A flexible needle puncture device for adjusting the needle insertion angle of a multi-degree-of-freedom robotic arm

Abstract

The present invention relates to a flexible needle puncture device for adjusting the needle insertion angle of a multi-degree-of-freedom robotic arm, belonging to the field of medical devices. It relies on the multi-degree-of-freedom robotic arm to adjust the flexible needle puncture mechanism to puncture at different angles, providing multi-angle puncture pose modes for puncture surgeries. In this invention, the positioning device and the robotic arm have five degrees of freedom, which can adjust the needle insertion angle of the bevel-tip flexible needle and form a fixed point at the intersection of the multi-joint axes of the robotic arm. When the robotic arm adjusts the needle insertion angle, it can ensure that the spatial position of the puncture point of the flexible needle tip remains unchanged. Compared with traditional flexible needle puncture devices, during the extension or contraction of the suspended robotic arm, it can effectively avoid the patient or other surgical equipment while ensuring that the puncture target point does not move. The operation is simple, and it is easier to obtain a suitable puncture needle insertion posture, improving the flexibility of the mechanism and ensuring the stability, accuracy, and safety of the puncture.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and relates to a flexible needle puncture device for adjusting the needle insertion angle by a multi-degree-of-freedom robotic arm. Background Art

[0002] Robot-assisted minimally invasive interventional medicine is a brand-new medical technology that has rapidly developed in recent years. It is a new medical method between surgery and internal medicine. The targeted puncture technology is one of the medical means with the broadest application prospects. Under the guidance of medical imaging equipment, using a flexible puncture needle for targeted puncture for local treatment has the advantages of small incision, fast recovery, and good treatment effect. Due to the large stiffness of the traditional rigid needle, the position of the needle tip cannot be effectively controlled during the puncture process, resulting in a large limitation in puncture. Therefore, flexible needles have rapidly developed and are gradually applied to puncture surgeries.

[0003] In the traditional flexible needle puncture surgery, the puncture mechanism is installed on a serial collaborative robotic arm. After adjusting the pose of the robotic arm, the puncture mechanism is controlled by a program to perform the puncture surgery. The ordinary serial robotic arm is placed on one side of the patient. If one wants to insert a needle from the other side of the patient, due to the limitations of the degrees of freedom and arm length of the robotic arm, the robotic arm needs to be adjusted to the other side of the patient, which increases the complexity of the surgery.

[0004] Based on the defects existing in the prior art, the technical problem to be solved by the present invention is to solve the problem that the method of adjusting the puncture position of the puncture mechanism is too cumbersome, to realize placing the robotic arm and the puncture mechanism in a certain position, and only by adjusting the pose of the robotic arm, a large range of needle insertion angle adjustment can be achieved; to reduce the workload of medical staff, and at the same time, to achieve a large movement space with a relatively small size of the robotic arm. Summary of the Invention

[0005] Aiming at the above problems, the technical problem to be solved by the present invention is to provide a flexible needle puncture device for adjusting the needle insertion angle by a multi-degree-of-freedom robotic arm. The overall pose of the robotic arm is adjusted in a large range through the lifting and rotational degrees of freedom of the base in the mechanism and the pitching degree of freedom in the positioning mechanism; the puncture needle insertion angle is adjusted through the rolling degree of freedom in the positioning mechanism and the extension and contraction of the robotic arm. After the pose is adjusted, the flexible needle puncture mechanism is controlled to perform the puncture surgery.

[0006] A flexible needle puncture device for adjusting the needle insertion angle of a multi-degree-of-freedom robotic arm, where the base mainly consists of a lifting mechanism and a rotating mechanism. The lifting mechanism is driven by a motor and a lead screw nut to achieve the lifting of the base, and the rotating mechanism is driven by a motor and a transfer flange through a belt drive to achieve the rotation of the transfer flange; the positioning joint mainly has two motors to adjust the two degrees of freedom of the robotic arm, namely the pitching degree of freedom and the rolling degree of freedom of the robotic arm; the robotic arm has three arms: the rear arm, the middle arm, and the front arm, forming a parallelogram structure. The end point of the parallelogram is the intersection of the projection of the direction pointed by the axis of the rear arm and the flexible needle guide wheel in the front arm on the side plane of the robotic arm. When the robotic arm extends or contracts, this puncture intersection point remains stationary in space. At the same time, the rotation axis of the rolling degree of freedom in the positioning joint passes through this intersection point. When the positioning joint adjusts the rolling pose of the robotic arm, the spatial position of the puncture intersection point remains unchanged.

[0007] A two-degree-of-freedom flexible needle puncture mechanism is installed on the front arm of the robotic arm to achieve the linear and rotational motion of the bevel-tip flexible needle; the end of the flexible needle puncture mechanism is connected to the flexible needle guide wheel on the front arm of the robotic arm through a catheter of a fixed length to prevent the flexible needle from warping due to puncture resistance during the puncture process; after the pose of the robotic arm is adjusted, the linear motion of the flexible needle realizes the feeding and retraction of the needle, and the rotational motion of the needle realizes the control of the bevel tip orientation, thereby realizing the control of the flexible needle trajectory.

[0008] The beneficial effects of the present invention are:

[0009] The four-degree-of-freedom pose control of the flexible needle, namely lifting, rotation, pitching, and rolling, is realized through the base and the positioning joint. The robotic arm is of a parallelogram structure and has one degree of freedom. When the robotic arm extends and contracts, the end point of the parallelogram remains stationary in space. The rolling axis of the robotic arm passes through the end point of the parallelogram. When the rolling pose is adjusted, the spatial position of the end point remains unchanged. Adjusting the end point of the parallelogram to the lesion point where the patient needs surgery only requires adjusting the two degrees of freedom of the rolling and extension / contraction of the robotic arm to achieve a large range of needle angle adjustment. Description of the Drawings

[0010] Figure 1 Overall schematic diagram of the flexible needle puncture device for adjusting the needle insertion angle of a multi-degree-of-freedom robotic arm

[0011] Figure 2 Schematic diagrams of four parts: the base, the positioning joint, the robotic arm, and the flexible needle puncture mechanism

[0012] Figure 3 Exploded view of the base

[0013] Figure 4 Exploded view of the positioning joint

[0014] Figure 5 Exploded view of the robotic arm

[0015] Figure 6 Auxiliary Exploded View of the Rear of the Robot Arm

[0016] Figure 7 Exploded View of the Flexible Needle Puncture Mechanism

[0017] Figure 8 Schematic Diagram of the Fixed Point of the Robot Arm Puncture

[0018] In the figure: 1 Base, 2 Positioning Joint, 3 Robot Arm, 4 Flexible Needle Puncture Mechanism, 1-1 Lifting Mechanism, 1-2 Rotating Mechanism, 1-1-1 Inner Cylinder, 1-1-2 Outer Cylinder, 1-1-3 Lead Screw Nut Mechanism, 1-1-4 Hole 1, 1-1-5 Hole 2, 1-1-6 Hole 3, 1-2-1 Rotating Motor, 1-2-2 Adapter Flange, 1-2-3 Pulley 1, 1-2-4 Pulley 2, 2-1 Arm Connection Seat, 2-2 Arm Rotating Motor Seat, 2-3 Arm Rotating Motor, 2-4 Bevel Gear 1, 2-5 Bevel Gear 2, 2-6 Pitching Motor Seat, 2-7 Support Shaft, 2-8 Pitching Motor, 2-2-1 Bearing Hole, 2-2-2 Step Shaft on One Side, 3-1 Rear Arm, 3-2 Middle Arm, 3-3 Front Arm, 3-1-1 Rear Arm Housing, 3-1-2 Arm Motor, 3-1-3 Harmonic Reducer, 3-2-1 Middle Arm Frame, 3-2-2 Middle Arm Link, 3-2-3 Middle Arm Transmission Shaft, 3-3-1 Front Arm Frame, 3-3-2 Front Arm Link, 3-3-3 Front Arm Transmission Shaft, 3-3-4 Flexible Needle Guide Wheel, 4-1 Flexible Needle Housing, 4-2 Needle Feeding Mechanism, 4-3 Needle Rotating Mechanism, 4-4 Flexible Needle, 4-5 Flexible Needle Catheter. Detailed Implementation Manner

[0019] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be described below through specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0020] Such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8As shown in the figure, the specific implementation of the present invention adopts the following technical solutions: A flexible needle puncture device for adjusting the needle insertion angle of a multi-degree-of-freedom robotic arm, which comprises: 1 base, 2 positioning joints, 3 robotic arm, 4 flexible needle puncture mechanism; characterized in that the 1 base comprises: 1-1 lifting mechanism, 1-2 rotating mechanism; the 1-1 lifting mechanism comprises: 1-1-1 inner cylinder, 1-1-2 outer cylinder, 1-1-3 lead screw nut mechanism; the 1-1-1 inner cylinder and the 1-1-2 outer cylinder are sleeved up and down through guide rails, and the 1-1-3 lead screw nut mechanism connects the 1-1-1 inner cylinder and the 1-1-2 outer cylinder, driven by a motor to drive the outer cylinder to perform a vertical linear motion; the 1-2 rotating mechanism comprises: 1-2-1 rotating motor, 1-2-2 adapter flange, 1-2-3 pulley one, 1-2-4 pulley two; the 1-2-1 rotating motor is installed on the 1-1-2 outer cylinder, the 1-2-2 adapter flange is installed on the 1-1-2 outer cylinder through bearings, the 1-2-3 pulley one is fixed to the output shaft of the 1-2-1 rotating motor, the 1-2-4 pulley two is fixed to the 1-2-2 adapter flange, the 1-2-3 pulley one and the 1-2-4 pulley two are connected in series through a synchronous belt, and the 1-2-1 rotating motor is decelerated through a synchronous belt pulley set to control the rotation of the adapter flange; the 2 positioning joint comprises: 2-1 arm connection seat, 2-2 arm rotating motor seat, 2-3 arm rotating motor, 2-4 bevel gear one, 2-5 bevel gear two, 2-6 pitching motor seat, 2-7 support shaft, 2-8 pitching motor; the 2-3 arm rotating motor is installed inside the 2-2 arm rotating motor seat, and the 2-1 arm connection seat is installed on the output flange of the 2-3 arm rotating motor; the lower part of the 2-6 pitching motor seat is a square tube and the upper part is a cylindrical structure; the 2-4 bevel gear one is installed on the side of the 2-2 arm rotating motor seat, the 2-7 support shaft passes through the 2-6 pitching motor seat through bearings and is installed on the side of the 2-2 arm rotating motor seat and passes through the 2-4 bevel gear one; the 2-8 pitching motor is installed inside the 2-6 pitching motor seat, and the 2-5 bevel gear two is fixed to the output shaft of the 2-8 pitching motor; the 2-4 bevel gear one meshes with the 2-5 bevel gear two; the 2 positioning joint is installed on the 1-2-2 adapter flange, and the 3 robotic arm is installed on the 2-1 arm connection seat; the 1-1 lifting mechanism adjusts the height and pose of the 3 robotic arm, and the 1-2 rotating mechanism adjusts the direction and pose of the 3 robotic arm; in the 2 pitching mechanism, the 2-8 pitching motor adjusts the pitching pose of the 3 robotic arm, and the 2-3 arm rotating motor adjusts the rolling pose of the 3 robotic arm.

[0021] The further composition of the 3 robotic arms includes: 3-1 rear arm, 3-2 middle arm, 3-3 front arm; The composition of the 3-1 rear arm includes: 3-1-1 rear arm housing, 3-1-2 arm motor, 3-1-3 harmonic reducer; The 3-1-1 rear arm housing is installed with the 3-1-2 arm motor on one side close to the 1 base, and the 3-1-3 harmonic reducer on the other side. The output shaft of the 3-1-2 arm motor and the input shaft of the 3-1-3 harmonic reducer are connected in series through a pulley and a synchronous belt; The composition of the 3-2 middle arm includes 3-2-1 middle arm frame, two identical 3-2-2 middle arm connecting rods, 3-2-3 middle arm transmission shaft; The two 3-2-2 middle arm connecting rods are symmetrically installed about the middle arm axis. One end is connected by a precision reamed hole screw to the side of the 3-1-1 rear arm housing where the 3-1-3 harmonic reducer is installed, and the other end is connected by a precision reamed hole screw to the 3-2-3 middle arm transmission wheel; The 3-2-3 middle arm transmission shaft is installed on the bearing hole of the 3-2-1 middle arm frame through a bearing. The cylindrical protrusion on the other side of the 3-2-1 middle arm frame is fixed to the output end of the 3-1-3 harmonic reducer by a screw; The composition of the 3-3 front arm includes 3-3-1 front arm frame, two identical 3-3-2 front arm connecting rods, 3-3-3 front arm transmission shaft, 3-3-4 flexible needle guide wheel; The hollow side of the 3-3-1 front arm frame is fixed to the non-flange side of the 3-2-3 middle arm transmission shaft. The stepped shaft of the 3-3-1 front arm frame passes through the 3-3-3 front arm transmission shaft through a bearing, and the 3-3-4 flexible needle guide wheel is fixed to the 3-3-3 front arm transmission shaft; The two 3-3-2 front arm connecting rods are symmetrically arranged about the front arm axis. One end is connected by a precision reamed hole screw to the side of the 3-2-1 middle arm frame where the 3-2-3 middle arm transmission shaft is installed, and the other end is connected by a precision reamed hole screw to the 3-3-3 front arm transmission shaft; In terms of installation position, the 3-3 front arm is parallel to the 3-1 rear arm, and the flexible needle guide hole of the 3-3-4 flexible needle guide wheel is parallel to the 3-2 middle arm; The rotation of the 3-1-2 arm motor is decelerated by the 3-1-3 harmonic reducer, driving the 3-2-1 middle arm frame to rotate. The two 3-2-2 middle arm connecting rods remain parallel under the action of the precision reamed hole screws. The rotation angle of the 3-2-3 middle arm transmission shaft remains unchanged, and the rotation angle of the 3-3-1 front arm frame fixed thereto remains unchanged. During the movement of the 3 robotic arms, the 3-3 front arm is always parallel to the 3-1 rear arm; Similarly, under the action of the 3-3-2 front arm connecting rod, the angle of the 3-3-4 flexible needle guide wheel is the same as the rotation angle of the 3-2-1 middle arm frame, and the axis of the flexible needle guide hole is parallel to the 3-2 middle arm; The 4 flexible needle puncture mechanism is installed on the side of the 3-3 front arm, and its composition includes: 4-1 flexible needle housing, 4-2 needle feeding mechanism, 4-3 needle rotation mechanism, 4-4 flexible needle, 4-5 flexible needle catheter; The 4-2 needle feeding mechanism is a lead screw nut mechanism driven by a motor, and the 4-3 needle rotation mechanism is a motor base and a motor, which rely on the needle feeding mechanism to drive and move linearly;The front end of the flexible needle housing 4-1 is provided with a flexible needle guiding hole, which is fixedly connected to one end of the flexible needle catheter 4-5. The other end of the flexible needle catheter 4-5 is fixedly connected to the flexible needle guiding hole of the flexible needle guiding wheel 3-3-4. The middle of 4-4 is penetrated by the flexible needle; the flexible needle 4-4 is fixed to the output shaft of the needle rotation mechanism motor and extends from the front end of the guiding hole of the flexible needle guiding wheel 3-3-4; the three arms of the manipulator 3 form a parallelogram structure. The position pointed by the tip of the flexible needle 4-4 and the intersection of the axes of the 2-3 arm rotation motors are the puncture centers. During the movement of the manipulator 3, the spatial position of the puncture center remains unchanged. When adjusting the roll attitude of the manipulator 3, the spatial position of the puncture center remains unchanged.;

[0022] Furthermore, the extension and contraction movements of the manipulator 3 require less space. The adjustment of the needle angle within a range of 180° can be achieved through one degree of freedom. The roll degree of freedom adjusted by the 2 swing joints can further sweep the sector formed by the needle entry angle range of the manipulator, realizing a larger adjustment of the needle entry angle while ensuring that the spatial position of the needle entry point remains unchanged and the movement amplitude of the manipulator is very small to avoid obstacles such as surgical equipment and patients.

[0023] The working principle of the specific embodiment of the present invention is as follows:

[0024] The lifting, rotation degrees of freedom of the base and the pitch degree of freedom of the swing joint position the puncture point at the end of the manipulator to the lesion point of the patient. Relying on the roll degree of freedom of the swing joint and the extension and contraction of the manipulator to adjust the puncture needle entry angle, a puncture operation is performed to plan the path of the flexible needle using the feeding and rotation of the flexible needle puncture mechanism.

[0025] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A flexible needle puncture device for adjusting the needle insertion angle of a multi-degree-of-freedom robotic arm, comprising: Base (1), positioning joint (2), robotic arm (3) and flexible needle puncture mechanism (4); characterized in that the base (1) includes: a lifting mechanism (1-1) and a rotating mechanism (1-2); the lifting mechanism (1-1) includes: an inner cylinder (1-1-1), an outer cylinder (1-1-2) and a lead screw nut mechanism (1-1-3), and the outer cylinder (1-1-2) is provided with a hole one (1-1-4), a hole two (1-1-5) and a hole three (1-1-6); the inner cylinder (1-1-1) and the outer cylinder (1-1-2) are sleeved up and down through guide rails, and the lead screw nut mechanism (1-1-3) is installed on the hole two (1-1-5) through a bearing, and the motor is connected to the lead screw through a coupling; the rotating mechanism (1-2) includes: a rotating motor (1-2-1), a transfer flange (1-2-2), a pulley one (1-2-3) and a pulley two (1-2-4); the rotating motor (1-2-1) is installed in the hole one (1-1-4) on the outer cylinder (1-1-2) through screws, the transfer flange (1-2-2) is installed in the hole three (1-1-6) through a bearing, the pulley one (1-2-3) is fixed to the output shaft of the rotating motor (1-2-1), the pulley two (1-2-4) is fixed to the transfer flange (1-2-2), the pulley one (1-2-3) and the pulley two (1-2-4) are connected in series through a synchronous belt, and the lead screw nut mechanism (1-1-3) passes through the synchronous belt; the positioning joint (2) includes: an arm connection seat (2-1), an arm rotating motor seat (2-2), an arm rotating motor (2-3), a bevel gear one (2-4), a bevel gear two (2-5), a pitching motor seat (2-6), a support shaft (2-7) and a pitching motor (2-8); the arm rotating motor seat (2-2) is a square tube structure, one end face is provided with a bearing hole (2-2-1), one side face is provided with a stepped shaft (2-2-2), and the end face of the stepped shaft (2-2-2) is provided with two circles of threaded holes; the arm rotating motor (2-3) is installed inside the arm rotating motor seat (2-2), and the arm connection seat (2-1) is installed on the output flange of the arm rotating motor (2-3); the end face of the support shaft (2-7) is provided with a circle of counterbored holes, the lower part of the pitching motor seat (2-6) is a square tube and the upper part is a cylindrical structure, and the two end faces of the cylinder are provided with bearing holes; the bevel gear one (2-4) is installed on the outer threaded holes of the stepped shaft (2-2-2) of the arm rotating motor seat (2-2), the support shaft (2-7) passes through the pitching motor seat (2-6) through a bearing and is installed on the inner threaded holes of the stepped shaft (2-2-2) on the side face of the arm rotating motor seat (2-2) through screws; the pitching motor (2-8) is installed inside the pitching motor seat (2-6), and the bevel gear two (2-5) is fixed to the output shaft of the pitching motor (2-8); the bevel gear one (2-4) meshes with the bevel gear two (2-5); the positioning joint (2) is installed on the transfer flange (1-2-2), and the robotic arm (3) is installed on the arm connection seat (2-1); the lifting mechanism (1-1) adjusts the height and pose of the robotic arm (3), and the rotating mechanism (1-2) adjusts the direction and pose of the robotic arm (3);The pitch motor (2-8) adjusts the pitch pose of the robotic arm (3), and the arm rotation motor (2-3) adjusts the roll pose of the robotic arm (3). The robotic arm (3) includes a rear arm (3-1), a middle arm (3-2) and a front arm (3-3); the front arm (3-3) includes a front arm frame (3-3-1), two identical front arm connecting rods (3-3-2), a front arm transmission shaft (3-3-3) and a flexible needle guide wheel (3-3-4); the flexible needle puncture mechanism (4) is installed on the side of the front arm (3-3), and the flexible needle puncture mechanism (4) includes a flexible needle housing (4-1), a needle feeding mechanism (4-2), a needle rotating mechanism (4-3), a flexible needle (4-4) and a flexible needle catheter (4-5); a flexible needle guide hole is provided at the front end of the flexible needle housing (4-1), which is fixedly connected to one end of the flexible needle catheter (4-5), and the other end of the flexible needle catheter (4-5) is fixedly connected to the flexible needle guide hole of the flexible needle guide wheel (3-3-4), and the flexible needle (4-4) passes through the middle of the flexible needle catheter (4-5).

2. The flexible needle puncture device for adjusting the needle insertion angle of a multi-degree-of-freedom robotic arm according to claim 1, wherein the specific The feature is that the rear arm (3-1) includes: The rear arm housing (3-1-1), the arm motor (3-1-2) and the harmonic reducer (3-1-3); the arm motor (3-1-2) is installed on one side of the rear arm housing (3-1-1) close to the base (1), and the harmonic reducer (3-1-3) is installed on the other side. The output shaft of the arm motor (3-1-2) and the input shaft of the harmonic reducer (3-1-3) are connected in series through a belt pulley and a synchronous belt; the middle arm (3-2) consists of a middle arm frame (3-2-1), two identical middle arm connecting rods (3-2-2) and a middle arm transmission shaft (3-2-3); a hollow cylindrical protrusion is provided on one side of the middle arm frame (3-2-1), and a bearing hole is provided on the other side; the two middle arm connecting rods (3-2-2) have the same structure, and through holes are provided at both ends; the middle arm transmission shaft (3-2-3) is a hollow shaft with a flange on one end face. The two middle arm connecting rods (3-2-2) are symmetrically installed about the middle arm axis. One end is connected to the side of the rear arm housing (3-1-1) where the harmonic reducer (3-1-3) is installed through a precision-fit bolt, and the other end is connected to the flange of the middle arm transmission shaft (3-2-3) through a precision-fit bolt; the middle arm transmission shaft (3-2-3) is installed on the bearing hole of the middle arm frame (3-2-1) through a bearing, and the cylindrical protrusion on the other side of the middle arm frame (3-2-1) is fixed to the output end of the harmonic reducer (3-1-3) by screws; One side of the forearm frame (3-3-1) is hollow, and the other side is provided with a hollow stepped shaft. The forearm transmission shaft (3-3-3) is a hollow shaft ring, and the flexible needle guide wheel (3-3-4) is a hollow ring structure. The ring is provided with a tapered extension plate in the radial direction, and the tapered extension plate is provided with a flexible needle guide hole. The flexible needle guide hole is along the radial direction of the flexible needle guide wheel (3-3-4); the hollow side of the forearm frame (3-3-1) is fixed to the non-flange side of the middle arm transmission shaft (3-2-3). The stepped shaft of the forearm frame (3-3-1) passes through the forearm transmission shaft (3-3-3) through a bearing, and the flexible needle guide wheel (3-3-4) is fixed to the forearm transmission shaft (3-3-3); the two forearm connecting rods (3-3-2) have the same structure, with through holes at both ends, arranged symmetrically about the forearm axis. One end is connected to one side of the middle arm frame (3-2-1) where the middle arm transmission shaft (3-2-3) is installed through a precision reamed hole screw, and the other end is connected to the forearm transmission shaft (3-3-3) through a precision reamed hole screw; in terms of the installation position, the forearm (3-3) is parallel to the rear arm (3-1), and the axis of the flexible needle guide hole of the flexible needle guide wheel (3-3-4) is parallel to the middle arm (3-2); the rotation of the arm motor (3-1-2) is decelerated by the harmonic reducer (3-1-3) to drive the middle arm frame (3-2-1) to rotate. The two middle arm connecting rods (3-2-2) remain parallel under the action of the precision reamed hole screws. The rotation angle of the middle arm transmission shaft (3-2-3) remains unchanged, and the rotation angle of the forearm frame (3-3-1) fixed thereto remains unchanged. During the movement of the robotic arm (3), the forearm (3-3) is always parallel to the rear arm (3-1); similarly, under the action of the forearm connecting rod (3-3-2), the angle of the flexible needle guide wheel (3-3-4) is the same as the rotation angle of the middle arm frame (3-2-1); the needle feeding mechanism (4-2) is a lead screw-nut mechanism driven by a motor, and the needle rotation mechanism (4-3) is a motor base and a motor. The needle rotation mechanism (4-3) is driven by the needle feeding mechanism (4-2) to move linearly; the flexible needle (4-4) is fixed to the motor output shaft of the needle rotation mechanism (4-3) and extends from the front end of the flexible needle guide hole of the flexible needle guide wheel (3-3-4); the three arms of the robotic arm (3) form a part of a parallelogram structure. The intersection of the axis of the flexible needle (4-4) tip and the axis of the arm rotation motor (2-3) is the puncture center. During the movement of the robotic arm (3), the spatial position of the puncture center remains unchanged. When adjusting the roll attitude of the robotic arm (3), the spatial position of the puncture center remains unchanged.

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