Stiffness-variable flexible surgical operating arm and method for operating same

Abstract

The present application relates to the field of surgical device technology. In particular, the present application discloses a stiffness-variable flexible surgical operating arm, comprising a support body and a joint part. A surgical arm body is connected to the joint part. A force sensor is disposed at a junction between the support body and the joint part. The end of the joint part opposite to the junction is provided with an ultrasonic sensor, a camera module, and an illumination assembly, and an orientation sensor is provided near the axial center position of the joint part. The support body comprises a DEA sensing actuator and an SMP stiffness-variable layer, and a shape sensing sensor is provided near the SMP stiffness-variable layer and the DEA sensing actuator. The end surface of the joint part located at the ultrasonic sensor is provided with a working channel penetrating through the support body. The present application enables the joint part to deform through the DEA actuator and to adapt to a human body cavity environment, and can achieve accurate movement within the cavity with the aid of a series of sensors, thus allowing an end effector of the surgical operating arm to perform surgical operations on the lesion. The present application further provides a method suitable for operating the described operating arm.

Description

A variable stiffness flexible surgical arm and its operation method Technical Field

[0001] This application relates to the technical field of surgical instruments, and more particularly to a variable stiffness flexible surgical arm and its operating method. Background Technology

[0002] Existing surgical robots typically consist of multiple joints and links, possessing multiple degrees of freedom. They can flexibly simulate the movements of a human arm and are equipped with imaging systems such as cameras, providing doctors with high-definition, three-dimensional images of the surgical site. Furthermore, by equipping the end of the robotic arm with surgical instruments, they can precisely locate and manipulate the surgical site.

[0003] However, in complex human cavities, such as in the presence of large amounts of mucus or tissue adhesions, relying solely on a camera is insufficient for precise operation. Mucus may obstruct the camera's view, affecting the doctor's judgment of the operating arm's position, while tissue adhesions may create additional resistance to the movement of the operating arm, which existing control mechanisms cannot handle well.

[0004] Therefore, there is an urgent need for a variable stiffness flexible surgical arm and its operation method to solve the above problems.

[0005] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0006] The main purpose of this application is to provide a variable stiffness flexible surgical arm to solve the problem that existing surgical arms cannot cope well with the complex environment of human cavities, thus preventing precise operation.

[0007] To achieve the above objectives, this application provides a variable stiffness flexible surgical arm, including a support body and a joint, wherein the surgical arm body is connected to the joint.

[0008] A force sensor is provided at the connection between the support body and the joint. An ultrasonic sensor, a camera module and an illumination component are provided at the end of the joint away from the connection. An angle sensor is also provided near the axis of the joint.

[0009] The supporting body includes a DEA sensing actuator and an SMP variable stiffness layer. The DEA actuator is located inside the SMP variable stiffness layer. Several DEA actuators are arranged around the sidewall of the joint. Shape sensing sensors are arranged near the SMP variable stiffness layer and the DEA sensing actuator.

[0010] It also includes a working channel, wherein the joint is located on the end face of the ultrasound sensor and has a working channel that passes through the support body. The working channel can be used to place a small surgical arm or surgical instrument.

[0011] As a preferred embodiment of this application, the main body of the operating arm includes an antibacterial coating, an outer encapsulation layer, a lubrication layer, an SMP variable stiffness layer, a DEA sensing actuator, and an inner encapsulation layer. The SMP variable stiffness layer and the DEA sensing actuator are both located between the outer encapsulation layer and the inner encapsulation layer. The antibacterial coating is disposed on the outside of the outer encapsulation layer, and the lubrication layer is disposed between the outer encapsulation layer and the SMP variable stiffness layer.

[0012] As a preferred embodiment of this application, the DEA sensing actuator includes a dielectric elastomer layer, a stretchable electrode layer, and a patterned electrode layer, wherein the stretchable electrode layer and the patterned electrode layer are located on opposite sides of the dielectric elastomer layer, and the patterned electrode layer is close to the SMP variable stiffness layer.

[0013] As a preferred embodiment of this application, it further includes a fault detection module, which is located inside the support body and is electrically connected to the DEA driver.

[0014] As a preferred embodiment of this application, it also includes a backup module, which is located inside the support body and shares some circuitry and control system with the DEA driver.

[0015] As a preferred embodiment of this application, it also includes a circuit switching system, which is electrically connected to the control system.

[0016] As a preferred embodiment of this application, the joint is made of a flexible material.

[0017] A method for operating a variable stiffness flexible surgical arm, applicable to any of the variable stiffness flexible surgical arms described above, includes the following steps:

[0018] Step 1: Zero-point calibration is performed using a force sensor, and the initial position of the joint is determined using an angle sensor, thereby calibrating and initializing the variable stiffness flexible surgical arm.

[0019] Step 2: Slowly insert the operating arm into the body cavity, use the lighting components and camera module to photograph the environment inside the cavity, and use an ultrasonic sensor for assisted positioning.

[0020] Step 3: When the camera module observes that the propulsion direction needs to be adjusted, the voltage is input to the DEA driver to change the direction of the joint, and the voltage is applied to the patterned electrode layer to make the shape of the manipulator match the human cavity, and then it moves slowly.

[0021] Step 4: Repeat steps 2 and 3 until the mechanical instrument is delivered to the patient's lesion.

[0022] Step 5: Repeat steps 2 and 3 to remove the variable stiffness flexible manipulator from the human body cavity.

[0023] As a preferred embodiment of this application, in step 3, when advancing the operating arm, the method further includes using an angle sensor to detect the angle change of the joint, using a shape sensing sensor to detect the shape of the supporting body, and using a force sensor to detect the external force at the connection between the operating arm body and the joint.

[0024] This application provides a variable stiffness flexible surgical arm. The surgical arm can be operated using a single arm or in combination with multiple arms, depending on the actual situation. The combined surgical arm is suitable for cavities with more complex environments. It provides six degrees of freedom of movement, enabling more precise control of the device in the face of complex environmental changes in natural cavities. By controlling the bending posture and extension length of the joint end effector in real time during surgery, the overall stiffness of the end effector and the bending radius of the joint end effector in the small surgical arm can be adjusted to adapt to the complex environmental changes in natural cavities. By employing a DEA actuator, which can deform the joint and achieve precise motion compensation for the support body, the deformation of the joint can be precisely controlled by controlling the input voltage, avoiding secondary errors caused by wire motion compensation and improving the positioning accuracy of the end effector. Simultaneously, during movement, ultrasonic sensors are used for assisted positioning, angle sensors detect changes in the joint angle, shape sensors detect the shape of the support body, and force sensors detect external forces at the connection between the surgical arm body and the joint, achieving precise adjustment. Attached Figure Description

[0025] Figure 1 is a structural diagram of a variable stiffness flexible surgical arm in a combined state bending according to an embodiment of this application;

[0026] Figure 2 is a schematic diagram of a variable stiffness flexible surgical arm structure in one embodiment of this application;

[0027] Figure 3 is a front view of a variable stiffness flexible surgical arm based on the structure shown in Figure 2 in one embodiment of this application;

[0028] Figure 4 is a schematic diagram of the structure of the support body in a variable stiffness flexible surgical arm according to an embodiment of this application;

[0029] Figure 5 is a structural diagram of a variable stiffness flexible surgical arm in an embodiment of this application, in which it is not bent in the combined state.

[0030] Explanation of reference numerals in the attached drawings: 1. Support body; 2. Joint; 3. DEA driver; 4. End effector; 5. Camera; 6. Illumination assembly; 7. Secondary manipulator; 8. Working channel; 9. Inner encapsulation layer; 10. Stretchable electrode layer; 11. Dielectric elastomer layer; 12. Patterned electrode layer; 13. SMP variable stiffness layer; 14. Lubricating layer; 15. Outer encapsulation layer; 16. Antibacterial coating; 17. Ultrasonic sensor. Detailed Implementation

[0031] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0032] Furthermore, descriptions using terms such as "first" and "second" in this application are for descriptive purposes only (e.g., to distinguish identical or similar elements) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed in this application.

[0033] Please refer to Figures 1, 2, 3, and 5. In one embodiment, a variable stiffness flexible surgical arm includes a support body 1 and a joint 2. The joint 2 is made of a flexible material, and the surgical arm body is connected to the joint 2.

[0034] A force sensor is provided at the connection between the support body 1 and the joint 2. An ultrasonic sensor 17, a camera module and an illumination component 6 are provided at the end of the joint 2 away from the connection. An angle sensor is also provided near the axis of the joint 2.

[0035] The supporting body 1 includes a DEA sensing actuator 3 and an SMP variable stiffness layer 13. The DEA actuator 3 is located inside the SMP variable stiffness layer 13. Several DEA actuators 3 are arranged around the side wall of the joint 2. Shape sensing sensors are arranged near the SMP variable stiffness layer 13 and the DEA sensing actuator 3.

[0036] It also includes a working channel 8. The joint 2 is located on the end face of the ultrasonic sensor 17 and has a working channel 8 that runs through the support body 1. The working channel 8 can be used to place a small surgical arm or surgical instrument.

[0037] It should be noted that in this embodiment, SMP is a smart responsive material, also known as shape memory polymer. It refers to a product with an initial shape that changes its shape under certain conditions and is temporarily fixed in that shape. It can recover its initial shape through external stimuli (such as electricity, heat, light, chemical induction, etc.).

[0038] In this embodiment, the lighting component 6 mainly includes LED beads and other components, and the camera module mainly includes camera 5 and other components. The lighting module, camera module, force sensor, ultrasonic sensor 17, angle sensor and shape perception sensor are connected to the microprocessor built into the support body 1. The microprocessor is then connected to the external control device through signal lines, power lines and other lines, and transmits the captured cavity images and data to the display screen of the control device.

[0039] It is understood that the surgical operating arm provided in this application can be operated by using a single surgical operating arm or by using multiple surgical operating arms in combination, depending on the actual situation. In the combined surgical operating arm, for easy distinction, taking a two-stage operating arm as an example, it is divided into a main operating arm and a secondary operating arm 7. The secondary operating arm 7 is installed in the working channel 8 of the main operating arm. The structure of the secondary operating arm 7 is the same as that of the main operating arm, only the size is different. The combined surgical operating arm can be used in cavities with more complex cavity environments. The combined surgical operating arm can provide 6 degrees of freedom of movement, which can cope with the complex environmental changes of natural cavities, making the control operation of this device more precise.

[0040] By controlling the bending posture and extension length of the end of the joint 2 in real time during surgery, the overall stiffness of the end effector 4 and the bending radius of the end of the joint in the small surgical arm can be adjusted to adapt to the complex environmental changes of the natural cavity. By using the DEA driver 3, the DEA driver 3 can drive the joint 2 to deform, and achieve precise motion compensation for the support body 1. The deformation of the joint 2 can be precisely controlled by controlling the input voltage, avoiding the secondary error caused by the motion compensation of the wire, and improving the end positioning accuracy of the operating arm.

[0041] Meanwhile, during the movement, the ultrasonic sensor 17 is used for auxiliary positioning. In the complex environment of human body cavities, when there is mucus or tissue adhesion, the mucus may obstruct the view of the camera module and affect the doctor's judgment of the position of the operating arm, while tissue adhesion may generate additional resistance to the movement of the operating arm. At this time, auxiliary positioning technology such as the ultrasonic sensor 17 can still determine the position of the operating arm when the view of the camera 5 is obstructed.

[0042] Furthermore, angle sensors are used to detect the angle changes of joint 2. Angle sensors, such as high-precision photoelectric encoders, are installed at the joints. Since the bending angle of the joint is a key factor affecting the position and posture of the end effector 4 of the manipulator arm, the photoelectric encoder can accurately measure the bending angle of the joint. Its position should be close to the rotation axis of the joint in order to accurately obtain the rotation information of the joint. For example, a photoelectric encoder is installed near the axis of each joint. When the joint rotates, the encoder disk rotates accordingly. The rotation angle of the joint is determined by detecting the change of the encoding pattern on the encoder disk. The resolution can reach 0.01 degrees or even higher.

[0043] Furthermore, a shape-sensing sensor is used to detect the shape of the support body 1. A shape-sensing sensor, such as a fiber optic sensor, is placed near the SMP variable stiffness layer 13 and the DEA sensing driver 3 of the support body 1. Since the stiffness change of the SMP variable stiffness layer 13 and the driving of the DEA sensing driver 3 affect the shape of the support body 1, the fiber optic sensor can sense the shape change of the support body 1 by detecting changes in the propagation characteristics of light in the optical fiber. For example, when the support body 1 bends or deforms, the light propagation path in the optical fiber changes, resulting in changes in the intensity, phase, and other characteristics of the light. By detecting these changes, the shape information of the support body 1 can be obtained.

[0044] Furthermore, a force sensor is used to detect the external force at the connection between the main body of the manipulator and the joint 2. A force / torque sensor, such as a strain gauge force / torque sensor, is installed at the connection between the joint and the supporting body 1. During operation, the joint will be subjected to forces and torques generated by factors such as tissue adhesion and mucosal resistance. The strain gauge force / torque sensor calculates the force and torque by measuring the strain of the strain gauge under the action of force or torque. When the joint is subjected to external force, the connection part will undergo slight deformation, and the resistance value of the strain gauge will change accordingly. By measuring the change in resistance value, the force and torque can be calculated with an accuracy of several millinewtons.

[0045] Specifically, referring to Figure 4, based on the above embodiment, the main body of the operating arm includes an antibacterial coating 16, an outer encapsulation layer, a lubrication layer 14, an SMP variable stiffness layer 13, a DEA sensing actuator 3, and an inner encapsulation layer 9. The SMP variable stiffness layer 13 and the DEA sensing actuator 3 are both located between the outer encapsulation layer and the inner encapsulation layer 9. The antibacterial coating 16 is disposed on the outside of the outer encapsulation layer 15, and the lubrication layer 14 is disposed between the outer encapsulation layer 15 and the SMP variable stiffness layer 13.

[0046] Furthermore, based on the above embodiments, the DEA sensing actuator 3 includes a dielectric elastomer layer 11, a stretchable electrode layer 10, and a patterned electrode layer 12. The stretchable electrode layer 10 and the patterned electrode layer 12 are located on both sides of the dielectric elastomer layer 11, and the patterned electrode layer 12 is close to the SMP variable stiffness layer 13. The sensing layer can be stretched.

[0047] It is understandable that when operating the support body 1, a direct current is applied to the patterned electrode layer 12 alone, which generates heat and heats the SMP variable stiffness layer 13. After the SMP variable stiffness layer 13 softens, its stiffness decreases, allowing the support body 1 to adapt to the cavity environment. When the power is turned off and heating stops, the temperature of the SMP variable stiffness layer 13 decreases, the material hardens, and the shape of the support body 1 gradually becomes fixed, so that the shape of the support body 1 adapts to the human cavity. After the SMP variable stiffness layer 13 hardens, precise force transmission can be achieved.

[0048] Specifically, based on the above embodiments, a fault detection module (not shown in the figure) is also included. The fault detection module is located inside the support body 1 and is electrically connected to the DEA driver 3.

[0049] It is understandable that the fault detection module can use a voltage sensor. The voltage sensor should be located near the voltage measurement point of the DEA driver 3 and connected to the microprocessor. The voltage sensor can monitor the electrical parameters of the DEA driver 3, such as voltage, current, and impedance, to detect faults. When a sudden voltage fluctuation exceeds the normal range, the current increases abnormally, or the impedance changes unexpectedly, it may indicate that the DEA driver 3 has failed. At this time, the microprocessor will transmit the detection data to the display screen of an external control device for further analysis by relevant technical personnel.

[0050] Specifically, based on the above embodiments, a backup module (not shown in the figure) is also included. The backup module is located inside the support body 1 and shares some circuitry and control system with the DEA driver 3.

[0051] It can be understood that the backup module is specifically a backup DEA drive 3. Since the DEA drives 3 are evenly distributed around the axis of the joint 2, the backup DEA drives 3 can be installed near each DEA ​​drive 3 or in the reserved space inside the joint 2. In this way, when the original DEA drive 3 fails, the backup drive can quickly take over the work.

[0052] Furthermore, the backup DEA drive 3 can share some of the wiring and control systems with the original DEA drive 3 to reduce space occupation and cost; specifically, they can share power lines and switch from the original drive to the backup drive through a switching circuit.

[0053] Specifically, based on the above embodiments, a circuit switching system (not shown in the figure) is also included, which is electrically connected to the control system.

[0054] It is understandable that switching of DEA driver 3 can be achieved using a circuit switching system composed of electronic components such as relays or transistors. When the fault detection system determines that a certain DEA driver 3 has failed, it will send a signal to the circuit switching system.

[0055] For example, during normal operation, the original DEA driver 33 is connected to the power supply and control system via the main circuit; when a fault is detected, the circuit switching system will disconnect the main circuit connection of the original DEA driver 33 and simultaneously connect the backup DEA driver 3 to the power supply and control system, thereby achieving automatic switching.

[0056] In summary, during use, the joint 2 can be bent by controlling one or two DEA actuators 3, thereby changing the direction of the joint 2 and adapting the joint 2 to the human body cavity.

[0057] During surgery, this device is inserted into the body cavity, and the support body 1 is slowly pushed forward. The camera 5 at the joint end transmits the image of the operating arm's forward direction to the computer terminal. The doctor uses the image to determine the position of the end effector 4 in real time. When the operating arm needs to turn, voltage is input to the DEA driver 3, which drives the joint to change direction. Then, current is applied to the patterned electrode layer 12, which heats up and heats the SMP variable stiffness layer 13. The stiffness of the SMP variable stiffness layer 13 decreases, allowing the operating arm to adapt to the cavity environment. When the power is turned off and heating stops, the temperature of the SMP variable stiffness layer 13 decreases, the material hardens, and the shape of the operating arm gradually fixes, making the shape of the support body 1 adapt to the human cavity. Then, the operating arm is pushed forward again. By repeating this process, the end effector 4 on the operating arm can be delivered to the lesion site in the human body. Then, the joint can be manipulated to change the direction of the end effector 4 and treat the lesion site. The flexible force sensing module can sense the force and direction of the joint and the human cavity, which can help the doctor control the operating arm more precisely and reduce the damage to the human body during the movement of the operating arm.

[0058] A method for operating a variable stiffness flexible surgical arm, applicable to any of the above-mentioned variable stiffness flexible surgical arms, includes the following steps:

[0059] Step 1: Zero-point calibration is performed using a force sensor, and the initial position of joint 2 is determined using an angle sensor, thereby calibrating and initializing the variable stiffness flexible surgical arm.

[0060] Step 2: Slowly insert the operating arm into the cavity of the human body, use the lighting component 6 and the camera module to take pictures of the environment inside the cavity, and use the ultrasonic sensor 17 for auxiliary positioning.

[0061] Step 3: When the camera module observes that the propulsion direction needs to be adjusted, the voltage is input to the DEA driver 3 to change the direction of the joint 2, and the voltage is applied to the patterned electrode layer 12 to make the shape of the operating arm match the human cavity, and then it moves slowly.

[0062] Step 4: Repeat steps 2 and 3 until the mechanical instrument is delivered to the patient's lesion.

[0063] Step 5: Repeat steps 2 and 3 to remove the variable stiffness flexible manipulator from the human body cavity.

[0064] Specifically, based on the above embodiments, in step 3, when advancing the operating arm, the method further includes using an angle sensor to detect the angle change of the joint 2, using a shape sensing sensor to detect the shape of the support body 1, and using a force sensor to detect the external force at the connection between the operating arm body and the joint 2.

[0065] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0066] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A variable stiffness flexible surgical arm, characterized in that, It includes a supporting body and a joint, with the main body of the surgical arm connected to the joint; A force sensor is provided at the connection between the support body and the joint. An ultrasonic sensor, a camera module and an illumination component are provided at the end of the joint away from the connection. An angle sensor is also provided near the axis of the joint. The supporting body includes a DEA sensing actuator and an SMP variable stiffness layer. The DEA actuator is located inside the SMP variable stiffness layer. Several DEA actuators are arranged around the sidewall of the joint. Shape sensing sensors are arranged near the SMP variable stiffness layer and the DEA sensing actuator. It also includes a working channel, wherein the joint is located on the end face of the ultrasound sensor and has a working channel that passes through the support body. The working channel can be used to place a small surgical arm or surgical instrument.

2. The variable stiffness flexible surgical arm according to claim 1, characterized in that, The main body of the operating arm includes an antibacterial coating, an outer encapsulation layer, a lubrication layer, an SMP variable stiffness layer, a DEA sensing actuator, and an inner encapsulation layer. The SMP variable stiffness layer and the DEA sensing actuator are both located between the outer encapsulation layer and the inner encapsulation layer. The antibacterial coating is disposed on the outside of the outer encapsulation layer, and the lubrication layer is disposed between the outer encapsulation layer and the SMP variable stiffness layer.

3. The variable stiffness flexible surgical arm according to claim 2, characterized in that, The DEA sensing actuator includes a dielectric elastomer layer, a stretchable electrode layer, and a patterned electrode layer. The stretchable electrode layer and the patterned electrode layer are located on opposite sides of the dielectric elastomer layer, and the patterned electrode layer is close to the SMP variable stiffness layer.

4. The variable stiffness flexible surgical arm according to claim 1, characterized in that, It also includes a fault detection module, which is located inside the support body and is electrically connected to the DEA driver.

5. The variable stiffness flexible surgical arm according to claim 1, characterized in that, It also includes a backup module, which is located inside the support body and shares some wiring and control system with the DEA driver.

6. The variable stiffness flexible surgical arm according to claim 5, characterized in that, It also includes a circuit switching system, which is electrically connected to the control system.

7. The variable stiffness flexible surgical arm according to claim 6, characterized in that, The joint is made of a flexible material.

8. A method for operating a variable stiffness flexible surgical arm, applicable to the variable stiffness flexible surgical arm described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Zero-point calibration is performed using a force sensor, and the initial position of the joint is determined using an angle sensor, thereby calibrating and initializing the variable stiffness flexible surgical arm. Step 2: Slowly insert the operating arm into the body cavity, use the lighting components and camera module to photograph the environment inside the cavity, and use an ultrasonic sensor for assisted positioning. Step 3: When the camera module observes that the propulsion direction needs to be adjusted, the voltage is input to the DEA driver to change the direction of the joint, and the voltage is applied to the patterned electrode layer to make the shape of the manipulator match the human cavity, and then it moves slowly. Step 4: Repeat steps 2 and 3 until the mechanical instrument is delivered to the patient's lesion. Step 5: Repeat steps 2 and 3 to remove the variable stiffness flexible manipulator from the human body cavity.

9. The method for operating a variable stiffness flexible surgical arm according to claim 8, characterized in that, In step 3, when advancing the manipulator, the method also includes using an angle sensor to detect changes in the angle of the joint, using a shape sensor to detect the shape of the support body, and using a force sensor to detect the external force at the connection between the manipulator body and the joint.

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