Electrode

Abstract

To enable an electric surgical treatment to be performed by a highly reliable and safe method even when a metal element exists in a region to be treated.SOLUTION: An electrode (16) of an electric surgical instrument includes a conductive wire having two end portions connected to an electrode support (14) of the electric surgical instrument. The conductive wire (18) has a cross section (25) of 0.5 mm to 1.0 mm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to electrodes for electrosurgical instruments. [Background technology]

[0002] Electrosurgical instruments, in particular resectoscopes, are used in urology primarily for electrosurgery. In this context, these devices are usually used for the resection and vaporization of tissue, for example of the lower urinary tract. For this purpose, electrosurgical instruments, in particular resectoscopes, can be equipped with a longitudinally displaceable electrode support, which can be advanced at the distal working end from the distal end of the instrument shaft of the electrosurgical instrument after the device has been inserted into the body of the subject to be treated. An electrosurgical electrode is placed on the electrode support at its distal end. This electrode can be, for example, in the form of a loop and, depending on the design of the instrument, is pulled or pushed through the tissue to manipulate it.

[0003] Known electrodes are formed from wires. In the case of loop electrodes, for example, it is known that a wire is formed into a loop and the two free ends are connected to the electrode support. When a high-frequency alternating voltage is applied, a plasma is ignited at the electrode, as a result of which a plasma is formed on the wire, interacting with the liquid around the electrode. The plasma ignites preferentially at the location of the electrode with a small radius of curvature, since there the electric field strength is greatest.

[0004] In high-frequency surgery, the situation has proven problematic where a metal implant or other element made of conductive material is inserted into the patient during a previous treatment in the area of ​​the tissue to be treated. When a high-frequency potential is applied to the electrode, discharges or sparks can occur between the electrode and the metal element. This leads to uncontrolled and even unwanted manipulation of human tissue. The resulting patient trauma cannot be predicted and therefore should not be avoided. Secondly, the electrode undergoes a significantly increased degree of erosion due to this discharge, which increases the risk of destruction. Also, very high currents occurring locally for a short time can directly melt the electrode. Two breaking points or two free ends of the electrode can result in serious damage to the patient. In addition, there is a risk of an electric arc being formed between the two breaking ends, which in turn leads to uncontrolled manipulation of the tissue. Summary of the Invention [Problem to be solved by the invention]

[0005] The invention is therefore based on the problem of creating an electrode with which electrosurgical treatment can be carried out in a reliable and safe manner, even in the presence of metal elements in the area to be treated. [Means for solving the problem]

[0006] The solution to this problem is described in claim 1. Thus, the electrode of the electrosurgical instrument consists of a conductive wire, the two ends of which are connected to the electrode support of the electrosurgical instrument. In this case, the conductive wire has a first section and a second section adjacent to the two ends of the electrode support and aligned parallel and straight to each other. These two first and second sections are adjacent by a third section that connects the two first and second sections to each other. According to the invention, the conductive wire shall have a cross section of 0.5 mm to 1.0 mm. This significantly increased cross section of the conductive wire results in an electrode that has sufficient strength even in the case of unpredictable sparkovers and does not break at least during the operating time. Due to the larger mass compared to known electrodes, material losses due to erosion are less severe. A particularly preferred embodiment of the invention may provide that the conductive wire has a cross section of 0.8 mm.

[0007] Preferably, the first and second sections of the conductive wire may be aligned parallel to each other. However, it is equally conceivable that the first and second sections are aligned non-parallel to each other and / or have a curved shape. It is equally conceivable that the third section is formed as an arc or a loop. Depending on the type of treatment as well as the embodiment of the electrode, it can have almost any shape. For example, it is conceivable that the first to third sections have further subsections that connect with each other. Due to this flexibility in the shape of the electrode, it is conceivable to use electrodes that are specially formed for each application.

[0008] Another particularly advantageous embodiment provides that the conductive wire is made of a conductive material with a very high melting point, such as tungsten, molybdenum or tantalum. These materials have been shown to be particularly well suited for the above mentioned applications. The melting point should be at least 2000°C, preferably above 3000°C, in particular above 3400°C.

[0009] Furthermore, according to the invention, it can be provided that the conductive wire has a round or circular cross section. This choice of electrode shape allows a particularly cost-effective production. Finally, the conductive wire of the above-mentioned material has to be bent into the correct shape for the production of the electrode. On the one hand, this production can be carried out without great effort and is, among other things, reproducible, so that the required cost-effective production is guaranteed, especially for so-called disposable tools.

[0010] It may be preferably provided that the first to third sections are in one plane, or in two different planes, In another embodiment, the first to third sections may be arranged at right angles to each other.

[0011] Preferred embodiments of the invention are explained in more detail below with reference to the drawings. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a resectoscope. [Diagram 2] FIG. [Diagram 3] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1 shows a schematic cross-sectional side view of a resectoscope 10. The resectoscope 10, an electrosurgical instrument according to the present invention, has a resectoscope shaft 11, which includes an outer shaft 12 or sheath tube. A tubular inner shaft 13 extends within the outer shaft 12. An electrode support 14 and, also shown, optics 15 are shown within the inner shaft 13. Additionally, other elements not shown herein, such as separate irrigation tubing, may be disposed within the resectoscope 10.

[0014] The electrode support 14 has at its distal end an electrosurgical tool or electrode 16. The electrode 16 shown here is shown as a loop, but may have other shapes.

[0015] The electrode support 14 can be forced to move axially in the distal and proximal directions by actuating the handle 19. In doing so, the electrode support 14 can be pushed beyond the distal ends of the inner shaft 13 and the outer shaft 12. This allows the surgeon to manipulate tissue further away from the tip of the resectoscope 10. Moreover, for this purpose the inner shaft 13 and / or the electrode support 14 can be mounted rotatably about their longitudinal axis. For the manipulation of the tissue, a high frequency current is applied to the electrode 16.

[0016] The resectoscope 10 shown in FIG. 1 has a passive transporter, in which the carrier 20 is displaced distally relative to the distal first handle part 21 by the relative movement of the handle parts 21 and 22 arranged proximally on the resectoscope shaft 11 against a spring force exerted by the spring bridge 23. When the carrier 20 is displaced distally relative to the handle part 21, the electrode support 14 is displaced distally in a manner not shown. When the load on the handle parts 21, 22 is released, the spring force generated by the spring bridge 23 pushes the carrier 20 back to its initial position and pulls the electrode support 14 proximally. When the carrier 20 is returned, an electrosurgical procedure can be performed with the electrode 16 without manual force from the operator, i.e. passively.

[0017] For targeted treatment with the electrodes 16, the optical element 15 is positioned so that the surgeon has an optimal view of the surgical area. For this purpose, the resectoscope 10 has an eyepiece 24 at its proximal end, which is connected to the optical element 15. Alternatively, instead of the eyepiece 24, it is also conceivable to arrange a camera in the resectoscope 10.

[0018] 2 and 3 show an exemplary embodiment of an electrode 16 according to the present invention. Notably, the electrode 16 has sections R and L, which are of equal length and oriented parallel to one another. Sections R and L are connected to the distal end of an electrode support tube. Sections R and L correspond to the first and second sections according to the present invention.

[0019] Section C is located between sections R and L. This section C corresponds to the third section according to the invention. In the example embodiment of electrode 16 shown here, section C or the plane in which section C is located is rotated by an angle α=90° with respect to the plane defined by the two sections L and R, respectively. Similarly, it is conceivable that the angle α can take different values.

[0020] The length of the two sections R and L may be from a few millimeters to 2 cm, the distance between the two sections R and L being a few millimeters. According to the invention described herein, the cross section 25 of the electrode 16 in all sections R, L and C is 0.5 mm to 1.0 mm, preferably 0.7 mm to 0.9 mm, in particular 0.8 mm. Such a dimensioning of the cross section 25 has been shown to act advantageously, in particular when further metal objects are located in the vicinity of the area to be treated.

[0021] In addition to the loop shape of electrode 16 shown here by way of example, it is contemplated that section C may have other shapes, such as a loop having a smaller or larger radius of curvature, etc. Similarly, it is contemplated that section C may include multiple subsections, each of which is angled. [Explanation of symbols]

[0022] 10 Resectoscope 11 Resectoscope shaft 12 Outer Shaft 13 Inner Shaft 14 Electrode support 15 Optical elements 16 electrodes 17 Guide Elements 18 Wire 19 Handle 20 Career 21 Handle part 22 Handle part 23 Spring Bridge 24 Eyepiece 25 Section R Section L Section C Section α angle

Claims

1. In an electrode of an electrosurgical instrument, a conductive wire having two ends connected to an electrode support of the electrosurgical instrument; The conductive wire is an electrode having a cross section of 0.5 mm to 1.0 mm.

2. The conductive wire is a first section and a second section each having a first end adjacent the electrode support; 2. The electrode of claim 1, further comprising a third section joining the first section and the second section between the second ends of the first section and the second section.

3. The electrode of claim 2 , wherein the first section and the second section are aligned parallel and straight with respect to one another.

4. The electrode of claim 2 , wherein the third section is formed as an arc or a loop.

5. The electrode of claim 1 , wherein the conductive wire is made of tungsten, molybdenum or tantalum.

6. The electrode of claim 1 , wherein the conductive wire has a melting point of 2000° C. or higher.

7. The electrode of claim 1 , wherein the conductive wire has a round or circular cross-section.

8. The electrode of claim 2 , wherein the first section, the second section, and the third section are in one plane or in two different planes.

9. The electrode of claim 2 , wherein the first section, the second section, and the third section are disposed at right angles to one another.

10. The electrode of claim 1 , wherein the conductive wire has a cross-section of 0.8 mm.

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