Cutting equipment

Abstract

The invention relates to a cutting instrument. In the inventive instrument (10) which can preferably be used for tissue fusion and cutting, a counter-support (22) configured as a film is assigned to a cutting electrode (17) arranged between two electrode pairs. The film spans a frame (25), and the peripheral surface of the film is held on the frame in a material-bound manner. Therefore, the peripheral surface extends at an angle, preferably at a right angle, relative to the coagulation electrode (28, 29) formed by the top side of the frame. Therefore, the pressing force exerted by the biological tissue (32) with its film pressed against the cutting electrode (17) is mainly generated by the tensile stress existing in the film.

Description

Technical Field

[0001] The present invention relates to an electrosurgical instrument configured and adapted for cutting or for tissue fusion or for tissue coagulation, in particular in combination with cutting of tissue. Background Art

[0002] JP 2004180843 A discloses a tissue coagulation and cutting instrument having two jaws of a forceps type, wherein the jaws are movable relative to each other and tissue can be held between the jaws. An electric current can be applied to the two jaws so as to coagulate the tissue held between them. In addition, one of the jaws includes a cutting element, to which an elastic counter-support arranged on the other jaw is assigned. Different configurations are proposed for the counter-support. For example, the elastic counter-support can have a square block cross section, a hollow cross section or a stepped cross section of a flat T-shaped type, and can be inserted into a downwardly opening groove of the bottom jaw. The counter-support includes a wider top section facing the cutting element and a narrower section extending into the groove. During the closing of the jaws, the counter-support is deformed into the groove. Although the central section of the counter-support does not abut anywhere, the edge of the counter-support is held and supported on a step extending along the central groove.

[0003] A coagulation and cutting instrument with an elastic counter-support is known from US 2004 / 0049185 A1. The counter-support has an approximately square cross section and is supported on its side opposite the cutting electrode between two legs of a jaw which is arranged apart therefrom in a U-shaped manner. The flanks of the counter-support are exposed.

[0004] US 2009 / 0234355 A1 discloses a coagulation and cutting instrument having a cutting electrode arranged in one jaw and a movably supported counter-support arranged in the other jaw. The counter-support is resiliently supported so as to be able to avoid the intruding cutting electrode.

[0005] Further examples of electrosurgical instruments having a coagulation electrode, a cutting electrode and a counter-support assigned to the cutting electrode can be taken from EP 1 632 192 A1 and EP 2 754 403 A2.

[0006] The requirements on coagulation and cutting instruments are increasing in many aspects. There is a trend towards miniaturization and demands on manufacturing reliability and manufacturing precision. Summary of the invention

[0007] In view of the above, it is an object of the present invention to provide an apparatus which is improved in at least one aspect.

[0008] The device according to the invention according to claim 1 meets this object:

[0009] The instrument according to the invention comprises a cutting electrode on one jaw and an elastic counter-support on the other opposing jaw. The counter-support is held in a frame, which is provided by the respective jaws themselves or by a separate component. The counter-support comprises a circumferential surface connected to the frame in a tensile manner. The frame fixes the counter-support at least on two sides opposite to each other. Preferably, the frame surrounds the counter-support on three sides, i.e. on its two flanks and on the distal end. The counter-support is connected to the frame at least at its two longitudinal sides or flanks and optionally also at its distal end. In the latter case, the counter-support completely closes the frame and does not allow material to enter the area below the counter-support. However, it is also possible to keep the membrane free at its distal end and / or at its proximal end, i.e. disconnected from the frame.

[0010] The frame comprises a surface facing the counter-support, which is connected to the circumferential surface of the counter-support. The connection is tensile resistant, i.e. a pulling force directed from the edge of the counter-support toward its center will not release the counter-support from the frame. The connection is preferably free of gaps, i.e. the circumferential surface of the counter-support is completely connected to the frame in two dimensions. Preferably, in the case of tensile stress, no part of the counter-support is lifted from the frame. Tension can be generated because during the closing of the jaws, the cutting electrode and the appropriate biological tissue present between the cutting electrode and the counter-support are pressed on the counter-support. Therefore, the counter-support is displaced from its resting position and is tensioned. Therefore, the counter-support is preferably flexible so that tensile stress is generated mainly due to the deformation of the counter-support, which is why the counter-support is also called a "membrane". In a preferred case, the counter-support is configured so that it is in a so-called membrane state, i.e. in terms of its mechanical stress, in the non-loaded state when the jaws are open, and preferably also in the loaded state when the jaws are closed, the tensile stress present in the material of the counter-support is at least approximately equal everywhere.

[0011] The tensile-resistant connection between the counter-support and the frame is preferably a material-bonded connection, if appropriate a dedicated material-bonded connection. This can be achieved in a simple manner, i.e. in the process of injection molding, the film is produced, whereby the frame forms part of the injection molding mold, i.e. the material flow of the static liquid counter-support is restricted at the circumferential surface of the produced counter-support. The frame is preferably made of metal. The counter-support is preferably made of a flexible plastic, such as a silicone plastic. The adhesion between the circumferential surface of the membrane and the frame can be increased by a corresponding surface design of the frame surface facing the membrane, for example by roughening. In addition, the frame surface can be fully or partially activated to improve the adhesion of the counter-support. To this end, the surface can be partially or completely subjected to a CVD or PVD coating process. If the frame is a stamped part, the surface unevenness of the frame produced during stamping can be used to improve the adhesion between the frame and the membrane.

[0012] The tensile-resistant connection between the counter-support and the frame can be supported by a form fit between the counter-support and the frame, for example in that the frame comprises form-fitting structures such as openings, cutouts or the like along its surface facing the counter-support.

[0013] Preferably, the counter-support is held in the frame without a support. In particular, it does not rest against any surface facing away from the cutting electrode in the direction of invasion. In other words, the free top surface facing the cutting electrode is as large as the free bottom surface of the counter-support facing away from the cutting electrode. As a result of this arrangement, the biological tissue held between the jaws is pressed particularly gently and evenly against the cutting electrode, so that the tissue held between the cutting electrode and the counter-support is cut electrically, but not mechanically squeezed. The separation process is completely electrical. This can be achieved in a large configuration of the instrument as well as in a miniaturized configuration thereof.

[0014] The counter-support is preferably made of an electrically insulating plastic such as silicone. However, it can also be made of a plastic that is inherently or non-inherently (i.e., by embedding conductive substances or particles) conductive. By doing so, additional thermal effects can be generated during the flow of current through the tissue.

[0015] Preferably, the counter-support comprises two flanks arranged at a constant distance from each other. However, this distance may also decrease in the distal direction.

[0016] In its central section, which contacts the cutting electrode in the closed state, the counter-support can have a thickness that is at most as great as the thickness at the edges of the counter-support. Preferably, the thickness in the central section is even smaller than at the edges of the counter-support. By doing so, the main advantages of the invention are supported. During closing of the instrument, the counter-support is preferably subjected to elongation and less to compression or bending, which is a common situation in the prior art. By doing so, the membranous counter-support can also adapt well to uneven tissues and keep it in soft contact with the cutting electrode. However, it is also possible to make the thickness of the counter-support in the center under the cutting electrode greater than at the edges (at the flanks or circumferential surfaces).

[0017] In the rest position, the counter-support can be arched away from or towards the cutting electrode. By doing so, different spring characteristics can be adjusted so that during compression, ie during closing of the instrument, a desired progression of the pressing force of the tissue against the cutting electrode is achieved.

[0018] In an advantageous embodiment, the counter-support is flush with the frame ends on its top side and on its bottom side. This simplifies the production of the device, in particular the formation of the counter-support in the frame.

[0019] The counter-support may comprise one or more sections extending on the frame. Preferably, such a section is arranged at least at the distal end of the counter-support or of the jaws comprising it. Such a section may serve as a spacer for the jaws and avoid their direct contact during closing. However, in addition to these sections, it is advantageous if the end of the counter-support separated from it is flush with the frame on the top and bottom sides. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further details of advantageous embodiments of the invention are obtained from the drawings, the associated description and the claims. In the drawings:

[0021] Figure 1 The device of the invention is shown in a closed state,

[0022] Figure 2 The cross-sectional view shows Figure 1 The top and bottom jaws of the instrument in the open position,

[0023] Figure 3 Unorganized base in a closed state, shown in cross section Figure 1 and Figure 2 of equipment,

[0024] Figure 4 The cross-sectional view shows Figure 3 An instrument in which tissue is held between the jaws,

[0025] Figure 5 A modified embodiment of the instrument is shown in cross section in a slightly opened state,

[0026] Figure 6 Another modified embodiment of the instrument of the invention is shown in cross section, with slightly opened jaws,

[0027] Figure 7 A partial perspective view showing Figure 6 The bottom jaw of the instrument, and

[0028] Figure 8 Shown for manufacturing according to Figures 1 to 5 A plastic injection molding mold for a reverse support member of an apparatus.

[0029] List of reference numerals:

[0030] 5 Leg surface of metal portion 14

[0031] 10. Instruments

[0032] 11. Handle

[0033] 12 Top jaw

[0034] 13 Bottom jaw

[0035] 14 Metal Parts

[0036] 15, 16 Coagulation electrode of top jaw 12

[0037] 17 Cutting Electrode

[0038] 18 Insulation body

[0039] 19 Extension of insulating body

[0040] 20, 21 Gap

[0041] 22 Counter support

[0042] 23 Central section of the counter support 22

[0043] 24 Circumferential surface of counter support

[0044] 25 Frame

[0045] 26 The top side of the counter support 22

[0046] 27 Bottom side of counter support

[0047] 28, 29 Coagulation electrode of bottom jaw 13

[0048] 30 Metal parts

[0049] 31 Gap

[0050] 32 Biological tissue

[0051] 33 - 35 Extension

[0052] 36 Plastic Injection Molding Mold

[0053] 37 Top mold half

[0054] 38 bottom mold half

[0055] 39 Carving Department

[0056] 40 protrusion

[0057] A Hinge axis

[0058] D M Thickness measured in the central section of the counter support

[0059] D R Thickness at the edge of the counter support. DETAILED DESCRIPTION

[0060] exist Figure 1 , an instrument configured for tissue fusion and cutting is shown. The instrument may be an instrument for open surgical use, an instrument for laparoscopic use or also an instrument for endoscopic use. The instrument 10 comprises jaws 12, 13, which are held, for example, on a flexible handle 11 or also on a rigid handle, whereby at least one of the jaws (in this example, the top jaw 12) is pivotally supported so as to be able to move towards and away from the other jaw (in this example, the bottom jaw 13). The pivotal movement about the hinge axis A is controlled by a mechanism, not further shown, extending through the handle 11.

[0061] As an alternative, the instrument 10 may also include two pivotally supported jaws that are movable toward and away from each other.

[0062] Figure 2 Along the Figure 1 The cross section taken along line II-II in FIG. Figure 1 The instrument 10 of the present invention. For example, the top jaw 12 can be made of a metal part 14 with a U-shaped cross section and can be bare metal or also electrically insulated on the outside, and its leg surface 5 can be used as coagulation electrodes 15, 16. The coagulation electrodes 15, 16 can be continuous strip electrodes, which can also be interrupted by insulating sections. Instead of the metal part 14, the upper jaw 12 can also include another part, for example made of a non-conductive material (such as, for example, plastic), in which the coagulation electrodes 15, 16 are embedded, for example, in the form of a thin plate part.

[0063] The top jaw 12 is provided with a cutting electrode 17, which is made of a thin metal sheet strip, for example. Preferably, the cutting electrode 17 is held in an insulating body 18, which is approximately centered between the coagulation electrodes 15, 16. The cutting electrode 17 is preferably arranged in an extension 19 of the insulating body 18, so that the two flat sides of the cutting electrode 17 are insulated. Between the extension 19 and the legs of the top jaw 12 supporting the coagulation electrodes 15, 16, gaps 20, 21 are created for positioning of tissue therein.

[0064] The bottom jaw 13 comprises a counter-support 22 for holding the biological tissue on the cutting electrode 17 during the cutting process. The counter-support 22 is a flexible body, for example made of silicone, with a thickness D measured in its central section 23 (in particular in the extension of the cutting electrode 17) of M Smaller than the width B measured transversely thereto. The counter-support 22 consists of a solid material. Preferably, it does not comprise any hollow space.

[0065] In the transverse direction, the counter-support 22 adjoins the frame 25 with its circumferential surface 24 and is connected thereto in a tensile manner, preferably in a materially bonded manner, for example by overmolding or gluing. The circumferential surface 24 is preferably unstructured, i.e. smooth except for machining traces such as stamping or fractured surfaces. However, it can also be structured in order to support the material connection between the counter-support 22 and the frame 25, for example by form fit.

[0066] The counter support 22 comprises, at its edge adjoining the peripheral surface 24, a thickness D R , which thickness is preferably at least equal to the thickness D in the central section 23. M In addition, the thickness D R Corresponding to the thickness of the frame 25 to be measured in the same direction, the counter-support 22 is therefore flush with the ends of the frame 25 on its top side 26 and its bottom side 27 .

[0067] The frame 25 is preferably made of metal, so that its top side forms the coagulation electrodes 28, 29. These can be transformed into each other at the distal end of the respective jaw 12 or 13.

[0068] The unit consisting of the counter-support 22 and the frame 25 can be manufactured in an injection molding process, in which the prefabricated frame 25 is inserted into a corresponding injection molding mold, and then the plastic material of the counter-support 22 is introduced into the mold so as to be tightly connected to the frame 25 at the circumferential surface 24. The unit produced in this way is connected to the remaining load-bearing part of the bottom jaw 13, which is made of a U-shaped metal part 30 in the present embodiment. It can be bare metal or electrically insulating, for example, with a plastic coating on its outer side. The frame 25 can also be bare metal, that is, conductive, or alternatively be provided with an insulator at its side facing outwards. The frame 25 can be electrically conductively connected to the metal part 30, or it can also be insulated relative to it. A gap 31 can be formed between the counter-support 22 and the metal part 30, which gap 31 can be separated from the environment or can also be connected to it through a suitable opening.

[0069] Figure 3 The instrument 10 is shown in the closed state. The electrodes 15, 28 are in contact with one another or are kept at a small distance from one another by means of a spacer not shown in further detail. The same applies to the coagulation electrodes 16, 29. The cutting electrode 17 stands on the counter-support 22 and presses it into the gap 31, without the bottom side 27 of the counter-support 22 coming into contact with the metal part 30 or any other part present in the gap 31. Since the counter-support 22 is thin in cross section, i.e., due to its thickness D M is significantly smaller than its width B, so the reverse support member 22 is Figure 3 The deformation shown is essentially in tension. It is stretched. Similarly, the connection between its peripheral surface 24 and the frame 25 is essentially in tension.

[0070] The device 10 operates as follows:

[0071] like Figure 4 As shown, in order to process biological tissue 32, it is first held between jaws 12, 13. Biological tissue 32 can be organ tissue, blood vessels, or other tissues. Jaws 12, 13 are moved toward each other to grasp tissue 32. At the same time or in a time sequence, coagulation voltage is applied to coagulation electrodes 15, 28, 16, 29, and cutting voltage is applied to cutting electrode 17. Figure 2As shown, during the closing of the instrument 10, the counter-support 22 has been away from the cutting electrode 17 and has therefore been tensioned. However, the counter-support thereby pushes the tissue 32 against the cutting electrode 17. The biological tissue 32 can enter the gaps 20, 21 on both sides of the extension 19. The coagulation electrodes 15, 28 and 16, 29 coagulate the tissue held between them and fuse it if it is a vessel, i.e. close it at these locations. The tissue, to which the cutting electrode 17 applies a correspondingly high cutting voltage, contracts and separates, whereby the counter-support 22 holds the contracted tissue on the cutting electrode 17.

[0072] Modifications may be made in the invention described thus far. Figure 5 As shown, the counter-support 22 can be convexly arched toward the cutting electrode 17. This has the result that during the closing of the instrument 10, the arch of the counter-support 22 must first be overcome, which may cause a certain breaking effect. Alternatively, the counter-support 22 can also be completely planar. In addition, Figures 1 to 4 The description applies accordingly to Figure 5 An embodiment of the device 10.

[0073] As in accordance with Figures 1 to 4 As in the embodiment of the present invention, the counter-support 22 can also be planar or concave, i.e. configured in a manner that arches away from the cutting electrode 17. With the progression of the thickness from the center 23 toward the edge of the counter-support 22 and the progression of the arch, the desired spring characteristic, i.e. the path-force-progression, can be adjusted, which can be achieved during the closing of the instrument 10.

[0074] In all the above-described embodiments, the counter-support 22 may comprise extensions 33, 34, 35 which protrude over the frame 25 and thus avoid direct contact of the coagulation electrodes 15, 16 with the coagulation electrodes 28, 29. In addition, however, also in this embodiment, the counter-support 22 is preferably flush with the ends of the frame 25 at its top side 26 and bottom side 27.

[0075] Will refer to Figure 8 The manufacture of the counter-support 22 is shown. For this purpose, a plastic injection-molding mold 36 is provided, between whose top mold half 37 and whose bottom mold half 38 a carving 39 is formed, which defines the shape of the counter-support to be produced. Figure 8 A central raised protrusion 40 is shown in FIG. 4 , which reduces the thickness of the counter-support 22 to be produced in the central section.

[0076] To produce the counter-support 22, the frame 25 is inserted into the engraving 39 while the plastic injection-molding mold 36 is open, and the injection-molding mold 36 is subsequently closed. Subsequently, liquid plastic is filled into the engraving 39 so that it completely fills the space provided and abuts against and is bonded to the inside of the frame 25. After solidification of the plastic, the plastic injection-molding mold 36 can be opened and the counter-support 22 can be removed.

[0077] In the device 10 of the invention which can preferably be used for tissue fusion and cutting, a counter-support 22 configured as a film is assigned to the cutting electrode 17 arranged between the two electrode pairs. The film spans in the frame 25, and the peripheral surface of the film is held on the frame 25 in a materially bonded manner. Therefore, the peripheral surface extends at an angle, preferably at a right angle, relative to the coagulation electrodes 28, 29 formed by the top side of the frame. Therefore, the pressing force exerted by the biological tissue 32 with its film pressed against the cutting electrode 17 is mainly generated by the tensile stress existing in the film.

Claims

1. An instrument (10) for cutting or for combined tissue fusion or coagulation and tissue cutting, having two jaws (12, 13), at least one of the two jaws being supported movably toward and away from the other, having a cutting electrode (17) arranged on one of the jaws (12), having an elastic counter-support (22) assigned to the cutting electrode (17), arranged on the other jaw (13) and held in a frame (25), the counter-support being arranged to abut against the frame completely in two dimensions with its circumferential surface (24), Features The counter support (22) is connected to the frame (25) at its circumferential surface (24) in a stretch-resistant manner, wherein the stretch-resistant manner is a material bonding manner; and The free top surface of the counter-support (22) facing the cutting electrode (17) is as large as the free bottom surface of the counter-support (22) facing away from the cutting electrode (17).

2. The device according to claim 1, characterized in that The counter-support (22) remains unsupported in the frame (25).

3. The apparatus according to claim 1, characterized in that The counter support (22) is connected to the frame (25) in a materially bonded manner.

4. The apparatus according to claim 1, characterized in that The counter-support (22) is a plastic film, wherein the thickness (DM) measured in a central section (23) of the plastic film on which the cutting electrode (17) rests during operation is at most as great as at the circumferential surface (24) in the direction of movement of the at least one movable jaw (12).

5. The apparatus according to claim 1, characterized in that The counter-support (22) is a plastic film, wherein the thickness (DM) measured in the central section (23) of the plastic film on which the cutting electrode (17) is placed during operation has a smaller thickness than in all other locations in the direction of movement of the at least one movable jaw (12).

6. The apparatus according to claim 1, characterized in that The counter-support (22) is a plastic film, wherein the thickness (DM) measured in the central section (23) of the plastic film on which the cutting electrode (17) rests during operation has a greater thickness than in all other locations in the direction of movement of the at least one movable jaw (12).

7. The apparatus according to claim 1, characterized in that The counter support (22) is formed in its resting state in the manner of a concave or convex curvature on its side facing the cutting electrode (17).

8. The apparatus according to claim 1, characterized in that The counter support (22) is configured and arranged in the opening defined by the frame (25) in such a way as to completely close the opening.

9. The apparatus according to claim 1, characterized in that The counter-support (22) is configured to be flush with the ends of the frame (25) at its top side (26) and its bottom side (27).

10. Apparatus according to any one of the preceding claims, characterized in that The counter support (22) comprises extensions (33, 34, 35) extending on the frame (25).

11. The apparatus according to claim 10, characterized in that The extensions (33, 34, 35) are arranged at the distal end of the jaw (13) comprising the counter-support (22).

12. A method for manufacturing a counter-support of an apparatus according to claim 1, comprising the following steps: providing a plastic injection molding die (36) having an engraved portion (39) for positioning the frame (25) therein, The frame (25) is arranged in the engraved portion (39), Introducing plastic into the engraved portion (39) so that the plastic contacts and is bonded to the frame (25), The plastic is hardened so that it forms the counter-support (22) together with the frame (25), and the injection-molding mold (36) is opened and the counter-support (22) is removed.

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