A tooth implant robot drill needle adaptive adjustment method and system and a storage medium

Abstract

A dental implant robot drill needle adaptive adjustment method, system and storage medium, the method comprises: mapping the real-time position of the drill needle to the CT image based on the registration relationship, obtaining the CT value of the corresponding position of the drill needle tip; based on the preset force control model, the actual torque and actual axial force of the drill needle tip are calculated according to the data collected by the force sensor; obtain a preset database, the preset database includes the mapping relationship between CT value and drill needle parameter; according to the CT value of the current drill needle tip corresponding position, the actual torque and actual axial force, combined with the preset database, the target running speed, target rotating speed and target torque of the drill needle are calculated in real time. By mapping the real-time position of the drill needle to the preoperative CT image, the bone density characteristics of the position are predicted in advance, the initial drill needle parameters are matched and adapted combined with the preset database, and the actual torque and axial force of the drill needle tip are monitored in real time during the operation, the drilling parameters are dynamically corrected, which can effectively prevent surgical complications.

Description

Technical Field

[0001] This application relates to the field of artificial intelligence technology, and more specifically to a method, system and storage medium for adaptive adjustment of the drill bit of a dental implant robot. Background Technology

[0002] In traditional dental implant surgery, dentists rely primarily on their experience and feel to manually control the torque and speed of the implant drill. However, bone quality can vary significantly between different patients or even within the same patient at different locations in the mouth. Bone density can also differ due to factors such as age, gender, and individual physiological conditions. Improper drill torque and speed settings can lead to excessive load on the drill in areas of high bone density, increasing the risk of breakage and causing excessive damage to bone tissue. Conversely, in areas of low bone density, it may be impossible to effectively control the drill depth and direction, damaging adjacent structures and affecting implant preparation.

[0003] In recent years, the emergence of dental implant robots has greatly improved implant precision. However, the rotation speed and torque still need to be set manually and cannot be automatically adjusted according to bone conditions, making it difficult to meet the needs of complex clinical situations. Traditional implant robots rely on pre-set fixed drill parameters, but the bone density of different patients' jaws varies greatly, and there are also gradient changes in bone density at different depths in the same surgical area of ​​the same patient. Fixed parameters can lead to: overheating, drill wear, and even breakage when drilling in high-density bone; and drill slippage and insufficient implant socket precision when drilling in low-density bone, affecting the initial stability of the implant. Summary of the Invention

[0004] This application is made to address the aforementioned problems. According to one aspect of this application, a method for adaptive adjustment of the drill bit in a dental implant robot is provided, the method comprising: Based on the registration relationship, the real-time position of the drill bit is mapped onto the CT image to obtain the CT value at the corresponding position of the drill bit tip; Based on a preset force control model, the actual torque and actual axial force at the drill bit tip are calculated according to the data collected by the force sensor. Obtain a preset database, which includes the mapping relationship between CT values ​​and drill bit parameters; Based on the CT value, actual torque, and actual axial force at the current drill bit tip position, and combined with a preset database, the target travel speed, target rotation speed, and target torque of the drill bit are calculated in real time.

[0005] In one embodiment of this application, the drill bit parameters include expected travel speed, expected rotational speed, expected torque, and expected axial force: Based on the preset database, obtain the expected travel speed, expected rotation speed, expected torque, and expected axial force corresponding to the CT value at the current drill bit tip position.

[0006] In one embodiment of this application, the step of calculating the target travel speed, target rotational speed, and target torque of the drill bit in real time based on the CT value, actual torque, and actual axial force at the current drill bit tip position, combined with a preset database, includes: The CT value is used as a feedforward adjustment, and the expected travel speed is corrected in a closed loop according to the expected axial force and the actual axial force to generate the target travel speed. The CT value is used as a feedforward adjustment, and the expected speed is corrected in a closed loop according to the expected torque and the actual torque to generate the target speed. Using the CT value as feedforward adjustment, a target torque is generated based on the expected travel speed, target travel speed, expected rotational speed, and target rotational speed.

[0007] In one embodiment of this application, the data collected by the force sensor includes the force and torque on the drill bit. The step of calculating the actual torque and actual axial force at the drill bit tip based on the data collected by the force sensor, using a preset force control model, includes: The torque of the drill bit is transferred to the drill bit tip to obtain the drill bit tip torque, and the actual torque of the drill bit tip is calculated based on the drill bit tip torque. The actual axial force at the tip of the drill bit is calculated based on the force applied to the drill bit.

[0008] In one embodiment of this application, the position vector of the drill bit tip relative to the force sensor measurement point and the unit direction vector of the drill bit are determined; The torque of the drill bit is transferred to the drill tip through the position vector and the force, thus obtaining the drill tip torque; The actual torque of the drill bit is calculated by projecting the torque at the drill bit tip onto the axial direction of the drill bit through a unit direction vector. The actual axial force of the drill bit is calculated by projecting the force on the drill bit into the axial direction of the drill bit through a unit direction vector.

[0009] In one embodiment of this application, the data collected by the force sensor includes the force and torque on the drill bit: The force on the drill bit is a three-dimensional force vector, which includes the force component in the first direction, the force component in the second direction, and the force component in the third direction. The torque of the drill bit is a three-dimensional torque vector, which includes a torque component in the first direction, a torque component in the second direction, and a torque component in the third direction.

[0010] In one embodiment of this application, the preset database is pre-established through the following steps: Using the variable control method, only one parameter among the drill bit travel speed, rotation speed, and torque is adjusted each time, while the other parameters remain unchanged, and multiple sets of simulated drill bit preparation experiments are conducted. In each set of experiments, force and torque data of the force sensor, as well as CT values ​​at the corresponding locations, were collected. The torque and axial force at the drill bit tip are calculated based on the force control model in each group of experiments, and the optimal parameter combination of the drill bit under the corresponding CT value is screened and recorded. The average value of multiple sets of optimal parameters corresponding to the same CT value is taken; for CT values ​​without corresponding experimental data, the corresponding drill bit parameters are calculated by linear interpolation. Establish a database of mapping relationships between different normalized CT values ​​and optimal drill bit travel speed, rotational speed, torque, and axial force.

[0011] In one embodiment of this application, the step of mapping the real-time position of the drill bit onto the CT image based on the registration relationship to obtain the CT value at the position corresponding to the drill bit tip includes: The registration relationship between the coordinate systems of the tracker, the robotic arm, and the oral CT image is obtained. Through the registration relationship, the real-time position of the drill tip can be mapped onto the oral CT image. In CT images, each pixel corresponds to a fixed image CT value. The image CT value corresponding to the pixel at the drill tip is obtained, and the image CT value is normalized to obtain the CT value at the position corresponding to the drill tip.

[0012] According to another aspect of this application, a dental implant robot drill bit adaptive adjustment system is provided, including a registration module, a force control calculation module, a parameter calculation module, and a control module: The registration module is used to map the real-time position of the drill bit onto the CT image based on the registration relationship, and obtain the CT value of the corresponding position of the drill bit tip. The force control calculation module is used to calculate the actual torque and actual axial force at the drill bit tip based on the data collected by the force sensor and a preset force control model. The parameter calculation module is used to obtain a preset database, which includes the mapping relationship between CT values ​​and drill bit parameters; based on the CT value, actual torque and actual axial force at the current drill bit tip position, and in conjunction with the preset database, the target travel speed, target rotation speed and target torque of the drill bit are calculated in real time. The control module is used to control the dental implant robot to perform the socket preparation operation based on the calculated target travel speed, target rotation speed and target torque.

[0013] According to another aspect of this application, a storage medium is provided, on which a computer program is stored, which, when running, executes the above-described method for adaptive adjustment of the drill bit in a dental implant robot.

[0014] This application maps the real-time position of the drill bit onto preoperative CT images to accurately obtain the CT value of the current contact position of the drill bit tip, predicts the bone density characteristics at that position in advance, and combines the initial drill bit parameters matched with a preset database to avoid the risk of drilling overheating and drill bit overload under high-density bone from the source. At the same time, it monitors the actual torque and axial force of the drill bit tip in real time during the operation and dynamically corrects the drilling parameters, which can effectively prevent surgical complications caused by bone mutation, drill bit wear or accidental disturbance during the operation. Attached Figure Description

[0015] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0016] Figure 1 A schematic flowchart is shown for an adaptive adjustment method of the drill bit of a dental implant robot according to an embodiment of this application.

[0017] Figure 2 A schematic flowchart of a method for adaptive adjustment of a dental implant robot drill bit according to another embodiment of this application is shown.

[0018] Figure 3 This diagram illustrates a system block diagram of an adaptive adjustment system for a dental implant robot drill bit according to an embodiment of this application.

[0019] Figure 4 A schematic diagram of the end effector structure of a dental implant robot according to an embodiment of this application is shown.

[0020] Reference numerals: 1. End of robotic arm; 2. Force sensor; 3. Base tracer; 4. Optical marker; 5. Fixing knob; 6. Fixing link; 7. Planter handle; 8. Drill bit. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. Based on the embodiments of this application described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of this application.

[0022] First, refer to Figure 1This describes an adaptive adjustment method for the drill bit of a dental implant robot used to implement embodiments of the present invention.

[0023] In step S100, the real-time position of the drill bit is mapped onto the CT image based on the registration relationship, and the CT value of the corresponding position of the drill bit tip is obtained.

[0024] In step S200, based on the preset force control model, the actual torque and actual axial force at the drill bit tip are calculated according to the data collected by the force sensor.

[0025] In step S300, a preset database is obtained, which includes the mapping relationship between CT values ​​and drill bit parameters.

[0026] In step S400, based on the CT value, actual torque, and actual axial force at the current drill bit tip position, and combined with a preset database, the target travel speed, target rotation speed, and target torque of the drill bit are calculated in real time.

[0027] This application maps the real-time position of the drill bit 8 onto preoperative CT images to accurately obtain the CT value of the current contact position of the drill bit 8 tip, predicts the bone density characteristics at that position in advance, and combines the initial drill bit 8 parameters matched with a preset database to avoid the risk of drilling overheating and drill bit 8 overload under high-density bone from the source. At the same time, the actual torque and axial force of the drill bit 8 tip are monitored in real time during the operation, and the drilling parameters are dynamically corrected, which can effectively prevent surgical complications caused by bone mutation, drill bit 8 wear or accidental disturbance during the operation.

[0028] During implant cavity preparation, the dental implant robot adjusts the torque and rotation speed of the drill bit 8 in real time based on bone density. The key to adjusting the torque and rotation speed of the drill bit 8 is identifying the bone density at its location. This solution primarily employs a combination of image-based bone density analysis and a real-time six-dimensional force control system to achieve real-time and precise control of the drill bit 8's torque, rotation speed, and travel speed, thereby enabling a safe and efficient implant cavity preparation process. The essence of CT value-based bone density prediction lies in the high correlation between the physical mechanism of CT imaging and the material composition of bone density; a stable quantitative positive correlation exists between the two. Each pixel in a CT image corresponds to a tiny voxel (volume element) in the human body, and its CT value reflects the average density of the tissue within that voxel. Preoperative CT scans obtain precise CT values ​​for each location along the implant path. The optimal expected parameters (travel speed, rotation speed, torque, and axial force) corresponding to each CT value are retrieved from the database.

[0029] In one embodiment, in step S100, the real-time position of the drill bit 8 is mapped onto the CT image based on the registration relationship, and the CT value of the corresponding position of the drill bit 8 tip is obtained.

[0030] In one embodiment, the real-time position of the drill bit 8 is mapped onto the CT image based on the registration relationship to obtain the CT value of the corresponding position of the drill bit 8 tip. This includes: obtaining the registration relationship of the coordinate systems of the tracker, the robotic arm, and the oral CT image. The real-time position of the drill bit 8 tip can be mapped onto the oral CT image through the registration relationship. In the CT image, each pixel corresponds to a fixed image CT value. The image CT value corresponding to the pixel at the drill bit 8 tip is obtained, and the image CT value is normalized to obtain the CT value of the corresponding position of the drill bit 8 tip.

[0031] like Figure 2 As shown, the dental implant robot mainly consists of an optical positioning and tracking device, a robotic arm, and a main unit. Before surgery, CT images of the patient's oral cavity are acquired, and the position and angle of the implant are planned on these images. During surgery, a registration fixture is used to register the coordinate systems of the optical positioning and tracking device, the robotic arm, and the patient's oral CT images. This registration relationship allows the real-time position of the drill bit 8 to be mapped onto the oral CT image, and it also allows the planned implant position to be converted to the robotic arm coordinate system.

[0032] Through this registration relationship, the host controls the robotic arm to reach the pre-planned implant. At this time, the position of the drill bit 8 at the end of the robotic arm can also be mapped in real time onto the patient's oral CT image. This position is the starting position of the prepared implant.

[0033] During the preparation of the implant site, the drill bit 8 is controlled by the robotic arm to move from the starting position to the end (terminal position) of the planned implant. The entire stroke of the drill bit 8, from the initial position to the terminal position, is the process of controlling the torque, rotation speed and travel speed of the drill bit 8 during the preparation of the implant site.

[0034] The initial position is not the top of the planned implant. According to clinical needs, the top of the implant is usually located inside the alveolar bone. Therefore, during the socket preparation process, the initial position of drill bit 8 has not yet entered the alveolar bone, but is outside the alveolar bone, that is, above the top of the planned implant.

[0035] Through intraoperative registration, the real-time position of drill bit 8 is mapped onto the CT image of the patient's oral cavity. The tip of drill bit 8 corresponds to a pixel in the CT image. In the CT image, each pixel corresponds to a fixed CT value, which reflects the density at each location. For example, the outer layer of alveolar bone is mainly cortical bone, while the inner layer is cancellous bone. The density of cortical bone is greater than that of cancellous bone, and the corresponding CT value is also larger. Thus, the CT value of the tip of drill bit 8 in the CT image of the patient's oral cavity can be obtained in real time during the movement of drill bit 8. For example, the CT value range of the CT image is -1024 to 65535. The CT value of each position of drill bit 8 during the entire preparation process is normalized to 0-1. The normalization algorithm adopts linear normalization, such as (X=(CT-CTmin) / (CTmax-CTmin)). Assuming the result is X1, X2, X3, X4, ..., X... n .

[0036] In one embodiment, in step S200, the actual torque and actual axial force at the tip of the drill bit 8 are calculated based on the data collected by the force sensor 2 according to a preset force control model.

[0037] In one embodiment, the data collected by the force sensor 2 includes the force and torque on the drill bit 8. Based on a preset force control model, the actual torque and actual axial force at the tip of the drill bit 8 are calculated according to the data collected by the force sensor 2, including: transferring the torque of the drill bit 8 to the tip of the drill bit 8 to obtain the torque at the tip of the drill bit 8; calculating the actual torque at the tip of the drill bit 8 based on the torque at the tip of the drill bit 8; and calculating the actual axial force at the tip of the drill bit 8 based on the force on the drill bit 8.

[0038] The actual torque and actual axial force are real physical quantities obtained by sensor acquisition and force control model calculation.

[0039] In one embodiment, the data collected by the force sensor 2 includes the force and torque on the drill bit 8, including: the force on the drill bit 8 is a three-dimensional force vector, which includes a force component in a first direction, a force component in a second direction, and a force component in a third direction; the torque on the drill bit 8 is a three-dimensional torque vector, which includes a torque component in a first direction, a torque component in a second direction, and a torque component in a third direction.

[0040] A six-dimensional force sensor 2 is installed at the end of the robotic arm 1 of the dental implant robot. The other end of the six-dimensional force sensor 2 is fitted with a fixed implant machine handle 7 and drill bit 8. Figure 4 As shown. The six-dimensional force sensor 2 is installed between the end effector 1 of the robotic arm and the planting machine. It can simultaneously measure the translational force and the rotational torque in three orthogonal directions in three-dimensional space, hence the name "six-dimensional" sensor.

[0041] The six-dimensional force sensor 2 (resolution: 0.1N, sampling frequency: 1000Hz) is mainly used to collect axial force data in real time. By establishing a force control model, it can analyze the force situation in various directions of the grinding drill. The force control model is shown below: A world coordinate system is established, with the coordinate system of the six-dimensional force sensor 2 itself serving as the world coordinate system. Specifically, the origin of the world coordinate system is the measurement point of the six-dimensional force sensor 2, and the x, y, and z directions correspond to the three force directions measured by the six-dimensional force sensor 2. The x direction is the first direction, the y direction is the second direction, and the z direction is the third direction.

[0042] In one embodiment, the position vector of the drill bit 8 tip relative to the measurement point of the force sensor 2 and the unit direction vector of the drill bit 8 are determined; the torque of the drill bit 8 is transferred to the tip of the drill bit 8 through the position vector and the force, and the tip torque of the drill bit 8 is obtained; the tip torque of the drill bit 8 is projected onto the axial direction of the drill bit 8 through the unit direction vector, and the actual torque of the drill bit 8 is calculated; the force on the drill bit 8 is projected onto the axial direction of the drill bit 8 through the unit direction vector, and the actual axial force of the drill bit 8 is calculated.

[0043] Assume the position of force sensor 2 in the world coordinate system is The tip of drill bit 8 is located at The coordinates of the end position of drill bit 8 are .

[0044] The vector from the origin to the tip of drill bit 8, that is, the position vector of the tip of drill bit 8 relative to the measuring point of force sensor 2, is: .

[0045] The unit direction vector of drill bit 8 is .

[0046] Output of the six-dimensional sensor: force torque .

[0047] Where F x F y F z M represents the force exerted on the six-dimensional force sensor 2 in the x, y, and z directions. x M y M z This represents the torque of the six-dimensional force sensor 2 in the x, y, and z directions.

[0048] The six-dimensional sensor outputs raw data from the sensor's measurement points, but what is truly needed is the force and torque at the tip of drill bit 8, since cutting occurs at the tip of drill bit 8. Geometric transformation is used to convert the torque at the sensor's measurement points into torque at the tip of drill bit 8, and then transfer this torque to the tip of drill bit 8. M tip This indicates the torque at the tip of drill bit 8.

[0049] Calculate the torque of drill bit 8 , .

[0050] Calculate the axial force of drill bit 8 , .

[0051] During the surgery, the CT value of the drill bit 8 mapped to the patient's oral CT image and the force feedback information when the drill bit 8 contacts the bone tissue are monitored in real time. This is achieved by analyzing the CT value X (X1, X2, X3, X4, ..., X...) corresponding to the drill bit 8 at each moment. n The axial forces F (F1, F2, F3, F4, ..., F) calculated by the force control model n ) and torque M (M1, M2, M3, M4, ..., M n ).

[0052] In one embodiment, a preset database is obtained in step S300. The preset database includes the mapping relationship between CT values ​​and drill bit parameters.

[0053] In one embodiment, the drill bit 8 parameters include expected travel speed, expected rotational speed, expected torque, and expected axial force: the expected travel speed, expected rotational speed, expected torque, and expected axial force corresponding to the CT value at the current position of the drill bit 8 tip are obtained from a preset database.

[0054] The expected travel speed, expected rotation speed, expected torque, and expected axial force are baseline reference values ​​generated preoperatively from CT values ​​and a database. During surgery, higher bone density (e.g., hard cortical bone) requires greater torque, lower rotation speed, and slower travel speed from drill bit 8; conversely, lower bone density (e.g., porous cancellous bone) results in the opposite parameters. Before surgery, the robot scans the patient's CT scan and calculates the CT value at each point along the entire drilling path. This allows the robot to retrieve the expected parameters for each point from the database beforehand, serving as a baseline for intraoperative adjustments.

[0055] In one embodiment, the preset database is established in advance through the following steps: using a variable control method, only one parameter of the drill bit 8's travel speed, rotation speed, and torque is adjusted each time, while the other parameters remain unchanged, and multiple sets of simulated test runs are conducted; in each set of tests, the force and torque data of the force sensor 2, as well as the CT value at the corresponding position, are collected; based on the force control model, the torque and axial force at the tip of the drill bit 8 in each set of tests are calculated, and the optimal parameter combination of the drill bit 8 under the corresponding CT value is selected and recorded; the average value of multiple sets of optimal parameters corresponding to the same CT value is taken; for CT values ​​without corresponding experimental data, the corresponding drill bit 8 parameters are calculated by linear interpolation; and a database of mapping relationships between different normalized CT values ​​and the optimal drill bit 8's travel speed, rotation speed, torque, and axial force is established.

[0056] A database was established to obtain the expected drill bit travel speed, drilling speed, and torque under different bone density conditions. Based on the preoperatively planned implant location, the expected values ​​of drill bit travel speed, rotation speed, and torque at each position along the entire drilling path can be obtained before implant preparation. The database establishment method is as follows: 1) Simulated planting experiment Equipment: Oral surgery navigation and positioning equipment. Test material: Model bone. CT images are taken using the model bone, then implant planning and navigation registration are completed. The implant preparation process is simulated by manually controlling the travel speed, rotation speed, and torque of drill bit 8. Using model bone with a hardness similar to human bone (replacing a living person), CT scans are taken first, then navigation registration is completed according to the actual surgical procedure, and finally, an experienced surgeon manually controls the parameters of drill bit 8 to complete the simulated implant preparation.

[0057] 2) Experimental Design Adjustable parameters: drill bit travel speed, rotation speed, and torque. Measured parameters: axial force and torque obtained from six-dimensional force acquisition. Adjustment method: variable control method (adjusting only one parameter at a time while keeping other parameters constant).

[0058] 3) Data Collection Acquire F of six-dimensional force sensor 2 x F y F z M x M y M z .

[0059] 4) Data processing Based on the force control model and the data from the six-dimensional force sensor 2, the axial force and torque of the drill bit 8 are calculated, and the parameters of the drill bit 8 with low force, stable torque and fast travel speed under the corresponding CT value are recorded.

[0060] 5) Data Analysis For experimental data with the same CT value, the speed, rotational speed, and torque of drill bit 8 were averaged. For drill bit 8 without a corresponding CT value, the speed, rotational speed, and torque were calculated using linear interpolation.

[0061] 6) Establish a database Using the methods described above, a database can be established to obtain the expected drill bit travel speed, rotation speed, torque, and axial force under different CT values. Before surgery, the robot only needs to input the patient's CT images and the pre-planned drilling path to calculate the CT value of each point on the path in advance. Then, it can retrieve the "expected parameters" for each point from the database with a single click, serving as the benchmark for real-time adjustments during the operation. This database forms the basis for the feedforward adjustment of the entire adaptive system.

[0062] In one embodiment, in step S400, the target travel speed, target rotation speed, and target torque of the drill bit 8 are calculated in real time based on the CT value, actual torque, and actual axial force at the current position corresponding to the tip of the drill bit 8, combined with a preset database.

[0063] The target travel speed, target rotational speed, and target torque are the final command values ​​output to the actuator after closed-loop correction. All target values ​​are based on expected values, and the actual values ​​are generated based on the corrections.

[0064] In one embodiment, based on the CT value, actual torque, and actual axial force at the current position corresponding to the tip of the drill bit 8, and in conjunction with a preset database, the target travel speed, target rotational speed, and target torque of the drill bit 8 are calculated in real time. This includes: using the CT value as feedforward adjustment to perform closed-loop correction on the expected travel speed based on the expected axial force and actual axial force to generate the target travel speed; using the CT value as feedforward adjustment to perform closed-loop correction on the expected rotational speed based on the expected torque and actual torque to generate the target rotational speed; and using the CT value as feedforward adjustment to generate the target torque based on the expected travel speed, target travel speed, expected rotational speed, and target rotational speed.

[0065] Based on the above information, the travel speed, rotational speed, and torque of the drill bit 8 are dynamically adjusted as follows: 1) Adjustment of travel speed V Using the CT value at the current drill bit 8 position as feedforward adjustment and the axial force F as closed-loop adjustment, the drill bit automatically decelerates when drilling resistance is high to prevent jamming. The travel speed of drill bit 8 can be pre-adjusted based on bone density while ensuring automatic adaptation to axial force, thus improving safety and efficiency. ; ; in Indicates the expected axial force. Indicates the current axial force. This represents the feedforward weights for CT (reference range 0.5~1.0). Indicates the minimum speed of travel. Indicates the maximum speed of travel. This indicates the calculation of travel speed. This indicates the CT value of the image corresponding to the current position of the drill bit tip 8.

[0066] Feedforward adjustment: CT values ​​are used to predict the bone hardness ahead. Before drill bit 8 touches the bone at that location, the velocity baseline is pre-adjusted based on bone density. Higher CT values ​​(harder bone): the feedforward mechanism directly lowers the velocity baseline; lower CT values ​​(looser bone): the feedforward mechanism directly raises the velocity baseline. Key parameter: CT feedforward weight (0.5~1.0). When weight = 1.0: the preoperative CT prediction is completely trusted, and the velocity baseline is 100% determined by the CT value. When weight = 0.5: CT prediction accounts for only 50%, and the remaining 50% is determined by real-time force feedback. Clinically, a value of 0.7~0.8 is generally used to balance predictability and flexibility.

[0067] Closed-loop adjustment: The actual drilling resistance is corrected using real-time axial force. The expected axial force corresponding to the CT value in the database is used as a comparison benchmark. When the current axial force is greater than the expected axial force: it indicates that the actual resistance is greater than predicted, and the speed is automatically reduced to prevent drill bit jamming and bone overheating damage. When the current axial force is less than the expected axial force: it indicates that the actual resistance is less than predicted, and the speed is automatically increased to improve surgical efficiency. When the current axial force equals the expected axial force: the current speed is maintained. Regardless of how the feedforward and closed-loop are adjusted, the final calculated speed will be limited between the minimum and maximum speeds.

[0068] 2) Rotational speed Regulation PI closed-loop control ensures that the torque of drill bit 8 remains within the current range under different resistances, achieving safe cutting. Combined with feedforward predictive adjustment based on bone density, when the torque is low, the rotational speed is increased to improve cutting efficiency; when the torque is high, the rotational speed is reduced to prevent drill bit wear. Additionally, based on the CT value at the drill bit tip, if the CT value is high, the rotational speed is further reduced. This combination is both safe and efficient. ; in This represents the calculated drilling rig rotation speed. Indicates torque weight (reference range 5~10 rpm / (N·M)), Indicates the expected torque. Indicates the current torque. The weighting of the torque integral (reference range 0.1~0.5 rpm / (N·M·s)) This indicates the weight of the CT value (reference range 0.5~1.0). This indicates the CT value of the image corresponding to the current position of the drill bit tip 8. This represents the actual rotational speed of drill bit 8 at present.

[0069] The PI controller, the most commonly used proportional-integral controller in industrial control, is crucial for ensuring torque stability. By changing the rotational speed, the actual torque of drill bit 8 is always kept equal to the expected torque. The numerator is a standard incremental PI controller, ensuring that the actual torque of drill bit 8 approaches the expected torque as closely as possible. When the actual torque is less than the expected torque, the current torque is insufficient, resulting in insufficient cutting force and an increase in rotational speed. When the actual torque is greater than the expected torque, the current torque exceeds the limit, posing a risk of drill breakage, and the rotational speed decreases. When the actual torque equals the expected torque, the rotational speed remains constant. The denominator is a CT bone density feedforward hard constraint. The PI controller is responsible for real-time correction of torque deviations, while the CT feedforward is responsible for setting the upper limit of rotational speed based on bone density. The two do not interfere with each other, resulting in more stable control.

[0070] 3) Torque control The speed, rotation speed, and bone density of the drill bit 8 are coupled to achieve multi-dimensional protection. When the travel speed is too high, the resistance to drilling by the drill bit 8 increases, resulting in an increase in the torque on the drill bit 8. This adjustment method is used to regulate the torque of the drill bit 8 in the implanter. Similarly, when the rotation speed is too high, the increased friction also leads to an increase in the torque on the drill bit 8. This adjustment method is used to regulate the torque of the drill bit 8 in the implanter. ; in This represents the calculated torque. Indicates the expected torque. This indicates the weight of the drill bit 8 travel speed (reference range 0.5~1.0 N·m / (mm / s)). This indicates the expected travel speed of drill bit 8. Indicates the speed weight (reference range 0.05~0.1 N·m / rpm). Indicates the expected rotational speed. This indicates the weight of bone mineral density (reference range 0.5~1.0).

[0071] The previous speed and RPM adjustments were both "indirect torque control," but they had a flaw: if both speed and RPM deviated from the expected values ​​simultaneously, a single adjustment might not be able to suppress the torque spike in time. This torque control formula, however, directly constrains the torque itself in multiple dimensions, ensuring that the final torque will not exceed the safe threshold regardless of changes in speed and RPM. By fully coupling the three variables of travel speed, RPM, and bone density, multi-dimensional torque protection is achieved.

[0072] This application innovatively combines theoretical data analysis with actual stress conditions, using image bone density analysis, force control model, and weight calculation model to calculate the weight corresponding to each position of the drill bit 8. Based on the calculation results and a pre-set database, the corresponding parameters such as travel speed, rotation speed, and torque are obtained, making the data results safer, more accurate, and more reliable.

[0073] Improve surgical safety: By monitoring bone density in real time and automatically adjusting the travel speed, torque and rotation speed of the drill bit 8, the risks of drill bit 8 breakage and excessive bone tissue damage caused by improper parameter settings can be effectively avoided, reducing the probability of surgical complications and ensuring the safety of patients during surgery.

[0074] Improving surgical precision: Precisely matching the working parameters of the drill bit 8 under different bone densities makes the preparation of the implantation site more in line with the requirements of implant placement, improves the initial stability of the implant, and lays the foundation for the success of the implantation surgery.

[0075] Enhanced surgical adaptability: Applicable to complex bone density conditions in different patients and implantation areas, reducing doctors' reliance on surgical experience and improving surgical consistency and repeatability.

[0076] Optimize surgical efficiency: Automatically adjusts 8 parameters of the drill bit, avoiding the time spent by doctors manually adjusting them during the operation, making the surgical process smoother, improving surgical efficiency, and shortening the operation time.

[0077] This application maps the real-time position of the drill bit 8 onto preoperative CT images to accurately obtain the CT value of the current contact position of the drill bit 8 tip, predicts the bone density characteristics at that position in advance, and combines the initial drill bit 8 parameters matched with a preset database to avoid the risk of drilling overheating and drill bit 8 overload under high-density bone from the source. At the same time, the actual torque and axial force of the drill bit 8 tip are monitored in real time during the operation, and the drilling parameters are dynamically corrected, which can effectively prevent surgical complications caused by bone mutation, drill bit 8 wear or accidental disturbance during the operation.

[0078] This application also provides an adaptive adjustment system 30 for the drill bit 8 of a dental implant robot, such as... Figure 3 As shown, the system includes a registration module 31, a force control calculation module 32, a parameter calculation module 33, and a control module 34. The registration module 31 is used to map the real-time position of the drill bit 8 onto the CT image based on the registration relationship, and obtain the CT value of the corresponding position of the drill bit 8 tip. The force control calculation module 32 is used to calculate the actual torque and actual axial force of the drill bit 8 tip based on the data collected by the force sensor 2 according to the preset force control model. The parameter calculation module 33 is used to obtain a preset database, which includes the mapping relationship between CT values ​​and drill bit 8 parameters. Based on the CT value, actual torque, and actual axial force of the current position of the drill bit 8 tip, and combined with the preset database, the target travel speed, target rotation speed, and target torque of the drill bit 8 are calculated in real time. The control module 34 is used to control the dental implant robot to perform the socket preparation operation according to the calculated target travel speed, target rotation speed, and target torque.

[0079] like Figure 4As shown, the dental implant robot's end effector includes: a robotic arm end effector 1, connected to the sixth joint of a six-axis robotic arm, providing power and position control; a force sensor 2, which acquires three-dimensional force and torque in real time; a base tracer 3, a target for the optical positioning tracker, used to track the spatial position of the end effector in real time; optical markers 4, four highly reflective small balls, captured by the optical positioning tracker to calculate precise coordinates; a fixing knob 5, enabling a detachable connection between the fixing link 6 and the base tracer 3, facilitating sterilization and tool replacement; the fixing link 6, connecting the base tracer 3 and the implant machine handle 7, ensuring their relative positions are fixed; the implant machine handle 7, with a built-in high-speed motor, drives the drill bit 8 to rotate for cutting; and the drill bit 8, a surgical tool that directly contacts bone tissue for implant site preparation.

[0080] A six-dimensional force sensor 2 is fixedly installed at the end of the robotic arm 1. A base tracer 3 is fixedly installed on the six-dimensional force sensor 2. Four optical markers 4 are fixed on the base tracer 3. The planting machine and the base tracer 3 are connected and fixed by a fixing rod 6. For easy disassembly, the fixing rod 6 and the base tracer 3 are installed and fixed by a knob mechanism.

[0081] After the robotic arm controls the drill bit 8 to reach the actual position of the implantation site, the drill bit 8 is controlled by a foot pedal to begin implantation. During the implantation process, as the drill bit 8 enters the bone tissue, the CT image values ​​corresponding to the position of the drill bit 8 and the force data from the six-dimensional force sensor 2 are acquired in real time. This real-time data is transmitted to the parameter calculation module 33. The module quickly processes the data according to a preset force control model, a weight calculation model, and a corresponding database to determine the current bone density. If a change in bone density is detected, the parameter calculation module 33 quickly calculates the drill bit 8's travel speed, torque, and rotation speed parameters that match the new bone density and sends an adjustment command to the host computer. Upon receiving the command, the host computer immediately adjusts the travel speed, torque, and rotation speed of the implantation drill bit 8 to ensure that the drill bit 8 continues the implantation site preparation operation with appropriate working parameters. Throughout the entire surgical procedure, the parameter calculation module 33 continuously monitors and adjusts the parameters of the drill bit 8 to ensure that the drill bit 8 is always in optimal working condition.

[0082] The hardware components of the dental implant robot drill bit 8 adaptive adjustment system 30 are as follows: CPU: Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz 8 cores; Memory: 16.0 GB; Hard drive: SATA CVB-CD1024 1TB HDD; Graphics card: NVIDIA GeForce GTX 1050 Ti 4.0GB; Monitor resolution: 1920*1080; Operating system: Windows 10; Programming language: C++.

[0083] Furthermore, this application also provides a storage medium storing a computer program thereon, which, when executed by a processor, causes the processor to perform the adaptive adjustment method for a dental implant robot drill bit according to the embodiments of this application described above. The storage medium may, for example, include a memory card of a smartphone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0084] The various component embodiments of this application can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some modules according to the embodiments of this application. This application can also be implemented as a program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such a program implementing this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0085] It should be noted that the above embodiments are illustrative of this application and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0086] The above description is merely a specific embodiment or illustration of the embodiments of this application. The scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A method for adaptive adjustment of the drill bit in a dental implant robot, characterized in that, The method includes: Based on the registration relationship, the real-time position of the drill bit is mapped onto the CT image to obtain the CT value at the corresponding position of the drill bit tip; Based on a preset force control model, the actual torque and actual axial force at the drill bit tip are calculated according to the data collected by the force sensor. Obtain a preset database, which includes the mapping relationship between CT values ​​and drill bit parameters; Based on the CT value, actual torque, and actual axial force at the current drill bit tip position, and combined with a preset database, the target travel speed, target rotation speed, and target torque of the drill bit are calculated in real time.

2. The adaptive adjustment method for the drill bit of a dental implant robot as described in claim 1, characterized in that, The drill bit parameters include expected travel speed, expected rotational speed, expected torque, and expected axial force: Based on the preset database, obtain the expected travel speed, expected rotation speed, expected torque, and expected axial force corresponding to the CT value at the current drill bit tip position.

3. The adaptive adjustment method for the drill bit of a dental implant robot as described in claim 2, characterized in that, The process of calculating the target travel speed, target rotational speed, and target torque of the drill bit in real time based on the CT value, actual torque, and actual axial force at the current drill bit tip position, combined with a preset database, includes: The CT value is used as a feedforward adjustment, and the expected travel speed is corrected in a closed loop according to the expected axial force and the actual axial force to generate the target travel speed. The CT value is used as a feedforward adjustment, and the expected speed is corrected in a closed loop according to the expected torque and the actual torque to generate the target speed. Using the CT value as feedforward adjustment, a target torque is generated based on the expected travel speed, target travel speed, expected rotational speed, and target rotational speed.

4. The adaptive adjustment method for the drill bit of a dental implant robot as described in claim 1, characterized in that, The data collected by the force sensor includes the force and torque on the drill bit. The calculation of the actual torque and actual axial force at the drill bit tip based on the data collected by the force sensor, according to the preset force control model, includes: The torque of the drill bit is transferred to the drill bit tip to obtain the drill bit tip torque, and the actual torque of the drill bit tip is calculated based on the drill bit tip torque. The actual axial force at the tip of the drill bit is calculated based on the force applied to the drill bit.

5. The adaptive adjustment method for the drill bit of a dental implant robot as described in claim 4, characterized in that, Determine the position vector of the drill bit tip relative to the force sensor measurement point, and the unit direction vector of the drill bit; The torque of the drill bit is transferred to the drill tip through the position vector and the force, thus obtaining the drill tip torque; The actual torque of the drill bit is calculated by projecting the torque at the drill bit tip onto the axial direction of the drill bit through a unit direction vector. The actual axial force of the drill bit is calculated by projecting the force on the drill bit into the axial direction of the drill bit through a unit direction vector.

6. The adaptive adjustment method for the drill bit of a dental implant robot as described in claim 4, characterized in that, The force sensor collects data including the force and torque on the drill bit: The force on the drill bit is a three-dimensional force vector, which includes the force component in the first direction, the force component in the second direction, and the force component in the third direction. The torque of the drill bit is a three-dimensional torque vector, which includes a torque component in the first direction, a torque component in the second direction, and a torque component in the third direction.

7. The adaptive adjustment method for the drill bit of a dental implant robot as described in claim 1, characterized in that, The preset database is established in advance through the following steps: Using the variable control method, only one parameter among the drill bit travel speed, rotation speed, and torque is adjusted each time, while the other parameters remain unchanged, and multiple sets of simulated drill bit preparation experiments are conducted. In each set of experiments, force and torque data of the force sensor, as well as CT values ​​at the corresponding locations, were collected. The torque and axial force at the drill bit tip are calculated based on the force control model in each group of experiments, and the optimal parameter combination of the drill bit under the corresponding CT value is screened and recorded. The average value of multiple sets of optimal parameters corresponding to the same CT value is taken; for CT values ​​without corresponding experimental data, the corresponding drill bit parameters are calculated by linear interpolation. Establish a database of mapping relationships between different normalized CT values ​​and optimal drill bit travel speed, rotational speed, torque, and axial force.

8. The adaptive adjustment method for the drill bit of a dental implant robot as described in claim 1, characterized in that, The process of mapping the real-time position of the drill bit onto CT images based on the registration relationship, and obtaining the CT value at the corresponding position of the drill bit tip, includes: The registration relationship between the coordinate systems of the tracker, the robotic arm, and the oral CT image is obtained. Through the registration relationship, the real-time position of the drill tip can be mapped onto the oral CT image. In CT images, each pixel corresponds to a fixed image CT value. The image CT value corresponding to the pixel at the drill tip is obtained, and the image CT value is normalized to obtain the CT value at the position corresponding to the drill tip.

9. A dental implant robot drill bit adaptive adjustment system, characterized in that... It includes a registration module, a force control calculation module, a parameter calculation module, and a control module: The registration module is used to map the real-time position of the drill bit onto the CT image based on the registration relationship, and obtain the CT value of the corresponding position of the drill bit tip. The force control calculation module is used to calculate the actual torque and actual axial force at the drill bit tip based on the data collected by the force sensor and a preset force control model. The parameter calculation module is used to obtain a preset database, which includes the mapping relationship between CT values ​​and drill bit parameters; Based on the CT value, actual torque, and actual axial force at the current drill bit tip position, and combined with a preset database, the target travel speed, target rotation speed, and target torque of the drill bit are calculated in real time. The control module is used to control the dental implant robot to perform the socket preparation operation based on the calculated target travel speed, target rotation speed and target torque.

10. A storage medium, characterized in that, The storage medium stores a computer program, which, when running, executes a method for adaptive adjustment of the drill bit of a dental implant robot as described in any one of claims 1-8.

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