Patent Description:
Generally forceps may be utilized for laparoscopic surgery. The forceps may be employed to control delicate movements inside a patient and may include a gripping assembly or a cutting assembly. Further, the forceps may utilize electrical energy in the gripping assembly. Typically, the forceps have a pair of opposed resilient jaws that are closed against each other by pulling the jaws into a distal end of a shaft that captures a portion of the jaws that is wider than the distal end opening of the shaft so that the jaws are moved together. Similarly the shaft may be pushed over the jaws so that the jaws are moved together to create a gripping force. In both of these arrangements, the shaft captures the jaws and acts as a cam that forces the jaws together to create the gripping force.

Current bipolar electrosurgical sealing forceps employ a pair of jaws with RF energy to coagulate a vessel and further employ a moveable cutting blade to cut the sealed vessel after coagulation. Such devices, however, require a high jaw force to compress the vessel tissue for desired sealing results. The high jaw force can cause unwanted tissue damage, since, for example, the jaw force requirements for large vessels and small vessels are different.

Document <CIT> discloses a device according to the preamble of claim <NUM>. <CIT> and <CIT> disclose further prior art electrosurgical forceps.

Accordingly, there is a need in the art for electrosurgical forceps that can seal both large and small vessels.

The need is satisfied by the subject matter of claim <NUM>. The invention is as defined by independent claim <NUM>. Optional features of the invention are defined in the dependent claims. Any methods of surgery in the disclosure are not claimed, but provide a better understanding of the invention.

The present disclosure provides an end effector assembly with a two-stage configuration that optimally seals both small and large vessels.

Accordingly, pursuant to one aspect of the is disclosure, an end effector assembly of a forceps includes a first jaw with a tissue sealing surface and an electrode on the sealing surface, and a second jaw with a tissue sealing surface and an electrode on the sealing surface. The first jaw and the second jaw move between an open position and a closed position. The sealing surface of at least one of the first jaw and the second jaw has a rigid medial section and flexible lateral sections.

The foregoing aspect of the disclosure can be further characterized by one or any combination of the features described herein, such as: the sealing surfaces of both the first jaw and the second jaw have a rigid medial section and flexible lateral sections; each lateral section has a cavity such that the lateral sections are cantilevered; the cavities are filled with a polymer; the medial section and the lateral sections are coplanar; each of the first jaw and the second jaw includes a jaw body and a sealing plate, the exterior surface of the sealing plate being the sealing surface of each of the first jaw and the second jaw; the jaw body of at least one of the first jaw and the second jaw includes a support member; a layer of pliable material is disposed between the support member and the sealing plate, the layer of pliable material being made of separate cells placed side by side with different stiffnesses, the center cells being more rigid than the lateral cells; the sealing plate of at least one of the first jaw and the second jaw has a central section connected to a central section of the respective jaw body, the lateral sections being cantilevered from the respective central section of the sealing plate; the lateral sections are chamfered and a wedge of compliant and electrically conductive material is disposed on the chamfer, the medial section and the lateral sections being coplanar; the medial section is a first plate and the lateral sections are a second plate that is coplanar with the first plate; non-conductive stops are disposed on the second plate that deflects the second plate prior to the first jaw and the second jaw closing; each of the first jaw and the second jaw has a first plate and a second plate; the non-conductive stops on one of the second plates deflects the second plates prior to the first jaw and the second jaw closing such that the medial plates contact each other; non-conductive stops are disposed on the first plate, the non-conductive stops of the second plate being longer than the non-conductive stops of the first plate such that the non-conductive stops of the second plate make contact before the non-conductive stops of the first plate make contact; the electrodes are connected to a source of electrosurgical energy, the source generating electrosurgical energy to coagulate tissue grasped between the first jaw and the second jaw; and at least one of the first jaw and the second jaw has a longitudinal slot and the end effector includes a blade that reciprocates within the slot.

Accordingly, pursuant to yet another aspect of the present disclosure, a method of using forceps includes one or more of the following steps: opening a first jaw and a second jaw of the forceps, the first jaw having a tissue sealing surface and an electrode on the sealing surface and the second jaw having a tissue sealing surface and an electrode on the sealing surface, the sealing surface of at least one of the first jaw and the second jaw has a rigid section and a flexible lateral; closing the first jaw and the second jaw to grasp tissue therebetween; \applying electrosurgical energy to coagulate tissue grasped between the first jaw and the second jaw; and pressing the first jaw and the second jaw together to cut the tissue.

The method of using the forceps may be further characterized by one or any combination of the following features: the sealing surfaces of at least one of the first jaw and the second jaw has a rigid medial section and flexible lateral sections; the medial section is a first plate and the lateral sections are a second plate that is coplanar with the first plate; non-conductive stops are disposed on the second plate that deflects the second plate prior to the first jaw and the second jaw closing; each of the first jaw and the second jaw has a first plate and a second plate; the non-conductive stops on one of the second plates deflects the second plates prior to the first jaw and the second jaw closing such that the medial plates contact each other; non-conductive stops are disposed on the first plate, the non-conductive stops of the second plate being longer than the non-conductive stops of the first plate such that the non-conductive stops of the second plate make contact before the non-conductive stops of the first plate make contact; at least one of the first jaw and the second jaw has a longitudinal slot in which a blade reciprocates; and the method further includes applying electrosurgical energy to coagulate tissue grasped between the first jaw and the second jaw after closing the first jaw and the second jaw and before cutting the tissue.

Accordingly, pursuant to another aspect of the present disclosure, an end effector of a forceps includes a first jaw with a tissue sealing surface and an electrode on the sealing surface, a second jaw with a tissue sealing surface and an electrode on the sealing surface, and a blade that reciprocates within a longitudinal slot, the first jaw and the second jaw moving between an open position and a closed position. The sealing surfaces of at least one of the first jaw and the second jaw has a first section on a first side of the slot and a second section on a second side of the slot, the first section being a first plate and the second section being a second plate that is coplanar with the first plate, the first section being a rigid section and the second section being a flexible section.

The foregoing aspect of the present disclosure can be further characterized by one or any combination of the features described herein, such as: the sealing surfaces of both the first jaw and the second jaw have a rigid section on a first side of the slot and a flexible section on a second side of the slot. Each of the first jaw and the second jaw includes a jaw body and a sealing plate, the exterior surface of the sealing plate being the sealing surface of each of the first jaw and the second jaw; and the jaw body of at least one of the first jaw and the second jaw includes a support member, a layer of pliable material being disposed between the support member and the sealing plate, the layer of pliable material being made of separate cells placed side by side with different stiffnesses, the center cells being more rigid than the lateral cells.

Further features, advantages, and areas of applicability will become apparent from the description provided herein.

In the drawings:.

Referring now to the drawings, a forceps, such as, for example, a laparoscopic forceps, embodying the principles of the present invention is illustrated therein and designated at <NUM>. The forceps <NUM> may function to grip an object. The forceps <NUM> may be used during surgery to grip a feature of interest including: a part of a body, an anatomical feature, tissue, veins, arteries, or a combination thereof. The forceps <NUM> may function to be used in surgery, for example, laparoscopic surgery. The forceps <NUM> may be used with or without power. Current may be passed through the forceps <NUM> so that the forceps are used for electrosurgery. For example, a therapy current may be passed from one jaw to a second jaw when tissue is located within the jaw and the therapy current may coagulate blood, cauterize, cut, or a combination thereof. The forceps <NUM> may generally include one or more working assemblies and sufficient controls to work the one or more assemblies. The forceps <NUM> may include parts employed to perform the recited functions and may include generally, a stylet (e.g., a tubular member, a hollow tube, or an assembly of tubes), a hand piece, one or more operable mechanisms used to actuate the stylet, or a combination thereof. The hand piece may be an assembly of parts or housing structures capable of forming a hand piece structure with a cavity. Note that the present invention is not limited to laparoscopic procedures. That is, the below described jaws can be employed with any type of medical device that clamps onto tissue.

Turning now to <FIG>, a side view of the forceps <NUM> is shown. The forceps <NUM> include a handpiece <NUM> having a distal end <NUM> and a proximal end <NUM>. The handpiece <NUM> also includes at least one operable mechanism <NUM>. A tubular member <NUM> has a proximal end <NUM> that is connected to the distal end <NUM> of the handpiece <NUM>. The tubular member <NUM> includes a distal end <NUM> that includes jaws <NUM> extending therefrom. The jaws <NUM> have members <NUM> and <NUM> that open and close when the tubular member <NUM> is moved forward along the longitudinal axis <NUM> of the tubular member into contact with the members <NUM> and <NUM> or the jaws <NUM> are moved backwards along the longitudinal axis <NUM> into contact with the tubular member <NUM>.

Referring further to <FIG> and <FIG>, a camming shaft <NUM> is located on the forceps <NUM> with the jaws <NUM> extending therefrom. The members <NUM> and <NUM> are biased by the camming shaft <NUM> so that the jaws <NUM> are opened and closed. The members <NUM> and <NUM> include inserts <NUM> and <NUM> and a pair of slots <NUM> and <NUM> that extend through the members <NUM> and <NUM>, respectively. The inserts <NUM> and <NUM> are made of any suitable pliable material, such as, an elastic polymer. Accordingly, a sealing surface <NUM> of the member <NUM> includes a first sealing surface <NUM> on lateral cantilevered portions or sections of the member <NUM>, that is, on both sides of the slot <NUM>, and a second sealing surface <NUM> on medial portions or sections on both sides of the slot <NUM>. The member <NUM> includes a first sealing surface <NUM> on lateral cantilevered portions or sections of the member <NUM>, that is, on both sides of the slot <NUM>, and a second sealing surface <NUM> on medial portions or sections on both sides of the slot <NUM>. Note that the use of the inserts <NUM> and <NUM> is optional. Hence, without the use of the inserts <NUM> and <NUM>, cavities would exist below the lateral cantilevered portions that define the first sealing surfaces <NUM> and <NUM>. Also note that the inserts <NUM> and <NUM> and/or the cavities can extend along a portion of or all of the jaw members <NUM> and <NUM>.

<FIG> illustrates the end of the tubular member <NUM> or a camming shaft showing a pair of internal flat portions <NUM> along the top surfaces and the bottom surfaces. A blade recess <NUM> extends between the pair of internal flat portions <NUM> so that a blade <NUM> (<FIG>) extends out of the tubular member <NUM>.

<FIG> illustrates a cross-sectional view of a tubular member <NUM>. The internal flat portions <NUM> include at least a portion that has a complementary shape to that of the legs of the jaws <NUM>. Accordingly, as the tubular member <NUM> or the legs <NUM> axially move, the internal flat portions <NUM> control the orientation and movement of the jaws.

<FIG> illustrates a perspective view of one example of a camming shaft <NUM> that is inserted into the tubular member <NUM>. The camming shaft <NUM> includes a molded flare <NUM> with a pair of protrusions <NUM> extending therefrom.

<FIG> illustrates the jaws <NUM> including a pin <NUM> located between the jaws. The pin <NUM> holds the jaw members <NUM> and <NUM> together and provide a pivot point for the jaw members <NUM> and <NUM> such that the members <NUM> and <NUM> close when the tubular member <NUM> is slid over the opposing members <NUM> and <NUM>.

Turning back to <FIG>, the first sealing surfaces <NUM> and <NUM> form a first compression zone above the inserts <NUM> and <NUM>, and the second sealing surfaces <NUM> and <NUM> form a second compression zone when the jaw members <NUM> and <NUM> are clamped together on a vessel. As such, the jaws <NUM> is a two-stage end-effector with the first compression zones produced by the compression surfaces <NUM> and <NUM> being more flexible than the second compression zones produced by the compression surfaces <NUM> and <NUM>.

In various arrangements, the jaw members <NUM> and <NUM> can be electrical connected to a generator that provides a source of electrosurgical energy so that a RF voltage with different potentials can be applied to the electrically connected sections of the jaw members <NUM> and <NUM>. The RF voltage produces a current that passes from one jaw member to the other jaw member electrode through tissue, thereby heating the tissue to coagulate or cut the tissue.

Turning now to <FIG>, there is shown a set of jaws <NUM> in accordance with the principles of the present invention. The jaws <NUM> include a first jaw member <NUM> and a second jaw member <NUM>. The first jaw member <NUM> includes a jaw body or support member <NUM> and a sealing plate <NUM> disposed on both sides of a slot <NUM>. The exterior surface of the sealing plate <NUM> defines a sealing surface <NUM>. A layer of pliable material <NUM>, <NUM> and <NUM> is disposed between the jaw body <NUM> and the sealing plate <NUM>. The layer of pliable mater is made of separate cells placed side by side with different stiffnesses, the medial or center cells <NUM> being stiffer than the lateral cells <NUM>. In certain arrangements, the layer of pliable material includes the medial cells <NUM> positioned adjacent to the lateral cells <NUM>, while in other arrangements the intermediate cells <NUM> are positioned between the medial cells <NUM> and the lateral cells <NUM> to provide an additional transition from the stiffer medial cells <NUM> to the more flexible lateral cells <NUM>.

The second jaw member <NUM> includes a jaw body <NUM> and a sealing plate <NUM> disposed on both sides of a slot <NUM>. The exterior surface of the sealing plate <NUM> defines a sealing surface <NUM>. A layer of pliable material <NUM>, <NUM> and <NUM> is disposed between the jaw body <NUM> and the sealing plate <NUM>. The layer of pliable mater is made of separate cells placed side by side with different stiffnesses, the medial or center cells <NUM> being stiffer than the lateral cells <NUM>. In certain arrangements, the layer of pliable material includes the medial cells <NUM> positioned adjacent to the lateral cells <NUM>, while in other arrangements the intermediate cells <NUM> are positioned between the medial cells <NUM> and the lateral cells <NUM> to provide an additional transition from the stiffer medial cells <NUM> to the more flexible lateral cells <NUM>. The layers of pliable material <NUM>, <NUM>, <NUM> and <NUM>, <NUM>, <NUM> can extend along a portion of or all of the jaw members <NUM> and <NUM>.

Accordingly, the sealing surfaces above the lateral cells <NUM> and <NUM> form a first compression zone and the sealing surfaces above the medial cells <NUM> and <NUM> form a second compression zone when the jaw members <NUM> and <NUM> are closed and clamped together on a vessel, the first compression zone being more flexible than the second compression zone. Again, if the jaw members <NUM> and <NUM> include the intermediate cells <NUM> and <NUM>, the stiffness of the cells <NUM> and <NUM> can be selected to provide a desired transition from the first compression zone to the second compression zone.

The cells <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be made from any suitable compliant materials such as elastomers. In some arrangements, none of the cells <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are electrically conductive. In other arrangements, some or all of the cells <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be electrically conductive. Hence, when the jaw members <NUM> and <NUM> are connected to a generator that provides a source of electrical energy, a voltage with different potentials can be applied to the electrically conductive cells such that a current passes from one jaw member to the other jaw member through tissue clamped between the jaw members to coagulate or cut the tissue.

Shown in <FIG> is another set of jaws <NUM> with a first jaw member <NUM> and a second jaw member <NUM>. The first jaw member <NUM> includes a jaw body <NUM> and cantilever members <NUM> attached to the jaw body <NUM> on both sides of a slot <NUM> with a layer of material <NUM>. The arrangement of the cantilever members <NUM> with respect to the jaw body <NUM> defines a cavity such as a gap <NUM> on each side of the slot <NUM> to enable the cantilever member <NUM> to flex with respect to the jaw body <NUM>. As such, the first jaw member <NUM> includes lateral first sealing surfaces <NUM> and medial second sealing surfaces <NUM>. Since the unattached region of the cantilever member <NUM> is able to flex into the gap <NUM>, the first sealing surface <NUM> defines a more flexible region of the cantilever member <NUM> than the second sealing surface <NUM>. Note that the stiffness of the layer of material <NUM> can be also be selected to adjust the stiffnesses of the first sealing surface <NUM> and the second sealing surface <NUM>.

The second jaw member <NUM> includes a jaw body <NUM> and cantilever members <NUM> attached to the jaw body <NUM> on both sides of a slot <NUM> with a layer of material <NUM>. The arrangement of the cantilever members <NUM> with respect to the jaw body <NUM> defines a cavity such as a gap <NUM> on each side of the slot <NUM> to enable the cantilever member <NUM> to flex with respect to the jaw body <NUM>. As such, the second jaw member <NUM> includes lateral first sealing surfaces <NUM> and medial second sealing surfaces <NUM>. Since the unattached region of the cantilever member <NUM> is able to flex into the gap <NUM>, the first sealing surface <NUM> defines a more flexible region of the cantilever member <NUM> than the second sealing surface <NUM>. Note that the stiffness of the layer of material <NUM> can be also be selected to adjust the stiffnesses of the first sealing surface <NUM> and the second sealing surface <NUM>. The cantilevered members <NUM> and <NUM> can extend along a portion of or all of the jaw members <NUM> and <NUM>.

Accordingly, the sealing surfaces <NUM> and <NUM> form a first compression zone and the sealing surfaces <NUM> and <NUM> form a second compression zone when the jaw members <NUM> and <NUM> are clamped together on a vessel, the first compression zone being more flexible than the second compression zone.

The jaw body <NUM> or cantilever members <NUM> or both the jaw body <NUM> and cantilever members <NUM> can be electrically conductive, and the jaw body <NUM> or cantilever members <NUM> or both the jaw body <NUM> and cantilever members <NUM> can be electrically conductive. Hence, when the jaw members <NUM> and <NUM> are connected to a generator that provides a source of electrical energy, a voltage with different potentials can be applied to the electrically conductive portions of the jaw members <NUM> and <NUM> such that a current passes from one jaw member to the other jaw member through tissue clamped between the jaw members to coagulate or cut the tissue.

Referring to <FIG>, there is shown yet another set of jaws <NUM>. The jaws <NUM> includes a first jaw member <NUM> and a second jaw member <NUM>. The first jaw member <NUM> includes a jaw body <NUM> and wedges of pliable material <NUM>, such as, for example, any compliant material including elastomers, attached to chamfered outer portions of the jaw body <NUM> on both sides of a slot <NUM>. As such, the jaw member <NUM> includes a first sealing surface <NUM> on lateral portions or sections of the member <NUM>, that is, on both sides of the slot <NUM>, and a second sealing surface <NUM> on medial portions or sections on both sides of the slot <NUM>. The second jaw member <NUM> includes a jaw body <NUM> and wedges of pliable material <NUM>, such as, for example, any compliant material including elastomers, attached to chamfered outer portions of the jaw body <NUM> on both sides of a slot <NUM>. Hence, the jaw member <NUM> includes a first sealing surface <NUM> on lateral portions or sections of the member <NUM>, that is, on both sides of the slot <NUM>, and a second sealing surface <NUM> on medial portions or sections on both sides of the slot <NUM>. The wedges of pliable material <NUM> and <NUM> can extend along a portion of or all of the jaw members <NUM> and <NUM>.

Accordingly, the first sealing surfaces <NUM> and <NUM> form a first compression zone above the pliable material <NUM> and <NUM>, and the second sealing surfaces <NUM> and <NUM> form a second compression zone when the jaw members <NUM> and <NUM> are clamped together on a vessel. Because of the pliable or compliant nature of the material <NUM> and <NUM>, the first compression zones produced by the compression surfaces <NUM> and <NUM> are more flexible than the second compression zones produced by the compression surfaces <NUM> and <NUM>.

The jaw body <NUM> or pliable material <NUM> or both the jaw body <NUM> and pliable material <NUM> can be electrically conductive, and the jaw body <NUM> or pliable material <NUM> or both the jaw body <NUM> and pliable material <NUM> can be electrically conductive. Hence, when the jaw members <NUM> and <NUM> are connected to a generator that provides a source of electrical energy, a voltage with different potentials can be applied to the electrically conductive portions of the jaw members <NUM> and <NUM> such that a current passes from one jaw member to the other jaw member through tissue clamped between the jaw members to coagulate or cut the tissue.

Any of the jaw arrangements <NUM>, <NUM>, <NUM> and <NUM> described previously can include a cutting blade. For example, as shown in <FIG>, the jaws <NUM> are shown with a blade <NUM>. The blade <NUM> includes a slot <NUM> that engages with the pin <NUM> to allow the blade <NUM> to reciprocate along the pin <NUM>. The blade <NUM> is connected to a blade shaft <NUM>. Hence, axial movement of the blade shaft <NUM> results in reciprocating axial movement of the blade <NUM> along the slots <NUM> and <NUM> of the jaw members <NUM> and <NUM> to cut tissue clamped between the jaw members <NUM> and <NUM>. A similar blade arrangement can be added to the jaws <NUM>, <NUM> and <NUM>.

Referring now to <FIG>, <FIG>, there is shown another set of jaws <NUM>. The jaws <NUM> includes a first jaw member <NUM> and a second jaw member <NUM>. The first jaw member <NUM> includes a lateral portion <NUM> and a medial or center portion <NUM> separated from the lateral portion <NUM> by a gap <NUM> to enable the lateral portion <NUM> to flex relative to the medial portion <NUM>. The lateral portion <NUM> has a first sealing surface <NUM> and the medial portion <NUM> has a sealing surface <NUM>. The second jaw member also has a lateral portion <NUM> with a first sealing surface <NUM> and a medial or center portion <NUM> with a second sealing surface <NUM>. In various arrangements, the lateral portions <NUM> and <NUM> are made of a first material <NUM> and the medial portions <NUM> and <NUM> are made of a second material <NUM> that is stiffer than the first material <NUM>.

The lateral portion <NUM> of the first jaw member includes a first set of non-conductive stops <NUM> and the medial portion <NUM> includes a second set of non-conductive stops <NUM>. The first set of non-conductive stops <NUM> has a height of h1 and the second set of non-conductive stops <NUM> has a height of h2 that is less than the height h1. When the jaw members <NUM> and <NUM> are in an open position, the lateral portion <NUM> is coplanar with the center portion <NUM> and the lateral portion <NUM> is coplanar with the medial portion <NUM>. As the jaw member <NUM> and <NUM> are closed together to clamp onto a vessel, the stops <NUM> deflect the lateral portions <NUM> and <NUM> prior to the first jaw member <NUM> and the second jaw member <NUM> fully closing such that the medial plates portions <NUM> and <NUM> contact each other if the medial portions <NUM> and <NUM> do not include the stops <NUM>. If the medial portions <NUM> and <NUM> include the stops <NUM>, the stops <NUM> of the lateral portion <NUM> make contact with the lateral portion <NUM> before the stops <NUM> of the medial portion <NUM> makes contact with the medial portion <NUM>.

Hence, when the jaw members <NUM> and <NUM> clamp onto a large vessel, V1, as shown in <FIG> and <FIG>, the gap <NUM> between the stops <NUM> and the lateral portion <NUM> is closed before the gap <NUM> between the stops <NUM> and the medial portion <NUM>. The lateral portions <NUM> and <NUM>, therefore, deflect relative to the medial portions <NUM> and <NUM> so that compressive forces are generated between the first sealing surfaces <NUM> and <NUM> and between the second sealing surfaces <NUM> and <NUM>.

When the jaw members <NUM> and <NUM> clamp onto a smaller vessel, V2, as shown in <FIG>, the stops <NUM> make contact with the lateral portion <NUM> to deflect the lateral potions <NUM> and <NUM> away from the medial portions <NUM> and <NUM> such that the stops <NUM> make contact with the medial portion <NUM> as well. Hence, when clamping onto a smaller vessel, V2, the compressive forces on the smaller vessel, V2, are generated primarily by the second sealing surfaces <NUM> and <NUM>. Although four stops <NUM> are shown in <FIG>, as few as one stop or more than four stops can be employed. Similarly, instead of the two stops <NUM> shown in <FIG>, as few as one stop or more than two stops can be employed.

The lateral portion <NUM> or the medial portion <NUM> or both the lateral portion <NUM> and the medial portion <NUM> can be electrically conductive, and lateral portion <NUM> or the medial portion <NUM> or both the lateral portion <NUM> and the medial portion <NUM> can be electrically conductive. Hence, when the jaw members <NUM> and <NUM> are connected to a generator that provides a source of electrical energy, a voltage with different potentials can be applied to the electrically conductive portions of the jaw members <NUM> and <NUM> such that a current passes from one jaw member to the other jaw member through tissue clamped between the jaw members to coagulate or cut the tissue.

Referring to <FIG>, there is shown another set of jaws <NUM>. The jaws <NUM> include a first jaw member <NUM> and a second jaw member <NUM>. The first jaw member <NUM> includes a jaw body or support member <NUM> and a sealing plate <NUM> disposed on both sides of a slot <NUM>. The exterior surface of the sealing plate <NUM> defines a sealing surface <NUM>. A layer of pliable material <NUM> and <NUM> is disposed between the jaw body <NUM> and the sealing plate <NUM>. The layer of pliable mater is made of separate cells with different stiffnesses, the cells <NUM> being stiffer than the cells <NUM>.

The second jaw member <NUM> includes a jaw body <NUM> and a sealing plate <NUM> disposed on both sides of a slot <NUM>. The exterior surface of the sealing plate <NUM> defines a sealing surface <NUM>. A layer of pliable material <NUM> and <NUM> is disposed between the jaw body <NUM> and the sealing plate <NUM>. The layer of pliable mater is made of separate cells with different stiffnesses, the cells <NUM> being stiffer than the cells <NUM>. The layers of pliable material <NUM>, <NUM> and <NUM>, <NUM> can extend along a portion of or all of the jaw members <NUM> and <NUM>.

Accordingly, the sealing surfaces above the cells <NUM> and <NUM> form a first compression zone and the sealing surfaces above the cells <NUM> and <NUM> form a second compression zone when the jaw members <NUM> and <NUM> are closed and clamped together on a vessel, the first compression zone being more flexible than the second compression zone.

The cells <NUM>, <NUM>, <NUM> and <NUM> can be made from any suitable compliant materials such as elastomers. In some arrangements, none of the cells <NUM>, <NUM>, <NUM> and <NUM> are electrically conductive. In other arrangements, some or all of the cells <NUM>, <NUM>, <NUM> and <NUM> can be electrically conductive. Hence, when the jaw members <NUM> and <NUM> are connected to a generator that provides a source of electrical energy, a voltage with different potentials can be applied to the electrically conductive cells such that a current passes from one jaw member to the other jaw member through tissue clamped between the jaw members to coagulate or cut the tissue.

The jaw arrangement <NUM> can include the cutting blade <NUM> shown previously in <FIG>. Again, the blade <NUM> includes the slot <NUM> that engages with the pin <NUM> to allow the blade <NUM> to reciprocate along the pin <NUM>. The blade <NUM> is connected to the blade shaft <NUM>. Hence, axial movement of the blade shaft <NUM> results in reciprocating axial movement of the blade <NUM> along the slots <NUM> and <NUM> of the jaw members <NUM> and <NUM> to cut tissue clamped between the jaw members <NUM> and <NUM>.

Claim 1:
An end effector of a forceps (<NUM>) comprising:
a first jaw (<NUM>) having a planar tissue sealing surface (<NUM>) extending from a lateral section to a medial section; and
a second jaw (<NUM>) having a planar tissue sealing surface (<NUM>) extending from a lateral section to a medial section,
wherein the first jaw and the second jaw move between an open position and a closed position, and
wherein the planar tissue sealing surface of the first jaw and the second jaw each include an electrode,
wherein a portion of the lateral section of at least one of the first jaw and the second jaw includes a material that is more pliable than a material forming a portion of the medial section such that the sealing surfaces of the at least one of the first jaw and the second jaw has a rigid medial section and flexible lateral section; and
wherein each of the first jaw (<NUM>) and the second jaw (<NUM>) includes a jaw body (<NUM>, <NUM>) and a sealing plate (<NUM>, <NUM>), the exterior surface (<NUM>) of the sealing plate (<NUM>, <NUM>) being the sealing surface (<NUM>, <NUM>) of each of the first jaw (<NUM>) and the second jaw (<NUM>);
characterized in that
the jaw body (<NUM>, <NUM>) of at least one of the first jaw (<NUM>) and the second jaw (<NUM>) includes a support member (<NUM>, <NUM>), and wherein a layer of the pliable material is disposed between the support member (<NUM>, <NUM>) and the sealing plate (<NUM>, <NUM>), the layer of pliable material being made of separate cells (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) placed side by side with different stiffnesses, the center cells (<NUM>, <NUM>) being more rigid than the lateral cells (<NUM>, <NUM>).