  may pull the linkage member  1076  and transducer assembly  1012  proximally, causing the blade  1018  to pivot about the pivot point  1072  in the direction indicated by arrow  1720 . Distal translation of the blade control member  1704  may push the linkage member  1076  and transducer assembly  1012  distally (shown at  1726 ) tending to pivot the blade  1018  about the pivot point  1072  in the direction indicated by arrow  1722 . 
     By manipulating the various control members  1702 ,  1704 , the blade  1018  and clamp arm  1016  of the end effector  1700  may be opened and closed, and also pivoted together about the pivot point  1072 , for example, to provide an additional degree of articulation to the end effector  1700 . For example, although the blade  1018  and clamp arm  1016  are shown in  FIG. 66  to be closed along the longitudinal axis  1002 , it will be appreciated that the components  1018 ,  1016  could be placed in a close position pivoted away from the longitudinal axis  1002  as well. 
       FIG. 67  illustrates one embodiment of the shaft  1600  coupled to an alternate pulley-driven end effector  1800 .  FIG. 68  illustrates one embodiment of the end effector  1800 . The end effector  1800  may comprise linkage members  1810 ,  1812  that may each be pivotably coupled to respective pulleys  1814 ,  1816 . The linkage members  1810 ,  1812  may be coupled to the pulleys  1814 ,  1816  at a position offset from a center  1817  of the pulleys  1814 ,  1816  such that rotation of the pulleys  1814 ,  1816  translates the linkage members  1810 ,  1812  distally and proximally. The pulleys  1814 ,  1816  may be individually driven. For example pulley  1816  may be rotated by differentially translating control members  1802 ,  1804 . Similarly, pulley  1814  may be rotated by differentially translating control members  1806 ,  1808 . As pulley  1814  is rotated, linkage member  1810  may be translated distally and proximally, causing pivoting of the clamp arm  1016  about pivot point  1072  in the directions indicated by arrows  1814 ,  1816 . Similarly, as pulley  1816  is rotated, linkage member  1812  may be translated distally and proximally, causing pivoting of the ultrasonic transducer assembly  1012  and blade  1018  about the pivot point  1072  in the direction of arrows  1818 ,  1820 . Differential translation of the control member pairs  1802 / 1804  and  1806 / 1808  may be brought about in any suitable manner. For example, in manual instruments, the control member pairs may be differentially translated as described above with respect to  FIGS. 39, 40 and 40A . In robotic instruments, the control member pairs may be differentially translated as described above with respect to  FIGS. 22-36C . It will be appreciated that the ultrasonic transducer assembly  1012  is illustrated in  FIGS. 67-68  without any outer housing so as to more clearly illustrate the embodiment. In use, the ultrasonic transducer assembly  1012  may be utilized with a housing such as the housing  1064  described herein above with respect to  FIG. 41 . 
     Non-Limiting Embodiments 
     Various embodiments are direct to a surgical instrument comprising and end effector, an articulating shaft and an ultrasonic transducer assembly. The end effector may comprise an ultrasonic blade. The articulating shaft may extend proximally from the end effector along a longitudinal axis and may comprise a proximal shaft member and a distal shaft member pivotably coupled at an articulation joint. The ultrasonic transducer assembly may comprise an ultrasonic transducer acoustically coupled to the ultrasonic blade. The ultrasonic transducer assembly may be positioned distally from the articulation joint. In some embodiments, the ultrasonic transducer assembly may be positioned such that a portion of the ultrasonic transducer assembly is proximal from the articulation joint and another portion of the ultrasonic transducer assembly is distal from the articulation joint. 
     In some embodiments, the instrument comprises first and second control members extending through the shaft such that proximal translation of the first control member causes the distal shaft member and end effector to pivot towards the first control member. Also, in some embodiments, the distal shaft portion may define a pulley at about the articulation joint such that rotation of the pulley causes articulation of the distal shaft portion. First and second control members may be positioned around the pulley such that differential translation of the first and second control members causes rotation of the pulley and articulation of the distal shaft member. 
     Also, some embodiments comprise a clamp arm pivotable about a clamp arm pivot point from an open position to a closed position substantially parallel to the ultrasonic blade. The clamp arm pivot point may be offset from the longitudinal axis. A clamp arm control member may be coupled to the clamp arm at a position offset from the longitudinal axis such that distal translation of the clamp arm control member pivots the clamp arm to the open position and proximal translation of the clamp arm control member pivots the clamp arm to the closed position. 
     In some embodiments, the clamp arm defines a clamp portion extending distally from the clamp arm pivot point and a proximal portion extending proximally from the clamp arm pivot point. A first linkage member may define a proximal end pivotably coupled to the clamp arm control member and a distal end pivotably coupled to a proximal portion of the ultrasonic transducer assembly. A second linkage member may define a proximal end pivotably coupled to the clamp arm control member and a distal end pivotably coupled to the proximal portion of the clamp arm. In some embodiments, the first linkage member may be coupled to a blade control member and the second linkage member may be coupled to a clamp arm control member. Also, in some embodiments, the first and second linkage members are coupled to respective pulleys separately rotatable by respective control members. Also, in some embodiments, the first and second linkage members may be coupled to respective first and second pulleys, where each pulley is separately rotatable to pivot the clamp arm and blade. 
     In some embodiments, a proximal portion of the ultrasonic transducer assembly and a distal portion of the ultrasonic transducer assembly are separated by a bendable, acoustically transmissive section having a transverse area less than a longitudinal diameter of the distal and proximal portions of the ultrasonic transducer assembly. The first linkage member may be connected as described above. The proximal portion of the ultrasonic transducer assembly may also be coupled to the clamp arm control member. 
     Applicant also owns the following patent applications that are each incorporated by reference in their respective entireties: 
     U.S. patent application Ser. No. 13/536,271, filed on Jun. 28, 2012 and entitled “Flexible Drive Member,” now U.S. Pat. No. 9,204,879; 
     U.S. patent application Ser. No. 13/536,288, filed on Jun. 28, 2012 and entitled “Multi-Functional Powered Surgical Device with External Dissection Features,” now U.S. Patent Publication No. 2014/0005718; 
     U.S. patent application Ser. No. 13/536,295, filed on Jun. 28, 2012 and entitled “Rotary Actuatable Closure Arrangement for Surgical End Effector,” now U.S. Pat. No. 9,119,657; 
     U.S. patent application Ser. No. 13/536,326, filed on Jun. 28, 2012 and entitled “Surgical End Effectors Having Angled Tissue-Contacting Surfaces,” now U.S. Pat. No. 9,289,256; 
     U.S. patent application Ser. No. 13/536,303, filed on Jun. 28, 2012 and entitled “Interchangeable End Effector Coupling Arrangement,” now U.S. Pat. No. 9,028,494 
     U.S. patent application Ser. No. 13/536,393, filed on Jun. 28, 2012 and entitled “Surgical End Effector Jaw and Electrode Configurations,” now U.S. Patent Publication No. 2014/0005640; 
     U.S. patent application Ser. No. 13/536,362, filed on Jun. 28, 2012 and entitled “Multi-Axis Articulating and Rotating Surgical Tools,” now U.S. Pat. No. 9,125,662; and 
     U.S. patent application Ser. No. 13/536,417, filed on Jun. 28, 2012 and entitled “Electrode Connections for Rotary Driven Surgical Tools,” now U.S. Pat. No. 9,101,385. 
     In some embodiments, the shaft further comprises a joint member positioned at about the articulation. The joint member may be pivotably coupled to the distal shaft member such that the distal shaft member is pivotable relative to the joint member about a first pivot axis substantially perpendicular to the longitudinal axis and pivotably coupled to the proximal shaft member such that the joint member is pivotable relative to the proximal shaft member about a second pivot axis substantially perpendicular to the longitudinal axis and substantially perpendicular to the first pivot axis. 
     It will be appreciated that the terms “proximal” and “distal” are used throughout the specification with reference to a clinician manipulating one end of an instrument used to treat a patient. The term “proximal” refers to the portion of the instrument closest to the clinician and the term “distal” refers to the portion located furthest from the clinician. It will further be appreciated that for conciseness and clarity, spatial terms such as “vertical,” “horizontal,” “up,” or “down” may be used herein with respect to the illustrated embodiments. However, surgical instruments may be used in many orientations and positions, and these terms are not intended to be limiting or absolute. 
     Various embodiments of surgical instruments and robotic surgical systems are described herein. It will be understood by those skilled in the art that the various embodiments described herein may be used with the described surgical instruments and robotic surgical systems. The descriptions are provided for example only, and those skilled in the art will understand that the disclosed embodiments are not limited to only the devices disclosed herein, but may be used with any compatible surgical instrument or robotic surgical system. 
     Reference throughout the specification to “various embodiments,” “some embodiments,” “one example embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one example embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one example embodiment,” or “in an embodiment” in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics illustrated or described in connection with one example embodiment may be combined, in whole or in part, with features, structures, or characteristics of one or more other embodiments without limitation. 
     While various embodiments herein have been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art. For example, each of the disclosed embodiments may be employed in endoscopic procedures, laparoscopic procedures, as well as open procedures, without limitations to its intended use. 
     It is to be understood that at least some of the figures and descriptions herein have been simplified to illustrate elements that are relevant for a clear understanding of the disclosure, while eliminating, for purposes of clarity, other elements. Those of ordinary skill in the art will recognize, however, that these and other elements may be desirable. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the disclosure, a discussion of such elements is not provided herein. 
     While several embodiments have been described, it should be apparent, however, that various modifications, alterations and adaptations to those embodiments may occur to persons skilled in the art with the attainment of some or all of the advantages of the disclosure. For example, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. This application is therefore intended to cover all such modifications, alterations and adaptations without departing from the scope and spirit of the disclosure as defined by the appended claims. 
     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 materials 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.