Patent Publication Number: US-2021177451-A1

Title: Assembly tool for ultrasonic surgical instruments and kits and methods including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 15/427,143, filed on Feb. 8, 2017, the entire contents of which being incorporated by reference herein. 
    
    
     FIELD 
     The present disclosure relates to surgical instruments and, more particularly, to an assembly tool for facilitating assembly of an ultrasonic surgical instrument, kits including the assembly tool, and methods of assembly using the assembly tool. 
     BACKGROUND 
     Ultrasonic surgical instruments utilize ultrasonic energy, i.e., ultrasonic vibrations, to treat tissue. More specifically, ultrasonic surgical instruments utilize mechanical vibration energy transmitted at ultrasonic frequencies to coagulate, cauterize, fuse, seal, cut, desiccate, and/or fulgurate tissue to effect hemostasis. 
     Ultrasonic surgical instruments typically employ a transducer that produces ultrasonic energy for transmission along a waveguide to an end effector designed to treat tissue with the ultrasonic energy. Some ultrasonic surgical instruments include a transducer and/or waveguide that is removable and, thus, requires releasable engagement of the transducer and waveguide. In such configurations, the transducer and waveguide should be sufficiently secured to one another during assembly to maintain the engagement therebetween during use and to ensure proper operation. 
     
       
     
     SUMMARY 
     As used herein, the term “distal” refers to the portion that is described which is further from a user, while the term “proximal” refers to the portion that is being described which is closer to a user. Further, any or all of the aspects described herein, to the extent consistent, may be used in conjunction with any or all of the other aspects described herein. 
     Provided in accordance with aspects of the present disclosure is an assembly tool for use with an ultrasonic surgical instrument including a housing and a rotation knob rotatable relative to the housing. The assembly tool includes a body portion, a neck attached to the body portion, and a head portion attached to the neck. The body portion includes a base and first and second legs extending from the base to define a receiving area therebetween. The head portion defines a central opening. The first and second legs of the body portion are configured to engage a portion of a housing of an ultrasonic surgical instrument received within the receiving area while the head portion is configured to engage a rotation knob of the ultrasonic surgical instrument received within the central opening to rotationally fix the rotation knob relative to the housing. 
     In aspects of the present disclosure, the head portion of the assembly tool includes first and second arms cooperating to define the central opening therebetween. The first and second arms include free ends defining a mouth therebetween that provides access to the central opening. The first and second arms may be movable to vary a width of the mouth. Additionally or alternatively, the mouth may be positioned to oppose the neck. 
     In aspects of the present disclosure, the head portion of the assembly tool includes an interior surface surrounding the central opening and configured complementary to an exterior surface of the rotation knob of the ultrasonic surgical instrument. The interior surface may include, for example, a plurality of alternating recesses and protrusions. 
     In aspects of the present disclosure, the receiving area of the body portion of the assembly tool is configured complementary to the portion of the housing of the ultrasonic surgical instrument configured for receipt within the receiving area. 
     In aspects of the present disclosure, the body portion, the neck, and the head are a single, monolithic component. 
     A kit provided in accordance with aspects of the present disclosure includes an ultrasonic surgical instrument including a housing and a rotation knob rotatable relative to the housing and an assembly tool according to any of the aspects above or otherwise herein. The assembly tool is releasably engagable with the ultrasonic surgical instrument to rotationally fix the rotation knob relative to the housing. 
     In aspects of the present disclosure, the ultrasonic surgical instrument includes an outer sleeve extending distally from the housing. The outer sleeve is configured to pass through the mouth of the head portion of the assembly tool and into the central opening of the assembly tool to enable engagement of the head portion of the assembly tool with the rotation knob of the ultrasonic surgical instrument. The first and second arms of the head portion of the assembly tool may be configured to move to vary a width of the mouth to facilitate passage of the outer sleeve of the ultrasonic surgical instrument through the mouth. Additionally or alternatively, the first and second arms may be configured to move to engage the rotation knob under bias. 
     In aspects of the present disclosure, the rotation knob includes a plurality of spaced-apart flutes defined on the exterior surface thereof, and an interior surface of the head portion of the assembly tool defines a plurality of spaced-apart protrusions configured for respective receipt within the plurality of spaced-apart flutes of the rotation knob of the ultrasonic surgical instrument. 
     In aspects of the present disclosure, the receiving area of the body portion of the assembly tool is configured complementary to the portion of the housing of the ultrasonic surgical instrument. 
     In aspects of the present disclosure, the first and second legs of the body portion of the assembly tool are configured to move to vary a width of the receiving area of the body portion of the assembly tool to facilitate receipt of the portion of the housing of the ultrasonic surgical instrument within the receiving area of the body portion of the assembly tool. Additionally or alternatively, the first and second legs of the body portion of the assembly tool may be configured to move to engage the portion of the housing of the ultrasonic surgical instrument received within the receiving area of the body portion of the assembly tool under bias. 
     A method of assembling an ultrasonic surgical instrument provided in accordance with aspects of the present disclosure includes positioning a threaded connector of a waveguide adjacent a threaded connector of an ultrasonic transducer with the waveguide and the ultrasonic transducer supported by a housing. The waveguide includes a rotation knob operably associated therewith and configured to rotate the waveguide relative to the housing. The method further includes engaging an assembly tool with the rotation knob and a portion of the housing such that the rotation knob is maintained in fixed rotational orientation relative to the housing, and rotating the ultrasonic transducer relative to the housing to engage the threaded connector of the ultrasonic transducer with the threaded connector of the waveguide. 
     In aspects of the present disclosure, positioning the threaded connector of the waveguide adjacent the threaded connector of the ultrasonic transducer with the waveguide and the ultrasonic transducer supported by the housing includes inserting the ultrasonic transducer onto or into the housing. Additionally or alternatively, positioning the threaded connector of the waveguide adjacent the threaded connector of the ultrasonic transducer with the waveguide and the ultrasonic transducer supported by the housing includes inserting the waveguide into the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and features of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings wherein like reference numerals identify similar or identical elements and: 
         FIG. 1  is a side, perspective view of an ultrasonic surgical instrument; 
         FIG. 2  is an enlarged, side, longitudinal, cross-sectional view of a proximal portion of the ultrasonic surgical instrument of  FIG. 1 ; 
         FIG. 3  is a side, perspective view of a proximal portion of the ultrasonic surgical instrument of  FIG. 1  with the transducer and generator assembly (“TAG”) removed therefrom and an assembly tool provided in accordance with the present disclosure operably engaged therewith; 
         FIG. 4A  is a front view of the assembly tool of  FIG. 3 ; 
         FIG. 4B  is a side view of the assembly tool of  FIG. 3 ; 
         FIG. 4C  is a perspective view of the assembly tool of  FIG. 3 ; 
         FIG. 5A  is a rear, perspective view of the ultrasonic surgical instrument of  FIG. 1  illustrating insertion of the TAG into engagement with the ultrasonic surgical instrument; and 
         FIG. 5B  is a rear, perspective view of the ultrasonic surgical instrument of  FIG. 1  including the assembly tool of  FIG. 3  engaged therewith, illustrating use of the assembly tool to facilitate engagement of the TAG with the ultrasonic surgical instrument. 
     
    
    
     DETAILED DESCRIPTION 
     Referring generally to  FIGS. 1-3 , the present disclosure relates to an assembly tool  20  ( FIG. 3 ) configured to facilitate assembly of an ultrasonic surgical instrument such as, for example, ultrasonic surgical instrument  10 . Although assembly tool  20  ( FIG. 3 ) is detailed herein for use in conjunction with ultrasonic surgical instrument  10 , assembly tool  20  ( FIG. 3 ) may likewise be used in conjunction with any suitable ultrasonic surgical instrument to facilitate assembly thereof. For the purposes herein, ultrasonic surgical instrument  10  is generally described. Ultrasonic surgical instrument  10  is described in greater detail in U.S. Pat. No. 10,368,898, the entire contents of which are hereby incorporated herein by reference. 
     Referring to  FIGS. 1 and 2 , ultrasonic surgical instrument  10  includes a handle assembly  100  and an elongated assembly  200  that is configured to releasably engage handle assembly  100 , although elongated assembly  200  may alternatively be permanently engaged with handle assembly  100 . Handle assembly  100  includes a housing  110  defining a body portion  112  and a fixed handle portion  114 . Handle assembly  100  further includes an activation button  120  and a clamp trigger  130 . 
     Body portion  112  of housing  110  is configured to support an ultrasonic transducer and generator assembly (“TAG”)  300  including a generator  310  and an ultrasonic transducer  320 . TAG  300  may be permanently engaged with body portion  112  of housing  110  or removable therefrom. Generator  310  includes a housing  312  configured to house the internal electronics of generator  310 , and a cradle  314  configured to rotatably support ultrasonic transducer  320 . Ultrasonic transducer  320  includes a piezoelectric stack  322  and a distally-extending horn  324 . Horn  324  defines a threaded female receiver  326 . A set of connectors  330  and corresponding rotational contacts  334  associated with generator  310  and ultrasonic transducer  320 , respectively, enable drive signals to be communicated from generator  310  to piezoelectric sack  322  of ultrasonic transducer  320  to drive ultrasonic transducer  320 . Ultrasonic transducer  320  further includes a rotation knob  328  extending proximally therefrom that, when rotated, rotates ultrasonic transducer  320  relative to generator  310  and housing  110 . As detailed below, rotation knob  328  facilitates engagement of ultrasonic transducer  320  with waveguide  230  of elongated assembly  200 . 
     With reference to  FIG. 2 , fixed handle portion  114  of housing  110  defines a compartment  116  configured to receive a battery assembly  400  and a door  118  configured to enclose compartment  116 . An electrical connection assembly  140  is disposed within housing  110  of handle assembly  100  and serves to electrically couple activation button  120 , generator  310  of TAG  300 , and battery assembly  400  with one another when TAG  300  is supported on or in body portion  112  of housing  110  and battery assembly  400  is disposed within compartment  116  of fixed handle portion  114  of housing  110 , thus enabling activation of ultrasonic surgical instrument  10  in response to depression of activation button  120 . 
     Referring still to  FIGS. 1 and 2 , elongated assembly  200  includes an outer drive sleeve  210 , an inner support sleeve  220  disposed within outer drive sleeve  210 , a waveguide  230  extending through inner support sleeve  220 , a drive assembly  250 , an integrated torque assembly  260 , a rotation knob  270 , and an end effector  280  including a blade  282  and a jaw  284 . A proximal portion of outer drive sleeve  210  is operably coupled to clamp trigger  130  of handle assembly  100  via drive assembly  250 , while a distal portion of outer drive sleeve  210  is operably coupled to jaw  284 . As such, clamp trigger  130  is selectively actuatable to thereby move outer drive sleeve  210  about inner support sleeve  220  to pivot jaw  284  relative to blade  282  of end effector  280  from a spaced-apart position to an approximated position for clamping tissue between jaw  284  and blade  282 . Drive assembly  250  provides a force-limiting feature whereby the clamping pressure applied to tissue is limited to a particular clamping pressure or particular clamping pressure range. Rotation knob  270  defines a plurality of spaced-apart flutes  272  arranged annularly about an exterior surface of rotation knob  270 . As a result of this configuration, rotation knob  270  defines alternating flutes  272  and protrusions  274  arranged annularly thereabout. This configuration facilitates rotation of rotation knob  270 , e.g., with a single finger. Flutes  272  define arcuate configurations, while protrusions  274  are squared-off; however, other configurations are also contemplated. 
     Waveguide  230 , as noted above, extends through inner support sleeve  220 . Waveguide  230  defines a body  232  and a blade  282  extending from the distal end of body  232 . Blade  282  serves as the blade of end effector  280 . Waveguide  230  further includes a proximal connector  236  configured to enable engagement of waveguide  230  with horn  324  of ultrasonic transducer  320  such that ultrasonic motion produced by ultrasonic transducer  320  is transmitted along waveguide  230  to blade  282  for treating tissue clamping between blade  282  and jaw  284  or positioned adjacent to blade  282 . To this end, proximal connector  236  includes a threaded male shaft  237  that is configured for threaded engagement within threaded female receiver  326  of horn  324  of ultrasonic transducer  320 . 
     As can be appreciated, waveguide  230  and ultrasonic transducer  320  should be sufficiently engaged with one another to maintain the engagement therebetween during use and to ensure proper operation, without over-tightening the engagement between threaded male shaft  237  and threaded female receiver  326 . Integrated torque assembly  260  helps ensure that waveguide  230  and ultrasonic transducer  320  are sufficiently engaged while inhibiting over-tightening. More specifically, integrated torque assembly  260  is operably coupled about outer drive sleeve  210 , inner support sleeve  220 , and waveguide  230  such that rotation of rotation knob  270  relative to handle assembly  100  rotates elongated assembly  200  relative to handle assembly  100  up to a torque threshold, at which point integrated torque assembly  260  decouples rotation knob  270  from the other components of elongated assembly  200  such that further rotation of rotation knob  270  does not impart rotation to the other components of elongated assembly  200 . 
     Referring generally to  FIGS. 1 and 2 , in order to engage threaded male shaft  237  and threaded female receiver  326  with one another to thereby engage waveguide  230  and ultrasonic transducer  320  with one another, rotation knob  328  of ultrasonic transducer  320  or rotation knob  270  of elongated assembly  200  is held in fixed rotational position, while the other rotation knob  328 ,  270  is rotated to thereby establish relative rotation between threaded male shaft  237  and threaded female receiver  326  to progressively engage threaded male shaft  237  and threaded female receiver  326  with one another. When sufficient engagement is achieved, integrated torque assembly  260  “slips” such that, upon further application of torque, threaded male shaft  237  and threaded female receiver  326  rotate together with one another, inhibiting further engagement therebetween. As an alternative to integrated torque assembly  260 , a separate torque wrench (not shown), for example, positionable about rotation knob  328  and utilized to rotate rotation knob  328  relative to rotation knob  270  until the torque wrench (not shown) “slips” and inhibits further rotation of rotation knob  328 , may be provided. In either configuration, assembly tool  20 , as detailed below with reference to  FIGS. 3-5B , is configured to facilitate the engagement of threaded male shaft  237  and threaded female receiver  326  with one another, thus facilitating the engagement of waveguide  230  and ultrasonic transducer  320  with one another. 
     Referring to  FIGS. 3 and 4A-4C , assembly tool  20  includes a body portion  22 , a neck  23 , and a head portion  24 . Assembly tool  20  may be monolithically formed, e.g., via injection molding, from a suitable plastic, although other formation methods and/or materials are also contemplated. Body portion  22  of assembly tool  20  includes a base  26  and first and second legs  30 ,  32 . Base  26  defines first and second end portions  28   a ,  28   b . Fixed ends  31   a ,  33   a  of first and second legs  30 ,  32  are attached, e.g., formed with, base  26  at first and second end portions  28   a ,  28   b , respectively, of base  26 . First and second legs  30 ,  32  extend from fixed ends  31   a ,  33   a  to free ends  31   b ,  33   b , respectively, thereof, such that body portion  22  of assembly tool  20  defines a substantially U-shaped configuration. More specifically, first and second legs  30 ,  32  extend in substantially perpendicular orientation relative to base  26 , e.g., within about 15 degrees of perpendicular, and are disposed in substantially parallel orientation relative to one another, e.g., within about 15 degrees of parallel. 
     As a result of the above-detailed configuration, body portion  22  of assembly tool  20  defines a U-shaped receiving area  34  having a width “W 1 .” Width “W 1 ” generally approximates the width of a portion of fixed handle portion  114  of housing  110  of handle assembly  100  of ultrasonic surgical instrument  10  so as to enable receipt of the portion of fixed handle portion  114  within receiving area  34 . Further, with legs  30 ,  32  of body portion  22  attached to base  26  at fixed ends  31   a ,  33   a , respectively, thereof, and extending to free ends  31   b ,  33   b , respectively, thereof, legs  30 ,  32  define cantilever configurations enabling flexion of legs  30 ,  32  towards and away from one another to vary the width “W 1 ” of receiving area  34 . In some embodiments, width “W 1 ” may be slightly smaller than the width of the portion of fixed handle portion  114  of housing  110  of handle assembly  100  such that body portion  22  is retained in position about the portion of fixed handle portion  114  under the bias of cantilever legs  30 ,  32  towards an at-rest position. It is also contemplated that legs  30 ,  32  define inner surface features that complement outer surface features of the portion of fixed handle portion  114  of housing  110  of handle assembly  100  so as to enable complementary-fit engagement of body portion  22  of assembly tool  20  about fixed handle portion  114  of housing  110  of handle assembly  100 . 
     Body portion  22  of assembly tool  20 , as detailed above, is configured for use with ultrasonic surgical instrument  10  and, thus, is configured complementarily thereto. Depending upon the particular ultrasonic surgical instrument (or instruments) for which assembly tool  20  is configured for use, the above-noted featured of assembly tool  20  may be varied. For example, with respect to ultrasonic surgical instruments having housing portions defining more V-shaped or C-shaped configurations, body portion  22  of assembly tool  20  may be configured such that receiving area  34  defines a more V-shaped or C-shaped configuration. Likewise, the width “W 1 ” may be varied in accordance with the dimensions of the portion of the housing of the particular ultrasonic surgical instrument (or instruments) for which assembly tool  20  is configured for use. 
     Continuing with reference to  FIGS. 3 and 4A-4C , head portion  24  of assembly tool  20  is attached to body portion  22  of assembly tool  20  by way of neck  23  and extends in generally perpendicular orientation relative to legs  30 ,  32  of body portion  22 . Head portion  24  defines a C-shaped configuration having a generally circular central opening  36  and a mouth  38  providing access to central opening  36 , although, in other embodiments, head portion  24  may define a closed, O-shaped configuration. Mouth  38  defines a width “W 2 ” and is disposed opposite the attachment of head portion  24  to neck  23  such that C-shaped head portion  24  defines a pair of substantially similar arms  40 ,  42  attached to one another adjacent neck  23  and spaced-apart from one another at the free ends  41 ,  43 , respectively, thereof to define mouth  38  therebetween. Arms  40 ,  42  are arcuate so as to define generally circular central opening  36  therebetween, although other configurations are also contemplated. Arms  40 ,  42  define cantilever configurations enabling flexion of arms  40 ,  42  towards and away from one another to vary the width “W 2 ” of mouth  38 . 
     The interior surfaces of arms  40 ,  42  that surround central opening  36  complement the exterior annular surface of rotation knob  270  of ultrasonic surgical instrument  10 . More specifically, the interior surfaces of arms  40 ,  42  include a plurality of alternating protrusions  44  and recesses  46 . Protrusions  44  define arcuate configurations and are configured for complementary receipt within flutes  272  of rotation knob  270 , while recesses  46  are squared-off so as to complementarily receive protrusions  274  of rotation knob  270 . Other configurations complementary to a particular rotation knob configuration, or universal for use with a plurality of different rotation knob configurations, are also contemplated. Further, head portion  24  of assembly tool  20  may be dimensioned relative to rotation knob  270  such that the cantilever configurations of arms  40 ,  42  help maintain arms  40 ,  42  in engagement about rotation knob  270  under the bias of arms  40 ,  42  towards an at-rest position. 
     With reference to  FIGS. 2, 3, and 5A-5B , the use of assembly tool  20  to facilitate engagement of waveguide  230  and ultrasonic transducer  320  with one another is detailed. Initially, TAG  300  is slid onto or into housing  110  of handle assembly  100  such that TAG  300  is supported thereon or therein and such that threaded male shaft  237  of waveguide  230  is positioned adjacent threaded female receiver  326  of ultrasonic transducer  320 . As can be appreciated, in configurations where elongated assembly  200  is removable from handle assembly  100 , elongated assembly  200  may alternatively be inserted into housing  110  such that elongated assembly  200  is supported by handle assembly  100  and such that threaded male shaft  237  of waveguide  230  is positioned adjacent threaded female receiver  326  of ultrasonic transducer  320 . 
     With threaded male shaft  237  of waveguide  230  positioned adjacent threaded female receiver  326  of ultrasonic transducer  320 , or prior thereto, assembly tool  20  is engaged with ultrasonic surgical instrument  10 . In order to engage assembly tool  20  with ultrasonic surgical instrument  10 , head portion  24  of assembly tool  20  is slid proximally over end effector  280  and outer drive sleeve  210  of elongated assembly  200  with end effector  280  and outer drive sleeve  210  passing through central opening  36  of head portion  24 . Alternatively, assembly tool  20  may be positioned about elongated assembly  200  by passing outer drive sleeve  210  through mouth  38  and into central opening  36  of head portion  24  of assembly tool  20 . 
     Once assembly tool  20  is disposed about elongated assembly  200  with outer drive sleeve  210  extending through central opening  36 , assembly tool  20  is translated proximally relative to ultrasonic surgical instrument  10  such that body portion  22  of assembly tool  20  is engaged about housing  110  of handle assembly  100  of ultrasonic surgical instrument  10  and such that head portion  24  of assembly tool  20  is engaged about rotation knob  270  of elongated assembly  200  of ultrasonic surgical instrument  10 . More specifically, with respect to the engagement of body portion  22  about housing  110 , assembly tool  20  is translated proximally relative to housing  110  such that a portion of fixed handle portion  114  of housing  110  is received within receiving area  34  of body portion  22  with cantilever legs  30 ,  32  of body portion  22  of assembly tool  20  engaging the portion of fixed handle portion  114  of housing  110  on either side thereof. 
     With respect to the engagement of head portion  24  about rotation knob  270 , assembly tool  20  is translated proximally relative to rotation knob  270  such that protrusions  44  of head portion  24  of assembly tool  20  are received within flutes  272  of rotation knob  270  and such that recesses  46  of head portion  24  of assembly tool  20  receive protrusions  274  of rotation knob  270 . With head portion  24  of assembly tool  20  positioned in this manner, cantilever arms  40 ,  42  of head portion  24  of assembly tool  20  engage rotation knob  270  annularly thereabout. It is contemplated that the engagement of body portion  22  of assembly tool  20  with housing  110  of handle assembly  100  and the engagement of head portion  24  of assembly tool  20  with rotation knob  270  occur substantially simultaneously with one another as assembly tool  20  is translated proximally, although other configurations are also contemplated. 
     With assembly tool  20  engaged about ultrasonic surgical instrument  10  as detailed above, rotation knob  270  is maintained in fixed rotational orientation relative to housing  110  of ultrasonic surgical instrument  10  due to the engagement of legs  30 ,  32  about housing  110  and the engagement of arms  40 ,  42  about rotation knob  270 . Thus, threaded male shaft  237  of waveguide  230  is maintained in fixed rotational orientation relative to housing  110  (in the absence of excess torque applied to rotation knob  270  so as to cause integrated torque assembly  260  to “slip”) without the need for the user to grasp and maintain rotation knob  270  in fixed rotational orientation relative to housing  110 . 
     In order to engage threaded female receiver  326  and threaded male shaft  237  with one another, the user grasps any suitable part of handle assembly  100 , e.g., fixed handle portion  114 , with one hand, and rotation knob  328  of TAG  300  with the other hand, as illustrated in  FIG. 5B , and rotates rotation knob  328 . As rotation knob  328  is rotated, threaded male shaft  237  is progressively engaged with threaded female receiver  326  until sufficient engagement is achieved, at which point integrated torque assembly  260  “slips” such that, upon further application of torque, threaded male shaft  237  and threaded female receiver  326  rotate together with one another, inhibiting further engagement therebetween. In embodiments where integrated torque assembly  260  is not provided, the above-detailed assembly is similar except that, rather than grasping rotation knob  328  directly, a separate torque wrench (not shown) is engaged about rotation knob  328  and utilized to rotate rotation knob  328 . The separate torque wrench (not shown) is configured to “slip,” inhibiting further rotation of the underlying rotation knob  238 , once sufficient engagement of threaded male shaft  237  and threaded female receiver  326  is achieved. 
     Once ultrasonic transducer  230  and waveguide  230  are sufficiently engaged with one another, assembly tool  20  may be removed in the opposite manner as the engagement thereof detailed above, and battery assembly  400  may be inserted into compartment  116  of fixed handle portion  114  of housing  110  (if not done so previously) to complete the assembly of ultrasonic surgical instrument  10 . Ultrasonic surgical instrument  10  may thereafter be used to perform one or more surgical tasks, e.g., to coagulate, cauterize, fuse, seal, cut, desiccate, and/or fulgurate tissue. 
     Once use of ultrasonic surgical instrument  10  is complete, and when it is desired to remove TAG  300  and/or elongated assembly  200  from handle assembly  100 , assembly tool  20  may be re-engaged about ultrasonic surgical instrument  10 . With assembly tool  20  engaged about ultrasonic surgical instrument  10 , the user grasps any suitable part of handle assembly  100 , e.g., fixed handle portion  114 , with one hand, and rotation knob  328  of TAG  300  with the other hand, and rotates rotation knob  328  in the opposite direction until threaded female receiver  326  and threaded male shaft  237  are fully disengaged, at which point TAG  300  and/or elongated assembly  200  may be removed from handle assembly  100 . 
     Referring generally to  FIGS. 1-5B , assembly tool  20  may be provided separately from ultrasonic surgical instrument  10 , may be provided together with ultrasonic surgical instrument  10 , or may be included as part of a kit including portions of ultrasonic surgical instrument  10 , e.g., a kit including TAG  300 , handle assembly  100 , and/or elongated assembly  200 . 
     While several embodiments of the disclosure have been detailed above and are 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 and accompanying drawings 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.