Tissue incision device

Abstract

The invention relates to the technical field of medical instruments, and provides a tissue incision device which comprises a tool bit electrode, an end tube, a sheath tube and a loop electrode. The scalpel head electrode is movably inserted into the end tube, the sheath tube is arranged outside the end tube in a sleeving mode, the protective electrode is located on the peripheral side of the scalpel head electrode, and when the scalpel head electrode stretches out, the protective electrode is located on the outer peripheral side of the scalpel head electrode. The distance between the protection electrode and the loop electrode is smaller than the distance between the tool bit electrode and the loop electrode, so that the protection electrode and the loop electrode discharge preferentially. According to the tissue incision device, the protection electrode and the loop electrode are preferentially discharged; through the arrangement, the cutter head electrode can be protected from being corroded and fused by electric sparks, and the service life of the tissue incision device can be prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a tissue cutting device. Background Art

[0002] Under the vision of a digestive endoscope, as a high-frequency electric knife serving as a tissue cutting device, high-frequency electricity is output from an electrode and acts on mucosal tissue, causing the mucosal tissue cells to vaporize or lose water, and cutting the mucosal tissue. However, during the use of a bipolar electric knife, the electric spark is intense in some areas of the electrode. After a long use time, these areas will be corroded and fused by the electric spark, resulting in damage to the instrument and delaying the operation. Summary of the Invention

[0003] Therefore, the present invention aims to solve the problem in the prior art that during the use of a bipolar electric knife, the electric spark is intense in some areas of the electrode. After a long use time, these areas will be corroded and fused by the electric spark, resulting in damage to the instrument and delaying the operation, so as to provide a tissue cutting device.

[0004] To solve the above technical problems, the technical solution of the present invention is as follows:

[0005] The present invention provides a tissue cutting device, including a knife head electrode, an end tube, a sheath tube, and a return electrode; the knife head electrode is movably inserted into the end tube, the sheath tube is sleeved outside the end tube, the return electrode is arranged at an interval from the knife head electrode, and further includes: a protection electrode, located on the outer peripheral side of the knife head electrode. At least when the knife head electrode extends out, the distance between the protection electrode and the return electrode is less than the distance between the knife head electrode and the return electrode, so that the protection electrode preferentially discharges with the return electrode.

[0006] Further, the knife head electrode includes an electrode rod and a distal head located at the distal end of the electrode rod. The protection electrode includes a first protection electrode protruding from the outer peripheral side of the electrode rod, and at least a part of the first protection electrode is located in the lumen of the end tube.

[0007] Further, the protection electrode includes a second protection electrode protruding from the outer peripheral side of the distal head.

[0008] Further, the protection electrode protrudes on the outer side wall of the knife head electrode; and / or, the protection electrode is arranged on the inner side wall of the end tube.

[0009] Further, the first protection electrode is arranged on the outer side wall of the electrode rod. When the knife head electrode extends out, the distal end of the first protection electrode is flush with, protrudes or concaves inward compared with the distal end of the end tube; and / or, the first protection electrode is arranged on the inner side wall of the end tube, and the distal end of the first protection electrode is flush with, protrudes or concaves inward compared with the distal end of the end tube.

[0010] Further, the second protection electrode is disposed on the outer sidewall of the distal head. When the cutter head electrode retracts, the distal end of the second protection electrode protrudes outward compared to the distal end of the end tube; and / or, the second protection electrode is disposed on the inner sidewall of the end tube, and the distal end of the second protection electrode is flush with or protrudes or recesses outward compared to the distal end of the end tube.

[0011] Further, a distal limit structure and / or a proximal limit structure is / are provided on the end tube; wherein, the distal limit structure limits the protruding position of the cutter head electrode. When the cutter head electrode protrudes, the first protection electrode preferentially discharges with the loop electrode; wherein, the proximal limit structure limits the retracting position of the cutter head electrode. When the cutter head electrode retracts, the second protection electrode disposed on the outer peripheral side of the distal head preferentially discharges with the loop electrode.

[0012] Further, the distal limit structure includes a first limiting portion at the proximal end of the cutter head electrode and a second limiting portion at the proximal end of the end tube. When the cutter head electrode protrudes, the first limiting portion and the second limiting portion abut against each other; wherein, the proximal limit structure includes a third limiting portion on the end tube and a limiting member on the cutter head electrode. When the cutter head electrode retracts, the third limiting portion abuts against the proximal end of the limiting member; the third limiting portion is a limiting step portion located at the distal end opening of the end tube or / and in the lumen of the end tube. When the third limiting portion is the distal end opening of the end tube, the limiting member is the second protection electrode. When the third limiting portion is the limiting step portion, the limiting member is the first protection electrode or an independent component.

[0013] Further, the protection electrode is circumferentially disposed around the outer peripheral side of the cutter head electrode.

[0014] Further, the protection electrode is a columnar structure that protrudes outward from the outer sidewall of the cutter head electrode in the radial direction; the columnar structure is sealed in the circumferential direction, or there are gaps in the circumferential direction and / or the axial direction of the columnar structure.

[0015] Further, when the distal end of the first protection electrode protrudes outward compared to the distal end of the end tube, the length range X1 of the protrusion of the first protection electrode in the axial direction of the first protection electrode is 0 mm < X1 ≤ 0.3 mm; and / or, when the distal end of the first protection electrode recesses inward compared to the distal end of the end tube, the length range X2 of the recess of the first protection electrode in the axial direction of the first protection electrode is 0.05 mm ≤ X2 ≤ 0.15 mm.

[0016] Further, in the proximal-to-distal direction, the distal end face of the protection electrode is inclined towards the axis of the cutting head electrode.

[0017] Further, the return electrode is arranged outside the sheath tube, and the return electrode is insulated from both the cutting head electrode and the protection electrode.

[0018] Further, the tissue cutting device further includes a sleeve and an elastic fluid seal; the cutting head electrode is provided with fluid outlet holes; the fluid seal is sleeved on the proximal end of the cutting head electrode; the sleeve is sleeved outside the fluid seal, and the distal ends of the sleeve and the fluid seal are both abutted against the proximal end of the end tube, and the fluid seal is restricted inside the sleeve through the end tube and the sleeve; the sheath tube is sleeved outside the sleeve, and the sleeve and the sheath tube are in interference fit, so that the sheath tube applies a force to compress the fluid seal to the sleeve.

[0019] Further, the end tube is provided with fluid outlet holes, and / or the sheath tube is provided with fluid outlet holes, and / or the cutting head electrode is provided with fluid outlet holes; an indication mark is arranged at the distal end of the sheath tube, and the indication mark is arranged close to the fluid outlet holes in the radial direction of the sheath tube.

[0020] Further, the tissue cutting device further includes an operation part, the operation part includes a main body and a sliding part slidably arranged on the main body, and the sliding part and the cutting head electrode are connected by a first wire; an electrical connector is arranged on the main body or the distal end of the main body or the sliding part, the electrical connector includes an active electrode and a passive electrode, the active electrode is electrically connected to the cutting head electrode through the first wire, and the passive electrode is connected to the return electrode through a second wire.

[0021] The technical solution of the present invention has the following advantages:

[0022] In the tissue cutting device provided by the present invention, a protection electrode is arranged on the outer peripheral side of the cutting head electrode. At least when the cutting head electrode extends out, the distance between the protection electrode and the return electrode is less than the distance between the cutting head electrode and the return electrode, so that the protection electrode discharges with the return electrode preferentially; arranged like this, the electric spark will act on the protection electrode, which can protect the cutting head electrode from being corroded and melted by the electric spark, and is beneficial to improving the service life of the tissue cutting device. Description of the Drawings

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Schematic diagram of the distal part of the tissue cutting device in the embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the knife head electrode in the tissue cutting device in the embodiment of the present invention;

[0026] Figure 3 Cross-sectional view of the knife head electrode in the extended state in the tissue cutting device in the embodiment of the present invention;

[0027] Figure 4 Cross-sectional view of the knife head electrode in the retracted state in the tissue cutting device in the embodiment of the present invention;

[0028] Figure 5 Cross-sectional view of the first protection electrode in the tissue cutting device in the embodiment of the present invention, located on the outer side wall of the knife head electrode and protruding beyond the distal end of the end tube, with an electrocorrosion notch;

[0029] Figure 6 Cross-sectional view of the first protection electrode or the second protection electrode in the tissue cutting device in the embodiment of the present invention, located on the inner side wall of the end tube and flush with the distal end of the end tube;

[0030] Figure 7 Cross-sectional view of the first protection electrode or the second protection electrode in the tissue cutting device in the embodiment of the present invention, located on the inner side wall of the end tube and protruding beyond the distal port of the end tube;

[0031] Figure 8 Cross-sectional view of the internal liquid channel in the tissue cutting device in the embodiment of the present invention;

[0032] Figure 9 Cross-sectional view of the sleeve and the elastic fluid seal in the tissue cutting device in the embodiment of the present invention;

[0033] Figure 10 Another schematic diagram of the distal part of the tissue cutting device in the embodiment of the present invention;

[0034] Figure 11 Schematic diagram of the proximal part of the tissue cutting device in the embodiment of the present invention;

[0035] Explanation of the reference numerals:

[0036] 1. Knife head electrode; 2. End tube; 3. Sheath tube; 4. Return electrode; 5. First protection electrode; 6. Second protection electrode; 7. Third limiting part; 8. Electrochemical corrosion notch; 9. Fluid seal; 10. Sleeve; 11. Fluid outlet hole; 12. Indication mark; 13. Connecting tube; 14. First wire; 15. Conductive tube; 16. Second wire; 17. Electrode channel; 18. Connecting tube channel; 19. Sheath tube channel; 20. Electrode rod; 21. Distal head; 22. Operation part; 23. Main body; 24. Sliding part; 25. Passive electrode; 26. Active electrode; M1. Current path; 27. Elongation mark; 28. Water injection port; 29. Elastic part. Detailed implementation mode

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] The "proximal end" and "distal end" involved in the embodiments of this specification can represent directions. The side facing the operator is the "proximal end", and the side facing the side extending into the human body for treatment is the "distal end"; the "proximal end" and "distal end" can also represent parts of the structure and ends located in the corresponding directions.

[0041] As used in the embodiments of this specification, "axial direction" and "radial direction" may represent directions. For example, the axial direction of the protection electrode refers to the direction along the center line of the protection electrode or the rotation axis, and the "radial direction" is perpendicular to the "axial direction".

[0042] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] As Figures 1 to 10 shown, this embodiment provides a tissue cutting device, including a cutting electrode 1, an end tube 2, a sheath tube 3, and a return electrode 4; for example, the end tube 2 is an insulating tube, specifically, it can be a ceramic tube, a metal tube with an insulating sleeve or an insulating coating, etc. The cutting electrode 1 is movably inserted into the end tube 2, and the sheath tube 3 is sleeved outside the end tube 2. For example, the return electrode 4 can be arranged on the outer side wall of the sheath tube 3. One of the channels of the sheath tube 3 can be provided with a second wire 16, such as a molybdenum wire. The second wire 16 is welded to the return electrode 4 through a conductive tube 15. The return electrode 4 and the cutting electrode 1 are arranged at intervals to achieve insulation. The interval arrangement can be achieved in various ways such as through a gap interval, an insulating member (such as the insulating end tube 2), etc. It further includes: a protection electrode located on the outer peripheral side of the cutting electrode 1, that is to say, in the radial direction of the cutting electrode 1, the protection electrode protrudes beyond the outer periphery of the cutting electrode 1. For example, the protection electrode can protrude and be arranged on the outer side wall of the cutting electrode 1; for another example, the protection electrode can be arranged on the inner side wall of the end tube 2. The protection electrode and the return electrode 4 are arranged at intervals to achieve insulation. The interval arrangement can be achieved in various ways such as through a gap interval, an insulating member (such as the insulating end tube 2), etc. At least when the cutting electrode 1 extends towards the distal end, the distance between the protection electrode and the return electrode 4 is less than the distance between the cutting electrode 1 and the return electrode 4, so that the protection electrode preferentially discharges with the return electrode 4, and the protection electrode and the return electrode 4 preferentially discharge with each other.

[0044] In the tissue cutting device provided in this embodiment, a protection electrode is arranged on the outer peripheral side of the cutting electrode 1. At least when the cutting electrode 1 extends out, the distance between the protection electrode and the return electrode 4 is less than the distance between the cutting electrode 1 and the return electrode 4, so that the protection electrode preferentially discharges with the return electrode 4; thus arranged, the electric spark will act on the protection electrode, which can protect the cutting electrode 1 from being corroded and melted by the electric spark, and is beneficial to improving the service life of the tissue cutting device.

[0045] As Figure 2 、 Figure 3 and Figure 4As shown, the cutting head electrode 1 includes an electrode rod 20 and a distal head 21 located at the distal end of the electrode rod 20. The cutting head electrode 1 can be a small needle knife, a hook knife, an IT knife, etc. The distal head 21 can be a cylinder with the same structure as the electrode rod 20, a cutting head disk radially protruding from the outer wall of the electrode rod 20, a hook portion radially protruding from the outer wall of the electrode rod 20, etc. The protection electrode includes a first protection electrode 5 protruding from the outer peripheral side of the electrode rod. At least part of the first protection electrode 5 is located in the lumen of the end tube 2. For example, the first protection electrode 5 can be arranged on the outer wall of the electrode rod. The electrode rod and the first protection electrode 5 can be integrally processed or welded. When the cutting head electrode 1 extends out, the distal end of the first protection electrode 5 is flush with, protrudes outward or concaves inward compared with the distal end of the end tube 2. For example, the first protection electrode 5 can be arranged on the inner wall of the end tube 2. The distal end of the first protection electrode 5 is flush with, protrudes outward or concaves inward compared with the distal end of the end tube 2. Regarding the position setting of being flush with, protruding outward or concaving inward, as long as the distance between the first protection electrode 5 and the return electrode 4 is less than the distance between the cutting head electrode 1 and the return electrode 4 and a shorter current path M1 is formed.

[0046] Wherein, when the distal end of the first protection electrode protrudes outward compared with the distal end of the end tube 2, the length range X1 of the outward protrusion of the first protection electrode in the axial direction of the first protection electrode is 0 mm < X1 ≤ 0.3 mm. For example, the length of the outward protrusion of the first protection electrode in the axial direction of the first protection electrode can be 0.15 mm. Wherein, when the distal end of the first protection electrode concaves inward compared with the distal end of the end tube 2, the length range X2 of the inward concavity of the first protection electrode in the axial direction of the first protection electrode is 0.05 mm ≤ X2 ≤ 0.15 mm. For example, the length of the inward concavity of the first protection electrode in the axial direction of the first protection electrode can be 0.1 mm.

[0047] Wherein, in the proximal-to-distal direction, the distal end face of the protection electrode is inclined towards the axis of the cutting head electrode 1. For example, the included angle range between the end face of the protection electrode and the axis of the cutting head electrode 1 on its distal side can be 117° - 123°. For example, this included angle can be 120°. With such a setting, the volume of the protection electrode can be further enlarged, and the service life of the cutting head electrode 1 can be increased.

[0048] Such as Figure 2 、 Figure 3 、 Figure 6 and Figure 7As shown, wherein the protection electrode includes a second protection electrode 6 protruding from the outer peripheral side of the distal head. For example, the second protection electrode 6 can be disposed on the outer side wall of the distal head. For example, some types of cutter head electrodes 1 have a cutter head disc, and the cutter head disc can directly serve as the second protection electrode 6. When the cutter head electrode 1 retracts towards the proximal end, the distal end of the second protection electrode 6 protrudes outward compared to the distal end of the end tube 2, which is convenient for marking. At this time, the distance between the second protection electrode 6 and the return electrode 4 is less than the distance between the cutter head electrode 1 and the return electrode 4, so that the second protection electrode 6 preferentially discharges with the return electrode 4.

[0049] For example, the second protection electrode 6 can be disposed on the inner side wall of the end tube 2. The distal end of the second protection electrode 6 is flush with, protrudes outward from, or recesses inward from the distal end of the end tube 2. At this time, whether the cutter head electrode 1 extends or retracts, the second protection electrode 6 on the inner side wall of the end tube 2 serves as the protection electrode. Therefore, when the protection electrode is disposed on the inner side wall of the end tube 2, the first protection electrode 5 and the second protection electrode 6 serving as the protection electrode can be the same component, and their related characteristics are also the same. For example, the protruding length range and the recessed length range of the second protection electrode 6 are the same as the data of the aforementioned first protection electrode 5 regarding X1 and X2. The distance between the second protection electrode 6 and the return electrode 4 is less than the distance between the cutter head electrode 1 and the return electrode 4, so that the second protection electrode 6 preferentially discharges with the return electrode 4. Such a setting can protect the cutter head electrode 1 from being corroded and melted by electric sparks, which is beneficial to improving the service life of the tissue cutting device.

[0050] Wherein, a distal limit structure and / or a proximal limit structure is / are provided on the end tube 2. Among them, the distal limit structure limits the extending position of the cutter head electrode 1. When the cutter head electrode 1 extends, the first protection electrode 5 preferentially discharges with the return electrode 4. For example, the distal limit structure includes a first limit portion located at the proximal end of the cutter head electrode 1 and a second limit portion located at the proximal end of the end tube 2. When the cutter head electrode 1 extends, the first limit portion and the second limit portion abut against each other. For example, the first limit portion can be an annular limiting member, and the second limit portion can be a limiting step.

[0051] Among them, the proximal limit structure restricts the retraction position of the cutter head electrode 1. When the cutter head electrode 1 retracts, the second protection electrode 6 provided on the outer peripheral side of the distal head preferentially discharges with the loop electrode 4. Among them, the proximal limit structure includes a third limit portion 7 located on the end tube 2 and a limiting member located on the cutter head electrode 1. When the cutter head electrode 1 retracts, the third limit portion 7 abuts against the proximal end of the limiting member; the third limit portion 7 is a limit step portion located at the distal end opening of the end tube 2 or / and in the lumen of the end tube 2. When the third limit portion 7 is the distal end opening of the end tube 2, the limiting member is the second protection electrode 6, and the outer diameter of the second protection electrode 6 is greater than the inner diameter of the tube opening of the end tube 2; when the third limit portion 7 is the limit step portion, the limiting member is the first protection electrode 5 or an independent component.

[0052] Among them, the protection electrode is circumferentially arranged around the outer peripheral side of the cutter head electrode 1. For example, the protection electrode is a columnar structure that protrudes outward from the outer wall of the cutter head electrode 1 in the radial direction; the columnar structure is sealed in the circumferential direction (such as tubular), or there are gaps in the circumferential direction or / and the axial direction of the columnar structure (such as multiple strip-shaped, multiple ring-shaped, spiral-shaped, etc.). For example, the protection electrode can be a ring-shaped structure, and there can be gaps in the circumferential or axial direction of the ring-shaped structure, or it can be a continuous structure. These gaps are preferably arranged at uniform intervals (such as making the intervals between multiple strip-shaped, multiple ring-shaped, spiral-shaped structures uniform to ensure the stability of the discharge between the protection electrode and the loop electrode 4); its specific structure and distribution form are not limited as long as it can ensure that when the cutter head electrode 1 extends or retracts, the protection electrode preferentially discharges with the loop electrode 4.

[0053] For example, the radial thickness range that the protection electrode protrudes from the cutter head electrode 1 in the radial direction can be 0.03 mm - 0.13 mm. For example, the radial thickness can be 0.08 mm. The axial thickness range in the axial direction can be 0.65 mm - 0.75 mm. For example, the axial thickness can be 0.70 mm.

[0054] As Figure 5 shown, among them, after the protection electrode is subjected to electric spark corrosion, an electric corrosion notch 8 will be formed to protect the inside of the cutter head electrode 1 from being corroded.

[0055] As Figure 8 、 Figure 9As shown in the figure, the tissue cutting device further includes a cannula 10 and an elastic fluid seal 9; the cutting electrode 1 is provided with a fluid outlet hole 11; the fluid seal 9 is sleeved on the proximal end of the cutting electrode 1; the cannula 10 is sleeved outside the fluid seal 9, and the distal ends of the cannula 10 and the fluid seal 9 are both abutted against the proximal end of the end tube 2, and the fluid seal 9 is restricted inside the cannula 10 by the end tube 2 and the cannula 10; the sheath 3 is sleeved outside the cannula 10, and the cannula 10 and the sheath 3 are interference-fitted so that the sheath 3 applies a force to compress the fluid seal 9 on the cannula 10. For example, the material of the elastic fluid seal 9 includes, but is not limited to, elastomers such as silica gel and rubber. The material of the cannula 10 includes, but is not limited to, metal and ceramic.

[0056] For example, the cutting electrode 1 can be welded to the connecting tube 13 inside the tissue cutting device, and the connecting tube 13 can be welded to the first wire 14 (such as a torque rope) inside the tissue cutting device. The liquid enters the connecting tube channel 18 from the sheath channel 19 inside the tissue cutting device, then enters the electrode channel 17, and flows out from the distal end of the cutting electrode 1. When the liquid enters the sheath channel 19, it will also enter the inside of the cannula 10 at the same time and apply liquid pressure to the elastic fluid seal 9. When the liquid pressure increases to about 600 kPa, the liquid pressure will cause the elastic fluid seal 9 to deform, and the liquid pressure is converted into seal pressure, further enhancing the sealing performance. With such a setting, an interference fit is formed between the cutting electrode 1 and the cannula 10 through the elastic fluid seal 9, and the elastic fluid seal 9 applies seal pressure to the cutting electrode 1 and the cannula 10 to achieve sealing. The sheath 3 applies pressure to the cannula 10 to achieve sealing. Above, the sealing of other channels for liquid outflow is realized, the liquid is concentrated in the electrode channel 17 and flows out from the fluid outlet hole at the distal end of the cutting electrode 1, and the concentrated liquid energy is more likely to rush into the submucosa, making the mucosal tissue bulge and improving the surgical efficiency. Moreover, when the cutting electrode 1 extends or retracts to a specified position, due to the elastic fluid seal 9 applying pressure to the cutting electrode 1, the generated frictional force can lock the cutting electrode 1 to the specified position, and the telescopic position of the electrode can be locked at any time without the need for manual control to hold, reducing the operation burden of personnel.

[0057] For example, in order to increase the flow rate, the cross-sectional area of the electrode channel 17 of the cutting electrode 1 can be increased, and the cross-sectional area range can be 0.0314 mm 2- 0.0707 mm 2 , and the flow rate is not less than 20 mL / min.

[0058] Such as Figure 10As shown, a fluid outlet hole 11 may also be provided at the distal end of the end tube 2, and / or, the sheath tube 3 may also be provided with a fluid outlet hole 11, and / or, the cutter head electrode 1 is provided with a fluid outlet hole 11; an indication mark 12 is provided at the distal end of the sheath tube 3, and the indication mark 12 is arranged close to the fluid outlet hole 11 in the radial direction of the sheath tube 3. With such an arrangement, the indication mark 12 and the offset fluid outlet hole 11 are on the same side, and the position of the fluid outlet hole 11 can be judged by observing the position of the indication mark 12, which is convenient for operation. An elongation mark 27 may also be provided at the distal end of the sheath tube 3 to judge the length of the instrument extended under the endoscopic view and prevent perforation caused by excessive extension. For example, when setting the indication mark 12 and the elongation mark 27, the ink can be printed and baked to be cured on the sheath tube 3 according to the specified dimensions.

[0059] Among them, the diameter of the distal part of the sheath tube 3 can be increased from 2.0 mm to 2.5 mm through a thermoforming process, so that a larger area at the distal end of the instrument presses against the mucosal tissue, and it is not easy to pierce through the mucosal tissue to cause perforation. At the same time, the already incised mucosal tissue is also supported, reserving more cutting space for the cutter head electrode 1.

[0060] As Figure 11 shown, it further includes an operation part 22, the operation part 22 includes a main body 23 and a sliding member 24 slidably arranged on the main body 23, and the sliding member 24 and the cutter head electrode 1 are connected by a first wire 14; an electrical connector is arranged on the main body 23 or the distal end of the main body 23 or the sliding member 24, the electrical connector includes an active electrode 26 and a passive electrode 25, the active electrode 26 is electrically connected to the cutter head electrode 1 through the first wire 14, and the passive electrode 25 is connected to the loop electrode 4 through a second wire 16.

[0061] A water injection port 28 is arranged on the main body 23 or the distal end of the main body 23 or the sliding member 24, and the water injection port 28 is communicated with the first wire 14, the sheath tube 3 and the cutter head electrode 1. An elastic member 29 (such as a crown spring, a spring, etc.) is arranged on the first wire 14, and the elastic member 29 is always in elastic contact with the first wire 14 and the active electrode 26 to maintain electrical connection.

[0062] When the tissue cutting device in the present application is in use, as Figure 3 shown, when the cutter head electrode 1 extends out, the first protection electrode 5 is closest to the loop electrode 4, and the conduction path is the current path M1, resulting in the most intense electric spark at the first protection electrode 5, as Figure 4As shown, when the cutter head electrode 1 retracts, the second protection electrode 6 is closest to the loop electrode 4, and the conduction path is the current path M1. The second protection electrode 6 protects the cutter head electrode 1. Of course, when the cutter head electrode 1 is in the middle position, current acts on the cutter head electrode 1. However, since the situation where the cutter head electrode 1 is in this position is rare, the thickness of the cutter head electrode 1 itself can meet the service life.

[0063] The operation method of this tissue cutting device is as follows:

[0064] S1: Obtain the characteristic information of the target object, and determine the target marking position based on the characteristic information;

[0065] S2: Energize, position the cutter head electrode 1 at the target marking position and perform marking. In this step, the cutter head electrode 1 retracts, and marking is performed through the distal head 21. A loop is generated between the second protection electrode 6 and the loop electrode 4;

[0066] S3: Determine the target pre-cutting position based on the target marking position;

[0067] S4: Energize, operate the cutter head electrode 1 to pre-cut the target object along the target pre-cutting position to form a pre-cut on the target object. In this step, the cutter head electrode 1 extends, and a loop is generated between the first protection electrode 5 and the loop electrode 4;

[0068] S5: Inject fluid into the pre-cut through the fluid outlet hole 11 or injection needle of the device to make the target object bulge;

[0069] S6: Energize, operate the cutter head electrode 1 to cut according to the target marking position to peel off the target object. In this step, the cutter head electrode 1 extends, and a loop is generated between the first protection electrode 5 and the loop electrode 4.

[0070] Obviously, the above embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A tissue cutting device, comprising a blade electrode (1), an end tube (2), a sheath tube (3), and a return electrode (4); the blade electrode (1) is movably inserted into the end tube (2), the sheath tube (3) is sleeved outside the end tube (2), and the return electrode (4) is spaced apart from the blade electrode (1), characterized in that: Also includes: A protective electrode is located on the outer peripheral side of the blade electrode (1); at least when the blade electrode (1) is extended, the distance between the protective electrode and the return electrode (4) is smaller than the distance between the blade electrode (1) and the return electrode (4), so that the protective electrode discharges preferentially with the return electrode (4).

2. The tissue cutting device according to claim 1, characterized in that: The blade electrode (1) comprises an electrode rod (20) and a distal head (21) located at the distal end of the electrode rod (20); the protective electrode comprises a first protective electrode (5) protruding from the outer peripheral side of the electrode rod (20); at least a portion of the first protective electrode (5) is located in the lumen of the end tube (2).

3. The tissue cutting device according to claim 2, characterized in that: The protective electrode comprises a second protective electrode (6) protruding from the outer peripheral side of the distal tip.

4. The tissue cutting device according to claim 1, 2 or 3, characterized in that: The protective electrode is protrudingly arranged on the outer side wall of the blade electrode (1); or / and, The protective electrode is arranged on the inner side wall of the end tube (2).

5. The tissue cutting device according to claim 2, characterized in that: The first protective electrode (5) is arranged on the outer side wall of the electrode rod, and when the blade electrode (1) is extended, the distal end of the first protective electrode (5) is flush with or convex or concave relative to the distal end of the end tube (2); or / and, The first protective electrode (5) is arranged on the inner side wall of the end tube (2), and the distal end of the first protective electrode (5) is flush with, convex outwardly, or concave inwardly compared to the distal end of the end tube (2).

6. The tissue cutting device according to claim 3, characterized in that: The second protective electrode (6) is arranged on the outer side wall of the distal end, and when the blade electrode (1) is retracted, the distal end of the second protective electrode (6) protrudes outward compared to the distal end of the end tube (2); or / and, The second protective electrode (6) is arranged on the inner side wall of the end tube (2), and the distal end of the second protective electrode (6) is flush with, convex outwardly, or concave inwardly compared to the distal end of the end tube (2).

7. The tissue cutting device according to claim 2, characterized in that: The end tube (2) is provided with a distal end limiting structure and / or a proximal end limiting structure; The distal limiting structure limits the extension position of the blade electrode (1), and when the blade electrode (1) is extended, the first protective electrode (5) discharges preferentially with the loop electrode (4); The proximal limiting structure limits the retracted position of the blade electrode (1), and when the blade electrode (1) is retracted, the second protective electrode (6) arranged on the outer peripheral side of the distal head discharges preferentially with the loop electrode (4).

8. The tissue cutting device according to claim 7, characterized in that: in, The distal limiting structure comprises a first limiting portion located at the proximal end of the blade electrode (1) and a second limiting portion located at the proximal end of the end tube (2), and when the blade electrode (1) is extended, the first limiting portion and the second limiting portion abut against each other; Wherein, the proximal limiting structure comprises a third limiting portion (7) located on the end tube (2) and a limiting piece located on the blade electrode (1); when the blade electrode (1) is retracted, the third limiting portion (7) abuts against the proximal end of the limiting piece; the third limiting portion (7) is a limiting step portion located at the distal tube opening of the end tube (2) or / and located in the tube cavity of the end tube (2); when the third limiting portion (7) is the distal tube opening of the end tube (2), the limiting piece is the second protective electrode (6); when the third limiting portion (7) is the limiting step portion, the limiting piece is the first protective electrode (5) or an independent component.

9. The tissue cutting device according to claim 1, characterized in that: The protective electrode is circumferentially arranged on the outer peripheral side of the tool head electrode (1).

10. The tissue cutting device according to claim 9, characterized in that: The protective electrode is a columnar structure that is convex in the radial direction compared to the outer side wall of the blade electrode (1); The columnar structure is sealed in the circumferential direction, or the columnar structure has a gap in the circumferential direction and / or in the axial direction.

11. The tissue cutting device according to claim 2, characterized in that: When the distal end of the first protective electrode protrudes outward compared to the distal end of the end tube (2), a protruding length range X1 of the first protective electrode along the axial direction of the first protective electrode is 0 mm < X1 ≤ 0.3 mm; or / and, When the distal end of the first protective electrode is recessed relative to the distal end of the end tube (2), a length range X2 of the recess of the first protective electrode along the axial direction of the first protective electrode is 0.05 mm ≤ X2 ≤ 0.15 mm.

12. The tissue cutting device according to claim 1, characterized in that: In the proximal to distal direction, the distal end surface of the protective electrode is arranged to be inclined toward the axis of the blade electrode (1).

13. The tissue cutting device according to claim 1, characterized in that: The loop electrode (4) is arranged outside the sheath tube (3), and the loop electrode (4) is insulated from the blade electrode (1) and the protective electrode.

14. The tissue cutting device according to claim 1, characterized in that: Also includes a sleeve (10) and an elastic fluid seal (9); The blade electrode (1) is provided with a fluid outlet hole (11); The fluid seal (9) is sleeved on the proximal end of the blade electrode (1); The sleeve (10) is sleeved outside the fluid seal (9), the distal ends of the sleeve (10) and the fluid seal (9) are both against the proximal end of the end tube (2), and the fluid seal (9) is confined inside the sleeve (10) by the end tube (2) and the sleeve (10); The sheath tube (3) is sleeved on the outside of the sleeve (10), and the sleeve (10) and the sheath tube (3) are interference fitted, so that the sheath tube (3) applies a force to the sleeve (10) to compress the fluid seal (9).

15. The tissue cutting device according to claim 1, characterized in that: The end tube (2) is provided with a fluid outlet hole (11), or / and the sheath tube (3) is provided with a fluid outlet hole (11), or / and the blade electrode (1) is provided with a fluid outlet hole (11); An indicator mark (12) is arranged at the distal end of the sheath tube (3), and the indicator mark (12) is arranged close to the fluid outlet hole (11) along the radial direction of the sheath tube (3).

16. The tissue cutting device according to claim 1, characterized in that: It also includes an operating part (22), the operating part (22) including a main body (23), a sliding member (24) slidably arranged on the main body (23), the sliding member (24) and the blade electrode (1) being connected via a first wire (14); An electrical connector is provided on the main body (23) or the distal end of the main body (23) or the sliding member (24), and the electrical connector comprises an active electrode (26) and a passive electrode (25), wherein the active electrode (26) is electrically connected to the blade electrode (1) via the first wire (14), and the passive electrode (25) is connected to the loop electrode (4) via a second wire (16).

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