Patent Publication Number: US-2021161585-A1

Title: Multi-function surgical instruments

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a divisional of U.S. application Ser. No. 15/432,212, filed Feb. 14, 2017, which is a continuation application of U.S. application Ser. No. 14/276,465, filed on May 13, 2014, now U.S. Pat. No. 9,579,117, which claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/882,172, filed on Sep. 25, 2013, the entire contents of each of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to surgical instruments and, more particularly, to multi-function surgical instruments for treating tissue. 
     Background of Related Art 
     Many surgical instruments include one or more movable handles, levers, actuators, triggers, etc. for actuating and/or manipulating one or more functional components of the surgical instrument. For example, a surgical forceps may include a movable handle that is selectively compressible relative to a stationary handle for moving first and second jaw members of the forceps between spaced-apart and approximated positions for grasping tissue therebetween. Such a forceps may further include a trigger for selectively deploying a knife between the jaw members to cut tissue grasped therebetween and a rotation wheel for rotating the end effector assembly about a longitudinal axis. 
     In general, each functional component provided with a surgical instrument requires a corresponding actuating mechanism for actuating that particular component, e.g., a movable handle, trigger, or rotation wheel. As the number of functional components increases, the arrangement, organization, and interplay between the various actuating mechanisms becomes increasingly important. 
     SUMMARY 
     As used herein, the term “distal” refers to the portion that is being described that is further from a user, while the term “proximal” refers to the portion that is being described that is closer to a user. Further, to the extent consistent, any of the aspects described herein may be used in conjunction with any of the other aspects described herein. 
     In accordance with aspects of the present disclosure, a surgical instrument is provided. The surgical instrument includes a housing having a shaft extending distally therefrom, an outer sleeve disposed about the shaft and selectively translatable relative to the shaft, a first drive shaft disposed within the shaft and translatable relative to the shaft independently of the outer sleeve, a second drive shaft disposed within the first drive shaft and coupled to the outer sleeve to translate in conjunction with the outer sleeve, and a rotatable nose wheel mounted about a distal end of the housing. The rotatable nose wheel is disposed about the outer sleeve and is rotatably coupled to each of the outer sleeve, the shaft, the first drive shaft, and the second drive shaft such that rotation of the rotatable nose wheel effects corresponding rotation of the outer sleeve, the shaft, the first drive shaft, and the second drive shaft in conjunction with one another and relative to the housing. 
     In aspects, the rotatable nose wheel includes a transverse bar extending through an interior thereof and each of the outer sleeve, the first drive shaft, and the second drive shaft define longitudinal slots configured to slidably receive the transverse bar to rotatably fix the outer sleeve, the first drive shaft, and the second drive shaft relative to one another and relative to the rotatable nose wheel. In such aspects, the shaft may define an aperture configured to receive the transverse bar to longitudinally and rotatably fix the shaft relative to the rotatable nose wheel. 
     In aspects, the surgical instrument further includes a first bushing disposed about the outer sleeve. The first bushing includes a pin extending through a longitudinal slot defined within the shaft, the longitudinal slot of the first drive shaft, and engaged within an aperture defined within the second drive shaft to longitudinally fix the outer sleeve and the second drive shaft to one another such that the outer sleeve and the second drive shaft translate in conjunction with one another independently of the shaft and the first drive shaft. 
     In aspects, an actuator assembly is provided for longitudinally translating the outer sleeve and the second drive shaft between a retracted position and a deployed position. The actuator assembly includes a linkage rotatably fixed relative to the housing and operably engaged to the first bushing for translating the outer sleeve and the second drive shaft relative to the housing regardless of the rotational orientation of the first bushing relative to the linkage. 
     In aspects, as an alternative to the first bushing, a second bushing is coupled to each of the outer sleeve, the shaft, the first drive shaft, and the second drive shaft in fixed rotational orientation relative thereto. The second bushing includes a pair of flanges rotatably fixed and slidably received within corresponding tracks defined within the rotatable nose wheel such that rotation of the rotatable nose wheel effects corresponding rotation of the outer sleeve, the shaft, the first drive shaft, and the second drive shaft. In such aspects, the second bushing may further include a pin extending therethrough for coupling the second bushing to each of the outer sleeve, the shaft, the first drive shaft, and the second drive shaft. 
     In aspects, the pin of the second bushing extends through an aperture defined within the outer sleeve, a longitudinal slot defined within the shaft, a longitudinal slot defined within the first drive shaft, and an aperture defined within the second drive shaft to longitudinally fix the second bushing, the outer sleeve, and the second drive shaft to one another such that the second bushing, the outer sleeve, and the second drive shaft translate in conjunction with one another independently of the shaft and the first drive shaft. 
     In aspects, the surgical instrument further includes an actuator assembly for longitudinally translating the outer sleeve and the second drive shaft between a retracted position and a deployed position. The actuator assembly includes a linkage rotatably fixed relative to the housing and operably engaged to the second bushing for translating the outer sleeve and the second drive shaft regardless of the rotational orientation of the second bushing relative to the linkage. 
     In aspects, the surgical instrument further includes an end effector assembly mounted at a distal end of the shaft. The rotatable nose wheel is rotatable relative to the housing to rotate the end effector assembly relative to the housing. In such aspects, the first drive shaft may be coupled to the end effector assembly at a distal end of the first drive shaft such that the first drive shaft is translatable relative to the end effector assembly to manipulate the end effector assembly between a first condition and a second condition. 
     In aspects, a third drive shaft is provided. The third drive shaft is disposed within the second drive shaft and is translatable relative to the shaft independently of the outer sleeve and the first drive shaft. The rotatable nose wheel is rotatably coupled to the third drive shaft such that rotation of the rotatable nose wheel effects corresponding rotation of the outer sleeve, the shaft, the first drive shaft, the second drive shaft, and the third drive shaft in conjunction with one another and relative to the housing. 
     A surgical instrument provided in accordance with aspects of the present disclosure includes a housing having a shaft extending distally therefrom. The shaft defines a longitudinal slot and an aperture distally of the longitudinal slot. An outer sleeve is slidably disposed about the shaft. The outer sleeve defines a longitudinal slot and an aperture proximally of the longitudinal slot. A first drive shaft is slidably disposed within the shaft. The first drive shaft defines a longitudinal slot. A second drive shaft is disposed within the first drive shaft. The second drive shaft defines a longitudinal slot and an aperture proximally of the longitudinal slot. A bushing is disposed about the outer sleeve. The bushing includes a pin extending through the aperture of the outer sleeve, the longitudinal slot of the shaft, the longitudinal slot of the first drive shaft, and the aperture of the second drive shaft to longitudinally fix the outer sleeve and the second drive shaft to one another and permit translation of the outer sleeve and the second drive shaft relative to the shaft and the first drive shaft. A rotatable nose wheel is mounted about a distal end of the housing. The rotatable nose wheel is disposed about the outer sleeve. The rotatable nose wheel includes a transverse bar extending through the aperture of the shaft and the longitudinal slots of the outer sleeve, the first drive shaft, and the second drive shaft such that rotation of the rotatable nose wheel effects corresponding rotation of the outer sleeve, the shaft, the first drive shaft, and the second drive shaft in conjunction with one another and relative to the housing. 
     In aspects, an actuator assembly is provided for longitudinally translating the outer sleeve and the second drive shaft between a retracted position and a deployed position. The actuator assembly includes a linkage rotatably fixed relative to the housing and operably engaged to the bushing for translating the outer sleeve and the second drive shaft relative to the housing regardless of the rotational orientation of the bushing relative to the linkage. 
     In aspects, an end effector assembly is mounted at a distal end of the shaft. The rotatable nose wheel is rotatable relative to the housing to rotate the end effector assembly relative to the housing. The first drive shaft may be coupled to the end effector assembly at a distal end of the first drive shaft. In such aspects, the first drive shaft may be translatable relative to the end effector assembly to manipulate the end effector assembly between a first condition and a second condition. 
     A surgical instrument provided in accordance with aspects of the present disclosure includes a housing having a shaft extending distally therefrom. The shaft defines a longitudinal slot. An outer sleeve is slidably disposed about the shaft and defines an aperture. A first drive shaft is slidably disposed within the shaft and defines a longitudinal slot. A second drive shaft is disposed within the first drive shaft and defines an aperture. A bushing is disposed about the outer sleeve. The bushing includes a pin extending through the aperture of the outer sleeve, the longitudinal slot of the shaft, the longitudinal slot of the first drive shaft, and the aperture of the second drive shaft to longitudinally fix the outer sleeve and the second drive shaft to one another and permit translation of the outer sleeve and the second drive shaft relative to the shaft and the first drive shaft. The bushing also includes a pair of flanges extending therefrom. A rotatable nose wheel is mounted about a distal end of the housing and is disposed about the outer sleeve. The rotatable nose wheel defines a pair of tracks configured to slidably receive the flanges of the bushing in fixed rotational orientation relative thereto such that rotation of the rotatable nose wheel effects corresponding rotation of the outer sleeve, the shaft, the first drive shaft, and the second drive shaft in conjunction with one another and relative to the housing. 
     In aspects, the surgical instrument further includes an actuator assembly for longitudinally translating the outer sleeve and the second drive shaft between a retracted position and a deployed position. The actuator assembly includes a linkage rotatably fixed relative to the housing and operably engaged to the bushing for translating the outer sleeve and the second drive shaft regardless of the rotational orientation of the bushing relative to the linkage. 
     In aspects, the surgical instrument further includes an end effector assembly mounted at a distal end of the shaft. The rotatable nose wheel is rotatable relative to the housing to rotate the end effector assembly relative to the housing. In such aspects, the first drive shaft may be coupled to the end effector assembly at a distal end of the first drive shaft such that the first drive shaft is translatable relative to the end effector assembly to manipulate the end effector assembly between a first condition and a second condition. 
     In aspects, a third drive shaft is provided. The third drive shaft is disposed within the second drive shaft and is translatable relative to the shaft independently of the outer sleeve and the first drive shaft. The rotatable nose wheel is rotatably coupled to the third drive shaft such that rotation of the rotatable nose wheel effects corresponding rotation of the outer sleeve, the shaft, the first drive shaft, the second drive shaft, and the third drive shaft in conjunction with one another and relative to the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of the present disclosure are described herein with reference to the drawings wherein like reference numerals identify similar or identical elements: 
         FIG. 1  is a side, perspective view of an endoscopic surgical forceps provided in accordance with the present disclosure; 
         FIG. 2A  is an enlarged, perspective view of the end effector assembly of the forceps of  FIG. 1  wherein jaw members of the end effector assembly disposed in a spaced-apart position; 
         FIG. 2B  is an enlarged, perspective view of the end effector assembly of  FIG. 2A  wherein the jaw members are disposed in an approximated position and wherein the monopolar assembly is disposed in a deployed position; 
         FIG. 3A  is a longitudinal, cross-sectional view of the distal end of the forceps of  FIG. 1  with the jaw members disposed in the spaced-apart position; 
         FIG. 3B  is a longitudinal, cross-sectional view of the distal end of the forceps of  FIG. 1  with the jaw members disposed in an approximated position; 
         FIG. 3C  is a longitudinal, cross-sectional view of the distal end of the forceps of  FIG. 1  with the jaw members disposed in the approximated position and the knife disposed in an extended position; 
         FIG. 3D  is a longitudinal, cross-sectional view of the distal end of the forceps of  FIG. 1  with the jaw members disposed in the approximated position and the monopolar assembly disposed in the deployed position; 
         FIG. 4A  is a side view of the proximal end of the forceps of  FIG. 1  shown in a first position, wherein a portion of the housing has been removed to show the internal components thereof; 
         FIG. 4B  is a side view of the proximal end of the forceps of  FIG. 1  shown in a second position, wherein a portion of the housing has been removed to show the internal components thereof; 
         FIG. 5  is an exploded, side view illustrating the arrangement of the actuation assemblies of the forceps of  FIG. 1 ; 
         FIG. 6A  is a side view of the proximal end of another forceps provided in accordance with the present disclosure shown in a first position, wherein a portion of the housing has been removed to show the internal components thereof; 
         FIG. 6B  is a side view of the proximal end of the forceps of  FIG. 6A  shown in a second position, wherein a portion of the housing has been removed to show the internal components thereof; 
         FIG. 7  is an exploded, side view illustrating the arrangement of the actuation assemblies of the forceps of  FIGS. 6A-6B ; 
         FIG. 8A  is an enlarged, top, perspective view of the internal components disposed within the housing of the forceps of  FIG. 1 ; and 
         FIG. 8B  is an enlarged, bottom, perspective view of the internal components disposed within the housing of the forceps of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIGS. 1-5 , a forceps provided in accordance with the present disclosure is shown generally identified by reference numeral  10 . Forceps  10  is configured to operate in both a bipolar mode, e.g., for grasping, treating, and/or dissecting tissue, and a monopolar mode, e.g., for treating and/or dissecting tissue, although other configurations are also contemplated. As such, and as will be described in greater detail below, forceps  10  includes multiple actuation assemblies and components configured to facilitate the various operations of forceps  10 . In particular, the various actuation assemblies and components of forceps  10  are particularly arranged and configured to minimize the size of the housing of forceps  10 , thus allowing a user to readily grasp forceps  10  and manipulate forceps  10  with a single handle, without compromising the functionality of any of the functional components of forceps  10 . Further, the actuation shafts and sleeves of the various functional components of forceps  10  are concentrically arranged so as to minimize the diameter of the elongated shaft portion of forceps  10 , thus facilitating use of forceps  10  in endoscopic procedures. Alternatively, forceps  10  may be configured for use in open surgical procedures. 
     Continuing with reference to  FIGS. 1-5 , forceps  10  includes an outer fixed shaft  12  defining a longitudinal axis “X-X,” a housing  20 , a handle assembly  30 , a trigger assembly  60 , a rotating assembly  70 , a lever assembly  80 , an end effector assembly  100 , and a monopolar assembly  200 . Outer fixed shaft  12  defines a distal end  14  that is configured to mechanically engage end effector assembly  100  and a proximal end  16  that mechanically engages housing  20 . Housing  20  is configured to house the internal working components of forceps  10 , which will be descried in detail below. Rotating assembly  70  includes a rotatable nose wheel  72  which is rotatably disposed about the distal end of housing  20 . Rotatable nose wheel  72  is rotatable about longitudinal axis “X-X” in either direction to effect corresponding and cooperative rotation of outer fixed shaft  12  (and the internal components therein), end effector assembly  100 , and monopolar assembly  200 , as will be described in detail below. 
     Referring to  FIGS. 2A-3D , end effector assembly  100  is shown attached at a distal end  14  of outer fixed shaft  12  and includes a pair of opposing jaw members  110  and  120 . Each jaw member  110  and  120  includes a distal jaw portion  110   a ,  120   a  and a proximal flange portion  110   b ,  120   b  extending proximally from the respective distal jaw portion  110   a ,  120   a . Proximal flange portions  110   b ,  120   b  of jaw members  110 ,  120 , respectively, are pivotably coupled to one another about a pivot  102 . Distal jaw portions  110   a ,  120   a  of jaw members  110 ,  120 , respectively, each include an electrically-insulative outer jaw housing  111 ,  121  and an electrically-conductive plate  112 ,  122  disposed atop respective jaw housings  111 ,  121 , although other configurations are also contemplated. Plates  112 ,  122  of jaw members  110 ,  120 , respectively, are adapted to connect to any suitable source of energy (not explicitly shown), e.g., electrosurgical, ultrasonic, microwave, light, etc., for conducting energy therebetween and through tissue grasped between jaw members  110 ,  120  to treat, e.g., seal, tissue. In one particular configuration, end effector assembly  100  defines a bipolar configuration wherein plate  112  is charged to a first electrical potential and plate  122  is charged to a second, different electrical potential such that an electrical potential gradient is created for conducting energy between plates  112 ,  122  and through tissue grasped therebetween for treating e.g., sealing, tissue. Activation switch  90  ( FIG. 1 ) is likewise coupled to plates  112 ,  122 , thus allowing the user to selectively apply energy to plates  112 ,  122  of end effector assembly  100  for treating, e.g., sealing, tissue during a bipolar mode of operation. Forceps  10  may further include a cable  2  ( FIG. 1 ) for connecting end effector assembly  100  to external power and energy sources, or may be configured as a wireless, battery-powered device having power and energy-generating components disposed within housing  20 . 
     End effector assembly  100  is designed as a unilateral assembly, i.e., where jaw member  120  is fixed relative to outer fixed shaft  12  and jaw member  110  is movable relative to outer fixed shaft  12  and fixed jaw member  120 . More specifically, jaw member  110  is operably coupled to a drive shaft  142  ( FIG. 5 ) such that proximal translation of drive shaft  142  ( FIG. 5 ) relative to jaw member  110  pulls jaw member  110  to pivot relative to jaw member  120  towards the approximated position, while distal translation of drive shaft  142  ( FIG. 5 ) relative to jaw member  110  urges jaw member  110  to pivot relative to jaw member  120  towards the spaced-apart position (although the reverse configuration or other suitable jaw-drive mechanisms are also contemplated). End effector assembly  100  may alternatively be configured as a bilateral assembly, i.e., where both jaw member  110  and jaw member  120  are movable relative to one another and to outer fixed shaft  12  in response to translation of drive shaft  142  ( FIG. 5 ). In some embodiments, a knife channel  115 ,  125  may be defined within one or both of jaw members  110 ,  120  to permit reciprocation of a knife  184  therethrough, e.g., upon actuation of trigger  62  of trigger assembly  60 . 
     With continued reference to  FIGS. 2A-3D , one of the jaw members  110 ,  120  of end effector assembly  100 , e.g., jaw member  120 , is configured to house energizable rod member  220  of monopolar assembly  200 . More specifically, the proximal flange portion of one of the jaw members, e.g., proximal flange portion  120   b  of jaw member  120 , includes an extension portion  126  having a lumen  128   a  and recess  128   b  defined therein. Lumen  128   a  extends through extension portion  126  into communication with recess  128   b , which is defined within the distal surface of proximal flange portion  120   b  of jaw member  120 . This configuration of proximal flange portion  120   b  of jaw member  120  permits body  222  of energizable rod member  220  of monopolar assembly  200  to extend through proximal flange portion  120   b  of jaw member  120 , e.g., through lumen  128   a , while also permitting distal tip  224  of rod member  220  of monopolar assembly  200  to be received within recess  128   b  of proximal flange portion  120   b  when monopolar assembly  200  is disposed in the retracted position, thereby helping to protect surrounding tissue. The entire proximal flange portion  120   b  of jaw member  120  or simply extension portion  126  thereof may be formed from an insulative material or may be coated with an insulative material to facilitate the insulation of distal tip  224  of rod member  220  when monopolar assembly  200  is disposed in the retracted position. 
     Referring again to  FIGS. 1-5 , monopolar assembly  200  includes an insulative sleeve  210  and an energizable rod member  220 . Insulative sleeve  210  is slidably disposed about outer fixed shaft  12  and is configured for translation about and relative to outer fixed shaft  12  between a retracted position ( FIGS. 2A and 3A-3C ), where insulative sleeve  210  is disposed proximally of end effector assembly  100 , and a deployed position ( FIGS. 2B and 3D ), wherein insulative sleeve  210  is disposed about end effector  100  so as to electrically insulate plates  112 ,  122  of jaw members  110 ,  120 , respectively, from the surroundings of insulative sleeve  210 . Energizable rod member  220  is coupled to an inner shaft  226  disposed within drive shaft  142  of drive assembly  140  for moving energizable rod member  220  between a retracted position, wherein energizable rod member  220  is disposed within recess  128   b  of extension portion  126  of proximal flange portion  120   b  of jaw member  120  ( FIG. 2A ), and a deployed position, wherein energizable rod member  220  extends distally from end effector assembly  100  ( FIG. 2B ). Energizable rod member  220  is coupled to insulative sleeve  210 , as will be described in greater detail below, such that advancement of insulative sleeve  210  between the retracted and deployed positions and advancement of energizable rod member  220  between the retracted and deployed positions are effected concurrently or near concurrently, via actuation of lever assembly  80 . Energizable rod member  220  is ultimately coupled to a source of energy for providing energy to distal tip  224  of energizable rod member  220 , e.g., upon actuation of activation switch  90  ( FIG. 1 ) in a monopolar mode of operation, for treating tissue using monopolar energy. 
     With continued reference to  FIGS. 1-5 , as mentioned above, forceps  10  is a multi-function surgical instrument capable of grasping tissue, dissecting tissue, treating tissue with monopolar energy, and/or treating tissue bipolar energy. In particular, handle assembly  30  is operably coupled to end effector assembly  100  via a drive assembly  140  for selectively pivoting jaw members  110 ,  120  between the spaced-apart and approximated positions to grasp tissue, trigger assembly  60  is operably coupled to knife assembly  180  for selectively translating knife  184  between jaw members  110 ,  120  and through tissue grasped therebetween to dissect tissue, and lever assembly  80  is operably coupled to monopolar assembly  200  for selectively moving monopolar assembly  200  between the retracted and deployed positions. Further, rotating assembly  70  is rotatable about longitudinal axis “X-X” to rotate outer fixed shaft  12  (and the internal components therein), end effector assembly  100 , and monopolar assembly  200  about longitudinal axis “X-X” and relative to housing  20 . Activation switch  90  is operably coupled to plates  112 ,  122  of jaw members  110 ,  120 , respectively, of end effector assembly  100 , and distal tip  224  of energizable rod member  220  of monopolar assembly  200 , for selectively supplying energy thereto for treating tissue in a bipolar mode of operation and a monopolar mode of operation, respectively. As will be described below, the arrangement and configuration of these various functional components and assemblies of forceps  10  provides for a minimally-sized housing  20  without compromising functionality. 
     Handle assembly  30  includes a movable handle  40  and a fixed handle  50 . Fixed handle  50  is integrally associated with housing  20 . Movable handle  40  includes a lever  42  defining a finger hole  43  and a bifurcated arm  46  extending upwardly from lever  42  and into housing  20 . Arm  46  is bifurcated to define first and second spaced-apart flanges that are pivotably coupled to opposed sides of housing  20  via a fixed split pivot  45 . Movable handle  40  is pivotable about split pivot  45  and relative to fixed handle  50  between an initial position, wherein movable handle  40  is spaced from fixed handle  50 , and a compressed position, wherein movable handle  40  is approximated relative to fixed handle  50 . The flanges of arm  46  are each coupled to a distal end of a drive linkage  48  via a first movable pivot  52  that is longitudinally spaced from fixed spit pivot  45 . The proximal ends of drive linkages  48 , in turn, are pivotably coupled to the free ends of legs  145  of spring cartridge  144  of drive assembly  140  via a second movable pivot  53 . 
     Drive assembly  140  includes a spring cartridge  144  slidably disposed within housing  20 , and a drive shaft  142 . Drive shaft  142  is coupled to and extends distally from spring cartridge  144 , through outer fixed shaft  12  of forceps  10 , ultimately coupling to jaw member  110  of end effector assembly  100 , as described above. Spring cartridge  144  houses a biasing member (not explicitly shown) that serves to bias drive shaft  142  distally and movable handle  40  towards the initial position, thus biasing jaw members  110 ,  120  towards the spaced-apart position. Spring cartridge  144  defines a lumen (not explicitly shown) extending longitudinally therethrough that is configured to slidably receive knife drive shaft  182 . Spring cartridge  144  further includes a pair of spaced-apart legs  145 , which extend proximally from spring cartridge  144 . The proximal ends of drive linkages  48 , as mentioned above, are pivotably coupled to the free ends of legs  145  of spring cartridge  144 . Thus, as movable handle  40  is moved from the initial position towards the compressed position, the flanges of arm  46  urge drive linkages  48  proximally which, in turn, urges legs  145 , spring cartridge  144 , and drive shaft  142  proximally such that jaw member  110  is pivoted towards the approximated position relative to jaw member  120 . Fixed split pivot  45  and first and second movable pivots  52 ,  53  further cooperate to define an over-center configuration for locking jaw members  110 ,  120  in the approximated position once movable handle  40  has been sufficiently compressed towards fixed handle  30 , e.g., once first movable pivot  52  is disposed above the line segment extending between fixed split pivot  45  and second movable pivot  53 . 
     Trigger assembly  60 , as mentioned above, is coupled to knife assembly  180  such that trigger  62  is selectively actuatable from an un-actuated position to an actuated position to advance knife  184  from a storage position ( FIG. 3B ), wherein knife  184  is disposed proximally relative to jaw members  110 ,  120 , to an extended position, wherein knife  184  extends between jaw members  110 ,  120  and through knife channels  115 ,  125 , respectively ( FIG. 3C ), to cut tissue grasped between jaw members  110 ,  120 . Knife assembly  180  includes a knife drive shaft  182  defining proximal and distal ends  183   a ,  183   b , respectively. Proximal end  183   a  of knife drive shaft  182  is coupled to the proximal base of connectors  68  of trigger assembly  60 . Knife drive shaft  182  extends distally between legs  145  of spring cartridge  144 , through the lumen (not explicitly shown) of spring cartridge  144 , and through inner shaft  226  of monopolar assembly  220 , ultimately engaging the proximal end of knife  184 . Knife  184  defines a distal cutting edge  185  configured to facilitate the cutting of tissue upon translation of knife  184  between jaw members  110 ,  120 . 
     Trigger assembly  60  includes a trigger  62  having a toggle member  63  and a bifurcated arm  66  extending upwardly from toggle member  63  and into housing  20 . Trigger  62  is pivotably coupled to housing  20  via pivot  65 , which extends through an intermediate portion  64  of trigger  62 . Arm  66  is bifurcated to define a pair of spaced-apart flanges disposed about spring cartridge  144  of drive assembly  140 . A pin  69  pivotably couples each flange of arm  66  of trigger  62  to a connector  68 . Connectors  68  extends proximally through housing  20  to the base of connectors  68 . The base of connectors  68  is coupled to proximal end  183   a  of knife drive shaft  182  of knife assembly  180  on either side thereof. The coupling of the base of connectors  68  to knife drive shaft  182  also permits rotation of knife drive shaft  182  relative to connectors  68 , the importance of which will become more apparent below. Upon pivoting of trigger  62  about pivot pin  65  and relative to housing  20  from the un-actuated position towards the actuated position, arm  66  is rotated to pull connectors  68  distally such that knife drive shaft  182  is pushed distally to translate knife  184  from the storage position towards the extended position. Return of trigger  62  towards the un-actuated position, on the other hand, pivots arm  66  to push connectors  68  proximally such that knife drive shaft  182  is pulled proximally to translate knife  184  back towards the storage position. A biasing member (not shown) may be provided for biasing trigger  62  towards the un-actuated position, thereby biasing knife  184  towards the retracted position. 
     Referring briefly to  FIGS. 8A and 8B , connectors  68  of trigger assembly  60  may define a pair of longitudinal grooves  68   a ,  68   b  on each side thereof. Housing  20  includes pairs of upper and lower pegs  22   a ,  22   b  extending inwardly from opposing sides thereof. Pegs  22   a ,  22   b  are configured for slidable receipt within grooves  68   a ,  68   b , respectively, of connectors  68  to guide translation of connectors  68  within housing  20 , thereby guiding translation of knife drive shaft  182  and knife  184  (see  FIGS. 1-5 ) between the storage and extended positions. 
     Referring again to  FIGS. 1-5 , lever assembly  80  is described. Although lever assembly  80  is shown disposed on only one side of housing  20 , lever assembly  80  may be configured to define a symmetrical configuration having substantially similar components disposed on either or both sides of housing  20 , thus allowing actuation of lever assembly  80  from either or both sides of housing  20 . However, for purposes of simplicity, only one side of lever assembly  80  will be described hereinbelow. 
     Lever assembly  80  is disposed within a recess  24  defined on an exterior side surface of housing  20  (although lever assembly  80  may also be positioned at any other suitable location) and includes a lever  82  that is rotatable about a pivot  84  between a first position, wherein free end  86  of lever  82  is disposed at a proximal end  25  of recess  24 , and a second position, wherein free end  86  of lever  82  is disposed at a distal end  27  of recess  24 . As will be described in greater detail below, movement of lever  82  between the first and second positions effects movement of monopolar assembly  200  between the retracted and deployed positions, respectively. Further, a dimple  28  formed within recess  24  of housing  20  may be provided adjacent distal end  27  thereof for receiving a corresponding protrusion (not explicitly shown) extending from an inwardly-facing surface of lever  82  such that, upon movement of lever  82  to the second position, the protrusion (not shown) of lever  82  is engaged within dimple  28  of recess  24  to retain lever  82  in the second position, thereby retaining monopolar assembly  200  in the deployed position. A biasing member (not shown) may be provided for biasing lever  82  towards the first position and, thus, monopolar assembly  200  towards the retracted position, in the absence of lever  82  being locked in the second position via the above-described dimple-protrusion engagement. Other suitable locking mechanisms are also contemplated. In configurations where lever assembly  80  defines a symmetrical configuration, a pair of levers  82  are provided on either side of housing  20 , each of which is similar to that described above and is coupled to one end of pivot  84 . Pivot  84  extends through housing  20  to operably couple lever  82  to the internal components of lever assembly  80 , as will be described below. 
     Lever assembly  80  includes a pair of spaced-apart lever linkages  87  disposed within housing  20 . Lever linkages  87  are coupled at the first ends thereof to pivot  84  such that rotation of lever  82  effects rotation of pivot  84  and, thus, lever linkages  87  in a similar direction. Lever linkages  87  are disposed on either side of knife drive shaft  182  and between legs  145  of spring cartridge  144  of drive assembly  140 . Lever linkages  87  are pivotably coupled to a first elongated linkage  88   a  at the second ends thereof via pivot  89   a . First elongated linkage  88   a  extends distally though housing  20  and is pivotably coupled to a second elongated linkage  88   b  via a pivot  89   b . Second elongated linkage  88   b  extends further distally through housing  20  and into rotatable nose wheel  72 , wherein second elongated linkage  88   b  couples lever  82  to both outer insulative sleeve  210  and inner shaft  226  of monopolar assembly  200 , as will be described in greater detail below. As a result of this configuration, rotation of lever  82  from the first position to the second position rotates lever linkages  87  which, in turn, urge first and second elongated linkages  88   a ,  88   b , respectively, to translate distally though housing  20 , thereby moving monopolar assembly  200  from the retracted position to the deployed position. 
     Forceps  10  further includes a rotatable member  150  operably disposed between second elongated linkage  88   b  and spring cartridge  144  for moving jaw members  110 ,  120  to the approximated position (if not already disposed in the approximated position) prior to deployment of monopolar assembly  200  to inhibit unintended interference between end effector assembly  100  and monopolar assembly  200  due to. Rotatable member  150  is rotatably coupled to housing  20  via pivot  152  and includes first and second ends  154 ,  156 , respectively, extending in substantially opposite directions from pivot  152 . Rotatable member  150  may be biased, e.g., via a torsion spring (not explicitly shown) or any other suitable biasing member, towards the position shown in  FIG. 4A , wherein second end  156  of rotatable member  150  is displaced from spring cartridge  144 . 
     Second elongated linkage  88   b  defines an expanded body portion  158   a  compared to distal tip  158   b  thereof. As a result, with second elongated linkage  88   b  in the proximal-most position, e.g., with monopolar assembly  200  in the fully retracted position, distal tip  158   b  of second elongated linkage  88   b  is positioned adjacent, but spaced-apart from, rotatable member  150 . Thus, rotatable member  150  is maintained in the position shown in  FIG. 4A , unabated by second elongated linkage  88   b . However, when second elongated linkage  88   b  is translated distally to deploy monopolar assembly  200 , body portion  158   a  of second elongated linkage  88   b  is urged into contact with first end  154  of rotatable member  150  to rotate rotatable member  150  about pivot  152  and against its bias such that second end  156  of rotatable member  156  contacts and urges spring cartridge  144  distally, thereby effecting pivoting of jaw members  110 ,  120  to the approximated position (see  FIG. 4B ). Thus, outer insulative sleeve  210  of monopolar assembly  200  is permitted to slide over end effector assembly  100  without interference from jaw members  110 ,  120 . Upon return of monopolar assembly  200  to the retracted position, second elongated linkage  88   b  is returned proximally and out of contact with rotatable member  150  such that rotatable member  150  is permitted to return to its biased position, thereby permitting jaw members  110 ,  120  to return to the spaced-apart position. Other suitable mechanisms for ensuring jaw members  110 ,  120  are disposed in the approximated position when monopolar assembly  200  is deployed or being deployed are also contemplated. 
     With continued reference to  FIGS. 1-5 , as mentioned above, rotating assembly  70  includes a rotatable nose wheel  72  disposed at the distal end of housing  20  and rotatable about longitudinal axis “X-X” to effect corresponding and cooperative rotation of outer fixed shaft  12  (and the internal components therein), end effector assembly  100 , and monopolar assembly  200 . In order to effect such rotation, rotatable nose wheel  72  is operably coupled to each of the plurality of shafts and sleeves extending through rotatable nose wheel  72 , which are variously movable relative to one another and rotatable nose wheel  72 . 
     As best shown in  FIG. 5 , rotatable nose wheel  72  defines a generally conical body  74  having a hollow interior  75  and a transverse bar  76  extending through hollow interior  75  of body  74 . Insulative sleeve  210  of monopolar assembly  200  extends through nose wheel  72  and defines a pair of opposed longitudinal slots  212  towards the proximal end thereof that are configured to receive transverse bar  76  therethrough. This engagement of bar  76  within slots  212  rotatably fixes sleeve  210  relative to nose wheel  72  but permits insulative sleeve  210  to translate longitudinally relative to nose wheel  72 , e.g., between a proximal position, wherein transverse bar  76  is disposed at the distal ends of slots  212 , and a distal position, wherein transverse bar  76  is disposed at the proximal ends of slots  212 . Insulative sleeve  210  further includes a pair of opposed apertures  214  defined therethrough proximally of slots  212 . A busing  216  is engaged about insulative sleeve  210  via a pin  217  extending through apertures  214  of insulative sleeve  210 . Bushing  216  defines an annular groove  218  configured to receive distal engagement end  219  of second elongated linkage  88   b  of monopolar assembly  200 , thereby coupling second elongated linkage  88   b  to insulative sleeve  210  regardless of the rotational orientation of insulative sleeve  210  (and, thus, bushing  216 ) relative to second elongated linkage  88   b . Accordingly, with second elongated linkage  88   b  coupled to bushing  216  of insulative sleeve  210 , translation of second elongated linkage  88   b  can be effected to move insulative sleeve  210  between the retracted and deployed positions. 
     Fixed shaft  12 , which secures fixed jaw member  120  at distal end  14  thereof, is disposed within insulative sleeve  210 . More specifically, fixed shaft  12  is rotatably coupled to housing  20  at proximal end  16  thereof and extends through nose wheel  72  and insulative sleeve  210  to fixed jaw  120 . Fixed shaft  12  defines a pair of opposed longitudinal slots  18  towards proximal end  16  thereof that are configured to receive pin  217  of bushing  216  therethrough, thus permitting outer sleeve  210  to translate relative to fixed shaft  12 . Fixed shaft  12  further defines an aperture  19  configured to receive transverse bar  76  of nose wheel  72  to rotatably fix fixed shaft  12  relative to nose wheel  72  and insulative sleeve  210 . 
     Drive shaft  142  is slidably disposed within fixed shaft  12  and, as mentioned above, is selectively translatable to effect movement of jaw members  110 ,  120  between the spaced-apart and approximated positions upon actuation of movable handle  40 . Drive shaft  142  defines a pair of opposed longitudinal slots  148  that are configured to receive both pin  217  of bushing  216  and transverse bar  76  of nose wheel  72 , thus allowing translation of drive shaft  142  and insulative sleeve  210  relative to one another and nose wheel  72 , and rotatably securing drive shaft  142  to nose wheel  72 . In other words, drive shaft  142  is independently translatable relative to insulative sleeve  210 , fixed shaft  12 , and nose wheel  72 , but is rotatably coupled thereto to rotate in concert therewith. 
     Inner shaft  226 , which supports energizable rod member  220  at the distal end thereof, is slidably disposed within drive shaft  142 . Inner shaft  226  includes a pair of opposed apertures  228  defined towards the proximal end thereof and a pair of opposed longitudinal slots  229  disposed towards the proximal end thereof distally of apertures  228 . Apertures  228  are configured to receive pin  217  of bushing  216  to fix inner shaft  226  in both rotation and translation relative to outer insulative sleeve  210  and such that movement of second elongated linkage  88   b  effects corresponding movement of outer insulative sleeve  210  and inner shaft  226 . Slots  229  are configured to receive transverse bar  76  to rotatably fix inner shaft  226  relative to nose wheel  72  while still permitting relative translation therebetween. 
     Knife drive shaft  182  is disposed within inner shaft  226  and is independently translatable relative to inner shaft  226 , drive shaft  142 , fixed shaft  12 , outer insulative sleeve  210 , and nose wheel  72 , but is rotatably coupled to each via engagement of transverse bar  76  within slots  188  defined within opposed sides of knife drive shaft  182 . As can be appreciated in view of the above, rotatable nose wheel  72  is rotatable in either direction about longitudinal axis “X-X” and relative to housing  20  to effect corresponding and cooperative rotation of outer fixed shaft  12  (and the internal components therein), end effector assembly  100 , and monopolar assembly  200 , without comprising the independent relative movements therebetween. 
     Turning now to  FIGS. 6A-7 , another embodiment of a rotating assembly of a multi-function forceps  10 ′ is shown generally identified by reference numeral  700 . Forceps  10 ′ is similar to forceps  10  ( FIGS. 1-5 ) except for the features of rotating assembly  700  and the cooperating features that couple rotating assembly  700  to the functional components of forceps  10 ′. All of the aspects and features of forceps  10  described above are equally applicable to forceps  10 ′, except where specifically contradicted below. For purposes of brevity, similar features which were described above are not repeated hereinbelow. 
     With continued reference to  FIGS. 6A-7 , rotating assembly  700  includes a rotatable nose wheel  720  disposed at the distal end of housing  20  and rotatable about longitudinal axis “X-X.” Rotatable nose wheel  720  defines a generally cylindrical body  740  having a hollow interior  760  and a pair of opposed longitudinal tracks  780  extending through hollow interior  760  of body  740 . 
     Insulative sleeve  210 ′ extends through nose wheel  720  and includes a pair of opposed apertures  212 ′ defined therethrough towards the proximal end of insulative sleeve  210 ′. A bushing  216 ′ is engaged about insulative sleeve  210 ′ via a pin  217 ′ extending through apertures  212 ′ of insulative sleeve  210 ′. Bushing  216 ′ defines an annular groove  218 ′ configured to receive distal engagement end  219 ′ of second elongated linkage  88   b ′. Bushing  216 ′ further includes a pair of flanges  240 ′ extending in opposite radial directions from bushing  216 ′. Flanges  240 ′ are configured for receipt within tracks  780  of nose wheel  720  to rotatably fix sleeve  210 ′ relative to nose wheel  720  but permitting sleeve  210 ′ to translate relative to nose wheel  720 , e.g., via translation of flanges  240 ′ along tracks  780 . 
     Fixed shaft  12 ′ is rotatably coupled to housing  20 ′ and defines a pair of opposed longitudinal slots  18 ′ configured to receive pin  217 ′ of bushing  216 ′ to rotatably fix fixed shaft  12 ′ relative to nose wheel  720 . Drive shaft  142 ′ is slidably disposed within fixed shaft  12 ′ and likewise defines a pair of opposed longitudinal slots  148 ′ configured to receive pin  217 ′ of bushing  216 ′, thus allowing independent translation of drive shaft  142 ′ relative to fixed shaft  12 ′ and insulative sleeve  210 ′, while rotatably coupling drive shaft  142 ′ to nose wheel  720 . Inner shaft  226 ′ is slidably disposed within drive shaft  142 ′ and defines a pair of opposed apertures  228 ′ configured to receive pin  217 ′ to fix inner shaft  226 ′ in both rotation and translation relative to outer insulative sleeve  210 ′. Knife drive shaft  182 ′ is longitudinally movable but rotatably coupled to each of the above shafts and sleeves via engagement of pin  217 ′ within slots  188 ′ defined within opposed sides of knife drive shaft  182 ′. 
     As a result of the above-described configuration, rotation of rotatable nose wheel  720  about longitudinal axis “X-X” and relative to housing  20  urges flanges  240 ′ of bushing  216 ′ to rotate similarly, thereby effecting corresponding and cooperative rotation of outer insulative sleeve  210 ′, fixed shaft  12 ′, drive shaft  142 ′, inner shaft  226 ′, and knife drive shaft  182 ′ without interfering with the independent relative movements of these various shafts and sleeves of forceps  10 ′. 
     Turning again to  FIGS. 1-5 , the use and operation of forceps  10  in both the bipolar mode, e.g., for grasping, treating and/or cutting tissue, and the monopolar mode, e.g., for electrical/electromechanical tissue treatment, is described. the use and operation of forceps  10 ′ ( FIGS. 6A-7 ) is similar to that of forceps  10  and, thus, will not be described hereinbelow to avoid unnecessary repetition. Initially, with respect to either mode of operation, forceps  10  is manipulated such that end effector assembly  100  is positioned and oriented as desired within a surgical site. In particular, nose wheel  72  may be rotated to orient end effector assembly  100  and monopolar assembly  200  in a desired orientation. Once positioned as desired, forceps  10  is ready for use. 
     In the bipolar mode, monopolar assembly  200  remains disposed in the retracted position, as shown in  FIGS. 2A and 3A-3C . With jaw members  110 ,  120  disposed in the spaced-apart position, end effector assembly  100  may be maneuvered into position such that tissue to be grasped, treated, e.g., sealed, and/or cut, is disposed between jaw members  110 ,  120 . Next, movable handle  40  is depressed, or pulled proximally relative to fixed handle  50  such that jaw member  110  is pivoted relative to jaw member  120  from the spaced-apart position to the approximated position to grasp tissue therebetween, as shown in  FIG. 3B . More specifically, upon actuation of movable handle  40 , drive shaft  142  is translated proximally through outer fixed shaft  12 , pulling jaw member  110  to pivot relative to jaw member  120  from the spaced-apart position to the approximated position. In this approximated position, energy may be supplied, e.g., via activation of switch  90 , to tissue-sealing plate  112  of jaw member  110  and/or tissue-sealing plate  122  of jaw member  120  and conducted through tissue to treat tissue, e.g., to effect a tissue seal or otherwise treat tissue. 
     As shown in  FIG. 3C , in conjunction with  FIG. 1 , once tissue treatment is complete (or to cut untreated tissue), knife  184  of knife assembly  180  may be deployed from within outer fixed shaft  12  to between jaw members  110 ,  120 , e.g., via actuation of trigger  82  of trigger assembly  80 , to cut tissue grasped therebetween. More specifically, upon actuation of trigger  82 , knife drive bar  184  is advanced distally through fixed shaft  12  such that knife  184  extends at least partially through knife channels  115 ,  125  of jaw members  110 ,  120 , respectively, to cut tissue grasped between jaw members  110 ,  120 . Thereafter, knife  184  may be returned to within outer fixed shaft  12  and jaw members  110 ,  120  may be moved back to the spaced-apart position ( FIG. 3A ) to release the treated and/or divided tissue. 
     With respect to the monopolar mode of operation, movable handle  40  is first depressed relative to fixed handle  50  to pivot jaw member  110  relative to jaw member  120  from the spaced-apart position to the approximated position. However, this step is not a necessity since, as described above, housing  20  includes a rotatable member  150  disposed therein and configured to move jaw members  110 ,  120  to the approximated position upon deployment of monopolar assembly  200 . Once jaw members  110 ,  120  are disposed in the approximated position, monopolar assembly  200  is translated from the retracted position ( FIG. 3B ) to the deployed position ( FIG. 3D ) via movement of lever  82  from the first position to the second position. Upon deployment of monopolar assembly  200 , outer insulative sleeve  210  is translated distally over end effector assembly  100  and energizable rod member  220  is translated distally such that distal tip  224  of energizable rod member  220  extends distally from both end effector assembly  100  and outer insulative sleeve  200 . 
     With monopolar assembly  200  disposed in the deployed position, as shown in  FIG. 3D , activation switch  90  may be actuated to supply energy to distal tip  224  of energizable rod member  220  for treating, e.g., electrically or electromechanically dissecting, tissue. Energy is returned via a remotely positioned return pad (not explicitly shown), although monopolar assembly  200  may alternatively be configured to operate in a biopolar fashion wherein tissue sealing plates  112 ,  122  are energized to the same potential (but different from the energization of distal tip  224  of energizable rod member  220 ), thus acting as the return electrode. During application of energy to distal tip  224  of energizable rod member  220 , forceps  10  may be moved relative to tissue, e.g., longitudinally along longitudinal axis “X-X” and/or radially therefrom, to facilitate electromechanical treatment of tissue. Alternatively or additionally, forceps  10  may be moved relative to tissue to facilitate mechanically dissecting tissue, e.g., scoring tissue planes, with distal tip  224  in the absence of energy being applied to distal tip  224 . 
     At the completion of tissue treatment, e.g., dissection, monopolar assembly  200  may be returned to the retracted position ( FIGS. 3A-3B ), e.g., via moving lever  82  back to the initial position. With monopolar assembly  200  once again in the retracted position, jaw members  110 ,  120  of end effector assembly  100  may one again be manipulated to grasp, treat, and/or cut tissue, as described above, in the bipolar mode. 
     From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.