AU2002302033B2 - Electrosurgical Device Having a Dielectric Seal - Google Patents

Description

S&F Ref: 552252D1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Sherwood Services AG Schwertstrasse 9 CH-8200 Schaffhausen Switzerland Arthur L. Schoenman Joe D. Sartor Vernita Kelm Spruson Ferguson St Martins Tower,Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Electrosurgical Device Having a Dielectric Seal The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c ELECTROSURGICAL DEVICE HAVING A

DIELECTRICSEAL

BACKGROUND

1. Technial 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. Patent 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 gefierator.

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 undesirable 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 biocontamination and dielectric protection by inhibiting the ingress of fluids and contaminants through the nose and the 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 the actuator areas.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages or at least to provide a useful alternative.

2 [R:\LIBTTJ03158.doc:hxa Summary of the Invention There is disclosed herein a method of manufacturing a seal on an electrosurgical device, said method comprising the steps of: placing components of the electrosurgical device within an elongated housing section, said housing section including an actuator opening; introducing the housing section within a mould filled with a liquid thermoplastic elastomer; and allowing the elastomer to cure and become integral with the housing to seal the components within the housing section.

Preferably, the method further comprises the step of forming an elastomeric actuator seal around the actuator opening.

Preferably, the method further comprises the step of insert moulding two inserts within the actuator seal to identify the cutting and coagulating modes.

Preferably, the method further comprises the step of forming an elastomeric lip portion circumferentially surrounding an opening at a distal end of the electrosurgical device for introducing an electrode therein prior to the step of allowing the elastomer to cure.

3 [R:\LIBTT]031 58.doc:hxa:KEH Brief Description of the Drawings A preferred embodiment is described herein with reference to the drawings, wherein: FIG. I 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 4 [R:\LIBTT]03158.doc:hxa 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. 1.0 is an enlarged, perspective view of the rotary gear of the counting mechanism; FIG. 11I 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 elastoineric 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 elcetrosurgical device; FIG. 16 is a cross-sectional view taken along line 16-16 in FIG. 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. having an electrode attached thereto; FIG. I8A 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 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 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. I 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 s 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 cfhimes device 10 is plugged into an ilecticaI generator 28. Electrical cord 26 preferably includes a silicone extruded jacket having three polytetrafluoroethyl ene insulated conductors therein and is approximately 4.5 meters in length. Switching mechanism 14 is fhrrher 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 theretbrough having a female hex 38 in proximity to a female electrode receptacle 39 which receives electrode sleeve 40 (FIG. It is contemplated thiat receptacle 39 can effectively retain a 3/32 inch diameter shank electrode fronm 0.6 to 0.9 inches in exposed length. An electrode's molded hex feature is inserted into receptacle 39 to prevent electrde 18 from rotating.

A metallic tube member 42 matingly engages one end of tubular member 32. A distal portion of electrode 18 niatingly engages metallic tube member 42 when 2B electrode 18 is inserted within tubular member 32. Metallic tube member 42 also makes contact with a wire 4 embedded withn 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. 2A.

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. I and 4. An elastomeric actuator switch seal 521is also formed in and around rocker switch 24. It is contemplaied 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 formnation 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. Secon ds the polypropylene filled housing partialsection 22 is overinolIded with a polypropylene-based thermoplastic. elastomer to form the final outer shape of device 10 including a soft lip 54 (FIG. 4C) round nose area 20 to maintain electrode sleeve 40 in place while preventing fluids from entering nose area 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 detail1. Each insert 56 which is insert molded within actuator seal 52 corresponds to a respective rocker ann 58 of rocker switch 24. Rocker switch 24 is h~ld in place by a support plate 60 which is press-filled 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 racross 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 With reference to FIGS. 6A and 613, switch contact plate 65 includes prongs 74 on both ends for embedding plate 65 within molding 46 (FIGS. 4A and 4D).

One prong 74A makes contact with wire 4 and other prongs 74B1, 74C and 74D make contact with wires 55 to provide cutting and coagulating electrical connections between wires 55 and electric generator 28. It is noted that prong 74C is connected to wire 4 via central connection or power bus 75 to provide grounding for both the cutting and coagulating electric circuits.

Switch contact plate 65 furthecr 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 correspond ing. station ary contact 628 and create an el ectrical 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 90a and 90b 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.

1 0) includes a cylindrical bead 98 having a marker 100 on a iop 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 niatingly engage a first cylindrical member 1 10 on housing half-section Counting 8car 94 includes a circular head 112 designed to matingly engage a second cylindrical member 114 on housing half-secti on 90b. Circular head 112 includes an- arrow 116 on a top surface 118 for pointing to a counting sequence 120 on housing half-section 90a as counting gear 94 is rotated as further described below.

Counting gear 94 also includes a gear wheel 122 underneath circular head 112. Springbiased 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 F1G. 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 12 8 (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 gearwheel 122 to cause counting. gear 94 to turn count er-cloccwise. .This causes arrow 1]6 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, Afier a predetermined amount of insertion and removal operations of counting mechanism 16, a point identified as on gear wheel 122 (FIG. 13) comes in proximity to rotary gear 92. Point 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'90a. It is contemplated that rotary gear 92 and counting gear 94 may be positioned during manufacturing such that point 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 showni herein as a mechanical or analog mechanism, it is als"o contemplated that the counter/disable mechanism can be electrical, magnetic, etc.

FJG. 1 3A 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 remoV'al 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 wvhich 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 p'ocedures. Electrosurgical device 152 introduces R.F 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 fingers .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. ISA, the diameter of elastic wall 176 of nose area 156 is less than the diameter of elongated body portion 162. The diameter 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 of lip portion 174 is shown to be less than the diameter 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 electrosurgicaI device. It is further contemplated that sea] 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. 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.

Claims (4)

1. A method of manufacturing a seal on an electrosurgical device, said method comprising the steps of: placing components of the electrosurgical device within an elongated housing section, said housing section including an actuator opening; introducing the housing section within a mould filled with a liquid thermoplastic elastomer; and allowing the elastomer to cure and become integral with the housing to seal the components within the housing section. t0

2. The method of Claim 1, further comprising the step of forming an elastomeric actuator seal around the actuator opening.

3. The method of Claim 2, further comprising the step of insert moulding two inserts within the actuator seal to identify the cutting and coagulating modes.

4. The method of Claim 1, further comprising the step of forming an elastomeric lip portion circumferentially surrounding an opening at a distal end of the electrosurgical device for introducing an electrode therein prior to the step of allowing the elastomer to cure. Dated 1 February 2005 Sherwood Services AG Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON 14 [R:\LIBTT1031 58speci.doc:hxa: KEH