Surgical instrument rod

Abstract

The utility model relates to a surgical instrument rod which is used for endoscopic surgery. Comprising a plurality of sets of bending joints and a plurality of active driving parts, each set of bending joints comprises a first rotating part and a second rotating part, each set of bending joints further comprises a rotating supporting rod, the two ends of each rotating supporting rod are movably connected with the corresponding first rotating part and the corresponding second rotating part respectively, each first rotating part is provided with a first guiding part, and each second rotating part is provided with a second guiding part; the first guide part and the second guide part are matched to achieve symmetrical rotation of the first rotating piece and the second rotating piece. According to the technical scheme, symmetrical rotation of the bending joints is achieved, the active driving pieces are consistent in folding and unfolding, the driving pieces are simple in movement path, and movement precision and control precision can be improved conveniently.

Description

Technical Field

[0001] This utility model relates to a medical device, and more particularly to a surgical instrument rod. Background Technology

[0002] With advancements in technology, laparoscopic surgery allows doctors to perform procedures through smaller incisions, resulting in shorter hospital stays, greater surgical safety, and faster recovery. In modern medicine, it is often referred to as "surgery that preserves quality of life."

[0003] Traditional laparoscopic techniques use long-handled surgical instruments with only four degrees of freedom, far fewer than the six degrees of freedom of the object itself. In addition, doctors need extensive training to overcome the effects of hand-eye coordination problems, motion inversion, and uncertain proportions. Therefore, the emergence of laparoscopic surgical robots has solved the difficulties in clinical operation.

[0004] The existing rotating structure of the bending joint of surgical instruments rotates around a single axis. Several equal drive ropes are arranged symmetrically on both sides of the axis, and their pulling and releasing actions control the direction and angle of joint rotation. However, in a single-axis rotating joint, the distance the drive ropes travel when pulled is not equal to the distance they travel when released. Pulling and releasing require different drive sources, hindering further reduction in the size of surgical instruments. Secondly, the distances from the rotating axis to the drive ropes that pull and release are also unequal, resulting in different changes in the driving force of the drive sources. This leads to different deformations of the drive ropes, affecting the control precision of joint rotation. Therefore, the joint structure currently used in laparoscopic surgical robots has the following defects: 1) The structure is complex, requiring four joint components to achieve multi-plane bending; 2) The drive rope inside needs to follow the angle formed by the joint bending to follow the zigzag line, which will generate greater friction during the movement, affecting the life of the rope and the control accuracy of the joint structure; 3) The joint rotation is asymmetrical, which will lead to inconsistent lengths of the contraction and release of the drive rope, increasing the complexity of control; at the same time, during the joint rotation, the lever arm lengths of the ropes on both sides to the center of rotation are inconsistent, resulting in unbalanced force. Utility Model Content

[0005] Based on this, a surgical instrument rod is provided, which solves the technical problem of how to make the bending joint symmetrical and rotate to ensure the control accuracy of the drive component.

[0006] The objective of this utility model can be achieved through the following technical solution: a surgical instrument rod, comprising multiple sets of bending joints and multiple active driving components. Each set of bending joints includes a first rotating component and a second rotating component. The multiple active driving components pass through at least a portion of the rotating component. Each set of bending joints also includes a rotation support rod. The two ends of the rotation support rod are respectively movably connected to the first rotating component and the second rotating component. The first rotating component has a first guide portion on the side facing the second rotating component, and the second rotating component has a second guide portion on the side facing the first rotating component. The first guide portion is sleeved on the outside of the second guide portion. The first guide portion and the second guide portion cooperate to achieve symmetrical rotation of the first rotating component and the second rotating component. The rotation support rod is disposed inside the first guide portion and the second guide portion. Adjacent sets of bending joints are connected by a connector.

[0007] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: By rotating the support rod and engaging with the first and second rotating components, the bending joint has two rotation origins. Then, through the cooperation of the first and second guide parts, the first and second rotating components can rotate symmetrically. Since the distance between the two rotation origins on the rotating support rod remains fixed, the first and second rotating components rotate at these two rotation origins. In this way, the change in the active drive components passing through the two symmetrical sides of the bending joint remains consistent during the movement. When the bending joint is driven to bend to the left, the shortening dimension of the left active drive component is equal to the extension dimension of the right active drive component, thus ensuring the control accuracy of the drive components.

[0008] In the aforementioned surgical instrument rod, a passive restraint is also included. Multiple identical passive restraints are provided for each pair of adjacent sets of the bending joints. The passive restraints begin at one of the bending joints and end at another adjacent bending joint.

[0009] When the instrument rod is in a straight extension state, the passive restraint member is wound around the instrument rod at one end 180° relative to the other end along the straight extension direction of the instrument rod, and the wound position of the passive restraint member is located at the connector between two adjacent sets of bending joints.

[0010] Compared with existing technologies, the technical effects achieved by this solution are as follows: The passive constraint is inserted into two adjacent sets of bending joints, linking the rotational relationship of the two bending joints together. Because the passive constraint is wound 180° at the connector between the two sets of bending joints, the path of the passive constraint in one set of bending joints and the path in the other set of bending joints are exactly on both sides of the instrument rod. This means that when one set of bending joints bends to one side, due to the unchanged length of the passive constraint, the other set of bending joints must also bend to the same side. This achieves the effect that adjacent bending joints can bend to one side simultaneously but cannot bend to different sides. This solves the technical problem of S-shaped deformation caused by force when the instrument rod is under load.

[0011] In the surgical instrument rod described above, the first rotating member and the second rotating member have a disk with multiple through holes, through which the active driving member and the passive restraining member pass.

[0012] In the aforementioned surgical instrument rod, the first guide portion has a non-spherical surface, and the second guide portion has a cylindrical surface that matches the first guide portion;

[0013] Alternatively, the first guide portion has a cylindrical surface, and the second guide portion has a non-spherical surface that matches the first guide portion.

[0014] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: the first guide part and the second guide part are not spherical. The first rotating part and the second rotating part can achieve symmetrical rotation through a specific curved surface. When the bending joint is driven to bend to the left, the shortening dimension of the left active driving part is equal to the extension dimension of the right active driving part, thus ensuring the control accuracy of the driving part.

[0015] In the aforementioned surgical instrument rod, the two ends of the rotating support rod are rotating spherical surfaces. The first rotating component and the second rotating component each have grooves that mate with the rotating spherical surfaces. The grooves are spherical or hemispherical. The first rotating component and the second rotating component can rotate around the center of the corresponding rotating spherical surface.

[0016] Compared with existing technologies, the technical effect achieved by this technical solution is that the matching of the rotating spherical surface and the groove allows the first and second rotating parts to rotate freely in any direction in space relative to the rotating support rod, so only two rotating parts are needed to achieve four degrees of freedom of rotation.

[0017] In the aforementioned surgical instrument rod, the first rotating member, the second rotating member, and the rotating support rod all have a through-hole in the center, which forms a passage through the bending joint. The passage passes through the first guide portion, the second guide portion, and the two rotating spherical surfaces.

[0018] Compared with existing technologies, the technical effects achieved by adopting this technical solution are as follows: the passage through the inside of the curved joint can provide a channel for the cable or drive rope of the surgical tool head, which can further facilitate the reduction of the size of the instrument rod.

[0019] In the aforementioned surgical instrument rod, the central through hole of both the first rotating member and the second rotating member has two channels. The groove is disposed at the connection between the first channel and the second channel. The rotating support rod is disposed in the first channel and stops at the groove. The second rotating member has the first channel on the side close to the first rotating member. The end of the first channel facing the second rotating member is a flared opening.

[0020] Compared with existing technologies, the technical effects achieved by adopting this technical solution are: the setting of the flared mouth helps to increase the angular range of mutual rotation between the first rotating component and the second rotating component.

[0021] The surgical instrument rod described above also includes a distal fixator and a proximal fixator. The distal fixator is fixed to one end of the plurality of bending joints, and the proximal fixator is fixed to the other end of the plurality of bending joints. The active drive member passes through the proximal fixator.

[0022] In one of the surgical instrument rods described above, the connector has a hollow channel that connects to the passageway.

[0023] The present invention provides a bending joint and a surgical instrument rod composed thereof. The bending joint can achieve bending in any bending plane and symmetrical rotation of the two rotating parts. Such a bending joint has a compact structure, and the active drive part retracts and extends in a consistent manner. The movement path of the active drive part is simple, which facilitates improved motion accuracy and control precision. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the surgical instrument rod according to an embodiment of the present invention;

[0025] Figure 2 This is an exploded view of a partial structure of the surgical instrument rod according to an embodiment of this utility model;

[0026] Figure 3 This is a schematic cross-sectional view of the surgical instrument rod according to an embodiment of the present invention;

[0027] Figure 4This utility model Figure 3 Enlarged view of region B in the middle;

[0028] Figure 5 This is a cross-sectional schematic diagram of the bending joint in an embodiment of the present invention;

[0029] Figure 6 This is a cross-sectional schematic diagram of another embodiment of the bending joint of this utility model.

[0030] In the diagram, 10 is the proximal fixation component;

[0031] 20. Bending joint; 21. First rotating component; 211. First guide portion; 212. First disk; 22. Second rotating component; 221. Second guide portion; 222. Second disk; 23. Rotating support rod; 231. First spherical surface of revolution; 2311. Auxiliary circle one; 232. Second spherical surface of revolution; 2321. Auxiliary circle two; 24. Connecting component;

[0032] 30. Remote fixing component;

[0033] 40. Passive constraint components;

[0034] 50. Active drive components. Detailed Implementation

[0035] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0036] In the description of this utility model, it should be understood that 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", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 this utility model.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0041] like Figures 1 to 6As shown, a surgical instrument rod includes multiple sets of bending joints 20 and multiple active drive members 50. Each set of bending joints 20 includes a first rotating member 21 and a second rotating member 22. The multiple active drive members 50 pass through at least a portion of the rotating member. Each set of bending joints 20 also includes a rotating support rod 23. The two ends of the rotating support rod 23 are movably connected to the first rotating member 21 and the second rotating member 22, respectively. The first rotating member 21 has a first guide portion 211 on the side facing the second rotating member 22, and the second rotating member 22 has a second guide portion 221 on the side facing the first rotating member 21. The first guide portion 211 is sleeved on the outside of the second guide portion 221. The first guide portion 211 and the second guide portion 221 cooperate to realize the symmetrical rotation of the first rotating member 21 and the second rotating member 22. The rotating support rod 23 is disposed inside the first guide portion 211 and the second guide portion 221. Adjacent sets of bending joints 20 are connected by a connector 24. The bending joint 20 used in this solution can achieve bending in any bending plane and symmetrical rotation of the two rotating parts. Such bending joint 20 has a compact structure, and the active drive part 50 retracts and extends in a consistent manner, which facilitates the improvement of motion accuracy and control accuracy.

[0042] The specific structure will be described in detail below with reference to the accompanying drawings.

[0043] See Figure 1 As shown, the entire surgical instrument shaft is composed of multiple sets of curved joints 20 connected by connectors 24. The curved joints 20 at both ends are connected to a distal fixator 30 and a proximal fixator 10, respectively. The proximal fixator 10 is used to connect to the drive source (not shown) or surgical arm (not shown) of the entire instrument shaft, while the distal fixator 30 is used to connect to the surgical tool head (not shown). The active drive 50 extends from the drive source, passes through the proximal fixator 10 and the multiple curved joints 20, and extends to the distal fixator 30. The active drive 50 may not pass through the distal fixator 30, but only to the curved joint 20 connected to the distal fixator 30; alternatively, it may pass through the distal fixator 30.

[0044] It should be noted that the active drive component 50 is used to drive the movement of the instrument rod, and the material can be alloy wire, nickel-titanium alloy wire, tungsten wire rope, etc. The extension endpoint of the active drive component 50 can be selected differently depending on the drive source. For example, if there are few drive sources, the active drive component 50 extends directly to the farthest bending joint 20, such as... Figure 1A minimum of three active drive units 50 are needed to achieve four-directional bending of the instrument rod. If the number of drive sources is large, the number of active drive units 50 can be increased. Some active drive units 50 extend to the middle bending joint 20. Depending on the number of groups of active drive units 50, each group should have no fewer than three active drive units 50, enabling multiple sections of the instrument rod to bend in different directions. Driving the instrument rod in groups using active drive units 50 also has the advantage of solving the technical problem of S-shaped deformation caused by force on the instrument rod. Because the rotation directions between any two bending joints 20 may be opposite, each bending joint 20 needs to be driven individually by an active drive unit 50.

[0045] See Figure 2 and Figure 4 As shown, the bending joint 20 comprises a first rotating member 21, a second rotating member 22, and a rotating support rod 23. Both the first rotating member 21 and the second rotating member 22 have through holes in the middle, and the rotating support rod 23 is positioned within these through holes. The rotating support rod 23 has rotating spherical surfaces at both ends, and the through holes of both the first rotating member 21 and the second rotating member 22 have grooves that mate with the rotating spherical surfaces. These grooves are spherical or hemispherical, allowing the first rotating member 21 and the second rotating member 22 to rotate around the center of their respective rotating spherical surfaces. The rotating member structure includes a disk and a guide portion. The disk of the first rotating member 21 has a first guide portion 211 facing the second rotating member 22, and the disk of the second rotating member 22 has a second guide portion 221 facing the first rotating member 21. The first guide portion 211 is fitted onto the outside of the second guide portion 221. This structural design allows the first rotating member 21 and the second rotating member 22 to rotate based on the rotating spherical surface of the rotating support rod 23, enabling each of them to rotate independently relative to the rotating support rod 23. The first disk 212 and the second disk 222 have several holes at the same distance from their centers, allowing the active drive member 50 to pass through. When the first rotating member 21 and the second rotating member 22 rotate on the two rotating spherical surfaces of the rotating support rod 23 and are limited by the first guide portion 211 and the second guide portion 221, they can rotate symmetrically. When the first rotating member 21 and the second rotating member 22 achieve symmetrical rotation, the active drive member 50, located on the disks and passing through the symmetrical holes on both sides, has the same extension and retraction length, ensuring precise control of the active drive member 50 in the symmetrical direction by the drive source, making the bending angle and the position of the instrument rod controllable.

[0046] Furthermore, the first rotating member 21, the second rotating member 22, and the rotating support rod 23 all have a through-hole in the center, which forms a passageway through the bending joint 20, passing through the first guide portion 211, the second guide portion 221, and the two rotating spherical surfaces. The through-hole in the center of both the first rotating member 21 and the second rotating member 22 has two sections of channel, with a groove located at the connection between the first and second sections. The rotating support rod 23 is located within the first section of the channel of the first rotating member 21 and the second rotating member 22 and stops at the groove. The side of the second rotating member 22 closest to the first rotating member 21 is the first section of channel, and the end of the first section facing the second rotating member 22 is a flared opening. (See [reference]). Figure 4 .

[0047] Further, see Figure 3 and Figure 4 The connector 24 also has a hollow channel at its center, which connects to the passage of the bending joint 20. This makes the entire instrument rod pass through the central part from the proximal end to the distal end. This pass through part can be used to pass the cable or drive rope of the surgical tool head, which simplifies the structure of the instrument rod and helps to reduce the diameter of the instrument rod.

[0048] refer to Figure 5 As shown, when the bending joint 20 rotates, its first rotating member 21 and second rotating member 22 rotate symmetrically. Figure 5 Taking the cross-section shown as an example, auxiliary circles 2311 and 2321 are drawn with the center of the first rotating sphere 231 and the center of the second rotating sphere 232 as reference points. These two auxiliary circles have the same radius and are tangent to each other. In order to achieve symmetrical rotation of the first rotating component 21 and the second rotating component 22, the auxiliary circles 2311 and 2321 need to rotate purely during the rotation process without slippage. Under this motion mode, a fixed point is taken on the first rotating component 21. The trajectory of this point relative to the second rotating component 22 is a fixed arc. The cylindrical surface where this point is located is used as the first guide part 211 of the first rotating component 21, and the non-spherical surface where the fixed arc trajectory is located is used as the second guide part 221 of the second rotating component 22. In this way, the mutual cooperation of the first guide part 211 and the second guide part 221 limits the rotation mode of the first rotating component 21 and the second rotating component 22 to be symmetrical rotation.

[0049] It should be noted that a fixed point can also be selected on the second rotating component 22, and this fixed point has a fixed arc trajectory relative to the first rotating component 21. This is similar to... Figure 6 As shown, the first guide part 211 is a non-spherical circular surface, and the second guide part 221 is a cylindrical surface. It is understandable that the cylindrical surface where the fixed point is located is used as one of the guide parts to simplify the structure. The cylindrical surface can be replaced with an arc-shaped cylindrical surface or a spherical surface.

[0050] Furthermore, based on the symmetrical rotation of the bending joint 20, a passive constraint 40 is added to address the S-deformation of the lever. (See also...) Figure 2 and Figure 3 Multiple identical passive restraint members 40 are threaded onto the disks of each pair of adjacent bending joints 20. The passive restraint members 40 begin at one bending joint 20 and end at the adjacent bending joint 20. For example... Figure 2 As shown, when the instrument bar is in a straight extension state, one end of the passive constraint member 40 is connected to the first disk 212 of one of the curved joints 20. The passive constraint member 40 passes through the second disk 222 of the curved joint 20, and is wound around the connector 24 between the two curved joints 20. After rotating 180° around the connector 24, it continues to pass through the first disk 212 and the second disk 222 of the other curved joint 20. The other end of the passive constraint member 40 is connected to the second disk 222 of the other curved joint 20. With this scheme, the passive constraint member 40 passes through two adjacent sets of curved joints 20, linking the rotational relationship of the two curved joints 20 together. Because the passive constraint member 40 is wound 180° at the connector 24 between the two sets of curved joints 20, the path of the passive constraint member 40 in one set of curved joints 20 and the path in the other set of curved joints 20 are exactly on opposite sides of the axis of the instrument bar. This means that when one set of bending joints 20 bends to one side, the other set of bending joints 20 must also bend to the same side due to the unchanged length of the passive constraint member 40. This achieves the effect that adjacent bending joints 20 can bend to one side at the same time but cannot bend to different sides. This solves the technical problem of S-shaped deformation caused by force when the instrument rod is under load.

[0051] It should be noted that the passive constraint 40 can be wound in a uniform direction on the connector 24, or the passive constraint 40 located on both sides of the instrument rod can be a group of symmetrical passive constraint 40s wound in opposite directions.

[0052] The specific details of the S-deformation mentioned above need to be explained. Figure 3Taking the left-hand view as an example, when the instrument rod is initially straight, an external force is applied to the distal end of the instrument rod. This force is perpendicular to the instrument rod. The bending joint 20 at the point of force application and the adjacent bending joint 20 on the proximal side will jointly cause S-shaped deformation. Although the active drive member 50 is mounted on the instrument rod, its length relative to the bending joint 20 on the instrument rod is fixed when the drive source does not drive the active drive member 50. However, the active drive member 50 cannot avoid S-shaped deformation. This is because the active drive member 50 is mounted on the disc of the bending joint 20. Except for its fixed relationship with the disc of the distal bending joint 20, it is movable relative to the discs of the other bending joints 20. When subjected to external force, the active drive component 50 acts like the two longest opposite sides of a parallelogram. Even after the four interior angles of the parallelogram change, the lengths of the two longest opposite sides remain constant. This means that adjacent sets of bending joints 20 and the active drive component 50 passing through them form a parallelogram-like structure. When subjected to external force, the two bending joints 20 rotate, but the length of the active drive component 50 remains constant. In this scenario, the instrument rod undergoes an approximately S-shaped deformation after being subjected to external force, which is the technical problem of the S-shaped deformation of the instrument rod.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A surgical instrument shaft comprising a plurality of sets of bending joints (20) and a plurality of active drives (50), each set of bending joints (20) comprising a first rotary member (21) and a second rotary member (22), the plurality of active drives (50) passing through at least part of the rotary members, characterized in that, Each bending joint (20) further comprises a rotating support rod (23) having two ends movably connected to the first rotating member (21) and the second rotating member (22) respectively, the first rotating member (21) has a first guide portion (211) on the side facing the second rotating member (22), the second rotating member (22) has a second guide portion (221) on the side facing the first rotating member (21), the first guide portion (211) is sleeved outside the second guide portion (221), the first guide portion (211) and the second guide portion (221) cooperate to realize symmetrical rotation of the first rotating member (21) and the second rotating member (22), the rotating support rod (23) is arranged inside the first guide portion (211) and the second guide portion (221), and adjacent two groups of the bending joints (20) are connected through a connecting member (24).

2. A surgical instrument shaft as in claim 1, wherein, Further comprising a passive constraint member (40), each adjacent two groups of the bending joints (20) are provided with a plurality of same passive constraint members (40), the passive constraint member (40) starts from one bending joint (20) and ends at another adjacent bending joint (20); When the instrument rod is in a straight extension state, one end of the passive constraint member (40) is wound around the instrument rod by 180° compared with the other end along the straight extension direction of the instrument rod, and the winding position of the passive constraint member (40) is located at the connecting member (24) between the adjacent two groups of the bending joints (20).

3. A surgical instrument shaft as in claim 2, wherein, The first rotating member (21) and the second rotating member (22) have a disc, the disc has a plurality of through holes, and the active driving member (50) and the passive constraint member (40) pass through the through holes.

4. The surgical instrument shaft of claim 1, wherein, The first guide portion (211) has a non-spherical circular surface, and the second guide portion (221) has a cylindrical surface matched with the first guide portion (211); Or, the first guide portion (211) has a cylindrical surface, and the second guide portion (221) has a non-spherical circular surface matched with the first guide portion (211).

5. The surgical instrument shaft of claim 1, wherein, The rotating support rod (23) has two rotating spherical surfaces at the two ends, the first rotating member (21) and the second rotating member (22) respectively have grooves matched with the rotating spherical surfaces, the grooves are spherical or hemispherical, and the first rotating member (21) and the second rotating member (22) can rotate around the centers of the corresponding rotating spherical surfaces.

6. A surgical instrument shaft as recited in claim 5, wherein, The first rotating member (21), the second rotating member (22) and the rotating support rod (23) all have a middle through hole penetrating therethrough, the middle through hole constitutes a passage penetrating the bending joint (20), and the passage passes through the first guide portion (211), the second guide portion (221) and the two rotating spherical surfaces.

7. A surgical instrument shaft as in claim 6, wherein, The middle through hole of the first rotating member (21) and the second rotating member (22) has two sections of passages, the groove is arranged at the joint of the first section of passage and the second section of passage, the rotating support rod (23) is arranged in the first section of passage and stops at the groove, and the first section of passage of the second rotating member (22) close to one side of the first rotating member (21) is provided with the first section of passage, and one end of the first section of passage towards the second rotating member (22) is a horn mouth.

8. The surgical instrument shaft of claim 1, wherein, Further comprising a distal end fixing member (30) and a proximal end fixing member (10), the distal end fixing member (30) is fixed to one end of a plurality of the bending joints (20), the proximal end fixing member (10) is fixed to the other end of a plurality of the bending joints (20), and the active driving member (50) penetrates the proximal end fixing member (10).

9. The surgical instrument shaft of claim 6, wherein, The connecting member (24) has a hollow passage, and the hollow passage communicates the passage.

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