Articulating bipolar electrosurgical instrument

<u>BACKGROUND</u>

Technical Field

0001The present disclosure relates to electrosurgical instruments and, more particularly, to bipolar electro-surgical instruments having an articulating linkage for operating and/or effectuating movement of an end effector thereof.

Background of Related Art

0002Surgical procedures of the lungs currently employ Video Assisted Thoroscopic Surgical (VATS) techniques wherein an endoscopic surgical stapler is used to perform wedge resections, iobotomies, segmental resections, wedge biopsies or lung volume reduction surgeries. Typically, the endoscopic surgical stapler can only be activated once per insertion into the thoracic cavity. For most surgical procedures involving the lungs, a single activation of the endoscopic surgical stapler cannot ligate and/or bisect all of the required areas for the given surgical procedure.

0003Accordingly, if multiple activations of the endoscopic surgical stapler are required to fully complete the surgical procedure, it is necessary to remove the endoscopic surgical stapler from the thoracic cavity after each fire; fit the endoscopic surgical stapler with a new, fully loaded staple cartridge, and reinsert the endoscopic surgical stapler into the thoracic cavity for the next activation thereof.

0004There is, therefore, a need for a surgical instrument that can be activated repetitively, as many times as the surgical procedure requires or as many times as necessary, without having to remove the surgical instrument from the thoracic cavity.

0005<patcit id="pcit0001" dnum="US5827323A"><text>US 5,827,323</text></patcit> discloses an endoscopic surgical instrument made up of two separate blade-like end effector pieces attached to a distal end of a tubular barrel by a pin. The end effector pieces are thus independently Pivotally about the pin. The pivotable movement is toward and away from the longitudinal axis of the tubular barrel. Pivotal movement of a trigger lever in either direction effects pivotal movement of one end effector piece. On the other hand, pivotal movement of the trigger lever does not result in movement of the other end effector piece. Rotation of a fingerwheel roller in a clockwise direction effects simultaneous movement of both end effector pieces toward an alignment with the longitudinal axis of the tubular barrel. Similarly, counter clockwise rotation of the fingerwheel roller results in pivoting both end effector pieces away from the aligned position.

<u>SUMMARY</u>

0006The present invention provides a bipolar electrosurgical instrument as defined in claim 1.

<u>BRIEF DESCRIPTION OF THE DRAWINGS</u>

0007By way of example only, embodiments of the electrosurgical instrument of the present invention will be described with reference to <figref idref="f0012 f0013 f0014 f0015 f0016 f0017">figures 21 to 31</figref>. The remaining figures and accompanying description do not constitute an embodiment of the present invention. <ul id="ul0001" list-style="none"><li><figref idref="f0001">FIG. 1</figref> is a perspective view of an articulating bipolar electro-surgical instrument according to an embodiment of the present disclosure;</li><li><figref idref="f0002">FIG. 2</figref> is an enlarged, right side perspective view of a distal end of the surgical instrument of <figref idref="f0001">FIG. 1</figref>, including an end effector in accordance with an embodiment of the present disclosure, depicting a pair of opposed jaw members thereof in an axially aligned orientation and in a closed condition;</li><li><figref idref="f0002">FIG. 3</figref> is an enlarged, front perspective view of the end effector of <figref idref="f0002">FIG. 2</figref>, depicting a fist of the pair of opposed jaw members in the axially aligned orientation and a second of the pair of opposed jaw members in an angled or open condition;</li><li><figref idref="f0003">FIG. 4</figref> is a left side perspective view of the end effector of <figref idref="f0002">FIGS. 2-3</figref>, depicting the a first of the pair of opposed jaw members in the axially aligned orientation and a second of the pair of opposed jaw members in an angled or open condition;</li><li><figref idref="f0003">FIG. 5</figref> is a left side perspective view of the end effector of <figref idref="f0002 f0003">FIGS. 2-4</figref>, depicting the pair of opposed jaw members in an articulated orientation and in a closed condition;</li><li><figref idref="f0004">FIG. 6</figref> is a left side perspective view of the end effector of <figref idref="f0002 f0003">FIGS. 2-5</figref>, with a portion of the outer tube broken away and/or removed in order to illustrate the locking mechanism and the articulating mechanism of the present disclosure;</li><li><figref idref="f0004">FIG. 7</figref> is a left side perspective view of the end effector of <figref idref="f0002 f0003 f0004">FIGS. 2-6</figref>, with the outer tube and locking shaft entirely removed in order to further illustrate the articulating mechanism of <figref idref="f0004">FIG. 6</figref>;</li><li><figref idref="f0005">FIG. 8</figref> is a perspective view of the locking mechanism and articulating mechanism according to an embodiment of the present disclosure;</li><li><figref idref="f0005">FIG. 9</figref> is a rear perspective view of the locking mechanism and articulating mechanism of <figref idref="f0005">FIG. 8</figref>;</li><li><figref idref="f0006">FIG. 10</figref> is an enlarged, right side perspective view of a distal end of a surgical instrument including an end effector, in accordance with an alternate embodiment of the present disclosure, showing a pair of opposed jaw members, in an axially aligned orientation;</li><li><figref idref="f0006">FIG. 11</figref> is an enlarges, right side, perspective view of the end effector of <figref idref="f0006">FIG. 10</figref>, in an first articulated condition, showing an outer tube shown in phantom to illustrate the internal articulation joint;</li><li><figref idref="f0007">FIG. 12</figref> is an enlarged, right side perspective view of the end effector of <figref idref="f0006">FIGS. 10 and 11</figref>, illustrating the jaw members in an open condition;</li><li><figref idref="f0007">FIG. 13</figref> is an enlarged, right side perspective view of the end effector of <figref idref="f0006 f0007">FIGS. 10-12</figref>, illustrating the jaw members in a closed condition;</li><li><figref idref="f0008">FIG. 14</figref> is an enlarged, front perspective view of the end elector of <figref idref="f0006 f0007">FIGS. 10-13</figref> showing the jaw members in the axially aligned orientation and with the jaws in the open condition;</li><li><figref idref="f0008">FIG. 15</figref> is an enlarged, right side perspective view of the end effector of <figref idref="f0006 f0007 f0008">FIGS. 10-14</figref>, in a second articulated orientation, with the outer tube shown in phantom;</li><li><figref idref="f0009">FIG. 16</figref> is an enlarged, top perspective view of the end effector of <figref idref="f0006 f0007 f0008 f0009">FIGS. 10-16</figref>;</li><li><figref idref="f0009">FIG. 17</figref> is an enlarged, rear perspective view of the end effector of <figref idref="f0006 f0007 f0008 f0009">FIGS. 10-16</figref>, showing an axle holder shown in phantom;</li><li><figref idref="f0010">FIG. 18</figref> is an enlarged, front perspective view of the end effector of <figref idref="f0006 f0007 f0008 f0009">FIGS. 10-17</figref>, with the jaw members shown in phantom, illustrating a knife carrier according to the present disclosure:</li><li><figref idref="f0011">FIG. 19</figref> is an enlarged, transverse, schematic cross-sectional view of an end effector according to another embodiment of the present disclosure, as taken through a pivot axis thereof;</li><li><figref idref="f0011">FIG. 20</figref> is an enlarged, transverse schematic cross-sectional view of an end effector according to yet another embodiment of the present disclosure, as taken through a pivot axis thereof:</li><li><figref idref="f0012">FIG. 21</figref> is an enlarged, right side perspective view of a distal end of the surgical instrument of <figref idref="f0001">FIG. 1</figref>, including an end effector, in accordance with an embodiment of the present invention, showing a pair of opposed jaw members, in an axially aligned orientation;</li><li><figref idref="f0012">FIG. 22</figref> is an enlarged, right side, perspective view of the end effector of <figref idref="f0012">FIG. 21</figref>, in an first articulated condition, showing an outertube shown in phantom to illustrate the internal articulation joint;</li><li><figref idref="f0013">FIG. 23</figref> is an enlarged, right side perspective view of the end effector of <figref idref="f0012">FIGS. 21 and 22</figref>, illustrating the jaw members in an open condition;</li><li><figref idref="f0013">FIG. 24</figref> is an enlarged, right side perspective view of the end effector of <figref idref="f0012 f0013">FIGS. 21-23</figref>, illustrating the jaw members in a closed condition;</li><li><figref idref="f0014">FIG. 25</figref> is an enlarged, front perspective view of the end effector of <figref idref="f0012 f0013">FIGS. 21-24</figref> showing the jaw members in the axially aligned orientation and with the jaws in the open condition;</li><li><figref idref="f0015">FIG. 26</figref> is an enlarged, right side perspective view of the end effector of <figref idref="f0012 f0013 f0014">FIGS. 21-25</figref>, in a second articulated condition, with the outer tube shown in phantom;</li><li><figref idref="f0015">FIG. 27</figref> is an enlarged, top perspective view of the end effector of <figref idref="f0012 f0013 f0014 f0015">FIGS, 21-26</figref>:</li><li><figref idref="f0016">FIG. 28</figref> is an enlarged, rear perspective view of the end effector of <figref idref="f0012 f0013 f0014 f0015">FIGS. 21-27</figref>, showing an axle holder shown in phantom;</li><li><figref idref="f0016">FIG. 29</figref> is an enlarged, front perspective view of the end effector of <figref idref="f0012 f0013 f0014 f0015 f0016">FIGS. 21-28</figref>, with the jaw members shown in phantom, illustrating a knife carrier according to an embodiment of the present invention;</li><li><figref idref="f0017">FIG. 30</figref> is an enlarged, transverse, schematic cross-sectional view of an end effector according to an embodiment of the present invention, as taken through a pivot axis thereof; and</li><li><figref idref="f0017">FIG. 31</figref> is an enlarged, transverse schematic cross-sectional view of an end effector according to yet another embodiment of the present invention, as taken through a pivot axis thereof.</li></ul>

<u>DETAILED DESCRIPTION</u>

0008Detailed embodiments of the presently disclosed instruments, devices and systems will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. In the drawings and in the description which follows, the term "proximal" as is traditional, will refer to the end of the instrument, device and/or system which is closest to the operator while the term "distal" will refer to the end of the instrument, device and/or system which is furthest from the operator.

0009Referring to <figref idref="f0001">FIG. 1</figref>, a bipolar electro-surgical instrument, according to an embodiment of the present disclosure, is shown generally as 10. Electrosurgical instrument 10 generally includes a housing 12, a handle assembly 14, an activation assembly 16, and an end effector 100, in accordance with the present disclosure, which operates to grasp, saal and/or cut tissue.

0010More particularly, instrument 10 includes a shaft 18, defining a longitudinal "X" axis, which has a distal end 20 dimensioned to mechanically engage end effector 100 and a proximal end 22 which mechanically engages housing 12. Instrument 10 also includes an electrical interface or plug 30 which connects instrument 10 to a source of electrosurgical energy, e.g., an electrosurgical generator (not shown). An electrical cable 32 extends from plug 30 and is securely connected to housing 12 of instrument 10. Cable 32 is internally divided within housing 12 to transmit electrosurgical energy through various electrical feed paths (not shown) to end effector 100. Handle assembly 14 includes a fixed handle 24 and a movable handle, e.g., a reverse pivot handle 26. Fixed handle 24 is integrally associated with housing 12 and movable handle 26 is displaceable relative to fixed handle 24 to actuate a pair of opposing jaw members 102 and 104 of end effector 100.

0011A collar 70 is operatively mounted to the proximal portion of housing 12 in a manner such that rotation of collar 70 will cause corresponding rotation of shaft 18 to increase the range of operability of surgical instrument 10.

0012Turning now to <figref idref="f0002 f0003 f0004">FIGS. 2-7</figref>, an end effector in accordance with an embodiment of the present disclosure is generally designated as 100. As briefly mentioned above, end elector 100 includes a first or upper jaw member 102 and a second or lower jaw member 104 pivotably associated with one another and pivotably associated with distal end 20 of shaft 18. Each jaw member 102, 104 has a respective electrode 106, 108 in juxtaposed relation to one another. Each electrode 106, 108 defines a respective tissue contacting surface 106a, 108a (see <figref idref="f0002">FIG. 3</figref>).

0013As best seen in <figref idref="f0004">FIGS. 6 and 7</figref>, the proximal end of second jaw member 104 includes a yoke 110 defined by a pair of opposed, spaced apart flanges 112, 114 which extend therefrom. Preferably, flanges 142, 114 are at least substantially orthogonally oriented with respect to a plane defined by tissue contacting surface 108a and at least substantially perallel to the longitudinal "X" axis of shaft 18. Each flange 112, 114 defines an arcuate edge including at least one, preferably a plurality of, inter-engaging element(s) 116, such as, for example, gears, teeth, or the like.

0014First jaw member 102 includes a knuckle 118 extending from a proximal end thereof. Knuckle 118 is configured and dimensioned to be positionable between flanges 112, 114. First jaw member 102 and second jaw member 104 are pivotably connected to one another by a pivot pin 120 extending through flanges 112,114 and knuckle 118. Pivot pin 120 defines a pivot axis "Z" (see <figref idref="f0002">FIG. 3</figref>) which is oriented in a direction at least substantially orthogonal to the longitudinal "X" axis of shaft 18, and is in a plane which is at least substantially parallel to the plane defined by tissue contacting surface 108a. Preferably, pivot pin 120 extends through the longitudinal "X" axis of shaft 18.

0015Preferably, second jaw member 104 is blased to an angled orientation with respect to the longitudinal "X" axis, as seen in <figref idref="f0003">FIG. 5</figref>, by a biasing member (not shown), such as, for example, a spring. The biasing member tends to maintain second jaw member 104 angled with respect to the central longitudinal "X" axis.

0016Preferably, instrument 10 is provided with a locking mechanism 140 for maintaining second jaw member 104 in an axially aligned orientation or in any number of angled orientations with respect to the longitudinal "X" axis. Preferably, the angled orientations include orientations up to a 90° orientation with respect to the longitudinal "X" axis and, more preferably, orientations up to a 60° orientation with respect to the longitudinal "X" axis. As seen in <figref idref="f0004">FIGS. 6</figref> and <figref idref="f0005">8</figref>, locking mechanism 140 includes an articulation locking shaft 142 having a distal end 142a, and a locking pin 144 extending from distal end 142a of locking shaft 142, preferably, diametrically from either side of distal end 142a of looking shaft 142. Preferably, locking shaft 142 is seized and positioned to be disposed between flanges 112, 114 of second jaw member 104 and locking pin 144 extends from either side of distal end 142a of locking shaft 142 an amount sufficient to selectively engage inter-engaging element(s) 116 of flanges 112, 114.

0017Locking mechanism 140 has a first position in which locking shaft 142 is in a distally advanced position such that locking pin 144 engages interengaging element(s) 116 of flanges 112, 114 and thereby prevents articulation (e.g., pivoting, angular displacement or rotational displacement) of second jaw member 104 with respect to the central longitudinal "X" axis, and at least one second position in which locking shaft 142 is proximally spaced from the first distally advanced position such that locking pin 144 is disengaged from inter-engaging elemen(s) 116 of flanges 112, 114 and thereby permits articulation (e.g., pivoting, angular displacement or rotational displacement) of second jaw member 104, about pivot pin 120. with respect to the central longitudinal "X" axis to any number of angled or articulated orientations.

0018As seen in <figref idref="f0005">FIG. 8</figref>, a proximal end 142b of locking shaft 142 is rotatably coupled to and/or otherwise journaled in a first or distal collar 146a. A pair of connecting rods 148 interconnect first collar 148a with a second or proximal collar 146b (see <figref idref="f0005">FIGS. 8 and 9</figref>). Preferably, connecting rods 148 extend along either side of an actuation mechanism and/or linkage 160. Second collar 146b is rotatably coupled to and/or otherwise journaled in an annular channel formed in an articulation knob 150.

0019The articulation knob 150 is operatively supported on a proximal end of housing 12. Articulation knob 150 defines a central axis of rotation which is preferably axially aligned with the longitudinal "X" axis.

0020Turning now to <figref idref="f0004 f0005">FIGS. 6-9</figref>, instrument 10 is further provided with an actuation mechanism 160 to effectuate articulation (e.g., angular movement "and/or rotation) of first jaw member 102 about pivot pin 120. Actuation mechanism 160 includes an actuation shaft 162 reciprocatingly received In locking shaft 142 of locking mechanism 140 (<figref idref="f0004">Fig. 6</figref>). Actuation shaft 162 includes a distal end 162a operatively connected to knuckle 116 of first jaw member 102, and a proximal end 162b operatively connected to a lead screw 154 of actuation mechanism 160 (<figref idref="f0005">Fig. 8</figref>). Actuation mechanism further includes a drive shaft 152 inter-connecting articulation knob 150 and lead screw 154.

0021In particular, actuation mechanism 160 includes a linkage 164 having a distal end 164a, extending through an aperture 142c formed in distal end 142a of locking shaft 142 and pivotably connected to knuckle 118 of first jaw member 102 by a pivot pin 166, and a proximal end 164b, pivotably connected to distal end 162a of actuation shaft 162. Preferably, pivot pin 166 is spaced a transverse distance from pivot pin 120. Linkage 164 has an angled shape for increased average.

0022In operation, as seen in <figref idref="f0004 f0005">FIGS. 6-9</figref> and as will be described in greater detail below, articulation knob 150 performs two functions: the first function being the articulation of first jaw member 102 and second jaw member 104, between an axially aligned orientation and a plurality of angled orientations; and the second function being the locking of second jaw member 104 in the axially aligned orientation or any of the plurality of angled orientations.

0023The first function of articulation knob 150 is performed as a result of rotation of articulation knob 150. As articulation knob 150 is rotated in the direction of arrow "A" (see <figref idref="f0005">FIG. 8</figref>), articulation knob 150 rotates drive shaft 152 which, in turn, rotates lead screw 154. As lead screw 154 is rotated in the direction of arrow "A", lead screw 154 is diseased in a proximal direction, extending the distance between pivot 166 and cam 168. Lead screw 154 also desirably lengthens shaft 162 so that the force applied to the compression spring 176 during activation remains consistent. As discussed below, predetermined pressure applied to the tissue optimizes tissue sealing. As actuation shaft 162 is displaced in an axially proximal direction, first jaw member 102 is articulated and/or pivoted about pivot pin 120 between an orientation in which first jaw member 102 is at least substantially axially aligned with the longitudinal "X" axis (see <figref idref="f0002">FIG. 2</figref>), and a plurality of orientations in which first jaw member 102 is angled with respect to the longitudinal "X" axis (see <figref idref="f0002 f0003 f0004">FIGS. 3-7</figref>).

0024With pin 144 engaged in engaging elements 116, the pivoting of first jaw member 102 occurs separately from second jaw member 104, which remains stationary. With pin 144 disengaged from engaging elements 116, the pivoting of first jaw member 102 and second jaw member 104 occurs jointly, as the second jaw member 104 is connected to the first jaw member 102 through the biasing member. The degree to which first jaw member 102 and second jaw member 104 is angled is dependent upon the amount that articulation knob 150 is rotated.

0025The second function of articulation knob 150 is performed as a result of axial displacement of articulation knob 150 in the direction of, and opposite to the direction of, arrow "B". As articulation knob 150 is displaced in the direction of arrow "B" (i.e., in a proximal direction), articulation knob 150 pulls on connecting rods 148 which, in turn, pull on locking shaft 142. As locking shaft 142 is displaced in the direction of arrow "B", locking pin 144 is disassociated and/or otherwise disengaged from inter-engagement element(s) 116. In so doing, the biasing member (not shown) is free to urge second jaw member 104 about pivot pin 120, from an axially aligned orientation (see <figref idref="f0002 f0003">FIGS. 2-4</figref>, <figref idref="f0004">6 and 7</figref>) to an angled and/or articulated orientation (see <figref idref="f0003">FIG. 5</figref>) as first jaw member 102 is articulated by rotation of articulation knob 150.

0026Once second jaw member 104 has been angled and/or articulated, articulation knob 150 is displaced in a direction opposite to arrow "B" (e.g., driven forward) in order to drive locking shaft 142 in a distal direction and re-engage locking pin 144 with inter-engagement element(s) 116 of flanges 112, 114. In so doing, second jaw member 104 is fixed in the needed and/or desired angle "θ" (see <figref idref="f0003">FIG. 5</figref>), and jaw member 102 may be pivoted separately.

0027Actuation shaft 162 is also axially displaced as a result of the manipulation of reverse pivot handle 26 (<figref idref="f0005">Fig. 8</figref>) and subsequent manipulation of actuation mechanism 160. In particular, as pivot handle 26 is squeezed, linkages 168a-168e (see <figref idref="f0005">FIG. 8</figref>) of actuation mechanism 160 are manipulated in such a manner so as to drive actuation shaft 162 in the proximal direction to pivot first jaw member 102 about pivot pin 120.

0028Desirably, a cam plate 174 is provided which is urged in a proximal direction, against the force of a biasing member 176 (e.g., a tensile loading spring), as pivot handle 26 is squeezed. In this manner, when pivot handle 26 is released, cam plate 174 is urged In a distal direction by biasing member 176 thereby urging actuation shaft 162 distally and, in turn, opening end effector 100 (e.g., spacing first jaw member 102 from second jaw member 104). Additional, biasing member 176 tends to return and/or maintain pivot handle 26 in an unsqueezed and/or un-actuated condition.

0029As seen in <figref idref="f0005">FIGS. 8 and 9</figref>, instrument 10 may be provided with an indexing plate 170 operatively associated with articulation knob 150. Indexing plate 170 includes a plurality of openings 1'i'2 formed at particular and/or discrete locations therein. Openings 172 are configured and dimensioned to selectively receive a pin 156 (see <figref idref="f0005">FIG. 9</figref>) extending distally from articulation knob 150. In use, as articulation knob 150 is rotated, pin 156, extending from articulation knob 150, selectively engages openings 172 of indexing plate 170 in order to define predetermined angular orientations for first jaw member 102. Preferably, openings 172 of indexing plate 170 are "clocked" (i.e., correspond with) the position of inter-engagement element(s) 116 of flanges 112, 114. In use, pin 156 is disengaged from openings 172 by pulling articulation knob 150 in a proximal direction.

0030Indexing plate 170 preferably incudes a pair of recesses 178 (see <figref idref="f0005">FIG. 9</figref>) formed therein for receipt and slidable engagement with rods 148. Recesses 178 and rods 148 Inter-engage with one another to thereby prevent rotation of indexing plate 170 about the longitudinal "X" axis and maintain the relative position of openings 172 with respect to articulation knob 150. In this manner, the discrete angular positions of second jaw member 104, for each position of opening 172, is maintained.

0031With reference to <figref idref="f0001 f0002 f0003 f0004 f0005">FIGS. 1-9</figref>, use and operation of instrument 10 will now be described in greater detail. Initially, with first and second jaw members 102, 104 of end effector 100 in a substantially axially aligned condition, end effector 100 of surgical instrument 10 is introduced into an operative site, e.g., the thoracic cavity, through a port or the like (not shown).

0032Once introduced into the operative site, and in the open jaw configuration, as briefly described above, articulation knob 150 is rotated in the direction of arrow "A" (see <figref idref="f0005">FIG. 8</figref>) to pivot and/or articulate first jaw member 102 about pivot pin 120. As articulation knob 150 is rotated in the direction of arrow "A", drive shaft 152 rotates lead screw 154 and, in turn, moves actuation shaft 162, in the direction opposite of arrow "B" (i.e., in a distal direction). As actuation shaft 162 is displaced in a distal direction, first jaw member 102 and second jaw member 104 are pivoted about pivot pin 120 to a desired and/or needed angled and/or articulated orientation. Aligning articulation knob 150 with indexing positions on indexing plate 170 will allow connecting rods 148 and locking shaft 142 to move distally and place pin 144 in recess 116.

0033With end effector 100 in the open condition, instrument 10 may be manipulated to place end effector 100 about the tissue to be treated, i.e., to place first and second jaw member 102, 104 on either side of the tissue to be treated. With end effector so positioned, articulation knob 150 is displaced In the direction of arrow "B", i.e., withdrawn in a proximal direction, to permit rotation and/or articulation of second jaw member 104, under the influence of the biasing member (not shown), about pivot pin 120. In particular, as articulation knob 150 is drawn in the proximal direction, connecting rods 148 and, in turn, looking shaft 142 are displaced in a proximal direction until locking pin 144 is disassociated and/or otherwise disengaged from inter-engagement alement(s) 116 of second jaw member 104.

0034Preferably, instrument 10 is configured and dimensioned to permit pivoting of first jaw member 102 and, in turn, second jaw member 104, to an angle "θ" (see <figref idref="f0003">FIG. 5</figref>) of from at least about 0° to at least about 60°, relative to the longitudinal "X" axis. For example, pulling on knob 150 releases second jaw member 104, which is free to rotate away from an axially-aligned position. Most preferably, indexing plate 170 is configured to inter-engage with articulation knob 150 such that first jaw member 102 and, in turn, second jaw member 104, are articulated in predetermined increments; for example, 10° increments may be used.

0035If needed and/or desired, end effector 100 may be rotated about the longitudinal "X" axis by rotating collar 70 (see <figref idref="f0001">FIG. 1</figref>) about the longitudinal "X" axis. In so doing, the user does not have to rotate the entirety of instrument 10, including housing 12, about the longitudinal "X" axis.

0036Closing and clamping of end effector 100 is accomplished by squeezing handle 26. In particular, as seen in <figref idref="f0004">FIGS. 7</figref> and <figref idref="f0005">8</figref>, as handle 26 is squeezed linkages 168a-168e of actuation mechanism 160 are manipulated in such a manner so as to move actuation shaft 162 in a proximal direction. Movement of actuation shaft 162 in a proximal direction results in pivoting or first jaw member 102 about pivot pin 120, thereby at least substantially approximating tissue contacting surface 106a of first jaw member 102 toward tissue contacting surface 108a of second jaw member 104.

0037With end effector 100 clamped onto the tissue to be treated, RF energy may then be transmitted to electrodes 106, 108 of first and second jaw members 102, 104, respectively, to seal or fuse the tissue to be treated. By way of example only, the RF energy may be activated by squeezing activation assembly 16 (see <figref idref="f0001">FIG. 1</figref>). Following sealing of the tissue to be treated, the handle member is moved forward to re-open end effector 100 and/or otherwise space first jaw member 102 from second jaw member 104 and thereby release the treated tissue therefrom. The process may be repeated as many times as necessary depending on the particular surgical procedure and/or depending on a particular surgical purpose.

0038Alternatively, following the surgical procedure and/or when desired, first and second jaw members 102, 104 are returned to the axially aligned orientation in order to withdraw surgical instrument 10 and, in turn, end effector 100, from the operative site. Instrument 10 is manipulated to space end effector 100 from the treated tissue, i.e., to position end effector 100 such that first and second jaw members 102, 104 are free to rotate and are not obstructed by other tissue and/or body organs.

0039With end effector 100 so positioned, articulation knob 150 is displaced in the proximal direction, i.e., in the direction of arrow "B", to once again free second jaw member 104 to rotate about pivot pin 120. Then, articulation knob 150 is rotated in a direction opposite to arrow "A" in order to pivot first jaw member 102 from the angled and/or articulated orientation to the axially aligned orientation, in so doing, first jaw member 102 engages second jaw member 104 and causes second jaw member 104 to be pivoted from the angled orientation to the axially aligned orientation. Once first and second jaw members 102, 104 are returned to the axially aligned orientation, instrument 10 and, in turn, end effector 100, may be withdrawn from the operative site.

0040It is envisioned that one of the first and second jaw members 102, 104, preferably second jaw member 104, is provided with a reciprocating knife assembly (not shown), operatively associated therewith. As best seen in <figref idref="f0002">FIGS. 3</figref>, <figref idref="f0003">4</figref> and <figref idref="f0004">7</figref>, second jaw member 104 defines a longitudinal oriented knife track 172a formed in tissue contacting surface 108a of electrode 108, which preferably extends proximally beyond tissue contacting surface 108a of second jaw member 104.

0041The knife assembly may include a carrier slidably disposed within second jaw member 104. The carrier is preferably fabricated from a flexible, pliable and/or resilient material such that the carrier may flex and/or bend with the articulation of first and second jaw members 102, 104. The knife assembly preferably further includes a knife blade extending from the carrier and through knife track 172a. For example, carrier 274 and knife blade 280 discussed below in connection with <figref idref="f0010">FIG. 18</figref> may be used in the instrument discussed above.

0042Preferably, first jaw member 102 is also provided with a longitudinally oriented knife track (not shown) formed in tissue contacting surface 106a of electrode 106. The knife track of first jaw member 102 is desirably disposed in vertical registration with knife track 172a of second jaw member 104 when first jaw member 102 and second jaw member 104 are in close approximation with one another. in this manner, the knife blade is also at least partially received and/or disposed in the knife track of first jaw member 102 when first and second jaw members 102, 104 are approximated toward one another. In addition, as the carrier of the knife assembly is displaced along second jaw member 104, the knife blade is also displaced through knife track 172a and through the knife track of the first jaw member.

0043Preferably, in operation, following the clamping of the tissue to be treated between first and second jaw members 102. 104 and, preferably following the application of RF energy to the tissue to be treated, the knife assembly is actuated in a manner to drive the carrier and, in turn, the knife blade, in a distal direction, along the entire length of knife track 172a or at least until the knife blade traverses the width of the effected tissue. In so doing, the treated tissue is severed and/or otherwise cut in half. Following cutting of the treated tissue, the knife assembly is actuated to draw the carrier and, in turn, the knife blade, in a proximal direction, preferably to a proximal-most position. It is envisioned that a biasing member (not shown) may be employed to automatically bias the knife in a proximal-most position.

0044In further embodiments, carrier member 578 and cable loop 574, as discussed below in connection with <figref idref="f0017">FIGS. 30 and 31</figref>, are used in the instrument discussed above.

0045Desirably, use of the knife assembly to sever, divide, cut and/or otherwise separate the tissue, following the application of RF energy, is left to the discretion of the surgeon.

0046Turning now to <figref idref="f0006 f0007 f0008 f0009 f0010">FIGS. 10-18</figref>, an end effector in accordance with an alternate embodiment of the present disclosure is generally designated as 200. End effector 200 is similar to end effector 100 and will only be discussed in detail to the extent necessary to identify differences in construction and operation. End effector 200 includes a first or upper jaw member 202 and a second or lower jaw member 204 pivotably associated with one another and pivotably associated with distal end 20 of shaft 18. Each jaw member 202, 204 has a respective electrode 206, 208 in juxtaposed relation to one another. Each electrode 206, 208 defines a respective tissue contacting surface 206a, 208a (see <figref idref="f0007">FIGS. 12</figref>, <figref idref="f0008">14 and 15</figref>).

0047As seen in <figref idref="f0006 f0007">FIGS. 11-13</figref>, the proximal end of second jaw member 204 includes a yoke 210 defined by a pair of opposed, spaced apart flanges 212, 214 which extend therefrom. Preferably, flanges 212, 214 are at least substantially orthogonally oriented with respect to a plane defined by tissue contacting surface 208a and at least substantially parallel to longitudinal axis "X" of shaft 18. Each flange 212, 214 defines an arcuate edge including at least one, preferably a plurality of, engaging element(s) 216, such as, for example, gears or teeth and the like.

0048First jaw member 202 includes a knuckle 218 extending from a proximal end thereof. Knuckle 218 is configured and dimensioned to be positionable between flanges 212, 214. First jaw member 202 and second jaw member 204 are pivotably connected to one another by a pivot pin 220 extending through flanges 212, 214 and knuckle 218. Pivot pin 220 defines a pivot axis "Z" which is oriented in a direction at least substantially orthogonal to longitudinal axis "X" of shaft 18 and is in a plane which is at least substantially parallel to the plane defined by tissue contacting surface 208a. Preferably, pivot pin 220 extends across longitudinal axis "X" of shaft 18.

0049As best seen in <figref idref="f0006 f0007">FIGS. 11-13</figref> and <figref idref="f0008 f0009 f0010">15-18</figref>, an articulation rack 230 is provided which extends through and is slidably associated with shaft 18 of instrument 10. Articulation rack 230 is desirably operatively associated with teeth 216 of second jaw member 204. Preferable, articulation rack 230 includes a pair of spaced apart fingers 232a, 232b extending distally therefrom. As will be described in greater detail below, fingers 232a, 232b are spaced apart an amount sufficient to allow a knife assembly 270 to be selectively reciprocated therebetween.

0050Each finger 232a, 232b includes at least one, preferably a plurality of, inter-engaging members 234, e.g., gears or teeth, formed thereon. Teeth. 234 of articulation rack 230 are configured and dimensioned to inter-engage with and/or complement engaging elements 216 of flanges 212, 214 of second jaw member 204. In this manner, and as will be described in greater detail below, as articulation rack 230 is selectively actuated in a distal direction relative to shaft 18, second jaw member 204, and, in turn, first jaw member 202, is pivoted about the "Z" axis (i.e., about pivot pin 220) from at least an axially-aligned position to any number of articulated and/or annular positions. Likewise, as articulation rack 230 is selectively actuated in a proximal direction relative to shaft 18, second jaw member 204, and, in turn, first jaw member 202, is pivoted about the "Z" axis from the articulated and/or angular position toward a more axially-aligned position. Stated differently, fingers 232a, 232b of articulation rack 230 act as the rack of a rack and pinion type linkage while flanges 212, 214 of second jaw member 204 act as the pinion of the rack and pinion type linkage. Rack 230 is connected to an articulation control knob (not shown), which has gears in engagement with teeth on the proximal end of rack 230, so that turning of the knob axially translates the rack, pivoting the second jaw member 204.

0051As seen in <figref idref="f0007">FIGS. 12, 13</figref> and <figref idref="f0008 f0009 f0010">15-18</figref>. end effector 200 further includes a jaw actuation assembiy 240 configured and adapted to permit selective movement of the first jaw member 202 relative to second jaw member 204. More particularly, actuation assembly 240 includes a resilient band 242 which extends at least substantially axially through shaft 18 and a guide 244 (see <figref idref="f0009">FIG. 17</figref>) which facilitates actuation of band 242. Actuation assembly 240 further includes a holder assembly 246 including a pair of spaced-apart flanges 246a, 246b. Preferably, guide 244 is rotatingly supported by flanges 246a, 246b. A supporting surface 244a of guide 244 is preferably spaced a distance "D" from the central longitudinal "X" axis of shaft 18. (see <figref idref="f0009">FIG. 17</figref>) The size of distance "D" determines the degree first jaw member 202 pivots relative to second jaw member 204. For example, the smaller distance "D" is, the smaller the degree of pivot of first jaw member 202 relative to second jaw member 204. Likewise, the greater distance "D" is, the greater the degree of pivot of second jaw member 204.

0052Band 242 is reciprocatingly-disposed between flanges 246a, 246b of holder assembly 246. As seen in <figref idref="f0009">FIG. 17</figref>, band 242 includes a "gooseneck-like" distal end portion 248 having a distal end 248a fixedly secured to knuckle 218 of first jaw member 202 and a proximal end 248b extending over guide 244. The proximal end 248b is connected to a movable handle (not shown) for actuating band 242 and jaws 202, 204.

0053In this manner, as will be described in greater detail below, as band 242 is selectively displaced and/or advanced in a distal direction, first jaw member 202 is pivoted about the "Z" axis (and about pivot pin 220) to space first jaw member 202 from second jaw member 204 for manipulating. Additionally, as band 242 is selectively displaced in a proximal direction, first jaw member 202 is pivoted about the "Z" axis and pivot pin 220 to approximate first jaw member 202 toward second jaw member 204 for grasping tissue.

0054Resilient band 242 is fabricated from a material which is sufficiently pliable to be conformable to a number of arcuate and/or wave-like configurations and which is sufficiently strong enough to withstand the various axial forces associated with repeatedly grasping and manipulating tissue. Preferably, resilient band 242 is fabricated from spring steel or the like.

0055End effector 200 is pivotably supported between tubular extensions 250a, 250b defined at the distal end of an outer tube 250 of shaft 18. Pivot pin 220 is operatively engaged with tubular extensions 250a, 250b. Preferably, the ends of pivot pin 220 extend through and are supported by tubular extensions 250a, 250b. Tubular extensions 250a, 250b are preferably configured and dimensioned to enable end effector 200 to be pivoted from about 0° to at least about 60° relative to longitudinal axis "X" of shaft 18.

0056With reference to <figref idref="f0006 f0007 f0008 f0009 f0010">FIGS. 10-18</figref>, the present disclosure also relates a method of sealing or fusing tissue. Initially, with first and second jaw members 202, 204 of end effector 200 in a substantially axially aligned orientation or condition, end effector 200 of surgical instrument 10 may be introduced into an operative site, e.g., the thoracic cavity, through a port or the like (not shown).

0057Once introduced into the operative site, articulation rack 230 is actuated and/or displaced in a distal direction, as indicated by arrow "A" of <figref idref="f0006">FIG. 11</figref>, relative to outer tube 250. In so doing, teeth 234 of articulation rack 230 inter-engage with teeth 216 of flanges 212, 214 of second jaw member 204. As such, first and second jaw members 202, 204 are manipulated and/or rotated from the axially aligned orientation (i.e., a first position or condition) to an articulated, angular or inclined orientation (i.e., second position or condition) in which first and second jaws 202, 204 are inclined at a desired and/or necessary angle relative to longitudinal axis "X" of shaft 18.

0058It is envisioned that first and second jaw members 202, 204 may be displaced in about 10° angular increments. This may be accomplished with a ratchet-like mechanism (not shown). For example, a resilient pawl may be arranged in outer tube 250 for allowing the jaws 202, 204 to articulate while preventing movement in an opposite direction. The resilient pawl is desirably releasable so the jaw members can resume an axially-aligned position. The pawl may be actuated at the handle using any known means. In a further example, a mechanism or the like may be used to prevent movement after articulating the jaws to the desired position. The ratchet-tike mechanism may be configured and adapted to provide sensory feedback relating to the position of end effector 200. For example, the ratchet-like mechanism may produce a "clicking" sound or other tactile or visual feedback for each 10° angular incremental displacement of end effector 200.

0059As jaw members 202 and 204 are pivoted about the "Z" axis and pivot pin 220, band 242 flexes and/or bends accordingly. With first and second jaw members 202, 204 in the open condition, band 242 is advanced in a distal direction, as indicated by arrow "A" of <figref idref="f0009">FIG. 17</figref>, to further rotate first jaw member 202, about the "Z" axis, relative to second jaw member 204 to thereby open end effector 200. in one embodiment, band 242 may be formed from any flexible and/or resilient material including metals or polymers, and laminates of metal layers, such as steel. Another possible material is a laminate of polymer and steel layers. Laminate materials allow the band to wrap around sharp radii.

0060With end effector 200 in the open condition, end effector 200 may be positioned within the operative site in such a manner so as to position first and second jaw members 202, 204 on opposite sides of the tissue to be treated. With end effector 200 so positioned, band 242 may be selectively drawn in a proximal direction (i.e., opposite to the direction indicated by arrow "A") in order to approximate first jaw member 202 toward second jaw member 204 and close end effector 200 about the tissue to be treated.

0061RF energy may then be transmitted to electrodes 206. 208 of the first and second jaw members 202, 204, respectively, to seal or fuse, the tissue. Following sealing, band 242 is again selectively driven in a distal direction to open and/or otherwise space first jaw member 202 from second jaw member 204 to release the tissue. If desired and/or necessary, the process may be repeated for new un-treated tissue. The process may be repeated as many times as necessary depending upon a particular surgical purpose.

0062Alternatively, when desired and/or when, the surgical procedure is completed, first and second jaw members 202, 204 may be returned to the axially aligned orientation by withdrawing articulation rack 230 in a direction opposite to the direction indicated by arrow "A". With first and second jaw members 202, 204 in the axially aligned orientation, end effector 200 may be withdrawn from the operative cavity.

0063Electrosurgical tissue fusion of lung parenchyma typically produces a seal quality which reduces the tendency of air leaks and the like, as compared to conventional surgical stapling apparatuses.

0064With particular reference to <figref idref="f0010">FIG. 18</figref>, one of first and second jaw members 202, 204, preferably second jaw member 204, is provided with a reciprocating knife assembly 270 operatively associated therewith. As seen in <figref idref="f0007">FIGS. 12</figref> and <figref idref="f0008 f0009">14-16</figref>, second jaw member 204 defines a longitudinally oriented knife track 272a formed in tissue contacting surface 208a of electrode 208, which extends proximally beyond tissue contacting surface 208a of second jaw member 204.

0065Knife assembly 270 includes a carrier 274 slidably disposed between fingers 232a, 232b of articulation rack 230. Carrier 274 is preferably fabricated from a flexible, pliable and/or resilient material such that carrier 274 may flex and/or bend with the articulation of first and second jaw members 202, 204. The carrier 274 is connected to a cutter actuation control, such as a button, knob, slider actuator or handle at the proximal end of the instrument. Carrier 274 has a perpendicular portion that is bent or otherwise formed on carrier 274 and blade 280 is welded or adhered to the perpendicular portion. Carrier 274 is preferably formed from spring metal, although polymers or other metals may be used. Knife assembly 270 further includes a knife blade 280 extending from carrier 274 and through knife track 272a.

0066Preferably, the first jaw member 202 is also provided with a longitudinally oriented knife track (not shown) formed in tissue contacting surface 206a of electrode 206. The knife track of first jaw member 202 is preferably dispose in vertical registration with knife track 272a of second jaw member 204 when first jaw member 202 and second jaw member 204 are in a closed orientation. In this manner, knife blade 280 is also at least partially received and/or disposed in the knife track of first jaw member 202. in addition, as carrier 274 is displaced along second jaw member 204, knife blade 280 is displaced through knife track 272a and through the knife track of first jaw member 202.

0067In operation and with carrier 274 in a proximal-most position in the proximal-most end of knife track 272a, first and second jaw members 202, 204 may be selectively opened and closed about tissue, as described above. Subsequent to the application of RF energy, carrier 274 may be actuated and/or driven in a distant direction thereby driving knife blade 280 through knife track 272a of second jaw member 204 and the knife track of first jaw member 202 in order to sever the effected tissue. Knife carrier 274 may also be actuated to cut tissue prior to electrosurgical activation depending upon a particular purpose.

0068Preferably, carrier 274 is driven in a distal direction until knife blade 280 traverses the entire length of knife track 272a or at least until knife blade 280 traverses the width of the effected issue. Following the actuation of carrier 274 along knife track 272a (and the knife track of first jaw member 202), knife blade 280 may be returned to the proximal-most position by withdrawing carrier 274 in the proximal direction. A spring (or the like) may be employed to automatically bias the knife in the proximal-most position.

0069Use of knife assembly 270 to sever, divide and/or otherwise separate the tissue, following the application of RF energy, is left to the discretion of the surgeon.

0070Turning now to <figref idref="f0011">FIG. 19</figref>, which shows a schematic, transverse cross-sectional view of an alternative embodiment of an end effector 300, taken through the "Z" axis. As seen in <figref idref="f0011">FIG. 19</figref>, first and second jaw members 302, 304, respectively, are pivotable about a common pivot axis identified as-axis "Z". A first jaw rack 312 is provided including a pair of spaced apart inter-engaging elements, e.g., gears or teeth, 316 for engaging complementary inter-engaging elements, e.g., gears or teeth, 306 provided on first jaw member 302. In this manner, as first jaw rack 312 is displaced in an axial direction relative to first jaw member 302, first jaw member 302 is pivoted about the "Z" axis. A second jaw rack 314 is provided which includes a pair of spaced apart inter-engaging elements, e.g., gear or teeth, 318 for engaging complementary inter-engaging elements, e.g., gear or teeth, 308 provided on second jaw member 304. In this manner, as second jaw rack 314 is displaced in an axial direction relative to second jaw member 304, second jaw member 304 is also pivoted about the "Z" axis. First rack 312 and second rack 314 are actuated at the proximal end of the instrument. For example, first jaw rack 312 is connected to the handle of the instrument and second jaw rack 314 is connected to a separate articulation control, such as a knob, slider or lever. Other actuators may also be used.

0071First jaw member 302 and second jaw member 304 are each independently pivotable about the "Z" axis relative to one another. Preferably, second jaw rack 314 is external disposed relative to first jaw rack 312.

0072Turning now to <figref idref="f0011">FIG. 20</figref>, which shows a schematic, transverse cross-sectional view of another embodiment of an end effector 400, taken through the "Z" axis. As seen in <figref idref="f0011">FIG. 20</figref>, first and second jaw members 402, 404, respectively, are pivotable about a common pivot axis identified as "Z". A first jaw rack 412 is provided and Includes a single set of inter-engaging elements, e.g., gears or teeth, 416 for engaging a complementary set of inter-engaging elements, e.g., gears or teeth, 406 provided on first jaw member 402. In this manner, as first jaw rack 412 is displaced in an axial direction relative to first jaw member 402, first jaw member 402 pivots about the "Z" axis. A second jaw rack 414 is provided and includes a single set of inter-engaging elements, e.g., gears or teeth, 418 for engaging a complementary set of inter-engaging elements, e.g., gears or teeth, 408 provided on second jaw member 404. In this manner, as second jaw rack 414 is displaced in an axial direction relative to second jaw member 404, second jaw member 404 also pivots about the "Z" axis.

0073Preferably, first jaw rack 412 is disposed along a first side of jaw members 402, 404 and second jaw rack 414 is disposed along a second side of jaw members 402,404, opposite first rack 412.

0074Knife assembly 270 may be provided between the first and second jaw members of each of end effectors 300, 400.

0075Turning now to <figref idref="f0012 f0013 f0014 f0015 f0016 f0017">FIGS. 21-31</figref>, an end elector in accordance with an embodiment of the present invention is generally designated as 500. End effector 500 is similar to end effectors 100 and 200 and will only be discussed in detail to the extent necessary to identify differences in construction and operation. End effector 500 includes a first or upper jaw member 502 and a second or lower jaw member 504 pivotably associated with one another and pivotably associated with distal end 20 of shaft 18. Each jaw member 502, 504 includes a respective electrode 506, 508 in juxtaposed relation to one another. Each electrode 506, 508 defines a respective tissue contacting surface 508a, 508a (see <figref idref="f0015">FIG. 27</figref>).

0076As best seen in <figref idref="f0013">FIGS. 23 and 24</figref>, the proximal end of second jaw member 504 includes a yoke 510 defined by a pair of opposed spaced apart flanges 512, 514 extending therefrom. Preferably, flanges 512, 514 are at least substantially orthogonally oriented with respect to a plane defined by tissue contacting surface 508a and at least substantially parallel to longitudinal axis "X" of shaft 18. Flange 512, 514 each terminate in a proximal arcuate edge including at least one, preferably a plurality of, inter-engagement elements 516, such as, for example, teeth and the like.

0077First jaw member 502 includes a knuckle 518 extending from a proximal end thereof. Knuckle 518 is configured and dimensioned to be positionable between flanges 512, 514. First jaw member 502 and second jaw member 604 are pivotably connected to one another by a pivot pin 520 extending through flanges 512, 514 and knuckle 518. Pivot pin 520 defines a pivot axis "Z" which is oriented in a direction at least substantially orthogonal to longitudinal axis "X" of shaft 18 and is in a plane which is at least substantially parallel to the plane defined by tissue contacting surface 508a. Preferably, pivot pin 520 extends through longitudinal axis "X" of shaft 18.

0078A biasing member 522, e.g., a torsion spring, is operatively associated with first jaw member 502 and second jaw member 504. Biasing member 522 tends to bias first jaw member 502 and second jaw member 504 towards one another and tend to maintain end effector 500 closed.

0079As best seen in <figref idref="f0012">FIGS. 22</figref> and <figref idref="f0013">24</figref>, an actuation arm 530 is provided which extends through and is slidably associated with shaft 18 of instrument 10. Actuation arm 530 is desirably operatively connected to knuckle 518 of first jaw member 502. Preferably, actuation arm 530 includes a yoke 532 defined by a pair of opposed spaced apart fingers 532a, 532b extending distally therefrom. Fingers 532a, 532b are spaced apart an amount sufficient for knuckle 518 to be positioned therebetween.

0080Actuation arm 530 is pivotably connected to knuckle 518 by a pivot pin 534 extending through fingers 532a, 532b and through knuckle 518. Preferably, pivot pin 534 defines a pivot axis "Z1" which is substantially parallel to pivot axis "Z" of pivot pin 520. Pivot pin 534 is offset and/or spaced from pivot pin 520 in a direction away from longitudinal axis "X" of shaft 18. in use, as will be described in greater detail below, as actuation arm 530 is displaced in a distal or proximal direction, end effector 510 is caused to be pivoted about pivot pin 520, in a direction orthogonal to a plane defined by longitudinal axis "X" of shaft 18 and the pivot axis of pivot pin 520, thereby angling end effector 500 with respect to longitudinal axis "X" of shaft 18.

0081End effector 500 is pivotably supported between a pair of spaced apart arms 550a, 550b extending distally from an outer tube 550 of shaft 18. Pivot pin 520 is operatively engaged with arms 550a, 550b. Preferably, pivot pin 520 extends into and/or through openings 552 formed in arms 550a, 550b. Arms 550a, 550b are configured and dimensioned to enable end effector 500 to be pivoted from about 0° to at least about 60° relative to longitudinal axis "X" of shaft 18.

0082An inner tube 560 is slidably disposed within outer tube 650 of shaft 18. Inner tube 560 includes at least one, preferably a pair of, engagement members 562a, 562b, configured and dimensioned to selectively engage with Inter-engagement elements 516 of flanges 512, 514 of second jaw member 504. Each engagement member 562a, 562b includes a plurality of teeth providing improved meshing characteristics with engagement elements 516 of flanges 512, 514. In addition, the Increased number of teeth tends to better distribute the load and/or forces over the entire length of engagement elements 516 of flanges 512, 514 and engagement members 562a, 562b of inner tube 560.

0083Preferably, inner tube 560 includes a yoke 564 defined by a pair of opposed spaced apart plate members 564a, 564b extending distally therefrom. Plate members 564a, 564b are spaced apart an amount sufficient for flanges 512, 514 of second jaw member 504 and knuckle 518 of first jaw member 502 to be positioned therebetween. Each plate member 564a, 564b includes a slot 566 formed therein. Preferably, slots 566 are longitudinally oriented and In registration with openings 552 formed in arms 550a, 550b of outer tube 550. Pivot pin 520 preferably extends through slots 566.

0084Outer tube 550 and inner tube 560 have a first position in which outer tube 550 is in a distal-most position relative to inner tube 560. When outer tube 550 is in the distal-most position, pivot pin 520 is positioned in the distal end of slots 566 and engagement members 562a, 562b of inner tube 560 are disengaged from inter-engagement elements 516 of flanges 512, 514. In addition, when outer tube 550 is in the distal-most position, end effector 500 is capable of being pivoted about pivot pin 520.

0085Outer tube 550 and inner tube 560 have a second position in which outer tube 550 is in a proximal-most position relative to inner tube 560. When outer tube 550 is in the proximal-most position, pivot pin 520 is positioned in the proximal end of slots 566 and engagement members 562a, 562b of inner tube 560 are engaged with inter-engagement elements 516 of flanges 512, 514. In this manner, when outer tube 550 is in the proximal-most position, end effector 500 is locked in position relative to shaft 18.

0086With reference to <figref idref="f0012 f0013 f0014 f0015 f0016">FIGS. 21-29</figref>, a method of operation and/or of using end effector 600 will be shown and described. Initially, with first and second jaw members 502, 504 of end effector 500 in a substantially aligned orientation and with outer tube 550 in the proximal-most position, end effector 500 can be introduced into an operative site, e.g., the thoracic cavity, through a thoroscopic port or the like.

0087Once introduced into the operative site, actuation arm 530 is actuated and/or displaced in a distal direction, as indicated by arrow "A" of <figref idref="f0014">FIG. 25</figref>, relative to shaft 18. In so doing, actuation arm 530 drives pivot pin 534 in a distal direction thereby causing first jaw 502 to pivot about axis "Z" of pivot pin 520, as indicated by arrow "B" of <figref idref="f0014">FIG. 25</figref>. With outer tube 550 in a distal-most position relative to inner tube 560, second jaw 504 is free to be urged through the biasing member about axis "Z" of pivot pin 520. With outer tube 550 in a proximal-most position relative to inner tube 560, second jaw 504 is engaged by inter-engagement element 516 and will remain in place while first jaw 502 pivots about pivot pin 520. inter-engagement elements 516 allow for a plurality of angular inclinations "Θ", of second jaw 504, from about 0° to about 60°, relative to longitudinal axis "X" of shaft 18.

0088Biasing member 522 has a spring constant "K" selected such that biasing member 522 tends to maintain end effector 500 in a closed condition (i.e., first jaw member 502 and second jaw member 504 at least substantially approximated toward one another) during manipulation of end effector 500 from the axially aligned orientation to the angularly inclined orientation.

0089It is envisioned that end effector 500 may be displaced in about 10° angular increments by using articulation knob 150 as described above with regard to <figref idref="f0001 f0002 f0003 f0004 f0005">FIGS. 1-9</figref>. It is envisioned that surgical instrument 10 may be provided with sensory feedback which indicates to the user the orientation or condition of end effector 500, For example, surgical instrument 10 may produce a "clicking" sound or other tactile feedback for each 10° angular incremental displacement of end effector 500.

0090With end effector 500 in the second condition (i.e., in the desired and/or necessary angular inclination "Θ"), outer tube 550 is displaced in a proximal direction relative to inner tube 560 to thereby inter-engage engagement members 562a, 562b of inner tube 560 with inter-engagement elements 516 of end effector 500. In so doing, pivot pin 520 is displaced from the distal-most position in slots 566 to the proximal-most position in slots 566. As such, end effector 500 is effectively locked in the second condition and prevented from returning to the first condition (i.e., the axially aligned condition).

0091With end effector 500 locked in the second condition, end effector 500 is caused to be opened by once again driving actuation arm 530 in a distal direction with a force sufficient to overcome the force of spring constant "K" of biasing member 522. In so doing, first jaw member 502 is caused to be pivoted about axis "Z" of pivot pin 520, e.g., actuation arm to presses into pivot pin 532 thereby urging first jaw member 502 to pivot about pivot pin 520 and space first jaw member 502 from second jaw member 504.

0092With end effector 500 in an opened condition, end effector 500 can be positioned within the operative site in such a manner so as to position jaw members 502, 504 on opposite sides of tissue to be effected. With end effector 500 so positioned, the force on actuation arm 530 can be removed or actuation arm 530 can be withdrawn in a proximal direction to thereby close end effector 500 (i.e., approximate first jaw member 502 toward second jaw member 504) on to the tissue. RF energy can then be transmitted to electrodes 505, 508 of jaw members 502, 504, respectively, to fuse, cauterize, seal and/or otherwise electrosurgically affect the tissue.

0093Following RF treatment of the tissue, actuation arm 530 is driven in a distal direction to once again open end effector 500. If desired and/or necessary, end effector 500 is disassociated from the affected tissue and positioned around new unaffected tissue and the process repeated. The process is repeated as many times as necessary to complete the surgical procedure and/or as many times as desired.

0094Alternatively, when desired and/or when the surgical procedure is completed, outer tube 550 is urged in a distal direction to disassociate interengagement elements 516 of flanges 512, 514 from engagement members 562a, 562b of inner tube 560. Actuation arm 530 can then be withdrawn in a proximal direction to return end effector 500 to the first or substantially axially aligned orientation with longitudinal axis "X" of shaft 18. With end effector 500 so positioned, end effector 500 can be withdrawn from the thoracic cavity.

0095With reference to <figref idref="f0017">FIGS. 30 and 31</figref>, one of jaw members 602, 504, preferably second jaw member 504 is provided with reciprocating knife assembly 570 operatively associated therewith. Second jaw member 504 defines a longitudinally oriented knife track 572 formed in tissue contacting surface 508a of electrode 508. Knife assembly 570 includes a cable loop 574 extending substantially along knife track 572 and wrapping around a spindle or turnaround 576. Cable loop 574 defines a first portion 574a and a second portion 574b. Operatively, first portion 574a or second portion 574b is fixedly secured to carrier member 578. For purposes of this disclosure, it is assumed that first portion of cable 574a is fixedly secured to carrier member 578.

0096Knife assembly 570 further includes a knife blade carrier member 578 slideably disposed within second jaw member 504 and operatively associated with cable loop 574. Knife assembly 570 further includes a knife blade 580 extending from carrier member 578 and extending through knife track 572.

0097Preferably, first jaw member 502 is also provided with a longitudinally oriented knife track (not shown) formed in tissue contacting surface 506a of electrode 506. The knife track of first jaw member 502 is preferably in registration with knife track 572 of second jaw member 504 when first jaw member 502 and second jaw member 504 are in approximation with one another. In this manner, when first jaw member 502 and second jaw member 504 are in approximation with one another, knife blade is also at least partially received in the knife track of first jaw member 502. in addition, as carrier member 578 is displaced along second jaw member 504, knife blade 580 is displaced through knife track 572 and through the knife track of first jaw member 502.

0098In operation, with carrier member 578 at a proximal-most position along the length of knife track 572, as first portion 574a of cable loop 574 is drawn in a proximal direction, second portion 574b of cable loop 574 is drawn around spindle 576 thereby causing carrier member 578, and in turn knife blade 580, to be pulled in a distal direction along knife track 572. Following actuation of cancer member 578 along knife track 572, carrier member 578 is returned to the proximal-most position by withdrawing second portion 574b of cable loop 574 in a proximal direction.

0099If desired, knife assembly 570 may be used in the procedure described above to sever, divide and/or otherwise separate the tissue following the application of RF energy thereto.

0100Preferably, cable loop 574 is fabricated from a flexible material thereby enabling carrier member 578 to be driven in a distal or proximal direction while end effector 500 is at any angular inclination "Θ" relative to longitudinal axis "X" of shaft 18.

0101From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications may also be made to the present disclosure without departing from the scope of the present disclosure.

0102For example, one or more stop members may be employed to regulate the gap distance between the opposing sealing or tissue contacting surfaces 106a, 108a to optimize sealing For example, as described in commonly-owned <patcit id="pcit0002" dnum="US11694402A" dnum-type="L"><text>U.S. Application Serial Nos. 10/116,944, filed on April 5, 2002</text></patcit> (<patcit id="pcit0003" dnum="US2002188294A"><text>US2002188294</text></patcit>); <patcit id="pcit0004" dnum="US10179863B"><text>10/179,863, filed on June 25, 2002</text></patcit> (<patcit id="pcit0005" dnum="US2003018331A"><text>US2003018331</text></patcit>); <patcit id="pcit0006" dnum="US10472295B"><text>10/472,295, filed on September 18, 2003</text></patcit> (<patcit id="pcit0007" dnum="US2004082952A"><text>US2004082952</text></patcit>); <patcit id="pcit0008" dnum="US10474169B"><text>10/474,169, filed on October 3, 2003</text></patcit> (<patcit id="pcit0009" dnum="US2004243125A"><text>US2004243125</text></patcit>); and International Application No. <patcit id="pcit0010" dnum="US0201890W"><text>PCT/US02/01890, filed on January 22, 2002</text></patcit> (<patcit id="pcit0011" dnum="WO02080799A"><text>WO 02080799</text></patcit>), each entitled "Vessel Sealer and Divider"; and <patcit id="pcit0012" dnum="US36989403A" dnum-type="L"><text>U.S. Application Serial No. 10/369,894, filed on February 20, 2003</text></patcit> (<patcit id="pcit0013" dnum="US200329344B"><text>US200329344</text></patcit>), entitled "Vessel Sealer and Divider and Method for Making Same", one or more stop members may be positioned on one or both sealing surfaces to regulate the gap distance to between about 0,0254 to 0,152 mm (0.001 inches to about 0.006 inches) for sealing tissue which is about 1 mm in diameter or thickness to about 11 mm in diameter or thickness. For larger tissue, it is envisioned that providing stop members which regulate the gap distance from about 0,0508 to about 0,229 mm (about 0.002 inches to about 0.009 inches) is desirably to optimize sealing. For a tissue sealing device optimized for lung applications, a gap distance of about 0,127 mm (0.005 inches) may be used.

0103It is also envisioned that articulation knob 150, when end effector 100 is damped on the tissue to be treated, may be rotated to provided adjustment in closure pressure, between the opposing sealing and/or tissue contacting surfaces 160a, 108a of first and second jaw members 102, 104, in the range of about 3 kg/cm² to about 15 kg/cm² and more preferably about 3.5 to about 8.5 kg/cm² to optimize sealing of larger structures such as lung and bowel tissue.

0104It is also envisioned that first and second jaw members 102, 104 may be configured to minimize collateral tissue damage and minimize thermal spread as disclosed in commonly-owned <patcit id="pcit0014" dnum="US47427303A" dnum-type="L"><text>U.S. Application Serial Nos. 10/474,273, filed on October 3, 2003</text></patcit> (<patcit id="pcit0015" dnum="US2005004568A"><text>US2005004568</text></patcit>), entitled "Electrosurgical Instrument Which Reduces Effect to Adjacent Tissue"; <patcit id="pcit0016" dnum="US10388953B"><text>10/388,953, filed on January 1, 2003</text></patcit>, entitled "Bi-Polar Electrosurgical Forceps with Non-Conductive Stop Member; <patcit id="pcit0017" dnum="US10474168B"><text>10/474,168, filed on October 3, 2003</text></patcit> (<patcit id="pcit0018" dnum="US2005021025A"><text>US2005021025</text></patcit>), entitled "Electrosurgical Instrument Which Reduces Collateral Damage to Adjacent Tissue"; and <patcit id="pcit0019" dnum="US10712486B"><text>10/712,486, filed on November 13, 2003</text></patcit> (<patcit id="pcit0020" dnum="US2004143263A"><text>US2004143263</text></patcit>), entitled "Compressible Jaw Configuration with Bipolar RF Output Electrodes for Soft Tissue Fusion".

0105It is further desirably, as seen in <figref idref="f0001">FIG. 1</figref>, that instrument 10 is provided with a reverse pivoting handle 26 for improved ergonomics and increased leverage (i.e., application of a squeezing force to handle 26 in order to actuate instrument 10). Orientation (i.e., the position and angle of rotation) of the movable handle in conventional surgical instruments are typically not naturally compatible with the human hand. For instance, rotation and/or actuation of the typical movable handle typically undergoes its greatest displacement in the area effected (i.e., the application of a squeezing force) by the smallest digit (i.e., the pinkie), meanwhile the smallest displacement of the typical moveable handle is associated with the application of a squeezing force by the index finger. As a result, many users may not be able to engage the movable handle, when in the fully un-actuated position, with their smallest digit and thus the smallest digit is unable to contribute to the squeezing and/or actuation of the movable handle.

0106In accordance with the present disclosure, the typical movable handle has been replaced with a reverse pivoting handle 26. In this manner, the greatest displacement of movable handle 26 takes place in the vicinity of the user's index finger while the smallest displacement of pivoting handle 26 takes place in the vicinity of the users smallest digit. Accordingly, the smallest digit, typically the pinkie, is able to contribute to the actuation and/or squeezing of movable handle 26.

0107Although the present disclosure has been described with respect to particular embodiments, it will be readily apparent to those having ordinary skill in the art to which it appertains that changes and modifications may be made thereto without departing from the scope of the present disclosure.