Abstract:
An end effector assembly of a forceps includes a first jaw member having an electrically conductive tissue sealing surface configured to connect to a source of electrosurgical energy and a second jaw member having an electrically conductive tissue sealing surface configured to connect to the source of electrosurgical energy. The first and the second jaw members are disposed in space opposition relation relative to one another, and at least one of the jaw members is movable relative to the other between a first, open position and a second, closed position for the jaw members to grasp tissue therebetween. The tissue sealing surfaces of the first and the second jaw members are configured to form complementary stepped portions along an axis perpendicular to the longitudinal axis of the end effector assembly. The complementary stepped portions include a medial portion and a lateral portion on each of the first and second jaw, and one or both of the lateral surfaces has nonconductive stops.

Description:
RELATED APPLICATION 
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application No. 62/317,858, filed on Apr. 4, 2016. The entire contents of the above application are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to an electrosurgical device. More specifically, the present disclosure relates to an electrosurgical device for vessel sealing. 
       BACKGROUND 
       [0003]    The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art. 
         [0004]    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. Examples of some forceps with resilient jaws closed by a camming action may be found in U.S. Pat. Nos. 5,458,598; 5,735,849; 5,445,638; 6,190,386; 6,113,596; and 6,679.882 and HALO cutting forceps, available at http://www.olympus-osta.com/halo.htm last accessed on Apr. 3, 2014, all of which are incorporated by reference herein in their entirety for all purposes. 
         [0005]    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 and may also reduce the device durability and reliability. 
         [0006]    Accordingly, it would be attractive for the electrosurgical forceps to not require high jaw forces for vessel sealing. 
       SUMMARY 
       [0007]    The present disclosure provides an electrosurgical bipolar forceps which does not require high jaw force for vessel sealing. 
         [0008]    Accordingly, pursuant to one aspect, an end effector assembly of a forceps includes a first jaw member having an electrically conductive tissue sealing surface configured to connect to a source of electrosurgical energy and a second jaw member having an electrically conductive tissue sealing surface configured to connect to the source of electrosurgical energy. The first and the second jaw members are disposed in space opposition relation relative to one another, and at least one of the jaw members is movable relative to the other between a first, open position and a second, closed position for the jaw members to grasp tissue therebetween. The tissue sealing surfaces of the first and the second jaw members are configured to form complementary stepped portions along an axis perpendicular to the longitudinal axis of the end effector assembly. The complementary stepped portions include a medial portion and a lateral portion on each of the first and second jaw, and one or both of the lateral surfaces has nonconductive stops. 
         [0009]    This aspect may be further characterized by one or any combination of the features described herein, such as: the sealing surface of the first jaw member includes a first compression surface along the medial portion, a second compression surface along the lateral portion, and a shearing surface between the first compression surface and the second compression surface; the sealing surface of the second jaw member includes a first compression surface along the medial portion, a second compression surface along the lateral portion, and a shearing surface between the first compression surface and the second compression surface; the shearing surface of each of the jaw members is arranged orthogonally to the first compression surface and the second compression surface of the respective jaw member; the shearing surface of each of the jaw members is arranged non-orthogonally to the first compression surface and the second compression surface of the respective jaw member; the non-conductive stop is a gripping member positioned along the outermost compression surface of at least one of the jaw members, the non-conductive stop preventing inadvertent shorting between the jaw members; and the source generates electrosurgical energy to coagulate tissue grasped between the first jaw member and the second jaw member. 
         [0010]    Accordingly, pursuant to another aspect, a forceps with an effector assembly a first jaw member having an electrically conductive tissue sealing surface configured to connect to a source of electrosurgical energy and a second jaw member having an electrically conductive tissue sealing surface configured to connect to the source of electrosurgical energy. The first and the second jaw members are disposed in space opposition relation relative to one another, and at least one of the jaw members movable relative to the other between a first, open position and a second, closed position for the jaw members to grasp tissue therebetween. The tissue sealing surfaces of the first and the second jaw members are configured to form complementary stepped portions along an axis perpendicular to the longitudinal axis of the end effector assembly, the complementary stepped portions comprising a medial portion and a lateral portion on each of the first and second jaw. One or both of the lateral surfaces has nonconductive stops. 
         [0011]    This aspect may be further characterized by one or any combination of the features described herein, such as: the sealing surface of the first jaw member includes a first compression surface along the medial portion, a second compression surface along the lateral portion, and a shearing surface between the first compression surface and the second compression surface; the sealing surface of the second jaw member includes a first compression surface along the medial portion, a second compression surface along the lateral portion, and a shearing surface between the first compression surface and the second compression surface; the shearing surface of each of the jaw members is arranged orthogonally to the first compression surface and the second compression surface of the respective jaw member; the shearing surface of each of the jaw members is arranged non-orthogonally to the first compression surface and the second compression surface of the respective jaw member; the non-conductive stop is a gripping member positioned along the outermost compression surface of at least one of the jaw members, the non-conductive stop preventing inadvertent shorting between the jaw members; the source generates electrosurgical energy to coagulate tissue grasped between the first jaw member and the second jaw member; and the tissue is gripped to provide tension and the forceps includes a reciprocating blade that cuts the tissue. 
         [0012]    Accordingly, pursuant to yet another aspect, a method of using forceps includes one or more of the following steps: opening a first jaw member and a second jaw member of the forceps, the first jaw member having an electrically conductive tissue sealing surface configured to connect to a source of electrosurgical energy and the second jaw member having an electrically conductive tissue sealing surface configured to connect to the source of electrosurgical energy, the first and the second jaw members being disposed in space opposition relation relative to one another, the tissue sealing surfaces of the first and the second jaw members being configured to form complementary stepped portions along an axis perpendicular to the longitudinal axis of the end effector assembly, the complementary stepped portions comprising a medial portion and a lateral portion on each of the first and second jaw, one or both of the lateral surfaces having nonconductive stops; closing the jaw members to grasp tissue therebetween; and pressing the jaw members together to cut tissue. 
         [0013]    The method of using the forceps may be further characterized by one or any combination of the following features: the sealing surface of the first jaw member includes a first compression surface along the medial portion, a second compression surface along the lateral portion, and a shearing surface between the first compression surface and the second compression surface; the sealing surface of the second jaw member includes a first compression surface along the medial portion, a second compression surface along the lateral portion, and a shearing surface between the first compression surface and the second compression surface; the shearing surface of each of the jaw members is arranged orthogonally to the first compression surface and the second compression surface of the respective jaw; the shearing surface of each of the jaw members is arranged non-orthogonally to the first compression surface and the second compression surface of the respective jaw member; the non-conductive stop is a gripping member positioned along the outermost compression surface of at least one of the jaw members, the non-conductive stop preventing inadvertent shorting between the jaw members; generating electrosurgical energy to coagulate tissue grasped between the first jaw member and the second jaw member; and the tissue is gripped to provide tension and the tissue is cut by a reciprocating blade. 
         [0014]    Further features, advantages, and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0015]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the drawings: 
           [0016]      FIG. 1  illustrates an electrosurgical forceps in accordance with the principles of the present invention; 
           [0017]      FIG. 2  an example of a set of jaws for the forceps shown in  FIG. 1 ; 
           [0018]      FIG. 3  illustrates an end of a tubular member and/or a camming shaft for the forceps; 
           [0019]      FIG. 4  illustrates an end view of a tubular member and/or a camming shaft; 
           [0020]      FIG. 5  illustrates a perspective view of a camming shaft; 
           [0021]      FIG. 6  illustrates a perspective view of the forceps shown in transparent; 
           [0022]      FIG. 7A  illustrates a cross-sectional view of the jaws sealing a vessel; 
           [0023]      FIG. 7B  illustrates a close-up cross-sectional view of the jaws; 
           [0024]      FIG. 8  illustrates a cross-sectional view of an alternative embodiment of a set of jaws sealing a vessel in accordance with the principles of the present invention; 
           [0025]      FIG. 9  illustrates a cross-sectional view of yet another alternative embodiment of a set of jaws in accordance with the principles of the present invention; 
           [0026]      FIG. 10  illustrates a cross-sectional view of yet another alternative embodiment of a set of jaws in accordance with the principles of the present invention; 
           [0027]      FIG. 11  illustrates a cross-sectional view of yet another alternative embodiment of a set of jaws in accordance with the principles of the present invention; 
           [0028]      FIG. 12  illustrates a perspective view of the jaws shown in  FIG. 6  with a cutting blade; and 
           [0029]      FIG. 13  illustrates a side view of the jaws shown in  FIG. 6  with the cutting blade. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
         [0031]    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  2 . The forceps  2  may function to grip an object. The forceps  2  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  2  may function to be used in surgery, for example, laparoscopic surgery. The forceps  2  may be used with or without power. Current may be passed through the forceps  2  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  2  may generally include one or more working assemblies and sufficient controls to work the one or more assemblies. The forceps  2  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. 
         [0032]    Turning now to  FIG. 1 , a side view of the forceps  2  is shown. The forceps  2  include a handpiece  4  having a distal end  6  and a proximal end  8 . The handpiece  4  also includes at least one operable mechanism  50 . A tubular member  20  has a proximal end  24  that is connected to the distal end  6  of the handpiece  4 . The tubular member  20  includes a distal end  22  that includes jaws  40  extending therefrom. The jaws  40  have members  92  and  94  that open and close when the tubular member  20  is moved forward along the longitudinal axis  26  of the tubular member into contact with the members  92  and  94  or the jaws  40  are moved backwards along the longitudinal axis  26  into contact with the tubular member  20 . 
         [0033]    Referring further to  FIGS. 2, 6 and 7A , a camming shaft  70  is located on the forceps  2  with the jaws  40  extending therefrom. The members  92  and  94  are biased by the camming shaft  70  so that the jaws  40  are opened and closed. A pair of slots  96  and  98  extend through the members  92  and  94 , respectively. The member  92  includes a first compression surface  100  on a lateral portion of the member  92 , that is on both sides of the slot  96 , a second compression surface  104  on a medial portion on both sides of the slot  96 , and a shearing surface  108  arranged orthogonally between the compression surfaces  100  and  104  on both sides of the slot  96 . The member  94  includes a first compression surface  102  on a lateral portion of the member  94  on both sides of the slot  98 , a second compression surface  106  on a medial portion on both sides of the slot  98 , and a shearing surface  110  arranged orthogonally between the compression surfaces  102  and  106  on both sides of the slot  98 . 
         [0034]      FIG. 3  illustrates the end of the tubular member  20  or a camming shaft showing a pair of internal flat portions  30  along the top surfaces and the bottom surfaces.  FIG. 4  illustrates a cross-sectional view of a tubular member  20 . The internal flat portions  30  include at least a portion that has a complementary shape to that of the legs of the jaws  44 . Accordingly, as the tubular member  20  or the legs  44  axially move, the internal flat portions  30  control the orientation and movement of the jaws. 
         [0035]      FIG. 5  illustrates a perspective view of one example of a camming shaft  70  that is inserted into the tubular member  20 . The camming shaft  70  includes a molded flare  74  with a pair of protrusions  72  extending therefrom. 
         [0036]      FIG. 6  illustrates the jaws  40  including a pin  90  located between the jaws. The pin  90  holds the jaw members  92  and  94  together and provide a pivot point for the jaw members  92  and  94  such that the members  92  and  94  close when the shaft  20  when the tubular member is slid over the opposing members  92  and  94 . 
         [0037]    Turning back to  FIG. 7A , the jaw members  92  and  94  are shown clamping and sealing a vessel, V. The jaw members  92  and  94 , as shown in  FIG. 7B , form a combined compression zones  112  and  114  and a stretching and shearing zone  116  on the vessel, V, when the jaw members  92  and  94  are clamped together. One jaw member can move while the other is kept stationary, or both jaw members  92  and  94  can be moved together. In various arrangements, the gap between the upper and lower jaw members  92  and  94  in the compression zones  112  and  114  is between about 0.006 inch and 0.012 inch when the jaw members  92  and  94  are fully closed. The gap between the upper and lower jaw members in the shearing zone  116  is between about 0.003 inch and 0.006 inch when the jaw members are partially closed or fully closed. 
         [0038]    Turning now to  FIG. 8 , there is shown an alternative set of jaws  240  in accordance with the principles of the present invention. Some of the features of the jaws  240  are the same as those of the jaws  40  and are therefore identified by the same reference numbers. The jaws  240 , however, has angled shearing surfaces rather than orthogonal shearing surfaces. Specifically, the jaw member  92  includes an angled shearing surface  208  between the compression surfaces  100  and  104  on both sides of the slot  96 , and the jaw member  94  includes an angled shearing surface  210  between the compression surfaces  102  and  106  on both sides of the slot  98 . 
         [0039]      FIG. 9  illustrates yet another alternative set of jaws  340  in accordance with the principles of the present invention. The features of the jaw that are similar to the features of the jaws  40  are identified by the same reference numbers. The jaws  340  include two elongated insulation stop members  342  on both sides of the slots  96  and  98 . The stop members  342  can be attached to either the compression surface  100  of the jaw member  92  or the compression surface  102  of the jaw member  94 . The elongated insulation stop members  342  help control the gap between the jaw members  92  and  94  for vessel sealing. Further, the elongated insulation stop members  342  reduce thermal spread because the coagulation of the vessel, V, does not happen on the side edges of the jaw members  92  and  94 . 
         [0040]      FIG. 10  illustrates yet another alternative set of jaws  440  with elongated insulation stop members  442  located on both sides of the slots  96  and  98 . The elongated insulation stop members  442  extend through the thickness of the jaw member  92  at the lateral portions of the jaw member  92 . Alternatively, the elongated insulation stop members  442  can extend through the thickness of the jaw member  94 . The benefits of the elongated insulation stop members  442  are similar to those of the elongated insulation stop members  342  described above. 
         [0041]      FIG. 11  illustrates yet another set of jaws  540  which includes a set of gripping members  542 . The members  542  are spaced apart along the length of the compression surface  100  of the jaw member  92  on both sides of the slot  96  or along the compression surface  106  of the jaw member  94  on both sides of the slot  98 . The members  542  can be either conductive or non-conductive. These gripping members  542  apply tension to tissue across the jaw surfaces while holding the tissue in place. As such, the tissue is stretched into the jaw members  92  and  94  as they are closed together. In some arrangements, the gripping members  542  retract, for example, on pins on springs when the jaw members  92  and  94  are closed together. In other arrangements, the gripping members  542  are coincident with recesses in opposite jaw member, which allows the jaw members to close. In various other arrangements, the gripping members  542  are made of a compressible material, such as, for example, silicone rubber, that compresses under the force generated when the jaw members  92  and  94  are closed together. In any of the aforementioned arrangements, a further benefit of the gripping members  542  is that they can allow retraction or compression of the gripping members  542  until a gap, for example, between about 0.003 inch and 0.006 inch is achieved between the jaw members  92  and  94  to prevent inadvertent shorting of the jaw members  92  and  94  when they are configured as two electrodes energized by an electrical energy source. 
         [0042]    Note that any of the members  342 ,  442 , or  542  described above can be used in the jaws  240 . Further note any of the aforementioned jaws enable stretching and thinning the vessel tissue by stretching, compressing and shearing the tissue before the jaws are energized to coagulate the tissue. In various implementations, shearing induces thinning of the vessel tissue and a state of increased tensile stresses in the tissue, that is, the shearing action stretches the tissue. In certain implementations, shearing increases the tensile stresses in the tissue to rupture or cut the tissue, that is, the shearing action severs the vessel. 
         [0043]    Any of the jaw arrangements  40 ,  240 ,  340 ,  440  and  540  described previously can include a cutting blade. For example, as shown in  FIGS. 12 and 13 , the jaws  40  are shown with a blade  400 . The blade  400  includes a slot  402  that engages with the pin  90  to allow the blade  400  to reciprocate along the pin  90 . The blade  400  is connected to a blade shaft  412 . Hence, axial movement of the blade shaft  412  results in reciprocating axial movement of the blade  400  along the slots  96  and  98  of the jaw members  92  and  94  to cut tissue clamped between the jaw members  92  and  94 . A similar blade arrangement can be implemented in the jaws  240 ,  340 ,  440  and  540 . 
         [0044]    The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.