Safe grinding method and system based on real-time thickness monitoring

Abstract

The invention discloses a safe grinding method and system based on real-time thickness monitoring, and the method comprises the step of measuring the residual thickness of a bone tissue in real time by adopting an ultrasonic sensing technology and utilizing the principle that ultrasonic waves are transmitted and reflected in the bone tissue. The residual thickness of the bone tissue is measured in real time through the ultrasonic sensing technology and compared with the preset safety threshold value, and grinding is stopped immediately when the threshold value is reached, so that the situation that due to excessive grinding, the bone tissue is penetrated, surrounding important nerves, blood vessels and other key structures are damaged can be effectively prevented, the surgical risk is reduced, and serious complications are reduced; such as paralysis caused by spinal cord injury, massive hemorrhage caused by great vessel rupture and the like; the remaining thickness data of the bone tissue is measured in real time, so that a doctor can clearly know the grinding progress condition and accurately master the grinding depth and the remaining workload of each stage, the grinding process is more accurately controlled, it is ensured that the expected operation effect is achieved, and the requirements of the doctor are met.

Description

Technical Field

[0001] This invention relates to the field of orthopedics, specifically to a safe grinding method and system based on real-time thickness monitoring. Background Technology

[0002] In orthopedic surgery, particularly spinal surgery, burrs are a commonly used surgical tool for grinding down bone tissue such as the vertebral laminae and vertebral bodies to achieve decompression or other surgical goals. However, existing burrs have a significant safety hazard: they lack the function to automatically identify bone thickness and stop when approaching critical structures. During surgery, surgeons must rely on experience and touch to judge whether the vertebral laminae are about to be ground through, which not only increases the difficulty of the surgery but also raises the risk of dura mater or nerve damage.

[0003] In spinal surgery, the lamina typically needs to be thinned to 1-2 mm to achieve adequate decompression. However, excessive grinding can lead to dural tears or spinal cord injury. Studies have shown that up to 29% of drilling operations using traditional burr tools result in penetrating injuries, and surgeons often struggle to accurately assess the remaining bone thickness by touch, making it difficult to meet their needs. Summary of the Invention

[0004] To address the aforementioned technical problems, this technical solution provides a safe grinding method and system based on real-time thickness monitoring, resolving the issues raised in the background section.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect of the invention, a safe grinding method based on real-time thickness monitoring is provided, comprising: Using ultrasonic sensing technology, the remaining thickness of bone tissue is measured in real time by utilizing the principle of ultrasonic wave propagation and reflection in bone tissue, and the measured remaining thickness data is transmitted to the data processing unit. Vibration / torque sensing technology is used to monitor the mechanical characteristics of the grinding tool in real time, such as vibration frequency, vibration amplitude, and torque magnitude, by setting vibration sensors and torque sensors on the grinding tool. These mechanical characteristic parameter data are then synchronously transmitted to the data processing unit. The data processing unit uses a preset intelligent algorithm to dynamically analyze the remaining thickness data of bone tissue, and calculates the actual effective thickness of the current bone tissue by combining mechanical property parameter data. At the same time, it comprehensively judges the grinding state, which includes grinding progress, grinding uniformity, and whether it is close to the key structure of bone tissue. The calculated remaining bone tissue thickness is compared with a preset safety threshold in real time. When the remaining bone tissue thickness reaches the preset safety threshold, the data processing unit sends a stop command to the control execution unit of the grinding equipment. Upon receiving a stop command, the control execution unit immediately and automatically stops the grinding operation of the grinding equipment to ensure the safety of the bone tissue grinding process and avoid damage to the bone tissue due to excessive grinding.

[0006] Preferably, the use of ultrasonic sensing technology, utilizing the principle of ultrasonic wave propagation and reflection in bone tissue, to measure the remaining thickness of bone tissue in real time, specifically includes: Use a high-frequency ultrasound probe with a frequency of 15-20MHz for ultrasound monitoring. For thicker bone tissue, appropriately reduce the frequency to 10-15MHz to improve penetration. The probe adopts a side-mounted design, embedded in the side of the drill bit, 1-2mm away from the end face of the drill bit, and the probe is tilted at 15°-20° to embed in the side of the drill bit to ensure that the ultrasound beam is perpendicularly incident on the surface of the vertebral lamina. High sampling rate ADC is used to acquire ultrasonic signals, and the signals are preprocessed by pre-processing hardware filtering and post-processing software filtering; Adaptive gain control is used to dynamically adjust the ultrasound transmission power and receiving gain according to the thickness of the lamina. A dual-interface peak recognition algorithm is used to identify the interface between the lamina surface and the cortical bone and the cancellous bone and dura mater. The time difference between the two interface echoes was calculated, and the thickness of the lamina was calculated by combining the propagation speed of ultrasound in bone tissue. A temperature compensation algorithm was then used to correct the ultrasound velocity.

[0007] Preferably, the ultrasonic monitoring process also includes anti-interference processing, specifically including: The signal line of the high-frequency ultrasonic probe adopts a double-layer shielding structure. The inner layer is a tin-plated copper mesh to shield differential mode interference, and the outer layer is an aluminum foil to shield common mode interference. Both ends of the cable are grounded to reduce the impact of external electromagnetic interference on ultrasonic signal transmission. A multi-stage filtering algorithm combined with adaptive noise cancellation technology is used to suppress bone grinding vibration noise and high-frequency noise from the electrosurgical unit. The rotation phase of the grinding drill is collected and recorded, and the preset algorithm automatically removes the collected data at the "vibration peak moment". The preset algorithm is as follows: The formula for calculating the rotation phase of the drill is: ; in, R represents the rotation phase of the grinding drill, R represents the number of pulses per revolution of the grinding drill, and N(t) represents the number of pulses collected at time t. N(t) is collected by a speed sensor installed on the spindle that drives the grinding drill to rotate. The calculated drill rotation phase at each moment is compared with the preset vibration peak threshold range; If the rotation phase of the drill falls within the vibration peak threshold range, the data collected at that moment will be discarded; otherwise, it will not be discarded.

[0008] Preferably, the use of vibration / torque sensing technology specifically includes: A high-precision torque sensor is integrated on the grinding spindle to measure torque and acquire torque data. The measurement range is 0-5 N·m, the resolution is 0.01 N·m, and a non-contact measurement principle is adopted. A triaxial vibration accelerometer was selected to measure the vibration of the grinding drill and obtain vibration data. The accelerometer has a frequency response range of 10-10000 Hz and a measurement range of ±50g (where g is the acceleration due to gravity, g=9.8 m / s²). 2 ); Time synchronization sampling technology is used to ensure time alignment of ultrasonic, torque and vibration data, and multi-sensor data is fused through algorithms such as Kalman filtering.

[0009] Preferably, it also includes analysis of vibration / torque signals, specifically including: Calculate the root mean square value, peak factor and other statistical characteristics of the vibration signal, monitor the average value, fluctuation range and abrupt change point of the torque signal, and determine the change of grinding resistance; The vibration signal is subjected to fast Fourier transform to extract the main frequency components and amplitudes, the amplitude of the first harmonic of the drill rotation frequency is analyzed, the resonant frequency changes are identified, and the changes in bone tissue properties are judged. Time-frequency analysis was performed using wavelet transform or short-time Fourier transform, and wavelet packet transform coefficients were extracted as classification features to distinguish between bone and cartilage tissue.

[0010] Preferably, the data processing unit uses a preset intelligent algorithm to dynamically analyze the remaining bone tissue thickness data, and combines it with mechanical property parameter data to calculate the actual effective thickness of the current bone tissue, while comprehensively judging the grinding state, specifically including: The ultrasound echo signal is filtered, peak value is identified, and time difference is calculated to output the current lamina thickness in real time. By combining preoperative CT / MRI data, a three-dimensional bone tissue model was established to predict changes in bone tissue thickness along the drill path; Set two levels of safety thresholds: warning threshold (remaining thickness = preset safety value + 0.5mm) and drilling stop threshold (remaining thickness = preset safety value); When the remaining thickness reaches the warning threshold, the grinding speed will be automatically reduced and an audible and visual warning will be issued. When the remaining thickness reaches the drilling stop threshold or a dura mater characteristic signal is detected, a safe drilling stop is immediately triggered.

[0011] Preferably, the formula for calculating the current lamina thickness is: ; in, The current lamina thickness reflects the amount of remaining bone tissue; The propagation speed of ultrasound in bone tissue needs to be obtained from literature (e.g., approximately 3200 m / s for cortical bone and approximately 2800 m / s for cancellous bone). Ultrasonic emission time With echo peak time The time difference is obtained by identifying the peak value of the filtered signal, and .

[0012] Preferably, the step of establishing a three-dimensional bone tissue model by combining preoperative CT / MRI data and predicting changes in bone tissue thickness along the drill path specifically includes: Acquire the patient's preoperative CT or MRI medical imaging data, and perform image enhancement and noise reduction on the acquired CT or MRI image data; The image is input into a pre-trained U-Net network, which outputs the probability value of each pixel belonging to bone tissue. By setting a threshold of 0.5, the probability map is converted into a binary segmentation image S(x,y), where the region with a pixel value of 1 represents bone tissue and the region with a pixel value of 0 represents non-bone tissue, thus achieving bone tissue segmentation. The segmented binary image S(x, y) is voxelized according to the voxel size, and the two-dimensional image information is converted into voxel data in three-dimensional voxel space. The Marching Cubes algorithm is used to reconstruct the three-dimensional data using the voxelized data. This algorithm constructs the three-dimensional surface model M of bone tissue by searching for isosurfaces in three-dimensional voxel space and connecting the vertices on the isosurfaces to form triangular patches. The A algorithm is used to search for the optimal path from the starting point of the drill to the target point in the three-dimensional bone tissue model M. The A algorithm selects the optimal path node by comprehensively considering the cost function f(n)=g(n)+h(n) of the path, where g(n) represents the actual cost from the starting point to the current node n, and h(n) represents the heuristically estimated cost from the current node n to the target point. By continuously expanding the node with the minimum cost, the optimal drill path P is finally found. The planned drilling path P is visualized on a 3D bone tissue model M. The drilling path P is discretized according to a certain step size to obtain a series of discrete path points. , ; For each discrete path point In the three-dimensional bone tissue model M, the thickness is measured along a direction perpendicular to the drill path, centered on this point. The ray projection method is used, starting from the path point... Rays are emitted to both sides, and the intersection points of the rays with the surface of the bone tissue model are recorded. and Calculate the distance between two points. , which is the bone tissue thickness at that path point; Based on the bone tissue thickness at all discrete path points , Generate a bone tissue thickness variation curve T(s) along the drill path, where s represents the positional parameter along the path. This curve is used to predict the bone tissue thickness variation along the drill path.

[0013] In a second aspect of the invention, a safe grinding system based on real-time thickness monitoring is also provided, comprising: The first acquisition module is used to measure the remaining thickness of bone tissue in real time by using ultrasonic sensing technology and utilizing the principle of ultrasonic waves propagating and reflecting in bone tissue, and transmit the measured remaining thickness data to the data processing unit. The second acquisition module is used to employ vibration / torque sensing technology to monitor the mechanical characteristic parameters of the grinding tool in real time, such as vibration frequency, vibration amplitude, and torque magnitude, by setting vibration sensors and torque sensors on the grinding tool, and synchronously transmit these mechanical characteristic parameter data to the data processing unit. The analysis module is used by the data processing unit to dynamically analyze the remaining thickness data of bone tissue using a preset intelligent algorithm, and calculate the actual effective thickness of the current bone tissue by combining it with mechanical property parameter data. At the same time, it comprehensively judges the grinding state, which includes grinding progress, grinding uniformity, and whether it is close to the key structure of bone tissue. The comparison module is used to compare the calculated remaining bone tissue thickness with a preset safety threshold in real time. When the remaining bone tissue thickness reaches the preset safety threshold, the data processing unit sends a stop command to the control execution unit of the grinding equipment. The control module is used to control the execution unit to automatically stop the grinding operation of the grinding equipment immediately after receiving the stop command, so as to ensure the safety of the bone tissue grinding process and avoid damage to the bone tissue due to excessive grinding.

[0014] Compared with the prior art, the present invention provides a safe grinding method and system based on real-time thickness monitoring, which has the following beneficial effects: This invention uses ultrasonic sensing technology to measure the remaining thickness of bone tissue in real time and compares it with a preset safety threshold. When the threshold is reached, grinding is stopped immediately. This effectively prevents excessive grinding from penetrating bone tissue and damaging important surrounding structures such as nerves and blood vessels, reducing surgical risks and the occurrence of serious complications, such as paralysis caused by spinal cord injury or massive bleeding caused by rupture of large blood vessels. Furthermore, the real-time measurement of the remaining bone tissue thickness allows doctors to clearly understand the progress of grinding, accurately grasp the grinding depth and remaining workload at each stage, and thus more precisely control the grinding process to ensure that the expected surgical results are achieved, meeting the needs of doctors. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the method flow for S101-S105 in this invention; Figure 2 This is a schematic diagram of the method flow for S201-S205 in this invention; Figure 3 This is a schematic diagram of the method flow for S301-S302 in this invention; Figure 4 This is a schematic diagram of the method flow for S401-S403 in this invention; Figure 5 This is a schematic diagram of the method flow for S501-S503 in this invention; Figure 6 This is a schematic diagram of the method flow of S601-S605 in this invention; Figure 7 This is a schematic diagram of the method flow of S701-S707 in this invention. Detailed Implementation

[0016] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0017] Example 1 Please refer to Figure 1 As shown, in a first aspect of the present invention, a safe grinding method based on real-time thickness monitoring is provided, comprising: S101. Using ultrasonic sensing technology, the remaining thickness of bone tissue is measured in real time by utilizing the principle of ultrasonic waves propagating and reflecting in bone tissue, and the measured remaining thickness data is transmitted to the data processing unit. S102. Vibration / torque sensing technology is adopted. By setting vibration sensors and torque sensors on the grinding tool, the mechanical characteristic parameters such as vibration frequency, vibration amplitude and torque magnitude of the grinding tool during the grinding process are monitored in real time, and these mechanical characteristic parameter data are synchronously transmitted to the data processing unit. S103 The data processing unit uses a preset intelligent algorithm to dynamically analyze the remaining thickness data of bone tissue and, in combination with mechanical property parameter data, calculates the actual effective thickness of the current bone tissue. At the same time, it comprehensively judges the grinding state, which includes grinding progress, grinding uniformity, and whether it is close to the key structure of bone tissue. S104. The calculated remaining bone tissue thickness is compared with the preset safety threshold in real time. When the remaining bone tissue thickness reaches the preset safety threshold, the data processing unit sends a stop command to the control execution unit of the grinding equipment. S105. After receiving the stop command, the control execution unit immediately and automatically stops the grinding operation of the grinding equipment to ensure the safety of the bone tissue grinding process and avoid damage to the bone tissue due to excessive grinding.

[0018] As will be understood by those skilled in the art, the present invention uses ultrasonic sensing technology to measure the remaining thickness of bone tissue in real time and compares it with a preset safety threshold. When the threshold is reached, grinding is stopped immediately. This can effectively prevent excessive grinding from penetrating bone tissue and damaging important surrounding nerves, blood vessels and other key structures, reducing surgical risks and the occurrence of serious complications, such as paralysis caused by spinal cord injury and massive bleeding caused by rupture of large blood vessels. Vibration / torque sensing technology can monitor the mechanical properties of grinding tools in real time, such as vibration frequency, amplitude, and torque. These parameters will change significantly when grinding approaches the critical structure of bone tissue or when abnormal situations occur (such as encountering hard foreign objects or uneven grinding leading to excessive local stress). Real-time measurements of remaining bone thickness allow surgeons to clearly understand the progress of the grinding process, accurately grasp the grinding depth and remaining workload at each stage, and thus more precisely control the grinding process to ensure the desired surgical outcome. Combined with mechanical property parameters and thickness data, the data processing unit can determine the uniformity of the grinding. If uneven grinding is detected, the surgeon can promptly adjust the position, angle, or force of the grinding tool to make the grinding more uniform, avoiding localized over- or under-grinding and improving surgical quality. When approaching critical bone structures, the mechanical properties and thickness of the bone tissue exhibit unique characteristics. Comprehensive analysis of real-time data allows for more accurate identification of the boundaries of critical structures, providing surgeons with more precise operational guidance and ensuring that the grinding operation is completed within safe limits. This invention enables doctors to understand the grinding status in a timely manner through real-time monitoring and intelligent judgment, avoiding ineffective grinding caused by blind operation or repeated attempts, saving surgical time and improving surgical efficiency; accurately grasping the grinding progress and status helps doctors to rationally arrange surgical steps and time, making the entire surgical process smoother and more efficient, reducing the time patients spend on the operating table, and reducing surgical risks and patient suffering.

[0019] Please refer to Figure 2 As shown, ultrasonic sensing technology is used to measure the remaining thickness of bone tissue in real time, utilizing the principle of ultrasound propagation and reflection in bone tissue. Specifically, this includes: S201. Select a high-frequency ultrasound probe with a frequency of 15-20MHz for ultrasound monitoring. For thicker bone tissue, appropriately reduce the frequency to 10-15MHz to improve penetration ability. S202. The probe adopts a side-mounted design, embedded in the side of the drill bit, 1-2mm away from the end face of the drill bit, and the probe is embedded in the side of the drill bit at a 15°-20° angle to ensure that the ultrasound beam is perpendicularly incident on the surface of the vertebral lamina. S203. High sampling rate ADC is used to acquire ultrasonic signals, and the signals are preprocessed by pre-hardware filtering and post-software filtering. S204. Adaptive gain control is used to dynamically adjust the ultrasound transmission power and receiving gain according to the thickness of the lamina. The dual-interface peak recognition algorithm is used to identify the interface between the lamina surface and the cortical bone and the cancellous bone and dura mater. S205. Calculate the time difference between the echoes from the two interfaces, calculate the lamina thickness by combining the propagation speed of ultrasound in bone tissue, and use a temperature compensation algorithm to correct the ultrasound velocity.

[0020] Please refer to Figure 3 As shown, the ultrasonic monitoring process also includes anti-interference processing, specifically including: The signal cable of the S301 high-frequency ultrasonic probe adopts a double-layer shielding structure. The inner layer is a tin-plated copper mesh to shield differential mode interference, and the outer layer is an aluminum foil to shield common mode interference. Both ends of the cable are grounded to reduce the impact of external electromagnetic interference on ultrasonic signal transmission. S302. A multi-stage filtering algorithm combined with adaptive noise cancellation technology is used to suppress bone grinding vibration noise and high-frequency noise from the electric knife, and the rotation phase of the grinding drill is collected and recorded. The preset algorithm automatically removes the collected data at the "vibration peak moment". The default algorithm is: The formula for calculating the rotation phase of the drill is: ; in, R represents the rotation phase of the grinding drill, R represents the number of pulses per revolution of the grinding drill, and N(t) represents the number of pulses collected at time t. N(t) is collected by a speed sensor installed on the spindle that drives the grinding drill. The calculated drill rotation phase at each moment is compared with the preset vibration peak threshold range; If the rotation phase of the drill falls within the vibration peak threshold range, the data collected at that moment will be discarded; otherwise, it will not be discarded.

[0021] Please refer to Figure 4 As shown, vibration / torque sensing technology is employed, specifically including: S401: A high-precision torque sensor is integrated on the grinding and drilling spindle to measure torque and acquire torque data. The measurement range is 0 - 5 N·m, the resolution is 0.01 N·m, and a non-contact measurement principle is adopted. S402. A triaxial vibration accelerometer is selected to measure the vibration of the grinding drill and obtain vibration data. The frequency response range of this accelerometer is 10-10000 Hz, and the measurement range is ±50g (g is the acceleration due to gravity, g=9.8 m / s²). 2 ); S403 employs time-synchronized sampling technology to ensure time alignment of ultrasonic, torque, and vibration data, and fuses multi-sensor data through algorithms such as Kalman filtering.

[0022] Please refer to Figure 5 As shown, it also includes the analysis of vibration / torque signals, specifically including: S501. Calculate the root mean square value, peak factor and other statistical characteristics of the vibration signal, monitor the average value, fluctuation range and abrupt change point of the torque signal, and judge the change of grinding resistance. S502. Perform fast Fourier transform on the vibration signal, extract the main frequency components and amplitudes, analyze the amplitude of the first harmonic of the drill rotation frequency, identify the resonant frequency changes, and judge the changes in bone tissue properties. S503. Time-frequency analysis is performed using wavelet transform or short-time Fourier transform, and wavelet packet transform coefficients are extracted as classification features to distinguish between hard bone and cartilage tissue.

[0023] Please refer to Figure 6 As shown, the data processing unit uses a preset intelligent algorithm to dynamically analyze the remaining bone tissue thickness data and, combined with mechanical property parameter data, calculates the actual effective thickness of the current bone tissue. Simultaneously, it comprehensively judges the grinding state, specifically including: S601: Filter, identify peak values, and calculate time difference for ultrasound echo signals, and output the current lamina thickness in real time; S602. Combine preoperative CT / MRI data to establish a three-dimensional bone tissue model and predict changes in bone tissue thickness along the drill path; S603. Set two levels of safety thresholds: warning threshold (remaining thickness = preset safety value + 0.5mm) and stop drilling threshold (remaining thickness = preset safety value). S604. When the remaining thickness reaches the warning threshold, the grinding speed is automatically reduced and an audible and visual warning is issued. S605. When the remaining thickness reaches the drilling stop threshold or a dura mater characteristic signal is detected, a safe drilling stop is immediately triggered.

[0024] The formula for calculating the current lamina thickness is as follows: ; in, The current lamina thickness reflects the amount of remaining bone tissue; The propagation speed of ultrasound in bone tissue needs to be obtained from literature (e.g., approximately 3200 m / s for cortical bone and approximately 2800 m / s for cancellous bone). Ultrasonic emission time With echo peak time The time difference is obtained by identifying the peak value of the filtered signal, and .

[0025] Please refer to Figure 7 As shown, a three-dimensional bone tissue model was established using preoperative CT / MRI data to predict changes in bone thickness along the drill path, specifically including: S701. Acquire the patient's preoperative CT or MRI medical image data, and perform image enhancement and noise reduction on the acquired CT or MRI image data; S702. Input the image into the pre-trained U-Net network. The network outputs the probability value of each pixel belonging to bone tissue. By setting a threshold of 0.5, the probability map is converted into a binary segmentation image S(x, y), where the region with a pixel value of 1 represents bone tissue and the region with a pixel value of 0 represents non-bone tissue, thus achieving bone tissue segmentation. S703. The segmented binary image S(x, y) is voxelized according to the voxel size, and the two-dimensional image information is converted into voxel data in the three-dimensional voxel space. The Marching Cubes algorithm is used to reconstruct the three-dimensional data using the voxelized data. This algorithm constructs the three-dimensional surface model M of bone tissue by searching for isosurfaces in the three-dimensional voxel space and connecting the vertices on the isosurfaces to form triangular patches. S704. The A algorithm is used to search for the optimal path from the starting point of the drill to the surgical target point in the three-dimensional bone tissue model M. The A algorithm selects the optimal path node by comprehensively considering the cost function f(n)=g(n)+h(n) of the path, where g(n) represents the actual cost from the starting point to the current node n, and h(n) represents the heuristic estimated cost from the current node n to the target point. By continuously expanding the node with the minimum cost, the optimal drill path P is finally found. S705. Visualize the planned drilling path P on the three-dimensional bone tissue model M. Discretize the drilling path P according to a certain step size to obtain a series of discrete path points. , ; S706, For each discrete path point In the three-dimensional bone tissue model M, the thickness is measured along a direction perpendicular to the drill path, centered on this point. The ray projection method is used, starting from the path point... Rays are emitted to both sides, and the intersection points of the rays with the surface of the bone tissue model are recorded. and Calculate the distance between two points. , which is the bone tissue thickness at that path point; S707, Based on the bone tissue thickness at all discrete path points , Generate a bone tissue thickness variation curve T(s) along the drill path, where s represents the positional parameter along the path. This curve is used to predict the bone tissue thickness variation along the drill path.

[0026] In a second aspect of the invention, a safe grinding system based on real-time thickness monitoring is also provided, comprising: The first acquisition module is used to measure the remaining thickness of bone tissue in real time by using ultrasonic sensing technology and utilizing the principle of ultrasonic waves propagating and reflecting in bone tissue, and transmits the measured remaining thickness data to the data processing unit. The second acquisition module is used to employ vibration / torque sensing technology. By setting vibration sensors and torque sensors on the grinding tool, it monitors the mechanical characteristic parameters of the grinding tool in real time, such as vibration frequency, vibration amplitude, and the magnitude of the torque it bears, and transmits these mechanical characteristic parameter data synchronously to the data processing unit. The analysis module is used by the data processing unit to dynamically analyze the remaining thickness data of bone tissue using a preset intelligent algorithm, and calculate the actual effective thickness of the current bone tissue by combining it with mechanical property parameter data. At the same time, it comprehensively judges the grinding status, including grinding progress, grinding uniformity, and whether it is close to the key structure of bone tissue. The comparison module is used to compare the calculated remaining bone tissue thickness with a preset safety threshold in real time. When the remaining bone tissue thickness reaches the preset safety threshold, the data processing unit sends a stop command to the control execution unit of the grinding equipment. The control module is used to control the execution unit to automatically stop the grinding operation of the grinding equipment immediately after receiving the stop command, so as to ensure the safety of the bone tissue grinding process and avoid damage to the bone tissue due to excessive grinding.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A safe grinding method based on real-time thickness monitoring, characterized in that, The application relates to a bone grinding device and a bone grinding method. The application adopts ultrasonic sensing technology to measure the residual thickness of bone tissue in real time by using the principle of ultrasonic wave propagation and reflection in bone tissue, and transmits the measured residual thickness data to a data processing unit; The application adopts vibration / torque sensing technology to monitor the vibration frequency, vibration amplitude and torque of the grinding tool in the grinding process in real time by arranging vibration sensors and torque sensors on the grinding tool, and synchronously transmits the mechanical characteristic parameter data to the data processing unit; The data processing unit dynamically analyzes the bone tissue residual thickness data by using a preset intelligent algorithm, calculates the actual effective thickness of the current bone tissue in combination with the mechanical characteristic parameter data, and comprehensively judges the grinding state, which includes the grinding progress, grinding uniformity and whether the key structure of the bone tissue is approached; The data processing unit compares the calculated bone tissue residual thickness with a preset safety threshold in real time, and sends a stop instruction to a control execution unit of the grinding equipment when the bone tissue residual thickness reaches the preset safety threshold; The control execution unit automatically stops the grinding operation of the grinding equipment immediately after receiving the stop instruction, so as to ensure the safety of the bone grinding process and avoid damage to the bone tissue caused by excessive grinding.

2. The safety grinding method based on real-time thickness monitoring according to claim 1, characterized in that, The application adopts ultrasonic sensing technology to measure the residual thickness of bone tissue in real time by using the principle of ultrasonic wave propagation and reflection in bone tissue, and transmits the measured residual thickness data to a data processing unit; A high-frequency ultrasonic probe with a frequency of 15-20 MHz is selected for ultrasonic monitoring, and the frequency is appropriately reduced to 10-15 MHz to improve the penetration ability for thicker bone tissue; The probe is designed in a side-placed mode and is embedded in the side surface of the drill bit at a distance of 1-2 mm from the end surface of the drill bit, and the probe is inclined by 15-20 DEG and embedded in the side surface of the drill bit, so that the ultrasonic beam is perpendicular to the surface of the lamina; High sampling rate ADC is adopted to collect ultrasonic signals, and the signals are pretreated through front-end hardware filtering and rear-end software filtering; Self-adaptive gain control is adopted to dynamically adjust the ultrasonic transmitting power and receiving gain according to the thickness of the lamina, and a double-interface peak value recognition algorithm is adopted to recognize the lamina surface-cortical bone interface and bone marrow-dura mater interface; The time difference of the echoes of the two interfaces is calculated, the thickness of the lamina is calculated in combination with the propagation speed of ultrasonic waves in bone tissue, and a temperature compensation algorithm is adopted to correct the ultrasonic speed.

3. The safety grinding method based on real-time thickness monitoring according to claim 2, characterized in that, The process of ultrasonic monitoring also includes anti-interference processing, which specifically includes: The signal line of the high-frequency ultrasonic probe adopts a double-layer shielding structure, the inner layer is a tinned copper mesh shielding differential mode interference, and the outer layer is an aluminum foil shielding common mode interference, and the cable is grounded at both ends to reduce the influence of external electromagnetic interference on ultrasonic signal transmission; A multi-stage filtering algorithm combined with self-adaptive noise cancellation technology is adopted to suppress bone grinding vibration noise and electric knife high-frequency noise, and the grinding drill rotation phase is collected and recorded, and a preset algorithm automatically removes the collection data at the "vibration peak value moment"; The preset algorithm is: The calculation formula of the grinding drill rotation phase is: ； wherein, is the rotation phase of the grinding drill, R is the number of pulses per revolution of the grinding drill, N(t) is the number of pulses collected at time t, said N(t) being collected by a rotation speed sensor provided on the main shaft driving the rotation of the grinding drill; The calculated grinding drill rotation phase at each moment is compared with a preset vibration peak value threshold range; If the grinding drill rotation phase falls within the vibration peak value threshold range, the collection data corresponding to the moment is removed, otherwise, the collection data is not removed.

4. The safety grinding method based on real-time thickness monitoring according to claim 3, characterized in that, The vibration / torque sensing technology specifically includes: Integrating a high-precision torque sensor on the grinding drill spindle to measure torque and obtain torque data, with a measurement range of 0-5 N・m and a resolution of 0.01 N・m, using a non-contact measurement principle; A triaxial vibration accelerometer is selected to measure the vibration of the grinding drill and obtain vibration data. The frequency response range of the accelerometer is 10-10000 Hz, and the measurement range is ±50g (g is the gravitational acceleration, g=9.8 m / s 2 ). Using time-synchronous sampling technology to ensure time alignment of ultrasonic, torque, and vibration data, and fusing multi-sensor data through Kalman filtering and other algorithms.

5. The safety grinding method based on real-time thickness monitoring according to claim 4, characterized in that, It also includes analyzing vibration / torque signals, specifically including: Calculating the root mean square value and peak factor of the vibration signal, monitoring the average value, fluctuation range, and abrupt points of the torque signal, and judging the change in grinding resistance; Performing fast Fourier transform on the vibration signal to extract the main frequency components and amplitudes, analyze the first harmonic amplitude of the grinding drill rotation frequency, identify changes in resonance frequency, and judge changes in bone tissue characteristics; Using wavelet transform or short-time Fourier transform for time-frequency analysis, extracting wavelet packet transform coefficients as classification features to distinguish between hard bone and soft bone tissue.

6. The safety grinding method based on real-time thickness monitoring according to claim 5, characterized in that: The data processing unit uses a preset intelligent algorithm to dynamically analyze the bone tissue remaining thickness data and combines with the mechanical property parameter data to calculate the actual effective thickness of the current bone tissue, and simultaneously comprehensively judges the grinding state, specifically including: Filtering, peak identification, and time difference calculation on the ultrasonic echo signal to output the current lamina thickness in real time; Establishing a three-dimensional bone tissue model based on preoperative CT / MRI data to predict the change in bone tissue thickness along the grinding drill path; Setting two-level safety thresholds: a warning threshold (remaining thickness = preset safety value + 0.5 mm) and a stop drilling threshold (remaining thickness = preset safety value); When the remaining thickness reaches the warning threshold, automatically reduce the grinding drill speed and issue an audible and visual prompt; When the remaining thickness reaches the stop drilling threshold or the dura mater characteristic signal is detected, immediately trigger the safety stop drilling.

7. The safety grinding method based on real-time thickness monitoring according to claim 6, characterized in that, The calculation formula for outputting the current lamina thickness is: ； in, The current lamina thickness reflects the amount of remaining bone tissue; The propagation speed of ultrasound in bone tissue needs to be obtained from literature (e.g., approximately 3200 m / s for cortical bone and approximately 2800 m / s for cancellous bone). Ultrasonic emission time With echo peak time The time difference is obtained by identifying the peak value of the filtered signal, and .

8. The safety grinding method based on real-time thickness monitoring according to claim 7, characterized in that, The three-dimensional bone tissue model is established based on preoperative CT / MRI data to predict the change in bone tissue thickness along the grinding drill path, specifically including: Obtain the patient's preoperative CT or MRI medical image data, and perform image enhancement and denoising on the obtained CT or MRI image data; Input the image into the pre-trained U-Net network, and the network outputs the probability value of each pixel point belonging to bone tissue. By setting a threshold of 0.5, the probability map is converted into a binary segmentation image S(x, y), where the region with a pixel value of 1 represents bone tissue, and the region with a pixel value of 0 represents non-bone tissue, achieving bone tissue segmentation; Voxelize the segmented binary image S(x, y) according to the voxel size, convert the two-dimensional image information into voxel data in the three-dimensional voxel space, and use the Marching Cubes algorithm to perform three-dimensional reconstruction on the voxelized data. This algorithm searches for an isosurface in a three-dimensional voxel space, connects the vertices on the isosurface to form triangular facets, and constructs a three-dimensional surface model M of the bone tissue. An A algorithm is used to search for an optimal path from the burr starting point to the surgical target point in the three-dimensional bone tissue model M. The A algorithm selects the optimal path node by comprehensively considering the path cost function f(n)=g(n)+h(n), wherein g(n) represents the actual cost from the starting point to the current node n, and h(n) represents the heuristic estimated cost from the current node n to the target point. By continuously expanding the node with the minimum cost, the optimal burr path P is finally found. The planned drill grinding path P is displayed on the three-dimensional bone tissue model M, and the drill grinding path P is discretized according to a certain step length to obtain a series of discrete path points, 、 ; For each discrete path point In the three-dimensional bone tissue model M, a thickness measurement is made at the point, in a direction perpendicular to the burr path, using ray casting, from the path point Ray casting is performed to both sides, recording the intersection of the ray with the surface of the bone tissue model And The distance between the two points is calculated As the bone tissue thickness at the path point; According to the bone tissue thickness at all discrete path points , , a bone tissue thickness change curve T(s) on the burring path is generated, where s represents a position parameter on the path, through which the bone tissue thickness change on the burring path is predicted.

9. A safe grinding system based on real-time thickness monitoring, characterized in that, The application discloses a safety grinding method based on real-time thickness monitoring. The first acquisition module is used for measuring the residual thickness of the bone tissue in real time by using the ultrasonic sensing technology and the principle of ultrasonic wave propagation and reflection in the bone tissue, and transmitting the measured residual thickness data to the data processing unit. The second acquisition module is used for monitoring the vibration frequency, vibration amplitude and torque size of the grinding tool in the grinding process by setting vibration sensors and torque sensors on the grinding tool, and synchronously transmitting the mechanical characteristic parameter data to the data processing unit. The analysis module is used for dynamically analyzing the bone tissue residual thickness data by using the preset intelligent algorithm, and calculating the actual effective thickness of the current bone tissue by combining the mechanical characteristic parameter data and comprehensively judging the grinding state, wherein the grinding state includes the grinding progress, the grinding uniformity and whether the key structure of the bone tissue is approached. The comparison module is used for comparing the calculated bone tissue residual thickness with the preset safety threshold in real time, and sending a stop instruction to the control execution unit of the grinding equipment when the bone tissue residual thickness reaches the preset safety threshold. The control module is used for automatically stopping the grinding operation of the grinding equipment immediately after the control execution unit receives the stop instruction, so as to ensure the safety of the bone tissue grinding process and avoid damage to the bone tissue caused by excessive grinding.

10. An electronic device, comprising at least one processor; and a memory connected in communication with the at least one processor; characterized in that, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method in any one of claims 1-8.

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