CN113171178B

CN113171178B - Snake-shaped joint, surgical instrument and endoscope

Info

Publication number: CN113171178B
Application number: CN202110443532.2A
Authority: CN
Inventors: 何裕源; 何超; 翟少朋
Original assignee: Shanghai Microport Medbot Group Co Ltd
Current assignee: Shanghai Microport Medbot Group Co Ltd
Priority date: 2021-04-23
Filing date: 2021-04-23
Publication date: 2023-09-22
Anticipated expiration: 2041-04-23
Also published as: WO2022223045A1; CN113171178A

Abstract

The invention relates to a snake-shaped joint, a surgical instrument and an endoscope, wherein the snake-shaped joint has at least one degree of freedom and comprises at least one joint connector, and the joint connector comprises a first joint, a second joint and a limiting mechanism; the first joint and the second joint are hinged through the limiting mechanism and form at least one pair of hinge axes, and at least one pair of hinge axes are not collinear. The surgical instrument or endoscope includes an instrument tip including a serpentine joint. The invention shortens the length of the snake-shaped joint and ensures that the snake-shaped joint has a larger movement range, thereby reducing the operation difficulty.

Description

Snake-shaped joint, surgical instrument and endoscope

Technical Field

The invention relates to the technical field of medical instruments, in particular to a snake-shaped joint, a surgical instrument and an endoscope.

Background

With the rapid development of robots, various robots with characteristics are continuously emerging, and research on bionic robots is more prominent, and research on snake-shaped robots is more and more. The root cause of the serpentine robot generation and development is that it can perform actions that a normal robot cannot do. The motion of the robot is similar to that of a snake in nature, plane torsion and space torsion can be realized, and obstacles are avoided in the motion process, so that tasks which cannot be completed by people or other machines are completed. In view of this feature, serpentine robots for medical procedures have also slowly emerged. Particularly, in the micro-wound operation process, because the wound is very small, in order to achieve better treatment effect, the damage to other tissues in the operation process is reduced, and the serpentine joint operation instrument is mostly adopted so as to avoid other organs in the operation process. This advantage allows the surgical instruments of the serpentine joint to be well used in the surgical field.

However, the existing surgical instrument needs a certain movement space to finish the swing of the joint at a certain angle, but when the space is narrow, the risk that the surgical instrument is difficult to operate due to movement interference of the surgical instrument exists. Not only this, in the snakelike joint that current surgical instruments used, the joint has passed through the structural connection of a kind of short connecting rod, and it can realize the torsion motion in space through different arrangement modes, but in the bending torsion process, have the joint length overlength when crooked the same angle demand, the motion precision is low, the structure is complicated, and a set of snake bone unit motion scope is little shortcoming.

Disclosure of Invention

In view of one or more of the above problems, an object of the present invention is to provide a snake-shaped joint, a surgical instrument and an endoscope, which solve the problems of long joint length, small movement range and the like of the existing snake-shaped joint.

In view of the above, the present invention provides a serpentine joint having at least one degree of freedom and comprising at least one articulation joint; the joint connector comprises a first joint, a second joint and a limiting mechanism; the first joint and the second joint are hinged through the limiting mechanism and form at least one pair of hinge axes, and at least one pair of hinge axes are not collinear.

Optionally, the first joint and the second joint are hinged through the limiting mechanism and form two pairs of hinge axes, and the two pairs of hinge axes are not collinear with each other; the two pairs of hinge axes comprise a first hinge axis, a second hinge axis, a third hinge axis and a fourth hinge axis;

the joint is provided with a first symmetrical surface and a second symmetrical surface, the first symmetrical surface is perpendicular to the second symmetrical surface, and the first hinge axis, the second hinge axis, the third hinge axis and the fourth hinge axis are all parallel to the first symmetrical surface; the first hinge axis and the second hinge axis are symmetrical about the first plane of symmetry and lie on the second plane of symmetry; the third hinge axis and the fourth hinge axis are symmetrical about the first plane of symmetry and are on the same side of the second plane of symmetry;

wherein: the height of the joint satisfies the following relationship:

d is the diameter of the joint; θ is the unilateral maximum bending angle of the joint; s is the thickness of the reserved structural strength of each joint; h is the height of the joint; m is 2 times the vertical distance from the third hinge axis or the fourth hinge axis to the second symmetry plane; n is 2 times the perpendicular distance of the third hinge axis or the fourth hinge axis to the first plane of symmetry.

Optionally, the limiting mechanism includes a first connecting portion and a second connecting portion, and the first joint includes a first hinge portion and a second hinge portion; the second joint comprises a third hinge part and a fourth hinge part;

the first hinge part is hinged with the first connecting part and forms the first hinge axis;

the second hinge part is hinged with the second connecting part and forms the second hinge axis;

the third hinge part is hinged with the first connecting part and forms the third hinge axis;

the fourth hinge portion is hinged with the second connecting portion and forms the fourth hinge axis.

Optionally, the first joint comprises a first joint base and a first articulation block; the second joint comprises a second joint base and a second hinge block; the first hinge block is detachably arranged on the first joint base; the second hinge block is detachably arranged on the second joint base, and the first hinge part and the second hinge part are arranged on the first hinge block; the third hinge portion and the fourth hinge portion are disposed on the second hinge block.

Optionally, the first hinge block includes a first positioning boss and a first extension, and the second hinge block includes a second positioning boss and a second extension;

The first joint base is provided with a first through central channel; the second joint base is provided with a second through central channel; the first central channel and the second central channel are provided with step surfaces; the first positioning boss is matched with the step surface of the first central channel, and the second positioning boss is matched with the step surface of the second central channel;

the first hinge part and the second hinge part are arranged on the first extension part, and the third hinge part and the fourth hinge part are arranged on the second extension part;

the first extension portion and the second extension portion are disposed between the first connection portion and the second connection portion, and one end of the first extension portion abuts against one end of the second extension portion.

Optionally, the limiting mechanism includes a connecting portion, and the first joint and the second joint are hinged by one connecting portion and form a pair of hinge axes;

the first joint comprises one hinge part, the second joint comprises another hinge part, and the one hinge part is hinged with the one connecting part and forms a hinge axis; the other hinge part is hinged with the one connecting part and forms another hinge axis; the one hinge axis and the other hinge axis are the first hinge axis and the third hinge axis, respectively, or the one hinge axis and the other hinge axis are the second hinge axis and the fourth hinge axis, respectively;

The first joint comprises a first limiting part; the second joint comprises a second limiting part; the first limiting parts are two and are symmetrically arranged relative to the first symmetrical plane; the second limiting parts are two and are symmetrically arranged relative to the first symmetrical plane; the first limiting parts and the second limiting parts are matched in a group of sliding way; one of the first limiting part and the second limiting part is an arc-shaped chute, the other one is a sliding column boss, and the arc-shaped chute is determined according to the track of the second joint or the track of the first joint when the first joint rotates towards the first direction and the second direction.

Optionally, the joint further comprises an anti-falling mechanism for limiting the position of the limiting mechanism.

Optionally, the limiting mechanism includes a first connecting portion and/or a second connecting portion; the first joint and the second joint are hinged by the first connecting part and form a pair of hinge axes, and/or the first joint and the second joint are hinged by the second connecting part and form another pair of hinge axes;

the anti-falling mechanism comprises a first stop block and a second stop block; the first stop block is detachably arranged on the first joint; the second stop block is detachably arranged on the second joint; one end of the first stop block is abutted with one end of the second stop block and is positioned between the first connecting part and the second connecting part, and the first stop block and the second stop block respectively resist the first connecting part and/or the second connecting part through the side surfaces.

Optionally, each stopper has a threading hole allowing the traction body to pass through, the threading hole is communicated with an arc-shaped guide wire slideway in the stopper, a transition cambered surface is arranged at a wire outlet of the arc-shaped guide wire slideway, and the bending radius of the transition cambered surface is larger than that of the rest part of the arc-shaped guide wire slideway.

Optionally, the first joint further has a first motion limiting surface and a second motion limiting surface, and the second joint further has a third motion limiting surface and a fourth motion limiting surface;

the first motion limiting surface is used for being matched with the third motion limiting surface so as to limit the maximum angle of the joint when the joint rotates towards the first direction;

the second motion limiting surface is used for being matched with the fourth motion limiting surface so as to limit the maximum angle when the joint connector rotates towards the second direction.

Optionally, the serpentine joint is deflected by a maximum angle of 140 ° in the first direction and by a maximum angle of 140 ° in the second direction.

Optionally, the first joint comprises a first threading channel, the second joint comprises a second threading channel, and the position of the second threading channel corresponds to the position of the first threading channel;

The outlet of the first threading channel is provided with an arc-shaped first guide surface, the bending radius of the first guide surface is larger than that of the rest of the first threading slideway, and/or the outlet of the second threading channel is provided with an arc-shaped second guide surface, and the bending radius of the second guide surface is larger than that of the rest of the second threading slideway.

Optionally, the first joint includes a first locating feature and a second locating feature, and the second joint includes a third locating feature and a fourth locating feature; one of the first locating feature and the second locating feature is a protrusion, and the other is a recess; one of the third positioning feature and the fourth positioning feature is a protrusion, and the other is a groove;

the first joint is configured to mate with an adjacent joint by the first and second locating features; the second joint is configured to mate with an adjacent joint head via the third and fourth locating features.

Optionally, the serpentine joint comprises two of the articulation joints, the two articulation joints being arranged in parallel or staggered.

The invention also provides a surgical instrument comprising an instrument end, an instrument rod and an instrument box which are connected in sequence, wherein the instrument end comprises an end instrument and a snake-shaped joint of any one, and the end instrument is connected with the instrument rod through the snake-shaped joint.

Based on the above object, the present invention also provides an endoscope, comprising an instrument end, an instrument bar and an instrument box, which are sequentially connected, wherein the instrument end comprises a probe and any snake-shaped joint, and the probe is connected with the instrument bar through the snake-shaped joint.

In the snake-shaped joint, the surgical instrument and the endoscope thereof provided by the invention, the two joints are articulated through the limiting mechanism to form at least one pair of non-collinear articulated axes, so that the snake-shaped joint is constructed as the offset hinge point connecting rod mechanism, the length of the snake-shaped joint is effectively shortened, and the snake-shaped joint has a larger deflection angle, so that the risk of motion interference of the surgical instrument or the endoscope in the process of surgery in a narrow space can be reduced, and the operation difficulty of the instrument is reduced.

In the snake-shaped joint, the surgical instrument and the endoscope thereof provided by the invention, the snake-shaped joint is provided with two pairs of mutually misaligned hinge axes, and the two pairs of hinge axes are arranged according to certain requirements, so that the length of the snake-shaped joint is shortened, the constant deflection angle is realized, and the larger deflection angle is realized.

In the snake-shaped joint, the surgical instrument and the endoscope thereof provided by the invention, the limiting mechanism can be blocked by arranging the anti-falling mechanism on the snake-shaped joint, so that the limiting mechanism is prevented from sliding off at the hinge position, and the safety and the reliability of the surgical instrument or the endoscope are improved.

In the snake-shaped joint, the surgical instrument and the endoscope thereof, the transmission precision of the snake-shaped joint is improved and the service life of the traction body is ensured by arranging the arc-shaped guide surface or transition surface at the outlet of the threading channel or the guide wire slideway of the snake-shaped joint.

Drawings

FIGS. 1a and 1b are an exploded view and an assembled view, respectively, of a serpentine joint according to a first embodiment of the present invention;

fig. 2a and 2b are an exploded elevation view and an assembled elevation view, respectively, of a serpentine joint of a first embodiment of the present invention.

FIGS. 3a and 3b are a schematic representation of a first joint of a serpentine joint of a first embodiment of the present invention, on a reverse side and a schematic representation on a front side, respectively;

FIGS. 4a and 4b are schematic front and back views, respectively, of a second joint of the serpentine joint of the first embodiment of the present invention;

FIGS. 5a and 5d are schematic views of a block of a serpentine joint according to a first embodiment of the present invention, wherein FIG. 5a is an isometric view of the block, FIG. 5b is a top view of the block, FIG. 5c is a cross-sectional view axially cut along the length of one of the wire-passing holes of the block, and FIG. 5d is a cross-sectional view axially cut along the width of both wire-passing holes of the block;

FIG. 6a is a schematic illustration of the geometry of a serpentine joint of a first embodiment of the present invention;

FIG. 6b is a schematic illustration of the geometry of a serpentine joint of a comparative embodiment of the present invention;

FIGS. 7a and 7b are schematic cross-sectional views of a serpentine joint lateral threading channel of a first embodiment of the present invention, wherein FIG. 7a is a front view and FIG. 7b is an isometric view;

FIGS. 8a and 8b are schematic cross-sectional views of the internal passages of the stop on the serpentine joint of the first embodiment of the present invention, wherein FIG. 8a is a front view and FIG. 8b is an isometric view;

FIGS. 9a and 9b are schematic cross-sectional views of a first embodiment of the invention after threading of the inner channel of the stop in the serpentine joint, wherein FIG. 9a is an isometric view and FIG. 9b is an isometric view;

FIGS. 10a and 10b are an assembled view and an exploded view, respectively, of two vertically staggered articulation joints, the axes of rotation of which are vertically staggered (i.e., out-of-plane), in accordance with a first embodiment of the present invention;

FIGS. 11a and 11b are an assembled view and an exploded view, respectively, of a second joint of two staggered arrangements according to a first embodiment of the invention;

FIGS. 12a and 12b are, respectively, a surgical instrument employing two vertically staggered articulation joints in a null position in accordance with a first embodiment of the present invention, wherein FIG. 12b is an enlarged view of a portion of the surgical instrument illustrated in FIG. 12 a;

FIGS. 13a and 13b are, respectively, a surgical instrument employing two vertically staggered articulation joints in a curved state in accordance with a first embodiment of the present invention, wherein FIG. 13b is an enlarged view of a portion of the surgical instrument illustrated in FIG. 13 a;

FIGS. 14a and 14b are an assembled view and an exploded view, respectively, of two parallel articulation joints according to a first embodiment of the present invention;

FIGS. 15a and 15b are an assembled view and an exploded view, respectively, of a first joint and a second joint in two parallel arrangements according to a first embodiment of the invention;

FIGS. 16a and 16b are, respectively, a surgical instrument employing two parallel articulation joints in a flexed state according to a first embodiment of the present invention, wherein FIG. 16b is an enlarged view of a portion of the surgical instrument shown in FIG. 16 a;

FIGS. 17a and 17b are, respectively, a laparoscope employing two parallel articulation joints in a curved state according to a first embodiment of the present invention, wherein FIG. 17b is an enlarged view of a portion of the surgical instrument illustrated in FIG. 17 a;

FIG. 18a is a schematic view of a serpentine joint of a first embodiment of the present invention in a null position;

FIG. 18b is a schematic view of a serpentine joint of a comparative embodiment of the present invention in a null position;

FIG. 19a is a schematic view of a first embodiment of the serpentine joint of the present invention rotated 90 from zero;

FIG. 19b is a schematic view of a serpentine joint of a comparative embodiment of the present invention rotated 90 from zero;

FIG. 20a is a schematic view of a first embodiment of the serpentine joint of the present invention rotated 45 from zero;

FIG. 20b is a schematic view of a serpentine joint of a comparative embodiment of the present invention rotated 45 from zero;

FIGS. 21a and 21b are schematic illustrations of a serpentine joint having increased degrees of motion, respectively, of a first embodiment of the present invention, wherein the serpentine joint of FIG. 21a is in a null position and the serpentine joint of FIG. 21b is rotated from a null position to a maximum angle;

FIGS. 22a and 22b are respectively an assembled schematic view and an exploded schematic view of a serpentine joint according to a second embodiment of the present invention;

FIGS. 23a and 23b are, respectively, front views of a serpentine joint of a second embodiment of the present invention, wherein the serpentine joint of FIG. 23a is in a null position and the serpentine joint of FIG. 23b is offset by an angle relative to the null position;

FIGS. 24a and 24b are respectively an assembled schematic view and an exploded schematic view of a serpentine joint according to a third embodiment of the present invention;

FIG. 25 is an exploded view of a serpentine joint of a third embodiment of the present invention;

fig. 26a and 26b are an assembled view and an exploded view, respectively, of a serpentine joint of a third embodiment of the present invention at an elevation angle.

In the figure:

1-instrument tip; 2-an instrument bar; 3-an instrument box; 11-an opening and closing device; 12-laparoscopic probe;

10. 10' -serpentine joints; 11' -joint;

101-a first stop; 1011-a substrate; 1011 a-positioning boss; 1011 b-extensions; 1012 a-a first stop surface; 1012 b-a second limiting surface; 1013 a-a first wire hole; 1013 b-a second wire hole; 1014 a-a first guidewire slide; 1014 b-a second guidewire slide; 1015-transitional cambered surface; 1015 a-a first transitional cambered surface; 1015 b-a first transitional cambered surface;

102-first joint; 1021-a first hinge; 1022-a second hinge; 1023 a-a first motion limiting surface; 1023 b-a second motion limiting surface; 1024-a first threading channel; 1025—a first positioning feature; 1026-a second positioning feature; 1027-a first central passage; 1028—a first guide surface;

103-a first connection; 1031-first reaming; 1032-second reaming; 104-a second connection; 1041-third reaming; 1042-fourth reaming;

105-second joint; 1051-third hinge; 1052-fourth hinge; 1053 a-third motion stop surface; 1053 b-fourth motion stop surface; 1054-a second threading channel; 1055-a third positioning feature; 1056-fourth positioning feature; 1057-a second central passage; 1058-second guide surface; 1058a, 1058 b-the location of the second guide surface;

106-a second stop;

13-channel serpentine joints; 131-channel type first joint; 1311-arc chute; 132-a channel type second joint; 1321-strut boss;

14-internal articulating serpentine joint; 141-a first hinge block; 141 a-first positioning boss; 141 b-a first extension; 1411-a first hinge; 1412-second hinge; 142-a first joint base; 143-a second joint base; 144-second hinge block; 144 a-a second positioning boss; 144 b-a second extension; 1441-third hinge; 1442-fourth hinge; 1421-first positioning step; 1451-a second positioning step;

100-a first traction body; 200-a second traction body; 300-a third traction body; 400-fourth traction body; 500-fifth traction body; 600-sixth traction body;

a-a first hinge point; b-a second hinge point; c. e-a third hinge point; d. f-fourth hinge point; h. g-limit position of joint deflection;

r1-a first hinge axis; r2-a second hinge axis; r3-a third hinge axis; r4-fourth hinge axis.

Detailed Description

The invention is described in further detail below with reference to the drawings and the specific examples. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention. In particular, the drawings are required to show different emphasis instead of different proportions.

In the present application, "proximal" and "distal", "lower" and "upper" are relative orientations, relative positions, directions of elements or actions relative to each other from the perspective of a physician using the instrument, although "proximal" and "distal", "lower" and "upper" are not limiting, the "proximal", "lower" and "lower" generally refer to the end of the medical device that is proximal to the physician during normal operation, and "distal", "upper" generally refer to the end that first enters the patient. It should be understood that although the terms first, second, third, fourth, fifth, sixth, etc. may be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first component discussed below could be termed a second component without departing from the teachings of the present application.

It is an object of the present application to provide a serpentine joint having at least one degree of freedom and comprising at least one articulation joint, the articulation joint comprising a first articulation, a second articulation and a spacing mechanism, the first articulation and the second articulation being articulated by the spacing mechanism and forming at least one pair of articulation axes, and at least one pair of the articulation axes being non-collinear. Compared with the prior art, the application shortens the length of the snake-shaped joint, and simultaneously ensures that the joint has a larger deflection angle, namely a larger movement range, for example, the application shortens the length of the snake-shaped joint and simultaneously ensures the same deflection angle with the existing snake-shaped joint. The existing snake-shaped joint increases the joint length to ensure a larger deflection angle, but the increase of the joint length can cause interference when an instrument using the snake-shaped joint moves in a small space area, so that the operation of the instrument becomes difficult. The application can ensure the joint to have a larger deflection angle even if the joint length is reduced, so that the device using the snake-shaped joint has a larger movement space, and even if the device moves in a region with a small space, the device is not easy to generate movement interference, so that the operation of the device is easy.

It is another object of the present invention to provide a surgical instrument comprising an instrument end, an instrument bar and an instrument box connected in sequence, said instrument end comprising an end instrument and at least one of said serpentine joints, said end instrument being connected to said instrument bar by said serpentine joint. Because the length of the snake-shaped joint is shortened, the length of the tail end joint of the surgical instrument is shortened, the deflection angle of the tail end instrument joint can be kept unchanged, and the surgical instrument has a larger movement range, so that the risk of movement interference of the surgical instrument in the movement of a narrow space area can be reduced in the surgical process, and the operation difficulty of the surgical instrument is reduced.

It is a further object of the present invention to provide an endoscope comprising an instrument tip, an instrument shaft and an instrument box connected in sequence, the instrument tip comprising a probe and at least one of the serpentine joints, the probe being connected to the instrument shaft by the serpentine joint. Because the length of the snake-shaped joint is shortened, the length of the tail end joint of the endoscope is shortened, the deflection angle of the tail end joint can be kept unchanged, and the movement range is larger, so that the risk of movement interference of the endoscope in the movement of a narrow space area in the operation process can be reduced, and the operation difficulty is reduced.

< first embodiment >

Referring to fig. 1 a-1 b, fig. 2 a-2 b, fig. 5 a-5 b, and fig. 8 a-10 b, the present embodiment provides a serpentine joint 10 having at least one degree of freedom and comprising at least one articulation joint comprising a first articulation 102, a second articulation 105, and a limiting mechanism. The first joint 102 and the second joint 105 are articulated by the spacing mechanism and form at least one pair of articulation axes that are not collinear. The function of the limiting mechanism is herein to define the relative position between the first joint 102 and the second joint 105 and to enable the first joint 102 and the second joint 105 to rotate relative to each other.

In this embodiment, the limiting mechanism includes a first connecting portion 103 and a second connecting portion 104, and of course, in other embodiments, the limiting mechanism may also include one of the first connecting portion 103 and the second connecting portion 104, that is, the first joint 102 and the second joint 105 may be hinged through the first connecting portion 103 and form a pair of non-collinear hinge axes, may be hinged through the second connecting portion 104 and form a pair of non-collinear hinge axes, and may also be hinged through the first connecting portion 103 and the second connecting portion 104 and form two pairs of non-collinear hinge axes at the same time.

For convenience of description, the following description will be schematically illustrated with the limiting mechanism including the first connecting portion 103 and the second connecting portion 104.

Referring to fig. 4a to 4b, the first joint 102 includes a first hinge 1021 and a second hinge 1022, the first hinge 1021 and the second hinge 1022 are disposed opposite to each other, and axes of the two hinges are parallel and not collinear.

Referring to fig. 3 a-3 b, the second joint 105 includes a third hinge 1051 and a fourth hinge 1052, the third hinge 1051 and the fourth hinge 1052 are disposed opposite to each other, and the axes of the two hinges are parallel and non-collinear.

Referring back to fig. 1a, the first hinge 1021 is hinged with the first connection 103 and forms a first hinge axis R1; the second hinge 1022 is hinged with the second connection 104 and forms a second hinge axis R2; the first connecting portion 103 is rotatable about a first hinge portion 1021; the second connecting portion 104 is rotatable about a second hinge 1022; the third hinge 1051 is hinged with the first connection 103 and forms a third hinge axis R3; the fourth hinge portion 1052 is hinged with the second connection portion 104 and forms a fourth hinge axis R4; the first connection part 103 is rotatable around a third hinge part 1051; the second connection 104 is rotatable about a fourth hinge 1052. The first, second, third and fourth hinge axes R1, R2, R3 and R4 are parallel to each other and do not coincide. Furthermore, for ease of understanding, the positions of the first, second, third and fourth hinge axes R1, R2, R3 and R4 are generally shown in fig. 1b, which should be determined from the assembly relationship shown in fig. 1 a.

In some embodiments, the first hinge 1021 and the second hinge 1022 are protruding portions, the third hinge 1051 and the fourth hinge 1052 are protruding portions, respectively, the first connection 103 is provided with a first hinge hole 1031 and a second hinge hole 1032, the second connection 104 is provided with a third hinge hole 1041 and a fourth hinge hole 1042, the first hinge 1021 is hinged in the first hinge hole 1031 (corresponding to the first hinge axis R1), the second hinge 1022 is hinged in the third hinge hole 1041 (corresponding to the second hinge axis R2), the third hinge 1051 is hinged in the second hinge hole 1032 (corresponding to the third hinge axis R3), and the fourth hinge 1052 is hinged in the fourth hinge hole 1042 (corresponding to the fourth hinge axis R4). Alternatively, the first hinge 1021, the second hinge 1022, the third hinge 1051 and the fourth hinge 1052 are all holes, and the first connecting portion 103 and the second connecting portion 104 are provided with corresponding protruding portions. For this purpose, the first joint 102 and the second joint 105 are articulated by two connection portions and form four articulation points, i.e. four articulation axes, so that the relative positions of the two joints are defined by the articulation of the first connection portion 103 and the second connection portion 104 with the two joints, and the two joints are able to rotate relative to each other. The structures of the first connecting portion 103 and the second connecting portion 104 may be the same or different, and preferably the same structure.

Referring to fig. 6a, 18a, 19a and 20a, the four hinge points are a first hinge point a, a second hinge point b, a third hinge point c and a fourth hinge point d, respectively. From the perspective shown in fig. 1a, the first hinge point a is a hinge point (a third hinge axis R3) formed by the second joint 105 and the first connection portion 103, the second hinge point b is a hinge point (a fourth hinge axis R4) formed by the second joint 105 and the second connection portion 104, the third hinge point c is a hinge point (a first hinge axis R1) formed by the first joint 102 and the first connection portion 103, and the fourth hinge point d is a hinge point (a second hinge axis R2) formed by the first joint 102 and the second connection portion 104.

Referring to fig. 6b, 18b, 19b and 20b, the present embodiment further provides a conventional serpentine joint 10 'as a comparative example, wherein two joints 11' of the serpentine joint 10 'are hinged and form two hinge axes (i.e., 2 hinge points) which are disposed in line, which is referred to as a single hinge serpentine joint 10'. Unlike the single-hinge serpentine joint 10', the serpentine joint 10 of the present embodiment is a double-hinge structure (4 non-collinear hinge axes) and the length of the joint is significantly reduced.

With continued reference to FIG. 6b, the existing serpentine joint 10' has a height H0 and satisfies the following relationship:

d is the diameter of the joint; θ is the unilateral maximum bending angle (i.e., unilateral maximum rotation angle) of the joint; s is the thickness of the joint that reserves the structural strength, and the value of S may be zero but is usually greater than zero. Typically D, θ, S are known fixed values, so the height H0 of the single-hinge serpentine joint 10' can be uniquely determined.

Referring to FIG. 6a, when the present application employs a dual hinge serpentine joint 10, if it is desired to achieve the yaw angle of the existing single hinge serpentine joint 10', thenThe serpentine joint 10 has a height H and satisfies the following relationship:

wherein: m is 2 times the vertical distance from the third hinge axis R3 or the fourth hinge axis R4 to the upper and lower symmetry plane (i.e., the second symmetry plane), that is, m=2h1, h1 is the vertical distance from the third hinge point c and the fourth hinge point d to the upper and lower symmetry plane (i.e., the second symmetry plane) of the joint, respectively; n is 2 times the perpendicular distance of the third hinge axis R3 or the fourth hinge axis R4 to the bilateral symmetry plane (i.e. the first symmetry plane), i.e. n is the perpendicular distance between the fourth hinge point d and the third hinge point c.

It will be appreciated that the first hinge point a and the second hinge point b are symmetrical about the plane of bilateral symmetry of the serpentine joint 10, while the first hinge point a and the second hinge point b lie on the plane of superior-inferior symmetry and the fourth hinge point d and the third hinge point c are symmetrical about the plane of bilateral symmetry. In more detail, the serpentine joint 10 has a first symmetry plane and a second symmetry plane, the left-right symmetry plane being the first symmetry plane and the up-down symmetry plane being the second symmetry plane from the perspective shown in fig. 6a, such that the first symmetry plane is perpendicular to the second symmetry plane, and both the first symmetry plane and the second symmetry plane are perpendicular to the plane of rotation of the serpentine joint 10. Wherein, the axes (i.e. the hinge axes) at the four hinge points are all parallel to the first symmetry plane, i.e. the first hinge axis R1, the second hinge axis R2, the third hinge axis R3 and the fourth hinge axis R4 are all parallel to the left-right symmetry plane of the joint.

Therefore, according to equation (2), the height H of the serpentine joint 10 provided in the present embodiment is smaller than the height H0 of the existing serpentine joint 10'.

In this way, the serpentine joint 10 of the present embodiment can effectively shorten the length of the serpentine joint while realizing the constant joint deflection angle θ. Further, when the serpentine joint 10 is applied to a surgical instrument or an endoscope, the length of the joint at the tail end of the surgical instrument or the endoscope can be effectively shortened, so that the risk of motion interference when the surgical instrument or the endoscope moves in a narrow space area is reduced, the operation difficulty of the instrument is reduced, and even if the joint length is shortened, a larger motion range can be still obtained, and the operation difficulty is reduced.

With continued reference to fig. 6a, in this embodiment, the second joint 105 and the first joint 102 can be exchanged, and the same effect can be achieved, and at this time, the third hinge point c and the fourth hinge point d are respectively the hinge points e and f, the hinge points c and e are symmetrical about the upper and lower symmetry planes, the hinge points d and f are symmetrical about the upper and lower symmetry planes, and the hinge points e and f are symmetrical about the left and right symmetry planes. It should also be appreciated that referring to fig. 6a and 19a, when the first joint 102 is rotated to the left limit position, the original third hinge point c moves to the point h, and when the first joint 102 is rotated to the right limit position, the original fourth hinge point d moves to the point g, and the arcs of d-g and c-h are the motion trajectories of the first joint 102.

Referring to fig. 21a and 21b, the serpentine joint 10 provided in this embodiment not only has a reduced length, but also has a large deflection angle, thereby ensuring a large range of motion, for example, a single-sided rotation angle of the first joint 102 and the second joint 105 of up to 140 degrees, such that the range of motion of the joint is up to 280 degrees (i.e., ±140°). In the existing single-hinge serpentine joint 10', if the same movement range as that of the present embodiment is to be achieved, the joint length must be increased, and meanwhile, the movement space of the instruments in a narrow space is reduced, so that the movement interference between the instruments is easily caused, and the operation difficulty is increased.

Further preferably, the serpentine joint 10 further comprises an anti-falling mechanism for limiting the position of the limiting mechanism, so as to prevent the limiting mechanism from falling off from the hinge, thereby improving the safety and reliability of the hinge.

Referring to fig. 1a, and fig. 7a and 8b, the anti-drop mechanism may include a first stop 101 and a second stop 106; the first stop block 101 is detachably arranged on the first joint 102; the second stop block 106 is detachably arranged on the second joint 105; the first stop block 101 and the second stop block 106 are configured to be disposed between two connecting portions, further, one end of the first stop block 101 and one end of the second stop block 106 may abut against each other (including abutting), one end of the first stop block 101 and one end of the second stop block 106 may be cambered surfaces, and the two stop blocks may rotate relatively. In use, the first stop block 101 blocks the two connecting portions through two opposite sides, and the second stop block 106 also blocks the two connecting portions through two opposite sides, so as to prevent the first connecting portion 103 and the second connecting portion 104 from falling off from the hinge. The first stop 101 and the second stop 106 may be identical or different, and preferably are identical in structure, so as to simplify the configuration of parts and reduce the manufacturing cost.

Here, the first block 101 is mainly taken as an example, the structure of the two blocks is further described, and the structure of the second block 106 may refer to the first block 101.

Referring to fig. 5a to 5d, in combination with fig. 1a, the first stopper 101 may include a base 1011, and the base 1011 has a first limiting surface 1012a and a second limiting surface 1012b.

Referring to fig. 4a and 3b, the first joint 102 further includes a first central passage 1027 therethrough, and the second joint 105 also includes a second central passage 1057 therethrough. The first central passage 1027 is used for positioning and mounting the first stopper 101. The second central passage 1057 is used for positioning and mounting the second stop 106. The shape of the first central passage 1027 preferably matches the shape of the base 1011 of the first stopper 101. The shape of the second central passage 1057 preferably matches the shape of the base of the second stop 106. The central channel of each joint is provided with a step for positioning and placing a stop block.

With continued reference to fig. 4a in combination with fig. 1a, the base 1011 of the first stop 101 is configured to fit into the first central channel 1027 of the first joint 102 to effect a positioning fixation. Referring to fig. 5a, the base 1011 of the first stop 101 may further include a positioning boss 1011a and an extension 1011b, wherein the positioning boss 1011a is used for positioning at the step surface of the first joint 102, and the extension 1011b is located between the two connection parts. The two opposite sides of the extension 1011b form a first limiting surface 1012a and a second limiting surface 1012b, which respectively block the two connecting parts.

Further, on the first stop 101, generally in the middle of the first stop 101, a plurality of threading holes are provided, wherein the threading holes are used for allowing the traction body for controlling the movement of the end instrument to pass through, and the traction body passes through the serpentine joint 10 mainly for controlling the movement of the end instrument. The number of the threading holes on the stop block is determined according to the number of the traction bodies for controlling the movement of the tail end instrument, and when the number of the traction bodies is multiple, the traction bodies can penetrate through the same threading hole on the stop block or penetrate through different threading holes on the stop block respectively. For example, in fig. 5b, in this embodiment, the first threading hole 1013a and the second threading hole 1013b are provided in the middle of the first stop block 101, so that two traction bodies can be penetrated, each threading hole only allows to penetrate one traction body, and the two traction bodies can control the opening, closing, deflection, and other movements of the end instrument.

Further, an arc-shaped wire guide slideway is arranged in the first stop block 101 and/or the second stop block 106 and is communicated with the wire through hole on the stop block. The arc-shaped guide wire slideway allows the traction body penetrating through the first stop block 101 and/or the second stop block 106 to twist a certain angle to penetrate out of the snake-shaped joint 10, so that 2 snake-shaped joints 10 can be arranged in a staggered manner, and the difficulty of joint staggered arrangement is reduced.

Referring to fig. 5 a-5 b, and fig. 9 a-9 b, an arc-shaped first guide wire slide 1014a and second guide wire slide 1014b are disposed inside the first stopper 101. Similarly, two arc-shaped guide wire slides (a third guide wire slide and a fourth guide wire slide) are preferably arranged in the second stop block 106. Referring to fig. 9a and 9b, the first wire slide 1014a of the first stop 101 corresponds in position to the third wire slide of the second stop 106 to allow the first pulling body 100 to pass through the first wire slide 1014a and the third wire slide, and the second wire slide 1014b of the first stop 101 corresponds in position to the fourth wire slide of the second stop 106 to allow the second pulling body 200 to pass through the second wire slide 1014b and the fourth wire slide. Therefore, each traction body can be twisted by a certain angle through the guide wire slideway, for example, the traction body can be twisted by 90 degrees, so that the staggered arrangement of 2 snake-shaped joints 10 is ensured. The shape of the guide wire slideway is generally matched to the outer contour of the traction body.

Further, each guide wire slideway is provided with a wire inlet and a wire outlet, the wire inlet is the position where the traction body penetrates into the stop block, and the wire outlet is the position where the traction body penetrates out of the stop block. It should be noted that, for each block, the inlet of the corresponding guide wire slideway is defined as a wire inlet and the outlet is defined as a wire outlet when the external traction body firstly penetrates into and out of the block. Preferably, referring to fig. 5d, a transition arc 1015 is provided at the wire outlet of each guide wire slideway, and the radius of curvature of the transition arc 1015 is larger than the radius of curvature of the rest of the guide wire slideway. Thus, the presence of the transition profile 1015 may provide the traction body with as large a radius of curvature as possible to increase the useful life of the traction body. Referring to fig. 8a, in this embodiment, a first transitional arc surface 1015a is disposed at the wire outlet of the first wire guide track 1014a, and a second transitional arc surface 1015b is disposed at the wire outlet of the second wire guide track 1014b. Correspondingly, as shown in fig. 8b, a transition cambered surface is disposed at the wire outlet of each wire guide rail of the second stop block 106, that is, the transition cambered surface of the second stop block 106 is disposed at the position indicated by S1 and S2.

Referring to fig. 4a and 4b, the first joint 102 also has a first motion limiting surface 1023a and a second motion limiting surface 1023b. Referring to fig. 3a and 3b, the second joint 105 further has a third motion stop surface 1053a and a fourth motion stop surface 1053b. The maximum angle of deflection of the serpentine joint 10 toward one side (e.g., first direction) is defined by the cooperation of the first motion stop surface 1023a and the third motion stop surface 1053a, and the maximum angle of deflection of the serpentine joint 10 toward the other side (e.g., second direction) is defined by the cooperation of the second motion stop surface 1023b and the fourth motion stop surface 1053b. Thus, the first motion stop surface 1023a, the second motion stop surface 1023b, the third motion stop surface 1053a, and the fourth motion stop surface 1053b collectively determine the range of rotation of the first joint 102 relative to the second joint 105. Each motion limiting surface is a cambered surface.

With continued reference to fig. 4a and 4b, the first joint 102 also has a first wire passage 1024, and the exit of the first wire passage 1024 preferably has an arcuate first guide surface 1028. With continued reference to fig. 3a and 3b, the second joint 105 also has a second threading channel 1054, and the exit of the second threading channel 1054 preferably has an arcuate second guide surface 1058. These threading channels function to thread the traction body that controls the movement of the serpentine joint. Here, for each joint, the direction when the external traction body first penetrates from the joint is the outlet of the corresponding threading channel. The first and second threading channels 1024, 1054 correspond in position to allow the same tractor to pass through the second joint 105 and the first joint 102 in sequence. In addition, the existence of the guide surface can enable the traction body to have the bending radius as large as possible, so that abrasion in the using process is reduced, and the service life of the traction body is prolonged.

Referring to fig. 7a, two arc-shaped second guiding surfaces 1058a and 1058b are disposed at the outlet of the second threading channel 1054, and two arc-shaped first guiding surfaces (not shown) may also be disposed at the outlet of the first threading channel 1024. The arrangement of the arc-shaped guide surface makes the traction body have the bending radius as large as possible (increases the guide radius) so as to improve the service life of the traction body, and on the other hand, avoids the reduction of the service life of the traction body caused by sharp turning of the surface, and can also make the elongation of the third traction body 300 (the broken line of which illustrates the third traction body 300 in fig. 7 a) basically equal to the shortening of the fourth traction body 400 (the broken line of which illustrates the fourth traction body 400 in fig. 7 a) so as to improve the transmission precision. Both the third traction body 300 and the fourth traction body 400 are used to control the movement of the serpentine joint. It should be appreciated that the number of threading channels is determined by the number of serpentine joints 10 to be controlled, and in general, if only one serpentine joint 10 is controlled, only 2 centrosymmetric threading channels need to be reserved, if two serpentine joints 10 in a vertically staggered arrangement need to be controlled, more than 3 threading channels need to be reserved, and the centers of the 3 threading channels are not collinear.

Referring to fig. 4a and 4b, the first joint 102 also has a first positioning feature 1025 and a second positioning feature 1026. Referring to fig. 3a and 3b, the second joint 105 also has a third positioning feature 1055 and a fourth positioning feature 1056. One of the first and second locating features 1025, 1026 is a protrusion and the other is a recess. One of the third and fourth locating features 1055, 1056 is a protrusion and the other is a recess. The design of these positioning features allows two adjacent articulating joints to be placed in parallel or staggered arrangements. That is, when two articulation joints are connected, the articulation of the two articulation joints are cooperatively connected by a locating feature to define the relative position of the two articulation joints, and in particular operation, one articulation of one articulation joint is cooperatively connected with one articulation of the other articulation joint, the two articulation joints that need to be mated are cooperatively connected by a groove and a protrusion.

In some embodiments, as shown in fig. 14a and 14b, the serpentine joint 10 comprises two articulation joints, the axes of rotation S3 and S4 of which are parallel, i.e. a parallel arrangement. In other embodiments, as shown in fig. 10a and 10b, the serpentine joint 10 comprises two articulation joints, the axes of rotation S3 and S4 of which are vertically staggered, i.e. staggered. The design of the positioning feature described above also allows the second joint 105 and the first joint 102 to be arranged in combination with two joints, such as the second joint 105 of one joint and the second joint 105 of the other joint being staggered or parallel, or the second joint 105 of one joint and the first joint 102 of the other joint being staggered or parallel (fig. 15a and 15 b), or the first joint 102 of one joint being staggered with the first joint 102 of the other joint (fig. 11a and 11 b) or parallel; thereby meeting the articulation requirements of surgical instruments or endoscopes.

As shown in fig. 12a to 13b, and fig. 16a to 17b, the present embodiment also provides a surgical instrument including an instrument end 1, an instrument bar 2, and an instrument box 3 connected in sequence, the instrument box 3 being capable of providing a driving force to the instrument end 1 to drive the instrument end 1 to move. The instrument tip 1 includes a serpentine joint 10 and a tip instrument (not labeled) connected to the distal end of the instrument shaft 2 by the serpentine joint 10, the specific type of tip instrument being not limited, such as forceps, scissors, needle holders, etc. As shown in fig. 13 a-13 b, the instrument end 1 comprises a serpentine joint 10, the serpentine joint 10 comprises two vertically staggered articulation joints, and an open-close instrument 11 (i.e., end instrument) is provided at the serpentine joint end, optionally with the deflection of the two articulation joints being controlled by four distractors, a third distractor 300, a fourth distractor 400, a fifth distractor 500 and a sixth distractor 600, respectively, to achieve 2 degrees of freedom. In other embodiments, as shown in fig. 16 a-16 b, the instrument tip 1 comprises a serpentine joint 10, the serpentine joint 10 comprising two articulating joints arranged in parallel, and an open-close instrument 11 disposed at the end of the serpentine joint. It should be appreciated that the type of end instrument is not limited to the opening and closing instrument 11. The number of the joint joints in the surgical instrument is not limited to 2, but may be 1 or 2 or more.

As shown in fig. 17a to 17b, the present embodiment further provides an endoscope, which includes an instrument end 1, an instrument rod 2 and an instrument box 3 sequentially connected, wherein the instrument end 1 includes a serpentine joint 10 and a laparoscopic probe 12, and the serpentine joint 10 may include two joint joints arranged in parallel. Of course, in other embodiments, the endoscope of the present embodiment may also include joint connectors arranged in a staggered manner, and the number of joint connectors is not limited to 2.

< second embodiment >

The same parts as those of the first embodiment will not be described in detail, and reference will be made to the first embodiment, and only the differences will be described below.

As shown in fig. 22 a-23 b, the present embodiment provides a channel snake joint 13 comprising at least one joint comprising a channel first joint 131, a channel second joint 132, and a spacing mechanism by which the first joint 131 and the second joint 132 articulate and form at least one pair of articulation axes that are non-collinear. The limiting mechanism is used for limiting the relative position between the first joint 131 and the second joint 132 and enabling the first joint 131 and the second joint 132 to rotate relatively.

Unlike the first embodiment, the limiting mechanism of the present embodiment includes the second connecting portion 104 or the first connecting portion 103. The second connection portion 104 is illustrated, and the first joint 31 and the second joint 132 are hinged by a second connection portion 104 to form a pair of hinge axes, and the implementation manner of the hinge is the same as that of the first embodiment, and will not be described in detail. In the present embodiment, the first joint 131 is hinged with the second connection part 104 by the second hinge part 1022 and forms the second hinge axis R2, and the second joint 132 is hinged with the second connection part 104 by the fourth hinge part 1052 and forms the fourth hinge axis R4.

The first joint 131 further includes a first limiting portion, the second joint 132 further includes a second limiting portion, the first limiting portion is two and symmetrically disposed with respect to a left-right symmetry plane, and the second limiting portion is two and symmetrically disposed with respect to the left-right symmetry plane. The first limiting portions and the second limiting portions are slidably connected in pairs to further define a relative position between the first joint 131 and the second joint 132. One of the first and second limiting portions is an arc chute 1311, and the other is a strut boss 1321 that mates with the arc chute 1311. In this embodiment, the first limiting portion is configured as an arc chute 1311 and the second limiting portion is configured as a strut boss 1321. The strut bosses 1321 are mated with the arcuate runners 1311 in a one-to-one correspondence.

It should be understood that the relative movement relationship between the first joint 131 and the second joint 132 is the same as that of the first embodiment, that is, it is assumed that the first connection portion 103 and the second connection portion 104 exist at the same time, and the center of the strut boss 1321 may draw a track on the first joint 131, where the track is the track of the arc chute 1311, and the arc chute 1311 and the strut boss 1321 are reserved and the first connection portion 103 is omitted. It should also be appreciated that the strut boss 1321 is disposed on the side-to-side symmetry plane of the articulation joint, and that the articulation joint of this embodiment is identical in construction to that of fig. 6a, i.e., structurally the articulation joint is identical in terms of retaining four articulation points and four articulation axes.

In another embodiment, the arc chute 1311 on the first joint 131 may be replaced with the strut boss 1321, and the strut boss 1321 on the second joint 132 may be replaced with the arc chute 1311, to achieve the same effect.

Therefore, in this embodiment, a channel-type serpentine joint 13 is implemented by the limiting mechanism, which effectively shortens the length of the end joint of the instrument under the condition that the deflection angle of the end instrument joint is unchanged, reduces the risk of motion interference of the surgical instrument or the endoscope in a space region with a small space, reduces the operation difficulty of the instrument, and has a larger motion range. It should also be appreciated that in this embodiment, one or two stops may be retained, and one hinge may be omitted from the first joint 131 and one hinge may be omitted from the second joint 132.

< third embodiment >

The layout of the hinge points of the parts in this embodiment and the first embodiment is identical, except that the parts disposed at the hinge points are changed, and only the different points will be described below.

Specifically, as shown in fig. 24 a-26 b, the present embodiment provides an internal hinged serpentine joint 14 comprising at least one articulation joint comprising a first articulation, a second articulation joint, and a spacing mechanism comprising a first connection 103 and a second connection 104. Wherein the first joint comprises a first articulation block 141 and a first articulation block 142, and the second joint comprises a second articulation block 143 and a second articulation block 144. The first hinge block 141 is provided with a first hinge portion 1411 and a second hinge portion 1412 which are disposed opposite to each other; the second hinge block 144 is provided with a third hinge 1441 and a fourth hinge 1442. The first hinge block 141 is detachably disposed on the first joint base 142, and the second hinge block 144 is detachably disposed on the second joint base 143. Therefore, in this embodiment, the first joint and the second joint are of a split structure.

The first hinge 1411 is hinged to the first connection 103 and forms a first hinge axis R1, and the second hinge 1412 is hinged to the second connection 104 and forms a second hinge axis R2. The third hinge 1441 is hinged to the first connection 103 and forms a third hinge axis R3, and the fourth hinge 1442 is hinged to the second connection 104 and forms a fourth hinge axis R4. At this time, the inner surfaces of the first and second joint bases 142 and 143 serve as stoppers for the first and second links 103 and 104.

Further, the first hinge block 141 includes a first positioning boss 141a and a first extension portion 141b, and the second hinge block 144 includes a second positioning boss 144a and a second extension portion 144b. The first joint base 142 is provided with a first through central channel, and the first central channel is formed with a first positioning step 1421 for positioning and fixing the first hinge block 141, that is, the first positioning boss 141a is matched with the step surface of the first central channel. The second joint base 143 is provided with a second through central channel, and the second central channel is formed with a second positioning step 1451 for positioning and fixing the second hinge block 144, i.e. the second positioning boss 144a is matched with the step surface of the second central channel. Further, the first hinge 1411 and the second hinge 1412 are provided on the first extension 141 b; the third hinge portion 1441 and the fourth hinge portion 1442 are disposed on the second extension portion 144b, the first extension portion 141b and the second extension portion 144b are disposed between the first connection portion 103 and the second connection portion 104, and one end of the first extension portion 141b abuts (including abutting against) one end of the second extension portion 144b.

Similar to the embodiment, the embodiment realizes the serpentine joint 14 through the double-link mechanism, can effectively shorten the length of the joint of the tail end instrument under the condition that the deflection angle of the joint of the tail end instrument is unchanged, and reduces the risk of motion interference of the instrument in a narrow space area of the space, thereby reducing the operation difficulty of the instrument and having a larger motion range.

Therefore, according to the technical scheme provided by the embodiment, the joint length is shortened under the condition of the same outer diameter and the same deflection angle, the occupied operation space is reduced, the risk of interference of the operation of the instrument in a narrow space is reduced, and the operation safety is improved. The snake-shaped joint can obtain a large range of movement angles, such as +/-140 degrees, and has high movement precision and good rigidity. It should also be appreciated that the structure of any of the serpentine joints of the first through third embodiments described above can be determined with reference to fig. 6 a.

The above examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by those skilled in the art without departing from the spirit of the invention, which falls within the scope of the invention.

Claims

1. A serpentine joint, wherein the serpentine joint has at least one degree of freedom and comprises at least one articulation joint; the joint connector comprises a first joint, a second joint and a limiting mechanism; the first joint and the second joint are hinged through the limiting mechanism and form at least one pair of hinge axes, and at least one pair of hinge axes are not collinear;

the limiting mechanism comprises a first connecting part and a second connecting part, the first joint and the second joint are hinged through the first connecting part and the second connecting part to form four hinge points, the four hinge points are a first hinge point, a second hinge point, a third hinge point and a fourth hinge point, the first connecting part is provided with the first hinge point and the third hinge point, the axes of the first hinge point and the third hinge point are not collinear, and the second connecting part is provided with the second hinge point and the fourth hinge point, the axes of the second hinge point and the fourth hinge point are not collinear;

the first hinge point is a hinge point formed by hinging the second joint with the first connecting part, the second hinge point is a hinge point formed by hinging the second joint with the second connecting part, the third hinge point is a hinge point formed by hinging the first joint with the first connecting part, and the fourth hinge point is a hinge point formed by hinging the first joint with the second connecting part;

The first hinge point and the second hinge point are symmetrical about a left-right symmetry plane of the snake-shaped joint, the first hinge point and the second hinge point are positioned on an upper symmetry plane and a lower symmetry plane of the snake-shaped joint, the third hinge point and the fourth hinge point are symmetrical about the left-right symmetry plane of the snake-shaped joint, the combination of the first hinge point and the fourth hinge point is symmetrical about the left-right symmetry plane with the combination of the second hinge point and the third hinge point, and the upper symmetry plane and the lower symmetry plane are perpendicular to the left-right symmetry plane.

2. The serpentine joint of claim 1, wherein the first joint and the second joint are articulated by the spacing mechanism and form two pairs of articulation axes, the two pairs of articulation axes being non-collinear with each other; the two pairs of hinge axes comprise a first hinge axis, a second hinge axis, a third hinge axis and a fourth hinge axis; the first joint is hinged with the first connecting part to form the first hinge axis, the first joint is hinged with the second connecting part to form the second hinge axis, the second joint is hinged with the first connecting part to form the third hinge axis, and the second joint is hinged with the second connecting part to form the fourth hinge axis;

The joint is provided with a first symmetrical plane and a second symmetrical plane, the first symmetrical plane is the left-right symmetrical plane, the second symmetrical plane is the upper-lower symmetrical plane, and the first hinge axis, the second hinge axis, the third hinge axis and the fourth hinge axis are all parallel to the first symmetrical plane; the first hinge axis and the second hinge axis are symmetrical about the first plane of symmetry and lie on the second plane of symmetry; the third hinge axis and the fourth hinge axis are symmetrical about the first plane of symmetry and are on the same side of the second plane of symmetry; wherein: the height of the joint satisfies the following relationship:

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3. The serpentine joint of claim 2, wherein the first joint comprises a first hinge and a second hinge, and wherein the second joint comprises a third hinge and a fourth hinge;

4. The serpentine joint of claim 3, wherein the first joint comprises a first joint base and a first articulation block; the second joint comprises a second joint base and a second hinge block;

the first hinge block is detachably arranged on the first joint base; the second hinge block is detachably arranged on the second joint base;

the first hinge part and the second hinge part are arranged on the first hinge block; the third hinge portion and the fourth hinge portion are disposed on the second hinge block.

5. The serpentine joint of claim 4, wherein the first articulation block comprises a first positioning boss and a first extension and the second articulation block comprises a second positioning boss and a second extension;

The first joint base is provided with a first through central channel; the second joint base is provided with a second through central channel; the first central channel and the second central channel are provided with step surfaces; the first positioning boss is matched with the step surface of the first central channel, and the second positioning boss is matched with the step surface matched with the second central channel;

the first hinge part and the second hinge part are arranged on the first extension part; the third hinge part and the fourth hinge part are arranged on the second extension part;

6. The serpentine joint of claim 2, wherein the first joint further comprises a first stop; the second joint further comprises a second limiting part; the first limiting parts are two and are symmetrically arranged relative to the first symmetrical plane; the second limiting parts are two and are symmetrically arranged relative to the first symmetrical plane; the first limiting parts and the second limiting parts are matched in a group of sliding way; one of the first limiting part and the second limiting part is an arc-shaped chute, the other one is a sliding column boss, and the arc-shaped chute is determined according to the track of the second joint or the track of the first joint when the first joint rotates towards the first direction and the second direction.

7. The serpentine joint of any one of claims 1-6, wherein the joint further comprises an anti-drop mechanism for defining the position of the stop mechanism.

8. The serpentine joint of claim 7, wherein the anti-drop mechanism comprises a first stop and a second stop; the first stop block is detachably arranged on the first joint; the second stop block is detachably arranged on the second joint; one end of the first stop block is abutted with one end of the second stop block and is positioned between the first connecting part and the second connecting part, and the first stop block and the second stop block respectively resist the first connecting part and/or the second connecting part through the side surfaces.

9. The serpentine joint according to claim 8, wherein each stop has a threading hole allowing the traction body to pass through, said threading hole being in communication with an arcuate guide wire slide inside the stop, a transition arc being provided at the wire outlet of said arcuate guide wire slide, the radius of curvature of said transition arc being greater than the radius of curvature of the remainder of said arcuate guide wire slide.

10. The serpentine joint of any one of claims 1-6, wherein the first joint has a first motion limiting surface and a second motion limiting surface, and wherein the second joint has a third motion limiting surface and a fourth motion limiting surface;

11. The serpentine joint of claim 10, wherein the serpentine joint is deflected by a maximum angle of 140 ° in a first direction and by a maximum angle of 140 ° in a second direction.

12. The serpentine joint of any one of claims 1-6, wherein the first joint comprises a first threading channel and the second joint comprises a second threading channel, the second threading channel having a position corresponding to the position of the first threading channel;

the outlet of the first wire penetrating channel is provided with an arc-shaped first guide surface, the bending radius of the first guide surface is larger than that of the rest of the first wire penetrating channel, and/or the outlet of the second wire penetrating channel is provided with an arc-shaped second guide surface, and the bending radius of the second guide surface is larger than that of the rest of the second wire penetrating channel.

13. The serpentine joint of any one of claims 1-6, wherein the first joint comprises a first positioning feature and a second positioning feature, and the second joint comprises a third positioning feature and a fourth positioning feature; one of the first locating feature and the second locating feature is a protrusion, and the other is a recess; one of the third positioning feature and the fourth positioning feature is a protrusion, and the other is a groove;

14. The serpentine joint of any one of claims 1-6, wherein the serpentine joint comprises two of the articulation joints arranged in parallel or staggered.

15. A surgical instrument comprising an instrument tip, an instrument stem, and an instrument box connected in sequence, the instrument tip comprising an end instrument and the serpentine joint of any one of claims 1-14, the end instrument being connected to the instrument stem by the serpentine joint.

16. An endoscope comprising an instrument tip, an instrument shaft and an instrument box connected in sequence, the instrument tip comprising a probe and a serpentine joint according to any one of claims 1-14, the probe being connected to the instrument shaft by the serpentine joint.