Teleoperated minimally invasive surgery flexible arm mechanism and system and teleoperation method thereof

Abstract

The application discloses a teleoperation minimally invasive surgery flexible arm mechanism and system and a teleoperation method thereof. The teleoperation minimally invasive surgery flexible arm system comprises a collection layer, a processing layer, a control layer and an execution layer. The collection layer comprises a gesture recognition sensor, and the execution layer comprises a moving platform, a driving motor, an arm body mechanism, an actuator and a driving rope. The teleoperation method comprises the following steps: in the first step, gesture information of a surgery operator is collected through the collection layer; in the second step, whether to execute is judged by the processing layer, the collected data is processed through proportional mapping, and a driving rope length change amount is solved; in the third step, motor operation data is solved by the control layer, and the result is sent to the execution layer; and in the fourth step, the execution layer moves to a corresponding position according to the received data. The application has the advantages of good flexibility, light weight, easy control, convenient operation, good interactivity and the like, and is suitable for minimally invasive surgery in a narrow space.

Description

Technical Field

[0001] This invention belongs to the field of minimally invasive surgical robot technology, and more specifically, to the remote operation of a flexible arm mechanism and system for minimally invasive surgery and its remote operation method. Background Technology

[0002] Teleoperated minimally invasive surgery is an emerging surgical paradigm that utilizes advanced surgical robots and teleoperation technology to allow surgeons to operate on patients at a distance. It also facilitates complex and precise minimally invasive surgeries within confined spaces. Teleoperated minimally invasive surgical systems not only help alleviate the current shortage of highly skilled surgeons and eliminate geographical barriers, but also assist surgeons in performing more complex surgeries, providing patients with timely and high-quality surgical interventions, reducing their financial burden, complications, and the inconvenience of long-distance medical travel.

[0003] However, most current teleoperation systems rely on master-slave coordination, which places high demands on the operator's technical skills and suffers from difficulties in precise positioning, as well as inconvenient wearable and bulky slave-end operating devices with limited interactivity. These problems hinder the development of teleoperation technology in the field of minimally invasive surgery.

[0004] The existing technology is as follows:

[0005] Publication No.: CN104622585B, titled "A Master-Slave Isomorphic Teleoperation Master Hand of a Laparoscopic Minimally Invasive Surgical Robot," mainly includes a base, a universal joint mechanism assembly I mounted on the base, and universal joint mechanism assemblies II, III, and IV, a thumb component, and an index finger component connected sequentially via joint connectors. Angle sensors S1, S2, S3, S4, S5, S6, and S7 are correspondingly mounted on universal joint mechanism assemblies I, II, III, and IV. The degrees of freedom of each joint on this teleoperation master hand correspond one-to-one with the degrees of freedom of the surgical instruments at the surgical execution end, achieving master-slave isomorphism. The teleoperation master hand can directly control and adjust the surgical execution end through the corresponding (mapping) relationship, avoiding the motion resolution time required for master-slave heterogeneous teleoperation and reducing system latency. It also enhances the intuitiveness of teleoperation itself, effectively reducing operational difficulty and errors.

[0006] The approach employed is a master-slave teleoperation method. The master teleoperation hand structure achieves master-slave isomorphism, meaning there is a one-to-one correspondence between the joints of the master teleoperation hand and the degrees of freedom of the surgical instruments on the surgical execution end. This correspondence (mapping) allows the master teleoperation hand to directly control and adjust the surgical execution end. Our patent, however, does not use a master-slave control method. Instead, it uses a gesture recognition sensor to directly capture hand movements and control the execution end in real time to complete the corresponding surgical task. We have added filtering and mapping preprocessing steps to accurately map the gesture pose to the execution end pose. This approach eliminates the need for a separate master robotic arm, enhances interactivity, and significantly reduces operational difficulty.

[0007] Publication No.: CN110584790A, titled "A Teleoperation Proportional Control Method for Surgical Robots Based on Arm Stiffness." This method involves collecting similar surgical cases before surgery to determine the range of arm stiffness variation levels for such procedures. During surgery, based on information about the operator's arm joint rotation and movement, the method calculates the relationship between arm stiffness variation levels and wrist joint rotational angular velocity and angular acceleration. Then, it obtains the relationship between arm stiffness variation levels and the rate of change of arm movement trajectory curvature. Based on this, a model is established relating arm stiffness variation levels to wrist joint angular velocity, angular acceleration, and the rate of change of movement trajectory curvature. The model is then normalized using the range of arm stiffness variation levels to obtain the teleoperation proportion.

[0008] The approach employed by the patent is to collect similar surgical cases before the procedure; during the procedure, data on the operator's arm movements acquired during the operation are used to establish a model relating the change in arm stiffness to the wrist joint angular velocity, angular acceleration, and rate of change of the curvature of the movement trajectory. Our patent, however, does not require extensive data collection. Instead, it uses a Newton-Raphson iterative algorithm for inverse kinematics calculation. After collecting and preprocessing the gesture coordinates, the coordinates are iteratively calculated into the change in the length of the flexible arm's drive rope, which is then sent to the motor. This calculation is faster, requires less upfront data collection, and is more operator-friendly. Compared to patent CN110584790A, which requires similar surgical cases, our approach has a greater advantage in exploring surgical procedures that are not yet fully mature.

[0009] Publication No.: CN111839740B, titled "Master-Slave Isomorphic Teleoperation Force Feedback Master Hand of Minimally Invasive Surgical Robot," comprising a universal joint mechanism assembly, a translational rotation assembly, a parallelogram mechanism, and a control handle connected to the translational rotation assembly. The universal joint mechanism assembly is fixed to a base, the translational rotation assembly is rotatably connected to the deflection frame of the universal joint mechanism assembly, and the parallelogram mechanism is rotatably connected to the translational rotation assembly. This invention enables four degrees of freedom: three-dimensional rotation around a fixed point and linear motion along the control handle axis. Force feedback is implemented for pitch, yaw, and linear motion degrees of freedom. Each degree of freedom is isomorphically arranged with the motion degrees of freedom of the minimally invasive surgical instrument, achieving a one-to-one mapping relationship, reducing delays in the master-slave control system and errors caused by kinematic solutions, and improving operational intuitiveness. The force feedback driver is fixedly installed and transmits motion and feedback force through the parallelogram mechanism, reducing the moment of inertia of the master hand's moving parts and improving operational flexibility.

[0010] It adds a force feedback device to the master-slave isomorphic teleoperation, while our solution uses a combination of pose feedback and operator visual feedback, which avoids problems such as inaccurate force feedback calculation, is more self-heating, more interactive, conforms to the operator's operating rules, and has less computation and smaller size, making it more suitable for high-precision minimally invasive surgery that requires real-time tracking and feedback.

[0011] Publication No.: CN106903665A, titled "A Master-Slave Teleoperation Surgical Robot Control System Based on Stereo Vision," includes a motion control system and a stereo vision system. The motion control system includes a motion control algorithm module and a low-level control module; the stereo vision system includes a stereo vision algorithm module. Each slave manipulator receives position control commands from the master manipulator in real time. The motion control algorithm module calculates the desired position of each joint, and the low-level control module controls the servo driver to move the slave manipulator to the designated position. The stereo vision system collects the position information of the slave manipulator in real time and transmits it to the vision algorithm calculation thread. The stereo vision algorithm module calculates the position of the manipulator relative to the world coordinate system and feeds the position information back to the motion control system via Ethernet. The operator observes the movement of the slave arms through a stereo display device and operates the master manipulator to complete the surgical task. This invention achieves a high level of system stability, real-time performance, and high precision.

[0012] This invention provides a master-slave teleoperated surgical robot based on stereo vision. By employing stereo vision at the hand end, it enhances the realism of the surgeon's experience when operating the teleoperated surgical robot, primarily utilizing the transformation from the world coordinate system to the camera coordinate system. Our patent, however, directly employs gesture recognition, reflecting hand movements in real time to the execution end. This, combined with endoscopes, further enhances the realism of the surgical procedure. Simultaneously, it boasts stronger interactivity, does not rely on large sensors or camera equipment, reduces space occupancy, and brings convenience to minimally invasive surgical procedures.

[0013] This invention combines gesture recognition technology to provide a flexible arm mechanism and system for remote operation of minimally invasive surgery, as well as its remote operation method, for performing minimally invasive surgical procedures. Summary of the Invention

[0014] To make minimally invasive surgical procedures more convenient and precise, and to overcome the limitations of traditional rigid devices, this invention proposes a teleoperated minimally invasive surgical flexible arm mechanism and system, as well as its teleoperation method. This system is accurate, flexible, and adaptable, capable of moving freely in confined spaces to replace human hands in surgical procedures. Through the design of a continuum-like structure, a forward kinematics model, and a robot intelligent control algorithm for specified end-effector movements, excellent human-computer interaction and teleoperation control are achieved, enabling surgical tasks such as grasping, moving, and dissecting target tissues within confined spaces.

[0015] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0016] This invention provides a remotely operated minimally invasive surgical flexible arm mechanism, including an end effector clamp actuator, a flexible arm, and a movable platform front structure. The end effector clamp actuator includes an end joint sleeve, a clamp sleeve, a clamp connector, movable clamps, and fixed clamps. The clamp connector connects two movable clamps to the clamp sleeve. The movable clamps rotate to open and close for holding surgical tools and lifting diseased tissue.

[0017] The flexible arm includes a fixed sleeve, an outer sleeve, a connecting rod, and a universal joint connected thereto. The connecting rod connects the outer sleeve and the universal joint as a joint unit. Two adjacent joint units share a universal joint and are connected in sequence to form a flexible arm.

[0018] Each joint unit has four identical small threading holes and one central threading hole. The moving traction rope that controls the movement of the flexible arm goes through the small threading holes and out through the threading holes, while the opening and closing traction rope that controls the opening and closing of the clamps goes through the central threading hole and out through the threading hole.

[0019] Two adjacent joint units rotate around the universal joint. By moving the length of the traction rope, each joint unit rotates around the universal joint, thereby achieving any bending angle.

[0020] Two opening and closing traction ropes are connected to the movable clamp. By controlling the tension and relaxation of the two opening and closing traction ropes, the movable clamp is rotated relative to the fixed clamp, thereby realizing the opening and closing of the clamp.

[0021] The front structure of the movable platform includes a drive motor, a movable platform, a fixing device, a motor fixing device, a motor fixing slot, a front fixing device for the rotating shaft, a rear fixing slot for the rotating shaft, a front fixing slot for the rotating shaft, a rotating shaft, an arm fixing structure, and a rear fixing device for the rotating shaft. The movable platform is connected to an external lifting device through the fixing device.

[0022] The drive motor is fixed to the motor fixing device with screws, and then the drive motor is fixed to the movable platform with screws through the fixing slot of the motor fixing device and the motor fixing slot of the movable platform.

[0023] The rotating shaft is fixed to the movable platform by the rotating shaft fixing front device, and is connected to the output shaft of the drive motor through the slot, thereby driving the drive motor to rotate the rotating shaft.

[0024] The rotating shaft fixing front device is fixed on the movable platform through the rotating shaft rear fixing groove, the rotating shaft front fixing groove, and the rotating shaft fixing back device, and the rotating shaft position can be freely moved through the motor fixing groove, the rotating shaft front fixing groove, and the rotating shaft rear fixing groove;

[0025] The movable traction rope is fixed through a small hole on the rotating shaft and connected to the threading hole of the arm body fixing structure. The tension of the traction rope can be adjusted by changing the number of turns of the movable traction rope on the rotating shaft.

[0026] The rotating shaft fixing back device is fixed to the rotating shaft front fixing groove through the small hole on the back, and the other end of the rotating shaft fixing back device is connected to the slot of the rotating shaft fixing front device to make them a whole.

[0027] The arm fixing structure is fixed by connecting the outer wall sleeve to the universal joint at the tail end of the arm.

[0028] As a further improvement to the structure of the present invention, the flexible arm is a three-stage robotic arm composed of three joint units.

[0029] As a further improvement to the structure of the present invention, the rotating shaft (2-8) has a groove to ensure the threading of the rope.

[0030] This invention provides a system for a remotely operated flexible arm mechanism for minimally invasive surgery, comprising a data acquisition layer, a processing layer, a control layer, and an execution layer. The data acquisition layer includes a gesture recognition sensor, and the execution layer includes a moving platform, a drive motor, an arm mechanism, an actuator, and a drive rope. The system acquires hand coordinate information via the gesture recognition sensor, performs inverse kinematics calculations, and achieves remote control of the flexible arm by changing the length of the drive rope.

[0031] The processing layer includes gesture recognition and determination of whether to execute, conversion from actual spatial coordinates to calculated coordinates through proportional mapping, and coordinate calculation using Newton's iteration method to obtain the change in the length of the driving rope.

[0032] The control layer includes the conversion of the change in drive rope length into motor running time;

[0033] The execution layer includes:

[0034] The drive motor and the moving platform are connected by a slide rail. The position of the flexible arm can be manually adjusted by changing the length and tension of the drive rope by adjusting the position of the drive motor.

[0035] The boom mechanism consists of multiple joint units. Each joint unit includes a boom cylinder, a connecting rod, and a connecting ring. The drive rope passes through each joint unit, and each joint unit bends at the same angle. The end joint unit is connected to the center of the mobile platform, and the front joint unit is connected to the actuator.

[0036] As a further improvement to the system of the present invention, the actuator includes an endoscope or surgical forceps.

[0037] This invention provides a remote operation method for a system of remotely operated flexible arm mechanisms for minimally invasive surgery, the specific steps of which are as follows:

[0038] S1: Gesture recognition sensor collects gesture information;

[0039] The gesture recognition sensor has a built-in gesture recognition module and a hand position information acquisition module. It detects and collects gesture information and hand position information in real time. It obtains the operator's operation intention through gesture information and determines the spatial position coordinates of the palm through hand position information.

[0040] S2: Determine if the gesture matches the preset execution gesture;

[0041] The system will not respond to the pose information of any gesture other than the executed gesture and will return to the data acquisition step to reacquire the gesture information and hand pose information. The pose information of the gesture will only be responded to when the gesture is the executed gesture mentioned above.

[0042] S3: Gesture recognition sensor collects palm coordinates;

[0043] When the gesture matches the preset execution gesture, the hand pose information collected by S1 is activated. The collected hand pose information includes palm coordinates and fingertip coordinates.

[0044] Data is collected on the palm coordinates, including the horizontal and vertical position coordinates of the palm and the height coordinates of the palm relative to the sensor. These three coordinates are used as outputs for wired information transmission with the lower-level computer. The collected data is subjected to mean filtering. When the hand basically stops moving, the program automatically records the data for a certain period of time and obtains the corresponding mean. If a fist gesture appears at this time, the mean coordinates are used as the position coordinates. If the hand starts moving again, the recorded values ​​are initialized.

[0045] S4: Perform coordinate transformation through proportional mapping to obtain the solved coordinates, which are used as the target position coordinates;

[0046] The palm coordinates are transformed to preprocess the collected palm coordinates, which are the distance coordinates between the palm and the sensor, to ensure that the target position coordinates do not exceed the limit range. At the same time, this embodiment displays the preprocessed palm coordinates on the host computer, so that the operator can adjust the hand position to achieve the purpose of accurately changing the target position coordinates. The transformed coordinates can be transmitted to the lower computer for calculation via a wired connection as the target position coordinates.

[0047] S5: The change in the length of the driving rope is obtained by performing inverse kinematics calculation on the target position coordinates using Newton's iteration method.

[0048] The bending angle and direction of each joint unit of the flexible arm need to be changed by altering the length of the drive rope, so that the flexible arm can move to the target position.

[0049] S6: Based on the total change in the length of the drive rope relative to the initial state, calculate the motor operation data, including the direction of operation and time, and send it to the drive motor.

[0050] Calculate the motor's operating time and direction based on the total change in drive rope length relative to the initial state, calculated using S5:

[0051]

[0052]

[0053] Where v is the set motor speed, The absolute value is the theoretical motor operating time calculated in this study, which is the motor operating time required for the flexible arm to move from its initial position to the target position. The absolute value is the theoretical operating time of the motor calculated last time, with an initial value of 0, t. jThe actual time for the drive motor to run this time is the time required for the motor to move from the current position to the target position. j = 1, 2, 3, 4, corresponding to the j-th motor.

[0054] By default, the direction in which the rope length is extended is the positive direction of motor rotation. If t j A positive value indicates the motor will run in the forward direction; a negative value indicates the motor will run in the reverse direction; and a zero value indicates the motor will not turn.

[0055] S7: The drive motor rotates according to the calculated data, causing the flexible arm actuator to move to the target position.

[0056] As a further improvement to the method of the present invention, the Newton iteration method in step S5 is to calculate the change in the length of the drive rope in reverse based on the target position of the flexible arm end effector. Specifically, it is calculated using the following formula:

[0057] A base coordinate system o-xyz is established at the end of the fixed sleeve for measuring the position of the end effector, and an auxiliary coordinate system ox′y′z′ is established to describe the bending direction of the flexible arm. The z′ axis coincides with the z axis of the base coordinate system o-xyz, the y axis is the intersection of the bending plane of the flexible arm and the o-xy plane of the base coordinate system o-xyz, and the bending direction angle is the angle between the y axis and the y′ axis, denoted as δ.

[0058] o i -x i y i z i (i = 1, 2, 3) is the coordinate system for each joint element, where the origin is o. i Located at the center of the universal joint of the i-th joint unit, z i Axis points to o i+1 And x i The bending angle of each joint unit is equal and denoted as θ, and is parallel to the x′ axis.

[0059] (P′ x , P′ y , P′ z The coordinates of the flexible arm end effector in the auxiliary coordinate system ox′y′z′ can be obtained by adding the projections of each joint unit onto the coordinate axes.

[0060]

[0061]

[0062] P′ x =0;

[0063] Where g is the length of the end effector, and l is the length of each joint unit;

[0064] Based on the relationship between coordinate systems o-xyz and ox′y′z′, the end effector is positioned P(p) in the base coordinate system. x p y p z The following can be calculated using its position coordinates in the auxiliary coordinate system ox′y′z′:

[0065] P x =P′ x sinδ;

[0066] P y =P′ y cosδ;

[0067] P z =P′ z ;

[0068]

[0069] Combining the above formulas, the bending angle of each joint element is calculated using Newton's iterative formula:

[0070] θ k+1 =θ k +Δθ k ;

[0071] F′(θ k )Δθ k =-F(θ) k );

[0072] F(θ k ) = P z ′(θ k );

[0073] Based on the bending angle θ of each unit joint, the change in rope length relative to the initial state is calculated:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] Where h is the length of the outer sleeve 1-2, and d is the inner radius of the universal joint. and The change in length of the four drive cables at each joint unit relative to the initial state, ΔH jH j Let be the total change in the length of the j-th driving rope relative to the initial state.

[0080] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0081] 1. This invention utilizes teleoperation technology to achieve precise control of the execution layer, overcoming the drawbacks of manual operation such as tremors and inconvenience. In the information acquisition section, accurate gesture recognition and judgment can improve the accuracy of teleoperation, allowing this invention to replace manual surgical procedures.

[0082] 2. The teleoperation provided by this invention, compared with traditional automatic control, does not require input of specific location coordinates and has stronger depth perception.

[0083] 3. The remote operating system designed in this invention can enhance the operator's sense of three-dimensionality and immersion with the help of an endoscope, and achieve a more natural human-computer interaction.

[0084] 4. This invention combines numerical calculation methods to quickly calculate the motor running time from the collected position information, achieving real-time, sensitive, and efficient control.

[0085] 5. Compared to conventional teleoperation systems, this invention uses a Leap Motion sensor, which is small in size and lightweight. Compared to large wearable devices, this sensor is more convenient to use and is more suitable for minimally invasive surgery.

[0086] 6. This invention rationally integrates and arranges the various structural components of the execution layer, and incorporates auxiliary fixing devices. This close and centralized integration achieves precise and reliable drive control. Attached Figure Description

[0087] Figure 1 This is a flowchart of the remote-operated minimally invasive surgical flexible arm system of the present invention;

[0088] Figure 2 This is a schematic diagram of the remote-operated minimally invasive surgical flexible arm system of the present invention;

[0089] Figure 3 This is a schematic diagram of the arm body structure of the execution layer of the remote-operated minimally invasive surgical flexible arm system of the present invention;

[0090] Figure 4 This is a schematic diagram of the outer arm sleeve structure of the execution layer of the remote-operated minimally invasive surgical flexible arm system of the present invention;

[0091] Figure 5 This is a schematic diagram of the front structure of the movable platform of the execution layer of the remote-operated minimally invasive surgical flexible arm system of the present invention;

[0092] Figure 6This is a schematic diagram of the back structure of the movable platform of the execution layer of the remote-operated minimally invasive surgical flexible arm system of the present invention;

[0093] Figure 7 This is a block diagram of the overall structure of the remote-operated minimally invasive surgical flexible arm system of the present invention;

[0094] In the picture:

[0095] 1-1 Fixed sleeve; 1-2 Outer wall sleeve; 1-3 Connecting rod; 1-4 Universal joint; 1-5 End joint sleeve; 1-6 Clamp sleeve; 1-7 Cable hole; 1-8 Clamp connector; 1-9 Cable hole; 1-10 Movable clamp; 1-11 Fixed clamp; 1-12 Small cable hole; 1-13 Center cable hole; 1-14 Movable traction rope; 1-15 Opening and closing traction rope; 2-1 Movable platform; 2-2 Fixing device; 2-3 Motor fixing device; 2-4 Motor fixing slot; 2-5 Front fixing device for rotating shaft; 2-6 Rear fixing slot for rotating shaft; 2-7 Front fixing slot for rotating shaft; 2-8 Rotating shaft; 2-9 Arm fixing structure; 2-10 Rear fixing device for rotating shaft. Detailed Implementation

[0096] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0097] Figure 1 The flowchart of the teleoperated minimally invasive surgical flexible arm system of the present invention is shown below. The overall structural block diagram of the teleoperated minimally invasive surgical flexible arm system is shown below. Figure 7 As shown in the diagram. A schematic diagram of the teleoperated minimally invasive surgical flexible arm system is shown below. Figure 2 As shown. The teleoperated minimally invasive surgical flexible arm operation method of the present invention includes the following steps:

[0098] S1: Gesture recognition sensor collects gesture information.

[0099] The Leap Motion sensor 3 incorporates a gesture recognition module and a hand pose information acquisition module. It can detect and acquire gesture information and hand pose information in real time. The gesture information reveals the operator's intention, and the hand pose information determines the spatial coordinates of the palm. In this embodiment, a clenched fist represents coordinate confirmation, while open fingers indicate the hand is in motion. The Leap Motion sensor 3 analyzes and models the acquired image information to obtain a hand model and its pose information. The Leap Motion sensor 3 is connected to a host computer via a wired connection, transmitting the acquired hand pose information to the host computer 2.

[0100] S2: Determine whether the gesture matches the preset execution gesture.

[0101] When using the sensor, users may perform gestures other than the preset execution gesture due to improper operation. In this embodiment, the pose information of gestures other than the executed gesture will not be responded to, and the data acquisition step will be returned to re-acquire gesture information and hand pose information. Only the pose information of the gesture when the gesture is the aforementioned executed gesture will be responded to.

[0102] S3: Gesture recognition sensor collects palm coordinates.

[0103] When the gesture matches the preset execution gesture, the hand pose information collected by S1 is activated. The collected hand pose information includes palm coordinates, fingertip coordinates, etc. This implementation mainly collects data on the palm coordinates, which include the horizontal and vertical axis position coordinates of the palm and the height coordinates of the palm's distance from the sensor. This implementation method uses the above three coordinates as outputs for wired information transmission with the lower-level computer. In order to reduce the error caused by hand tremors when the hand is clenched into a fist, this implementation method performs mean filtering on the collected data. When the hand basically stops moving, the program automatically records the data for a certain period of time and obtains the corresponding mean. If a fist clenching gesture occurs at this time, the mean coordinates are used as the position coordinates; if the hand resumes movement, the recorded values ​​are initialized.

[0104] S4: Perform coordinate transformation through proportional mapping to obtain the solved coordinates, which are used as the target position coordinates.

[0105] In this embodiment, the acquired palm coordinates cannot be directly output to the lower-level computer as the target position coordinates. Due to limitations in coordinate units and the maximum range of motion of the flexible arm controlled by the lower-level computer, the palm coordinates need to be transformed. The acquired palm coordinates, primarily the distance coordinates between the palm and the sensor, are preprocessed to ensure the target position coordinates do not exceed the limits. Simultaneously, this embodiment displays the preprocessed palm coordinates on the upper-level computer 2, facilitating the operator's adjustment of hand position to precisely change the target position coordinates. The transformed coordinates can then be transmitted to the lower-level computer for calculation via a wired connection.

[0106] S5: The change in the length of the driving rope is obtained by performing inverse kinematics calculation on the target position coordinates using Newton's iteration method.

[0107] In this embodiment, the bending angle and direction of each joint unit of the flexible arm need to be changed by changing the length of the drive rope, so that the flexible arm moves to the target position.

[0108] Based on Newton's iteration method, the change in the length of the drive rope is calculated in reverse from the target position of the end effector of the flexible arm.

[0109] Specifically, the solution is obtained using the following formula:

[0110] A base coordinate system o-xyz is established at the end of the fixed sleeve 1-1 that measures the position of the end effector, and an auxiliary coordinate system ox′y′z′ is established to describe the bending direction of the flexible arm. The z′ axis coincides with the z axis of the base coordinate system o-xyz, the y axis is the intersection of the bending plane of the flexible arm and the o-xy plane of the base coordinate system o-xyz, and the bending direction angle is the angle between the y axis and the y′ axis, denoted as δ.

[0111] o i -x i y i z i (i = 1, 2, 3) is the coordinate system for each joint element, where the origin is o. i Located at the center of universal joint 1-4 of the i-th joint unit, z i Axis points to o i+1 And x i The bending angle of each joint element is equal and denoted as θ, and is parallel to the x' axis.

[0112] (P′ x , P′ y , P′ z The coordinates of the flexible arm end effector in the auxiliary coordinate system ox′y′z′ can be obtained by adding the projections of each joint unit onto the coordinate axes.

[0113]

[0114]

[0115] P′ x =0;

[0116] Where g is the length of the end effector clamp actuator, and l is the length of each joint unit.

[0117] Based on the relationship between coordinate systems o-xyz and ox′y′z′, the end effector is positioned P(p) in the base coordinate system. x p y p z It can be calculated from its position coordinates in the auxiliary coordinate system ox′y′z′:

[0118] P x =P′ x sinδ;

[0119] P y =P′ y cosδ;

[0120] P z =P′ z ;

[0121]

[0122] Combining the above formulas, the bending angle of each joint element can be calculated using Newton's iterative formula:

[0123] θ k+1 =θ k +Δθ k ;

[0124] F′(θ k )Δθ k =-F(θ) k );

[0125] F(θ k )=P′ z (θ k );

[0126] Based on the bending angle θ of each unit joint, the change in rope length relative to the initial state can be calculated:

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] Where h is the length of the outer sleeve 1-2, and d is the inner radius of the universal joint 1-4. and The change in length of the four drive cables at each joint unit relative to the initial state, ΔH j H j Let be the total change in the length of the j-th driving rope relative to the initial state.

[0133] S6: Based on the total change in the length of the drive rope relative to the initial state, calculate the motor operation data, including the direction of operation and time, and send it to the drive motor.

[0134] Calculate the motor's operating time and direction based on the total change in drive rope length relative to the initial state, calculated using S5:

[0135]

[0136]

[0137] Where v is the set motor speed, The absolute value is the theoretical motor operating time calculated in this study, which is the motor operating time required for the flexible arm to move from its initial position to the target position. The absolute value is the theoretical operating time of the motor calculated last time, with an initial value of 0, t. j The actual time for the drive motor to run this time is the motor running time required to move from the current position to the target position (j = 1, 2, 3, 4, corresponding to the j-th motor).

[0138] By default, the direction in which the rope length is extended is the positive direction of motor rotation. If t j A positive value indicates the motor will run in the forward direction; a negative value indicates the motor will run in the reverse direction; and a zero value indicates the motor will not turn.

[0139] S7: The drive motor rotates according to the calculated data, causing the flexible arm actuator to move to the target position.

[0140] The host computer 2 sends the driving motor's operating time, direction, and speed information calculated in steps 4-6 to the motor drive chip, causing the driving motor to rotate according to the specified instructions. This causes the drive rope to extend or contract by a specified length, and the corresponding joint unit to bend at a specified angle, moving the flexible arm end effector to the target position.

[0141] This embodiment provides a schematic diagram of the execution layer mechanism of a remotely operated minimally invasive surgical flexible arm system, as shown below. Figure 3 As shown, it includes:

[0142] The end effector includes an end joint sleeve 1-5, a clamp sleeve 1-6, a clamp connector 1-8, a movable clamp 1-10, and a fixed clamp 1-11. The clamp connector 1-8 connects the two clamps to the clamp sleeve 1-6. The movable clamp 1-10 can be rotated open and closed for holding surgical instruments and lifting diseased tissue.

[0143] The flexible arm includes a fixed sleeve 1-1, an outer sleeve 1-2, a connecting rod 1-3, and a universal joint 1-4 connected thereto.

[0144] like Figure 4 The figure shows a joint unit. Link 1-3 connects the outer sleeve 1-2 to the universal joint 1-4. Two adjacent joint units share a universal joint and are connected in sequence to form a flexible arm. This embodiment is a three-stage robotic arm composed of three joint units.

[0145] Each joint unit has four identical small threading holes 1-12 and one central threading hole 1-13. The traction rope 1-14, which controls the movement of the flexible arm, enters through the small threading hole 1-12 and exits through the threading hole 1-7. The opening and closing traction rope 1-15, which controls the opening and closing of the clamp, enters through the central threading hole 1-13 and exits through the threading hole 1-9.

[0146] Two adjacent joint units can rotate around the universal joint 1-4. By moving the length of the traction rope 1-14, each joint unit can rotate and shift around the universal joint, thereby achieving any bending angle.

[0147] Two opening and closing traction ropes 1-15 are connected to the movable clamp 1-10. By controlling the tension and relaxation of the two opening and closing traction ropes, the movable clamp 1-10 is driven to rotate relative to the fixed clamp 1-11, thereby realizing the opening and closing of the clamp.

[0148] exist Figure 5 In the schematic diagram of the front structure of the flexible arm mobile platform for minimally invasive surgery shown, the mobile platform 2-1 is connected to the external lifting device through the fixing device 2-2. The position of the mobile platform can be adjusted through the external lifting device to make the device more flexible.

[0149] The drive motor can be fixed to the motor mounting device 2-3 with screws, and then the motor can be fixed to the platform with screws through the mounting slot of the motor mounting device 2-3 and the mounting slot 2-4 of the movable platform, thereby avoiding the problem of the motor rolling over during rotation.

[0150] The rotating shaft 2-8 is fixed on the moving platform 2-1 by the rotating shaft fixing front device 2-5, and is connected to the motor output shaft through the slot, so that the motor can drive the rotating shaft 2-8 to rotate.

[0151] The front mounting device 2-5 of the rotating shaft is fixed to the movable platform 2-1 through the rear mounting groove 2-6 of the rotating shaft, the front mounting groove 2-7 of the rotating shaft, and the back mounting device 2-10 of the rotating shaft.

[0152] The free movement of the shaft 2-8 is achieved by using the motor fixing slot 2-4, the front fixing slot 2-7 of the shaft, and the rear fixing slot 2-6 of the shaft. This facilitates the adjustment of the tension of the traction rope and ensures that the traction rope is always taut, thereby reducing device error.

[0153] The groove on the shaft ensures easy rope threading. At the same time, the traction rope is fixed through the small hole on the shaft 2-8 and connected to the threading hole of the arm body fixing structure. The tension of the traction rope can be adjusted by changing the number of turns of the traction rope on the shaft 2-8.

[0154] Figure 6The diagram shows the back of the movable platform 2-1. The rotating shaft fixing back device 2-10 is fixed to the rotating shaft front fixing groove 2-7 through the small hole on the back. The other end of the rotating shaft fixing back device 2-10 is connected to the slot of the rotating shaft fixing front device 2-5 to make them a whole.

[0155] The arm fixing structure 2-9 is connected to the universal joint 1-4 at the tail end of the arm via the outer wall sleeve 1-2 to fix the arm body.

[0156] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A remotely operated minimally invasive surgical flexible arm mechanism, comprising an end effector, a flexible arm, and a movable platform front structure, characterized in that: The end effector includes an end joint sleeve (1-5), a clamp sleeve (1-6), a clamp connector (1-8), movable clamps (1-10), and a fixed clamp (1-11). The clamp connector (1-8) connects two movable clamps (1-10) to the clamp sleeve (1-6). The movable clamps (1-10) can be rotated open and closed to hold surgical instruments and lift diseased tissue. The flexible arm includes a fixed sleeve (1-1), an outer sleeve (1-2), a connecting rod (1-3), and a universal joint (1-4) connected thereto. The connecting rod (1-3) connects the outer sleeve (1-2) and the universal joint (1-4) as a joint unit. Two adjacent joint units share a universal joint and are connected in sequence to form the flexible arm. Each joint unit has four identical small threading holes (1-12) and one central threading hole (1-13). The moving traction rope (1-14) that controls the movement of the flexible arm passes through the small threading holes (1-12) and exits through the threading hole (1-7). The opening and closing traction rope (1-15) that controls the opening and closing of the clamps passes through the central threading hole (1-13) and exits through the threading hole (1-9). Two adjacent joint units rotate around the universal joint (1-4). By moving the length of the traction rope (1-14), each joint unit rotates around the universal joint, thereby achieving any bending angle. Two opening and closing traction ropes (1-15) are connected to the movable clamp (1-10). By controlling the tension and relaxation of the two opening and closing traction ropes, the movable clamp (1-10) is rotated relative to the fixed clamp (1-11) to realize the opening and closing of the clamp. The front structure of the movable platform includes a drive motor, a movable platform (2-1), a fixing device (2-2), a motor fixing device (2-3), a motor fixing slot (2-4), a front fixing device for the rotating shaft (2-5), a rear fixing slot for the rotating shaft (2-6), a front fixing slot for the rotating shaft (2-7), a rotating shaft (2-8), an arm fixing structure (2-9), and a rear fixing device for the rotating shaft (2-10). The movable platform (2-1) is connected to an external lifting device through the fixing device (2-2). The drive motor is fixed to the motor fixing device (2-3) with screws, and then the drive motor is fixed to the movable platform (2-1) by screws through the fixing slot of the motor fixing device (2-3) and the motor fixing slot (2-4) of the movable platform (2-1); The rotating shaft (2-8) is fixed on the movable platform (2-1) by the rotating shaft fixing front device (2-5), and is connected to the output shaft of the drive motor through the slot, thereby driving the drive motor to rotate the rotating shaft (2-8); The rotating shaft fixing front device (2-5) is fixed on the movable platform (2-1) through the rotating shaft rear end fixing groove (2-6), the rotating shaft front end fixing groove (2-7), and the rotating shaft fixing back device (2-10). The rotating shaft (2-8) can move freely through the motor fixing groove (2-4), the rotating shaft front end fixing groove (2-7), and the rotating shaft rear end fixing groove (2-6). The movable traction rope (1-14) is fixed through a small hole on the rotating shaft (2-8) and connected to the wire hole of the arm body fixing structure. The tension of the traction rope is adjusted by changing the number of turns of the movable traction rope (1-14) on the rotating shaft (2-8). The rotating shaft fixing back device (2-10) is fixed to the rotating shaft front fixing groove (2-7) through the small hole on the back. The other end of the rotating shaft fixing back device (2-10) is connected to the slot of the rotating shaft fixing front device (2-5) to make them a whole. The arm fixing structure (2-9) is connected to the universal joint (1-4) at the tail end of the arm via the outer wall sleeve (1-2) to achieve arm fixing.

2. The remote-operated minimally invasive surgical flexible arm mechanism according to claim 1, characterized in that: The flexible arm is a three-stage robotic arm consisting of three joint units.

3. The remote-operated minimally invasive surgical flexible arm mechanism according to claim 1, characterized in that: The rotating shaft (2-8) has a groove to ensure that the rope can be threaded through.

4. A system corresponding to the teleoperated minimally invasive surgical flexible arm mechanism of any one of claims 1-3, comprising a data acquisition layer, a processing layer, a control layer, and an execution layer, characterized in that, The acquisition layer includes a gesture recognition sensor, and the execution layer includes a mobile platform, a drive motor, an arm mechanism, an actuator, and a drive rope. The hand coordinate information is acquired through the gesture recognition sensor, and inverse kinematics calculation is performed. The remote operation control of the flexible arm is achieved by changing the length of the drive rope. The processing layer includes gesture recognition and determination of whether to execute, conversion from actual spatial coordinates to calculated coordinates through proportional mapping, and coordinate calculation using Newton's iteration method to obtain the change in the length of the driving rope. The control layer includes the conversion of the change in drive rope length into motor running time; The execution layer includes: The drive motor and the moving platform are connected by a slide rail. The position of the flexible arm can be manually adjusted by changing the length and tension of the drive rope by adjusting the position of the drive motor. The boom mechanism consists of multiple joint units. Each joint unit includes a boom cylinder, a connecting rod, and a connecting ring. The drive rope passes through each joint unit, and each joint unit bends at the same angle. The end joint unit is connected to the center of the mobile platform, and the front joint unit is connected to the actuator.

5. The system of the remotely operated minimally invasive surgical flexible arm mechanism according to claim 4, characterized in that: The actuator includes an endoscope or surgical forceps.

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