A lumbar lamina precise grinding surgical robot hardware system and a control method thereof

Abstract

The application provides a lumbar lamella precision grinding operation robot hardware system for selective spinal nerve posterior root resection of cerebral palsy patients, which comprises a six-degree-of-freedom mechanical arm, a bone drill tail end, a six-dimensional force / torque sensor, a grinding area three-dimensional scanning camera, a main control system and a surgical area marker point; wherein the grinding area three-dimensional scanning camera is used for acquiring a three-dimensional model of a surgical area; the six-dimensional force / torque sensor is used for acquiring real-time six-dimensional force / torque data; the main control system acquires the three-dimensional model of the surgical area and the real-time six-dimensional force / torque data in real time through a data acquisition device, and is positioned to a grinding position through the surgical area marker point. Through the method provided by the application, the robot can more flexibly reach the grinding position and more stably perform the grinding task in the implementation of the selective spinal nerve posterior root resection of cerebral palsy patients.

Description

Technical Field

[0001] This invention belongs to the field of surgical robots. Background Technology

[0002] In selective posterior rhizotomy for cerebral palsy patients, surgeons typically use a handheld bone drill for traditional lumbar laminectomy, which carries several risks for the patient. The lumbar laminectomy consists of three layers: outer cortical bone, cancellous bone, and inner cortical bone. Cortical bone is dense, requiring significant force to drill with a bone drill; cancellous bone is more porous and can be drilled with less force, making it easier to remove. Relying solely on the surgeon's manual manipulation can lead to risks such as damaging nerve tissue beneath the inner cortical layer due to the uneven structure of the lumbar laminectomy, or excessively long drilling time due to insufficient force. Furthermore, the confined surgical area often prevents the surgeon from finding a suitable point of support due to posture, or prolonged drilling can cause a rapid decline in physical strength and energy, affecting both the drilling effect and subsequent surgical procedures. While some methods have been proposed in existing techniques:

[0003] 1) Manual lumbar laminectomy relies heavily on the surgeon's experience. Taking selective spinal nerve resection as an example, in this procedure, the surgeon needs to open the patient's lumbar laminectomy, divide the nerve tissue into several bundles, and sever a certain number of these bundles. When relying solely on the surgeon's manual manipulation, the uneven texture of the lumbar laminectomy may lead to damage to the nerve tissue beneath the inner cortical bone when drilling, or insufficient force may result in excessively long drilling times. Robots, using force sensors for precise force sensing and control, can maintain a stable contact force during the grinding process, improving safety and accelerating the procedure.

[0004] 2) The safety of most spinal surgery grinding procedures depends on meticulous control and flexible work in confined spaces, while minimizing damage to nearby tissues, especially nerve tissue. When using a handheld bone drill for grinding, the narrow surgical area often leads to a lack of good support points for the surgeon due to posture, or a rapid decline in physical strength and energy due to prolonged grinding, affecting the grinding effect.

[0005] 3) Traditional manual ablation surgery involves a large wound area and significant blood loss, making it more susceptible to radiation exposure and infection, potentially leading to complications such as nerve damage and spinal instability. Robotic lumbar laminectomy, on the other hand, results in a smaller wound area, less bleeding, and less postoperative pain. The risk of intraoperative infection is significantly reduced, increasing the success rate of the surgery.

[0006] 4) Currently, most surgical robots are not equipped with force control sensors and force-position hybrid control algorithms. Adding force-position hybrid control to the robot can make the robot's state observation during surgery more comprehensive, achieving a more accurate and safer goal. Summary of the Invention

[0007] The present invention aims to at least partially solve one of the technical problems in the related art.

[0008] Therefore, the purpose of this invention is to propose a surgical robot hardware system for lumbar laminectomy in selective posterior rhizotomy of spinal nerves in patients with cerebral palsy, which enables the robot to reach the area requiring grinding more flexibly.

[0009] To achieve the above objectives, a first aspect of the present invention provides a hardware system for a lumbar lamina resurfacing precision grinding surgical robot, comprising:

[0010] The system includes a six-DOF robotic arm, a bone drill tip, a six-dimensional force / torque sensor, a three-dimensional scanning camera for the grinding area, a main control system, and surgical area markers; among these components...

[0011] The three-dimensional scanning camera in the grinding area is used to acquire a three-dimensional model of the surgical area;

[0012] The six-dimensional force / torque sensor is used to acquire real-time six-dimensional force / torque data;

[0013] The main control system acquires the three-dimensional model of the treatment area and the real-time six-dimensional force / torque data through the data acquisition device, and locates the position to be ground by the marking points of the treatment area.

[0014] In addition, the lumbar laminectomy robot hardware system for selective posterior rhizotomy of cerebral palsy patients according to the above embodiments of the present invention may also have the following additional technical features:

[0015] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0016] A force analysis of the grinding process is performed, including grinding inwards with the bone drill perpendicular to the bone surface. The force is decomposed into three components or torques in the direction of the drill bit, namely the pressure F in the direction of the drill bit. z The component of force F perpendicular to the drill bit direction x The torque M generated along the drill bit direction due to the drill bit grinding the bone. z .

[0017] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0018] The grinding position is located by the marked points of the surgical area. The process includes using the joint angle as the output, displacement control as the inner loop and torque control system as the outer loop. First, the actual contact force at the end of the bone drill is obtained by using a six-dimensional force sensor at the end of the drill. The difference between the actual contact stress and the expected value is used to obtain the output force error. Then, the output force error is converted into the displacement error using a formula. The sum of the expected displacements is used as the entry point of the displacement inner loop for control, thereby realizing the control of the contact force.

[0019] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0020] To achieve control of the contact force, the impedance control model is reduced in dimensionality to obtain...

[0021]

[0022] m d For quality b d For the damping ratio k d The elastic coefficient f is F z Directional force deviation;

[0023] Adding the desired position and desired force to equation (1), we obtain

[0024]

[0025] x d For the desired position, f d Desired contact force;

[0026] Performing a Laplace transform on equation (2) yields...

[0027] m d s 2 X e (s)+b d sX e (s)+k d X e (s)=F e (s) (3)

[0028] The control function is obtained from equation (3).

[0029]

[0030] The input to the control function is the force deviation, and the output is the desired position offset.

[0031] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0032] Determining whether the bone drill has ground down to the inner cortical bone includes real-time monitoring of the axial torque. When the torque increases for the first time, it is confirmed that the drill bit has contacted the bone and started grinding. When the torque decreases, it is confirmed that the drill bit has drilled through the outer cortical bone and entered the cancellous bone.

[0033] When the second torque increases, it is confirmed that the drill bit has penetrated the cancellous bone and reached the inner cortical bone. At this point, the drill bit has reached the target depth, the robot stops grinding and returns along the original path to the initial position, completing the grinding work.

[0034] To achieve the above objectives, a second aspect of the present invention proposes a force-position hybrid control method for a lumbar lamina precision grinding robot, applied to a hardware system of a lumbar lamina precision grinding surgical robot, characterized in that:

[0035] Obtain a 3D model of the surgical area;

[0036] Obtain real-time six-dimensional force / torque data;

[0037] Based on the three-dimensional model of the surgical area and real-time six-dimensional force / torque data, the grinding position is located by using the surgical area marker points.

[0038] Furthermore, in one embodiment of the present invention, the step of locating the grinding position by means of the marking point of the grinding area further includes:

[0039] Determining whether the bone drill has ground down to the inner cortical bone includes real-time monitoring of the axial torque. When the torque increases for the first time, it is confirmed that the drill bit has contacted the bone and started grinding. When the torque decreases, it is confirmed that the drill bit has drilled through the outer cortical bone and entered the cancellous bone.

[0040] When the second torque increases, it is confirmed that the drill bit has penetrated the cancellous bone and reached the inner cortical bone. At this point, the drill bit has reached the target depth, the robot stops grinding and returns along the original path to the initial position, completing the grinding work.

[0041] To achieve the above objectives, a third aspect of the present invention provides a computer device, characterized in that it includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements a lumbar laminectomy robot hardware system for selective posterior rhizotomy of spinal nerves in patients with cerebral palsy, as described above.

[0042] To achieve the above objectives, a fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements a lumbar laminectomy robot hardware system for selective posterior rhizotomy of spinal nerves in patients with cerebral palsy as described above.

[0043] The lumbar laminectomy robot hardware system proposed in this invention for selective posterior rhizotomy of cerebral palsy patients integrates position-based impedance force control into the grinding control of the lumbar laminectomy robot. This ensures the stability of axial pressure during lumbar laminectomy, avoids the problem of unstable force control in manual grinding, and shortens the operation time. Furthermore, the control strategy of the lumbar laminectomy robot is analyzed, and a method is proposed to use axial torque monitoring to enable the robot to judge the grinding state and autonomously decide whether to reach the target grinding depth. This avoids the problem of accidentally drilling through the lumbar laminectomy in manual grinding and improves the safety of the operation. Attached Figure Description

[0044] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0045] Figure 1 This is a schematic diagram of the hardware system of a lumbar laminectomy robot for selective posterior spinal nerve rhizotomy in patients with cerebral palsy, provided in an embodiment of the present invention.

[0046] Figure 2 This is a control block diagram of a lumbar laminectomy robot hardware system for selective posterior spinal nerve rhizotomy in patients with cerebral palsy, provided in an embodiment of the present invention.

[0047] Figure 3 This is a flowchart illustrating a method for force-position hybrid control of a lumbar laminae precision grinding robot for selective posterior spinal nerve rhizotomy in patients with cerebral palsy, as provided in an embodiment of the present invention. Detailed Implementation

[0048] Embodiments of the present invention are described in detail below, examples of which are illustrated 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 the present invention, and should not be construed as limiting the present invention.

[0049] The hardware system of the lumbar lamina precision grinding surgical robot according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0050] Figure 1 This is a schematic diagram of a lumbar laminectomy robot hardware system for selective posterior spinal nerve rhizotomy in patients with cerebral palsy, provided in an embodiment of the present invention.

[0051] like Figure 1 As shown, the hardware system of this lumbar lamina resurfacing precision grinding surgical robot includes the following:

[0052] The system includes a six-DOF robotic arm, a bone drill tip, a six-dimensional force / torque sensor, a three-dimensional scanning camera for the grinding area, a main control system, and surgical area markers; among these components...

[0053] The three-dimensional scanning camera in the grinding area is used to acquire a three-dimensional model of the surgical area;

[0054] The six-dimensional force / torque sensor is used to acquire real-time six-dimensional force / torque data;

[0055] The main control system acquires the three-dimensional model of the treatment area and the real-time six-dimensional force / torque data through the data acquisition device, and locates the position to be ground by the marking points of the treatment area.

[0056] The precision grinding pre-treatment position control process includes: using a 3D camera and marker points to locate the grinding position in real time; accurately establishing the bone surface morphology of the grinding area using a 3D model; and then guiding the six-degree-of-freedom robotic arm through motion planning to move the bone drill end to the target grinding position. The main control system can acquire the 3D model of the surgical area and real-time six-dimensional force / torque data through a data acquisition device. The main control system can locate the grinding position using the surgical area marker points.

[0057] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0058] A force analysis of the grinding process is performed, including grinding inwards with the bone drill perpendicular to the bone surface. The force is decomposed into three components or torques in the direction of the drill bit, namely the pressure F in the direction of the drill bit. z The component of force F perpendicular to the drill bit direction x The torque M generated along the drill bit direction due to the drill bit grinding the bone. z .

[0059] Analysis shows that F z This is the primary force generated during grinding, and its magnitude will be much larger than the component forces. Torque M z Since the drilling speed remains constant, the change in its magnitude is only related to the pressure applied during grinding and the hardness of the lumbar lamina. From the above analysis, it can be seen that when a robot performs grinding, the main forces to consider are the pressure in the direction of the drill bit and the torque in the same direction, and the torque is also affected by the pressure factor.

[0060] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0061] The grinding position is located by the marked points of the surgical area. The process includes using the joint angle as the output, displacement control as the inner loop and torque control system as the outer loop. First, the actual contact force at the end of the bone drill is obtained by using a six-dimensional force sensor at the end of the drill. The difference between the actual contact stress and the expected value is used to obtain the output force error. Then, the output force error is converted into the displacement error using a formula. The sum of the expected displacements is used as the entry point of the displacement inner loop for control, thereby realizing the control of the contact force.

[0062] Control block diagram as follows Figure 2 As shown.

[0063] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0064] To achieve control of the contact force, the impedance control model is reduced in dimensionality to obtain...

[0065]

[0066] m d For quality b d For the damping ratio k d The elastic coefficient f is F z Directional force deviation;

[0067] Adding the desired position and desired force to equation (1), we obtain

[0068]

[0069] x d For the desired position, f d Desired contact force;

[0070] Performing a Laplace transform on equation (2) yields...

[0071] m d s 2 X e (s)+b d sX e (s)+k d X e (s)=F e (s) (3)

[0072] The control function is obtained from equation (3).

[0073]

[0074] The input to the control function is the force deviation, and the output is the desired position offset.

[0075] In addition to axial contact pressure, there is also an axial torque, which is only related to the axial contact pressure and the stiffness of the lumbar vertebrae. Since the axial contact pressure was stabilized in the previous section to prevent significant changes, the axial torque can now be considered to be solely related to the stiffness of the lumbar vertebrae. The lumbar lamina consists of three layers from the outside in: the outer cortical bone, the cancellous bone, and the inner cortical bone. The outer and inner cortical bone layers are both composed of dense bone structures, crucial for maintaining bone stiffness. The middle cancellous bone layer is composed of a loose and porous bone structure, its purpose being to reduce the mass of the lumbar vertebrae. Because the stiffness of the inner cortical bone is greater than that of the cancellous bone inside the lumbar vertebrae, it is inferred that the axial torque is greater when grinding the inner and outer cortical bone layers, and smaller when grinding the cancellous bone. Based on this inference, a decision is made regarding whether the robot's grinding depth reaches the target position during grinding. During grinding, the robot monitors and records the axial torque in real time. When the torque increases for the first time, it indicates that the drill bit has contacted the bone and begun grinding. Subsequent decreases in torque indicate that the drill bit has penetrated the outer cortical bone and entered the cancellous bone. When the torque increases for the second time, it indicates that the drill bit has penetrated the cancellous bone and reached the inner cortical bone. At this point, the target depth has been reached, and the robot stops grinding and returns along the original path to its initial position, completing the grinding operation.

[0076] Furthermore, in one embodiment of the present invention, the main control system is further configured to:

[0077] Determining whether the bone drill has ground down to the inner cortical bone includes real-time monitoring of the axial torque. When the torque increases for the first time, it is confirmed that the drill bit has contacted the bone and started grinding. When the torque decreases, it is confirmed that the drill bit has drilled through the outer cortical bone and entered the cancellous bone.

[0078] When the second torque increases, it is confirmed that the drill bit has penetrated the cancellous bone and reached the inner cortical bone. At this point, the drill bit has reached the target depth, the robot stops grinding and returns along the original path to the initial position, completing the grinding work.

[0079] The lumbar laminectomy robot hardware system proposed in this invention for selective posterior rhizotomy of cerebral palsy patients integrates position-based impedance force control into the grinding control of the lumbar laminectomy robot. This ensures the stability of axial pressure during lumbar laminectomy, avoids the problem of unstable force control in manual grinding, and shortens the operation time. Furthermore, the control strategy of the lumbar laminectomy robot is analyzed, and a method is proposed to use axial torque monitoring to enable the robot to judge the grinding state and autonomously decide whether to reach the target grinding depth. This avoids the problem of accidentally drilling through the lumbar laminectomy in manual grinding and improves the safety of the operation.

[0080] To achieve the above embodiments, the present invention also proposes a force-position hybrid control method for a lumbar laminar precision grinding robot for selective posterior rhizotomy of spinal nerves in patients with cerebral palsy.

[0081] Figure 3 This is a flowchart illustrating a method for force-position hybrid control of a lumbar laminae precision grinding robot for selective posterior spinal nerve rhizotomy in patients with cerebral palsy, as provided in an embodiment of the present invention.

[0082] like Figure 3 As shown, the force-position hybrid control method of the lumbar lamina precision grinding robot includes:

[0083] Obtain a 3D model of the surgical area;

[0084] Obtain real-time six-dimensional force / torque data;

[0085] Based on the three-dimensional model of the surgical area and real-time six-dimensional force / torque data, the grinding position is located by using the surgical area marker points.

[0086] Furthermore, in one embodiment of the present invention, the step of locating the grinding position by means of the marking point of the grinding area further includes:

[0087] Determining whether the bone drill has ground down to the inner cortical bone includes real-time monitoring of the axial torque. When the torque increases for the first time, it is confirmed that the drill bit has contacted the bone and started grinding. When the torque decreases, it is confirmed that the drill bit has drilled through the outer cortical bone and entered the cancellous bone.

[0088] When the second torque increases, it is confirmed that the drill bit has penetrated the cancellous bone and reached the inner cortical bone. At this point, the drill bit has reached the target depth, the robot stops grinding and returns along the original path to the initial position, completing the grinding work.

[0089] To achieve the above objectives, a third aspect of the present invention provides a computer device, characterized in that it includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the lumbar lamina precision grinding surgical robot hardware system as described above.

[0090] To achieve the above objectives, a fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the lumbar lamina precision grinding surgical robot hardware system as described above.

[0091] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A robotic hardware system for lumbar laminectomy for selective posterior rhizotomy of spinal nerves in patients with cerebral palsy, characterized in that, include: The system includes a six-DOF robotic arm, a bone drill tip, a six-dimensional force / torque sensor, a three-dimensional scanning camera for the grinding area, a main control system, and surgical area markers; among these components... The three-dimensional scanning camera in the grinding area is used to acquire a three-dimensional model of the surgical area; The six-dimensional force / torque sensor is used to acquire real-time six-dimensional force / torque data; The main control system acquires the three-dimensional model of the surgical area and real-time six-dimensional force / torque data in real time through the data acquisition device, and locates the grinding position through the surgical area marker points. The main control system is further used for: A force analysis of grinding is performed, including grinding inwards with the bone drill perpendicular to the bone surface. The force is decomposed into three components or torques in the direction of the drill bit, namely the pressure in the direction of the drill bit. Component of force perpendicular to the drill bit direction The torque along the drill bit direction generated by the drill bit grinding the bone. ; The main control system is also used for: The grinding position is located by the marked points of the surgical area. The method includes using the joint angle as the output, displacement control as the inner loop and torque control system as the outer loop. First, the actual contact force at the end of the bone drill is obtained by using a six-dimensional force sensor at the end of the drill. The difference between the actual contact force and the expected value is used to obtain the contact force error. Then, the contact force error is converted into the displacement error using a formula. The sum of the expected displacements is used as the entry point of the displacement inner loop for control, thereby realizing the control of the contact force. The main control system is also used for: To achieve control of the contact force, the impedance control model is reduced in dimensionality to obtain... （1） For quality Damping ratio elasticity coefficient for Directional force deviation; Adding the desired position and desired force to equation (1), we get （2） For the desired position, Desired contact force; Performing a Laplace transform on equation (2) yields... （3） The control function is obtained from equation (3). （4） The input to the control function is the force deviation, and the output is the desired position offset.

2. The system according to claim 1, characterized in that, The main control system is also used for: Determining whether the bone drill has ground down to the inner cortical bone includes real-time monitoring of the axial torque. When the torque increases for the first time, it is confirmed that the drill bit has contacted the bone and started grinding. When the torque decreases, it is confirmed that the drill bit has drilled through the outer cortical bone and entered the cancellous bone. When the second torque increases, it is confirmed that the drill bit has penetrated the cancellous bone and reached the inner cortical bone. At this point, the drill bit has reached the target depth, the robot stops grinding and returns along the original path to the initial position, completing the grinding work.

3. A computer device, characterized in that, The computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The computer device is used in the lumbar laminectomy robot hardware system for selective posterior rhizotomy of cerebral palsy patients as described in any one of claims 1-2.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer-readable storage medium is used in the lumbar laminectomy robot hardware system for selective posterior spinal nerve rhizotomy in patients with cerebral palsy as described in any one of claims 1-2.

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