Cutter head assembly, loop cutter having the cutter head assembly, and method of operation thereof

Abstract

This invention discloses a blade assembly, comprising: a through delivery conduit having a first limiting portion therein; and a blade that moves axially and rotates circumferentially along the delivery conduit, the blade having a second limiting portion. The blade moves axially along the delivery conduit such that the second limiting portion abuts against the end face of the first limiting portion facing away from the delivery conduit outlet to limit the blade, or the second limiting portion passes over the first limiting portion and abuts against the end face of the first limiting portion facing the delivery conduit outlet to limit the blade. This invention's blade assembly, the snare cutter having the blade assembly, and its operating method enable control over the blade's extension length and achieve blade fixation within a preset extension length, preventing the blade from shifting during surgery and improving surgical accuracy and safety.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to scalpels, and more particularly to a blade head assembly with adjustable blade length and angle, a snare cutter having the blade head assembly, and a method for operating the same. Background Technology

[0002] Endoscopic submucosal dissection (ESD) is a novel minimally invasive treatment technique developed in recent years. It can completely remove early-stage gastrointestinal cancers in a single endoscopic procedure, offering advantages such as minimal trauma and rapid recovery. Compared to traditional open surgery and endoscopic mucosal resection (EMR), ESD spares patients the pain and risks of open surgery and organ removal, while also providing complete histopathological specimens for analysis. It can achieve a resection rate of over 96% even for large, irregularly shaped tumors or those with ulcers or scarring.

[0003] Due to their slender structure, existing endoscopic electrosurgical units are prone to displacement of the blade due to external forces, making it difficult to fix the blade in the intended position. In such cases, it is difficult for the surgeon to accurately control the initial position and cutting depth of the electrosurgical procedure, increasing the difficulty and risk of the operation and affecting the accuracy and safety of the surgery to some extent.

[0004] Current endoscopic electrosurgical units (ESUs) rely solely on a handle assembly and spindle for blade positioning, which can lead to blade wobble or displacement during surgery. Therefore, achieving precise control of the ESU blade position to improve the accuracy and safety of electrosurgical resection is a pressing technical challenge. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in order to solve the technical problem of the difficulty in accurately positioning the blade in the prior art, the present invention provides a blade assembly, a loop cutter having the blade assembly, and a method for operating the same, which can control the extension length of the blade and fix the blade at a preset extension length, thereby avoiding the blade from shifting during the operation and improving the accuracy and safety of the operation.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a cutter head assembly, comprising: a through delivery conduit, wherein the delivery conduit has a first limiting portion; a cutter head that moves axially and rotates circumferentially along the delivery conduit, wherein the cutter head is provided with a second limiting portion; the cutter head moves axially along the delivery conduit such that the second limiting portion abuts against the end face of the first limiting portion away from the outlet to limit the cutter head, or the second limiting portion passes over the first limiting portion and abuts against the end face of the first limiting portion facing the outlet of the delivery conduit to limit the cutter head.

[0007] The present invention provides a cutter head assembly in which the cutter head can move axially and rotate circumferentially to adjust the extension distance, so that the second limiting part and the first limiting part abut and limit each other at different axial positions, thereby precisely controlling the extension position of the cutter head.

[0008] Furthermore, in order to adjust and fix the extension position of the cutter head in the axial direction, the second limiting part is a protrusion extending outward along the outer side of the cutter head. The protrusion moves toward the first limiting part and abuts against the inner side of the first limiting part in the axial and circumferential directions to limit the cutter head. Alternatively, after the protrusion moves toward the first limiting part and passes the first limiting part, the cutter head is moved so that the protrusion abuts against the outer side of the first limiting part in the axial and circumferential directions to limit the cutter head.

[0009] Furthermore, in order to control the extension length of the cutter head, the first limiting part includes axial ribs arranged along the inner wall of the delivery conduit. The axial ribs have an outer limiting end face facing the outlet of the delivery conduit. After the protrusion passes the outer limiting end face, the cutter head moves and the protrusion abuts against the outer limiting end face to limit the cutter head.

[0010] Furthermore, in order to provide a selection of different blade extension lengths, the first limiting part includes axial ribs arranged along the inner wall of the delivery conduit, and the axial ribs have transverse ribs arranged along the inner wall of the delivery conduit at one end facing the outlet of the delivery conduit.

[0011] The transverse rib has an outer limiting end face facing the outlet of the delivery conduit. After the protrusion passes the outer limiting end face, the cutter head moves and the protrusion abuts against the outer limiting end face to limit the cutter head.

[0012] The inner end face of the transverse rib and the inner side face of the axial rib form an inner limiting end face, and the protrusion abuts against the inner limiting end face to limit the cutting head.

[0013] Furthermore, in order to provide more options for the extension length of the cutter head, the axial rib is also provided with a secondary transverse rib. The secondary transverse ribs are spaced apart at the rear end of the transverse rib, and the protrusion engages with the inner or outer side of the secondary transverse rib to limit the cutter head.

[0014] Furthermore, in order to enable the cutter head to be more easily positioned with the secondary transverse rib, the end of the secondary transverse rib has a guide tip, and the cutter head rotates to make the protrusion slide along the guide tip toward the secondary transverse rib.

[0015] Furthermore, in order to fix the extended cutter head, the outer limiting end face is an arc-shaped limiting end face that is concave from both sides to the middle, and the protrusion abuts against the middle of the outer limiting end face to position the cutter head.

[0016] Furthermore, to prevent the cutter head from getting stuck when entering the delivery conduit, the axial rib has a protruding guide end at one end away from the outlet of the delivery conduit. The protruding guide end has a guide slope. The protrusion moves axially and contacts the end of the guide slope. The guide slope causes the protrusion to rotate and deflect along the guide slope and then move along the side of the axial rib.

[0017] Furthermore, in order to smoothly guide the cutter head to move along the axial rib, the slope of the guide ramp is ≤10°.

[0018] Furthermore, in order to provide sufficient movement space for the cutter head, the width of the axial rib gradually decreases from the outer limiting end face to the protruding guide end.

[0019] Furthermore, in order to provide another limiting structure for the extension position of the cutter head, the first limiting part is a limiting boss provided at the outlet of the delivery conduit and extending inward. The protrusion abuts against the inner side of the limiting boss to limit the inner cutter head, or the protrusion abuts against the outer side of the limiting boss to limit the outer cutter head. The protrusion and the limiting boss are circumferentially offset to release the cutting head limiting.

[0020] Furthermore, in order to ensure that the cutter head can pass smoothly through the limiting boss, the width of the protrusion along the circumference of the cutter head is less than half of the circumference of the outer circumference of the cutter head, and the extension height of the protrusion is less than the gap between the cutter head and the inner wall of the delivery conduit.

[0021] Furthermore, in order to achieve position locking of the cutter head, the inner and / or outer sides of the limiting boss are provided with receiving grooves, and the receiving grooves correspond to the cross-sectional shape of the protrusion.

[0022] Furthermore, in order to drive the movement of the cutter head, the cutter head assembly also includes a collar ring, one end of which is connected to the cutter head and the other end of which is connected to the spindle. The collar ring is located at the rear end of the second limiting part, and the spindle drives the cutter head to move axially and rotate circumferentially.

[0023] The technical solution adopted by the present invention to solve its technical problem is: a snare cutting knife, including a handle assembly, the handle assembly being connected to the above-mentioned cutter head assembly, the handle assembly including a rotating wheel and an operating handle, the rotating wheel being connected to a spindle and driving the cutter head assembly to rotate, and the operating handle being connected to the spindle and driving the cutter head assembly to move axially.

[0024] The technical solution adopted by this invention to solve its technical problem is: an operating method of the above-mentioned snare cutting knife, comprising the following steps:

[0025] S1. Control the operating handle and drive the cutter head into the delivery conduit and move it axially, so that the cutter head gradually approaches the first limit part, and selectively enter step S2 or S3 according to the cutter length.

[0026] S2. The cutter head is rotated by the rotating wheel, and the second limiting part and the first limiting part overlap at least partially on the shaft, and the second limiting part and the first limiting part contact each other to limit the cutter head;

[0027] S3. The cutter head is rotated by the rotating wheel so that the second limiting part and the first limiting part do not coincide on the shaft. The cutter head is pushed so that the second limiting part completely passes over the first limiting part. Then the cutter head is rotated so that the second limiting part and the first limiting part at least partially coincide on the shaft. The cutter head is pulled back so that the second limiting part and the first limiting part contact to limit the cutter head.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. The present invention relates to a blade head assembly, a loop cutting blade having the blade head assembly, and an operating method thereof, wherein the second limiting part is engaged with the first limiting part at different axial positions, and the second limiting part presets the extension position of the blade head during surgery, so that the blade head can switch between inner and outer limiting positions, thereby flexibly adjusting the extension position of the blade head.

[0030] 2. The present invention provides a cutter head assembly, a loop cutter having the cutter head assembly, and a method for operating the cutter head, which uses axial ribs and protruding guide ends to guide and limit the cutter head, ensuring that the cutter head can move smoothly within the delivery conduit.

[0031] 3. The blade assembly, the loop cutting blade having the blade assembly, and the operating method thereof of the present invention utilize the arc-shaped outer limiting end face to support the blade head, so that the outer limiting end face forms a certain resistance to the blade head, thereby preventing the blade head from deflecting during the operation and affecting the surgical effect.

[0032] 4. The blade assembly, the loop cutter having the blade assembly, and the operating method thereof of the present invention utilize transverse ribs and secondary transverse ribs to achieve inner limiting of the blade head, which can provide more options for the extension length of the blade head and adapt to different surgical needs. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] Figure 1 This is a schematic diagram of the snare cutting blade of the present invention;

[0035] Figure 2 This is a partial structural diagram of the cutter head assembly in Embodiment 1;

[0036] Figure 3 This is a schematic diagram of another state of the cutter head assembly;

[0037] Figure 4 A schematic diagram showing the expanded state of the loop of the cutter head assembly;

[0038] Figure 5 for Figure 4 A partial structural diagram;

[0039] Figure 6 This is a schematic diagram of the outer limit of the cutter head;

[0040] Figure 7 for Figure 6 A partial structural diagram;

[0041] Figure 8 This is a partial structural diagram of the cutter head assembly in Embodiment 2;

[0042] Figure 9 This is a schematic diagram of the inner limit of the cutting head;

[0043] Figure 10 This is a diagram showing the unlocked state of the blade head.

[0044] Figure 11 This is a schematic diagram of another inner limit of the cutter head;

[0045] Figure 12 This is a partial structural schematic diagram of the cutter head assembly in Embodiment 3;

[0046] Figure 13 This is a schematic diagram of the tool structure of the cutting head;

[0047] Figure 14 This is a schematic diagram of the inner limit of the cutting head;

[0048] Figure 15 This is a top view of the delivery catheter;

[0049] Figure 16 This is a partial schematic diagram of the delivery catheter;

[0050] Figure 17 A schematic diagram showing the unlocked state of the delivery tube and the cutting head;

[0051] Figure 18 This is a schematic diagram of the structure of another cutting head;

[0052] Figure 19 This is a schematic diagram of the structure of another cutting head;

[0053] Figure 20 This is a schematic diagram of the structure of another cutting head;

[0054] Figure 21 This is a schematic diagram of the structure of another cutting head;

[0055] Figure 22 This is a schematic diagram of the structure of another cutting head.

[0056] In the picture:

[0057] 1. Cutter head assembly; 11. Delivery conduit; 111. Axial rib; 112. Outer limiting end face; 113. Protruding guide end; 114. Guide slope; 115. Transverse rib; 1151. Inner limiting end face; 116. Secondary transverse rib; 1161. Guide tip; 117. Limiting boss; 1171. Receiving groove; 12. Cutter head; 121. Protrusion; 13. Loop ring;

[0058] 2. Rotary wheel;

[0059] 3. Operating handle. Detailed Implementation

[0060] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0061] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0062] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0063] In particular, in the description of the following embodiments, those skilled in the art should understand that, unless otherwise expressly specified and limited, the terms "proximal end" and "distal end" are relative to the operator; "proximal end" refers to the end of the snare cutter with the blade assembly that is closer to the user in one dimension when being operated, i.e., the rear end, while "distal end" refers to the end of the snare cutter with the blade assembly that is further away from the user in one dimension when being operated, i.e., the front end. Furthermore, those skilled in the art should understand that "far" and "near" do not refer to the three-dimensional linear distance from the user.

[0064] like Figure 1 As shown, a snare cutter includes a handle assembly connected to a cutter head assembly 1. The handle assembly includes a rotating wheel 2 and an operating handle 3. The cutter head assembly 1 includes a through delivery conduit 11, a cutter head 12 that moves axially and rotates circumferentially along the delivery conduit 11, and a snare ring 13. One end of the snare ring 13 is connected to the cutter head 12, and the other end is connected to a spindle. The spindle drives the cutter head 12 to move axially and rotate circumferentially. The rotating wheel 2 is connected to the spindle and drives the cutter head assembly 1 to rotate. The operating handle 3 is connected to the spindle and drives the cutter head assembly 1 to move axially.

[0065] The cutting head 12 can cut the target tissue when energized. Both the mandrel and the snare 13 are made of conductive metal wire, and their materials can be the same or different. The mandrel extends linearly within the lumen of the delivery catheter 11 and can drive the cutting head 12 and the snare 13 to move axially and rotate circumferentially. Furthermore, the snare 13 has a certain degree of flexibility; after extending from the delivery catheter 11, it can open radially to form a ring structure to surround the tissue to be removed. When pulled back into the delivery catheter 11, the snare 13 can partially retract and enter the delivery catheter 11. By controlling the axial movement and rotation of the mandrel, the position and direction of the snare 13 can be adjusted, thereby achieving precise retrieval and removal of the target tissue. The delivery catheter 11 is made of insulating material to insulate and protect the cutting head 12 and the snare 13, preventing current leakage during surgery.

[0066] The rotating wheel 2 is located at the front end of the operating handle 3. The doctor can rotate the rotating wheel 2 by turning it with their thumb. The rotating wheel 2 is connected to the spindle through a transmission structure. When the rotating wheel 2 rotates, it can drive the spindle and the blade head 12 to rotate at a corresponding angle, thereby adjusting the circumferential position of the blade head 12. The operating handle 3 can slide back and forth along its axial direction, and through the internal connecting structure, it drives the spindle to move axially accordingly, thereby controlling the extension or retraction of the blade head 12 into the delivery catheter 11, realizing the adjustment of the extension and retraction length of the blade head 12. The spindle is locked by the handle assembly and is in a stretched state to fix the blade head 12. The actions of the rotating wheel 2 and the operating handle 3 will not be specifically described in the following description of the adjustment of the blade head 12. Of course, the handle assembly can also have a conventional locking function (see the applicant's earlier patent application CN202010324211.6), and the function of the handle locking will not be described in detail here.

[0067] Specifically, the delivery conduit 11 has a first limiting portion located near the outlet of the delivery conduit 11. The cutter head 12 has a second limiting portion located in the middle-rear part of the cutter head, close to the end of the collar 13. The cutter head 12 moves axially along the delivery conduit 11, such that the second limiting portion abuts against the end face of the first limiting portion facing away from the outlet of the delivery conduit 11 to limit the cutter head 12, or the second limiting portion passes over the first limiting portion and abuts against the end face of the first limiting portion facing the outlet of the delivery conduit 11 to limit the cutter head 12.

[0068] Specifically, the second limiting part is a protrusion 121 extending outward along the outer side of the cutter head 12. The protrusion 121 moves toward the first limiting part and abuts against the inner side of the first limiting part axially and circumferentially to limit the cutter head 12. Alternatively, after the protrusion 121 moves toward and passes the first limiting part, the cutter head 12 is moved so that the protrusion 121 abuts against the outer side of the first limiting part axially and circumferentially to limit the cutter head 12. When the cutter head 12 moves axially within the delivery conduit 11, it can be limited by the inner or outer side of the first limiting part, thereby achieving adjustment of different extension lengths of the cutter head 12. The different structures of the first and second limiting parts will be specifically described in the following embodiments.

[0069] Example 1, as Figures 2 to 7As shown, specifically, the first limiting part includes axial ribs 111 arranged along the inner wall of the delivery conduit 11. The axial ribs 111 have an outer limiting end face 112 facing the outlet of the delivery conduit 11. After the protrusion 121 passes the outer limiting end face 112, the cutting head 12 moves, and the protrusion 121 abuts against the outer limiting end face 112 to limit the cutting head 12. When the cutting head 12 moves axially along the delivery conduit 11, since there are no limiting structures on the sidewalls of the axial ribs 111, the cutting head 12 will not be internally limited when passing through the axial ribs 111. Therefore, the protrusion 121 can move along the delivery conduit 11 until it passes the outer limiting end face 112 of the axial ribs 111. At this point, the cutting head 12 and the snare 13 have free extension length until the snare 13 fully extends out of the delivery conduit 11 and opens, at which point the corresponding surgical operation can be performed. After the protrusion 121 passes the outer limiting end face 112, the cutter head 12 is rotated circumferentially so that the protrusion 121 and the outer limiting end face 112 partially overlap in the axial direction. At this time, the cutter head 12 retracts axially until the protrusion 121 abuts against the outer limiting end face 112, thus forming an outer limit on the cutter head 12. At this time, the handle assembly can be locked. With the outer limit and the handle assembly locked, the extension length of the cutter head 12 is completely locked. The cutter head 12 performs surgical operations with a preset extension length and angle, and there will be no shaking during the operation.

[0070] Preferably, the outer limiting end face 112 is an arc-shaped limiting end face that is concave from both sides to the middle, and the protrusion 121 abuts against the middle of the outer limiting end face 112 to position the cutter head 12. In order to ensure that the outer limiting end face 112 effectively fixes the cutter head 12, the outer limiting end face 112 is designed as an arc-shaped limiting end face. When the cutter head 12 is externally limited, only a small part of the protrusion 121 and the arc-shaped limiting end face need to overlap. Once the protrusion 121 contacts the arc-shaped limiting end face, the protrusion 121 will move along the arc-shaped limiting end face towards its center during the retraction of the cutter head 12 until the protrusion 121 is located at the center of the arc-shaped limiting end face, thus completing the external limiting lock of the cutter head 12 (at this time, the collar 13 is located inside the delivery conduit 11).

[0071] Of course, the outer limiting end face 112 is the widest part of the axial rib, and the width of the channel formed between the sides of the two outer limiting end faces 112 must be greater than the width of the collar 13 so as not to interfere with the collar 13. Two or more protrusions 121 are arranged along the axial direction, so that the cutter head 12 can have more extension positions to choose from.

[0072] When the blade 12 enters the delivery catheter 11, the relative positions of the protrusion 121 and the axial rib 111 cannot be clearly determined. If the protrusion 121 is in direct contact with the end of the axial rib 111 at this time, the protrusion may be stuck by the end of the axial rib 111. In this case, the doctor needs to rotate the blade 12 to push the blade 12 forward again. During the operation, the doctor does not want this to happen, as it will affect the doctor's operation speed.

[0073] Specifically, the axial rib 111 has a raised guide end 113 at one end away from the outlet of the delivery conduit 11. The raised guide end 113 has a guide slope 114 with a slope ≤10°. The width of the axial rib 111 gradually decreases from the outer limiting end face 112 to the raised guide end 113. The protrusion 121 moves axially and contacts the end of the guide slope 114. The guide slope 114 causes the protrusion 121 to rotate and deflect along the guide slope 114 before contacting the side of the axial rib 111. Under the action of the protruding guide end 113, even when the blade head 12 enters the delivery catheter 11, the protrusion 121 directly contacts the protruding guide end 113. Under the action of the guide slope 114, the protrusion 121 will move along the protruding guide end 113. Since the width of the protruding guide end 113 and the axial rib 111 gradually increases, the protruding guide end 113 and the axial rib 111 will generate a certain thrust on the protrusion 121 and play a guiding role in this process. This thrust will generate torque on the blade head 12. At this time, the doctor only needs to use a small force to push the blade head 12 smoothly, so that the snare ring 13 can fully extend out of the tube and be in a free expansion state. The same applies when the blade head 12 retracts.

[0074] Of course, in this embodiment, the end of the protruding guide end is sharp. The shape of the protruding guide end 113 and the protrusion 121 can also be further adjusted. For example, the end faces of the two can be designed as arcs or other shapes to further optimize the guiding effect and make the two lock together.

[0075] After the snare ring 13 retracts, the cutter head 12 is rotated. Since the cross-section of the snare ring 13 is circular, the snare ring 13 can smoothly pass over the side of the axial rib 111 and enter the inner side of the axial rib 111. At this time, the protrusion 121 is located within the range of the arc-shaped limiting end face. The cutter head 12 can be locked by retracting.

[0076] Preferably, the circumferential length of the outer limiting end face 112 is less than or equal to 1 / 3 of the inner circumference of the delivery conduit 11. This ensures that the space reserved between the two outer limiting end faces 112 allows the loop ring 13 to pass through, preventing interference between the loop ring 13 and the axial rib 111. Of course, the axial rib 111 can be arranged completely along the axial direction of the delivery conduit 11, or it can be reasonably chosen to have a small angular offset from the axial direction of the delivery conduit 11.

[0077] Specifically, the radial extension height of the protrusion 121 along the cutter head 12 and the radial extension height of the axial rib 111 along the delivery conduit 11 are both less than the gap between the cutter head and the inner wall of the delivery conduit 11.

[0078] Preferably, the area on the outer periphery of the delivery catheter 11 corresponding to the outer limiting end face 112 can be marked with color. In the operating room, the doctor can observe the corresponding position of the protrusion 121 and the color mark through an endoscope, and can quickly determine the angle of the blade 12, thereby realizing the locking and unlocking of the blade 12.

[0079] Preferably, a first mark can also be provided at the blade tip 12. The mark is not limited to a color mark, notch, or other irregular structure, and the mark can be directly opposite any protrusion 121. A second color mark can be applied to the area on the outer periphery of the delivery catheter 11 corresponding to the outer limiting end face 112. During surgery, the doctor can observe the corresponding position of the first mark on the blade tip 12 and the second color mark on the delivery catheter 11 through an endoscope, and can quickly determine the angle of the blade tip 12, thereby achieving locking and unlocking of the blade tip 12.

[0080] Example 2 differs from Example 1 in that, as Figures 8 to 11 As shown, the first limiting portion includes axial ribs 111 arranged along the inner wall of the delivery conduit 11. At one end of the axial ribs 111 facing the outlet of the delivery conduit 11, there are transverse ribs 115 arranged along the inner wall of the delivery conduit 11. The transverse ribs 115 have an outer limiting end face 112 facing the outlet of the delivery conduit 11. After the protrusion 121 passes over the outer limiting end face 112, the cutting head 12 moves, and the protrusion 121 abuts against the outer limiting end face 112 to limit the cutting head 12. The inner end face of the transverse rib 115 and the inner surface of the axial rib 111 form an inner limiting end face 1151. The protrusion 121 abuts against the inner limiting end face 1151 to limit the cutting head 12.

[0081] The structure of the axial rib 111 is the same as in Embodiment 1, and the process of the cutter head 12 entering the delivery conduit 11 can be referred to Embodiment 1. When the cutter head 12 continues to move axially along the axial rib 111, the cutter head 12 will first contact the inner limiting end face 1151 to achieve inner limiting of the cutter head 12, and the extension length of the cutter head 12 is at a preset length. When it is necessary to adjust the extension length of the cutter head 12, the cutter head 12 can be rotated again (until the protrusion 121 contacts the other end of the axial rib 111, and there is no transverse rib 115 in the circumferential direction of this end face), so that the protrusion 121 and the transverse rib 115 are misaligned. At this time, the cutter head 12 can continue to extend, and the state of the cutter head 12 after extension is also referred to Embodiment 1.

[0082] After the cutter head 12 is fully extended, it can be retracted again. The cutter head 12 is rotated and pulled back in the same way as in Embodiment 1. The protrusion 121 contacts the outer limiting end face 112 (which has the same shape as the outer limiting end face 112 in Embodiment 1) and is limited under the action of the outer limiting end face 112, thereby realizing the outer limiting of the cutter head 12.

[0083] Similarly, the axial ribs 111 and the transverse ribs 115 can also be arranged symmetrically, and the protrusions 121 are also symmetrically arranged on the cutter head. The distance between the two transverse ribs 115 must be greater than the width of the collar 13 to avoid the transverse ribs 115 interfering with the movement of the collar 13.

[0084] Compared with Embodiment 1, Embodiment 2 adds an inner limiting structure to further meet the adjustment of different blade head 12 extension lengths, adapt to the requirements of different surgeries, and under different fixed extension lengths, the limiting surfaces of the transverse rib 115 and the secondary transverse rib 116 can fix the blade head 12 to avoid the blade head 12 from shaking.

[0085] Preferably, the axial rib 111 is further provided with a secondary transverse rib 116, which is spaced apart at the rear end of the transverse rib 115. The protrusion 121 engages with the inner or outer side of the secondary transverse rib 116 to limit the cutting head 12. The secondary transverse rib 116 also performs an internal limiting function, and adding secondary transverse ribs 116 can provide more options for the extension length. The internal limiting process of the secondary transverse rib 116 is the same as that of the transverse rib 115, and will not be described again here.

[0086] Preferably, the end of the secondary transverse rib 116 has a guide tip 1161. The cutting head 12 rotates, causing the protrusion 121 to slide along the guide tip 1161 towards the secondary transverse rib 116. The guide tip 1161 functions the same as the protrusion guide end 113, guiding the protrusion 121 to smoothly enter the secondary transverse rib 116, thereby limiting the movement of the cutting head 12. As shown in the figure, the number of secondary transverse ribs 116 can be arbitrarily selected, and will not be elaborated further here.

[0087] Due to the arrangement of the axial ribs 111 and the transverse ribs 116, one side of the axial rib 111 allows the protrusion 121 to pass through, while the other side is blocked by the transverse rib 116. Therefore, multiple operating methods are available during surgery to meet the needs of different procedures.

[0088] During surgery, the blade 12 can directly enter the delivery conduit 11. If the protrusion 121 of the blade 12 does not contact the protruding guide end 113, the blade 12 and the snare may extend directly out of the delivery conduit 11 when they are in contact with the transverse rib 115 or the secondary transverse rib 116. At this time, the external limit can be directly performed, or the blade can be retracted and rotated for the internal limit.

[0089] If the protrusion 121 of the cutter head 12 contacts the protrusion guide end 113, the protrusion 121 may shift towards the transverse rib 115 or the secondary transverse rib 116. At this time, the cutter head 12 will be internally limited. If the cutter head 12 needs to be adjusted, the cutter head 12 can be rotated again until the protrusion 121 abuts against the other end of the axial rib 111 and the cutter head 12 can no longer rotate. At this time, the cutter head 12 can be pushed to complete the external locking.

[0090] If the protrusion 121 of the cutter head 12 does not contact the protrusion guide end 113, it may move toward the transverse rib 115 or the secondary transverse rib 116, causing the cutter head 12 to be internally limited first. The cutter head 12 can be rotated and adjusted to select a different limiting position again.

[0091] If the protrusion 121 of the cutter head 12 comes into contact with the protrusion guide end 113, the protrusion 121 may shift in the opposite direction to the transverse rib 115 or the secondary transverse rib 116. At this time, the cutter head 12 can directly perform external limiting or retract again to perform internal limiting.

[0092] Example 3, as Figures 12 to 17As shown, specifically, the first limiting part is a limiting boss 117 located at the outlet of the delivery conduit 11 and extending inward. The protrusion 121 abuts against the inner side of the limiting boss 117 to limit the inner cutting head 12, or the protrusion 121 abuts against the outer side of the limiting boss 117 to limit the outer cutting head 12. The protrusion 121 and the limiting boss 117 are circumferentially offset to release the limiting of the cutting head 12. During operation, the blade 12 moves along the axial direction of the delivery conduit 11, and the protrusion 121 gradually approaches the limiting boss 117. If the protrusion 121 and the limiting boss 117 partially overlap in the axial direction, when the protrusion 121 moves to the inner end face of the limiting boss 117, the protrusion 121 is blocked by the limiting boss 117. At this time, the blade 12 can no longer move forward, thus achieving the inner limiting of the blade 12. At this time, the extension length of the blade 12 is limited, and surgical operations can be performed. When further extension of the blade is required, simply rotate the blade head 12 circumferentially and apply a small axial thrust. Once the protrusion 121 separates from the limiting boss 117, the protrusion 121 will pass through the limiting boss 117 and continue to move forward axially until the protrusion 121 completely passes through the limiting boss 117. At this point, the blade head 12 and the snare 13 have free extension length until the snare 13 fully extends out of the delivery conduit 11 and opens. At this point, the surgery can continue. Next, the blade head 12 needs to retract again until the snare 13 is retracted into the delivery conduit 11. Then, rotate the blade head 12 circumferentially at a small angle again, and the protrusion 121 and the limiting boss 117 continue to partially overlap axially. Continue to pull the blade head 12 back until the outer surfaces of the protrusion 121 and the limiting boss 117 overlap to achieve external limiting of the blade head 12. At this point, the blade head 12 has another fixed extension length.

[0093] Preferably, the width of the protrusion 121 along the circumference of the cutter head 12 is less than half the circumference of the outer circumference of the cutter head 12, and the extension height of the protrusion 121 is less than the gap between the cutter head 12 and the inner wall of the delivery conduit 11. The inner and / or outer sides of the limiting boss 117 are provided with receiving grooves 1171, and the receiving grooves 1171 correspond to the cross-sectional shape of the protrusion 121. Correspondingly, the circumferential width of the receiving groove 1171 along the delivery conduit 11 is less than half the circumference of the inner side of the delivery conduit 11, so as to ensure that there is enough space to arrange the receiving groove 1171. For example, when a protrusion 121 is arranged on the outer circumferential surface of the cutter head 12 and a limiting boss 117 is arranged on the circumferential surface of the limiting conduit outlet, the protrusion 121 can occupy up to half the circumference of the outer circumferential surface of the cutter head 12, so as to ensure that an axial through hole can be provided in the remaining circumferential space at the outlet of the delivery conduit 11, and the size of the axial through hole is larger than the size of the protrusion 121, so as to ensure that it can meet the smooth passage of the protrusion 121.

[0094] Of course, the limiting boss 117 can also selectively provide receiving grooves 1171 on the inner and outer sides to achieve inner or outer limiting separately.

[0095] Preferably, when the outer circumferential surface of the cutter head 12 is provided with two protrusions 121, the two protrusions 121 can be evenly arranged around the circumference of the cutter head 12, that is, spaced 180° apart from each other; correspondingly, the distal end of the delivery conduit 11 is also provided with two limiting bosses 117 spaced 180° apart around the circumference. When the cutter head 12 rotates 90°, the two protrusions 121 can simultaneously pass through the outlet of the delivery conduit 11, allowing the cutter head 12 to move axially; when the cutter head 12 continues to rotate 90°, the two protrusions 121 can simultaneously engage in the receiving grooves 1171 of the two limiting bosses 117, achieving locking. When there are three or more protrusions 121, the same principle applies.

[0096] Preferred, such as Figures 18 to 22 As shown, the cross-section of the protrusion 121 is rectangular, circular, elliptical, fan-shaped, triangular or other geometric shape; the shape of the receiving groove 1171 is adapted to the cross-sectional shape of the protrusion 121, and can also be configured as a corresponding rectangular, circular, elliptical, fan-shaped, triangular or other geometric shape.

[0097] Preferably, the area on the outer periphery of the delivery catheter 11 corresponding to the outer limiting end face 112 can be marked with color. In the operating room, the doctor can observe the corresponding position of the protrusion 121 and the color mark through an endoscope, and can quickly determine the angle of the blade 12, thereby realizing the locking and unlocking of the blade 12.

[0098] Preferably, a first mark can also be provided at the blade tip 12. The mark is not limited to a color mark, notch, or other irregular structure, and the mark can be directly opposite any protrusion 121. A second color mark can be applied to the area on the outer periphery of the delivery catheter 11 corresponding to the outer limiting end face 112. During surgery, the doctor can observe the corresponding position of the first mark on the blade tip 12 and the second color mark on the delivery catheter 11 through an endoscope, and can quickly determine the angle of the blade tip 12, thereby achieving locking and unlocking of the blade tip 12.

[0099] In summary, the blade assembly, the loop cutter having the blade assembly, and the operating method thereof of the present invention can control the extension length of the blade and fix the blade at a preset extension length, thereby preventing the blade from shifting during surgery and improving the accuracy and safety of the surgery.

[0100] The above description is based on the preferred embodiments of the present invention. Through the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the contents of the specification, but must be determined by the scope of the claims.

Claims

1. A blade assembly, characterized in that, include: A through delivery conduit (11), wherein the delivery conduit (11) has a first limiting part; A cutter head (12) that moves axially and rotates circumferentially along the delivery conduit (11) is provided with a second limiting part, which is a protrusion (121) extending outward along the outer side of the cutter head (12). The cutting head (12) moves along the axial direction of the delivery conduit (11) so that the second limiting part abuts against the end face of the first limiting part away from the outlet of the delivery conduit (11) to limit the cutting head (12), or the second limiting part passes over the first limiting part and abuts against the end face of the first limiting part facing the outlet of the delivery conduit (11) to limit the cutting head (12). The first limiting part includes an axial rib (111) arranged along the inner wall of the delivery conduit (11), and the axial rib (111) has a transverse rib (115) arranged along the inner wall of the delivery conduit (11) at one end facing the outlet of the delivery conduit (11). The transverse rib (115) has an outer limiting end face (112) facing the outlet of the delivery conduit (11). After the protrusion (121) passes the outer limiting end face (112), the cutter head (12) moves and the protrusion (121) abuts against the outer limiting end face (112) to limit the cutter head (12). The inner end face of the transverse rib (115) and the inner side face of the axial rib (111) form an inner limiting end face (1151), and the protrusion (121) abuts against the inner limiting end face (1151) to limit the cutting head (12). The axial rib (111) is also provided with a secondary transverse rib (116), which is spaced apart at the rear end of the transverse rib (115). The protrusion (121) is engaged with the inner or outer side of the secondary transverse rib (116) to limit the cutter head (12).

2. The cutter head assembly according to claim 1, characterized in that, The protrusion (121) moves toward the first limiting part and abuts against the inner side of the first limiting part in the axial and circumferential directions to limit the cutting head (12), or the protrusion (121) moves toward the first limiting part and passes the first limiting part, and then moves the cutting head (12) so that the protrusion (121) abuts against the outer side of the first limiting part in the axial and circumferential directions to limit the cutting head (12).

3. The cutter head assembly according to claim 2, characterized in that, The first limiting part includes an axial rib (111) arranged along the inner wall of the delivery conduit (11). The axial rib (111) has an outer limiting end face (112) facing the outlet of the delivery conduit (11). After the protrusion (121) passes the outer limiting end face (112), the cutter head (12) moves and the protrusion (121) abuts against the outer limiting end face (112) to limit the cutter head (12).

4. The cutter head assembly according to claim 1, characterized in that, The end of the secondary transverse rib (116) has a guide tip (1161), and the cutter head (12) rotates to make the protrusion (121) slide along the guide tip (1161) toward the secondary transverse rib (116).

5. The cutter head assembly according to claim 3 or 4, characterized in that, The outer limiting end face (112) is an arc-shaped limiting end face that is concave from both sides to the middle. The protrusion (121) abuts against the middle of the outer limiting end face (112) to position the cutter head (12).

6. The cutter head assembly according to claim 5, characterized in that, The axial rib (111) has a raised guide end (113) at one end away from the outlet of the delivery conduit (11). The raised guide end (113) has a guide slope (114). The raised portion (121) moves axially and contacts the end of the guide slope (114). The guide slope (114) causes the raised portion (121) to rotate and deflect along the guide slope (114) and then move along the side of the axial rib (111).

7. The cutter head assembly according to claim 6, characterized in that, The slope of the guide ramp (114) is ≤10°.

8. The cutter head assembly according to claim 7, characterized in that, The width of the axial rib (111) gradually decreases from the outer limiting end face (112) to the protruding guide end (113).

9. The cutter head assembly according to claim 2, characterized in that, The first limiting part is a limiting boss (117) located at the outlet of the delivery conduit (11) and extending inward. The protrusion (121) abuts against the inner side of the limiting boss (117) to limit the inner cutting head (12), or the protrusion (121) abuts against the outer side of the limiting boss (117) to limit the outer cutting head (12). The protrusion (121) and the limiting boss (117) are circumferentially offset to release the cutting head (12) from the limiting position.

10. The cutter head assembly according to claim 9, characterized in that, The width of the protrusion (121) along the circumference of the cutter head (12) is less than half the circumference of the outer circumference of the cutter head (12), and the extension height of the protrusion (121) is less than the gap between the cutter head (12) and the inner wall of the delivery conduit (11).

11. The cutter head assembly according to claim 10, characterized in that, The inner and / or outer sides of the limiting boss (117) are provided with receiving grooves (1171), and the receiving grooves (1171) correspond to the cross-sectional shape of the protrusion (121).

12. The cutter head assembly according to claim 1, characterized in that, The cutter head assembly also includes a collar (13), one end of which is connected to the cutter head (12) and the other end is connected to the spindle. The collar (13) is located at the rear end of the second limiting part, and the spindle drives the cutter head (12) to move axially and rotate circumferentially.

13. A snare-cutting knife, characterized in that, The device includes a handle assembly connected to a cutter head assembly (1) as described in any one of claims 1-12. The handle assembly includes a rotary wheel (2) and an operating handle (3). The rotary wheel (2) is connected to a spindle and drives the cutter head assembly (1) to rotate. The operating handle (3) is connected to the spindle and drives the cutter head assembly (1) to move axially.

14. A method for operating the snare cutter as described in claim 13, characterized in that, Includes the following steps: S1. Control the operating handle (3) and drive the cutter head (12) into the delivery conduit (11) and move it along the axis, so that the cutter head (12) gradually approaches the first limit part, and selectively enter step S2 or S3 according to the cutter length; S2. The cutter head (12) is driven to rotate by the rotating wheel (2), and the second limiting part and the first limiting part overlap at least partially on the shaft, and the second limiting part and the first limiting part contact each other to limit the cutter head (12); S3. Drive the cutter head (12) to rotate by the rotating wheel (2) so that the second limiting part and the first limiting part do not overlap on the shaft. Push the cutter head (12) so that the second limiting part completely passes over the first limiting part. Then rotate the cutter head (12) so that the second limiting part and the first limiting part overlap at least partially on the shaft. Pull the cutter head (12) back so that the second limiting part and the first limiting part contact to limit the cutter head (12).

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