Patent Publication Number: US-9883880-B2

Title: Articulating surgical device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/047,930, filed on Mar. 15, 2011, now U.S. Pat. No. 8,968,355, which claims the benefit of and priority to each of U.S. Provisional Application Ser. No. 61/424,251, filed on Dec. 17, 2010 and U.S. Provisional Application Ser. No. 61/316,404, filed on Mar. 23, 2010 and which is a continuation-in-part of U.S. patent application Ser. No. 12/511,614, filed on Jul. 29, 2009, now U.S. Pat. No. 8,801,752, which claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/085,997, filed on Aug. 4, 2008, the entire disclosures of each of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to endoscopic surgical devices, and more particularly, to endoscopic surgical devices capable of multiple degrees of articulation. 
     2. Background of the Related Art 
     Endoscopic surgery is a minimally invasive technique for performing surgery intracorporeally without requiring a large incision. Typically, endoscopic surgery is conducted by inserting a number of ports through small incisions in the patient&#39;s skin to access a surgical site. One of the ports receives an endoscope, which is a video camera-like device. The surgeon views the surgical site via the endoscope and performs the surgery by inserting various surgical devices into the patient through the ports. During endoscopic surgery, the surgeon may introduce different surgical devices through the ports. For example, the surgeon may insert a hand operated endoscopic grasper, a dissector, shears, scissors and the like. This technique does not require “opening up” the patient, resulting in less invasive surgery than conventional procedures. 
     In an effort to reduce the number of incisions required, single incisions procedures and related surgical devices have been developed over the years. For instance, the surgeon may make one incision and maneuver a surgical device through the patient&#39;s body until it reaches the desired surgical site. However, it is often challenging to steer a surgical device through the complexities of the human anatomy. In light of this difficulty, a need exist for surgical devices capable of multitude degrees of operation and motion. 
     SUMMARY 
     The present disclosure relates to a surgical device capable of multiple degrees of articulation. This surgical device generally includes a handle assembly, an elongate member extending from the handle assembly, an articulation mechanism operatively associated with the handle assembly, and an end effector. The elongate member has an articulating section and straight section. The articulating section is configured to articulate with respect to the straight section. The articulation mechanism is operatively associated with the handle assembly and the articulating section such that the articulating section articulates toward a first direction relative to the straight section upon movement of the handle assembly towards the first direction with respect to the straight section. The end effector is operatively coupled to the articulating section of the elongate member and includes first and second jaw members. The first and second jaw members are configured to move relative to each other between an open position and an approximated position. The surgical device further includes a locking mechanism configured for fixing a relative position of first and second jaw members. The locking mechanism includes a first ratchet assembly and a second ratchet assembly positioned within the handle assembly. The first and second ratchet assemblies are moveable relative to each other between an engaged position to lock the relative position of the first and second jaw members and a disengaged position to unlock the relative position of the first and second jaw members. 
     In accordance with another embodiment of the present disclosure, there is provided a surgical device for performing surgery including an elongate member defining a longitudinal axis, an articulation section extending from the elongate member, and an end effector operatively coupled to the articulation section. The articulation section is transitionable between a straight position in which the articulation section is aligned with the longitudinal axis and a plurality of articulated positions in which the articulation section is offset from the longitudinal axis. The articulation section includes a plurality of articulation links arranged in a linear fashion. Each articulation link includes chamfered portions such that the chamfered portions of adjacent articulation links are in juxtaposed relation to one another. 
     In an embodiment, each of the plurality of articulation links may include proximal and distal surfaces, and each surface may include a pair of chamfered portions. The pair of chamfered portions may be defined at an outer periphery of the proximal or distal surface. In addition, the pair of chamfered portions may diametrically oppose each other. 
     In another embodiment, each articulation link may include at least a pair of bores adapted and dimensioned to receive an articulation cable therein. In addition, each articulation link may further define a channel adapted and dimensioned to receive an actuation cable therethrough for actuation of the end effector. 
     In yet another embodiment, the surgical device may further include a handle assembly operatively coupled to the articulation section. The articulation cable may interconnect the articulation section with the handle assembly, whereby movement of the handle assembly to angle the handle assembly with respect to the longitudinal axis of the elongate member results in corresponding articulation of the articulation section to an angled position with respect to the longitudinal axis of the elongate member. 
     In still another embodiment, one of the proximal and distal surfaces of the articulation link may define a pair of recesses. The other one of the proximal and distal surfaces may include a pair of extension members extending axially therefrom. The pair of extension members may be configured and dimensioned to at least partially slidably engage the pair of recesses of an adjacent articulation link. 
     In still yet another embodiment, the distal surface may include a contoured profile that is configured to mate with a contoured profile of the proximal surface of the adjacent articulation link. 
     In still yet another embodiment, the surgical device may further include a conformable sheath substantially encasing the articulation section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the presently disclosed surgical devices are described herein with reference to the accompanying drawings, wherein: 
         FIG. 1  is a rear, perspective view of a surgical device according to an embodiment of the present disclosure; 
         FIG. 2  is a side, elevational view of the surgical device of  FIG. 1  with an articulating section in a straight position; 
         FIG. 3  is a side, elevation view of the surgical device of  FIG. 1  with the articulating section in an articulated position; 
         FIG. 4  is a top view of the surgical device of  FIG. 1  with the articulating section in a straight position; 
         FIG. 5  is a top view of the surgical device of  FIG. 1  with the articulating section in an articulated position; 
         FIG. 6  is a front, perspective view of the surgical device of  FIG. 1 ; 
         FIG. 7  is a perspective sectional view of an end effector and the articulating section of the surgical device of  FIG. 1 , taken around section  7  of  FIG. 1  and showing a sheath covering the articulating section of the surgical device; 
         FIG. 8  is a perspective sectional view of the end effector and the articulating section of the surgical device of  FIG. 1 , depicting the articulating section without the sheath shown in  FIG. 7 ; 
         FIG. 9  is a perspective cutaway view of a handle assembly of the surgical device of  FIG. 1 , showing the internal components of the handle assembly; 
         FIG. 10A  is a perspective exploded view of the surgical device of  FIG. 1 ; 
         FIG. 10B  is a side view of an alignment tube of the surgical device of  FIG. 1 ; 
         FIG. 10C  is a front view of the alignment tube shown in  FIG. 10B ; 
         FIG. 10D  is a front view of a rotation wheel of the surgical device of  FIG. 1 ; 
         FIG. 10E  is a cross-sectional view of the rotation wheel shown in  FIG. 10D , taken along section line  10 E- 10 E of  FIG. 10D ; 
         FIG. 11A  is a perspective exploded view of an articulation mechanism, the end effector, and the articulating section of the surgical device of  FIG. 1 ; 
         FIG. 11B  is a side view of a torque shaft of the surgical device of  FIG. 1 ; 
         FIG. 11C  is a side view of a proximal torque tube of the torque shaft shown in  FIG. 11B ; 
         FIG. 11D  is a perspective view of a rotation wheel, a distal tubular member  388 , and a proximal torque tube  456  of the surgical device of  FIG. 1 ; 
         FIG. 12  is a perspective cross-sectional view of an articulation cable plate and an articulation lock ring of the articulation mechanism of  FIG. 11A , taken along section line  12 - 12  of  FIG. 11A ; 
         FIG. 13  is a front, exploded view of a portion of the articulating section of the surgical device of  FIG. 1 ; 
         FIG. 14  is a rear, exploded view of a portion of the articulating section the surgical device of  FIG. 1 ; 
         FIG. 15  is a perspective view of the articulating section of the surgical device of  FIG. 1 , showing articulation cables passing through articulation links and a distal outer tube of the articulating section; 
         FIG. 16  is a rear cross-sectional view of the handle assembly of  FIG. 9 , taken along section line  16 - 16  of  FIG. 9 ; 
         FIG. 17  is a side cross-sectional view of the surgical device of  FIG. 1 ; 
         FIG. 18  is a rear cross-sectional view of the surgical device of  FIG. 1 ; taken along section line  18 - 18  of  FIG. 17 ; 
         FIG. 19  is a rear cross-sectional view of the surgical device of  FIG. 1 ; taken along section line  19 - 19  of  FIG. 17 ; 
         FIG. 20  is a side cross-sectional view of the end effector and the articulating section of the surgical device of  FIG. 1 , taken around section  20  of  FIG. 17 ; 
         FIG. 21  is a side cross-sectional view of a portion of the handle assembly of the surgical device of  FIG. 1 , taken around section  21  of  FIG. 17 ; 
         FIG. 22  is a rear cross-sectional view of a portion of the handle assembly of the surgical device of  FIG. 1 , taken along section line  22 - 22  of  FIG. 21 ; 
         FIG. 23  is a perspective view of the end effector and the articulating section of the surgical device of  FIG. 1  during various stages of rotation along its longitudinal axis; 
         FIG. 24  is a perspective cutaway view of the handle assembly of the surgical device of  FIG. 1 ; 
         FIG. 25  is a perspective view of a portion of the articulation mechanism of the surgical device of  FIG. 1 ; 
         FIG. 26  is a side cross-sectional view of articulation mechanism of the surgical device of  FIG. 1 , showing a cup moving upwardly relative to a ball of the handle assembly; 
         FIG. 27  is a side cross-sectional view of the end effector and the articulation section of the surgical device of  FIG. 1 , showing the articulating section in an articulated position; 
         FIG. 28  is a side, cutaway view of a portion of the articulation mechanism of the surgical device of  FIG. 1 , showing an articulation lock trigger being actuated; 
         FIG. 29  is a side cross-sectional view of a portion of the articulation mechanism of the surgical device of  FIG. 1 , depicting articulation cables moving proximally in response to an actuation of the articulation lock trigger shown in  FIG. 28 ; 
         FIG. 30  is a side cross-sectional view of a portion of the handle assembly of the surgical device of  FIG. 1 , showing a movable thumb loop being actuated; 
         FIG. 31  is a side cross-sectional view of the end effector and a portion of the articulating section of the surgical device of  FIG. 1 , depicting end effector moving an approximated position in response to an actuation of the movable thumb loop shown in  FIG. 30 ; 
         FIG. 32  is a perspective view of a surgical device according to another embodiment of the present disclosure, showing an end effector including shearing blades; 
         FIG. 33  is a perspective view of the end effector and a portion of the articulating section of the surgical device of  FIG. 32 ; 
         FIG. 34  is a perspective exploded view of the end effector of the surgical device of  FIG. 32 ; 
         FIG. 35  is a side cross-sectional view of the articulating section and the end effector of the surgical device of  FIG. 32 ; 
         FIG. 36  is a perspective view of a surgical device according to a further embodiment of the present disclosure, showing an end effector including grasping forceps; 
         FIG. 37  is a perspective view of the end effector of the surgical device of  FIG. 36 ; 
         FIG. 38  is a perspective exploded view of the end effector of the surgical device of  FIG. 36 ; 
         FIG. 39  is a side cross-sectional view of an articulating section and the end effector of the surgical device of  FIG. 36 ; 
         FIG. 40  is a perspective view of a locking mechanism for any of the embodiments of the surgical device shown above; 
         FIG. 41  is a perspective view of a release assembly of the locking mechanism of  FIG. 40 ; 
         FIG. 42  is a side cross-sectional view of the locking mechanism of  FIG. 40  in a locked position; 
         FIG. 43  is a side cross-sectional view of the locking mechanism of  FIG. 40  in an unlocked position; 
         FIG. 44  is a perspective view of a surgical device according to another embodiment of the present disclosure, showing an end effector having a probe; 
         FIG. 45  is a perspective view of the end effector and a portion of an articulating section of the surgical device of  FIG. 44 ; 
         FIG. 46  is a side cross-sectional view of the end effector and the articulating section of the surgical device of  FIG. 44 ; 
         FIG. 47  is a side, cutaway view of a handle assembly of the surgical device of  FIG. 44 ; 
         FIG. 48  is a side, elevational view of the surgical device of  FIG. 44 , depicting the articulating section in an articulated position; 
         FIG. 49  is a top view of the surgical device of  FIG. 44 , depicting the articulating section in an articulated position; 
         FIG. 50  is a side, cutaway view of an embodiment of a straightening mechanism for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 51  is a front view of the straightening mechanism of  FIG. 50 ; 
         FIG. 52  is a front view of the straightening mechanism of  FIG. 50  with detents for securing an articulation mechanism in a neutral position; 
         FIG. 53  is side, cutaway view of another embodiment of a straightening mechanism with a helix spring for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 54  is a side cross-sectional view of an embodiment of a straightening mechanism including an elastomeric boot for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 55  is a side cross-sectional view of an embodiment of a straightening mechanism having an elastomeric member for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 56  is a side cross-sectional view of an embodiment of a straightening mechanism having a superelastic member for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 57  is side, cut-away view of an embodiment of a straightening mechanism with an elongate ball for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 58  is side, cut-away view of an embodiment of a straightening mechanism with elastic bands for incorporation in any of the embodiments of the surgical devices discussed above; 
         FIG. 59  is a side cross-sectional view of an embodiment of straightening mechanism with proximally-located springs for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 60  is a side cross-sectional view of an embodiment of straightening mechanism with distally-located springs for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 61  is a side cross-sectional view of an embodiment of a straightening mechanism with a ring and springs for incorporation in any of the embodiments of the surgical device discussed above; 
         FIG. 62  is a side cross-sectional view of a further embodiment of a locking mechanism for any of the embodiments of the surgical device shown above, wherein the locking mechanism is shown in a locked position; 
         FIG. 63  is a side cross-sectional view of the locking mechanism of  FIG. 62  shown in an unlocked position; 
         FIG. 64  is a side cross-sectional view of the locking mechanism of  FIG. 62  transitioning between the unlocked position and the locked position; 
         FIG. 65A  is a rear, perspective cut-away view of one embodiment of an articulation mechanism shown in a shipping position; 
         FIG. 65B  is a side, cut-away view of the articulation mechanism of  FIG. 65A  shown in a use position; 
         FIG. 66A  is a rear, perspective cut-away view of another embodiment of an articulation mechanism shown in the use position; 
         FIG. 66B  is a front, perspective cut-away view of the articulation mechanism of  FIG. 66A  shown in the use position; 
         FIG. 67A  is a side, cut-away view of another embodiment of an articulation mechanism shown in the shipping position; 
         FIG. 67B  is a side cross-sectional view of the articulation mechanism of  FIG. 67A  shown moving toward the use position; 
         FIG. 68A  is a perspective cut-away view of still another embodiment of an articulation mechanism shown in the shipping position; 
         FIG. 68B  is a perspective cut-away view of the articulation mechanism of  FIG. 68A  shown in the use position; 
         FIG. 69  is a perspective cut-away view of a two-bar linkage coupling an articulation lock trigger and an articulation cable plate in accordance with the present disclosure; 
         FIG. 70A  is a perspective cut-away view of the articulation lock trigger of  FIG. 69  shown in the shipping position; 
         FIG. 70B  is a perspective cut-away view of the articulation lock trigger of  FIG. 69  shown in the unlocked position; 
         FIG. 70C  is a perspective cut-away view of the articulation lock trigger of  FIG. 69  shown in the locked position; 
         FIG. 71A  is a perspective cut-away view of another embodiment of an articulation mechanism, according to the present disclosure, shown in the shipping position; 
         FIG. 71B  is an isolated, rear, perspective view of the articulation mechanism of  FIG. 71A  shown in the shipping position; 
         FIG. 72  is an isolated, rear, perspective view of the articulation mechanism of  FIG. 71A  shown in the unlocked, use position; 
         FIG. 73  is an isolated, front, perspective view of the articulation mechanism of  FIG. 71A  shown in the locked, use position; 
         FIG. 74  is an isolated, rear, perspective view of a cable plate of the articulation mechanism of  FIG. 71A ; 
         FIG. 75  is an isolated, front, perspective view of the cable plate of the articulation mechanism of  FIG. 71A  shown coupled to the articulation lock trigger of  FIG. 71A ; 
         FIG. 76  is a front, perspective cut-away view of yet another embodiment of an articulation mechanism shown transitioning from the shipping position to the use position; 
         FIG. 77  is an isolated, rear, perspective view of the articulation mechanism of  FIG. 76  shown in the use position; 
         FIG. 78  is an enlarged, rear perspective view of the articulation lock trigger of the articulation mechanism of  FIG. 76 ; 
         FIG. 79  is an isolated, front, perspective view showing the cable plate and the articulation lock trigger of the articulation mechanism of  FIG. 76  coupled to one another; 
         FIG. 80  is a front, perspective, cut-away view of another articulation mechanism in accordance with the present disclosure; 
         FIG. 81  is a rear, perspective, cut-away view of the articulation mechanism of  FIG. 80 ; 
         FIG. 82  is an isolated, perspective view of the articulation mechanism of  FIG. 80  showing a shaft coupled to an articulation lock trigger; 
         FIG. 83  is an isolated, perspective view of the articulation mechanism of  FIG. 80  showing a slider engaged to a cable plate; 
         FIG. 84  is a side, cross-sectional view of the articulation mechanism of  FIG. 80  shown in a shipping position; 
         FIG. 85  is a side, cross-sectional view of the articulation mechanism of  FIG. 80  shown transitioning from the shipping position to a use position; 
         FIG. 86  is a side, cross-sectional view of the articulation mechanism of  FIG. 80  shown moving to a locked position; 
         FIG. 87  is a side, cross-sectional view of the articulation mechanism of  FIG. 80  shown in an unlocked position; 
         FIG. 88  is a side, cross-sectional view of the articulation mechanism of  FIG. 80  shown being reset back to the shipping position; 
         FIG. 89  is a rear, perspective cut-away view of yet another articulation mechanism in accordance with the present disclosure; 
         FIG. 90  is a front, perspective cut-away view of the articulation mechanism of  FIG. 89  shown in a shipping position; 
         FIG. 91  is an isolated, perspective view of a shaft and cable plate of the articulation mechanism of  FIG. 89 ; 
         FIG. 92  is an isolated, perspective view of the cable plate of the articulation mechanism of  FIG. 89 ; 
         FIG. 93  is a front, perspective cut-away view of the articulation mechanism of  FIG. 89  transitioning to a use position; 
         FIG. 94  is a rear, perspective cut-away view of the articulation mechanism of  FIG. 89  shown in the use position; 
         FIG. 95  is a rear, perspective cut-away view of the articulation mechanism of  FIG. 89  wherein the shaft has been removed; 
         FIG. 96  is a rear, perspective cut-away view of the articulation mechanism of  FIG. 95  with the shaft in place; 
         FIG. 97  is a side, cross-sectional view of the articulation mechanism of  FIG. 89  shown in the use position; 
         FIG. 98  is a front, perspective view of a handle assembly for housing an articulation mechanism in accordance with yet another embodiment of the present disclosure; 
         FIG. 99  is an enlarged, perspective view of a linkage for use with the articulation mechanism of any of the embodiments above; 
         FIG. 100  is a front, perspective cut-away view of an articulation mechanism for use with the handle assembly of  FIG. 98 ; 
         FIG. 101  is a side, cross-sectional view of a cable tensioning mechanism in accordance with the present disclosure; 
         FIG. 102A  is a rear, perspective view of a cam member of the cable tensioning mechanism of  FIG. 101 ; 
         FIG. 102B  is a rear, perspective view of a pusher of the cable tensioning mechanism of  FIG. 101 ; 
         FIG. 102C  is a rear, perspective view of a ferrule of the cable tensioning mechanism of  FIG. 101 ; 
         FIG. 103  is a rear, perspective cut-away view of the cable tensioning mechanism of  FIG. 101 ; 
         FIG. 104  is a front, perspective view of a cable guide rod for use with any of the surgical devices above; 
         FIG. 105  is a front, perspective view of another embodiment of an articulation linkage for use with the articulating sections of any of the surgical devices above; 
         FIG. 106  is a rear, perspective view of the articulation linkage of  FIG. 105 ; 
         FIG. 107  is a front, perspective view of another embodiment of a proximal-most linkage for use with the articulating sections of any of the surgical devices above; 
         FIG. 108  is a rear, perspective view of the proximal-most articulation linkage of  FIG. 107 ; 
         FIG. 109  is a side, elevational view of an articulation section including a plurality of articulation links as illustrated in  FIG. 105  and a proximal-most link as illustrated in  FIG. 107 ; 
         FIG. 110  is a longitudinal, cross-sectional view of the articulation section of  FIG. 109  taken along section line  110 - 110  of  FIG. 109 ; 
         FIG. 111  is a longitudinal, cross-sectional view of the articulation section of  FIG. 109  shown encased with a sheath; and 
         FIG. 112  is a cross-sectional view of the articulation section of  FIG. 111  shown in an articulated position. 
     
    
    
     DETALIED DESCRITION OF THE EMBODIMENTS 
     Embodiments of the presently disclosed surgical device are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the surgical device, or component thereof, farther from the user, while the term “proximal” refers to that portion of the surgical device, or component thereof, closer to the user. 
       FIG. 1  illustrates an endoscopic surgical device designated with reference number  100 . Surgical device  100  generally includes a handle assembly  300  and an endoscopic assembly  200  extending distally from handle assembly  300 . Handle assembly  300  is configured to move relative to endoscopic assembly  200 . Endoscopic assembly  200  has an elongate configuration and is operatively associated with handle assembly  300 . In some embodiments, handle assembly  300  can be held and operated with only one hand. 
     As seen in  FIGS. 2-6 , endoscopic assembly  200  includes an elongate outer tube  210  having a proximal end  212  and a distal end  214 . Proximal end  212  of elongate outer tube  210  is secured to handle assembly  300 . In the embodiment shown in  FIG. 2 , elongate outer tube  210  has a straight configuration and defines a longitudinal axis “X” therealong; however, elongate outer tube  210  may have a curved configuration. In some embodiments, elongate outer tube  210  is made wholly or partly from a substantially rigid or stiff biocompatible material such as polyetheretherketone (PEEK), titanium alloy, aluminum alloy, stainless steel, cobalt chromium alloy, or any combination thereof. 
     With continued reference to  FIGS. 2-6 , endoscopic assembly  200  further includes an articulating section  230  supported on distal end  214  of elongate outer tube  210 . Articulating section  230  has a proximal end  236  and a distal end  238  and is configured to articulate towards a particular direction with respect to elongate outer tube  210  upon movement of handle assembly  300  towards the same direction with respect to elongate outer tube  210 . 
     Elongate outer tube  210  and articulating section  230  are longitudinally aligned with each other when handle assembly  300  is positioned in a neutral position, as seen in  FIGS. 2 and 4 . When handle assembly  300  is moved relative to elongate outer tube  210  toward one direction, articulating section  230  articulates toward the same direction. For example, an operator can move handle assembly  300  upwardly relative to elongate outer tube  210  to articulate articulating section  230  upwardly relative to elongate outer tube  210 , as depicted in  FIG. 3 . In addition to this upward motion, the operator can move handle assembly  300  laterally with respect to elongate outer tube  210  to articulate articulating section  230  laterally relative to elongate outer tube  210 , as illustrated in  FIG. 5 . Although the drawings merely show upward and lateral movements of articulating section  230 , articulating section  230  has multitude of degrees of motion. Irrespective of the specific degrees of motion, the movement of articulating section  230  relative to elongate outer tube  210  mirrors the motion of handle assembly  300  with respect to elongate outer tube  210 . 
     With reference to  FIGS. 6-8 , endoscopic assembly  200  further includes a tool assembly or end effector  260  operatively coupled to distal end  238  of articulating section  230 . In certain embodiments, articulating section  230  includes a sheath  270  covering at least a portion of articulating section  230 . Sheath  270  is made (wholly or partly) of any suitable flexible material. In some embodiments, sheath  270  is made of a biocompatible polymer. Other embodiments of surgical device  100  do not include sheath  270 . Articulating section  230  additionally includes at least two articulation links  232 ,  234  configured for pivotable movement relative to each other. However, articulating section  230  may include more articulation links. In the depicted embodiment, articulation section  230  includes ten (10) articulation links  232 ,  234 . It is understood that a greater number of articulation links  232 ,  234  provides articulating section  230  with more degrees of articulation. Regardless of the exact number of articulation links  232 ,  234 , articulation links  232 ,  234  allows articulating section  230  to articulate relative to elongate outer tube  210 . In particular, articulating section  230  can move from a first position longitudinally aligned with elongate outer tube  210  to a myriad of positions that are not longitudinally aligned with elongate outer tube  210 . 
     As discussed above, articulating section  230  is operatively associated with end effector  260 . Although the drawings show a specific kind of end effector  260 , it is envisioned that surgical device  100  may include any end effector suitable for engaging tissue. For example, an embodiment of surgical device  100  includes the end effector described in U.S. Patent Application Publication Serial No. 2009/0012520, filed on Sep. 19, 2008, which entire contents are herein incorporated by reference. 
     End effector  260  includes a first jaw member  262  and a second jaw member  264  pivotally coupled to each other. First and second jaw members  262 ,  264  are configured to move from a first or open position to a second or approximated position. In the first position, first and second jaw members  262 ,  264  are spaced apart from each other and can receive tissue between them (see  FIGS. 7 and 8 ). In the second position, first and second jaw members  262 ,  264  are approximated to each other and can grasp or clamp any tissue positioned between them (see  FIG. 31 ). 
     Each of first and second jaw members  262 ,  264  includes a tissue engaging surface  266 ,  268  and a housing  276 ,  278 . Tissue engaging surfaces  266 ,  268  each include teeth  272 ,  274  extending along their lengths. Teeth  272 ,  274  aid in grasping tissue located between first and second jaw members  262 ,  264  when first and second jaw members  262 ,  264  are located in the approximated position. 
     In some embodiments, tissue engaging surfaces  266 ,  268  are made of an electrically conductive material and housings  276 ,  278  are formed of an electrical insulating material. As such, tissue engaging surfaces  266 ,  268  are adapted to receive electrosurgical energy and conduct electrosurgical energy to the tissue grasped between first and second jaw members  262 ,  264 . First and second jaw members  262 ,  264  are electrically isolated from each other and form a bipolar arrangement. This electrical arrangement allows first and second jaw members  262 ,  264  to effectively transfer electrical energy through tissue. In a bipolar arrangement, the electrical current travels from one tissue engaging surface ( 266  or  268 ) to another tissue engaging surface ( 266  or  268 ) through the grasped tissue to complete the circuit. In an alternate embodiment, surgical device  100  has a monopolar electrical arrangement. In this embodiment, end effector  260  transmits electrosurgical energy to the tissue grasped between first and second jaw members  262 ,  264  and this electrosurgical energy passes through the patient&#39;s body until it reaches a patient return electrode (not shown) to complete the circuit. This patient return electrode is electrically coupled to surgical device  100 . The user may control the intensity, frequency and duration of the electrosurgical energy applied to the tissue to cauterize, dissect, coagulate, desiccate, seal, and/or simply reduce or slow bleeding during a medical procedure. The electrosurgical energy received by first and second jaw members  262 ,  264  originates from an electrosurgical generator (not shown) or any other suitable source of electrosurgical energy. In certain embodiments, surgical device  100  is electrically coupled to an electrosurgical generator including a high voltage direct current (HVDC) power supply configured for supplying a DC voltage, an output filter for smoothing the switching of the HVDC into a DC level, and a radio frequency (RF) output stage coupled to the HVDC and configured to convert the DC energy generated by the HVDC into RF energy. In some embodiments, surgical device  100  is electrically coupled to the electrosurgical generator described in U.S. Pat. No. RE40,388, filed on May 8, 2003, the entire contents of which are hereby incorporated by reference. 
     With reference to  FIGS. 9 and 10 , handle assembly  300  is configured to be electromechanically coupled to an electrosurgical generator (not shown) and includes a housing  340  for storing, among other things, at least some parts of an articulation mechanism  330 . As seen in  FIG. 10A , housing  340  includes a first half  340   a  and a second half  340   b  configured to attach to one another. In several embodiments, first and second halves  340   a ,  340   b  may be made of a polymer (or any other suitable material). First and second halves  340   a ,  340   b  collectively form a cup  332  for holding a ball  331  of articulation mechanism  330 . Cup  332  is positioned on a distal end portion  344  ( FIG. 9 ) of handle assembly  300 . Handle assembly  300  further includes a movable thumb loop  301  positioned on a proximal end portion  342  ( FIG. 9 ) thereof. Movable thumb loop  301  is operatively connected to end effector  260  ( FIG. 7 ) and is configured to move upwardly and downwardly relative to housing  340 . In various embodiments, movable thumb loop  301  is pivotally secured to housing  340 . Moving movable thumb loop  301  with respect to housing  340  causes end effector  260  to move between the open position and the approximated position, as discussed in detail below. Movable thumb loop  301  defines an aperture  346  dimensioned to receive a user&#39;s finger. Aperture  346  is located in a proximal end portion  358  of movable thumb loop  301 . At least a distal end portion  360  of movable thumb loop  301  is positioned inside housing  340 . 
     Handle assembly  300  further includes a finger loop  302  defining an opening  348  dimensioned to receive a user&#39;s finger. Finger loop  302  remains stationary relative to housing  340 . Finger loop  302  includes a longitudinal cavity  352  ( FIG. 10A ) for retaining a post  350  adapted to facilitate electromechanical coupling between surgical device  100  and an electrosurgical generator (not shown). Post  350  is partially positioned within finger loop  302  and is made wholly or partly of an electrically conductive material. In one embodiment, an electrical and thermal insulating sheath (not shown) wraps a portion of post  350  located outside of finger loop  302 . This insulating sheath protects the user from the electrical current traveling through post  350  during the operation of surgical device  100 . The portion of post  350  located inside finger loop  302  is electromechanically coupled to an electrical connector  356  made of an electrically conductive material. Electrical connector  356  extends through finger loop  302  into an inner portion of housing  340 . A portion of electrical connector  356  located inside housing  340  is disposed in electromechanical cooperation with an alignment tube  207  made of an electrically conductive material. Alignment tube  207  surrounds a portion of an actuation cable  205  ( FIG. 10A ). In some embodiments, actuation cable  205  is made of an electrically conductive material. In these embodiments, an electrical current traveling through alignment tube  207  can reach actuation cable  205 . 
     A proximal end  250  ( FIG. 10A ) of actuation cable  205  is operatively connected to distal end portion  360  of movable thumb loop  301 . In certain embodiments, distal end portion  360  of movable thumb loop  301  defines a longitudinal recess  362  aligned transversely relative to actuation cable  205 . Longitudinal recess  362  is dimensioned to receive a pin  364 . Pin  364  has a hole  366  longitudinally aligned with actuation cable  205 . Longitudinal hole  366  is adapted to receive proximal end  250  of actuation cable  205 . Ferrule  368  surrounds proximal end  250  of inner shaft  205  and retains proximal end  250  of actuation cable  205  within longitudinal hole  366  of pin  364 . Pin  364  in turn connects proximal end  250  of actuation cable  205  to distal end portion  360  of movable thumb loop  301 . Alignment tube  207  is crimped onto the actuation cable  205  distally of pin  364 . Thus, ferrule  368  and alignment tube  207  sandwich pin  364 , maintaining the axial relationship between actuation cable  205  and pin  364 . Accordingly, when pin  364  is moved, actuation cable  205  moves as well. However, actuation cable  205  is capable of axial rotation in relation to the pin  364 . 
     As seen in  FIGS. 10B and 10C , alignment tube  207  does not have a circular external cross shape. Instead, alignment tube  207  has one or more flat sides. At least one side of alignment tube  207  may have a round profile. The non-circular external cross section of alignment tube  207  corresponds to the internal cross section of the internal passageway  399  extending through proximal elongated portion  386  ( FIGS. 10A, 10D, and 10E ) of rotation wheel  303 . Thus, when the rotation wheel  303  is rotated, alignment tube  207  rotates as well and, because it is crimped to actuation cable  205 , the actuation cable  205  will also rotate. 
     Movable thumb loop  301  is configured to move relative to housing  340  to actuate end effector  260 . In various embodiments, movable thumb loop  301  can pivot toward and away from finger loop  302 . When an operator moves movable thumb loop  301  toward finger loop  302 , actuation cable  205  translates in a proximal direction. As a result of this proximal translation, first and second jaw members  262 ,  264  of end effector  260  move from an open position ( FIG. 20 ) to an approximated position ( FIG. 31 ). Moving movable thumb loop  301  away from finger loop  301 , on the other hand, urges actuation cable  205  in a distal translation. In response to this distal translation, first and second jaw members  262 ,  264  of end effector  260  move from the approximated position ( FIG. 31 ) to the open position ( FIG. 20 ). 
     Handle assembly  300  also includes a rotation wheel  303  mounted on alignment tube  207 . Rotation wheel  303  is configured to rotate relative to housing  340 . Some portions of rotation wheel  303  stick out of housing  340 , allowing an operator to reach rotation wheel  303 . Other portions of rotation wheel  303  are secured within housing  340 . Housing  340  includes a first inner wall  370  and a second inner wall  372  spaced apart from each other. First and second inner walls  370 ,  372  define a gap  374  ( FIG. 10A ) therebetween. Gap  374  is dimensioned to receive at least a portion of rotation wheel  303  and is disposed in communication with a first slot  376  ( FIG. 10A ) of first half  340   a  and a second slot  378  ( FIG. 10A ) of second half  340   b  of housing  340 . At least some portions of rotation wheel  303  exit housing  340  through first and second slots  376 ,  378 , thereby providing access to rotation wheel  303 . Each of first and second inner walls  370 ,  372  defines a recess  382  and  384  ( FIG. 10A ) for holding portions of rotation wheel  303 . Specifically, recess  382  of inner wall  370  supports a proximal elongate portion  386  of rotation wheel  303 . Proximal elongate portion  386  extends proximally from rotation wheel  303  and surrounds at least a portion of alignment tube  207  (see  FIG. 9 ). Recess  384  of second inner wall  372  supports a distal tubular member  388  releasably attached to a distal end of rotation wheel  303 . 
     With reference to  FIGS. 11B and 11C , a torque shaft  499  has a proximal end portion  495  and a distal end portion  497  and, during operation, transfers rotational torque from rotation wheel  303  ( FIG. 11A ) to end effector  260  ( FIG. 8 ). The distal end portion  497  of torque shaft  499  is operatively connected to coupling member  222 , while the proximal end portion  495  of torque shaft  499  is coupled rotation wheel  303  ( FIG. 21 ). Torque shaft  499  includes a proximal torque tube  456 , a proximal torque coil  468 , a distal torque tube  492 , and a distal torque coil  494 . Each component of torque shaft  499  is connected to one another. In certain embodiments, all the components comprising torque shaft  499  are welded together and distal torque coil  494  is welded to coupling member  222 . In some embodiments, proximal torque coil  468  and distal torque coil  494  are each made of three layers of torque coil sold by ASAHI INTECC CO. or equivalents. The different layers of the torque coil have opposite direction winds so that the coil can be rotated in either direction without unwinding. As seen in  FIG. 11C , proximal torque tube  456  includes a diamond knurl patterned section  457  at its proximal end. 
     Referring to  FIG. 11D , rotating rotation wheel  303  causes proximal torque tube  456  to rotate in the same direction. The torque and resulting rotation is then transferred through the other elements of torque shaft  499  to the coupling member  222 , thus rotating the end effector  260  (see  FIG. 23 ). Rotation wheel  303  includes a plurality of undulations  380  positioned around its periphery and four distal extension members  381 . Undulations  380  are ergonomically configured to receive a user&#39;s fingers and facilitate rotation of wheel  303  by the user. Proximal torque tube  456  fits within the four distal extension members  381  with at least a portion of the diamond knurled pattern section  457  contacting the inner surfaces of the four distal extending members  381 . A distal tubular member  388  is placed over the four distal extension members  381 . Distal tubular member  388  defines a longitudinal opening  390  dimensioned for receiving the four distal extension members  381  and includes a flange  392  disposed around a distal end thereof. Longitudinal opening  390  of distal tubular member  388  contacts the external surfaces of the four distal extension members  381 . The internal diameter of the longitudinal opening  390  is such that, when distal tubular member  388  is placed over the four extension members  381  and the proximal torque tube  456 , the four extension members  381  are pressed into the diamond knurled pattern section  457 , creating a press fit. 
     With continued reference to  FIGS. 9 and 10 , articulation mechanism  330  includes an articulation lock trigger  304  positioned distally of rotation wheel  303  and configured for locking the position of articulating section  230  ( FIG. 2 ) relative to elongate outer tube  210 . Articulation lock trigger  304  is operatively coupled to an articulation cable plate  311  and can move relative to housing  340 . In several embodiments, articulation lock trigger  304  can pivot with respect to housing  340  between a first or unlocked position and a second or locked position. When an operator moves articulation lock trigger  304  from the unlocked position toward the locked position, articulation cable plate  311  moves proximally with respect to housing  340  to lock the position of articulating section  230  with respect to elongate outer tube  210 , as discussed in detail below. In the depicted embodiment, articulation lock trigger  304  defines a detent recess  398  positioned on a proximal surface therefore and adapted to receive a detent  394  of articulation cable plate  311 . Detent  394  of articulation cable plate  311  engages detent recess  398  when articulation lock trigger  304  is located in the locked position. Articulation lock trigger  304  also include at least one tab  396  positioned within housing  340 . In some embodiments, articulation lock trigger  304  includes two tabs  396  located on opposite sides of articulation lock trigger  304 . 
     Referring to  FIGS. 11 and 12 , articulation mechanism  330  includes an articulation lock ring  400  partially surrounding articulation lock plate  311 . Articulation lock ring  400  defines an opening  404  ( FIG. 11A ) dimensioned to receive articulation lock plate  311  and includes a plurality of locking fingers  402  extending proximally therefrom. Locking fingers  402  are positioned around a periphery of articulation lock ring  400  and may be (wholly or partly) made of a resilient material. Articulation lock ring  400  is positioned inside cup  332  of housing  340  ( FIG. 9 ) and includes two lateral slots  406  ( FIG. 11A ) disposed in a diametrically opposed relation to each other. Each lateral slot  406  is adapted to receive an extension member  408  of ball  331 . In some embodiments, ball  331  includes two extension members  408  disposed in diametrically opposed relation to each other. Each extension member  408  extends proximally from ball  331 . When extension members  408  of ball  331  engage slots  406  of articulation lock ring  400 , ball  331  is precluded, or at least hindered, from rotating relative to articulation lock ring  400 . Ball  331  further includes snap-fit detents  410 , or any other apparatus, mechanism, or means suitable for facilitating secure engagement between the ball  331  and articulation lock ring  400 . Snap-fit detents  410  are configured to securely engage engagement walls  412  located around an inner surface of articulation lock ring  400  and between fingers  402 . 
     As shown in  FIG. 11A , articulation lock ring  400  partially surrounds an articulation cable plate  311 . Articulation cable plate  311  has an elongate portion  414  and a cable engaging portion  416 . Elongate portion  414  of articulation cable plate  311  has a proximal end  418  and a distal end  420  and defines an opening  422  at proximal end  418  and a bore  424  extending therethrough. Opening  422  leads to bore  424  and is dimensioned to receive proximal torque tube  456  ( FIG. 12 ). Bore  424  is also dimensioned to receive elongate section  458  of annular hub  310  ( FIG. 10A ). 
     With continued reference to  FIG. 12 , cable engaging portion  416  of articulation cable plate  311  is coupled to a distal end  420  of elongate portion  414  and defines an inner cavity  426 . In some embodiments, cable engaging portion  416  has a frusto-conical shape. Inner cavity  426  is disposed in communication with bore  424 . Additionally, cable engaging portion  416  includes a proximal section  428  connected to elongate portion  414  and a distal section  430  defining a plurality of channels  432 . Channels  432  are positioned around the perimeter of distal section  430  of cable engaging portion  416  and each is configured to accommodate an articulation cable  240  ( FIG. 11A ) and a ferrule or crimp  242  ( FIG. 11A ). 
     Returning to  FIG. 12 , articulation mechanism  330  includes one or more articulation cables  240  operatively coupled to articulation cable plate  311 . In the depicted embodiment, four articulation cables  240  are operatively connected to articulation cable plate  311 . A ferrule  242  retains each of the four articulation cables  240  in articulation cable plate  311 . Specifically, a ferrule  242  is positioned in a channel  432  of articulation cable plate  311  which surrounds and holds a portion of an articulation cable  240 , thereby maintaining articulation cable  240  connected to articulation cable plate  311 . 
     With reference to  FIGS. 13-15 , articulation cables  240  are operatively coupled to articulating section  230  (see also  FIG. 20 ). Articulating section  230  includes a plurality of articulation links  232 ,  234  (see also  FIG. 11A ), a distal outer tube  220 , and a coupling member  222 . In certain embodiments, coupling member  22  is a knuckle coupler. Each articulation link  232 ,  234  defines at least one bore  224  adapted to receive an articulation cable  240  ( FIG. 15 ) and a central opening  226  adapted to receive distal torque tube  492  ( FIG. 20 ). In the depicted embodiment, each articulation link  232 ,  234  includes four bores  224  located around central opening  226 . Articulation links  232 ,  234  further include extension members  228  extending distally therefrom and recesses  244  ( FIG. 14 ) for receiving extension members  228 . Recesses  244  are positioned on a proximal surface  246  of each articulation link  232 ,  234 . Proximal surfaces  246  of articulation links  232 ,  234  each have a contoured profile. The contoured profile of proximal surfaces  246  is configured to mate with the contoured profile of distal surfaces  248  of articulation links  232 ,  234 . Although proximal surfaces  246  and distal surfaces  248  mate with each other, the contoured profile of these surfaces  246 ,  248  provide articulation links  232 ,  234  certain degree of motion relative to each other. In addition, articulation links  232 ,  234 , albeit substantially similar, have different orientations with respect to each other. In some embodiments, articulation link  232  is oriented about 90 degrees relative to articulation link  234 , as shown in  FIG. 13 . 
     With continued reference to  FIGS. 13-15 , distal outer tube  220  has a proximal surface  254  contoured to mate with distal surface  248  of either articulation link  232  or  234  while permitting movement of the adjacent articulation link  232  or  234  relative to distal outer tube  220 . Recesses  282  are defined on proximal surface  254  and each is configured to receive an extension member  228  of articulation links  232 ,  234 . Proximal surface  254  of distal outer tube  220  further defines one or more holes  258  dimensioned to receive articulation cables  240 . In the depicted embodiment, distal outer tube  220  has four holes  258 . It is envisioned, however, that distal outer tube  220  may have more or fewer holes  258 . Moreover, distal outer tube  220  defines a central opening  256  adapted to receive at least a portion of coupling member  222  and at least one channel  284  for holding a portion of an articulation cable  240  within distal outer tube  220 . In some embodiments, distal outer tube  220  includes four channels  284  disposed around an inner surface of distal outer tube  220 . In addition, distal outer tube  220  include two retaining wall  286  positioned on opposite sides of each channel  284  to retain an articulation cable  240  in channel  284 . (See also  FIG. 15 ). 
     With continued reference to  FIGS. 13-15 , coupling member  222  includes two legs  288  defining a space therebetween and a proximal projection  292 . Each leg  288  of coupling member  222  includes a transverse opening  298  and a longitudinal track  202  disposed along an inner surface thereof. Proximal projection  292  of coupling member  222  defines an annular recess  296  adapted to receive a seal or band  294 . In the illustrated embodiment, band or seal  294  has a substantially C-shaped. Band  294  aids in securing coupling member  222  to distal outer tube  220  when band  294  is placed in recess  296  and proximal projection  292  is positioned inside distal outer tube  220 . When projection  292  is placed within distal outer tube  220 , portions of band  294  stick out through circumferential slots  221  of distal outer tube  220 , securing coupling member  222  to distal outer tube  220 . Distal outer tube  220  may have one or more circumferential slots  221 . In the depicted embodiment, distal outer tube  220  has four circumferential slots  221  positioned around a periphery thereof. 
     Referring to  FIG. 16 , articulation cables  240  are operatively coupled to articulation lock trigger  304 . In some embodiments, articulation lock trigger  304  includes two tabs  396  located on opposite sides of articulation lock trigger  304 , as discussed above. Articulation lock trigger  304  can move relative to housing  340  between a locked position and an unlocked position, as discussed in detail below. Additionally, in some embodiments, as will be discussed in detail below (see  FIGS. 65A-68B ), articulation lock trigger  304  may initially be disposed in a “shipping” configuration wherein articulation cables  240   A ,  240   B ,  240   C ,  240   D  are substantially un-tensioned. Upon the initial actuation of articulation lock trigger  304 , articulation lock trigger  304  is permanently moved into a “use” configuration, wherein the articulation lock trigger  304  may be moved between the locked and unlocked positions. When articulation lock trigger  304  is placed in the locked position, articulation mechanism  330  ( FIG. 9 ) fixes the position of articulation cables  240 , thus precluding, or at least inhibiting, articulation of articulating section  230  relative to longitudinal axis “X.” (See  FIG. 2 ). Conversely, when articulation lock trigger  304  is placed in the unlocked position ( FIG. 16 ), articulation mechanism  330  ( FIG. 9 ) allows articulating section  230  to articulate relative to longitudinal axis “X.” (See  FIG. 2 ). In the unlocked position, tabs  396  of articulation lock trigger  304  seat on internal ribs  322  of housing  340 , thereby holding articulation lock trigger  304  in the unlocked position. 
     As seen in  FIGS. 17-19 , an embodiment of surgical device  100  includes four (4) articulation cables  240   A ,  240   B ,  240   C ,  240   D . Each articulation cable  240   A ,  240   B ,  240   C ,  240   D  extends from articulation cable plate  311  to articulating section  230 . While extending through surgical device  100 , articulation cables  240   A ,  240   B ,  240   C ,  240   D  change their position 180 degrees (see  FIGS. 18 and 19 ), allowing articulating section  230  to articulate in the same direction as handle assembly  300 . 
     With reference to  FIG. 20 , articulating section  230  is operatively coupled to end effector  260 . Actuation cable  205  extends through articulating section  230  and is connected to end effector  260 . A distal torque coil  494  surrounds a portion of actuation cable  205  extending through articulating section  230 . In one embodiment, distal torque coil  494  is a SUS304 or SUS316 grade stainless steel torque coil sold by ASAHI INTECC CO., LTD. Distal end  252  of actuation cable  205  is operatively coupled to end effector  260 . In some embodiments, a coupling  436  connects distal end  252  of actuation cable  205  to end effector  260  (see also  FIG. 11A ). Coupling  436  defines a transverse hole  438  dimensioned to receive a pin  440 . In these embodiments, pin  440  passes through hole  438  and cam slots  442 ,  444  of first and second jaw members  262 ,  264 , thereby pivotally coupling actuation cable  205  to end effector  260 . First jaw member  262  has a cam slot  444  located at a proximal portion  265  thereof. Cam slot  444  defines an oblique angle relative to actuation cable  205 . Second jaw member  264  has a cam slot  442  located at a proximal portion thereof  263 . Cam slot  442  defines an angle with respect to actuation cable  205 . Pin  440  is slidably positioned in cam slots  442 ,  442 . As a consequence, first and second jaw members  262 ,  264  move between open and approximated positions upon longitudinal translation of actuation cable  205 . As discussed in detail below, an operator can move first and second jaw members  262 ,  264  from the open position to the approximated position by moving movable thumb loop  301  toward finger loop  302  (see  FIG. 17 ). As movable thumb loop  301  moves toward finger loop  302 , actuation cable  205  translates proximally to urge pin  440  in a proximal direction. When pin  440  is urged proximally, pin  440  slides along cam slots  442 ,  440 , causing first and second jaw members  262 ,  264  to move toward each other. 
     With continued reference to  FIG. 20 , first and second jaw members  262 ,  264  are pivotally coupled to each other. In certain embodiments, a pivot pin  446  pivotally interconnects first and second jaw members  262 ,  264 . First jaw member  262  defines an opening  448  ( FIG. 11A ) dimensioned to receive pivot pin  446 . Second jaw member  264  defines an opening  450  ( FIG. 11A ) dimensioned to receive pivot pin  446 . As seen in  FIGS. 13 and 14 , coupling member  222  has a pair of traverse openings  298  configured to receive pivot pin  446  ( FIG. 20 ). Longitudinal tracks  202  engage pivot pin  446  and guide the translation of pivot pin  446  during actuation of end effector  260 . 
       FIG. 20  shows (in phantom) articulation cables  240  secured within distal outer tube  220  of articulating section  230 . Articulation cables  240  pass through bores  224  ( FIG. 13 ) of articulation links  232 ,  234  until reaching distal outer tube  220 . In some embodiments, a ferrule or crimp  452  is attached to the distal end  454  of each articulation cable  240 . (See also  FIGS. 11 and 15 ). Ferrules  452  (shown in phantom) help retain distal ends  454  of articulation cables  240  within distal outer tube  220 . As discussed above, distal outer tube  220  is operatively coupled with an articulation link  234 . Articulation links  232 ,  234  are operatively coupled to each other. Such connection allows articulating section  230  to articulate relative to longitudinal axis “X” ( FIG. 2 ). It is envisioned that the degrees of motion of articulating section  230  is directly proportional to the number of articulation links  232 ,  234 . Articulating section  230  includes a most-proximal link  496 . Most-proximal articulation link  496  is substantially similar to articulation links  232 ,  234 . However, most-proximal articulation link  496  includes an extension  498  protruding proximally. Extension  498  is adapted to be securely received within distal end  214  of endoscopy assembly  200 . 
     Referring to  FIG. 21 , actuation cable  205  is operatively connected to movable thumb loop  301 . Alignment tube  207  surrounds a portion of actuation cable  205  extending from movable thumb loop  301  to rotation wheel  303 . Handle assembly  300  further includes a proximal torque tube  456  surrounding a portion of actuation cable  205  extending from rotation wheel  303  to articulation cable plate  311  (see also  FIG. 11A ). Proximal torque tube  456  is partially positioned within an annular hub  310 . Annular hub  310  is partially positioned inside articulation cable plate  311  and includes an elongate section  458  and a cable holding section  460 . Elongate section  458  of annular hub  310  is at least partially positioned within elongate portion  414  of articulation cable plate  311  and defines a bore  462  dimensioned to receive actuation cable  205  and proximal torque tube  456 . Cable holding section  460  includes a plurality of recesses  464  ( FIG. 11A ) configured to accommodate articulation cables  240  and an cavity  466  leading to bore  462  of elongate section  458 . Another proximal torque coil  468  is partially positioned in cavity  466  and surrounds a portion of actuation cable  205  extending from elongate section  458  to cable holding portion  460  of annular hub  310  (see also  FIG. 11A ). In certain embodiments, proximal torque coil  468  is made of a flexible material. In several embodiments, proximal torque coil  468  is (wholly or partly) made of a shape-memory material such Nickel Titanium Alloy. In some embodiments, proximal torque coil  468  is made (wholly or partly) of a stainless steel torque coil sold by ASAHI INTECC CO., LTD. Cable holding section  460  further includes an elastic wall  476  covering cavity  466 . Elastic wall  476  has a slit  478  ( FIG. 11A ) that allows passage of proximal torque coil  468  through elastic wall  476 . Articulation lock ring  400  encircles at least a portion of annular hub  310 . As discussed above, articulation lock ring  400  includes a plurality of locking fingers  402 . Each locking finger  402  includes a detent  470  for engaging an inner surface  472  of cup  332 . As explained below, inner surface  472  of cup  332  defines a plurality of cavities  474  ( FIG. 26 ) each adapted to retain a detent  470 . When detents  474  are placed in cavities  474 , end effector  260  ( FIG. 11A ) is maintained in the neutral position. 
     In an alternate embodiment, rotating wheel  303  in a first direction causes actuation cable  205  to rotate in the same direction, as indicated by arrows “A”. Upon rotation of actuation cable  205  in the first direction, end effector  260  rotates in the same direction, as indicated by arrows “B.” For example, a clockwise rotation of rotation wheel  303  with respect to housing  340  causes end effector  260  to rotation in a clockwise direction as well. 
     With reference to  FIGS. 24 and 25 , articulation cables  240  are connected to articulation cable plate  311  through ferrules  242 . Ferrules  242  are positioned in channels  432  ( FIG. 25 ) of articulation cable plate  311 . As a result, articulation cables  240  extend distally from channels  432  of articulation cable plate  311 . Channels  432  are aligned with openings  480  ( FIG. 25 ) defined around the perimeter of cable holding section  460 . Each opening  480  leads to a recess  464  ( FIG. 25 ) of cable holding section  460 . Accordingly, each articulation cable  240  passes through a channel  432 , an opening  480 , and a recess  464 . In certain embodiments, recesses  464  have a triangular profile. Articulation cables  240  also pass through ball  331  and endoscopic assembly  200 , as shown in  FIG. 24 . 
     With continued reference to  FIG. 24 , ball  331  includes a distal tube  482  extending distally therefrom. Distal tube  482  defines a bore  484  dimensioned to receive a portion of elongate outer tube  210  and a portion of an elongate inner tube  486  of endoscopic assembly  200 . Elongate outer tube  210  defines a bore  488  ( FIG. 11A ) configured to receive elongate inner tube  486 . In turn, elongate inner tube  486  defines a bore  490  adapted to receive actuation cable  205 , articulation cables  240 , and a distal torque tube  492 . Distal torque tube  492  surrounds a portion of actuation cable  205  extending from ball  331  to distal end  214  of endoscopic assembly  200  (see  FIG. 20 ). 
     Referring to  FIGS. 26 and 27 , surgical device  100  allows an operator to articulate articulating section  230  relative to longitudinal axis “X” ( FIG. 2 ) with only one hand. In use, the operator grabs handle assembly  300  with one hand. For example, the operator may place the thumb in movable thumb loop  301  ( FIG. 9 ) and some of the other fingers in finger loop  302  ( FIG. 9 ). Once the operator has grabbed handle assembly  300 , the operator moves the wrist to articulate handle assembly  300  relative to elongate outer tube  210  and ball  331 . The operator may articulate handle assembly in any direction.  FIG. 26 , for example, shows handle assembly  300  articulated upwardly with respect to the elongate outer tube  210  (see also  FIG. 3 ). Handle assembly  300 , however, may be articulated downwardly or laterally, as shown in  FIG. 5 . Regardless of the articulation direction, articulating handle assembly  300  with respect to elongate outer tube  210  causes the articulation of articulating section  230 , as seen in  FIGS. 3 and 5 . Articulating section  230  mirrors the movement of handle assembly  300  and articulates relative to elongate outer tube  210  in the same direction as handle assembly  300 . 
     For instance, when the operator articulates handle assembly  300  upwardly with respect to elongate outer tube  210 , one articulation cable  240   D  moves proximally while another articulation cable  240   C  moves distally. As a results, articulation cable  240   D  tightens, while articulation cable  240   C  slacks. In particular, articulation cable plate  311  moves along with handle assembly  300  upon articulation of handle assembly  300  while ball  331  remains stationary relative to elongate outer tube  210 . Since articulation cable plate  311  is attached to articulation cables  240 , moving articulation cable plate  311  causes articulation cables  240  to move. When articulation cable plate  311  is slanted upwardly relative to ball  331 , an articulation cable  240   C  move distally, while articulation cable  240   D  moves proximally, as depicted in  FIG. 26 . 
     As seen in  FIG. 27 , the combination of a proximal motion by one articulation cable  240   D  and the distal motion by articulation cable  240   C  causes articulating section  230  to articulate upwardly relative to longitudinal axis “X” ( FIG. 2 ). As explained above, articulation cables  240   C ,  240   D  change positions along elongate outer tube  210 . (See  FIGS. 18 and 19 ). Although articulation cable  240   C  is positioned above articulation cable  240   D  at the proximal end  212  ( FIG. 2 ) of elongate outer tube  210 , articulation cables  240   C ,  240   D  switch positions at some point along elongate outer tube  210 . As a result, articulation cable  240 C is positioned below articulation cable  240 D at the distal end  214  ( FIG. 2 ) of elongate outer tube  210  and in articulating section  230  ( FIG. 27 ). Therefore, a distal translation of articulation cable  240   C  allows articulation cable  240   C  to slack, thereby loosening a lower portion of articulating section  230 . Conversely, a proximal translation of articulation cable  240   D  causes tightening on articulation cable  240 D, compressing an upper portion articulating section  230 . As a result of the compression of an upper portion of articulating section  230 , articulating section  230  articulates upwardly relative to longitudinal axis “X” ( FIG. 2 ). The operator may similarly articulate articulating section  230  downwardly or laterally by moving handle assembly  300  with respect to longitudinal axis “X” ( FIG. 2 ). Upon movement of handle assembly  300  with respect to longitudinal axis “X,” articulating section  230  articulates in the same direction as handle assembly  300 . 
     Referring to  FIGS. 28 and 29 , the operator can fix the position of articulating section  230  by actuating articulation lock trigger  304 . To actuate articulation lock trigger  304 , the operator moves articulation lock trigger  304  toward rotation wheel  303 , as shown in  FIG. 28 . Upon actuation of articulation lock trigger  304 , detent recess  398  engages detent  394  of articulation cable plate  311 , urging articulation cable plate  311  in a proximal direction. As articulation cable plate  311  moves proximally, cable engaging portion  416  of pushes fingers  402  of articulation lock ring  400  outwardly toward inner surface  472  of cup  332 . When fingers  402  flex outwardly, detents  470  of fingers  402  frictionally engage inner surface  472  of cup  322 , thereby locking the position of handle assembly  300  with respect to elongate outer tube  210  and ball  331 . In addition, the proximal translation of articulation cable plate  311  causes all articulation cables  240  to move proximally. As a consequence of this proximal motion, all articulation cables  240  are tightened, compressing articulation links  232 ,  234  together. Therefore, the compressed articulation links  232 ,  234  fix the position of articulating section  230  ( FIG. 27 ) relative to elongate outer tube  210 . 
     With reference to  FIGS. 30 and 31 , the operator can move first and second jaw members  262 ,  264  between an open position ( FIG. 27 ) and an approximated position ( FIG. 31 ) by actuation of movable thumb loop  301 . To actuate end effector  260 , the operator moves movable thumb loop  301  toward finger loop  302 , as shown in  FIG. 30 . Since distal end portion  360  of movable thumb loop  301  is operatively connected to actuation cable  205 , the actuation of movable thumb loop  301  causes the proximal translation of actuation cable  205 . As actuation cable  205  moves proximally, coupling member  436 , which interconnects end effector  260  and actuation cable  205 , urges pin  440  proximally. The proximal motion of pin  440  along cam slots  442 ,  444  urges first and second jaw members  262 ,  264  toward each other. An operator may initial place tissue between first and second jaw members  262 ,  264  while end effector  260  is in the open position and then move first and second jaw members  262 ,  264  to the approximated position to clamp the tissue. 
       FIGS. 32 and 33  show an embodiment of surgical device  100  substantially similar to the embodiments depicted in  FIGS. 1-4 , except for end effector  1260 . End effector  1260  includes first and second shearing blades  1262 ,  1264  configured to mechanically or electromechanically cut tissue. First and second shearing blades  1262 ,  1264  are electrically isolated from one another and are adapted to move between an open position and an approximated position. 
     With reference to  FIGS. 34 and 35 , although coupling member  222  connects articulating section  230  to end effector  1260 , end effector  1260  additionally includes a clevis coupler  1500 . Clevis coupler  1500  is attached to actuation cable  205  and includes two legs  1538 ,  1540  extending distally therefrom. First and second legs  1538 ,  1540  define a space therebetween dimensioned to receive proximal portions  1572 ,  1574  of first and second shearing blades  1262 ,  1264 . Each leg  1538 ,  1540  defines a hole  1548 ,  1550  adapted to receive a pin  1580 . Pin  1580  is also configured to be slidably received in cam slots  1442 ,  1444  of first and second shearing blades  1262 ,  1264 . Cam slot  1442  is defined along a proximal portion  1572  of shearing blade  1262 , whereas cam slot  1444  is defined along a proximal portion  1574  of shearing blade  1264 . A disk made  1600  of electrically insulating material electrically isolates shearing blades  1262 ,  1264  from each other. As seen in  FIG. 34 , disk  1600  is positioned between first and second shearing blades  1262 ,  1264  and defines a hole  1602  configured to receive pin  1580 . 
       FIGS. 37 and 38  depict another embodiment of surgical device  100 . The structure and operation of this embodiment is substantially similar to the embodiment shown in  FIGS. 1-5 . This embodiment of surgical device  100  includes an end effector  2260  configured for grasping tissue. End effector  2260  includes first and second grasping forceps  2262 ,  2264  configured to grasp tissue. Although the drawings of this embodiment show surgical device  100  without a post  350  ( FIG. 10A ), this embodiment of surgical device  100  may include a post  350  for electrically coupling end effector  2226  to a generator. First and second grasping forceps  2262 ,  2264  are configured to move between an open position and an approximated position. Each of the first and second grasping forceps  2262 ,  2264  includes a tissue engaging surface  2266 ,  2268 . Both tissue engaging surfaces  2266 ,  2268  includes a plurality of teeth  2272 ,  2274  for engaging tissue. 
     With reference to  FIGS. 38 and 39 , first and second grasping forceps  2262 ,  2664  are pivotally connected to each other by pivot pin  446 . End effector  2260  is operatively coupled to actuation cable  205  through coupling  436  and pin  440 . Each of the first and second grasping forceps  2262 ,  2264  includes cam slots  2442 ,  2444  adapted for slidably receiving pin  440 . Such connection allows first and second grasping forceps  2262 ,  2264  to move to the approximated position upon a proximal motion of actuation cable  205 . 
     Referring to  FIGS. 40-43 , any of the embodiments of surgical device  100  may include a locking mechanism  3000  for fixing the relative position of first and second jaw members  262 ,  264 . As discussed above, movable thumb loop  301  is operatively coupled to first and second jaw members  262 ,  264 . In operation, pivoting movable thumb loop  301  toward finger loop  301  causes first and second jaw members  262 ,  264  to move from the open position and the approximated position. (See  FIGS. 30 and 31 ). Thus, maintaining movable thumb loop  301  close to finger loop  302  would keep first and second jaw members  262 ,  264  in the approximated position. In use, locking mechanism  3000  can maintain thumb loop  301  close to finger loop  302  to fix first and second jaw members  262 ,  264  in the approximated position. In some embodiments, locking mechanism  3000  includes a first ratchet assembly  3002  attached to the movable thumb loop  301 . Specifically, first ratchet assembly  3002  is attached to the lateral wall of a portion of movable thumb loop located inside handle assembly  300 . First ratchet assembly  3002  includes a curved column  3004  and a plurality of teeth  3006  extending proximally from curved column  3004 . Each tooth  3006  is angled upwardly relative to movable thumb loop  301 . 
     Locking mechanism  3000  further includes biasing member  3008 , such as a spring, secured to a portion of movable thumb loop  301  located within handle assembly  300  and operatively coupled to a release assembly  3010 . Biasing member  3008  biases release assembly  3010  in a distal direction. In the depicted embodiment, biasing member  3008  is a torsion spring. It is contemplated, however, that biasing member  3008  may be any apparatus or means suitable for biasing release assembly  3010  distally. 
     Release assembly  3010  includes a trigger  3012  adapted to receive a finger, an elongate section  3014  extending proximally from trigger  3012 , a second ratchet assembly  3016  configured to securely engage first ratchet assembly  3002 , and a guiding bar  3018  protruding from a lower portion of elongate section  3014 . 
     Guiding bar  3018  has camming surfaces  3020  and transverse pin  3022  disposed at a proximal end  3024  thereof. Camming surfaces  3020  are configured to slidably engage projections  3026 ,  3028  of handle assembly  300  ( FIGS. 42 and 43 ) to guide the translation of release assembly  3010  through handle assembly  300 . Transverse pin  3022  is configured to engage a mechanical stop  3030  disposed inside handle assembly  300  to prevent, or at least inhibit, further proximal advancement of release assembly  3010 . 
     Turning momentarily to  FIGS. 62-64 , a locking mechanism  3100  according to another embodiment of the present disclosure is shown. Locking mechanism  3100  includes a release assembly  3110  having a trigger  3112 , an elongate section  3114 , a second ratchet assembly  3116  configured to engage the first ratchet assembly (see  FIGS. 42-43 ) and a guiding bar  3118  extending from elongate section  3114 . Guiding bar  3118  includes a proximal portion  3119  extending from elongate section  3114 , a longitudinally extending portion  3120  and a distal portion  3121  extending from proximal portion  3119 . The distal portion  3121  of guiding bar  3118  includes a transverse pin  3122  that is configured and dimensioned to cam along and engage a stop member  3130  during translation of guiding bar  3118  between the locked and the unlocked position. 
     Longitudinally extending portion  3120  remains substantially parallel to elongate section  3114  when locking mechanism  3100  is in the locked position ( FIG. 62 ) and when locking mechanism  3100  is in the unlocked position ( FIG. 63 ). This substantially parallel configuration of longitudinally extending portion  3120  corresponds to an un-stressed position of guiding bar  3118 . Alternatively, longitudinally extending section  3120  of guiding bar  3118  may be configured such that longitudinally extending section  3120  is disposed at a predetermined angle with respect to elongate section  3114  in both the locked and the unlocked position so long as the predetermined angle corresponds to an un-stressed state of guiding bar  3118 . In other words, the configuration of release assembly  3110  and stop member  3130  allow guiding bar  3118  to be maintained in an un-stressed state in both the locked and the unlocked position. As can be appreciated, with guiding bar  3118  in an un-stressed state in both of the stable positions, i.e., the locked position and the unlocked position, the flexibility, resiliency, and durability of guiding bar  3118  is not affected by prolonged disposition of locking mechanism  3100  in either the locked or the unlocked position. 
     As discussed above, both embodiments of the release assembly, e.g., release assembly  3010  ( FIGS. 40-43 ) and release assembly  3100  ( FIGS. 62-64 ), include a second ratchet assembly  3016 ,  3116  configured to engage first ratchet assembly  3002 . Second ratchet assembly  3016 ,  3116  includes a wall  3032 ,  3132  extending proximally from elongate section  3014 ,  3114  and a curved column  3034 ,  3134  positioned along a proximal end  3038 ,  3138  of wall  3032 ,  3132 . A plurality of teeth  3036 ,  3136  protrude distally from at least a portion of curved column  3034 ,  3134 . Teeth  3036 ,  3136  are adapted to securely engage teeth  3006  of first ratchet assembly  3002 . In some embodiments, teeth  3036 ,  3136  are angled downwardly with respect to movable thumb loop  301 . When teeth  3036 ,  3136  of second ratchet assembly  3016 ,  3116  engage teeth  3006  of first ratchet assembly  3002 , the position of movable thumb loop  301  is fixed relative to finger loop  302 . (See  FIG. 42 ). 
     In operation, an operator can utilize the locking mechanism  3000 ,  3100  to fix the relative position of first and second jaw members  262 ,  264  ( FIG. 31 ). Initially, the locking mechanism  3000 ,  3100  is in the locked position (see  FIGS. 42, 62 ), such that at least a portion of teeth  3006  of first ratchet  3002  are engaged with at least a portion of teeth  3036 ,  3136  of second ratchet  3016 ,  3116 . As the operator moves movable thumb loop  301  toward finger loop  302 , to move first and second jaw members  262 ,  264  ( FIG. 31 ) toward the approximated position, teeth  3006  of first ratchet assembly  3002  further engage teeth  3036 ,  3016  of second ratchet assembly  3016 ,  3116 . 
     The orientation of teeth  3006  and teeth  3036 ,  3136  precludes, or at least hinders, movable thumb loop  301  from moving away from finger loop  302  while allowing movable thumb loop  301  to move further toward finger loop  302 . In other words, teeth  3006  of first ratchet assembly  3002  and teeth  3036 ,  3136  of second ratchet assembly  3016 ,  3116  are configured as a one-way ratchet. Accordingly, the locking mechanism  3000 ,  3100 , when in the locked position, may be used to incrementally fix the position of movable thumb loop  301  relative to finger loop  302 , as shown in  FIG. 42 . Since movable thumb loop  301  is operatively connected to first and second jaw members  262 ,  264  ( FIG. 31 ), the relative position of first and second jaw members  262 ,  264  is incrementally fixed when locking mechanism  3000 ,  3100  fixes the position of movable thumb loop  301  with respect to finger loop  302 . As can be appreciated, the operator may further advance movable thumb loop  301  toward finger loop  302  until first and second jaw members  262 ,  264  ( FIG. 31 ) reach the approximated position. At this point, the locking mechanism  3000 ,  3100  operates to fix the first and second jaw members  262 ,  264  ( FIG. 31 ) in the approximated position. 
     To release movable thumb loop  301 , the operator presses the trigger  3012 ,  3112  proximally against the influence of biasing member  3008 ,  3108 . When trigger  3012 ,  3112  moves proximally, elongate section  3014 ,  3114  and guiding bar  3018 ,  3118  are translated proximally. Simultaneously, teeth  3036 ,  3136  of second ratchet assembly  3016 ,  3116  are moved proximally, disengaging teeth  3002  of first ratchet assembly  3002 . Consequently, movable thumb loop  301  moves away from finger loop  302  under the influence of biasing member  3008 ,  3108  thereby moving first and second jaw members  262 ,  264  toward the open position, as shown in  FIG. 43 . (See also  FIG. 20 ). 
     Upon further pressing of trigger  3012 ,  3112 , guiding bar  3018 ,  3118  is translated proximally such that transverse pin  3022 ,  3122  cams along a surface of stop member  3030 ,  3130  (see  FIG. 43 ) and around lower flange  3133  ( FIGS. 62-64 ). Upon release of trigger  3012 ,  3112 , due to the configuration of stop member  3030 ,  3130 , transverse pin  3022 ,  3122  is pulled distally under the bias of biasing member  3008 ,  3108  into groove  3135  (see  FIG. 63 ). More specifically, the engagement of transverse pin  3022 ,  3122  within groove  3135  of stop member  3130  prevents guiding bar  3018 ,  3118  from returning fully distally under the bias of biasing member  3008 ,  3108  to the locked position. Groove  3135  of stop member  3130  retains guiding bar  3018 ,  3118  in a proximal, or unlocked position wherein teeth  3036 ,  3136  of second ratchet  3016 ,  3116  are spaced apart, or disengaged, from teeth  3006  of first ratchet  3002 . When locking mechanism  3000 ,  3100  is in this unlocked position, moveable thumb loop  301  may still be moved toward finger loop  302  to move first and second jaw members  262 ,  264  ( FIG. 31 ) toward the approximated position. However, since the teeth  3036 ,  3136  of second ratchet  3016 ,  3116  and teeth  3006  of first ratchet  3002  are disengaged in the unlocked position, the position of the moveable thumb loop  301 , and thus the relative position of the first and second jaw members  262 ,  264  ( FIG. 31 ), is not incrementally fixed by the locking mechanism  3000 ,  3100 . 
     As mentioned above, and as shown in  FIG. 63 , guiding bar  3118  is in an un-stressed position when transverse pin  3122  is engaged within groove  3135  of stop member  3130 . More specifically, groove  3135  of stop member  3130  is dimensioned and positioned such that distal portion  3121  of guiding bar  3118  is not deflected (either upwardly or downwardly) when transverse pin  3122  is engaged within groove  3135 . In other words, guiding bar  3118  is maintained at a fixed angle, or position, e.g., substantially parallel, with respect to elongate section  3114 , when in the locked position and in the unlocked position. Maintaining guiding bar  3118  in an un-stressed state maintains the resiliency and durability of guiding bar  3118 , allowing transverse pin  3122  to accurately and consistently cam along stop member  3130  and over lower flange  3133  into groove  3135  and from groove  3135  over upper flange  3137 , as is required during repeated locking and unlocking of the locking mechanism  3100 . 
     In order to re-lock the locking mechanism  3000 ,  3100  trigger  3012 ,  3112  is once again pressed. As trigger  3012 ,  3112  is once again pressed, guiding bar  3018 ,  3118  is translated proximally from the unlocked position ( FIG. 63 ) toward the locked position ( FIG. 64 ). More specifically, transverse pin  3022 ,  3122  is translated proximally from groove  3135  of stop member  3130  and around upper flange  3137  ( FIG. 64 ). The translation of transverse pin  3022 ,  3122  around upper flange  3137  releases, or frees transverse pin  3022 ,  3122  from groove  3135  of stop member  3130 . Accordingly, upon release of trigger  3012 ,  3112 , transverse pin  3022 ,  3122  and thus guiding bar  3018 ,  3118  are returned to the proximal, or locked position ( FIG. 62 ) under the bias of biasing member  3008 ,  3108 . Simultaneously, teeth  3036 ,  3136  of second ratchet assembly  3016 ,  3116  are brought into engagement with teeth  3006  of first ratchet assembly  3002 . Thus, with the locking mechanism  3000 ,  3100  back in the locked position, the relative position of first and second jaw members  262 ,  264  ( FIG. 31 ) may once again be fixed. 
       FIGS. 44-46  show another embodiment of surgical device  100 . The operation and structure of this embodiment of surgical device  100  is substantially similar to the embodiments described above. In this embodiment, surgical device  100  includes an end effector  4260  including an electrode assembly  4262 . Electrode assembly  4262  includes at least one probe or electrode  4264  adapted to conduct and apply electrosurgical energy to tissue. In the depicted embodiment, electrode assembly  4262  has one probe  4264  having a hook-like shape. Probe  4264 , however, may have any suitable shape or configuration. Regardless of its shape, probe  4264  is electrically linked to actuation cable  205  of surgical device  100 , as shown in  FIG. 46 . 
     With continued reference to  FIGS. 44-46 , this embodiment of surgical device  100  includes an electrical switch  4700  supported on handle assembly  300 . Electrical switch  4700  is configured to set surgical device  100  to one of a number of modes of operation, such as cutting, blending, and/or coagulating. More specifically, electrical switch  4700  is adapted to vary the waveform and/or amount of energy that is delivered from the source of electrosurgical energy to electrode assembly  4262 . In several embodiments, electrical switch  4700  has two discrete positions. In a first discrete position, electrical switch  4700  sets surgical device  100  to transmit “a cutting waveform” output to electrode assembly  4262  and, in a second discrete position, electrical switch  4700  sets surgical device  100  to transmit a “coagulating waveform” output to electrode assembly  4262 . It is envisioned that electrical switch  4700  may also include some measure of tactile feedback capable of being felt by the operator and/or some measure of audible feedback produced by electrical switch  4700  (e.g., “click” sound). 
     In addition to electrical switch  4700 , surgical device  100  includes an electrical interface or plug  4800  configured to be mechanically and electrically connected to a source of electrosurgical energy such as a generator. Plug  4800  includes a plurality of prongs  4802  adapted to mechanically and electrically coupled plug  4800  to a source of electrosurgical energy. An electrical cable  4804  electrically links plug  4800  with handle assembly  300 . 
     Referring to  FIG. 47 , this embodiment of surgical device  100  includes a stationary handle  4301  housing a portion of electrical cable  4804 . Electrical cable  4804  encompasses a plurality of electrical wires  4806  configured to transmit electrosurgical energy from a source of electrosurgical energy (not shown). Electrical wires  4806  are electrically coupled to electrical switch  4700 . 
     In the embodiment shown in  FIG. 47 , electrical switch  4700  includes a button  4702  configured to move between a first position and a second position and first and second transducers  4704 ,  4706 . It is contemplate that transducers  4704 ,  4706  may be pressure transducers. Button  4702  includes first and second prongs  4708 ,  4710  extending downwardly toward first and second transducers  4704 ,  4706 . When button  4702  is located in the neutral position, as shown in  FIG. 47 , first and second prongs  4708 ,  4710  are not in contact with first and second transducers  4704 ,  4706 . Button  4702 , however, may be moved between first and second positions. In the first position, first prong  4708  contacts and applies pressure to first transducer  4704 . In response, first transducer  4704  converts this pressure into a signal that is transmitted to the electrosurgical generator (not shown) via electrical wires  4806 . In turn, the electrosurgical generator transmits a corresponding amount of electrosurgical energy (such as RF energy) or an appropriate waveform output to electrode assembly  4262 . As such, button  4702 , in combination with first and second transducers  4704 ,  4706  allow the operator to control the amount of energy and/or waveform output of the electrosurgical generator (not shown) electrically coupled to surgical device  100 . For example, when button  4702  is placed in the first position, a “cutting-type” waveform is selected. Conversely, when button  4702  is placed in the second position, second prong  4710  contacts and applies pressure to second transducer  4706 . In turn, second transducer  4706  converts this pressure into a signal that is transmitted to the electrosurgical generator (not shown) via electrical wires  4806 . In response to this signal, electrosurgical generator transmits a “cutting-type” waveform output to electrode assembly  4262 . Accordingly, the operator can select the therapeutic effect desired by simply moving button  4702  between the first and second positions. It is envisioned that surgical device  100  may be deactivated (i.e., de-energized) when button  470  is in the neutral position. 
     Handle assembly  300  further includes an electrical wire  4808  electrically linking electrical switch  4700  and inner rod  4205 . Inner rod  4205  is made of an electrically conductive material and electrically couples electrode assembly  4262  with an electrosurgical generator (not shown) connected to surgical device  100 . 
     With continued reference to  FIG. 47 , this embodiment of surgical device  100  also includes articulation mechanism  330  operatively associated with articulating section  230  of endoscopic assembly  200 . Articulating section  230  is configured to articulate towards a particular direction with respect to elongate outer tube  210  upon movement of handle assembly  300  toward the same direction with respect to elongate outer tube  210 , as seen in  FIGS. 48 and 49 . 
     Referring to  FIGS. 50-51 , any of the embodiments of surgical device  100  may include a straightening mechanism  5000  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  5000  includes a first set of magnets  5002  attached to ball  331  and a second set of magnets  5004  attached to cup  332 . It is envisioned that magnets  5002 ,  5004  may be rear earth magnets  5002 . Magnets  5002 ,  5004  may be permanent magnets or electromagnets. In the embodiments where magnets  5002 ,  5004  are permanent magnets, magnets  5002 ,  5004  are oriented so that opposite poles of magnets  5002 ,  5004  face each other, thus triggering attraction forces. Magnets  5002  are disposed around the periphery of ball  331 , whereas magnets  5004  are positioned around an inner surface of cup  331 . (See  FIG. 51 ). When articulating section  230  is longitudinal aligned with elongate outer tube  210 , magnets  5002  are radially aligned with magnets  5004 . The position and orientation of magnets  5002  relative to magnets  5004  trigger attraction forces between them. The attraction forces between magnets  5002 ,  5004  maintain cup  332  aligned with ball  331 . As discussed above, when ball  331  is aligned with cup  332 , articulating section  230  is longitudinal aligned with elongate outer tube  210 . (See  FIG. 2 ). If cup  332  is moved relative to ball  331  to articulate articulating section  230 , the attraction forces of magnets  5002 ,  5002  draws ball  331  back into alignment with cup  332 , as seen in  FIG. 2 . As seen in  FIG. 51 , in some embodiments, ball  331  includes detents  5008  attached to each magnets  5002 . In turn, cup  332  includes concavities  5006  adapted to securely receive detents  5008 . The engagement between detents  5008  and concavities  5006  help secure ball  331  in the neutral position. 
     With reference to  FIG. 53 , any of the embodiments of surgical device  100  may include a straightening mechanism  6000  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  6000  includes a conical helical spring  6002  positioned within ball  331 . Conical helical spring  6002  has a proximal end  6004  attached to cable holding section  460  and a distal end  6006  attached to actuation cable  205 . When handle assembly  300  is articulated relative to elongate outer tube  210  ( FIG. 3 ), one side of conical helical spring  6002  is in tension, while the other side of conical helical spring  6002  is in compression, creating a moment that urges handle assembly  300  back to its neutral position (see  FIG. 2 ). As discussed above, when handle assembly  300  is in its neutral position, articulating section  230  is longitudinally aligned with elongate outer tube  210 . It is envisioned that conical helical spring  6002  may be pre-tensioned to increase the moment. 
     With reference to  FIG. 54 , any of the embodiments of surgical device  100  may include a straightening mechanism  7000  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  7000  includes a flexible boot  7002  covering ball  331 . It is contemplated that flexible boot  7002  may be made of an elastomeric material or any other suitable material. Flexible boot  7002  has a proximal end portion  7004  attached to cup  332  and a distal end portion  7006  attached to a portion of elongate outer tube  210  located adjacent ball  331 . In operation, when cup  332  is moved relative to ball  331 , one side of flexible boot  7002  stretches and is in tension, creating a moment that urges ball  331  back to its neutral position (see  FIG. 2 ). 
     With reference to  FIG. 55 , any of the embodiments of surgical device  100  may include a straightening mechanism  8000  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  8000  includes a protruding member  8002  extending proximally from ball  331  and an elastic member  8004  attached to a proximal end  8006  of protruding member  8002 . Elastic member  8004  has a distal end  8010  attached to protruding member  8002  and a proximal end  8012  attached to articulation cable plate  311  ( FIG. 21 ). A housing  8008  encloses protruding member  8002  and at least a portion of elastic member  8004 . In operation, when ball  331  is moved relative to cup  332  ( FIG. 21 ), elastic member  8004  stretches (as shown in phantom). As a result, tension builds up on elastic member  8004 . This tension creates a restoring moment that biases ball  331  toward the neutral position. (See  FIG. 2 ). 
     With reference to  FIG. 56 , any of the embodiments of surgical device  100  may include a straightening mechanism  9000  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  9000  includes a tube or rod  9002  made of a material exhibiting superelastic properties. It is envisioned that tube  9002  is substantially resilient. In some embodiments, tube  9002  is wholly or partly made of a shape memory material such as Nitinol. Tube  9002  has a proximal end  9004  and a distal end  9006 . Proximal end  9004  of rod  9002  is attached to proximal torque tube  456 , while distal end  9006  of rod  9002  is fixed to ball  331 . When ball  331  is articulated with respect to cup  332 , tube  9002  articulates and creates a moment that biases ball  331  towards its neutral position (see  FIG. 2 ). In some embodiments, tube  9002  corresponds to proximal torque coil  468  shown in  FIG. 24 . 
     With reference to  FIG. 57 , any of the embodiments of surgical device  100  may include a straightening mechanism  500  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. In straightening mechanism  500 , ball  331  includes an elongate portion  502  extending proximally therefrom. When ball  331  is moved relative to cup  332 , elongate portion  502  spreads cup  332 . As a consequence, cup  332  exerts a force on elongate portion  502  and urges ball  331  to its neutral position (see  FIG. 2 ). 
     With reference to  FIG. 58 , any of the embodiments of surgical device  100  may include a straightening mechanism  600  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  600  includes a plurality of elastic bands  602  configured to bias ball  331  to a neutral position (see  FIG. 2 ). Each elastic band  602  has a proximal end  606  and a distal end  604 . Proximal ends  606  of each elastic band  602  are attached to elongate portion  414  of articulation cable plate  311 . Distal ends  604  of each elastic band are attached to a distal portion of ball  331 . During operation, when ball  331  is moved relative to cup  332  ( FIG. 21 ), at least one elastic bands  602  stretches and biases ball  331  toward its neutral position (see  FIG. 2 ). It some embodiments, straightening mechanism  600  includes three elastic bands  602 , but it is envisioned that straightening mechanism  600  may include more or fewer elastic bands  602 . 
     With reference to  FIG. 59 , any of the embodiments of surgical device  100  may include a straightening mechanism  700  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  700  includes an annular wall  702  extending radially and inwardly from an inner surface of cup  332  and a ring  704  positioned adjacent a proximal portion  708  of ball  331 . Moreover, straightening mechanism  700  includes a plurality of springs  706  located between annular wall  702  and ring  704 . Springs  706  are configured to bias ball  331  to its neutral position (see  FIG. 2 ) upon movement of ball  331  with respect to cup  332 . In operation, when ball  331  is moved relative to cup  332 , some springs  706  compress, while other springs  706  stretch. The combined elongation and compression of springs  706  urges ball  331  back to its neutral position (see  FIG. 2 ). 
     With reference to  FIG. 60 , any of the embodiments of surgical device  100  may include a straightening mechanism  800  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  800  includes a ring  804  positioned distally of cup  332  and around a portion of ball  331 . Moreover, straightening mechanism  800  includes a plurality of springs  806  located between ring  804  and a distal end  802  of cup  332 . Springs  806  are configured to bias ball  331  to its neutral position (see  FIG. 2 ) upon movement of ball  331  with respect to cup  332 . In operation, when ball  331  is moved relative to cup  332 , some springs  806  compress, while other springs  806  stretch. The combined elongation and compression of springs  806  urges ball  331  back to its neutral position (see  FIG. 2 ). 
     With reference to  FIG. 61 , any of the embodiments of surgical device  100  may include a straightening mechanism  900  for returning articulating section  230  ( FIG. 2 ) into longitudinal alignment with elongate outer tube  210  ( FIG. 2 ) after articulation. Straightening mechanism  900  includes an annular wall  902  extending radially and inwardly from an inner surface of cup  332  and a ring  904  positioned adjacent a proximal portion  908  of ball  331 . Ring  904  defines an annular slot  910  configured to slidably receive proximal portion  908  of ball  331 . Moreover, straightening mechanism  900  includes a plurality of springs  906  located between annular wall  902  and ring  904 . Springs  906  are configured to bias ball  331  to its neutral position (see  FIG. 2 ) upon movement of ball  331  with respect to cup  332 . In operation, when ball  331  is moved relative to cup  332 , springs  906  elongate, causing tension in springs  906 . As a result of the tension, springs  906  urges ball  331  back to its neutral position (see  FIG. 2 ). 
     As can be appreciated, some, or all of articulation cables  240   A-D  are tensioned depending on the position of handle assembly  300  with respect to elongate outer tube  210 . Prolonged tensioning of articulation cables  240   A-D  may cause undesired stretching of articulation cables  240   A-D , which may ultimately result in imprecise or inconsistent articulation of articulating section  230 , and which may reduce the overall lifetime of the surgical device  100 . Additionally, maintaining surgical device  100  in one position for a prolonged period of time, e.g., the time between packaging after manufacture and use, may cause articulation cables  240   A-D , if under a prolonged tension force, to stretch. This may also affect the articulation of surgical instrument  100 . 
     Accordingly, as shown in  FIGS. 65A-68B  and as will be described hereinbelow, various embodiments are provided in which articulation lock trigger  304  is configured to initially be disposed in a “shipping” position wherein cables  240   A-D  are substantially un-tensioned. Upon the initial actuation of articulation lock trigger  304 , articulation mechanism  330  is permanently transitioned to a “use” position wherein cables  240   A-D  are placed into tension in order to articulate articulation section  230 , as described above. As can be appreciated, the “shipping” position allows surgical instrument  100  to be maintained, or stored for extended periods of time without the risk of prolonged tensioning of articulation cables  240   A-b . 
     With reference now to the embodiment of  FIGS. 65A-65B , an articulation lock trigger  1304  of an articulation mechanism  1330  is shown. As seen in  FIG. 65A , articulation lock trigger  1304  of articulation mechanism  1330  is shown disposed in the shipping position and correspondingly, articulation cable plate  1311  is disposed in a distal-most position due to the coupling of articulation lock trigger  1304  and articulation cable plate  1311  via a linkage  1310 . With articulation cable plate  1311  in this distal-most position, articulation cables  240   A-D  ( FIG. 15 ) are substantially un-tensioned. It is contemplated that articulation cable plate  1311  may be biased toward this distal-most position wherein, absent any opposing forces, i.e., where articulation lock trigger  1304  is not being depressed, the articulation mechanism  1330  is retained in the shipping position. It is envisioned that surgical device  100  be initially disposed in this shipping position. 
     With continued reference to  FIG. 65A , articulation cable plate  1311  supports a spring member in the form of a flat spring  1350 . Flat spring  1350  includes a pair of flexible legs  1352 ,  1354  interconnected by a backspan, or base  1356 . Base  1356  is fixedly connected to articulation cable plate  1311  at a proximal end  1313  of articulation plate  1313  to retain flat spring  1350  thereon. Legs  1352 ,  1354  extend proximally from base  1356  and each leg  1352 ,  1354  includes a laterally protruding flange  1353 ,  1355 , respectively, disposed at a proximal end thereof and defining camming surfaces. 
     Housing  1340  includes a bumper  1342  positioned proximally of and substantially aligned with articulation plate  1311 . Bumper  1342  defines a shelf  1344  having a pair of notched members  1346  positioned thereon, although only one notched member  1346  is shown in the cut-away view of  FIG. 65A . Notched members  1346  each include a ramped distal portion  1347  and a recessed proximal portion  1349  configured to retain flanges  1353 ,  1355  of respective legs  1352 ,  1354  of spring  1350 , as will be described below. 
     To move articulation mechanism  1330  from the shipping position ( FIG. 65A ) to the use position ( FIG. 65B ), articulation lock trigger  1304  is depressed, or pulled proximally. As articulation lock trigger  1304  is pulled proximally, articulation lock trigger  1304  pivots about pivot  1335 , translating linkage  1310  proximally and thereby translating articulation cable plate  1311  proximally. As articulation cable plate  1311  is translated proximally, articulation cables  240   A-D  ( FIG. 15 ) are increasingly tensioned. At the same time, the proximal translation of articulation cable plate  1311  translates flat spring  1350  proximally. More specifically, flanges  1353 ,  1355  of respective legs  1352 ,  1354  of flat spring  1350  are translated proximally toward notched members  1346  disposed on bumper  1342 . 
     Upon further proximal translation of articulation lock trigger  1304 , and, thus, articulation cable plate  1311 , flanges  1353 ,  1355  of respective legs  1352 ,  1354  of flat spring  1350  ramp up and over distal portions  1347  of notched members  1346  until flanges  1353 ,  1355  of legs  1352 ,  1354  drop into engagement with recessed proximal portions  1349  of notched members  1346  ( FIG. 65B ). Once flanges  1353 ,  1355  drop into engagement with recessed proximal portions  1349  of notched members  1346 , articulation lock trigger  1304  may be released, allowing articulation lock trigger  1304  and articulation cable plate  1311  to begin to return distally under the bias of articulating cables  240  ( FIG. 15 ), due to the tension of articulation cables  240 . However, the engagement of flanges  1353 ,  1355  within recessed proximal portions  1349  of notched members  1346  inhibits distal translation of articulation cable plate  1311  back to the un-tensioned, or shipping position. Instead, articulation cables  240   A-D  ( FIG. 15 ) remain in a tensioned state. With articulation cables  240   A-D  ( FIG. 15 ) in this tensioned state due to the engagement of flanges  1353 ,  1355  within recessed proximal portions  1349 , surgical device  100  is in the use position ( FIG. 65B ). It is envisioned that flat spring  1350  and notched members  1346  be configured such that articulation mechanism  1330  is permanently transitioned from the shipping position to the use position upon the initial depression of articulation lock trigger  1304 . In other words, it is envisioned that, once moved to the use position, articulation mechanism  1330  is prevented from returning to the shipping position. 
     With continued reference to  FIGS. 65A-65B , recessed proximal portions  1349  of notched members  1346  have a greater length than flanges  1353 ,  1355  of flat spring  1350  such that flanges  1353 ,  1355  may still translate longitudinally, e.g., proximally and distally, when in the use position, e.g., when flanges  1353 ,  1355  are engaged within recessed proximal portions  1349  of notched members  1346 . As can be appreciated, the dimensions of recessed proximal portions  1349  of notched members  1346  may be configured according to the desired range of motion of articulation lock trigger  1304 . Accordingly, a greater lengthed recessed portion  1349  would allow for greater translation of flanges  1353 ,  1355  therein, thus allowing a larger range of motion of articulation lock trigger  1304  and articulation cable plate  1311 . It is envisioned that recessed proximal portions  1349  be sufficiently dimensioned to permit the locking and unlocking of articulation cables  240   A-D  ( FIG. 15 ) in position, as will be described in greater detail hereinbelow. On the other hand, it is envisioned that recessed proximal portions  1349  be sufficiently dimensioned to prevent articulation cables  240   A-D  ( FIG. 15 ) from becoming untensioned and/or over-tensioned. 
     Referring now to  FIGS. 66A-66B , another embodiment of an articulation mechanism  2330  is shown. Similar to articulation mechanism  1330 , articulation lock trigger  2304  and articulation cable plate  2311  of articulation mechanism  2330  are initially disposed in the shipping, or distal-most position. Articulation lock trigger  2304  and articulation cable plate  2311  are biased toward this distal-most position by articulation cables  240   A-D  ( FIG. 15 ), with articulation cables  240  ( FIG. 15 ) being biased toward a substantially un-tensioned position. As mentioned above, this un-tensioned shipping position allows surgical device  100  to be stored or maintained for a prolonged period of time prior to use, without the risk of prolonged strain on articulation cables  240   A-D  ( FIG. 15 ). 
     With continued reference to  FIGS. 66A-66B , articulation cable plate  2311  includes a recessed portion  2313  defined in a surface thereof toward a proximal end thereof. A spring member  2350  is fixedly engaged at one end thereof to housing  2340  via retainer  2342 . Initially, when articulation cable plate  2311  is disposed in the shipping position, a free end  2352  of spring member  2350  is positioned proximal of articulation cable plate  2311 . 
     To move articulation mechanism  2330  from the shipping position to the use position, articulation lock trigger  2304  is pulled proximally to pivot about pivot  2335 . As articulation lock trigger  2304  is pulled proximally, linkage  2310  is pivoted such that articulation cable plate  2311  is translated proximally against the bias of articulation cables  240   A-D  ( FIG. 15 ), thereby increasing tension on articulation cables  240   A-D  ( FIG. 15 ). Translation of articulation cable plate  2311  proximally moves articulation cable plate  2311  toward free end  2352  of spring member  2350 . Upon further pulling of articulation lock trigger  2304 , free end  2352  of spring member  2350  cams along a surface of articulation cable plate  2311  as articulation cable plate  2311  is translated further proximally. Eventually, free end  2352  of spring  2350  cams along the surface of articulation cable plate  2311  until free end  2352  of spring  2350  drops into engagement with recessed portion  2313  of articulation cable plate  2311  due to the bias of spring  2350 , as shown in  FIGS. 66A-B . The engagement of spring  2350  within recessed portion  2313  of articulation cable plate  2311  corresponds to the use position of articulation mechanism  2330 . Once spring  2350  is engaged within recessed portion  2313 , spring  2350  is maintained therein due to the bias of spring  2350 , such that articulation mechanism  2330  is retained in the use position. 
     Similar to articulation mechanism  1330  described above, the dimensions of recessed portion  2313  define the range of motion of articulation lock trigger  2304  and thus define the range of tension imparted to articulation cables  240   A-D  ( FIG. 15 ). Thus, as articulation lock trigger  2304  is pulled and released, spring  2350  is translated relative to recessed portion  2313  of articulation cable plate  2311  along a length thereof to move the articulation mechanism  2330  between a locked position and an unlocked position. Additionally, recessed portion  2313  is preferably dimensioned to prevent articulation cables  240   A-D  ( FIG. 15 ) from becoming untensioned and/or over-tensioned. 
     Referring now to  FIGS. 67A-67B , still another embodiment of an articulation mechanism is shown as  3330 . Articulation mechanism  3330  is capable of transitioning from an initial shipping position to a use position is shown. Articulation cable plate  3311  includes an elongated flat spring  3350  disposed thereon and mechanically engaged therewith at a proximal end  3352  of elongated flat spring  3350 . Elongated flat spring  3350  extends distally along articulation cable plate  3311  and includes a notch  3356  disposed at a distal end  3354  thereof. Notch  3356  includes a ramped proximal end and a substantially vertical distal end to define triangular-shaped notch  3356 . 
     Initially, when in the shipping position, as shown in  FIG. 67A , distal end  3354  of elongated flat spring  3350 , including notch  3356 , are disposed distal of cup  3332 . Correspondingly, articulation lock trigger  3304  and articulation cable plate  3311  are disposed in the shipping, or distal-most position wherein cables  240  are substantially un-tensioned. 
     To move articulation mechanism  3330  from the shipping position ( FIG. 67A ) to the use position, articulation lock trigger  3304  is pulled proximally and pivoted about pivot  3335 , thereby pivoting linkage  3310  and translating articulation cable plate  3311  and elongated flat spring  3350  proximally. As articulation cable plate  3311  and elongated flat spring  3350  are translated proximally, notch  3356  approaches cup  3332 . Upon further proximal translation, notch  3356  contacts cup  3332  causing elongated flat spring  3350  to compress. With a sufficient pulling force on articulation lock trigger  3304 , flat spring  3350  compresses to allow notch  3356  to pass under cup  3332 , as cup  3332  is ramped over ramped distal end  3354  of notch  3356 , as shown in  FIG. 67B . In other words, notch  3356  is flexed to pass through the opening  3359  defined between cup  3332  and articulation cable plate  3311  to a position proximal of cup  3332 . 
     Once notch  3356  has been translated to a position proximal of cup  3332 , articulation mechanism  3330  is in the use position wherein articulation cables  240   A-D  are tensioned. Articulation mechanism  3330  is prevented from returning to the shipping position due to the vertical distal end of notch  3356 , which inhibits the passage of notch  3356  back through the opening  3359  defined between cup  3332  and articulation cable plate  3311 . In the use position, as will be described in greater detail below, articulation lock trigger  3304  may be depressed to fix the position of articulating section  230  ( FIG. 27 ). 
     With reference now to  FIGS. 68A-68B , another embodiment of an articulation mechanism is shown as  4330 . Articulation mechanism  4330  is capable of transitioning from an initial shipping position to a use position is shown. The shipping position in shown in  FIG. 68A , wherein articulation lock trigger  4304  and articulation cable plate  4311  are disposed in a distal-most position, such that articulation cables  240   A-D  ( FIG. 15 ) are substantially un-tensioned. A pair of wire springs  4350  extending along upper and lower surfaces of articulation cable plate  4311  are connected at a distal end to housing  4340  and at a proximal end to stop members  4360 . In the shipping position, stop members  4360  displace wire springs  4350  outwardly from the upper and lower surfaces of articulation cable plate  4311  at a proximal end thereof, as best shown in  FIG. 68A . As can be appreciated, the outward displacement of wire springs  4350  tensions wire springs  4350 , thereby biasing articulation cable plate  4311  distally. This tensioned configuration of wire springs  4350 , in the shipping configuration, maintains articulation cable plate  4311  in a distal-most position, such that articulation cables  240   A-D  ( FIG. 15 ) are substantially un-tensioned. 
     To move articulation mechanism  4330  from the shipping position ( FIG. 68A ) to the use position ( FIG. 68B ), articulation lock trigger  4304  is pulled proximally. As articulation lock trigger  4304  is pulled proximally from the initial, shipping position, articulation lock trigger  4304  is pivoted about pivot  4335  and linkage  4310  is pivoted to translate articulation cable plate  4311  proximally. Upon proximal translation of articulation cable plate  4311 , stop members  4360  fall into recesses  4362  defined within the upper and lower surfaces of articulation cable plate  4311  under the bias of wire springs  4350 . With stop members  4360  disposed in recesses  4360  of articulation cable plate  4311  ( FIG. 68B ), wire springs  4350  are no longer displaced outwardly from the surface of articulation cable plate  4311  and, thus, the tension on wire springs  4350  is eliminated. This position corresponds to the use position, wherein articulation cables  240  ( FIG. 15 ) are tensioned. Articulation mechanism  4330  is prevented from returning to the shipping configuration due to the positioning of wire springs  4350 , which resist compression. Further, articulation cables  240  ( FIG. 15 ) remain in a tensioned state because the force exerted by wire springs  4350  against compression prevents articulation cables  240  ( FIG. 15 ) from returning to the un-tensioned position (the shipping position). 
     In another embodiment, as shown in  FIG. 69 , articulation lock trigger  5304  is pivotably engaged with articulation cable plate  5311  via a two-bar linkage  5332 . More specifically, articulation lock trigger  5304  is coupled to articulation cable plate  5311  on one side by a first linkage bar  5332  and on the other side by a second linkage bar (not shown). First linkage bar  5332  is pivotably engaged at one end to articulation lock trigger  5304  via pivot  5336  and pivotably engaged at the other end to articulation cable plate  5311  via pivot  5337 . The second linkage bar (not shown) similarly engages articulation lock trigger  5304  and articulation cable plate  5311  on the opposite sides thereof. Pivot  5336  is disposed within a notch  5339  defined within articulation lock trigger  5304  such that, as articulation lock trigger  5304  is depressed, notch  5339  urges linkage bars  5332  to pivot about pivot  5336 . 
     Articulation lock trigger  5304  may initially be disposed in a shipping position, as shown in  FIG. 70A . Accordingly, any one of the embodiments discussed above, or any other suitable mechanism, may be employed to initially maintain articulation mechanism  5330  in a shipping position, wherein articulation cables  240   A-D  ( FIG. 15 ) are substantially un-tensioned, and to allow the peimanent transition of articulation mechanism  5330  to the use position upon the initial depression of articulation lock trigger  5304 . 
     With articulation lock trigger  5304  in the use position, an over-center clamp mechanism  5331  is configured for movement between an unlocked position ( FIG. 70B ), wherein pivot  5336  is offset below pivots  5335  and  5337 , through a center position, wherein pivots  5335 ,  5336 , and  5337  are substantially aligned with one another, to an over-center, or locked position ( FIG. 70C ), wherein pivot  5336  is offset above pivots  5335  and  5337 . As shown in  FIG. 70C , in the over-center, or locked position, pivot  5336  may be offset from pivots  5335  and  5337  by about two degrees (2°) to about three degrees (3°). 
     Once articulation lock trigger  5304  is permanently moved to the use position, e.g., by the initial depressing of articulation lock trigger  5304 , the position of articulation section  230  ( FIG. 27 ) may be fixed with respect to elongate outer tube  210 . When in the use position, articulation lock trigger  5304  is biased toward the unlocked position ( FIG. 70B ) via spring  5350  ( FIGS. 66A-66B ). Thus, articulation lock trigger  5304  must be depressed with sufficient force to overcome the bias of spring  5350  to move pivot  5336  through the center position to the over-center position ( FIG. 70C ) in order to lock the position of articulating section  230  ( FIG. 27 ). 
     In operation, to fix the position of articulating section  230  ( FIG. 27 ), articulation lock trigger  5304  is depressed proximally against the bias of spring  5350 . As articulation lock trigger  5304  is depressed from the unlocked position shown in  FIG. 70B , articulation lock trigger  5304  is pivoted about pivot  5335 , and pivot  5336  is urged toward the center position due to the engagement of pivot  5336  within notch  5339 . As pivot  5336  is urged toward the center position, linkage bar  5332  is urged proximally, thereby urging articulation cable plate  5311  proximally due to the pivotable coupling of linkage bar  5332  and articulation cable plate  5311 . Consequently, articulation cables  240  ( FIG. 15 ) are tightened, thereby compressing articulation links  232 ,  234  together ( FIG. 27 ) and fixing the position of articulating section  230  ( FIG. 27 ) relative to elongate outer tube  210 . Upon further proximal pulling of articulation lock trigger  5304 , pivot  5336  is moved to the over-center position, offset above pivots  5335  and  5337 . In this position, as shown in  FIG. 70C , over-center clamp mechanism  5331  is “locked” in position and, thus, the fixed position of the articulating section  230  ( FIG. 27 ) is maintained. Accordingly, the articulation lock trigger  5304  may be released, while the articulating section  230  ( FIG. 27 ) remains fixed in position due to the over-center configuration of over-center clamp mechanism  5331 , as shown in  FIG. 70C . To unlock the over-center clamp mechanism  5331 , the articulation lock trigger  5304  is once again depressed proximally, allowing pivot  5336  to move back past the center position towards the unlocked position ( FIG. 70B ). 
     With reference now to  FIGS. 71A-75 , another embodiment of an articulation mechanism is shown as  6300 . Articulation mechanism  6300  is configured to transition between a shipping position ( FIGS. 71A-71B ) and a use position. When in the use position, articulation mechanism  6300  is further configured for transitioning between an unlocked position ( FIG. 72 ), and a locked position ( FIG. 73 ). Articulation mechanism  6300  includes an articulation lock trigger  6310 , a shaft  6320  having a lock plate  6324  disposed at a distal end  6332  thereof, a cable plate  6330  configured to secure proximal ends of articulation cables  240   A-D  ( FIG. 15 ) therein, and an articulation sphere (see  FIGS. 70A-70C ) operably positioned within spherical-shaped cavity  6352  of housing  6350 . 
     Referring now to  FIG. 74 , cable plate  6330  defines a circular wall front cross-section  6330   a  and includes an aperture  6332  centrally defined therethrough. Four (4) ferrules  6334  are positioned annularly about cable plate  6330  toward an outer circumference thereof and extend proximally from cable plate  6330 . Each ferrule  6334  is configured to securely retain a proximal end of one of articulation cables  240   A-D  ( FIG. 15 ) therein. As can be appreciated, with the proximal ends of articulation cables  240  ( FIG. 15 ) engaged within ferrules  6334  of cable plate  6330 , translating cable plate  6330  proximally tensions articulation cables  240  ( FIG. 15 ) and translating cable plate  6330  distally slackens, or un-tensions articulation cables  240  ( FIG. 15 ). 
     Cable plate  6330  further includes a pair of arms  6336  extending proximally therefrom. Each arm  6336  includes a tab  6338  disposed at a proximal, or free end  6337  thereof and may define a generally tapered configuration, decreasing in width from a distal, or fixed end  6339  thereof to free end  6337  thereof. When articulation mechanism  6330  is assembled, as shown in  FIG. 71A , arms  6336  of cable plate  6330  are inserted proximally through a central aperture (not explicitly shown) defined within lock plate  6324  such that cable plate  6330  is positioned distally of, and substantially mating with respect to lock plate  6324 , while arms  6336  extend proximally through longitudinal channels  6327  defined along opposite longitudinal sides  6326  of shaft  6320 . 
     With reference again to  FIGS. 71A-75 , articulation mechanism  6300  includes an articulation lock trigger  6310  pivotably coupled to shaft  6320 . More specifically, articulation lock trigger  6310  includes a pair of upwardly-extending flanges  6312  that are pivotably coupled to shaft  6320  on opposite sides thereof via pivot  6360 . Articulation lock trigger  6310  is selectively depressible from a shipping position, wherein shaft  6320  and cable plate  6330  are in a distal-most position, to a use position, wherein arms  6336  of cable plate  6330  are translated proximally to tension articulation cables  240   A-D  ( FIG. 15 ). Once in the use position, articulation lock trigger  6310  is selectively depressible between an unlocked position ( FIG. 72 ), wherein articulating section  230  is permitted to articulate relative to longitudinal axis “X” (see  FIGS. 3 and 5 ), and a locked position ( FIG. 73 ), wherein articulation mechanism  6330  fixes the position of articulating section  230  relative to longitudinal axis “X” (see  FIGS. 3 and 5 ). 
     Articulation lock trigger  6310  further includes a slot  6314  defined within each of flanges  6312 . Each slot  6314  is configured to retain one of tabs  6338  of arms  6336  of cable plate  6330  therein. As will be described in greater detail below, slots  6314  are specifically configured and dimensioned such that tabs  6338  of arms  6336  are translated along slots  6314  during depression and/or release of articulation lock trigger  6310 . Further, each slot  6314  defines a groove  6315  toward a top end  6314   a  thereof. As tabs  6338  are moved from grooves  6315  into slots  6314 , e.g., as articulation lock trigger  6310  is depressed from the shipping position to the use position, proximal longitudinal movement of arms  6336  and, thus, cable plate  6330  is effected to tension cables  240  ( FIG. 15 ). 
     Flanges  6312  of articulation lock trigger  6310  also define a specifically configured proximal surface profile. More particularly, proximally-facing surfaces  6317  of flanges  6312  of articulation lock trigger  6310  define a cam surface  6317  having three distinct segments, a shipping position segment  6317   a  and two use position segments: an unlocked position segment  6317   b , and a locked position segment  6317   c . As will be described in greater detail below, proximal earning surfaces  6317  of flanges  6312  slide, or cam with respect to side protrusions  6329  disposed on opposite sides  6326  of shaft  6320  during pivoting of articulation lock trigger  6310  with respect to shaft  6320  about pivot  6360 . Due to the configuration of proximally-facing surfaces  6317  of flanges  6312 , as articulation lock trigger  6310  is depressed or released when in the use position, the earning of proximal surfaces  6317  of flanges  6312  with respect to side protrusions  6329  of shaft  6320  effects longitudinal movement of shaft  6320  to move shaft  6320  between the unlocked position ( FIG. 72 ), wherein articulation section  230  ( FIGS. 3 and 5 ) is permitted to articulate with respect to longitudinal axis “X” (see  FIGS. 3 and 5 ), and the locked position ( FIG. 73 ), wherein shaft  6320  is in the proximal-most position, fixing the position of articulating section  230  ( FIG. 15 ) with respect to longitudinal axis “X” (see  FIG. 2 ). 
     Articulation mechanism  6300  may initially be disposed in the shipping position, as shown in  FIGS. 71A-71B , wherein articulation lock trigger  6310 , shaft  6320 , and cable plate  6330  are in distal-most positions and wherien articulation cables  240   A-D  ( FIG. 15 ) are substantially un-tensioned. More particularly, in the shipping position, tabs  6338  of arms  6336  of cable plate  6330  are each disposed within grooves  6315  of slots  6314  of flanges  6312  of articulation lock trigger  6310 . Grooves  6315  protrude distally from slots  6314  such that, when tabs  6338  are disposed within grooves  6315 , i.e., when articulation lock trigger  6310  is in the shipping position, tabs  6338  are in the distal-most position and, accordingly, cable plate  6330  and articulation cables  240  ( FIG. 15 ) are in the distal-most, substantially un-tensioned position. Further, a stopper  6316  is positioned within slots  6314  of flanges  6312 , as best shown in  FIG. 73 , to inhibit tabs  6338  of aims  6336  of cable plate  6330  from “slipping” out of grooves  6315  and into slots  6314 , i.e., to retain cable plate  6330  and articulation cables  240  ( FIG. 15 ) in the untensioned, shipping position. 
     With continued reference to  FIGS. 71A-71B , when articulation mechanism  6300  is in the shipping position, as mentioned above, shaft  6320  is disposed in a distal-most position. More specifically, when articulation lock trigger  6310  is disposed in the shipping position, side protrusions  6329  are disposed within shipping position segments  6317   a  of proximally-facing surfaces  6317  of flanges  6312  of articulation lock trigger  6310 . Shipping position segments  6317   a  of proximally-facing surfaces  6317  of flanges  6312  define a cut-out area, such that side protrusions  6329  are substantially undisturbed, i.e., such that side protrusions  6329  are not urged proximally, when side protrusions  6329  are disposed within shipping position segments  6317   a  of proximally-facing surfaces  6317  of flanges  6312 . Thus, with side protrusions  6329  of shaft  6312  disposed within shipping position segments  6317   a  of articulation lock trigger  6310 , shaft  6320  is permitted to be biased toward the distal-most, or un-locked position. 
     As mentioned above, with articulation mechanism  6300  in the shipping position, surgical instrument  100  may be maintained, or stored for extended periods of time without the risk of prolonged tensioning of articulation cables  240   A-D , arms  6336  of cable plate  6330 , and/or shaft  6320 . 
     To move articulation mechanism  6300  from the shipping position to the use position, articulation lock trigger  6310  is pulled proximally to pivot with respect to shaft  6320  about pivot  6360 . As articulation lock trigger  6310  is pulled proximally, or depressed, grooves  6315  and slots  6314  defined within flanges  6312  of articulation lock trigger  6310  are moved with respect to tabs  6338  of arms  6336  of cable plate  6330  such that tabs  6338  are translated proximally over stoppers  6316 , disengaging from grooves  6315  and moving into the more proximally-disposed slots  6314  of flanges  6312  of articulation lock trigger  6310 . Moving tabs  6338  proximally translates arms  6336 , cable plate  6330 , and, thus, articulation cables  240  ( FIG. 15 ) proximally, thereby transitioning articulation cables  240  ( FIG. 15 ) from the un-tensioned, shipping position to the tensioned, use position. Once tabs  6338  are moved into slots  6314 , stoppers  6316  prevent tabs  6338  from moving back into engagement with grooves  6315 , i.e., stoppers  6316  prevent cable plate  6330  and, thus, articulation cables  240  ( FIG. 15 ) from moving distally back to the un-tensioned, shipping position. 
     As shown in  FIGS. 71A-73 , slots  6314  are arcuately-shaped according to the pivotal radius of motion of articulation lock trigger  6310  about pivot  6360  such that, once tabs  6338  are moved out of grooves  6315  and into slots  6314 , i.e., once articulation lock trigger  6310  is moved from the shipping position to the use position and cables  240  ( FIG. 15 ) are tensioned, cable plate  6330  is maintained in a fixed longitudinal position. In other words, articulation lock trigger  6310  is moved from the shipping position to the use position to move tabs  6338  from grooves  6315  to slots  6314  of flanges  6312  of articulation lock trigger  6310  to tension cables  240  ( FIG. 15 ). However, once articulation lock trigger  6310  is moved to the use position and cables  240  ( FIG. 15 ) are tensioned, the tension on cables  240  ( FIG. 15 ) remains relatively constant, even as articulation lock trigger  6310  is further moved in the use position between the un-locked and locked positions. 
     Simultaneously, or near-simultaneously with the tensioning of cables  240  ( FIG. 15 ), shaft  6320  is moved from the distal-most, shipping position to the use position when articulation lock trigger  6310  is pulled from the shipping position to the use position. More particularly, upon pivoting of articulation lock trigger  6310  with respect to shaft  6320 , side protrusions  6329  disposed on shaft  6320  cam downwardly with respect to proximally-facing surfaces  6317  of flanges  6312  of articulation lock trigger  6310  from shipping position segment  6317   a , over shelf  6318  and into the use position sections, e.g., into unlocked position segment  6317   b . When side protrusions  6329  are cammed into unlocked position segments  6317   b , shaft  6320  is translated proximally to the unlocked, use position. The unlocked, use position of shaft  6320  corresponds to a position wherein shaft  6320  is more-proximally positioned than in the shipping position, but more distally-positioned than in the locked position. With articulation mechanism in the un-locked, use position, handle assembly  6350 , as mentioned above, may be moved relative to elongate outer tube  210  ( FIG. 67A ) in any direction to cause the articulation of articulating section  230  (see  FIGS. 3 and 5 ) in that same direction. 
     When it is desired to fix the position of articulating section  230  (see  FIGS. 3 and 5 ), articulation lock trigger  230  may further be pulled proximally, or depressed, from the unlocked position ( FIG. 72 ) to the locked position ( FIG. 73 ). As shown in  FIG. 73 , when articulation lock trigger  6310  is moved to the locked position, the pivoting of articulation lock trigger  6310  with respect to shaft  6320  causes side protrusions  6329  to cam along proximally-facing surfaces  6317  of flanges  6312  from unlocked position segment  6317   b  to locked position segment  6317   c . Locked position segment  6317   c  is configured such that, as side protrusions  6329  cam therealong, i.e., as articulation lock trigger  6310  is depressed from the unlocked position to the locked position, locked position segments  6317   c  of proximally-facing surfaces  6317  of flanges  6312  urge side protrusions  6329  and, thus, shaft  6320  proximally. As side protrusions  6329  and shaft  6320  are translated proximally, articulation lock plate  6324 , disposed at distal end  6322  of shaft  6320 , pinches, or frictionally-engages, the sphere (see  FIGS. 70A-70C ) to the proximal surface of spherical-shaped cavity  6350 , preventing articulation of handle assembly  6350  with respect to elongate outer tube  210  ( FIG. 67A ) and, thus, fixing the position of articulation section  230  with respect to longitudinal axis “X” (see  FIGS. 3 and 5 ). 
     Any of the locking mechanisms described above in connection with any of the embodiments discussed herein may be provided for locking, or fixing articulation lock trigger  6310  in the locked position. Accordingly, with the use of a locking mechanism, a surgeon need not continually retain, e.g., squeeze, articulation lock trigger  6310  toward the locked position. However, when it is desired to release articulation lock trigger  6310  from the locked position, e.g., when it is desired to re-position articulating section  230  (see  FIGS. 3 and 5 ), articulation lock trigger  6310  may be moved distally to release the locking mechanism, allowing articulation lock trigger  6310 , shaft  6320 , and lock plate  6324  to move distally back to the unlocked position. 
     With reference now to  FIGS. 76-79 , another embodiment of an articulation mechanism is shown as  7300 . Articulation mechanism  7300  is similar to articulation mechanism  6300  and, thus, only the differences will be described hereinbelow to avoid repetition. More particularly, as opposed to articulation mechanism  6300 , which, as discussed above with reference to  FIGS. 71A-75 , includes specifically-configured proximal surfaces  6317  of flanges  6312  of articulation lock trigger  6310  that cam with respect to protrusions  6329  of shaft  6320  to move articulation mechanism  6300  between the shipping and use positions, articulation mechanism  7300  includes a pair of linkages  7380  pivotably engaged to both articulation lock trigger  7310  and shaft  7320  and a spring-loaded latch  7370  for longitudinally translating shaft  7320  with respect to handle assembly  7350  from the shipping position to the use position(s), e.g., the unlocked use position and the locked use position, upon pulling of articulation lock trigger  7310  with respect to shaft  7320  about pivot  7360  from the shipping position to the use position. 
     Referring momentarily to  FIG. 78 , articulation mechanism  7300 , similar to articulation mechanism  6300 , includes a slot  7314  defined within each of flanges  7312  of articulation lock trigger  7310 . Each slot  7314  is configured to retain a tab  7338  of an arm  7336  of cable plate  7330  therein (see  FIG. 79 ). Slots  7314 , including grooves  7315  defined therein, are specifically configured and dimensioned such that tabs  7338  of arms  7336  are translated along slots  7314  as articulation lock trigger  7310  is depressed from the shipping position to the use position to translate cable plate  7330  proximally, thereby tensioning cables  240  ( FIG. 15 ). In other words, a similar configuration as discussed above in relation to articulation mechanism  6300  is used in articulation mechanism  7300  to tension cables  240  ( FIG. 15 ) upon movement of articulation lock trigger  7310  from the shipping position to the use position. 
     Referring now to  FIGS. 76-77 , and as mentioned above, articulation mechanism  7300  includes a pair of linkages  7380  pivotably engaged to both articulation lock trigger  7310  and shaft  7320  and a spring-loaded latch, or latch spring  7370  for transitioning articulation mechanism  7300  with respect to handle assembly  7350  between the shipping position, the unlocked use position and the locked use position. 
     More specifically, linkages  7380  are pivotably engaged to flanges  7312  via apertures  7316  defined within articulation lock trigger  7310  at first ends  7382  of linkages  7380  and are pivotably engaged to side protrusions  7329  disposed on opposite longitudinal sides  7323  of shaft  7320  at second ends  7384  of linkages  7384 . As best shown in  FIG. 78 , apertures  7316  defined within flanges  7312  of articulation lock trigger  7310  each include a transverse rib  7318  on an inner surface thereof to facilitate securing of linkages  7380  to articulation lock trigger  7310  during assembly. 
     As can be appreciated, upon proximal pulling, or pivoting of articulation lock trigger  7310  with respect to shaft  7320  about pivot  7360 , linkages  7380  are pivoted with respect to flanges  7312  at first ends  7382  thereof and are translated proximally and pivoted with respect to shaft  7320  at second ends  7384  thereof, urging shaft  7320  proximally. Similarly, upon release, or distal pushing of articulation lock trigger  7310 , linkages  7380  are translated distally, urging shaft  7320  distally. 
     Initially, articulation mechanism  7300  is in a shipping position wherein articulation lock trigger  7310 , shaft  7320  and lock plate  7324  are in respective distal-most positions. Latch spring  7370 , which is coupled to handle assembly  7350  and is positioned toward a proximal end  7321  of shaft  7320 , is spaced-apart, or disengaged from shaft  7320  when articulation mechanism  7300  is in the shipping position. Further, in the shipping position, tabs  7338  of arms  7336  of cable plate  7330  are disposed within grooves  7315  of flanges  7312  of articulation lock trigger  7310  such that articulation cables  240  ( FIG. 15 ) are substantially untensioned. 
     In order to transition articulation mechanism  7300  from the shipping position to the use position, as shown in  FIG. 76 , articulation lock trigger  7310  is pulled, or depressed proximally. Upon pivoting of articulation lock trigger  7310  with respect to shaft  7320  about pivot  7360 , tabs  7338  of arms  7336  of cable plate  7330  are moved proximally from grooves  7315  to slots  7314  defined within flanges  7312  of articulation lock trigger  7310  to tension cables  240  ( FIG. 15 ). At the same time, linkages  7380  pivot and urge shaft  7320  proximally to the use position. As articulation lock trigger  7310  is depressed further, shaft  7320  is translated further proximally such that latch spring  7370  cams over the bottom surface of proximal end  7321  of shaft  7320 . As shown in  FIG. 77 , latch spring  7370  eventually engages a notch (not explicitly shown) disposed on the bottom surface of shaft  7320  to retain articulation mechanism  7300  in the use position. Thus, once latch spring  7370  is engaged within the notch of shaft  7320 , the release of articulation lock trigger  7310 , from the locked use position, only returns articulation mechanism to the unlocked use position (and not the shipping position). 
     As in the previous embodiments, once articulation mechanism  7300  has been transitioned from the shipping position to the use position, articulation mechanism  7300  may further be transitioned between an unlocked position and a locked position to permit and inhibit, respectively, articulation of articulating section  230  (see  FIGS. 3 and 5 ). More specifically, the notch in the bottom surface of shaft  7320  has a sufficient length to permit longitudinal translation of shaft  7320  with respect to latch spring  7370 , i.e., to permit longitudinal translation of latch spring  7370  relative to shaft  7320  from a first end of the notch to a second end of the notch, between the more-distal unlocked position and the more-proximal locked position. Thus, although the engagement of latch spring  7370  within the notch of shaft  7320  permits articulation mechanism  7300  to transition between the unlocked use position and the locked use position, the engagement of latch spring  7370  within the notch prevents articulation mechanism  7300  from returning to the shipping position. Further, any of the locking mechanisms described above in connection with any of the embodiments discussed herein may be provided for locking (or unlocking) articulation mechanism  7300  in the locked (or unlocked) position. 
     As best shown in  FIG. 76 , articulation mechanism  7300  is configured to permit articulation mechanism  7300  to be reset, allowing articulation mechanism  7300  to return to the shipping position after the initial transition from the shipping position to the use position. Such a feature allows, for example, a manufacturer to test the instrument in all three positions (the shipping, unlocked use and locked use positions) without permanently locking-out the shipping position and/or permits a surgeon to restore the articulation mechanism  7300  back to the shipping position where there may be an extended length of time between uses. 
     With continued reference to  FIG. 76 , in order to reset articulation mechanism  7300  back to the shipping position, a manufacturer or surgeon may insert any suitable elongated rod-like member (not shown), upwardly into handle assembly  7350  through trigger slot  7390 . Trigger slot  7390  is an opening defined within handle assembly  7350  to permit articulation lock trigger  7310  to move between the shipping, unlocked use, and locked use positions. By inserting any suitable member (not shown) through the trigger slot  7390 , the manufacturer or surgeon may manually disengage latch spring  7370  from the notch defined within shaft  7320 , thereby permitting shaft  7320 , and articulation lock trigger  7310  to return to the distal-most, or shipping position. Releasing latch spring  7370  also allows tabs  7338  of aims  7336  of cable plate  7330  to return back to grooves  7315  defined within flanges  7312  of articulation lock trigger  7310  to un-tension cables  240  ( FIG. 15 ). 
     Turning now to  FIGS. 80-88 , another embodiment of an articulation mechanism is shown as  8300 . Articulation mechanism  8300 , as in previous embodiments, is transitionable between a shipping position and a use position, the use position including an unlocked position and a locked position. Articulation mechanism  8300  is disposed within handle assembly  8350  and includes an articulation lock trigger  8310  pivotably coupled to a shaft  8320  about a pivot  8360 . Shaft  8320  includes a lock plate  8324  disposed at a distal end  8321  thereof. A cable plate  8330  is positioned distal of and adjacent lock plate  8324  and includes a pair of arms  8336  extending proximally therefrom. A pair of linkages  8370  disposed on either side of articulation mechanism  8300  are pivotably coupled at first ends  8372  thereof to articulation lock trigger  8310  and at second ends  8374  thereof to shaft  8320  such that pivotal movement of articulation lock trigger  8310  with respect to shaft  8320  effects longitudinal movement of shaft  8320 . A slider  8380 , configured for tensioning cables  240  ( FIG. 15 ) upon the depression of articulation lock trigger  8310  from the shipping to the use position, is disposed about shaft  8320  toward a proximal end  8322  thereof. A pair of spring-loaded latches  8390 ,  8395  rotatable about a pivot  8399  are also provided for transitioning and maintaining articulation mechanism  8300  in each of the shipping, unlocked use, and locked use positions. 
     With reference to  FIGS. 80-83 , cable plate  8330  has four (4) ferrules  8334  positioned annularly therearound for securely retaining the proximal ends of articulation cables  240   A-D  ( FIG. 15 ) therein. Each arm  8336  of cable plate  8330  further includes a post  8338  disposed at a proximal end  8337  (see  FIG. 83 ) thereof that extends outwardly therefrom. Arms  8336  of cable plate  8330  extend proximally through an aperture (not explicitly shown) defined within lock plate  8324  to extend along longitudinal sides  8326  of shaft  8320 , while cable plate  8330  is positioned distally of lock plate  8324  when articulation mechanism  8300  is fully assembled. Slider  8380  straddles shaft  8320  and includes a pair of legs  8382  extending downwardly along opposite longitudinal sides  8326  of shaft  8320  toward proximal end  8322  thereof. Each leg  8382  includes an aperture  8384  defined therein that is dimensioned and configured to secure a post  8338  of one of arms  8336  of cable plate  8330 . As can be appreciated, with posts  8338  of arms  8336  of cable plate  8330  secured within apertures  8384  of legs  8382  of slider  8380 , cable plate  8330  is translated longitudinally upon longitudinal translation of slider  8380 . Thus, as slider  8380  is translated proximally, cable plate  8330  is similarly translated proximally to tension cables  240  ( FIG. 15 ). 
     As mentioned above, with continued reference to  FIGS. 80-83 , articulation lock trigger  8310  is pivotable about pivot  8360  between a shipping position and a use position (and articulation lock trigger  8310  is further moveable between an unlocked position and a locked position once disposed in the use position). More specifically, articulation lock trigger  8310  includes a pair of flanges  8312  that extend upwardly on opposite longitudinal sides  8326  of shaft  8320 , ultimately coupling to pivot  8360  for pivotably-engaging articulation lock trigger  8310  to shaft  8320 . Flanges  8312  of articulation lock trigger  8310  each define a specifically-configured proximally-facing surface. Similar to articulation lock trigger  6310  of articulation mechanism  6300 , proximal-facing surfaces  8316  of articulation lock trigger  8310  define three distinctly configured segments: a shipping segment  8316   a , an unlocked use segment  8316   b , and a locked use segment  8316   c.    
     When in the shipping position, as shown in  FIGS. 80 and 84 , articulation lock trigger  8310  is in a distal-most position and distally-facing surfaces  8386  of legs  8382  of slider  8380  are engaged within shipping segments  8316   a  of flanges  8312  of articulation lock trigger  8310 . The configuration of shipping segments  8316   a  is such that slider  8380  is in a distal-most position when engaged within shipping segments  8316   a  of articulation lock trigger  8310  and, accordingly, such that arms  8336 , cable plate  8330 , and cables  240  ( FIG. 15 ) are in a distal-most, or un-tensioned position. 
     When articulation lock trigger  8310  is pulled proximally, as shown in  FIGS. 81 and 85 , proximal surfaces  8316  of flanges  8312  of articulation lock trigger  8310  cam with respect to distal surfaces  8386  of legs  8382  of slider  8380 . Flanges  8312  cam with respect to legs  8382  such that legs  8382  are moved relative to flanges  8312  over humps  8318  defined between shipping segments  8316   a  and unlocked use segments  8316   b  of flanges  8312 . As articulation lock trigger  8310  is further pulled proximally, legs  8382  clear humps  8318  and are engaged within unlocked use segments  8316   b . As legs  8382  are moved into engagement with unlocked use segments  8316   b , the configuration of humps  8318  and unlocked use segments  8316   b  urge legs  8382 , and, thus slider  8380  proximally. In other words, unlocked use segments  8316   b  protrude further proximally with respect to slider  8380  than shipping segments  8316   a . As a result, when articulation lock trigger  8310  is pulled to the use position, slider  8380  is translated proximally thereby, as mentioned above, translating cable plate  8330  proximally and tensioning cables  240  ( FIG. 15 ). 
     With reference now to  FIGS. 84-85  in conjunction with  FIGS. 80, 81 and 83 , slider  8380  includes a pair of side rails  8388  slidably engaged within grooves  8354  defined within opposing inner surfaces of handle assembly  8350 . The engagement of side rails  8388  within grooves  8354  limits the range of motion of slider  8380 . More specifically, when side rails  8388  of slider  8380  are disposed at a distal end  8355  of grooves  8354 , slider  8380 , and thus cable plate  8330 , are in a distal-most, or shipping position wherein cables  240  ( FIG. 15 ) are substantially un-tensioned and articulation lock trigger  8310  is in the shipping position such that legs  8382  of slider  8380  are engaged within shipping segments  8316   a  of flanges  8312  of articulation lock trigger  8310 . When slider  8380  is translated proximally, e.g., when articulation lock trigger  8310  is pulled proximally from the shipping position to the use position, as discussed above, slider  8380  and, thus side rails  8388  are moved to proximal ends  8356  of grooves  8354  and cable plate  8330  is translated proximally to tension cables  240  ( FIG. 15 ). 
     As mentioned above, and as shown in  FIGS. 80-82 , linkage  8370  couples articulation lock trigger  8310  to shaft  8320  such that proximal pulling of articulation lock trigger  8310  effects proximal longitudinal translation of shaft  8320 , and such that releasing or returning articulation lock trigger  8310  distally effects distal longitudinal translation of shaft  8320 . 
     Accordingly, pulling, or depressing articulation lock trigger  8310  initially from the shipping position to the use position(s) moves slider  8380  proximally to tension cables  240  ( FIG. 15 ) and similarly moves shaft  8320  proximally to the use positions. Once slider  8380  has been moved to proximal ends  8356  of grooves  8354 , and once shaft  8320  has been moved to the use position(s), spring-loaded latches  8390 ,  8395  engage shaft  8320  and slider  8380 , respectively, to retain articulation mechanism  8300  in the use position. Accordingly, once retained in the use position, articulation mechanism  8300  may be transitioned between the unlocked position and the locked position for fixing and/or unlocking the relative position of articulation section  230  with respect to longitudinal axis “X” (see  FIGS. 3 and 5 ). 
     Referring now to  FIGS. 84-85 , in conjunction with  FIGS. 82-83 , when articulation mechanism  8300  is disposed in the shipping position, spring-loaded latches  8390 ,  8395  are disengaged from shaft  8320  and slider  8380 , respectively. More particularly, proximal crossbar  8397  of latch  8395  is displaced from recess  8389  defined within slider  8380  when articulation mechanism  8300  is disposed in the shipping position and proximal finger  8392  of latch  8390  is disengaged from recess  8329  defined within shaft  8320  when articulation mechanism  8300  is disposed in the shipping position. 
     Latch  8395  is pivotable about pivot  8399  and includes a proximal crossbar  8397  and a distal crossbar  8398  disposed at opposite longitudinal ends of latch  8395 . A spring  8396  biases latch  8395  about pivot  8399  in a clockwise direction (as illustrated in  FIG. 83 ). In other words, spring  8396  biases proximal cross-bar  8397  of latch  8396  downwardly toward slider  8380 . Latch  8390  includes proximal and distal fingers  8392 ,  8394 , respectively, and is similarly pivotable about pivot  8399 . Latch  8390  is also spring-biased, by spring  8391 , in a clockwise direction (as illustrated in  FIG. 82 ) such that proximal finger  8392  is biased downwardly toward shaft  8320 . 
     Upon proximal pulling of articulation lock trigger  8310  from the shipping position to the use position, spring-loaded latches  8390 ,  8395  are engaged within respective recess  8329 ,  8389  defined within shaft  8320  and slider  8380 , respectively, to maintain articulation mechanism  8300  in the use position wherein articulation lock trigger  8310  may further be moved between the unlocked and locked positions. More particularly, as pulling of articulation lock trigger  8310  translates slider  8380  proxiamlly from distal ends  8355  of grooves  8354  to proximal ends  8356  of grooves  8354 , slider  8380  cams proximally along spring-biased latch  8395  until proximal crossbar  8397  of latch  8395  is biased into engagement within recess  8389  defined within slider  8380 . Once engaged within recess  8389 , crossbar  8397  of latch  8395 , due to the spring bias of latch  8395 , in maintained within recess  8389 , thereby preventing slider  8380  form returning to the shipping position, and, thus, maintaining articulation cables  240  ( FIG. 15 ) in the tensioned state. 
     Further, with slider  8380  fixed in position at proximal ends  8356  of grooves  8354  by spring biased latch  8395 , articulation cables  240  ( FIG. 15 ) are maintained in a constant, tensioned state. In other words, fixing slider  8380  fixes the relative position of cable plate  8330 , thus fixing the tension imparted to articulation cables  240  ( FIG. 15 ), regardless of the position of shaft  8320  and/or articulation lock trigger  8310  (i.e., regardless of whether articulation mechanism  8300  is in the unlocked or the locked position). 
     With continued reference to  FIGS. 82-85 , as shaft  8320  is translated proximally, i.e., as articulation lock trigger  8310  is depressed from the shipping position to the use position, shaft  8320  cams proximally along proximal finger  8392  of latch  8390  such that proximal finger  8392  is eventually biased into engagement with recess  8329  defined within shaft  8320 . Similar to latch  8395 , latch  8390  is maintained in engagement within recess  8329  of shaft  8320  due to the biasing-effect of spring  8391 . Accordingly, latch  8390 , when engaged to shaft  8320 , maintains shaft  8320  in more-proximal, use position. 
     When proximal finger  8392  is engaged within recess  8329  of shaft  8320 , shaft  8320  is prevented from returning to the distal-most, or shipping position. However, recess  8329  defines a sufficient length such that shaft  8320  may still translated longitudinally with respect to latch  8390  when latch  8390  is engaged thereto. 
     More specifically, with proximal finger  8392  of latch  8390  disposed within recess  8329  of shaft  8320 , shaft  8320  may be longitudinally translated with respect to latch  8390  such that proximal finger  8392  is translated from proximal end  8329   a  of recess  8329  to distal end  8329   b  of recess  8329  of shaft  8320 . When proximal finger  8392  is disposed at proximal end  8329   a  of recess  8329 , shaft  8320  is disposed in a more-distal position such that lock plate  8324  is in an unlocked position, allowing handle assembly  8350  to be articulated with respect to longitudinal axis “X” to similarly articulate articulation section  230  (see  FIGS. 3 and 5 ) with respect to longitudinal axis “X.” This configuration corresponds to the unlocked, use position of articulation mechanism  8300 . 
     When articulation lock trigger  8310  is pivoted proximally, i.e., depressed, from the unlocked position toward the locked position, shaft  8320  is translated proximally with respect to latch  8390  such that latch  8390  is moved to distal end  8329   b  of recess  8329  of shaft  8320 . As shaft  8320  is moved proximally, lock plate  8324  is similarly moved proximally to pinch, or frictionally-engage the sphere (see  FIGS. 70A-70C ) to the proximal surface of spherical-shaped cavity  8352 , preventing articulation of handle assembly  8350  with respect to elongate outer tube  210  ( FIG. 67A ) and, thus, fixing the position of articulation section  230  with respect to longitudinal axis “X” (see  FIGS. 3 and 5 ). Any of the locking mechanisms described herein may be provided for fixing the position of articulation section  230  (see  FIGS. 3 and 5 ) relative to longitudinal axis “X.” Accordingly, articulation lock trigger  8310  may be selectively depressible to lock and unlock the relative position of articulation section  230  (see  FIGS. 3 and 5 ) with respect to longitudinal axis “X.” 
     If it is desired to “reset” articulation mechanism  8300 , i.e., to return articulation mechanism  8300  to the shipping position, latches  8390  and  8395  may be manually pivoted (as shown in the present embodiment in a counter-clockwise direction) about pivot  8399  to disengage latches  8390  and  8395  from shaft  8329  and slider  8380 , respectively, such that cables  240  ( FIG. 15 ) are returned to the un-tensioned state and such that articulation lock trigger  8310  and shaft  8320  are returned to their respective shipping positions. 
     With reference now to  FIG. 88 , in order to “reset” articulation mechanism  8300 , the user may insert an elongated instrument  9999  (or any other suitable elongated member) through an aperture  8357  defined within the upper portion of handle assembly  8350 . As instrument  9999  is translated through aperture  8357 , instrument  9999  eventually contacts distal ends  8394 ,  8398  of latches  8390 ,  8395 , respectively, urging distal ends  8394 ,  8398  of respective latches  8390 ,  8395  to pivot about pivot  8399  in a counter-clockwise direction (as illustrated in  FIG. 88 ). As can be appreciated, urging latches  8390 ,  8395  in a counter-clockwise direction urges distal ends  8394 ,  8398 , respectively downward and, thus, urges proximal ends  8392 ,  8397  upward, disengaging proximal ends  8392 ,  8397  of respective latches  8390 ,  8395  from recesses  8329 ,  8389  of shaft  8320  and slider  8380 , respectively. As such, the disengagements of latches  8390  and  8395  from shaft  8320  and slider  8380 , respectively, permits slider  8380  and shaft  8320  to be moved back to their respective shipping positions. Accordingly, as slider  8320  is moved distally, cable plate  8330  is similarly moved distally and cables  240  ( FIG. 15 ) are un-tensioned. Shaft  8320  is similarly moved distally to the shipping position such that articulation mechanism  8300  is returned to the shipping position shown in  FIGS. 83 and 84 . 
     Referring now  FIGS. 89-97 , yet another embodiment of an articulation mechanism is shown by  9300 . Articulation mechanism  9300  is similar to articulation mechanism  8300  and is transitionable between a shipping position, an unlocked use position, and a locked use position. As with articulation mechanism  8300 , articulation mechanism  9300  is disposed within handle assembly  9350  and includes an articulation lock trigger  9310  pivotably coupled to a shaft  9320  via a pivot  9360  and a pair of linkages  9390  such that proximal pulling, or rotation of articulation lock trigger  9310  effects proximal longitudinal movement of shaft  9320 . Shaft  9320  includes a lock plate  9324  disposed at a distal end  9322  thereof. A cable plate  9330  including four (4) ferrules  9332  is configured to secure the proximal ends of cables  240  ( FIG. 15 ) therein. Cable plate  9330  is positioned adjacent and distal of lock plate  9324  and includes a pair of arms  9336  extending therefrom. Arms  9336  of cable plate  9330  extend proximally through an aperture defined within lock plate  9324  and along shaft  9320 . A slider  9370  configured for tensioning cables  240  ( FIG. 15 ) upon the initial depression of articulation lock trigger  9310  from the shipping position to the use position(s) is disposed on shaft  9320  toward a proximal end  9323  thereof and is slidable with respect to shaft  9320  within a pair of grooves  9352  defined within handle assembly  9350 . A rocker  9380  is rotatable about a pivot  9382  for retaining slider  9370  in the proximal, use position once articulation lock trigger  9310  is moved from the shipping position to the use position. As will be described below, rocker  9380  is manually resettable, allowing a user to return articulation mechanism  9300  from the use position(s) to the shipping position. 
     With continued reference now to  FIGS. 89-97 , articulation lock trigger  9310  includes a pair of flanges  9312  that extend upwardly on either side of shaft  9320  and are pivotally engaged to shaft  9320  via pivot  9360 . Flanges  9312  include specifically-configured proximal surface segments  9314  that are shaped to rotate rocker  9380  upon depression of articulation lock trigger  9310  from the shipping position to the use position to thereby urge slider  9370  proximally and retain slider  9370  in the proximal-most, or use position. 
     With reference to  FIGS. 89-90 , in conjunction with  FIGS. 91-92 , arms  9336  of cable plate  9330  extend proximally along shaft  9320 . More specifically, arms  9336  are positioned between guide rails  9326  defined along shaft  9320 . Guide rails  9326  permit longitudinal translation of aims  9336  with respect to shaft  9320  but otherwise maintain arms  9336  in fixed relation with respect to shaft  9320 . Shaft  9320  may include specific features, e.g., a dovetail configuration  9328 , to help retain arms  9336  therein. As best shown in  FIG. 92 , each arm  9336  includes a tab  9338  disposed at a proximal end  9337  thereof. Tabs  9338  protrude outwardly (away from shaft  9320 ) and are engaged within notches  9374  defined within legs  9372  of slider  9370 , as best shown in  FIG. 93 . As can be appreciated, due to the engagement of tabs  9338  of arms  9336  of cable plate  9330  within notches  9374  of legs  9372  of slider  9370 , when slider  9370  is translated proximally, e.g., via proximal depression of articulation lock trigger  9310 , arms  9336  and, thus, cable plate  9330 , are similarly translated proximally to thereby tension cables  240  ( FIG. 15 ). 
     Referring now to  FIG. 93-97 , as mentioned above and similarly to articulation mechanism  8300 , slider  9370  of articulation mechanism  9300  is disposed within grooves  9352  of handle assembly  9350 , which limits the range of motion of slider  9370 . More specifically, side rails  9376  of slider  9370  are moveable from distal ends  9353  of grooves  9352 , wherein slider  9370  is in a distal-most position and, thus, wherein cables  240  ( FIG. 15 ) are substantially un-tensioned (the shipping position) to proximal ends  9354  of grooves  9352 , wherein slider  9370  is in a proximal-most position and, thus, wherein cables  240  ( FIG. 15 ) are tensioned (the use position(s)). 
     Rocker  9380  is pivotably engaged to handle assembly  9350  via pivot  9382 . Rocker  9380  includes proximal and distal ends  9284 ,  9386 , respectively. Distal end  9386  of rocker  9380  is configured to engage proximal segments  9314  of flanges  9312  of articulation lock trigger  9310  upon depression of articulation lock trigger  9310  from the shipping position to the use position such that rocker  9380  is rotated in a clockwise direction (as illustrated in  FIG. 94 ). As rocker  9380  is rotated in a clockwise direction (as illustrated in  FIG. 94 ), proximal end  9386  of rocker  9380  is disengaged from its initial position within notches  9358  defined within handle assembly  9350  and is rotated toward protrusion  9378  of slider  9370 . Proximal end  9384  of rocker  9380  engages protrusion  9378  of slider  9370  and urges slider  9370  proximally to proximal ends  9354  of grooves  9352  (the use position), ultimately maintaining slider  9370  in the proximal position, thereby maintaining cables  240  ( FIG. 15 ) in the tensioned state. When rocker  9380  is reset, e.g., when rocker  9380  is rotated in a counter-clockwise direction (as illustrated in  FIG. 93 ), proximal end  9384  of rocker  9380  disengages from protrusion  9378  of slider  9370 , allowing slider  9370  to return to distal end  9356  of grooves  9352  such that cables  240  ( FIG. 15 ) are substantially un-tensioned. 
     The operation of articulation mechanism  9300  and, in particular, the transitioning of articulation mechanism  9300  from the shipping to the use positions (the unlocked and locked positions) will be described with reference to  FIGS. 89-97 . Initially, as shown in  FIG. 89 , articulation mechanism  9300  is disposed in a shipping position wherein articulation lock trigger  9310 , shaft  9320 , cable plate  9330  and slider  9370  are all disposed in distal-most positions and wherein cables  240  ( FIG. 15 ) are substantially un-tensioned. 
     To move articulation mechanism  9300  from the shipping position to the use position, articulation lock trigger  9310  is depressed, or pulled proximally, as shown in  FIG. 93 . Upon pulling of articulation lock trigger  9310 , as mentioned above, shaft  9320  is translated proximally (due to the coupling of articulation lock trigger  9310  and shaft  9320  via linkages  9340 ). Upon further pulling of articulation lock trigger  9310 , proximal segment  9314  of flanges  9312  of articulation lock trigger  9310  engage distal end  9386  of rocker  9380  and rotate rocker  9380  in a clockwise direction (as illustrated in  FIG. 94 ). Rotation of rocker  9380  causes proximal end  9384  of rocker  9380  to disengage notches  9358  of handle assembly  9350  and rotate toward slider  9370 . Further rotation of rocker  9380  eventually engages proximal end  9384  of rocker  9380  with protrusion  9378  of slider  9370 , thereby urging slider  9370  proximally with respect to shaft  9320  from distal end  9353  of grooves  9352  of handle assembly  9350  to proximal end  9354  of grooves  9352  of handle assembly  9350  to tension cables  240  ( FIG. 15 ), as mentioned above. As can be appreciated, proximal end  9384  of rocker  9380  and protrusion  9378  of slider  9370  may include complementary-shaped surface features  9385 ,  9379  respectively, to help maintain the engagement between rocker  9380  and slider  9370  when rocker  9380  is rotated into engagement with slider  9370 . 
     As best shown in  FIG. 94 , the engagement of proximal end  9384  of rocker  9380  with protrusion  9378  of slider  9370  fixedly retains slider  9370  at proximal end  9353  of grooves  9352  and, thus, maintains cables  240  ( FIG. 15 ) in a tensioned state. It should be noted that the tensioning mechanism, e.g., slider  9370  and rocker  9380 , which transition articulation mechanism  9300  from the un-tensioned to the tensioned state, is independent of the locking mechanism, which locks, i.e., fixed, and unlocks the relative position of articulation section  230  (see  FIGS. 3 and 5 ) with respect to longitudinal axis “X.” Thus, when articulation lock trigger  9310  is moved initially from the shipping position to the use position, cables  240  ( FIG. 15 ) are tensioned via the proximal translation of slider  9370  which, in turn, translates arms  9336  of cable plate  9330  proximally. However, once moved to the tensioned state, the tension on cables  240  ( FIG. 15 ) remains substantially constant, regardless of the longitudinal movement of shaft  9320 . 
     Referring momentarily to  FIG. 97 , handle assembly  9350  may include an interference member  9390  disposed thereon and configured to engage distal end  9386  of rocker  9380  upon rotation of rocker  9380  in the clockwise direction (as illustrated in  FIG. 94 ). Interference member  9390  is configured to help maintain rocker  9380  in a fixed position when engaged with protrusion  9378  of slider  9370  such that slider  9370  is maintained in the tensioned position. In other words, interference member  9390 , along with the complementary-shaped surface features  9385 ,  9379  of proximal end  9384  of rocker  9380  and protrusion  9378  of slider  9370 , respectively, fix the position of rocker  9380 , thereby fixing the position of slider  9370  at proximal ends  9354  of grooves  9352 . 
     With reference again to  FIGS. 89-97 , in order to lock (or unlock) articulation mechanism  9300  once in the use position, articulation lock trigger  9310  is pulled proximally which, as mentioned above, translates shaft  9320  proximally. As shaft  9320  is translated proximally, lock plate  9324  is similarly moved proximally to pinch the sphere (see  FIGS. 70A-70C ) to the proximal surface of spherical-shaped cavity  9356 , preventing articulation of handle assembly  9350  with respect to elongate outer tube  210  ( FIG. 67A ) and, thus, fixing the position of articulation section  230  with respect to longitudinal axis “X” (see  FIGS. 3 and 5 ). Any of the locking mechanisms described herein may be provided for fixing the position of articulation section  230  (see  FIGS. 3 and 5 ) relative to longitudinal axis “X.” Accordingly, articulation lock trigger  9310  may be selectively depressible to lock and unlock the relative position of articulation section  230  (see  FIGS. 3 and 5 ) with respect to longitudinal axis “X.” 
     The “reset” feature of articulation mechanism  9300  is substantially similar to that of articulation mechanism  8300 . More specifically, as mentioned above in relation to articulation mechanism  8300 , the user may insert an elongated instrument (or any other suitable elongated member) through aperture  9359  defined within handle assembly  9350 . As the instrument is translated through aperture  9359 , the instrument eventually contacts distal end  9386  of rocker  9380  and urges rocker  9380  to rotate, for example, in a counter-clockwise direction (as illustrated in  FIG. 93 ). As can be appreciated, urging rocker  9380  to rotate in a counter-clockwise direction (as illustrated in  FIG. 93 ) disengages proximal end  9384  of rocker  9380  from protrusion  9378  of slider  9370  (and/or from interference member  9390  of handle assembly  9350 ). The disengagement of rocker  9380  and slider  9370  permits slider  9370  to move back to the distal-most position, wherein cables  240  ( FIG. 15 ) are substantially un-tensioned. Shaft  9320  is similarly moved distally such that articulation mechanism  9300  is returned to the shipping position, as shown in  FIG. 89 . 
     Turning now to  FIGS. 98-100 , in another embodiment of the articulation mechanism, shown as articulation mechanism  9300 ′, rocker  9380 ′ includes a lever  9388 ′ extending upwardly therefrom. Lever  9388 ′ extends through a slot  9359 ′ defined within handle assembly  9350 ′. Rocker  9380 ′ of articulation mechanism  9300 ′ differs from rocker  9380  of articulation mechanism  9300  in that rocker  9380 ′ of articulation mechanism  9300 ′ may be manually rotated by depressing lever  9388 ′ (rather than by pulling articulation lock trigger  9310 ′). Additionally, rocker  9380 ′ obviates the need to insert an elongated instrument into handle assembly  9350 ′ to reset articulation mechanism  9300 ′. 
     As shown in  FIGS. 98 and 99 , when articulation mechanism  9300 ′ is in the shipping position, lever  9388 ′ extends from handle assembly  9350 ′ (when rocker  9380 ′ is disengaged from slider  9370 ′ ( FIG. 100 ). Thus, in order to tension cables  240  ( FIG. 15 ), e.g., to move articulation mechanism  9300 ′ to the use position, the user depressed lever  9388 ′, which rotates rocker  9380 ′ clockwise (as illustrated in  FIG. 94 ) into engagement with slider  9370 ′ such that, fixing slider  9370 ′ at the proximal ends of the grooves (not explicitly shown) and, thus, maintaining cables  240  ( FIG. 15 ) in a tensioned state. To move articulation mechanism  9300 ′ back to the shipping position, lever  9388 ′ is pulled upwardly to rotate rocker  9380 ′ in a counter-clockwise direction (as illustrated in  FIG. 93 ), thereby disengaging rocker  9380 ′ from slider  9370 ′, allowing slider  9370 ′ to translate distally and un-tension cables  240  ( FIG. 15 ). 
     Turning now to  FIGS. 99-100 , articulation mechanism  9300 ′ may also include flexible linkages  9340 ′. Flexible linkages  9340 ′ of articulation mechanism  9300 ′ each define a generally “C”-shaped configuration that provides additional flexibility to linkages  9340 ′. The flexible configuration of linkages  9340 ′ facilitate a uniform clamping force as articulation lock trigger  9310 ′ is moved between the unlocked and locked positions despite unavoidable tolerance variations, thereby allowing for smooth, efficient transition of articulation mechanism  9300 ′ between the unlocked and locked positions. Additionally, the opposed fingers  9342 ′ and  9344 ′ of linkages  9340 ′ may be configured to contact one another when linkages  9340 ′ are flexed under a heavy load, thereby preventing further flexion of linkage  9340 ′. In other words, while linkages  9340 ′ permit some flexion to promote a uniform clamping force upon depression of articulation lock trigger  9310 ′, fingers  9342 ′,  9344 ′ provide support to linkage  9340 ′ by inhibiting over-flexion of linkages  9340 ′. 
     Referring now to  FIGS. 101-103 , a cable tensioning mechanism is shown by  10100 . Cable tensioning mechanism  10100  is configured for transitioning between a shipping position, wherein cables  240  ( FIG. 15 ) are substantially un-tensioned, and a use position, wherein cables  240  ( FIG. 15 ) are tensioned. Cable tensioning mechanism  10100  includes a cam member  10110  that is rotatable 90 degrees with respect to outer shaft  10120  between a shipping position and a use position. Cam member  10110  is coupled to a pusher  10130  that translates longitudinally upon rotation of cam member  10110  between the shipping and use positions to tension (or un-tension) cables  240  ( FIG. 15 ). A ferrule  10140  is engaged to cable shaft  10150  and provides reinforcement to cable shaft  10150  at the interface between cable shaft  10150  and handle assembly  10160 . 
     As best shown in  FIG. 103 , cable plate  10170  includes four (4) apertures  10172  defined therethrough for fixedly retaining the four (4) articulation cables  240  ( FIG. 15 ) therein. Cable plate  10170  is fixedly retained in longitudinal position within spherical cavity  10162  of handle assembly  10160  such that the proximal ends of articulation cables  240  ( FIG. 15 ) are similarly fixedly retained in longitudinal position within spherical cavity  10162  of handle assembly  10160 . Thus, instead of cable plate  10170  translating longitudinally with respect to handle assembly  10160  to tension (or un-tension) articulation cables  240  ( FIG. 15 ) as in some of the previous embodiments, the entire cable shaft  10150  is translated with respect to handle assembly  10160  and, thus, with respect to cable plate  10170 , for tensioning (and un-tensioning) articulation cables  240  ( FIG. 15 ). 
     Referring now to  FIGS. 101-102C , pusher  10130  is disposed annularly about outer shaft  10120  and includes a tubular body  10132  and a proximal mouth  10134  including a pair of slots  10136  defined therein. Pusher  10130  is also coupled to ferrule  10140 . More particularly, tabs  10138 , which extend inwardly from pusher  10130  at distal end  10133  thereof, engage lips  10144 , which extend outwardly from distal end  10143  of ferrule  10140 . As mentioned above, ferrule  10140  is engaged to cable shaft  10150  and reinforces cable shaft  10150  at the proximal end thereof. Cam member  10110  includes a body portion  10112  disposable about tubular body  10132  of pusher  10130  and a pair of proximally-extending arms  10114 . Each arm  10114  includes a peg  10116  extending inwardly therefrom and defining a cam surface  10118 . Pegs  10116  are configured to be rotatably disposed within slots  10136  of pusher  10130 . As mentioned above, cam member  10110  is rotatable 90 degrees with respect to outer shaft  10120  about pusher  10130 . More specifically, cam member  10110  is rotatable from a shipping position, wherein body portion  10112  of cam member  10110  is positioned adjacent tubular body  10132  of pusher  10130  to a use position, wherein cam member  10110  is rotated about pegs  10116  (which are disposed within slots  10136  of pusher  10130 ) such that body portion  10112  of cam member is displaced from tubular body  10132  of pusher  10130 . Upon rotation of cam member  10110  with respect to pusher  10130 , cam surfaces  10118  of pegs  10116  cam along slots  10136  of mouth  10134  of pusher  10130 , urging pusher  10130  distally which, in turn, urges ferrule  10140  and cable shaft  10150  distally relative to handle assembly  10160 . Thus, as can be appreciated, translating ferrule  10140  and cable shaft  10150  distally with respect to handle assembly  10160  translates the entire proximal portion of the instrument distally, including the proximal ends of articulation cables  240  ( FIG. 15 ) such that articulation cables  240  ( FIG. 15 ) are tensioned. 
     The operation of cable tensioning mechanism  10100  will now be described with reference to  FIGS. 101 and 103 . Initially, when tensioning mechanism  10100  is in the shipping, or un-tensioned position, as shown in  FIG. 101 , body portion  10112  of cam member  10110  is positioned adjacent tubular body  10132  of pusher  10130  and cable shaft  10150  is in a proximal-most position with respect to handle assembly  10160  such that articulation cables  240  ( FIG. 15 ) are substantially un-tensioned. 
     In order to tension articulation cables  240  ( FIG. 15 ), i.e., in order to transition tensioning mechanism  10100  to the use position, cam member  10110  is rotated 90 degrees about pegs  10116  from the shipping position to the use position. As mentioned above, rotating cam member  10110  about pegs  10116  causes cam surfaces  10118  of pegs  10116  to cam along slots  10136  of mouth  10134  of pusher  10130 , urging pusher  10130 , ferrule  10140 , and cable shaft  10150  distally. As a result, the proximal end of the instrument is urged distally with respect to handle assembly  10160  to tension articulation cables  240  ( FIG. 15 ). To reset, or return tensioning mechanism  10100  to the shipping position, cam member  10110  is simply rotated back to the position adjacent outer shaft  10120 , allowing pusher  10130 , ferrule  10140  and cable shaft  10150  to return proximally to the shipping position to un-tension articulation cables  240  ( FIG. 15 ). 
     As can be appreciated, tensioning mechanism  10100  may be used in conjunction with any of the above-described articulation mechanisms to provide independent mechanisms for transitioning the instrument from a shipping position to a use position, i.e., for tensioning articulation cables  240  ( FIG. 15 ), and for locking (or un-locking) the relative position of articulation section  230  (see  FIGS. 3 and 5 ) relative to longitudinal axis “X.” 
     Turning now to  FIG. 104 , a cable guiding rod is shown generally as  10200 . Cable guiding rod  10200  is configured for positioning within elongate shaft  210  (see  FIG. 5 ) for guiding articulation cables  240  ( FIG. 15 ) from articulation section  230  (see  FIGS. 3 and 5 ), through elongate shaft  210  (see  FIG. 5 ), to cable plate  311  ( FIG. 11A ) wherein the proximal ends of articulation cables  240  ( FIG. 15 ) are secured. As discussed above, articulation cables  240  ( FIG. 15 ) are selectively tensionable to transition between a shipping position and a use position. Further, each of articulation cables  240   A-D  ( FIG. 15 ) is selectively tensionable upon articulation of the handle assembly  300  ( FIG. 1 ) with respect to longitudinal axis “X” (depending on the direction of articulation) to articulate articulation section  230  (see  FIGS. 3 and 5 ) with respect to longitudinal axis “X” in a similar direction. 
     In order for the articulation of articulation section  230  (see  FIGS. 3 and 5 ) to correspond to the same direction of articulation as handle assembly  300  (see  FIG. 1 ), the distal ends of articulation cables  240   A-D  ( FIG. 15 ), which are engaged to cable plate  311  (see  FIG. 11A ), are rotated 180 degrees with respect to the proximal ends of articulation cables  240   A-D  ( FIG. 15 ), which are engaged within distal outer tube  220  ( FIG. 20 ). Thus, cable guiding rod  10200  includes four (4) channels  10240  defined on external surface  10210  thereof, each channel  10240   A-D  configured to retain one of articulation cables  240   A-D  ( FIG. 15 ) therein. Each channel  10240   A-D  winds helically about cable guide rod  10200  such that, for example, proximal end  10230   C  of channel  10240   C  is disposed on a top side of cable guiding rod  10200  and winds therearound from proximal end  10230  of cable guiding rod  10200  to distal end  10220  of cable guiding rod  10200  such that distal end  10220   C  of channel  10240   C  is disposed on a bottom side of cable guiding rod  10200 . Similarly, for example, proximal end  10230   E  of channel  10240   B  is disposed on a right side of cable guiding rod  10200  and winds therearound from proximal end  10230  of cable guiding rod  10200  to distal end  10220  of cable guiding rod  10200  such that distal end  10220   C  of channel  10240   C  is disposed on a left side of cable guiding rod  10200 . This configuration of cable guiding rod  10200  reduces the friction on articulation cables  240  ( FIG. 15 ) and improves the stability of consistency of articulation of articulation section  230  (see  FIGS. 3 and 5 ). 
     With continued reference to  FIG. 104 , cable guiding rod  10200  further includes a central lumen  10250  extending therethrough. Central lumen  10250  is configured for insertion of torque shaft  499  (see  FIGS. 11B and 11C ) therethrough. Torque shaft  499  (see  FIGS. 11B and 11C ) receives increased support by being disposed within cable guiding rod  10200 . 
     Referring now to  FIGS. 105-106 , another embodiment of the articulation links is shown. Articulation links  1232  are substantially similar to articulation links  232 ,  234 , discussed above (see  FIGS. 13-15 ), and thus will only be discussed in detail herein to the extent necessary to describe differences in construction and use thereof. As seen in  FIGS. 105 and 106 , each articulation link  1232  includes a central opening  1234  and a plurality of bores  1236 , e.g., four (4) bores  1236 , positioned about central opening  1234 . Central openings  1234  of articulation links  1232  are adapted to receive distal torque tube  492  ( FIG. 20 ) therethrough, while each bore  1236  is configured to receive an articulation cable  240  ( FIG. 25 ) therethrough. 
     Each articulation link  1232  further includes a pair of recesses  1238  defined within proximal surfaces  1240  thereof and a pair of extension members  1242  extending distally from distal surfaces  1244  thereof. Further, proximal and distal surfaces  1240 ,  1244 , respectively, of adjacent articulation links  1232  are contoured to mate with one another, while still allowing a certain degree of motion relative to one another. Likewise, the corresponding extension members and recesses  1238 ,  1242 , respectively, of adjacent articulation links  1232  are configured to engage one another, while allowing for a certain degree of motion relative to one another. 
     With continued reference to  FIGS. 105-106 , each articulation link  1232  further includes one or more indents, or chamfers  1246 ,  1248 , defined within proximal and distal surfaces  1240 ,  1244 , respectively, thereof. More specifically, as shown in  FIG. 105 , a pair of chamfers  1248  are defined within distal surface  1244  of each articulation link  1232  between adjacent bores  1236  thereof and on the outer periphery of distal surface  1244 . Similarly, as shown in  FIG. 106 , a pair of chamfers  1246  are defined within proximal surface  1240  of each articulation link  1232  between adjacent bores  1236  thereof and on the outer periphery of proximal surface  1240 . However, it is contemplated that more or fewer chamfers  1246 ,  1248  may be provided and/or that chamfers  1248 ,  1246  of proximal and distal surfaces  1240 ,  1244 , respectively, of articulation links  1232  may be positioned in various other configurations on proximal and distal surfaces  1240 ,  1244 , respectively, of articulation links  1232 . 
     Referring now to  FIGS. 107-108 , proximal-most articulation link  1250  is substantially similar to proximal-most link  496 , discussed above (see  FIG. 11A ), and thus will only be discussed in detail herein to the extent necessary to describe differences in construction and use thereof. Specifically, proximal-most articulation link  1250  includes a distal surface  1252  that is substantially similar to distal surfaces  1244  of articulation links  1232  discussed above (see  FIGS. 105-106 ). In other words, proximal-most articulation link  1250  includes one or more chamfers  1254  defined within distal surface  1252  of proximal-most articulation link  1250  toward the outer periphery thereof. However, unlike articulation links  1232 , proximal-most articulation link  1250  further includes an extension  1256  protruding proximally therefrom that is configured to be securely received within the distal end of endoscopy assembly  200  (see  FIG. 32 ). 
     With reference now to  FIGS. 109 and 110 , there is illustrated an articulation section  2230  including a plurality of articulation links  1232  and a proximal-most articulation link  1250 . Articulation section  2230  may be supported on distal end  214  of elongate outer tube  210  ( FIG. 3 ). Articulation section  2230  is configured to articulate with respect to elongate outer tube  210  upon actuation of handle assembly  300  ( FIG. 3 ). As described hereinabove, elongate outer tube  210  and articulating section  2230  are longitudinally aligned with each other when handle assembly  300  is positioned in a neutral position. The movement of articulation section  2230  relative to elongate outer tube  210  mirrors the motion of handle assembly  300  with respect to elongate outer tube  210 . Furthermore, a tool assembly or any suitable end effector such as end effector  260  ( FIG. 7 ), may be operatively coupled to a distal end  2238  of articulation section  2230 . 
     The number of articulation links  1232  may be tailored to a particular application to achieve the desired flexibility or degree of articulation. Regardless of the number of the articulation links  1232 , articulation section  2230  may move from a first position that is longitudinally aligned with elongate outer tube  210  to numerous offset positions with respect to elongate outer tube  210 . 
     With continued reference to  FIGS. 109 and 110 , each articulation link  1232  is oriented or offset 90 degrees relative to an adjacent articulation link  1232  about a longitudinal axis “L-L” defined by articulation section  2230 . In this manner, when extension members  1242  of articulation links  1232  are slidably disposed in the corresponding recesses  1238  of an adjacent articulation link  1232 , chamfers  1248  defined in distal surface  1244  of articulation link  1232  at least partially overlap with chamfers  1246  defined in proximal surface  1240  of the adjacent articulation link  1232  to define a gap  2275  therebetween. Similarly, chamfers  1254  defined in distal surface  1252  of proximal-most articulation link  1250  at least partially overlap with chamfers  1246  defined in proximal surface  1240  of an adjacent articulation link  1232  to define a gap  2375  therebetween. 
     Gaps  2275 ,  2375  defined by or near the outer peripheries of adjacent links  1232 ,  1250  are particularly advantageous in embodiments where articulation section  2230  is encased within a shrink-wrap material, such as sheath  270  ( FIGS. 7,11A and 20 ) or other form-fitting encasement material, as shown in  FIGS. 111 and 112 . More specifically, by providing this clearance, chamfers  1246 ,  1248  and  1254  reduce the likelihood of catching, pinching and/or tearing of the shrink wrap material or sheath  270  between adjacent articulation links  1232  and/or proximal-most articulation link  1250  during articulation of articulation section  2230 , which creates a portion of the plurality of articulation links  1232  and proximal-most articulation link  1250  in compression, as shown in  FIG. 112 . Further, during the shrink-wrapping, e.g., heat-shrinking, process, chamfers  1246 ,  1248  and  1254  help ensure that the shrink-wrap material or sheath  270  is uniformly distributed over articulation section  2230 . A uniform distribution of the shrink-wrap material or sheath  270  promotes more evenly-distributed stress concentrations along the shrink-wrap material or sheath  270  during articulation of articulation section  2230 , thereby reducing the likelihood of tearing of the shrink-wrap material or sheath  270 . 
     It will be understood that various modifications may be made to the embodiments of the presently disclosed surgical device. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.