Abstract:
An electrosurgical instrument for treating tissue includes a housing having a flexible shaft extending therefrom having an axis A-A defined therethrough. The flexible shaft has first and second jaw members attached at a distal end thereof and each jaw member includes an electrically conductive tissue contacting surface adapted to connect to a source of electrosurgical energy. A drive assembl is disposed in the housing and has a first actuator operably coupled to a drive rod for reciprocation thereof and a second actuator operably coupled to the drive rod for rotation thereof. A knife is operably coupled to a distal end of the drive rod. Actuation of the first actuator moves the jaw members relative to one another for engaging tissue and actuation of the second actuator rotates the drive rod about the axis A-A to translate the knife to cut tissue disposed between the jaw members.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to an apparatus, system, and method for performing an electrosurgical procedure. More particularly, the present disclosure relates to an apparatus, system, and method for performing an electrosurgical procedure that employs an electrosurgical apparatus that includes an end effector assembly configured for use with various size access ports. 
         [0003]    2. Description of Related Art 
         [0004]    Electrosurgical apparatuses (e.g., electrosurgical forceps) are well known in the medical ails and typically include a handle, a shaft and an end effector assembly operatively coupled to a distal end of the shaft that is configured to manipulate tissue (e.g., grasp and seal tissue). Electrosurgical forceps utilize both mechanical clamping action and electrical energy to effect hemostasis by heating the tissue and blood vessels to coagulate, cauterize, seal, cut, desiccate, and/or fulgurate tissue 
         [0005]    As an alternative to open electrosurgical forceps for use with open surgical procedures, many modern surgeons use endoscopes and endoscopic electrosurgical apparatus (e.g., endoscopic forceps) and laparoscopic apparatus for remotely accessing organs through smaller, puncture-like incisions or natural orifices. As a direct result thereof patients tend to benefit from less scarring and reduced healing time. Typically, the forceps are inserted into the patient through one or more various types of cannulas or access ports (typically having an opening that ranges from about five millimeters to about twelve millimeters) that has been made with a trocar; as can be appreciated, smaller cannulas are usually preferred. 
         [0006]    Forceps that are configured for use with small cannulas (e.g., cannulas less than five millimeters) may present design challenges for a manufacturer of electrosurgical instruments. 
       SUMMARY 
       [0007]    As noted above, smaller cannulas or access ports are usually preferred during an endoscopic or laparoscopic procedure. However, because of size constraints of the cannula or access port, endoscopic forceps that are configured for use with smaller cannulas may present design challenges for a manufacturer (e.g., designing an end effector assembly of an endoscopic forceps without compromising the integrity and/or functionality thereof). 
         [0008]    Therefore, it may prove useful in the relevant arts to provide an electrosurgical forceps that includes an end effector assembly that is configured for use with various types of cannulas or access ports including those that are less than five millimeters. With this purpose in mind, the present disclosure provides an electrosurgical forceps adapted to connect to an electrosurgical energy source for performing an electrosurgical procedure. The electrosurgical forceps includes a housing having a shaft that extends therefrom that defines a longitudinal axis therethrough. An end effector assembly operatively connects to a distal end of the shaft and includes a pair of first and second jaw members one of which is partially manufactured from a shape memory alloy (SMA). Each of the first and second jaw members are adapted to connect to a heat source and an electrical electrosurgical energy source. One of the jaw members is movable relative to the other from a normally open configuration to a closed configuration upon transition of the SMA from a martensite phase to an austenite phase as a result of selectively supplying heat from the heat source thereto. 
         [0009]    The present disclosure also provides a method for performing an electrosurgical procedure. The method includes the initial step of providing a bipolar forceps adapted to connect to an electrosurgical energy source for performing an electrosurgical procedure. The bipolar forceps includes a housing having a shaft that extends therefrom that defines a longitudinal axis therethrough. An end effector assembly operatively connects to a distal end of the shaft and includes a pair of first and second jaw members one which being partially manufactured from a shape memory alloy (SMA). Each of the first and second jaw members adapted to connect to a heat source and an electrical electrosurgical energy source. One of the jaw members is movable relative to the other from a normally open spaced configuration to a closed configuration upon transition of the SMA from a martensite phase to an austenite phase as a result of selectively supplying heat from the heat source thereto. The method includes the steps of: activating the heat source causing at least one of the jaw members to move towards the other such that tissue is grasped therebetween; and applying electrosurgical energy to the jaw members such that a tissue seal may be effected therebetween. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0010]    Various embodiments of the present disclosure are described hereinbelow with references to the drawings, wherein: 
           [0011]      FIG. 1  is a perspective view of a bipolar forceps including an end effector assembly, an electrosurgical generator including a control system, and a fluid source according to an embodiment of the present disclosure; 
           [0012]      FIG. 2  is a schematic representation of an electrical configuration for connecting the bipolar forceps to the electrosurgical generator depicted in  FIG. 1 ; 
           [0013]      FIGS. 3A-3C  are enlarged, side views of the end effector assembly of  FIG. 1 ; and 
           [0014]      FIG. 4  is a flowchart illustrating a method for performing an electrosurgical procedure in accordance with the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. 
         [0016]    As noted above, it may prove useful in the arts to provide an electrosurgical apparatus that is suitable for use with various access ports, including but not limited to those that are greater than and/or less than five millimeters. With this purpose in mind, the present disclosure includes an electrosurgical forceps that includes an end effector assembly having a jaw assembly that includes a pair of jaw members in operative communication with a source of electrosurgical energy that is in operative communication with or includes a control system One or both of the jaw members are made from memory alloy metal and heat-activated. 
         [0017]    With reference to  FIG. 1 , an illustrative embodiment of an electrosurgical apparatus (e.g., bipolar forceps  10 ) for performing an electrosurgical procedure is shown. Bipolar forceps  10  is operatively and selectively coupled to an electrosurgical generator (generator  200 ) for performing an electrosurgical procedure. As noted above, an electrosurgical procedure may include sealing, cutting, cauterizing coagulating, desiccating, and fulgurating tissue; all of which may employ RF energy. Generator  200  may be configured for monopolar and/or bipolar modes of operation. Generator  200  may include or is in operative communication with a system (system  300 ) that may include one or more processors in operative communication with one or more control modules that are executable on the processor. A control module (not explicitly shown) instructs one or more modules to transmit electrosurgical energy, which may be in the form of a wave or signal/pulse, via one or more cables (e.g., a cable  410 ) to one or both of the seal plates  118 ,  128 . For a more detailed description of the generator  200  and/or system  300  reference is made to commonly owned U.S. application Ser. No. 10/427,832. 
         [0018]    With continued reference to  FIG. 1 , the electrosurgical apparatus can be any suitable type of electrosurgical apparatus, including but not limited to electrosurgical apparatuses that can grasp and/or perform any of the above mentioned electrosurgical procedures. As noted above, one type of electrosurgical apparatus may include bipolar forceps  10  as disclosed in United States Patent Publication No. 2007/0173814 entitled “Vessel Sealer and Divider For Large Tissue Structures”. A brief discussion of bipolar forceps  10  and components, parts, and members associated therewith is included herein to provide further detail and to aid in the understanding of the present disclosure. 
         [0019]    Bipolar forceps  10  is shown for use with various electrosurgical procedures and generally includes a housing  20 , a handle assembly  30  that includes a movable handle  40  and a fixed handle  50 , a rotating assembly  80 , a push button assembly  60 , a trigger assembly  70 , a shaft  12 , and an end effector assembly  100 , which mutually cooperate to grasp, seal and divide large tubular vessels and large vascular tissues. Although the majority of the figure drawings depict a bipolar forceps  10  for use in connection with endoscopic surgical procedures, the present disclosure may be used for more traditional open surgical procedures or laparoscopic procedures. 
         [0020]    Shaft  12  has a distal end  16  dimensioned to mechanically engage the end effector assembly  100  and a proximal end  14  that mechanically engages the housing  20 . In the drawings and in the descriptions which follow, the term “proximal,” as is traditional, will refer to the end of the forceps  10  that is closer to the user, while the term “distal” will refer to the end that is farther from the user. 
         [0021]    The distal end  16  may include one or more structures  250  (see  FIG. 3A , for example) that is/are configured to support each of the jaw members  110 ,  120  of end effector assembly  100 . The distal end  16  of shaft  12  may be configured to allow the jaw members  110 ,  120  to move from an open position, wherein the jaw members  110 ,  120  are disposed in spaced relation relative to one another, to a clamping or closed position, wherein the jaw members  110 ,  120  cooperate to grasp tissue therebetween. 
         [0022]    Forceps  10  includes an electrosurgical cable  410  that connects the forceps  10  to a source of electrosurgical energy, e.g., generator  200 , shown schematically in  FIG. 2 . As shown in  FIG. 2 , cable  410  is internally divided into cable leads  410   a,    410   b,    410   c,  and  425   b  which are designed to transmit electrical potentials through their respective feed paths through the forceps  10  to the end effector assembly  100 . 
         [0023]    For a more detailed description of shaft  12 , handle assembly  30 , push button assembly  60 , trigger assembly  70 , rotating assembly  80  and electrosurgical cable  410  (including line-feed configurations and/or connections) reference is made to commonly owned Patent Publication No., 2003-0229344, filed on Feb. 20, 2003, entitled VESSEL SEALER AND DIVIDER AND METHOD OF MANUFACTURING THE SAME. 
         [0024]    With reference again to  FIG. 1 , bipolar forceps  10  operatively couples to generator  200  such that jaw members  110 ,  120  may be heat activated. End effector assembly  100  is shown attached at the distal end  16  of shaft  12  and includes the pair of opposing jaw members  110  and  120 . 
         [0025]    Jaw member  110  includes an insulative jaw housing  117  and an electrically conductive seal plate  118  (seal plate  118 ). Insulator  117  is configured to securely engage the electrically conductive seal plate  118 . This may be accomplished by stamping, by overmolding, by overmolding a stamped electrically conductive sealing plate and/or by overmolding a metal injection molded seal plate. All of these manufacturing techniques produce an electrode having a seal plate  118  that is substantially surrounded by the insulating substrate. Within the purview of the present disclosure, jaw member  110  may include a jaw housing  117  that is integrally formed with a seal plate  118 . In embodiments, jaw housing  117  is made from a malleable, heat resistant material such that jaw housing  117  may flex or bend upon application of heat to jaw member  110  and/or seal plate  118 . That is, because the jaw members  110 ,  120 , or members associated therewith (e.g., seal plates  118 ,  128 ), are configured to move from opened to closed positions upon the application of heat thereto, so too should the jaw housings  117 ,  127 . 
         [0026]    Jaw member  120  includes a similar structure having an outer insulative housing  127  that is overmolded to capture seal plate  128  and configured to function as described hereinabove with regard to insulative housing  117 . 
         [0027]    In the embodiments illustrated in  FIGS. 3A-3C , each of the jaw members  110 ,  120  are in electrical communication with one or more cable leads (e.g.,  410   b,    425   b,  respectively) of cable  410 . 
         [0028]    Additionally, each of the jaw members  110 ,  120  are in electrical communication with one or more heating wires or cables  132  that operatively connects to one or both of the jaw members  110 ,  120 . In the embodiments illustrated in  FIGS. 3A-3C , heating cable  132  operatively connects to a heating element or filament  150  (filament  150 ) that is disposed between jaw members  110 ,  120 . In some embodiments, an insulative substrate (not explicitly shown) may be disposed between the filament  150  and each of the jaw members  110 ,  120  and/or their respective seal plates  118 ,  128 . The insulative substrate may facilitate in preventing shorts from occurring between the jaw members  110 ,  120 . Filament  150  is configured to heat one or both of the jaw members  110 ,  120  such that one or both of the jaw members  110 ,  120  transition from an open position to a closed position. With this purpose in mind, electrosurgical surgical energy is transmitted to filament  150  such that the electrical resistance of the filament  150  generates heat that enables one or both of the jaw members  110 ,  120  to transition form an open position to a closed position. In other embodiments, filament  150  is in the form of thermoelectric coolers (TEC&#39;s). 
         [0029]    In the illustrated embodiment, one or both of the jaw members  110 ,  120 , or portions thereof, are made from shape memory alloy (SMA) also referred to in the art as smart alloy, memory metal, and muscle wire. In some embodiments, seal plates  118 ,  128  are each made from shape memory alloy. Shape memory alloy suitable for use with the jaw members  110 ,  120  may include by are not limited to copper-zinc-aluminum-nickel, copper-aluminum-nickel, and nickel-titanium (NiTi), commonly referred to in the art as Nitinol) alloys. In some embodiments, the SMA may be configured for one-way or two-way shape memory effect. Each of the seal plates  118 ,  128  may include a non-stick surface  142  such as, for example, a wire mesh made from PTFE that facilitates tissue from sticking to the seal surfaces of the seal plates  118 ,  128 . 
         [0030]    Operation of bipolar forceps  10  is now described. For illustrative purposes, operation of forceps  10  is described in terms of an SMA that is configured for two-way shape memory effect. In this instance, the SMA associated with each of the sealing plates  118 ,  128  of jaw members  110 ,  128 , respectively, remembers two different shapes, a “cold” shape (e.g., jaw members are in an open position) and a “hot” shape (e.g., jaw members are in a closed position). For purposes herein, M f  is the temperature at which the transition to a martensite phase or stage is finished during cooling, and A s  and A f  are the temperatures at which the transition from the martensite phase to austenite phase starts and finishes, during heating. A s  may be determined by the SMA material and composition and, typically, ranges from about −150° C. to about 200° C. A f  may also be determined by the SMA material and composition and/or the loading conditions and, typically, ranges from about 2° C. to about 20° C. or hotter. 
         [0031]    The jaw members  110 ,  120  initially may be in an open position. This open position is a result of the SMA associated with the seal plates  118 ,  128  being in a cold state, that is, the SMA is in a martensite state (e.g., M f  a point below A s ). A user positions tissue between the jaw members  110 ,  120 . A user may then activate the generator  200 , for example, by way of switch  60  which may instruct one or more modules (e.g., a control module) to transmit electrosurgical energy to the heating filament  150  via heating cable  132 . As heating element  150  “heats up” it causes the seal plates  118 ,  128  to “heat up” as well. As the seal plates  118 ,  128  reach an austenite state (e.g., A s ) they begin to transition from their “cold” shape to their “hot” shape, which, in turn, causes the jaw members  110 ,  120  to move, i.e., bend or flex, toward one another. During the austenite phase transition (e.g., A s →A f ), the jaw members  110 ,  120  continue to move toward one another until the jaw members  110 ,  120  reach a threshold or final austenite stage (A f ). At this stage of the austenite phase, the jaw members are capable of grasping tissue such that a desired tissue effect may be achieved. Once tissue is securely and properly grasped between the jaw members  110 ,  120 , electrosurgical energy may be transmitted to one or both of the seal plates  118 ,  128  of the jaw members  110 ,  118 , respectively to cause a tissue effect therebetween. As the temperature of the seal plates  118 , 128  cools, the SMA associated with each of the seal plates  118 ,  128  transitions from the austenite stage back to the martensite stage such that the jaw members  110 ,  120  and/or seal plates  118 ,  128  are caused to return to their initial open positions. 
         [0032]    From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example, a knife or cutter blade configured to divide tissue after a desired tissue effect (e.g., tissue seal) has been achieved may be operatively disposed at the distal end of the end effector assembly  100  and in operative communication therewith. 
         [0033]    It is contemplated that each of the jaw members  110 ,  120  may include one or more channels  160  ( FIG. 3A ) that operatively couples to a fluid source  500  (via a fluid tube  502 , see  FIG. 1  for example), which may be in operative communication with the generator  200  and/or system  300  and configured to circulate a suitable fluid (e.g., saline or other suitable fluid) therethrough. As described herein, fluid may be defined as a gas, liquid, or combination thereof. More particularly, the fluid source  500  may circulate chilled saline to the channels  160  operatively disposed on one or both of the jaw members  110 ,  120 . In this instance, the chilled saline is intended reduce or “bring down” the temperature of one or both of the seal plates  118 ,  128  of jaw members  110 ,  120 , respectively, after the seal plates  118 ,  128  have reached the A f  phase. 
         [0034]    It is contemplated that system  300  may include a module (e.g., fluid control module) that is configured to regulate the fluid source. For example, the control module and/or fluid control module may control the amount, rate, and/or temperature of fluid flow provided by the fluid source  500 . 
         [0035]    It is further contemplated that a sensor module senses electromagnetic, electrical, and/or physical parameters or properties at the operating site and communicates with the control module and/or fluid control module. The sensor module may be configured to measure, i.e., “sense”, various electromagnetic, electrical, physical, and/or electromechanical conditions, such as at or proximate the operating site, including: tissue impedance, tissue and/or seal plate  118 ,  128  temperature, pressure, etc. For example, sensors of the sensor module may include sensors  316  (see  FIG. 3A  for example) and/or other suitable sensors (e.g., optical sensor(s), proximity sensor(s), etc). The sensor module measures one or more of these conditions continuously or in real-time such that the control module  304  can continually modulate the electrosurgical output and/or control the vacuum source  500 . 
         [0036]    It is envisioned that in some embodiments, one or more of the sensors (e.g., sensors  316 ) may include a smart sensor assembly (e.g., a smart sensor, smart circuit, computer, and/or feedback loop, etc. (not explicitly shown)). For example, the smart sensor may include a feedback loop which indicates when a tissue seal is complete based upon one or more of the following parameters: tissue and/or seal surface temperature, tissue impedance at the seal, change in impedance of the tissue over time and/or changes in the power or current applied to the tissue over time. An audible or visual feedback monitor may be employed to convey information to the surgeon regarding the overall seal quality or the completion of an effective tissue seal. 
         [0037]      FIG. 5  shows a method  500  for performing an electrosurgical procedure. At step  502 , an electrosurgical apparatus including a pair of jaw members configured to grasp tissue therebetween is provided. At step  504 , tissue is positioned between the jaw members. At step  506 , the electrosurgical energy source is activated causing the first and second jaw members to move towards each other such that tissue is grasped therebetween. And at step  508 , electrosurgical energy is applied to the jaw members such that a desired tissue seal may be effected therebetween. 
         [0038]    While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.