Coupling mechanisms for surgical instruments

A surgical instrument includes a shaft defining a longitudinal axis therethrough and having an end effector assembly disposed at a distal end thereof. The shaft includes first and second shaft components that are releasably engageable with one another. A drive sleeve is disposed within the shaft and is longitudinally translatable relative to the shaft to transition the end effector assembly between a first state and a second state. The drive sleeve includes first and second drive sleeve components that are releasably engageable with one another. A coupling mechanism includes one or more shaft cantilever springs configured to releasably engage the first and second shaft components to one another and one or more drive sleeve cantilever springs configured to releasably engage the first and second drive sleeve components to one another.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical instruments and, more particularly, to coupling mechanisms for surgical instruments having separable and/or replaceable components.

2. Background of Related Art

A forceps is a plier-like instrument which relies on mechanical action between its jaws to grasp, clamp and constrict vessels or tissue. Electrosurgical forceps utilize both mechanical clamping action and electrical energy to affect hemostasis by heating tissue and blood vessels to coagulate and/or cauterize tissue. Certain surgical procedures require more than simply cauterizing tissue and rely on the unique combination of clamping pressure, precise electrosurgical energy control and gap distance (i.e., distance between opposing jaw members when closed about tissue) to “seal” tissue, vessels and certain vascular bundles. Typically, once a vessel is sealed, the surgeon has to accurately sever the vessel along the newly formed tissue seal. Accordingly, many vessel sealing instruments have been designed which incorporate a knife or blade member which effectively severs the tissue after forming a tissue seal.

Generally, surgical instruments, including forceps, can be classified as single-use instruments, e.g., instruments that are discarded after a single use, partially-reusable instruments, e.g., instruments including both disposable portions and portions that are sterilizable for reuse, and completely reusable instruments, e.g., instruments that are completely sterilizable for repeated use. As can be appreciated, those instruments (or components of instruments) that can be sterilized and reused help reduce the costs associated with the particular surgical procedure for which they are used. However, although reusable surgical instruments are cost-effective, it is important that these instruments be capable of performing the same functions as their disposable counterparts, that any disposable components of these instruments be efficiently removable and replaceable with new components, and that the reusable components be efficiently and satisfactorily sterilizable for reuse.

SUMMARY

As used herein, the term “distal” refers to the portion that is being 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.

Any of the aspects disclosed herein, to the extent they are consistent, may be used in conjunction with any of the other aspects disclosed herein.

In accordance with one aspect of the present disclosure, a surgical instrument is provided. The surgical instrument includes a shaft defining a longitudinal axis therethrough and having an end effector assembly disposed at a distal end thereof. The shaft includes first and second shaft components that are releasably engageable with one another. A drive sleeve is disposed within the shaft and is longitudinally translatable relative to the shaft to transition the end effector assembly between a first state and a second state. The drive sleeve also includes first and second drive sleeve components that are releasably engageable with one another. A coupling mechanism includes one or more shaft cantilever springs and one or more drive sleeve cantilever springs that are coupled to the one or more shaft cantilever springs. The shaft cantilever springs are configured to engage the first shaft component at a first end thereof and the second shaft component at a second end thereof to releasably engage the first and second shaft components to one another. Similarly, the drive sleeve cantilever springs are configured to engage the first drive sleeve component at a first end thereof and the second drive sleeve component at a second end thereof to releasably engage the first and second drive sleeve components to one another.

In one aspect, the shaft cantilever springs include a first tab disposed at the first end thereof and extending therefrom and a second tab disposed at the second end thereof and extending thereform. The first tab and second tabs are configured to bias into engagement within apertures defined within the first and second shaft components, respectively, to engage the first and second shaft components to one another. Further, the drive sleeve cantilever springs may also include a first tab disposed at the first end thereof and extending therefrom and a second tab disposed at the second end thereof and extending thereform. The first tab and second tabs are configured to bias into engagement within apertures defined within the first and second drive components, respectively, to engage the first and second drive sleeve components to one another.

In another aspect, the shaft cantilever spring and the drive sleeve cantilever spring are coupled to one another via a break-away feature. The break-away feature is configured to break, decoupling the shaft cantilever spring and the drive sleeve cantilever spring from one another to permit the drive sleeve to translate relative to the shaft.

In still another aspect, a knife assembly is disposed within the drive sleeve. The knife assembly includes a knife bar having a knife disposed at a distal end of the knife bar. The knife bar is longitudinally translatable through the shaft and relative to the end effector assembly to translate the knife between a retracted position and an extended position for cutting tissue.

Another aspect of a surgical instrument provided in accordance with the present disclosure includes a shaft defining a longitudinal axis therethrough and having an end effector assembly disposed at a distal end thereof. The shaft includes first and second shaft components that are releasably engageable with one another. The first shaft component includes a tab disposed on an outer surface thereof and extending outwardly therefrom, while the second shaft component includes a track defined within an outer peripheral surface thereof. The track includes a longitudinal portion, a transverse portion, and a tab retaining portion. The first shaft component is configured for insertion at least partially into the second shaft component such that the tab is translated along the longitudinal portion of the track into position adjacent the transverse portion of the track. The first shaft component is then rotatable about the longitudinal axis and relative to the second shaft component to translate the tab along the transverse portion of the track and into the tab retaining portion for releasably engaging the first and second shaft components to one another.

In one aspect, a biasing member configured to bias the first and second shaft components apart from one another is provided. The biasing member biases the tab into engagement within the tab retaining portion of the track to maintain the first and second shaft components in engagement with one another.

In another aspect, the first and second shaft components are configured to permit translation of a drive sleeve therethrough for transitioning the end effector assembly between a first state and a second state.

In yet another aspect, the surgical instrument further includes a knife assembly disposed within the drive sleeve. The knife assembly includes a knife bar having a knife disposed at a distal end of the knife bar and is longitudinally translatable through the shaft and relative to the end effector assembly to translate the knife between a retracted position and an extended position for cutting tissue.

Still another aspect of a surgical instrument provided in accordance with the present disclosure includes a shaft defining a longitudinal axis therethrough and having an end effector assembly disposed at a distal end thereof. The shaft includes first and second shaft components that are releasably engageable with one another. The first shaft component includes an insertion portion, while the second shaft component includes a receiving portion configured to receive the insertion portion of the first shaft component therein to frictionally engage the first and second shaft components to one another. The receiving portion is configured to constrict about the insertion portion upon translation of the insertion portion apart from the receiving portion to inhibit withdrawal of the insertion portion, thereby maintaining the engagement between the first and second shaft components.

In one aspect, receiving portion defines a braided configuration configured to elongate and reduce a diameter of a lumen extending therethrough upon extension of the receiving portion.

In another aspect, the insertion portion defines a textured outer peripheral surface configured to facilitate frictional engagement between the insertion portion and the receiving portion.

In still another aspect, a release ring is provided. The release ring is disposed about the first shaft component and is slidable about the first shaft component into position adjacent the receiving portion of the second shaft component to inhibit constriction of the receiving portion about the insertion portion, thereby permitting withdrawal of the insertion portion from the receiving portion to disengage the first and second shaft components from one another. The surgical instrument may further be configured similar to any of the previous aspects mentioned hereinabove.

DETAILED DESCRIPTION

Referring now toFIG. 1, a forceps10for use in connection with endoscopic surgical procedures is shown, although forceps10may also be configured for use in connection with traditional open surgical procedures. Forceps10defines a longitudinal axis “A-A” and includes a housing20, a handle assembly30, a trigger assembly70, a rotating assembly80, and an end effector assembly100. End effector assembly100includes first and second jaw members110,120, respectively, configured to pivot relative to one another between a spaced-apart position (FIG. 1) and an approximated position (FIG. 8B) for grasping tissue therebetween. Forceps10further includes a shaft12having a distal end14configured to mechanically engage end effector assembly100and a proximal end16that mechanically engages housing20.

Forceps10also includes an electrosurgical cable310that connects forceps10to a generator (not shown) or other suitable power source, although forceps10may alternatively be configured as a battery powered instrument. Cable310includes a wire (or wires) (not explicitly shown) extending therethrough, into housing20and through shaft12to ultimately connect the source of electrosurgical energy (not explicitly shown) to jaw member110and/or jaw member120of end effector assembly100. However, any other suitable electrical connection(s) for supplying energy to jaw member110and/or jaw member120may also be provided.

With continued reference toFIG. 1, handle assembly30includes a fixed handle50and a moveable handle40. Fixed handle50is integrally associated with housing20and handle40is moveable relative to fixed handle50. Rotating assembly80is rotatable in either direction about a longitudinal axis “A-A” to rotate end effector100about longitudinal axis “A-A.” The housing20houses the internal working components of the forceps10.

End effector assembly100is attached at a distal end14of shaft12and includes a pair of opposing jaw members110and120. End effector assembly100is designed as a unilateral assembly, i.e., where jaw member120is fixed relative to shaft12and jaw member110is moveable relative to both shaft12and fixed jaw member120. However, end effector assembly100may alternatively be configured as a bilateral assembly, i.e., where both jaw member110and jaw member120are moveable relative to one another and with respect to shaft12.

As shown inFIG. 1, each jaw member110,120includes an electrically conductive tissue sealing plate112,122disposed thereon. Tissue sealing plates112,122are positioned on jaw members110,120, respectively, to define opposed tissue sealing surfaces for grasping and sealing tissue between jaw members110,120. In some embodiments, a knife assembly180(seeFIGS. 2A-2C) is disposed within shaft12and a knife channel115,125(FIGS. 2A-2C) is defined within one or both of tissue sealing plates112,122, of jaw members110,120, respectively, to permit reciprocation of a knife184(seeFIGS. 2A-2C) therethrough for cutting tissue grasped between jaw members110,120. In such an embodiment, trigger72of trigger assembly70is operable to advance the knife184(FIGS. 2A-2C) between a retracted position (seeFIGS. 2A-2B), wherein knife184(FIGS. 2A-2C) is disposed within shaft12, and an extended position (seeFIG. 2C), wherein knife184(FIGS. 2A-2C) extends between jaw members110,120to cut tissue grasped therebetween.

Continuing with reference toFIG. 1, moveable handle40of handle assembly30is ultimately connected to a drive assembly including a drive sleeve60(FIG. 4) that, together, mechanically cooperate to impart movement of jaw members110and120between a spaced-apart position and an approximated position to grasp tissue between sealing plates112and122of jaw members110,120, respectively. As shown inFIG. 1, moveable handle40is initially spaced-apart from fixed handle50and, correspondingly, jaw members110,120are disposed in the spaced-apart position. Moveable handle40is depressible from this initial position to a depressed position corresponding to the approximated position of jaw members110,120(seeFIGS. 2B-2C). With tissue grasped between tissue sealing plates112,122of jaw members110,120, respectively, electrosurgical energy may be conducted between tissue sealing plates112,122, e.g., upon actuation of activation switch90, to seal tissue disposed between jaw members110,120.

With reference now toFIGS. 2A-2C, in conjunction withFIG. 1, drive sleeve60is disposed within shaft12and is coupled to jaw member110at the distal end thereof such that, as drive sleeve60is translated proximally through shaft12and relative to jaw member120, e.g., via depressing movable handle40, jaw member110is pulled to pivot from the spaced-apart position (FIG. 2A) to the approximated position (FIGS. 2B,2C). On the other hand, when drive sleeve60is translated distally, e.g., via releasing or returning movable handle40to its initial position, jaw member110is urged to pivot from the approximated position (FIGS. 2B,2C) back to the spaced-apart position (FIG. 2A). However, this configuration may be reversed, e.g., where proximal translation of drive sleeve60moves jaw members110,120to the spaced-apart position and wherein distal translation of drive sleeve60moves jaw members110,120to the approximated position.

Continuing with reference toFIGS. 2A-2C, shaft12further includes a knife assembly180disposed therein. Knife assembly180is disposed within drive sleeve60and includes a knife bar182having knife184coupled thereto at the proximal end of185of knife184. Knife184defines a cutting blade186at distal end187thereof. Knife184is translatable between a retracted position (FIGS. 2A-2B), wherein knife184is disposed within shaft12, and an extended position (FIG. 2C), wherein knife184extends through knife channels115,125defined within jaw members110,120, respectively, to cut tissue grasped between jaw members110,120. More specifically, upon actuation of trigger72(FIG. 1) of trigger assembly70(FIG. 1), knife bar182is advanced distally through shaft12and drive sleeve60to urge knife184from the retracted position to the extended position. Further, knife assembly180may be biased, e.g., via a spring (not explicitly shown), toward the retracted position such that, upon release of trigger72, knife184is automatically returned to the retracted position.

Turning now toFIGS. 3-4, in conjunction withFIGS. 1-2C, shaft12of forceps10is separable, or decouplable into first and second shaft sections17and18, respectively. More specifically, second section18of shaft12, including end effector assembly100, is removable from the remainder of forceps10, thus allowing second section18of shaft12and end effector assembly100to be replaced with new components after each use (or each procedure), or to be cleaned, sterilized, or otherwise prepared for reuse independently of the remaining components of forceps10. Such a configuration also permits the use of various different end effector assemblies with forceps10by simply selecting the desired end effector assembly and coupling that end effector assembly and the second shaft section18thereof to first section17of shaft12.

Put more generally, the replaceable distal portion, e.g., second shaft section18and end effector assembly100, of forceps10helps reduce the equipment costs associated with performing a particular surgical procedure by obviating the need to provide an entire new surgical instrument, facilities sterilization and cleaning of the components of the instrument by providing greater access to the components of the instrument and allowing different components of the instrument to be cleaned and/or sterilized via different procedures, and increases the versatility of the instrument by allowing different shaft components and/or end effectors to be coupled thereto.

However, while it is advantageous to provide a surgical instrument, e.g., forceps10, that includes a shaft12that is separable into first and shaft sections17and18, respectively, significant considerations apply when configuring a shaft coupling mechanism for releasably coupling first and second shaft sections17,18, respectively, to one another. In particular, it is important to consider the various components and connections extending through shaft12. More specifically, as best shown inFIG. 4, shaft12defines an outer tube, or lumen that houses drive sleeve60. Drive sleeve60, as mentioned above, is selectively translatable through and relative to shaft12to pivot jaw member110relative to jaw member120between the spaced-apart and approximated positions. Drive sleeve60also includes knife bar182disposed therein that, as described above, is selectively translatable relative to drive sleeve60and shaft12to advance knife184from the retracted position to the extended position to cut tissue grasped between jaw members110,120. Further, electrical connections, e.g., wires (not explicitly shown), extend through shaft12to connect the source of electrosurgical energy (not explicitly shown) to jaw member110and/or jaw member120of end effector assembly100for providing energizing end effector assembly.

Various embodiment of coupling mechanisms configured to releasably couple the first and second sections17and18, respectively, of shaft12to one another in accordance with those considerations addressed above will be described in detail below with reference toFIGS. 5A-15. More particularly, the coupling mechanisms described hereinbelow may be configured for coupling the first and second sections17,18of shaft12, the components of drive sleeve60, and/or the components of knife bar182to one another, as well as for re-establishing and electrical connections extending through shaft12. Further, the various coupling mechanisms described hereinbelow may be used alone or in combination with one another to releasably couple one or more of the respective components of shaft12, drive sleeve60, and/or knife bar182to one another. Thus, while certain coupling mechanisms may be shown and described with reference to only a single connection, e.g., for coupling the first and second sections17,18of shaft12to one another, such mechanisms (or other coupling mechanisms) may also be used for further coupling the other components, e.g., first and second sections of the drive sleeve60and/or knife bar182, to one another. Likewise, the electrical connections described hereinbelow in connection with some embodiments of coupling mechanisms for electrically coupling the first and second sections17,18, respectively, of shaft12to one another such that electrosurgical energy may be supplied from housing20to end effector assembly100may also be used in conjunction with any of the other coupling mechanisms described herein.

Additionally, although the embodiments herein are described with reference to a forceps10, the presently disclosed coupling mechanisms may be used in conjunction with any shafted surgical instrument (including single or multiple component shafts) having an end effector assembly disposed at one end and a handle, housing, grip, control, etc. disposed at the other end. Further, the attachment point of first and second sections17,18, respectively, of shaft12may be disposed at various positions along the length of shaft12, e.g., closer towards distal end14such that second section18defines a greater length than first portion17, closer toward proximal end16such that first section17defines a greater length than first portion17, or anywhere between proximal end16and distal end14of shaft12.

Referring now toFIGS. 5A-5B, one embodiment of a tube coupling mechanism for coupling first and second components517,518, respectively, of shaft512to one another as well as for coupling first and second components567,568, respectively, of drive sleeve560to one another is shown generally identified by reference numeral500. Tube coupling mechanism500includes two sets of cantilever springs520,530and570,580. Each cantilever spring520,530of the first set includes an arm522,532that has a first tab524,534disposed at a first end525,535, respectively, thereof and a second tab526,536disposed at second end527,537, respectively, thereof. First tabs524,534are engaged within apertures542,544, respectively, of second component518of shaft512, while second tabs526,536are configured for engagement within apertures546,548, respectively, defined within first component517of shaft512. More specifically, as will be described below, cantilever springs520,530are configured to resiliently bias second tabs526,536, respectively, into engagement with respective apertures546,548of first component517upon insertion into shaft512to engage first and second components517,518, respectively, of shaft512to one another.

Each cantilever spring570,580of the second set similarly includes an arm572,582that has a first tab574,584disposed at a first end575,585, respectively, thereof and a second tab576,586disposed at second end577,587, respectively, thereof. First tabs574,584are engaged within apertures592,594, respectively, of second component568of drive sleeve560, while cantilever springs570,580are configured to resiliently bias second tabs576,586, respectively, into engagement with respective apertures566,568of first component567of drive sleeve560upon positioning about drive sleeve560to engage first and second components567,568, respectively, of drive sleeve560to one another. Further, cantilever springs520,570may be coupled, engaged, or otherwise formed to one another adjacent first end525of cantilever spring520and second end577of cantilever spring570via a break-away feature, or coupling549. Cantilever springs530,580may likewise be coupled, engaged, or otherwise formed to one another adjacent first end535of cantilever spring530and second end587of cantilever spring580via a break-away feature, or coupling599.

With continued reference toFIGS. 5A-5B, in order to couple first and second components517,518, respectively, of shaft512to one another and first and second components567,568, respectively, of drive sleeve560to one another, first and second component517,518of shaft512are brought into approximation with one another. As can be appreciated, approximation of first and second component517,518of shaft512likewise approximates first and second components567,568of drive sleeve560due to the engagement of cantilever springs520,570and530,580via break-away couplings549,599, respectively. More specifically, as first and second component517,518of shaft512are brought into approximation with one another, second tabs526,536of cantilever springs520,530, respectively, are flexed inwardly, i.e., toward one another, to permit passage of cantilever springs520,530into lumen514defined through shaft512. On the other hand, second tabs576,586of cantilever springs570,580, respectively, are flexed outwardly, i.e., apart from one another, to permit passage of cantilever springs570,580about drive sleeve560.

As first and second components517,518of shaft512are further approximated relative to one another, second tabs526,536of cantilever springs520,530, respectively, are eventually translated through lumen514of shaft512into position adjacent apertures542,544of first component517, whereby cantilever springs520,530are resiliently biased back to their initial, un-flexed position, thus urging second tabs526,536into engagement within apertures542,544, respectively, to engage first and second components517,518, respectively, of shaft512to one another. Similarly, second tabs576,586of cantilever springs570,580, respectively, are eventually translated about the outer periphery of first component567of drive sleeve560into position adjacent apertures592,594of first component567, whereby cantilever springs570,580are resiliently biased back to their initial, un-flexed position, thus urging second tabs576,586into engagement within apertures592,594, respectively, to engage first and second components567,568, respectively, of drive sleeve560to one another.

With first and second components517,518of shaft512engaged to one another and with first and second components567,568of drive sleeve560engaged to one another, drive sleeve560may be translated relative to shaft512an initial time, e.g., via depressing movable handle40(FIG. 1), to break, tear, or otherwise destroy break-away couplings549and599. As can be appreciated, with break-away couplings549,599no longer securing cantilever springs520,270to one another nor cantilever springs530,580to one another, drive sleeve560is free to translate through lumen514and relative to shaft512for moving jaw members110,120(FIG. 1) between the spaced-apart and approximated positions.

In order to decouple shaft components517,518from one another, a tool (not shown) or other implement may be used to urge tabs526,536inwardly such that tabs526,536are no longer disposed within apertures546,548, respectively. With tabs526,536removed from apertures546,548, shaft components517,518may be translated apart from one another to decouple shaft component517,518from one another. First and second components567,568of drive sleeve560may similarly be decoupled from one another.

Turning now toFIGS. 6A-6E, another embodiment of a tube coupling mechanism is shown generally identified via reference numeral600. Tube coupling mechanism600is configured to releasably engage first and second components617,618of shaft612to one another. More specifically, tube coupling mechanism600includes a pair of resilient locking tabs620,630formed in the outer periphery of second component618and extending outwardly therefrom (although locking tabs620,630may alternatively be formed on shaft component617to extend inwardly therefrom). As best shown inFIG. 6A, in an at-rest position, locking tabs620,630are bent, or folded-back onto themselves and protrude from the outer periphery of second shaft component618. Each locking tab620,630defines a free end622,632, respectively, that permits resilient flexion of locking tabs620,630relative to second shaft component618. First shaft component617, on the other hand, includes a pair of apertures640,650configured to receive locking tabs620,630, respectively, therein. Further, first shaft component617may define a slightly larger diameter than second shaft component618such that second shaft component618may be inserted at least partially into lumen614of first shaft component617to couple first and second shaft components617,618, respectively, to one another, as will be described below.

With continued reference toFIGS. 6A-6E, in order to engage first and second shaft components617,618, respectively, to one another, second shaft component618is inserted into lumen614defined through first shaft component617. As second shaft component618is urged into lumen614of first shaft component617, resilient locking tabs620,630are flexed, or compressed inwardly into second shaft component618in order to permit passage of second shaft component618into lumen614of first shaft component617, as best shown inFIG. 6B.

As second shaft component618is translated further through lumen614of first shaft components617tabs620,630are eventually translated into position adjacent apertures640,650of first shaft component617, whereby tabs620,630are resiliently biased back to their initial, un-compressed position (extending from second shaft component618). That is, tabs620,630are urged under bias into engagement within apertures640,650, respectively, to engage first and second components617,618, respectively, of shaft612to one another. Similarly as described above, in order to decouple shaft components617,618from one another, a tool (not shown) or other implement may be used to urge tabs620,630inwardly such that tabs620,630are no longer disposed within apertures640,650, respectively. With tabs620,630removed from apertures640,650, second shaft component618may be removed from lumen614of first shaft component617to decouple shaft component617,618from one another.

Turning now toFIGS. 7A-7B, another embodiment of a tube coupling mechanism is shown generally identified by reference numeral700. Tube coupling mechanism700is configured to engage first and second shaft component717,718, respectively, of shaft712to one another. One of the shaft components, e.g., first shaft component717, includes an insertion portion720extending from end722thereof, while the other shaft component, e.g., second shaft component718, includes a receiving portion730disposed at end732thereof. Insertion portion720is configured for insertion into lumen734of receiving portion730for securing first and second shaft components717,718, respectively, to one another.

As shown inFIG. 7A, insertion portion720of first shaft component717defines a diameter that is smaller relative to the diameter of receiving portion730of shaft component718, such that insertion portion720may be inserted into lumen734of receiving portion730until ends722,732of first and second shaft components717,718, respectively, are abutting one another, as shown inFIG. 7B. Thereafter, insertion portion720and/or receiving portion730are transitioned from this first condition, wherein the diameter of insertion portion720is smaller than the diameter of receiving portion730, to a second, or engaged condition, wherein insertion portion720is retained in engagement within receiving portion730via friction-fitting. As can be appreciated, in the engaged condition, the diameters of insertion portion720and receiving portion730may be substantially similar to one another to retain first and second shaft components717,718, respectively, in engagement with one another.

In order to engage insertion portion720and receiving portion730to one another, one or both of the portions720,730are heated, or otherwise treated to achieve the first condition; insertion portion720in inserted into receiving portion730; and, finally, insertion portion720and/or receiving portion730are transitioned to the engaged condition to engage first and second shaft components717,718, respectively, to one another. For example, receiving portion730of second shaft component718may be heated to an expanded state (i.e., the first condition) such that insertion portion720of first shaft component717may be inserted into lumen734of receiving portion730. Thereafter, receiving portion730is cooled, or allowed to cool, such that receiving portion730is contracted about insertion portion720back to its initial condition to engage insertion portion720therein.

Alternatively, insertion portion720and receiving portion730may be formed from materials having different coefficients of expansion such that both insertion portion720and receiving portion730may be heated to permit insertion portion720to be inserted into receiving portion730. Thereafter, both insertion portion720and receiving portion730are allowed to cool, or are cooled, back to their initial states to engage insertion portion720within receiving portion730. Insertion portion720and/or receiving portion730may also be formed form shape memory materials, or may include thermal or electric bimetal materials disposed thereon to facilitate transitioning of insertion portion720and receiving portion730between the first and second conditions for securing first and second shaft components717,718, respectively, to one another.

In order to decouple first and second shaft components717,718, respectively, from one another, one or both of insertion portion720and receiving portion730are transitioned, e.g., heated, to once again achieve the first condition, thus allowing first and second shaft components717,718to be translated apart from one another such that insertion portion720is removed from lumen734of receiving portion730.

FIG. 8shows another embodiment of a shaft coupling mechanism800that is configured to releasably engage first and second shaft components817,818, respectively, of shaft812to one another. Shaft coupling mechanism800generally includes a tab820disposed on and extending from an outer periphery of one of the shaft components, e.g., second shaft component818, and a slot830defined within the outer periphery of the other shaft component, e.g., first shaft component817. Slot830includes a longitudinal segment836having an open distal end837at distal end832of first shaft component817and a locking segment840in communication with longitudinal segment836at proximal end838thereof. Locking segment840includes a transverse portion842extending in substantially-transverse relation relative to longitudinal segment836, and a distally-extending tab-retaining portion844in communication therewith. First shaft component817further includes a biasing member, e.g., a spring848disposed within lumen834thereof, the importance of which will be described below.

With continued reference toFIG. 8, second shaft component818defines a diameter smaller than that of first shaft component817to permit passage of second shaft component818into lumen834of first shaft component817. Further, tab820of second shaft component818is configured to be received within, and to translate through slot830of first shaft component817to engage first and second shaft components817,818, respectively, to one another.

In order to engage first and second shaft components817,818, respectively, to one another, second shaft component818is inserted into lumen834of first shaft component817such that tab820is inserted into longitudinal segment836of slot830via open distal end837thereof. As second shaft component818is translated further into lumen834of first shaft component817, tab820is translated proximally along longitudinal segment836of slot830towards proximal end838thereof. However, prior to tab820reaching proximal end838of longitudinal segment836of slot830, proximal end822of second shaft component818contacts biasing member848. As such, in order to translate second shaft component818further through lumen834of first shaft component817, second shaft component818must be urged sufficiently to overcome the bias of biasing member848.

Eventually, second shaft component818is translated proximally, against the bias of biasing member848, such that tab820is disposed at proximal end838of longitudinal segment836of slot830. Once this position is achieved, second shaft component818is rotated about longitudinal axis “A-A” relative to first shaft component817such that tab820is translated along transverse portion842of locking segment840into position adjacent tab-retaining portion844of locking segment840of slot830. Thereafter, second shaft component818may be released, allowing biasing member848to bias second shaft component818distally such that tab820is translated distally into tab-retaining portion844of locking segment840of slot830to engage first and second shaft components817,818, respectively, to one another.

In order to disengage first and second shaft components817,818, respectively, from one another, second shaft component818is translated proximally relative to first shaft component817such that tab820is translated proximally from tab-retaining portion844of locking segment840into transverse portion842of locking segment840of slot830. Thereafter, second shaft component818is rotated relative to first shaft component817about longitudinal axis “A-A” such that tab820is once again aligned with longitudinal segment836of slot830so that second shaft component818can be translated distally and removed from first shaft component817, thereby decoupling first and second shaft components817,818, respectively, from one another.

Referring now toFIG. 9, shaft coupling mechanism900is configured to engage first and second shaft components917,918, respectively, of shaft912to one another. Shaft coupling mechanism900includes a first hub920disposed on one of the shaft components, e.g., first shaft component917, and a second hub930disposed on the other shaft component, e.g., second shaft component918. More specifically, first hub920extends from distal end922of first shaft component917and defines a reduced diameter relative to first shaft component917such that a distally-facing shoulder924is defined therebetween. Further, first hub920includes a helical track926defined within an outer periphery thereof, the helical track926including an open distal end927and a retaining notch928formed at proximal end929thereof. An O-ring940, or other suitable resilient biasing member, is disposed about first hub920adjacent shoulder924.

Second hub930extends from proximal end932of second shaft component918and defines a lumen934extending therethrough that is configured to receive first hub920of first shaft component917therein. Second hub930further includes a tab936disposed on an inner surface thereof and extending inwardly into lumen934. Tab936is configured to be received within, and to translate through track926of first hub920.

In use, to couple first and second shaft components917,918, respectively, to one another, first and second shaft components917,918are translated toward one another until first hub920extends partially into second hub930such that tab936enters open distal end927of track926. With tab936positioned within track926, second shaft component918is rotated relative to first shaft component917about longitudinal axis “A-A” such that tab936is translated proximally through track926, thereby further engaging first hub920within second hub930. Upon further rotation of second shaft component918relative to first shaft component917and, thus, upon further translation of first hub920into second hub930, tab936is translated through track926into position adjacent retaining notch928of track926. However, in this position, second hub930is positioned adjacent O-ring940. Thus, in order to translate tab936into notch928, second shaft component918is rotated with sufficient urging to compress O-ring940, thus permitting further proximal translation of tab936through helical track926. Ultimately, once tab936has reached notch928, second shaft component918may be released, allowing O-ring940to resiliently return to its at rest condition such that second shaft component918is biased distally and, thus, tab936is biased into engagement within notch928to engage first and second shaft components917,918, respectively, to one another.

In order to decouple first and second shaft components917,918, respectively, from one another, second shaft component918is translated proximally relative to first shaft component917such that second shaft component918is urged against first O-ring940to compress O-ring940, allowing second shaft component918to translate further proximally. In this position, tab936of second shaft component918is once again aligned with helical track926such that second shaft component918may be rotated about longitudinal axis “A-A” to translate tab936distally through helical track926, ultimately disengaging first and second shaft components917,918, respectively, from one another.

FIG. 10shows another embodiment of a shaft coupling mechanism1000configured for releasably engaging first and second shaft components1017,1018, respectively, of shaft1012to one another. Shaft coupling mechanism1000includes a first hub1020disposed on one of the shaft components, e.g., first shaft component1017, and a second hub1030disposed on the other shaft component, e.g., second shaft component1018. Shaft coupling mechanism1000further includes a sleeve1050slidably disposed about shaft1012, the importance of which will be describe below.

First hub1020of shaft coupling mechanism1000extends from distal end1022of first shaft component1017and defines a pair of opposed notches1024within the outer periphery thereof. Alternatively, rather than notches1024, an annular groove (not shown) may be defined therein. An O-ring1040, or other suitable biasing member is disposed about first shaft component1017and is disposed within each of notches1024.

Second hub1030extends from proximal end1032of second shaft component1018and defines a lumen1034extending therethrough that is configured to receive first hub1020of first shaft component1017therein. Second hub1030further includes a pair of opposed cantilever springs1036extending proximally therefrom. Each of the cantilever springs1036defines a tab1038at a free end thereof. Tabs1038extend inwardly toward one another and are configured for engagement within notches1024of first hub1020. Alternatively, rather than a pair of opposed cantilever spring1036, second hub1030may include an annular biasing member (not shown) configured for engagement within an annular groove (not shown) defined within first hub1020.

First and second hubs1020,1030may each further include complementary electrical connection members1060,1070, respectively. More specifically, one of the first and second hubs, e.g., first hub1020, may include a female connection member1060, while the other hub, e.g., second hub1030, includes a male connection member1070configured for insertion into female connection member1060to electrically couple first and second shaft components1017,1018, respectively, to one another, thus permitting energy to be supplied from the energy source (not explicitly shown) to end effector assembly100(FIG. 1).

In order to engage first and second components1017,1018, respectively, of shaft1012to one another, first and second component1017,1018of shaft1012are brought into approximation with one another. As first and second components1017,1018of shaft1012are brought into approximation with one another, tabs1038of cantilever springs1036are flexed outwardly, i.e., apart from one another, to permit passage first hub1020into lumen1034of second hub1030.

As first hub1020is inserted further into lumen1034of second hub1030, tabs1038are translated proximally along the outer periphery of first hub1020. Eventually, tabs1030are translated into position adjacent notches1024defined within first hub1020. Once disposed adjacent notches1024, the resilient biasing force of cantilever springs1036urges tabs1038inwardly back toward their initial position such that tabs1038are engaged within notches1024, thereby engaging first and second shaft components1017,1718to one another. O-ring1040, which is also disposed within notches1024, biases tabs1038into frictional engagement within notches1024, ensuring sufficiently engagement therebetween. Translation of first hub1020further into lumen1034of second hub1030also translates male connection member1070into engagement with female connection member1060to electrically couple first and second shaft components1017,1018, respectively, to one another.

With first and second shaft components1017,1018, respectively, engaged to one another, sleeve1050may be slid distally about shaft1012to substantially surround first and second hubs1020,1030, respectively. As can be appreciated, with sleeve1050disposed about first and second hubs1020,1030, sleeve1050helps maintain the engagement between first and second shaft components1017,1018, respectively.

In order to disengage first and second shaft components1017,1018, sleeve1050is first slid proximally (or distally) such that sleeve1050is no longer disposed about first and second hubs1020,1030, respectively. Thereafter, tabs1038are disengaged from notches1024and first and second shaft components1017,1018are translated apart from one another, thus disengaging first and second shaft components1017,1018from one another.

FIG. 11shows another embodiment of a tube coupling mechanism1100configured to releasably engage first and second components1117,1118of shaft1112to one another. Shaft components1117,1118each include a lumen1122,1124extending therethrough. More specifically, lumens1122,1124are configured to cooperate with one another to permit reciprocation of drive sleeve60(FIGS. 2A-2C) and/or knife bar182(FIGS. 2A-2C) therethrough to facilitate moving jaw members110,120(FIGS. 2A-2C) between the spaced-apart position and the approximated position and for translating knife184(FIGS. 2A-2C) between the retracted position and the extend position, respectively.

With continued reference toFIG. 11, one of the shaft components, e.g., first shaft component1117, includes a pair of pins1020extending distally therefrom, while the other shaft components, e.g., second shaft component118includes a pair of apertures1130defined therethrough. Pins1020and apertures1030are radially-spaced from lumens1122,1124, respectively, so as not to interfere with the internal components of shaft1112. Pins1020are configured to be inserted into apertures1030to secure first and second shaft components to one another. More specifically, pins1020define a substantially similar, or slightly smaller, diameter than that of apertures1030to facilitate friction-fitting engagement between first and second shaft components1117,1118, respectively. Further, pins1020may include a resilient material disposed on the outer periphery thereof (or may be formed from a resilient material or structure), and/or apertures1030may also include a resilient material disposed on the internal surface thereof. In such an embodiment, pins1020and/or apertures1030are configured to be compressed upon insertion of pins1030and/or apertures1030to resiliently bias first and second shaft components1117,1118to one another.

Turning now toFIG. 12, yet another embodiment of a tube coupling mechanism configured for engaging first and second shaft components1217,1218, respectively, of shaft1212to one another is shown generally identified by reference numeral1200. One of the shaft components, e.g., first shaft component1217, includes a male connection member1220extending distally from distal end1222therefrom, while the other shaft component, e.g., second shaft component1218, includes a recess, or female connection member1230defined therein at proximal end1232thereof. Male connection member1220and/or female connection member1230are shaped complementary to one another to facilitate engagement therebetween for engaging first and second shaft components1217,1218, respectively, to one another. Further, male connection member1220may include an adhesive disposed on an outer peripheral surface thereof (or may be formed from an adhesive material) and/or female connection member1230may include an adhesive disposed on an inner surface thereof (or may be formed from an adhesive material) to facilitate engagement therebetween. More specifically, the adhesive may include UV-activated adhesives, heat-activated adhesives, pressure-activated adhesives, gamma ray-activated adhesives, solvent adhesives, or other suitable adhesives. Alternatively, temporary welding may be used to secure first and second shaft components1217,1218, respectively, to one another. A cleaning solution (not shown), removal instrument (not shown) or any other suitable mechanism may be used for disengaging the adhered components1217,1218.

With reference now toFIG. 13, tube coupling mechanism1300is shown configured for releasably engaging first and second shaft components1317,1318, respectively, of shaft1312to one another. Tube coupling mechanism1300includes one or more magnets1322,1324imbedded within, coupled to, or disposed on first shaft component1317and one or more magnets1332,1334imbedded within, coupled to, or disposed on second shaft component1318. Magnets1322,1332are complementarily-shaped relative to one another and are oriented to define opposite polarities at the exposed surfaces thereof. Similarly, magnets1324,1334are complementarily-shaped relative to one another and are oriented to define opposite polarities at the exposed surfaces thereof. Accordingly, upon approximation of shaft components1317,1318, magnets1322,1332are attracted to one another, and magnets1324,1334are attracted to one another to engage first and second shaft components1317,1318, respectively, to one another. Further, as shown inFIG. 13, magnets1322,1324and magnets1332,1334are offset relative to one another and are positioned to define a keyed-configuration, thus inhibiting rotation or disengagement of first and second shaft components1317,1318, respectively, from one another in response to axial and/or rotational loading thereof.

Referring now toFIG. 14, another embodiment of a tube coupling mechanism is shown generally identified via reference numeral1400. Tube coupling mechanism1400is configured to releasably engage first and second components1417,1418of shaft1412to one another. More specifically, tube coupling mechanism1400includes a plurality of cantilever arms1420disposed radially about longitudinal axis “A-A” and extending distally from one of the shaft components, e.g., first shaft component1417, and a plurality of complementary-shaped recesses1432defined within hub1430of the other shaft component, e.g., second shaft component1418. Similarly as described above with respect to previous embodiments, tabs1422extending from cantilever arms1420are configured for engagement within recesses1432of hub1430upon approximation of first and second shaft components1417,1418, respectively, to engage first and second shaft components1417,1418to one another.

Turning now toFIG. 15, tube coupling mechanism1500is configured to releasably engage first and second shaft components1517,1518, respectively, of shaft1512to one another. One of the shaft components, e.g., first shaft component1517, includes an insertion portion1520extending from distal end1522thereof, while the other shaft component, e.g., second shaft component1518, includes a receiving portion1530disposed at proximal end1532thereof that is configured to receive insertion portion1520therein for releasably engaging first and second shaft component1517,1518, respectively, to one another. Further, a release ring1540is disposed on first shaft component1517and is longitudinally slidable thereabout to permit disengagement of first and second shaft components1517,1518, as will be described below.

Continuing with reference toFIG. 15, insertion portion1520of first shaft component1517defines a diameter that is slightly smaller than a diameter of lumen1534of receiving portion1530of second shaft component1518to permit insertion of insertion portion1520into lumen1534of receiving portion1530and to retain insertion portion1520in engagement within receiving portion1530via friction-fitting. Further, insertion portion1520defines a textured outer peripheral surface1524configured to facilitate engagement of insertion portion1520within lumen1534of receiving portion1530.

Receiving portion1530of second shaft component1518defines a generally cylindrical configuration and is formed from a helically-wound braid, e.g., a biaxial braid, of material. Due to this braided configuration, receiving portion1530is elongated and constricted, i.e., the length of receiving portion1530is increased and the diameter of lumen1534is reduced, upon axial extension of receiving portion1530. Receiving portion1530is normally disposed in an at-rest position, wherein receiving portion1530defines a relatively smaller length and wherein lumen1534defines a relatively larger diameter as compared to the extended position.

In use, in order to engage first and second shaft components1517,1518, respectively, to one another, insertion portion1520is inserted into lumen1534of receiving portion1530. In this position, textured outer peripheral surface1524of insertion portion1520facilitates the frictional engagement of insertion portion1520of first shaft component1517within receiving portion1530of second shaft component1518. Further, removal of insertion portion1520from receiving portion1530is inhibited by the braided-configuration of receiving portion1530. More specifically, attempted withdrawal of insertion portion1520causes axial extension of receiving portion1530which, in turn, constricts, or reduces the diameter of lumen1534of receiving portion1530. Accordingly, receiving portion1530is constricted about insertion portion1520, thereby increasing the frictional engagement therebetween and inhibiting withdrawal of insertion portion1520from receiving portion1530.

In order to disengage first and second shaft components1517,1518, respectively, release ring1540is slid distally over first shaft component1517into position abutting the proximal end of receiving portion1530of second shaft components1518. Thereafter, while maintaining release ring1540in position abutting receiving portion1530, first shaft component1517is translated proximally relative to second shaft component1518to withdraw insertion portion1520from receiving portion1530, thereby disengaging first and second shaft component1517,1518, respectively, from one another. Release ring1540inhibits extension of receiving portion1530during withdrawal of first shaft component1517such that the diameter of lumen1534of receiving portion1530is maintained. In other words, release ring1540inhibits extension and constriction of receiving portion1530, thus permitting disengagement of first and second shaft components1517,1518, respectively, from one another.