An electrosurgical electrode, a method of manufacturing the electrosurgical electrode, and an electrosurgical instrument comprising the electrosurgical electrode

Abstract

An electrosurgical electrode (1;23) comprises a conductive electrode main body (2;24) having a cutting part (3;25) configured for applying radio-frequency electrical energy to tissue and an opposite shank part (5;26) configured to be coupled to an electrosurgical instrument, and a covering (6;27) on at least a part of the conductive electrode main body (2;24) The covering (6;27) is a one-piece covering (6;27) comprised of a first covering part (15;32) on the shank part (5;26), and a second covering part (20;37) on the cutting part (3;25), which covering (6;27) preferably is provided by plastic injection molding on an electrode main body (2;24) made by metal injection molding.

Description

[0001] An elect rosurgical electrode, a method of manufacturing the elect rosurgical electrode, and an elect rosurgical instrument comprising the electrosurgical electrode

[0002] The present invention concerns an electrosurgical electrode of the kind comprising a conductive electrode main body having a cutting part configured for applying high-frequency electrical energy to tissue and an opposite shank part configured to be coupled to an electrosurgical instrument , and a covering on at least a part of the conductive electrode main body .

[0003] Electrosurgery includes using a single surgical instrument for both cutting and coagulation during surgery on a patient . The instrument can be an electrosurgical pencil (ESU) configured to remove tissue and control bleeding by use of the high-frequency electrical energy . Today most ESUs , as well as many other kinds of electrosurgical instruments , are fully disposable . Only few parts are replaceable or reusable .

[0004] A typically electrosurgical electrode has a non-stick coating provided on its cutting part in a dipping or spraying process , and a sleeve mounted around a part of the shank part in extension of the cutting part . Some electrosurgical electrodes has a further sleeve heat-shrinked to cover the transition between the sleeve and the non-stick coating . For electrosurgical electrodes having energy transmitting cutting areas of the cutting part with without non-stick coating, such cutting areas must be masked before dipping or spraying, and the non-stick coating must cure before the mask ( s ) can be removed . This conventional method of manufacturing an electrosurgical electrode requires many method steps , is timeconsuming, and thus expensive . It is a main aspect of the present invention to provide an electrosurgical electrode that can be manufactured in fewer method steps than a conventional electrosurgical electrode .

[0005] In another aspect of the present invention is provided an electrosurgical electrode which is cost-effective to produce .

[0006] In another aspect of the present invention is provided an electrosurgical electrode which is simple and efficient to manufacture .

[0007] In another aspect of the present invention is provided an electrosurgical electrode which efficiently inhibit s the buildup of charred tissue during an electrosurgical procedure on a patient ' s tissue .

[0008] In another aspect of the present invention is provided an electrosurgical instrument , e . g . an electrosurgical pencil , having the novel conductive electrode .

[0009] The novel and unique features whereby these and other aspects are achieved according to the present invention consist in that the covering is a one-piece covering comprised of a first covering part on the shank part , and a second covering part on the cutting part of the conductive electrode main body . The conductive electrode main body is the substrate for said covering .

[0010] The huge difference between the conventional electrosurgical electrodes and the electrosurgical electrode of the present invention is that the sleeve on the shank part and the coating on the cutting part are made unitary and constitutes a one- piece covering that can be made in one single application step . Thus the second covering part is an integral extens ion of the first covering part , wherein said first covering part of the covering of the present invention replaces the conventional sleeve on the shank part , and the second covering part replaces the conventional non-stick coating on the cutting part of the conventional electrosurgical electrode . Moreover, use of a heat-shrinked extra sleeve is not needed .

[0011] So in respect of the electrosurgical electrode of the present invention the first covering part of the one-piece covering acts as the sleeve , thus as an insulator . The first covering part also provides protection, and facilitates firm fastening of the electrosurgical electrode to the electrosurgical instrument . The second covering part of the one-piece covering acts as the coating on the cutting part that resist s the buildup of eschar, or at least facilitates easy removal of eschar in case of such eschar building-up despite if the potential nonstick properties of the covering .

[0012] The first covering part can conveniently be molded integral with the second covering part onto said shank part and said cutting part , respectively, in an injection molding process .

[0013] Preferably the first covering part and the second covering part can be made from the same material , preferably a plastic material , in which case the injection molding process may be a 1-component injection molding process ( IK) to apply e . g . a plastic material or silicone rubber to the relevant areas of the conductive electrode main body in one casting . However within the scope of the present invention a multi-component injection molding process (multi-K, such as 2K or 3K) is not excluded, as this process may be useful if two or more different materials are to be used for the one-piece covering of the present invention, e . g . either to provide a layered structure of the one-piece covering, and / or to make the one- piece covering so that the first covering part and the second covering part are of different , but fusible , materials in extension of each other . In principle the electrode conductive electrode main body, which serves as the substrate for the covering, can be made in any suitable casting process or by stamping, however in a preferred embodiment the conductive electrode main body is made by metal injection molding (MIM) .

[0014] In MIM, fine metal powders are mixed with a binder and injected into molds , in a manner similar to plastic injection molding . After molding, the binder is removed from the part , and the remainder is a compact part , which is sintered, whereby it shrinks . During sintering and subsequent shrinkage the surface structure of the substrate undergoes a microscopic change that improves bonding of the covering to said substrate .

[0015] Metal injection molding is generally known to the person skilled in the art and will not be discussed in further details , however it advantages is evident , in that use of metal injection molding for manufacturing the conductive electrode main body allows high-volume manufacturing of the finished electrosurgical electrode with high precision, tight tolerances , accurate details , and high bonding strength of the covering .

[0016] It may be preferred that the one-piece covering comprises a fluoropolymer, e . g . a polytetrafluoroethylene (FIFE ) and / or silicone . Most preferred the covering is entirely made of the polytetrafluoroethylene known under the trademark Teflon® . Teflon® is chemical inertness , durable , and has temperature resistance ranging up to 260 ° C, as well as excellent non-stick properties , that provides the required high resistance to building up of eschar and potential removal of said eschar in case the need arises .

[0017] A cutting area of the cutting part may be free of the second covering part in order to allow the radio-frequency electrical energy to be applied to the patient ' s tissue via said cutting area to make the necessary cuts during the electrosurgical procedure .

[0018] The shank part may have a free end part not covered by the first covering part , which free end part serves to obtain electric contact between the act ive conductive electrode main body and the electrical circuitry which carries current from the electrical generator leads to said conductive electrode main body . When the shank part is mounted to the electrosurgical instrument the first covering part on said shank part is conveniently configured with dimensions to firmly mount the electrosurgical electrode into a mounting end of a hand piece of the electrosurgical instrument .

[0019] The covering may conveniently have both non-stick and insulating properties as said covering functions as both the sleeve and the non-stick coating on the conductive electrode main body .

[0020] The electrosurgical electrode may be a blade electrode, wherein the cutting part is the blade , and wherein the cutting area is a free cutting edge . Such an embodiment of an electrosurgical electrode is particular useful for both disposable and nondisposable electrosurgical pencils .

[0021] Emphasi ze is made that the present invention is not limited to blade electrodes . Any design of electrosurgical electrodes is within the scope of the present invention, such as L-shaped, J- shaped, needle-shaped, loop electrodes , spatula and ball electrodes , etc . This list is not to be considered exhaustive , neither limiting the scope of the present invention .

[0022] The present invention further concerns a method of manufacturing an electrosurgical electrode , e . g . the electrosurgical electrode described above . Said method comprises the steps of a) manufacturing a conductive electrode main body having a cutting part and a shank part ; preferably the manufacturing method is metal injection molding, and b) overmolding the shank part with a first covering part , and the cutting part ( 3 ; 25 ) with a second covering part , wherein said first covering part and said second covering part is a one-piece covering, and wherein said first covering part and said second covering part are molded integral with each other .

[0023] Preferably the one-piece covering in step b) is made by IK plastic in ection molding using Teflon ® as the plastic material .

[0024] The present invention further concerns an electrosurgical instrument comprising the electrosurgical electrode described above ; preferably the electrosurgical instrument is an electrosurgical pencil .

[0025] The invention will now be described in further details with reference to the drawing, in which :

[0026] Fig . 1 is a perspective exploded side view of a first embodiment of an electrosurgical blade electrode according to the present invention,

[0027] Fig . 2 shows the same in assembled state ,

[0028] Fig . 3 is a perspective exploded side view of a second embodiment of an electrosurgical spatula electrode according to the present invention,

[0029] Fig . 4 shows the same in assembled state

[0030] Fig . 5 is a cross-sectional view along line V-V in fig . 1 Fig. 6 is a cross-sectional view along line VI-VI in fig. 1,

[0031] Fig. 7 is a cross-sectional view along line VII-VII in fig. 1, and

[0032] Fig. 8 is a cross-sectional view along line VIII-VIII in fig.

[0033] The electrosurgical blade electrode 1 seen in figs. 1 and 2 is comprised of a conductive electrode main body 2 having a cutting part 3 in form of a cutting blade 4 in extension of an opposite shank part 5, and a one-piece covering 6. The conductive electrode main body 2 is made by metal injection molding (MIM) and the one-piece covering is then applied as an overmold to the conductive electrode main body 2 in a plastic injection molding step.

[0034] As also seen in the cross-sectional view of fig. 8, the cutting blade 4 has an annular cutting edge 7 surrounding a central blade part 8 exposing opposite, substantially flat, side faces 9,10 for application of the one-piece covering 6. The shank part 5 of the conductive electrode main body 2 has an intermediate part 11 opposite a free end part 12, which intermediate part 11 tapers towards the cutting blade 4. The annular cutting edge 7 and the flat side faces 9,10 delimit opposite flat cavities 13,14 adapted to receive a part of the one-piece covering 6, as explained below.

[0035] The one-piece covering 6 has a first covering part 15 that constitutes a sleeve 16 on the shank part 5. The free end part 12 of the shank part 5 is not covered by the sleeve 16, which free end part 12 serves for mounting the electrosurgical blade electrode 1 in electric contact onto an electrosurgical instrument (not shown) . The sleeve 16 has a first sleeve end part 17 facing the free end part 12 of the shank part 5 , which first sleeve end part 17 extends into a main sleeve part 18 and ends in a second sleeve end part 19 , which second sleeve end part 19 constitutes a front sleeve part .

[0036] As also seen in the cross-sectional view of fig . 5 the first sleeve end part 17 is configured as a male end fitt ing having a polygonal cross-section that mate in a complementary female end fitting of a hand piece of an electrosurgical instrument (not shown) to provide an anti-rotational connection to said electrosurgical instrument (not shown) .

[0037] As also seen in the cross-sectional view of fig . 6 in the present embodiment of an electrosurgical electrode 1 the main sleeve part 18 has a cross-sectional area that increases towards the second sleeve end part 19 , which second sleeve end part 19 , as seen in the cross-sectional view of fig . 7 , tapers lengthwise towards the cutting blade 4 to cover the remainder of the shank part 5 before the first covering part 15 extends into the second covering part 20 on said cutting blade 4 , as seen in the cross-sectional view of fig . 8 . Accordingly said sleeve 16 is configured and conformed to be accommodated inside a tapering front end of the hand piece of an electrosurgical instrument .

[0038] The second sleeve end part 19 extends into a partially bifurcated second covering part 20 on opposite flat side faces 9 , 10 of the cutting blade 4 . The partially bifurcated second covering part 20 is comprised of opposite side cover parts 21 , 22 configured to coat and cover opposite cavities 13 , 14 of the central blade part 8 , thereby exposing the annular cutting edge 7 .

[0039] Figs . 1 and 2 are perspective views of the first embodiment of an electrosurgical electrode 1 seen from the side . In the present embodiment the electrosurgical electrode 1 is symmetrical about its longitudinal axis , and just one of the sides of the cutting blade 4 and cavities 13 , 14 are visible . The presence of the symmetrical features on the opposite flat side is indicated by the inserted corresponding reference numbers .

[0040] A second embodiment of an electrosurgical electrode is the electrosurgical spatula electrode 23 seen in figs . 3 and 4 , which electrosurgical spatula electrode 23 is manufactured in a similar manner as the blade electrode 1 seen in figs . 1 and 2 , by overmolding in a plastic injection molding process a substrate in form of conductive electrode main body 24 made by metal injection molding . In essence the electrosurgical spatula electrode 23 is also an electrosurgical blade electrode , but it has a cutting part 25 that is shorter .

[0041] The electrosurgical spatula electrode 23 has a second embodiment of a conductive electrode main body 24 having a spatula-shaped cutting part 25 in extension of an opposite long shank part 26 , and a second embodiment of a one-piece covering

[0042] 27 on a part of said opposite long shank part 26 .

[0043] The spatula-shaped cutting part 25 has an annular cutting edge

[0044] 28 that delimits a central spatula part 29 for appl ication of the one-piece covering 27 . The shank part 26 of the conductive electrode main body 24 has an intermediate part 30 opposite a free end part 31 , which intermediate part 30 tapers towards the spatula-shaped cutting part 25 .

[0045] The second embodiment of the one-piece covering 27 has a first covering part 32 that constitutes a sleeve 33 on the shank part 26 , which first covering part 32 extends integral with a second covering part 37 on the spatula-shaped cutting part 25 . The free end part 31 of the shank part 26 is not covered by the sleeve 33 , which free end part 31 serves for mounting the electrosurgical spatula electrode 23 in electric contact to an electrosurgical instrument (not shown) .

[0046] The sleeve 33 has a first sleeve end part 34 facing the free end part 31 of the shank part 26 , which first sleeve end part 34 extends into a main sleeve part 35 , that further extends into a second s leeve end part 36 that ends in the second covering part 37 .

[0047] The first sleeve end part 34 is configured as a male end fitting having a polygonal cross-section that mate in a complementary female end fitting of a hand piece of an electrosurgical instrument (not shown) to provide an anti- rotational connection to said electrosurgical instrument (not shown) .

[0048] In the second embodiment of an electrosurgical electrode 23 the main sleeve part 35 has a cross-sectional area that increases towards the second sleeve end part 36 , which second sleeve end part 36 tapers lengthwise along the second sleeve end part 36 , thus said second embodiment of a sleeve 33 is configured and conformed to be accommodated inside a tapering front end of the hand piece of the electrosurgical instrument . The second sleeve end part 36 extends integral with the partially bifurcated second covering part 37 on the spatula-shaped cutting part 25 .

[0049] The partially bifurcated second covering part 37 is applied to the central spatula part 29 of the spatula-shaped cutting part 25 thereby exposing the annular cutting edge 28 .

[0050] Figs . 3 and 4 are perspective views of the second embodiment of an electrosurgical electrode 23 seen from the side . The second embodiment the electrosurgical electrode 23 is symmetrical about its longitudinal axis , and just one of the flat sides of the spatula-shaped cutting part 25 is visible . The presence of the symmetrical features of the opposite flat side is indicated by the inserted corresponding reference numbers .

[0051] Both the cutting blade 4 of the electrosurgical blade electrode 1 and the spatula-shaped cutting part 25 of the electrosurgical spatula electrode 23 have through holes 38 , that can be utili zed for better bonding the second covering part 20 ; 37 onto the said cutting blade 4 and said spatula-shaped cutting part 25 , respectively, as the material of the second covering part flows into said through holes 38 to provides a mechanical bond of the opposite parts of the bifurcated second covering part of the one-piece covering, in addition to said one-piece covering being fuse-bonded to the surfaces of the conductive electrode main bodies 2 ; 24 .

[0052] Figs . 5 - 8 are cross-sectional views taken along the length of the first embodiment of an electrosurgical electrode 1 seen in fig . 1 to illustrate that the one-piece covering changes thickness and outline along the length of the conductive electrode main body 2 . In particular fig . 8 shows that the cutting edge 7 is exposed from the second covering part 20 .

Claims

Claims1. An electrosurgical electrode (1;23) , said electrosurgical electrode (1;23) comprises a conductive electrode main body (2; 24) having a cutting part (3; 25) configured for applying radiofrequency electrical energy to tissue and an opposite shank part (5; 26) configured to be coupled to an electrosurgical instrument, and a covering (6; 27) on at least a part of the conductive electrode main body (2; 24) , characterised in that the covering (6; 27) is a one-piece covering (6; 27) comprised of- a first covering part (15; 32) on the shank part (5; 26) , and- a second covering part (20; 37) on the cutting part (3; 25) .

2. An electrosurgical electrode (1;23) according to claim 1, characterised in that the first covering part (15; 32) is molded integral with the second covering part (20; 37) onto said shank part (5; 26) and said cutting part (3; 25) , respectively, in an injection molding process.

3. An electrosurgical electrode (1;23) according to claims 1 or 2, characterised in that the first covering part (15; 32) and the second covering part (20; 37) is made from the same material, preferably a plastic material.

4. An electrosurgical electrode (1;23) according to any of claims 1, 2 or 3, characterised in that the conductive electrode main body (2; 24) is made by metal injection molding .

5. An electrosurgical electrode (1;23) according to any of the preceding claims, characterised in that the covering (6; 27) comprises a fluoropolymer, preferably a polytetrafluoroethylene (PTFE) and / or a silicone, more preferred the covering (6; 27) is entirely made of polytetrafluoroethylene .

6. An electrosurgical electrode (1;23) according to any of the preceding claims, characterised in that a cutting area (7; 28) of the cutting part (3; 25) is free of the second covering part (20; 37) .

7. An electrosurgical electrode (1;23) according to any of the preceding claims, characterised in that the shank part (5; 26) has a free end part (12; 31) not covered by the first covering part (15; 32) .

8. An electrosurgical electrode (1;23) according to any of the preceding claims, characterised in that the first covering part (15; 32) on the shank part (5; 26) is configured to firmly mount the electrosurgical electrode (1;23) into a mounting end of an electrosurgical instrument .

9. A method of manufacturing an electrosurgical electrode (1;23) comprising the steps of a) manufacturing a conductive electrode main body (2) having a cutting part (3; 25) and a shank part (5; 26) ; preferably the manufacturing method is metal injection molding, and b) overmolding the shank part (5; 26) with a first covering part (15; 32) , and the cutting part (3; 25) with a second covering part (20; 37) , wherein said first covering part (15; 32) and said second covering part (20; 37) is a one- piece covering (6; 27) wherein said first covering part (15; 32) and said second covering part (20; 37) aremolded integral with each other; preferably the overmolding process is plastic injection molding.

10. An electrosurgical instrument comprising the electrosurgical electrode (1;23) according to any of the preceding claims.

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