Abstract:
A hemostat-type device for ablative treatment of tissue, particularly for treatment of atrial fibrillation, is constructed with features that provide easy and effective treatment. The device may include a swiveling head assembly that allows the jaws to be adjusted in pitch and/or roll. The device may include a malleable or articulating handle shaft, as well as, malleable or curved rigid jaws that can permit curved lesion shapes. A locking detent can secure the jaws in a closed position during the procedure. The device may include one or more remote actuators making the hemostat-type device useful for minimally invasive procedures.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. patent application. Ser. No. 10/621,893, filed Jul. 17, 2003, which claims priority from U.S. Provisional Patent Application No. 60/422,330 filed Oct. 30, 2002, incorporated herein by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to surgical tools and procedures generally and relates more particularly to the use of electrosurgical ablation to treat atrial fibrillation.  
         [0003]     In patients with chronic atrial fibrillation or having atrial tachycardia that is resistant to medical treatment, the Maze III procedure has been employed. This procedure controls propagation of the depolarization wavefronts in the right and left atria by means of surgical incisions through the walls of the right and left atria. The incisions create blind or dead end conduction pathways, which prevent re-entrant atrial tachycardias from occurring. While the Maze procedure is successful in treating atrial fibrillation, the procedure is quite complex and is currently practiced by only a few very skilled cardiac physicians in conjunction with other open-heart procedures. The procedure also is quite traumatic to the heart, as in essence the right and left atria are cut into pieces and sewed back together, to define lines of lesion across which the depolarization wavefronts will not propagate.  
         [0004]     It has been suggested that procedures similar to the Maze procedure could be instead performed by means of electrosurgical ablation, for example, by applying radiofrequency (RF) energy to internal or external surfaces of the atria to create lesions across which the depolarization wavefronts will not propagate. Such procedures are disclosed in U.S. Pat. No. 5,895,417, issued to Pomeranz, et al., U.S. Pat. No. 5,575,766, issued to Swartz, et al., U.S. Pat. No. 6,032,077, issued to Pomeranz, U.S. Pat. No. 6,142,944, issued to Swanson, et al., U.S. Pat. No. 5,871,523, issued to Fleischman, et al. and U.S. Pat. No. 6,502,575, issued to Jacobs et al., all incorporated herein by reference in their entireties. Hemostat type, electrosurgical or cryo-ablation devices for use in performing such procedures are described in U.S. Pat. No. 5,733,280 issued to Avitall, U.S. Pat. No. 6,237,605 issued to Vaska, et al, U.S. Pat. No. 6,161,543, issued to Cox, et al., PCT published Application No. WO99/59486, by Wang and in pending U.S. patent application Ser. No. 09/747,609 filed Dec. 22, 2000 by Hooven, et al., all incorporated herein by reference in their entireties. In order for such procedures to be effective it is desirable that the electrosurgically created lesions are continuous along their length and extend completely through the tissue of the heart (i.e. transmural lesions). These goals may be difficult to accomplish employing dry ablation electrodes or electrodes applied only to the interior or exterior surfaces of the heart tissue. Electrosurgical hemostats configured to allow fluid-assisted tissue ablation are generally described in U.S. Pat. No. 6,096,037, issued to Mulier, also incorporated by reference in its entirety.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides an ablation hemostat, particularly useful in performing a maze type procedure by applying ablation energy (e.g. RF energy) across the walls of the left and right atria by means of delivery means located on either side of the atrial walls. In a preferred embodiment of the invention, the hemostat is provided with elongated RF electrodes malleable to assume various straight and curved configurations to produce lesions that approximate the incisions that would occur during the Maze III procedure as described in the book ‘Cardiac Surgery Operative Technique’ by Donald B. Doty, M.D. at pages 410-419, incorporated herein by reference in its entirety, or to allow creation of lines of lesion corresponding to the incisions that would be provided by other forms of the Maze procedure. The hemostat may be useful in conjunction with other procedures as well.  
         [0006]     The hemostat of the present invention is provided with a number of useful features, particularly adapted to ease its use in conjunction with creating elongated lines of lesion. While the disclosed and most preferred embodiments of the invention employ a number of the of the improved features, each of the improved features discussed below is believed valuable in and of itself to improve the performance and ease of use of prior art electrosurgical hemostats.  
         [0007]     In order to allow the hemostat, in one embodiment of the invention, to produce straight and curved elongated lesions, the jaws of the hemostat are malleable to allow the physician to set the specific jaw configuration. The jaws are fabricated of a flexible plastic sheath enclosing elongated bendable or malleable backbones and electrodes to achieve this result. The backbones and electrodes may be shaped by the physicians&#39; fingers into a desired curvature and serve to retain the curvature imparted to them until reshaped for creation of a subsequent lesion. The backbones take the form of elongated plates having thicknesses substantially less than their widths to encourage bending of the jaws within a single plane so that the opposed electrodes can more readily be maintained in alignment along their lengths. The backbones are also preferably tapered along their length such that the width of the backbones diminishes as they approach the tips of the jaws, in turn making it easier to provide the jaws with the curvature extending over the entire length of the jaws.  
         [0008]     In one embodiment of the invention, the hemostat includes an elongated handle portion or handle and a jaw assembly mounted at the distal end of the handle. The elongated handle portion may include one or more malleable and/or articulating components. The jaw assembly preferably includes two elongated jaws carrying RF electrodes or other ablation elements, extending along the lengths of the jaws and arranged so that they are located on opposite sides of tissue compressed between the jaws. In preferred embodiments, the electrodes take the form of fluid irrigated RF electrodes, however, other ablation mechanisms such as cyroablation, direct current ablation, microwave ablation, ultrasound ablation, and the like may be substituted for RF ablation electrodes.  
         [0009]     The jaw assembly may include a swiveling head assembly adapted to allow the jaws to be rotated relative to the axis of the handle (roll) and/or allowing the jaws to pivot around an axis perpendicular to the axis of the handle (pitch). Adjustment of the jaws relative to the handle (pitch and/or roll) is made manually by the physician, and the jaws are retained in their desired orientation relative to the handle by means of detent mechanisms.  
         [0010]     The jaws may be mounted to one another at a pivot point and are opened and closed by means of a trigger, mounted to the handle, which applies tensile force to a cable or other tension member extending along the handle. The cable, when pulled, pulls the jaws toward one another to compress tissue between them. In the particular embodiments disclosed, the cable is anchored offset from the pivot point to a first one of the jaws. The first jaw is fixed, i.e. retains its location during jaw closure regardless of the pitch and/or roll adjustment made to the jaw assembly. The second, pivoting jaw, is mounted to the fixed jaw at a pivot point and the cable passes around an internal boss within the pivoting jaw, also offset from the pivot point. Application of tension to the tension member pulls the internal boss in the pivoting jaw toward the cable mounting point in the fixed jaw and thereby causes movement of the jaws toward one another. Tissue placed between the jaws can thus be engaged by the jaws and compressed between the jaws as the jaws close.  
         [0011]     A cable may enter the jaw assembly along its rotational (roll) axis, so that rotation of the jaw assembly about the roll axis does not alter the operation of the cable. The cable may extend around a shoulder internal to the fixed jaw, which shoulder remains essentially in the same location regardless of the pitch adjustment of the jaw assembly, so that pitch adjustment of the jaw assembly does not significantly effect operation of the cable to close the jaws.  
         [0012]     In some embodiments, the trigger mechanism is provided with a locking detent mechanism which may be engaged or disengaged and which, when engaged, retains the trigger in its position, in turn maintaining compression of the jaws against tissue located there between. The detent mechanism in a preferred embodiment is activated or deactivated by means of a sliding button, mounted to the handle.  
         [0013]     In some embodiments, irrigation fluid is provided to the electrodes by means of plastic tubing that is provided with in-line flow limiters, controlling the delivery rate of irrigation fluid to the electrodes. This feature allows the use of a simplified fluid pumping mechanism and also provides balanced, even fluid flow to the electrodes. In one embodiment, the trigger, when released, also serves to block fluid flow to the electrodes, preventing irrigation while the hemostat is not in use.  
         [0014]     In one embodiment, the RF electrode assembly can take the form of an elongated porous material coupled to the fluid delivery lines and carrying elongated electrode wires on their inner, facing services. The electrode wires may be coupled to the porous material by means of a series of spikes extending from the electrode wires into the porous material. Other alternative electrode designs may of course be substituted, including electrodes comprised of elongated coil electrodes or perforated tubular electrodes with porous material located either inside of or surrounding the electrodes. For example, a perforated tubular electrode can be seated inside a porous polymeric support such the electrode is entirely within the support. In this embodiment, conductive fluid flows through the interior of the electrode, out of perforations in the electrode and through the porous support to facilitate ablation such that the polymeric support, not the electrode, is on the facing surfaces of the jaws to contact the tissue to be ablated.  
         [0015]     The hemostat may optionally also include a thermocouple, located along the jaws allowing for temperature controlled feedback of power provided to the RF electrodes and may also preferably include an indicator LED mounted to the handle, activated to indicate that delivery of RF energy is underway. The hemostat may be useable with conventional RF generators. Alternatively, the hemostat may be used in conjunction with an RF generator system, which incorporates a transmurality measurement and automatic shut off of ablation energy.  
         [0016]     In some embodiments of the invention, the jaws or portions thereof may be rigidly straight and/or curved. One or more portions of the jaw assemblies might be replaceable or interchangeable. The upper and/or lower jaw of the jaw assembly may include one or more pivots. In some embodiments of the invention, the device includes a means for opening and/or closing the lower jaw of the jaw pair while maintaining the upper jaw in a stationary position. In alternative embodiments of the invention, the device includes a means for opening and/or closing the upper jaw of the jaw pair while maintaining the lower jaw in a stationary position. In alternative embodiments of the invention, the device includes a means for opening and/or closing the upper and lower jaws of the jaw pair while neither jaw is maintained in a stationary position. In some embodiments of the invention, the device may include one or more sensors. In some embodiments of the invention, the device includes one or more remote actuators for remotely actuating one or more components of the device. In some embodiments of the invention, the device includes one or more shapeable or malleable components. In some embodiments of the invention, the device includes one or more components that actuated via a cable or rod mechanism. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a plan view of an assembled hemostat according to one embodiment of the present invention.  
         [0018]      FIG. 2  is an exploded view of the jaw assembly of the hemostat of  FIG. 1 .  
         [0019]      FIG. 3A  is a cross-section view through the jaw assembly of the hemostat of  FIG. 1 .  
         [0020]      FIG. 3B  is a cross-section view through lines  3 B- 3 B of  FIG. 3A .  
         [0021]      FIG. 4  is an end view in partial cross-section of the proximal end of the knuckle portion of the jaw assembly of the hemostat of  FIG. 1 .  
         [0022]      FIG. 5A  is a plan view of an elongated tubular electrode used in the hemostat of  FIG. 1 .  
         [0023]      FIG. 5B  is an enlarged cross-section view taken along lines  5 B- 5 B of the electrode illustrated in  FIG. 5A .  
         [0024]      FIG. 6A  is an end view of an electrode support as used in the jaw assembly of the hemostat of  FIG. 1 .  
         [0025]      FIG. 6B  is a cross-section view taken along lines  6 A- 6 A of  FIG. 6A  illustrating the electrode support.  
         [0026]      FIG. 7A  is an end view of an electrode sheath as included in the jaw assembly of the hemostat of  FIG. 1 .  
         [0027]      FIG. 7B  is a cross-section view taken along lines  7 B- 7 B of  FIG. 7A  illustrating the electrode sheath.  
         [0028]      FIG. 8A  is a plan view of the right half of the handle employed in the hemostat of  FIG. 1 .  
         [0029]      FIG. 8B  is an enlarged plan view of the distal portion of the right handle half illustrated in  FIG. 8A .  
         [0030]      FIG. 8C  is a cross-section view taken along lines  8 C- 8 C through the right handle half of the hemostat of  FIG. 1 .  
         [0031]      FIG. 9A  is a plan view of the left half of the handle employed in the hemostat of  FIG. 1 .  
         [0032]      FIG. 9B  is an enlarged plan view of the distal portion of the left handle half illustrated in  FIG. 9A .  
         [0033]      FIG. 9C  is a cross-section view taken along lines  9 C- 9 C through the left handle half of the hemostat of  FIG. 1 .  
         [0034]      FIG. 10  is an enlarged view of the trigger portion of a hemostat as in  FIG. 1  with the left handle half removed.  
         [0035]      FIG. 11A  is a perspective view of a trigger lock as employed in the trigger assembly of the hemostat as in  FIG. 1 .  
         [0036]      FIG. 11B  is a plan view of the trigger lock of  FIG. 11A .  
         [0037]      FIG. 12A  is a top plan view of a link arm as employed in the trigger assembly of an assembled hemostat as in  FIG. 1 .  
         [0038]      FIG. 12B  is a side plan view of the link arm of  FIG. 12A .  
         [0039]      FIG. 13A  is a side plan view from the distal end of the trigger employed in the trigger assembly of the hemostat of  FIG. 1 .  
         [0040]      FIG. 13B  is a cross-section view taken along lines  13 B- 13 B through the trigger of  FIG. 13A .  
         [0041]      FIG. 14  is a cut-away view of the proximal portion of the hemostat of  FIG. 1  with the left handle half removed.  
         [0042]      FIG. 15A  is a sectional view through an alternative embodiment of an upper and lower jaw for use with a hemostat otherwise as in  FIG. 1 .  
         [0043]      FIG. 15B  is a cross-sectional view taken along lines  15 B- 15 B of  FIG. 15A .  
         [0044]      FIG. 16A  is a plan view of an electrode extension employed in the alternative embodiment of the upper and lower jaw depicted in  FIGS. 15A and 15B .  
         [0045]      FIG. 16B  is an expanded view of a barb of the electrode extension depicted in  FIG. 16A .  
         [0046]      FIG. 17  is a view of an assembled hemostat according to one embodiment of the present invention.  
         [0047]      FIG. 18  is a view of a portion of a hemostat according to one embodiment of the present invention.  
         [0048]      FIG. 19  is a cross-section view taken of a portion of the right handle half of one embodiment of the present invention.  
         [0049]      FIG. 20  is a cross-section view taken of a portion of the right handle half of one embodiment of the present invention.  
         [0050]      FIG. 21  is a cross-section view taken of a portion of the right handle half of one embodiment of the present invention.  
         [0051]      FIG. 22  is a view of an assembled hemostat according to one embodiment of the present invention.  
         [0052]      FIG. 23  is a view of a portion of the hemostat according to one embodiment of the present invention.  
         [0053]      FIG. 24  is an exploded view of a jaw assembly of one embodiment of the present invention.  
         [0054]      FIG. 25  is a cross-section view through the jaw assembly of one embodiment of the present invention.  
         [0055]      FIG. 26  is a view of a portion of the hemostat according to one embodiment of the present invention.  
         [0056]      FIG. 27  is a cross-section view of a portion of the hemostat according to one embodiment of the present invention.  
         [0057]      FIG. 28  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0058]      FIG. 29  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0059]      FIG. 30  is a view of the jaw assembly of one embodiment of the present invention.  
         [0060]      FIG. 31  is an exploded view of a jaw assembly of one embodiment of the present invention.  
         [0061]      FIG. 32  is a view of the jaw assembly of one embodiment of the present invention.  
         [0062]      FIG. 33  is a cross-section view of the jaw assembly of one embodiment of the present invention.  
         [0063]      FIG. 34  is a cross-section view of the jaw assembly of one embodiment of the present invention.  
         [0064]      FIG. 35  is a view of the jaw assembly of one embodiment of the present invention.  
         [0065]      FIG. 36  is a cross-section view of the jaw assembly of one embodiment of the present invention.  
         [0066]      FIG. 37  is a cross-section view of the jaw assembly of one embodiment of the present invention.  
         [0067]      FIG. 38  is a view of the jaw assembly of one embodiment of the present invention.  
         [0068]      FIG. 39  is a view of the jaw assembly of one embodiment of the present invention.  
         [0069]      FIG. 40  is a view of the jaw assembly of one embodiment of the present invention.  
         [0070]      FIG. 41  is a view of the jaw assembly of one embodiment of the present invention.  
         [0071]      FIG. 42  is a view of the jaw assembly of one embodiment of the present invention.  
         [0072]      FIG. 43  is a view of the jaw assembly of one embodiment of the present invention.  
         [0073]      FIG. 44  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0074]      FIG. 45  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0075]      FIG. 46  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0076]      FIG. 47  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0077]      FIG. 48  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0078]      FIG. 49  is a view of a portion of the jaw assembly of one embodiment of the present invention.  
         [0079]      FIG. 50  is a view of a portion of a hemostat according to one embodiment of the present invention.  
         [0080]      FIG. 51  is a view of a portion of a hemostat according to one embodiment of the present invention.  
         [0081]      FIG. 52  is a view of a portion of a hemostat according to one embodiment of the present invention.  
         [0082]      FIG. 53  is a view of a portion of a hemostat according to one embodiment of the present invention.  
         [0083]      FIG. 54  is a view of a hemostat according to one embodiment of the present invention.  
         [0084]      FIG. 55  is a view of a hemostat according to one embodiment of the present invention.  
         [0085]      FIG. 56  is a view of a hemostat according to one embodiment of the present invention.  
         [0086]      FIG. 57  is a view of a hemostat according to one embodiment of the present invention.  
         [0087]      FIG. 58  is a view of a portion of a hemostat according to one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0088]     In reference to  FIG. 1 , one embodiment of the hemostat of the present invention generally comprises an elongated handle assembly or handle  10  having a jaw assembly  90  mounted at handle distal end  15 , a trigger  20  intermediate the handle proximal and distal ends  95  and  15 , and a strain relief  60  located at handle proximal end  95 . An elongated cable is coupled to the strain relief  60  and comprises a fluid conduit  70  extending to a proximal fluid fitting  75  adapted to be coupled to a source of conductive fluid and a multi-conductor electrical cable  80  extending to a proximal electrical connector  85  adapted to be coupled to an electrosurgical unit. The trigger  20  is employed to move the jaws of the first or lower jaw assembly  40  with respect to the second or upper jaw assembly  30  of the jaw assembly  90  together to compress tissue therebetween to allow for creation of a linear RF ablation by electrically conductive fluid emitted from electrodes and contacting tissue or direct contact of the electrodes located along the upper and lower jaws  35  and  45 .  
         [0089]     The jaw assembly  90  includes an upper jaw assembly  30 , a lower jaw assembly  40 , and a swivel assembly  50 , discussed in more detail below. The upper jaw and lower jaw assemblies  30  and  40  have opposed upper and lower jaws  35  and  45 , respectively, each comprising a fluid assisted elongated electrode assembly. The upper and lower jaw assemblies  30  and  40  support elongated electrodes, discussed in more detail below, each coupled to one of the insulated conductors within conduit  80  extending proximately through the strain relief  60  to electrical connector  85 . Each of the jaws  35  and  40  of respective upper and lower jaw assemblies  30  and  40  are also coupled to fluid conduit  70  enabling delivery of saline or other conductive fluid from a source coupled to fitting  75  along the lengths of the opposed jaws  35  and  45 .  
         [0090]     The swivel assembly  50 , provides the physician with the opportunity to position the jaw assembly  90  in a variety of orientations relative to the handle  10 , to facilitate placing the  35  and  45  jaws against tissue to form desired lines of lesions, e.g., the heart wall in performance of the above-described Maze procedure. In one embodiment, the physician may manually grasp and rotate the swivel assembly  50  and the jaw assembly  90  to provide a roll adjustment R, preferably through an arc of at least 300 degrees, relative to the axis of the distal end  15  of the handle  10  through interaction of components of the handle and swivel assembly described further below. In one embodiment, the physician may manually grasp the jaw assembly  90  and adjust it in pitch P relative to the swivel assembly  50  through the interaction of components of the jaw assembly  90  and the swivel assembly  50  described further below. In one embodiment, the available arc of pitch P adjustment extends over at least 90 degrees. Moreover, the upper and lower jaws  35  and  45  may be malleable as described further below. The combination of these features make the hemostat highly versatile in use. In one embodiment, the trigger  20  is employed to open (separate apart) and close (draw together) the jaws  35  and  45  and to compress tissue between the jaws  35  and  45  prior to application of RF energy to create an elongated lesion. A thumb slide  25  may be provided in conjunction with an internal trigger lock, allowing the position of the trigger  20  and the jaws  35 ,  45  to be locked. After the trigger  20  is drawn toward the handle  10  to close the jaws  35  and  45 , the thumb slide  25  is moved distally relative to the handle  10  to cause an internal trigger lock to engage one of a series of ratcheting lock points that define a set of locking locations for the jaws  35 ,  45 , as described further below. Movement of the thumb slide  25  proximally relative to the handle  10  releases the trigger  20  and the jaw assembly  90 , allowing the jaws  35 ,  45  to return to a fully open position. The interaction of the trigger  20 , thumb slide  25  and the associated trigger lock mechanism frees the physician from the need to maintain pressure on the trigger  20  to compress tissue between the jaws  35 ,  45  during the ablation, simplifying operation of the hemostat.  
         [0091]     Referring to  FIG. 2 , the upper jaw assembly  30 , in one embodiment of the invention, includes a pivotable, relatively rigid, upper jaw mount  300 , an elongated backbone  310 , an elongated insulated electrode sheath  320 , an elongated conductive electrode  330 , and an elongated electrode support  340 . Upper jaw mount  300  may be fabricated of plastic or other insulated material, and in preferred embodiments may be fabricated of Teflon filled polycarbonate plastic. Backbone  310  is preferably fabricated of malleable stainless steel or other malleable metal and is attached at a proximal end to upper jaw mount  300 . An insulated electrode sheath  320  is fitted over spine  310  with its proximal end located adjacent upper jaw mount  300 . The elongated conductive electrode  330  comprises a length of malleable conductive metal tubing as shown in  FIGS. 5A and 5B  fitted into a lumen of the elongated electrode support  340 . The insulated electrode sheath  320  is formed with a channel that receives the sub-assembly of the elongated conductive electrode  330  and electrode support  340  disposed along the jaw  35 . Electrode sheath  320  may be fabricated of a flexible, electrically insulating, material, for example, silicone rubber. Elongated electrode support  340  is preferably fabricated of a porous material, such as Porex™ plastic, allowing for conductive fluid infiltration through its sidewall along its length and correspondingly delivery of conductive fluid along the length of jaw  35 . The jaw  35  can therefore be bent laterally with respect to the upper jaw mount  300  to form a curve along the length thereof.  
         [0092]     The lower jaw assembly  40  also includes a relatively rigid, lower jaw mount  400 , an elongated backbone  410 , an elongated insulated electrode sheath  420 , an elongated conductive electrode  430 , and an elongated electrode support  440  that are all formed of the same materials as the corresponding elements of the upper jaw assembly  30 . The assembly of the elongated backbone  410 , elongated insulated electrode sheath  420 , elongated conductive electrode  430 , and elongated electrode support  440  is also shown in  FIG. 3B .  
         [0093]     The jaw  45  can therefore also be bent laterally with respect to the lower jaw mount  400  to form a curve along the length thereof. In use, the physician manually forms a lateral curve in both the upper and lower jaws  35  and  45  to fit the contour of the tissue, e.g., the heart wall.  
         [0094]     The lower jaw mount  400  is formed with a pair of spaced apart, parallel, plates or flanges  401  and  403  each bearing a series of notches  402  and  404 , respectively, along the edges thereof. When assembled, a proximal portion of the upper jaw mount  300  is fitted between the flanges  401  and  403 . A pin  480  extends through aligned holes through the proximal portion of upper jaw mount  300  and the flanges  401  and  403 . The ends of pin  480  are fixed to the flanges  401  and  403  allowing the proximal portion of the upper jaw mount  300  to be rotated about the pin  480 , thereby allowing jaws  35  and  45  to open and close. The upper and lower jaws  35  and  45  are separated apart a predetermined distance in the fully closed positions although the electrically insulated distal ends of the insulated electrode sheaths  320  and  420  may contact one another. A spring  450  urges the upper and lower jaws  35  and  45  apart from one another, facilitating opening of the jaws  35  and  45  upon release of the trigger  20  after application of RF energy.  
         [0095]     As shown in  FIGS. 2 and 3 A, the swivel assembly  50  includes a swivel  500  that may also be fabricated of Teflon filled polycarbonate plastic to have a tubular proximal swivel portion  506 , a pair of parallel plates or flanges  502  and  504  extending distally from swivel proximal portion  506  and a extending detent  501  extending laterally between flanges  502  and  504 . The jaw assembly  90  is mounted to the swivel assembly  50  by outwardly and laterally extending bosses  405  on the outer surfaces of flanges  401  and  403  that are fitted into bores  503  through swivel flanges  502  and  504 . The upper jaw mount  300  is mounted to the lower jaw mount  400  by pin  480  as described above, and the lower jaw mount is  400  pivotably mounted relative to the swivel  500 . Therefore, the upper and lower jaw assemblies  30  and  40  may be pivoted together relative to the swivel  500 , allowing for movement of the jaws  35  and  45  together through the range of pitch P adjustment. The selected pitch P adjustment is maintained by the engagement of the detent  501  into an opposed pair of notches  402  and  404 , stabilizing the upper and lower jaws  35  and  45  in a desired orientation relative to the swivel assembly  50 . In use, the physician adjusts the relative positions of the jaws  35  and  45  relative to the swivel assembly  50  by simply manually moving the jaw assemblies  30  and  40  in the pitch P direction around the pivot axis defined by bosses  405  within the corresponding bores  505  in swivel flanges  502  and  504 . The detent  501  simply rides over the ridges separating adjacent notches  402  and  404 .  
         [0096]     As noted above, the swivel assembly  50  and the upper and lower jaw assemblies  30  and  40 , in one embodiment of the invention, may be rotated around the axis of the distal end  15  of the handle  10  to a desired roll adjustment R to facilitate positioning the jaws  35  and  45  for creation of elongated lesions. The proximal portion  506  of swivel  500  is rotatably mounted within a collar  550  that is mounted fixedly to the distal end  15  of the handle  10  as shown in  FIG. 3A . The collar  550  has a wavy or sinusoidal distally facing surface  551  of collar  550 . A washer-shaped insert  510  having a wavy or sinusoidal proximally facing surface  511  is fitted over the elongated proximal portion  506  of swivel  500  and attached to the swivel  500  through notches  514 , engaging corresponding bosses  557  and  567  (shown in  FIG. 4 ) formed on swivel  500 . A C-clip  524  mounted in a circumferential groove formed in the proximal portion  506  of swivel  500  maintains the proximal portion  506  within the lumen of collar  550 . A spring washer  522  and a flat washer  520  are interposed between the C-clip  524  and the proximal end of collar  550 . Spring washer  522  urges the wavy or sinusoidal surfaces of collar  550  and insert  510  against one another, whereby a plurality of detent locations are defined that maintain a selected roll R adjustment relative to the distal end  15  of the handle  10 . In use, the physician may adjust the roll R of the jaw assembly  90  by simply turning the swivel assembly  50  relative to the handle  10 . The detent mechanism maintains the swivel assembly  50  in the selected desired roll R adjustment prior to and during closure of the jaws  35 ,  45  to compress tissue during application of RF energy.  
         [0097]     A cable  390  is also shown in  FIGS. 3A and 4  that extends from the trigger  20  and that is employed to open and close the jaws  35  and  45 . Cable  390  passes through the internal lumen of proximal swivel portion  502 , through cable bore  565 , around shoulder  404  of lower jaw mount  400 , around boss  303  in upper jaw mount  300  and then upward into bore  408  in lower jaw mount  400 . The distal end of the cable  390  is maintained within bore  408  by ball  350 . When the cable  390  is pulled proximally by squeezing trigger  25 , boss  303  of upper jaw  300  is pulled toward bore  408  in lower jaw  400 , thereby pulling upper jaw  35  toward lower jaw  45 , allowing for compression of tissue there between. It should be noted that during this operation, the lower jaw mount  400  remains fixed relative to the swivel assembly  50  and only upper jaw mount  300  moves relative to the swivel assembly  50  or the handle  10 . Proximal movement of cable  380  does not affect the position of the lower jaw  45  relative to the handle  10 , nor does it affect the selected roll R adjustment of swivel  500 . Rotation of the jaw assembly  90  and swivel  500  about the roll axis does not affect the operation of the cable  390  because the cable  390  passes through the swivel  500  and enters the jaw assembly  90  along the roll axis. Pitch P adjustment of the jaw assembly  90  does not significantly effect operation of the cable  390  in opening or closing the jaws  35 ,  45  because shoulder  404  is at the center of rotation of lower jaw mount  400  relative to swivel  500  and remains essentially in the same location regardless of the pitch P adjustment.  
         [0098]      FIGS. 3A and 4  also internal electrical wiring and fluid delivery conduits of this embodiment of the invention including, insulated conductors  360  and  460  and fluid conduits  370  and  470  that both terminate at connections with the proximal ends of the upper and lower electrodes  330  and  430 , respectively. The fluid conduits  370  and  470  deliver conductive fluid into the lumens of the tubular upper and lower electrodes  330  and  430 , respectively. As shown in  FIG. 4 , the upper insulated conductor  360  and the upper fluid conduit  370  are routed to one side of the cable  390 , and the lower insulated conductor  460  and the lower fluid conduit  470  are routed to the other side of the cable  390  while passing through the lumen  534 .  
         [0099]     The elongated tubular electrodes  330  and  430  are illustrated in  FIGS. 5A and 5B . The tubular electrodes  330  and  430  are preferably formed of thin-walled, malleable stainless steel tubing extending between a proximal open end  331 ,  431  and a distal closed end  333 ,  433 . A series of fluid ports  335 ,  435  are formed, e.g., by laser drilling, through the sidewall of the tubing from the lumen  339 ,  439  and extending in a single line, although the fluid ports could be formed in any selected array extending around the circumference of the sidewall of the tubing. The proximal ends  331 ,  431  are notched in alignment with the series of fluid ports  335 ,  435  to assist in assembly so that the fluid ports  335 ,  435  are directed in a particular alignment with the porous electrode support  340 ,  440 .  
         [0100]     The porous electrode support  340 ,  440 , depicted in  FIGS. 6A and 6B , comprises a length of non-conductive, porous, malleable tubing having a channeled side  343 ,  443  adapted to fit within an elongated channel  323 ,  423  of the insulated electrode sheath  320 ,  420 , depicted in  FIGS. 7A and 7B . The porous electrode support  340 ,  440  is conically shaped at the support distal end  347 ,  447  to fit within a conically shaped terminus  327 ,  427  of the elongated channel  323 ,  423  of the insulated electrode sheath  320 ,  420 . During assembly, the elongated tubular electrode  330 ,  430  is inserted into the elongated lumen  341 ,  441  of the porous electrode support  340 ,  440 . Preferably, the series of fluid ports  335 ,  435  are oriented toward the channeled side  343 ,  443  so that the conductive fluid emitted from the lumen through the series of fluid ports  335 ,  435  then migrates laterally through the pores of the porous electrode support  340 ,  440  and around its circumference to thoroughly and uniformly wet the porous electrode support  340 ,  440  along the upper and lower jaws  35  and  45 .  
         [0101]     The sub-assembly so formed is fitted into the shaped terminus  327 ,  427  and the elongated channel  323 ,  423  of the insulated electrode sheath  320 ,  420  as also shown in  FIGS. 3A and 3B . Adhesive is applied to the contacting surfaces  323 ,  343  and  423 ,  443  to maintain the sub-assembly of the elongated tubular electrode  330 ,  430  inserted into the elongated lumen  341 ,  441  of the porous electrode support  340 ,  440  affixed to the insulated electrode sheath  320 ,  420 . The adhesive does not block migration of conductive fluid around the porous electrode support  340 ,  440 . Electrode sheathe  320 ,  420  is also formed having an elongated tapered internal recess  421   441  that receives the malleable backbone  310 ,  410  as shown in  FIGS. 2 and 3 . Again, adhesive may be applied to the contacting surfaces of the backbone  310 ,  410  and the elongated tapered internal recess  421   441 .  
         [0102]     The handle  10  is formed of a right handle half  600  depicted in  FIGS. 8A-8C  and a left handle half  700  depicted in  FIGS. 9A-9C . Trigger sections  620  and  720  of the respective right and left handle halves  600  and  700  include downwardly opening recesses  621  and  721  in which trigger  20  is mounted (as shown in  FIGS. 1 and 10 ) to pivot inward to apply tension on cable  390  or outward to release tension on cable  390 . Upward openings  627  and  727  in respective right and left handle halves  600  and  700  receive the thumb slide  25 . Inwardly extending projections  630  and  730  are also formed in respective right and left handle halves  600  and  700  that function to constrict the fluid conduits  370  and  470  to prevent conductive fluid flow therethrough when the trigger  20  is released as described further below.  
         [0103]     A set of circular matching, laterally opposed, sockets  623  and  723  are formed in the interior surfaces of the respective right and left handle halves  600  and  700 . The set of sockets  623 ,  723 , receive a pair of pivot bosses  206 ,  206 ′ of trigger  20  (shown in  FIG. 13A ) about which the trigger  20  pivots as described further below. A set of matching, laterally opposed, and slightly elongated or oblong, sockets  624  and  724  are formed in the interior surfaces of the respective right and left handle halves  600  and  700 . The set of sockets  624 ,  724  receive and guide a trigger lock  27  (shown in  FIGS. 11A and 11B ) that interacts with trigger  20  as described further below. The oblong shape of the set of sockets  624 ,  724  assists in allowing the trigger  20  to ratchet along the trigger lock  27  when trigger is drawn inward to tension the cable  390  during closing of the jaws  35 ,  45  as described further below.  
         [0104]     A further set of matching, laterally opposed, elongated sockets  625  and  725  are also formed in the interior surfaces of the respective right and left handle halves  600  and  700 . The set of sockets  625 ,  725  receive and guide a link arm  26  (shown in  FIGS. 12A and 12B ) that interacts with trigger  20  as described further below.  
         [0105]     As shown in  FIGS. 8B and 9B , the distal portions of right and left handle halves  600  and  700  are formed with internal cylindrical recesses or sockets  612  and  712  that receive the laterally extending bosses  552  of collar  550  ( FIG. 2 ). Internal grooves  611  and  711  are also formed within the distal portions of right and left handle halves  600  and  700  in which the c-clip  524 , flat washer  520  and spring washer  522  ( FIGS. 2 and 3 A) are fitted.  
         [0106]     As shown in  FIGS. 8C and 9C , the right and left handle halves  600  and  700  are also provided with a series of laterally extending, perpendicular internal walls  628  and  728  that include slots and recesses for routing the fluid conduits or tubes  370  and  470 , the cable  390  and the insulated wire conductors  360  and  460  that extend through the length of handle  10 .  
         [0107]     The trigger  20 , thumb slide  25 , and the associated link arm  26  and trigger lock  27  are shown assembled to the right handle half  600  in  FIG. 10  with the trigger  20  in the released position and the thumb slide  25  in the unlocked distal or retracted position. The trigger lock  27  is shown in greater detail in  FIGS. 11A-11B , the link arm  26  is shown in greater detail in  FIGS. 12A-12B , and the trigger  20  is shown in isolation in  FIGS. 13A-13B .  
         [0108]     Trigger  20  is provided with laterally extending cylindrical pivot bosses  206 ,  206 ′ that are mounted into sockets  723  and  623 , respectively. When released, trigger  20  extends outward through downwardly opening recesses  621  and  721 . When pulled, trigger  20  is pivoted inwardly into the handle recesses  621  and  721  about pivot bosses  206 ,  206 ′ to apply tension to the cable  390  that draws the upper and lower jaws  35  and  45  together. Cable  390  is mounted within a lubricious tube  391 , extending from the proximal wall  628  to the distal end  15  of the handle  10 , to allow the cable  390  to move freely within the handle  10  when trigger  20  is pulled or released.  
         [0109]     Trigger  20  is coupled to the proximal end of cable  390  through link arm  26 , illustrated in isolation in  FIGS. 12A and 12B . Link arm  26  is provided at a distal end with two laterally extending bosses  262  and  262 ′ that are received in circular sockets  204  (one of which is shown in  FIG. 13B ) formed on the interior walls of the internal chamber  202  of trigger  20  to thereby pivotally mount the distal end of the link arm  26  to the trigger  20 . Link arm  26  is formed with a longitudinally extending slot  266 , allowing compression of the distal end of the link arm  26  to facilitate positioning of cylindrical bosses  262  and  262 ′ within the corresponding sockets  204  within the trigger  20 . As also shown in  FIG. 13B , longitudinal slots  215  are provided in the interior  202  to assist insertion of the bosses  262 ,  262 ′ on link arm  26  into sockets  204  in trigger  20  during assembly. Link arm  26  is provided at its proximal end with two laterally extending, circular bosses  264  and  264 ′that are received within the elongated slots  625  and  725 , respectively, in the respective right and left handle halves  600  and  700 . When trigger  20  is released, the circular bosses  264  and  264 ′are disposed at the distal ends of the opposed elongated slots  625  and  725 , respectively. When trigger  20  is pulled inward, the proximal end of the link arm  26  is moved proximally within the opposed slots  625  and  725 , applying tension to cable  390 .  
         [0110]     Cable  390  is coupled to the link arm  26  by means of a swaged retainer  24 , mounted within a coil spring  28 . Coil spring  28  is fitted within a generally cylindrical chamber  266  formed extending at 90 degrees to the proximal end of link arm  26 . Cable  390  passes through an upwardly facing slot  270  in link arm  26  and through the interior of spring  28  to retainer  24 . Spring  28  is normally extended within chamber  266  but is compressed to provide protection against over tensioning of the cable  390 , if the upper and lower jaws  35  and  45  encounter significant resistance to further movement toward one another. The configuration of the trigger  20 , link arm  26  and slots  625  and  725  provide a mechanism whereby, the cable  390  is pulled proximally relatively quickly during initial upward movement of the trigger  20  to facilitate initial rapid closing of the jaws  35  and  45 . The cable  390  is pulled relatively more slowly during further upward movement of the trigger  20  to provide increased control to the physician during final compression of the jaws  35  and  45  against the tissue to be ablated.  
         [0111]     Trigger  20  is also provided with a distally extending projection  208  terminating with a laterally extending, generally cylindrical, boss  210  shown best in  FIG. 13B . As illustrated in  FIG. 10 , when the trigger  20  is released and in its most downward position (corresponding to the point of maximum jaw opening), the fluid conduits or tubes  370  and  470  are disposed side by side and compressed between cylindrical boss  210  and the inwardly extending projections  630  and  730 . This compression of the fluid conduits or tubes  370  and  470  prevents flow of conductive fluid from the fluid source and out of the electrodes  330  and  430  and the electrode mounts  340  and  440  when the hemostat is not in use.  
         [0112]     The trigger  20  is also formed with a laterally extending slot  212  having an array of teeth  214  formed along one side of the slot  212 . A trigger lock mechanism is provided involving the interaction of the thumb slide  25  with the trigger  20  through a trigger lock  27  that is coupled at one end with the thumb slide  25  and selectively engages the teeth  214  to retain the upper and lower jaws  35  and  45  at a fixed position adjacent tissue to be ablated without requiring the physician to continually apply pressure to trigger  20 . Distal or forward movement of the thumb slide  25  causes the trigger lock  27  to engage the teeth  214 , and proximal or rearward movement of the thumb slide  25  releases the engagement. The trigger  20  can be operated freely by the physician to open or close the upper and lower jaws  35  and  45  when the thumb slide  25  is in the rearward position. With the thumb slide  25  in the forward position, the trigger  20  can be moved inward ratcheting over the teeth  214  to close the upper and lower jaws  35  and  45 , but the trigger  20  will not move outward upon release by the physician.  
         [0113]     The trigger lock  27  depicted in isolation in  FIGS. 11A and 11B  comprises an elongated link arm  275  having rods  272  and  278  laterally extending parallel to one another from opposed ends of the link arm  275 . As shown in  FIG. 10 , the rod  272  is inserted through the slot  202  so that the link arm  275  extends alongside the trigger  20  within the recess  721 . The rod  278  extends into a generally centrally located notch  252  of a resilient beam section  250  of the thumb slide  25 . Cylindrical pivot bosses  276  and  276 ′ extend laterally on either side of the link arm  275  in alignment with rod  272  and are inserted into sockets  724  and  624 , respectively.  
         [0114]     The rod  272  inserted through the slot  212  extending through the trigger  20  is formed with a laterally extending ramped tooth  274  that is selectively engagable with one of the ramped teeth  214  formed along the proximal edge of slot  212 , when the trigger lock  27  is pivoted forward from the position illustrated in  FIG. 10  by distal or forward movement of the thumb slide  25  by the physician. Movement of the trigger  20  inwardly into the handle recess with the trigger lock  27  advanced forward from the position illustrated in  FIG. 10  causes the interaction of the tooth  274  on the trigger lock  27  with the teeth  214  to retain the trigger  20  in position when pressure is released. The oblong configuration of sockets  624  and  724  that receive bosses  276 ′ and  276  of the trigger lock  27  allow the trigger lock  27  to move slightly forward during inward movement of the trigger  20  so that the tooth  276  on trigger lock  27  may ratchet along the ramped teeth  214  of trigger  20 . Interaction of the teeth  214  with the ramped tooth  274  on the trigger lock  27  prevents outward movement of the trigger  20  as long as the thumb slide  25  remains in the forward position in the slot formed by openings  627  and  727 .  
         [0115]     Release of the trigger  20  is accomplished by proximal or rearward movement of thumb slide  25 , pivoting the ramped tooth  274  out of engagement with a tooth of the teeth  214  along slot  212  which allows the upper and lower jaws  35  and  45  to open unless the physician holds the trigger  20  in position. The trigger  20  is urged outwardly out of the recess in handle  10  by spring  23  upon release of the trigger  20  and rearward movement of the thumb slide  25 . When the trigger  20  reaches its full outward position, flow of conductive fluid through fluid conduits  370  and  470  is terminated as the tubing is compressed between the laterally extending boss  210  and the inwardly extending projections  630  and  730 , as discussed above.  
         [0116]     The thumb slide  25  is provided with a resilient beam section  250 , having a generally centrally located notch  252  which engages the laterally extending rod  278  on trigger lock  27 , coupling the thumb slide  25  to the trigger lock  27 . The thumb slide  25  is preferentially retained at either the proximal, rearward or distal, forward point of its travel, without the necessity of the physician manually maintaining pressure on the thumb slide  25  due to the resilience of the beam  250  and the arcuate path of travel of the rod  278 .  
         [0117]      FIG. 14  illustrates a proximal portion of the assembled hemostat of  FIG. 1  with the left handle half  700  removed to show the multi-conductor cable  80  and fluid conduit  70  extending through the strain relief  60  and their joinder to the wire conductors  360 ,  460  and the fluid conduits  370 ,  470 .  
         [0118]     The distal end of the fluid conduit  80  is coupled through a fitting  802  to proximal end of flexible tubing  804 . The distal end of flexible tubing  804  is coupled to the trunk of a Y-connector  806 , and the distal legs of the Y connector  806  are coupled to arms of a D-connector  810 . The D connector  810  is formed of a flexible plastic, e.g., silicone rubber, providing spaced apart fluid channels that are coupled to the proximal ends of the fluid conduits  370  and  470 .  
         [0119]     The fitting  804  supports a proximal flow controller or regulator  820  that has a precisely sized orifice that limits conductive fluid flow into the Y-connector  806 . The flow regulator  820  establishes a fixed flow rate and pressure within the Y-connector  806  regardless of the pressure of the fluid source that is available in the surgical theatre. The flow rate is established depending upon the upper and lower electrode area and design.  
         [0120]     The D connector  810  supports a pair of downstream flow regulators  822  and  824  that have equal, precisely sized orifices that further reduce the fluid flow rate and pressure of the conductive fluid entering the fluid conduits  370  and  470 . The downstream flow regulators  822  and  824  ensure that an even flow of conductive fluid is provided from within the Y connector  806  into the fluid conduits  370  and  470 . By this mechanism, the hemostat may be operated without the necessity of an associated pressurized fluid source and still provide controlled and even fluid flow to the upper and lower jaws  35  and  45  that contact the tissue to be ablated.  
         [0121]     An optional light emitter, e.g., an LED  830 , is depicted in  FIG. 14  located within the strain relief  60  and coupled through an electrical junction  832  with the insulated wire conductors  360  and  460 . The wire conductors  360  and  460  can take the form of a twisted wire cable that extends distally from the electrical junction  832  through the length of the handle to the swivel assembly  50  where they are separated as shown in  FIGS. 3A and 4 . Separate wire conductors within a cable  834  extend from the electrical junction  832  to the LED  830 . In use, the LED  830  is illuminated in response to activation of an associated RF electrosurgical generator, and the LED illumination illuminates the strain relief  60 , which is preferably fabricated of a translucent flexible material, such as silicone rubber or the like. The physician will typically hold the handle  10  in orientations that make the strain relief  60  visible, and illumination of the LED  830  indicates to the physician that RF energy is being applied to the electrodes  
         [0122]     The proximal portion of the handle  10  may also optionally carry other electronic components including circuitry containing calibration information, for example calibrating a thermocouple if provided to sense electrode or tissue temperature. Circuitry containing identification information or providing re-use prevention may also be included, however such features are not believed to be essential to or a part of the present invention.  
         [0123]      FIGS. 15A and 15B  illustrate an alternative embodiment of the electrode described above that can be employed in modified upper and lower jaw assemblies  30 A and  40 A corresponding generally to upper and lower jaw assemblies  30  and  40 . The upper and lower jaw assemblies  30 A,  40 A have a malleable backbone  310 ,  410  and a sheath  320 ,  420  as described above that are attached to the respective upper and lower jaw mounts  300  and  400  as shown in  FIGS. 2 and 3 . However, electrode  330 A,  430 A incorporates an exposed elongated electrode extension  350 A,  450 A extending to the outer surface of porous electrode support  340 A,  440 A and along the jaw  35 ,  45  that is intended to directly contact the tissue to be ablated. In this embodiment, conductive fluid is delivered as described above into the lumen of the internal tubular electrode  330 A,  430 A, which may be substantially the same as the tubular electrodes  330 ,  430 . An elongated electrode surface  352 A,  452 A of the electrode extension  350 A,  450 A and the contacted tissue are irrigated by conductive fluid emitted through the fluid ports of the internal tubular electrode  330 A,  430 A and conducted through the pores of the electrode support  340 A,  440 A.  
         [0124]     The electrode extension  350 A,  450 A is depicted prior to assembly with the electrode support  340 A,  440 A and the elongated tubular electrode  330 A,  430 A in  FIGS. 16A and 16B . As formed, the electrode extension  350 A,  450 A includes an elongated straight portion  352 A,  452 A that is mounted against the exposed to the exterior of the electrode support  340 A,  440 A. A distally extending portion  360 A,  460 A is adapted to be inserted into the lumen of the electrode support  340 A,  440 A to extend alongside the elongated tubular electrode  330 A  430 A as shown in  FIG. 15B .  
         [0125]     A series of barbed projections  354 A,  454 A extend laterally away from the elongated straight portion  352 A,  452 A. The electrode extension  350 A,  450 A is adapted to be bent back at junction  356 A,  456 A to enable insertion of the series of barbed projections  358 A,  458 A into the electrode support  340 A,  440 A. The proximal end  362 A,  462 A is electrically connected to the proximal ends of the tubular electrodes  330 A,  430 A and the distal ends of the wire conductors  360 ,  460 .  
         [0126]     This alternative exposed electrode embodiment can be formed by modifying the tubular electrode  330 ,  430  to have a conductive electrode band extending from the tubular electrode along the surface of the electrode support  340 ,  440 . Alternatively, this alternative electrode design can be accomplished without use of the tubular electrode  330 ,  430 , whereby conductive fluid is delivered to a lumen of the electrode support  340 ,  440  or to a fluid channel between the electrode support  340 ,  440  and the sheath  320 ,  420 , and the exposed electrode band is supported by the electrode support  340 ,  440 .  
         [0127]     In reference to  FIG. 17 , one embodiment of the hemostat of the present invention generally comprises an elongated handle assembly or handle  10  having a jaw assembly  90  mounted at handle distal end  15 , a trigger  20  intermediate the handle proximal and distal ends  95  and  15 , and a strain relief  60  located at handle proximal end  95 . An elongated cable is coupled to the strain relief  60  and comprises a fluid conduit  70  extending to a proximal fluid fitting  75  adapted to be coupled to a source of conductive fluid and a multi-conductor electrical cable  80  extending to a proximal electrical connector  85  adapted to be coupled to an electrosurgical unit. The trigger  20  is employed to move the jaws of the first or lower jaw assembly  40  with respect to the second or upper jaw assembly  30  of the jaw assembly  90  together to compress tissue therebetween to allow for creation of a linear RF ablation by electrically conductive fluid emitted from electrodes and contacting tissue or direct contact of the electrodes located along the upper and lower jaws  35  and  45 .  
         [0128]     The jaw assembly  90  includes an upper jaw assembly  30 , a lower jaw assembly  40 , and a swivel assembly  50 , discussed in more detail below. The upper jaw and lower jaw assemblies  30  and  40  have opposed upper and lower jaws  35  and  45 , respectively, each comprising a fluid assisted elongated electrode assembly. The upper and lower jaw assemblies  30  and  40  support elongated electrodes, discussed in more detail below, each coupled to one of the insulated conductors within conduit  80  extending proximately through the strain relief  60  to electrical connector  85 . Each of the jaws  35  and  40  of respective upper and lower jaw assemblies  30  and  40  also may be coupled to fluid conduit  70  enabling delivery of saline or other conductive fluid from a source coupled to fitting  75  along the lengths of the opposed jaws  35  and  45 .  
         [0129]     The swivel assembly  50 , provides the physician with the opportunity to position the jaw assembly  90  in a variety of orientations relative to the handle  10 , to facilitate placing the  35  and  45  jaws against tissue to form desired lines of lesions, e.g., the heart wall in performance of the above-described Maze procedure. In one embodiment, the physician may manually grasp and rotate the swivel assembly  50  and the jaw assembly  90  to provide a roll adjustment R, preferably through an arc of at least 300 degrees, relative to the axis of the distal end  15  of the handle  10  through interaction of components of the handle and swivel assembly described further below. Moreover, the upper and lower jaws  35  and  45  may be rigid in a straight or curved configuration or the upper and lower jaws  35  and  45  may be malleable as described further below. The combination of these features make the hemostat highly versatile in use.  
         [0130]     In one embodiment, the trigger  20  is employed to open (separate apart) and close (draw together) the jaws  35  and  45  and to compress tissue between the jaws  35  and  45  prior to application of RF energy to create an elongated lesion. A thumb slide  25  may be provided in conjunction with an internal trigger lock, allowing the position of the trigger  20  and the jaws  35 ,  45  to be locked. After the trigger  20  is drawn toward the handle  10  to close the jaws  35  and  45 , the thumb slide  25  is moved distally relative to the handle  10  to cause an internal trigger lock to engage one of a series of ratcheting lock points that define a set of locking locations for the jaws  35 ,  45 , as described further below. Movement of the thumb slide  25  proximally relative to the handle  10  releases the trigger  20  and the jaw assembly  90 , allowing the jaws  35 ,  45  to return to a fully open position. The interaction of the trigger  20 , thumb slide  25  and the associated trigger lock mechanism frees the physician from the need to maintain pressure on the trigger  20  to compress tissue between the jaws  35 ,  45  during the ablation, simplifying operation of the hemostat.  
         [0131]     The handle  10  may include an elongated shaft portion  11  proximal the handle distal end  15 . One or more portions of elongated shaft  11  may be straight, curved, rigid and/or malleable. For example, as shown in  FIG. 18 , elongated shaft  11  may comprise a malleable corrugated tube member  12 , thereby providing the physician with the opportunity to manually position the jaw assembly  90  in a variety of orientations, relative to the distal portion of handle  10 , to facilitate placing the  35  and  45  jaws against tissue to form desired lines of lesions. For example, the physician may manually grasp and bend or shape malleable corrugated tube member  12  to adjust the orientation of jaw assembly  90  relative to the distal portion of handle  10 . Elongated shaft member  11  may comprise one or more lumens or a multi-lumen member, e.g., a multi-lumen plastic tube, may be placed within elongated shaft member  11 . One or more portions of elongated member  11  may comprise one or more cross sectional shapes, e.g., round, oval, triangular, rectangular or square. The cross sectional area of elongated member  11  may very along its length. For example, elongated member may comprise ridges and grooves. Elongated member  11  may comprise one or more materials, e.g. plastic materials, metal materials, rigid materials, malleable materials, etc. For example, one or more portions of elongated member  11  may comprise malleable stainless steel. One or more portions of elongated member  11  may be covered, for example with a sheath material such as a plastic material.  
         [0132]     As shown in  FIG. 19 , trigger  20  is mounted to handle  10  to pivot inward to apply tension on cable  390  or outward to release tension on cable  390 . Upward openings in respective right and left handle halves receive the thumb slide  25 . The trigger  20 , thumb slide  25 , and the associated link arm  26  and trigger lock  27  of one embodiment of the invention are shown assembled to the right handle half  600  in  FIG. 19  with the trigger  20  in the released position and the thumb slide  25  in the unlocked distal or retracted position. The trigger  20 , thumb slide  25 , and trigger lock  27  are shown in greater detail in  FIG. 20 , a portion of link arm  26  is shown in greater detail in  FIG. 21 .  
         [0133]     Trigger  20  is provided with laterally extending cylindrical pivot bosses that are mounted into sockets, respectively. When released, trigger  20  extends outward through downwardly opening recesses. When pulled, trigger  20  is pivoted inwardly into the handle recesses about the pivot bosses to apply tension to the cable  390  that draws the upper and lower jaws  35  and  45  together. Cable  390  is mounted to move freely within the handle  10  when trigger  20  is pulled or released.  
         [0134]     Trigger  20  is coupled to the proximal end of cable  390  through link arm  26 , illustrated in  FIGS. 19 and 21 . Link arm  26  is provided at a distal end with two laterally extending bosses  262  and  262 ′ that are received in circular sockets  204  formed on the interior walls of the internal chamber of trigger  20  to thereby pivotally mount the distal end of the link arm  26  to the trigger  20 . When trigger  20  is pulled inward, the proximal end of the link arm  26  is moved proximally thereby applying tension to cable  390 .  
         [0135]     Cable  390  is coupled to the link arm  26  by means of a swaged retainer  24 , mounted within a coil spring  28 . Coil spring  28  is fitted within a generally cylindrical chamber or spring cage  266  pivotally coupled at  31  to the proximal end of link arm  26 . Cable  390  passes through the interior of spring  28  to retainer  24 . Spring  28  is normally extended within chamber  266  but is compressed to provide protection against over tensioning of the cable  390 , if the upper and lower jaws  35  and  45  encounter significant resistance to further movement toward one another.  
         [0136]     Trigger  20  is also provided with a distally extending projection  208  terminating with a laterally extending, generally cylindrical, boss  210  as shown in  FIG. 20 . As illustrated in  FIG. 20 , when the trigger  20  is released and in its most downward position (corresponding to the point of maximum jaw opening), the fluid conduits are compressed between cylindrical boss  210  and the inwardly extending projections  630 . This compression of the fluid conduits prevents flow of conductive fluid from the fluid source and out of the electrodes when the hemostat is not in use.  
         [0137]     The trigger  20  is also formed with a laterally extending slot  212  which may have an array of teeth formed along one side of the slot  212 . A trigger lock mechanism may be provided involving the interaction of the thumb slide  25  with the trigger  20  through a trigger lock  27  that is coupled at one end with the thumb slide  25  and may selectively engage the teeth  214  to retain the upper and lower jaws  35  and  45  at a fixed position adjacent tissue to be ablated without requiring the physician to continually apply pressure to trigger  20 . Distal or forward movement of the thumb slide  25  causes the trigger lock  27  to engage the teeth  214 , and proximal or rearward movement of the thumb slide  25  releases the engagement. The trigger  20  can be operated freely by the physician to open or close the upper and lower jaws  35  and  45  when the thumb slide  25  is in the rearward position. With the thumb slide  25  in the forward position, the trigger  20  can be moved inward ratcheting over the teeth  214  to close the upper and lower jaws  35  and  45 , but the trigger  20  will not move outward upon release by the physician. Release of the trigger  20  is accomplished by proximal or rearward movement of thumb slide  25 .  
         [0138]      FIG. 21  illustrates a proximal portion of the assembled hemostat of  FIG. 17  with the left handle half removed to show the multi-conductor cable  80  and fluid conduit  70  extending through the strain relief  60 . The distal end of the fluid conduit  80  is coupled through a fitting  802  to proximal end of flexible tubing  804 . The distal end of flexible tubing  804  is coupled to the trunk of a Y-connector  806 , and the distal legs of the Y connector  806  are coupled to arms of a D-connector  810 . The D connector  810  is formed of a flexible plastic, e.g., silicone rubber, providing spaced apart fluid channels that are coupled to the proximal ends of the fluid conduits  370  and  470 .  
         [0139]     The fitting  804  supports a proximal flow controller or regulator  820  that has a precisely sized orifice that limits conductive fluid flow into the Y-connector  806 . The flow regulator  820  establishes a fixed flow rate and pressure within the Y-connector  806  regardless of the pressure of the fluid source that is available in the surgical theatre. The flow rate is established depending upon the upper and lower electrode area and design.  
         [0140]     The D connector  810  supports a pair of downstream flow regulators  822  and  824  that have equal, precisely sized orifices that further reduce the fluid flow rate and pressure of the conductive fluid entering the fluid conduits  370  and  470 . The downstream flow regulators  822  and  824  ensure that an even flow of conductive fluid is provided from within the Y connector  806  into the fluid conduits  370  and  470 . By this mechanism, the hemostat may be operated without the necessity of an associated pressurized fluid source and still provide controlled and even fluid flow to the upper and lower jaws  35  and  45  that contact the tissue to be ablated.  
         [0141]     In reference to  FIG. 22 , elongated shaft portion  11  may comprise an articulating portion in one embodiment of the invention. As shown in  FIG. 23 , articulating shaft  11  may comprise a plurality of “ball and socket” links, for example.  FIG. 23  is a partial view of a section of links  392  and cable  393 . Each link may have a hole  397  that passes through it center. Each link may comprise, on its distal end, a hemispherical protrusion, and on its proximal end, a hemispherical indentation. The hemispherical shapes of adjacent links may be nearly identical, such that the links rotate smoothly against one another provided they are not under undue tension with each other.  FIG. 23  shows the engagement of the cable  393  with the side wall of the links as the arm is bent. Cable  393  passes through hole of all the links and is connected between the distal end of handle  10  and the tightening mechanism  394 . Tightening mechanism  394  may comprise a thumb slide thereby allowing a physician to tighten and loosen cable  393  by moving a mechanism proximally and distally, for example. Alternatively, tightening mechanism  394  may comprise a screw or handle mechanism that allows cable  393  to be tighten and loosened via a rotation motion. Alternatively, other types of tightening mechanisms may be used to tighten and loosen cable  393  thereby locking and unlocking the articulating section of handle  10 . Tightening of the cable  393  causes the links to hold against each other in place. Immobilization of the links relative to each other during tightening of the cable is facilitated by the shape of the hole  397 . As seen hole  397  is flared, having a larger opening with the surface of the hemispherical protrusion and a smaller opening through the surface of the hemispherical indentation. The links may very along the length of elongate member  11 . The links may comprise one or more plastics and/or metals. For example, the links may be fabricated out of highly rigid engineered thermoplastics such as glass filled Ultem™. The cable may be a multi-stranded stainless steel cable. The links and cable may also be manufactured from other materials, including any other suitable highly engineered polymers or plastics including any number of liquid crystal polymers for the links, as well as many other types of cables, including bundle stranded, braided or cabled titanium as well as Kevlar™ for the cable.  
         [0142]     A textured surface molded or otherwise formed into the hemispherical features of the links may be employed to increase the friction between adjacent surfaces when the links are pulled together. Alternatively, texture may be provided through a symmetrical structure, such as a series of interlocking dimples and hemispheres. Other geometries may also be used, including both surfaces having the same elements, such as hemispheres, as well as other shapes, including notches or grooves, for example.  
         [0143]     Referring to  FIG. 24 , the upper jaw assembly  30 , in one embodiment of the invention, includes a pivotable, relatively rigid, upper jaw mount  300 , an elongated backbone  310 , an elongated insulated electrode sheath  320 , an elongated conductive electrode  330 , and an elongated electrode support  340 . Upper jaw mount  300  may be fabricated of plastic or other insulated material, and in preferred embodiments may be fabricated of Teflon filled polycarbonate plastic. Backbone  310  is preferably fabricated of malleable stainless steel or other malleable metal and is attached at a proximal end to upper jaw mount  300 . An insulated electrode sheath  320  is fitted over spine  310  with its proximal end located adjacent upper jaw mount  300 . The elongated conductive electrode  330  comprises a length of malleable conductive metal tubing fitted into a lumen of the elongated electrode support  340 . The insulated electrode sheath  320  is formed with a channel that receives the sub-assembly of the elongated conductive electrode  330  and electrode support  340  disposed along the jaw  35 . Electrode sheath  320  may be fabricated of a flexible, electrically insulating, material, for example, silicone rubber or PVC. Elongated electrode support  340  is preferably fabricated of a porous material, such as Porex™ plastic, allowing for conductive fluid infiltration through its sidewall along its length and correspondingly delivery of conductive fluid along the length of jaw  35 . The jaw  35  can therefore be bent laterally with respect to the upper jaw mount  300  to form a curve along the length thereof.  
         [0144]     The lower jaw assembly  40  also includes a relatively rigid, lower jaw mount  400 , an elongated backbone  410 , an elongated insulated electrode sheath  420 , an elongated conductive electrode  430 , and an elongated electrode support  440  that are all formed of the same materials as the corresponding elements of the upper jaw assembly  30 .  
         [0145]     The jaw  45  can therefore also be bent laterally with respect to the lower jaw mount  400  to form a curve along the length thereof. In use, the physician may manually form a lateral curve in both the upper and lower jaws  35  and  45  to fit the contour of the tissue, e.g., the heart wall, to be ablated.  
         [0146]     The lower jaw mount  400  is formed with an opening  381  for receiving the proximal end of upper jaw mount  300 . When assembled, a proximal portion of the upper jaw mount  300  is fitted within the opening  381 . A pin  480  extends through aligned holes through the proximal portion of upper jaw mount  300  and the lower jaw mount  400 . The ends of pin  480  are fixed to the lower jaw  400  thereby allowing the proximal portion of the upper jaw mount  300  to be rotated about the pin  480 , thereby allowing jaws  35  and  45  to open and close. A spring  450  urges the upper and lower jaws  35  and  45  apart from one another, facilitating opening of the jaws  35  and  45  upon release of the trigger  20  after application of RF energy.  
         [0147]     As shown in  FIGS. 24 and 25 , the swivel assembly  50  includes a swivel  500  that may be fabricated of Teflon filled polycarbonate plastic to have a tubular structure. The jaw assembly  90  is mounted to the swivel assembly  50  by fitting the distal end of swivel  500  into collar  382  of lower jaw mount  400 . The upper jaw mount  300  is mounted to the lower jaw mount  400  by pin  480  as described above, and the lower jaw mount is  400  rotatably mounted relative to the swivel  500 . Therefore, the upper and lower jaw assemblies  30  and  40  may be rotated together relative to the swivel  500 , allowing for movement of the jaws  35  and  45  together to be rotated around the axis of the distal end  15  of the handle  10  to a desired roll adjustment R to facilitate positioning the jaws  35  and  45  for creation of elongated lesions. The distal portion  507  of swivel  500  is rotatably mounted within collar  382  of lower jaw mount  400 .  
         [0148]     A washer-shaped member  510  having a wavy or sinusoidal proximally facing surface  511  is fitted over the elongated distal portion  507  of swivel  500  and attached to the lower jaw mount  400 . C-clips  524  mounted in a circumferential grooves formed in the distal portion  507  of swivel  500  maintain the distal portion  507  within the lumen of collar  382 . Washer-shaped member  510  is prevented from rotating relative to lower jaw mount  400  through notch  613 , engaging corresponding boss  614  formed on lower jaw mount  400  as shown in  FIG. 29 . A washer-shaped member  517  having a wavy or sinusoidal distally facing surface  518  is fitted over the elongated distal portion  507  of swivel  500  and attached to the distal end  15  of handle  10 . Washer-shaped member  517  is prevented from rotating relative to swivel  500  through a notch engaging a corresponding boss of member  517  and swivel  500 . A spring washer  522  is interposed between the proximal end of collar  382  and the washer-shaped member  510 . Spring washer  522  urges the wavy or sinusoidal surfaces of washer-shaped members  510  and  517  against one another, whereby a plurality of detent locations are defined that maintain a selected roll R adjustment relative to the distal end  15  of the handle  10 . In use, the physician may adjust the roll R of the jaw assembly  90  by simply turning the swivel assembly  50  relative to the handle  10 . The detent mechanism maintains the swivel assembly  50  in the selected desired roll R adjustment prior to and during closure of the jaws  35  and  45  to compress tissue during application of RF energy.  
         [0149]     As shown in  FIG. 26 , in one embodiment of the invention, elongated malleable member  12  may be coupled to swivel member  500 . Plastic tube  591  may reside within the lumen of elongated member  12 . Plastic tube  591  may be made of a Pebax™ plastic material. As shown in  FIG. 27 , plastic tube  591  may comprise multiple lumens. In one embodiment of the invention, cable  390  passes through the center lumen  592  of tube  591 . Insulated conductors  360  and  460  pass through lumen  593  whereas fluid conduits  370  and  470  pass through lumens  594  and  595 , respectively. Tube  591  may be made of material that allows cable  390  to move or slide easily back and forth within lumen  593 . A lubricant may be used to reduce friction between lumen  593  and cable  390 .  
         [0150]     The distal end of cable  390  is shown in  FIGS. 28 and 29 . Cable  390  extends from the trigger  20  and is employed to open and close the jaws  35  and  45 . Cable  390  passes through the internal lumen of distal swivel portion  507 , around pulley  509  comprising a roller and a pin in lower jaw mount  400 , then upward through channel  513  (shown in  FIG. 25 ) of upper jaw mount  300 , and then back downward through bore  516  (shown in  FIG. 25 ) in lower jaw  400 . The distal end of the cable  390  is maintained within bore  516  by ball  350 . When the cable  390  is tensioned by squeezing trigger  25 , cable  390  is pulled through channel  513  and around pulley  509 , thereby pulling upper jaw  35  toward lower jaw  45 , allowing for compression of tissue therebetween. It should be noted that during this operation, the lower jaw mount  400  remains fixed relative to the swivel assembly  50  and only upper jaw mount  300  moves relative to the swivel assembly  50  or the handle  10 . Proximal movement of cable  390  does not affect the position of the lower jaw  45  relative to the handle  10 , nor does it affect the selected roll R adjustment of swivel  500 . Rotation of the jaw assembly  90  and swivel  500  about the roll axis does not affect the operation of the cable  390  because the cable  390  passes through the swivel  500  and enters the jaw assembly  90  along the roll axis.  
         [0151]      FIGS. 28 and 29  also show internal electrical wiring and fluid delivery conduits of this embodiment of the invention including, insulated conductors  360  and  460  and fluid conduits  370  and  470  that both terminate at connections with the proximal ends of the upper and lower electrodes  330  and  430 , respectively. The fluid conduits  370  and  470  deliver conductive fluid into the lumens of the tubular upper and lower electrodes  330  and  430 , respectively.  
         [0152]     In one embodiment of the invention, the porous electrode supports  340  and  440 , depicted in  FIGS. 24 and 25 , comprise a length of non-conductive, porous, malleable material adapted to fit within elongated channels  323  and  423  of the insulated electrode sheaths  320  and  420  and upper and lower jaw mounts  300  and  400 . In one embodiment of the invention, porous electrode supports  340  and  440  have a relatively square cross sectional area. During assembly, the elongated tubular electrodes  330  and  430  are inserted into elongated lumens of the porous electrode supports  340  and  440 . In one embodiment of the invention, the series of fluid ports alternate along two rows that are 90 degrees relative to each other. In one embodiment, each electrode has twelve ports arranged so that the two rows each include six alternating ports. The fluid ports of the tubular electrodes of upper and lower jaws  35  and  45  are oriented away from each other so that the conductive fluid emitted from the lumen through the series of fluid ports then migrates laterally through the pores of the porous electrode supports  340  and  440  and around its circumference to thoroughly and uniformly wet the porous electrode supports  340  and  440  along the upper and lower jaws  35  and  45 .  
         [0153]     The sub-assemblies so formed are fitted into the elongated channels  323  and  423  of the insulated electrode sheaths  320  and  420  and the upper and lower jaw mounts  300  and  400  as shown in  FIG. 25 . Adhesive may be used to affix the sub-assembly of the elongated tubular electrodes  330  and  430  inserted into the porous electrode supports  340  and  440  to the insulated electrode sheaths  320  and  420 . The adhesive does not block migration of conductive fluid around the porous electrode supports  340  and  440 . Electrode sheaths  320  and  420  are formed having an elongated tapered internal recess that receives the malleable backbones  310  and  410 , respectively, as shown in  FIGS. 24 and 25 .  
         [0154]     Referring to  FIGS. 30 and 31 , in one embodiment of the invention, upper and lower jaws  35  and  45  have a predetermined corresponding curved shape and are relatively rigid so as not to be malleable. Upper jaw  35  includes a relatively rigid, upper jaw mount  300 , an elongated relatively rigid backbone  310 , an elongated insulated electrode sheath  320 , an elongated conductive electrode  330 , and an elongated electrode support  340 . Upper jaw mount  300  may be fabricated of plastic or other insulated material, and in preferred embodiments may be fabricated of Teflon filled polycarbonate plastic. Backbone  310  is made of rigid stainless steel or other rigid metal and is attached at a proximal end to upper jaw mount  300 . An insulated electrode sheath  320  is fitted over spine  310  with its proximal end located adjacent upper jaw mount  300 . The elongated conductive electrode  330  comprises a length of conductive metal tubing fitted into a lumen of the elongated electrode support  340 . The insulated electrode sheath  320  is formed with a channel that receives the sub-assembly of the elongated conductive electrode  330  and electrode support  340  disposed along the jaw  35 . Electrode sheath  320  may be fabricated of a flexible, electrically insulating, material, for example, silicone rubber or PVC. Elongated electrode support  340  is preferably fabricated of a porous material, such as Porex™ plastic, allowing for conductive fluid infiltration through its sidewall along its length and correspondingly delivery of conductive fluid along the length of jaw  35 .  
         [0155]     The lower jaw assembly  40  also includes a relatively rigid, lower jaw mount  400 , an elongated relatively rigid backbone  410 , an elongated insulated electrode sheath  420 , an elongated conductive electrode  430 , and an elongated electrode support  440  that are all formed of the same materials as the corresponding elements of the upper jaw assembly  30 .  
         [0156]     Referring to  FIGS. 32 and 33 , an alternative configuration of upper and lower jaw assemblies may be used according to one embodiment of the invention. Upper and lower jaw assemblies  30  and  40  are configured so that upper jaw  35  moves in a parallel fashion relative to lower jaw  45 . Upper jaw  35  includes upper jaw mount  300  having a portion contained within a lumen of lower jaw mount  400 . The portion of upper jaw mount  300  contained within a lumen of lower jaw mount  400  is free to travel within lower jaw mount  400 . The distal end of cable  390  is attached to upper jaw mount  300 . A spring washer  613  is interposed between the distal end of collar  382  and the proximal end of upper jaw mount  300 . Spring washer  613  urges the upper and lower jaws  35  and  45 , respectively, into a closed configuration, i.e., spring washer  613  urges the upper jaw  35  towards the lower jaw  45 .  
         [0157]     Cable  390  extends from the trigger  20  and is employed to open and close the jaws  35  and  45 . In one embodiment of the invention, when the cable  390  is tensioned by squeezing trigger  25 , cable  390  is pulled in a proximal direction thereby pulling upper jaw  35  in a parallel direction away from lower jaw  45 . Therefore, tensioning cable  390  opens jaws  35  and  45  while releasing the tension in cable  390  closes the jaws  35  and  45 . It should be noted that during this operation, the lower jaw mount  400  remains fixed relative to the swivel assembly  50  and only upper jaw mount  300  moves relative to the swivel assembly  50  or the handle  10 . Proximal movement of cable  390  does not affect the position of the lower jaw  45  relative to the handle  10 , nor does it affect the selected roll R adjustment of swivel  500 . Rotation of the jaw assembly  90  and swivel  500  about the roll axis does not affect the operation of the cable  390  because the cable  390  passes through the swivel  500  and enters the jaw assembly  90  along the roll axis. Alternatively, the trigger mechanism may be designed so that the squeezing of trigger  25  opens the jaws  35  and  45 . Alternatively, as shown in  FIG. 34 , cable  390  may run through a lumen or channel in upper jaw mount  300 , around a pulley  509  mounted within a recess in lower jaw mount  400  and back to upper jaw mount  300  where cable  390  is fixed. In the embodiment shown in  FIG. 34 , tensioning of cable  390  will close jaws  35  and  45 .  
         [0158]     Referring to  FIGS. 35 and 36 , an alternative configuration of upper and lower jaw assemblies may be used according to one embodiment of the invention. Upper and lower jaw assemblies  30  and  40  are configured so that lower jaw  45  moves in a parallel fashion relative to upper jaw  35 . Upper jaw  35  includes upper jaw mount  300  having a portion comprising a lumen for receiving a proximal portion of lower jaw mount  400 . The portion of lower jaw mount  400  contained within a lumen of upper jaw mount  300  is free to travel within upper jaw mount  300 . Upper jaw mount  300  includes collar  382 . The distal end of cable  390  is attached to lower jaw mount  400 . A spring washer  613  is interposed between the distal end of collar  382  and the proximal end of lower jaw mount  400 . Spring washer  613  urges the upper and lower jaws  35  and  45 , respectively, into an open configuration, i.e., spring washer  613  urges the lower jaw  45  away from the upper jaw  35 .  
         [0159]     Cable  390  extends from the trigger  20  and is employed to open and close the jaws  35  and  45 . In one embodiment of the invention, when the cable  390  is tensioned by squeezing trigger  25 , cable  390  is pulled in a proximal direction thereby pulling lower jaw  45  in a parallel direction towards upper jaw  35 . Therefore, tensioning cable  390  closes jaws  35  and  45  while releasing the tension in cable  390  opens the jaws  35  and  45 . It should be noted that during this operation, the upper jaw mount  300  remains fixed relative to the swivel assembly  50  and only lower jaw mount  400  moves relative to the swivel assembly  50  or the handle  10 . Proximal movement of cable  390  does not affect the position of the upper jaw  35  relative to the handle  10 , nor does it affect the selected roll R adjustment of swivel  500 . Rotation of the jaw assembly  90  and swivel  500  about the roll axis does not affect the operation of the cable  390  because the cable  390  passes through the swivel  500  and enters the jaw assembly  90  along the roll axis.  
         [0160]     Referring to  FIG. 37 , an alternative configuration of upper and lower jaw assemblies may be used according to one embodiment of the invention. Upper and lower jaw assemblies  30  and  40  are configured so that lower jaw  45  moves in a parallel fashion relative to upper jaw mount  300 . Upper jaw  35  includes upper jaw mount  300  having a portion comprising a lumen for receiving a proximal portion of lower jaw mount  400 . The portion of lower jaw mount  400  contained within a lumen of upper jaw mount  300  is free to travel within upper jaw mount  300 . Upper jaw mount  300  includes collar  382 . The distal end of cable  390  is attached to lower jaw mount  400 . A spring washer  613  is interposed between the distal end of collar  382  and the proximal end of lower jaw mount  400 . Spring washer  613  urges the upper and lower jaws  35  and  45 , respectively, into an open configuration, i.e., spring washer  613  urges the lower jaw  45  away from the upper jaw  35 . A pin  680  extends through aligned holes through the distal portion of upper jaw mount  300  and upper jaw  35 . The ends of pin  680  are fixed to the upper jaw mount  300  thereby allowing upper jaw  35  to rotate about pin  680 . The distal end of jaw  35  fits within a groove or recess  682  within lower jaw mount  400 . Having upper jaw  35  rotatably attached to upper jaw mount  300  allows jaws  35  and  45  to be opened wider, thereby making it easier to place tissue in between the upper and lower jaws  35  and  45 . Further, as tissue is compressed between jaws  35  and  45 , jaw  35  is capable of rotating into parallel alignment with jaw  45 , thereby more evenly compressing tissue between jaws  35  and  45 . Recess  682  may be configured so that jaw  35  is rotated into a fully open position as spring washer  613  urges lower jaw  45  away from the upper jaw  35 .  
         [0161]     Cable  390  extends from the trigger  20  and is employed to open and close the jaws  35  and  45 . In one embodiment of the invention, when the cable  390  is tensioned by squeezing trigger  25 , cable  390  is pulled in a proximal direction thereby pulling lower jaw  45  in a direction towards upper jaw  35 . Therefore, tensioning cable  390  closes jaws  35  and  45  while releasing the tension in cable  390  opens the jaws  35  and  45 . It should be noted that during this operation, the upper jaw mount  300  remains fixed relative to the swivel assembly  50  and only lower jaw mount  400  moves relative to the swivel assembly  50  or the handle  10 . Proximal movement of cable  390  does not affect the position of the upper jaw  35  relative to the handle  10 , nor does it affect the selected roll R adjustment of swivel  500 . Rotation of the jaw assembly  90  and swivel  500  about the roll axis does not affect the operation of the cable  390  because the cable  390  passes through the swivel  500  and enters the jaw assembly  90  along the roll axis.  
         [0162]     As shown in  FIG. 33 , in one embodiment of the invention, jaw assembly  90  may be designed so that lower jaw  45  is fixedly oriented about 90 degrees relative to swivel assembly  50 . Alternatively, as shown in  FIG. 25 , jaw assembly  90  may be designed so that lower jaw  45  is fixedly oriented in a range between about 90 degrees and about 180 degrees relative to swivel assembly  50 .  
         [0163]     As shown in  FIG. 36 , in one embodiment of the invention, jaw assembly  90  may be designed so that upper jaw  35  is fixedly oriented about 90 degrees relative to swivel assembly  50 . Alternatively, as shown in  FIG. 37 , jaw assembly  90  may be designed so that upper jaw  35  is fixedly oriented in a range between about 90 degrees and about 180 degrees relative to swivel assembly  50 .  
         [0164]     To help prevent rotation of jaw mounts  300  and  400  relative to each other in jaw assemblies shown in  FIGS. 33, 36  and  37 , jaw mounts  300  and  400  may include interlocking features. For example, jaw mount  400  may comprise a slot or groove wherein fits a boss or pin, for example, of jaw mount  300 , thereby preventing rotation of jaw mounts  300  and  400  relative to each other yet still allowing a sliding or translational movement to occur.  
         [0165]     Referring to  FIG. 38 , an alternative configuration of upper and lower jaw assemblies may be used according to one embodiment of the invention. Upper jaw mount  300  comprises a pair of parallel plates or flanges  691  and  692 . A pin  680  extends through aligned holes through flanges  691  and  692  and upper jaw  35 . The ends of pin  680  are fixed to flanges  691  and  692  thereby allowing upper jaw  35  to rotate about pin  680 . The distal end of jaw  35  includes a pin or boss  687  that fits within a slot  688  within flanges  691  and  692 . Pin  687  and slot  688  limit the amount of movement jaw  35  has relative to jaw mount  300 . The lower jaw mount  400  is formed with an opening  381  for receiving the proximal end of upper jaw mount  300 . When assembled, a proximal portion of the upper jaw mount  300  is fitted within the opening  381 . A pin  480  extends through aligned holes through the proximal portion of upper jaw mount  300  and the lower jaw mount  400 . The ends of pin  480  are fixed to the lower jaw  400  thereby allowing the proximal portion of the upper jaw mount  300  to be rotated about the pin  480 , thereby allowing jaws  35  and  45  to open and close. Having upper jaw  35  rotatably attached to upper jaw mount  300  allows jaw  35  to be capable of assuming a parallel alignment relative to jaw  45  even as upper jaw mount  300  is rotated about pin  480  as jaws  35  and  45  are opened and closed. For example, as tissue is compressed between jaws  35  and  45 , jaw  35  is capable of rotating into parallel alignment with jaw  45 , thereby more evenly compressing tissue between jaws  35  and  45 . The pivoting upper jaw  35  may be spring loaded using a spring or other elastic material, for example, to bias the jaw  35  into an open configuration.  
         [0166]     In one embodiment of the invention, jaw assembly  90  may be designed so that either the upper jaw  35  or the lower jaw  45  is fixedly oriented about 180 degrees relative to swivel assembly  50 . For example, lower jaw mount  400  and lower jaw  45  are shown in  FIG. 39  to be fixed about 180 degrees relative to swivel assembly  50 . Having jaws  35  and  45  in alignment with shaft  11  of handle  10 , as shown in  FIG. 39 , would make the device suitably configured for delivery through a small, percutaneous penetration, for example a small cut, incision, stab wound, hole, port, cannula, trocar sleeve or the like. The term “trocar sleeve” appearing herein also refers to cannulae and ports.  
         [0167]     Alternative embodiment of jaw assembly  90  is shown in  FIG. 40 , wherein jaw assembly  90  includes an upper jaw assembly  30 , a lower jaw assembly  40 , and a swivel assembly  50 . The upper jaw and lower jaw assemblies  30  and  40  have opposed upper and lower jaws  35  and  45 . The swivel assembly  50  provides the physician with the opportunity to position the jaw assembly  90  in a variety of orientations relative to the handle  10 . In one embodiment, the physician may manually grasp and rotate the swivel assembly  50  and the jaw assembly  90  to provide a roll adjustment R, preferably through an arc of at least 300 degrees, relative to the axis of the distal end  15  of the handle  10  through interaction of components of the handle and swivel assembly described further above. In one embodiment, the physician may manually grasp the jaw assembly  90  and adjust it in pitch P relative to the swivel assembly  50  through the interaction of components of the jaw assembly  90  and the swivel assembly  50 . In one embodiment, the available arc of pitch P adjustment extends over at least 90 degrees. As shown in  FIG. 40 , upper jaw mount  300  may comprise a pair of parallel plates or flanges  691  and  692 . A pin  680  extends through aligned holes through flanges  691  and  692  and upper jaw  35 . The ends of pin  680  are fixed to flanges  691  and  692  thereby allowing upper jaw  35  to rotate about pin  680 . The distal end of jaw  35  includes a pin or boss  687  that fits within a slot  688  within flanges  691  and  692 . Pin  687  and slot  688  limit the amount of movement jaw  35  has relative to jaw mount  300 . Having upper jaw  35  rotatably attached to upper jaw mount  300  allows jaw  35  to be capable of assuming a parallel alignment relative to jaw  45  even as upper jaw mount  300  is rotated about pin  480  as jaws  35  and  45  are opened and closed. For example, as tissue is compressed between jaws  35  and  45 , jaw  35  is capable of rotating into parallel alignment with jaw  45 , thereby more evenly compressing tissue between jaws  35  and  45 .  
         [0168]     As shown in  FIG. 40 , the swivel assembly  50  includes a swivel  500  that has a pair of parallel plates or flanges  502  and  504  extending distally from swivel proximal portion  506  and a extending detent  501  extending laterally between flanges  502  and  504 . The lower jaw mount  400  is mounted to the swivel assembly  50  by fitting the proximal end of lower jaw mount  400  in swivel flanges  502  and  504 . The lower jaw mount  400  is pivotably mounted to the swivel  500  by pin  780 . Therefore, the upper and lower jaw assemblies  30  and  40  may be pivoted together relative to the swivel  500 , allowing for movement of the jaws  35  and  45  together through the range of pitch P adjustment. The selected pitch P adjustment is maintained by the engagement of the detent  501  into an opposed pair of notches  402  located at the proximal end of lower jaw mount  400 , stabilizing the upper and lower jaws  35  and  45  in a desired orientation relative to the swivel assembly  50 , as described above. In use, the physician adjusts the relative positions of the jaws  35  and  45  relative to the swivel assembly  50  by simply manually moving the jaw assemblies  30  and  40  in the pitch P direction around the pivot axis pin  780 . The detent  501  simply rides over the ridges separating adjacent notches  402 .  
         [0169]     As shown in  FIG. 40 , upper jaw mount  300  may comprise a pair of parallel plates or flanges  691  and  692 . A pin  680  extends through aligned holes through flanges  691  and  692  and upper jaw  35 . The ends of pin  680  are fixed to flanges  691  and  692  thereby allowing upper jaw  35  to rotate about pin  680 . The distal end of jaw  35  includes a pin or boss  687  that fits within a slot  688  within flanges  691  and  692 . Pin  687  and slot  688  limit the amount of movement jaw  35  has relative to jaw mount  300 . The lower jaw mount  400  is formed with an opening for receiving the proximal end of upper jaw mount  300 . When assembled, a proximal portion of the upper jaw mount  300  is fitted within the opening. A pin  480  extends through aligned holes through the proximal portion of upper jaw mount  300  and the lower jaw mount  400 . The ends of pin  480  are fixed to the lower jaw  400  thereby allowing the proximal portion of the upper jaw mount  300  to be rotated about the pin  480 , thereby allowing jaws  35  and  45  to open and close. Having upper jaw  35  rotatably attached to upper jaw mount  300  allows jaw  35  to be capable of assuming a parallel alignment relative to jaw  45  even as upper jaw mount  300  is rotated about pin  480  as jaws  35  and  45  are opened and closed. For example, as tissue is compressed between jaws  35  and  45 , jaw  35  is capable of rotating into parallel alignment with jaw  45 , thereby more evenly compressing tissue between jaws  35  and  45 .  
         [0170]     As shown in  FIG. 41 , one embodiment of the jaw assembly  90 , as described above and shown in  FIGS. 1 and 2 , may include an upper jaw mount  300  comprising a pair of parallel plates or flanges as described above. A pin  680  extends through aligned holes through the pair of flanges of upper jaw mount  300  and upper jaw  35 . The ends of pin  680  are fixed to the flanges thereby allowing upper jaw  35  to rotate about pin  680 . The distal end of jaw  35  includes a pin or boss  687  that fits within a slot  688  within the flanges. Pin  687  and slot  688  limit the amount of movement jaw  35  has relative to jaw mount  300 . Having upper jaw  35  rotatably attached to upper jaw mount  300  allows jaw  35  to be capable of assuming a parallel alignment relative to jaw  45  even as upper jaw mount  300  is pivoted relative to lower jaw mount  400  as jaws  35  and  45  are opened and closed. For example, as tissue is compressed between jaws  35  and  45 , jaw  35  is capable of rotating into parallel alignment with jaw  45 , thereby more evenly compressing tissue between jaws  35  and  45 .  
         [0171]     As shown in  FIGS. 42 and 43 , one embodiment of the jaw assembly  90  suitably configured for delivery through a small, percutaneous penetration, for example a small cut, incision, stab wound, hole, port, cannula, trocar sleeve or the like.  FIG. 42  is a bottom view of an alternative embodiment of jaw assembly  90  with jaws  35  and  45  a closed position, whereas  FIG. 43  is a bottom view of jaw assembly  90  with jaws  35  and  45  an open position. As seen in  FIGS. 42 and 43 , in this embodiment of the invention, jaws  35  and  45  are oriented parallel to each other during the entire process of opening and closing the jaws. In addition, neither jaw is fixed in place, but instead move relative to each other. Cable  390  may extend between jaw assembly  90  and handle  10  through shaft  11 . The proximal end of cable  390  is connected to actuator lever or trigger  20  on handle  10 . The distal end of cable  390  is connected to jaw assembly  90 . Trigger  20  may be used to remotely and controllably actuate the jaw assembly  90  as described below.  
         [0172]     As shown in  FIGS. 42 and 43 , cable  390  passes through collar  382  of anchor  840 . The jaw assembly  90  may be mounted to the swivel assembly  50  (as described above) by fitting the distal end of swivel  500  into collar  382  of anchor  840 . The distal end of cable  390  is coupled to slide  850  which is slidably coupled to anchor  840 . Referring to  FIGS. 44 and 45 , plan views of upper and lower jaw mounts  300  and  400  are shown with a portion of jaw  35  coupled to jaw mount  300  and a portion of jaw  45  coupled to jaw mount  400 . In this embodiment, jaw mounts  300  and  400  include first, second and third slots  871 ,  872 ,  873  with the second slot  872  being oriented substantially perpendicular to the jaws  35  and  45 . The second slot  872  of jaw mounts  300  and  400  are aligned so that a pin passing through the second slots  872  helps maintain jaws  35  and  45  parallel to one another throughout movement between a closed and an open position. The first and third slots  871 ,  873  of each of jaw mounts  300  and  400  are parallel to one another and oriented 45 degrees relative to the jaws  35  and  45 . Referring to  FIG. 42 , first, second and third pins  875 ,  876 ,  877  pass through the first, second and third slots  871 ,  872 ,  873 .  
         [0173]     Referring to  FIGS. 46 and 47 , side and plan views of slide  850  are shown. Slide  850  includes throughhole  880  for receiving cable  390 . The distal end of cable  390  preferably has an anchor (not shown) which prevents withdrawal of cable  390  through throughhole  880 . Slide  850  includes first and second holes  881 ,  882  extending through first and second sides  883 ,  884 . The first and third pins  875 ,  877  extend through first and second holes  881 ,  882  of slide  850  and first and third slots  871 ,  873  of jaw mounts  300  and  400  for moving spreader members  860 ,  870  when slide  850  is moved. Slide  850  also includes grooves  890  extending between the first and second holes  881 ,  882 .  
         [0174]     Referring to  FIGS. 48 and 49 , side and plan views of anchor  840  are shown. Anchor  840  includes central guides  900  which are positioned in grooves  890  of slide  850 . Central guides  900  and grooves  890  cooperate to help maintain the linearly slidable relationship between slide  850  and anchor  840 . Central guides  900  also include holes  901  therethrough for receiving the second pin  876  which extends through second slots  872  in spreader members  860 ,  870 . Anchor  840  includes throughhole  902  for receiving cable  390  and the distal end of swivel  500 . Proximal end  910  of anchor  840  includes four arms  815 , three of which are shown in  FIGS. 48 and 49 , which extend between central guides  900  and proximal end  910 .  
         [0175]     Referring to  FIGS. 50 and 51 , in an alternative embodiment of the invention, anchor  840  may be connected to coupling member  983  of linkage  950 . Linkage  950  comprises longitudinal cable or rod  990  slidably disposed within shaft  11  of handle  10  and a link  980  having a first and second ends  981 ,  982 . The proximal end of rod  990 , as shown in  FIG. 52 , is coupled to handle  10 . Coupling member  983  of linkage  950  has a bifurcated proximal end with first and second coupling points  984  and  985 . First end  981  of link  980  is coupled to the distal end of rod  990  and second end  982  of link  980  is coupled to coupling member  983  at coupling point  985 . Shaft  11  has an angled opening  1000  (as seen in  FIGS. 50 and 51 ) at its distal end to allow jaw assembly  90  to pivot into an orientation transverse to shaft  11 . Second coupling point  984  of coupling member  983  is pinned to distal end of shaft  11  to form a pivot point  910 . Jaw assembly  90  which is connected to coupling member  983  will therefore pivot about a transverse axis through pivot point  910 . Fluid and/or electrical power may be routed through conduit  960  to jaws  35  and  45 .  
         [0176]     Referring to  FIG. 52 , in one embodiment of the invention, a thumb slide  925 , for example, a slidable button within a longitudinal slot, may be used to move cable or rod  990  in proximal and distal directions, thereby remotely and controllably actuate jaw assembly  90  to pivot or rotate about pivot point  910 . An actuator knob may be used instead of a thumb slide  925 , for example, to remotely and controllably actuate linkage  950 . The knob may be fixed to rod  990 . The proximal end of rod  990  would be threaded at so that rod  990  mates with a threaded inner bore within handle  10 . Rotation of an actuator knob would move knob and rod  990  in an axial direction with respect to shaft  11 . Movement of rod  990  in an axial direction with respect to shaft  11  would controllably pivot jaw assembly  90  about pivot point  910 , thereby allowing a surgeon to remotely control the orientation of jaws  35  and  45  relative to shaft  11  of handle  10 . Note that handle  10  may alternatively include another type of actuator mechanism to remotely control linkage  850 , for example, a plunger mechanism, a pair of scissor-type handles or a lever mechanism.  
         [0177]     In an alternative embodiment of the invention, the ablation device may comprise multiple joints may comprises one or more remotely actuated variable linkages or joints, as described above. Shaft  11  may include, for example, a plurality of remotely actuable variable joints such as elbows, wrists, hinges, linkages and/or ball and sockets, as is well known in the art. These joints may be remotely actuable via cables or rods, for example, extending between the joint and the proximal portion of handle  10  through shaft  11 . The distal end of the cables or rods would be connected to the joint. The proximal end of the cables or rods would be connected to an actuator mechanism on handle  10 . The actuator mechanism used to remotely control a joint may be, for example, a knob, a lever mechanism, a plunger mechanism, a pair of scissor-type handles, or a slidable button within a longitudinal slot. The actuator mechanism may be, for example, voice-activated comprising voice-recognition technologies. A visual and/or audible signal, such as a flashing light and/or beeping tone, may be incorporated to alert a surgeon to the completion or resumption of the actuator. The joint may be slaved to a robotic system which may include, for example, head-mounted displays which integrate 3-D visualization of surgical anatomy and related diagnostic and monitoring data, miniature high resolution 2-D and 3-D digital cameras, a computer, a high power light source and a standard video monitor.  
         [0178]     Referring to  FIGS. 53, 54  and  55 , in an alternative embodiment of the invention, the ablation device may comprise a pair of joints, one located at the distal end of shaft  11  and the other located at the proximal end of shaft  11 . The joint  1014  located at the distal end of shaft  11  is coupled to jaw assembly  90  while the joint  1012  coupled at the proximal end is coupled to handle  10 . The distal end of cable or rod  990  is coupled to joint  1014  while the proximal end of cable or rod  990  is coupled to joint  1012 . Rod  990  is coupled to both joints so that movement of one joint creates movement in the other joint. As shown in  FIG. 53 , jaw assembly  90  will pivot about a transverse axis through pivot point  910  while handle  10  will pivot about a transverse axis through pivot point  1010 . In this embodiment, movement of jaw assembly  90  is remotely controlled or actuated via movement of handle  10 . In one embodiment as shown in  FIGS. 53, 54  and  55 , pivoting of handle  10  in one direction will pivot jaw assembly  90  in the opposite direction. In an alternative embodiment, the two joints may be coupled together so that pivoting of handle  10  in one direction will pivot jaw assembly  90  in the same direction.  
         [0179]     In one embodiment of the invention, shaft  10  may comprise a flexible neck portion  1150  as shown in  FIGS. 56, 57  and  58 . The device may be used to ablate cardiac tissue using a sub-xiphoid approach. The flexible neck enables the device to be inserted through a small incision while enabling jaw assembly  90  to be orientated in the proper position to ablate cardiac tissue such as tissue around the pulmonary veins. A cable  1152  that is connected to the thumb slide  925  actuates the flexible neck. The cable  1152  runs through the neck off center, as shown in  FIG. 58 , and is attached at the distal end. Pulling back on the thumb slide  925  angles up the jaws, as shown in  FIG. 57 , the memory of the material that the flexible neck is made of is what pulls it back to its home position, although some type of spring assist may be used. The handle  10  may be notched in the thumb slide groove to allow the flexible neck to be incrementally locked, for example, at 10-degree increments. The flexible neck has one or more lumens to allow wires, conductors, tubes and/or conduits, for example, to pass through.  
         [0180]     Handle  10  may alternatively include another type of actuator mechanism  20  to remotely control the opening and closing of jaws  35  and  45 , for example, a knob, a plunger mechanism, a pair of scissor-type handles, or a slidable button within a longitudinal slot. The actuator mechanism may be, for example, voice-activated comprising voice-recognition technologies. A visual and/or audible signal, such as a flashing light and/or beeping tone, may be incorporated to alert a surgeon to the completion or resumption of the actuator. Jaw assembly  90  may be slaved to a robotic system which may include, for example, head-mounted displays which integrate 3-D visualization of surgical anatomy and related diagnostic and monitoring data, miniature high resolution 2-D and 3-D digital cameras, a computer, a high power light source and a standard video monitor. Jaw assembly  90  may be coupled to gearing, which in turn, is coupled to a motor. The motor is further coupled to a power source. The motor and power source which may be used together are coupled to a controller which detects and controls the opening and closing of jaws  35  and  45 . Of course, further designs to control the opening and closing of jaws  35  and  45  may also be used, such as other mechanical or hydraulic activated or controlled systems.  
         [0181]     One or more embodiments of the present invention may be used for small incision or port access ablation procedures. For these types of procedures, the size of the distal portion of the device including the jaw assembly and swivel assembly must be sized to fit within the desired port size or incision length. In addition, the length of the handle shaft must be of a sufficient length to reach the desired anatomy. In one embodiment of the present invention, the jaw assembly, swivel assembly, and any joints the device comprises may be manipulated and positioned with the aid of a second endoscopic instrument, such as an endoscopic forceps. Alternatively, the use of “pull wires”, “push rods” or other means of integrated steering and/or manipulation may be used to remotely, from outside of the patient&#39;s body, manipulate and control various components of the ablation device including the jaw assembly, the swivel assembly and any joints that the device comprises.  
         [0182]     In an alternative embodiment, jaw assembly  90  may be designed so that the electrode assemblies of jaws  35  and  45  are replaceable, i.e., the device would be “resposable.” For example, the electrode assemblies, i.e., the assembly of the electrode, the porous electrode support and the insulated electrode sheath, may be removable from the backbone or spine of the upper and lower jaws, thereby allowing the electrode assemblies to be replaced between procedures. Alternatively, the entire jaw assembly may be designed to be replaceable. For example, the jaw assemblies including the backbone or spine may be designed to snap into position with upper and lower jaw mounts  300  and  400 .  
         [0183]     Shaft  11  may be comprised of several elements. For example, it may comprise one or more lumens or a tube having one or more lumens. The lumens may be used to route one or more electrical conductors, fluid lines, drive cables and/or rods. Shaft  11  may be used to direct or steer the jaw assembly  90 . Shaft  11  may be of sufficient rigidity to support the weight of jaw assembly  90  while being malleable enough to be shaped for manipulating around a patient&#39;s anatomy. Shaft  11  may be comprised of one or metals, such as stainless steel, or other materials such as polymers or composites.  
         [0184]     In one embodiment of the invention, a means for controlling the ablation energy, e.g., a switch, may be incorporated into handle  10 . Alternatively, a switch remote from the device, e.g. a foot pedal, may be used to control the delivery of ablation energy. In one embodiment, the hand piece has a trigger that closes the electrode jaws. Simultaneous with the actuation of the trigger and closing the jaws, the trigger will activate the ablation energy. Therefore, the ablation energy will only be delivered when the jaws are in a closed configuration. Alternatively, a sensor may used to determine if the jaws are in a closed or open configuration. If the sensor determines the jaws are in an open configuration, ablation energy may be delivered to the electrodes. If the jaws are sensed to be in an open configuration, the delivery of ablation energy to the electrodes is not allowed, will not occur or is stopped from occurring. The delivery of ablation energy may also be, for example, voice-activated comprising voice-recognition technologies. A visual and/or audible signal, such as a flashing light and/or beeping tone, may be incorporated to alert a surgeon to the completion or resumption of the delivery of ablation energy. A delivery of ablation energy to the device may be slaved to a robotic system which may include, for example, head-mounted displays which integrate 3-D visualization of surgical anatomy and related diagnostic and monitoring data, miniature high resolution 2-D and 3-D digital cameras, a computer, a high power light source and a standard video monitor. In one embodiment of the invention, built into electrical connector  85  may be a small fuse and/or EEPROM that can be used to prevent re-use.  
         [0185]     In one embodiment of the invention, a means to control the flow of fluid to the electrodes, e.g., a fluid controller such as a valve, may be incorporated into handle  10 . Alternatively, a fluid controller remote from the ablation device may be used. A fluid controller may also be, for example, voice-activated comprising voice-recognition technologies. A visual and/or audible signal, such as a flashing light and/or beeping tone, may be incorporated to alert a surgeon to the completion or resumption of fluid delivery. A fluid controller may be slaved to a robotic system which may include, for example, head-mounted displays which integrate 3-D visualization of surgical anatomy and related diagnostic and monitoring data, miniature high resolution 2-D and 3-D digital cameras, a computer, a high power light source and a standard video monitor. Fluid, such as saline, may be delivered to the device, for example, from an infusion pump or from a saline bag pressurized with a pressure cuff. In one embodiment, the hand piece has a trigger that closes the electrode jaws. Simultaneous with the actuation of the trigger and closing the jaws, the trigger will activate the fluid delivery. Therefore, fluid will only be delivered when the jaws are in a closed configuration. Alternatively, a sensor may used to determine if the jaws are in a closed or open configuration. If the sensor determines the jaws are in an open configuration, fluid may be delivered to the electrodes. If the jaws are sensed to be in an open configuration, the delivery of fluid to the electrodes is not allowed, will not occur or is stopped from occurring.  
         [0186]     The ablation device of the present invention may include additional features, for example, a light means to provide light to where the surgical procedure will be performed, for example, via an optical fiber coupled to a remote light source. The ablation device may feature one or more cutting means or visual means. The ablation device may include one or more sensors. For example, a sensor may be used to determine if the shaft of a device having an articulating shaft is in a locked position. If the sensor determines the articulating shaft is not in a locked position the sensor could prevent the delivery of fluid and/or ablation energy to the electrodes or ablation elements. A sensor could be used to determine if tissue is present between the jaws. If tissue is not present, the sensor could prevent the delivery of fluid and/or ablation energy to the ablation elements. In one embodiment of the invention, the ablation device may include one or more temperature-sensitive elements, such as a thermocouple, to allow a surgeon to monitor temperature changes of a patient&#39;s tissue. The ablation device may include one or more sensors for sensing voltage, amperage, wattage and/or impedance. The ablation device may include one or more sensors suitable for sensing blood pressure or flow, for example a Doppler ultrasound sensor system.  
         [0187]     The ablation device may include one or more biosensors, for example, comprising an immobilized biocatalyst, enzyme, immunoglobulin, bacterial, mammalian or plant tissue, cell and/or subcellular fraction of a cell. For example, a biosensor may comprise a mitochondrial fraction of a cell, thereby providing the sensor with a specific biocatalytic activity. The ablation device may include one or more sensors based on potentiometric technology or fiber optic technology. For example, a sensor may comprise a potentiometric or fiber optic transducer. An optical sensor may be based on either an absorbance or fluorescence measurement and may include an UV, a visible or an IR light source.  
         [0188]     The ablation device may include one or more sensors used to detect naturally detectable properties representative of one or more characteristics, e.g., chemical, physical or physiological, of a patient&#39;s bodily tissues or fluids. For example, naturally detectable properties of patient&#39;s bodily tissues or fluids may include pH, fluid flow, electrical current, impedance, temperature, pressure, components of metabolic processes, chemical concentrations, for example, the absence or presence of specific peptides, proteins, enzymes, gases, ions, etc. The ablation device may include one or more imaging systems, camera systems operating in UV, visible, or IR range; electrical sensors; voltage sensors; current sensors; piezoelectric sensors; electromagnetic interference (EMI) sensors; photographic plates, polymer-metal sensors; charge-coupled devices (CCDs); photo diode arrays; chemical sensors, electrochemical sensors; pressure sensors, vibration sensors, sound wave sensors; magnetic sensors; UV light sensors; visible light sensors; IR light sensors; radiation sensors; flow sensors; temperature sensors; or any other appropriate or suitable sensor.  
         [0189]     One or more sensors may be incorporated into the ablation device of the present invention, for example, in or one the handle  10  or the jaw assembly  90 . The ablation device may be slaved to one or more sensors. For example, the ablation device may be designed to automatically stop ablation if a sensor measures a predetermined sensor value, e.g., a particular temperature value. In one embodiment of the invention, if a sensor of the present invention indicates that ablated tissue has reached a particular temperature, ablation is stopped automatically, thereby preventing charring of the tissue.  
         [0190]     One or more sensors of the present invention may include a visual and/or audible signal used to alert a surgeon to any change in the one or more characteristics the sensor is monitoring. For example, a beeping tone or flashing light that increases in frequency as tissue temperature rises may be used to alert the surgeon.  
         [0191]     In one embodiment of the invention, the tissue contacting surfaces of jaws  35  and  45  may be slightly curved such that the surface will conform generally to the curvature of the heart. The heart contacting surfaces of jaws  35  and  45  may comprise one or more conformable materials such as a pliable polymer to facilitate conforming to the shape of the tissue to be ablated. The conformable or pliable material may comprise of one or more materials, for example, polymers, such as silicon, low durometer PVC or polyurethane, which are pliable and biocompatible may be used. In one embodiment of the invention, jaws  35  and  45  may comprise one or more ablating elements used to ablate tissue via RF ablation, cryo ablation, microwave ablation and/or ultrasound ablation.  
         [0192]     In one embodiment of the invention, the ablation device is a handheld, single-patient use, bipolar, RF ablation device. The device may be used to ablate soft tissue during general surgery using radiofrequency energy. The device may be a dual linear electrode device that has integral fluid delivery to both electrodes. It may be able to rapidly create linear transmural lesions in both atria of the heart during cardiac surgical procedures. The device may comprise one or more articulating joints to allow a wide range of flexibility and positioning. The electrodes may be malleable to allow contouring of the electrode to match specific physiologies. Therefore, the device may be designed to have a wide range of flexibility to access virtually all lesions required for the currently defined Maze III procedure. The device may be used in stopped-heart and beating-heart procedures. The device may be used in conjunction with a concomitant procedure such as a mitral valve surgery.  
         [0193]     The embodiments of the electrosurgical hemostat described above contain a number of valuable features and components, all of which contribute to provide a hemostat, which is convenient to use while providing substantial flexibility in use. However, many of the features of the hemostat could be employed in hemostats of other designs. For example, the trigger mechanism and/or the trigger lock mechanism of the above-described hemostat would certainly be of use in conjunction with cable activated hemostats having jaws of alternative designs to that described above. Similarly, the jaw assembly of the present hemostat might well be employed in conjunction with alternative trigger mechanisms. And/or in conjunction with alternative electrode designs, including electrodes which might not include provision for fluid irrigation and/or in the context of the hemostat having jaws that are rigid and not malleable by the physician to assume desired configurations. Further the specific electrode design employed in the hemostat design described above would be of significant use in conjunction with other hemostat types, including hemostats having jaws which are moved toward one another by alternative mechanisms. Similarly, a strain relief of the type described above including an LED indicator is believed to be of value in conjunction with any number of electrosurgical tools, particularly those in which the strain relief is within the physician&#39;s field of view, during normal operation of the hemostat.  
         [0194]     It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein.