Tissue sealing device

Abstract

To provide an instrument that can be closed and securely held to prevent tissue from being pulled out before the end of the procedure. [Solution] The tissue sealing device 11 according to the present invention comprises two jaws 13 and 14, both of which are provided with sealing electrodes 18, 19, and 33. One of the jaws includes a cutting electrode 25, and the other includes an elastic counter support. The cutting electrode is held within a flexible plastic body housed in a narrow groove. In contrast, the counter support is housed in a relatively substantially wider recess. Therefore, the counter support is wider (preferably significantly wider) than the insulator containing the cutting electrode. By defining these different dimensions, a wide range of desired features of the tissue sealing device can be defined.

Description

Technical Field

[0001] The present invention relates to a tissue sealing instrument, and more particularly to a forceps-like instrument having sealing electrodes on two jaw portions and a stationary cutting electrode.

Background Art

[0002] The tissue sealing instrument of the recited form is generally known and commercially available for open surgery, laparoscopy, or even endoscopy. Examples of such instruments, particularly the configuration of the head portion, having substantially two jaw portions in addition to the sealing electrode and the cutting electrode can be obtained from, for example, Patent Document 1. Such an instrument has two jaw portions, at least one of which is movably supported in the form of forceps together with the other jaw portion to hold tissue. An insulator is disposed to hold the cutting electrode on one of the jaw portions, and the other jaw portion includes a counter support portion that is itself elastically flexible and presses the tissue against the cutting electrode.

[0003] This instrument particularly functions to seal and separate a tube, for example, a blood vessel. During sealing that must be performed more reliably within the instrument, tissue holding spaces are formed on both sides of the cutting electrode to hold the two ends of the separated blood vessel. As long as the instrument is closed, the bulged ends of the separated tube are held in the tissue holding space by shape fitting.

[0004] A similar instrument is also known from Patent Document 2. This instrument is characterized in that a flexible counter support portion made of silicone bends around the cutting electrode during tissue incision.

[0005] Further tissue sealing instruments having a cutting electrode are known from Patent Document 3, Patent Document 4, Patent Document 5, and Patent Document 6.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] European Patent No. 2992849 [Patent Document 2] European Patent No. 3138522 [Patent Document 3] European Patent Application Publication No. 1632192 [Patent Document 4] European Patent No. 2409653 [Patent Document 5] U.S. Patent No. 8679115 [Patent Document 6] European Patent Application Publication No. 1632192 [Overview of the project] [Problems that the invention aims to solve]

[0007] In particular, instruments that must be inserted into the patient's body through restricted channels, such as the working channel of an endoscope or a trocar, have their structural width, and even more so, their sealing tools, limited. Furthermore, the jaws of instruments must usually be curved laterally to simplify work on organs with naturally curved surfaces.

[0008] Under all these circumstances, the tissue must close and hold the instrument securely to prevent it from coming loose before the completion of the procedure.

[0009] Based on these considerations, the objective of the present invention is to provide an improved device. [Means for solving the problem]

[0010] This objective is achieved by the tissue sealing device described in claim 1.

[0011] The tissue sealing instrument according to the present invention comprises two jaws that can move toward and away from each other in the form of forceps. One of the jaws is provided with a groove for arranging an insulator in which a cutting electrode is held. The other jaw also includes a groove-like recess in which a flexible counter support for the cutting electrode is arranged. The uniqueness of the present invention is that the recess and together with the counter support are wider, preferably significantly wider, than the width of the groove. This provides the possibility of arranging the cutting electrode in a flexible insulating material, thereby allowing the cutting electrode to bend slightly laterally without becoming unstable. The wider recess for the counter support allows for the formation of a more spacious tissue holding space, on the one hand, and on the other hand, the tissue held in the holding space can be held under pressure, particularly due to the material displacement effect of the counter support.

[0012] Preferably, the elastic counter support portion has a width that extends not only to the cutting electrode and the insulator holding the cutting electrode, but also to the distance between the insulator and the side coagulation electrode. Preferably, the surface provided within this distance is rigid enough to clearly define the position of the tissue relative to the cutting electrode. This can contribute to the quality of the incision and the reliability of fixing the swollen tissue edge within the tissue retention space. This design also contributes to the stability of the jaw portion that holds the cutting electrode.

[0013] The sealing electrodes are positioned on two jaws, preferably on the edges. In this case, the sealing electrodes follow the outer contour of the jaws. This maximizes the lateral extension of the tissue retention space, and the available space inside the instrument is used optimally.

[0014] The sealing electrodes in the jaw region preferably extend from the hinge-side end of the jaw region toward the distal end. Each sealing electrode in the jaw region can be connected to each other at their distal ends. In particular, the sealing electrode can be formed from a single, seamless, and continuous, substantially U-shaped component. It is advantageous that one of the sealing electrodes in each jaw region initially extends along a straight line from the region near the junction to the distal end region, with a portion of the smaller radius adjacent to this straight line. In contrast, the other sealing electrode extends from the region near the junction to the distal end region in an arc with a relatively (very) larger radius. It is preferable that this arc is positioned such that the distance between the sealing electrodes is minimized at a position between the region near the junction and the distal end region, or at a position adjacent to the distal end region. In this way, a width is provided in the space surrounded between the sealing electrodes, particularly in the region near the junction and the distal end region, and as a result, biological tissue can be particularly securely held in that space. Ensuring secure retention of tissue in the region near the junction and the end region is particularly important to prevent the tissue end from unintentionally slipping out of the closed tool. This configuration also contributes to ensuring that the effect on the tissue is uniform along the length of the cutting electrode and the sealing electrode. This shape of the sealing electrode is advantageous regardless of the groove width and recess width, and whether they match or mismatch. Furthermore, this shape of the sealing electrode is advantageous in combination with the shape of the cutting electrode described in relation to embodiments of the invention described below. Again, this is independent of the groove width, recess width, sealing electrode shape, and whether they match or mismatch.

[0015] The recess for the counter support portion is preferably aligned with the shape of the seal electrode in the second jaw portion. In contrast, the groove in the first jaw portion is not aligned with the shape of the seal electrode. Rather, the groove is preferably composed of parallel flanks (sides) such that the distance from the groove flank to the adjacent seal electrode varies. This makes it possible to manufacture the groove simply, in particular, and at the same time, it makes it possible to create the shape of the seal electrode independently of the groove. As a result, the seal electrode can have a single arc-shaped curve or two further curves (slightly S-shaped). This feature can also be provided in a tool in which the recess is the same width as the groove, and that tool otherwise corresponds to the tool described according to the present invention. In this case, the recess and groove are aligned with each other so that the counter support portion and the cutting electrode are precisely aligned vertically when closed. However, here again, it is applicable that the distance from the groove to the seal electrode may vary along the length of the groove. For example, the groove or cutting electrode may have the minimum distance to one seal electrode and the maximum distance to the other seal electrode at approximately the center of its longitudinal extension. Furthermore, the distances from the groove to the two sealing electrodes can vary along their longitudinal extensions. For example, the distance to one of the sealing electrodes can be locally increased, while the distance to the other electrode at the same location can be locally decreased.

[0016] The insulator is preferably configured to be flexible and to include a first portion held in the groove and a second portion protruding from the groove. This allows the cutting electrode to extend through the second portion into the first portion, ensuring good lateral stability of the cutting electrode and guaranteeing electrical insulation, even when the insulator is very thin. Thus, the cutting electrode extends within the groove such that the portion with its accessible cutting edge is located above the groove and a portion is located inside the groove. The portion of the cutting electrode protruding from the groove can have its two flat sides covered by the insulating material of the insulator, thereby providing electrical insulation. This allows the groove to extend in an arc (a single-curved arc) or even an S-shape (a double-curved arc) from a region near the joint toward a distal region to hold the insulator. However, if necessary, the groove may have groove walls extending toward each other in some parts, particularly at the distal end.

[0017] Furthermore, it is advantageous for the counter support part to have a portion supported at the bottom of the groove, preferably approximately at the center. In combination with the optional empty space that can be provided between the jaw part and the counter support part, the flexibility of the counter support part and the force with which the counter support part presses the tissue against both sides of the cutting electrode (in particular, the force that varies depending on the distance) can be appropriately adjusted. In particular, even when the counter support part is slightly deformed, a high force can already be obtained initially. Thereby, regarding the manufacture of the counter support part and its fixation inside the jaw part, it is further advantageous that the counter support part is directly adjacent to the sealing electrode, and thus the sealing electrode is insulated from the held biological tissue. In addition, since the counter support part is directly connected to the inner flank of the sealing electrode, resulting in electrical insulation of the flank, surface current can be effectively avoided. Since the counter support part is supported at the bottom of the recess, the connection between the counter support part and the sealing electrode is held in a force-free state, and thus the connection by the adhesive or bonding agent formed there is not significantly affected. The distance between the counter support part and the jaw part can be directly set where the counter support part is adjacent to the sealing electrode. This distance disconnects the connection between the counter support part and the sealing electrode with respect to force, and thus supports the durability of the material bond connection at this position.

[0018] Further details of advantageous embodiments of the present invention are the subject matter of the specification or the dependent claims and the supplementary drawings.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is a partial perspective view of an instrument according to the present invention provided with a tool part. [Figure 2] FIG. 2 is a top view of each of the two jaws in the instrument according to FIG. 1. [Figure 3] FIG. 3 is a top view of each of the two jaws in the instrument according to FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view at position A2 of the jaw in the instrument according to FIG. 1. [Figure 5]Figure 5 is a cross-sectional view at position A28 of a further embodiment of the jaw portion of the device according to the present invention. [Figure 6] Figure 6 is a cross-sectional view at position A28 of a further embodiment of the jaw portion of the device according to the present invention. [Figure 7] Figure 7 is a diagram of the jaw section according to Figure 4 during sealing and separation of the tube. [Figure 8] Figure 8 is a diagram of the jaw region according to Figure 5 during the sealing and separation of the biological tubule. [Figure 9] Figure 9 is a diagram of the jaw section according to Figure 6 during the sealing and separation of the tube. [Modes for carrying out the invention]

[0020] Figure 1 shows a tool 12 attached distal to the shank 10 of a sealing device 11. Part of this tool are a first jaw 13 and a second jaw 14, which are pivotably positioned to face and move away from each other in the form of forceps. For this purpose, at least one of the two jaws 13 and 14, in this embodiment the second jaw 14, is pivotally movable relative to the first jaw 13 by a hinge device indicated by a pivot axis 15, while the first jaw 13 is positioned immovably. Alternatively, both jaws 13 and 14 could be pivotably positioned to face and move away from each other. The hinge device can be implemented by one or two pivot bearings, a slotted guide, a spring hinge, and the like.

[0021] The tissue sealing device 11 is primarily used to close, seal, and cut tubes, such as blood vessels, but can also be used for other surgical procedures, such as the preparation of organs or other living tissues.

[0022] To illustrate the further structure of the jaw portions 13 and 14, refer to Figures 2, 3, and 4. The first jaw portion 13 is formed by a rigid support portion 16 made of, for example, metal, which may have electrical insulating properties on its outer surface 17. Alternatively, the support portion 16 may also be made of an electrically insulating plastic that is mechanically stable and slightly flexible or non-flexible, in whole or in part. Furthermore, the support portion 16 may be a composite component, for example, a metal inlay overmolded with plastic.

[0023] The support portion 16 of the first jaw portion 13 can be provided with sealing electrodes 18 and 19 along its two edges, and the sealing electrodes 18 and 19 can further be connected to a generator via lines not shown. The two sealing electrodes 18 and 19 can be physically and electrically connected to each other in the distal end region 20 of the first jaw portion 13, as shown in Figure 2. Alternatively, separate sealing electrodes 18 and 19 that are not physically connected in the distal end region 20 may be provided, which may have equal or different potentials.

[0024] The first jaw portion 13 has a groove 21 between the sealing electrodes 18 and 19, and the groove 21 is limited by groove flanks 22 and 23. The groove flanks 22 and 23 are preferably spaced at a certain distance from each other and parallel to each other, as is clear from Figures 2 and 4, and this distance defines the groove width BN. The groove width BN is preferably constant along the length of the groove 21, or only in a portion thereof, preferably in the distal end region. The groove 21 is preferably rectangular or square in cross-section. However, it is also possible to provide a groove 21 with a trapezoidal cross-section such that the bottom of the groove 21 is narrower than the opening facing the other jaw portion 14.

[0025] An insulator 24, made of, for example, silicone or another insulating material, particularly plastic, is placed inside the groove 21. It is preferable to use a plastic that has remarkable flexibility or elasticity and high creepage current strength. This greatly improves the mechanical and electrical function of the tissue sealing device 11.

[0026] A cutting electrode 25, made of a thin metal strip, is positioned within the insulator 24. To securely fix the cutting electrode 25 inside the insulator 24, the cutting electrode 25 may have one or more openings through which the insulator 24 penetrates. The two flanks of the cutting electrode 25 are covered by the insulator 24 and thus electrically insulated. In this way, the insulator forms a wall that rises in the direction toward the jaw portion 14, and the cutting electrode 25 is exposed at the top of the wall. There, only the narrow face edge of the cutting electrode 25 and, optionally, a small strip-shaped lateral region adjacent to the face edge are exposed. It is preferable that this lateral region is not as wide as the width of the face edge.

[0027] The insulator 24 includes a first portion 26 located inside the groove 21 and a second portion 27 protruding from the first portion 26, forming a rising wall. The cutting electrode 25 extends through the second portion 27 and into the first portion 26.

[0028] Refer to Figure 2 for the longitudinal shape of the first jaw portion 13. From the region 28 near the joint to the distal end region 20, the seal electrode 18 extends in a substantially straight line. Adjacent to it, an arc portion 18a with a large curvature is located inside or close to the end portion 20. In contrast, the seal electrode 19 extends from the region 28 near the hinge in an arc with a small curvature. This curvature is smaller than the curvature of region 18a. In the transition of region 19a, the seal electrode 19 extends toward the seal electrode 18, and then away from the seal electrode 18. For example, as shown in Figure 2, the minimum distance A between the seal electrodes 18 and 19 is minIt can be located between the region 28 near the hinge and the distal end region 20 or near or within the further distal end region 20. Therefore, the distance A in the region 28 near the hinge 28 and distance A in the distal end region 20 20 This is the distance A measured between region 28 and region 20. min It is preferable that it be longer than distance A. 20 , A min and A 28 The measurement must always be taken in a direction transverse (orthogonal) to the linearly extended seal electrode. The measurement direction coincides with the direction in which the force pulling the tissue primarily acts. In the distal end region 20, the seal electrodes 18 and 19 approach each other in order to transition to each other at the distal end. The sizes of the region near the hinge 28 and the distal end region 20 can be defined differently. For example, the end region near the hinge may end where the linear portion of the seal electrode 19 terminates. The distal end region 20 may begin where the linear portion of the seal electrode 18 terminates. In addition, the minimum distance A min The region containing this is located between regions 20 and 28 in all cases.

[0029] The groove 21 includes different extensions. The groove 21 can follow an arc having the minimum curvature, and as the arc progresses, the groove 21 approaches the straight seal electrode 18 slightly at approximately the midpoint between the hinge region 28 and the distal end region 20, but not below the minimum insulation distance. Thus, the groove 21 can follow an arc that is curved only once, or it can be slightly S-shaped, which can be achieved by positioning the cutting electrode 25 in the hinge region 28 in a portion at least parallel to the cutting electrode 18. At least in most embodiments of the present invention, the distance between the cutting electrode 25 and at least one of the seal electrodes 18, 19, in this case the seal electrode 18, is characterized by variation. This distance starts in the hinge region and is initially large. Further away from the hinge region 28, the distance is minimum at approximately the midpoint of the jaw portion 13, and then slightly increases again in the distal end region 20. This electrode configuration can also be used with tools whose groove 21 and recess 32 have matching widths and shapes. Otherwise, the remaining description applies as appropriate to such tools.

[0030] As is clear from Figure 4, surface areas 29 and 30 of the first jaw portion 13 are provided on both sides of the insulator 24, with the surface areas 29 and 30 adjacent to the insulator 24 on one side and adjacent to the sealing electrodes 18 and 19 on the other side. These surface portions 29 and 30 can be exposed metal and can make electrical contact with the sealing electrodes 18 and 19. However, it is preferable that these surface portions 29 and 30 are provided with an insulating coating or cover, such as a ceramic cover or a plastic cover (e.g., made of parylene). The support portion 16 can be made of plastic (with or without a metal inlay), and therefore a separate insulating material is not required. The surface areas 29 and 30 can be shifted backward, which, referring to Figure 4, means being positioned deeper than the sealing surfaces 18v and 19v provided on the electrodes 18 and 19. Furthermore, the sealing region can be adjacent to the insulator 24 without any step.

[0031] The sealing surfaces 18v and 19v of the sealing electrodes 18 and 19 shown in Figure 4 are configured to be "narrow." This means that the width of the sealing surfaces 18v and 19v measured in the drawing plane of Figure 4 is smaller, preferably significantly smaller, than the distance between the sealing electrode 18 and the cutting electrode 25 measured in the same direction. The same applies to the sealing electrode 19. This requirement applies to at least a portion of the sealing electrodes 18 and 19, or preferably their entire length. This configuration provides a narrow but reliable sealing seam on the tissue, and further provides a large tissue retention space for fixing the tissue during treatment.

[0032] The second jaw portion 14 includes a support portion 31 that limits the groove-shaped recess 32 (Figure 3). Again, the support portion 31 may be made of metal or further made of plastic or a metal-plastic composite. The support portion 31 supports seal electrodes 33, 34 at its outer edge, which extend from the region near the hinge 28 to the distal end region 20. The seal electrodes 33, 34, which follow the shape of the support portion 31, are arranged mirror-symmetrically with respect to the seal electrodes 18, 19. When the jaw portion is closed, the seal electrode 34 coincides with the seal electrode 18. Furthermore, the seal electrode 33 coincides with the seal electrode 19. The descriptions of the extensions and shapes of the seal electrodes 18, 19 so far apply to the seal electrodes 33, 34 in a mirror-symmetric manner as appropriate. Furthermore, the seal electrodes 33, 34 can be electrically and physically connected to each other in the distal end region 20.

[0033] The recess 32 has a width BA that can vary along the longitudinal extension of the second jaw portion 14. However, the width BA is wider than the width BN of the groove 21 at any point. Preferably, the width BA coincides with the distance between the seal electrodes 33 and 34. Thus, the seal electrodes 33, 34 and the recess 32 have the same external shape. However, it should be noted that the external shapes of the seal electrodes 33, 34 and the recess 32 can also be defined to be different from each other. Thus, the distance between the seal electrodes 33 and 34 and their extensions along the length of the jaw portion 14 coincide with the distance between the seal electrodes 18 and 19 and their extensions, and they are substantially congruent.

[0034] A counter support portion 35 made of flexible plastic is positioned inside the recess 32. This is preferably made of a flexible plastic material, such as silicone. The counter support portion 35 is preferably a closed, one-piece structure without any hollow spaces. The counter support portion 35 is deformable but cannot be significantly compressed. This means that, in a preferred embodiment, the volume of the counter support portion 35 cannot be significantly reduced due to the clamping force acting within the tool.

[0035] The counter support portion 35 can either completely fill the recess 32, or, as shown in Figure 4, leave smaller air pockets unfilled, allowing for displacement corresponding to the size of the air pockets during deformation. Furthermore, the counter support portion 35 extends inside the seal electrodes 33 and 34 to which it is attached by extensions 35a and 35b. This electrically isolates the seal electrodes 33 and 34 from the tissue retention space. Because portion 38 of the counter support portion 35 is supported at the bottom of the recess 32, there is virtually no force at the connection point between the extensions 35a and 35b and the inside of the seal electrodes 33 and 34, and therefore the existing connection is unaffected or hardly affected by stress.

[0036] Many modifications can be made to the embodiments of tool 12 described so far. For example, the tool 12 shown in Figure 5 can be configured to be significantly narrower. By using an optional air pocket provided between the support portion 31 and the counter support portion 35, the deformation of the counter support portion can be particularly controlled during use. However, the counter support portion 35 includes a portion 38 that is directly supported at the bottom of the recess 32, as already shown in the embodiment shown in Figure 4. Furthermore, as shown in Figure 5 as an example, the air pockets 36 and 37 can be extended by portions 36a and 37a to the connection point between the counter support portion 35 and the seal electrodes 33 and 34. In this case, the connection point can be freed from mechanical shear and tensile forces.

[0037] Furthermore, in the embodiment shown in Figure 6, air pockets 36, 37 (not shown) and support portions 38 can be provided, and therefore the above description applies appropriately based on the same reference numerals. The unique feature of the embodiment shown in Figure 6 is the insulator 24, which includes extensions 39, 40 that protrude beyond the surface portions 29, 30. Otherwise, the remaining description of the embodiments described above applies as appropriate.

[0038] In all embodiments, the seal electrodes 18 and 19 can be inserted into the respective cavities of the support portion 16. This simplifies assembly and allows for precise positioning of the seal electrodes 18 and 19.

[0039] Furthermore, one or more recesses are provided in the side walls 22 and 23 of the groove 21, allowing the insulator 24 to extend within these recesses by its respective protrusions. These recesses can be positioned along one or both of the two side walls 22 and 23. This allows for specific definition of the lateral flexibility of the electrode 25. The electrode 25 may also have lateral extensions at its edges located inside the groove 21. These extensions can extend within the recesses together with the insulator 24, if lateral recesses are provided. This means, by simultaneously using a highly flexible plastic as the insulator 24, enables particularly good lateral stabilization of the cutting electrode.

[0040] The tissue sealing device 11 described above operates as follows:

[0041] During use, the tissue is held between jaws 13 and 14, for example, as shown in Figure 7. This connects the sealing electrodes 18 and 19 to one pole of the generator, and the sealing electrodes 33 and 34 to the other pole of the generator. Therefore, the biological tissue, such as tube 41, held and compressed between jaws 13 and 14, fuses and solidifies between the sealing electrodes 18, 33; 19, 34. This causes the cutting electrode 25 to press the biological tissue against the counter support 35, allowing the counter support 35 to release the pressure. However, instead, the counter support 35 presses the tissue against both sides of the cutting electrode 25 in its pressure-releasing motion. The tissue is held in the tissue-holding spaces 42 and 43 formed on both sides of the cutting electrode 25. The pressure-releasing motion of the counter support 35, by retracting from the tissue 41, creates space within the holding spaces 42 and 43 for the tissue 41 to be available. In this way, the tissue 41, for example, the end of a tube, is held securely within the instrument and fixed so as not to come loose unintentionally. Simultaneously with or with a time delay, sealing the tissue between electrode pairs 18 / 34 and 33 / 19, a current is applied to the cutting electrode 25 so as to cut the tissue 41.

[0042] As shown in Figures 8 and 9, the conditions are similar even for narrower instruments. However, in these instruments, because there are air pockets 36, 37, the counter support 35 can be allowed to release pressure into these air pockets as well, so as not to increase the pressure on the tissue 41 excessively.

[0043] The tissue sealing device 11 according to the present invention comprises two jaws 13 and 14, both of which are provided with sealing electrodes 18, 19, 33, and 34. One of the jaws includes a cutting electrode 25, and the other includes an elastic counter support 35. The cutting electrode 25 is held within a flexible plastic body 24 that is housed in a narrow groove 21. In contrast, the counter support 35 is housed in a relatively substantially wider recess. Therefore, the counter support 35 is wider (preferably significantly wider) than the insulator 24 containing the cutting electrode 25. By defining these different dimensions, a wide range of desired features of the tissue sealing device 11 can be defined. [Explanation of Symbols]

[0044] 10 Shank 11. Tissue sealing devices 12 Tools 13. First jaw 14. Second jaw 15. Bearing device, connecting shaft 16 Support part 17 Lateral side of the first jaw portion 13 18, 19 Seal electrodes 18V, 19V sealing surface 18a Part of the seal electrode 18 19a Part of the sealing electrode 19 20 Distal end region 21 Groove 22, 23 Grooved flank 24 Insulator 25 Cutting electrodes 26. First part of the insulator (leg portion) 27. The second part of the insulator (wall portion) 28 Region near the joint 29, 30 surface area 31 Support part 32 recesses 33, 34 Seal electrodes 35 Counter support section 35a, 35b Extension of counter support part 35 36, 37 Air pockets 38 Counter support section 39, 40 Insulator portion 41 Organization 42, 43 Retention space

Claims

1. A tissue sealing device (11) comprising a first jaw portion (13) and a second jaw portion (14), wherein the first jaw portion (13) and the second jaw portion (14) are pivotably supported by a bearing device (15) so as to be toward and away from each other, and each includes sealing electrodes (18, 19; 33, 34), The first jaw portion (13) has a groove (21) between the sealing electrodes (18, 19) that is limited by two opposing flanks (22, 23), the distance between the flanks (22, 23) defines a first width (BN), and within the groove (21), the cutting electrode (25) is held in an insulator (24). The second jaw portion (14) has a recess (32) between the electrodes (33, 34) that is limited by two opposing sides, and a flexible counter support portion (35) for the cutting electrode (25) is disposed in the recess (32), and the distance between the sides defines a second width (BA), The first width (BN) is smaller than the second width (BA). Equipment.

2. The sealing electrodes (18, 19) of the first jaw portion (13) are positioned at the edge of the first jaw portion (13). The apparatus according to claim 1.

3. The sealing electrodes (33, 34) of the second jaw portion (14) are positioned at the edge of the second jaw portion (14). The apparatus according to claim 1 or 2.

4. The sealing electrodes (18, 19) of the first jaw portion (13) are positioned on both sides of the groove (21) that extends toward the distal end region (20). The apparatus according to claim 1.

5. The sealing electrodes (18, 19) of the first jaw portion (13) are connected to each other in the distal end region (20). The apparatus according to claim 4.

6. The sealing electrodes (33, 34) of the second jaw portion (14) are arranged on both sides of the recess (32) that extends toward the distal end region (20). The apparatus according to claim 1.

7. The sealing electrodes (33, 34) of the second jaw portion (14) are connected to each other in the distal end region (20). The apparatus according to claim 6.

8. One of the sealing electrodes (18; 34) of each jaw portion (13, 14) extends in a straight line from the region near the hinge (28) to the distal end region (20), and the other sealing electrode (19, 33) extends in an arc from the region near the hinge (28) to the distal end region (20), and the arc is the minimum distance (A) between the sealing electrodes (18, 19; 33, 34). ｍｉｎ The hinge is positioned between the region (28) near the hinge and the distal end region (20), or adjacent to the distal end region (20). The apparatus according to claim 1.

9. The groove (21) includes an arc-shaped curved extension. The apparatus according to claim 1.

10. The first width (BN) is constant along the length of the groove (21). The apparatus according to claim 1.

11. The second width (BA) is defined to vary along the length of the recess (32). The apparatus according to claim 1.

12. The insulator (24) is configured to be flexible and includes a first portion (26) held inside the groove (21) and a second portion (27) protruding from the groove (21). The apparatus according to claim 1.

13. The cutting electrode (25) is positioned to penetrate the second portion (27) and extend within the first portion (26). The apparatus according to claim 12.

14. The recess has a bottom, and the counter support portion (35) includes a portion (38) supported by the bottom of the recess (32). The apparatus according to claim 1.

15. The counter support portion (35) has portions (35a, 36b) adjacent to the seal electrodes (33, 34). The apparatus according to claim 1.

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