GB2585048A

GB2585048A - A method of manufacturing an electrode

Info

Publication number: GB2585048A
Application number: GB1909173.5A
Authority: GB
Inventors: Schlottmann Ole
Original assignee: Gyrus Medical Ltd
Current assignee: Gyrus Medical Ltd
Priority date: 2019-06-26
Filing date: 2019-06-26
Publication date: 2020-12-30
Anticipated expiration: 2039-06-26
Also published as: GB2585048B; GB201909173D0

Abstract

The method comprises printing a first portion of insulation material 300, inserting an electrode 306 into the portion and printing a second portion of insulating material (314, fig 3C) to partially enclose the electrode such that a gap 312 is formed between the electrode and the inner walls of the portions. The part is then heat treated to fuse the first and second portions around the electrode to form an electrode assembly. The gap allows for shrinkage when the insulating material is fired to fuse the arrangement together. A further method is disclosed where at least two portions of insulating material are printed and configured to receive the electrode (figs 7 & 8), the portions are heat treated to form an outer moulding then an electrode inserted. The insulating material may be a ceramic material.

Description

A Method of Manufacturing an Electrode

Technical Field

The present invention relates to a method of manufacturing an electrode assembly. More specifically, the present invention relates to a method of manufacturing an electrode assembly for use in an electrosurgical instrument.

Background to the Invention and Prior Art

It is known to provide bipolar RF surgical instruments with at least one electrode located within the tip of the instrument. In order to manufacture such instruments, over-moulding of a ceramic material directly onto the electrical components has been previously suggested. One example of an over-moulding technique is described in US 2015/006973, in which a plastics material is first over-moulded onto the electrode, followed by an insulating ceramic material. The plastics material is then removed during the firing of the ceramics material to leave a cavity within the instrument, for example, to provide a channel for electrical connections or to provide a suction lumen.

However, such over-moulding techniques do not allow for shrinkage of the moulded ceramic material during the firing process, which can result in a weakening of the retention between the electrode and the ceramic. Consequently, as the instrument is used over time, the active tip can become eroded and fall out of the ceramic moulding. This can be particularly problematic if this occurs during surgery, especially in the context of keyhole procedures.

Summary of the Invention

Embodiments of the present invention provide a method of manufacturing an electrode assembly having advantages over the prior art. In particular, the present invention provides a method of manufacturing an electrode assembly in which an insulating material is 3D printed around the electrical component, leaving a gap to allow for shrinkage when the binding agent is removed and the insulating material is fired to fuse the arrangement together.

According to a first aspect, the present invention provides a method of manufacturing part of an electrosurgical instrument, comprising printing a first portion of an insulating material, the first portion of the insulating material being configured to receive an electrode, inserting at least a first part of the electrode into the first portion of the insulating material, printing a second portion of the insulating material so as to partially enclose the first part of the electrode, and such that a gap between the first part of the electrode and an inner wall of the first and second portions of the insulating material is formed therebetween, and performing a heat treatment process to fuse the first and second portions of the insulating material around the first part of the electrode to form a first electrode assembly.

As such, the two portions of insulating material are provided with a cavity in which at least part of the electrode sits, such that a small gap is formed between the inner walls of the cavity and the electrode. By providing a gap between the electrode and the inner walls of the cavity, any shrinkage of the insulating material when the two portions of are fused together is accounted for to ensure the electrode is firmly retained therein.

The electrode may be an active electrode. More specifically, the first part of the electrode may be a tissue treatment portion.

In some examples, the method may comprise inserting a second part of the electrode into the first portion of the insulating material prior to printing the second portion of the insulating material. That is to say, both parts of the electrode may be inserted into the first portion of insulating material at substantially the same time, the second portion of insulating material being subsequently printed and fused to the first portion, thereby retaining both parts of the electrode therein.

In another example, the method may comprise inserting a second part of the electrode into the first electrode assembly, wherein the first electrode assembly comprises a cavity configured to receive the second part of the electrode such that it abuts the first part of the electrode. That is to say, the second part of the electrode may be inserted once the first electrode assembly has been formed. In this respect, the first electrode assembly will be formed with a cavity into which the second part of the electrode can be inserted.

The second part of the electrode may be a connection portion, for example, to allow electrical connection of the tissue treatment portion to a generator. The connection portion may comprise a suction lumen connected to an aperture in the first part of the electrode, for example, to allow the delivery of fluid to and from the tissue treatment portion.

The method may further comprise joining a second electrode assembly to the first electrode assembly. For example, the second electrode assembly may comprise a return electrode.

The insulating material may be a ceramic material, for example, alumina, zirconia toughened alumina (ZTA), yttria stabilized zirconia (YTZP) or the like. In such cases, the heat treatment process may be a sintering process.

In a further aspect, the present invention provides a method of manufacturing part of an electrosurgical instrument, comprising printing at least two portions of an insulating material, the at least two portions of the insulating material being configured to receive an electrode therebetween, performing a heat treatment process to fuse the at least two portions of the insulating material to form an outer moulding having at least one opening for receiving the electrode, inserting at least a first part of the electrode into the outer moulding via the at least one opening to thereby form a first electrode assembly.

As such, in this aspect, the insulating portion is first printed and fused together before any part of the electrode is inserted. The active tip of the electrode may then be inserted into the cavity within the insulating outer moulding via the proximal end or the distal end. As such, the electrode may be configured to fit the final outer moulding once it has undergone the heat treatment and any subsequent shrinkage. In cases where the active tip is inserted via the proximal end, another part of the electrode, for example, forming a suction lumen, may be used to push the active tip into place at the distal end of the electrode assembly.

Brief Description of the Drawings

Embodiments of the invention will now be further described by way of example only and with reference to the accompanying drawings, wherein like reference numerals refer to like parts, and wherein: Figure 1 is an example of the electrosurgical instrument system comprising an electrode manufactured according to the present invention; Figure 2 is a flow diagram illustrating a method of manufacturing an electrode according to the present invention; Figures 3A-D illustrate the method of manufacturing an electrode according to the present invention; Figure 4 is a perspective view of an electrode manufactured according to the present invention; Figure 5 is a cross-sectional view of an electrode manufactured according to the present invention; Figure 6 is a cross-sectional diagram further illustrating the method of manufacturing an electrode according to the present invention; Figures 7A-B are cross-sectional diagrams further illustrating the method of manufacturing an electrode according to the present invention; Figures 8A-B are diagrams further illustrating the method of manufacturing an electrode according to the present invention.

Detailed Description of the Embodiments

Referring to the drawings, Figure 1 shows an electrosurgical apparatus including an electrosurgical generator 1 having an output socket 2 providing a radio frequency (RF) output, via a connection cord 4, for an electrosurgical instrument 3. Activation of the generator 1 may be performed from the instrument 3 via a handswitch (not shown) on the instrument 3, or by means of a footswitch unit 5 connected separately to the rear of the generator 1 by a footswitch connection cord 6. In the illustrated embodiment, the footswitch unit 5 has two footswitches 7 and 8 for selecting a coagulation mode or a cutting or vaporisation (ablation) mode of the generator 1 respectively. The generator front panel has push buttons 9 and 10 for respectively setting ablation (cutting) or coagulation power levels, which are indicated in a display 11. Push buttons 12 are provided as an alternative means for selection between the ablation (cutting) and coagulation modes.

Figure 2 illustrates a method of manufacturing an electrode assembly for use in an electrosurgical instrument 3 as described above. The steps of the method are further illustrated by Figures 3A-D.

At step 2.2, illustrated by Figure 3A, a first portion 300 of the insulating material that will form the final outer moulding of the electrode assembly is printed. The insulating material may be any suitable material, for example, a ceramic material. The first portion 300 is printed so as to comprise a recess 302 configured to receive an electrode component. In this example, the recess 302 has a "J" configuration, with a wider portion 304 at one edge of the first portion 300, however, it will be appreciated that any suitable recess may be provided according to the configuration of the electrode that the outer moulding is to encase.

At step 2.4, illustrated by Figure 3B, an active electrode 306 is inserted to the recess 302 of the first portion 300. The active electrode 306 is a metal component having a planar active tip 308 and a tubular portion 310, which may comprise a lumen (not shown) for delivering fluids to and from the active tip 308. It will of course be appreciated that the active electrode 306 may be any number of different configurations according to the intended use. The active electrode 306 sits within the recess 302 such that a small gap 312 is formed between the active electrode 306 and the walls of the recess 302, with the active tip 308 sitting within the wider portion 304 of the recess 302.

At step 2.6, illustrated by Figure 3C, a second portion 314 of insulating material is printed and placed over the opposite side of the active electrode 306. The second portion 314 is effectively the mirror image of the first portion 300 such that the two halves 300, 314 enclose the active electrode 306, with only the active tip 308 being exposed to the outside. As before, there is a gap 312 formed between the active electrode 306 and the inner walls of both portions 300, 314.

At step 2.8, illustrated by Figure 3D, the two portions 300, 314 undergo a de-binding process, followed by a sintering process to fuse the two portions 300, 314 to form a single outer moulding 316 surrounding the electrode 306. During this sintering process, the whole assembly is placed in a furnace to heat the assembly to a high temperatures so as to remove the binding agent and fuse the two portions 300, 314 together. As discussed above, the insulating material will undergo shrinkage during this firing process, which can be up to 20% shrinkage for ceramic materials. Consequently, the provision of the gap 312 allows the final outer moulding 316 to shrink around the active electrode 306, such that the active electrode 306 sits securely within the outer moulding 316.

As such, no further materials or components are required to assemble the active electrode 306 within the retention moulding 316, thereby simplifying the manufacturing process.

The final result is an electrode assembly 400, as illustrated by Figures 4 and 5, wherein the active electrode 306, and in particular the active tip 309, is retained firmly within the recess of the outer moulding 316. As can be seen from Figure 5, the inner walls of the outer moulding 316 fit closely around the active electrode 306 so as to firmly retain the electrode 308 therein.

In this example, the active tip 308 also comprises an opening 402, which may be the opening to a lumen 404 within the active tubular portion 310 of the active electrode 306, which may be used for delivering fluids to and from the active tip 308.

The electrode assembly 400 also includes a return electrode 406 in which a further length of active suction tube 408 is enclosed. The return electrode 408 is connected to the outer moulding 316 by some suitable joining method, for example, by welding, gluing or configuring the two components to have a push fit. Similarly, the active electrode 306 can be connected to the active suction tube 408 by some suitable joining method such as welding. In some examples, the electrode assembly 500 may further comprise internal insulation (not shown) between the return electrode 406 and active suction tube 408, for example, by means of a heat shrink wrap around the outside of the active suction tube 408.

Figure 6 illustrates an alternative example of how the method of manufacturing may be performed to provide an electrode assembly 500. As before, an outer moulding 504, preferably made of ceramic, is printed around an active electrode 502 in accordance with steps 2.2 to 2.8 described above. However, in this example, the active electrode 502 only comprises the active tip portion shown in the previous examples. During the sintering step 2.8, the outer moulding 504 shrinks around the active electrode tip 502, leaving a cavity 506 in which an active suction tube 508 can be inserted. In this respect, the cavity 506 comprises a ramp 510 at the distal end of the outer moulding 504, which pushes the active suction tube 508 up against the active electrode tip 502, which in turn pushes the active electrode tip 502 up into the opening 512 of the outer moulding 504 and locks it into position. A return electrode 512 is then connected to the proximal end of the outer moulding 504 by some suitable joining method, for example, by welding.

As noted above, the electrode assembly 500 may further comprise internal electrical insulation 514 between the return electrode 512 and active suction tube 508, for example, by means of a heat shrink wrap around the outside of the active suction tube 508.

Various further modifications to the above described embodiments, whether by way of addition, deletion or substitution, will be apparent to the skilled person to provide additional embodiments, any and all of which are intended to be encompassed by the appended claims.

In the above examples, the insulating materials and electrodes are printed separately, however, it will be appreciated that the parts of the insulating outer moulding and the active electrode may be printed concurrently, again ensuring that a gap between the inner walls of the outer moulding and the active electrode is provide to allow for shrinkage during the firing process.

In another example illustrated by Figures 7A and 7B, similar to that of Figure 6, the outer moulding 604 may be first printed and fired, as describe previously, the active tip 602 then being inserted to the cavity 606 within the outer moulding 604 via the proximal end 610. As shown in Figure 7B, the active tip 602 is then pushed into final position by inserting the suction tube 608 into the proximal end 610, the suction tube 608 retaining the active tip 602 in place in the same way as described with reference to Figure 6. In this way, the outer moulding 604 has already been through the sintering processing before the active tip 602 is inserted, and so the active tip 602 can be made to fit the final outer moulding 604 once it has undergone any shrinkage.

Similarly, in another example shown in Figures 8A-8B, the portions of insulating material that will form the outer moulding 704 may be printed first, the active tip 702 then being inserted to the cavity 706 of the outer moulding 704, this time via the distal end 708. Once the active tip 702 is in place, the insulating material of the outer moulding 704 may then be subjected to the sintering process to fuse the portions of insulating material together around the active tip 702. Alternatively, the active tip 702 may be inserted to an outer moulding 704 that is already fused together, thereby removing the need to fire the arrangement after the active tip 702 is inserted.

Claims

CLAIMS1. A method of manufacturing part of an electrosurgical instrument, comprising: printing a first portion of an insulating material, the first portion of the insulating material being configured to receive an electrode; inserting at least a first part of the electrode into the first portion of the insulating material; printing a second portion of the insulating material so as to partially enclose the first part of the electrode, and such that a gap between the first part of the electrode and an inner wall of the first and second portions of the insulating material is formed therebetween; and performing a heat treatment process to fuse the first and second portions of the insulating material around the first part of the electrode to form a first electrode assembly.
2. A method according to claim 1, wherein the electrode is an active electrode.
3. A method according to claims 1 or 2, wherein the first part of the electrode is a tissue treatment portion.
4. A method according to any preceding claim, further comprising inserting a second part of the electrode into the first portion of the insulating material prior to printing the second portion of the insulating material.
5. A method according to any of claims 1 to 3, further comprising inserting a second part of the electrode into the first electrode assembly, wherein the first electrode assembly comprises a cavity configured to receive the second part of the electrode such that it abuts the first part of the electrode.
6. A method according claims 4 or 5, wherein the second part of the electrode is a connection portion.
7. A method according to claim 6, wherein the connection portion comprises a suction lumen connected to an aperture in the first part of the electrode.
8. A method according to any preceding claim, further comprising joining a second electrode assembly to the first electrode assembly.
9. A method according to claim 8, wherein the second electrode assembly comprises a return electrode.
10. A method according to any preceding claim, wherein the insulating material is a ceramic material.
11. A method according to claim 10, wherein the heat treatment process is a sintering process.
12. A method of manufacturing part of an electrosurgical instrument, comprising: printing at least two portions of an insulating material, the at least two portions of the insulating material being configured to receive an electrode therebetween; performing a heat treatment process to fuse the at least two portions of the insulating material to form an outer moulding having at least one opening for receiving the electrode; inserting at least a first part of the electrode into the outer moulding via the at least one opening to thereby form a first electrode assembly.