Powered tacker instrument

[0001] The present application is a Continuation of, and claims the benefits of and priority to U.S. patent application Ser. No. 11/801,507, now U.S. Pat. No. 7,931,660, which was filed on May 10, 2007. The entire contents of which are incorporated herein by reference.

[0002] 1. Technical Field

[0003] The present disclosure relates to a surgical instrument for installing fasteners into tissue. More particularly, the present disclosure relates to a powered tacker instrument for use in applying surgical fasteners through a prosthetic mesh and into tissue during hernia repair surgery.

[0004] 2. Background of Related Art

[0005] Various surgical procedures require instruments capable of applying fasteners to tissue to form tissue connections or to secure objects to tissue. For example, during hernia repair procedures it is often desirable to fasten a mesh to body tissue. In certain hernias, such as direct or indirect inguinal hernias, a part of the intestine protrudes through a defect in the abdominal wall to form a hernial sac. The defect may be repaired using an open surgery procedure in which a relatively large incision is made and the hernia is closed off outside the abdominal wall by suturing. The mesh is attached with sutures over the opening to provide reinforcement.

[0006] Less invasive surgical procedures are currently available to repair a hernia. For example, in laparoscopic procedures, the hernia repair surgery is performed through a small incision in the abdomen while in endoscopic procedures, the hernia repair surgery is performed through narrow endoscopic tubes or cannulas inserted through small incisions in the body. Laparoscopic and endoscopic procedures generally require the use of long and narrow surgical instruments capable of reaching deep within the body and configured to seal with the incision or tube they are inserted through. Additionally, the instruments must be capable of being actuated remotely, that is, from outside the body.

[0007] Currently, endoscopic techniques for hernia repair utilize fasteners, such as, surgical staples or clips, to secure the mesh to the tissue to provide reinforcement in the repair and structure for encouraging tissue regrowth. The staples or clips are compressed against the tissue and mesh to secure the two together.

[0008] One other type of fastener suited for use in affixing mesh to tissue, during procedures such as hernia repair, is a coil fastener having a helically coiled body portion terminating in a tissue penetrating tip or a hollow screw type fastener having an external thread. Unique instruments have been developed to rotate these fasteners into tissue. Examples of some of these types of surgical fasteners and surgical instruments are disclosed in U.S. Pat. Nos. 5,258,000 and 5,830,221, the contents of which are incorporated by reference herein.

[0009] Most surgical instruments for applying fasteners to tissue can be actuated without the distal end of the surgical instrument actually in contact with tissue. This may result in a fastener being inadvertently ejected prior to placement against tissue or only partially installed in tissue.

[0010] In hernia repair surgery it is necessary to place multiple fasteners through a prosthetic mesh and into tissue. Often it is necessary to actuate the surgical instrument several times to rotate a single fastener through the mesh and into tissue. This can cause fatigue in the operator's hand. Additionally, it may be necessary to use a large amount of force on the actuator to install the fastener through various stiffness meshes resulting in further fatigue to the user's hand.

[0011] Thus, there is a need for a surgical instrument which can not be actuated to apply a fastener until the surgical instrument is securely positioned against the target tissue.

[0012] Furthermore, there is also need for a surgical instrument which has a power source to easily and comfortably install multiple fasteners and provide sufficient torque to drive the fasteners through a prosthetic mesh and into tissue.

[0013] There is disclosed a powered tacker device having a handle assembly and a tacker assembly extending distally from the handle assembly. The handle assembly includes a power source and a drive assembly mounted within the handle assembly. The drive assembly includes a keyed journal rotatably mounted within the handle assembly and rotatable in response to actuation of the power source. The drive assembly further includes a drive bar longitudinally movable relative to the keyed journal and rotatable in response to rotation of the keyed journal. The tacker assembly includes an inner tube terminating in a driver engageable with a fastener contained within the driver. The inner tube is connected to the rotator and rotatable in response to rotation of the keyed journal. The powered tacker device additionally includes an actuator associated with the handle assembly and operable to engage the power source with the drive assembly.

[0014] The keyed journal includes a threaded bore and the drive rod includes a threaded outer surface engageable with the threaded bore. Rotation of the keyed journal within the handle assembly moves the drive rod in a longitudinal direction within the handle assembly. The drive bar is connected to the rotator to move the rotator longitudinally within the handle assembly in response to rotation of the keyed journal. Keyed journal further includes distally extending keys. The rotator includes slots engageable with the keys such that the rotator is rotated in response to rotation of the keyed journal. In one embodiment, the rotator is longitudinally movable along the keys.

[0015] In one embodiment, the handle assembly includes a first limit switch and a second limit switch. The first and second limit switches are operable to deactivate the power source from the drive assembly. The drive rod includes a contact assembly which is engageable with the first limit switch when the drive bar is in a proximal most position and engageable with the second limit switch when the drive bar is in a distal most position. The handle assembly includes at least one indicator providing a visual indication when the contact assembly has engaged one of the limit switches.

[0016] In one embodiment, the power source includes a motor engageable with the keyed journal so as to rotate the keyed journal and a battery to power the motor. The drive assembly includes a drive gear engageable with the keyed journal to rotate the keyed journal. The drive gear is engageable with a spur gear on the motor to rotate the keyed journal.

[0017] In one embodiment, the drive assembly includes a mesh gear engageable with the keyed journal and the drive gear. The drive assembly includes a spring to bias the mesh gear into engagement with the keyed journal. The spring allows the mesh gear to disengage from the drive gear to prevent over rotation of the keyed journal.

[0018] The handle assembly includes a safety mechanism preventing actuation of the power source prior to the proper positioning of the powered tacker device relative to tissue. The safety mechanism includes an outer tube mounted for longitudinal movement relative to the handle assembly and a safety switch actuable in response to movement of the outer tube. The safety switch prevents actuation of the power source when the outer tube is in the distal most position.

[0019] There is also disclosed a powered tacker device having a handle assembly and a tacker assembly extending distally from the handle assembly. The handle assembly includes a power source in the drive assembly mounted for rotation within the handle assembly and rotatable in response to activation of the power source. The tacker assembly includes an inner tube containing a plurality of surgical fasteners and connected to the drive assembly. A driver is mounted on the distal end of the in the tube to rotate the surgical fasteners into tissue. The inner tube is rotatable a limited predetermined initial amount relative to the driver. The tacker assembly includes a spring positioned intermediate the inner two and driver to bias the inner tube relative to the driver.

[0020] In one embodiment, the inner tube includes a longitudinally extending transfer bar is configured to maintain the surgical fasteners in a predetermined orientation. The driver includes tabs engageable with the surgical fasteners to drive the surgical fasteners into tissue. The inner tube is rotatable relative to the driver to move the transfer bar into and out of alignment with the drive tabs. This allows only one fastener at a time to be positioned within the driver while the driver drives the faster into tissue. Once the transfer bars have been realigned with the drive tabs a subsequent fastener may be advanced from within the inner tube and into the driver.

[0048] An embodiment of the presently disclosed powered tacker device will now be described in detail with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views. As is common in the art, the term “proximal” refers to that part or component closer to the user or operator, i.e. surgeon or physician, while the term “distal” refers to that part or component further away from the user.

[0049] Referring to FIG. 1, there is disclosed a powered tacking instrument, or powered tacker 10, for use in installing surgical fasteners in tissue. Powered tacker 10 generally includes a handle assembly 12 and an elongate distal tacker assembly 14 extending distally from handle assembly 12. Handle assembly 12 includes a handle housing 16 which is formed from two housing halves 16a and 16b. Handle housing 16 has a grip portion 18, a body portion 20 and a nose cone portion 22 extending distally from body portion 20. Handle assembly 12 has a motor 24, mounted in body portion 20, which powers powered tacker 10 to drive surgical fasteners into tissue. A trigger 26 is mounted in body portion 20 to actuate motor 24 in a manner described in more detail hereinbelow. Handle assembly 12 may also include an indicator or light assembly 28, which is provided to indicate the status of the various cycles and/or operational status of powered tacker 10. It is also envisioned that a switch 27 (e.g., a push-button switch in FIG. 1) may be used to turn powered tacker 10 on and off.

[0050] Distal tacker assembly 14 includes an outer tube 30 which is mounted for movement relative to handle assembly 12. Specifically, a proximal end 32 is movably mounted through an open distal end 34 of nose cone portion 22. Engagement of a distal end 36 of outer tube 30 with tissue moves outer tube 30 relative to handle assembly 12 to activate a lockout or safety mechanism as described hereinbelow. An inner tube 38 is positioned within outer tube 30 and also extends distally from handle assembly 12. A driver 40 is positioned on a distal end 42 of inner tube 38 such that driver 40 can be rotated by inner tube 38 in response to activation of powered tacker 10. A torsion spring 44 is connected to, and positioned between, a proximal end 46 of driver 40 and a distal end 42 of inner tube 38 to allow driver to have a limited amount of reversible rotation relative to inner tube 38. This limited amount of reversible rotation assists in managing the advancement of a fastener 50 from inner tube 38 into driver 40, out a distal end 52 of driver 40, and into tissue.

[0051] Referring now to FIGS. 2 and 3, as noted above, handle assembly 12 includes a motor 24 which is provided to rotate and advance inner tube 38 in response to actuation of trigger 26 in order to install a surgical fastener into tissue. Handle assembly 12 includes a battery 54 to powered motor 24. A trigger switch 56 is provided on grip portion 18 and is actuated by trigger 26 in order to operate motor 24. Trigger switch 56 may be a multiposition type switch allowing actuation of motor 24 in both a forward and reverse direction. Handle assembly 12 additionally includes a circuit board 58 which is provided to control the electronics of powered tacker 10. In addition to managing the flow of current from battery 54 through trigger switch 56 and to motor 24, circuit board 58 additionally acts as the “brain” of powered tacker 10. Circuit board 58 receives signals from various safety and motion limiting switches and displays the various operational status conditions of powered tacker 10 by means of indicator light assembly 28.

[0052] As noted hereinabove, inner tube 38 is rotatably mounted to handle assembly 12 so as to drive a surgical fastener into tissue. Handle assembly 12 contains a drive assembly 60 which is rotatably mounted within handle assembly 12. Drive assembly 60 rotates, as well as moves longitudinally, inner tube 38 in response to actuation of trigger 26. Drive assembly 60 is rotatably mounted on first and second housing flanges 62 and 64 formed in handle housing halves 16a and 16b. Specifically, drive assembly 60 includes a distal journal 66 which is rotatably mounted in first housing flange 62 and a proximal journal 68 which is rotatably mounted within second housing flange 64. In order to rotate drive assembly 60, drive assembly 60 includes a drive gear 70 which is engageable with a worm gear 72 provided on motor 24.

[0053] In order to ensure that inner tube 38 rotates and translates within predetermined parameters, handle assembly 12 includes a proximal limit switch 74 and a distal limit switch 76. Limit switches 74 and 76 are electronically connected to motor 24 through circuit board 58. It should be noted that, while not specifically shown, the various electronic components of powered tacker 10 are wired or connected in known manner to achieve the various switching and display functions. Proximal limit switch 74 corresponds to the initial or unactuated condition of powered tacker 10 while distal limit switch 76 corresponds to the fully actuated condition of powered tacker 10. A contact arm 78 is associated with drive assembly 60 to engage proximal and distal limit switches 74 and 76.

[0054] Powered tacker 10 is provided with a safety mechanism or electronic lockout 80 which prevents actuation of powered tacker 10 when powered tacker 10 has not been correctly positioned against tissue. Specifically, electronic lockout 80 prevents actuation of powered tacker 10 until such time as outer tube 30 has been pressed against tissue and moved proximately a predetermined distance relative to handle assembly 12. At least one safety switch 82 (a pair of safety switches 82a are illustrated in FIG. 4) may be provided within handle housing 12. It is envisioned that powered tacker 10 cannot be actuated until at least one safety switch 82 has been activated to indicate that outer tube 30 has been moved proximately a predetermined amount. Further, it is envisioned that for powered tacker 10 to be activated, at least one safety switch 82 is activated, then outer tube 30 travels from the end of the stroke until contact arm 78 contacts distal limit switch 76. Upon release of pressure on outer tube 30, contact arm 78 retracts until proximal limit switch 74 is activated, indicating powered tacker 10 is in its original position.

[0055] Electronic lockout 80 includes a first doglegged arm 84 (FIG. 4) and a second doglegged arm 86. Doglegged arms 84 and 86 are supported for longitudinal movement within handle housing 16 by mounting brackets 88. Electronic lockout 80 further includes a base block (FIG. 6 illustrates block halves 90a and 90b) which is engageable with proximal end 32 of outer tube 30, as well as doglegged arms 84 and 86, to actuate safety switches 82a and 82b. Base block may be formed as first and second block halves 90a and 90b which clamp about outer tube 30 in the manner described hereinbelow. Thus, proximal movement of outer tube 30 relative to handle housing 12 actuates safety switches 82a and 82b to permit operation of powered tacker 10.

[0056] As noted hereinabove, handle assembly 12 includes an indicator light assembly 28 which is provided to indicate the various operational conditions of powered tacker 10. Indicator light assembly 28 includes four lights provided on body portion 20 of handle housing 16. In this embodiment, the four lights comprise first, second, third, and fourth LED type indicator lights 92, 94, 96 and 98 respectively. First indicator light 92 is green and corresponds to the condition where outer tube 30 has been moved proximately to actuate safety switches 82a and 82b. Second indicator light 94 is red and corresponds to the condition where outer tube 30 is in the initial distal most position prior to engagement with tissue and thus actuation on safety switches 82a and 82b. Likewise, third indicator light 96 corresponds to the initial position of drive assembly 60 where proximal limit switch 74 has been actuated and fourth indicator light 98 corresponds to the final position of drive assembly 60 where distal limit switch 76 has been actuated. In this manner, the operational status and condition of powered tacker 10 at any point during a surgical procedure is visually indicated to the user.

[0057] Referring now to FIGS. 4 and 5, the various components of drive assembly 60 will now be described. Drive assembly 60 generally includes a keyed journal 100 having a central flange 102. Keyed journal 100 includes a distal hub 104 extending distally from central flange 102. A pair of longitudinally extending distal keys 106a and 106b extend distally from distal hub 104. Distal keys 106a and 106b are provided to rotate inner tube 38 as well as allow inner tube 38 to move longitudinally as keyed journal 100 is rotated. Keyed journal 100 additionally includes a proximal hub 108. Keyed journal 100 is rotatably mounted within handle housing 16. Distal hub 104 is rotatably supported within distal journal 66 while proximal hub 108 is rotatably supported within proximal journal 68. Keyed journal 100 additionally includes a threaded throughbore 110 which enables keyed journal 100 to be rotated within handle assembly 12.

[0058] A biasing spring 112 is mounted about proximal hub 108 and is provided to urge a mesh gear 114 into engagement with drive gear 70. Mesh gear 114 includes a key 116 which is configured to engage a longitudinally extending slot (not shown) formed in proximal hub 108. In order to engage mesh gear 114 with drive gear 70, mesh gear 114 includes a plurality of teeth 118 which are engageable with distal teeth 120 formed on drive gear 70. The provision of key 116 within the longitudinally extending slot formed in proximal hub 108 allows mesh gear 114 to rotate keyed journal 100 while at the same time allowing for a limited amount of longitudinal movement of mesh gear 114 relative to keyed journal 100 against the bias of biasing spring 112. Thus, mesh gear 114 may move into and out of engagement with drive gear 70 against the bias of biasing spring 112. This provides protection against a surgical fastener from being over rotated into tissue due to excessive torque provided by drive gear 70 to mesh gear 114.

[0059] A C-clip 124 is provided within a proximal groove 126 formed in proximal hub 108 in order to retain biasing spring 112, mesh gear 114 and drive gear 70 on proximal hub 108.

[0060] As noted hereinabove, the degree and direction of rotation of inner tube 38 is controlled and limited by proximal and distal limit switches 74 and 76. Limit switches 74 and 76 are turned on and turned off by engagement with contact arm 78. A contact assembly 128 is provided on contact arm 78 to engage limit switches 74 and 76. Contact arms 78 and contact assembly 128 are part of a limit drive bar 130. Limit drive bar 130 is a part of drive assembly 60 and, in addition to moving contact assembly 128 between limit switches 74 and 76, converts rotary motion of keyed journal 100 into longitudinal motion of inner tube 38 relative to handle assembly 12. Limit drive bar 130 includes a threaded distal surface 132 which is engageable with threaded throughbore 110 of keyed journal 100. Thus, as keyed journal 100 is rotated about limit drive bar 130, limit drive bar 130 is moved longitudinally in the distal and proximal directions relative to handle assembly 12.

[0061] As shown, contact assembly 128 includes a plate 134 having a pin 136 which is engageable with limit switches 74 and 76. Plate 134 is affixed by means of a screw 138 to a proximal end 140 of contact arm 78. Limit drive bar 130 additionally includes a throughbore 142 for passage of a needle associated with powered tacker 10 as described in more detail hereinbelow. Limit drive bar 130 further includes a generally round, distally extending circumferential projection 144 which is provided to move inner tube 38 longitudinally in response to longitudinal motion of limit drive bar 130 as well as allowing inner tube 38 to rotate relative to limit drive bar 130.

[0062] In order to transfer the rotational motion of keyed journal 100 and the longitudinal motion of limit drive bar 130 to inner tube 38, drive assembly 60 is provided with a rotator 146. Rotator 146 includes a pair of side slots 148a and 148b which are configured to engage and move along distal keys 106a and 106b of keyed journal 100. Additionally, the engagement of distal keys 106a and 106b with side slots 148a and 148b allows keyed journal 100 to rotate rotator 146. Rotator 146 includes a proximal slot 150 for receipt of circumferential projection 144 of limit drive bar 130. Circumferential projection 144 is free to rotate within proximal slot 150 so that limit drive bar 130 can move rotator 146 longitudinally within handle assembly 12 and still allow rotator 146 to rotate in response to rotation of keyed journal 100.

[0063] Rotator 146 includes a center hole 152 for receipt of proximal end 48 of inner tube 38. A pin 154 secures rotator 146 to inner tube 38. Specifically, rotator 146 includes a side hole 158 while proximal end 48 of inner tube 38 includes a side hole 158 for receipt of pin 154 therethrough. Pin 154 additionally includes a pin hole 160 receipt therethrough of a needle as described in more detail hereinbelow. (See also FIG. 7).

[0064] As noted hereinabove, electric lockout 80 includes a pair of first and second doglegged arms 84 and 86. Doglegged aims 84 and 86 include respective proximal ends 162 and 164 which are engageable with safety switches 82a and 82b. Additionally, doglegged arms 84 and 86 include respective distal ends 166 and 168 which are configured to engage base block 90. In order to bias base block 90, and thus outer tube 30 in an initial distal direction, electronic lockout 80 includes a biasing spring 170 having a proximal spring guide 172. Biasing spring 170 is positioned between spring guide 172 and base block 90. A bushing 174 supports spring guide 172 within handle housing 16. Thus, as outer tube 30 is moved proximally against the bias of biasing spring 170, proximal ends 162 and 164 of doglegged arms 84 and 86 engage safety switches 82a and 82b to allow powered tacker 10 to be actuated.

[0065] Referring now to FIGS. 4 and 6, the details of distal tacker assembly 14 will now be described. As noted hereinabove, outer tube 30 is mounted for longitudinal movement relative to handle assembly 12. Outer tube 30 includes a longitudinal slot 176 near proximal end 32 for engagement with base block 90 as described in more detail hereinbelow (see FIG. 7). A plurality of circumferential crenellations 178 are formed all on distal end 36 of the outer tube 30. Crenellations 178 assist in securing a prosthetic mesh in position against tissue and preventing the prosthetic mesh from rotating as powered tacker 10 rotates fastener 50 therethrough.

[0066] Distal tacker assembly 14 further includes a bottom guide 180 which is provided to facilitate the transfer is of fasteners 50 from within inner tube 38 and into driver 42 a position to be engaged with driver 40. A friction ring 182 is provided on driver 40 and is configured to engage an interior of outer tube 30 to allow inner tubes 38 to initially rotate a predetermined distance prior to rotating driver 40 in a manner described in more detail hereinbelow.

[0067] As noted hereinabove, distal tacker assembly 14 contains a plurality of fasteners 50. Fasteners 50 are contained within an interior of inner tube 38 which acts as a fastener cartridge. In order to move the plurality of fasteners 50 towards driver 40, a spring 184 is provided within an interior of inner tube 38. A distal spring guide 186 is provided between spring 184 and fasteners 50 and a proximal spring guide 188 is provided between spring 184 and proximal end 48 of inner tube 38.

[0068] As indicated hereinabove, powered tacker 10 includes an elongate needle 190 which extends from handle assembly 12 through distal tacker assembly 14. Needle 190 is provided with a distal penetrating tip 192. Needle 190 extends through fasteners 50 in a manner described in more detail below. Penetrating tip 192 is provided to make an initial, or pilot, hole in mesh and/or tissue for installation of fasteners 50. A proximal end 194 of needle 90 is affixed to handle housing 12 by means of a bushing 196 which has a pin 198 engageable with handle housing halve 16a. Thus, needle 190 is affixed to, and remains stationary relative to, handle assembly 12.

[0069] Referring now to FIG. 6, and as noted hereinabove, proximal end 32 of outer tube 30 is affixed to base block 90. Specifically, base block 90 includes a pair of inward projections 200b (one inward projection being hidden from view in FIG. 6) which each engage proximal slot 176 (only a single slot 176 is visible in FIG. 6) in outer tube 30. Base block 90 further includes a circumferential flange formed as two flange halves 202b (one flange half being hidden from view in FIG. 6) which are configured to engage in secure biasing spring 170 (FIG. 7) within handle assembly 12. Base block 90 further includes a pair of proximal detents 204a and 204b which are configured to engage and move distal ends 166 and 168 of doglegged arms 84 and 86. In the embodiment illustrated in FIG. 7, side hole 158 of inner tube 38 is disposed on a substantially flat portion 49 adjacent proximal end 48 thereof. Flat portion 49 is included on both sides of inner tube 38, such that inner tube 38 may be oriented with rotator 146 and locked via pin 154, as discussed above.

[0070] With reference to FIG. 7A, a partially exploded view of several elements illustrated in FIG. 7 is shown. Here, a spring retainer 175 is illustrated in place of spring guide 172 of FIG. 7. It is envisioned that spring retainer 175 may be used without or in addition to spring guide 172 and/or bushing 174. Additionally, outer tube 30 is shown positioned adjacent spring 170 and covering a portion of inner tube 38.

[0071] Referring to FIG. 8, the details of the distal end of distal tacker assembly 14 will now be described. As noted hereinabove, distal tacker assembly 14 is configured to install a surgical fastener 50 into tissue. Surgical fasteners 50 are of the type disclosed in U.S. patent application Ser. No. 10/560,879, filed on Dec. 13, 2005, the contents of which are incorporated herein by reference. Fastener 50 includes an outer helical thread 206 for rotation into tissue. Fastener 50 additionally includes a throughbore 208 for receipt of tissue penetrating tip 192 of needle 190. As noted hereinabove, fastener 50 is driven into tissue by means of driver 40. Thus fastener 50 includes a slotted head to tend which is configured to be engaged by drive tabs 212 formed in distal end 52 of driver 40. Driver 40 includes a distal circumferential groove 214 for receipt of friction ring 182.

[0072] Driver 40 is mounted on inner tube 38 by inserting driver 40 over stepped down distal end 42 of inner tube 38. As noted hereinabove, a spring 44 is provided between driver 40 and inner tube 38. Spring 44 includes a proximal spring end 216 and a distal spring end 218. Spring 44 allows inner tube 38 to rotate an initial predetermined amount relative to driver 40 against the bias of spring 44. Proximal end 216 of spring 44 is affixed within a slot 220 in inner tube 38 while a distal end 218 of spring 44 is affixed within a driver slot 222 formed in driver 40. Inner tube 38 is provided with a pair of longitudinally extending transfer bars 224 which extends substantially along the length of inner tube 38. In an initial position, transfer bars 224 are in longitudinal alignment with drive tabs 212 formed in driver 40. Initial rotation of inner tube 38 relative to driver 40 rotates transfer bars 222 out of alignment with drive tabs 212.

[0073] As discussed, inner tube 38 is capable of an initial limited amount of rotation relative to driver 40 before inner tube 38 begins to rotate driver 40. Inner tube 38 includes a set screw 226 which extends through a hole 228 provided in distal end 42 of inner tube 38. Referring for the moment to FIG. 8A, driver 40 includes an index slot 230 which is configured to receive set screw 226 and allow inner tube 38 to rotate a predetermined distance before set screw 226 engages an edge of slot 230 to rotate driver 40 along with inner tube 38. This allows driver 40 to rotate and install a fastener 50 into tissue while preventing subsequent fasteners 50 from moving along transfer bars 224 and into driver 40.

[0074] As noted hereinabove, distal tacker assembly 14 further includes a bottom guide 180 which assists in transferring fasteners 50 from inner tube 38 and into driver 40. Bottom guide 180 includes a guide rail 232 and a guide pin 234. Bottom guide 180 is mounted within a slot (not shown) formed in driver 40 while guide pin 234 extends through a hole (not shown) formed in proximal end 48 of inner tube 38.

[0075] Referring now to FIG. 9, as discussed hereinabove, distal tacker assembly 14 includes spring 184 to bias a plurality of fasteners 50 distally within inner tube 38. Distal spring guide 186 includes a throughbore 236 for receipt of needle 190 therethrough. Distal spring guide 186 further includes a pair of longitudinally extending slots 238 which are configured to ride along transfer bars 224 are formed in inner tube 38. A recess 240 is provided in distal spring guide 186 to capture spring 184. Similarly, proximal spring guide 188 includes a throughbore 248 and longitudinally extending slots 246. Proximal spring guide 188 additionally includes a recess 248 to capture and stabilize spring 184 within inner tube 38. Engagement of slots 238 and 246 in distal spring guides 186 and 188, respectively, with transfer bars 224 ensure that fasteners 50 remain in proper alignment to be transferred into driver 40.

[0076] Referring now to FIGS. 10-18, and initially with regard to FIG. 10, the use of powered tacker 10 to install surgical fastener 50 through prosthetic match and into tissue will now be described. In the initial position, distal end 36 of outer tube 30 is in the distal most position shielding tissue penetrating tip 92 of needle 90 and fastener 50. Base block 90 is also in a distal most position against the bias of spring 170. Referring for the moment back to FIG. 2, doglegged arm 86 is also in a distal most position remote from the safety switch 82. As noted hereinabove, safety switch 82 prevents actuation of powered tacker 10 until outer tube 30 has been properly positioned against tissue.

[0077] Trigger 26 is in the unactuated position and contact assembly 128 is engaged with proximal limit switch 74. As noted hereinabove, actuation of proximal limit switch 74 triggers one of the LEDs in indicate light assembly 28 to signify to the user that powered tacker 10 is ready for use.

[0078] As best shown in FIG. 11, rotator 146 and limit drive bar 130 are in a proximal most position relative to keyed journal 100. In this position, inner tube 38 is also in a proximal most position. As shown in FIG. 12, drive tabs 212 of driver 40 are engaged with slotted head 210 of fastener 50.

[0079] Referring now to FIG. 13, to attach a prosthetic mesh M to tissue T, distal end 36 of outer tube 30 is urged against mesh M and tissue T causing tissue penetrating tip 192 of needle 190 to penetrate through mesh M and into tissue T. Crenellations 178 provided on distal end 36 of outer tube 30 secure and stabilize mesh M as fastener 50 is subsequently rotated therethrough. As shown, this biases outer tubes 30 proximally in the direction of arrow A.

[0080] As best shown in FIG. 14, as outer tube 30 is biased proximally, outer tube 30 moves base block 90 proximally against the bias of spring 170. Proximal movement of base block 90 moves doglegged arm 86, and specifically proximal end 164 of doglegged arm 86, against safety switch 82b to actuate switch 82b. Once switch 82b has been actuated, it signals circuit board 58 that powered tacker 10 has been properly positioned and it is safe to actuate powered tacker 10.

[0081] Referring now to FIG. 15, once powered tacker 10 has been properly positioned, trigger 24 may be actuated in the direction of arrow B to cause circuit board 58 to turn on motor 26. Once motor 24 has been actuated it rotates worm gear 72 which in turn rotates drive gear 70. Rotation of drive gear 70 rotates mesh gear 114 and keyed journal 100 to initiate rotation and translation of inner tube 38 relative to handle assembly 12. As noted hereinabove, should anything restrict the motion of inner tube 38, mesh gear 114 can compress against the bias of spring 112 and thereby disengage distal tacker 14 from handle assembly 12. Rotation of keyed journal 100 causes threaded inner surface 110 to move limit drive bar 130 in response to engagement of threaded inner surface 110 with threads 132 of limit drive bar 130. Engagement of distal projection 144 of limit drive bar 130 within the slot 150 of rotator 146 causes distal longitudinal motion of rotator 146. As rotator 146 moves distally it moves inner tube 38 distally.

[0082] As noted hereinabove, rotation of keyed journal 100 also causes rotation of rotator 146. Additionally, rotator 146 can move longitudinally along distal keys 106 of keyed journal 100. Thus, keyed journal 100 servers the dual purpose of rotating rotator 146, and thus inner tube 38, as well as allowing for distal motion of rotator 146 relative to keyed journal 100.

[0083] Referring now to FIG. 16, once limit drive bar 130 has been moved to its distal most position, contact assembly 128 engages distal limit switch 76 to turn off motor at 24 and prevent any over rotation of inner tube 38.

[0084] As best shown in FIG. 17, full distal movement and rotation of inner tube 38 causes driver 40 to advance and rotate fastener 50 through prosthetic mesh M and into tissue T to thereby secure prosthetic mesh M to tissue T.

[0085] While not specifically shown, once a first fastener 50 has been properly installed, trigger 26 can be moved to reverse the rotation of motor 24. Reverse rotation of motor 24 causes reverse rotation of keyed journal 100 thereby moving inner tube 38 proximally to an initial position. As inner tube 38 is rotated in the reverse direction it causes set screw 226 to rotate back through slot 230 in driver 40 an initial position. In the initial position, transfer bars 224 are in alignment with drive tabs 212 so that a subsequent fastener can be transferred into driver 40. Once inner tube 38 is moved back to its initial position, contact assembly 128 contacts proximal limit switch 76 to indicate to the user powered tacker 10 is in condition for subsequent use. As powered tacker 10 is moved away from tissue, outer tube 30 moves back to a distal most position shielding the next subsequent fastener 50 to be installed. When outer tube 30 is in the distal most position safety switch 82 is deactivated preventing powered tacker 10 from operation until outer tube 30 has been again properly positioned against tissue and safety switch 82 is actuated.

[0086] Before pressure is applied to powered tacker 10, transfer bars 224 are in alignment with drive tabs 212 and distal end of fastener 50 is contacting a retention feature 191 (FIG. 19) on needle 190. Retention feature 191 prevents fastener 50 in contact therewith from being pushed off needle 190 by spring 184. It is envisioned that when safety switch 82 is engaged, transfer bars 224 rotate clockwise, such that after the initial 90 degree rotation of transfer bars 224, transfer bars 224 and drive tabs 212 are diametrically opposed. It is envisioned that transfer bars 224 and drive tabs 212 remain diametrically opposed for the remainder of the stroke. Here, transfer bars 224 may create the force necessary to push fastener 50 distally and drive tabs 212 are capable of maintaining the frictional fit with head 210 of fastener 50.

[0087] Upon completion of the firing stroke, the pressure of powered tacker 10 is released and powered tacker 10 moved proximally—away from ejected fastener 50. Torsion spring 44 may then bring drive tabs 212 back to their resting position, such that drive tabs 212 are substantially aligned with transfer bars 224. Once drive tabs 212 and transfer bars 224 are aligned, spring 184 pushes the next fastener 50 distally until distal portion of fastener 50 contacts retention feature 191 of needle.

[0088] An embodiment of the present disclosure is illustrated in FIGS. 18-20. In this embodiment, inner tube 38 includes at least one tab 302 (two tabs 302 are shown in FIG. 20) and needle 190 includes a retention feature 191 (FIG. 19) proximal of distal penetrating tip 192. Retention feature 191 opposes the force exerted by spring 184, such that fastener 50 does not prematurely become ejected from powered tacker 10. To force fastener 50 past retention feature 191, tabs 302 on inner tube 38 are deflected inwardly such that tabs 302 are disposed proximal of distal-most fastener 50 (see FIG. 20) and inner tube 38 is moved distally. Thus, tabs 302 of inner tube 38 contact a proximal portion of fastener 50 and force fastener to move past retention feature 191 and distally toward tissue. It is envisioned that tabs 302 are biased inwardly. It is also envisioned that tabs 302 are deflected inwardly after contacting a fluted section (not explicitly shown in this embodiment) of outer tube 30 (FIG. 18).

[0089] Other embodiments of the present disclosure are illustrated in FIGS. 21 and 22. FIG. 21 illustrates needle 190 having a cut-out portion 350 and a rod 360, and FIG. 22 illustrates needle 190 having a channel 354 and rod 360. In both embodiments, rod 360 includes a protrusion 362 adjacent its distal end and is secured to needle 190 adjacent its proximal end (e.g., via a weld). It is envisioned that rod 360 is cantilevered and its distal end is biased away from needle 190. Fastener 50 (e.g., distal-most fastener) is shown in FIG. 21 around a portion of needle 190. Protrusion 362 opposes the force exerted by spring 184 (FIG. 6), such that fastener 50 does not prematurely become ejected from powered tacker 10. To force fastener 50 past protrusion 362, rod 360 is deflected against the biasing force (e.g., downwardly in FIGS. 21 and 22) by exerting additional force on fastener 50, such that protrusion 362 is able to pass through throughbore 208 of fastener 50. After fastener 50 passes rod 360, rod 360 returns to its original biased position as the distal end of rod 360, including protrusion 362, springs away from needle 190 and is thus in a position to maintain a subsequent fastener 50 on needle 190.

[0090] FIGS. 23-25 illustrate additional embodiments of the present disclosure. In these embodiments, a plate 370 is illustrated adjacent distal end 42 of inner tube 38. Plate 370 is shown with a plate groove 372 adjacent its distal end and plate groove 372 is configured to accept a plate ring 374 therein. Further, a needle ring 380 is shown in FIG. 23 and is disposed within a needle groove (hidden from view in FIG. 23). It is envisioned that the needle groove is dimensioned to allow needle ring 380 to be at least partially compressed therein in response to a sufficient amount of force exerted against needle ring 380. Therefore, needle ring 380 and the needle groove combine to maintain distal-most fastener 50 on needle 190 until an additional force is exerted on fastener 50 to compress needle ring 380 and push fastener 50 over and distally past needle ring 380, thus ejecting distal-most fastener 50 from needle 190.

[0091] Referring more specifically to FIGS. 24 and 25, enlarged, cross-sectional views of distal end 42 of inner tube 38 are illustrated including plate 370 thereon. Plate 370 is shown including two halves 370a and 370b, but is also envisioned that plate 370 may be a single part that is disposed around needle 190 and/or at least partially within inner tube 38. It is envisioned that a proximal portion of each plate half 370a, 370b is secured to inner tube 38, and a distal portion of each plate half 370a, 370b is floating, or otherwise unsecured, in relation to inner tube 38. Plate ring 374 encircles plates 370a, 370b within plate groove 372 and confines outward movement of plates 370a, 370b. It is also envisioned that plate ring 374 inwardly biases each plate half 370a, 370b, as illustrated in FIG. 24. Here, plate lips 376a, 376b are disposed proximal of head 210 of distal-most fastener 50, thus restricting proximal translation of distal-most fastener 50.

[0092] With reference to FIG. 25, upon distal movement of fastener 50 held adjacent plates 370a, 370b, fastener 50 forces distal portion of plates 370a, 370b outward in the direction of arrows C and D (within the confines of plate ring 374). Plates 370a, 370b are moved outward far enough to allow fastener 50 to pass therethrough and be ejected from needle 190. A ramp 378 may also be included on inner surface of each plate 370a, 370b to facilitate fastener 50 passing therethrough.

[0093] It will be understood that various modifications may be made to the embodiments disclosed herein. For example, the disclosed powered tacker devices may be provided with an AC type power source which is not self-contained within the powered tacker device. Further, the disclosed circuit board may be configured to automatically rotate the motor in the reverse direction to reset the powered tacker devices after a surgical fastener has been installed in tissue. Additionally, various other mechanisms of transferring individual fastener is from within a cartridge assembly to a driver are contemplated herein. Yet still further, the disclosed powered tacker devices may be configured so that the distal tacker assembly is removable, and or disposable, from the associated handle assembly. 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.