Stereotactic micro-surgical robot

Abstract

The present invention discloses a stereoscopic positioning micro-surgical robot, comprising a first position control unit, a second position control unit, a depth control unit, a puncture needle connecting device, a first movable unit, a second movable unit and a first base; the first base provides an installation foundation, the first and second position control units respectively have two active motion degrees of freedom, which are respectively composed in series and parallel forms, the end position working space is a plane, the depth control unit has one active motion degree of freedom linear feed, the first and second movable units respectively have passive degrees of freedom of pitch and yaw, and there is also one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion between the two, and the puncture needle connecting device fixes the needle; the present invention is small in size and easy to install, the end actuator has at least 5 degrees of freedom, can reach the required position in space, can cooperate with different instruments to complete different operations, can provide real-time image information for doctors, and ensure the smooth completion of the operation.

Description

Technical Field

[0001] The present invention is a stereo positioning micro surgical robot, which relates to the field of minimally invasive surgical robots, and in particular to a stereo positioning targeted puncture surgical robot system based on image guidance. Background Art

[0002] With the development of precise minimally invasive medical devices, the effect of surgical operations has been significantly improved. Stereo positioning is an important requirement for minimally invasive surgical robots. In minimally invasive treatment methods such as puncture biopsy, ablation, cryosurgery, and particle implantation, it is necessary to accurately implant the instrument into the lesion site and work stably according to the judgment of medical images during the operation. In the diagnosis and treatment of tumors such as thyroid, liver and gallbladder, lung, uterus, and prostate, percutaneous puncture is usually used. Under the guidance of medical imaging equipment (B-ultrasound, MRI, and CT, etc.), surgical instruments (such as puncture needles, biopsy needles, ablation needles, etc.) are quickly and accurately placed into the patient's organs for tissue extraction or ablation treatment. This type of surgery has the characteristics of less trauma, fewer complications, and faster postoperative recovery, which is a major change in traditional open surgery. Traditional puncture interventional surgery mainly relies on the doctor's experience. The doctor holds the needle and inserts it into the body. There are problems such as low surgical accuracy, radiation exposure to both the doctor and the patient during the operation, and many postoperative complications. There are also problems such as inaccurate positioning, unstable clamping, and difficult path planning during the puncture process.

[0003] With the development of robotics and medical imaging technology, robot-assisted surgery has become an important branch of the robotics field. Robot-assisted surgery can not only overcome the limitations of low surgical precision, radiation exposure to both doctors and patients during surgery, and many postoperative complications, but also enhance the ability of doctors to perform surgery, giving full play to the advantages of high repeat positioning accuracy of robots and rich experience of doctors. First, the anatomical structure of tissues and organs is processed and analyzed through medical images, and the position of the lesion (target) is calculated. According to the design of the fixed point of puncture on the body surface, the robot is controlled to reach a certain value for the terminal position and posture, so that when the puncture needle passes through this position and posture and is inserted into the human body, it can directly reach the lesion through the fixed point of puncture and work stably, obtaining the characteristics of high puncture position accuracy, stable clamping, and flexible approach, and also avoiding problems such as radiation and infection at the bedside during surgery.

[0004] At present, common positioning systems include frame-type neurosurgical positioning devices, frameless neurosurgical devices, orthopedic robots based on traditional industrial robots, lung biopsy robots, and specialized abdominal puncture robots. Most of these robots use industrial 6-DOF manipulators, passive manipulators, or frame positioning systems. The configuration can be divided into series or parallel. Robots with series configurations are prone to long error propagation paths in the joints, low positioning accuracy at the end, and poor rigidity of the robot. Robots with parallel configurations are prone to small working space ranges and large robot volumes. Positioning robot systems often need to be installed or placed in specific operating rooms. Systems based on industrial robots are very inconvenient to move or carry, and are difficult to popularize in hospitals of different levels, and are not suitable for a variety of indications. Summary of the invention

[0005] The purpose of the present invention is to provide a stereotactic micro-surgical robot to address the problems of current surgical robots, such as large size, insufficient rigidity of the mechanical arm, insufficient positioning accuracy, insufficient flexible freedom of the terminal, and single function. The robot adopts a series-parallel hybrid mechanism, which is suitable for targeted puncture or stereotactic treatment of different tissues and organs. The stereotactic surgical robot is small in size and easy to install. The end actuator has at least 5 degrees of freedom and can reach the required position in space. The end actuator can cooperate with different surgical instruments (such as puncture needles, biopsy needles, ablation needles, etc.) to complete different operations, and provide doctors with real-time image information with medical imaging equipment (such as B-ultrasound, nuclear magnetic resonance, CT, etc.), ensuring the smooth completion of the operation.

[0006] The present invention adopts the following technical solution:

[0007] A stereo positioning micro surgical robot, comprising a multi-degree-of-freedom stereo positioning robot and a bedside positioning arm; characterized in that: the multi-degree-of-freedom stereo positioning robot comprises a first position control unit, a second position control unit, a depth control unit, a puncture needle connecting device, a first movable unit, a second movable unit and a first base; the first base provides an installation foundation, the first and second position control units respectively have two active motion degrees of freedom, respectively composed in series and parallel forms, the working space of the end position is a plane, the depth control unit has a linear feed of one active motion degree of freedom, the first and second movable units respectively have at least pitch and yaw passive degrees of freedom, and there is also one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion between the two, and the puncture needle connecting device fixes the needle;

[0008] The first position control unit and the second position control unit are connected to the depth control unit and the puncture needle connecting device in the form of a parallel mechanism through the first movable unit and the second movable unit, thereby allowing the puncture needle connecting device to be positioned in three-dimensional space and to perform pitch and flip posture-fixed movements. The multi-degree-of-freedom stereo positioning robot has at least 5 degrees of freedom, so that the terminal puncture needle moves to the spatial target position;

[0009] One end base of the first position control unit and the second position control unit is fixedly mounted on the first base, and the output of the other end is respectively connected to the first movable unit and the second movable unit; the output of the first movable unit is fixedly connected to the base of the depth control unit; the puncture needle connecting device is fixedly mounted on the output of the depth control unit.

[0010] As another structural form, a stereoscopic positioning micro-surgical robot includes a multi-degree-of-freedom stereoscopic positioning robot and a bedside positioning arm; the multi-degree-of-freedom stereoscopic positioning robot includes a first position control unit, a second position control unit, a depth control unit, a puncture needle connecting device, a first movable unit, a second movable unit and a first base; the first base provides an installation foundation, the first and second position control units respectively have two active motion degrees of freedom, respectively composed in series and parallel forms, the working space of the end position is a plane, the depth control unit has a linear feed of one active motion degree of freedom, the first and second movable units respectively have at least pitch and yaw passive degrees of freedom, and there is also one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion between the two, and the puncture needle connecting device fixes the needle;

[0011] The first position control unit and the second position control unit are connected to the depth control unit and the puncture needle connecting device in the form of a parallel mechanism through the first movable unit and the second movable unit, thereby allowing the puncture needle connecting device to be positioned in three-dimensional space and to perform pitch and flip posture-fixed movements. The multi-degree-of-freedom stereo positioning robot has at least 5 degrees of freedom, so that the terminal puncture needle moves to the spatial target position;

[0012] The first base is fixedly mounted on the output of the depth control unit; one end of the first position control unit and the second position control unit are fixedly mounted on the first base, and the other end outputs are respectively connected to one end of the first movable unit and the second movable unit; the puncture needle connecting device is fixedly mounted on the output of the first movable unit.

[0013] Wherein, the first position control unit and the second position control unit are both modularly designed and have the same structure. Each active motion degree of freedom of each position control unit is directly driven by an actuator, or is pre-installed on a base by an actuator and then driven by a connecting rod transmission; each position control unit is composed of a first joint, a second joint, a drive system and an end connecting rod; each joint is driven by a separate motor, and the transmission mechanism adopts a connecting rod transmission. Each joint can rotate under the action of the motor to control the two-degree-of-freedom position of the end; each position control unit adopts a double-axis connecting rod design at each joint hinge to increase the positioning accuracy of the first position control unit; a connecting rod of the second joint is designed as a bent rod to increase the range of motion of the second joint;

[0014] The first joint is composed of a first joint output rod, a first motor, and a first transfer rod, a fifth connecting rod, a sixth connecting rod, and a main shaft, which are hinged to each other to form a crank slider mechanism, and converts the up and down vertical movement of the first motor into the rotation of the first joint;

[0015] The second joint is a four-bar linkage mechanism consisting of a second motor passing through a main shaft around the first joint and articulated with a third link, a fourth link, a curved rod, a seventh link, an eighth link and the first joint, and a ninth link and a tenth link, which converts the vertical up and down movement of the second motor into the rotation of the second joint output rod;

[0016] The driving system, the motor and the transmission mechanism are combined to form a crank slider mechanism, so that the driving motor can maintain vertical movement;

[0017] The end connecting rod is designed with two gear adjustment holes for adjusting the range of motion on the second joint output rod.

[0018] Another structural form of the first position control unit and the second position control unit is: two motors are used to drive the two nuts on the screw rod to move parallel to a straight line respectively, and two parallel four-bar linkage mechanisms are used to drive the second connecting base at the end to move horizontally and vertically in the plane, and the posture of the second connecting base remains parallel to the horizontal plane during the movement.

[0019] The first and second movable units have pitch and yaw rotation axes that are orthogonal to each other, and the first and second movable units also have one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion. The central axis of the rolling motion is parallel to the linear motion direction axis or the central axis, and is orthogonal to the pitch rotation axes of the first and second movable units, and intersects with the yaw rotation axes of the first and second movable units; the first and second movable units provide at least 5 degrees of freedom of passive activity for the end.

[0020] A structural form of the first movable unit, which is composed of a first yaw axis, a first U-shaped block, a first pitch axis, and a first support platform, wherein one end of the first yaw axis is connected to one end of the first position control unit and is rotatable relative to one end of the first position control unit, with the rotation center being the first yaw rotation axis; the other end of the first yaw axis is fixedly connected to the first U-shaped block; the first pitch axis is connected to the first U-shaped block and is rotatable relative to the first U-shaped block, with the rotation center axis being the first pitch rotation axis; the first support platform is fixedly connected to the first pitch axis, and a threaded hole is designed in the middle along the direction of the central axis of the tumbling motion;

[0021] A structural form of the second movable unit is composed of a second pitch axis hole, a second U-shaped block, and a second yaw axis; the second yaw axis is connected to one end of the second position control unit and is fixedly connected to the second U-shaped block; the second pitch axis hole is connected to the second U-shaped block and is rotatable relative to the second U-shaped block, and the rotation center axis is the second pitch rotation axis; the second pitch axis hole is designed with a light hole in the middle along the direction of the rolling motion center axis; the first movable unit and the second movable unit are connected through a first sliding rod, and one end of the first sliding rod is connected to the first pitch axis, and the other end cooperates with the light hole of the second pitch axis hole; the first sliding rod can slide relatively linearly in the direction of the first sliding rod axis line and relatively roll around the first sliding rod relative to the second pitch axis hole.

[0022] Among them, a relative position assembly form of the first movable unit and the second movable unit is: the first pitch axis and the first yaw axis are perpendicular to point O1; the second pitch axis hole and the second yaw axis are perpendicular to point O2; the first slide bar rotation axis is perpendicular to the axis of the first pitch axis and the second pitch axis hole at point O1 and point O2 respectively; the puncture needle direction is parallel to the direction of the first slide bar rotation axis, and is offset by a distance u1, and the typical offset surface is still within the plane formed by the first yaw axis and the second yaw axis.

[0023] Another relative position assembly form of the first movable unit and the second movable unit is: the first support platform is L-shaped, the depth control unit is installed inward, the first pitch axis and the first yaw axis are perpendicular to point O1; the second pitch axis hole and the second yaw axis are perpendicular to point O2; the rotation axis of the first sliding rod coincides with the axis of the puncture needle, and both are perpendicular to the axes of the first pitch axis and the second pitch axis hole at points O1 and O2, respectively.

[0024] The pitch and yaw rotation axes of the first and second movable units are orthogonal to each other, and the first and second movable units also have one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion. The central axis of the rolling motion is parallel to the linear motion direction axis or the central axis, and is orthogonal to the pitch rotation axes of the first and second movable units, and intersects with the yaw rotation axes of the first and second movable units; the first and second movable units provide at least 5 degrees of freedom of passive activity for the end;

[0025] The first movable unit is composed of a first yaw axis, a first U-shaped block, a first pitch axis, and a first support platform. One end of the first yaw axis is connected to one end of the first position control unit and is rotatable relative to one end of the first position control unit, with the rotation center being the first yaw rotation axis; the other end of the first yaw axis is fixedly connected to the first U-shaped block; the first pitch axis is connected to the first U-shaped block and is rotatable relative to the first U-shaped block, with the rotation center axis being the first pitch rotation axis; the first support platform is fixedly connected to the first pitch axis, and a threaded hole is designed in the middle along the direction of the central axis of the rolling motion;

[0026] The second movable unit has a second structural form, including three parts: a fifth yaw axis, a spherical outer ring, and a spherical inner ring; one end of the fifth yaw axis is connected to one end of the second position control unit, and the fifth yaw axis can rotate relative to one end of the second position control unit, and the rotation center axis is the yaw rotation axis; the other end of the fifth yaw axis is fixedly connected to the spherical outer ring; the spherical outer ring and the spherical inner ring form a ball joint; the spherical inner ring is hollow to form a light hole; the spherical inner ring is connected to one end of the first sliding rod, and the first sliding rod can slide linearly and roll relative to the axis of the light hole of the spherical inner ring.

[0027] Among them, the depth control unit includes a depth control unit base, a third motor, a first coupling, a first screw rod, a nut seat, and a light rod, and the depth control unit base is fixedly mounted on the first support platform; the third motor is fixedly mounted on the depth control unit base; the third motor is connected to one end of the first screw rod through the first coupling; the other end of the first screw rod is connected to the depth control unit base; the nut seat is connected to the first screw rod and the light rod, and can slide along the light rod; the light rod is parallel to the first screw axis, and both ends are connected to the depth control unit base to constrain the rotational movement of the nut seat; the output shaft of the third motor rotates, driving the first screw rod to rotate through the first coupling, thereby driving the nut seat to move forward and backward in the length direction of the first screw rod; the two rotation directions of the output shaft of the third motor correspond to the forward and backward movements of the nut seat.

[0028] Among them, the puncture needle connecting device includes a needle connecting base, a puncture needle, a sleeve, and an instrument fixing device; the needle connecting base is fixedly installed on the nut seat or the first movable unit of the depth control unit; the needle connecting base is designed with two positioning slots for installing the instrument fixing device, and the instrument fixing device is installed on at least one of the positioning slots of the needle connecting base according to needs, the sleeve is connected to the instrument fixing device, and the puncture needle is connected to the sleeve and is coaxial; the two rotation directions of the output shaft of the third motor of the depth control unit correspond to the forward and backward movements of the nut seat, thereby driving the needle connecting base forward and backward, and then driving the puncture needle to move to complete the puncture task.

[0029] A design method of a stereotactic micro-surgical robot includes: the end working spaces W1 and W2 of the first position control unit and the second position control unit, and the depth control unit control the travel L of the puncture needle, which is determined by the working mode of the precision puncture surgery; the lesion point and the surface incision determine the design goals of the first and second position control units and the depth control unit; the lesion (g i ) and puncture point (t j ) calculates the needle path, and calculates the end working spaces W1 and W2 of the first and second position control units from the intersection of the needle paths on the planes XY1 and XY2 where the end working spaces of the first and second position control units are located; i ) to the puncture point (t j ) The maximum value of the distance is calculated, and the depth control unit controls the stroke L of the puncture needle; the specific process is as follows:

[0030] During the design, it is assumed that the puncture needle coincides with the central axis of the rolling motion, and the global coordinate system is established as O W , assuming that the target organ is located in the space W o , the lesion in the target organ is g i (i=1,2,3...); the distribution space of the surface incision is W t The puncture point of the surface incision is t j (j=1, 2, 3...); the end working space of the first position control unit is W1, the plane where W1 is located is XY1, the end working space of the second position control unit is W2, the plane where W2 is located is XY2, and the planes XY1 and XY2 are in the global coordinate system O W X W Y W The planes are parallel, the distance between W1 and W2 is d, and the distance between W2 and W t The distance between them is h, W t With W o The distance between them is k, l j The straight line where the puncture needle is located;

[0031] It is assumed in the design that the axis of the puncture needle coincides with the central axis of the rolling motion, and the connection points between the ends of the first and second position control units and the puncture needle are respectively O d1 , O d2 , respectively in the XY1 and XY2 planes; the feeding depth of the puncture needle along the puncture direction, i.e., the stroke L of the puncture needle, is controlled by the depth control unit; in order to achieve the needle path covering as many lesions as possible in the organ (g i ) and the puncture needle accurately penetrates the lesion and avoids dangerous tissues and organs, while reducing the number of incisions and determining the appropriate puncture point according to the surgical style (t j ) location and quantity;

[0032] Lesions in target organs i The coordinates of gi (x i ,y i , z i )(i=1,2,3.....), puncture point t j The coordinates of tj (x j ,y j , z j )(j=1,2,3.....), then l j The equation of the space line is:

[0033]

[0034] XY1, XY2 plane and global coordinate system O w X w Y w If the planes are parallel, the plane equations of XY1 and XY2 are:

[0035] z1=E1 (2)

[0036] z2=E1-d (3)

[0037] Among them, E1 is the plane XY1 and Z in the global coordinate system W The z coordinate value of the axis intersection point;

[0038] Assume that the equation of the straight line where the puncture needle is located is l j The intersection points with the XY1 and XY2 planes are O 1j , O 2j , then the intersection point O can be obtained by combining equations (1) and (2) 1j The coordinates are:

[0039]

[0040] The intersection point O can be obtained by combining equations (1) and (3) 2j The coordinates are:

[0041]

[0042] Based on formulas (4) and (5), the coordinates P of all lesions in the target organ are gi (x i ,y i ,z i )(where i=1,2,3…) and all puncture points t j The coordinates P tj (x j ,y j ,z j )(where j = 1, 2, 3…), we can find all the intersection points O with planes XY1 and XY2 1j and O 2j Coordinates of all points O 1j The coordinate distribution space is W s1 , all points O 2j The coordinate distribution space is W s2 , spatial point distribution W s1 and W s2 The end O of the first position control unit and the second position control unit are d1 , O d2 The workspace design input is W s1 ∈W1 and W s2 ∈W2, according to the end O of the first position control unit and the second position control unit described in this design d1 , O d2 The working spaces W1 and W2 should be no less than W s1 and W s2 , that is, W1≥W s1 and W2 ≥ W s2 In this way, the first position control unit and the second position control unit can control the puncture needle to move to all puncture points on the body surface to complete the puncture task;

[0043] The lesion coordinates P in the target organ gi (x i ,y i ,z i )(i=1,2,3…) and puncture point t j The coordinates P tj (x j ,y j ,z j The maximum distance between )(j=1,2,3.....) is:

[0044]

[0045] In order to enable the puncture needle to reach all lesion locations in the target organ, the depth control unit controls the puncture needle to have a stroke L no less than L P , that is, L ≥ L P , so that the depth control unit can control the puncture needle to reach all lesion locations.

[0046] A kinematic control method of the stereotactic micro-surgical robot includes forward kinematics and inverse kinematics, wherein the transmission branch chain includes the kinematics of the puncture needle, the needle connecting device, the depth control unit, the activity unit and the position control unit;

[0047] Among them, the specific process of positive kinematics control is as follows:

[0048] According to the DH parameter rule, the coordinate systems and variables of each component are established; let the global coordinate system be W O ; Establish the coordinate system W of the first position control unit base b1 b1 ; At the pitch and yaw orthogonal point O1 of the first active unit, establish the terminal output coordinate system of the first position control unit as W o1 , the terminal output coordinates of the first position control unit are The yaw rotation coordinate system of the first active unit is W yaw1 , the first active unit pitch rotation axis coordinate system is W pitch1 The point where the common perpendicular line of the puncture needle axis and the first pitch axis intersects the central axis of the first slide bar rolling motion is r1, the point where the common perpendicular line of the puncture needle axis and the first pitch axis intersects the puncture needle axis is p1, and the coordinate system connected to the base of the depth control unit is established at point r1 as W r1 Similarly, establish the variables related to the second position control unit: the point where the common perpendicular line of the puncture needle axis and the second pitch axis intersects the central axis of the first slide bar rolling motion is r2, the point where the common perpendicular line of the puncture needle axis and the second pitch axis intersects the puncture needle axis is p2, and the coordinate system connected to the base of the depth control unit is established at point r2 as W r2 ; The distance between r1 and r2 is n; The distance between the puncture needle and the central axis of the first slide bar rolling motion is d1; The distance between the first slide bar axis and the first active unit pitch yaw orthogonal point O1 is d2, and the distance from the second active unit pitch yaw orthogonal point O2 is d'2, and the coordinates of the end of the puncture needle e are P e The coordinates of the base and the end output of the first and second position control units are P b1 , P b2 , P o1 , P o2 ; The initial position of the depth control unit is h0, and the displacement is h1, which is h=h0+h1; The rotation angle of the central axis of the first sliding bar rolling motion is c; s 11 、s 12are two actuator control variables of the first position control unit respectively;

[0049] The forward kinematics calculation of the stereotactic surgical robot is as follows:

[0050] S1: Calculate kinematics from the first position control unit side

[0051] The base coordinate system W of the first position control unit b1 Relative to the global coordinate system W O The homogeneous coordinate transformation of is: b1 According to the kinematics of the first position control unit, the end output coordinate system W of the first position control unit o1 Relative to the base coordinate system W of the first position control unit b1 The homogeneous coordinate transformation of is:

[0052] T1=T f (s 11 ,s 12 ) (7)

[0053] The coordinate system W where point r1 is located r1 After the yaw and pitch motion of the first active unit, the output coordinate system W relative to the end of the first position control unit o1 The homogeneous coordinate transformation of is:

[0054] T h1 =Rot(Y o1 ,a1)Rot(X yaw1 ,b1)Trans(Y pitch1 ,d2) (8)

[0055] Among them, Rot(Y o1 ,a1) is around Y o1 4×4 homogeneous rotation matrix with axis rotation angle a1; Rot(X yaw1 ,b1) is around X yaw1 4×4 homogeneous rotation matrix of axis rotation b1 angle; Trans(Y pitch1 ,d2) is expressed as along Y pitch1 4×4 homogeneous translation matrix with axis translation distance d2;

[0056] The coordinate system W where point r1 is located r1 The first branched chain mechanism of the first movable unit and the first position control unit is calculated to obtain the coordinate relative to the global coordinate system W O The homogeneous coordinate transformation of is: 11 =T b1 T1T h1 ;

[0057] S2: Calculate kinematics from the second position control unit

[0058] W b2 Relative to W O The homogeneous coordinate transformation of is: b2

[0059] According to the kinematics of the second position control unit, W o2 Relative W b2 The homogeneous coordinate transformation of is:

[0060] T2=T f (s 21 ,s 22 ) (9)

[0061] W r2 Relative to W o2 The homogeneous coordinate transformation of is:

[0062] T h2 =Rot(Y o2 ,a2)Rot(X yaw2 ,b2)Trans(Y pitch2 ,d 2' ) (10)

[0063] Among them, Rot(Y o2 ,a2) is around Y o2 4×4 homogeneous rotation matrix with axis rotation angle a2; Rot(X yaw2 ,b2) is around X yaw2 4×4 homogeneous rotation matrix of axis rotation b2 angle; Trans(Y pitch2 ,d 2' ) is represented by the pitch2 Axis translation d 2' 4×4 homogeneous translation matrix of distance;

[0064] When the coordinate system W where point r2 is located r2 Rotate around the first slide bar rolling motion center axis c angle, then move along the first slide bar motion center axis distance n, W r2 Coordinate system and W r1 The coordinate systems coincide, and the coordinate transformation is:

[0065] T r2r1 =Rot(X,c)Trans(X,-n) (11)

[0066] Then the coordinate system W r1 Through the coordinate system W r2 , the global coordinate transformation calculated from the second branch of the depth control unit, the second active unit, and the second position control unit is: T 12 =T b2 T2T h2T r2r1

[0067] S3: After the same coordinate system undergoes transformations of two branches, the following equation is obtained:

[0068]

[0069] Or

[0070]

[0071] Solve using the following step A1 - A3 iterative method. Let the six variables in formula (12) be a1, b1, a2, b2, n, c = x1, x6;

[0072] A1: Given X 0 = [x1, x6]' initial value;

[0073] A2: Calculate F = [f1, f9]' and T = [t1, t3]' respectively according to formula (12);

[0074] A3: If f i <e1 and t j <e2, the calculation is completed. Otherwise, calculate the iterative value as follows and substitute it into the A2 loop:

[0075]

[0076] In the formula, a and β are given convergence coefficients, non - negative numbers, and their sum is 1;

[0077] S4: Calculate the coordinate system on the puncture needle

[0078] Establish the coordinate systems of each component according to the D - H parameter rule. The axis of the puncture needle intersects the common perpendicular of the first and second pitch axes at the puncture needle axis points p1 and p2 respectively, and the end point of the puncture needle is e. Establish the coordinate systems W p1 、W p2 、W e connected to the puncture needle with these three points as the origin respectively;

[0079] W p1 The homogeneous coordinate transformation relative to W r1 is: T p1 = Trans(Y r1 , d1), and the homogeneous coordinate transformation of W p2 relative to W p1 is: T p1p2 = Trans(Z p1 , - n), and the homogeneous coordinate transformation of W e relative to W p1 is: T e=Trans(Z p1 ,-h);

[0080] W e In the global coordinate system W O The homogeneous coordinate transformation of is: We =T b1 T1T h1 T p1 T e ;

[0081] W e The coordinates of point e under e In the global coordinate system W O The coordinates below are: P we =T We P e , from T We The resulting rotation matrix R e is the posture matrix of the puncture needle.

[0082] Inverse kinematics of the stereotactic surgical robot:

[0083] H1: Set the variables corresponding to the six passive joints a1, b1, a2, b2, n, c and s 11 、s 12 、s 21 、s 22 The control variables of the four actuators are unknown variables, which are combined to form a vector X = [x i ] 10×1 ;

[0084] Lesions in known target organs i The coordinates of gi (x i ,y i ,z i ), (i=1,2,3....), puncture point t j The coordinates of tj (x j ,y j ,z j ), (j=1,2,3......), then the equation of the straight line in the space where the puncture needle is located is as shown in formula (1),

[0085] Coordinate system W of points p1 and p2 p1 and W p2 In the global coordinate system W O The homogeneous coordinate transformations are:

[0086] T Wp1 =T b1 T1T h1 T p1

[0087] T Wp2 =T Wp1 T p1p2 (13)

[0088] Points p1 and p2 are respectively in coordinate system W p1 , W p2 The coordinates of the following are p p1 、p p2 , then points p1 and p2 are in the global coordinate system W O The coordinates below are:

[0089] p w1 =T wp1 p p1

[0090] p w2 =T wp2 p p2 (14)

[0091] H2: Solve for variable X

[0092] B1: Point p1 (p2) is located on the axis of the puncture needle, so it satisfies the spatial straight line equation (1). Therefore, substituting equation (14) into equation (1) forms 4 independent equations;

[0093] B2: According to the methods of steps S1, S2, S3 and S4, formula (12) is obtained and 12 equations are calculated;

[0094] B3: Similarly, refer to the steps A1-A3 for iterative solution and obtain X. The last four elements of the X vector are s 11 、s 12 、s 21 、s 22 ;

[0095] H3: Calculate P based on positive kinematics e The depth control unit controls the movement of the puncture needle to:

[0096] The present invention provides a stereo positioning micro surgical robot, which has the advantages of providing two preferred stereo positioning robot assembly forms, three position control units, a parameter design method of the stereo positioning robot position control unit, and a kinematic calculation method of the stereo positioning robot. From the structure of the surgical robot, the robot is very small and very convenient to carry or move to a desired position. The stereo positioning robot has at least 5 degrees of freedom, and provides at least 4 degrees of freedom for positioning and positioning of the terminal puncture needle through two position control units, and provides 1 degree of freedom for feeding through a depth control unit, which greatly increases the flexibility of the terminal puncture needle and enables the puncture needle to move accurately to the target position to complete the puncture.

[0097] This stereotactic micro-surgical robot is small in size and easy to install. The end effector has at least 5 degrees of freedom and can reach the required position in space. The end effector can cooperate with different surgical instruments (such as puncture needles, biopsy needles, ablation needles, etc.) to complete different operations, and cooperate with medical imaging equipment (such as B-ultrasound, MRI, CT, etc.) to provide doctors with real-time imaging information to ensure the smooth completion of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 The figure shows the overall structure of a stereo positioning micro surgical robot of the present invention.

[0099] Figure 2a The figure shows the overall structure of an assembly form I of a multi-degree-of-freedom stereo positioning robot according to an embodiment of the present invention.

[0100] Figure 2b Shown Figure 2a Structural explosion diagram

[0101] Figure 3 The figure shows a schematic diagram of the working space and puncture path of a multi-degree-of-freedom stereo positioning robot of the present invention.

[0102] Figure 4a The figure shows the overall structure of an assembly form II of a multi-degree-of-freedom stereo positioning robot according to an embodiment of the present invention.

[0103] Figure 4b Shown Figure 4a Structural explosion diagram

[0104] Figure 5 The figure shows a structural form A of the first position control unit in an embodiment of the present invention.

[0105] Figure 6 Shown Figure 5 The partial structure diagram of the driving system of the first position control unit shown in FIG.

[0106] Figure 7 Shown Figure 5 Schematic diagram of the gear adjustment hole of the second joint output rod of the first position control unit shown

[0107] Figure 8 Shown Figure 5 , 6 , Schematic diagram of the first gear motion range of the first position control unit shown in FIG.

[0108] Fig. 9 Shown Figure 5 , 6 , 7 shows a schematic diagram of the second gear motion range of the first position control unit

[0109] Fig.10 The figure shows the overall structure of the first movable unit and the second movable unit of the present invention in a relative position assembly form.

[0110] Fig.11 The overall structure of a depth control unit of the present invention is shown as follows

[0111] Fig.12 The figure shows the overall structure of a puncture needle connection device of the present invention.

[0112] Fig.13 The figure shows the overall structure of a bedside positioning arm of the present invention.

[0113] Fig.14 The figure shows the overall structure of a structure B of the first position control unit in an embodiment of the present invention.

[0114] Fig.15 The figure shows the overall structure of an assembly form III of the multi-degree-of-freedom stereo positioning robot in an embodiment of the present invention.

[0115] Fig.16 The figure shows the overall structure of a structure form C of the first position control unit in an embodiment of the present invention.

[0116] Fig.17 Shown Fig.16 Structural composition diagram and explosion diagram

[0117] Fig.18 The figure shows the overall structure of an assembly form IV of a multi-degree-of-freedom stereo positioning robot according to an embodiment of the present invention.

[0118] Fig.19 The figure shows the overall structure of another relative position assembly form of the first movable unit and the second movable unit of the present invention.

[0119] Fig. 20 The figure shows the overall structure of an assembly form V of a multi-degree-of-freedom stereo positioning robot according to an embodiment of the present invention.

[0120] Fig.21 Shown Fig. 20 The first and second movable units have a partially enlarged structure and a schematic diagram of the relationship between the rotation axes

[0121] Fig. 22 The overall structure diagram of the second active unit D of the present invention is shown as follows:

[0122] Fig.23 FIG. 6 is an overall structural diagram of an assembly form VI of a multi-degree-of-freedom stereo positioning robot according to an embodiment of the present invention.

[0123] Fig.24 Shown Fig.23 The first and second movable units have a partially enlarged structure and a schematic diagram of the relationship between the rotation axes

[0124] Fig.25 The figure shows the overall structure of an assembly form VII of a multi-degree-of-freedom stereo positioning robot according to an embodiment of the present invention.

[0125] Fig.26 Shown Fig.25 The first and second movable units have a partially enlarged structure and a schematic diagram of the relationship between the rotation axes

[0126] Fig. 27 Schematic diagram of the kinematic coordinate system definition and coordinate transformation of the stereotactic micro-surgical robot

[0127] Fig.27a , b, c are Fig. 27 Schematic diagram of the split

[0128] Fig.27d for Fig. 27 Flowchart

[0129] Fig.28 The figure shows the kinematic coordinate definition and parameter variables of the position control unit A.

[0130] Fig.29a , b shows the kinematic coordinate definition and parameter variables of the position control unit B

[0131] Fig.30a , b shows the kinematic coordinate definition and parameter variables of the position control unit C

[0132] The numbers in the figure are explained in the following table:

[0133]

[0134] DETAILED DESCRIPTION

[0135] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0136] A stereotactic micro-surgical robot, such as Figure 1 As shown in FIG. 1 , the stereo positioning micro surgical robot is mainly composed of a multi-degree-of-freedom stereo positioning robot 1 and a bedside positioning arm 2. The multi-degree-of-freedom stereo positioning robot 1 is as shown in FIG. Figure 2a , Figure 2b As shown, Figure 2b for Figure 2aThe exploded diagram includes a first position control unit 3, a second position control unit 4, a depth control unit 5, a puncture needle connecting device 6, a first movable unit 7, a second movable unit 8 and a first base 9. The first base 9 provides a mounting base. The first and second position control units respectively have two active motion degrees of freedom, and the working space of the end position is a plane. The depth control unit has a linear feed with one active motion degree of freedom. The first and second movable units respectively have at least pitch and yaw passive degrees of freedom, and there is also one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion between the two. The puncture needle connecting device 6 fixes the needle (including but not limited to any targeted puncture-related needle such as a puncture needle, a biopsy needle, an ablation needle, or an instrument with terminal tissue sampling, radiofrequency ablation, microwave ablation, laser ablation, freezing or jetting). The multi-degree-of-freedom stereo positioning robot 1 provides positioning, orientation (orientation) posture and depth control capabilities of no less than 5 degrees of freedom, and can puncture into the human body through different incisions (puncture points) on the body to reach the predetermined lesion point.

[0137] The first position control unit 3 and the second position control unit 4 each have at least two active motion degrees of freedom, respectively, and are respectively composed in series and parallel forms, and each active motion degree of freedom is directly driven by an actuator (motor) or, more preferably, in order to reduce the distal load, is driven by a motor pre-installed on the base and then driven by a connecting rod transmission. The first position control unit 3 and the second position control unit 4 are connected to the depth control unit 5 and the puncture needle connecting device 6 in the form of a parallel mechanism through the first movable unit 7 and the second movable unit 8, thereby allowing the puncture needle connecting device 6 to be positioned in three-dimensional space and to move in pitch, roll and posture (direction). The multi-freedom stereo positioning robot 1 has at least 5 degrees of freedom, so that the terminal puncture needle can move to the spatial target position.

[0138] The end working spaces W1 and W2 of the first position control unit 3 and the second position control unit 4 and the depth control unit 5 control the travel L of the puncture needle, which is determined by the working mode of the precision puncture surgery; the lesion point and the surface incision (needle entry point) determine the design goals of the first and second position control units and the depth control unit; the lesion (g i ) and puncture point (t j ) calculates the needle path, and calculates the end working spaces W1 and W2 of the first position control unit 3 and the second position control unit 4 from the intersection of the needle path on the planes XY1 and XY2 where the end working spaces of the first and second position control units are located; i ) to the puncture point (t j )The maximum value in the distance is calculated and the depth control unit 5 controls the stroke L of the puncture needle.

[0139] like Figure 3As shown in the figure, it is assumed that the puncture needle coincides with the central axis of the rolling motion during design, and the global coordinate system is established as O W , assuming that the target organ is located in the space W o , the lesion in the target organ is g i (i=1,2,3...); the distribution space of the surface incision is W t The puncture point of the surface incision is t j (j=1, 2, 3...); the end working space of the first position control unit is W1, the plane where W1 is located is XY1, the end working space of the second position control unit is W2, the plane where W2 is located is XY2, and the planes XY1 and XY2 are in the global coordinate system O W X W Y W The planes are parallel, the distance between W1 and W2 is d, and the distance between W2 and W t The distance between them is h, W t With W o The distance between them is k (the distance can be the shortest Euclidean distance), l j The straight line where the puncture needle is located;

[0140] It is assumed in the design that the axis of the puncture needle coincides with the central axis of the rolling motion, and the connection points between the ends of the first and second position control units and the puncture needle are respectively O d1 , O d2 , respectively in the XY1 and XY2 planes; the feeding depth of the puncture needle along the puncture direction, i.e., the stroke L of the puncture needle, is controlled by the depth control unit 5; the needle path determines the effectiveness, accuracy, and minimally invasiveness of the puncture surgery; in order to achieve the needle path covering as many lesions as possible in the organ (g i ) and the puncture needle accurately penetrates the lesion and avoids dangerous tissues and organs, while reducing the number of incisions and determining the appropriate puncture point according to the surgical style (t j ) location and quantity.

[0141] Lesions in target organs i The coordinates of gi (x i ,y i ,z i )(i=1,2,3…), puncture point t j The coordinates of tj (x j ,y j ,z j )(j=1,2,3.....), then l j The equation of the space line is:

[0142]

[0143] XY1, XY2 plane and global coordinate system Ow X w Y w If the planes are parallel, the plane equations of XY1 and XY2 are:

[0144] z1=E1 (2)

[0145] z2=E1-d (3)

[0146] Among them, E1 is the plane XY1 and Z in the global coordinate system W The z-coordinate value of the axis intersection point.

[0147] Assume that the equation of the straight line where the puncture needle is located is l j The intersection points with the XY1 and XY2 planes are O 1j , O 2j , then the intersection point O can be obtained by combining equations (1) and (2) 1j The coordinates are:

[0148]

[0149] The intersection point O can be obtained by combining equations (1) and (3) 2j The coordinates are:

[0150]

[0151] Based on formulas (4) and (5), the coordinates P of all lesions in the target organ are gi (x i ,y i ,z i )(where i=1,2,3…) and all puncture points t j The coordinates P tj (x j ,y j ,z j )(where j = 1, 2, 3…), we can find all the intersection points O with planes XY1 and XY2 1j and O 2j Coordinates of all points O 1j The coordinate distribution space is W s1 , all points O 2j The coordinate distribution space is W s2 , spatial point distribution W s1 and W s2 are the working space design inputs of the ends O1 and O2 of the first position control unit and the second position control unit, respectively. Then W s1 ∈W1 and W s2 ∈W2, according to this design, the working spaces W1 and W2 of the ends O1 and O2 of the first position control unit and the second position control unit should be no less than W s1and W s2 , that is, W1≥W s1 and W2 ≥ W s2 In this way, the first position control unit and the second position control unit can control the puncture needle to move to all puncture points on the body surface to complete the puncture task.

[0152] The lesion coordinates P in the target organ gi (x i ,y i ,z i )(i=1,2,3…) and puncture point t ( The coordinates P tj (x j ,y j ,z j The maximum distance between )(j=1,2,3.....) is:

[0153]

[0154] In order to enable the puncture needle to reach all lesion locations in the target organ, the depth control unit 5 is designed to control the puncture needle to have a stroke L not less than L P , that is, L>L P , so that the depth control unit can control the puncture needle to reach all lesion locations.

[0155] As an embodiment of the present invention, an assembly form I of the multi-degree-of-freedom stereo positioning robot 1 is as follows: Figure 2a , 2b As shown, Figure 2b for Figure 2a In the exploded diagram, one end base of the first position control unit 3 and the second position control unit 4 is fixedly mounted on the first base 9, and the outputs of the other ends are respectively connected to the first movable unit 7 and the second movable unit 8; the output of the first movable unit 7 is fixedly connected to the base of the depth control unit 5; the puncture needle connecting device 6 is fixedly mounted on the output (nut seat) of the depth control unit 5.

[0156] As an embodiment of the present invention, another assembly form II of the multi-degree-of-freedom stereo positioning robot 1 is as follows: Figure 4a , as shown in 4b, where Figure 4b for Figure 4a In the exploded diagram, the first base 11 is fixedly mounted on the output (nut seat) of the depth control unit 10; one end of the first position control unit 12 and the second position control unit 13 are fixedly mounted on the first base 11, and the other end outputs are respectively connected to one end of the first movable unit 16 and the second movable unit 14; the puncture needle connecting device 15 is fixedly mounted on the output of the first movable unit 16.

[0157] The distance between the first position control unit and the second position control unit is d.

[0158] The first position control unit and the second position control unit are both modularly designed and have the same structure. Each position control unit has at least two active motion degrees of freedom. Each active motion degree of freedom of each position control unit is directly driven by an actuator (motor) or, more preferably, driven by a motor pre-installed on a base and then driven by a connecting rod to reduce the remote load; because the structures of the two position control units are exactly the same, only the first position control unit is described in detail below.

[0159] The first position control unit is composed of two joints, namely the first joint and the second joint. Each joint is driven by a separate motor. The transmission mechanism adopts connecting rod transmission. Each joint can rotate under the action of the motor to control the two-degree-of-freedom position of the end. First, in order to improve the force transmission performance, strength and rigidity of the first position control unit, a double-axis connecting rod design is adopted at the hinge of each joint of the first position control unit, and the positioning accuracy of the first position control unit can also be increased; second, in order to improve the motion range of the first position control unit, a connecting rod of the second joint is counted as a bending rod, which can significantly improve the motion range of the second joint of the first position control unit.

[0160] The structure of the first position control unit is as follows Figure 5 , 6 As shown in , 7, the first position control unit is composed of a first joint, a second joint, a driving system and an end link.

[0161] The first joint is composed of a first joint output rod 33, a first motor 19, and a first transfer rod 32, a fifth connecting rod 31, a sixth connecting rod 45, and a main shaft 28, which are hinged to each other to form a crank slider mechanism, and the vertical movement of the first motor is converted into the rotation of the first joint. Specific description: The first motor 19 is connected to the inner side of the housing 24 through the first motor fixing seat 17 and the first motor base 21, and is completely fixed by the hexagon socket bolt 23 and the bolt hole reserved by the housing 24; the first motor 19 is fixedly connected to the first motor shaft 26 through threads, and the first transfer rod 32 is sleeved on the first motor shaft 26; the first transfer rod 32 and the fifth connecting rod 31 and the sixth connecting rod 45 are all hinged to the third shaft 29, and one end of the third shaft 29 is designed with threads and connected to the hexagonal nut 41; the other ends of the fifth connecting rod 31 and the sixth connecting rod 45 are hinged to the first joint output rod 33, and the first joint output rod 33 is also hinged to the main shaft 28, and the main shaft 28 is hinged to the housing 24 and fixed on the housing 24. Through the structural features described above, the first motor drives the first joint to rotate.

[0162] The second joint is composed of a four-bar linkage mechanism formed by the second motor 20 bypassing the first joint through the main shaft 28 and hinged to each other through the third connecting rod 46, the fourth connecting rod 48, the bent rod 44, the seventh connecting rod 36, the eighth connecting rod 43 and the first joint, and the ninth connecting rod 38 and the tenth connecting rod 42, which convert the vertical up and down movement of the second motor into the rotation of the second joint output rod 39. Specific description: The second motor 20 is connected to the inner side of the housing 24 through the second motor fixing seat 18 and the second motor base 22, and is completely fixed by the hexagon socket bolts and the bolt holes reserved in the housing; the second motor 20 is fixedly connected to the second motor shaft 51 by threads, and the second transfer rod 50 is sleeved on the second motor shaft 51; the second transfer rod 50 and the first connecting rod 47 and the second connecting rod 49 are all hinged to the first shaft 25, and one end of the first shaft 25 is designed with threads and connected to the hexagonal nut; the first connecting rod 47, the second connecting rod 49 and the third connecting rod 46 The fourth connecting rod 48 and the bent rod 44 are all hinged through the second shaft 27, the third connecting rod 46, the fourth connecting rod 48, the sleeve 52 and the main shaft 28 are hinged; the other end of the bent rod 44 is hinged with the seventh connecting rod 36, the eighth connecting rod 43 and the ninth connecting rod 38, the tenth connecting rod 42 through the sixth shaft 35, the ninth connecting rod 38, the tenth connecting rod 42 and one of the two gear adjustment holes of the second joint output rod 39 are hinged, and the other ends of the seventh connecting rod 36 and the eighth connecting rod 43 are hinged with the first joint output rod 33 and the second joint output rod 39 through the fifth shaft 34. According to the structural features described above, when the second motor moves in the vertical direction, the first connecting rod, the second connecting rod, the third connecting rod, the fourth connecting rod, the bent rod, the seventh connecting rod, the eighth connecting rod and the first joint output rod are hinged to form a four-bar mechanism and the ninth connecting rod and the tenth connecting rod, which are driven by the main shaft to transmit the motion to the second joint output rod so that it rotates around the fifth shaft 34.

[0163] The drive system, such as Figure 6As shown, the motor is combined with the transmission mechanism to form a crank slider mechanism, so that the drive motor can maintain vertical movement. The structure of the drive system is as follows: the first motor 19 is connected to the first motor shaft 26 by a thread, the first motor shaft 26 is connected to the first transfer rod 32, and the first transfer rod 32 is sleeved on the first motor shaft 26; the second motor 20 is connected to the second motor shaft 51 by a thread, the second motor shaft 51 is connected to the second transfer rod 50, and the second transfer rod 50 is sleeved on the second motor shaft 51. The first transfer rod 32 is hinged to one end of the fifth connecting rod 31 and the sixth connecting rod 45, and the other ends of the fifth connecting rod 31 and the sixth connecting rod 45 are hinged to the first joint output rod 33 to drive the first joint to rotate. Movement process: The first motor is extended and retracted in the vertical direction, driving the first motor shaft and the fifth connecting rod, the sixth connecting rod and other components to move, thereby driving the first joint output rod to rotate. At the same time, the second motor extends and retracts in the vertical direction, driving the second motor shaft and the first connecting rod, the second connecting rod, the third connecting rod, the fourth connecting rod, the curved rod, the seventh connecting rod, the eighth connecting rod and the first joint output rod to form a four-bar mechanism, as well as the ninth connecting rod and the tenth connecting rod, thereby driving the second joint output rod to rotate.

[0164] The end connecting rod, such as Figure 7 As shown, while ensuring that the volume of the connecting rod is as small as possible, two gear adjustment holes with adjustable motion range are designed on the second joint output rod 39, which are the first gear adjustment hole 53 and the second gear adjustment hole 54. When the ninth connecting rod and the tenth connecting rod are connected to the first gear adjustment hole, the end of the connecting rod is in a straight state, and the motion range is small. When the ninth connecting rod and the tenth connecting rod are connected to the second gear adjustment hole, the end of the connecting rod is in a slightly bent state, and the motion range is large, which improves the adaptability of the first position control unit in terms of motion range, and the gear adjustment process is simple and easy to operate. The motion ranges of the first gear and the second gear of the first position control unit are shown as follows: Figure 8 , Fig. 9 As shown, the dark black area is the motion range of the end of the first position control unit.

[0165] The first motor 19 is fixedly connected to the first motor shaft 26, and the first transfer rod 32 is sleeved on the first motor shaft 26; the first transfer rod 32 and the fifth connecting rod 31 and the sixth connecting rod 45 are all hinged to the third shaft 29, and one end of the third shaft 29 is designed with a thread and connected to the hexagonal nut 41; the other ends of the fifth connecting rod 32 and the sixth connecting rod 45 are hinged to the first joint output rod 33 through the fourth shaft 30, and the first joint output rod 33 is also hinged to the main shaft 28, and the main shaft 28 is hinged and fixed to the housing 24;

[0166] The second motor 20 is fixedly connected to the second motor shaft 51 by threads, and the second transfer rod 50 is sleeved on the second motor shaft 51; the second transfer rod 50 and the first connecting rod 47 and the second connecting rod 49 are all hinged to the first shaft 25, and one end of the first shaft 25 is designed with threads and connected to the hexagonal nut 41; the first connecting rod 47, the second connecting rod 49 and the third connecting rod 46, the fourth connecting rod 48 and the bent rod 44 are all hinged through the second shaft 27, and the third connecting rod 46, the fourth connecting rod 48, the sleeve 52 and the main shaft 28 are hinged; the other end of the bent rod 44 is hinged to the eighth connecting rod 43, the seventh connecting rod 36 and the ninth connecting rod 38, the tenth connecting rod 42 through the sixth shaft 35, and the first connecting rod 47, the second connecting rod 49 and the third connecting rod 46, the fourth connecting rod 48 and the bent rod 44 are all hinged through the second shaft 27. One of the two gear adjustment holes of the ninth connecting rod 38, the tenth connecting rod 42 and the second joint output rod 39 is hinged through the seventh shaft 37, and the other ends of the seventh connecting rod 36 and the eighth connecting rod 43 are hinged at the same time through the fifth shaft 34 and the first joint output rod 33 and the second joint output rod 39; through the above structure, when the second motor 20 moves in the vertical direction, the four-bar mechanism composed of the first connecting rod and the second connecting rod, the third connecting rod, the fourth connecting rod, the curved rod, the seventh connecting rod, the eighth connecting rod and the first joint output rod, as well as the ninth connecting rod and the tenth connecting rod, is driven by the second transfer rod 50 to hinge with each other to form a four-bar mechanism, and the ninth connecting rod and the tenth connecting rod, and the motion is transmitted to the second joint output rod to rotate it around the fifth axis.

[0167] The movement process of the first position control unit is as follows: Since the first position control unit is independently driven by two motors, the first joint remains stationary when the first position control unit is in a vertical state, and the second joint can also rotate through the drive of the second motor. The two joints are independently driven by two motors, and the driving part is designed as a crank slider mechanism so that the first motor and the second motor can keep moving in the vertical direction, ensuring the reliability of the movement. When the first position control unit starts to move, the first joint is formed by the first motor through the transfer rod, the fifth connecting rod, the sixth connecting rod, the first joint output rod, and the main shaft, which are hinged to each other to form a crank slider mechanism, which converts the vertical movement of the first motor into the rotation of the first joint, so that the first joint begins to bend; at the same time, the second joint is formed by the second motor bypassing the first joint through the main shaft and through the third connecting rod, the fourth connecting rod, the curved rod, the seventh connecting rod, the eighth connecting rod and the first joint output rod. The four-bar mechanism and the ninth connecting rod and the tenth connecting rod are hinged to each other to form a four-bar mechanism to convert the vertical movement of the second motor into the rotation of the second joint, so that the second joint can achieve bending movement. When the first motor is fully retracted, the first joint stops rotating, and the bending of the first joint reaches its maximum value. Considering that the range of motion of the end of the second joint should be as large as possible, the stroke of the second motor is selected to be greater than the stroke of the first motor. At this time, the second motor continues to extend, and the second joint continues to expand its range of motion. When the second motor is fully extended, the second joint stops bending and reaches the maximum range of motion, while cooperating with the first joint to complete the motion process. The end connecting rods of the first position control unit and the second position control unit are designed with mounting holes, which are connected to the first movable unit and the second movable unit.

[0168] As an embodiment of the present invention, another structural form B of the two position control units is as follows: Fig.14As shown, similarly; the structures of the two position control units are exactly the same, and are both composed of a fourth motor 82, an eleventh connecting rod 83, a twelfth connecting rod 84, a first connecting base 85, an eighth shaft 86, a thirteenth connecting rod 87, a ninth shaft 88, a fourteenth connecting rod 89, a fifth motor 90, a second base 91, a tenth shaft 92, etc. The fourth motor 82 and the fifth motor 90 are fixedly mounted on the second base 91, and there is a distance between the fourth motor 82 and the fifth motor 90; the eleventh connecting rod 83 is connected to the output shaft of the fourth motor 82; the eleventh connecting rod 83 is connected to the twelfth connecting rod 84 through the tenth shaft 92; the twelfth connecting rod 84, the first connecting base 85 and the thirteenth connecting rod 87 are connected through the eighth shaft 86, and the first connecting base 85 is rigidly connected to the twelfth connecting rod 84 or the thirteenth connecting rod 87 through a fastener; the thirteenth rod 87 is connected to the fourteenth rod 89 through the ninth shaft 88; the fourteenth connecting rod 89 is connected to the output shaft of the fifth motor 90. The output shaft of the fourth motor 82, the eighth shaft 86, the ninth shaft 88, the output shaft of the fifth motor 90, and the tenth shaft 92 are parallel. The rotation of the output shafts of the fourth motor and the fifth motor respectively drives the rotation of the eleventh connecting rod 83 and the fourteenth connecting rod 89, thereby controlling the position of the first connecting base 85 at the end in the XY plane (working space). As an embodiment, the second base 91 and the first connecting base 85 are designed with mounting holes, so that the two position control units are connected to the first base 9, the depth control unit 5, the first and second movable units 7, 8 and the puncture needle connecting device 6 in parallel with the plane of the working space, so as to realize needle positioning and posture determination, such as Fig.15 shown.

[0169] As an embodiment of the present invention, the present invention provides another structural form C of the two position control units, such as Fig.16 , 17As shown; the structure drives two nuts on the screw rod to move parallelly along a straight line through two motors respectively, and drives the second connecting base at the end to move horizontally and vertically in a plane through a parallel four-bar linkage, and the posture of the second connecting base remains parallel to the horizontal plane during the movement; the structure includes: a first support base 93, a first support slider 94, a slide bar 104-1, a first support nut seat 95, a second screw rod 96, a second coupling 97, a sixth motor 98, a third base 99, a seventh motor 100, a third coupling 101, a second support nut seat 102, a second support slider 103, a slide bar 104-2, a third screw rod 105, a second support base 106, a fifteenth connecting rod 107, a sixteenth connecting rod 108, a second connecting base 109, a seventeenth connecting rod 110, an eighteenth connecting rod 111, a nineteenth connecting rod 112, a twentieth connecting rod 113, etc. The first support base 93 and the second support base 106 are fixedly installed in the third base 99, the sixth motor 98 and the seventh motor 100 are fixedly installed on the first support base 93 and the second support base 106 respectively, the second screw rod 96 and the third screw rod 105 are connected to the output shafts of the sixth motor 98 and the seventh motor 100 respectively through the second coupling 97 and the third coupling 101 respectively; the first support nut seat 95 and the second support nut seat 102 are connected to the second screw rod 96, the third screw rod 105, the slide rods 104-1 and 104-2 respectively, and slide linearly along the slide rods 104-1 and 104-2. The slide rods 104-1 and 104-2 are parallel to the second screw rod 96 and the third screw rod 105, respectively, and the two ends are connected to the first support base 93 and the second support base 106 respectively, respectively constraining the rotation of the first support nut seat 95 and the second support nut seat 102.The first supporting slider 94 and the second supporting slider 103 are fixedly mounted on the first supporting nut seat 95 and the second supporting nut seat 102 respectively; the first supporting slider 94 is connected to one end of the seventeenth connecting rod 110, the eighteenth connecting rod 111 and the twentieth connecting rod 113 in an articulated manner, and the other ends of the seventeenth connecting rod 110, the eighteenth connecting rod 111 and the twentieth connecting rod 113 are connected to one end of the second connecting base 109 in an articulated manner to form an articulated parallelogram connecting rod mechanism; the second supporting slider 103 is connected to one end of the fifteenth connecting rod 107, the sixteenth connecting rod 108 and the nineteenth connecting rod 112 in an articulated manner, and the other ends of the fifteenth connecting rod 107, the sixteenth connecting rod 108 and the nineteenth connecting rod 112 are connected to the other end of the second connecting base 109 in an articulated manner The output shafts of the sixth motor 98 and the seventh motor 100 rotate, respectively driving the second screw rod 96 and the third screw rod 105 to rotate through the second coupling 97 and the third coupling 101, thereby respectively driving the first support nut seat 95 and the second support nut seat 102 to move forward and backward in the length direction of the second screw rod and the third screw rod, and then respectively driving the first support slider 94 and the second support slider 103 to move forward and backward in the length direction of the second screw rod and the third screw rod, thereby controlling the position of the second connecting base 109 at the end in the XY plane, and the posture of the second connecting base 109 remains parallel to the horizontal plane during the movement; the use of an articulated parallelogram linkage mechanism can ensure that the posture of the second connecting base 109 remains unchanged. As an embodiment, the third base 99 and the second connecting base 109 are designed with mounting holes, so that the two position control units are parallel to the plane of the working space and connected with the first base 9, the depth control unit 5, the first and second movable units 7, 8 and the puncture needle connecting device 6, etc., so as to realize the positioning and posture of the puncture needle, such as. Fig.18 shown.

[0170] The first movable unit 7 and the second movable unit 8 are as follows Figure 2a and Fig.10 As shown. The pitch and yaw rotation axes of the first and second active units are orthogonal. The first and second active units also have one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion. The central axis of the rolling motion is parallel to the linear motion direction axis (or central axis), and is orthogonal to the pitch rotation axis of the first and second active units, and intersects with the yaw rotation axis of the first and second active units; the first and second active units provide at least 5 degrees of freedom of passive activity for the end, so that the transmission of displacement and posture can be achieved.

[0171] like Fig.10As shown, a structural form A of the first movable unit 7 is mainly composed of a first yaw axis 55, a first U-shaped block 56, a first pitch axis 57, a first support platform 58, etc., one end of the first yaw axis 55 is connected to one end of the first position control unit, the first yaw axis 55 is rotatable relative to one end of the first position control unit, and the rotation center is the first yaw rotation axis; the other end of the first yaw axis 55 is fixedly connected to the first U-shaped block 56; the first pitch axis 57 is connected to the first U-shaped block 56, the first pitch axis 57 is rotatable relative to the first U-shaped block 56, and the rotation center axis is the first pitch rotation axis; the first support platform 58 is fixedly connected to the first pitch axis 57, and a threaded hole is designed in the middle along the direction of the central axis of the rolling motion.

[0172] like Fig.10 As shown, a structural form A of the second movable unit 8 is mainly composed of a second pitch axis hole 59, a second U-shaped block 60, a second yaw axis 61, etc.; the second yaw axis 61 is connected to one end of the second position control unit, and the second yaw axis 61 can rotate relative to one end of the second position control unit, and the rotation center is the second yaw rotation axis; the second yaw axis 61 is fixedly connected to the second U-shaped block 60; the second pitch axis hole 59 is connected to the second U-shaped block 60, and the second pitch axis hole 59 can rotate relative to the second U-shaped block 60, and the rotation center axis is the second pitch rotation axis. The second pitch axis hole 59 is designed with a light hole in the middle along the direction of the center axis of the rolling motion. The first movable unit 7 and the second movable unit 8 are connected through a first sliding rod 62, and one end of the first sliding rod 62 is designed with a thread and is fixedly connected to the threaded hole of the first pitch axis 57 through a thread, and the other end of the first sliding rod 62 cooperates with the light hole of the second pitch axis hole 59; the first sliding rod 62 can slide relatively linearly in the axial direction of the first sliding rod 62 relative to the second pitch axis hole 59, and can roll and rotate relatively around the first sliding rod 62 in a circumferential direction.

[0173] As an embodiment, a relative position assembly form of the first movable unit 7 and the second movable unit 8 is as follows: Fig.10 As shown. The first pitch axis 57 and the first yaw axis 55 are perpendicular to point O1; the second pitch axis hole 59 and the second yaw axis 61 are perpendicular to point O2; the rotation axis of the first slide bar 62 (the center axis of rolling motion, the axis of linear motion direction) is perpendicular to the axis of the first pitch axis 57 and the second pitch axis hole 59 at points O1 and O2 respectively; the direction of the puncture needle is parallel to the direction of the rotation axis of the first slide bar 62, and is offset by a distance u1. The typical offset surface is still in the plane formed by the first yaw axis 55 and the second yaw axis 61, as shown in FIG. Figure 2a shown.

[0174] As an embodiment, another relative position assembly form of the first movable unit 7 and the second movable unit 8 is as follows: Fig.19 As shown; the threaded hole of the second support platform 117 is at a horizontal distance u2 from the axis of the first yaw axis, and at a vertical distance u3 from the axis of the first pitch axis; the light hole of the second pitch axis hole 119 is at a vertical distance u4 from the axis of the second pitch axis hole through the supporting cylinder 118 and the third support platform 122; the first pitch axis 116 and the first yaw axis 114 are perpendicularly orthogonal to point O1; the second pitch axis hole 119 and the second yaw axis 120 are perpendicularly orthogonal to point O2; the rotation axis (rolling motion center axis, linear motion direction axis) of the first sliding bar 123 is perpendicular to the axes of the first pitch axis 116 and the second pitch axis hole 119, respectively, but is offset by d2 and d2' relative to point O1 and point O2, as shown Fig.19 and 27a The first and second position control units and the depth control unit are designed with mounting holes so that the puncture needle direction is parallel to the rotation axis direction of the first slide bar 123 and offset by a distance u5. The typical offset plane is still within the plane formed by the first yaw axis 114 and the second yaw axis 120. Fig. 20 and 21 shown.

[0175] As an embodiment, the third relative position assembly form of the first movable unit 7 and the second movable unit 8 is as follows: Fig.26 As shown, the first support platform 58 is L-shaped, and the depth control unit is installed inward. The first pitch axis 57 and the first yaw axis 55 are perpendicular to point O1; the second pitch axis hole 59 and the second yaw axis 61 are perpendicular to point O2; the rotation axis (rolling motion center axis, linear motion direction axis) of the first slide bar 62 coincides with the puncture needle axis, and both are perpendicular to the first pitch axis 57 and the second pitch axis hole 59 at points O1 and O2, respectively.

[0176] As an embodiment, the second structural form of the second active unit of the present invention is as follows: Fig. 22As shown, it is mainly composed of three parts, namely, the fifth yaw axis 124, the spherical outer ring 125, and the spherical inner ring 126; one end of the fifth yaw axis 124 is connected to one end of the second position control unit, and the fifth yaw axis 124 is rotatable relative to one end of the second position control unit, and the rotation center axis is the yaw rotation axis; the other end of the fifth yaw axis 124 is fixedly connected to the spherical outer ring 125; the spherical outer ring 125 and the spherical inner ring 126 form a ball joint, and the spherical inner ring 126 forms a spherical kinematic pair relative to the spherical outer ring 125; the spherical inner ring 126 is hollow to form a light hole. The spherical inner ring 126 is connected to one end of the first sliding rod 62, and the first sliding rod 62 can slide linearly and roll relative to the light hole axis of the spherical inner ring 126. As an embodiment, the first and second position control units and the depth control unit are designed with mounting holes, so that the first movable unit 7 and the second structural form of the second movable unit are connected with the first and second position control units, the depth control unit, the first base and the puncture needle connecting device 6, etc., so as to realize needle positioning and posture determination, such as Fig.23 , 24 As shown, Fig.24 for Fig.23 Magnified view of the first and second active units.

[0177] The depth control unit 5 is as follows: Fig.11 As shown, it is mainly composed of a depth control unit base 68, a third motor 63, a first coupling 64, a first screw rod 66, a nut seat 67, a light rod 65, etc. The depth control unit base 66 is fixedly mounted on the first support platform 58; the third motor 63 is fixedly mounted on the depth control unit base 68. The third motor 63 is connected to one end of the first screw rod 66 through the first coupling 64, and the other end of the first screw rod 66 is connected to the depth control unit base. The nut seat 67 is connected to the first screw rod 66 and the light rod 65 and can slide along the light rod. The light rod is parallel to the first screw axis, and both ends are connected to the depth control unit base 68 to constrain the rotation of the nut seat. The output shaft of the third motor 63 rotates, and drives the first screw rod 66 to rotate through the first coupling 64, thereby driving the nut seat 67 to move forward and backward in the length direction of the first screw rod; the two rotation directions of the output shaft of the third motor correspond to the forward and backward movements of the nut seat.

[0178] The puncture needle connecting device, such as Fig.12As shown, it is mainly composed of a needle connection base 69, a puncture needle 70, a sleeve 71, an instrument fixing device 72, etc. The needle connection base 69 is fixedly mounted on the nut seat 67 or the first movable unit 7 of the depth control unit; the needle connection base 69 is designed with two positioning slots for mounting the instrument fixing device 72, and the instrument fixing device 72 is installed on at least one of the positioning slots of the needle connection base according to the needs, the sleeve 71 is connected to the instrument fixing device 72, and the puncture needle 70 is connected to the sleeve 71 and is coaxial. The sleeve 71 and the instrument fixing device 72 adjust the structure according to the shape and parameters of the puncture needle. The two rotation directions of the output shaft of the third motor 63 of the depth control unit 5 correspond to the forward and backward movements of the nut seat 67, thereby driving the needle connection base 69 forward and backward, and then driving the puncture needle to move to complete the puncture task.

[0179] The bedside positioning arm is as follows Fig.13 As shown, it is mainly composed of a first fixing bolt 73, a positioning slider 74, a first rod 75, a first universal joint 76, a second rod 77, a second fixing bolt 78, a third rod 79, a second universal joint 80, a fourth rod 81, etc. The positioning slider 74 can be fixedly installed on the sliding track beside the operating bed. A sliding groove is designed on one side of the positioning slider, which can be conveniently installed and connected with the track beside the operating bed. The positioning slider 74 is designed with a mounting hole, which is connected to the first rod 75. The first rod can move up and down relative to the positioning slider; the vertical movement of the first rod 75 is limited by the first fixing bolt 73. The positioning slider 74 is connected with a threaded hole, which is connected to the first fixing bolt 73; the loosening movement of the first fixing bolt can make the first rod move up and down relative to the positioning slider, and the tightening movement of the first fixing bolt can fix the first rod so that the first rod cannot move up and down relative to the positioning slider. The first universal joint 76 is fixedly connected to the first rod 75 and the second rod 77. The first universal joint 76 has at least two degrees of freedom, thereby allowing the second rod to pitch and roll in three-dimensional space. One end of the second rod 77 and one end of the third rod 79 are both designed with threaded holes, and are connected by the second fixing bolt 78. The third rod 79 can do pitch motion in three-dimensional space relative to the second rod, and has at least one degree of freedom; when the third rod is adjusted to a suitable position, the second fixing bolt can be used to fix the relative motion between the second rod and the third rod, thereby ensuring that the third rod is in a relatively static state. The second universal joint 80 is fixedly connected to the third rod 79 and the fourth rod 81. The second universal joint 80 has at least two degrees of freedom, thereby allowing the fourth rod to pitch and roll in three-dimensional space. The other end of the fourth rod 81 is fixedly connected to the multi-degree-of-freedom stereo positioning robot 1.

[0180] The present invention discloses a stereo positioning micro surgical robot, and the installation process thereof is as follows: the bedside positioning arm is installed at a suitable position beside the operating bed, the height of the bedside positioning arm is adjusted by adjusting the first fixing bolt, and the first fixing bolt is tightened when the height is adjusted to a suitable height, so that the first rod remains in a relatively static state. Then, the stereo positioning robot is moved to the upper part of the target position by adjusting the first universal joint, the second fixing bolt, and the second universal joint, and the doctor operates the multi-degree-of-freedom stereo positioning robot through a remote control handle, and the first position control unit and the second position control unit start to control the depth control unit and the puncture needle connecting device to move in space through the information provided by the medical imaging device and the spatial positioning system, and when the depth control unit controls the puncture needle on the puncture needle connecting device to puncture the target lesion position, and according to the medical imaging information, the end of the puncture needle uses the spatial positioning system to establish a mapping relationship of the surgical space, monitor the position of the surgical instrument in real time, and accurately move according to the planned motion path according to the motion steps and calculated motion parameters of the system, and accurately complete the puncture.

[0181] The stereotactic micro-surgical robot is controlled by kinematics, including forward kinematics and inverse kinematics, and the transmission branch chain links include the kinematics of the puncture needle, the needle connecting device, the depth control unit, the activity unit and the position control unit.

[0182] As an embodiment, the present invention provides a stereoscopic micro-surgery robot such as Fig. 20 The kinematics of the assembly form V shown in the figure includes forward kinematics and inverse kinematics, such as Fig. 27 The solution flowchart is shown in Fig.27d shown.

[0183] like Fig.27a As shown in the figure, the coordinate system and variables of each component are established according to the DH parameter rule; let the global coordinate system be W O ; Establish the coordinate system W of the first position control unit base b1 b1 , the base coordinates of the first position control unit are At the pitch and yaw orthogonal point O1 of the first active unit, the terminal output coordinate system of the first position control unit is established as W o1 , the terminal output coordinates of the first position control unit are The yaw rotation coordinate system of the first active unit is W yaw1 , the first active unit pitch rotation axis coordinate system is W pitch1 The point where the common perpendicular line of the puncture needle axis and the first pitch axis intersects the central axis of the first slide bar rolling motion is r1, the point where the common perpendicular line of the puncture needle axis and the first pitch axis intersects the puncture needle axis is p1, and the coordinate system connected to the base of the depth control unit is established at point r1 as W r1Similarly, establish the variables related to the second position control unit: the point where the common perpendicular line of the puncture needle axis and the second pitch axis intersects the central axis of the first slide bar rolling motion is r2, the point where the common perpendicular line of the puncture needle axis and the second pitch axis intersects the puncture needle axis is p2, and the coordinate system connected to the base of the depth control unit is established at point r2 as W r2 ; The distance between r1 and r2 is n; The distance between the puncture needle and the central axis of the first slide bar rolling motion is d1; The distance between the first slide bar axis and the first active unit pitch yaw orthogonal point o1 is d2, and the distance from the second active unit pitch yaw orthogonal point o2 is d'2, and the coordinates of the end of the puncture needle e are P e The coordinates of the base and the end output of the first and second position control units are P b1 , P b2 , P o1 , P o2 ; The initial position of the depth control unit is h0, and the displacement is h1, which is h=h0+h1; The rotation angle of the central axis of the first sliding bar rolling motion is c; s 11 、s 12 They are the two actuator control variables of the first position control unit.

[0184] The forward kinematics calculation of the stereotactic surgical robot assembly form V is as follows:

[0185] S1: Calculate kinematics from the first position control unit side.

[0186] The base coordinate system W of the first position control unit b1 Relative to the global coordinate system W O The homogeneous coordinate transformation of is: b1 According to the kinematics of the first position control unit, the end output coordinate system W of the first position control unit o1 Relative to the base coordinate system W of the first position control unit b1 The homogeneous coordinate transformation of is:

[0187] T1=T f (s 11 ,s 12 ) (7)

[0188] according to Fig.27a , the coordinate system W where point r1 is located r1 After the yaw and pitch motion of the first active unit, the output coordinate system W relative to the end of the first position control unit o1 The homogeneous coordinate transformation of is:

[0189] T h1 =Rot(Y o1 ,a1)Rot(X yaw1 ,b1)Trans(Ypitch1 ,d2) (8)

[0190] Among them, Rot(Y o1 ,a1) is around Y o1 4×4 homogeneous rotation matrix with axis rotation angle a1; Rot(X yaw1 ,b1) is around X yaw1 4×4 homogeneous rotation matrix of axis rotation b1 angle; Trans(Y pitch1 ,d2) is expressed as along Y pitch1 A 4x4 homogeneous translation matrix that translates the axis by a distance d2.

[0191] The coordinate system W where point r1 is located r1 The first branched chain mechanism of the first movable unit and the first position control unit is calculated to obtain the coordinate relative to the global coordinate system W O The homogeneous coordinate transformation of is: 11 =T b1 T1T h1 .

[0192] S2: Calculate kinematics from the second position control unit side.

[0193] like Figure 27b As shown, W b2 Relative to W O The homogeneous coordinate transformation of is: b2

[0194] According to the kinematics of the second position control unit, W o2 Relative W b2 The homogeneous coordinate transformation of is:

[0195] T2=T f (s 21 ,s 22 ) (9)

[0196] W r2 Relative to W o2 The homogeneous coordinate transformation of is:

[0197] T h2 =Rot(Y o2 ,a2)Rot(X yaw2 ,b2)Trans(Y pitch2 ,d 2' ) (10)

[0198] Among them, Rot(Y o2 ,a2) is around Y o2 4×4 homogeneous rotation matrix with axis rotation angle a2; Rot(X yaw2 ,b2) is around X yaw24×4 homogeneous rotation matrix for the shaft to rotate by an angle b2; Trans(Y pitch2 , d 2' ) is represented as a 4×4 homogeneous translation matrix for translating by a distance d along the Y pitch2 axis. 2'

[0199] When the coordinate system W where the point r2 is located r2 rotates by an angle c around the rolling motion center axis of the first slide bar and then moves a distance n along the rolling motion center axis of the first slide bar, and the W r2 coordinate system coincides with the W r1 coordinate system, the coordinate transformation is:

[0200] T r2r1 = Rot(X, c)Trans(X, -n) (11)

[0201] Then, the global coordinate transformation obtained by calculating through the second branch chain of the depth control unit, the second moving unit, and the second position control unit after the coordinate system W r1 passes through the coordinate system W r2 is: T 12 = T b2 T2T h2 T r2r1

[0202] S3: After the same coordinate system is transformed by two branch chains, the following equation (either of the two equations) is obtained:

[0203]

[0204] Or

[0205]

[0206] Solve using the A1 - A3 iteration method. Let the 6 variables in formula (12) be a1, b1, a2, b2, n, c = x1, x6;

[0207] A1: Given X 0 = [x1, x6]' initial value;

[0208] A2: Calculate F = [f1, f9]' and T = [t1, t3]' respectively according to formula (12);

[0209] A3: If f i < e1 and t j < e2, the calculation is completed; otherwise, calculate the iteration value as follows and substitute it into the A2 loop.

[0210]

[0211] In the formula, a and β are given convergence coefficients, non-negative numbers, and their sum is 1.

[0212] S4: Calculate the coordinate system on the puncture needle.

[0213] like Fig.27c As shown, the coordinate systems of each component are established according to the DH parameter rule. The axis of the puncture needle intersects the common perpendicular lines of the first and second pitch axes at the axis points p1 and p2 of the puncture needle, respectively. The end point of the puncture needle is e. The coordinate systems W connected to the puncture needle are established with the three points as the origin. p1 , W p2 , W e .

[0214] W p1 Relative W r1 The homogeneous coordinate transformation of is: p1 =Trans(Y r1 ,d1),W p2 Relative W p1 The homogeneous coordinate transformation of is: p1p2 =Trans(Z p1 ,-n),W e Relative W p1 The homogeneous coordinate transformation of is: e =Trans(Z p1 ,-h).

[0215] W e In the global coordinate system W O The homogeneous coordinate transformation of is: We =T b1 T1T h1 T p1 T e .

[0216] W e The coordinates of point e under e In the global coordinate system W O The coordinates below are: P we =T We P e , from T We The resulting rotation matrix R e is the posture matrix of the puncture needle.

[0217] Inverse kinematics of the stereotactic surgical robot assembly form V.

[0218] H1: Set the variables corresponding to the six passive joints a1, b1, a2, b2, n, c and s 11 、s 12 、s 21 、s 22The control variables of the four actuators (active joints) are unknown variables, and they are combined to form a vector X = [x i ] 10×1 .

[0219] Lesions in known target organs i The coordinates of gi (x i ,y i ,z i ), (i=1,2,3....), puncture point t j The coordinates of tj (x j ,y j ,z j ), (j=1,2,3......), then the equation of the space line where the puncture needle is located is as follows:

[0220] Coordinate system W of points p1 and p2 p1 and W p2 In the global coordinate system W O The homogeneous coordinate transformations are:

[0221] T Wp1 =T b1 T1T h1 T p1

[0222] T Wp2 =T Wp1 T p1p2 (13)

[0223] Points p1 and p2 are respectively in coordinate system W p1 , W p2 The coordinates of the following are p p1 、p p2 , then points p1 and p2 are in the global coordinate system W O The coordinates below are:

[0224] p w1 =T wp1 p p1

[0225] p w2 =T wp2 p p2 (14)

[0226] H2: Solve for variable X.

[0227] B1: Point p1 (p2) is located on the axis of the puncture needle, so it satisfies the spatial straight line equation (1). Therefore, substituting equation (14) into equation (1) forms 4 independent equations;

[0228] B2: Then, according to the methods of S1, S2, S3 and S4, we obtain formula (12) and calculate 12 equations.

[0229] B3: Similarly, refer to the A1-A3 iterative method to solve and get X. The last four elements of the X vector are s 11 、s 12 、s 21 、s 22 .

[0230] H3: Calculate P based on positive kinematics e The depth control unit controls the movement of the puncture needle to:

[0231] The stereotactic micro-surgical robot is as follows Figure 4a , b shows the kinematics of the second assembly form, the first base 11 is mounted on the depth control unit 5, such as Figure 4a As shown, h = h0. The base coordinate system W of the first and second position control units b1 , W b2 Relative to the global coordinate system W O The linear sliding stroke h1 of the depth control unit occurs along the Z W The translation of the axis, then the homogeneous coordinate transformation is: b1 =Trans(Z W ,h1)T b10 and T b2 =Trans(Z W ,h1)T b20 , where T b10 , T b20 is the initial state value.

[0232] The forward kinematics calculation method is the same as the forward kinematics of the stereo positioning robot assembly form V.

[0233] The inverse kinematics calculation method is to set the variables corresponding to the six passive joints a1, b1, a2, b2, n, and c, and s 11 、s 12 、s 21 、s 22 The control variables of the four actuators (active joints) and the linear sliding stroke h1 are unknown variables, which are combined to form a vector X = [x i ] 11×1 The coordinates of the end point e of the puncture needle are P we =P gi , where P we =T We P e , T We The formula T We =T b1 T1Th1 T p1 T e Get the expression; then combine the 16 equations in B1 and B2 in the inverse kinematics H2 step to form 19 equations; similarly refer to the A1-A3 iteration method to solve and get X, the last five elements of the X vector are s 11 、s 12 、s 21 、s 22 、h1.

[0234] like Fig.28 As shown, the kinematics of the position control unit A and the control relationship between the terminal output coordinate point o1 (o2) and the first and second motors can be calculated by forward and inverse kinematics. The terminal output coordinate point o1 (o2) and the workspace are calculated by forward kinematics, and the extension and retraction amounts of the first and second motors required for the terminal output coordinate point o1 (o2) are obtained by inverse kinematics. The forward kinematics calculation method of the position control unit A is to first calculate S1, then S2, and then S3. The inverse kinematics calculation method is to first calculate S3, and then S1 and S2.

[0235] S1: establishing an analytical relationship between the extension amount L1 of the first motor shaft and the bending angle θ1 of the first joint;

[0236] Take the intersection point A of the main axis and the shell as the origin (coordinate P A =(0,0,0,1)', the following coordinate vectors are supplemented with 1 at the end to align with the homogeneous coordinate transformation matrix), the extension direction of the first motor axis is the X axis, the plane where the finger workspace is located is the XY plane, and the plane perpendicular to this plane is the Z axis. A right-handed coordinate system {O A}~XYZ; Point B is the intersection of the fifth link, one end of the sixth link and the first transfer rod; Initially, the distance between point B and point A in the X-axis direction is L 1init , the horizontal axis y B If it is fixed, the coordinates of point B are:

[0237] P B =(x B ,y B ,z B ,1)'=(L 1init +L1,y B ,0,1)' (15)

[0238] Point C is the intersection of the other end of the fifth link, the sixth link and the output rod of the first joint; the rotation angle around the Z axis perpendicular to the XY plane at point C is θ1, and the rotation angle along the XY plane is θ2. AC Axis translation L AC , get the coordinates of point C:

[0239] PC =(x C ,y C ,z C ,1)'=Rot(Z,θ1)·Trans(X AC ,L AC ) A (16)

[0240] AC is the X-axis and A is the origin of the follower coordinate system connected to the output rod of the first joint. AC is the X-axis of the moving coordinate system; L AC is the length of AC rod. The distance between BC is fixed, and the constraint equation is obtained:

[0241]

[0242] Substituting equations (15) and (16) into equation (17), we obtain equation (18): f(L1,θ1)=0.

[0243] In forward kinematics, equation (18) can be analytically solved to calculate θ1 based on L1:

[0244]

[0245] In inverse kinematics, equation (18) can be analytically solved to calculate L1 based on θ1:

[0246]

[0247] According to the actual value of the extension and contraction amount L1 of the first motor shaft, the positive and negative signs of equation (20) are selected. When A is between B and C in the X-axis direction, a negative sign is taken.

[0248] S2: According to L1 and θ1 in step S1, establish an analytical relationship between the extension amount L2 of the second motor shaft and the bending angle θ2 of the second joint; Point D is the intersection of the second connecting rod and one end of the first connecting rod and the second connecting rod, P D is the coordinate of point D. Initially, the distance between point D and point A in the X-axis direction is L 2init , the horizontal axis y D If it is fixed, the coordinates of point D are:

[0249] P D =(x D ,y D ,z D ,1)'=(L 2init +L2,y D ,0,1)' (21)

[0250] Point F is the intersection of the first link, the second link, the third link, the fourth link and the curved link.F is the coordinate of point F, L DF is the coordinate distance between point D and point F, a1 is the rotation angle of AF around point A; similarly to equation (16), the coordinates of point F are obtained:

[0251] P F =(x F ,y F ,z F ,1)'=Rot(Z,a1)·Trans(X AF ,L AF ) A (twenty two)

[0252] Similar to equation (17), the distance between DFs is fixed, and the constraint equation is obtained:

[0253]

[0254] Substituting equations (21) and (22) into equation (23), we obtain equation (24): f(L2, a1) = 0. Similar to equations (19) and (20), we obtain the calculation relationship between L2 and a1 in forward and inverse kinematics, respectively.

[0255] In forward kinematics, equation (24) is analytically solved to calculate a1 based on L2:

[0256]

[0257] In inverse kinematics, equation (24) is analytically solved to calculate L2 based on a1:

[0258]

[0259] According to the actual value of the extension and contraction amount L2 of the second motor shaft, the positive and negative signs of equation (26) are selected. When A is between D and F in the X-axis direction, a negative sign is taken.

[0260] Point H is the intersection of the first joint output rod and the second joint output rod, P H is the coordinate of point H, point G is the intersection of the other end of the curved rod and the seventh connecting rod, the eighth connecting rod, the ninth connecting rod and the tenth connecting rod, P G is the coordinate of point G, L GF is the coordinate distance between point G and point F, point I is the intersection of the ninth link, the tenth link and the second joint output rod, and a2 is the rotation angle of GH around point A.

[0261] The coordinates of point H are:

[0262] P H =(x H ,y H ,z H,1)'=Rot(Z,θ1)·Trans(X AH ,L AH ) A (27)

[0263] The coordinates of point G are:

[0264] P G =(x G ,y G ,z G ,1)'=Rot(Z,a2)·Trans(Y GH ,L GH ) H (28)

[0265] Similar to equation (17), the distance between GFs is fixed, and the constraint equation is obtained:

[0266]

[0267] The rotation angle of HI relative to AH is:

[0268] θ2=a2+∠GHI (30)

[0269] Substituting equations (22), (27), (28) and (30) into equation (29), we obtain equation (31): f(a1, θ1, θ2) = 0.

[0270] In forward kinematics, the analytical solution of equation (31) is to calculate θ2 (θ2 = a2 + ∠GHI) based on a1 and θ1:

[0271]

[0272] In inverse kinematics, equation (31) is analytically solved into equation (33), and a1 is calculated according to θ1 and θ2 (a2 = θ2 - ∠GHI):

[0273]

[0274] Then calculate L2 based on equation (26).

[0275] S3: Calculate the coordinates P of θ1, θ2 and the end output K in the kinematics of the position control unit A K =(x K ,y K ,z K ,1)'(z K is a fixed value).

[0276] In forward kinematics, P is calculated based on θ1 and θ2. K :

[0277]

[0278] In inverse kinematics, according to P K Calculate θ1 and θ2:

[0279]

[0280] The Rot(Z,θ) is a 4×4 homogeneous rotation matrix that rotates by an angle of θ around the Z axis; and the Trans(X,d) is a 4×4 homogeneous translation matrix that translates by a distance d along the X axis.

[0281] Another solution method for equations (18), (24), and (31) is to substitute known quantities into the unknown quantities after giving initial values, and then use iterative Newton-Euler method, Runge-Kutta method, or nonlinear optimization method to obtain numerical solutions.

[0282] The kinematics of the position control unit B. Fig.29a and Fig.29b As shown, Fig.29b This is a flowchart for solving the forward and inverse kinematics of the position control unit B. The kinematics of the position control unit B uses the DH parameter method to establish the coordinate systems of each component. Assume that the global coordinate system is W b1 , the coordinate system at the fourth motor base is W s120 , the coordinate system at the intersection of one end of the eleventh connecting rod and the fourth motor is W s12 , the coordinate system at the base of the fifth motor is W s110 , the coordinate system at the intersection of one end of the fourteenth connecting rod and the fifth motor is W s11 , the coordinate system at the tenth axis is W N , the coordinate system at the intersection of the eighth axis and the first connection base is W K , the coordinate system on the first connection base is W o1 , the coordinate system at the ninth axis is W M ; Assume that the length of the eleventh connecting rod is l1, the length of the twelfth connecting rod is l2, the length of the thirteenth connecting rod is l3, and the length of the fourteenth connecting rod is l4; the passive joint angle of the tenth axis is nn, and the passive joint angle of the ninth axis is mm; the output angle of the fifth motor is s 11 , the output angle of the fourth motor is s 12 .

[0283] Then the coordinate system where the tenth axis is located is W N Relative to the fourth motor base coordinate system W s120 The homogeneous coordinate transformation of is: N =Rot(Z s120 ,s 12 )Trans(Y 12 ,l1)Rot(Z N ,nn), the coordinate system W of the ninth axisM Relative to the fifth motor base coordinate system W s110 The homogeneous coordinate transformation of is: M =Rot(Z s110 ,s 11 )Trans(Y 11 ,l4)Rot(Z M , mm), where Rot(Z,θ) is a 4×4 homogeneous rotation matrix that rotates around the Z axis by an angle of θ; Trans(X,d) is a 4×4 homogeneous translation matrix that translates along the X axis by a distance of d. Because the position control unit moves only in the XY plane, the above matrix can be expanded to obtain a system of equations consisting of two equations, denoted as: B1. Coordinate system W K Relative coordinate system W I The homogeneous coordinate transformation of is: NK =Trans(Y K ,l2). Assuming that the first connecting base is rigidly connected to the twelfth connecting rod (thirteenth connecting rod) through a fastener, the coordinate system W o1 Relative coordinate system W K The homogeneous coordinate transformation of is a constant: T Ko1 .

[0284] Coordinate system W where the fourth motor is located s120 Relative to the global coordinate system W b1 The homogeneous coordinate transformation of is: s12 , the coordinate system W where the fifth motor is located s110 Relative to the global coordinate system W b1 The homogeneous coordinate transformation of is: s11 , the point of the eighth axis in the XY plane is in the global coordinate system W b1 The coordinates of k , click p k The coordinates of can be obtained from the branches on the left and right sides respectively. The calculation equation of the left branch is B 21 For: p k =T s12 T N [0,l2,0,1]', right-hand side chain calculation equation B 22 For: p k =T s11 T M [0,l3,0,1]'.

[0285] The forward kinematics of the position control unit B, let equation B 21 With equation B 22 If the two sides are equal, then after the matrix expansion, we get two equations on the XY plane (the X coordinates on both sides are equal, and the Y coordinates on both sides are equal), which are recorded as equation group B3. 11 、s 12is known, and the two variables nn and mm are unknown. By solving equation group B3, we can find nn and mm, and then we can find T N , then the coordinate system W o1 Relative to the global coordinate system W b1 The homogeneous coordinate transformation is: T1 = T s12 T N T NK T ko1 .

[0286] Inverse kinematics of position control unit B, coordinate system W o1 Relative coordinate system W b1 The coordinate transformation T1 is known, T N =(T s12 ) -1 T1(T NK T ko1 ) -1 , calculate nn and s according to equation group B1 12 According to equation B 21 , calculate point p k The coordinates of the point p k Substitute the coordinates of into equation B 22 , we get two independent equations, and then solve for s 11 and mm are two position variables, so as to obtain the rotation angle s of the fifth motor and the sixth motor 11 and 12 .

[0287] The kinematics of the position control unit C. Fig.30a and Fig.30b As shown, Fig.30b This is a flowchart for solving the forward and inverse kinematics of the position control unit C. The kinematics of the position control unit C uses the DH parameter method to establish the coordinate system of each component. Assume that the global coordinate system is W b1 , the coordinate system at the seventh motor base is W s120 , the coordinate system at the sixth motor base is W s110 The intersection point of one end of the nineteenth connecting rod and the sliding axis of the second supporting slider is N, and the coordinate system at point N is W N The intersection point of one end of the seventeenth connecting rod and the sliding axis of the first supporting slider is M, and the coordinate system at point M is W G , the coordinate system on the second connection base is W o1 The output angle of the sixth motor passes through the screw unit and the linear sliding stroke is s 11 The linear sliding stroke of the output angle of the seventh motor after passing through the screw unit is s 12; The initial position of the second supporting slider is l1, the initial position of the first supporting slider is l4, the rotation angle of the nineteenth connecting rod relative to the sliding direction of the second supporting slider is nn, and the rotation angle of the seventeenth connecting rod relative to the sliding direction of the first supporting slider is mm; the length of the nineteenth connecting rod is l2, the length of the seventeenth connecting rod is l3, the intersection point of the second connecting base and the seventeenth connecting rod and the nineteenth connecting rod is K, and the coordinate system fixedly connected to the nineteenth connecting rod at the intersection K is W K1 , the coordinate system fixedly connected to the second connection base is W K .

[0288] Then the coordinate system W N The seventh motor base coordinate system W relative to the position control unit s120 The coordinate transformation is: T N =Trans(Y s120 ,l1+s 12 )Rot(Z s12 ,nn), coordinate system W G The sixth motor base coordinate system W relative to the position control unit s110 The coordinate transformation is: T M =Trans(Y s110 ,l4+s 11 )Rot(Z s11 , mm). Since the position control unit C moves only in the XY plane, the above matrix can be expanded to obtain a system of two equations: B1. Coordinate system W K1 Relative coordinate system W N The homogeneous coordinate transformation of is: NK1 =Trans(Y N ,l2), because the coordinate system W o1 , W K are fixedly connected to the second connection base, so the coordinate system W o1 Relative coordinate system W K The homogeneous coordinate transformation of is a constant: T Ko1 Since the position control unit C adopts an articulated parallelogram linkage mechanism, the coordinate system W K The posture remains unchanged.

[0289] Coordinate system W s120 Relative to the global coordinate system W b1 The coordinate transformation is: T s12 , coordinate system W s110 Relative to the global coordinate system W b1 The coordinate transformation is: T s11 . Assume that point K is in the global coordinate system W b1 The coordinates of k , then p kThe coordinates of can be calculated from the left and right side branches respectively. The calculation equation of the left side branch is B 21 For: p k =T s12 T N [0,l2,0,1]'; calculation equation of right side branch B 22 For: p k =T s11 T M [0,l2,0,1]'.

[0290] The forward kinematics of the position control unit C, let equation B 21 With equation B 22 If the matrix is ​​equal, then two equations on the XY plane are obtained after the matrix expansion (the X coordinates on both sides are equal, and the Y coordinates on both sides are equal), which is recorded as equation group B3. When solving the forward kinematics of the position control unit C, s 11 and 12 is known, while nn and mm are unknown. By solving equation group B3, nn and mm can be obtained, and then T can be solved. N . Then the coordinate system W k1 Relative to the global coordinate system W b1 The coordinate transformation is: T b1k1 =T s12 T N T NK1 =[R 3×3 ;t 3×1 ; 0,0,0,1], let T b1k1 R=[0] 3×3 , thus solving T1=T b1k1 T ko1 . Or according to s 11 and nn, coordinate system W K Relative coordinate system W s120 In Y s120 Axial translation distance y=l1+s 12 +l2cos(nn), in X s120 The axial translation distance x = l2sin(nn), thus solving T1 = T s120 Trans(Y s120 ,y)Trans(X s120 ,x)T ko1 .

[0291] Inverse kinematics of the position control unit C, coordinate system W o1 Relative to the global coordinate system W b1 The coordinate transformation T1 is known, the coordinate system W K Relative coordinate system W s120 The coordinate transformation is: T s120k =(Ts12 ) -1 T1(T ko1 ) -1 =[R 3×3 ;t 3×1 ; 0,0,0,1], then s 12 =t(2)-l2cos(nn); and the coordinate system W s120 and coordinate system W s110 The distance between the Y axes is d1, then s 11 =t(2)-l4-l3cos(mm); In summary, the inverse solution sliding stroke s can be obtained 11 and 12 .

[0292] The kinematic calculation optimization of the first movable unit and the second movable unit can simplify the kinematic model by determining whether the puncture needle, the slide rod and the central axis of the rolling motion coincide with each other according to the relative position assembly form of the first movable unit 7 and the second movable unit 8.

[0293] The kinematic model parameter of the relative position assembly form B1 of the first movable unit 7 and the second movable unit 8 is d2=d 2' .

[0294] The kinematic model parameters of the relative position assembly form B3 of the first movable unit 7 and the second movable unit 8 are: d1 = d2 = d 2' =0.

[0295] The kinematic model parameters of the second active unit D, d 2' =0.

[0296] In summary, the present invention provides a stereotactic surgical robot system, and provides two preferred stereotactic robot assembly forms and three position control units. From the perspective of the structure of the surgical robot, the robot is very small and very convenient to carry or move to a desired position. The stereotactic robot has at least 5 degrees of freedom, and provides at least 4 degrees of freedom for positioning and positioning of the terminal puncture needle through two position control units, and provides feeding through a depth control unit, which greatly increases the flexibility of the terminal puncture needle and enables the puncture needle to move accurately to the target position to complete the puncture.

[0297] The stereotactic surgical robot is small in size and easy to install. The end effector has at least 5 degrees of freedom and can reach the required position in space. The end effector can cooperate with different surgical instruments (such as puncture needles, biopsy needles, ablation needles, etc.) to complete different operations, and cooperate with medical imaging equipment (such as B-ultrasound, MRI, CT, etc.) to provide doctors with real-time imaging information to ensure the smooth completion of the operation.

Claims

1. A stereo positioning micro surgical robot, comprising a multi-degree-of-freedom stereo positioning robot and a bedside positioning arm; characterized in that: The multi-degree-of-freedom stereo positioning robot comprises a first position control unit, a second position control unit, a depth control unit, a puncture needle connecting device, a first movable unit, a second movable unit and a first base; the first base provides an installation foundation, the first and second position control units respectively have two active motion degrees of freedom, respectively composed in series and parallel forms, the working space of the end position is a plane, the depth control unit has one active motion degree of freedom linear feed, the first and second movable units respectively have at least pitch and yaw passive degrees of freedom, and there is also one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion between the two, and the puncture needle connecting device fixes the needle; The first position control unit and the second position control unit are connected to the depth control unit and the puncture needle connecting device in the form of a parallel mechanism through the first movable unit and the second movable unit, thereby allowing the puncture needle connecting device to be positioned in three-dimensional space and to perform pitch and flip posture-fixed movements. The multi-degree-of-freedom stereo positioning robot has at least 5 degrees of freedom, so that the terminal puncture needle moves to the spatial target position; The bases of one end of the first position control unit and the second position control unit are fixedly mounted on the first base, and the outputs of the other ends are respectively connected to the first movable unit and the second movable unit; the output of the first movable unit is fixedly connected to the base of the depth control unit; the puncture needle connecting device is fixedly mounted on the output of the depth control unit; The depth control unit comprises a depth control unit base, a third motor, a first coupling, a first screw rod, a nut seat, and a light rod. The depth control unit base is fixedly mounted on the first support platform; the third motor is fixedly mounted on the depth control unit base; the third motor is connected to one end of the first screw rod through a first coupling; the other end of the first screw rod is connected to the depth control unit base; the nut seat is connected to the first screw rod and the light rod and can slide along the light rod; the light rod is parallel to the first screw axis, and both ends are connected to the depth control unit base to constrain the rotational movement of the nut seat; the output shaft of the third motor rotates, driving the first screw rod to rotate through the first coupling, thereby driving the nut seat to move forward and backward in the length direction of the first screw rod; the two rotation directions of the output shaft of the third motor correspond to the forward and backward movements of the nut seat; The puncture needle connecting device comprises a needle connecting base, a puncture needle, a sleeve, and an instrument fixing device; the needle connecting base is fixedly mounted on the nut seat or the first movable unit of the depth control unit; the needle connecting base is designed with two positioning slots for mounting the instrument fixing device, and the instrument fixing device is installed on at least one of the positioning slots of the needle connecting base according to needs, the sleeve is connected to the instrument fixing device, and the puncture needle is connected to the sleeve and is coaxial; the two rotation directions of the output shaft of the third motor of the depth control unit correspond to the forward and backward movements of the nut seat, thereby driving the needle connecting base forward and backward, and then driving the puncture needle to move to complete the puncture task.

2. A stereoscopic micro-surgical robot, comprising a multi-degree-of-freedom stereoscopic positioning robot and a bedside positioning arm; characterized in that: The multi-degree-of-freedom stereo positioning robot comprises a first position control unit, a second position control unit, a depth control unit, a puncture needle connecting device, a first movable unit, a second movable unit and a first base; the first base provides an installation foundation, the first and second position control units respectively have two active motion degrees of freedom, respectively composed in series and parallel forms, the working space of the end position is a plane, the depth control unit has one active motion degree of freedom linear feed, the first and second movable units respectively have at least pitch and yaw passive degrees of freedom, and there is also one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion between the two, and the puncture needle connecting device fixes the needle; The first position control unit and the second position control unit are connected to the depth control unit and the puncture needle connecting device in the form of a parallel mechanism through the first movable unit and the second movable unit, thereby allowing the puncture needle connecting device to be positioned in three-dimensional space and to perform pitch and flip posture-fixed movements. The multi-degree-of-freedom stereo positioning robot has at least 5 degrees of freedom, so that the terminal puncture needle moves to the spatial target position; The first base is fixedly mounted on the output of the depth control unit; one end of the first position control unit and the second position control unit are fixedly mounted on the first base, and the other end outputs are respectively connected to one end of the first movable unit and the second movable unit; the puncture needle connection device is fixedly mounted on the output of the first movable unit; The depth control unit comprises a depth control unit base, a third motor, a first coupling, a first screw rod, a nut seat, and a light rod. The depth control unit base is fixedly mounted on the first support platform; the third motor is fixedly mounted on the depth control unit base; the third motor is connected to one end of the first screw rod through a first coupling; the other end of the first screw rod is connected to the depth control unit base; the nut seat is connected to the first screw rod and the light rod and can slide along the light rod; the light rod is parallel to the first screw axis, and both ends are connected to the depth control unit base to constrain the rotational movement of the nut seat; the output shaft of the third motor rotates, driving the first screw rod to rotate through the first coupling, thereby driving the nut seat to move forward and backward in the length direction of the first screw rod; the two rotation directions of the output shaft of the third motor correspond to the forward and backward movements of the nut seat; The puncture needle connecting device comprises a needle connecting base, a puncture needle, a sleeve, and an instrument fixing device; the needle connecting base is fixedly mounted on the nut seat or the first movable unit of the depth control unit; the needle connecting base is designed with two positioning slots for mounting the instrument fixing device, and the instrument fixing device is installed on at least one of the positioning slots of the needle connecting base according to needs, the sleeve is connected to the instrument fixing device, and the puncture needle is connected to the sleeve and is coaxial; the two rotation directions of the output shaft of the third motor of the depth control unit correspond to the forward and backward movements of the nut seat, thereby driving the needle connecting base forward and backward, and then driving the puncture needle to move to complete the puncture task.

3. The stereotactic micro-surgical robot according to claim 1 or 2, characterized in that: The first position control unit and the second position control unit are both modularly designed and have the same structure. Each active motion degree of freedom of each position control unit is directly driven by an actuator, or is driven by a connecting rod transmission after the actuator is pre-installed on the base. Each position control unit is composed of a first joint, a second joint, a drive system and a terminal connecting rod; each joint is driven by a separate motor, and the transmission mechanism adopts connecting rod transmission. Each joint can rotate under the action of the motor to control the two-degree-of-freedom position of the terminal; Each position control unit adopts a double-axis connecting rod design at each joint hinge to increase the positioning accuracy of the first position control unit; One link of the second joint is designed as a bent rod to improve the range of motion of the second joint; The first joint is composed of a first joint output rod, a first motor, and a first transfer rod, a fifth connecting rod, a sixth connecting rod, and a main shaft, which are hinged to each other to form a crank slider mechanism, and converts the up and down vertical movement of the first motor into the rotation of the first joint; The second joint is a four-bar linkage mechanism consisting of a second motor passing through a main shaft around the first joint and articulated with a third link, a fourth link, a curved rod, a seventh link, an eighth link and the first joint, and a ninth link and a tenth link, which converts the vertical up and down movement of the second motor into the rotation of the second joint output rod; The driving system, the motor and the transmission mechanism are combined to form a crank slider mechanism, so that the driving motor can maintain vertical movement; The end connecting rod is designed with two gear adjustment holes for adjusting the range of motion on the second joint output rod.

4. The stereotactic micro-surgical robot according to claim 1 or 2, characterized in that: Another structural form of the first position control unit and the second position control unit is: two motors are used to drive the two nuts on the screw rod to move parallel to a straight line respectively, and two parallel four-bar linkage mechanisms are used to drive the second connecting base at the end to move horizontally and vertically in the plane, and the posture of the second connecting base remains parallel to the horizontal plane during the movement.

5. The stereotactic micro-surgical robot according to claim 1 or 2, characterized in that: The pitch and yaw rotation axes of the first active unit and the second active unit are orthogonal to each other, and the first and second active units also have one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion, and the central axis of the rolling motion is parallel to the linear motion direction axis, and is orthogonal to the pitch rotation axes of the first and second active units, and intersects with the yaw rotation axes of the first and second active units; The first and second activity units provide at least 5 degrees of freedom of passive activity for the end. A structural form of the first movable unit, which is composed of a first yaw axis, a first U-shaped block, a first pitch axis, and a first support platform, wherein one end of the first yaw axis is connected to one end of the first position control unit and is rotatable relative to one end of the first position control unit, with the rotation center being the first yaw rotation axis; the other end of the first yaw axis is fixedly connected to the first U-shaped block; the first pitch axis is connected to the first U-shaped block and is rotatable relative to the first U-shaped block, with the rotation center axis being the first pitch rotation axis; the first support platform is fixedly connected to the first pitch axis, and a threaded hole is designed in the middle along the direction of the central axis of the tumbling motion; A structural form of the second movable unit is composed of a second pitch axis hole, a second U-shaped block, and a second yaw axis; the second yaw axis is connected to one end of the second position control unit and is fixedly connected to the second U-shaped block; the second pitch axis hole is connected to the second U-shaped block and is rotatable relative to the second U-shaped block, and the rotation center axis is the second pitch rotation axis; the second pitch axis hole is designed with a light hole in the middle along the direction of the rolling motion center axis; the first movable unit and the second movable unit are connected through a first sliding rod, and one end of the first sliding rod is connected to the first pitch axis, and the other end cooperates with the light hole of the second pitch axis hole; the first sliding rod can slide relatively linearly in the direction of the first sliding rod axis line and relatively roll around the first sliding rod relative to the second pitch axis hole.

6. The stereotactic micro-surgical robot according to claim 5, characterized in that: A relative position assembly form of the first movable unit and the second movable unit is: the first pitch axis and the first yaw axis are perpendicular to point O1; the second pitch axis hole and the second yaw axis are perpendicular to point O2; the first slide bar rotation axis is perpendicular to the axes of the first pitch axis and the second pitch axis hole and is perpendicular to point O1 and point O2 respectively; the puncture needle direction is parallel to the direction of the first slide bar rotation axis and is offset by a distance, and the typical offset surface is still within the plane formed by the first yaw axis and the second yaw axis.

7. The stereotactic micro-surgical robot according to claim 5, characterized in that: The third relative position assembly form of the first movable unit and the second movable unit is: the first support platform is L-shaped, the depth control unit is installed inward, the first pitch axis and the first yaw axis are perpendicular to point O1; the second pitch axis hole and the second yaw axis are perpendicular to point O2; the rotation axis of the first sliding rod coincides with the axis of the puncture needle, and both are perpendicular to the axes of the first pitch axis and the second pitch axis hole at points O1 and O2, respectively.

8. The stereotactic micro-surgical robot according to claim 1 or 2, characterized in that: The pitch and yaw rotation axes of the first active unit and the second active unit are orthogonal to each other, and the first and second active units also have one passive degree of freedom of rolling motion and one passive degree of freedom of linear motion, and the central axis of the rolling motion is parallel to the linear motion direction axis, and is orthogonal to the pitch rotation axes of the first and second active units, and intersects with the yaw rotation axes of the first and second active units; The first and second activity units provide at least 5 degrees of freedom of passive activity for the end; The first movable unit is composed of a first yaw axis, a first U-shaped block, a first pitch axis, and a first support platform. One end of the first yaw axis is connected to one end of the first position control unit and is rotatable relative to one end of the first position control unit, with the rotation center being the first yaw rotation axis; the other end of the first yaw axis is fixedly connected to the first U-shaped block; the first pitch axis is connected to the first U-shaped block and is rotatable relative to the first U-shaped block, with the rotation center axis being the first pitch rotation axis; the first support platform is fixedly connected to the first pitch axis, and a threaded hole is designed in the middle along the direction of the central axis of the rolling motion; The second movable unit has a second structural form, including three parts: a fifth yaw axis, a spherical outer ring, and a spherical inner ring; one end of the fifth yaw axis is connected to one end of the second position control unit, and the fifth yaw axis can rotate relative to one end of the second position control unit, and the rotation center axis is the yaw rotation axis; the other end of the fifth yaw axis is fixedly connected to the spherical outer ring; the spherical outer ring and the spherical inner ring form a ball joint; the spherical inner ring is hollow to form a light hole; the spherical inner ring is connected to one end of the first sliding rod, and the first sliding rod can slide linearly and roll relative to the axis of the light hole of the spherical inner ring.

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