Flexible arm

Abstract

The utility model discloses a flexible arm. The flexible arm comprises a first joint assembly, a second joint assembly and a third joint assembly which are connected in sequence. The first restraining assembly is arranged in the first joint assembly and the second joint assembly in a penetrating mode, the first restraining assembly comprises a plurality of first restraining pieces, the near end of each first restraining piece is fixed to the near end of the first joint assembly, the far end of each first restraining piece is fixed to the far end of the second joint assembly, and each first restraining piece is spiral according to a first preset angle; the second restraining assembly is arranged in the second joint assembly and the third joint assembly in a penetrating mode, the second restraining assembly comprises a plurality of second restraining pieces, the near end of each second restraining piece is fixed to the near end of the second joint assembly, the far end of each second restraining piece is fixed to the far end of the third joint assembly, and each second restraining piece is spiral according to a second preset angle. According to the method and the device, S-shaped deformation generated by the flexible arm which comprises three or more than three joint assemblies and is relatively long can be restrained.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a flexible arm. Background Technology

[0002] Currently, various surgical instruments are widely used. Surgical instruments typically consist of an instrument case, a flexible arm, and a tool head connected in sequence. A drive cable, connected to a drive unit within the instrument case, runs through the flexible arm. During surgery, the tool head and at least part of the flexible arm are inserted into the patient's body. The surgeon then operates the drive unit to retract or extend the drive cable. When the cable is extended or retracted, the flexible arm bends in the corresponding direction. This bending of the flexible arm causes the tool head to move. Once the flexible arm has bent to a certain angle, it moves the tool head to a designated position. The surgeon then uses the tool head to perform surgical procedures on the patient.

[0003] In practice, when the flexible arm bends, the components within it will shift and produce S-shaped deformation under external load. This S-shaped deformation causes the flexible arm to bend in an unstable posture in the corresponding direction, ultimately preventing it from moving the tool head to the designated position and severely impacting the smooth progress of the surgical procedure. In the prior art, patent CN111481245A describes a flexible arm with five discs. Two adjacent discs form a pair of snake-bone components, resulting in four pairs of snake-bone components within the entire flexible arm. Two adjacent pairs of snake-bone components form a joint component, creating two joint components within the entire flexible arm. This patent also includes a constraint component; one end of the constraint component is fixed to one end of the flexible arm, and the other end of the constraint component spirally passes through the five discs and is then fixed to the other end of the flexible arm.

[0004] In patent CN111481245A, the arrangement of the constraint members can only restrain the S-shaped deformation of a flexible arm containing two joint components. However, currently, for ease of surgery, longer flexible arms are manufactured, containing three or more joint components. If the constraint members are arranged as described above to constrain a longer flexible arm with three or more joint components, the length of the constraint members increases, the tension and preload decrease, and when the flexible arm bends, the joint components within the flexible arm will also move and produce S-shaped deformation under external load. Therefore, the arrangement of the constraint members in patent CN111481245A cannot restrain the S-shaped deformation of a longer flexible arm with three or more joint components; a new constraint method is urgently needed to restrain the S-shaped deformation of a longer flexible arm with three or more joint components. Summary of the Invention

[0005] The purpose of this application is to provide a flexible arm that can constrain the S-shaped deformation of a long flexible arm containing three or more joint components.

[0006] The embodiments of this application are implemented as follows:

[0007] This application provides a flexible arm, which includes a first joint assembly, a second joint assembly, a third joint assembly, a first constraint assembly, and a second constraint assembly; wherein the first joint assembly, the second joint assembly, and the third joint assembly are sequentially connected from proximal to distal end; the first constraint assembly is inserted into the first joint assembly and the second joint assembly, and the first constraint assembly includes a plurality of first constraint members, the proximal end of each first constraint member being fixed to the proximal end of the first joint assembly, and the distal end of each first constraint member being fixed to the distal end of the second joint assembly, and each first constraint member being spirally arranged at a first preset angle; the second constraint assembly is inserted into the second joint assembly and the third joint assembly, and the second constraint assembly includes a plurality of second constraint members, the proximal end of each second constraint member being fixed to the proximal end of the second joint assembly, and the distal end of each second constraint member being fixed to the distal end of the third joint assembly, and each second constraint member being spirally arranged at a second preset angle; the first constraint assembly and the second constraint assembly are interleaved within the second joint assembly.

[0008] In one embodiment, the flexible arm has an axis, and each first constraint member is inserted into a first joint assembly in a direction parallel to the axis, spiraled at 180° at the connection between the first and second joint assemblies, and inserted into a second joint assembly in a direction parallel to the axis; and / or, each second constraint member is inserted into a second joint assembly in a direction parallel to the axis, spiraled at 180° at the connection between the second and third joint assemblies, and inserted into a third joint assembly in a direction parallel to the axis.

[0009] In one embodiment, the first joint assembly is connected to the second joint assembly via a first straight pipe segment, and each first constraint member is helically wound at 180° at the first straight pipe segment; and / or, the second joint assembly is connected to the third joint assembly via a second straight pipe segment, and each second constraint member is helically wound at 180° at the second straight pipe segment.

[0010] In one embodiment, each first constraint member is spiraled 360° within a first joint assembly and a second joint assembly; and / or, each second constraint member is spiraled 360° within a second joint assembly and a third joint assembly.

[0011] In one embodiment, each first constraint is helically wound at 180° within a first joint assembly and at 180° within a second joint assembly; and / or, each second constraint is helically wound at 180° within a second joint assembly and at 180° within a third joint assembly.

[0012] In one embodiment, the flexible arm has an axis that is the intersection of a first bending plane and a second bending plane; four first constraint members are provided, wherein two of the first constraint members are symmetrical about the first bending plane in their insertion positions on the first joint assembly and the second joint assembly, and the other two of the first constraint members are symmetrical about the second bending plane in their insertion positions on the first joint assembly and the second joint assembly; four second constraint members are provided, wherein two of the second constraint members are symmetrical about the first bending plane in their insertion positions on the second joint assembly and the third joint assembly, and the other two of the second constraint members are symmetrical about the second bending plane in their insertion positions on the second joint assembly and the third joint assembly.

[0013] In one embodiment, in the first joint assembly, the center distance from each first constraint member to the axis is b1; in the second joint assembly, the center distance from each first constraint member to the axis is b2, and the center distance from each second constraint member to the axis is b3; in the third joint assembly, the center distance from each second constraint member to the axis is b4; the bending angle of the first joint assembly is θ1, the bending angle of the second joint assembly is θ2, and the bending angle of the third joint assembly is θ3.

[0014] When b1 = b2 and b3 = b4, θ1 = θ2 = θ3;

[0015] When b1 = b2 and b3 ≠ b4, θ1 = θ2 ≠ θ3;

[0016] When b1≠b2 and b3=b4, θ1≠θ2=θ3;

[0017] When b1≠b2, b3≠b4, and b1 / b2≠b4 / b3, then θ1≠θ2≠θ3.

[0018] In one embodiment, each joint assembly includes two pairs of planar serpentine components, wherein the first pair of planar serpentine components in each joint assembly rotates relative to a first and a second parallel rotation axis, and the second pair of planar serpentine components in each joint assembly rotates relative to a third and a fourth parallel rotation axis, wherein the second and third rotation axes are orthogonally arranged.

[0019] In one embodiment, each joint assembly includes a spatial serpentine assembly, each spatial serpentine assembly being rotatable relative to multiple rotation axes.

[0020] In one embodiment, a flexible segment is formed by a first joint assembly, a second joint assembly, and a third joint assembly connected sequentially from proximal to distal end, and the flexible arm includes a plurality of flexible segments connected sequentially from proximal to distal end.

[0021] In one embodiment, the flexible arm further includes a straight tube and a target joint assembly, the proximal end of the straight tube being connected to the distal end of the target joint assembly, and the distal end of the straight tube being connected to the proximal end of the first joint assembly.

[0022] The advantages of this application compared to the prior art are:

[0023] In this application, when the flexible arm contains three or more joint components, multiple sets of constraint components are provided. Each set of constraint components is inserted into two adjacent joint components, so that each set of constraint components can provide sufficient tension and preload to constrain the S-shaped deformation generated by the two adjacent joint components when the flexible arm bends. When multiple sets of constraint components are simultaneously inserted into the corresponding joint components in the flexible arm in the above manner, the S-shaped deformation generated by a long flexible arm containing three or more joint components can be effectively constrained. By constraining the S-shaped deformation generated by the flexible arm, the flexible arm can bend in a fixed posture when bending in the corresponding direction, thereby driving the tool head to move to the designated position, improving the precision of surgical control, and enabling the surgical operation to proceed smoothly. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram showing the connection of the surgical instruments as illustrated in this application;

[0026] Figure 2 This is a schematic diagram of a flexible arm containing three joint components as shown in this application;

[0027] Figure 3 This is a schematic diagram of a flexible arm containing six joint components as shown in this application;

[0028] Figure 4 Schematic diagram of the constraint components shown in this application Figure 1 ;

[0029] Figure 5 A schematic diagram of the bending of the flexible arm shown in this application. Figure 1 ;

[0030] Figure 6 Schematic diagram of the flexible arm shown in this application Figure 1 ;

[0031] Figure 7 This application illustrates the insertion of the constraint assembly within the flexible arm. Figure 1 ;

[0032] Figure 8 Schematic diagram of the constraint components shown in this application Figure 2 ;

[0033] Figure 9 A schematic diagram of the first projection shown in this application;

[0034] Figure 10 Schematic diagram of the joint assembly shown in this application Figure 1 ;

[0035] Figure 11 Schematic diagram of the joint assembly shown in this application Figure 2 ;

[0036] Figure 12 Schematic diagram of the joint assembly shown in this application Figure 3 ;

[0037] Figure 13 Schematic diagram of the joint assembly shown in this application Figure 4 ;

[0038] Figure 14 Schematic diagram of the joint assembly shown in this application Figure 5 ;

[0039] Figure 15 This is a schematic diagram of the rotation axis of the joint assembly shown in this application;

[0040] Figure 16 Schematic diagram of the flexible arm shown in this application Figure 2 ;

[0041] Figure 17 This application illustrates the insertion of the constraint assembly within the flexible arm. Figure 2 ;

[0042] Figure 18 This application illustrates the insertion of the constraint assembly within the flexible arm. Figure 3 ;

[0043] Figure 19 Schematic diagram of the constraint components shown in this application Figure 3 ;

[0044] Figure 20 This application illustrates the insertion of the constraint assembly within the flexible arm. Figure 4 ;

[0045] Figure 21 This application illustrates the insertion of the constraint assembly within the flexible arm. Figure 5 ;

[0046] Figure 22A schematic diagram of the bending of the flexible arm shown in this application. Figure 2 ;

[0047] Figure 23 This application illustrates the insertion of the constraint assembly within the flexible arm. Figure 6 ;

[0048] Figure 24 A schematic diagram of the bending of the flexible arm shown in this application. Figure 3 ;

[0049] Figure 25 Schematic diagram of the flexible arm shown in this application Figure 3 ;

[0050] Figure 26 This is a schematic diagram showing the second drive rope threaded through the target joint assembly as illustrated in this application;

[0051] Figure 27 A schematic diagram of the bending of the flexible arm shown in this application. Figure 4 .

[0052] Figure label:

[0053] 1-Surgical instrument; 10-Instrument box; 20-Long straight tube; 30-Flexible arm; 31-First straight tube segment; 32-Second straight tube segment; 40-Tool head; 51-First bending plane; 52-Second bending plane; 61-First constraint assembly; 62-Second constraint assembly; 63-Third constraint assembly; 64-Fourth constraint assembly; 65-Fifth constraint assembly; 71-First disc; 711-First surface; 712-First connecting part; 713-Third surface; 72-Second disc; 721-Second surface; 722-Second connecting part; 723-Fourth surface; 81-First drive rope; 82-Second drive rope; 91-Straight tube; 92-Target joint assembly. Detailed Implementation

[0054] The terms “first,” “second,” “third,” etc., are used only for distinguishing descriptions and do not indicate a sequence number, nor should they be interpreted as indicating or implying relative importance.

[0055] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0056] In the description of this application, it should be noted that the terms "inner", "outer", "left", "right", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0057] In the description of this application, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” shall be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components.

[0058] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings.

[0059] Example 1:

[0060] This embodiment provides a surgical system, which includes a control terminal and a surgical robot remotely connected to the control terminal. The surgical robot has a body and surgical instruments 1 detachably connected to the body; wherein, the surgical instruments 1 can be connected to the body by means of clips, bolts, magnetic attraction, etc. Figure 1 As shown, the surgical instrument 1 includes an instrument box 10, a long straight tube 20, a flexible arm 30, a tool head 40, and a first drive rope (not shown in the figure), connected sequentially from proximal to distal. The first drive rope passes through the flexible arm 30 and the long straight tube 20. One end of the first drive rope is connected to a drive unit (not shown in the figure) inside the instrument box 10, and the other end of the first drive rope is fixed at any position inside the flexible arm 30. A drive motor for driving the drive unit is provided inside the instrument. For example, the first drive rope can be a flexible material such as silk or rope, or it can be a semi-rigid material such as alloy wire or steel wire.

[0061] During surgery, the tool head 40 and at least part of the flexible arm 30 are inserted into the patient's body. The doctor then operates the drive motor inside the main body through the control terminal. After the drive motor operates, it drives the drive unit to operate. After the drive unit operates, it retracts and extends the first drive rope. After the first drive rope is retracted and extended, the flexible arm 30 bends in the corresponding direction. During the bending process of the flexible arm 30, it drives the tool head 40 to move. When the flexible arm 30 bends at a certain angle, it will drive the tool head 40 to move to the designated position. After the tool head 40 moves to the designated position, the surgical operation is performed on the patient by operating the tool head 40.

[0062] In practice, when the flexible arm 30 bends, the components within it will laterally shift under external load, resulting in an S-shaped deformation. This S-shaped deformation causes the flexible arm 30 to have an unstable bending posture when bending in the corresponding direction, ultimately preventing it from moving the tool head 40 to the designated position and severely impacting the smooth operation of the surgery. In the prior art, patent CN111481245A describes a flexible arm 30 with five discs. Two adjacent discs form a pair of snake-bone components, resulting in four pairs of snake-bone components within the entire flexible arm 30. Two adjacent pairs of snake-bone components form a joint component, resulting in two joint components within the entire flexible arm 30. In this patent, the flexible arm 30 also includes a constraint member. One end of the constraint member is fixed to one end of the flexible arm 30, and the other end, spirally passing through the five discs, is fixed to the other end of the flexible arm 30. By arranging the constraint member in this manner, the S-shaped deformation generated during bending of the flexible arm 30, which contains two joint components, is restrained.

[0063] In practice, the more joint components contained in the flexible arm 30, the smaller the bending angle required for each joint component. For example, if the flexible arm 30 includes 3 joint components, each joint component needs to bend 30° to bend 90°; if the flexible arm 30 includes 6 joint components, each joint component only needs to bend 15° to bend 90°. The smaller the bending angle of each joint component, the less friction there is between the first drive rope and the joint components, significantly improving the service life of the first drive rope. Furthermore, when the flexible arm 30 contains a large number of joint components, it can achieve continuous bending in confined spaces while still meeting the required load-bearing capacity. Therefore, currently, to improve the service life of the first drive rope and to enable the flexible arm 30 to achieve continuous bending in confined spaces while meeting the required load-bearing capacity, it is common to manufacture a longer flexible arm 30 containing 3 or more joint components. When constraining a long flexible arm 30 containing three or more joint components using the method described in the aforementioned patent, one end of the constraint member is fixed to one end of the flexible arm 30, and the other end of the constraint member spirally passes through all the joint components within the flexible arm 30 and is finally fixed to the other end of the flexible arm 30. However, in this constraint method, the constraint member is long, resulting in poor tension and preload. When the flexible arm 30 bends, the joint components within the flexible arm 30 will also undergo S-shaped deformation due to external load. Therefore, it can be seen that the arrangement of the constraint member in patent CN111481245A cannot constrain the S-shaped deformation produced by a long flexible arm 30 containing three or more joint components. Therefore, to solve the problem that the prior art cannot constrain the S-shaped deformation produced by a long flexible arm 30 containing three or more joint components, this embodiment provides a new method of inserting the constraint member. The solution of this application will be explained in detail below:

[0064] like Figure 2As shown, in this embodiment, the flexible arm 30 includes a first joint assembly P1, a second joint assembly P2, and a third joint assembly P3 connected sequentially from proximal to distal end. The flexible arm 30 also includes a first constraint assembly 61 and a second constraint assembly 62. The first constraint assembly 61 is inserted within the first joint assembly P1 and the second joint assembly P2. The first constraint assembly 61 includes multiple first constraint members, each with its proximal end fixed to the proximal end of the first joint assembly P1 and its distal end fixed to the distal end of the second joint assembly P2. Each first constraint member is spiraled at a first preset angle. The second constraint assembly 62 is inserted within the second joint assembly P2 and the third joint assembly P3. The second constraint assembly 62 includes multiple second constraint members, each with its proximal end fixed to the proximal end of the second joint assembly P2 and its distal end fixed to the distal end of the third joint assembly P3. Each second constraint member is spiraled at a second preset angle. The first constraint assembly 61 and the second constraint assembly 62 are interleaved within the second joint assembly P2. For example, the first preset angle can be 180° or 360°; the second preset angle can be 180° or 360°.

[0065] The first constraint component 61 has sufficient tension and preload to constrain the S-shaped deformation caused by the lateral movement of the first joint component P1 and the second joint component P2 when the flexible arm 30 bends. The second constraint component 62 has sufficient tension and preload to constrain the S-shaped deformation caused by the lateral movement of the second joint component P2 and the third joint component P3 when the flexible arm 30 bends. When the first constraint component 61 and the second constraint component 62 are simultaneously installed inside the flexible arm 30, the S-shaped deformation of the flexible arm 30 containing three joint components can be constrained.

[0066] When the flexible arm 30 contains more than three joint components, the S-shaped deformation produced by the flexible arm 30 can be constrained in the following way:

[0067] like Figure 3 and Figure 5 As shown, the flexible arm 30 includes a first joint assembly P1, a second joint assembly P2, a third joint assembly P3, a fourth joint assembly P4, a fifth joint assembly P5, and a sixth joint assembly P6 connected sequentially from proximal to distal end; as Figure 4As shown, the flexible arm 30 also includes a first constraint assembly 61, a second constraint assembly 62, a third constraint assembly 63, a fourth constraint assembly 64, and a fifth constraint assembly 65. The first constraint assembly 61 is inserted into the first joint assembly P1 and the second joint assembly P2 as described above. The second constraint assembly 62 is inserted into the second joint assembly P2 and the third joint assembly P3 as described above. The third constraint assembly 63 is inserted into the third joint assembly P3 and the fourth joint assembly P4. The third constraint assembly 63 includes a plurality of third constraint members, the proximal end of each third constraint member being fixed to the proximal end of the third joint assembly P3, and the distal end of each third constraint member being fixed to the distal end of the fourth joint assembly P4. Each third constraint member is configured according to the third constraint assembly P4. A preset angle spiral is formed. A fourth constraint component 64 is inserted within a fourth joint component P4 and a fifth joint component P5. The fourth constraint component 64 includes multiple fourth constraint members, each with its proximal end fixed to the proximal end of the fourth joint component P4 and its distal end fixed to the distal end of the fifth joint component P5. Each fourth constraint member is spiraled at a fourth preset angle. A fifth constraint component 65 is inserted within a fifth joint component P5 and a sixth joint component P6. The fifth constraint component 65 includes multiple fifth constraint members, each with its proximal end fixed to the proximal end of the fifth joint component P5 and its distal end fixed to the distal end of the sixth joint component P6. Each fifth constraint member is spiraled at a fifth preset angle. For example, the first preset angle can be 180° or 360°; the second preset angle can be 180° or 360°; the third preset angle can be 180° or 360°; the fourth preset angle can be 180° or 360°; and the fifth preset angle can be 180° or 360°.

[0068] The first constraint component 61 has sufficient tension and preload to constrain the S-shaped deformation caused by the lateral movement of the first joint component P1 and the second joint component P2 when the flexible arm 30 bends. The second constraint component 62 has sufficient tension and preload to constrain the S-shaped deformation caused by the lateral movement of the second joint component P2 and the third joint component P3 when the flexible arm 30 bends. The third constraint component 63 has sufficient tension and preload to constrain the S-shaped deformation caused by the lateral movement of the third section component and the fourth joint component P4 when the flexible arm 30 bends. The fourth constraint component 64 has sufficient tension and preload to constrain the S-shaped deformation caused by the lateral movement of the fourth section component and the fifth joint component P5 when the flexible arm 30 bends. The fifth constraint component 65 has sufficient tension and preload to constrain the S-shaped deformation caused by the lateral movement of the fifth section component and the sixth joint component P6 when the flexible arm 30 bends. When the first constraint component 61, the second constraint component 62, the third constraint component 63, the fourth constraint component 64 and the fifth constraint component 65 are simultaneously inserted into the flexible arm 30, the S-shaped deformation produced by the flexible arm 30 containing 6 joint components can be constrained.

[0069] When the flexible arm 30 contains six joint components, the constraint components can be inserted into the flexible arm 30 in the following manner: the first constraint component 61 is inserted into the first joint component P1 and the second joint component P2, the second set of constraint components is inserted into the third joint component P3 and the fourth joint component P4, and the third set of constraint components is inserted into the fifth joint component P5 and the sixth joint component P6. However, with this insertion method, when the flexible arm 30 bends, the second joint component P2 and the third joint component P3 are prone to lateral movement, resulting in S-shaped deformation, and the fourth joint component P4 and the fifth joint component P5 are also prone to lateral movement, resulting in S-shaped deformation. It can be seen that this insertion method of the constraint components cannot effectively constrain the S-shaped deformation generated by the flexible arm 30. In this application, each pair of constraint components has an overlapping part, for example, the first constraint component 61 and the second constraint component 62 overlap in the second joint component P2. By arranging the constraint components in an overlapping manner, the S-shaped deformation that occurs in the above insertion method is constrained, thereby fully constraining the S-shaped deformation generated by the flexible arm 30 when bending.

[0070] As can be seen from the above, in this embodiment, when the flexible arm 30 contains three or more joint components, multiple sets of constraint components are provided. Each set of constraint components is inserted into two adjacent joint components, so that each set of constraint components can provide sufficient tension and preload to constrain the S-shaped deformation generated by the two adjacent joint components when the flexible arm 30 bends. When multiple sets of constraint components are simultaneously inserted into the corresponding joint components in the flexible arm 30 in the above manner, the S-shaped deformation generated by the long flexible arm 30 containing three or more joint components can be effectively constrained. By constraining the S-shaped deformation generated by the flexible arm 30, the flexible arm 30 can bend in a fixed posture when bending in the corresponding direction, thereby driving the tool head 40 to move to the designated position, improving the precision of surgical control, and enabling the surgical operation to proceed smoothly.

[0071] Example 2:

[0072] Based on the above embodiment one, this embodiment takes the first constraint component 61 and the second constraint component 62 as examples to explain the first way of the constraint components being installed in the joint assembly:

[0073] The method of attaching the first constraint component 61:

[0074] When the first joint assembly P1 and the second joint assembly P2 are directly connected, each first constraint member in the first constraint assembly 61 is inserted into the first joint assembly P1 in a direction parallel to the axis L of the flexible arm 30. At the connection between the first joint assembly P1 and the second joint assembly P2, the first constraint member is inserted into the second joint assembly P2 in a 180° spiral and in a direction parallel to the axis L of the flexible arm 30.

[0075] The 180° spiral refers to the first constraint member being inserted at position A1 at the connection between the two joint components and the first constraint member being exited at position A2 at the connection between the two joint components. A1 and A2 are located on both sides of the axis L of the flexible arm 30. When A1, A2 and the axis L of the flexible arm 30 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A1, A2 and the axis L of the flexible arm 30 can form a central angle of 180°.

[0076] The installation method of the second constraint component 62:

[0077] When the second joint assembly P2 and the third joint assembly P3 are directly connected, each second constraint member in the second constraint assembly 62 is inserted into the second joint assembly P2 in a direction parallel to the axis L of the flexible arm 30. At the connection between the second joint assembly P2 and the third joint assembly P3, the second constraint member is inserted into the third joint assembly P3 in a 180° spiral and in a direction parallel to the axis L of the flexible arm 30.

[0078] The 180° spiral refers to the second constraint member being inserted at position A3 at the connection between the two joint components and exiting at position A4 at the connection between the two joint components. A3 and A4 are located on both sides of the axis L of the flexible arm 30. When A3, A4 and the axis L of the flexible arm 30 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A3, A4 and the axis L of the flexible arm 30 can form a central angle of 180°.

[0079] In the above embodiment, the first constraint member is inserted into the first joint assembly P1 and the second joint assembly P2 in a direction parallel to the axis L of the flexible arm 30. This insertion method allows the first constraint member to be inserted into the first joint assembly P1 and the second joint assembly P2 in a straight line, and multiple first constraint members are distributed in parallel within the first joint assembly P1 and the second joint assembly P2. This allows the first constraint member to more accurately constrain the S-shaped deformation generated by the first joint assembly P1 and the second joint assembly P2 when the flexible arm 30 bends.

[0080] Similarly, in the above embodiment, the second constraint member is inserted into the second joint assembly P2 and the third joint assembly P3 in a direction parallel to the axis L of the flexible arm 30. This insertion method allows the second constraint member to be inserted into the second joint assembly P2 and the third joint assembly P3 in a straight line, and multiple second constraint members are distributed in parallel within the second joint assembly P2 and the third joint assembly P3. This allows the second constraint member to more accurately constrain the S-shaped deformation generated by the second joint assembly P2 and the third joint assembly P3 when the flexible arm 30 bends.

[0081] Of course, this is understandable. Figure 6 and Figure 7 As shown, the first joint assembly P1 can be connected to the second joint assembly P2 through the first straight tube segment 31. At this time, the first constraint member is inserted into the first joint assembly P1 in a direction parallel to the axis L of the flexible arm 30. After passing out of the first joint assembly P1, the first constraint member spirals around the first straight tube segment 31 by 180° and then enters the second joint assembly P2 in a direction parallel to the axis L of the flexible arm 30.

[0082] The second joint assembly P2 can be connected to the third joint assembly P3 through the second straight tube section 32. At this time, the second constraint member is inserted into the second joint assembly P2 in a direction parallel to the axis L of the flexible arm 30. After passing out of the second joint assembly P2, the second constraint member spirals around the second straight tube section 32 by 180° and then enters the third joint assembly P3, and is inserted into the third joint assembly P3 in a direction parallel to the axis L of the flexible arm 30.

[0083] A straight tube 91 segment is provided between two adjacent joint components within the flexible arm 30, enabling the flexible arm 30 to achieve a greater bending distance when bending in any direction, thereby expanding the working space of the tool head 40. Furthermore, in this embodiment, when the constraint members are inserted in a 180° manner, the arrangement of the constraint members is more regular.

[0084] The following section explains in detail how the first constraint member is inserted into the first joint assembly P1 and the second joint assembly P2:

[0085] like Figure 6 , Figure 7 and Figure 8 As shown, the flexible arm 30 is symmetrical about axis L, and the extension direction of axis L is the same as the extension direction of the flexible arm 30. The flexible arm 30 has a first bending plane 51 and a second bending plane 52 orthogonally distributed, and axis L of the flexible arm 30 is the intersection line of the first bending plane 51 and the second bending plane 52. There are four first constraint members. For distinction, the four first constraint members are named first constraint member G1, first constraint member G2, first constraint member G3, and first constraint member G4, respectively. When the four first constraint members are inserted into the first joint assembly P1 and the second joint assembly P2 in the above-mentioned 180° spiral manner, the insertion positions of first constraint member G1 and first constraint member G2 on the first joint assembly P1 and the second joint assembly P2 are symmetrical about the first bending plane 51, and the insertion positions of first constraint member G3 and first constraint member G4 on the first joint assembly P1 and the second joint assembly P2 are symmetrical about the second bending plane 52.

[0086] That is, the positions of the first constraint members G1 and G2 on the first joint assembly P1 are symmetrical about the first bending plane 51, and the positions of the first constraint members G1 and G2 on the second joint assembly P2 are symmetrical about the first bending plane 51; the positions of the first constraint members G3 and G4 on the first joint assembly P1 are symmetrical about the second bending plane 52, and the positions of the first constraint members G3 and G4 on the second joint assembly P2 are symmetrical about the second bending plane 52.

[0087] Connection holes can be provided on the first joint assembly P1 and the second joint assembly P2, and the first constraint members G1, G2, G3 and G4 can be inserted into the connection holes. If the first joint assembly P1 is composed of multiple first elements, and the first connection hole N1 on any one of the first elements is used for the first constraint member G1 to pass through, and the second connection hole N2 on any one of the first elements is used for the first constraint member G2 to pass through, then the symmetry of the insertion positions of the first constraint members G1 and G2 on the first joint assembly P1 about the first bending plane 51 means that the first connection hole N1 and the second connection hole N2 are symmetrical about the first bending plane 51.

[0088] If the third connecting hole N3 on any one of the first elements of the first joint assembly P1 is used for the first constraint member G3 to pass through, and the fourth connecting hole N4 on any one of the first elements is used for the first constraint member G4 to pass through, then the symmetry of the positions of the first constraint member G3 and the first constraint member G4 on the first joint assembly P1 about the second bending plane 52 means that the third connecting hole N3 and the fourth connecting hole N4 are symmetrical about the second bending plane 52.

[0089] If the second joint assembly P2 is composed of multiple second elements, and the fifth connecting hole N5 on any of the second elements is used for the first constraint member G1 to pass through, and the sixth connecting hole N6 on the second element is used for the first constraint member G2 to pass through, then the symmetry of the positions of the first constraint member G1 and the first constraint member G2 on the second joint assembly P2 about the first bending plane 51 means that the fifth connecting hole N5 and the sixth connecting hole N6 are symmetrical about the first bending plane 51.

[0090] If the seventh connecting hole N7 on any of the second elements of the second joint assembly P2 is used for the first constraint member G3 to pass through, and the eighth connecting hole N8 on the second element is used for the first constraint member G4 to pass through, then the symmetry of the positions of the first constraint member G3 and the first constraint member G4 on the second joint assembly P2 about the second bending plane 52 means that the seventh connecting hole N7 and the eighth connecting hole N8 are symmetrical about the second bending plane 52.

[0091] When the four first constraint members are inserted into the first joint assembly P1 and the second joint assembly P2 as described above, the four first constraint members constrain the S-shaped deformation of the first joint assembly P1 and the second joint assembly P2 when the flexible arm 30 bends in the following manner:

[0092] When the flexible arm 30 is projected onto the second bending plane 52, the first projection can be obtained, such as... Figure 9As shown, in the first projection, the first constraint member G1 and the first constraint member G2 are arranged crosswise at the first straight pipe segment 31. In the first projection, the first constraint member and the second constraint member are inserted into the first joint assembly P1 and the second joint assembly P2 in a direction parallel to the axis L of the flexible arm 30. Because the first projection exhibits this pattern, when the flexible arm 30 bends in a certain direction, the lengths of the first constraint member G1 and the first constraint member G2 at the first straight pipe segment 31 remain unchanged. The length change of the first constraint member G1 within the first joint assembly P1 is k1. The length change of component G1 within the second joint assembly P2 is k2, where k1 and k2 represent elongation and shortening, respectively. K1 is always equal to k2. The length of the first constraint component remains constant when the flexible arm 30 bends in a certain direction. The length change of the first constraint component G2 within the first joint assembly P1 is k3, and the length change of the first constraint component G2 within the second joint assembly P2 is k4, where k3 and k4 represent elongation and shortening, respectively. K3 is always equal to k4. The length of the second constraint component remains constant when the flexible arm 30 bends in a certain direction. Specifically, when k1 is elongation, k3 is shortening; when k1 is shortening, k3 is elongation.

[0093] Similarly, if the first constraint member G3 and the first constraint member G4 are inserted into the first joint assembly P1 and the second joint assembly P2 in the manner described above, and the first constraint member G3 and the first constraint member G4 are projected onto the first bending plane 51, a second projection can be obtained. In the second projection, the first constraint member G3 and the first constraint member G4 are arranged in a cross configuration at the first straight pipe segment 31. In the second projection, the first constraint member G3 and the first constraint member G4 are inserted into the first joint assembly P1 and the second joint assembly P2 in a manner parallel to the axis L. Because the second projection exhibits the above-mentioned pattern, when the flexible arm 30 bends in a certain direction, the first constraint member G3 and the first constraint member G4 at the first straight pipe segment 31... The length of the first constraint member G3 remains constant within the first joint assembly P1. The length change of the first constraint member G3 within the second joint assembly P2 is k5, and the length change of the first constraint member G3 within the second joint assembly P2 is k6. One of k5 and k6 represents elongation, and the other represents shortening. k5 is always equal to k6. The length of the first constraint member G3 remains constant when the flexible arm 30 bends in a certain direction. Similarly, the length change of the first constraint member G4 within the first joint assembly P1 is k7, and the length change of the first constraint member G4 within the second joint assembly P2 is k8. One of k7 and k8 represents elongation, and the other represents shortening. k7 is always equal to k8. The length of the first constraint member G4 remains constant when the flexible arm 30 bends in a certain direction. Specifically, when k5 is elongation, k7 is shortening; when k5 is shortening, k7 is elongation.

[0094] When the flexible arm 30 bends, if the joint assembly moves laterally and produces an S-shaped deformation, the lengths of the first constraint member G1, the first constraint member G2, the first constraint member G3, and the first constraint member G4 will change. In this embodiment, when the flexible arm 30 bends, the lengths of the first constraint member G1, the first constraint member G2, the first constraint member G3, and the first constraint member G4 are kept constant, thereby constraining the S-shaped deformation of the first joint assembly P1 and the second joint assembly P2 when the flexible arm 30 bends.

[0095] It is understandable that there could be four second constraint members. For distinction, these four second constraint members are named second constraint member K1, second constraint member K2, second constraint member K3, and second constraint member K4, respectively. When the four second constraint members are threaded through the second joint assembly P2 and the third joint assembly P3 in the aforementioned 180° spiral configuration, the threading positions of second constraint members K1 and K2 on the second joint assembly P2 and the third joint assembly P3 are symmetrical about the first bending plane 51, and the threading positions of second constraint members K3 and K4 on the second joint assembly and the third joint assembly P3 are symmetrical about the second bending plane 52. The principle of symmetry regarding the bending plane is the same as that of the first constraint member and will not be repeated here.

[0096] The principle by which the second constraint members K1, K2, K3, and K4 constrain the S-shaped deformation of the second joint assembly P2 and the third joint assembly P3 when the flexible arm 30 bends is the same as the principle by which the first constraint members G1, G2, G3, and G4 constrain the S-shaped deformation of the first joint assembly P1 and the second joint assembly P2 when the flexible arm 30 bends, and will not be repeated here.

[0097] It is understandable that each joint assembly may include one spatial serpentine assembly, and each spatial serpentine assembly may be able to rotate relative to multiple rotation axes.

[0098] Of course, this is understandable. Figure 10As shown, each joint assembly may include two pairs of planar snake-like components. Specifically, the pair above the dashed line in the figure represents one pair of planar snake-like components, and the pair below the dashed line represents another pair. Each pair of planar snake-like components is rotatable about two parallel rotation axes. Each pair of planar snake-like components includes a first disk 71 and a second disk 72. The first surface 711 of the first disk 71 has two first connecting portions 712 spaced apart. The second disk 72 has a second surface 721 opposite to the first surface 711, and the second surface 721 has two second connecting portions 722 spaced apart. The first connecting portions 712 mate one-to-one with the second connecting portions 722. The two first connecting portions 712 are arranged in a first direction, and the two second connecting portions 722 are arranged in a second direction. The first and second directions are parallel to the rotation axes of the planar snake-like components. Specifically, as shown... Figure 10 and Figure 11 As shown, the first connecting portion 712 may have a first protrusion, and the second connecting portion 722 may have a first groove. When the first protrusion and the first groove mate, the first connecting portion 712 mates with the second connecting portion 722. Figure 12 As shown, the first connecting portion 712 may be provided with a first protruding tooth, and the second connecting portion 722 may be provided with a first concave tooth. When the first protruding tooth and the first concave tooth engage, the first connecting portion 712 engages with the second connecting portion 722. Figure 13 As shown, the first connecting part 712 has two first mating holes spaced apart in a direction perpendicular to the rotation axis, and the second connecting part 722 has two second mating holes spaced apart in a direction perpendicular to the rotation axis. When one end of the cross member is located in the first mating hole and the other end of the cross member is located in the second mating hole, the first connecting part 712 mates with the second connecting member through the cross member; wherein, as Figure 13 As shown, the crossing component can be a crossing spring, or it can be a crossing rope, i.e., two ropes crossing together; for example... Figure 14 As shown, the first connecting part 712 may be provided with two cams, one long and one short, and the second connecting part 722 may be provided with two matching holes. Each cam corresponds to one matching hole in a one-to-one manner. When the cams are engaged with the matching holes, the first connecting part 712 is engaged with the second connecting part 722. Each pair of planar serpentine components also includes a support structure, which is used to keep the center distance between the first disk 71 and the second disk 72 constant. The structure of the support structure is the same as that in the prior art and will not be described in detail here.

[0099] like Figure 13As shown, when two pairs of planar snake-bone components are connected together to form a joint assembly, the second disk 72 of the second pair of planar snake-bone components can be connected to the first disk 71 of the first pair of planar snake-bone components. Specifically, the first disk 71 of each pair of planar snake-bone components is also provided with a third surface 713 opposite to the first surface 711, and the second disk 72 of each pair of planar snake-bone components is also provided with a fourth surface 723 opposite to the second surface 721. When two pairs of planar snake-bone components are connected together to form a joint assembly, the third surface 713 of the first disk 71 of the first pair of planar snake-bone components can be connected to the fourth surface 723 of the second disk 72 of the second pair of planar snake-bone components. After the connection is completed, a joint assembly is formed.

[0100] In each joint assembly, the first pair of planar serpentine components can rotate relative to a first and a second parallel rotation axis, and the second pair of planar serpentine components can rotate relative to a third and a fourth parallel rotation axis. The second and third rotation axes can be orthogonally arranged.

[0101] The rotation axes of two adjacent joint components can be arranged in the following two ways:

[0102] like Figure 15 As shown, the first joint assembly P1 includes a first pair of planar serpentine assemblies and a second pair of planar serpentine assemblies arranged sequentially from proximal to distal end; the second joint assembly P2 includes a third pair of planar serpentine assemblies and a fourth pair of planar serpentine assemblies arranged sequentially from proximal to distal end; the first pair of planar serpentine assemblies rotates about a first rotation axis m1 and a second rotation axis m2; the second pair of planar serpentine assemblies rotates about a third rotation axis m3 and a fourth rotation axis m4, with the second rotation axis m2 and the third rotation axis m3 being orthogonally distributed; the third pair of planar serpentine assemblies rotates about a fifth rotation axis m5 and a sixth rotation axis m6; the fourth pair of planar serpentine assemblies rotates about a seventh rotation axis m7 and a third rotation axis m8, with the sixth rotation axis m6 and the fourth rotation axis m7 being orthogonally distributed;

[0103] (i)If Figure 15 As shown, when the first rotation axis m1, the second rotation axis m2, the fifth rotation axis m5 and the sixth rotation axis m6 are arranged in parallel, and the third rotation axis m3, the fourth rotation axis m4, the seventh rotation axis m7 and the third rotation axis m8 are arranged in parallel, the rotation axes of the first joint assembly P1 and the second joint assembly P2 will be arranged in an ABAB pattern.

[0104] (ii) When the first rotation axis m1, the second rotation axis m2, the seventh rotation axis m7 and the third rotation axis m8 are arranged in parallel, and the third rotation axis m3, the fourth rotation axis m4, the fifth rotation axis m5 and the sixth rotation axis m6 are arranged in parallel, the rotation axes of the first joint assembly P1 and the second joint assembly P2 will be arranged in an ABBA pattern.

[0105] Example 3:

[0106] Based on the first embodiment described above, this embodiment takes the first constraint component 61 and the second constraint component 62 as examples to explain the second method of the constraint components being installed within the joint assembly:

[0107] The method of attaching the first constraint component 61:

[0108] like Figure 16 , Figure 17 , Figure 18 and Figure 19 As shown, in this embodiment, the first joint assembly P1 and the second joint assembly P2 are directly connected; each first constraint member is spiraled 360° within the first joint assembly P1 and the second joint assembly P2. The 360° spiral arrangement means that when the first constraint member is fixed at position A5 near the proximal end of the first joint assembly P1 and at position A6 near the distal end of the second joint assembly P2, A5 and A6 coincide when projected onto a plane perpendicular to the axis L of the flexible arm 30.

[0109] It is understandable that each first constraint member can be spiraled 180° within the first joint assembly P1, and each first constraint member can be spiraled 180° within the second joint assembly P2.

[0110] It is understandable that each joint assembly may include one spatial serpentine assembly. In this case, the first constraint member can be spiraled 180° within the first joint assembly P1 and 180° within the second joint assembly P2. A 180° spiral means that when the first constraint member's insertion position within a joint assembly is A7 and its exit position within a joint assembly is A8, A7 and A8 are located on either side of the axis L of the flexible arm 30. When A7, A8, and the axis L of the flexible arm 30 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A7, A8, and the axis L of the flexible arm 30 can form a central angle of 180°.

[0111] It is understandable that each joint assembly may include two pairs of planar serpentine components. In this case, if the first joint assembly P1 includes a first pair and a second pair of planar serpentine components, and the second joint assembly P2 includes a third pair and a fourth pair of planar serpentine components, then the first constraint member can be spiraled at 90° within the first pair of planar serpentine components, spiraled at 90° within the second pair of planar serpentine components, spiraled at 90° within the third pair of planar serpentine components, and spiraled at 90° within the fourth pair of planar serpentine components. A 90° spiral means that when the insertion position of each first constraint member within a joint assembly is A9 and the exit position within the joint assembly is A10, when A9, A10, and the axis L of the flexible arm 30 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A9, A10, and the axis L of the flexible arm 30 can form a 90° central angle. In this embodiment, the rotation axes of the first joint assembly P1 and the second joint assembly P2 can be arranged in an ABAB pattern, or the rotation axes of the first joint assembly P1 and the second joint assembly P2 can be arranged in an ABBA pattern.

[0112] It is understandable that in this embodiment, there may be four first constraint members, namely first constraint member G1, first constraint member G2, first constraint member G3 and first constraint member G4. The first constraint members G1, first constraint member G2, first constraint member G3 and first constraint member G4 are symmetrical about the axis L of the flexible arm 30.

[0113] In this embodiment, when the flexible arm 30 bends, the lengths of the first constraint member G1, the first constraint member G2, the first constraint member G3 and the first constraint member G4 can remain unchanged, thereby constraining the S-shaped deformation generated by the first joint assembly P1 and the second joint assembly P2.

[0114] It is understandable that the second joint assembly P2 and the third joint assembly P3 can be directly connected; each second constraint member is spiraled 360° within the second joint assembly P2 and the third joint assembly P3. The specific insertion method of the second constraint member is the same as that of the first constraint member, and will not be described again here.

[0115] As can be seen, in this embodiment, the flexible arm 30 does not have a straight tube 91 section, so the structure of the flexible arm 30 is more compact.

[0116] It is understandable that, in practice, the above-mentioned embodiments two and three can be used in combination. That is, when the flexible arm 30 includes a first joint assembly P1, a second joint assembly P2 and a third joint assembly P3 connected sequentially from the proximal end to the distal end, the first restraint assembly 61 can be threaded in the first joint assembly P1 and the second joint assembly P2 in a 180° spiral manner, and the second restraint assembly 62 can be threaded in the second joint assembly P2 and the third joint assembly P3 in a 360° spiral manner.

[0117] Example 4:

[0118] As can be seen from the above, two sets of constraint components are threaded through the three adjacent joint components. The different threading methods of the two sets of constraint components will result in different bending conditions of the three joint components. This will be explained in detail below:

[0119] like Figure 20 and Figure 21 As shown, the flexible arm 30 has three adjacent joint components, namely the first joint component P1, the second joint component P2 and the third joint component P3. The flexible arm 30 also has two sets of constraint components, namely the first constraint component 61 and the second constraint component 62. The first constraint component 61 is inserted into the first joint component P1 and the second joint component P2, and the second constraint component 62 is inserted into the second joint component P2 and the third joint component P3. Figure 20 This is a schematic diagram showing the first constraint component 61 and the second constraint component 62 inserted into the three joint components in a 180° insertion manner. Figure 21 This is a schematic diagram showing the first constraint component 61 and the second constraint component 62 being inserted into the three joint components in a 360° insertion manner.

[0120] like Figure 20 and Figure 21As shown, in the first joint assembly P1, the distance from each first constraint member in the first constraint assembly 61 to the axis L of the flexible arm 30 is b1; in the second joint assembly P2, the distance from each first constraint member in the first constraint assembly 61 to the axis L of the flexible arm 30 is b2, and the distance from each second constraint member in the second constraint assembly 62 to the axis L of the flexible arm 30 is b3; in the third joint assembly P3, the distance from each second constraint member in the second constraint assembly 62 to the axis L of the flexible arm 30 is b4; when the first drive rope 81 drives the flexible arm 30 to bend upward, the bending angle of the first joint assembly P1 is θ1, the bending angle of the second joint assembly P2 is θ2, and the bending angle of the third joint assembly P3 is θ3; when the flexible arm 30 bends, the first constraint assembly... The change in each first constraint member within 61 within the first joint assembly P1 is t1, and the change in the second joint assembly P2 is t2; where t1 and t2 represent elongation and shortening, respectively; t1 satisfies the following relationship (1), and t2 satisfies the following relationship (2); when the flexible arm 30 bends, the change in each second constraint member within the second constraint assembly 62 within the second joint assembly P2 is t3; and the change in the third joint assembly P3 is t4; where t3 and t4 represent elongation and shortening, respectively; t3 satisfies the following relationship (3), and t4 satisfies the following relationship (4); since t1 = t2 and t3 = t4, when b1, b2, b3, and b4 exhibit different relationships, the bending conditions of the three joint assemblies are as follows:

[0121]

[0122]

[0123] (i)If Figure 20 and Figure 22 As shown, when b1 = b2 and b3 = b4, according to the above relationships (1), (2), (3), and (4), it can be seen that θ1 = θ2 = θ3, that is, the bending angles of the three joint components are equal; Figure 22 As shown, when the bending angles of the three joint components are equal, the flexible arm 30 can achieve constant curvature bending. When the flexible arm 30 can achieve constant curvature bending, the bending shape of the flexible arm 30 is fixed, which facilitates the control of the drive unit inside the instrument box 10, and the overall ability of the flexible arm 30 to resist S-shaped deformation is greatly improved.

[0124] (ii) such as Figure 23 As shown, when b1 = b2 and b3 ≠ b4, according to the above relationships (1), (2), (3), and (4), it can be seen that θ1 = θ2 ≠ θ3, and the bending angles of the three joint components are not completely equal. Figure 24As shown, when the bending angles of the three joint components are not completely equal, the flexible arm 30 can achieve non-uniform curvature bending.

[0125] (iii) When b1≠b2 and b3=b4, according to the above relations (1), (2), (3) and (4), it can be seen that θ1≠θ2=θ3, the bending angles of the three joint components are not completely equal. When the bending angles of the three joint components are not completely equal, the flexible arm 30 can achieve non-uniform curvature bending.

[0126] (iv) When b1≠b2, b3≠b4, and b1 / b2≠b4 / b3, according to the above relationships (1), (2), (3) and (4), it can be seen that θ1≠θ2≠θ3, and the bending angles of the three joint components are completely unequal. When the bending angles of the three joint components are completely unequal, the flexible arm 30 can achieve non-uniform curvature bending.

[0127] When the flexible arm 30 achieves non-uniform curvature bending, the shape of the flexible arm 30 is unique and fixed, and it can be applied to some scenarios where it is easier to stretch compared to uniform curvature bending.

[0128] Example 5:

[0129] like Figure 25 As shown, in this embodiment, the flexible arm 30 includes a first joint assembly P1, a second joint assembly P2, and a third joint assembly P3 connected sequentially from proximal to distal end. The flexible arm 30 also includes a straight tube 91 and a target joint assembly 92; wherein, the proximal end of the straight tube 91 is connected to the distal end of the target joint assembly 92, and the distal end of the straight tube 91 is connected to the proximal end of the first joint assembly P1. Wherein, as... Figure 26 As shown, multiple second drive ropes 82 are threaded through the target joint assembly 92. The second drive ropes 82 are threaded through the target joint assembly 92 in a direction parallel to the vertical axis L of the flexible arm 30. The distal end of the second drive rope 82 is fixed to the distal end of the target joint assembly 92, and the proximal end of the second drive rope 82 is connected to the drive unit in the instrument box 10. The structure of the target joint assembly 92 is the same as that of a single joint assembly in the above embodiment, and will not be described again here. Multiple first drive ropes 81 and two sets of restraints are threaded through the first joint assembly P1, the second joint assembly P2, and the third joint assembly P3. The first drive ropes 81 are threaded in the three joint assemblies, the long straight tube 20, and the target joint assembly 92 in a direction parallel to the axis L of the flexible arm 30. The distal end of the first drive rope 81 is fixed at any position within the three joint assemblies, and the proximal end of the first drive rope 81 is connected to the drive unit in the instrument box 10. The two sets of restraints can be threaded in the three joint assemblies in a 180° threading manner as described in the previous embodiment; or they can be threaded in the three joint assemblies in a 360° threading manner as described in the previous embodiment.

[0130] In this embodiment, the three joint components within the flexible arm 30 form the second flexible segment, and the target joint component 92 within the flexible arm 30 forms the second flexible segment. Figure 27 This is a schematic diagram of the bending of the flexible arm 30, as shown below. Figure 27 As shown, in the structure of the flexible arm 30 in this embodiment, the first flexible segment can be bent at a certain angle. For example, the first flexible segment can be bent at 45° to 50°, and the second flexible segment has a larger bending angle. For example, the second flexible segment can be bent at 135° to 150°. The flexible arm 30 has a larger working space and a stronger load-bearing capacity.

[0131] Example 6:

[0132] In this embodiment, a flexible segment is formed by a first joint assembly P1, a second joint assembly P2, and a third joint assembly P3 connected sequentially from proximal to distal end. The flexible arm 30 includes multiple flexible segments connected sequentially from proximal to distal end. Simultaneously, the flexible arm 30 can constrain the S-shaped deformation generated by each joint assembly within the flexible arm 30 when it bends, as described in the above embodiment.

[0133] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A flexible arm, characterized in that, The flexible arm includes: The first joint assembly, the second joint assembly, and the third joint assembly are connected sequentially from proximal to distal; A first constraint component is disposed within the first joint component and the second joint component. The first constraint component includes a plurality of first constraint members. The proximal end of each first constraint member is fixed to the proximal end of the first joint component, and the distal end of each first constraint member is fixed to the distal end of the second joint component. Each first constraint member is spiraled at a first preset angle. The second constraint component is inserted into the second joint component and the third joint component. The second constraint component includes a plurality of second constraint members. The proximal end of each second constraint member is fixed to the proximal end of the second joint component, and the distal end of each second constraint member is fixed to the distal end of the third joint component. Each second constraint member is spiraled at a second preset angle. The first constraint component and the second constraint component are interleaved within the second joint component.

2. The flexible arm according to claim 1, characterized in that, The flexible arm has an axis, and each of the first constraint members is inserted into the first joint assembly in a direction parallel to the axis. At the connection between the first joint assembly and the second joint assembly, the first constraint member is spiraled at 180° and inserted into the second joint assembly in a direction parallel to the axis. And / or, each of the second constraint members is inserted into the second joint assembly in a direction parallel to the axis, spirals at 180° at the connection between the second joint assembly and the third joint assembly, and is inserted into the third joint assembly in a direction parallel to the axis.

3. The flexible arm according to claim 2, characterized in that, The first joint assembly is connected to the second joint assembly via a first straight pipe segment, and each of the first constraint members is spiraled at 180° at the first straight pipe segment; And / or, the second joint assembly is connected to the third joint assembly via a second straight tube segment, each of the second constraint members being spiraled at 180° at the second straight tube segment.

4. The flexible arm according to claim 1, characterized in that, Each of the first constraint members is spiraled 360° within the first joint assembly and the second joint assembly; And / or, each of the second constraint members is spiraled 360° within the second joint assembly and the third joint assembly.

5. The flexible arm according to claim 4, characterized in that, Each of the first constraint members is spiraled at 180° within the first joint assembly and at 180° within the second joint assembly; And / or, each of the second constraint members is helically wound at 180° within the second joint assembly and at 180° within the third joint assembly.

6. The flexible arm according to claim 1, characterized in that, The flexible arm has an axis, which is the intersection of a first bending plane and a second bending plane; The first constraint member is provided in four parts, wherein two of the first constraint members are symmetrical about the first bending plane in the positions of their insertion on the first joint assembly and the second joint assembly, and the other two first constraint members are symmetrical about the second bending plane in the positions of their insertion on the first joint assembly and the second joint assembly. The second constraint member is provided in four parts, wherein two of the second constraint members are symmetrical about the first bending plane in the positions through which they pass on the second joint assembly and the third joint assembly, and the other two second constraint members are symmetrical about the second bending plane in the positions through which they pass on the second joint assembly and the third joint assembly.

7. The flexible arm according to claim 6, characterized in that, In the first joint assembly, the center distance from each first constraint member to the axis is b1; in the second joint assembly, the center distance from each first constraint member to the axis is b2, and the center distance from each second constraint member to the axis is b3; in the third joint assembly, the center distance from each second constraint member to the axis is b4; the bending angle of the first joint assembly is θ1, the bending angle of the second joint assembly is θ2, and the bending angle of the third joint assembly is θ3. When b1 = b2 and b3 = b4, θ1 = θ2 = θ3; When b1 = b2 and b3 ≠ b4, θ1 = θ2 ≠ θ3; When b1≠b2 and b3=b4, θ1≠θ2=θ3; When b1≠b2, b3≠b4, and b1 / b2≠b4 / b3, then θ1≠θ2≠θ3.

8. The flexible arm according to claim 1, characterized in that, Each joint assembly includes two pairs of planar serpentine assemblies. In each joint assembly, the first pair of planar serpentine assemblies rotates relative to a first and a second parallel rotation axis, and the second pair of planar serpentine assemblies rotates relative to a third and a fourth parallel rotation axis. The second and third rotation axes are orthogonally arranged.

9. The flexible arm according to claim 1, characterized in that, Each joint assembly includes one spatial serpentine assembly, and each spatial serpentine assembly is capable of rotating relative to multiple rotation axes.

10. The flexible arm according to any one of claims 1-9, characterized in that, The first joint assembly, the second joint assembly, and the third joint assembly, connected sequentially from proximal to distal, form a flexible segment, and the flexible arm includes a plurality of the flexible segments connected sequentially from proximal to distal.

11. The flexible arm according to any one of claims 1-9, characterized in that, The flexible arm also has a straight tube and a target joint assembly, the proximal end of the straight tube being connected to the distal end of the target joint assembly, and the distal end of the straight tube being connected to the proximal end of the first joint assembly.

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