Abstract:
An electrosurgical device including a switch assembly having electronic circuitry positioned in a first plane, and a blade in electrical communication with the circuitry and fixedly positioned in a second plane spaced vertically apart from the first plane and substantially parallel thereto.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This is a continuation-in-part of U.S. Design Patent Application Ser. No. 29/189,853 entitled CAUTERY DEVICE and filed Sep. 11, 2003. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates generally to electrosurgical devices. More particularly, the invention relates to electrosurgical cautery devices.  
       BACKGROUND AND SUMMARY OF THE INVENTION  
       [0003]     Handheld electrosurgical cautery devices desire improvement in their configuration to render them more readily controlled by a user. For example, such devices may be difficult to grip in a manner which enables fine positioning during use. It is also often difficult for a user to manipulate the electrical switch of the device in a desirable manner while positioning the device. With regard to the foregoing, the present invention is directed to an electrosurgical device.  
         [0004]     In a preferred embodiment, the device includes a switch assembly having electronic circuitry positioned in a first plane, and a blade in electrical communication with the circuitry and fixedly positioned in a second plane spaced vertically apart from the first plane and substantially parallel thereto.  
         [0005]     In another aspect, the invention relates to a housing for an electrosurgical cautery device. The housing preferably includes an electrically insulative elongate body having a forward tip end an aperture defined therethough for receiving a mode selection associated with an electrical circuit to be housed by the housing. The distance between a forward most portion of the aperture and the tip end of the housing is preferably less than about 0.6 inches, most preferably between about 0.4 and 0.5 inches.  
         [0006]     In yet another aspect, the invention relates to a coupler for coupling an electrosurgical blade to an electrical circuit. In a preferred embodiment, the coupler includes a conductive material having a first end configured to receive a portion of the blade and a second end configured to be engageable with a portion of the circuit. The second end also includes a substantially J-shaped portion that connects to an intermediate segment that bridges between the first and second ends. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     Further features of preferred embodiments of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the figures, which are not to scale, wherein like reference numbers, indicate like elements through the several views, and wherein,  
         [0008]      FIG. 1  is a perspective view of an electrosurgical device according to a preferred embodiment of the invention.  
         [0009]      FIG. 2  is a top plan view of the device of  FIG. 1 .  
         [0010]      FIG. 3  is a bottom plan view of the device of  FIG. 1 .  
         [0011]      FIG. 4  is a right side view of the device of  FIG. 1 .  
         [0012]      FIG. 5  is a partial exploded perspective view of the device of  FIG. 1 .  
         [0013]      FIG. 6  is an exploded perspective view of the cautery device of  FIG. 1 .  
         [0014]      FIG. 7  is perspective view of a coupler for use with the device of  FIG. 1 .  
         [0015]      FIG. 8  is a detailed view showing connection of the coupler of  FIG. 7  to a circuit board of the device of  FIG. 1 .  
         [0016]      FIGS. 9A-9C  show details of a lower body portion of a housing of the device of  FIG. 1 .  
         [0017]      FIGS. 10A-10C  show details of a upper body portion of a housing of the device of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0018]     With reference to the drawings, the invention relates to an electrosurgical device  10  having a housing  12 , an electrical cable  14 , a switch assembly  16 , a blade-holder or coupler  18 , and a blade  20 . A significant aspect of the invention relates to the relative short displacement between a mode selection button  22  associated with the switch assembly  16 , and an operative portion  24  of the blade  20 .  
         [0019]     The housing  12  is preferably of two-piece plastic construction and includes first and second mating elongate body portions  30  and  32 . The body portions  30  and  32  may be snap-fit together, mated by sonic welding, and by other conventional ways of joining mating plastic parts. The portions  30  and  32  are configured for housing the electrical switch  16  and providing access for the cable  14 , the coupler  18  and a portion of the blade  20 .  
         [0020]     With additional reference to  FIG. 6 , the first body portion  30  includes a rear end  34  and an opposite tip end  36 . The rear end  34  defines a cable aperture portion  38  and the tip end  36  defines a blade aperture portion  40 . A switch aperture  42  extends through the body portion  30  adjacent the tip end  36 . A raised window or frame  43  preferably surrounds the aperture  42  for aesthetics and to add additional material to help retain the button  22  laterally.  
         [0021]     The body portions  30  and  32  may be shaped and otherwise configured for aesthetics and to facilitate gripping thereof and to provide an aesthetically pleasing appearance. For example, the housing  12  preferably includes various contours and topographies, such as the topographies  41 , with the dimension of the housing  12  being generally tapered and increasing in dimension from the rear end  34  to the tip end  36 , and most preferably having a substantially abrupt increase in dimension, at point A. For example, the thickness or height of the housing increases by about fifty percent, increasing from about 0.5 inches to about 0.75 inches. Also, an underside portion  45  of the housing  12  immediately rearward of the abrupt increase indicated by point A is preferably substantially planar.  
         [0022]     The switch aperture  42  is configured according to the button  22  and preferably includes holes or slots  44  on opposite sides thereof for mounting of a portion of the switch assembly  16 , as explained below. The aperture  42  may be of various configurations, e.g., rectangular, round, etc., depending upon the switch assembly used. For example, in one alternative, the button  22  may be a pair of buttons and the aperture  42  a pair of apertures.  
         [0023]     The second body portion  32  is configured to mate with the first body portion  30  and includes a corresponding rear end  46  and an opposite tip end  48 . The rear end  46  defines a cable aperture portion  50  and the tip end  48  defines a blade aperture portion  52 .  
         [0024]     The electrical cable  14  is preferably a conventional electrical cable of the type used for electro-surgical cautery devices and includes an end  54  placeable in electrical communication with the switch assembly  16  and an opposite end  56  connectable to an electrical power device for supplying electrical power to the device  10 . The electrical power device may preferably be an electrical generator which provides a high frequency signal which is transmitted to the blade  20  via the cable  14  and a circuit associated with the switch assembly  16 . For cutting purposes, the generator may supply a continuous signal. For coagulation, the generator may supply a pulsed signal. The switch assembly  16  enables selection of a cutting signal, a coagulation signal, or no signal corresponding to an “off” condition.  
         [0025]     The switch assembly  16  preferably includes the selection button  22  and a membrane  60 , a pair of domes  62  and  64 , and a overmolded circuit  66 . In operation, the button  22  is activated to select cutting or coagulation signals via the circuit  66 . In the absence of a selection, no power is supplied. The domes  62  and  64  are made of a flexible electrically conductive sheet material, such as thin metal, and flex when depressed by the projections  84  and  86  to make contact with electrical contacts of the circuit  66  to complete an electrical circuit. Alternatively, the projections  84  and  86  may be configured to be integral with the button  22 .  
         [0026]     In this regard, while the button  22  is shown as a rocker type button of molded plastic construction, it will be understood that it and its associated structure could be of a variety of configurations so as to be suitable for manipulation by a user to serve to enable the device  10  to be turned of and off, i.e., such as push-buttons or other common switch components.  
         [0027]     Returning to  FIG. 6 , the button  22  includes a pair of pegs  68  located on opposite sides thereof substantially proximate the midpoint of the length of the button  22  for being received within the slots  44  of the aperture  42  to support the button  22  relative to the aperture  42  and to enable the button  22  to be rocked back and forth by a user.  
         [0028]     The button  22  includes a user contact surface  70  having plateaus  72  and  74  at opposite ends thereof for being contacted by a user to rock the button  22  between first and second depressed or activated positions, such as between a first position for selecting electrical power suitable for cutting purposes and a second position for selecting electrical power suitable for coagulation purposes. The user may apply pressure to maintain the button in the desired position and, upon release, the button will return to a neutral position wherein no power is supplied.  
         [0029]     Projections  76  and  78  project from an opposite surface  80  at locations below the plateaus  72  and  74 . The projections  76  and  78  are configured to urge against respective portions of a surface  82  of the membrane  60  when the button  22  is manipulated by depression of the plateau  72  or the plateau  74 .  
         [0030]     The membrane  60  is made of a flexible, electrically non-conductive material, such as rubber. The membrane  60  is preferably of one-piece construction and includes substantially rigid projections  84  and  86  also preferably made of rubber and extending from an opposite surface  88  thereof at locations generally aligned with the projections  76  and  78 . The projections  84  and  86  are configured to contact the domes  62  and  64 , respectively, which are received within apertures  90  and  92 , respectively, defined through a surface  94  of the overmolded circuit  66 .  
         [0031]     The overmolded circuit  66  provides an electrical circuit board  66   a  ( FIG. 8 ) substantially encased in an electrically nonconductive housing  95 , preferably as by overmolding the circuit board with a non-conductive plastic material. The overmolded circuit  66  includes an input end  96  into which the end  54  of the cable  14  extends for electrical communication with the encased circuit board  66   a  and an opposite output end  98  having an aperture  100  through which the coupler  18  extends. In this regard, wit will be understood that the aperture  100  is formed during molding as the molding process encases the circuit board  66   a  and a connecting portion  102  of the coupler  18  which is electrically connected to the board  66   a.    
         [0032]     With reference to  FIGS. 7 and 8 , the connecting end  102  of the coupler  18  preferably includes ears  101  which fit into corresponding apertures  103  of the board  66   a  and may be bent down to provide a mechanical connection. The end  102  may also be welded or soldered in place to enhance electrical communication.  
         [0033]     Returning to  FIG. 6 , a lower surface  104  of the overmolded circuit  66  is located opposite the surface  94  and the coupler  18  is situated adjacent the surface  104  in the assembled device  10 . The apertures  90  and  92  provide access to electrical contacts  106  and  108  of the overmolded circuit board. Activation of the contact  106  preferably enables application of a cutting signal and activation of the contact  108  preferably enables application of a coagulation signal. The general construction of circuit boards suitable for cautery devices and the encasement thereof, are well known in the art.  
         [0034]     The domes  62  and  64  flex when depressed by the projections  84  and  86  (as urged by the projections  76  and  78 ) and flex to make contact with electrical contacts  106  and  108 , respectively, of the circuit  66  to complete an electrical circuit for supplying desired power amounts to the blade  20 . For example, a user may hold down or depress the plateau  72  to urge the projection  86  against the dome  62  and thereby flex the dome  62  downwardly to make contact with the contact  106  of the circuit  66  and complete an electrical circuit configured to provide cutting power to the blade  20 . Likewise, depression of the plateau  74  preferably supplies coagulation power to the blade  20 . Absent depression of one of the plateaus  72  or  74 , the circuit is open and no power is supplied to the blade  20 .  
         [0035]     The coupler  18  is preferably of one-piece construction and made of a relatively rigid and electrically conductive material such as copper. The coupler  18  includes a sleeve  110  from which extends a strip  112 . Circumferential edge  111  of the sleeve is preferably flared outwardly.  
         [0036]      FIG. 7  shows the coupler  18  in a pre-assembly configuration. The coupler  18  preferably has the following length dimensions:  
                                                   Dimension   Distance (inches)                           D1   0.34           D2   0.70           D3   0.08                        
         [0037]     After installation of the coupler onto the board  66   a , as by connecting the ears  101  to the apertures  103  and applying a solder to enhance electrical communication, a portion of the strip  112  of the coupler  18  is preferably shaped as by bending to provide bend B to form the coupler  18  into a generally J-shape, wherein the strip  112  and the sleeve  100  of the coupler  18  are positioned below and closely adjacent the surface  104  of the overmolded circuit  66  ( FIG. 5 ).  
         [0038]     The blade  20  is a small surgical electrode with the operative end  24  preferably configured to provide a thin knife-like tip  24 ′which may be applied to a patient (who is generally grounded) during a surgical procedure. The blade  20  is generally replaceable and may be available in a variety of lengths and configurations. The small contact area of the portion of the tip  24 ′, when supplied with appropriate electrical current, enables cutting or cauterizing functions. The operative end  24  begins immediately adjacent the fitting  114  and extends to the end of the tip  24 ′. Thus, the distances described herein which reference the “operative end” of the blade will be understood to relate to the shortest distance to the operative end, i.e., to the beginning of the operative end and to be independent of the actual length of the operative end.  
         [0039]     The blade  20  also includes a non-operative connecting end  112  and an electrically insulative collet or fitting  114  frictionally located on the blade  20 , as by molding, between the non-operative end  112  and the operative end  24 . The end  112  is configure, preferably as a cylinder, to be received within the sleeve  110  of the coupler  18  and the fitting  114  is made of an electrically insulating material such as a plastic material. The fitting  114  is configured to be fittingly received by the blade aperture portions  40  and  52  when the body portions  30  and  32  of the housing  12 . In this regard, the collet  114  preferably includes a series of rings  116  which facilitate fixed positioning of the blade  20  relative to the housing  12 .  
         [0040]     Turning now to  FIGS. 9A-9C  and  10 A- 10 C, internal details of the body portions  30  and  32  of the housing  12  are configured to inhibit movement of the circuit, the coupler, and the blade. For example, the body portion  32  ( FIGS. 9A-9C ) includes channeled ribs  118  for snugly receiving the fitting  114 , channeled rib  120  for receiving the coupler  18 , and channel ribs  122  for receiving the end  112 . A stop or wall  124  is located behind the rearmost rib  120  to provide a barrier to rearward movement of the end  112 . In addition, it is preferred to include a pair of fingers  126  adjacent the forward edge of the rib  120  and spaced slightly forward thereof.  
         [0041]     The fingers  126  are configured, preferably as by tapering toward the rib  120 , to enable passage of the flared circumferential edge  111  of the sleeve  110  during installation of the coupler  18  onto the body portion  32 . However, once the coupler  18  is installed, the flared edge  111  is located in the space between the fingers  126  and the rib  120  and is of a larger dimension than the smallest passage dimension of the fingers. In this regard, it is noted that the flared edge  111  is preferably initially slightly greater in dimension than the smallest passage dimension of the fingers, yet expands to an even greater dimension when the blade  24  is inserted. However, during installation of the coupler  18 , the edge  111  is able to flex inwardly an amount sufficient to enable passage between the fingers  126 .  
         [0042]     The body portion  30  ( FIGS. 10A-10C ) preferably includes an internal wall  130  adjacent the forward tip end  36  and positioned between the aperture portion  40  and the aperture  42  so as to provide a barrier against forward movement (movement toward the tip end  36 ) of the coupler  18  in the assembled device  10 . In this regard, the wall  130  is located and configured to abut the bend B of the installed coupler  18 .  
         [0043]     A significant aspect of the invention relates to the location of the aperture  42  relative to the tip  36  of the housing  12 , and the configuration of the coupler  18  which cooperate to enable the relatively short displacement, as compared to prior devices, between the on/off button  22  and the operative portion  24  of the blade  20 . The device  10  enables the blade  20  to be located below the circuit  66  in the assembled device  10 , advantageously providing a configuration wherein the distances between the components of the device activated to provide power to the blade  20 , such as the plateaus  70  and  72 , and the operative end  24  of the blade  20  is reduced as compared to conventional cautery devices.  
         [0044]     For example, with reference to  FIG. 2 , the distance D 1  between a portion of the button  22  and the operative end  24  of the blade  20  is preferably less than about 0.9 inches and is most preferably from about 0.7 to about 0.85 inches. The distance D 2  defined between a portion of the button  22  and tip end  36  of the housing  12  is preferably less than about 0.6 inches and is most preferably from about 0.4 to about 0.5 inches.  
         [0045]     The foregoing description of certain exemplary embodiments of the present invention has been provided for purposes of illustration only, and it is understood that numerous modifications or alterations may be made in and to the illustrated embodiments without departing from the spirit and scope of the invention as defined in the following claims.