Plasma probe and electrode assembly method thereof

Abstract

The plasma probe according to the invention comprises a hose in which a conductor is arranged, which supports an electrode at least at its distal end. The electrode is either fixed directly on the conductor or the conductor is provided with a plastic sheath at least at its distal end, by means of which the electrode is held. The electrode can be inserted between the conductor and the plastic sheath and can be clamped. After the first use, the plastic sheath can be fused to the electrode. In any case, the conductor is placed with a gap in the passage or hollow space of the electrode, however, in the case of a punctiform contact between the conductor and the electrode, the heat transfer from the electrode onto the conductor is impeded due to the gap provided between them and thus the introduction of heat in the plasma probe is limited. This is beneficial for the lifetime of the plasma probe and at the same time reduces its external temperature and thus its tendency to adhere to the tissue. The risk of an unwanted perforation of sensitive or thin tissue layers is reduced.

Description

Technical Field

[0001] The subject of this invention is a plasma probe, particularly an argon plasma probe, and a method for assembling electrodes for such a plasma probe. Background Technology

[0002] Electrosurgical instruments with electrodes that directly affect tissue are known. For example, WO 2017 / 076721 A1 discloses a radiofrequency instrument having electrodes implemented as resection loops. The electrodes, bent into a U-shape, are inserted at both ends into corresponding retainers, into which power supply wires are respectively guided. The electrodes are crimped or soldered to the power supply wires; however, in either case, the connection is mechanically rigid. Therefore, the conductor insulation of the power supply wire extends beyond the electrode ends, insulating the latter relative to the outer sheath.

[0003] An instrument for tubal coagulation is known from EP 1 568 325 A1, which includes an accessory at its distal end with a plurality of electrodes. These electrodes are connected to a coaxial power supply line by means of a coaxial plug. The arrangement consisting of the power supply line and the plug allows free axial movement within the working channel of the endoscope.

[0004] Furthermore, existing plasma probes essentially consist of a flexible tube that can be connected to a gas source, with the distal end of the tube open for emitting a plasma jet. Electrodes are arranged in the distal end of the tube and are typically held by means of an electrode holder, such as a thin metal sheet extending diametrically through the tube's lumen. The electrodes extend proximally through the tube's lumen in the form of metal wires and can be connected to a power source to generate a discharge at the distal end. Plasma probes constructed according to this principle are also known from DE 10 2017127 976 A1, DE 100 30 111 B4, or EP 3 769 707 A1.

[0005] The plasma flow originates from the electrodes of the plasma probe, which impact the tissue to be treated. Because the electrodes are positioned at the distal end of the tubing, at least a portion of the generated heat also reaches the surrounding wall of the distal end of the tubing. For protection, a ceramic sleeve can be placed here, for example, as known from WO 2005 / 046495 A1 above. However, the central support of the electrodes is provided by a metal sheet, which transfers heat to the tubing and can cause damage to the tubing during prolonged operation. This is particularly true because the electrodes must be rigidly connected to the metal sheet, resulting in significant heat transfer from the electrodes to the sheet. This problem is even more pronounced if the metal sheet itself is used as the electrode, for example, as proposed in DE 100 30 111 B4.

[0006] Therefore, the object of this invention is to provide a concept by which a long-term stable plasma probe can be provided in a simple manner. Consequently, particular attention should be paid to the assembly of the electrodes. Summary of the Invention

[0007] This objective is achieved by means of the plasma probe according to claim 1 and the method according to claim 15:

[0008] The plasma probe according to the invention comprises a flexible tube, for example made of a plastic material, which may include one or more lumens extending from a proximal end of the tube to its distal end. The lumens are used to guide a suitable gas, preferably an inert gas (e.g., argon), from the proximal end to the distal end. The lumens of the tube are open at the distal end, allowing gas to flow out from there.

[0009] An electrical conductor is arranged inside the flexible tube, preferably extending along the entire length of the tube from its proximal end to its distal end, where it connects to the electrode. The conductor is provided with a plastic sheath at least at its distal end. The plastic sheath may be made of the same plastic as the tube; however, different plastics may also be provided.

[0010] Preferably, the electrode is a straight-arranged needle-like or rod-like electrode, comprising a proximal end and a distal end. The electrode is configured entirely or at least hollow along a portion of its length, i.e., it includes an internal channel that is open at both ends or closed at the distal end, forming a hollow space. The conductor extends with clearance into this hollow space at its distal end. The electrode is thus supported by the conductor, and in some embodiments of the invention, also by a plastic sheath of the conductor. The electrode can be arranged such that its proximal end extends into the plastic sheath of the conductor and is axially fixed by the plastic sheath. When not in use, the fixation between the plastic sheath and the electrode can be achieved by means of a frictional fit. After initial use, the plastic sheath can be fused to the electrode, thereby bonding it to the electrode, providing a material bond between the proximal end of the electrode and the plastic sheath.

[0011] Preferably, the conductor extends into the electrode with a gap fit. Since the conductor always has slight wrinkles or bends, or simply due to imperfect alignment between the conductor and the electrode, electrical contact is always provided between the conductor and the electrode. Furthermore, the RF voltage applied to the conductor is so high that any possible gaps between the conductor and the electrode can be easily overcome by the current. After initial use, slight material flow between the conductor and the electrode can occur at the contact point, resulting in a material bond similar to a brazed joint or welded joint.

[0012] Regardless of whether the electrode extends into the plastic sheath, the electrode can be slightly deformed radially inward to secure it to the conductor, for example, by means of compression or crimping. This deformation can be formed at the distal end of the electrode, at the proximal end of the electrode, or between the distal and proximal ends of the electrode. The conductor then extends at least beyond the deformed area in the distal direction.

[0013] Plasma probes constructed according to this concept can be easily manufactured. This manufacturing process includes the following steps: - providing a flexible tube comprising a proximal end and a distal end, forming at least one lumen between the proximal and distal ends, wherein an electrical conductor is arranged within the tube, extending from the proximal end to its distal end, the distal end comprising a plastic sheath; - optionally removing the plastic sheath from the distal segment of the tube, thus exposing it; - providing an electrode comprising at least one end configured in a hollow manner; - pushing the hollow end of the electrode onto the conductor's preferably exposed end, inserting the hollow end of the electrode into the conductor's plastic sheath. Thus, the electrode can be inserted into and secured within the plasma probe in a single assembly step, as it is inserted only onto the preferred exposed end of the conductor and, if necessary, into the gap opening between the conductor and the plastic sheath. Due to the resulting expansion of the plastic material, it firmly abuts against the electrode under pre-tension.

[0014] Preferably, the electrode is composed of metal. It may be coated, particularly on its outer surface, especially with a coating made of metal or metal alloy. Preferably, the melting temperature of the coating metal is lower than that of the material constituting the electrode. Silver or silver alloys are suitable as the coating metal. However, other metals may also be used, particularly those with low oxidation tendency and / or high electrical and / or thermal conductivity.

[0015] A particular advantage of the structure according to the invention is provided by thermal decoupling of the electrode and the tubing. Furthermore, if the electrode heats up after prolonged use, it will not melt the outer tubing due to heat conduction. Therefore, compared to conventional probes, the plasma probe according to the invention comprises a cooler distal end, thus allowing for a longer lifespan. The effects of heat originating from the probe on the tissue are also reduced. Moreover, at the two-dimensional connection between the proximal end of the electrode and the plastic sheath of the conductor, the plastic sheath slightly melts, thus establishing a rigid material bond between the electrode and the conductor or its plastic sheath during use.

[0016] Furthermore, the concept according to the invention allows for precise axial and radial orientation of the electrodes. Even if the hose deforms at its exterior for a short period, the positioning of the electrodes will not be affected.

[0017] The lumen surrounded by the hose can be divided into two or more sub-lumens extending parallel to each other. This separation can extend along the entire length of the hose or only along a portion of its length. Lumen separation of the sub-lumens can be achieved by radially extending or inclined walls connecting the hose to the plastic sheath. These walls can help support and maintain the conductor's centering within the hose. Therefore, the hose, along with the conductor's plastic sheath and the at least one connecting wall between the hose and the plastic sheath, can be manufactured in a single process, for example, by plastic extrusion. Preferably, only one plastic material is used. However, different plastics can also be used for the hose and the plastic sheath, and the probe can be produced by co-extrusion. Furthermore, the plastic sheath and hose can be provided as separate elements made of the same or different plastic materials. The conductor with the plastic sheath can be movably arranged inside the hose, for example, along the axial direction and / or along the radial direction.

[0018] In all these embodiments, there is no metallic connection between the conductor and electrode on one side and the hose on the other. If there is a material joint between the plastic sheath and the hose, this connection preferably does not contain any metallic elements or other elements with good thermal conductivity. In this way, heat conduction between the electrode and the hose is minimized. Furthermore, the distal end of the hose may be provided with a heat-resistant sleeve, preferably electrically insulated, for example, made of ceramic, to avoid direct contact between the generated plasma flow and the hose made of plastic.

[0019] Electrodes held only at their proximal ends are preferably cantilevered and extend distally away from the conductor without protruding from the lumen of the tubing. This avoids direct contact between the electrode and biological tissue. However, electrodes can also be arranged protruding from the tubing, in which case, preferably, the insulator is placed at the distal end of the electrode. Attached Figure Description

[0020] Other properties and features of the plasma probe according to the invention can be obtained from the accompanying drawings or the following description. The drawings show:

[0021] Figure 1 A plasma probe connected to a supply device according to the present invention is illustrated in the schematic diagram.

[0022] Figure 2 The distal end of the plasma probe is shown in a schematic perspective view.

[0023] Figure 3 It is based on Figure 2 A side view of the plasma probe.

[0024] Figure 4 According to along Figure 3 The dotted line IV-IV shown is cut by Figure 3plasma probe,

[0025] Figure 5 A modified embodiment of the plasma probe according to the present invention is shown in a longitudinal sectional view.

[0026] Figure 6-8 Further modified embodiments of the plasma probe according to the present invention are shown in longitudinal sectional views.

[0027] Figure 9 A plasma probe with an insulator is shown in a partial cross-sectional side view.

[0028] Figure 10 This is a front view of a modified embodiment of the plasma probe according to the present invention;

[0029] Figure 11 This is a front view of a further modified embodiment of the plasma probe according to the present invention. Detailed Implementation

[0030] Figure 1 The image shows a plasma probe 11 connected to a supply device 12. Device 12 provides the necessary operating medium and power for the operation of the plasma probe 11. For this purpose, device 12 includes a radio frequency generator 13 and a gas source 14. This includes, for example, a pressure regulator and valve, through which a gas flow (e.g., an argon flow) obtained from a gas cylinder can be directed to the plasma probe 11 in a controlled manner.

[0031] The plasma probe 11 includes a flexible tube 15 extending from a proximal end 16 to a distal end 17. The face 18 of the distal end 17 of the flexible tube 15 surrounds a plasma emission port 19, which emits a plasma jet during operation. The terms end, distal end, and proximal end always refer to the end segment.

[0032] Furthermore, electrode 20 is arranged in plasma emission port 19, which is electrically connected to RF generator 13. For this purpose, an electrical conductor 21 is provided, for example from... Figure 3 and Figure 4 As is evident, the electrical conductor 21 extends along the entire length of the flexible tube 15 from its proximal end 16 to its distal end 17. In all embodiments, the electrode 20 may be made of a heat-resistant material (e.g., stainless steel). Furthermore, in all embodiments, it may be provided with a coating, particularly a coating whose melting temperature is preferably lower than that of the electrode 20. In particular, the coating may consist of silver or a silver alloy.

[0033] Conductor 21 can be made of a monofilament metal wire (e.g., stainless steel wire) or a metal wire made of another material. Therefore, conductor 21 is provided with a plastic sheath 22 at least along a portion of its length, which preferably surrounds conductor 21 (360°) around its entire circumference. Thus, the plastic sheath 22 can extend along the entire length of the conductor to its distal end 23. The distal end 23 of conductor 21 can itself be exposed, i.e., released from the plastic sheath. The exposed section can have a length of one millimeter or several millimeters. Starting from the distal end 23, the plastic sheath 22 extends at least several centimeters in a proximal direction. However, it can also cover the entire length of conductor 21.

[0034] exist Figure 4 In the illustrated embodiment, the plastic sheath 22 is connected to the hose 15 by means of at least one, preferably multiple, walls 24, 25, 26, such as from Figure 3 It is obvious. They divide the lumen 27, which is enclosed by the hose 15, into two or more (three in this example) sub-lumens 28, 29, 30. As from... Figure 3 As is evident, walls 24, 25, and 26 may extend obliquely relative to the radial direction, or may be arranged in other ways. Furthermore, as shown, the walls may be configured in planar and curved configurations.

[0035] like Figure 4 As shown, electrode 20 can be implemented using a metal tube. It includes a central channel or hollow space into which the distal end 23 of conductor 21 extends. Preferably, the inner diameter of this channel or hollow space is slightly larger than the outer diameter of conductor 21, creating a gap fit between them. According to... Figure 4 In this embodiment, electrode 20 is configured as a hollow cylinder and has an opening at its distal end 31. The proximal end 32 of electrode 20 is pushed against conductor 21 until it is inserted between the plastic sheath 22 and conductor 21. Therefore, Figure 4 The plastic sheath 22 is shown to be released and partially extended from the conductor 21, thereby initially securing the electrode 20 at least by means of a frictional engagement. The distal end 23 of the conductor 21 is loosely arranged within the channel or hollow space of the electrode 20, and thus selectively abuts against the electrode 20 initially. Preferably, the connection between the conductor 21 and the electrode 20 is loose in the axial direction, i.e., there is no tension transmission.

[0036] In all embodiments of the sleeve-shaped electrode 20 described above or below, it may have a face oriented at an angle relative to its longitudinal direction. For this purpose, the tubular electrode 20 may be cut at an angle relative to its axis at its distal end, corresponding to the distal end of a syringe cannula.

[0037] Independent of the tilt of the electrode 20 surface, the power supply line can extend through the electrode 20 and protrude beyond the distal end of the electrode 20. This helps to improve ignition capability.

[0038] The plasma probe 11 described so far can be manufactured by first providing a flexible tube 15 in which a conductor 21 is arranged. For example, the flexible tube 15 with the conductor 21 can be produced by means of plastic extrusion, like a cable. The plasma probe 11 is cut to the required length from the material provided in this way, and the conductor 21 is first exposed at its distal end 23. Consequently, the corresponding material of the plastic sheath 22 and the walls 24-26 is removed. Thus, the distal end 23 of the conductor 21 is exposed.

[0039] In the subsequent process, electrode 20 is now pushed onto the exposed distal end 23 of conductor 21 and into the plastic sheath 22. From Figure 4 As can be seen, electrode 20 thus pushes the plastic sheath 22 radially outward, thereby clamping itself. Electrode 20 is now held in a frictional engagement. The distal end 23 of conductor 21 selectively and loosely abuts against the inner wall of electrode 20. Preferably, electrode 20 is thus inserted to such an extent that, viewed from the outside, it is located behind the distal side 18 of the flexible tube 15, i.e., offset proximally relative to that side 18. Plasma probe 11 is now ready for use.

[0040] To operate the plasma probe 11, it is connected to the device 12. Thus, the proximal end of conductor 21 is electrically connected to the RF generator 13. The proximal end of lumen 27 is connected to a gas source 14. For operation, a gas, such as argon or another inert gas, is supplied to lumen 27, causing a gas flow to be generated within lumen 27 in a distal direction. The RF generator 13 supplies an RF voltage, typically several hundred volts, relative to a neutral potential applied to the patient to be treated via a neutral electrode (not shown).

[0041] Now, a so-called spark is generated at electrode 20, which ionizes the exhaust gas, causing a plasma jet to form. Current then flows from conductor 21 through the contact point between distal end 23 and electrode 20 into electrode 20, and from there flows to the patient via the ionized gas. Thus, the current allows for selective brazing or welding between conductor 21 and electrode 20, thereby achieving a mechanical connection. Furthermore, electrode 20 is significantly heated, causing the plastic sheath 22 to melt or fuse in the area covering electrode 20. This creates a physical bond between sheath 22 and electrode 20 and / or between conductor 21 and electrode 20.

[0042] The plasma probe 11 can be modified without departing from the scope of the invention. For example, according to Figure 5Each of the walls 24, 25, and 26 may be omitted. The conductor 21 is loosely located within the lumen 27 with its sheath 22 and can move axially and / or radially therein.

[0043] Independently, a closed end 33 can be provided to electrode 20, which forms the distal end of electrode 20. The above explanation applies accordingly, particularly regarding the connection between conductor 21 and electrode 20.

[0044] Similarly, many modifications are possible regarding the connection between electrode 20 and conductor 21. For example, such as... Figure 6 As shown, needle-shaped or rod-shaped electrodes 20' can also be used instead of those shown. Figure 4 Alternatively, a sleeve-shaped electrode 20 may be used. Furthermore, this electrode can be inserted between the conductor 21 and the plastic sheath 22, and can be clamped therebetween. The conductor 21 can be a solid metal wire, as in the embodiment explained above. However, in this embodiment and also according to the above... Figure 3 and Figure 4 In some embodiments, braided metal wire can be used instead of solid metal wire.

[0045] According to Figure 6 In the plasma probe, the exposure of the distal end 23 of conductor 21, i.e., the removal of the plastic sheath 22 in that area, can be omitted. Although according to Figure 1-4 In embodiments, conductor 21 or its distal end 23 guides electrode 20 during insertion of plastic sheath 22, but according to Figure 6 In this embodiment, such guidance is not necessary. Preferably, the sharp electrode 20' at its proximal end is simply inserted into the plastic sheath 22 near the conductor 21.

[0046] According to Figure 3-6 In all probes, the distal end 17 of the flexible tube 15 can also be formed of a heat-resistant sleeve 34, for example, made of ceramic. For all other embodiments, this... Figure 6 The example shown is illustrated below. Sleeve 34 can be connected to hose 15 via tapered seat 35.

[0047] It is not necessary to move the electrode 20 between the conductor 21 and its plastic sheath 22 and to fix it by means of clamping. Figure 7 An embodiment of a plasma probe 11 for this purpose is shown, wherein the electrode 20 is connected only to the distal end 23 of the conductor 21 released from the plastic sheath 22. Due to radial deformation, the electrode 20 can be held onto the distal end 23 of the conductor 21 in a drop-proof manner, such as by crimping. Figure 7The plasma probe 11 described herein is by way of illustration only, in which the conductor 21, its plastic sheath 22, and the electrode 20 are not rigidly connected to the hose 15. The construction principle of having an electrode 20 fixed only to the conductor 21 can also be implemented in any other plasma probe 11 described above. Furthermore, all arrangements of the electrode 20, conductor 21, and plastic sheath 22 described above or below can also be used in probes in which there is no connection between the hose 15 and the plastic sheath 22. For example, the conductor 21 and its plastic sheath 22 can be placed inside the hose 15 as a single-metallic wire cable.

[0048] In any probe in which the conductor 21 and its sheath 22 are not connected to the hose 15, the sleeve 34 disposed on the distal end 17 may have three or more inwardly facing noses 36, 37 or another structure restricting the radial mobility of the electrode 20 or the conductor 21. Thus, the noses 36, 37 are adapted to achieve adequate centering of the electrode 20. If the electrode 20 is mechanically connected to the conductor 21, for example due to... Figure 7 The radial extrusion shown can also completely omit the plastic sheath 22. This applies to all embodiments.

[0049] Figure 8 Another modification of the invention is shown, which can be used for all plasma probes 11 described herein. Electrode 20 consists of a first sleeve 20a located on the distal end 23 of conductor 21 and inserted into a plastic sheath 22. A second sleeve 20b is located on the sleeve 20a, which is, for example, welded or pressed to the sleeve 20a, or simply disposed on the sleeve 20a by friction fit. The two sleeves 20a, 20b are preferably composed of different materials or combinations of materials. For example, the hollow cylindrical sleeve 20b may be silver-plated on its outer surface, thereby concentrating the plasma discharge at its distal end and minimizing heat introduction into the sleeve 20b. Conversely, sleeve 20a may be composed of uncoated stainless steel with poor thermal conductivity, thereby minimizing heat introduction into the plastic sheath 22. Regardless of the material choice, heat introduction into the plastic can be reduced by means of the distance between sleeve 20b and plastic sheath 22.

[0050] The joint between sleeves 20a and 20b forms a thermal barrier between the discharged portion of electrode 20 and the rest of the plasma probe 11. This improves the durability of electrode 20 and the entire plasma probe 11, both due to the increased electrode surface area and the reduced heat flow originating from electrode 20.

[0051] In all embodiments of the plasma probe 11 described above, it has been assumed that the electrodes 20, 20' do not protrude beyond the distal side 18 of the flexible tube 15. However, based on any of the embodiments described above, alternatives may also be provided. Figure 9Example of a plasma probe 11. An electrode 20, which can be connected to a conductor 21 in any of the ways described above, then protrudes distally beyond the surface 18 and can support an insulator 38, which is made, for example, of ceramic or another heat-resistant plastic. The insulator 38 can thus be formed in a spherical, mushroom-shaped or any other form and is supported by the electrode 20.

[0052] There are many degrees of freedom in the configuration of the hose 15 and the plastic sheath 22. For example, as Figure 10 As shown, walls 24, 25, and 26 can be arranged radially. Conductor 21 can also be initially surrounded by insulation 39 embedded in the plastic sheath 22. Furthermore, as... Figure 11 As shown, the number of walls or other connectors between the plastic sheath 22 and the hose 15 may differ from the embodiments described above. Here, only a single connecting wall 24 is provided between the hose 15 and the plastic sheath 22.

[0053] The plasma probe 11 according to the invention includes a flexible tube in which a conductor is arranged, the conductor supporting an electrode 20 at least at its distal end. The electrode 20 is either directly fixed to the conductor 21, or the conductor 21 is provided with a plastic sheath 22 at least at its distal end, by means of which the electrode 20 is held. The electrode 20 can be inserted between the conductor 21 and the plastic sheath 22, and can be clamped in this manner. After the first use, the plastic sheath 22 can be fused to the electrode 20. In either case, the conductor 21 is spaced within the channel or hollow space of the electrode 20; however, in the case of point contact between the conductor 21 and the electrode 20, heat transfer from the electrode 20 to the conductor 21 is hindered due to the gap between them, thus limiting heat introduction into the plasma probe 11. This is beneficial to the lifespan of the plasma probe 11 and simultaneously reduces its external temperature, and therefore reduces its tendency to adhere to tissue. This reduces the undesirable risk of perforation of sensitive or thin tissue layers. Furthermore, the concept according to the invention allows for the long-term maintenance of the probe's roundness.

[0054] List of reference numerals in the attached diagram:

[0055] 11 Plasma Probe

[0056] 12 devices

[0057] 13 RF Generator

[0058] 14 Gas Source

[0059] 15 Hose

[0060] 16. Proximal end of hose 15

[0061] 17. Distal end of hose 15

[0062] 18. Distal side of hose 15

[0063] 19 Plasma emission ports

[0064] 20, 20' electrodes

[0065] 20a and 20b sleeves

[0066] 21 conductors

[0067] 22 Plastic sheath

[0068] 23. Conductor distal end

[0069] 24 – 26 walls

[0070] 27. Lumen

[0071] 28–30 Sub-lumens

[0072] 31. Distal end of electrode 20

[0073] 32 Proximal end of electrode 20

[0074] 33. Closed distal end of electrode 20

[0075] 34 Sleeve

[0076] 35 Conical Seat

[0077] 36, 37 Nose

[0078] 38. Insulators.

Claims

1. Plasma probe, including: A flexible tube, the flexible tube including a proximal end and a distal end, forming at least one lumen between the proximal end and the distal end; An electrical conductor is disposed inside the hose and extends from the proximal end of the hose to its distal end, and includes a plastic sheath; An electrode, the electrode comprising an end electrically connected to the conductor and an end extending in a distal direction; The plastic sheath extends substantially along the entire length of the conductor; The electrode is held by the plastic sheath of the conductor; The plastic sheath is connected to the hose by means of at least one flexible wall or by means of multiple flexible walls; The electrode comprises a first sleeve and a second sleeve, wherein the first sleeve is located at the distal end of the conductor and inserted into the plastic sheath, and the second sleeve is located on top of the first sleeve; and The electrode extends into the plastic sheath and is located between the plastic sheath and the conductor, thereby providing axial fixation.

2. The plasma probe of claim 1, wherein The lumen is connected to a gas source at its proximal end.

3. The plasma probe according to claim 1, characterized in that, The conductor is connected to a power source at its proximal end.

4. The plasma probe according to claim 1, characterized in that, The lumen is divided into two or more sub-lumens arranged in parallel with each other.

5. The plasma probe according to claim 1, characterized in that, The conductor is centrally located inside the flexible tube.

6. The plasma probe according to claim 1, characterized in that, The plastic sheath and the conductor disposed therein are movably arranged within the hose.

7. The plasma probe according to claim 1, characterized in that, The conductor is supported within the hose only by means of the at least one or more flexible walls.

8. The plasma probe according to claim 1, characterized in that, The end of the electrode connected to the conductor or the entire electrode is hollow, and the conductor extends into and / or through the electrode.

9. The plasma probe according to claim 1, characterized in that, The electrode includes a coating.

10. The plasma probe according to claim 1, characterized in that, The proximal end of the electrode extends between the conductor and the sheath.

11. The plasma probe according to claim 1, characterized in that, The conductor is arranged longitudinally and movably relative to the electrode inside the electrode.

12. The plasma probe according to claim 1, characterized in that, The electrode is held on the conductor by means of plastic deformation.

13. The plasma probe according to any one of the preceding claims, characterized in that, An insulator is provided at the distal end of the electrode.

14. A method for assembling electrodes for a plasma probe, comprising the following steps: A flexible tube is provided, comprising a proximal end and a distal end, forming a lumen between the proximal end and the distal end, wherein an electrical conductor is disposed inside the flexible tube, extending from the proximal end to its distal end, and comprising a plastic sheath, wherein the plastic sheath is connected to the flexible tube by means of at least one flexible wall or by means of multiple flexible walls. An electrode is provided, the electrode comprising a first sleeve and a second sleeve having at least one hollow end. Push the hollow end of the electrode onto the end of the conductor. The hollow end of the electrode is inserted into the plastic sheath of the conductor and positioned between the plastic sheath and the conductor. The conductor is placed into the electrode with a gap fit.

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