16 and 18 may include a suitable mechanical interface (e.g., a wire holder) configured to releasably retain thecable 28 to help prevent thecable 28 from interfering with the surgeon's hand during operation of theforceps 10.

Referring now to fig. 3-7,electrode assembly 21 includes a generallycircular boss member 49 configured to be seated (e.g., friction fit) within acomplementary aperture 71 disposed through the distal end ofhousing half 70a to releasably attachelectrode assembly 21 thereto. Theelectrode assembly 21 is bifurcated such that two

prongs

103 and 105 extend distally therefrom to support the

electrodes

110 and 120, respectively. Theelectrode 120 includes an electricallyconductive sealing surface 126 configured to conduct electrically surgical energy therethrough and an electrically insulatingsubstrate 121 for electrically insulating thejaw member 42 from the sealingsurface 126. The sealingsurface 126 and thesubstrate 121 are attached to each other by any suitable assembly method, such as a snap-fit engagement or by overmolding thesubstrate 121 to the sealingsurface 126. In some embodiments, thesubstrate 121 is made of an injection molded plastic material. Thesubstrate 121 includes a plurality ofbifurcated anchor members 122 extending therefrom that are configured to be compressed during insertion into a corresponding plurality ofsockets 43 disposed at least partially through the inward-facing surface 47 (fig. 3) of thejaw member 44 and then expanded after insertion to releasably engage the correspondingsockets 43 to couple theelectrodes 120 to the inward-facingsurface 47. Thesubstrate 121 also includes alignment pins 124 (fig. 6) configured to engageholes 65 disposed at least partially through the inward-facingsurface 47 of thejaw member 44 to ensure proper alignment of theelectrode 120 with thejaw member 44 during assembly. Theconductive sealing surface 126 includes anextension 135 having awire crimp 117 configured to be inserted into thedistal end 106 of theprong 105 of theelectrode assembly 21 and electrically connected to the wire 61 (fig. 5) disposed therein.

Substantially as described above with respect toelectrode 120,electrode 110 includes an electricallyconductive sealing surface 116 configured to conduct electrically surgical energy therethrough and an electrically insulatingsubstrate 111 attached thereto, as shown in fig. 7. Thesubstrate 111 includes a plurality ofbifurcated anchor members 112 extending therefrom that are configured to compress during insertion into a respective plurality of sockets 41 disposed at least partially through the inwardly facing surface 45 (fig. 3) of thejaw member 42 and then expand after insertion to releasably engage the respective sockets 41 to couple theelectrodes 110 to the inwardly facingsurface 45. Thesubstrate 111 also includes alignment pins 128 (fig. 4) configured to engage theholes 67 disposed at least partially through the inward-facingsurface 45 of thejaw member 42 to ensure proper alignment of theelectrode 110 with thejaw member 42 during assembly. Sealingsurface 116 includes anextension 155 having awire crimp 119 configured to be inserted intodistal end 104 oftines 103 ofelectrode assembly 21 and electrically connected to wire 62 disposed therein. Thesubstrate 111 includes anextension 165 extending proximally therefrom and configured to couple to theextension 155 of the sealingsurface 116.

Referring to fig. 4, at least one of the

fork members

103, 105 is flexible such that the

fork members

105 and 103 are easily movable relative to each other. In some embodiments, theelectrode assembly 21 is removably attached to themechanical forceps 20 by initially moving the

prongs

103, 105 toward each other. When the

jaw members

42, 44 are in the open configuration, the

electrodes

120 and 110 may be slid between the opposing

jaw members

44 and 42 such that the anchoring

members

122 and 112 and the guide pins 124 and 128 may be aligned with and inserted into therespective sockets 43 and 41 or

holes

65 and 67, respectively, to couple the

electrodes

120 and 110 with the

jaw members

44 and 42, respectively. The

housing halves

70a, 70b may then be releasably coupled to form thehousing 70 to contain at least a portion of theshaft member 14 in the manner described above.

To electrically controlend effector 24,housing 70 supports a pair of

depressible actuation buttons

50a, 50b that are operable by a user to actuate

respective switches

60a, 60b disposed withinhousing 70. Although not specifically shown,

switches

60a, 60b are electrically interconnected with

wires

61, 62, respectively, and are used to initiate and terminate the delivery of electrosurgical energy from a suitable energy source to end-effector 24 to effect tissue closure.

Once tissue closure is established, thescalpel blade 85 can be advanced through thescalpel channel 58 to transect the closed tissue, as described in more detail below. However, in some embodiments, thescalpel blade 85 can be advanced through thescalpel channel 58 before, during, or after tissue closure. In some embodiments, ascalpel locking mechanism 80 is provided to prevent thescalpel blade 85 from extending into thescalpel channel 58 when the

jaw members

42, 44 are in the open configuration, thus preventing accidental or premature transection of tissue, as described in more detail below.

Referring to fig. 3, ascalpel actuation mechanism 90 is operatively associated with thetrigger 45 having opposing handle

members

45a, 45b extending from opposite sides of thehousing 70. When the

handle members

45a, 45b are actuated, theknife actuating mechanism 90 is responsive to actuating theknife blade 85 through theknife channel 58 using a series of cooperating elements to sever tissue grasped between the

jaw members

42, 44, as described in detail below with reference to fig. 9C. More specifically, thescalpel actuation mechanism 90 includes afirst link 92 operatively coupled at one end to theshaft member 47 and at an opposite end to asecond link 94 by apivot pin 92 a. Theshaft member 47 extends laterally through thehousing 70 to operatively connect the

handle members

45a, 45b from opposite sides of thehousing 70. Thesecond link 94 is operatively coupled at one end to thefirst link 92 by apivot pin 92a and at the other end to the proximal end of thescalpel blade 85 by apivot pin 94a (fig. 9A). Theshaft member 14 defines alongitudinal slot 14a therethrough configured to receive the first and

second links

92, 94 therein. When the

handle members

45a, 45b are actuated, the first and

second links

92, 94 extend through thelongitudinal slot 14a and freely move therethrough, as described in further detail below with reference to fig. 9C.

A biasing member 95 (e.g., a torsion spring) is disposed coaxially around at least a portion of theshaft member 47 between thefirst link 92 and thehandle member 45 a. The biasingmember 95 is operatively coupled at one end to a portion of thefirst link 92 and at the other end to a suitable mechanical interface within thehousing 70 that supports or stabilizes the biasingmember 95 during use of thescalpel actuation mechanism 90. The biasingmember 95 serves to bias thetrigger 45 such that upon actuation of thescalpel blade 85 through the scalpel channel 58 (fig. 9C), thehandle members 45a, 45B are biased to return to the unactuated position (fig. 9A and 9B), thereby retracting thescalpel blade 85 proximally to the unactuated position (fig. 9A and 9B).

Referring to fig. 3, the pivot axle 25 includes a pair of

holes

25a, 25b disposed therethrough that are configured to receive a pair of

complementary projections

13a, 13b, respectively, therein that extend from thedistal end portion 17 of theshaft member 12 and define alongitudinal passageway 27 therebetween. The

projections

13a, 13b extend sufficiently from the distal portion of theshaft member 14 such that the

apertures

25a, 25b can receive the

projections

13a, 13b therein, respectively, while maintaining the pivot shaft 25 in spaced relation to the distal portion of theshaft member 14 to allow theknife guide 86 to be received through thepassageway 27. Movement of the

shaft members

12, 14 relative to each other results in rotational movement of the pivot shaft 25 within thepivot hole 29.

Aknife guide 86 is supported withinhousing 70 betweenend effector 24 andknife actuating mechanism 90 and extends throughpassageway 27. Thelongitudinal slot 87 of thescalpel guide 86 provides lateral support for thescalpel blade 85 and limits left and right lateral movement of thescalpel blade 85. Thus, thedistal scalpel guide 86 serves to urge thescalpel blade 85 into a centered position relative to theend effector 24, thereby ensuring proper alignment of thescalpel blade 85 as thescalpel blade 85 enters the scalpel channel 58 (fig. 2) defined in the

electrodes

110, 120.

In some embodiments,forceps 10 include a scalpelblade locking mechanism 80 supported withinhousing 70 for preventing ascalpel blade 85 from being advanced intoscalpel channel 58 when

jaw members

42, 44 are in an open configuration (fig. 9A). Referring to fig. 3, the surgicalblade locking mechanism 80 includes asafety link 81 operatively coupled with a biasing member 83 (e.g., a leaf spring) and pivotally supported within thehousing 70. In the open configuration of the

jaw members

42, 44, thescalpel blade 85 is in an unactuated position (fig. 9A and 9B) and thesafety link 81 is engaged with thepivot pin 94a (fig. 9A) such that distal advancement of thescalpel blade 85 is inhibited. As shown in fig. 1, thehousing 70 includes alongitudinal opening 70c that opposes theshaft member 12 and exposes the surgicalblade locking mechanism 80 such that thesafety link 81 is engaged by theshaft member 12 when the

shaft members

12, 14 are approximated to move the

jaw members

42, 44 to the closed position (fig. 9B). The pressure applied to thesafety link 81 by the approach of the

shaft members

12, 14 serves to bias the biasingmember 83 against thescalpel blade 85 and in turn rotate thesafety link 81 clear of thepivot pin 94a (fig. 9B) such that thescalpel blade 85 is allowed to advance distally into the scalpel channel 58 (fig. 9C). The operation of thescalpel actuation mechanism 90, thescalpel locking mechanism 80, and the actuation of thescalpel blade 85 are further described below with reference to fig. 9A-9C.

The tissue closure thickness and tissue closure effect may be affected by the pressure applied to the tissue between the

jaw members

44, 42 during tissue closure and the gap distance between the opposingelectrodes 110 and 120 (fig. 5). In the closed configuration, the separation or gap distance "G" may be maintained between the sealing

surfaces

116, 126 by an array of stop members 54 (fig. 2) disposed on one or both of the sealing surfaces 116, 126 (shown only as being disposed on the sealingsurface 126 for illustration purposes). Thestop member 54 contacts the sealing surface on the opposing jaw member and inhibits further access of the sealing surfaces 116, 126. In some embodiments, to provide effective tissue closure, a suitable gap distance of about 0.001 inch to about 0.010 inch, and desirably between about 0.002 to about 0.005 inch, can be provided. In some embodiments, thestop member 54 is constructed of a non-conductive plastic or other material molded onto the sealing surfaces 116, 126, such as by a process such as overmolding or injection molding. In other embodiments, thestop feature 54 is constructed of a heat resistant ceramic deposited onto the sealing surfaces 116, 126.

Fig. 8 showsbipolar forceps 10 during use, with

shaft members

12 and 14 approximated to apply a clamping force totissue 150 and effect tissue closure. Once closed, thetissue 150 may be cut along the tissue closure by actuation of thesurgical blade 85, as described in detail below with reference to fig. 9A-9C.

In some embodiments, virtual tissuevascular test forceps 10 performance may be used. More specifically, the user may place a virtual tissue vessel between the sealing

surfaces

116, 126 and apply a clamping force to the vessel. The virtual tissue vessels may be, for example, any suitable plastic having impedance. The user may use the surgical instrument from a suitable electrosurgical generator, such as that sold by Covidien

Vascular occlusion generator and

the electrosurgical energy of the generator closes the virtual tissue vessel. The user may also actuate the

handle members

45a, 45b to advance thescalpel blade 85 through thescalpel channel 58 to cut closed the virtual tissue vessel. In this case, the electrosurgical generator may be configured to automatically run a test program for sensing the applied clamping force, the gap distance between the opposing

electrodes

110, 120 and/or the impedance of the virtual tissue vessel before, during or after closure. From this sensed information, the electrosurgical generator may be used to verify that theforceps 10 are in the proper working condition (e.g., proper clamping force, gap distance, etc.) after assembly of theelectrode assembly 21 to themechanical forceps 20 and prior to use of the assembledforceps 10 during vessel closure.

Referring now to fig. 9A, 9B and 9C, a sequence of movement may be initiated by moving the

shaft members

12, 14 to close the

jaw members

42, 44 and by rotating thehandle members 45a, 45B to cause thescalpel actuation mechanism 90 to translate thescalpel blade 85 through thescalpel channel 58. Initially, the

shaft members

12, 14 are in an open configuration and the

handle members

45a, 45b are in an unactuated position, as shown in fig. 9A. This arrangement of the

shaft members

12, 14 and the

handle members

45a, 45b maintains theend effector 24 in an open configuration with the

jaw members

42, 44 substantially spaced apart from one another and thesurgical blade 85 in a retracted or proximal position relative to the

jaw members

42, 44. The initial position of thehandle members 45a, 45B shown in fig. 9A and 9B is positively maintained by the influence of the biasingmember 95 on thetrigger 45. When the

jaw members

42, 44 are in the open configuration, as shown in fig. 9A, thesafety link 81 is engaged with thepivot pin 94a such that rotational movement of the

handle members

45a, 45b in the proximal direction (depicted by rotational arrow a4 in fig. 9C) is inhibited such that thescalpel blade 85 is inhibited from advancing into thescalpel channel 58.

The

jaw members

42, 44 may be moved from the open configuration of fig. 9A to the closed configuration shown in fig. 9B. When the

shaft members

12, 14 pivot about the pivot 25 in the directions of arrows a1 and a2 (fig. 9B), respectively, theshaft member 12 engages thesafety link 81. As the

shaft members

12, 14 are further pivoted about the pivot 25 in the directions of arrows a1 and a2, respectively, theshaft member 12 applies a force to thesafety link 81 causing the biasingmember 83 to flex against the bias of thesurgical blade 85, thereby causing thesafety link 81 to rotate in the direction depicted by rotational arrow A3 in fig. 9B. Rotation of thesafety link 81 in the direction of rotational arrow a3 is used to move thesafety link 81 off of thepivot pin 94a as shown in fig. 9C.

When thesafety link 81 is moved clear of thepivot pin 94a, thehandle members 45a, 45B can be selectively moved from the unactuated configuration of fig. 9A and 9B to the actuated position of fig. 9C to distally advance thescalpel blade 85 through thescalpel channel 58. More specifically, when the

handle members

45a, 45b are rotated in a generally proximal direction depicted by rotational arrow a4 to the actuated configuration shown in fig. 9C, thefirst link 92 applies a rotational force to thesecond link 94, thereby causing thesecond link 94 to rotate about thepivot pin 94a and move in a generally distal direction to distally advance thesurgical blade 85 through theknife channel 58.

In some embodiments, theknife actuating mechanism 90 can be positioned relative to theshaft member 14 differently than depicted in fig. 3 for theknife actuating mechanism 90. For example, if thescalpel actuation mechanism 90 shown in FIG. 3 is disposed generally between the

shaft members

14 and 12, in some embodiments, thescalpel actuation mechanism 90 can be disposed on an opposite side of theshaft member 14 such that theshaft member 14 is disposed between thescalpel actuation mechanism 90 and theshaft member 12. In this case, the

shaft members

12, 14 may alternatively be configured to allow thescalpel blade 85 to be advanced through thelongitudinal passageway 27 defined by the

projections

13a, 13b (e.g., via the scalpel guides 86) and into thescalpel channel 58. For example, the respective distal ends 17, 19 of the

shaft members

12, 14 can be configured in various interlocking relationships (e.g., a lock-and-box configuration) that facilitate the entry of thescalpel 85 into thescalpel channel 58 in various orientations relative to the

shaft members

12, 14 and/or thescalpel channel 58.

While several embodiments of the disclosure have been shown in the drawings, the disclosure should not be limited thereto as it should be as broad in scope as the art will allow and the specification should be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Although the foregoing disclosure has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims.

Claims

1. Bipolar forceps (10) comprising:

mechanical forceps (20) including first and second shafts (12, 14) each having jaw members (42, 44) extending from distal ends (17, 19) thereof and handles (16, 18) disposed at proximal ends (13, 15) thereof for effecting movement of the jaw members relative to each other about pivots (25) from a first position in which the jaw members are disposed in spaced relation to each other to a second position in which the jaw members cooperate to grasp tissue therebetween;

a disposable housing (70) comprising housing halves (70a, 70b) configured to matingly engage and releasably contain at least a portion of at least one of the first and second shafts;

an electrode assembly (21) associated with the disposable housing and having a first electrode (110) releasably coupleable to the jaw member of the first shaft and a second electrode (120) releasably coupleable to the jaw member of the second shaft, each of the first and second electrodes adapted to be connected to a source of electrosurgical energy to allow electrosurgical energy to be selectively conducted through tissue held therebetween;

at least one of the first and second electrodes includes a scalpel channel (58) defined along a length thereof, the scalpel channel configured to receive a scalpel blade (85) therethrough to cut tissue clamped between the jaw members;

an actuation mechanism (90) disposed at least partially within the disposable housing and configured to selectively advance the surgical blade through the surgical knife channel to cut tissue; and

a scalpel locking mechanism (80) configured to inhibit advancement of a scalpel blade into the scalpel channel when the jaw members are in the first position,

characterized in that the bipolar forceps further include a scalpel guide (86) supported within the disposable housing (70) and having a longitudinal slot (87) defined therethrough that receives a scalpel blade (85) therein to align the scalpel blade with the scalpel channel (58), wherein the scalpel guide (86) extends through a longitudinal slot (27) defined through the pivot (25).

2. The bipolar forceps (10) of claim 1, wherein the scalpel locking mechanism (80) moves from a first position of the scalpel locking mechanism, in which the scalpel locking mechanism engages the actuation mechanism (90) when the jaw members (42, 44) are in the first position of the jaw members, to a second position of the scalpel locking mechanism, in which the scalpel locking mechanism disengages the actuation mechanism when the jaw members (42, 44) are in the second position of the jaw members, to allow the scalpel blade (85) to be selectively advanced through the scalpel channel (58).

3. The bipolar forceps (10) of claim 1, wherein at least one of the first and second shafts (12, 14) is configured to engage the scalpel locking mechanism (80) and move the scalpel locking mechanism out of engagement with the actuation mechanism (90) to allow the scalpel blade (85) to advance through the scalpel channel (58) when the jaw members (42, 44) are moved to the second position.

4. The bipolar forceps (10) of any one of claims 1-3, further including at least one depressible button (50a, 50b) supported by the disposable housing (70), the at least one depressible button configured to selectively deliver electrosurgical energy to the first and second electrodes (110, 120).

5. The bipolar forceps (10) according to any one of claims 1 to 4, wherein the surgical blade (85) is configured to move within a longitudinal slot (27) defined through the pivot (25) as it translates.

6. The bipolar forceps (10) of any one of claims 1-5, further including at least one handle member (45a, 45b) configured to effect advancement of the scalpel blade (85) through the scalpel channel (58), the at least one handle member extending from the disposable housing (70) and being operably coupled to the actuation mechanism (90).

7. The bipolar forceps (10) of any one of claims 1-6, wherein each of the first and second electrodes (110, 120) includes a conductive sealing surface (116, 126) and an insulating substrate (111, 121) coupled to the conductive sealing surface.

8. The bipolar forceps (10) according to any one of claims 1 to 7, wherein each of the first and second electrodes (110, 120) includes at least one mechanical interface (112, 122) configured to complement a respective mechanical interface (41, 43) on one of the jaw members (42, 44) to releasably couple the electrode to the jaw member.

9. The bipolar forceps (10) according to any one of claims 1-8, wherein the actuation mechanism (90) includes a first biasing member (95) configured to bias the actuation mechanism to an unactuated position.

10. The bipolar forceps (10) according to any one of claims 1-9, wherein the scalpel locking mechanism (80) includes a safety link (81) operably coupled with a second biasing member (83) and pivotally supported within the disposable housing (70), wherein the safety link is configured to engage a pivot pin (94a) of the actuation mechanism (90) to inhibit advancement of the scalpel blade (85) into the scalpel channel (58) when the jaw members (42, 44) are in the jaw members' first position.

11. The bipolar forceps (10) of claim 10, wherein at least one of the first and second shafts (12, 14) is configured to engage the safety link (81) and move the safety link (81) out of engagement with the pivot pin (94a) to allow the scalpel blade (85) to advance through the scalpel channel (58) when the jaw members (42, 44) are moved to the jaw members second position.