A novel telecentric mechanism micro-anastomosis surgical robot slave device

Abstract

The present invention provides a novel telecentric mechanism micro-anastomosis surgical robot slave device, relating to the field of medical devices. The device comprises a novel telecentric mechanism, a position adjustment mechanism, and a test module. The position adjustment mechanism is composed of three identical linear motion modules and is used to adjust the coordinate position of the novel telecentric mechanism. The novel telecentric mechanism comprises an AB deflection motion base, a BC rod, an AF rod, a CE rod, an EH rod, an FJ rod, a HI rod, an IJ rotation motion base, and a pitch drive motor. A position-attitude decoupling configuration is employed, whereby the three-axis platform meets high-precision positioning requirements, while the novel telecentric mechanism meets a larger rotation range requirement. This conforms to the "small position, large attitude, high precision" motion requirements of micro-anastomosis surgery, improving the robot's motion flexibility. The decoupling configuration can also reduce the complexity of the control algorithm, thereby improving motion accuracy and the safety of the surgical procedure.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a novel telecentric mechanism micro-anastomosis surgical robot slave device. Background Art

[0002] Microanastomosis is a crucial surgical technique in microsurgery, requiring the doctor to use a medical microscope (5-40X) to repair and reconstruct tiny blood vessels (0.3-3mm in diameter). This procedure is widely used in delicate reconstructive surgeries requiring long-distance transplantation, such as breast reconstruction, finger replantation, and facial transplantation. General microanastomosis requires the coordination of multiple surgical instruments, and its operating steps can be briefly summarized as follows: the doctor first secures the blood vessel with microtweezers and vascular clamps, using a background plate to provide a clear surgical field; further, the doctor uses microscissors to peel off the vascular adventitia as much as possible, which provides the necessary foundation for preventing postoperative thrombosis; after further dilating the blood vessel with the help of a vascular dilator, the doctor can use a needle holder and microtweezers to perform the anastomosis. The needle insertion process, as the most important step in the anastomosis operation, will directly affect the anastomosis quality. A skilled doctor can sew up to 10 stitches on a 1mm diameter blood vessel.

[0003] Although artificial vascular anastomosis is still considered the gold standard for microsurgery, some objective factors still make this procedure difficult to perform. The first is the flexibility of the movement mechanism. Needle threading requires high-precision positional movement of the hand, while knotting requires flexible posture changes. This "small position-large posture-high precision" movement pattern poses certain challenges to manual operation. Secondly, the physiological tremor of the human hand, although this can be suppressed to around 70μm with practice, still has certain limitations when it comes to the 30μm precision required for microanastomosis operations. Finally, due to the limited workspace, all operations need to be performed in a narrow surgical field to ensure safety, while also ensuring that there is no direct interference with the microscope or the patient.

[0004] Existing Solutions and Their Shortcomings: Robot-assisted surgery, with its superior tremor suppression capabilities and flexible motion scaling, has been proven in fields such as laparoscopic surgery, neurosurgery, and ophthalmology. However, these technologies are not fully applicable to microsurgery. For example, the Davinci laparoscopic surgical robot has successfully achieved ex vivo anastomosis of 1.5mm arteries. However, due to limitations in motion scaling and insufficient resolution, it cannot be applied to anastomoses of vessels with a diameter of less than 1mm. Furthermore, its large size makes it difficult to use with medical microscopes. The NeuroArm neurosurgery robot also suffers from insufficient positioning accuracy (1mm), making it inadequate for microsurgery. Furthermore, there are also issues with incompatibility between surgical instruments. The PRECEYES ophthalmic surgical robot utilizes a dual parallelogram mechanism to achieve telecentric motion, achieving high motion accuracy and enabling the world's first robot-assisted retinal macular detachment surgery. However, due to its lack of degrees of freedom, it cannot be directly applied to microsurgery. While some currently available microsurgery robots can achieve a precision exceeding the 1mm limit, they still present some challenges. MUSA's robotic arm uses a simple serial configuration to achieve anastomosis. Its positional motion is not well-suited to surgical requirements, resulting in poor dexterity and difficulty eliminating the cumulative error of multiple joints, limiting further precision improvements. The Symani robot uses a wire drive system to achieve a smaller end-piece configuration and flexible wrist motion, but the creep effect of the wire cable remains difficult to address, posing even greater challenges to precise control and system stability. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the deficiencies of the prior art, the present invention provides a novel telecentric mechanism micro-anastomosis surgical robot slave device, which solves the problems raised in the above-mentioned background technology.

[0007] (2) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: a novel telecentric mechanism micro-anastomosis surgical robot slave device, including a novel telecentric mechanism, a position adjustment mechanism, and a test module. The position adjustment mechanism is composed of three completely identical linear motion modules and is used to adjust the coordinate position of the novel telecentric mechanism. The novel telecentric mechanism includes an AB deflection motion base, a BC rod, an AF rod, a CE rod, an EH rod, an FJ rod, a HI rod, an IJ rotation motion base, and a pitch drive motor. The AB deflection motion base, AF rod, and FJ rod are hinged in sequence, and the BC rod, CE rod, EH rod, and HI rod are hinged in sequence. The bottom end of the BC rod is hinged to the middle end of the AB deflection motion base, the middle ends of the CE rod and AF rod are hinged, and the middle ends of the EH rod and FJ rod are hinged. The head and tail ends of the IJ rotation motion base are hinged to the top ends of the FJ rod and HI rod. The pitch drive motor is used to drive the hinge shaft between the AF rod and the FJ rod. The test module is arranged on the IJ rotation motion base.

[0009] Preferably, the test module includes a test rod, a spherical measuring head, and a rotation drive motor. The rotation drive motor is arranged on the IJ rotation motion base. The test rod is fixedly connected to the drive shaft of the rotation drive motor, and the spherical measuring head is threadedly connected to the test rod.

[0010] Preferably, the spherical measuring head is a three-coordinate special measuring head with a ball head diameter of mm, which can accurately measure the motion performance of the designed robot's slave hand.

[0011] Preferably, the linear motion module includes a support frame, a stepper motor, a lead screw, a nut, a guide rail, and a slider. The two ends of the lead screw are pivotally connected to the support frame through bearing seats. The stepper motor is connected to the lead screw. The nut thread is adapted outside the lead screw. The guide rail is arranged at the bottom of the support frame along the length direction of the lead screw. The slider is slidably adapted on the guide rail and is connected to the nut. The support frame of the upper linear motion module is connected to the nut of the lower linear motion module.

[0012] Preferably, it also includes an angle connecting plate, a rotating table, and a rotating motor. The angle connecting plate is connected to the nut of the uppermost linear motion module through a connecting block. The tail end of the AB deflection motion base is rotatably set on the angle connecting plate through the rotating table. The rotating motor is set on the rotating table and is used to drive the rotating table to rotate.

[0013] Preferably, the motion scaling ratio relationship among the AB segment, CE segment, and DF segment on the AB deflection motion base, BC rod, AF rod, and CE rod is as shown in the following formula: .

[0014] (3) Beneficial effects

[0015] The present invention provides a novel telecentric mechanism micro-anastomosis surgical robot slave device, which has the following beneficial effects:

[0016] 1. The new telecentric mechanism micro-anastomosis surgery robot slave device adopts a position-posture decoupling configuration. The three-axis platform meets the high-precision position requirements, and the new telecentric mechanism meets the larger rotation range requirements. It meets the "small position-large posture-high precision" motion requirements of micro-anastomosis surgery and improves the robot's movement flexibility. At the same time, the decoupling configuration can reduce the complexity of the control algorithm, improve the movement accuracy and the safety of the surgical process.

[0017] 2. The new telecentric mechanism micro-anastomosis surgical robot slave device is designed based on the new double triangle principle, which ensures that the surgical instruments can flexibly adjust their posture in a narrow working space. Compared with the traditional double parallelogram telecentric mechanism, it has a more compact size and a larger motion scaling ratio.

[0018] 3. The new telecentric mechanism micro-anastomosis surgical robot slave device has a symmetrical arrangement of the connecting rod group of the telecentric mechanism, which improves the structural rigidity of the slave hand and reduces the influence of the flexural deformation caused by gravity during the deflection of the telecentric mechanism, thereby ensuring the movement accuracy of the robot slave hand during posture changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the overall axonometric drawing of the present invention;

[0020] Figure 2 It is a schematic diagram of the position adjustment mechanism of the present invention;

[0021] Figure 3 It is a side sectional view of the novel telecentric mechanism of the present invention;

[0022] Figure 4 A process diagram for constructing the novel telecentric mechanism of the present invention;

[0023] Figure 5 This is a diagram showing the relationship between input and output motion ratios in Example 1 of the present invention;

[0024] Figure 6 This is a diagram showing the relationship between input and output motion ratios in the second embodiment of the present invention;

[0025] Figure 7 This is a diagram showing the relationship between input and output motion ratios according to the third embodiment of the present invention.

[0026] In the figure: 1 new telecentric mechanism, 2 position adjustment mechanism, 3 test module, 11AB deflection motion base, 12BC rod, 13AF rod, 14CE rod, 15EH rod, 16FJ rod, 17HI rod, 18IJ rotation motion base, 19 pitch drive motor, 21 support frame, 22 stepper motor, 23 lead screw, 24 nut, 25 guide rail, 26 slider, 31 spherical measuring head, 32 measuring rod, 33 rotation drive motor, 4 connecting block, 5 angle connecting plate, 6 rotation table, 7 rotation motor. DETAILED DESCRIPTION

[0027] The embodiment of the present invention provides a novel telecentric mechanism micro-anastomosis surgical robot slave device, such as Figure 1-7 As shown, it includes a novel telecentric mechanism 1, a position adjustment mechanism 2, and a test module 3.

[0028] like Figure 2 As shown, the position adjustment mechanism 2 is composed of three completely identical linear motion modules, and is used to adjust the coordinate position of the new telecentric mechanism 1, respectively realizing adjustment in the three directions of X, Y, and Z. The linear motion module includes a support frame 21, a stepper motor 22, a lead screw 23, a nut 24, a guide rail 25, and a slider 26. The two ends of the lead screw 23 are pivotally connected to the support frame 21 through bearing seats. The stepper motor 22 is fixedly connected to the support frame 21 by bolts. The drive shaft of the stepper motor 22 is connected to the lead screw 23. The nut 24 is threadedly adapted on the outside of the lead screw 23. The lead screw 23 and the nut 24 together form a spiral motion pair. The guide rail 25 is arranged at the bottom of the support frame 21 along the length direction of the lead screw 23. The slider 26 is slidably adapted on the guide rail 25. The slider 26 and the guide rail 25 form a linear motion pair. The slider 26 is connected to the nut 24. The support frame 21 located at the upper linear motion module is connected to the nut 24 of the lower linear motion module. The linear motion module converts the rotational motion of the stepper motor 22 into the linear motion of the nut 24 .

[0029] The device also includes an angle connecting plate 5, a rotating platform 6, and a rotating motor 7. The angle connecting plate 5 is connected to the nut 24 of the uppermost linear motion module via a connecting block 4. The tail end of the AB deflection motion base 11 is rotatably mounted on the angle connecting plate 5 via the rotating platform 6. The rotating motor 7 is mounted on the rotating platform 6 and is used to drive the rotating platform 6. The drive shaft of the rotating motor 7 is connected to the rotating platform 6 via a worm gear kinematic pair, which is used to adjust the angle of the novel telecentric mechanism 1.

[0030] like Figure 2As shown, the test module 3 includes a test rod 32, a spherical measuring head 31, and a rotation drive motor 33. The rotation drive motor 33 is mounted on the IJ rotation motion base 18. The test rod 32 is fixedly connected to the drive shaft of the rotation drive motor 33. The test rod 32 is fixedly connected to the rotation drive motor 33 by positioning it with an axial hole and tightening it with a set screw. The spherical measuring head 31 is threaded onto the test rod 32. The spherical measuring head 31 is a special three-dimensional measuring head with a ball diameter of 1mm, which can accurately measure the kinematic performance of the designed robot's slave hand.

[0031] like Figure 1 and Figure 3 As shown, the novel telecentric mechanism 1 includes an AB deflection motion base 11, a BC rod 12, an AF rod 13, a CE rod 14, an EH rod 15, an FJ rod 16, a HI rod 17, an IJ rotation motion base 18, and a pitch drive motor 19. The AB deflection motion base 11, the AF rod 13, and the FJ rod 16 are hinged in sequence, and the BC rod 12, the CE rod 14, the EH rod 15, and the HI rod 17 are hinged in sequence. The bottom end of the BC rod 12 is hinged to the middle end of the AB deflection motion base 11, the middle ends of the CE rod 14 and the AF rod 13 are hinged, and the middle ends of the EH rod 15 and the FJ rod 16 are hinged. The head and tail ends of the IJ rotation motion base 18 are hinged to the top ends of the FJ rod 16 and the HI rod 17. The pitch drive motor 19 is fixed on the AF rod 13 and is used to drive the hinge shaft between the AF rod 13 and the FJ rod 16. The test module 3 is arranged on the IJ rotation motion base 18.

[0032] Specifically, the new telecentric mechanism 1 is designed based on the double triangle principle. The connecting rod assembly composed of the AB deflection motion base 11, BC rod 12, AF rod 13, CE rod 14, EH rod 15, FJ rod 16, HI rod 17, and IJ rotation motion base 18 is arranged symmetrically in space to obtain higher structural stiffness. The length of each rod is determined according to the double triangle principle.

[0033] like Figure 4 As shown in FIG, the design principle of the new telecentric mechanism 1 is: the parallel and unequal length connecting rods AD and BC can construct a set of similar triangles AOD and BOC in the plane, as shown in FIG. Figure 4 As shown in figure a, due to the properties of similar triangles, the extension line of CD will definitely intersect the extension line of connecting rod AB at point O. This lays the geometric foundation for creating the telecentric fixed point O. However, at this time, point O is still in a floating position on connecting rod CD. This is because the length of rod OD is constantly changing when connecting rod AD swings. In order to obtain a stable point O, connecting rods DE, EF, and FC of equal length are symmetrically arranged along the direction of connecting rod CD, as shown in Figure 3. Figure 4As shown in b, this construction method geometrically obtains a set of congruent triangles AOD and DOE, which ensures that the link OE is a fixed value. Furthermore, in order to provide a stable parallel constraint and reduce the number of hinge points, the link DJ and link DI are added inside the link, as shown in Figure 4 As shown in Figure c, the parallelograms ABJD and DIFE provide sufficient angular constraints for the rhombus DJCI, thereby maintaining the motion characteristics of the telecentric mechanism. In other words, changing the position of the non-fixed link in the parallelogram can obtain a new variant mechanism. First, the non-fixed link AD is translated along the straight line AB to obtain the first variant mechanism, as shown in Figure 4. Figure 4 Finally, the non-fixed link ED can be translated along the straight line EF to obtain the second variant mechanism, as shown in Figure d. Figure 4 Comparing the variant mechanism with the original mechanism, it is not difficult to find that the variant mechanism provides a more flexible mechanism installation distance OB and instrument installation distance OF, which brings greater flexibility to the use of the telecentric mechanism; at the same time, under the same motion parameters, the second variant mechanism has a more compact size than the original mechanism. The motion diagram of the constructed new telecentric mechanism 1 is shown as follows Figure 4 f, for ease of understanding, Figure 4 The correspondence between the connecting rods in f and the model in the technical solution is as follows: AB is the AB deflection motion base 11; BC is the BC rod 12; AF is the AF rod 13; CE is the CE rod 14; EH is the EH rod 15; FJ is the FJ rod 16; HI is the HI rod 17; IJ is the IJ rotation motion base 18.

[0034] by Figure 4 The joint F in f serves as the input joint of the pitch motion motor 19, and the motion scaling ratio relationship between the AB segment, CE segment, and DF segment on the AB yaw motion base 11, BC rod 12, AF rod 13, and CE rod 14 is shown in the following formula; .

[0035] According to the above formula, three embodiments are used to explore the different motion performances of the telecentric mechanism when the lengths of the AB segment, CE segment, and DF segment have different mathematical relationships.

[0036] Example 1, when When the input and output motion ratio is Figure 5 As shown, the ratio at this time is less than 1, and the new telecentric mechanism 1 presents the performance of motion reduction, and the maximum input angle is 180°.

[0037] Example 2, when When the input and output motion relationship is as follows Figure 6As shown, at this time, the ratio of input motion / output motion is equal to 1, and the new telecentric mechanism 1 does not have motion scaling performance. In particular, the new telecentric mechanism 1 at this time degenerates into a double parallelogram mechanism.

[0038] Example 3, when When the input and output motion ratio is Figure 7 As shown, the ratio at this time is greater than 1, the new telecentric mechanism 1 presents the function of motion amplification, and the maximum output angle is 180°.

[0039] By exploring different rod length conditions, we can draw the following conclusions: First, the dual parallelogram mechanism is only a special form, and its motion scaling ratio is not adjustable. Second, we can choose between motion reduction and motion amplification by varying the relationship between DF and (CE - AB). Third, the numerical adjustment of this motion scaling can be further determined by DF / (CE - AB).

[0040] Kinematic model of the robot: The novel telecentric mechanism 1 micro-anastomosis surgery robot slave device adopts a posture decoupling configuration, and its kinematics can be expressed as follows:

[0041] in is the position transformation matrix, represents the motion parameters of the linear table, which can be expressed as follows:

[0042] in Indicates that along Axis moving distance The transformation matrix, is the output angle of the drive motor.

[0043] For the other part of the direction transformation matrix , which contains the angle information of the RCM manipulator's rotation axis, as shown in the following formula:

[0044] in Indicates the surrounding Axis rotation angle The transformation matrix, Represents the initial pitch angle of the RCM operator, Respectively by The motors are driven independently, and their corresponding relationships are shown as follows:

[0045] Substituting equations (2)-(4) into equation (1) yields the complete robot kinematic model. Clearly, this posture decoupling configuration greatly simplifies the kinematic model, which also facilitates error modeling and control model construction.

[0046] Working principle of the robot slave: The new telecentric mechanism micro-anastomosis surgical robot slave device adopts a master-slave operation mode, including a remote operating table, a surgical operating table and a control module. The surgical operating table consists of a surgical microscope and a micro-anastomosis surgical robot slave. The robot slave performs surgical interactive actions in the surgical area. The process is captured in real time by the surgical microscope, and the video signal is transmitted to the remote operating table. The remote operating table includes a display, a master operator and a PC host. The doctor observes the display and uses the master operator to complete the remote surgery. The motion instructions of the master operator are sent to the control module via the PC host. The control module consists of a controller and a driver. The controller further processes the received motion instructions, converts them into electrical signals through the driver and sends them to the micro-anastomosis robot slave to achieve corresponding motor control.

[0047] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A novel telecentric mechanism micro-anastomosis surgical robot slave device, comprising a novel telecentric mechanism (1), a position adjustment mechanism (2), and a test module (3), wherein the position adjustment mechanism (2) is composed of three completely identical linear motion modules and is used to adjust the coordinate position of the novel telecentric mechanism (1), and is characterized in that: The novel telecentric mechanism (1) comprises an AB deflection motion base (11), a BC rod (12), an AF rod (13), a CE rod (14), an EH rod (15), an FJ rod (16), a HI rod (17), an IJ rotation motion base (18), and a pitch drive motor (19). The AB deflection motion base (11), the AF rod (13), and the FJ rod (16) are hinged in sequence. The BC rod (12), the CE rod (14), the EH rod (15), and the HI rod (17) are hinged in sequence. The bottom end of the BC rod (12) is hinged to the middle end of the AB deflection motion base (11). The middle ends of the CE rod (14) and the AF rod (13) are hinged. The middle ends of the EH rod (15) and the FJ rod (16) are hinged. The head and tail ends of the IJ rotation motion base (18) are hinged to the FJ rod (1 6), the top end of the HI rod (17) is hinged, the pitch drive motor (19) is used to drive the hinge shaft between the AF rod (13) and the FJ rod (16), and the test module (3) is set on the IJ rotation motion base (18); the test module (3) includes a test rod (32), a spherical measuring head (31), and a rotation drive motor (33), the rotation drive motor (33) is set on the IJ rotation motion base (18), the test rod (32) is fixedly connected to the drive shaft of the rotation drive motor (33), and the spherical measuring head (31) is threadedly connected to the test rod (32); the motion scaling ratio relationship between the AB segment, CE segment, and DF segment on the AB deflection motion base (11), the BC rod (12), the AF rod (13), and the CE rod (14) is as shown in the following formula; .

2. The novel telecentric mechanism micro-anastomosis surgical robot slave device according to claim 1 is characterized by: The spherical measuring head (31) is a three-coordinate special measuring head with a spherical head diameter of 1 mm, and can accurately measure the motion performance of the designed robot's slave hand.

3. The novel telecentric mechanism micro-anastomosis surgical robot slave device according to claim 1 is characterized by: The linear motion module comprises a support frame (21), a stepper motor (22), a lead screw (23), a nut (24), a guide rail (25), and a slider (26). Both ends of the lead screw (23) are pivotally connected to the support frame (21) through a bearing seat. The stepper motor (22) is connected to the lead screw (23). The nut (24) is threadedly adapted outside the lead screw (23). The guide rail (25) is arranged at the bottom of the support frame (21) along the length direction of the lead screw (23). The slider (26) is slidably adapted on the guide rail (25) and is connected to the nut (24). The support frame (21) of the upper linear motion module is connected to the nut (24) of the lower linear motion module.

4. The novel telecentric mechanism micro-anastomosis surgical robot slave device according to claim 3 is characterized by: It also includes an angle connecting plate (5), a rotating table (6), and a rotating motor (7), wherein the angle connecting plate (5) is connected to a nut (24) located at the top of the linear motion module via a connecting block (4), and the tail end of the AB deflection motion base (11) is rotatably arranged on the angle connecting plate (5) via the rotating table (6), and the rotating motor (7) is arranged on the rotating table (6) and is used to drive the rotating table (6) to rotate.

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