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.

BACKGROUND OF THE INVENTION

The present invention relates to surgical tools and procedures generally and relates more particularly to the use of electrosurgical ablation to treat atrial fibrillation.

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.

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

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.

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.

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' 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In reference toFIG. 1, one embodiment of the hemostat of the present invention generally comprises an elongated handle assembly or handle10having a jaw assembly90mounted at handle distal end15, a trigger20intermediate the handle proximal and distal ends95and15, and a strain relief60located at handle proximal end95. An elongated cable is coupled to the strain relief60and comprises a fluid conduit70extending to a proximal fluid fitting75adapted to be coupled to a source of conductive fluid and a multi-conductor electrical cable80extending to a proximal electrical connector85adapted to be coupled to an electrosurgical unit. The trigger20is employed to move the jaws of the first or lower jaw assembly40with respect to the second or upper jaw assembly30of the jaw assembly90together 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 jaws35and45.

The jaw assembly90includes an upper jaw assembly30, a lower jaw assembly40, and a swivel assembly50, discussed in more detail below. The upper jaw and lower jaw assemblies30and40have opposed upper and lower jaws35and45, respectively, each comprising a fluid assisted elongated electrode assembly. The upper and lower jaw assemblies30and40support elongated electrodes, discussed in more detail below, each coupled to one of the insulated conductors within conduit80extending proximately through the strain relief60to electrical connector85. Each of the jaws35and40of respective upper and lower jaw assemblies30and40are also coupled to fluid conduit70enabling delivery of saline or other conductive fluid from a source coupled to fitting75along the lengths of the opposed jaws35and45.

The swivel assembly50, provides the physician with the opportunity to position the jaw assembly90in a variety of orientations relative to the handle10, to facilitate placing the35and45jaws 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 assembly50and the jaw assembly90to provide a roll adjustment R, preferably through an arc of at least 300 degrees, relative to the axis of the distal end15of the handle10through interaction of components of the handle and swivel assembly described further below. In one embodiment, the physician may manually grasp the jaw assembly90and adjust it in pitch P relative to the swivel assembly50through the interaction of components of the jaw assembly90and the swivel assembly50described further below. In one embodiment, the available arc of pitch P adjustment extends over at least 90 degrees. Moreover, the upper and lower jaws35and45may be malleable as described further below. The combination of these features make the hemostat highly versatile in use. In one embodiment, the trigger20is employed to open (separate apart) and close (draw together) the jaws35and45and to compress tissue between the jaws35and45prior to application of RF energy to create an elongated lesion. A thumb slide25may be provided in conjunction with an internal trigger lock, allowing the position of the trigger20and the jaws35,45to be locked. After the trigger20is drawn toward the handle10to close the jaws35and45, the thumb slide25is moved distally relative to the handle10to cause an internal trigger lock to engage one of a series of ratcheting lock points that define a set of locking locations for the jaws35,45, as described further below. Movement of the thumb slide25proximally relative to the handle10releases the trigger20and the jaw assembly90, allowing the jaws35,45to return to a fully open position. The interaction of the trigger20, thumb slide25and the associated trigger lock mechanism frees the physician from the need to maintain pressure on the trigger20to compress tissue between the jaws35,45during the ablation, simplifying operation of the hemostat.

Referring toFIG. 2, the upper jaw assembly30, in one embodiment of the invention, includes a pivotable, relatively rigid, upper jaw mount300, an elongated backbone310, an elongated insulated electrode sheath320, an elongated conductive electrode330, and an elongated electrode support340. Upper jaw mount300may be fabricated of plastic or other insulated material, and in preferred embodiments may be fabricated of Teflon filled polycarbonate plastic. Backbone310is preferably fabricated of malleable stainless steel or other malleable metal and is attached at a proximal end to upper jaw mount300. An insulated electrode sheath320is fitted over spine310with its proximal end located adjacent upper jaw mount300. The elongated conductive electrode330comprises a length of malleable conductive metal tubing as shown inFIGS. 5A and 5Bfitted into a lumen of the elongated electrode support340. The insulated electrode sheath320is formed with a channel that receives the sub-assembly of the elongated conductive electrode330and electrode support340disposed along the jaw35. Electrode sheath320may be fabricated of a flexible, electrically insulating, material, for example, silicone rubber. Elongated electrode support340is 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 jaw35. The jaw35can therefore be bent laterally with respect to the upper jaw mount300to form a curve along the length thereof.

The lower jaw assembly40also includes a relatively rigid, lower jaw mount400, an elongated backbone410, an elongated insulated electrode sheath420, an elongated conductive electrode430, and an elongated electrode support440that are all formed of the same materials as the corresponding elements of the upper jaw assembly30. The assembly of the elongated backbone410, elongated insulated electrode sheath420, elongated conductive electrode430, and elongated electrode support440is also shown inFIG. 3B.

The jaw45can therefore also be bent laterally with respect to the lower jaw mount400to form a curve along the length thereof. In use, the physician manually forms a lateral curve in both the upper and lower jaws35and45to fit the contour of the tissue, e.g., the heart wall.

The lower jaw mount400is formed with a pair of spaced apart, parallel, plates or flanges401and403each bearing a series of notches402and404, respectively, along the edges thereof. When assembled, a proximal portion of the upper jaw mount300is fitted between the flanges401and403. A pin480extends through aligned holes through the proximal portion of upper jaw mount300and the flanges401and403. The ends of pin480are fixed to the flanges401and403allowing the proximal portion of the upper jaw mount300to be rotated about the pin480, thereby allowing jaws35and45to open and close. The upper and lower jaws35and45are separated apart a predetermined distance in the fully closed positions although the electrically insulated distal ends of the insulated electrode sheaths320and420may contact one another. A spring450urges the upper and lower jaws35and45apart from one another, facilitating opening of the jaws35and45upon release of the trigger20after application of RF energy.

As shown inFIGS. 2 and 3A, the swivel assembly50includes a swivel500that may also be fabricated of Teflon filled polycarbonate plastic to have a tubular proximal swivel portion506, a pair of parallel plates or flanges502and504extending distally from swivel proximal portion506and a extending detent501extending laterally between flanges502and504. The jaw assembly90is mounted to the swivel assembly50by outwardly and laterally extending bosses405on the outer surfaces of flanges401and403that are fitted into bores503through swivel flanges502and504. The upper jaw mount300is mounted to the lower jaw mount400by pin480as described above, and the lower jaw mount is400pivotably mounted relative to the swivel500. Therefore, the upper and lower jaw assemblies30and40may be pivoted together relative to the swivel500, allowing for movement of the jaws35and45together through the range of pitch P adjustment. The selected pitch P adjustment is maintained by the engagement of the detent501into an opposed pair of notches402and404, stabilizing the upper and lower jaws35and45in a desired orientation relative to the swivel assembly50. In use, the physician adjusts the relative positions of the jaws35and45relative to the swivel assembly50by simply manually moving the jaw assemblies30and40in the pitch P direction around the pivot axis defined by bosses405within the corresponding bores505in swivel flanges502and504. The detent501simply rides over the ridges separating adjacent notches402and404.

As noted above, the swivel assembly50and the upper and lower jaw assemblies30and40, in one embodiment of the invention, may be rotated around the axis of the distal end15of the handle10to a desired roll adjustment R to facilitate positioning the jaws35and45for creation of elongated lesions. The proximal portion506of swivel500is rotatably mounted within a collar550that is mounted fixedly to the distal end15of the handle10as shown inFIG. 3A. The collar550has a wavy or sinusoidal distally facing surface551of collar550. A washer-shaped insert510having a wavy or sinusoidal proximally facing surface511is fitted over the elongated proximal portion506of swivel500and attached to the swivel500through notches514, engaging corresponding bosses557and567(shown inFIG. 4) formed on swivel500. A C-clip524mounted in a circumferential groove formed in the proximal portion506of swivel500maintains the proximal portion506within the lumen of collar550. A spring washer522and a flat washer520are interposed between the C-clip524and the proximal end of collar550. Spring washer522urges the wavy or sinusoidal surfaces of collar550and insert510against one another, whereby a plurality of detent locations are defined that maintain a selected roll R adjustment relative to the distal end15of the handle10. In use, the physician may adjust the roll R of the jaw assembly90by simply turning the swivel assembly50relative to the handle10. The detent mechanism maintains the swivel assembly50in the selected desired roll R adjustment prior to and during closure of the jaws35,45to compress tissue during application of RF energy.

A cable390is also shown inFIGS. 3A and 4that extends from the trigger20and that is employed to open and close the jaws35and45. Cable390passes through the internal lumen of proximal swivel portion502, through cable bore565, around shoulder404of lower jaw mount400, around boss303in upper jaw mount300and then upward into bore408in lower jaw mount400. The distal end of the cable390is maintained within bore408by ball350. When the cable390is pulled proximally by squeezing trigger25, boss303of upper jaw300is pulled toward bore408in lower jaw400, thereby pulling upper jaw35toward lower jaw45, allowing for compression of tissue there between. It should be noted that during this operation, the lower jaw mount400remains fixed relative to the swivel assembly50and only upper jaw mount300moves relative to the swivel assembly50or the handle10. Proximal movement of cable380does not affect the position of the lower jaw45relative to the handle10, nor does it affect the selected roll R adjustment of swivel500. Rotation of the jaw assembly90and swivel500about the roll axis does not affect the operation of the cable390because the cable390passes through the swivel500and enters the jaw assembly90along the roll axis. Pitch P adjustment of the jaw assembly90does not significantly effect operation of the cable390in opening or closing the jaws35,45because shoulder404is at the center of rotation of lower jaw mount400relative to swivel500and remains essentially in the same location regardless of the pitch P adjustment.

FIGS. 3A and 4also internal electrical wiring and fluid delivery conduits of this embodiment of the invention including, insulated conductors360and460and fluid conduits370and470that both terminate at connections with the proximal ends of the upper and lower electrodes330and430, respectively. The fluid conduits370and470deliver conductive fluid into the lumens of the tubular upper and lower electrodes330and430, respectively. As shown inFIG. 4, the upper insulated conductor360and the upper fluid conduit370are routed to one side of the cable390, and the lower insulated conductor460and the lower fluid conduit470are routed to the other side of the cable390while passing through the lumen534.

The elongated tubular electrodes330and430are illustrated inFIGS. 5A and 5B. The tubular electrodes330and430are preferably formed of thin-walled, malleable stainless steel tubing extending between a proximal open end331,431and a distal closed end333,433. A series of fluid ports335,435are formed, e.g., by laser drilling, through the sidewall of the tubing from the lumen339,439and 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 ends331,431are notched in alignment with the series of fluid ports335,435to assist in assembly so that the fluid ports335,435are directed in a particular alignment with the porous electrode support340,440.

The porous electrode support340,440, depicted inFIGS. 6A and 6B, comprises a length of non-conductive, porous, malleable tubing having a channeled side343,443adapted to fit within an elongated channel323,423of the insulated electrode sheath320,420, depicted inFIGS. 7A and 7B. The porous electrode support340,440is conically shaped at the support distal end347,447to fit within a conically shaped terminus327,427of the elongated channel323,423of the insulated electrode sheath320,420. During assembly, the elongated tubular electrode330,430is inserted into the elongated lumen341,441of the porous electrode support340,440. Preferably, the series of fluid ports335,435are oriented toward the channeled side343,443so that the conductive fluid emitted from the lumen through the series of fluid ports335,435then migrates laterally through the pores of the porous electrode support340,440and around its circumference to thoroughly and uniformly wet the porous electrode support340,440along the upper and lower jaws35and45.

The sub-assembly so formed is fitted into the shaped terminus327,427and the elongated channel323,423of the insulated electrode sheath320,420as also shown inFIGS. 3A and 3B. Adhesive is applied to the contacting surfaces323,343and423,443to maintain the sub-assembly of the elongated tubular electrode330,430inserted into the elongated lumen341,441of the porous electrode support340,440affixed to the insulated electrode sheath320,420. The adhesive does not block migration of conductive fluid around the porous electrode support340,440. Electrode sheathe320,420is also formed having an elongated tapered internal recess421441that receives the malleable backbone310,410as shown inFIGS. 2 and 3. Again, adhesive may be applied to the contacting surfaces of the backbone310,410and the elongated tapered internal recess421441.

The handle10is formed of a right handle half600depicted inFIGS. 8A-8Cand a left handle half700depicted inFIGS. 9A-9C. Trigger sections620and720of the respective right and left handle halves600and700include downwardly opening recesses621and721in which trigger20is mounted (as shown inFIGS. 1 and 10) to pivot inward to apply tension on cable390or outward to release tension on cable390. Upward openings627and727in respective right and left handle halves600and700receive the thumb slide25. Inwardly extending projections630and730are also formed in respective right and left handle halves600and700that function to constrict the fluid conduits370and470to prevent conductive fluid flow therethrough when the trigger20is released as described further below.

A set of circular matching, laterally opposed, sockets623and723are formed in the interior surfaces of the respective right and left handle halves600and700. The set of sockets623,723, receive a pair of pivot bosses206,206′ of trigger20(shown inFIG. 13A) about which the trigger20pivots as described further below. A set of matching, laterally opposed, and slightly elongated or oblong, sockets624and724are formed in the interior surfaces of the respective right and left handle halves600and700. The set of sockets624,724receive and guide a trigger lock27(shown inFIGS. 11A and 11B) that interacts with trigger20as described further below. The oblong shape of the set of sockets624,724assists in allowing the trigger20to ratchet along the trigger lock27when trigger is drawn inward to tension the cable390during closing of the jaws35,45as described further below.

A further set of matching, laterally opposed, elongated sockets625and725are also formed in the interior surfaces of the respective right and left handle halves600and700. The set of sockets625,725receive and guide a link arm26(shown inFIGS. 12A and 12B) that interacts with trigger20as described further below.

As shown inFIGS. 8B and 9B, the distal portions of right and left handle halves600and700are formed with internal cylindrical recesses or sockets612and712that receive the laterally extending bosses552of collar550(FIG. 2). Internal grooves611and711are also formed within the distal portions of right and left handle halves600and700in which the c-clip524, flat washer520and spring washer522(FIGS. 2 and 3A) are fitted.

As shown inFIGS. 8C and 9C, the right and left handle halves600and700are also provided with a series of laterally extending, perpendicular internal walls628and728that include slots and recesses for routing the fluid conduits or tubes370and470, the cable390and the insulated wire conductors360and460that extend through the length of handle10.

The trigger20, thumb slide25, and the associated link arm26and trigger lock27are shown assembled to the right handle half600inFIG. 10with the trigger20in the released position and the thumb slide25in the unlocked distal or retracted position. The trigger lock27is shown in greater detail inFIGS. 11A-11B, the link arm26is shown in greater detail inFIGS. 12A-12B, and the trigger20is shown in isolation inFIGS. 13A-13B.

Trigger20is provided with laterally extending cylindrical pivot bosses206,206′ that are mounted into sockets723and623, respectively. When released, trigger20extends outward through downwardly opening recesses621and721. When pulled, trigger20is pivoted inwardly into the handle recesses621and721about pivot bosses206,206′ to apply tension to the cable390that draws the upper and lower jaws35and45together. Cable390is mounted within a lubricious tube391, extending from the proximal wall628to the distal end15of the handle10, to allow the cable390to move freely within the handle10when trigger20is pulled or released.

Trigger20is coupled to the proximal end of cable390through link arm26, illustrated in isolation inFIGS. 12A and 12B. Link arm26is provided at a distal end with two laterally extending bosses262and262′ that are received in circular sockets204(one of which is shown inFIG. 13B) formed on the interior walls of the internal chamber202of trigger20to thereby pivotally mount the distal end of the link arm26to the trigger20. Link arm26is formed with a longitudinally extending slot266, allowing compression of the distal end of the link arm26to facilitate positioning of cylindrical bosses262and262′ within the corresponding sockets204within the trigger20. As also shown inFIG. 13B, longitudinal slots215are provided in the interior202to assist insertion of the bosses262,262′ on link arm26into sockets204in trigger20during assembly. Link arm26is provided at its proximal end with two laterally extending, circular bosses264and264′that are received within the elongated slots625and725, respectively, in the respective right and left handle halves600and700. When trigger20is released, the circular bosses264and264′are disposed at the distal ends of the opposed elongated slots625and725, respectively. When trigger20is pulled inward, the proximal end of the link arm26is moved proximally within the opposed slots625and725, applying tension to cable390.

Cable390is coupled to the link arm26by means of a swaged retainer24, mounted within a coil spring28. Coil spring28is fitted within a generally cylindrical chamber266formed extending at 90 degrees to the proximal end of link arm26. Cable390passes through an upwardly facing slot270in link arm26and through the interior of spring28to retainer24. Spring28is normally extended within chamber266but is compressed to provide protection against over tensioning of the cable390, if the upper and lower jaws35and45encounter significant resistance to further movement toward one another. The configuration of the trigger20, link arm26and slots625and725provide a mechanism whereby, the cable390is pulled proximally relatively quickly during initial upward movement of the trigger20to facilitate initial rapid closing of the jaws35and45. The cable390is pulled relatively more slowly during further upward movement of the trigger20to provide increased control to the physician during final compression of the jaws35and45against the tissue to be ablated.

Trigger20is also provided with a distally extending projection208terminating with a laterally extending, generally cylindrical, boss210shown best inFIG. 13B. As illustrated inFIG. 10, when the trigger20is released and in its most downward position (corresponding to the point of maximum jaw opening), the fluid conduits or tubes370and470are disposed side by side and compressed between cylindrical boss210and the inwardly extending projections630and730. This compression of the fluid conduits or tubes370and470prevents flow of conductive fluid from the fluid source and out of the electrodes330and430and the electrode mounts340and440when the hemostat is not in use.

The trigger20is also formed with a laterally extending slot212having an array of teeth214formed along one side of the slot212. A trigger lock mechanism is provided involving the interaction of the thumb slide25with the trigger20through a trigger lock27that is coupled at one end with the thumb slide25and selectively engages the teeth214to retain the upper and lower jaws35and45at a fixed position adjacent tissue to be ablated without requiring the physician to continually apply pressure to trigger20. Distal or forward movement of the thumb slide25causes the trigger lock27to engage the teeth214, and proximal or rearward movement of the thumb slide25releases the engagement. The trigger20can be operated freely by the physician to open or close the upper and lower jaws35and45when the thumb slide25is in the rearward position. With the thumb slide25in the forward position, the trigger20can be moved inward ratcheting over the teeth214to close the upper and lower jaws35and45, but the trigger20will not move outward upon release by the physician.

The trigger lock27depicted in isolation inFIGS. 11A and 11Bcomprises an elongated link arm275having rods272and278laterally extending parallel to one another from opposed ends of the link arm275. As shown inFIG. 10, the rod272is inserted through the slot202so that the link arm275extends alongside the trigger20within the recess721. The rod278extends into a generally centrally located notch252of a resilient beam section250of the thumb slide25. Cylindrical pivot bosses276and276′ extend laterally on either side of the link arm275in alignment with rod272and are inserted into sockets724and624, respectively.

The rod272inserted through the slot212extending through the trigger20is formed with a laterally extending ramped tooth274that is selectively engagable with one of the ramped teeth214formed along the proximal edge of slot212, when the trigger lock27is pivoted forward from the position illustrated inFIG. 10by distal or forward movement of the thumb slide25by the physician. Movement of the trigger20inwardly into the handle recess with the trigger lock27advanced forward from the position illustrated inFIG. 10causes the interaction of the tooth274on the trigger lock27with the teeth214to retain the trigger20in position when pressure is released. The oblong configuration of sockets624and724that receive bosses276′ and276of the trigger lock27allow the trigger lock27to move slightly forward during inward movement of the trigger20so that the tooth276on trigger lock27may ratchet along the ramped teeth214of trigger20. Interaction of the teeth214with the ramped tooth274on the trigger lock27prevents outward movement of the trigger20as long as the thumb slide25remains in the forward position in the slot formed by openings627and727.

Release of the trigger20is accomplished by proximal or rearward movement of thumb slide25, pivoting the ramped tooth274out of engagement with a tooth of the teeth214along slot212which allows the upper and lower jaws35and45to open unless the physician holds the trigger20in position. The trigger20is urged outwardly out of the recess in handle10by spring23upon release of the trigger20and rearward movement of the thumb slide25. When the trigger20reaches its full outward position, flow of conductive fluid through fluid conduits370and470is terminated as the tubing is compressed between the laterally extending boss210and the inwardly extending projections630and730, as discussed above.

The thumb slide25is provided with a resilient beam section250, having a generally centrally located notch252which engages the laterally extending rod278on trigger lock27, coupling the thumb slide25to the trigger lock27. The thumb slide25is 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 slide25due to the resilience of the beam250and the arcuate path of travel of the rod278.

FIG. 14illustrates a proximal portion of the assembled hemostat ofFIG. 1with the left handle half700removed to show the multi-conductor cable80and fluid conduit70extending through the strain relief60and their joinder to the wire conductors360,460and the fluid conduits370,470.

The distal end of the fluid conduit80is coupled through a fitting802to proximal end of flexible tubing804. The distal end of flexible tubing804is coupled to the trunk of a Y-connector806, and the distal legs of the Y connector806are coupled to arms of a D-connector810. The D connector810is formed of a flexible plastic, e.g., silicone rubber, providing spaced apart fluid channels that are coupled to the proximal ends of the fluid conduits370and470.

The fitting804supports a proximal flow controller or regulator820that has a precisely sized orifice that limits conductive fluid flow into the Y-connector806. The flow regulator820establishes a fixed flow rate and pressure within the Y-connector806regardless 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.

The D connector810supports a pair of downstream flow regulators822and824that have equal, precisely sized orifices that further reduce the fluid flow rate and pressure of the conductive fluid entering the fluid conduits370and470. The downstream flow regulators822and824ensure that an even flow of conductive fluid is provided from within the Y connector806into the fluid conduits370and470. 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 jaws35and45that contact the tissue to be ablated.

An optional light emitter, e.g., an LED830, is depicted inFIG. 14located within the strain relief60and coupled through an electrical junction832with the insulated wire conductors360and460. The wire conductors360and460can take the form of a twisted wire cable that extends distally from the electrical junction832through the length of the handle to the swivel assembly50where they are separated as shown inFIGS. 3A and 4. Separate wire conductors within a cable834extend from the electrical junction832to the LED830. In use, the LED830is illuminated in response to activation of an associated RF electrosurgical generator, and the LED illumination illuminates the strain relief60, which is preferably fabricated of a translucent flexible material, such as silicone rubber or the like. The physician will typically hold the handle10in orientations that make the strain relief60visible, and illumination of the LED830indicates to the physician that RF energy is being applied to the electrodes

The proximal portion of the handle10may 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.

FIGS. 15A and 15Billustrate an alternative embodiment of the electrode described above that can be employed in modified upper and lower jaw assemblies30A and40A corresponding generally to upper and lower jaw assemblies30and40. The upper and lower jaw assemblies30A,40A have a malleable backbone310,410and a sheath320,420as described above that are attached to the respective upper and lower jaw mounts300and400as shown inFIGS. 2 and 3. However, electrode330A,430A incorporates an exposed elongated electrode extension350A,450A extending to the outer surface of porous electrode support340A,440A and along the jaw35,45that 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 electrode330A,430A, which may be substantially the same as the tubular electrodes330,430. An elongated electrode surface352A,452A of the electrode extension350A,450A and the contacted tissue are irrigated by conductive fluid emitted through the fluid ports of the internal tubular electrode330A,430A and conducted through the pores of the electrode support340A,440A.

The electrode extension350A,450A is depicted prior to assembly with the electrode support340A,440A and the elongated tubular electrode330A,430A inFIGS. 16A and 16B. As formed, the electrode extension350A,450A includes an elongated straight portion352A,452A that is mounted against the exposed to the exterior of the electrode support340A,440A. A distally extending portion360A,460A is adapted to be inserted into the lumen of the electrode support340A,440A to extend alongside the elongated tubular electrode330A430A as shown inFIG. 15B.

A series of barbed projections354A,454A extend laterally away from the elongated straight portion352A,452A. The electrode extension350A,450A is adapted to be bent back at junction356A,456A to enable insertion of the series of barbed projections358A,458A into the electrode support340A,440A. The proximal end362A,462A is electrically connected to the proximal ends of the tubular electrodes330A,430A and the distal ends of the wire conductors360,460.

This alternative exposed electrode embodiment can be formed by modifying the tubular electrode330,430to have a conductive electrode band extending from the tubular electrode along the surface of the electrode support340,440. Alternatively, this alternative electrode design can be accomplished without use of the tubular electrode330,430, whereby conductive fluid is delivered to a lumen of the electrode support340,440or to a fluid channel between the electrode support340,440and the sheath320,420, and the exposed electrode band is supported by the electrode support340,440.

In reference toFIG. 17, one embodiment of the hemostat of the present invention generally comprises an elongated handle assembly or handle10having a jaw assembly90mounted at handle distal end15, a trigger20intermediate the handle proximal and distal ends95and15, and a strain relief60located at handle proximal end95. An elongated cable is coupled to the strain relief60and comprises a fluid conduit70extending to a proximal fluid fitting75adapted to be coupled to a source of conductive fluid and a multi-conductor electrical cable80extending to a proximal electrical connector85adapted to be coupled to an electrosurgical unit. The trigger20is employed to move the jaws of the first or lower jaw assembly40with respect to the second or upper jaw assembly30of the jaw assembly90together 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 jaws35and45.

The jaw assembly90includes an upper jaw assembly30, a lower jaw assembly40, and a swivel assembly50, discussed in more detail below. The upper jaw and lower jaw assemblies30and40have opposed upper and lower jaws35and45, respectively, each comprising a fluid assisted elongated electrode assembly. The upper and lower jaw assemblies30and40support elongated electrodes, discussed in more detail below, each coupled to one of the insulated conductors within conduit80extending proximately through the strain relief60to electrical connector85. Each of the jaws35and40of respective upper and lower jaw assemblies30and40also may be coupled to fluid conduit70enabling delivery of saline or other conductive fluid from a source coupled to fitting75along the lengths of the opposed jaws35and45.

The swivel assembly50, provides the physician with the opportunity to position the jaw assembly90in a variety of orientations relative to the handle10, to facilitate placing the35and45jaws 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 assembly50and the jaw assembly90to provide a roll adjustment R, preferably through an arc of at least 300 degrees, relative to the axis of the distal end15of the handle10through interaction of components of the handle and swivel assembly described further below. Moreover, the upper and lower jaws35and45may be rigid in a straight or curved configuration or the upper and lower jaws35and45may be malleable as described further below. The combination of these features make the hemostat highly versatile in use.

In one embodiment, the trigger20is employed to open (separate apart) and close (draw together) the jaws35and45and to compress tissue between the jaws35and45prior to application of RF energy to create an elongated lesion. A thumb slide25may be provided in conjunction with an internal trigger lock, allowing the position of the trigger20and the jaws35,45to be locked. After the trigger20is drawn toward the handle10to close the jaws35and45, the thumb slide25is moved distally relative to the handle10to cause an internal trigger lock to engage one of a series of ratcheting lock points that define a set of locking locations for the jaws35,45, as described further below. Movement of the thumb slide25proximally relative to the handle10releases the trigger20and the jaw assembly90, allowing the jaws35,45to return to a fully open position. The interaction of the trigger20, thumb slide25and the associated trigger lock mechanism frees the physician from the need to maintain pressure on the trigger20to compress tissue between the jaws35,45during the ablation, simplifying operation of the hemostat.

The handle10may include an elongated shaft portion11proximal the handle distal end15. One or more portions of elongated shaft11may be straight, curved, rigid and/or malleable. For example, as shown inFIG. 18, elongated shaft11may comprise a malleable corrugated tube member12, thereby providing the physician with the opportunity to manually position the jaw assembly90in a variety of orientations, relative to the distal portion of handle10, to facilitate placing the35and45jaws against tissue to form desired lines of lesions. For example, the physician may manually grasp and bend or shape malleable corrugated tube member12to adjust the orientation of jaw assembly90relative to the distal portion of handle10. Elongated shaft member11may comprise one or more lumens or a multi-lumen member, e.g., a multi-lumen plastic tube, may be placed within elongated shaft member11. One or more portions of elongated member11may comprise one or more cross sectional shapes, e.g., round, oval, triangular, rectangular or square. The cross sectional area of elongated member11may very along its length. For example, elongated member may comprise ridges and grooves. Elongated member11may comprise one or more materials, e.g. plastic materials, metal materials, rigid materials, malleable materials, etc. For example, one or more portions of elongated member11may comprise malleable stainless steel. One or more portions of elongated member11may be covered, for example with a sheath material such as a plastic material.

As shown inFIG. 19, trigger20is mounted to handle10to pivot inward to apply tension on cable390or outward to release tension on cable390. Upward openings in respective right and left handle halves receive the thumb slide25. The trigger20, thumb slide25, and the associated link arm26and trigger lock27of one embodiment of the invention are shown assembled to the right handle half600inFIG. 19with the trigger20in the released position and the thumb slide25in the unlocked distal or retracted position. The trigger20, thumb slide25, and trigger lock27are shown in greater detail inFIG. 20, a portion of link arm26is shown in greater detail inFIG. 21.

Trigger20is provided with laterally extending cylindrical pivot bosses that are mounted into sockets, respectively. When released, trigger20extends outward through downwardly opening recesses. When pulled, trigger20is pivoted inwardly into the handle recesses about the pivot bosses to apply tension to the cable390that draws the upper and lower jaws35and45together. Cable390is mounted to move freely within the handle10when trigger20is pulled or released.

Trigger20is coupled to the proximal end of cable390through link arm26, illustrated inFIGS. 19 and 21. Link arm26is provided at a distal end with two laterally extending bosses262and262′ that are received in circular sockets204formed on the interior walls of the internal chamber of trigger20to thereby pivotally mount the distal end of the link arm26to the trigger20. When trigger20is pulled inward, the proximal end of the link arm26is moved proximally thereby applying tension to cable390.

Cable390is coupled to the link arm26by means of a swaged retainer24, mounted within a coil spring28. Coil spring28is fitted within a generally cylindrical chamber or spring cage266pivotally coupled at31to the proximal end of link arm26. Cable390passes through the interior of spring28to retainer24. Spring28is normally extended within chamber266but is compressed to provide protection against over tensioning of the cable390, if the upper and lower jaws35and45encounter significant resistance to further movement toward one another.

Trigger20is also provided with a distally extending projection208terminating with a laterally extending, generally cylindrical, boss210as shown inFIG. 20. As illustrated inFIG. 20, when the trigger20is released and in its most downward position (corresponding to the point of maximum jaw opening), the fluid conduits are compressed between cylindrical boss210and the inwardly extending projections630. 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.

The trigger20is also formed with a laterally extending slot212which may have an array of teeth formed along one side of the slot212. A trigger lock mechanism may be provided involving the interaction of the thumb slide25with the trigger20through a trigger lock27that is coupled at one end with the thumb slide25and may selectively engage the teeth214to retain the upper and lower jaws35and45at a fixed position adjacent tissue to be ablated without requiring the physician to continually apply pressure to trigger20. Distal or forward movement of the thumb slide25causes the trigger lock27to engage the teeth214, and proximal or rearward movement of the thumb slide25releases the engagement. The trigger20can be operated freely by the physician to open or close the upper and lower jaws35and45when the thumb slide25is in the rearward position. With the thumb slide25in the forward position, the trigger20can be moved inward ratcheting over the teeth214to close the upper and lower jaws35and45, but the trigger20will not move outward upon release by the physician. Release of the trigger20is accomplished by proximal or rearward movement of thumb slide25.

FIG. 21illustrates a proximal portion of the assembled hemostat ofFIG. 17with the left handle half removed to show the multi-conductor cable80and fluid conduit70extending through the strain relief60. The distal end of the fluid conduit80is coupled through a fitting802to proximal end of flexible tubing804. The distal end of flexible tubing804is coupled to the trunk of a Y-connector806, and the distal legs of the Y connector806are coupled to arms of a D-connector810. The D connector810is formed of a flexible plastic, e.g., silicone rubber, providing spaced apart fluid channels that are coupled to the proximal ends of the fluid conduits370and470.

The fitting804supports a proximal flow controller or regulator820that has a precisely sized orifice that limits conductive fluid flow into the Y-connector806. The flow regulator820establishes a fixed flow rate and pressure within the Y-connector806regardless 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.

The D connector810supports a pair of downstream flow regulators822and824that have equal, precisely sized orifices that further reduce the fluid flow rate and pressure of the conductive fluid entering the fluid conduits370and470. The downstream flow regulators822and824ensure that an even flow of conductive fluid is provided from within the Y connector806into the fluid conduits370and470. 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 jaws35and45that contact the tissue to be ablated.

In reference toFIG. 22, elongated shaft portion11may comprise an articulating portion in one embodiment of the invention. As shown inFIG. 23, articulating shaft11may comprise a plurality of “ball and socket” links, for example.FIG. 23is a partial view of a section of links392and cable393. Each link may have a hole397that 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. 23shows the engagement of the cable393with the side wall of the links as the arm is bent. Cable393passes through hole of all the links and is connected between the distal end of handle10and the tightening mechanism394. Tightening mechanism394may comprise a thumb slide thereby allowing a physician to tighten and loosen cable393by moving a mechanism proximally and distally, for example. Alternatively, tightening mechanism394may comprise a screw or handle mechanism that allows cable393to be tighten and loosened via a rotation motion. Alternatively, other types of tightening mechanisms may be used to tighten and loosen cable393thereby locking and unlocking the articulating section of handle10. Tightening of the cable393causes 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 hole397. As seen hole397is 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 member11. 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.

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.

Referring toFIG. 24, the upper jaw assembly30, in one embodiment of the invention, includes a pivotable, relatively rigid, upper jaw mount300, an elongated backbone310, an elongated insulated electrode sheath320, an elongated conductive electrode330, and an elongated electrode support340. Upper jaw mount300may be fabricated of plastic or other insulated material, and in preferred embodiments may be fabricated of Teflon filled polycarbonate plastic. Backbone310is preferably fabricated of malleable stainless steel or other malleable metal and is attached at a proximal end to upper jaw mount300. An insulated electrode sheath320is fitted over spine310with its proximal end located adjacent upper jaw mount300. The elongated conductive electrode330comprises a length of malleable conductive metal tubing fitted into a lumen of the elongated electrode support340. The insulated electrode sheath320is formed with a channel that receives the sub-assembly of the elongated conductive electrode330and electrode support340disposed along the jaw35. Electrode sheath320may be fabricated of a flexible, electrically insulating, material, for example, silicone rubber or PVC. Elongated electrode support340is 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 jaw35. The jaw35can therefore be bent laterally with respect to the upper jaw mount300to form a curve along the length thereof.

The lower jaw assembly40also includes a relatively rigid, lower jaw mount400, an elongated backbone410, an elongated insulated electrode sheath420, an elongated conductive electrode430, and an elongated electrode support440that are all formed of the same materials as the corresponding elements of the upper jaw assembly30.

The jaw45can therefore also be bent laterally with respect to the lower jaw mount400to form a curve along the length thereof. In use, the physician may manually form a lateral curve in both the upper and lower jaws35and45to fit the contour of the tissue, e.g., the heart wall, to be ablated.

The lower jaw mount400is formed with an opening381for receiving the proximal end of upper jaw mount300. When assembled, a proximal portion of the upper jaw mount300is fitted within the opening381. A pin480extends through aligned holes through the proximal portion of upper jaw mount300and the lower jaw mount400. The ends of pin480are fixed to the lower jaw400thereby allowing the proximal portion of the upper jaw mount300to be rotated about the pin480, thereby allowing jaws35and45to open and close. A spring450urges the upper and lower jaws35and45apart from one another, facilitating opening of the jaws35and45upon release of the trigger20after application of RF energy.

As shown inFIGS. 24 and 25, the swivel assembly50includes a swivel500that may be fabricated of Teflon filled polycarbonate plastic to have a tubular structure. The jaw assembly90is mounted to the swivel assembly50by fitting the distal end of swivel500into collar382of lower jaw mount400. The upper jaw mount300is mounted to the lower jaw mount400by pin480as described above, and the lower jaw mount is400rotatably mounted relative to the swivel500. Therefore, the upper and lower jaw assemblies30and40may be rotated together relative to the swivel500, allowing for movement of the jaws35and45together to be rotated around the axis of the distal end15of the handle10to a desired roll adjustment R to facilitate positioning the jaws35and45for creation of elongated lesions. The distal portion507of swivel500is rotatably mounted within collar382of lower jaw mount400.

A washer-shaped member510having a wavy or sinusoidal proximally facing surface511is fitted over the elongated distal portion507of swivel500and attached to the lower jaw mount400. C-clips524mounted in a circumferential grooves formed in the distal portion507of swivel500maintain the distal portion507within the lumen of collar382. Washer-shaped member510is prevented from rotating relative to lower jaw mount400through notch613, engaging corresponding boss614formed on lower jaw mount400as shown inFIG. 29. A washer-shaped member517having a wavy or sinusoidal distally facing surface518is fitted over the elongated distal portion507of swivel500and attached to the distal end15of handle10. Washer-shaped member517is prevented from rotating relative to swivel500through a notch engaging a corresponding boss of member517and swivel500. A spring washer522is interposed between the proximal end of collar382and the washer-shaped member510. Spring washer522urges the wavy or sinusoidal surfaces of washer-shaped members510and517against one another, whereby a plurality of detent locations are defined that maintain a selected roll R adjustment relative to the distal end15of the handle10. In use, the physician may adjust the roll R of the jaw assembly90by simply turning the swivel assembly50relative to the handle10. The detent mechanism maintains the swivel assembly50in the selected desired roll R adjustment prior to and during closure of the jaws35and45to compress tissue during application of RF energy.

As shown inFIG. 26, in one embodiment of the invention, elongated malleable member12may be coupled to swivel member500. Plastic tube591may reside within the lumen of elongated member12. Plastic tube591may be made of a Pebax™ plastic material. As shown inFIG. 27, plastic tube591may comprise multiple lumens. In one embodiment of the invention, cable390passes through the center lumen592of tube591. Insulated conductors360and460pass through lumen593whereas fluid conduits370and470pass through lumens594and595, respectively. Tube591may be made of material that allows cable390to move or slide easily back and forth within lumen593. A lubricant may be used to reduce friction between lumen593and cable390.

The distal end of cable390is shown inFIGS. 28 and 29. Cable390extends from the trigger20and is employed to open and close the jaws35and45. Cable390passes through the internal lumen of distal swivel portion507, around pulley509comprising a roller and a pin in lower jaw mount400, then upward through channel513(shown inFIG. 25) of upper jaw mount300, and then back downward through bore516(shown inFIG. 25) in lower jaw400. The distal end of the cable390is maintained within bore516by ball350. When the cable390is tensioned by squeezing trigger25, cable390is pulled through channel513and around pulley509, thereby pulling upper jaw35toward lower jaw45, allowing for compression of tissue therebetween. It should be noted that during this operation, the lower jaw mount400remains fixed relative to the swivel assembly50and only upper jaw mount300moves relative to the swivel assembly50or the handle10. Proximal movement of cable390does not affect the position of the lower jaw45relative to the handle10, nor does it affect the selected roll R adjustment of swivel500. Rotation of the jaw assembly90and swivel500about the roll axis does not affect the operation of the cable390because the cable390passes through the swivel500and enters the jaw assembly90along the roll axis.

FIGS. 28 and 29also show internal electrical wiring and fluid delivery conduits of this embodiment of the invention including, insulated conductors360and460and fluid conduits370and470that both terminate at connections with the proximal ends of the upper and lower electrodes330and430, respectively. The fluid conduits370and470deliver conductive fluid into the lumens of the tubular upper and lower electrodes330and430, respectively.

In one embodiment of the invention, the porous electrode supports340and440, depicted inFIGS. 24 and 25, comprise a length of non-conductive, porous, malleable material adapted to fit within elongated channels323and423of the insulated electrode sheaths320and420and upper and lower jaw mounts300and400. In one embodiment of the invention, porous electrode supports340and440have a relatively square cross sectional area. During assembly, the elongated tubular electrodes330and430are inserted into elongated lumens of the porous electrode supports340and440. 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 jaws35and45are 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 supports340and440and around its circumference to thoroughly and uniformly wet the porous electrode supports340and440along the upper and lower jaws35and45.

The sub-assemblies so formed are fitted into the elongated channels323and423of the insulated electrode sheaths320and420and the upper and lower jaw mounts300and400as shown inFIG. 25. Adhesive may be used to affix the sub-assembly of the elongated tubular electrodes330and430inserted into the porous electrode supports340and440to the insulated electrode sheaths320and420. The adhesive does not block migration of conductive fluid around the porous electrode supports340and440. Electrode sheaths320and420are formed having an elongated tapered internal recess that receives the malleable backbones310and410, respectively, as shown inFIGS. 24 and 25.

Referring toFIGS. 30 and 31, in one embodiment of the invention, upper and lower jaws35and45have a predetermined corresponding curved shape and are relatively rigid so as not to be malleable. Upper jaw35includes a relatively rigid, upper jaw mount300, an elongated relatively rigid backbone310, an elongated insulated electrode sheath320, an elongated conductive electrode330, and an elongated electrode support340. Upper jaw mount300may be fabricated of plastic or other insulated material, and in preferred embodiments may be fabricated of Teflon filled polycarbonate plastic. Backbone310is made of rigid stainless steel or other rigid metal and is attached at a proximal end to upper jaw mount300. An insulated electrode sheath320is fitted over spine310with its proximal end located adjacent upper jaw mount300. The elongated conductive electrode330comprises a length of conductive metal tubing fitted into a lumen of the elongated electrode support340. The insulated electrode sheath320is formed with a channel that receives the sub-assembly of the elongated conductive electrode330and electrode support340disposed along the jaw35. Electrode sheath320may be fabricated of a flexible, electrically insulating, material, for example, silicone rubber or PVC. Elongated electrode support340is 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 jaw35.

The lower jaw assembly40also includes a relatively rigid, lower jaw mount400, an elongated relatively rigid backbone410, an elongated insulated electrode sheath420, an elongated conductive electrode430, and an elongated electrode support440that are all formed of the same materials as the corresponding elements of the upper jaw assembly30.

Referring toFIGS. 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 assemblies30and40are configured so that upper jaw35moves in a parallel fashion relative to lower jaw45. Upper jaw35includes upper jaw mount300having a portion contained within a lumen of lower jaw mount400. The portion of upper jaw mount300contained within a lumen of lower jaw mount400is free to travel within lower jaw mount400. The distal end of cable390is attached to upper jaw mount300. A spring washer613is interposed between the distal end of collar382and the proximal end of upper jaw mount300. Spring washer613urges the upper and lower jaws35and45, respectively, into a closed configuration, i.e., spring washer613urges the upper jaw35towards the lower jaw45.

Cable390extends from the trigger20and is employed to open and close the jaws35and45. In one embodiment of the invention, when the cable390is tensioned by squeezing trigger25, cable390is pulled in a proximal direction thereby pulling upper jaw35in a parallel direction away from lower jaw45. Therefore, tensioning cable390opens jaws35and45while releasing the tension in cable390closes the jaws35and45. It should be noted that during this operation, the lower jaw mount400remains fixed relative to the swivel assembly50and only upper jaw mount300moves relative to the swivel assembly50or the handle10. Proximal movement of cable390does not affect the position of the lower jaw45relative to the handle10, nor does it affect the selected roll R adjustment of swivel500. Rotation of the jaw assembly90and swivel500about the roll axis does not affect the operation of the cable390because the cable390passes through the swivel500and enters the jaw assembly90along the roll axis. Alternatively, the trigger mechanism may be designed so that the squeezing of trigger25opens the jaws35and45. Alternatively, as shown inFIG. 34, cable390may run through a lumen or channel in upper jaw mount300, around a pulley509mounted within a recess in lower jaw mount400and back to upper jaw mount300where cable390is fixed. In the embodiment shown inFIG. 34, tensioning of cable390will close jaws35and45.

Referring toFIGS. 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 assemblies30and40are configured so that lower jaw45moves in a parallel fashion relative to upper jaw35. Upper jaw35includes upper jaw mount300having a portion comprising a lumen for receiving a proximal portion of lower jaw mount400. The portion of lower jaw mount400contained within a lumen of upper jaw mount300is free to travel within upper jaw mount300. Upper jaw mount300includes collar382. The distal end of cable390is attached to lower jaw mount400. A spring washer613is interposed between the distal end of collar382and the proximal end of lower jaw mount400. Spring washer613urges the upper and lower jaws35and45, respectively, into an open configuration, i.e., spring washer613urges the lower jaw45away from the upper jaw35.

Cable390extends from the trigger20and is employed to open and close the jaws35and45. In one embodiment of the invention, when the cable390is tensioned by squeezing trigger25, cable390is pulled in a proximal direction thereby pulling lower jaw45in a parallel direction towards upper jaw35. Therefore, tensioning cable390closes jaws35and45while releasing the tension in cable390opens the jaws35and45. It should be noted that during this operation, the upper jaw mount300remains fixed relative to the swivel assembly50and only lower jaw mount400moves relative to the swivel assembly50or the handle10. Proximal movement of cable390does not affect the position of the upper jaw35relative to the handle10, nor does it affect the selected roll R adjustment of swivel500. Rotation of the jaw assembly90and swivel500about the roll axis does not affect the operation of the cable390because the cable390passes through the swivel500and enters the jaw assembly90along the roll axis.

Referring toFIG. 37, an alternative configuration of upper and lower jaw assemblies may be used according to one embodiment of the invention. Upper and lower jaw assemblies30and40are configured so that lower jaw45moves in a parallel fashion relative to upper jaw mount300. Upper jaw35includes upper jaw mount300having a portion comprising a lumen for receiving a proximal portion of lower jaw mount400. The portion of lower jaw mount400contained within a lumen of upper jaw mount300is free to travel within upper jaw mount300. Upper jaw mount300includes collar382. The distal end of cable390is attached to lower jaw mount400. A spring washer613is interposed between the distal end of collar382and the proximal end of lower jaw mount400. Spring washer613urges the upper and lower jaws35and45, respectively, into an open configuration, i.e., spring washer613urges the lower jaw45away from the upper jaw35. A pin680extends through aligned holes through the distal portion of upper jaw mount300and upper jaw35. The ends of pin680are fixed to the upper jaw mount300thereby allowing upper jaw35to rotate about pin680. The distal end of jaw35fits within a groove or recess682within lower jaw mount400. Having upper jaw35rotatably attached to upper jaw mount300allows jaws35and45to be opened wider, thereby making it easier to place tissue in between the upper and lower jaws35and45. Further, as tissue is compressed between jaws35and45, jaw35is capable of rotating into parallel alignment with jaw45, thereby more evenly compressing tissue between jaws35and45. Recess682may be configured so that jaw35is rotated into a fully open position as spring washer613urges lower jaw45away from the upper jaw35.

Cable390extends from the trigger20and is employed to open and close the jaws35and45. In one embodiment of the invention, when the cable390is tensioned by squeezing trigger25, cable390is pulled in a proximal direction thereby pulling lower jaw45in a direction towards upper jaw35. Therefore, tensioning cable390closes jaws35and45while releasing the tension in cable390opens the jaws35and45. It should be noted that during this operation, the upper jaw mount300remains fixed relative to the swivel assembly50and only lower jaw mount400moves relative to the swivel assembly50or the handle10. Proximal movement of cable390does not affect the position of the upper jaw35relative to the handle10, nor does it affect the selected roll R adjustment of swivel500. Rotation of the jaw assembly90and swivel500about the roll axis does not affect the operation of the cable390because the cable390passes through the swivel500and enters the jaw assembly90along the roll axis.

As shown inFIG. 33, in one embodiment of the invention, jaw assembly90may be designed so that lower jaw45is fixedly oriented about 90 degrees relative to swivel assembly50. Alternatively, as shown inFIG. 25, jaw assembly90may be designed so that lower jaw45is fixedly oriented in a range between about 90 degrees and about 180 degrees relative to swivel assembly50.

As shown inFIG. 36, in one embodiment of the invention, jaw assembly90may be designed so that upper jaw35is fixedly oriented about 90 degrees relative to swivel assembly50. Alternatively, as shown inFIG. 37, jaw assembly90may be designed so that upper jaw35is fixedly oriented in a range between about 90 degrees and about 180 degrees relative to swivel assembly50.

To help prevent rotation of jaw mounts300and400relative to each other in jaw assemblies shown inFIGS. 33,36and37, jaw mounts300and400may include interlocking features. For example, jaw mount400may comprise a slot or groove wherein fits a boss or pin, for example, of jaw mount300, thereby preventing rotation of jaw mounts300and400relative to each other yet still allowing a sliding or translational movement to occur.

Referring toFIG. 38, an alternative configuration of upper and lower jaw assemblies may be used according to one embodiment of the invention. Upper jaw mount300comprises a pair of parallel plates or flanges691and692. A pin680extends through aligned holes through flanges691and692and upper jaw35. The ends of pin680are fixed to flanges691and692thereby allowing upper jaw35to rotate about pin680. The distal end of jaw35includes a pin or boss687that fits within a slot688within flanges691and692. Pin687and slot688limit the amount of movement jaw35has relative to jaw mount300. The lower jaw mount400is formed with an opening381for receiving the proximal end of upper jaw mount300. When assembled, a proximal portion of the upper jaw mount300is fitted within the opening381. A pin480extends through aligned holes through the proximal portion of upper jaw mount300and the lower jaw mount400. The ends of pin480are fixed to the lower jaw400thereby allowing the proximal portion of the upper jaw mount300to be rotated about the pin480, thereby allowing jaws35and45to open and close. Having upper jaw35rotatably attached to upper jaw mount300allows jaw35to be capable of assuming a parallel alignment relative to jaw45even as upper jaw mount300is rotated about pin480as jaws35and45are opened and closed. For example, as tissue is compressed between jaws35and45, jaw35is capable of rotating into parallel alignment with jaw45, thereby more evenly compressing tissue between jaws35and45. The pivoting upper jaw35may be spring loaded using a spring or other elastic material, for example, to bias the jaw35into an open configuration.

In one embodiment of the invention, jaw assembly90may be designed so that either the upper jaw35or the lower jaw45is fixedly oriented about 180 degrees relative to swivel assembly50. For example, lower jaw mount400and lower jaw45are shown inFIG. 39to be fixed about 180 degrees relative to swivel assembly50. Having jaws35and45in alignment with shaft11of handle10, as shown inFIG. 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.

Alternative embodiment of jaw assembly90is shown inFIG. 40, wherein jaw assembly90includes an upper jaw assembly30, a lower jaw assembly40, and a swivel assembly50. The upper jaw and lower jaw assemblies30and40have opposed upper and lower jaws35and45. The swivel assembly50provides the physician with the opportunity to position the jaw assembly90in a variety of orientations relative to the handle10. In one embodiment, the physician may manually grasp and rotate the swivel assembly50and the jaw assembly90to provide a roll adjustment R, preferably through an arc of at least 300 degrees, relative to the axis of the distal end15of the handle10through interaction of components of the handle and swivel assembly described further above. In one embodiment, the physician may manually grasp the jaw assembly90and adjust it in pitch P relative to the swivel assembly50through the interaction of components of the jaw assembly90and the swivel assembly50. In one embodiment, the available arc of pitch P adjustment extends over at least 90 degrees. As shown inFIG. 40, upper jaw mount300may comprise a pair of parallel plates or flanges691and692. A pin680extends through aligned holes through flanges691and692and upper jaw35. The ends of pin680are fixed to flanges691and692thereby allowing upper jaw35to rotate about pin680. The distal end of jaw35includes a pin or boss687that fits within a slot688within flanges691and692. Pin687and slot688limit the amount of movement jaw35has relative to jaw mount300. Having upper jaw35rotatably attached to upper jaw mount300allows jaw35to be capable of assuming a parallel alignment relative to jaw45even as upper jaw mount300is rotated about pin480as jaws35and45are opened and closed. For example, as tissue is compressed between jaws35and45, jaw35is capable of rotating into parallel alignment with jaw45, thereby more evenly compressing tissue between jaws35and45.

As shown inFIG. 40, the swivel assembly50includes a swivel500that has a pair of parallel plates or flanges502and504extending distally from swivel proximal portion506and a extending detent501extending laterally between flanges502and504. The lower jaw mount400is mounted to the swivel assembly50by fitting the proximal end of lower jaw mount400in swivel flanges502and504. The lower jaw mount400is pivotably mounted to the swivel500by pin780. Therefore, the upper and lower jaw assemblies30and40may be pivoted together relative to the swivel500, allowing for movement of the jaws35and45together through the range of pitch P adjustment. The selected pitch P adjustment is maintained by the engagement of the detent501into an opposed pair of notches402located at the proximal end of lower jaw mount400, stabilizing the upper and lower jaws35and45in a desired orientation relative to the swivel assembly50, as described above. In use, the physician adjusts the relative positions of the jaws35and45relative to the swivel assembly50by simply manually moving the jaw assemblies30and40in the pitch P direction around the pivot axis pin780. The detent501simply rides over the ridges separating adjacent notches402.

As shown inFIG. 40, upper jaw mount300may comprise a pair of parallel plates or flanges691and692. A pin680extends through aligned holes through flanges691and692and upper jaw35. The ends of pin680are fixed to flanges691and692thereby allowing upper jaw35to rotate about pin680. The distal end of jaw35includes a pin or boss687that fits within a slot688within flanges691and692. Pin687and slot688limit the amount of movement jaw35has relative to jaw mount300. The lower jaw mount400is formed with an opening for receiving the proximal end of upper jaw mount300. When assembled, a proximal portion of the upper jaw mount300is fitted within the opening. A pin480extends through aligned holes through the proximal portion of upper jaw mount300and the lower jaw mount400. The ends of pin480are fixed to the lower jaw400thereby allowing the proximal portion of the upper jaw mount300to be rotated about the pin480, thereby allowing jaws35and45to open and close. Having upper jaw35rotatably attached to upper jaw mount300allows jaw35to be capable of assuming a parallel alignment relative to jaw45even as upper jaw mount300is rotated about pin480as jaws35and45are opened and closed. For example, as tissue is compressed between jaws35and45, jaw35is capable of rotating into parallel alignment with jaw45, thereby more evenly compressing tissue between jaws35and45.

As shown inFIG. 41, one embodiment of the jaw assembly90, as described above and shown inFIGS. 1 and 2, may include an upper jaw mount300comprising a pair of parallel plates or flanges as described above. A pin680extends through aligned holes through the pair of flanges of upper jaw mount300and upper jaw35. The ends of pin680are fixed to the flanges thereby allowing upper jaw35to rotate about pin680. The distal end of jaw35includes a pin or boss687that fits within a slot688within the flanges. Pin687and slot688limit the amount of movement jaw35has relative to jaw mount300. Having upper jaw35rotatably attached to upper jaw mount300allows jaw35to be capable of assuming a parallel alignment relative to jaw45even as upper jaw mount300is pivoted relative to lower jaw mount400as jaws35and45are opened and closed. For example, as tissue is compressed between jaws35and45, jaw35is capable of rotating into parallel alignment with jaw45, thereby more evenly compressing tissue between jaws35and45.

As shown inFIGS. 42 and 43, one embodiment of the jaw assembly90suitably 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. 42is a bottom view of an alternative embodiment of jaw assembly90with jaws35and45a closed position, whereasFIG. 43is a bottom view of jaw assembly90with jaws35and45an open position. As seen inFIGS. 42 and 43, in this embodiment of the invention, jaws35and45are 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. Cable390may extend between jaw assembly90and handle10through shaft11. The proximal end of cable390is connected to actuator lever or trigger20on handle10. The distal end of cable390is connected to jaw assembly90. Trigger20may be used to remotely and controllably actuate the jaw assembly90as described below.

As shown inFIGS. 42 and 43, cable390passes through collar382of anchor840. The jaw assembly90may be mounted to the swivel assembly50(as described above) by fitting the distal end of swivel500into collar382of anchor840. The distal end of cable390is coupled to slide850which is slidably coupled to anchor840. Referring toFIGS. 44 and 45, plan views of upper and lower jaw mounts300and400are shown with a portion of jaw35coupled to jaw mount300and a portion of jaw45coupled to jaw mount400. In this embodiment, jaw mounts300and400include first, second and third slots871,872,873with the second slot872being oriented substantially perpendicular to the jaws35and45. The second slot872of jaw mounts300and400are aligned so that a pin passing through the second slots872helps maintain jaws35and45parallel to one another throughout movement between a closed and an open position. The first and third slots871,873of each of jaw mounts300and400are parallel to one another and oriented 45 degrees relative to the jaws35and45. Referring toFIG. 42, first, second and third pins875,876,877pass through the first, second and third slots871,872,873.

Referring toFIGS. 46 and 47, side and plan views of slide850are shown. Slide850includes throughhole880for receiving cable390. The distal end of cable390preferably has an anchor (not shown) which prevents withdrawal of cable390through throughhole880. Slide850includes first and second holes881,882extending through first and second sides883,884. The first and third pins875,877extend through first and second holes881,882of slide850and first and third slots871,873of jaw mounts300and400for moving spreader members860,870when slide850is moved. Slide850also includes grooves890extending between the first and second holes881,882.

Referring toFIGS. 48 and 49, side and plan views of anchor840are shown. Anchor840includes central guides900which are positioned in grooves890of slide850. Central guides900and grooves890cooperate to help maintain the linearly slidable relationship between slide850and anchor840. Central guides900also include holes901therethrough for receiving the second pin876which extends through second slots872in spreader members860,870. Anchor840includes throughhole902for receiving cable390and the distal end of swivel500. Proximal end910of anchor840includes four arms815, three of which are shown inFIGS. 48 and 49, which extend between central guides900and proximal end910.

Referring toFIGS. 50 and 51, in an alternative embodiment of the invention, anchor840may be connected to coupling member983of linkage950. Linkage950comprises longitudinal cable or rod990slidably disposed within shaft11of handle10and a link980having a first and second ends981,982. The proximal end of rod990, as shown inFIG. 52, is coupled to handle10. Coupling member983of linkage950has a bifurcated proximal end with first and second coupling points984and985. First end981of link980is coupled to the distal end of rod990and second end982of link980is coupled to coupling member983at coupling point985. Shaft11has an angled opening1000(as seen inFIGS. 50 and 51) at its distal end to allow jaw assembly90to pivot into an orientation transverse to shaft11. Second coupling point984of coupling member983is pinned to distal end of shaft11to form a pivot point910. Jaw assembly90which is connected to coupling member983will therefore pivot about a transverse axis through pivot point910. Fluid and/or electrical power may be routed through conduit960to jaws35and45.

Referring toFIG. 52, in one embodiment of the invention, a thumb slide925, for example, a slidable button within a longitudinal slot, may be used to move cable or rod990in proximal and distal directions, thereby remotely and controllably actuate jaw assembly90to pivot or rotate about pivot point910. An actuator knob may be used instead of a thumb slide925, for example, to remotely and controllably actuate linkage950. The knob may be fixed to rod990. The proximal end of rod990would be threaded at so that rod990mates with a threaded inner bore within handle10. Rotation of an actuator knob would move knob and rod990in an axial direction with respect to shaft11. Movement of rod990in an axial direction with respect to shaft11would controllably pivot jaw assembly90about pivot point910, thereby allowing a surgeon to remotely control the orientation of jaws35and45relative to shaft11of handle10. Note that handle10may alternatively include another type of actuator mechanism to remotely control linkage850, for example, a plunger mechanism, a pair of scissor-type handles or a lever mechanism.

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. Shaft11may 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 handle10through shaft11. 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 handle10. 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.

Referring toFIGS. 53,54and55, in an alternative embodiment of the invention, the ablation device may comprise a pair of joints, one located at the distal end of shaft11and the other located at the proximal end of shaft11. The joint1014located at the distal end of shaft11is coupled to jaw assembly90while the joint1012coupled at the proximal end is coupled to handle10. The distal end of cable or rod990is coupled to joint1014while the proximal end of cable or rod990is coupled to joint1012. Rod990is coupled to both joints so that movement of one joint creates movement in the other joint. As shown inFIG. 53, jaw assembly90will pivot about a transverse axis through pivot point910while handle10will pivot about a transverse axis through pivot point1010. In this embodiment, movement of jaw assembly90is remotely controlled or actuated via movement of handle10. In one embodiment as shown inFIGS. 53,54and55, pivoting of handle10in one direction will pivot jaw assembly90in the opposite direction. In an alternative embodiment, the two joints may be coupled together so that pivoting of handle10in one direction will pivot jaw assembly90in the same direction.

In one embodiment of the invention, shaft10may comprise a flexible neck portion1150as shown inFIGS. 56,57and58. 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 assembly90to be orientated in the proper position to ablate cardiac tissue such as tissue around the pulmonary veins. A cable1152that is connected to the thumb slide925actuates the flexible neck. The cable1152runs through the neck off center, as shown inFIG. 58, and is attached at the distal end. Pulling back on the thumb slide925angles up the jaws, as shown inFIG. 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 handle10may 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.

Handle10may alternatively include another type of actuator mechanism20to remotely control the opening and closing of jaws35and45, 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 assembly90may 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 assembly90may 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 jaws35and45. Of course, further designs to control the opening and closing of jaws35and45may also be used, such as other mechanical or hydraulic activated or controlled systems.

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'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.

In an alternative embodiment, jaw assembly90may be designed so that the electrode assemblies of jaws35and45are 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 mounts300and400.

Shaft11may 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. Shaft11may be used to direct or steer the jaw assembly90. Shaft11may be of sufficient rigidity to support the weight of jaw assembly90while being malleable enough to be shaped for manipulating around a patient's anatomy. Shaft11may be comprised of one or metals, such as stainless steel, or other materials such as polymers or composites.

In one embodiment of the invention, a means for controlling the ablation energy, e.g., a switch, may be incorporated into handle10. 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 connector85may be a small fuse and/or EEPROM that can be used to prevent re-use.

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 handle10. 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.

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'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.

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.

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's bodily tissues or fluids. For example, naturally detectable properties of patient'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.

One or more sensors may be incorporated into the ablation device of the present invention, for example, in or one the handle10or the jaw assembly90. 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.

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.

In one embodiment of the invention, the tissue contacting surfaces of jaws35and45may be slightly curved such that the surface will conform generally to the curvature of the heart. The heart contacting surfaces of jaws35and45may 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, jaws35and45may comprise one or more ablating elements used to ablate tissue via RF ablation, cryo ablation, microwave ablation and/or ultrasound ablation.

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.

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's field of view, during normal operation of the hemostat.