CUTTING ELECTRODE, SURGICAL INSTRUMENT AND METHOD FOR MANUFACTURING THE CUTTING ELECTRODE

Abstract

A method for manufacturing a cutting electrode for a surgical instrument. The method involves starting with a material blank that is provided with a rated break location. The material blank is dimensioned to allow for separation with forces sufficiently low that they can also be transmitted by the plastic body. The rated break location separates the material blank in a first section serving exclusively for handling and positioning of the material blank in a mold as well as in a second section that self-supportingly projects in a mold hollow space and is overmolded by plastic. After removal, the first section can be easily broken off the cutting electrode. The created breaking edge forms a cutting edge.

Claims

1. A method for manufacturing a cutting electrode for a surgical instrument, particularly a fusion and cutting instrument, the method comprising the following steps: providing a material blank; providing a rated break location that is arranged at the material blank separating it in a first and second section; inserting the material blank provided with the rated break location in a mold that comprises an engraving holding the first section with contact and defining a hollow space around the second section; inserting plastic in the mold for creating a plastic body that encloses the second section; opening the mold and removing the plastic body with the material blank held therein; and breaking the first section of the second section along the rated break location.

2. The method according to claim 1, wherein the first section is at least as large as the second section.

3. The method according to claim 1, wherein the first section is positioned in the mold in correct positional arrangement by means of at least one positioning structure.

4. The method according to claim 1, wherein the material blank is provided with an electrical connection conductor prior to the insertion in the mold.

5. The method according to claim 1, wherein the rated break location is configured as a line-like area with reduced material thickness.

6. The method according to claim 5, wherein the area with reduced material thickness is formed by at least one groove that is arranged at at least one flat side of the material blank.

7. The method according to claim 6, wherein the groove is created by an etching process.

8. A cutting electrode, particularly cutting electrode that is manufactured according to a method according to claim 1, the cutting electrode comprising a plastic body in which an electrode is embedded that has a breaking edge that remains uncovered.

9. The cutting electrode according to claim 8, wherein the plastic body is made of a flexible plastic, particularly an elastic plastic, particularly silicone.

10. The cutting electrode according to claim 8, wherein the electrode has a uniform constant thickness and comprises a reduced thickness in direct proximity of the breaking edge, such that a tapering section is formed adjoining the breaking edge.

11. The cutting electrode according to claim 10, wherein the plastic body is configured to extend up to the tapering section.

12. The cutting electrode according to claim 10, wherein the plastic body is configured to extend beyond in the tapering section.

13. The cutting electrode according to claim 8, wherein the cutting electrode comprises holes penetrated by plastic.

14. The cutting electrode according to claim 8, wherein the width of the breaking edge is smaller than the thickness of the electrode, preferably at most half as large as the thickness of the electrode.

15. An instrument having the cutting electrode according to claim 8.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Further details of embodiments of the invention result from the drawings, the description or the claims. The drawings show:

[0028] FIG. 1 a surgical instrument in an exemplary configuration and in perspective simplified illustration,

[0029] FIG. 2 a tool supported by the instrument according to FIG. 1 in a simplified vertical cut illustration,

[0030] FIG. 3 a cutting electrode of the tool according to FIG. 2 in a simplified perspective illustration,

[0031] FIG. 4 a material blank for manufacturing a cutting electrode in a side view,

[0032] FIG. 5 a mold with a material blank in explosion illustration cut orthogonal to a separation plane of the mold,

[0033] FIG. 6 a material blank in partly cut illustration in the area of a rated break location,

[0034] FIG. 7 an alternative embodiment of a material blank in partly cut illustration in the area of a rated break location,

[0035] FIG. 8 a material blank provided with a plastic body for manufacturing of a cutting electrode,

[0036] FIG. 9 a cutting electrode in a vertical partly cut illustration in a first embodiment, and

[0037] FIG. 10 a cutting electrode in the illustration according to FIG. 9, however in a modified embodiment.

DETAILED DESCRIPTION

[0038] FIG. 1 illustrates a surgical instrument 11 that is particularly configured for laparascopic treatment of a patient. The instrument 11 comprises a housing 12 with a handle 13 and a hand lever 14 provided thereon. A tool 17 is supported at the distal end 16 of a shank 15 extending away from housing 12. The tool comprises a first jaw member 18 and a second jaw member 19, at least one of which is movable toward the other and away from the other by actuating the hand lever 14 in order to be able to clamp tissue in between.

[0039] The jaw members 18, 19 form a forceps-like tool 17 that is configured for tissue sealing and/or tissue cutting. For this the jaw members 18, 19 can be connected with different poles of a voltage source and thus define coagulation gaps 20, 21 between its legs as it is, for example, generally known from EP 3 132 765 A1. Between these coagulation gaps 20, 21 a preferably elastic counter support 22 and in the opposing jaw member 19 a cutting electrode 23 are arranged. It comprises a mounting or base section 24 and a wall section 25, both consisting of plastic, preferably an elastic plastic, wherein an electrode 26 preferably consisting of metal is embedded in the wall section 25 and if applicable, at least partly also extending in the base section 24. At the face side 27 only a narrow edge 28 of the electrode 26 remains uncovered. Apart therefrom the electrode 26 is embedded into the wall section 25 and the base section 24 such that it is electrically insulated.

[0040] The tool 17 can also be part of another instrument, e.g. an instrument that can be used in an endoscopic manner or an instrument configured for the open surgery use.

[0041] The manufacturing of the cutting electrode 23 is as follows:

[0042] Manufacturing is started with a material blank 29, as illustrated in FIG. 4. The material blank 29 consists of a suitable electrode material, e.g. a steel alloy, a titanium alloy or of an electrically conductive ceramic. Preferably the material blank 29 consists of a spring elastic material that, however, does not provide any remarkable plastic deformability. Particularly, a material is preferred a breaking point of which is reached without prior plastic deformation.

[0043] The material blank 29 is provided with a preferably line-shaped rated break location 30 that separates a first section 31 of the material blank 29 from a second section 32. The second section 32 forms the subsequent electrode 26, whereas the first section 31 serves for temporary handling only. The rated break location 30 is a line-like weakening of the material of the material blank 29, e.g. by means of a groove 33 manufactured in the material blank 29 as apparent from FIG. 7. Instead of one groove 33 that is only provided in one flat side of the material blank 29, the rated break location 30 can also be formed by two grooves 33, 34 that are provided parallel to each other in flat sides of the material blank 29 facing away from each other, as shown in FIG. 6. The two grooves 33, 34 thereby extend along same paths and are arranged in the same position.

[0044] Independent from whether only one groove 33 or two grooves 33, 34 are provided, they can be manufactured by any suitable method, e.g. by grinding, milling, embossing, roller burnishing or etching. The cross-section of the grooves 33, 34 can be created depending on the selected method and the desired edge shape as being round, angled, triangular, quadrangular, trapezoid-shaped or in a non-defined form, particularly by an etching method. However, the depth and the width of the groove are also defined by the etching method.

[0045] One or more positioning structures can be provided in the first section 31, e.g. in the form of positioning holes 35, 36. They can serve, for example, for positioning of the material blank 29 in a mold 37 having two mold halves 38, 39 as apparent from FIG. 5.

[0046] The mold halves 38, 39 are respectively provided with an engraving that is configured in its form and depth in the area of the first section 31 of the material blank that the material blank 29 is retained at the first section 31, if the mold 37 is closed, wherein the two mold halves 38, 39 abut two-dimensionally at the first section 31. Particularly the region of the mold halves 38, 39 holding the first section 31 terminates substantially flush at the rated break location 30. If mold 37 is closed, a hollow space 40 is thereby created around the second section 32 into which the second section 32 extends in a cantilever manner. This hollow space 40, however, terminates at flush at the rated break location 30.

[0047] For manufacturing the cutting electrode 23 with the mold 37 closed the section 32 is filled with a suitable plastic, e.g. silicone, that thereby can also pass through the holes 41 that can be configured in the second section 32 for form fit fixation of the plastic at the material blank. The shape of the holes can be round or angular.

[0048] After curing of the plastic and the opening of the mold 37 the material blank 29 with the plastic body 42 formed thereon can be removed from mold 37. As illustrated in FIG. 8, the rated break location 30 now directly adjoins the upper end of the wall section 25. A cable 43 attached to section 32 of the material blank 29 extends out of the plastic body 42 if applicable.

[0049] For finishing the cutting electrode 23 the first section 31 is now moved forth and back in a direction characterized by an arrow P relative to the plastic body 42, whereby the first section 31 breaks off the second section at the rated break location 30. A breaking edge 44 is thereby formed as shown in FIG. 9. From the former groove 32 a tapering section 45 is created such that the breaking edge 44 has a smaller width than the thickness of the second section 32 embedded in the plastic body. The width of the breaking edge 44, as well as the thickness of the second section 32, are measured horizontally in FIG. 9, i.e. in any case orthogonal to the flat side of the second section 32.

[0050] The wall section 25 comprises at its face side 27 on both sides of the breaking edge 44 planar or rounded surface sections 46, 47, the width thereof is preferably in each case at most ten times as large and further preferably at most three times as large or also at most two times as large as the thickness of the second section 32.

[0051] While the wall section 25 can directly adjoin the tapering section 45 at the face side, as illustrated in FIG. 9, it can also extend into the tapering section 45 according to FIG. 10 such that also the tapering section 45 can be partly or completely covered with plastic and only the breaking edge 44 remains uncovered. In so doing, a particularly high current concentration is achieved.

[0052] The breaking edge 44 can be rough due to breaking and does not need to be postprocessed. After breaking the first section 31 of the second overmolded section 32, according to FIG. 8, the cutting electrode 23 is finished and can be mounted in the instrument according to FIG. 1. At the breaking edge local current concentrations occur during cutting due to the roughness supporting the cutting. It is, however, also possible to postprocess the breaking edge, e.g. by polishing, particularly electro-polishing.

[0053] The details described in connection with FIGS. 5 and 8-10 apply similarly for material blanks 29 according to FIG. 6 and material blanks 29 according to FIG. 7.

[0054] Embodiments of the inventive method serve to manufacture a cutting electrode for a surgical instrument 11, wherein the method avoids applying of forces for separating the cross-section of the cutting electrode 23 after attachment of the plastic body at the cutting electrode 23. For manufacturing the cutting electrode 23 it is started with a material blank 29 that is provided with a rated break location 30. It is dimensioned that its separation is possible with low forces that are particularly so low, such that they can also be transmitted by the plastic body. The rated break location 30 separates the material blank 29 in a first section 31 serving exclusively for handling and positioning of the material blank 29 in a mold 37 as well as in a second section 32 that self-supportingly projects in a mold hollow space 40 and is overmolded by plastic.

[0055] After the removal the first section 31 can be easily broken off the cutting electrode 23. The created breaking edge 44 forms an ideal cutting edge.