Minimally invasive surgery cutter

Abstract

The utility model discloses a minimally invasive surgery cutter which comprises a shell, an outer cutter tube, an inner cutter tube, a driving shaft arranged in the shell, a driven shaft driven by the driving shaft to rotate and a switching operation piece for operation. The driving shaft extends out of the shell from the first end wall of the shell, the driven shaft is arranged in the shell, and the driven shaft is further in sliding sleeve connection with the driving shaft in the axial direction of the driven shaft; one end of the outer cutter tube is assembled on the opposite second end wall of the shell, and the inner cutter tube is arranged in the outer cutter tube and fixedly connected with the driven shaft; the switching operation piece can be assembled at the shell in a sliding mode in the radial direction of the driven shaft and is at least provided with a joint position and a separation position relative to the shell, and the switching operation piece enables the driven shaft and the inner cutter tube to axially slide relative to the driving shaft in the joint position and in the rotating process of the driven shaft; therefore, the minimally invasive surgery cutter is convenient to switch and operate, simple in structure and high in cutting efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of medical instruments, in particular to a kind of minimally invasive surgical knives. BACKGROUND

[0002] With the development of gynecological uterine cavity surgery treatment technology, a kind of brand-new mechanical cold knife cutting operation, gynecological uterine cavity minimally invasive surgery appears, compared with transmission electrocision, gynecological uterine cavity minimally invasive surgery can reduce the side injury to the lesion peripheral tissue maximumly, improve the fertility of women, while shorten operation time, do not affect daily professional work, it is a kind of safer, effective surgical solution.

[0003] Among them, the power system for hysteroscope surgery is suitable for trained gynecologists to perform uterine surgery under hysteroscopy, and remove uterine tissue including submucous myoma and endometrial polyps, and the planing cutter head needs to suck tissue into the window to cut during work;However, due to the fact that larger hard myoma tissue is not suitable for deformation, it is difficult to suck these tissues into the window by suction force to realize the cutting of these tissues, resulting in extremely low efficiency of the cutting process.

[0004] Although, there is also a scheme of relative rotation of inner cutter and outer cutter to realize rotary cutting in the market, but when encountering larger hard myoma tissue which is not suitable for deformation, the scheme also has the problem of being difficult to be cut by suction force due to the fact that these tissues are difficult to be sucked into the window, and also has the defect of low efficiency.

[0005] Therefore, a minimally invasive surgical knife is needed to overcome the above-mentioned defects. UTILITY MODEL CONTENTS

[0006] The utility model aims at providing a kind of minimally invasive surgical knife, to have the advantages such as switching operation is convenient, simple structure and high cutting efficiency.

[0007] In order to achieve the above-mentioned purpose, the utility model microtraumatic surgical cutter includes shell, outer sword tube, inner sword tube, built-in main shaft in the shell, driven shaft which is rotated by the main shaft and switching operation part for operation. The main shaft extends from the first end wall of the shell to the shell, the driven shaft is built-in in the shell, the driven shaft is also slidably sleeved with the main shaft in the axial direction; one end of the outer sword tube is assembled at the second end wall opposite to the shell, the inner sword tube is placed in the outer sword tube, the inner sword tube is also fixedly connected with the driven shaft; the switching operation part is slidably assembled at the shell along the radial direction of the driven shaft and has at least an engagement position and a separation position relative to the shell, the switching operation part makes the driven shaft together with the inner sword tube relative to the main shaft axial sliding in the process of the rotation of the driven shaft in the engagement position.

[0008] Compared with the prior art, the driven shaft which is fixedly connected with the inner sword tube is also slidably sleeved with the main shaft in the axial direction, and the switching operation part which is slidably assembled at the shell along the radial direction of the driven shaft and has at least an engagement position and a separation position relative to the shell, so that the switching between the single rotary cutting mode and the composite mode (i.e. including planing and rotary cutting together) can be realized by switching the switching operation part between the engagement position and the separation position, and the utility model has the advantages of convenient switching operation, simple structure and high cutting efficiency.

[0009] Preferably, a spiral groove is arranged around the axis of the driven shaft on the side wall of the driven shaft, a matching convex which protrudes from the end face of the driven shaft for matching with the spiral groove is arranged on the end face of the driven shaft opposite to the driven shaft, the matching convex enters the spiral groove in the engagement position, and the matching convex exits the spiral groove in the separation position.

[0010] Preferably, the matching convex includes a first matching convex and a second matching convex which are separated from each other in the axial direction of the driven shaft.

[0011] Preferably, an axial accommodation cavity and a radial accommodation cavity which communicates with the axial accommodation cavity are arranged in the shell, the switching operation part is located at the radial accommodation cavity, and the driven shaft and the main shaft are located in the axial accommodation cavity.

[0012] Preferably, the utility model microtraumatic surgical cutter further includes a reset part for resetting the switching operation part, the reset part is located at the radial accommodation cavity, and the reset part is arranged between the shell and the switching operation part.

[0013] Preferably, the shell is provided with an abutting convex in the radial accommodation cavity, the reset member is a spring abutting the abutting convex and the end face of the switching operating member opposite to the driven shaft in the radial direction of the driven shaft, and the matching convex is located in the spring.

[0014] Preferably, the minimally invasive surgical cutter further comprises a shaft sleeve fixedly sleeved in the axial accommodation cavity, the driven shaft is sleeved in the shaft sleeve, and the shaft sleeve is further provided with an avoiding opening for the matching convex to enter or exit the shaft sleeve, and the avoiding opening is arranged opposite to the spiral groove.

[0015] Preferably, the minimally invasive surgical cutter further comprises an elastic member located in the axial accommodation cavity and arranged between the driven shaft and the driving shaft, and the elastic member is configured to drive the driven shaft to slide away from the driving shaft.

[0016] Preferably, the outer cutter tube further extends into the axial accommodation cavity.

[0017] Preferably, an end of the outer cutter tube away from the shell is provided with a cutter opening in communication with the inside of the outer cutter tube, one end of the inner cutter tube extends to the cutter opening, and the other end of the inner cutter tube passes through the driven shaft and extends out of the driving shaft.

[0018] Preferably, the projection profile of the position where the driven shaft and the driving shaft are sleeved and matched in the respective axial directions is an ellipse, a rectangle, a rectangle with a chamfer, a regular polygon or a square with a chamfer. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a perspective view of the minimally invasive surgical cutter when the switching operating member is in the disengaged position.

[0020] Figure 2 is Figure 1 a perspective exploded view of the minimally invasive surgical cutter.

[0021] Figure 3 is Figure 1 a plan view of the minimally invasive surgical cutter viewed in the direction of arrow A.

[0022] Figure 4 is an internal view along the B-B line in Figure 3

[0023] Figure 5 is Figure 4 an enlarged view of the D part in

[0024] Figure 6 is a state diagram showing that the switching operating member is switched to the engaged position on the basis of Figure 5 .​

[0025] Figure 7 is Figure 1 a perspective view of the minimally invasive surgical cutter shown in Fig.

[0026] Figure 8 is Figure 7 an enlarged view of the E portion in Fig.

[0027] Figure 9 is a perspective view of a driven shaft in the minimally invasive surgical cutter of the present application.

[0028] Figure 10 is Figure 9 a plan view of the driven shaft shown in Fig.

[0029] Figure 11 is Figure 9 a plan view of the driven shaft shown in Fig.

[0030] Figure 12 is a perspective view of a driving shaft in the minimally invasive surgical cutter of the present application.

[0031] Figure 13 is Figure 12 a plan view of the driving shaft shown in Fig. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with specific implementation examples and the accompanying drawings, and the technical solutions of the present application will be described and explained. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present application. The specific implementation manners of the present application will be described in detail below in conjunction with the accompanying drawings. In the following description, a lot of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below. The embodiments of the present application will be described below with reference to the accompanying drawings, and similar elements in the drawings are denoted by similar reference numerals.

[0033] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0034] Please refer to Figure 1 、 Figure 2 、 Figure 4 、 Figure 5 and Figure 6 The minimally invasive surgical cutter 100 of the utility model comprises a shell 10, an outer cutter tube 20, an inner cutter tube 30, a driving shaft 40 built in the shell 10, a driven shaft 50 rotated by the driving shaft 40 and a switching operation piece 60 for operation.

[0035] The driving shaft 40 extends out of the shell 10 from the first end wall 11 of the shell 10, so as to better meet the need of assembling and connecting the driving shaft 40 with the power equipment outside, and to achieve the purpose of providing driving power for the rotation of the driving shaft 40 by the power equipment outside.

[0036] The driven shaft 50 is built in the shell 10, and the driven shaft 50 is also in slidable sleeve connection with the driving shaft 40 in the axial direction (see the direction indicated by the arrow A and the opposite direction), so as to meet the need that the driven shaft 50 can also axially slide relative to the driving shaft 40. Figure 5 Figure 6 In the utility model, as an example, the axial center lines C of the driven shaft 50 and the driving shaft 40 coincide with each other, which effectively reduces the space position occupation amount of the driven shaft 50 and the driving shaft 40 in the radial direction, so that the driven shaft 50 and the driving shaft 40 are more compact. Figure 5 Figure 6 Obviously, according to actual needs, the axial center lines C of the driven shaft 50 and the driving shaft 40 can also be arranged in parallel with a separation, so the utility model is not limited to the shown.

[0037] ​​One end (e.g., the tail end) of the outer blade tube 20 is fitted to the opposite second end wall 12 of the housing 10, such that the outer blade tube 20 and the drive shaft 40 are arranged oppositely on opposite sides of the housing 10; the inner blade tube 30 is placed inside the outer blade tube 20, and the inner blade tube 30 is also fixedly connected to the driven shaft 50, for example, but not limited to, welding or gluing, to meet the need for the inner blade tube 30 to rotate and slide with the driven shaft 50. The switching operating element 60 is slidably fitted to the housing 10 along the radial direction of the driven shaft 50, and has at least a certain angle relative to the housing 10. Figure 6 The shown joint position and Figure 5 The separation position shown indicates that the switching operation member 60, in the engagement position, causes the driven shaft 50, along with the inner blade tube 30, to slide axially relative to the drive shaft 40 during the rotation of the driven shaft 50, thereby enabling the minimally invasive surgical instrument 100 of this invention to switch from a single rotation mode to a composite mode (i.e., including planing and rotary cutting). Specifically, in Figures 1 to 7 In this example, the switching operation element 60 is a button structure, allowing the operator to switch the switching operation element 60 from the disengaged position to the engaged position by pressing it, thus improving the convenience of operation. Obviously, depending on actual needs, the switching operation element 60 can also be other types of operation elements, so it is not limited to this example. Figures 1 to 7 The above is a limited description. More specifically, as follows:

[0038] Combination Figure 2 , Figure 5 , Figure 6 , Figure 9 and Figure 10 As an example, a spiral groove 52 is provided on the side wall 51 of the driven shaft 50, arranged around the axis C of the driven shaft 50. Correspondingly, a mating protrusion 62 is provided on the end face 61 of the switching operation member 60 facing the driven shaft 50, protruding from the end face 61 for engaging with the spiral groove 52. When in the engaged position, the mating protrusion 62 enters the spiral groove 52, as shown in the figure. Figure 6 As shown; when the convex 62 is in the disengaged position, it exits the spiral groove 52, as shown in the diagram. Figure 5 As shown; therefore, by means of the cooperation between the mating convex 62 and the spiral groove 52, on the one hand, the smoothness and reliability of the engagement or disengagement of the switching operation member 60 and the driven shaft 50 are ensured, and on the other hand, the switching operation member 60, when in the engaged position, ensures that the driven shaft 50 makes more reliable axial sliding relative to the driving shaft 40. Specifically, in Figure 2 , Figure 5 and Figure 6In the embodiment, as an example, the engaging convex 62 comprises a first engaging convex 621 and a second engaging convex 622 which are spaced apart from each other in the axial direction of the driven shaft 50. By means of the first engaging convex 621 and the second engaging convex 622, the number of positions at which the switching operating member 60 is engaged with the driven shaft 50 when in the engaged position can be increased, and the reliability of the switching operating member 60 in the engaged position to cause the driven shaft 50 to axially slide relative to the driving shaft 40 can be further improved.

[0039] As shown in Figures 4 to 6 , as an example, the housing 10 is provided with an axial accommodation cavity 13 and a radial accommodation cavity 14 which communicates with the axial accommodation cavity 13. Optionally, as an example, the axial accommodation cavity 13 also respectively exposes from the first end wall 11 and the second end wall 12 of the housing 10. When the housing 10 is provided with the axial accommodation cavity 13 and the radial accommodation cavity 14, the switching operating member 60 is located at the radial accommodation cavity 14, the driven shaft 50 and the driving shaft 40 are located in the axial accommodation cavity 13, and the outer cutter tube 20 also extends into the axial accommodation cavity 13 so as to facilitate the assembly connection between the outer cutter tube 20 and the housing 10, and the state is shown in Figure 5 and Figure 6 . Specifically, in Figure 5 and Figure 6 , as an example, a fixed tube 90b is fixedly sleeved on one end (for example, the tail end) of the outer cutter tube 20 adjacent to the housing 10, that is, the fixed tube 90b is fixedly connected with the outer cutter tube 20; the fixed tube 90b also extends into the axial accommodation cavity 13 and is fixedly connected with the second end wall 12 of the housing 10, for example, by means of gluing or the like, so as to improve the support strength of the housing 10 to the outer cutter tube 20 and effectively avoid that the outer cutter tube 20 is suspended too long. In addition, in Figure 7 and Figure 8 , as an example, one end (for example, the head end) of the outer cutter tube 20 which is away from the housing 10 is provided with a cutter opening 21 which communicates with the inside of the outer cutter tube 20, and one end (for example, the head end) of the inner cutter tube 30 extends to the cutter opening 21, and the other end (for example, the tail end) of the inner cutter tube 30 extends through the driven shaft 50 and out of the driving shaft 40, and the state is shown in Figure 4 . So as to facilitate the assembly connection of the inner cutter tube 30 with the external negative pressure suction device, so that the cut tissues are sucked out through the space in the inner cutter tube 30 by the external negative pressure suction device. It should be noted that since the structures of the outer cutter tube 20 and the inner cutter tube 30 are well known in the art, they will not be described here. In addition, since the inner cutter tube 30 extends through the driven shaft 50 and the driving shaft 40, the driven shaft 50 and the driving shaft 40 are respectively provided with a through passage 54 (42) for the inner cutter tube 30 to extend through, and the state is shown in Figure 9 , Figure 11 , Figure 12 and Figure 13 .

[0040] As shown in Figure 2and Figures 4 to 6 As shown in the drawings, as an example, the minimally invasive surgical cutter 100 of the utility model further comprises a reset member 70 for resetting the switching operating member 60, the reset member 70 is located at the radial accommodation cavity 14, and the reset member 70 is arranged between the shell 10 and the switching operating member 60; in this way, the reset force of the automatic reset of the switching operating member 60 from the engagement position to the separation position is provided, thereby facilitating the reset operation of the switching operating member 60. Specifically, the reset member 70 is a spring arranged in the radial direction of the driven shaft 50 and abutting against the abutting convex 15 and the end surface 61 of the switching operating member 60 opposite to the driven shaft 50, and the cooperation convex 62 is located in the spring; in this way, the connection relationship between the reset member 70 and the shell 10 and the switching operating member 60 is simplified; obviously, according to actual needs, the reset member 70 can also be a first magnetic structure and a second magnetic structure containing each other and repelling each other, and at least one of the first magnetic structure and the second magnetic structure is a magnet. Figure 5 and Figure 6 As shown in the drawings, as an example, the shell 10 is provided with an abutting convex 15 protruding into the radial accommodation cavity 14, and optionally, the abutting convex 15 is in the form of an annular structure arranged around the center line of the radial accommodation cavity 14, and obviously, the abutting convex 15 can also have other structures; in addition, the reset member 70 is a spring abutting against the abutting convex 15 and the end surface 61 of the switching operating member 60 opposite to the driven shaft 50 in the radial direction of the driven shaft 50, and the cooperation convex 62 is located in the spring; in this way, the connection relationship between the reset member 70 and the shell 10 and the switching operating member 60 is simplified; obviously, according to actual needs, the reset member 70 can also be a first magnetic structure and a second magnetic structure containing each other and repelling each other, and at least one of the first magnetic structure and the second magnetic structure is a magnet.

[0041] As shown in the drawings, Figure 2 and Figures 4 to 6 As shown in the drawings, as an example, the minimally invasive surgical cutter 100 of the utility model further comprises a shaft sleeve 80 fixedly sleeved in the axial accommodation cavity 13, that is, the shaft sleeve 80 is fixed together with the shell 10; at this time, the driven shaft 50 is sleeved in the shaft sleeve 80, and the shaft sleeve 80 is also provided with an avoiding opening 81 for the cooperation convex 62 to enter and exit the shaft sleeve 80, and the avoiding opening 81 is arranged opposite to the spiral groove 52; in order to provide a guiding effect for the axial sliding of the driven shaft 50 by means of the shaft sleeve 80, so that the axial sliding of the driven shaft 50 is more stable, smoother and more sensitive.

[0042] As shown in the drawings, Figure 2 and Figures 4 to 6 As shown in the drawings, as an example, the minimally invasive surgical cutter 100 of the utility model further comprises an elastic member 90a located in the axial accommodation cavity 13 and arranged between the driven shaft 50 and the driving shaft 40, and the elastic member 90a is configured to drive the driven shaft 50 to slide away from the driving shaft 40; therefore, by means of the elastic member 90a, the driven shaft 50 always maintains an axially fixed position, thereby facilitating the cooperation convex 62 of the switching operating member 60 to enter the spiral groove 52 of the driven shaft 50, and effectively ensuring the smoothness of the cooperation convex 62 of the switching operating member 60 entering and exiting the spiral groove 52 of the driven shaft 50. In addition, in combination with Figure 11 and Figure 13As an example, the projection profile 53(41) of the position where the driven shaft 50 and the driving shaft 40 are fitted together in the respective axial directions is a square with chamfered corners; obviously, according to actual needs, the projection profile 53(41) can also be an ellipse, a rectangle, a rectangle with chamfered corners, or a regular polygon, and is not limited to the one shown in the drawings. Figure 11 and Figure 13

[0043] The working principle of the minimally invasive surgical cutter of the present application is described in conjunction with the drawings.

[0044] In use, the minimally invasive surgical cutter tool 100 of the present application is connected to the power equipment as a whole, and is also clamped by the integral connection of the shell 10 and the power equipment, thereby achieving stable fixation of the minimally invasive surgical cutter tool 100 of the present application as a whole.

[0045] The negative pressure suction device is connected to the position (e.g., the tail end) of the inner cutter tube 30 passing through the driving shaft 40, so as to exert a negative pressure suction force on the position (e.g., the tail end) of the inner cutter tube 30 passing through the driving shaft 40.

[0046] Then, the driving shaft 40 is rotated by the power equipment, so that the inner cutter tube 30 and the outer cutter tube 20 rotate relatively, thereby achieving the purpose of cutting the tissue; and the cut tissue is sucked out through the internal space of the inner cutter tube 30.

[0047] When the relative rotation between the head ends of the inner cutter tube 30 and the outer cutter tube 20 is blocked by the tissue during the cutting process, or in the extreme case of insufficient suction pressure, the switching operating member 60 can be pressed at this time, so that the matching convex 62 of the switching operating member 60 enters the spiral groove 52 of the driven shaft 50, that is, the inner cutter tube 30 can slide reciprocally in the axial direction, and the suction pressure at the cutting edge 21 will instantaneously increase, which is more conducive to the discharge of the liquid or the cut tissue.

[0048] In addition, after long-term use, cleaning and disinfection, the head ends of the inner cutter tube 30 and the outer cutter tube 20 will be worn out, and the gap between the inner cutter tube 30 and the outer cutter tube 20 will increase, which will greatly reduce the cutting efficiency. Therefore, by realizing the reciprocating sliding of the inner cutter tube 30, it is more conducive to cutting the tissue in the axial direction and improving the operation efficiency.

[0049] In summary, the minimally invasive surgical cutter 100 of the present application has the following advantages: (1) improving the discharge efficiency of the cut tissue; (2) realizing small size and multiple functions; (3) realizing a multi-modal control mode, increasing the axial movement during radial rotation, and realizing controllable functions; (4) greatly reducing the cutting efficiency achieved by the size requirements of the original parts.

[0050] ​In summary, the minimally invasive surgical cutter 100 of the present application can solve the existing problems with simple structure and simple process. The prior art is mainly to achieve the purpose of rotating cutting and realizing tissue discharge, but it needs to control the cooperation and firmness of each component to prevent the overall surgical efficiency from being reduced due to the excessive gap between the inner cutter tube 30 and the outer cutter tube 20 or the reduced suction efficiency caused by long-term wear.

[0051] In the minimally invasive surgical cutter 100 of the present application, only the relative cooperation between the components needs to be controlled to reduce the risk of reduced cutting efficiency caused by excessively high requirements for a single component. In addition, the minimally invasive surgical cutter 100 of the present application can also integrate many components to achieve the purpose of reducing the number of components while achieving the same function.

[0052] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be considered as limiting the claims. Meanwhile, the above disclosure is only the preferred embodiments of the present application, and of course cannot limit the scope of the present application, so equivalent changes made in the scope of the patent application of the present application are still within the scope of the present application.

Claims

1. A minimally invasive surgical instrument, comprising a shell, an outer blade tube, an inner blade tube, and a drive shaft built into the shell, the drive shaft extending from a first end wall of the shell, one end of the outer blade tube being fitted to a second end wall opposite to the shell, and the inner blade tube being disposed within the outer blade tube, characterized in that, The minimally invasive surgical instrument also includes a driven shaft driven to rotate by the drive shaft and a switching mechanism for operation. The driven shaft is built into the housing and is slidably sleeved with the drive shaft in its axial direction. The inner blade tube is also fixedly connected to the driven shaft. The switching mechanism is slidably mounted on the housing along the radial direction of the driven shaft and has at least one engaging position and one disengaging position relative to the housing. In the engaging position, the switching mechanism causes the driven shaft and the inner blade tube to slide axially relative to the drive shaft during the rotation of the driven shaft.

2. The minimally invasive surgical instrument according to claim 1, characterized in that, The driven shaft has a spiral groove arranged around its axis on its side wall. The switching operation member has a mating protrusion on its end face facing the driven shaft for engaging with the spiral groove. The mating protrusion enters the spiral groove when in the engagement position and exits the spiral groove when in the disengagement position.

3. The minimally invasive surgical instrument according to claim 2, characterized in that, The mating protrusions include a first mating protrusion and a second mating protrusion that are spaced apart from each other axially from the driven shaft.

4. The minimally invasive surgical instrument according to claim 2, characterized in that, The housing has an axial receiving cavity and a radial receiving cavity communicating with the axial receiving cavity. The switching operation element is located in the radial receiving cavity, and the driven shaft and the driving shaft are located in the axial receiving cavity.

5. The minimally invasive surgical instrument according to claim 4, characterized in that, It also includes a reset member for resetting the switching operation member, the reset member being located at the radial receiving cavity, and the reset member being disposed between the housing and the switching operation member.

6. The minimally invasive surgical instrument according to claim 5, characterized in that, The outer casing is provided with an abutment protrusion protruding into the radial receiving cavity. The reset member is a spring that abuts against the abutment protrusion and the end face of the switching operation member facing the driven shaft in the radial direction of the driven shaft. The mating protrusion is located inside the spring.

7. The minimally invasive surgical instrument according to claim 4, characterized in that, It also includes a bushing that is fixedly fitted in the axial receiving cavity, the driven shaft being fitted inside the bushing, and the bushing having an clearance opening for the mating protrusion to enter and exit the bushing, the clearance opening being arranged opposite to the spiral groove.

8. The minimally invasive surgical instrument according to claim 4, characterized in that, It also includes an elastic element located in the axial receiving cavity and disposed between the driven shaft and the driving shaft, the elastic element being configured to drive the driven shaft to slide away from the driving shaft; the outer blade tube also extends into the axial receiving cavity.

9. The minimally invasive surgical instrument according to claim 1, characterized in that, The outer blade tube has a cutting edge at one end away from the outer casing that communicates with the interior of the outer blade tube. One end of the inner blade tube extends toward the cutting edge, and the other end of the inner blade tube passes through the driven shaft and extends out from the driving shaft.

10. The minimally invasive surgical instrument according to claim 1, characterized in that, The projection contours of the positions where the driven shaft and the driving shaft are fitted together along their respective axes are elliptical, rectangular, chamfered rectangular, regular polygonal, and chamfered square.

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