Two-segment wire-driven continuum soft robot structure

Abstract

The application discloses a two-section line-driven minimally invasive surgery continuum robot structure and belongs to the technical field of minimally invasive medical instruments and robots. The structure mainly comprises a proximal continuum section, a distal continuum section, a central hose, four proximal driving wires and four distal driving wires. The outer diameter of the proximal continuum section is greater than that of the distal continuum section, the two are connected in series, and the central hose for accommodating a minimally invasive surgery instrument is arranged through the center. The core of the application is that the inner and outer ring layered wiring design is adopted, the four distal driving wires are extended and fixed to the distal end through the inner ring wire passing holes of the proximal interval disc, and the four proximal driving wires are fixed to the proximal end through the outer ring wire passing holes. The application realizes independent decoupling control of two-section continuum multi-degree-of-freedom bending through layered wiring, effectively eliminates motion interference, and cooperates with the variable-diameter design and the gap mechanical limiting to greatly improve the robot end obstacle avoidance flexibility and the narrow space penetration force, and ensure the anti-buckling safety of the central working lumen in the limit bending state.

Description

Technical Field

[0001] This invention relates to the field of minimally invasive medical devices and robotics, specifically to a two-segment linearly driven continuum soft robot structure with a central working cavity and decoupled control with multiple degrees of freedom. Background Technology

[0002] Continuum robots, with their absence of traditional rigid joints, high redundancy of degrees of freedom, and excellent structural compliance, have shown great application potential in minimally invasive medicine and the exploration of complex and narrow industrial environments. Compared to traditional rigid surgical instruments, line-driven continuum robots can conform to complex anatomical structures, achieving continuous and compliant bending in unstructured environments like biological tentacles. This effectively avoids rigid collisions with surrounding tissues or tube walls, significantly reducing pressure and damage to the operating environment.

[0003] As minimally invasive medical and precision detection technologies extend into deeper, narrower, and more complex areas with numerous bends, traditional single-segment continuous robots, limited by their single bending form, can no longer meet the clinical or engineering needs of navigating complex obstacles. Therefore, the industry has gradually proposed multi-segment line-driven continuous robot structures. By arranging multiple sets of independent drive cables in different segments, it is theoretically possible to endow the robot with multi-degree-of-freedom spatial reach and greater end-effector flexibility.

[0004] However, when meeting the demands for high-precision operation in more extreme micro-spaces, existing multi-segment line driven continuum robots still face the following pressing technical challenges:

[0005] In traditional multi-segment drive structures, the distal drive cable is usually arranged on the same circumferential surface as the proximal drive cable or runs randomly. This makes it easy for bending deformation of the proximal segment to cause unexpected changes in the path length of the distal drive cable, resulting in strong tension and friction, causing severe motion coupling and significantly reducing the accuracy of independent decoupling control at the end.

[0006] Minimally invasive surgery not only requires robots to precisely reach the lesion, but also needs to provide safe passageways for the miniature surgical forceps, laser scalpels, or endoscopes inside. Existing partial continuum structures are prone to buckling, deformation, or even closure of the central channel when subjected to large-angle extreme bending, leading to jamming of internal surgical instruments and making it difficult to ensure the smoothness and safety of the operation.

[0007] Existing multi-segment continuous structures mostly adopt a homogeneous design with equal diameters at the top and bottom. If the overall outer diameter of the structure is reduced in order to penetrate extremely narrow spaces, the stiffness of the near-end foundation support is severely insufficient, and it cannot resist the reaction force generated during end-operation. If the overall outer diameter is increased in order to ensure stiffness, the end lacks the ability to penetrate small spaces, thus limiting the application scenarios. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a two-segment linearly driven minimally invasive surgical continuum robot structure, which solves the problems of severe motion coupling interference, easy buckling of working cavities, and difficulty in balancing stiffness and flexibility in existing continuum robots in extremely confined spaces.

[0009] To achieve the above objectives, the present invention adopts the following technical solution;

[0010] A two-segment wire-driven minimally invasive surgical continuum robot structure, characterized in that it includes a base, a proximal continuum segment, a distal continuum segment, a central flexible tube, four proximal drive wires, and four distal drive wires.

[0011] One end of the proximal continuous segment is connected to the base, and the other end is connected to the distal continuous segment. The outer diameter of the proximal continuous segment is larger than the outer diameter of the distal continuous segment.

[0012] The proximal continuum segment includes several proximal spacers, which are connected by a flexible trunk. The sidewalls of the proximal spacers are alternately provided with orthogonally arranged flexible curved notches. The proximal spacer is provided with a first central through hole and eight proximal wire passage holes arranged around the first central through hole. The eight proximal wire passage holes are divided into four distal drive wire channels in the inner circle and four proximal drive wire channels in the outer circle.

[0013] The distal continuum segment includes several distal spacer discs, and a flexible main trunk connects adjacent distal spacer discs. A second central through hole and four distal drive wire holes arranged around the second central through hole are provided on the distal spacer disc along the axial direction.

[0014] The central flexible tube passes through the first central through hole and the second central through hole in sequence.

[0015] The four distal drive wires pass through the four distal drive wire channels of the inner ring of the proximal continuum segment, and extend through the four distal drive wire holes of the distal continuum segment, with their ends fixed to the end of the distal continuum segment.

[0016] The four proximal drive wires pass through the four proximal drive wire channels of the outer ring of the proximal continuum segment, and their ends are fixed to the end of the proximal continuum segment.

[0017] To optimize the above technical solution, the specific measures also include:

[0018] Furthermore, two adjacent flexible bending notches on the sidewall of the proximal continuum segment are arranged at a 90-degree angle in space, and the flexible bending notches are V-shaped or U-shaped groove structures.

[0019] Furthermore, the closing angle of the flexible bending notch constitutes the maximum bending mechanical limit in the bending direction of the proximal continuous segment, which is used to prevent excessive bending from causing buckling of the internal central hose.

[0020] Furthermore, the four distal drive wire holes of the distal continuum segment and the four distal drive wire channels of the inner ring of the proximal continuum segment are radially corresponding and distributed in the same straight line, so that the distal drive wires are arranged along the neutral axis close to the central hose.

[0021] Furthermore, the proximal drive wire channel, the distal drive wire channel, and the distal drive wire hole all have smooth chamfered structures at both ends.

[0022] Furthermore, both the proximal continuous segment and the distal continuous segment are integrally formed structures.

[0023] Furthermore, the base is a stepped mounting bracket with four independent drive motors distributed on it; each drive motor has a flanged winding wheel fixed on its output shaft.

[0024] Furthermore, the four proximal drive wires and the four distal drive wires are grouped into pairs to form four pairs of antagonistic drive wire groups; each pair of antagonistic drive wire groups is wound in opposite directions on the same flanged winding wheel, and the drive wire on one side is wound up and the drive wire on the other side is released by the forward and reverse rotation of the drive motor.

[0025] Furthermore, the flanged winding wheel is provided with flanged flanges on both sides to prevent the drive wire from slipping or becoming tangled during high-speed winding and unwinding.

[0026] Furthermore, a tapered guide bracket (or transition wire block) is provided at the connection between the base and the proximal continuous segment; the tapered guide bracket has a wire hole that converges towards the center, which is used to smoothly guide and gather the drive wire with a relatively wide spacing on the winding wheel into the proximal wire hole of the proximal continuous segment.

[0027] The beneficial effects of this invention are:

[0028] This invention innovatively places the distal drive wire in the inner ring of the proximal spacer and the proximal drive wire in the outer ring. The distal wire is closer to the robot's neutral axis, which greatly suppresses the coupling and pulling interference of proximal bending on the distal pose, and realizes independent decoupling control of the two continuum segments.

[0029] The central flexible tube runs through both main sections and cleverly utilizes the closing angle of the flexible bend notch in the external continuum as a mechanical limit. When the bending limit is reached, the notch closes, preventing further pressure and deformation of the central channel and ensuring the smooth and safe passage of internal surgical instruments.

[0030] It adopts a two-segment structural design with a thicker near end and a thinner far end. The thicker near end retains sufficient structural rigidity and basic support, while the thinner far end greatly improves the penetration and obstacle avoidance flexibility of the end in extremely narrow and winding spaces.

[0031] Adopting a "one machine, two wires" antagonistic drive mode, only 4 drive motors are needed to control 8 drive wires, which greatly reduces the size and weight of the base; in conjunction with a flanged winding wheel, it effectively prevents the drive wires from slipping, jumping out of grooves or jamming due to frequent tension, thus ensuring the stability of the transmission.

[0032] An innovative tapered guide bracket was added between the wide-spacing arrangement of the motors and the compact arrangement of the continuous body. This structure enables a smooth geometric transition in the trajectory of the drive wire, avoiding severe friction and stress concentration caused by excessive bends in the drive wire, and extending the fatigue life of the cable. Attached Figure Description

[0033] Figure 1 This is a side view of the overall structure of the two-segment continuous robot of the present invention;

[0034] Figure 2 This is a side view of the main structure of the two-segment continuous flexible arm of the present invention;

[0035] Figure 3 This is a schematic diagram of the three-dimensional structure of a single-segment spacer disk at the proximal end of the continuum robot of the present invention;

[0036] Figure 4 This is a schematic diagram of the three-dimensional structure of a single-segment spacer disk at the distal end of the continuum robot of the present invention;

[0037] Explanation of reference numerals: 1. Base; 2. Winding wheel; 3. Flange baffle; 4. Drive motor; 5. Guide bracket; 6. Proximal continuous section; 7. Distal continuous section; 9. Center through hole; 61-66. Proximal spacer disc; 71-76. Distal spacer disc; 67. Proximal drive line through hole; 77. Distal drive line through hole. Detailed Implementation

[0038] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0039] This invention provides a two-segment, line-driven, minimally invasive surgical continuum robot structure, such as... Figures 1 to 4As shown, the system includes a base 1, a proximal continuous segment 6, a distal continuous segment 7, a central flexible tube, four proximal drive wires, and four distal drive wires. This robot system mainly consists of three parts: the drive end, the transition end, and the actuator end.

[0040] like Figure 1 As shown, the base 1 is a stepped motor mounting bracket with four independent drive motors 4 staggered on it. In a preferred embodiment, the drive motors 4 can be high-precision stepper motors or servo motors. A winding wheel 2 is fixedly mounted on the output shaft of each drive motor 4. Protruding flange baffles 3 are provided on both sides of the winding wheel 2. Four near-end drive wires and four far-end drive wires are grouped in pairs to form four pairs of antagonistic drive wire groups. Each pair of antagonistic drive wire groups is wound in opposite directions from top to bottom onto the same winding wheel 2. When the drive motors 4 rotate forward or reverse, the winding of one side of the drive wire and the release of the other side of the drive wire can be realized simultaneously, that is, "one machine, two wires" antagonistic drive, so that the precise control of eight drive wires is achieved with four drive motors 4, which greatly reduces the size of the drive module.

[0041] like Figure 1 and Figure 2 As shown, a guide bracket 5 (a funnel-shaped conical transition block) is fixedly installed at the connection between the base 1 and the proximal continuous segment 6. The guide bracket 5 has a smooth wire channel that converges towards the center inside. In a preferred embodiment, because the four drive motors 4 are widely spaced on the base 1, and the diameter of the continuous robotic arm is extremely small, the guide bracket 5 can smoothly gather and guide the widely distributed drive wires to the entrance of the proximal continuous segment 6, effectively reducing the frictional resistance of the drive wires and avoiding stress concentration.

[0042] like Figure 2 As shown, the proximal continuum segment 6 is composed of multiple proximal spacer discs (61-66) connected in series; the distal continuum segment 7 is composed of multiple distal spacer discs (71-76) connected in series, forming a stepped, two-segment variable-diameter structure. This design provides sufficient support stiffness at the proximal end, while the distal end possesses extremely high penetration and flexibility in extremely confined spaces. All spacer discs are aligned along the axis.

[0043] like Figure 3 and Figure 4As shown, a central through-hole 9 is provided at the very center of both the proximal spacer discs 61-66 and the distal spacer discs 71-76. A flexible central tube passes sequentially through all the central through-holes 9, extending from the base 1 to the distal spacer disc 76, forming a central working channel for accommodating minimally invasive surgical instruments (such as laser scalpels, biopsy forceps, or endoscopes). Furthermore, V-shaped or U-shaped flexible bending notches arranged orthogonally at 90-degree angles are alternately formed on the sidewalls of the proximal continuum segment 6 and the distal continuum segment 7. In a preferred embodiment, the closing angle of the notch constitutes the maximum bending limit of the robotic arm; when the bending reaches the design limit, the two sidewalls of the notch physically close, fundamentally preventing the internal central tube from buckling under pressure.

[0044] like Figure 3 As shown, on the proximal spacer (61-66) of the proximal continuum segment, eight proximal drive line through holes 67 are formed around the periphery of the central through hole 9. These eight proximal drive line through holes 67 are divided into inner and outer rings (or into an inner group closer to the neutral axis and an outer group farther from the neutral axis). Figure 4 As shown, four remote drive line through holes 77 are provided around the central through hole 9 on the remote spacer disk (71-76) of the remote continuous segment.

[0045] The specific wiring path is as follows: After passing through the guide bracket 5, the four distal drive wires enter the proximal drive wire through hole 67 of the inner ring of the proximal spacer (61-66), and then enter the distal drive wire through hole 77 of the distal spacer (71-76), and are finally fixed on the distal end (distal spacer 76); after passing through the guide bracket 5, the four proximal drive wires enter the proximal drive wire through hole 67 of the outer ring of the proximal spacer (61-66), and are finally fixed on the proximal end (proximal spacer 66).

[0046] By rotating the drive motor 4, the proximal drive wire of the outer ring is driven backward, enabling independent bending deformation of the proximal continuous segment in direction 6. Similarly, by rotating the drive motor 4, the distal drive wire of the inner ring is driven backward, enabling independent bending deformation of the distal continuous segment in direction 7. Because the distal drive wire is located in the inner ring close to the neutral axis of the robotic arm, the motion coupling effect on the distal drive wire is greatly suppressed during large bending of the proximal end, thus easily achieving multi-degree-of-freedom obstacle avoidance operations.

[0047] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. 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.

[0048] The above description is merely of preferred embodiments of the present invention. It should be understood that the scope of protection of the present invention is not limited to the above embodiments. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention, or any combination of features of the embodiments without conflict, should be considered within the scope of protection of the present invention.

Claims

1. A two-segment, line-driven, minimally invasive surgical continuum robot structure, characterized in that, include: Base (1), proximal continuum segment (6), distal continuum segment (7), central hose, four proximal drive wires and four distal drive wires; One end of the proximal continuum segment (6) is connected to the base (1), and the other end is connected to the distal continuum segment (7), and the outer diameter of the proximal continuum segment (6) is larger than the outer diameter of the distal continuum segment (7); The proximal continuum segment (6) includes several proximal spacer discs (61-66), which are connected by a flexible trunk. The sidewalls of the proximal spacer discs are alternately provided with orthogonally arranged flexible curved notches. The proximal spacer disc is provided with a first central through hole (9) and eight proximal drive wire through holes (67) arranged around the first central through hole (9). The eight proximal drive wire through holes (67) are divided into four distal drive wire channels in the inner ring and four proximal drive wire channels in the outer ring. The distal continuum segment (7) includes several distal spacer discs (71-76), and a flexible main trunk is connected between adjacent distal spacer discs. A second central through hole (9) and four distal drive line through holes (77) are arranged around the second central through hole on the distal spacer disc along the axial direction. The central flexible tube passes through the first central through hole and the second central through hole in sequence. The four distal drive wires pass through the four distal drive wire channels of the inner ring of the proximal continuum segment (6) and extend through the four distal drive wire through holes (77) of the distal continuum segment (7), with their ends fixed to the end of the distal continuum segment (7). The four proximal drive wires pass through the four proximal drive wire channels of the outer ring of the proximal continuum segment (6), and their ends are fixed to the end of the proximal continuum segment (6).

2. The two-segment linearly driven minimally invasive surgical continuum robot structure according to claim 1, characterized in that: The two adjacent flexible bending notches on the sidewall of the proximal continuum segment (6) are arranged at a 90-degree angle in space, and the flexible bending notches have a V-shaped or U-shaped groove structure.

3. The two-segment linearly driven minimally invasive surgical continuum robot structure according to claim 2, characterized in that: The closing angle of the flexible bending notch constitutes the maximum bending mechanical limit of the proximal continuous segment (6) in the corresponding bending direction, which is used to prevent excessive bending from causing the internal central hose to buckle under pressure.

4. The two-segment linearly driven minimally invasive surgical continuum robot structure according to claim 1, characterized in that: The four distal drive wire through holes (77) of the distal continuum segment (7) correspond radially to the four distal drive wire channels of the inner ring of the proximal continuum segment (6) and are on the same straight line, so that the distal drive wires are arranged along the neutral axis close to the central hose.

5. The two-segment linearly driven minimally invasive surgical continuum robot structure according to claim 1, characterized in that: The base (1) is a stepped motor mounting bracket with four independent drive motors (4) distributed on it; each drive motor (4) has a winding wheel (2) fixed on its output shaft, and both sides of the winding wheel (2) are provided with protruding flange baffles (3).

6. The two-segment linearly driven minimally invasive surgical continuum robot structure according to claim 5, characterized in that: The four proximal drive wires and the four distal drive wires are grouped into pairs to form four pairs of antagonistic drive wire groups; each pair of antagonistic drive wire groups is wound in opposite directions from top to bottom onto the same winding wheel (2), configured to achieve the winding of one side of the drive wire and the release of the other side of the drive wire through the rotation of the drive motor (4).

7. The two-segment linearly driven minimally invasive surgical continuum robot structure according to claim 1, characterized in that: A guide bracket (5) is fixedly installed at the connection between the base (1) and the proximal continuous segment (6). The guide bracket (5) has a smooth wire channel that converges towards the center, which is used to smoothly gather the widely distributed drive wires and guide them into the proximal drive wire through hole (67) of the proximal continuous segment (6).

8. The two-segment linearly driven minimally invasive surgical continuum robot structure according to claim 1, characterized in that: Both ends of the near-end drive line through hole (67) and the far-end drive line through hole (77) are provided with a smooth chamfer structure.

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