COAGULATION INSTRUMENTS

Description

[0001] The invention relates to an instrument with at least one electrode that can be brought into contact with biological tissue for energizing biological tissue.

[0002] Instruments of this type, in particular coagulation instruments with coagulation electrodes, are known in principle. EP 2 853 219 A1 discloses such an instrument with a forceps-like tool having two interacting branches that can be moved towards and away from each other. Each of the two branches comprises a plastic body to which a coagulation electrode is attached. The coagulation electrode has an angled edge that serves as an anchoring section and extends into the plastic body. For anchoring in the plastic, the anchoring section has openings through which the plastic passes. This ensures a positive anchoring of the electrode to the plastic body. The plastic body leaves a tissue contact surface free and has a central knife channel that forms an elongated groove. This groove passes through the electrode and extends into the plastic body.

[0003] EP 2 719 352 A1 discloses a similar electrode arrangement with an electrode formed from sheet metal, which has an anchoring section on both sides of its tissue contact surface. Anchoring openings are provided in these sections, which extend either as a through-opening through the anchoring section or as pockets into the anchoring section. Furthermore, this document discloses spacers arranged on the tissue contact surface in the form of electrically non-conductive elevations.

[0004] US 2021 / 0205003 A1 discloses an instrument whose branch comprises an inner plastic body, a metal support receiving the latter and having a U-shaped cross-section, and an outer plastic body, wherein a tissue contact surface is provided on the upper side of this branch.

[0005] US 2012 / 01272873 A1 also discloses a branch with a structurally stiffening metal inlay and an inner insulator defining the knife channel, which is overlapped by an electrode and its anchoring section. The branch is externally surrounded by another plastic body that contacts the anchoring section of the electrode as well as the inner plastic body and the stiffening metal body.

[0006] Further industries made up of plastic and metal parts are known from DE 10 2016 100 549 A1 and EP 2 092 905 B1.

[0007] US 2011 / 072638 A1 discloses a coagulation instrument according to the preamble of claim 1.

[0008] Instruments of this type exist as disposable instruments and as sterilizable, reusable instruments. Both during normal use and during sterilization, the instruments are exposed to thermal stress, which can lead to the formation of gaps, e.g., due to different expansion coefficients of plastic and metal. This can lead to difficulties both in ensuring sterility during sterilization and in terms of mechanical strength. Therefore, it is desirable to mitigate the problems associated with thermal stress for both disposable and reusable instruments.

[0009] The object of the invention is to create a coagulation instrument improved in this respect.

[0010] The coagulation instrument according to the invention has at least one branch to which an electrode is attached, which has a tissue contact surface. Such an instrument can be, for example, a monopolar instrument with a single electrode, or a forceps-like element with two branches. Each of the branches can have at least one electrode. Other instrument designs are possible.

[0011] The electrode has an anchoring section provided with at least one anchoring opening. The anchoring opening can be a through-hole or a blind opening, for example in the form of a flat pocket or the like. The anchoring opening can be created by punching, punch-bending, drilling, laser cutting, etching, eroding, water jet cutting, and other machining methods. In particular, the opening can have a smooth edge or an edge with one or more tabs extending therefrom.

[0012] According to the invention, the electrode is mounted on an insulator assembly, which includes at least two plastic bodies, between which the anchoring section extends. The two plastic bodies are positively connected to the electrode and / or to one another. For this purpose, each of the plastic bodies has at least one, preferably several projections, which engage in the at least one or more anchoring openings of the electrode, i.e., extend into or through them. Alternatively, only one of the two plastic bodies has projections that extend through the anchoring openings and into the other plastic body, which in turn interlocks the two plastic bodies.

[0013] When the two plastic bodies are interlocked in one or more of the ways mentioned, a positive fit is created between the two plastic bodies, ensuring a good, permanent, and secure connection between the two plastic bodies and thus also a secure anchoring of the electrode to the insulator assembly. This allows for the production of exceptionally reliable coagulation instruments. This applies regardless of whether the plastic bodies are interlocked near, at, or within the anchoring opening.

[0014] The anchoring section of the electrode encompasses an inner plastic body and is itself encompassed by an outer plastic body. Both plastic bodies are positively connected to one another and to the anchoring section of the electrode in one of the aforementioned ways. The extensions of the plastic body extending through the anchoring openings have a length L that can be at least as great as the thickness D of the anchoring section. However, it is also possible to select the length L of the extensions of the plastic bodies to be smaller than the thickness D of the anchoring section, so that the extensions of the two plastic bodies adjoin one another at a contact surface that lies entirely within the anchoring opening.

[0015] The presented concept allows the plastic bodies to be formed from different plastics, even if these plastics do not form mechanically strong welded connections with one another. Production can be carried out using the injection molding process, in which one of the plastic bodies is first produced by injecting plasticized plastic in a suitable injection mold. Anchoring structures are formed in the first plastic body, e.g. in the form of depressions (blind openings). After the first plastic body has at least partially solidified, the other of the two plastic bodies can then be produced by injecting plasticized plastic. The plastic then flows into the anchoring structures and thereby forms an interlock with the first plastic body and the electrode. A strong, reliable connection between the plastic bodies is created, particularly in the area of ​​the anchoring section of the electrode.

[0016] Further details of advantageous embodiments of the invention can be found in the drawings, the associated description, or the claims. The drawings illustrate exemplary embodiments of the invention. They show: Figure 1 a coagulation instrument intended for laparoscopic use, in perspective principle representation, Figure 2 a tool part of the instrument Figure 1 , in perspective view, Figure 3 a tool industry Figure 2 , in perspective view, Figures 4 to 7 different views of an electrode of the tool after Figure 2 and 3 , Figure 8 an embodiment of an anchoring opening of the anchoring section of the electrode produced using a punching and bending technique, in a partial perspective view, Figure 9a modified embodiment of an anchoring opening of the anchoring section of an electrode of an instrument according to the invention, produced using a punching and bending technique, Figure 10 the industry Figure 3 in a sectional view, in a first embodiment, Figure 11 a partial sectional view of the industry according to Figure 10 , in perspective view, Figure 12 a partial sectional view of a branch of an instrument according to the invention, in a second embodiment, Figure 13 the industry similar Figure 10 or 12 , in a further embodiment, Figure 14 the industry similar Figure 12 , in a modified embodiment, and Figure 15 to Figure 19various embodiments of the branches based on sectional views of the plastic body and the anchoring section of the electrode, cut in the direction of the anchoring openings parallel to the tissue contact surface, each in a partial view.

[0017] In Figure 11 shows a coagulation instrument 20 having a forceps-like tool part 21. The tool part 21 is arranged at the distal end of a shaft 22, the proximal end of which is carried by a housing 23 with a handle 24 and an actuating lever 25. This serves to move branches 26, 27 of the tool part 21 towards and away from each other in order to grip and coagulate biological tissue, in particular, for example, hollow vessels such as blood vessels or the like. For this purpose, the two branches 26, 27 are each provided with an electrode 28 on the sides facing each other, between which an electrical voltage can be applied so that a current flows through the tissue grasped therebetween. The tool part 21 can have further elements, such as a mechanically movable knife or a cutting electrode.

[0018] The Figures 1 and 2The instrument 20 shown is a bipolar tool and is intended here only for illustrative purposes. However, the invention can equally be applied to instruments designed for open surgical use or for endoscopic use. The invention can also be applied to instruments whose tool part 21 has only a single electrode and is held immovably on the instrument. Furthermore, the invention can be used on instruments that are similar Figures 1 and 2 are designed like pincers, but only one of the electrodes is movable.

[0019] Branch 27 is in Figure 3 illustrated separately. It comprises an insulator assembly 29 to which the electrode 28 is held.

[0020] The electrode 28 is in Figure 4 , as well as in the Figures 5 to 7illustrated separately. It can be formed from a sheet metal and has a tissue contact surface 30. The tissue contact surface 30 can, for example, be formed as a flat surface. Approximately centrally, it can be perforated by a knife slot 31 extending from the proximal end to the distal end. Such a knife slot 31 can be present if the tool part 21 has a mechanical knife that can be advanced along the knife slot 31 (not shown).

[0021] An anchoring section 34, 35 can be connected to the edge of the tissue contact surface 30 at a bending line 32, 33, which is formed, for example, by the two edges of the electrode 28 that are bent downwards at approximately right angles. The anchoring sections 34, 35 can merge into one another at the distal end of the electrode 28 or, as in Figure 5 recognizable, end at a distance from each other.

[0022] The anchoring sections 34, 35 are essentially identical in design, so that the following description of the anchoring section 35 applies accordingly to the anchoring section 34. The anchoring section 35 is provided with at least one, preferably several, anchoring openings 36, 36a, 36b, which, as shown, can be slit-like or alternatively also oval, round, circular, or elongated openings. These openings can essentially be designed as through-holes or alternatively as flat pockets.

[0023] The anchoring openings 36, 36a, 36b can be designed as openings with a smooth edge or with a tab 37, 38 attached to the edge, as shown in the Figures 8 or 9This flag 37 or 38 can be produced during the creation of the anchoring opening 36 in the stamping process by bending a released tongue away from the anchoring opening 36. In the case of the embodiment according to Figure 8 this flag is formed perpendicular to the fabric contact surface 30, while in the embodiment according to Figure 9 can be oriented essentially parallel thereto. An anchoring opening 36, 36a, 36b can also have several such flags.

[0024] The electrode 28 is preferably designed as a sheet metal part and can be Figures 4 to 7 have a contact lug 39 for connecting an electrical cable. Other connection options for connecting an electrical conductor may also be provided.

[0025] One or more spacers 40, 41, 42, which are preferably made of an electrically non-conductive material, such as plastic or ceramic, can be provided on the tissue contact surface 30. The spacers 40 to 42 can also be applied to the tissue contact surface 30. Alternatively, they can have a shaft that is designed to extend through an opening in the tissue contact surface 30.

[0026] The electrode 28 described so far is anchored in the insulator assembly 29, which, as Figure 10 shows, comprises a first, inner, one-part or multi-part plastic body 44 and an outer one-part or multi-part plastic body 45, which are positively connected to the electrode 28.

[0027] In the embodiment according to Figure 10The two plastic bodies 44, 45 are interlocked in the region of the anchoring opening 36. For this purpose, the inner plastic body 44 has an extension 46 which extends into the anchoring opening 36. The second plastic body 45 also has an extension 47 which also extends into the anchoring opening 36. The two extensions 46, 47 can, as can be seen from Figure 10 visible, interlock, for example, in that the first extension 46 has a recess into which the second extension 47 engages. Figure 11 illustrates the plastic body 44 and its hollow pin-like extension 46 separately. It has an opening into which the pin-like extension 47 of the other plastic body 45 is molded.

[0028] The resulting interlocking of the extensions 46, 47 of the two plastic bodies 44, 45 with one another and thus simultaneously the firm interlocking with the electrode 28 or the anchoring section 35 results in a permanent connection between the two plastic bodies 44, 45. This is the case even when the two plastic bodies 44, 45 are made of plastics that, when successively introduced into an injection mold, do not bond intimately, for example, by welding. The inventive concept thus enables the selection of the plastics for the first and second plastic bodies 44, 45 without having to take great consideration of their tendency to bond. The selection of the plastics can thus be optimized with regard to biological mechanical or electrical properties as well as thermal properties. For example,The plastic body 44 can be made of a wear-resistant fiber-reinforced plastic, while the plastic body 45 consists of a different, non-fiber-reinforced plastic. While one plastic can be selected or optimized with respect to certain properties, e.g., sliding properties or rigidity, the other plastic can be selected or optimized with respect to other properties, e.g., sterilizability or biocompatibility.

[0029] In the embodiment according to Figure 10 the projections 46, 47 are approximately long enough to fill the anchoring opening 36, but do not protrude through it. In a variation of this, Figure 12An enlarged view of an embodiment modified in this respect. The plastic body 45 resting against the outer side 48 of the anchoring section 35 here has an extension 47 with a length L that is greater than the thickness D of the anchoring section 35, measured between the outer side 48 and the inner side 49 of the anchoring section 35. While the extension 47 thus projects beyond the inner side 49, the extension 46 is flush with the outer side 48. The extensions 46, 47 and thus the plastic bodies 44, 45 are interlocked. Furthermore, they are additionally interlocked with the electrode 28 or its anchoring section 35. However, it is also possible to dimension the length L of the projection 47 to be less than the thickness D.

[0030] In the embodiment according to Figure 13The plastic bodies 44, 45 in turn have extensions 46, 47 that extend into or through the anchoring opening 36. The extensions 46, 47 can extend side by side into the anchoring opening 36. As shown, the extensions 46, 47 can be flush with the outer side 48 and the inner side 49 or even protrude beyond them. It is also possible to make the extension 47 somewhat shorter, so that it comes from the outer side 48 and does not reach the inner side 49, which in Figure 13 is indicated by dashed lines 50. Additionally or alternatively, the extension 46 shown in the figure flush with the outer side 48 can be shortened and thus end within the anchoring opening 36, which in Figure 12 by a dashed line 51. Nevertheless, regardless of this, the two plastic bodies 44, 45 in the embodiment according to Figure 12interlocked with each other. They are also interlocked with the anchoring section 35 of the electrode 28.

[0031] A modified embodiment illustrates Figure 14 . In this case, the extension 47 of the plastic body 45 penetrates the anchoring opening 36 and extends into the plastic body 44. The extension 47 extends beyond the inner side 49 of the anchoring section 35 into the plastic body 44, whereby the plastic bodies 44, 45 are interlocked with one another. While the second plastic body 45 is thereby simultaneously interlocked with the electrode 28, the plastic body 44 is not directly interlocked with the electrode 28. However, the positive connection of the two plastic bodies 44, 45 to one another still provides a firm connection between the electrode 28 and the insulator assembly 29.

[0032] The interlocking of the two plastic bodies 44, 45 does not necessarily have to be within a single anchoring opening 36. It is also possible to divide the interlocking into several anchoring openings 36, 36a, 36b, as Figure 15 The anchoring openings 36a, 36b can, as Figure 15 suggests, be arranged in a row along the anchoring section 35. For example, the extension 47 can extend inwards through the anchoring opening 36a, that is, beyond the inner side 49, while the extension 46 extends from the inside to the outside through the anchoring opening 36b beyond the outer side 48. However, it is also possible that the extensions 46, 47, as Figure 16illustrated, each divide an opening 36 and protrude through it side by side. They can be flush with the inner side 49 and the outer side 48 or they can extend individually or both beyond these sides 48, 49, as Figure 16 illustrated.

[0033] Based on the embodiment according to Figure 15 It is also possible to arrange the extensions 46, 47 alternately in the row of anchoring openings 36a, 36b, wherein one or both of the extensions 46, 47 terminate with the outer side 48 and the inner side 49. In this embodiment, both plastic bodies 44, 45 are interlocked with the anchoring section 35 of the electrode 28, but not with each other. In contrast, the plastic bodies 44, 45 in the embodiments according to Figures 15 and 16 both with each other and with the anchoring section 35.

[0034] Figure 18 and Figure 19illustrate further embodiments in which the plastic bodies 44, 45 are interlocked with the anchoring section 35 and thus with the electrode 28, but not with each other. In the embodiment according to Figure 18 The anchoring openings 36a, 36b are formed as flat pockets into which the projections 46, 47 extend. This results in an interlocking of the plastic body 44 with the anchoring section 35 and thus with the electrode 28. Likewise, an interlocking of the plastic body 45 with the anchoring section 35 and thus with the electrode 28 is achieved.

[0035] In the embodiment according to Figure 19The interlocking of the extensions 46, 47 with the anchoring section 35 is achieved by both extensions 46, 47 extending into the anchoring opening 36 and meeting therein. They can meet at a surface 52 located within the anchoring opening 36. The surface 52 can be a flat surface or a non-flat, for example curved, contact surface. It can be oriented parallel to the inner side 49 and the outer side 48 or at an angle to them and extend obliquely through the anchoring opening 36. Such a non-flat and oblique contact line is in Figure 19 indicated as dashed line 53.

[0036] A coagulation element according to the invention has an insulator assembly 29 consisting of at least two plastic bodies 44, 45, between which an anchoring section 35 of an electrode 28 is arranged. The anchoring section 35 has at least one anchoring opening, preferably a plurality of anchoring openings, which serves for the positive coupling of the electrode to the insulator assembly 29. For this purpose, at least one of the plastic bodies 29, 44 is provided with an extension 47 which extends into or through the anchoring opening 36. It can extend into the other plastic body 44. Alternatively, the plastic body 44 can have one or more projections 46 which extend at least into or through one anchoring opening 36 and optionally into the other plastic body 45. Reference symbols:

[0037] 20Coagulation instrument 21Tool part 22Shaft 23Housing 24Handle 25Actuating lever 26, 27Blades 28Electrode 29Insulator assembly 30Tissue contact surface 31Knife slot 32, 33Bending line 34, 35Anchoring section 36Anchoring opening 36a, 36b 37, 38Flag 39Contact flag 40 - 42Spacer 44First plastic body 45Second plastic body 46Extension of the first plastic body 44 47Extension of the second plastic body 45 48Outside of the anchoring section 35 49Inside of the anchoring section 35 50, 51Dashed line 52Surface 53Dashed line

Claims

1. A coagulation instrument (20), in particular for coagulation and / or fusion of biological tissue, having at least one jaw (26, 27) comprising an electrode (28) comprising a tissue contact surface (30) and at least one anchor section (35) which comprises at least one anchor opening (36), characterized by an insulator unit (29) comprising two plastic bodies (44, 45) between which the anchor section (35) extends, wherein both plastic bodies (44, 45) are connected in form-fitting manner to the electrode and / or to each other.

2. The coagulation instrument according to claim 1, characterized in that the plastic bodies (44, 45) are interlocked with one another.

3. The coagulation instrument according to one of the preceding claims, characterized in that the plastic bodies (44, 45) are interlocked with one another at the anchor opening (36).

4. The coagulation instrument according to one of the preceding claims, characterized in that the plastic bodies (44, 45) are interlocked with one another inside the anchor opening (36).

5. The coagulation instrument according to one of the preceding claims, characterized in that the anchor section (35) of the electrode (28) embraces one of the plastic bodies (44, 45).

6. The coagulation instrument according to one of the preceding claims, characterized in that the plastic body (44) embraced by the anchor section (35) comprises extensions (46) extending into and / or through openings (36) of the anchor section (35).

7. The coagulation instrument according to one of the preceding claims, characterized in that one of the plastic bodies (45) embraces the anchor section (35) of the electrode (28).

8. The coagulation instrument according to one of the preceding claims, characterized in that the plastic body (45) embracing the anchor section (35) comprises extensions (47) extending into and / or through openings (36) of the anchor section (35).

9. The coagulation instrument according to claim 6 or 8, characterized in that the extensions (46, 47) have a length (L) which is at least as great as the thickness (D) of the anchor section (35).

10. The coagulation instrument according to one of the preceding claims, characterized in that the anchor section (35) is formed by an edge extending at an angle away from the tissue contact surface (30), wherein the edge is in contact with one side (48) with one of the plastic bodies (45) and with its opposite side (49) with the other of the plastic bodies (44).

11. The coagulation instrument according to one of the preceding claims, characterized in that the anchor opening (36) is a through-opening.

12. The coagulation instrument according to one of the preceding claims, characterized in that one of the plastic bodies (44) is a fiber-reinforced plastic body.

13. The coagulation instrument according to one of the preceding claims, characterized in that one of the plastic bodies (44) surrounds a knife channel (31).

14. The coagulation instrument according to one of the preceding claims, characterized in that the plastic bodies (44, 45) are made of different plastic materials.

15. The coagulation instrument according to one of the preceding claims, characterized in that the plastic bodies (44, 45) are connected to one another in a substance bond manner.