Handheld electrosurgical instrument, insulating insert, and electrode support for handheld electrosurgical instrument

Abstract

To provide an insulation insert, an electrode carrier, and a hand-held electric surgical tool that can be used in a particularly efficient mode and can be manufactured in a particularly highly cost-effective mode.SOLUTION: In the present invention, an insulation insert (29) has a tube shape and can be connected to a distal end of a tube-shape shaft of a hand-held device by a proximal end region in an attachable and detachable manner. A center passage (36) receives an inside shaft of the hand-held device. Two holes (37, 38) for receiving an electrode carrier tube of each electrode carrier are arranged in a wall (35) of the insulation insert (29) in parallel with the center passage (36) in both sides of the center passage (36).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an insulating insert for an electrosurgical handheld instrument according to claim 1 and to an electrode support for an electrosurgical handheld instrument according to claim 5. Furthermore, the present invention relates to a method for manufacturing an electrode support according to claim 18 and to an electrosurgical handheld instrument according to claim 20. [Background technology]

[0002] Electrosurgical handheld instruments of the type described above, particularly resectoscopes, are primarily used for electrosurgical work in urology. In this context, these instruments are typically used for resection and vaporization of tissue, for example, tissue of the lower urinary tract. For this purpose, handheld instruments, particularly resectoscopes, can be equipped with a longitudinally displaceable electrode support that can be advanced from the distal end of the instrument shaft of the handheld instrument to the distal working end after the instrument has been inserted into the body of the subject. An electrosurgical electrode is disposed at the distal end of the electrode support. This electrode may be in the form of, for example, a loop that, depending on the instrument configuration, can be pulled or pushed through tissue to manipulate it.

[0003] In these applications, a high-frequency current is applied to the electrode. It is important to ensure that the electrode does not come into electrical contact with the shaft tube of the handpiece. If such electrical contact occurs, a short circuit can occur, causing device failure or unintended trauma to the body of the person being treated. To prevent such a short circuit, the handheld device includes an electrically insulating insulating insert, also called an insulating tip, in the distal end region. The insulating insert can be attached either to the inner shaft or shaft tube through which the electrode support is guided, or to the outer shaft of the instrument. Because such handheld instruments can be designed for multiple uses and therefore require periodic sterilization or autoclaving, the insulating insert is designed to be removable for cleaning.

[0004] In the case of the hand instruments described herein for minimally invasive treatment of patients, the objective is to minimize the size or cross-section of the instrument as much as possible to minimize trauma to the patient during treatment. Likewise, the objective is to perform the procedure in a particularly efficient manner. For efficient surgery, electrode selection is crucial. Optimal treatment goals can only be achieved using appropriate application-specific electrodes. In particular, the effective cross-sectional area of ​​the electrode or working instrument relative to the cross-section of the instrument can be crucial. However, the effective cross-sectional area or size of the electrode is limited by the shape and diameter of the shaft of the electrosurgical hand instrument. Therefore, it is not practical for the effective cross-sectional area of ​​the electrode to be larger than the cross-sectional area of ​​the outer periphery of the shaft. However, known devices do not optimally utilize the space available for the electrode. Approaches to more efficiently utilize the available space require highly complex electrode shapes, which, on the one hand, are highly complex and expensive to manufacture, and, on the other hand, require significant efforts in quality control. Summary of the Invention

[0005] The present invention is therefore based on the problem of creating an insulating insert, an electrode support and a handheld electrosurgical instrument that can be used particularly efficiently and can be produced in a particularly cost-effective manner.

[0006] The solution to this problem is described in claim 1. Accordingly, an insulating insert according to the present invention is provided that is tubular and can be removably coupled by its proximal end portion to the distal end of a tubular shaft of a handheld device, with a central passage serving to receive an inner shaft of the handheld device. This inner shaft may be a shaft for receiving a tool or an optical component. According to the present invention, the wall of the insulating insert is provided with two holes arranged on either side of and parallel to the central passage, in each case for receiving an electrode support tube of an electrode support. Receiving the electrode support tube through the two holes in the insulating insert improves the stability of the electrode support and thus the electrode. Supporting the distal end region of the electrode support within the holes improves the stability of at least one electrode support across the longitudinal axis of the hand instrument. This guidance of the electrode support within the holes allows the electrode to be inserted in a particularly precise and therefore efficient manner.

[0007] In particular, it is provided that the two holes have an elliptical cross section, with the height of the elliptical cross section being greater than the width of the elliptical cross section. Furthermore, it is preferred that the two holes be displaced upward relative to the central longitudinal axis or central hole. The elliptical configuration of the holes and their upward or downward displacement from their central location also displaces the position of the electrode support tube passing through the insulating insert and hand instrument. This displacement and the elliptical configuration of the holes allow for the insertion of an electrode having a greater height than the previous electrode while maintaining the same width. This hole configuration allows for the use of an electrode with a larger effective cross section compared to the cross section of the insulating insert.

[0008] A further advantageous embodiment of the invention can provide that the wall of the insulating insert is reinforced around the two holes and that the wall thickness is reduced elsewhere. The otherwise thin-walled insulating insert has two inward bulges in the region of the holes, which minimize the open cross section of the inside of the insulating insert. In particular, by moving these bulges upward from the central edge region, a space can be created in the center of the insulating insert.

[0009] According to the present invention, it may be provided that an insulating insert formed of an electrically insulating material, such as a temperature- and plasma-stable plastic, has a coupling means for removably connecting to the shaft. During assembly of the handheld instrument, an electrode support with two electrode support tubes is passed through the hole and then removably attached to the distal end of the shaft. The proximal end of the electrode support tubes may be connected to the body of the hand instrument. When disassembling the hand instrument, the above steps are performed in reverse order.

[0010] An electrode support for solving the above problem has the features of claim 5. Thus, an electrode support for an electrode of an electrosurgical hand instrument has at least one, preferably two, electrode support tubes, with the electrode disposed at the distal end of the at least one electrode support tube. The electrode support can be coupled to the body of the hand instrument via the proximal end of the at least one electrode support tube. The electrode support can be axially moved and exposed to high-frequency current via the body. According to the present invention, the cross section of the at least one electrode support tube is provided to be elliptical or convex, particularly over its entire length. This elliptical shape of at least one portion of the electrode support tube provides improved stability against forces acting on the electrode support tube transverse to the longitudinal axis of the hand instrument. Furthermore, the elliptical shape reduces the space required by the at least one electrode support tube within the instrument shaft. Furthermore, the position of the distal end of the at least one electrode support tube, and thus the distal end of the electrode, can be optimized.

[0011] Preferably, the distal portion of at least one electrode support tube has an elliptical or convex cross-section. The remaining portions of the electrode support tube may also have a circular or any other cross-section. In this regard, it is provided that at least one electrode support tube is oriented such that the height of the elliptical cross-section is greater than the width of the cross-section, the height being the dimension perpendicular to the horizontal plane.

[0012] Preferably, the height-to-width ratio is 1.1:1 to 1.7:1, preferably 1.4:1, over the entire length or over only the distal portion. It has been found that this dimension of the at least one electrode support tube allows for a particularly space-saving arrangement within the instrument shaft. This width-to-height ratio represents an optimal compromise between stability and repositioning of the electrode at the distal end of the electric tractor. Preferred dimensions for the height include 1.4 mm and for the width, 1 mm. However, the present invention also provides for absolute dimensions of the elliptical cross-section to deviate at least slightly from these values. Due to the elliptical cross-section, the at least one electrode support tube can be moved upward from the center of the instrument without changing the distance between the two distal ends of the electrode support tube. The elliptical shape allows the distal end of the tube to be moved upward relative to the central axis of the hand instrument while maintaining the same spacing, thereby increasing the loop size of the electrode without protruding beyond the cross-section of the hand instrument. This reshaping of the electrode support tube therefore allows it to work with electrodes having an optimized working cross-section.

[0013] A preferred embodiment of the invention provides that the distal portion of at least one electrode support tube has a length of 20 mm to 50 mm, preferably 24 mm to 40 mm, in particular greater than 30 mm, so that only this distal portion has an oval cross section, the length of which corresponds at least to the stroke length of the electrode support within the instrument shaft.

[0014] Preferably, the present invention further provides that the transition between the proximal and distal portions of at least one electrode support tube is formed by a crimp. This crimp corresponds to locally reforming the outer periphery of the electrode support tube into a hexagonal cross-section. Thus, the diameter of the electrode support tube is reduced in a specific area. This tube formation serves as a predetermined transition from a tube portion having a circular cross-section to a tube portion having an elliptical cross-section. Furthermore, the formation serves to secure the conductor or wire within the tube.

[0015] The hexagonal crimp of at least one electrode support tube is oriented so that two opposing sides of the hexagonal cross section are parallel to one another and perpendicular to the horizontal plane. Due to this orientation of the crimp, the maximum diameter of the crimped tube portion does not exceed the oval diameter of the distal portion, preventing binding of the electrode support during back and forth movement relative to the longitudinal axis of the instrument.

[0016] Additionally, the distal end of at least one electrode support tube also preferably has a hexagonal crimp that allows the interior of the tube to be sealed in a watertight manner, thereby protecting the internal wiring from incoming fluids. This hexagonal formation of the cross section may also be provided to be aligned in the same way as the crimp between a portion having a circular cross section and a portion having an oval cross section.

[0017] Another particularly preferred embodiment of the present invention may provide that at least one electrode support tube has at least one, preferably two, S-bends, i.e., a proximal S-bend and a distal S-bend, which displace a portion of the electrode support tube parallel to the other portion of the electrode support tube. This S-bend allows the distal end of the at least one electrode support tube, to which the electrode is attached, to be displaced relative to a central axis through the instrument. This distal end displacement is particularly possible because the distal end has the aforementioned elliptical cross-section. It can therefore be assumed that the S-bend needs to be performed only in one dimension, not two. Therefore, the relative distance between the two distal ends of the parallel guide electrode support tubes does not change as a result of the S-bend. Only the two distal ends are moved upward relative to the central axis. Because the cross-section of the distal end region has changed, no collision between the electrode support tube and the instrument shaft occurs. This distal end displacement allows the use of electrodes with a larger effective cross-section without protruding beyond the cross-section of the instrument shaft.

[0018] Preferably, it is provided that at least one S-shaped bend, in particular the distal S-shaped bend, has a height of 0.2 mm to 2 mm, preferably 0.7 mm. The length of the at least one S-shaped bend may be 2 mm to 20 mm, preferably 5 mm to 10 mm.

[0019] Furthermore, the present invention may provide that the distal portion of at least one electrode support tube having an elliptical or convex cross section has at least one distal S-bend. If at least one electrode support tube has two S-bends, i.e., a distal S-bend and a proximal S-bend, it may be provided that these two S-bends lie in a common plane. Similarly, it is also conceivable that the two planes of the S-bends are twisted relative to each other.

[0020] A method for solving the above problem has the means of claim 18. Thus, a method for manufacturing an electrode support for an electrode of an electrosurgical hand instrument having at least one, preferably two, electrode support tubes according to claim 5 comprises forming the distal section of the electrode support tube into an elliptical cross section (step A), and / or crimping the transition from a section having a circular cross section to a section having an elliptical cross section (step B), and / or providing a distal region having an elliptical cross section with at least one S-bend (step C). According to the invention, it is provided that steps A, B and C are performed sequentially or simultaneously.

[0021] A handheld electrosurgical device for solving the above-mentioned problem has the features of claim 20. In particular, the handheld electrosurgical device may be a resectoscope or the like. The handheld device has a body to which a tubular shaft is connected. An insulating insert as described in claims 1 to 4 can be arranged at the distal end of the shaft, and an electrode support as described in claims 5 to 17 extends through the shaft and the insulating insert and is attached to the body at its proximal end. An electrode can be arranged at the distal end of the electrode support or electrode support tube.

[0022] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram of a handheld surgical device, specifically a resectoscope. [Figure 2] FIG. [Figure 3] FIG. 3 is a side view of the distal part of the electrode support according to FIG. 2. [Figure 4] FIG. [Figure 5] 5 is a view of the insulating insert according to FIG. 4 with an electrode support. DETAILED DESCRIPTION OF THE INVENTION

[0024] 1 shows a schematic cross-sectional side view of a resectoscope generally designated 10. The resectoscope 10 has a resectoscope shaft 11, which includes an outer shaft 12 or sheath tube, as shown. A tubular inner shaft 13 extends within the outer shaft 12. An electrode array 14 and illustrated optics 15 are shown within the inner shaft 13. Additionally, other elements not shown may be located within the resectoscope 10, such as separate irrigation tubing.

[0025] The electrode array 14 has at its distal end an electrosurgical tool or electrode 16. The electrode 16 shown here is shown as a loop, but may also be formed as a button or the like.

[0026] The electrode holder 14 can be forced axially in the distal and proximal directions by actuating the handle 19. Doing so pushes the electrode holder 14 beyond the distal ends of the inner shaft 13 and outer shaft 12. This allows the surgeon to manipulate tissue further away from the tip of the resectoscope. Furthermore, for this purpose, the inner shaft 13 and / or the electrode support 14 can be mounted rotatably about their longitudinal axes. To manipulate tissue, a high-frequency current is applied to the electrode 16.

[0027] The resectoscope 10 shown in FIG. 1 has a passive transporter in which the carriage 20 is moved distally relative to the distal first handle portion 21 by relatively moving the handle portions 21 and 22, which are located proximally on the resectoscope shaft 11, against a spring force applied by a spring bridge 23. When the carriage 20 is displaced distally relative to the handle portion 21, the electrode support 14 is displaced distally in a manner not shown. When the load on the handle portions 21 and 22 is relieved, the spring force generated by the spring bridge 23 pushes the slide 20 back to its initial position and pulls the electrode support 14 proximally. When the slide 20 is moved rearward, an electrosurgical procedure can be performed using the electrode 16 without any manual force by the surgeon, i.e., not passively.

[0028] In the case of targeted treatment with electrodes 16, the optical system 15 is positioned to allow the surgeon an optimal view of the surgical field. For this purpose, the resectoscope 10 has an eyepiece 24 at its proximal end, which is connected to the optical system 15. Alternatively, it is conceivable that a camera is arranged on the resectoscope 10 instead of the eyepiece 24.

[0029] The electrode support 14 essentially consists of two parallel electrode support tubes 25, 26 ( FIG. 2 ). These electrode support tubes 25, 26 hold the electrodes 16 and provide electrical energy to them. To this end, an electrical conductor extends from a proximal end 27 to a distal end 28 within at least one of the electrode support tubes 25, 26. One of the two electrode support tubes 25, 26 is locked at its proximal end 27 within the carriage 20 and connected to a cable that contacts the RF generator. The other electrode support tube 25, 26 is also locked into the carriage 20 to form a neutral electrode. To further stabilize the elongated electrode support tubes 25, 26, they can be connected to each other via guide elements 17. These guide elements 17 also serve to clamp the electrode support 14 onto the inner shaft 13 or below the inner shaft 13 or optic 15. Furthermore, the electrode support tubes 25, 26 are guided by insulating inserts 29, which stabilize them against lateral forces.

[0030] For the resectoscope to function properly, it is important that the electrode support 14, together with the electrode 16, can be fully retracted into the outer shaft 12. To this end, the effective or outer cross section of the electrode 16 must not be larger than the inner diameter of the distal region of the outer shaft 12. Therefore, the electrode support tubes 25, 26 are known to have an S-bend 30. This S-bend 30 displaces two parallel, consecutive sections along the electrode support tubes 25, 26 parallel to the longitudinal axis 18, such that the distal ends 28 of the electrode support tubes 25, 26 are offset from the longitudinal axis 18. To optimize the shape of the electrode 16 and increase the space within the shaft 13, the present invention provides that the electrode support tubes 25, 26 include a second S-bend 31. As a result of this second S-bend 31, the two distal sections 32 of the electrode support tubes 25, 26 are further spaced from the longitudinal axis 18 than already achieved by the S-bend 30. Additionally, the present invention provides that the distal portion 32 of the electrode support tubes 25, 26 has an elliptical cross-section, in contrast to the remaining portions of the electrode support tubes 25, 26. This elliptical cross-section is formed such that the height of the cross-section perpendicular to the horizontal plane is greater than the width of the cross-section. This portion having an elliptical cross-section includes both the distal portion 32 and the S-bend portion 31. The remaining portions of the electrode support tubes 25, 26 also have a circular cross-section. To provide a clear transition from the circular cross-section portion to the elliptical cross-section portion, the electrode support tubes 25, 26 each have a crimped portion 33 or an embossed or deformed portion. This crimped portion 33 also secures the electrical conductors within the electrode support tubes 25, 26 (FIG. 3).

[0031] The present invention further contemplates that the distal ends of the electrode support tubes 25, 26 may have a crimped portion 34 or an embossed or deformed portion. This hexagonally shaped crimped portion 34 is oriented so that two parallel sides of the crimped portion 34 extend transversely relative to a horizontal plane through the electrode support tube 14. As a result, the cross-section of the crimped portion 34 behaves similarly to the oval cross-section of the electrode support tubes 25, 26. Thus, the electrode support tubes 25, 26 can be fully retracted without the crimped portion 34 becoming jammed within the insulating insert 29. In this regard, it should be clearly pointed out that the insulating insert 29 in FIGS. 2 and 3 is shown very diagrammatically and for illustrative purposes only.

[0032] 4 and 5 show front views of an insulating insert 29 according to the present invention. It is known to place an electrically insulating tip at the distal tip of the inner shaft 13 to prevent contact between the energized electrode 16 and the metallic, conductive outer shaft 12. This tip, which is typically tubular, is formed from a non-conductive material, such as a plasma- and temperature-stable plastic. The insulating insert 29 may be releasably coupled to the shaft 13 by a coupling element.

[0033] The insulating insert 29 according to the invention, shown here in a schematic form, is also tubular and has a thin wall 35. This wall 35 is provided with a central passage 36 through which, for example, the optical system 15 and other tools can be guided. Furthermore, the insulating insert 29 has two holes 37, 38. These holes 37, 38 are aligned parallel to each other and to the longitudinal axis 18, but are displaced upward relative to the longitudinal axis 18, so that the holes 37, 38 are not centered or in the same horizontal plane as the longitudinal axis 18. The holes 37, 38 serve to receive the two electrode support tubes 25, 26. To receive the electrode support tubes 25, 26, the holes 37, 38 are also oval in shape, with the height of the holes 37, 38 being greater than their width. Due solely to the oval shape of the holes 37, 38, the oval cross-section of the electrode support tubes 25, 26, and the second S-bend 31, it is possible to displace the two holes 37, 38 relative to the longitudinal axis 18 without actually changing the distance between them. As a result, the electrode 16 can also maintain its known width and need not be modified. Rather, this reshaping or displacement allows the effective cross-section of the electrode 16 to be increased by maintaining the width of the electrode 16 and adapting its length or height to the dimensions of the resectoscope 10. Due to the fact that the distance between the two holes 37, 38 is unchanged, the previous electrode 16 can also be used with the electrode support 14.

[0034] 5 shows the insulating insert 29 with two electrode support tubes 25, 26 passing through two holes 37 and 38. In particular, it is clear that the crimped portions 34 at the distal ends of the electrode support tubes 25, 26 do not protrude beyond the diameter of the oval cross section of the distal portion 32, and therefore the electrode support tubes 25, 26 are freely displaceable through the holes 37, 38 in the insulating insert 29. [Explanation of symbols]

[0035] 10 Resectoscope 11 Resectoscope shaft 12 outer shaft 13 Inner shaft 14 Electrode support 15 Optical system 16 electrodes 17 Guide Elements 18 Longitudinal Axis 19 Handle 20 slides 21 Handle 22 Handle 23 Spring Bridge 24 eyepiece 25 Electrode support tube 26 Electrode support tube 27 Proximal end 28 Distal end 29 Insulating Insert 30 S-shaped bend 31 S-shaped bend 32 distal portion 33 Crimping section 34 Crimping section 35 Wall 36 Passage 37 holes 38 holes

Claims

1. a tubular shaft (13); an electrode support (14) disposed within the shaft (13); an optical system (15) disposed within the shaft (13); a handle portion (21, 22) disposed proximally of the shaft (13); A resectoscope (10) comprising: The shaft (13) further includes a tubular insulating insert (29) removably disposed in a distal region opposite the proximal region within the shaft (13); The insulating insert (29) a central passage (36) through which the optical system (15) is guided; two holes (37, 38) in the wall of the central passage (36) for receiving two electrode support tubes (25, 26) of the electrode support (14), the two holes (37, 38) passing through the central passage (36) parallel to the longitudinal axis (18); and The two holes (37, 38) have an elliptical cross section, a minor axis of the elliptical cross section is a first direction in which the two holes (37, 38) are aligned, and a major axis of the elliptical cross section is a second direction perpendicular to the first direction; The resectoscope (10) is characterized in that the minor axes of the two holes (37, 38) are arranged offset in the second direction with respect to a diameter parallel to the minor axis in the cross section of the central passage (36).

2. 2. The resectoscope (10) according to claim 1, characterized in that the two holes (37, 38) of the insulating insert (29) are displaced in the second direction relative to a central longitudinal axis (18) passing through the insulating insert (29).

3. 2. The resectoscope (10) according to claim 1, characterized in that the wall (35) of the insulating insert (29) is reinforced around the two holes (37, 38) and has a reduced wall thickness elsewhere.

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