A continuum mechanism and surgical tool of a coupled kinematic chain

Abstract

The present invention relates to the field of medical devices, and discloses a continuum mechanism and a surgical tool with a coupled kinematic chain. It includes: a continuum mechanism and a kinematic chain. The continuum mechanism includes a base plate, a stop plate, and a structural bone. The structural bone is fixedly connected to the stop plate and penetrates through the base plate. The kinematic chain is connected to the stop plate and the base plate. The kinematic chain includes at least one polyhedron unit. Each polyhedron unit includes two edges that are spatially staggered and perpendicular to each other. The edges of adjacent two polyhedron units coincide with each other. The surgical tool includes the above-mentioned continuum mechanism. The continuum mechanism and the surgical tool with a coupled kinematic chain provided by the present invention have the ability of flexible bending, while improving the torsional resistance of the continuum mechanism along the axial direction of the tube body, enhancing the load capacity and motion accuracy, reducing the difficulty of surgical operation, and prolonging the service life of the surgical tool.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and particularly to a continuum mechanism and a surgical tool with a coupled motion chain. Background Art

[0002] Traditional rigid surgical instruments are mostly slender rod-shaped structures, with a surgical actuator provided at the end. The rod-shaped structure is connected in series and articulated by multiple rods, and is driven by the tension of a wire rope to enable the surgical instrument to bend at the articulated joints. Due to the complex hand-eye coordination operation requirements, traditional rigid surgical instruments have disadvantages such as limited flexibility and a small working range, which restricts their popularization and application. With the research and development of surgical robot systems, flexible robotic arms are currently beginning to replace traditional rigid surgical instruments, greatly improving the degrees of freedom and flexibility of the surgical instruments and increasing the flexibility of the instrument movement.

[0003] Existing flexible robotic arms are coupled to a drive mechanism through drive wires, causing the flexible robotic arm to produce corresponding bending deformations, thereby generating the desired motion. However, existing flexible robotic arms generally have problems of insufficient rigidity and low load capacity. Since the flexible robotic arm is elastic and easily bendable, the torsional resistance of the flexible robotic arm around the axis is poor. When the flexible robotic arm is subjected to an external load, it is prone to torsional rotation around the axis, resulting in the loss of motion accuracy of the flexible robotic arm. At the same time, the torsional motion of the flexible robotic arm is likely to cause the flexible robotic arm to bend or be damaged, reducing the service life of the surgical instrument. Summary of the Invention

[0004] Based on the above problems, the purpose of the present invention is to provide a continuum mechanism and a surgical tool with a coupled motion chain, which can improve the torsional resistance performance and extend the service life.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A continuum mechanism with a coupled motion chain, comprising: a continuum mechanism and a motion chain;

[0006] The continuum mechanism includes a base plate, a stop plate, and a structural bone;

[0007] The base plate and the stop plate are arranged at intervals;

[0008] The distal end of the structural bone is fixedly connected to the stop plate, and the proximal end of the structural bone penetrates through the base plate;

[0009] The distal end and the proximal end of the motion chain are respectively connected to the stop plate and the base plate;

[0010] The motion chain includes at least one polyhedron unit, and each polyhedron unit includes two edges that are staggered and perpendicular to each other in space. The edges of adjacent two polyhedron units coincide with each other;

[0011] With the above configuration, the kinematic chain itself does not have the ability to rotate around the axis direction, thus restricting the rotational ability of the continuum mechanism around the axis and not affecting the bending motion of the continuum.

[0012] As a preferred embodiment of the continuum mechanism of the present invention, the polyhedral unit is a polyhedral structure formed by folding a sheet, or the polyhedral unit is configured to be formed by 3D printing.

[0013] As a preferred embodiment of the continuum mechanism of the present invention, the polyhedral unit includes a first V-shaped structure and a second V-shaped structure fixedly connected to each other;

[0014] The two planes of the first V-shaped structure intersect at a first edge;

[0015] The two planes of the second V-shaped structure intersect at a second edge;

[0016] The first edge and the second edge are staggered and perpendicular to each other in space.

[0017] As a preferred embodiment of the continuum mechanism of the present invention, a plurality of the polyhedral units are stacked on top of each other to form a tower-like structure, the edges of adjacent two polyhedral units coincide, and the adjacent coincident edges are perpendicular to each other;

[0018] A plurality of mutually perpendicular edges are provided, thereby increasing the degrees of freedom of the kinematic chain during bending motion and avoiding the kinematic chain from affecting the bending motion of the continuum mechanism. As a preferred embodiment of the continuum mechanism of the present invention, a plurality of the structural bones are provided, and the proximal end of each structural bone is configured to be connectable to a driving mechanism;

[0019] Or a plurality of the structural bones are configured to be connectable to a driving mechanism.

[0020] As a preferred embodiment of the continuum mechanism of the present invention, the structural bone is made of an elastic material; preferably, the structural bone is made of a nickel-titanium wire.

[0021] The continuum mechanism of the coupled kinematic chain further includes at least one retaining disk disposed between the stop disk and the base disk;

[0022] The distal end of the structural bone is fixedly connected to the stop disk, the proximal end of the structural bone sequentially penetrates the retaining disk and the base disk, and the structural bone is disposed circumferentially along the base disk, the retaining disk and the stop disk;

[0023] The retaining disk is provided so that the structural bones still remain parallel during the bending deformation process, preventing the structural bones from becoming unstable during the bending motion.

[0024] As a preferred embodiment of the continuum mechanism of the present invention, the continuum mechanism of the coupled kinematic chain further includes a support structure disposed on the outer periphery of the continuum mechanism;

[0025] The support structure includes a helical steel strip and a metal braided mesh. The helical steel strip abuts against the outer peripheral surface of the continuum mechanism, and the metal braided mesh abuts against the outer peripheral surface of the helical steel strip;

[0026] The bending retention performance of the continuum mechanism is maintained by the support structure.

[0027] As a preferred embodiment of the continuum mechanism of the present invention, the structural bone is made of an elastic material; preferably, the structural bone is prepared from nickel-titanium wire.

[0028] The present invention also provides a surgical tool, including an end effector and the continuum mechanism of the coupled kinematic chain as described above. The end effector is fixedly connected to the stop disk at the distal end of the continuum mechanism.

[0029] The beneficial effects of the present invention are:

[0030] For the continuum mechanism of the coupled kinematic chain and the surgical tool provided by the present invention, by arranging a kinematic chain between the continuum mechanisms, since the kinematic chain has two edges that are spatially staggered and perpendicular to each other, the edges of two adjacent polyhedral units 41 coincide with each other, so that the kinematic chain does not have the ability to rotate around the axis direction, and can generate a bending motion to conform to the bending of the continuum mechanism, thereby avoiding torsion around the axis during the bending motion, enabling the continuum mechanism to have a flexible bending ability while improving the anti-torsion ability of the continuum mechanism around the axis, further enhancing the load capacity and motion accuracy, reducing the difficulty of surgical operation, and extending the service life of the surgical tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the content of the embodiments of the present invention and these drawings.

[0032] Figure 1 is a schematic structural diagram of the continuum mechanism provided by the specific embodiment of the present invention;

[0033] Figure 2 is a schematic structural diagram of the kinematic chain provided by the specific embodiment of the present invention;

[0034] Figure 3 is a schematic structural diagram of a single polyhedral unit provided by the specific embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of the structure in which multiple polyhedron units provided by the specific embodiment of the present invention are stacked on top of each other.

[0036] In the figure:

[0037] 1 - base plate; 2 - stop plate; 3 - structural bone; 4 - kinematic chain; 5 - retaining plate;

[0038] 41 - polyhedron unit;

[0039] 411 - first edge; 412 - second edge. Specific embodiment

[0040] To make the technical problems solved by the present invention, the technical solutions adopted, and the achieved technical effects clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0042] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0043] In the present invention, when referring to "distal or the distal end", this term refers to the side or end relatively far from the operator. When referring to "proximal or the proximal end", this term refers to the side or end relatively close to the operator.

[0044] Such as Figures 1 - 3As shown in the figure, this embodiment provides a continuum mechanism with a coupled kinematic chain, including: a continuum mechanism and a kinematic chain 4;

[0045] The continuum mechanism includes a base plate 1, a stop plate 2, and a structural bone 3. The base plate 1 and the stop plate 2 are arranged at intervals. The distal end of the structural bone 3 is fixedly connected to the stop plate 2, and the proximal end of the structural bone 3 penetrates through the base plate 1. The distal end and the proximal end of the kinematic chain 4 are respectively fixedly connected to the stop plate 2 and the base plate 1. The kinematic chain 4 includes at least one polyhedron unit 41. Each polyhedron unit 41 includes two edges that are spatially staggered and perpendicular to each other. The edges of two adjacent polyhedron units 41 coincide with each other. Specifically, when the continuum mechanism bends, it drives the kinematic chain 4 to bend. The bending trajectories of the continuum mechanism and the kinematic chain 4 are approximately arc-shaped. Since the kinematic chain 4 has two edges that are spatially staggered and perpendicular to each other, and the edges of two adjacent polyhedron units 41 coincide with each other, the kinematic chain 4 itself does not have the ability to rotate around the axis direction, thus restricting and constraining the rotation ability of the continuum mechanism around the axis. At the same time, the kinematic chain 4 can conform to the bending of the continuum mechanism in space as the continuum mechanism bends. By arranging the kinematic chain 4 between the stop plate 2 and the base plate 1, while enabling the continuum mechanism to have flexible bending ability, it can also improve the torsional resistance of the continuum mechanism around the axis, thereby enhancing the load capacity and motion accuracy, reducing the difficulty of surgical operations, and extending the service life of surgical tools.

[0046] In this embodiment, the stop plate 2 and the base plate 1 can be circular rings or rectangular shapes, etc., and preferably are circular rings. The distal end of the structural bone 3 is fixedly connected to the stop plate 13, and the proximal end of the structural bone 3 penetrates through the base plate 1 and is configured to be connected to a driving mechanism. The base plate 1 serves as a fixed end, and the stop plate 2 serves as a moving end for carrying a load (such as an end effector).

[0047] Preferably, multiple structural bones 3 are provided. The multiple structural bones 3 are circumferentially spaced on the stop plate 2 and the base plate 1. Each structural bone 3 is arranged along the direction parallel to the axis of the kinematic chain 4. Each structural bone 3 is configured to be connected to a driving mechanism or multiple structural bones 3 are configured to be connected to a driving mechanism. It can be understood that when a certain driving mechanism applies an active driving force to push one structural bone 3, and other driving mechanisms do not apply active driving forces, since the base plate 1 is a fixed end, this pushed structural bone 3 drives the kinematic chain 4 through the stop plate 2 to produce a bending deformation under the restriction of the base plate 1, and other structural bones 3 follow. The entire continuum mechanism completes a preset bending action away from this pushed structural bone 3 under the action of this pushed structural bone 3, and the stop plate 2, as the moving end, reaches the preset position. When multiple driving mechanisms apply active driving forces simultaneously, by the multiple driving mechanisms cooperatively pushing and pulling multiple structural bones 3, according to the different displacement amounts generated by pushing or pulling, the entire continuum mechanism generates corresponding bending deformations, thereby realizing the desired motion of the load at the moving end (such as an end effector).

[0048] More preferably, after multiple structural bones 3 pass through the base plate 1, they are connected to another fixed plate, and the fixed plate is driven to flip by a driving mechanism, so that the multiple structural bones 3 can also be bent in any direction, and the stop plate 2 serves as the moving end to reach the preset position.

[0049] In practical applications, the distal and proximal ends of the structural bone 3 are arranged along the circumferential distribution of the stop plate 2 and the base plate 1. For example, they can be arranged in a circular distribution so that the structural bone 3 encloses an accommodating space, and the kinematic chain 4 is located in this accommodating space.

[0050] To ensure the overall compliance of the continuum mechanism, optionally, the structural bone 3 is made of an elastic material. Preferably, the structural bone 3 is prepared from nitinol wire.

[0051] In a specific embodiment, the polyhedral unit 41 is a polyhedral structure formed by folding a sheet, or the polyhedral unit 41 is formed by 3D printing. Exemplarily, the sheet can be a plastic sheet or a sheet structure made of a special material, and a polyhedral structure can be formed by folding it.

[0052] Specifically, the polyhedral unit 41 includes a first V-shaped structure and a second V-shaped structure that are fixedly connected to each other; the two planes of the first V-shaped structure intersect at a first edge 411, and the two planes of the second V-shaped structure intersect at a second edge 412. The first edge 411 and the second edge 412 are staggered in space and perpendicular to each other. It should be understood that the bottom surface corresponding to the first edge 411 of the first V-shaped structure overlaps with the bottom surface corresponding to the second edge 412 of the second V-shaped structure, and the side surfaces of the first V-shaped structure on both sides of the first edge 411 gradually extend from this bottom surface along the direction of the first edge 411 into the interior of the first V-shaped structure, and the side surfaces of the second V-shaped structure on both sides of the second edge 412 gradually extend from this bottom surface along the direction of the second edge 412 into the interior of the second V-shaped structure. However, it should be understood that the polyhedral unit 41 can also be a tetrahedral structure, which can also have two edges that are staggered in space and perpendicular to each other.

[0053] In this embodiment, as Figure 4As shown, multiple polyhedral units 41 are stacked on top of each other to form a tower-like structure. The edges of adjacent polyhedral units 41 coincide, and the adjacent coincident edges are perpendicular to each other. Specifically, the second edge 412 of the polyhedral unit 41 located above coincides with the second edge 412 of the adjacent polyhedral unit 41 located below, while the first edge 411 of the lower polyhedral unit 41 coincides with the first edge 411 of its adjacent polyhedral unit 41. Stacking them in sequence forms a tower-like structure. The adjacent coincident edges refer to the second edge 412 and the first edge 411 that coincide with each other. Two adjacent coincident edges are equivalent to two rotating pairs of the kinematic chain. Therefore, the kinematic chain 4 of the tower-like structure can be understood as including multiple spatially staggered and mutually perpendicular rotating joints, and the axis of rotation is perpendicular to the extending direction of the kinematic chain 4, thus preventing the kinematic chain 4 from rotating axially when bent. Further, when the continuum mechanism bends, it drives the kinematic chain 4 to bend. The bending trajectories of the continuum mechanism and the kinematic chain 4 are approximately arc-shaped. The extending direction of the kinematic chain 4 refers to the tangent direction of the kinematic chain 4 at the bending part. For example, when the kinematic chain 4 is not bent, its extending direction refers to the direction along the axis, that is, the vertical direction.

[0054] In this embodiment, at least one retaining disk 5 is provided between the stop disk 2 and the base disk 1. The distal end of the structural bone is fixedly connected to the stop disk 2, and the proximal end of the structural bone 3 sequentially penetrates through the retaining disk 5 and the base disk 1. Preferably, the number of retaining disks 5 is multiple, and they are respectively arranged at intervals between the stop disk 2 and the base disk 1. The retaining disk 5 is used to support the structural bone 3 radially from the structural bone 3, so that each structural bone 3 remains parallel during the bending deformation process, preventing the structural bone 3 from becoming unstable during the bending movement.

[0055] A plurality of locking holes for fixing the end of the structural bone 3 are circumferentially provided on the stop disk 2, and a plurality of through holes for the structural bone 3 to slide through are circumferentially provided on the base disk 1 and the retaining disk 5. The specific hole positions and the number of holes of the through holes and the locking holes on different disks depend on the distribution position and the number of the structural bones 3. Exemplarily, when the structural bones 3 are circumferentially distributed, the specific hole positions are also circumferentially distributed, and the number of each hole position is consistent with the number of the structural bones 3. It can be understood that the number of each hole position can be greater than the number of the structural bones 3, and the structural bones 3 can also be arranged circumferentially in a matrix.

[0056] To maintain the bending retention performance of the continuum mechanism, optionally, the continuum mechanism may further include a support structure (not shown in the figure). The support structure is used to support the continuum mechanism to maintain the bending retention performance of the continuum mechanism, so as to prevent the continuum mechanism from not being able to smoothly return to the initial position after bending. Specifically, the support structure can be made of an inner layer of spiral steel belt and an outer layer of metal braided mesh. The metal braided mesh is woven into a mesh structure by metal wires and is tightly sleeved on the outer periphery of the spiral steel belt.

[0057] An elastic spacer (such as a spring, not shown in the figure) can be installed between adjacent disks of the continuum mechanism to separate the disks from each other.

[0058] This embodiment also provides a surgical tool, which includes the above-mentioned continuum mechanism and further includes an end effector. The end effector is fixedly connected to the stop disk 2 at the distal end of the continuum mechanism. By driving the mechanism to push and pull the structural bone 3 at different positions cooperatively, according to different driving amounts generated by pushing or pulling, the entire continuum mechanism generates corresponding bending deformations, so as to achieve the desired movement of the end effector. While the continuum mechanism has the ability to flex flexibly, it improves the torsional resistance of the continuum mechanism around the axial direction, enhances the load capacity and movement accuracy, reduces the difficulty of surgical operation, and prolongs the service life of the surgical tool.

[0059] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments here, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A continuum mechanism of a coupled kinematic chain, characterized in that, Comprising: A continuum mechanism and a kinematic chain (4); The continuum mechanism includes a base plate (1), a stop plate (2), and a structural bone (3); The base plate (1) and the stop plate (2) are arranged at intervals; The distal end of the structural bone (3) is fixedly connected to the stop plate (2), and the proximal end of the structural bone (3) penetrates through the base plate (1); The distal end and the proximal end of the kinematic chain (4) are respectively connected to the stop plate (2) and the base plate (1); The kinematic chain (4) includes at least one polyhedron unit (41), and each polyhedron unit (41) includes two edges that are spatially staggered and perpendicular to each other, and the edges of two adjacent polyhedron units (41) coincide with each other; The polyhedron unit (41) includes a first V-shaped structure and a second V-shaped structure that are fixedly connected to each other; The two planes of the first V-shaped structure intersect at a first edge (411); The two planes of the second V-shaped structure intersect at a second edge (412); The first edge (411) and the second edge (412) are spatially staggered and perpendicular to each other; A plurality of the polyhedron units (41) are stacked on top of each other to form a tower-like structure, the edges of two adjacent polyhedron units (41) coincide, and the adjacent coincident edges are perpendicular to each other.

2. The continuum mechanism of the coupled kinematic chain according to claim 1, characterized in that, The polyhedron unit (41) is a polyhedron structure formed by folding a sheet, or the polyhedron unit (41) is arranged to be formed by 3D printing.

3. The continuum mechanism of the coupled kinematic chain according to claim 1, characterized in that, A plurality of the structural bones (3) are provided, and the proximal end of each structural bone (3) is configured to be capable of being connected to a driving mechanism; Or a plurality of the structural bones (3) are configured to be capable of being connected to a driving mechanism.

4. The continuum mechanism of the coupled kinematic chain according to claim 1, characterized in that, The structural bone (3) is made of an elastic material.

5. The continuum mechanism of the coupled kinematic chain according to claim 4, characterized in that, The structural bone (3) is prepared from a nickel-titanium wire.

6. The continuum mechanism of the coupled kinematic chain according to any one of claims 1-5, characterized in that, It further includes at least one retaining disk (5) arranged between the stop plate (2) and the base plate (1); The distal end of the structural bone (3) is fixedly connected to the stop plate (2), the proximal end of the structural bone (3) sequentially penetrates through the retaining disk (5) and the base plate (1), and the structural bone (3) is respectively arranged along the circumferences of the base plate (1), the retaining disk (5), and the stop plate (2).

7. The continuum mechanism of the coupled kinematic chain according to claim 6, characterized in that, It further includes a support structure arranged on the outer periphery of the continuum mechanism; The support structure includes a spiral steel strip and a metal braided net, the spiral steel strip abuts against the outer peripheral surface of the continuum mechanism, and the metal braided net abuts against the outer peripheral surface of the spiral steel strip.

8. The continuum mechanism of the coupled kinematic chain according to claim 6, characterized in that, Elastic spacers are installed between adjacent two disks of the continuum mechanism.

9. A surgical tool, characterized in that, It includes an end effector and a continuum mechanism coupled with a kinematic chain according to any one of claims 1-8, and the end effector is fixedly connected to the stop plate at the distal end of the continuum mechanism.

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