Flexible operation arm for orthopedic surgery

Abstract

The flexible operation arm comprises a base vertebra joint, middle vertebra joints and a tail end vertebra joint, after the middle vertebra joints are sequentially connected in series, the head of the middle vertebra joints is connected with the base vertebra joint, and the tail of the middle vertebra joints is connected with the tail end vertebra joint; driving wire threading holes and rectangular elastic beam threading holes are formed in the base vertebra joint, the middle vertebra joint and the tail end vertebra joint, and a driving wire penetrates through the driving wire threading holes to achieve connection of the base vertebra joint, the middle vertebra joint and the tail end vertebra joint. A rectangular elastic beam penetrates through the rectangular elastic beam threading hole to realize the connection of the base vertebra joint, the middle vertebra joint and the tail end vertebra joint; and working channels are formed in the base vertebra joint, the middle vertebra joint and the tail end vertebra joint.

Description

Technical Field

[0001] The present invention relates to the field of robotic arms, and in particular discloses a flexible operating arm for orthopedic surgery. Background Art

[0002] Although the existing continuum manipulator configuration design can achieve continuous bending and has high operational flexibility in minimally invasive orthopedic surgery, its rigidity is seriously insufficient and it is difficult to meet the requirements of large-load surgical operations. At the same time, when faced with a variety of complex surgical operation requirements, such as hard tissue grinding, soft tissue clamping, tissue stripping and other operations in narrow spaces, it is necessary to frequently replace the continuum manipulator arm for different operation scenarios, which seriously reduces the efficiency of surgical operations. There is an urgent need for a new type of continuum manipulator arm that can provide both dexterous operation capabilities and the ability to adjust stiffness in real time in minimally invasive orthopedic surgery, meet a variety of soft / hard operation requirements, expand the application range of flexible continuum manipulator arms, and improve surgical operation efficiency.

[0003] Existing methods for varying the stiffness of flexible continuum manipulators primarily include those based on phase change materials, shape locking, blocking particles, and beam feature reconstruction. However, these methods suffer from complex structures, unrealistic stiffness adjustments, large external dimensions, limited stiffness improvements, and the coupling of stiffness changes with posture, limiting their application in surgical scenarios. Therefore, a flexible manipulator capable of adaptive stiffness adjustment while ensuring flexible surgical operations is crucial for effectively improving minimally invasive surgeries within narrow cavities.

[0004] Patent CN 202210523193.3 discloses a joint stiffness changing method and device based on friction locking, wherein a stiffness control line is set so that the stiffness control line passes through the rotation center of each of the N joints; one end of the stiffness control line is fixed to the Nth joint, and a tension is applied through the other end of the stiffness control line to change the contact positive pressure between the joints, thereby changing the friction between the joints and further changing the rotational stiffness of the joints; however, the device disclosed in the patent It is only suitable for flexible grasping operations in industrial scenarios and is difficult to apply to dexterous operations in minimally invasive surgery scenarios. The specific reasons can be explained as follows: 1. The axis area is arranged with stiffness control wires and threading holes, which cannot integrate the operating instruments required for the surgical scene; at the same time, it is also impossible to expand the multi-level flexible operating arm.

[0005] 2. The serial joint can only achieve bending and clamping operations under gravity suspension, which is difficult to meet the requirements of dexterous operation in various postures and directions in minimally invasive surgical environments.

[0006] 3. Changing the stiffness of the joint simply by pulling the stiffness control wire may not always meet the actual surgical needs. Summary of the Invention

[0007] In response to a series of problems in the variable stiffness of the above-mentioned continuum manipulator arm, such as complex structure, large size, stiffness adjustment delay, limited stiffness improvement, and coupling between stiffness change and posture, the present invention proposes a continuum manipulator arm based on joint friction, which can realize real-time and in-situ adjustment of the stiffness of the continuum manipulator arm without increasing the external size and structural complexity of the continuum.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A flexible operating arm for orthopedic surgery includes a base vertebral joint, an intermediate vertebral joint, an end vertebral joint, a driving wire and a rectangular elastic beam, wherein the intermediate vertebral joint is connected in series, the head portion is connected to the base vertebral joint, and the tail portion is connected to the end vertebral joint, the base vertebral joint, the intermediate vertebral joint and the end vertebral joint are provided with driving wire threading holes and rectangular elastic beam threading holes, the driving wire passes through the driving wire threading holes to achieve connection between the base vertebral joint, the intermediate vertebral joint and the end vertebral joint, and the rectangular elastic beam passes through the rectangular elastic beam threading holes to achieve connection between the base vertebral joint, the intermediate vertebral joint and the end vertebral joint; and working channels are formed inside the base vertebral joint, the intermediate vertebral joint and the end vertebral joint.

[0009] The present invention is aimed at a micro-continuum manipulator for minimally invasive orthopedic surgery, and innovatively integrates a rectangular elastic beam structure. A rectangular elastic beam is placed at the neutral plane of the bending, rather than at the axis, to provide space for expansion of the manipulator's axis. This beam serves as a stiffness control component, regulating the overall stiffness of the manipulator. Tensioning the beam increases inter-joint friction, enabling in-situ stiffness control. Rotating the beam angle changes the manipulator's cross-sectional moment of inertia, increasing its overall rigidity. When the cross-sectional moment of inertia is sufficiently large, the manipulator can be treated as a rigid straight arm for high-load operations. The placement of the beam evens out the curvature of each joint of the manipulator, enabling high-precision kinematic modeling and control.

[0010] As a further technical solution, the base vertebral joint includes a hollow cylindrical joint body, and two arc-shaped grooves are symmetrically arranged at one end of the cylindrical joint body.

[0011] As a further technical solution, the terminal vertebral joint includes a hollow cylindrical joint body, and two arc-shaped protrusions are symmetrically arranged at one end of the cylindrical joint body.

[0012] As a further technical solution, each intermediate vertebral joint includes a hollow cylindrical joint body, two arc-shaped grooves are symmetrically arranged at one end of the cylindrical joint body, and two arc-shaped protrusions are symmetrically arranged at the other opposite end; the arc-shaped protrusion cooperates with the arc-shaped groove of another vertebral joint; the arc-shaped groove cooperates with the arc-shaped protrusion of another vertebral joint; the arc-shaped protrusion of the intermediate vertebral joint located in the first section cooperates with the arc-shaped groove of the base vertebral joint, and the arc-shaped groove of the intermediate vertebral joint located in the last section cooperates with the arc-shaped protrusion of the terminal vertebral joint.

[0013] As a further technical solution, the drive wire threading holes are located on both sides of the arc-shaped groove and the arc-shaped protrusion of the cylindrical joint body.

[0014] As a further technical solution, the rectangular elastic beam threading hole is located at the center of the arc-shaped groove and the arc-shaped protrusion, and passes through the arc-shaped groove and the arc-shaped protrusion.

[0015] As a further technical solution, the rectangular elastic beam threading hole is a fan-shaped hole.

[0016] As a further technical solution, one end of the rectangular elastic beam is connected to the driving device, and the other end is formed into a spherical shape and is clamped outside the rectangular elastic beam threading hole of the terminal vertebral joint.

[0017] As a further technical solution, one end of the driving wire is connected to the driving device, and the other end is fixed outside the driving wire threading hole of the terminal vertebral joint.

[0018] As a further technical solution, the rectangular elastic beam can be replaced by an elastic beam with a trapezoidal, triangular, diamond or circular cross-sectional area. The beneficial effects of the present invention are as follows: The structure of the present invention is more miniature and compact, with a wider range of application scenarios and higher control accuracy. The operating arm based on this patented design can be applied to minimally invasive orthopedic surgery. By integrating different surgical tools at the end and nesting different types of flexible operating arms, the operational functionality and movement flexibility are improved to meet the various soft and hard tissue operation requirements in orthopedic surgery. The rectangular elastic beam structure embedded in the operating arm can regulate the stiffness of the operating arm body and the operation implementation process in two dimensions. The tensioning operation of the rectangular elastic beam can adjust the operational stiffness in real time according to demand under bending. The axial angle rotation operation of the rectangular elastic beam can change the stiffness of the operating arm body. The operating arm can perform high-precision kinematic modeling, and has the ability to combine high-precision control and large-scale stiffness regulation.

[0019] Integrating the flexible surgical manipulator arm of the present invention into a surgical robot can not only achieve flexible bending in narrow orthopedic cavities such as the spine and joints, but also perform real-time in-situ adjustment of stiffness as needed. Using one flexible surgical manipulator arm can meet multiple operation requirements of different tissues, such as bone tissue grinding, soft tissue stripping, clamping, etc., avoiding frequent replacement of different types of flexible instruments during surgery; the integrated application of the flexible manipulator arm can effectively broaden the application scope of orthopedic surgery, reduce the frequency of instrument replacement, and greatly improve the efficiency of orthopedic surgery operations. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of a single vertebral joint of the present invention; Figure 3 is a schematic diagram of the driving wire and rectangular elastic beam passing through the vertebral joint; FIG4 is a schematic diagram of stiffness control of the axial angle rotation of a rectangular elastic beam; Figure 5 It is a schematic diagram of the overall structure of the continuum manipulator integrated with the grinding tool; In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0021] Figure: 1. Base vertebral joint, 2. Intermediate vertebral joint, 3. Drive wire, 4. Rectangular elastic beam, 5. Terminal vertebral joint, 6. Miniature bearing, 7. Connecting seat, 8. Support bearing, 9. Drill bit, 10. Transmission flexible shaft; 2-1. Drive wire threading hole, 2-2. Arc-shaped groove surface, 2-3. Rectangular elastic beam threading hole, 2-4. Working channel, 2-5. Arc-shaped raised surface, 2-6. Sector-shaped space; 4-1. Rectangular elastic beam at 90°, 4-2. Rectangular elastic beam at 0-90°, 4-3. Rectangular elastic beam at 0°; DETAILED DESCRIPTION It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly indicated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprising" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations; For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0023] As introduced in the background technology, there are deficiencies in the existing technology. In order to solve the above technical problems, the present invention proposes a flexible operating arm for orthopedic surgery and an in-situ variable stiffness method thereof.

[0024] Example 1 In a typical embodiment of the present invention, Figure 1 As shown, this embodiment provides a flexible operating arm for orthopedic surgery and an in-situ stiffness variable method thereof; The variable stiffness continuum manipulator disclosed in this embodiment is composed of discrete vertebral joints connected in series, including a base vertebral joint 1, an intermediate vertebral joint 2, and an end vertebral joint 5. Multiple intermediate vertebral joints 2 can be provided. After the multiple intermediate vertebral joints 2 are connected in series, the head portion is connected to the base vertebral joint 1, and the tail portion is connected to the end vertebral joint 5. Furthermore, the base vertebral joint 1 comprises a hollow cylindrical joint body, and two arc-shaped grooves are symmetrically provided at one end of the cylindrical joint body; Furthermore, the terminal vertebral joint 5 comprises a hollow cylindrical joint body, and two arc-shaped protrusions are symmetrically arranged at one end of the cylindrical joint body; like Figure 2 As shown, each intermediate vertebral joint 2 includes a hollow cylindrical joint body, with two arcuate grooves 2-2 symmetrically provided at one end of the cylindrical joint body and two arcuate protrusions 2-6 symmetrically provided at the opposite end; the arcuate protrusions cooperate with the arcuate grooves of another vertebral joint; the arcuate grooves cooperate with the arcuate protrusions of another vertebral joint; the arcuate protrusions of the intermediate vertebral joint 2 located at the first section cooperate with the arcuate grooves of the base vertebral joint 1, and the arcuate grooves of the intermediate vertebral joint 2 located at the last section cooperate with the arcuate protrusions of the terminal vertebral joint 5; Furthermore, each intermediate vertebral joint 2 is also designed with a drive wire threading hole 2-1, a rectangular elastic beam threading hole 2-3 and a working channel 2-4. The drive wire threading holes 2-1 include four, the rectangular elastic beam threading holes 2-3 include two, and the working channel 2-4 is a channel formed inside the hollow cylindrical joint body; the four drive wire threading holes 2-1 are located on both sides of the arc-shaped groove 2-2 and the arc-shaped protrusion 2-6 of the cylindrical joint body, two are set on the left, and two are set on the right, and the left and right sides are symmetrically arranged; the rectangular elastic beam threading hole 2-3 is located at the center of the arc-shaped groove 2-2 and the arc-shaped protrusion 2-5, and passes through the arc-shaped groove 2-2 and the arc-shaped protrusion 2-5; and the rectangular elastic beam threading hole 2-3 is designed with a fan-shaped space 2-6 to ensure that when the flexible continuum operating arm bends, the rectangular elastic beam can bend normally. The four drive wires 3 pass through their respective corresponding drive wire threading holes 2-1, and the two rectangular elastic beams 4 pass through their respective corresponding rectangular elastic beam threading holes 2-3; as shown Figure 3 As shown, a group of driving wires 3 are arranged on both sides of the bending of the continuum operating arm, and each group of driving wires includes two driving wires 3. The four driving wires 3 pass through the four driving wire threading holes 2-1 on each vertebral joint respectively; two rectangular elastic beams 4 pass through the rectangular elastic beam threading holes 2-3 on each vertebral joint respectively; As a further technical solution, one end of the rectangular elastic beam 4 is connected to the driving device, and the other end is formed into a spherical shape and is clamped outside the rectangular elastic beam threading hole of the terminal vertebral joint.

[0025] As a further technical solution, one end of the driving wire 3 is connected to the driving device, and the other end is fixed outside the driving wire threading hole of the terminal vertebral joint.

[0026] Furthermore, the rectangular elastic beam 4 in this embodiment is made of nickel-titanium alloy material and has high elasticity; of course, the rectangular elastic beam 4 can also be designed into other irregular or regular cross-sectional shapes, such as diamond, trapezoid, triangle or circle, etc., to adjust the stiffness in different ranges; Furthermore, the continuum manipulator arm can achieve continuous bending in a unilateral direction under the tension of the driving wire 3, and at the same time, the spatial position can be achieved by coordinating the overall feeding and overall rotational freedom of the manipulator arm, as shown in the bending of the continuum manipulator arm in Figure 4.

[0027] Furthermore, in response to the large-load operation requirements during surgical operations, the present invention introduces two sets of rectangular elastic beams 4 made of nickel-titanium alloy to the neutral plane of the flexible continuum manipulator. The rectangular elastic beams at this position have two functions: (1) improving the resilience of the flexible continuum manipulator to ensure uniform and smooth changes in the joint bending angle; (2) changing the rigidity of the flexible continuum manipulator. By rotating the angle between the rectangular elastic beam and the neutral plane through an external drive device, the cross-sectional inertia moment of the manipulator bending can be changed, thereby changing the rigidity of the manipulator body. When the cross-sectional inertia moment reaches a certain level, the flexible manipulator instrument can be converted into a rigid straight rod instrument, so that the manipulator has both rigidity and flexibility. See Figure 4 (a), Figure 4 (b), and Figure 4 (c) for details. Figure 4 (a) shows the rectangular elastic beam 4-1 at 90°, with the largest cross-sectional inertia moment; Figure 4 (b) shows the rectangular elastic beam 4-2 at 0-90°, with the intermediate cross-sectional inertia moment; and Figure 4 (c) shows the rectangular elastic beam at 0°, with the smallest cross-sectional inertia moment. (3) Changing the operating stiffness of the flexible continuum manipulator. By tightening the rectangular elastic beam 4 and applying positive pressure to each joint to increase the friction between the joints, the overall deformation resistance of the continuum manipulator can be improved, thereby improving the stiffness of the flexible continuum manipulator. Unlike other stiffness-changing methods, the stiffness-changing method proposed in the present invention only requires the introduction of two sets of rectangular elastic beams into the continuum manipulator to achieve stiffness control, without increasing the outer diameter and complexity of the continuum.

[0028] It should also be noted that because the rectangular elastic beam 4 is positioned at the center of the arc-shaped groove and arc-shaped protrusions 2-5, when the rectangular elastic beam is tightened and applied to each joint, each joint is subjected to positive pressure, but no additional torque is generated, and thus the equilibrium state of the continuum manipulator arm is not affected. The continuum manipulator arm increases its deformation resistance under a fixed bending shape, thereby achieving in-situ stiffness variation of the continuum manipulator arm. When the continuum manipulator arm is bent to any state, the rectangular elastic beam is pulled as required, and the stiffness of the flexible continuum manipulator arm changes accordingly while maintaining the same posture. This function has great application advantages in the orthopedic surgery scenario of the present invention. In narrow orthopedic cavities, there are many complex soft and hard tissues. The corresponding hard tissues require high stiffness, while the soft tissues in the narrow area require high flexibility. The variable stiffness method proposed in the present invention can effectively meet the above requirements. Furthermore, the present invention adopts a hollow structural design for the continuum manipulator arm, with a reserved channel at the axis, which can provide a channel for smaller flexible continuum manipulator arms or surgical tools, allowing for more flexible or complex surgical operations.

[0029] Example 2 As shown in Figure 4, the flexible grinding and drilling instrument commonly used in orthopedic surgery is integrated. The flexible grinding and drilling instrument includes a connecting seat 7, a support bearing 8, a grinding drill bit 9, a transmission soft shaft 10 and other parts. It is integrated into a variable stiffness flexible operating arm and can perform high-rigidity grinding and drilling operations on bone tissue.

[0030] During the surgical procedure, the flexible manipulator's drive wire must be controlled first. The wire's stretch is calculated based on the kinematic model, and the manipulator's bending is controlled to the target position. Once the target position is reached, the rectangular elastic beam drive wire is driven, applying tension through the drive end to increase friction at each joint. The applied tension can be determined by a force sensor installed at the drive end. Because the rectangular elastic beam is located at the center plane, it applies positive pressure to the vertebral joints from the very end, generating no torque. The position of the flexible manipulator remains unchanged, allowing in-situ stiffness adjustment of the manipulator. Based on this flexible manipulator configuration, in-situ stiffness adjustment is achieved solely by applying tension to the rectangular elastic beam.

[0031] Integrating the flexible surgical manipulator arm of the present invention into a surgical robot can not only achieve flexible bending in narrow orthopedic cavities such as the spine and joints, but also perform real-time in-situ adjustment of stiffness as needed. Using one flexible surgical manipulator arm can meet multiple operation requirements of different tissues, such as bone tissue grinding, soft tissue stripping, clamping, etc., avoiding frequent replacement of different types of flexible instruments during surgery; the integrated application of the flexible manipulator arm can effectively broaden the application scope of orthopedic surgery, reduce the frequency of instrument replacement, and greatly improve the efficiency of orthopedic surgery operations. Finally, it should be noted that relational terms such as first and second are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0032] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A flexible operating arm for orthopedic surgery, characterized in that: The invention comprises a base vertebral joint, an intermediate vertebral joint, an end vertebral joint, a driving wire and a rectangular elastic beam, wherein the intermediate vertebral joint is connected in series in sequence, with the head connected to the base vertebral joint and the tail connected to the end vertebral joint. The base vertebral joint, the intermediate vertebral joint and the end vertebral joint are provided with a driving wire threading hole and a rectangular elastic beam threading hole. The driving wire passes through the driving wire threading hole to realize the connection between the base vertebral joint, the intermediate vertebral joint and the end vertebral joint, and the rectangular elastic beam passes through the rectangular elastic beam threading hole to realize the connection between the base vertebral joint, the intermediate vertebral joint and the end vertebral joint; and working channels are formed inside the base vertebral joint, the intermediate vertebral joint and the end vertebral joint.

2. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: The base vertebral joint comprises a hollow cylindrical joint body, and two arc-shaped grooves are symmetrically arranged at one end of the cylindrical joint body.

3. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: The terminal vertebral joint comprises a hollow cylindrical joint body, and two arc-shaped protrusions are symmetrically arranged at one end of the cylindrical joint body.

4. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: Each intermediate vertebral joint comprises a hollow cylindrical joint body, with two arcuate grooves symmetrically arranged at one end of the cylindrical joint body and two arcuate protrusions symmetrically arranged at the other end; the arcuate protrusion cooperates with the arcuate groove of another vertebral joint; the arcuate groove cooperates with the arcuate protrusion of another vertebral joint; the arcuate protrusion of the intermediate vertebral joint located in the first section cooperates with the arcuate groove of the base vertebral joint, and the arcuate groove of the intermediate vertebral joint located in the last section cooperates with the arcuate protrusion of the terminal vertebral joint.

5. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: The drive wire threading holes are located on both sides of the arc-shaped groove and the arc-shaped protrusion of the cylindrical joint body.

6. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: The rectangular elastic beam threading hole is located at the center of the arc-shaped groove and the arc-shaped protrusion, and passes through the arc-shaped groove and the arc-shaped protrusion.

7. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: The rectangular elastic beam threading hole is a fan-shaped hole.

8. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: One end of the rectangular elastic beam is connected to the driving device, and the other end is formed into a sphere and clamped outside the rectangular elastic beam threading hole of the terminal vertebral joint.

9. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: One end of the driving wire is connected to the driving device, and the other end is fixed outside the driving wire threading hole of the terminal vertebral joint.

10. The flexible operating arm for orthopedic surgery according to claim 1, characterized in that: The rectangular elastic beam can be replaced by an elastic beam with a trapezoidal, triangular, diamond or circular cross-sectional area.

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