Abstract:
One embodiment of the present invention relates to an electrosurgical handpiece that has a first main body and a second main body. A squeezable handle connects to and across the first main body and the second main body such that, when the handle is unsqueezed, the first main body and the second main body assume a first position relative to one another. When the handle is squeezed, the first main body and the second main body assumes a second position relative to one another. An active electrosurgical electrode is slidingly mounted within the second main body and extends from the second end. A spacer is positioned around and in sliding engagement with the smaller diameter region of the first main body.

Description:
BACKGROUND 
       [0001]    This Application claims priority to U.S. Provisional Patent Application No. 62/337,802 entitled Depth Control for Electrosurgical Electrode, filed May 17, 2016, the entirety of which is hereby incorporated by reference. 
       BACKGROUND 
       [0002]    The present invention relates to surgery and, more specifically, the present invention relates to back surgery. Specialized back surgery on or in-between vertebrae of the spine and on spinal discs involves various meticulous surgical procedures which can be challenging, even for experienced surgeons who specialize in this particular surgery. Minimally invasive techniques are preferred over traditional open surgical procedures which require extensive operating time and post-operative recovery time. 
         [0003]    When employing minimally invasive surgical techniques on or between spinal vertebrae or on discs, one of the challenging requirements relates to providing electrodes of an electrosurgical device into the operative field. More specifically, care must be taken to ensure that the electrode penetrates the vertebrae or other areas of the spine to a proper depth. To accomplish this, surgeons often are careful when positioning or actuating electrosurgical instruments to ensure that electrode only travels a certain distance into the operative field. 
       SUMMARY OF THE INVENTION 
       [0004]    One embodiment of the present invention relates to an electrosurgical handpiece that has a first main body having a larger diameter region and a smaller diameter region. The larger diameter region has a first main body face extending radially from the smaller diameter region to the larger diameter region. 
         [0005]    a second main body has an outer surface and an axially oriented aperture defining an inner surface. The second main body has a second main body face axially extending from the inner surface to the outer surface, wherein the inner surface slidingly engages the smaller diameter region of the first main body. The first main body face faces the second main body face. The second main body has a first end proximate the first main body and a second end distally located from the second main body. 
         [0006]    A squeezable handle connects to and across the first main body and the second main body such that, when the handle is unsqueezed, the first main body and the second main body assume a first position relative to one another. When the handle is squeezed, the first main body and the second main body assumes a second position relative to one another. 
         [0007]    A spring is located in the aperture and biases against the smaller diameter region to bias the first main body and the second main body into their first position. 
         [0008]    An active electrosurgical electrode is slidingly mounted within the second main body and extends from the second end. The active electrosurgical electrode is affixed to the first main body. 
         [0009]    A spacer is positioned around and in sliding engagement with the smaller diameter region of the first main body. The spacer has a first face facing the first main body face and a second face facing the second main body face. 
         [0010]    The first face contacts the first main body face and the second face contacts the second main body face when the first main body and the second main body are in the second position. 
         [0011]    An axial width of the spacer controls a length at which the active electrosurgical electrode extends from the second end of the second main body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of an electrosurgical instrument according to one aspect of the invention; 
           [0013]      FIG. 2  is a plan view of an electrosurgical instrument according to one aspect of the invention; 
           [0014]      FIG. 3  is a cross-sectional view of an electrosurgical instrument according to an aspect of the invention; 
           [0015]      FIG. 4  is a perspective view of a spacer according to an aspect of the invention; 
           [0016]      FIG. 5  is a plan view of a set of spacers according to an aspect of the invention; 
           [0017]      FIG. 6A  is a cross sectional view of an electrosurgical instrument with a spacer according to an aspect of the invention; 
           [0018]      FIG. 6B  is a cross sectional view of an electrosurgical instrument with a spacer according to an aspect of the invention; 
           [0019]      FIG. 7  is a perspective view of a spacer according to an aspect of the invention; 
           [0020]      FIG. 8  is a cross sectional view of a spacer according to an aspect of the invention; 
           [0021]      FIG. 9  is a plan view of a spacer according to an aspect of the invention; and 
           [0022]      FIG. 10  is a plan view of a portion of an electrosurgical instrument according to an aspect of the invention; 
           [0023]      FIG. 11  is a plan view of a portion of an electrosurgical instrument according to an aspect of the invention; 
           [0024]      FIG. 12  is a plan view of a portion of an electrosurgical instrument according to an aspect of the invention; and 
           [0025]      FIG. 13  is a plan view of a portion of an electrosurgical instrument according to an aspect of the invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0026]      FIGS. 1 and 2  show one form of electrosurgical handpiece  10  according to one aspect of the invention,  FIG. 3  shows a cross-sectional view, and  FIG. 4  shows another form of electrosurgical handpiece  10 . The present application incorporates U.S. Pat. Nos. 7,101,370; 6,357,533 and 7,905,882 in their entirety by reference. It will be observed that the cross-sectional view of the handpiece interior of  FIG. 3  is identical to that of  FIG. 2 . It comprises a squeezable handle  12  assembly connected to and across two front  14  and rear  16  main slideable coaxially-aligned body parts enclosing an elongated outer tubular housing  18  from whose distal end  20  an inner electrode assembly  22  can be extended and retracted when the handle  12  is squeezed or released, respectively. The handpiece common axis is designated  8  in  FIG. 2 . At the right end an electrical cord  26  is terminated in a plug connector (not shown). Internally of the handpiece, wires of the electrical cord  26  are connected to the active electrode assembly  22 . The outer tubular housing  18  extends from the front at the left and through the center of the front body part  14 . Although the tubular housing  18  is shown as tubular or cylindrical, it will be appreciated that other shapes such as diamond, oval, square or any other shape may be employed. The front body part  14  contains a bore  32  which houses a compression spring  34  engaged by a reduced diameter projecting member of the rear body part  16 . The compression spring  34  biases apart the two body parts  14 ,  16 . In one aspect, the handle  12  keeps the body parts  14 ,  16  from relatively axially rotating. However, the body parts may be keyed or other means to keep the two body parts from rotating. Each of the front and rear handle parts, designated generally  64  and  66 , are rigid members from their lowest points, designated  88 ,  90 , to where they join at the fulcrum axis  70 . The electrode assembly, in one aspect, is affixed in rear body part  16  and slidable in tubular housing  18  such that squeezing of handle  12  causes electrode assembly  22  to extend from distal end  20 . 
         [0027]    Referring now to  FIG. 4 , a spacer according to one aspect of the present invention is shown and described. Generally, the spacer is used in connection with an electrosurgical instrument to control the depth at which the electrode, extending from the instrument, penetrates the operative field during surgery. In the illustration, the spacer  100  is generally cylindrical in shape having an outer surface  101  and an inside diameter or ID  112 . An entrance  106  is shown that provides a passage from the external environment around the spacer  100  into the interior for reasons that will be described. Chamfer regions  108  are located at the entrance  106  on each of the upper portion  102  and lower portion  104 . A tab or grip  110  extends from the outer surface  101 . In one aspect the grip  110  has gnarling or abrasive surfacing to permit easier gripping by an individual using the spacer. 
         [0028]    Referring to  FIG. 6A , spacer  100  is shown being used in conjunction with an electrosurgical instrument  10 . In the illustration, spacer  10  encapsulates outside diameter or OD  114  of the body part  16  that engages with the body part  14 . As such, in one embodiment, ID  112  rides atop OD  114  such that ID  112  and OD  114  are in sliding engagement. Accordingly, in operation, when the handles  12  are actuated, as shown in  FIG. 6B , face  116  approaches face  118 . Likewise, face  120  approaches face  122  until each of the respective faces contact each other. Once these faces contact, the movement of the body part  16  stops with respect to body part  14  and the travel of the electrode  22  exiting the electrosurgical instrument is set. Accordingly, the width of the spacer  110  dictates the amount of travel that body part  16  can travel with respect to body part  14 . Thus, for example, looking at  FIG. 6B , the distance the electrode is able to extend from the end of the electrosurgical instrument is shortened by distance  182  which corresponds to the width of the spacer. 
         [0029]    To position the spacer  110  around OD  114 , grip  110  is first gripped by the fingers of the surgeon or the operator. Next, the surgeon presses the chamfer regions  108  against the OD  114  such that the elastic material of the spacer  100  flexes to permit upper portion  102  to move away from lower portion  104  and permit the upper portion  102  and lower portion  104  to slide over the OD  114 . The spacer may be made of a malleable or flexible material, soft plastic or rubber, to permit elastic deformation of the spacer to move around the OD  114 . 
         [0030]    As shown in  FIG. 5 , spacer  100  may come in a set of multiple spacers  100 A,  100 B,  100 C, and  100 D. Each of the spacers has a different width to provide depth control of an electrosurgical instrument to a different depth. For example, in one embodiment, the surgeon may select spacer  100 A which has a relatively thinner thickness to provide a relatively deeper depth or may select spacer  100 D that has a relatively thicker thickness to obtain a relatively shallower depth. 
         [0031]    Referring now to  FIG. 7 , another embodiment of the present invention is shown and described. In  FIG. 7 , a perspective view of the spacer  100  according to another aspect is illustrated. In the embodiment of  FIG. 7 , spacer  100  is shown as a fully encapsulated cylinder without any entrance such as entrance  106  in  FIG. 4 . As such, spacer  100  of  FIG. 7  is intended to reside permanently on the electrosurgical instrument at the location where spacer  100  is shown in  FIGS. 6A and 6B . In the present embodiment, adjustment, as will be described, of the spacer  100  changes the overall width of the spacer  0  change the resulting depth at which the electrode of the electrosurgical instrument may penetrate the operative field. 
         [0032]    With reference to  FIG. 8 , a cross-section of the spacer  100  is shown. In  FIG. 8 , spacer  100  is shown having a first portion  126  and a second portion  128 . The first portion  126  has a smaller outside diameter area  127  and a larger outside diameter area  129 . The second portion  128  includes threads located at an outside diameter of a portion residing next to and under the larger outside diameter area  129  of the first portion  126 . The threads on the outside diameter of the second portion  128  engage threads on the inside diameter of the larger outside diameter portion  129 . As such, the first portion  126  may be threaded together with the second portion  128 . 
         [0033]    The first portion  126  may be threaded toward or away from second portion  128 . In response thereto, the distance between face  118  and face  120  expands and contracts depending on which direction the two bodies are rotated with respect to one another. This movement changes the width of the overall spacer  110  to adjust the resulting depth of the electrode on the electrosurgical instrument similar to different choices of spacer with in the embodiment described with respect to  FIG. 4 . Thus, the overall distance  182  is a function of the width of the spacer which is changed as a function of the rotation of portions  126  and  128 . 
         [0034]    With reference to  FIG. 9 , the outer surface of second portion  128  is shown including markings  134 . The markings  134  may include various depth information (shown in this embodiment as 1, 2, and 3) that illustrates the depth or with of the spacer  100  or the penetration of the electrode into the operative field or any other meaningful information relating to the width of the spacer. One skilled in the art will understand that such depth or with may represent, for example, the depth at which the electrode of the electrosurgical instrument will penetrate the operative field or into a vertebrae for other spinal region. For example, instead of the number “1”, a number such as 2 mm may be etched on the surface to indicate that such is the depth associated with a spacer  100  with first portion  126  and second portion  128  rotated to a particular position. Other markings might indicate into which area of the spine the electrode will extend. For example, a setting of 1 might result in penetration just into the annulus or other region which settings of 2 or 3 might result in different depths. 
         [0035]    Referring now to  FIG. 10 , another embodiment of the present invention is shown and described. In  FIG. 10 , the body part  16  is shown engaged to body part  14 . Spacer  100  is shown having threads on its inside diameter that meet with threads on the outside diameter of the body part  16 . Accordingly, spacer  100  may be rotated on threads around body part  16  to move the spacer  100  closer or away from body part  14 . As such, face  120  gets closer or further from face  122 , thereby setting a gap and resulting in a setting of the depth at which the electrode of the electrosurgical instrument may penetrate the operative field. Similar to the previous embodiment, markings  134  may be etched on the side of the body part  16  to permit a depth setting to be understood and set by the surgeon using the electrosurgical instrument. 
         [0036]    Referring now to  FIG. 11 , another embodiment of the present invention is shown and described. In  FIG. 11 , an electrosurgical instrument  200  is shown having a plunger  202  slidingly engaged to a main body  204  through insertion of the plunger  202  into the main body  204  through the entrance  206 . An electrode is fixedly connected to the plunger  202  and passes through the main body  204  such that it passes through the outer tubular housing  18 . As seen in the figure, inner electrode assembly  22  extends from the outer tubular assembly  18 . In operation, compression of plunger  202  into main body  204  causes the inner electrode assembly  22  to extend from the outer tubular housing similar to that described in previous embodiments. 
         [0037]    Referring to  FIG. 12 , the plunger  202  is shown including a plunger portion  210  connected to a cap  212  by an inside region  216 . Threads  218  circumscribe the outside surface of the inside region  216 . While inside region  216  is affixed to plunger portion  210 , cap  212  is threaded on threads  218  to allow cap to rotate closer to and farther from plunger portion  210 . In one embodiment, raised portion  214  releases cap  212  upon pressing raised portion  214  to allow cap  212  to rotate about the threads to screw the cap down and up along the threads. When raised portion  214  is impressed, cap  212  can no longer rotate about the threads. By this way, rotation of the cap  212  can be actuated to control the depth of the electrode as discussed in previous embodiments and then locked into place once the desired depth is achieved. 
         [0038]    Referring now to  FIG. 13 , another embodiment of the invention is described. In  FIG. 13 , threads  218  are formed as a set of ribs. Raised portion  214  rides along the top of the ribs to permit cap  212  to ratchet-like move toward and away from the plunger portion and set the depth. In this way, the cap portion  212  to be ratcheted in and out to set the desired depth. 
         [0039]    In this specification, various preferred embodiments may have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The present invention is thus not to be interpreted as being limited to particular embodiments and the specification and drawings are to be regarded in an illustrative rather than restrictive sense. 
         [0040]    It will be appreciated that the system and methods described herein have broad applications. The foregoing embodiments were chosen and described in order to illustrate principles of the methods and apparatuses as well as some practical applications. The preceding description enables others skilled in the art to utilize methods and apparatuses in various embodiments and with various modifications as are suited to the particular use contemplated. In accordance with the provisions of the patent statutes, the principles and modes of operation of this invention have been explained and illustrated in exemplary embodiments. 
         [0041]    It is intended that the scope of the present methods and apparatuses be defined by the following claims. However, it must be understood that this invention may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. It should be understood by those skilled in the art that various alternatives to the embodiments described herein may be employed in practicing the claims without departing from the spirit and scope as defined in the following claims. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future examples. Furthermore, all terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims.