Abstract:
A surgical instrument includes a reusable base component including a handle and an electrically activatable modular component removably coupled to the base component. The modular component includes an end effector operable from the handle to treat tissue. The end effector is responsive to manipulation of the handle. A first energy storage component is disposed onboard the base component and is electrically coupled to a source of electricity. A second energy storage component is disposed onboard the modular component and is electrically insulated from the first energy storage component. The second energy storage component is arranged such that a current may be selectively induced in the modular component by delivery of electrical energy to the first energy storage component.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates generally the field of reusable surgical instruments. In particular, the disclosure relates electrical couplings for instruments having separable and replaceable components to provide clean, sterile or refurbished surfaces in each instance of use. 
         [0003]    2. Background of Related Art 
         [0004]    Instruments such as electrosurgical forceps are commonly used in open and endoscopic surgical procedures to coagulate, cauterize and seal tissue. Such forceps typically include a pair of jaws that can be controlled by a surgeon to grasp targeted tissue, such as, e.g., a blood vessel. The jaws may be approximated to apply a mechanical clamping force to the tissue, and are associated with at least one electrode surface to permit the delivery of electrosurgical energy to the tissue. The combination of the mechanical clamping force and the electrosurgical energy has been demonstrated to join adjacent layers of tissue captured between the jaws. When the adjacent layers of tissue include the walls of a blood vessel, sealing the tissue may result in hemostasis. Thereafter, the sealed tissue may be transected by advancing a knife through the jaws. A detailed discussion of the use of an electrosurgical forceps may be found in U.S. Pat. No. 7,255,697 to Dycus et al. 
         [0005]    In use, various tissue-contacting components of an electrosurgical forceps tend to become contaminated or degraded. For example, electrodes may become contaminated as portions of the treated tissue adhere to the tissue-contacting surfaces of the electrodes. Also, a knife blade may become dull and less effective in transecting sealed tissue after repeated use, even in a single surgical procedure. In order to provide clean electrodes and a sharp knife for a particular surgical procedure, a brand new instrument is often used. Once the procedure is complete, the used instrument is discarded. 
         [0006]    Instruments that are reusable for multiple procedures reduce the instrumentation costs per procedure. Some reusable forceps include a reusable component adapted for persistent use coupled to a removable and replaceable component adapted for limited use. The reusable component may include, for example, a control element such as a handle that remains primarily outside the surgical field. The handle may be constructed ruggedly to sustain regular and recurring usage in numerous surgical procedures. The removable and replaceable component may include a tool element, such as an end effector containing the delicate and tissue-contacting wear surfaces. Replacing a worn end effector to refurbish an instrument provides refreshed surfaces with minimal waste. 
         [0007]    Providing replaceable components for a reusable electrosurgical forceps, however, presents various challenges. For example, many of these instruments require arduous disassembly and reassembly procedures to ensure proper electrical continuity is provided between the reusable and replaceable components. Also, electrical couplings on the reusable component may be difficult to clean. 
       SUMMARY 
       [0008]    The present disclosure describes a surgical instrument for treating tissue. The instrument includes a reusable base component with a handle assembly and an electrically-activated modular component removably coupled to the base component. The modular component includes an end effector operable from the handle assembly to treat tissue, and the end effector is responsive to manipulation of the handle assembly to move between first and second configurations. A first energy storage component is disposed onboard the base component, and the first energy storage component is electrically coupled to a source of electricity. A second energy storage component is disposed onboard the modular component. The second energy storage component is electrically insulated from the first energy storage component and is arranged with respect to the first energy storage component such that a current may be selectively induced in the modular component by delivery of electrical energy to the first energy storage component. 
         [0009]    The first energy storage component may include a first inductive coil and the second energy storage component may include a second inductive coil. The second inductive coil may be inductively coupled to the first inductive coil such that a current is induced in the second coil in response to a current flow in the first coil. 
         [0010]    The source of electricity may be an electrosurgical generator, and the modular component may include at least one electrode. The electrode may be electrically coupled to the second coil and configured for delivering electrosurgical energy to tissue. 
         [0011]    The modular component may include pair of opposing jaw members, and one or both of the jaw member may be movable between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for clamping tissue therebetween. The end effector may include a sensor for detecting a parameter of the tissue treatment, and the sensor may be powered by the induced current in the second coil. The sensor may be a gap sensor configured to detect a separation distance between the opposing jaw members. 
         [0012]    The first energy storage component may include a first capacitor having a pair of conductive plates separated by a dielectric material. The second energy storage component may include a second capacitor having a pair of conductive plates arranged on opposite sides of the first capacitor. Each of the conductive plates of the second capacitor may be separated from a conductive plate of the first capacitor by a dielectric material. The conductive plates of the second capacitor may be arranged on a respective opposing jaw member. 
         [0013]    According to another aspect of the disclosure, a modular end effector for a surgical instrument includes an electrically-activated component and an inductor coil electrically coupled to the electrically-activated component. The end effector includes a contactless mechanical interface configured to removably couple the end effector to a corresponding interface on a base component of the surgical instrument. The mechanical interface is electrically isolated from the electrically-activated component. 
         [0014]    The end effector may include a pair of opposing jaw members, and one or both of the jaw members may be movable between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for clamping tissue therebetween. The electrically-activated component may include an electrode disposed on an opposed clamping surface of one of the jaw members, and the contactless mechanical interface may include a linkage for receiving reciprocal motion from the base component. The linkage may be operable to move the at least one of the pair of jaw members between the open configuration and the closed configuration. 
         [0015]    According to another aspect of the disclosure, a surgical instrument includes a reusable base component with a handle assembly and an elongated tube extending distally from the handle assembly. An electrically-activated modular component is removably coupled to the base component, and the modular component includes a pair of jaw members operable from the handle assembly and configured to move between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for clamping tissue. A first capacitor plate is operatively associated with the elongated tube, and a second capacitor plate is operatively associated with one of the jaw members. The second capacitor plate forms a capacitor with the first capacitor plate to capacitively couple the base component and the modular component. 
         [0016]    The first capacitor plate may be electrically coupled to a source of electrosurgical energy, the second capacitor plate may be electrically coupled to an electrode configured to deliver the electrosurgical energy to tissue. A pair of capacitor plates may be operatively associated with the elongated tube, and each of the jaw members may include a capacitor plate forming a respective capacitor with a respective capacitor plate of the elongated tube. 
         [0017]    The one of the jaw members may include a pair of capacitor plates straddling the first capacitor plate on the elongated tube. The pair of capacitor plates of the one of the jaw members may define legs of a generally U-shaped conductive portion of the first jaw member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the detailed description of the embodiments given below, serve to explain the principles of the disclosure. 
           [0019]      FIG. 1  is a perspective view of an endoscopic surgical instrument in accordance with an embodiment of the present disclosure having modular jaw members inductively coupled to a distal end of an elongated shaft; 
           [0020]      FIG. 2  is an enlarged, perspective view of a distal end of the instrument of  FIG. 1  depicting the modular jaw members separated from the elongated shaft; 
           [0021]      FIG. 3  is a perspective view of an alternate embodiment of an instrument in accordance with the present disclosure having a modular end effector separated from an elongated shaft; 
           [0022]      FIG. 4A  is a perspective view of an alternate embodiment of an instrument in accordance with the present disclosure having modular jaw members for capacitive coupling with an elongated shaft; 
           [0023]      FIG. 4B  is a cross-sectional view of the modular jaw members of  FIG. 4A  capacitively coupled to the elongated shaft; 
           [0024]      FIG. 4C  is a schematic view of a current path through tissue captured between the modular jaw members of  FIG. 4A ; 
           [0025]      FIG. 5  is a perspective view of an alternate embodiment of modular jaw members configured for capacitive coupling with an elongated shaft wherein multiple plates are employed; and 
           [0026]      FIG. 6  is an alternate embodiment of a surgical instrument in accordance with the present disclosure configured for use in open surgical procedures. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    Referring initially to  FIG. 1 , an embodiment of an electrosurgical instrument  10  is depicted. The instrument  10  includes a handle assembly  12 , an end effector  14  and an elongated shaft  16  therebetween. A surgeon may manipulate the handle assembly  12  to remotely control the end effector  14  through the elongated shaft  16 . This configuration is typically associated with instruments for use in laparoscopic or endoscopic surgical procedures. Various aspects of the present disclosure may also be practiced with traditional open instruments (see  FIG. 5 ), and in connection with endoluminal procedures as well. 
         [0028]    The instrument  10  is coupled to a source of electrosurgical energy, e.g., an electrosurgical generator  18 . The generator  18  may include devices such as the LIGASURE™ Vessel Sealing Generator and the Force Triad™ Generator as sold by Covidien. A cable  20  extends between the handle assembly  12  and the generator  18 , and includes a connector  22  for coupling the instrument  10  to the generator  18 . The connector  22  includes two prong members  22   a  and  22   h  that are dimensioned to mechanically and electrically connect the instrument  10  to opposite terminals, e.g., positive or active (+) and negative or return (−) terminals associated with the generator  18 . Thus, bipolar energy may be provided through the instrument  10 . Alternatively, the instrument  10  may be configured for delivering monopolar energy to the tissue. In a monopolar configuration, the instrument  10  delivers electrosurgical energy from an active terminal, e.g. (+), while a return pad (not shown) is placed generally beneath a patient and provides a return path to the opposite terminal, e.g. (−), of the generator  18 . 
         [0029]    To control the end effector  14 , the handle assembly  12  includes a stationary handle  24  and movable handle  26 . The movable handle  26  may be separated and approximated relative to the stationary handle  24  to respectively open and close the end effector  14 . A trigger  30  is also disposed on the handle assembly  12 , and is operable to extend and retract a knife  76  ( FIG. 3 ) through the end effector  14 . A footswitch (not shown) may be provided to initiate and terminate the delivery of electrosurgical energy to the end effector  14 . 
         [0030]    Referring now to  FIG. 2 , end effector  14  includes upper and lower jaw members  32  and  34 . Each of the modular jaw members  32 ,  34  is coupled to the elongated shaft  16  about a pivot pin  36 . The jaw members  32 ,  34  include respective proximal flanges  38 ,  40  extending into a bifurcated distal end of the elongated shaft  16 , where a respective bore  38   a ,  40   a  engages the pivot pin  36 . The proximal flanges  38 ,  40  are operatively associated with the movable handle  26  ( FIG. 1 ) to open and close the jaw members  32 ,  34 . The jaw members  32 ,  34  are movable between an open configuration where the jaw members  32 ,  34  are substantially spaced to receive tissue and a closed configuration where the jaw members  32 ,  34  are closer together to clamp the tissue therebetween. Retraction of the movable handle  26  induces the jaw members  32 ,  34  to move to the open configuration and separation of the movable handle  26  from the stationary handle  24  induces the jaw members  32 ,  34  to move to the closed configuration. 
         [0031]    Various mechanisms may be provided to operatively associate the movable handle  26  with the proximal flanges  38 ,  40 . For example, the movable handle  26  may be coupled to a reciprocating member (not shown) that extends through the elongated shaft  16  as described in commonly owned U.S. Pat. No. 7,255,697 to Dycus et al. The reciprocating member may engage cam slots (not shown) on each of the proximal flanges  38 ,  40  to change the position of both of the jaw members  32 ,  34  relative to the elongated shaft. This type of construction induces bilateral jaw motion. Other unilateral constructions are also envisioned in which only one jaw member  32 ,  34  moves with respect to the elongated shaft. 
         [0032]    When clamped about tissue, the jaw members  32 ,  34  may deliver electrosurgical energy to the tissue through a pair of opposed electrodes  42 ,  44 . The electrodes  42 ,  44  are configured to selectively apply an effective amount of pressure and electrosurgical energy to the tissue. The opposed electrodes are associated with opposite electrical potentials (+), (−) to permit an electrosurgical current to flow through the tissue situated between the jaw members  32 ,  34  to effect a tissue seal. 
         [0033]    The modular jaw members  32  and  34  are selectively removable from the elongated shaft  16  to facilitate replacement the jaw members  32 ,  34  following a surgical procedure. Replacement of the jaw members  32 ,  34  may serve to refurbish the instrument  10  for subsequent use. The pivot pin  36  may be spring loaded to retain the flanges  38  and  40  within the bifurcated distal end of the elongated shaft  16  when the instrument  10  is in use. Following an electrosurgical procedure, the spring loaded pivot pin  36  may be manipulated to release the used jaw members  32 ,  34  without requiring a cumbersome disassembly process. Thereafter, the pivot pin  36  may snap into a set of bores  38   a ,  40   a  of a clean, new or refurbished set of jaw members  32 ,  34 . 
         [0034]    In the illustrated embodiment, when the jaw members  32 ,  34  are connected to the elongated shaft, a contactless electrical coupling is established. The proximal flange  40  of lower jaw member  34  is inductively coupled to the elongated shaft  16  through a pair of spiral coils  48 ,  52 . The spiral coils  48 ,  52  form inductors, which store energy by generating a magnetic field when an electrical current is passed therethrough. The first coil  48  is disposed onboard the elongated shaft  16 , which forms part of a reusable base component of the instrument  10 . The first coil  48  is electrically coupled to the two prongs  22   a ,  22   b  of the connector  22  ( FIG. 1 ) through respective lead wires  48   a ,  48   b  extending through the instrument  10 . The two lead wires  48   a ,  48   b  may be associated with the opposite electrical potentials of the prongs  22   a  (+),  22   b  (−) The second coil  52  is disposed on board the modular jaw member  34 , which forms a replaceable component of the instrument  10 . The second coil  52  is electrically coupled to the two electrodes  42  (+) and  44  (−) of opposite electrical potential. 
         [0035]    The coils  48 ,  52  are constructed of an appropriate electrically conductive material, such as copper or stainless steel wire. The coils  48 ,  52  are separated by an electrically insulative material such that no direct contact exists between the coils  48 ,  52 . One or both of the elongated shaft  16  and the proximal flange  40  of the lower jaw member  34  may be constructed of an insulative material such as a ceramic or reinforced plastic that contains the respective coil  48 ,  52 . The insulative material protects the coils  48 ,  52  from mechanical damage, and may form a flat interface on the exterior of the respective component  16 ,  40  that may be cleaned without undue difficulty. 
         [0036]    The coils  48 ,  52  are arranged such that when the lower jaw member  34  is installed, the coils  48 ,  52  are axially aligned, and face-to-face in parallel planes. The two coils  48 ,  52  are spatially as close to one another as is practical since inductive coupling is most effective at short distances. In use, a current is supplied by the electrosurgical generator  18  ( FIG. 1 ) to the first coil  48 . The current in the first coil  48  generates a magnetic field passing through the second coil  52 . The magnetic field induces a current in the second coil  52  that is used to power the electrodes  42 ,  44 . 
         [0037]    Referring now to  FIG. 3 , an alternate embodiment of an instrument  60  includes a reusable base component  62  and a removable modular component  64 . The base component  62  includes a first elongated shaft portion  66   a  extending from a handle assembly  12  (see  FIG. 1 ), and the modular component  64  includes a second elongated shaft component  66   b  extending to an end effector  68 . The two elongated shaft portions  66   a ,  66   b  may be mechanically fastened to one another to permit mechanical motion of jaw members  72 ,  74  between open and closed configurations and advancement and retraction of an optional reciprocating knife blade  76  through the lower jaw member  74 . 
         [0038]    Advancement of the reciprocating knife  76  permits the transaction of tissue, particularly once the tissue has been sealed. To facilitate the mechanical motion of the jaw members  72 ,  74  and/or the knife blade  76 , the modular component  64  includes a first linkage  77   a  for receiving reciprocal motion from a corresponding second linkage  77   b  on the base component  62 . The first linkage  77   a  may be directly coupled to the knife  76  such that reciprocal motion of the first linkage  77   a  induces a corresponding reciprocal motion in the knife  76 . Alternatively or additionally, the reciprocal motion of the first linkage may be converted to pivotal motion of the jaw members  72 ,  74  through the use of cam surfaces (not shown) or other conventional mechanisms. The second linkage  77   b  extends to the handle assembly  12  ( FIG. 1 ) and may receive reciprocal motion therefrom. 
         [0039]    An electrical coupling between the modular component  64  and the base component  62  may be established by inductive coupling. The base component  62  includes a first coil  78  electrically coupled to the opposite poles of electrosurgical generator  18  ( FIG. 1 ). The modular component includes a second coil  80  that may be coupled to electrodes  82  and  84 . First and second coils  78 ,  80  are longitudinally arranged in respective elongated shaft portions  66   a ,  66   b . The elongated shaft portions  66   a ,  66   b  provide ample length for a significant number of coils. The coils  78 ,  80  are laterally separated from one another. Other configurations are envisioned, such as a coaxial configuration wherein one coil is situated longitudinally within the other. This type of electrical coupling permits a contactless mechanical interface to be established between the removable component  64  and the base component  62 . The mechanical interface may be contactless in that electricity is not transmitted through any of the mechanically engaging surfaces such that the mechanical interface is electrically isolated from the electrodes  82 ,  84 . 
         [0040]    In addition to the electrodes  82 ,  84 , other electrical devices may be included on the modular component  64  to be powered by a current flowing through the second coil  80 . For example, a gap sensor  86  is included on the lower jaw member  74 . The gap sensor  86  is configured to sense the separation or “gap distance” between the jaw members  72 ,  74 . An appropriate gap distance for generating an effective tissue seal may be between about 0.001 inches and about 0.006 inches. A gap distance between about 0.002 inches and about 0.003 inches may be preferred in some instances. The gap sensor  86  may include any suitable sensor such as optical sensor, and may receive power and communicate data with the electrosurgical generator  18  through the inductive coupling. An appropriate gap sensor is described in commonly owned U.S. Patent Application Publication No. 2009/0204114 to Odom. 
         [0041]    Referring now to  FIG. 4A , an alternate embodiment of an instrument  100  includes modular jaw members  102 ,  104  configured for non-contact, capacitive coupling with a base component  106 . The base component  106  includes a pair of electrically conductive plates  110   a ,  110   b  disposed at a distal end of an elongated shaft  112 . The plates  110   a ,  110   b  are coupled to the electrosurgical generator  18  ( FIG. 1 ) such that a first conductive plate  110   a  is coupled to a first terminal of the generator, e.g. active (+), and a second conductive plate  110   b  is coupled to a second terminal, e.g. return (−). The conductive plates  110   a ,  110   b  are separated by an electrically insulative, dielectric material  114 . A pair of dielectric plates  116   a  and  116   b  are disposed laterally exterior to the conductive plates  110   a ,  110   b.    
         [0042]    A proximal flange  118  of the upper jaw member  102  includes a flat-plate electrically conductive portion  120  adjacent a structural body portion  122 . Similarly, a proximal flange  124  of the lower jaw member  104  includes a flat-plate electrically conductive portion  126  adjacent a structural body portion  128 . The conductive plate portions  120 ,  126  are in electrical communication with respective electrodes  132 ,  134 . 
         [0043]    The modular jaw members  102 ,  104  may be assembled to the base component  106  as depicted in  FIG. 4B . The distal end of elongated shaft  112  is interposed between the electrically conductive plates  120 ,  126  of the jaw members  102 ,  104 . The dielectric plate  116   a  is interposed between conductive plates  110   a  and  120  to define a first parallel plate capacitor  136 . The conductive plate  120  of the upper jaw member  102  may thus be capacitively coupled to the base component  106 . The dielectric plate  116   b  is similarly interposed between conductive plates  110   b  and  126  to define a second capacitor  138 . The conductive plate  126  of the lower jaw member  104  may thus be capacitively coupled to the base component  106 . 
         [0044]    When the modular jaw members  102 ,  104  are assembled to the base component  106  and tissue “t” is captured between the electrodes  132 ,  134 , an electrosurgical current “I” may be induced through the tissue “t” as indicated in  FIG. 4C . Electrosurgical energy, such as electrosurgical current “I” at a predetermined output frequency and power may pass from a first terminal, e.g. an active terminal (+), of the generator  18  through the first capacitor  136  to upper jaw member  102 . The current “I” is transmitted through the active electrode  132  and the tissue “t” to return electrode  134 . The current “I” returns through second capacitor  138  to a second terminal, e.g., a return terminal (−), of the generator  18 . 
         [0045]    Referring now to  FIG. 5 , an alternate embodiment of a modular jaw member  152  is configured for capacitive coupling to a base shaft  154 . The modular jaw member  154  includes an electrically conductive plate  156  and an electrically conductive U-shaped portion  158  having a pair of generally flat legs or plates  158   a  and  158   b . The conductive plate  156  and U-shaped portion  158  are disposed in an insulative structural body portion  160 , and may be electrically coupled to an electrode (not shown) configured to deliver electrosurgical energy to tissue. The base shaft  154  includes first and second conductive plates  162 ,  164  each electrically coupled to an active terminal (+) of electrosurgical generator  18 . The conductive plates  162 ,  164  are disposed in an insulative body portion  166 . 
         [0046]    The modular jaw member  152  may be assembled to the base shaft  154  such that the U-shaped portion  158  of jaw member  152  straddles the first conductive plate  162  of the shaft  164 . In the assembled configuration, the first conductive plate  162  of the shaft  154  forms a parallel plate capacitor with each of the legs  158   a ,  158   b  of the U-shaped portion  158 . Additionally, the second conductive plate  164  of the shaft  154  forms a parallel plate capacitor with conductive plate  156  of the modular jaw member  152 . 
         [0047]    A similar construction may be defined for an opposing jaw member (not shown) configured for capacitive coupling to a return terminal (−), of the generator  18 . Since each of the terminals (+), (−) of the generator  18  are capacitively coupled a respective jaw member, e.g., jaw member  152 , through plates, e.g.,  156 ,  158   a ,  158   b ,  162 ,  164  forming multiple capacitors, a greater current may be induced through tissue. 
         [0048]    With regard to  FIG. 6 , a forceps  200  configured for use in various open surgical procedures may also incorporate many of the features described above. Forceps  200  includes a pair of opposing elongated shafts  212   a  and  212   b  having an end effector assembly  230  attached to the distal ends  216   a  and  216   b  thereof, respectively. End effector assembly  230  is similar in design to end effector assembly  14  described above with reference to  FIG. 1 . End effector assembly  230  includes pair of opposing jaw members  232  and  234  that are pivotably connected about a pivot pin  265 , and which are movable relative to one another to grasp tissue. 
         [0049]    Each shaft  212   a  and  212   b  includes a handle  215  and  217 , respectively, disposed at the proximal end  214   a  and  214   b  thereof which each define a finger hole  215   a  and  217   a , respectively, therethrough for receiving a finger of the clinician. Finger holes  215   a  and  217   a  facilitate movement of the shafts  212   a  and  212   b  relative to one another which, in turn, pivot the jaw members  232  and  234  from an open position wherein the jaw members  232  and  234  are disposed in spaced relation relative to one another to a clamping or closed position wherein the jaw members  232  and  234  cooperate to grasp tissue therebetween. 
         [0050]    An electrosurgical cable  268  couples the instrument  200  to a source of electrosurgical energy, and conductive pathways  270  are provided to transmit electrosurgical energy to the jaw members  232 ,  234 . A knife trigger  280  is provided to induce a knife (not shown) to transect tissue captured between the jaw members  232 ,  234 . 
         [0051]    The jaw members  232  and  234  may be configured as modular and selectively removable components separable from the rest of the forceps  200 . The jaw members may be coupled with a contactless electrical interface as described above to connect the jaw members  232 ,  234  to the conductive pathways  270 . For example, an inductive coupling as described above with reference to  FIGS. 2 and 3  may be provided, or a capacitive coupling interface as described above with reference to  FIGS. 4A and 4B  may be selected. 
         [0052]    Although the foregoing disclosure has been described in some detail by way of illustration and example, for purposes of clarity or understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the appended claims.