Abstract:
An electrosurgical device is provided having at least one elastomeric seal capable of providing bio-contamination and dielectric protection by inhibiting the ingress of fluids and contaminants through the nose and actuator areas. The elastomeric seal is manufactured from a thermoplastic elastomer or resin which while in liquid form is placed within a mold. A housing section having the main circuit components and mechanisms of the electrosurgical device is then placed within the mold. Once the elastomer cures, the elastomeric seal seals the components and mechanisms within the housing partial-section. The elastomeric seal defines a flexible first opening at a distal end of the electrosurgical device to accommodate varying diameters of electrodes or blades connected to the nose area of the electrosurgical device. An actuator seal is also provided on the actuator area of the electrosurgical device to prevent fluids and contaminants from entering the electrosurgical device through the actuator area. Two buttons are insert molded within the actuator seal and are operatively associated with a self-cleaning switching mechanism within the housing section to operate the electrosurgical device between a cutting and coagulating mode. The actuator seal is also manufactured from a thermoplastic elastomer or resin.

Description:
PRIORITY 
     This application claims priority to U.S. Provisional Applications 60/101,489 and 60/105,367 filed on Sep. 23, 1998 and Oct. 23, 1998, respectively; the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     This disclosure relates generally to an electrosurgical device of the type having an actuator for alternating between a cauterizing and a cutting mode. More particularly, the present disclosure relates to an electrosurgical device having an elastomeric seal for providing bio-contamination and dielectric protection by preventing fluids from entering the nose and actuator areas of the electrosurgical device. 
     2. Background of the Related Art 
     Electrosurgical devices suitable for use in surgical procedures such as cauterizing, cutting and similar procedures are well known. For example, U.S. Pat. Nos. 3,648,001; 3,801,766; 4,827,911; 4,827,927; 5,088,997; 5,217,457; and 5,244,462, the contents of which are incorporated herein by reference, disclose such electrosurgical devices. Typically, these electrosurgical devices introduce RF cauterizing current, cutting current, or a blend thereof to a conductive blade inserted within a nose area of a longitudinal housing by means of a finger-operated switch actuating member disposed on the housing and electrically coupled to the electrode and a generator. Optionally, such devices include suction and irrigation capabilities. These features are typically controlled through control mechanisms contained within the electrosurgical device and are actuated with the actuating member or some other actuator disposed on the housing or on the generator. 
     In some procedures, the advancement of the blade into body tissue to perform a surgical procedure causes fluids and bio-materials to collect near the device adjacent the nose or actuator areas. These fluids and bio-materials may deposit on the control mechanisms and wires within the housing thereby making it difficult to sterilize and reuse the device. Additionally, conductive fluids can provide an undersirable conductive path from the electrode to the surgeon and other objects in the surgical site, if fluid enters the nose or actuator areas. 
     Accordingly, a need exists for an electrosurgical device where the main operating components and mechanisms are provided within a sealed environment to provide bio-contamination and dielectric protection. A need further exists for a method of manufacturing an electrosurgical device where the method provides at least one seal for the electrosurgical device. Another need which exists is for an electrosurgical device having a counting mechanism for indicating to an operator the number of times the device has been plugged into an electric generator. Still, a need exists for the counting mechanism to have a disable mechanism for preventing the electrosurgical device from being plugged into the electric generator after a pre-determined amount of insertion and removal operations. A need also exists for a seal that can be easily applied to an electrosurgical device, is inexpensive, simple and reliable and which provides bio-contamination and dielectric protection by inhibiting the ingress of fluids and contaminants through the nose and actuator areas. A need further exists for a seal that provides bio-contamination and dielectric protection by inhibiting the ingress of fluids and contaminants through the nose and actuator areas. 
     SUMMARY 
     In accordance with the present disclosure, an electrosurgical device is provided having at least one elastomeric seal capable of providing bio-contamination and dielectric protection by inhibiting the ingress of fluids and contaminants through the nose and actuator areas. The electrosurgical device is of the type used to perform cauterizing and cutting of body tissue by means of a finger-actuated switch actuating means. The elastomeric seal is manufactured from a thermoplastic elastomer or resin which is placed in liquid form within a mold. A housing partial-section having the main circuit components and mechanisms of the electrosurgical device is then placed within the mold. Once the elastomer cures, the elastomeric seal seals the components and mechanisms within the housing partial-section. The elastomeric seal defines a flexible first opening at a distal end of the electrosurgical device to accommodate varying diameters of electrodes or blades connected to the nose area of the electrosurgical device. 
     An actuator seal is also provided on the actuator area of the electrosurgical device to prevent fluids and contaminants from entering the electrosurgical device through the actuator area. Two buttons are insert molded within the actuator seal and are operatively associated with a self-cleaning switching mechanism within the housing partial-section to operate the electrosurgical device between a cutting and coagulating mode. The actuator seal is also manufactured from a thermoplastic elastomer or resin. 
     The preferred self-cleaning switching mechanism includes a switch contact plate having pair of movable contacts with contact faces. Each movable contact corresponds to a stationary contact positioned within a circuit mold. Each stationary contact has a contact face aligned with a respective contact face of the corresponding movable contact. As the actuator seal is depressed, contact faces of the movable and stationary contacts slide along each other to clean the contacts of, e.g., non-conductive corrosion and contaminants. 
     The electrosurgical device is further provided with a counting mechanism for counting the number of times the device is plugged into an electric generator. The counting mechanism is included at the proximal end of an electrical cord electrically connecting circuitry within the electrosurgical device and the electric generator. 
     Further, in accordance with the present disclosure, an elastomeric seal is disclosed which is manufactured separately from an electrosurgical device it is intended to seal. The seal defines a first opening at a distal end and a second opening at a proximal end for fitting the elastomeric seal over the electrosurgical device. An actuating member pocket is defined in proximity to the second opening for fitting the actuating member therein. The seal further includes a lip portion having an elastic wall circumferentially surrounding the first opening to accommodate varying diameters of electrodes. 
     In an alternate embodiment, an elastomeric seal is chemically adhered, if the seal is desired to be reusable, or mechanically attached, if the seal is desired to be disposable, to the nose area of an electrosurgical device to prevent fluids and bio-materials from entering the nose area and preventing establishment of a conductive path. It is contemplated that the seal can be friction fit to the nose area of the electrosurgical device as well. Preferably, the elastomeric seal includes a soft lip to permit electrodes and blades of varying diameters to be inserted and sealed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment is described herein with reference to the drawings, wherein: 
     FIG. 1 is a perspective view of an electrosurgical device having an elastomeric seal and a counting mechanism according to the present disclosure; 
     FIGS. 2 and 2A are perspective views of the electrosurgical device of FIG. 1 without the elastomeric seal; 
     FIG. 3 is a cross-sectional view taken along line  3 — 3  of FIG. 2; 
     FIG. 4 is a perspective view showing the bottom of the electrosurgical device of FIG. 1; 
     FIG. 4A is a cross-sectional view of the electrosurgical device of FIG. 1; 
     FIG. 4B is an enlarged view of the switch area shown in FIG. 4A; 
     FIG. 4C is an enlarged view of the tip area shown in FIG. 4A; 
     FIG. 4D is a cross-sectional view of the electrosurgical device of FIG. 1 having an electrode attached thereto; 
     FIG. 5 is an enlarged, side view of the self-cleaning switching mechanism of the electrosurgical device shown in FIG. 1; 
     FIG. 6 is an enlarged, side view of the self-cleaning switching mechanism being depressed to actuate the electrosurgical device shown in FIG. 1; 
     FIGS. 6A and 6B are enlarged, perspective views of a switch contact plate having a pair of moving contacts; 
     FIG. 7 is an enlarged, perspective view of the plug connector with an integral counting mechanism shown in FIG. 1; 
     FIG. 8 is an enlarged, top view of the plug connector of FIG. 7; 
     FIG. 9 is an exploded, assembly view of the plug connector detailing the counting mechanism; 
     FIG. 10 is an enlarged, perspective view of the rotary gear of the counting mechanism; 
     FIG. 11 is an enlarged, assembly view of the plug connector with the top half-section of the housing removed; 
     FIG. 12 is a top view of the inner components of the plug connector showing the counting mechanism; 
     FIG. 13 is a top view of the inner components of the plug connector and counting mechanism when the plug connector is inserted within the electric generator; 
     FIG. 13A is an alternative embodiment of the counting mechanism; 
     FIG. 14 is a perspective view of an elastomeric seal configured to fit over an electrosurgical device; 
     FIG. 15 is a perspective view of the elastomeric seal of FIG. 14 in place over an electrosurgical device; 
     FIG. 16 is a cross-sectional view taken along line  16 — 16  in FIG. 15; 
     FIG. 17 is an enlarged view of the tip area of the electrosurgical device shown in FIG. 16; 
     FIG. 18 is a cross-sectional view of the electrosurgical device of FIG. 15 having an electrode attached thereto; 
     FIG. 18A is an enlarged view of the electrode interface area of the electrosurgical device shown in FIG. 18; 
     FIG. 19 is a perspective view of the nose area of an electrosurgical device having an elastomeric seal according to a second embodiment adhered thereto; and 
     FIG. 20 is an enlarged, cross-sectional view taken along line  20 — 20  in FIG.  19 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     An electrosurgical device having a seal formed integrally with the electrosurgical device and two embodiments of an elastomeric seal for a standard electrosurgical device will now be described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. A self-cleaning switching mechanism and a counting mechanism for the electrosurgical device having the seal formed integrally therewith are also described. 
     While the electrosurgical device having a seal formed integrally or monolithically therewith and the two embodiments of the elastomeric seal of this disclosure are useful to provide bio-contamination and dielectric protection, particularly in arthroscopic procedures where there are large amounts of fluid at the surgical site, by preventing fluid from entering the nose and actuator areas of the electrosurgical device disclosed herein or other standard electrosurgical devices, other functions such as inhibiting contamination of the device or the devices the seals are fitted onto are also contemplated. 
     With reference to FIGS. 1-13, a preferred embodiment of an electrosurgical device having an integrally or monolithically formed seal, a self-cleaning switching mechanism and a counting mechanism which counts the number of times the device is plugged into an electric generator will now be described. FIG. 1 illustrates the electrosurgical device designated generally by reference numeral  10  having an elastomeric seal  12 , a self-cleaning switching mechanism  14  and a counting mechanism  16 . Electrosurgical device  10  is suitable for use in surgical procedures such as cauterizing, cutting and similar procedures. Electrosurgical device  10  introduces RF cauterizing current, cutting current, or a blend thereof to an electrode  18  (FIG. 4D) protruding from a nose area  20  by means of self-cleaning switching mechanism  14  disposed within housing partial-section  22 . Device  10  can be sterilized by accepted sterilization techniques such as, for example, autoclaving or EtO. 
     Self-cleaning switching mechanism  14  includes a rocker switch  24  capable of operating device  10  between a cutting mode and a coagulating mode. Counting mechanism  16  is included at a proximal end of electrical cord  26  for counting the number of times device  10  is plugged into an electrical generator  28 . Electrical cord  26  preferably includes a silicone extruded jacket having three polytetrafluoroethylene insulated conductors therein and is approximately 4.5 meters in length. Switching mechanism  14  is further described below with reference to FIGS. 4A and 4B and counting mechanism  16  is further described below with reference to FIGS. 7-13. 
     With reference to FIGS. 2-3, housing partial-section  22  includes an elongated body portion  30  supporting a tubular member  32  at a distal end  34 . Although shown as a housing half-section, other configurations of the housing are also contemplated such as third sections, quarter sections, full sections, etc. Tubular member  32  includes a bore  36  therethrough having a female hex  38  in proximity to a female electrode receptacle  39  which receives electrode sleeve  40  (FIG.  4 D). It is contemplated that receptacle  39  can effectively retain a {fraction (3/32)} inch diameter shank electrode from 0.6 to 0.9 inches in exposed length. An electrode&#39;s molded hex feature is inserted into receptacle  39  to prevent electrode  18  from rotating. 
     A metallic tube member  42  matingly engages one end of tubular member  32 . A distal portion of electrode  18  matingly engages metallic tube member  42  when electrode  18  is inserted within tubular member  32 . Metallic tube member  42  also makes contact with a wire  44  embedded within molding  46  to energize metallic tube member  42  and in turn energize electrode  18  upon depression of rocker switch  24  as further described below. 
     Body portion  30  includes an actuating member pocket  48  for exposing rocker switch  24  as shown by FIG.  2 . Body portion  30  further includes several protrusions  50  at a proximal end for supporting electric cord  26  as shown by FIG.  2 A. 
     Elastomeric seal  12  is formed in and around housing partial-section  22  to seal the various components and the self-cleaning switching mechanism  14  within housing partial-section  22  and form device  10  as shown by FIGS. 1 and 4. An elastomeric actuator switch seal  52  is also formed in and around rocker switch or actuator  24 . It is contemplated that actuator switch seal  52  provides a tactile response to the operator upon contact closure in either of the two positions: CUT or COAG (FIG.  1 ). 
     The formation of seal  12  entails introducing polypropylene within the bottom of body portion  30  of housing partial-section  22  to fill body portion  30  and add stiffness to electrosurgical device  10 . Second, the polypropylene filled housing partial-section  22  is overmolded with a polypropylene-based thermoplastic elastomer to form the final outer shape of device  10  including a soft lip  54  (FIG. 4C) around nose area  20  to maintain electrode sleeve  40  in place while preventing fluids from entering nose area  20 . 
     In forming actuator seal  52 , a pair of contact inserts  56  are positioned such that a contact insert  56  coincides with each end of actuating member pocket  48 . Polypropylene is then added to form actuator seal  52  and to also insert mold inserts  56  within seal  52 . One insert is colored yellow to designate the cutting mode and the other insert is colored blue to designate the coagulating mode. Preferably, the color yellow is used to identify the cutting insert and the color blue is used to identify the coagulating insert. 
     With reference to FIGS. 4A and 4B, self-cleaning switching mechanism  14  will now be described in greater detail. Each insert  56  which is insert molded within actuator seal  52  corresponds to a respective rocker arm  58  of rocker switch  24 . Rocker switch  24  is held in place by a support plate  60  which is press-fitted within housing partial-section  22 . Support place  60  includes two openings  62  in alignment with a respective protrusion  64  from rocker switch  24 . Each protrusion  64  is capable of contacting a switch contact plate  65  (see FIGS. 6A and 6B) which includes a pair of moving contacts  66  which engage a corresponding stationary contact  68  when rocker switch  24  is depressed for facilitating cutting or coagulating. Cutting is facilitated if the yellow insert is depressed and coagulating is facilitated if the blue insert is depressed. 
     As seen in FIGS. 5 and 6, to facilitate self-cleaning of contact faces  70  of moving contacts  66  and of contact faces  72  of stationary contacts  68 , stationary contacts  68  are angled with respect to moving contacts  66  and moving contacts  66  are slightly flexible so that contact faces  70  slide across contact faces  72  during operation of switching mechanism  14 . This eliminates buildup of non-conductive corrosion and contaminants on contact faces  50  and  52  during operation of electrosurgical device  10 . 
     With reference to FIGS. 6A and 6B, switch contact plate  65  includes prongs  74  on both ends for embedding plate  65  within molding  46  (FIGS.  4 A and  4 D). One prong  74 A makes contact with wire  44  and other prongs  74 B,  74 C and  74 D make contact with wires  55  to provide cutting and coagulating electrical connections between wires  55  and electric generator  28 . It is noted that prong  74 C is connected to wire  44  via central connection or power bus  75  to provide grounding for both the cutting and coagulating electric circuits. 
     Switch contact plate  65  further includes two rounded portions  76  capable of making contact with protrusions  64  of rocker arms  58 . Rounded portions  76  flex downwards when rocker switch  24  is depressed to cause one of the two moving contacts  66  to contact its corresponding stationary contact  68  and create an electrical connection between wires  55 , power bus  75 , wire  44  and electric generator  28 . 
     Counting mechanism  16  will now be described with reference to FIGS. 7-13. Counting mechanism  16  is provided within a plug connector  88 . Plug connector  88  includes a housing  90  having housing half-sections  90   a  and  90   b  for housing various components of counting mechanism  16  therein. Counting mechanism  16  includes a rotary gear  92 , a counting gear  94 , and a spring-biased member  96 . Rotary gear  92  (FIG. 10) includes a cylindrical head  98  having a marker  100  on a top surface  102  and a contact member  104  protruding from a lateral surface  106 . A gear wheel  108  is connected to one end of rotary gear  92 . Rotary gear  92  is designed to matingly engage a first cylindrical member  110  on housing half-section  90   b.    
     Counting gear  94  includes a circular head  112  designed to matingly engage a second cylindrical member  114  on housing half-section  90   b.  Circular head  112  includes an arrow  116  on a top surface  118  for pointing to a counting sequence  120  on housing half-section  90   a  as counting gear  94  is rotated as further described below. Counting gear  94  also includes a gear wheel  122  underneath circular head  112 . Spring-biased member  96  includes a cane-shaped member  124  and a spring  126 . Spring  126  is designed to rest upon a section of bar member  128  when counting mechanism  16  is not plugged within electric generator  28 . 
     Housing  90  further includes three openings  130  for placement of prongs  132  therein for creating an electrical connection between electric generator  28  and electrosurgical device  10 . Another opening  134  is also included for placement of a tubular cord housing  136  housing a proximal end of electrical cord  26 . Wires  55  extend from the proximal end of electrical cord  26  and are each electrically coupled to a corresponding prong  132  as shown by FIG.  12 . 
     When prongs  132  are plugged into electric generator  28 , the distal end of cane-shaped member  124  contacts electric generator  28  and is forced proximally to push spring  126  against bar-member  128  (FIG.  13 ). As cane-shaped member  124  moves proximally, a protrusion  140  makes contact with gear wheel  108  to turn rotary gear  92  clockwise. Consequently, as rotary gear  92  turns clockwise, contact member  104  makes contact with gear wheel  122  to cause counting gear  94  to turn counter-clockwise. This causes arrow  116  to point to a different position on counting sequence  120 . When counting mechanism  16  is removed from the electric generator  28 , spring  126  springs back to move cane-shaped member  124  distally. 
     After a predetermined amount of insertion and removal operations of counting mechanism  16 , a point identified as “X” on gear wheel  122  (FIG. 13) comes in proximity to rotary gear  92 . Point “X” does not include a gear for contact member  104  to contact and cause the rotation of counting gear  96 . Consequently, counting gear  96  remains stationary with arrow  116  pointing to the end of counting sequence  120 , thereby notifying the operator to dispose electrosurgical device  10  as indicated by the icon (hand and trash bin) on housing half-section  90   a.  It is contemplated that rotary gear  92  and counting gear  94  may be positioned during manufacturing such that point “X” comes in proximity to contact member  104  after a predetermined amount of insertion and removal operations, and not necessarily when arrow  116  points to the end of counting sequence  120 . Although shown herein as a mechanical or analog mechanism, it is also contemplated that the counter/disable mechanism can be electrical, magnetic, etc. 
     FIG. 13A depicts an alternative plug connector having a disable mechanism  142  for preventing the plug connector from being plugged into the electric generator after a pre-determined amount of insertion and removal operations. Disable mechanism  142  includes a sprocket  144  on gear wheel  122  which engages protrusion  146  on bar member  128  to prevent gear wheel  122  from turning counter-clockwise after gear wheel  122  has moved a pre-determined number of times. When sprocket  144  engages protrusion  146 , cane-shaped member  124  does not move proximally upon insertion into electric generator  28 , since gear wheel  108  is prevented from turning upon contact with protrusion  140 . 
     With reference now to FIGS. 14-18, an elastomeric seal of a first embodiment will be described which is designated generally by reference numeral  150 . Seal  150  of FIG. 14 is designed to fit upon a standard electrosurgical device of the type shown by FIG.  15  and designated generally by reference numeral  152 . Similarly to electrosurgical device  10 , electrosurgical device  152  is suitable for use in surgical procedures such as cauterizing, cutting and similar procedures. Electrosurgical device  152  introduces RF cauterizing current, cutting current, or a blend thereof to an electrode  154  protruding from a nose area  156  of a longitudinal housing  158  by means of a finger-operated switch actuating member  160  disposed on housing  158 . 
     Elastomeric seal  150  includes an elongated body portion  162  having a first opening  164  at a distal end  166  to accommodate varying diameters of electrodes or blades connected to electrosurgical device  152 . A second opening  168  is defined at a proximal end  170  for partially fitting elastomeric seal  150  over housing  158  of electrosurgical device  152  as shown in FIG.  15 . Seal  150  includes an actuating member pocket  172  in proximity to second opening  168  for fitting actuating member  160  therein. Seal  150  further includes a lip portion  174  and an elastic wall  176  in nose area  156  having a thickness that is greater than the thickness of body portion  162 , thus providing a more rigid structure, for allowing seal  150  to maintain electrode  154  in place while preventing fluids from entering nose area  156  as shown by FIGS. 16-17A. 
     As can be seen from FIG. 18A, the diameter “d” of elastic wall  176  of nose area  156  is less than the diameter “D” of elongated body portion  162 . The diameter “d 1 ” of lip portion  174  is less than the outer diameter of electrode  154  for seal  150  to further adhere to electrosurgical device  152  and prevent the ingress of contaminants. Lip portion  174  and elastic wall  176  also allow the accommodation of varying diameters of electrodes. Although the diameter “d 1 ” of lip portion  174  is shown to be less than the diameter “d” of elastic wall  176 , it is also contemplated that they can be the same diameter. 
     After use, seal  150  can be resterilized or disposed of. Elastomeric seal  150  can be sterilized by accepted sterilization techniques such as, for example, autoclaving or EtO. 
     It is contemplated that seal  150  can be custom-molded for a particular electrosurgical device. It is further contemplated that seal  150  covers the entire housing  158  of electrosurgical device  152 . Further still, it is contemplated that seal  150  fits snugly around housing  158  to a minimum of 32 mm beyond the closest active contact point of actuating member  160 . 
     With reference to FIGS. 19 and 20 there is shown an elastomeric seal of a second embodiment designated by reference numeral  200  and attached to nose area  156  of electrosurgical device  152 . Seal  200  is chemically adhered to the nose area  156  which allows for seal  200  to be reusable. It is also contemplated that seal  200  can be mechanically attached to nose area  156  by rivets or other type of mechanical structure for allowing seal  200  to be disposable. It is further contemplated that seal  200  can be friction fit to nose area  156  of the electrosurgical device as well. Elastomeric seal  200  includes a soft lip  202  and an opening  204 , as in the embodiment of FIGS. 14-18, to permit electrodes and blades of varying diameters to be inserted and sealed as shown by FIG.  20 . 
     It is contemplated that seal  200  can be custom-molded for a particular electrosurgical device. Seal  200  is preferably manufactured from shore A durometer silicone or a thermoplastic elastomer. Seal  200  can be sterilized by accepted sterilization techniques such as, for example, autoclaving or EtO. After use, seal  200  can be resterilized or disposed of. 
     It will be understood that various modifications may be made to the embodiments disclosed herein. The above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.