An adaptive control system for directly measuring the depth of a skull drill hole and a method thereof

Abstract

The application discloses a self-adaptive control system for directly measuring skull drilling depth and a method thereof, and belongs to the technical field of experimental animal medical instruments. The system comprises a drilling execution unit for executing skull drilling; an integrated dual-mode sensing unit for measuring skull thickness and analyzing microstructure changes of bone; the integrated dual-mode sensing unit comprises a coaxial pulse echo ultrasonic module and a structural acoustic emission analysis module; the coaxial pulse echo ultrasonic module is used for measuring skull thickness under a drill bit in real time, and the structural acoustic emission analysis module is used for collecting structural vibration and sound waves generated in the process of cutting bone by the drill bit; the application adopts a dual-mode sensing and fusion decision mechanism, cross-verification of information is carried out, the problems that a single sensor in the prior art may fail or misjudge in a complex biological environment can be improved, and therefore the safety and reliability of surgery are improved.

Description

Technical Field

[0001] This invention belongs to the field of laboratory animal medical device technology, and specifically relates to an adaptive control system and method for directly measuring the depth of skull drilling. Background Technology

[0002] In the field of neuroscience, rats have become a core model organism for studying brain function mechanisms, exploring the pathology of nervous system diseases, and validating potential treatments due to their advantages such as high homology between their brain structure and that of humans, short reproductive cycles, and controllable breeding costs. Traumatic brain injury (TBI) is a major global public health issue, and research on its secondary injury mechanisms, neural repair pathways, and drug intervention targets relies heavily on standardized rat TBI models. Specific brain region injection models are key tools for analyzing the function of individual brain regions, exploring local neural circuit regulation mechanisms, and validating the efficacy of targeted drugs. They are widely used in basic research on neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and epilepsy, as well as mental illnesses.

[0003] In the construction of rat brain-brain lesion (TBI) models (such as the drop test and hydraulic impact test) and the administration of drugs to specific brain regions, skull drilling is a core step connecting in vitro intervention and intracranial targeting. Its technical precision directly determines the effectiveness and reliability of the experiment. For TBI models, the drilling location must precisely correspond to the target injury area (such as the cortex, hippocampus, thalamus, etc.), and the borehole diameter and drilling depth must strictly match the requirements of the injury mechanism—too shallow may result in incomplete skull penetration, failing to form a standard injury; too deep may directly damage the dura mater or brain tissue, causing unexpected hemorrhage and edema, interfering with the authenticity of the injury pathological process. For drug administration models to specific brain regions, the requirements for drilling precision are even more stringent: based on the rat brain stereotactic atlas, the three-dimensional coordinates (anteroposterior diameter, lateral diameter, ventral-dorsolateral diameter) of the target brain region must be precisely located to ensure that the drilling location completely coincides with the injection needle path. If the drilling is off-target, the drug may be injected into a non-target brain region, which may not only fail to achieve the experimental purpose, but may also cause false positive / false negative results due to the drug acting on unrelated neural circuits. Furthermore, the degree of damage to the dura mater and the amount of bone debris left during the drilling process may affect the diffusion efficiency of subsequent drug injections, and may even induce local inflammatory reactions, interfering with the stability of experimental data.

[0004] Currently, existing cranial drilling techniques have the following drawbacks: cranial drilling is highly dependent on the operator's experience and feel, resulting in high experimental repeatability; the mechanical limiting depth of the device is a fixed value, so it cannot be better adapted to different experimental individuals, and there is a risk of damaging the experimental individuals. Summary of the Invention

[0005] The purpose of this invention is to provide an adaptive control system and method for directly measuring the depth of skull drilling, addressing the aforementioned problems. This aims to improve existing drilling systems that cannot directly measure skull bone thickness in real time, and to address the inability of separate sensors to achieve instantaneous and accurate detection.

[0006] The technical solution adopted in this invention is as follows: an adaptive control system for directly measuring the depth of skull drilling, the system comprising the following units: A drilling execution unit is used to perform skull drilling; the drilling execution unit includes a sliding guide rail, a drill bit holder and a drill bit, the drill bit holder holding the drill bit and moving it on the sliding guide rail; An integrated dual-mode sensing unit is used to measure skull thickness and analyze changes in the microstructure of bone. The integrated dual-mode sensing unit includes a coaxial pulse-echo ultrasound module and a structural acoustic emission analysis module. The coaxial pulse-echo ultrasound module is used to measure the skull thickness under the drill bit in real time, and the structural acoustic emission analysis module is used to collect the structural vibrations and sound waves generated during the drill bit cutting bone. The integrated dual-mode sensing unit is coaxially integrated into the drilling execution unit, and is used to provide the drilling execution unit with accurate drilling data.

[0007] Furthermore, the system also includes a central control unit, which receives signals transmitted by the integrated dual-mode sensing unit and issues control commands according to the algorithm to control the drilling execution unit to move.

[0008] Furthermore, the drilling execution unit is driven by a drilling drive unit, which includes a Z-axis motor and a drilling motor. The Z-axis motor is connected to the drill bit and drill bit holder of the drilling execution unit and drives the drill bit and drill bit holder to move on the sliding guide rail. The drilling motor is connected to the drill bit and drives the drill bit to perform rotary cutting.

[0009] Furthermore, a coaxial pulse echo ultrasonic module is fitted around the drill bit, and the coaxial pulse echo ultrasonic module measures the thickness of the skull under the drill bit by emitting ultrasonic waves.

[0010] Furthermore, a structural acoustic emission analysis module is installed on the drilling execution unit. The structural acoustic emission analysis module collects the structural vibrations and sound waves generated during the drill bit cutting bone and analyzes the microstructural changes of the skull.

[0011] Furthermore, an adaptive control method for directly measuring the depth of skull drilling is provided, the adaptive control method comprising the following steps: Step S100: Initialize parameters and system modules, perform adaptive calibration of each unit and module of the system, initialize the total skull thickness RT_initial, and establish the baseline voiceprint model AE_baseline; Step S200: Data acquisition and feature extraction, extracting real-time data acquired by the integrated dual-mode sensing unit and calculating feature parameters used for algorithm decision-making; Step S300: The central control unit adopts a four-stage predictive fusion control algorithm to perform stage judgment and dynamic weight allocation; based on the ratio of initialization parameters and characteristic parameters, it determines the current drilling stage and assigns different decision weights to each characteristic parameter; Step S400: Phased control strategy execution. The central control unit executes different control strategies cyclically according to the current phase. Step S500: Set and determine the final stop condition. At the end of each control cycle, the central control unit will make redundant decisions on the final stop condition. Step S600: Execute stop and reverse; if the control cycle meets the final stop condition, the central control unit immediately stops all motors and controls the Z-axis motor to move in the opposite direction to raise the drill bit to a safe distance from the skull, and the drilling ends; if the cycle does not meet the final stop condition, return to step S200 and start the next control cycle.

[0012] Furthermore, in step S100, the coaxial pulse echo ultrasound module measures and stores the initial total skull thickness RT_initial; the drill bit drills into the skull at an extremely low speed, and the structural acoustic emission analysis module collects the signals during the drilling process, establishes the baseline acoustic signature model AE_baseline, and calculates two baseline parameters: the initial baseline high-frequency energy ratio HFER_base and the initial baseline spectral centroid SCS_base.

[0013] Furthermore, in step S200, the system executes the following steps in real time and periodically: Step S201: The central control unit synchronously acquires the raw data from the coaxial pulse echo ultrasonic module and the structural acoustic emission analysis module, and performs digital filtering and preprocessing. Step S202: Calculate four feature parameters based on the preprocessed data from step S201: The remaining skull thickness RT_current is calculated based on the ultrasound flight time. Echo intensity ESS_current represents the reflected energy of ultrasound waves at the intracranial interface. HFER_current is the ratio of high-frequency energy to total energy in the acoustic emission signal in the structural acoustic emission analysis module. The spectral centroid SCS_current is used to reflect the concentrated frequency point of the acoustic emission signal spectral energy. Its drastic changes are used to predict abrupt changes in material properties.

[0014] Furthermore, the phased control strategy execution in step S400 specifically includes four stages: The first stage involves determining the execution phase by assessing the drilling speed. The second stage is the high-speed approach stage of the drilling execution unit. During this stage, the system executes high-speed feed V_fast and high-speed rotation R_fast. The low-weight acoustic emission signal AE collected by the structural acoustic emission analysis module plays a safety redundancy role. If the drilling execution unit suddenly deviates from the baseline acoustic model AE_baseline, the system will temporarily reduce speed and issue an alarm. The third stage is the deceleration transition stage of the drilling execution unit. During this stage, the system operates at a medium speed V_medium and a medium rotation speed R_medium. The fourth stage is the integration of early warning and fine control. In this stage, the central control unit will perform core cross-validation. Only when both conditions are met simultaneously, such as RT_current≤20%RT_initial and HFER_current>1.5HFER_base, can the fine control mode be confirmed. The drilling execution unit will then execute the extremely low speed V_slow or the pecking drill mode.

[0015] Furthermore, the final stopping conditions in step S500 include: RT_current < the set absolute safety limit value; The current value of ESS has dropped by more than 50% compared to the previous time. SCS_current experiences a drastic frequency shift compared to SCS_base; The final stopping condition will be triggered if any two of the above conditions are met.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention uses a coaxial pulse echo ultrasonic module to directly and physically measure the thickness of the skull bone, thereby measuring the remaining bone thickness in real time during drilling. The measurement data is not easily affected by complex factors such as uneven bone density and microcracks, ensuring high precision and reliability of drilling from the measurement principle. In addition, the structural acoustic emission analysis module collects the structural vibrations and sound waves generated during the drill bit cutting bone, which is used to assist the drilling execution unit in determining the drilling rate, thereby achieving precise drilling by the drilling device.

[0017] 2. This invention employs a dual-mode sensing and fusion decision-making mechanism to cross-verify information, which can improve the fatal flaw of existing technologies that use a single sensor, which may fail or misjudge in complex biological environments, thus raising the safety of surgery to a whole new level. Attached Figure Description

[0018] Figure 1 This is a system architecture diagram of the present invention; Figure 2 This is a structural schematic diagram of a preferred layout of the coaxial pulse echo ultrasonic module of the present invention; Figure 3 This is a structural schematic diagram of the preferred layout of the structural acoustic emission analysis module of the present invention; Figure 4 This is a flowchart of the method of the present invention.

[0019] Figure labels: 1. Sliding guide rail; 2. Z-axis motor; 3. Drill motor; 4. Drill bit holder; 5. Drill bit; 6. Scalp; 7. Skull; 8. Dura mater; 9. Cerebral cortex; 10. Rat skull (section); 11. Microphone sensor; 12. Acoustic emission (AE) signal; 13. Ring ultrasonic transducer; 14. Emitted ultrasonic wave; 15. Reflected echo; 16. Ultrasonic pulse / echo signal; 17. Central control unit; 18. Control command; AM, Y1, Y2, N1, N2, Algorithm flowchart labels. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings.

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] In neuroscience research, creating rat models of traumatic brain injury or drug injection into specific brain regions is a routine experimental procedure, and precise craniotomy (S7-hole drilling) is crucial. Currently, existing S7-hole drilling techniques have the following main drawbacks: 1. High dependence on human experience: Traditional methods rely entirely on the operator's feel and experience to control the drilling depth. If not careful, the drill can penetrate the skull, causing irreversible damage to the rat's brain tissue, leading to experimental failure and poor repeatability.

[0023] 2. Limitations of mechanical restraint devices: Some improved devices have added mechanical restraints. While this method can prevent excessive drilling, the restraint depth needs to be preset. Due to the differences in skull thickness among different strains, ages, and even individuals of rats, a fixed restraint value is not universally applicable and still carries the risk of injury.

[0024] 3. The hysteresis of passive electrical signal induction: Some advanced devices use current sensors to trigger an emergency stop by monitoring the sudden drop in motor load the moment the drill 5 penetrates the skull 7. This is essentially a reactive response rather than a pre-emptive prediction; due to system inertia, the drill 5 may still damage the meninges or cerebral cortex 9 before stopping.

[0025] 4. Fundamental Defects of Existing Sensing and Control Schemes: A search revealed existing technologies (such as Japanese Patent Document JP3558355B2) that disclose ultrasonic monitoring of the drilling process. However, these schemes have inherent and insurmountable defects: First, the measurement principle is indirect, raising questions about accuracy and reliability. This technology indirectly infers drilling depth by measuring the energy attenuation of laterally propagating surface acoustic waves, rather than directly measuring the remaining bone thickness. This correlation is easily affected by complex factors such as uneven bone density and microcracks. Second, the sensor layout limits real-time performance. The separate, side-mounted sensor layout cannot achieve instantaneous and accurate detection of the area directly below the drill bit 5. Third, the control logic is simple, lacking sufficient safety redundancy. It uses a single energy threshold for judgment and control; once the signal fluctuates or interferes, it is prone to system misjudgment, lacking necessary safety redundancy and fault diagnosis mechanisms.

[0026] Therefore, there is an urgent need in this field for a new drilling system that adopts the principle of direct measurement, has the ability to cross-validate multi-dimensional information, and has an intelligent phased control strategy, so as to fundamentally solve the reliability and safety bottlenecks of existing technologies.

[0027] This invention provides an adaptive control system and method for directly measuring the drilling depth of the skull. The system features an innovative hardware structure, employing an integrated dual-mode sensing unit—a combination of a coaxial pulse-echo ultrasonic module and a structural acoustic emission analysis module—fundamentally different from existing single-sensor or split-type sensing technologies. The measurement principle is also innovative, combining direct measurement with indirect analysis. It uses the Time-of-Flight (ToF) principle for macroscopic and direct geometric dimension measurement, while simultaneously employing the acoustic emission principle for microscopic and indirect material state analysis. Finally, the core algorithm is innovative, featuring a four-stage predictive fusion control algorithm that adjusts the measurement method according to the drilling speed.

[0028] Example 1 like Figure 1 As shown, one embodiment of the present invention is an adaptive control system for directly measuring the depth of skull drilling, the system comprising the following units: A drilling execution unit is used to perform drilling of the skull 7; the drilling execution unit includes a sliding guide rail 1, a drill bit holder 4 and a drill bit 5, the drill bit holder 4 holds the drill bit 5 and moves it on the sliding guide rail 1; An integrated dual-mode sensing unit is used to measure the thickness of the skull 7 and analyze the microstructural changes of the bone. The integrated dual-mode sensing unit includes a coaxial pulse-echo ultrasound module and a structural acoustic emission analysis module. The coaxial pulse-echo ultrasound module is used to measure the thickness of the skull under the drill bit 5 in real time, and the structural acoustic emission analysis module is used to collect the structural vibrations and sound waves generated during the process of the drill bit 5 cutting the bone. Central control unit 17 is used to receive signals transmitted by the integrated dual-mode sensing unit and issue control commands 18 according to the algorithm to control the drilling execution unit to move. The drilling drive unit includes a Z-axis motor 2 and a drilling motor 3. The Z-axis motor 2 is connected to the drill bit 5 and drill bit holder 4 of the drilling execution unit and drives the drill bit 5 and drill bit holder 4 to move on the sliding guide rail 1. The drilling motor 3 is connected to the drill bit 5 and drives the drill bit 5 to perform rotary cutting. The integrated dual-mode sensing unit is coaxially integrated into the drilling execution unit, and is used to provide the drilling execution unit with accurate drilling data.

[0029] The coaxial pulse echo ultrasonic module is fitted around the drill bit 5. The coaxial pulse echo ultrasonic module measures the thickness of the skull 7 under the drill bit 5 by emitting ultrasonic waves.

[0030] The structural acoustic emission analysis module is installed on the drilling execution unit. The structural acoustic emission analysis module collects the structural vibrations and sound waves generated by the drill bit 5 during the cutting of bone, and analyzes the microstructural changes of the skull 7.

[0031] This embodiment integrates the coaxial pulse echo ultrasonic module and the structural acoustic emission analysis module into the drilling execution unit. During drilling, it performs real-time data acquisition on the thickness of the skull 7 and the microstructural changes of the skull 7 bone, thereby realizing real-time monitoring and adaptive control of the drilling process.

[0032] Example 2 like Figure 2 As shown, in another embodiment of the present invention, the coaxial pulse echo ultrasonic module is preferably a ring ultrasonic transducer 13. This embodiment takes the ring ultrasonic transducer 13 as an example.

[0033] The annular ultrasonic transducer 13 is based on the time-of-flight principle of ultrasound and is used to directly and in real time measure the absolute remaining thickness of the skull 7 directly below the drill bit 5; the annular ultrasonic transducer 13 emits ultrasonic waves 14 and receives reflected echoes 15; the reflected echoes 15 are reflected on the inner surface of the skull 7 and then received by the transducer as ultrasonic signals; the ultrasonic pulse / echo signal 16 is a bidirectional signal transmitted between the transducer and the central control unit 17.

[0034] Control command 18 is issued by the central control unit 17 based on algorithm decision and is used to control the action of Z-axis motor 2 and drilling motor 3. The central control unit 17 is the decision core of the system, responsible for receiving sensor signals, running fusion algorithm and issuing control command 18.

[0035] The coaxial pulse echo ultrasonic module determines the thickness of the remaining skull 7 under the borehole by emitting ultrasonic waves 14 and calculating the flight time of the ultrasonic waves. The central control unit 17 calculates the control command 18 based on the thickness of the remaining skull 7, which drives the drilling execution unit to move.

[0036] This embodiment uses a direct measurement method to collect the remaining thickness of the skull 7 while drilling, thus ensuring high precision and high reliability from the measurement principle.

[0037] Example 3 like Figure 3 As shown, in another embodiment of the present invention, the structural acoustic emission analysis module is preferably a high-sensitivity piezoelectric ceramic sensor or a MEMS microphone. In this embodiment, microphone sensor 11 is used as an example.

[0038] The sliding guide rail 1 provides a stable and precise vertical motion reference for the entire drilling assembly; the Z-axis motor 2 drives the drilling assembly to perform precise vertical feed or retraction along the sliding guide rail 1; the drilling motor 3 is responsible for driving the drill bit 5 to perform high-speed rotational cutting; the microphone sensor 11 is the structural acoustic emission analysis module of this embodiment, used to collect the structural vibration and sound wave signals generated when the drill bit 5 cuts bone in real time; the structure of the skull 7 is as follows: the scalp 6 is the surface tissue of the experimental subject; the skull 7 is the target object of the drilling operation; the dura mater 8 is the protective meninges below the skull 7, which is the boundary that the drilling operation must never touch; the cerebral cortex 9 is the brain tissue below the dura mater 8; the rat skull (section) 10 shows the tissue layer structure of the drilling area.

[0039] The acoustic emission (AE) signal 12 is acquired by the microphone sensor 11 and transmitted to the central control unit 17 for analysis. The control command 18 is issued by the central control unit 17 based on the algorithm decision and is used to control the operation of the Z-axis motor 2 and the drilling motor 3. The central control unit 17 is the decision-making core of the system, responsible for receiving sensor signals, running the fusion algorithm, and issuing the control command 18.

[0040] In this embodiment, the structural acoustic emission analysis module collects the structural vibrations and sound waves generated during the cutting of bone by the drill bit 5, namely the acoustic emission AE signal 12, to analyze the microstructural changes of the bone; and performs multidimensional analysis of the microstructure of the skull 7, thereby assisting the drilling execution unit in adjusting the drilling rate.

[0041] Example 4 like Figure 4 As shown, another embodiment of the present invention is an adaptive control method for directly measuring the depth of skull drilling. The adaptive control method includes the following steps: Step S100: Initialize parameters and system modules; each unit and module of the system undergoes adaptive calibration; initialize the total thickness of the skull 7 (RT_initial); and establish the baseline voiceprint model (AE_baseline). Figure 4 In this diagram, A represents the start of the algorithm; B represents the initialization parameters and system modules. The coaxial pulse echo ultrasound module measures and stores the initial total thickness of the skull 7, RT_initial; the drill bit 5 drills into the skull 7 at an extremely low speed to a very small depth, such as 0.1 mm; the structural acoustic emission analysis module collects the signals during the drilling process of the drill bit 5, establishes the baseline acoustic signature model AE_baseline, and calculates two baseline parameters: the initial baseline high-frequency energy ratio HFER_base and the initial baseline spectral centroid SCS_base.

[0042] Step S200: Data Acquisition and Feature Extraction. Real-time data acquired by the integrated dual-mode sensing unit is extracted, and feature parameters used for algorithm decision-making are calculated; wherein, Figure 4 C and D in the text represent data acquisition and feature extraction; In step S200, the system executes the following steps in real time and periodically: Step S201: The central control unit 17 synchronously acquires the raw data from the coaxial pulse echo ultrasonic module and the structural acoustic emission analysis module, and performs digital filtering and preprocessing. Step S202: Calculate four feature parameters based on the preprocessed data from step S201: The remaining thickness of skull 7, RT_current, is calculated based on the ultrasound flight time. Echo intensity ESS_current, used to represent the reflected energy of ultrasound waves at the interface inside the skull 7; HFER_current is the ratio of high-frequency energy to total energy in the acoustic emission signal in the structural acoustic emission analysis module. The spectral centroid SCS_current is used to reflect the concentrated frequency point of the acoustic emission signal spectral energy. Its drastic changes are used to predict abrupt changes in material properties.

[0043] Step S300: The central control unit 17 adopts a four-stage predictive fusion control algorithm to perform stage judgment and dynamic weight allocation; based on the ratio of initialization parameters and characteristic parameters, it judges the current drilling stage and assigns different decision weights to each characteristic parameter; Step S400: Phased control strategy execution. The central control unit 17 executes different control strategies cyclically according to the current phase. The phased control strategy in step S400 and the final stop condition judgment in step S500 are in... Figure 4The process is fully reflected in the following steps: The algorithm starts from module A (start), passes through module B (initialization, corresponding to step S100), and then enters module C / D (data acquisition and feature extraction, corresponding to step S200). Module C / D is the entry point of the entire adaptive control loop. The central control unit 17 acquires real-time data here, calculates the feature parameters used for decision-making, and starts the main control loop.

[0044] Module E is the first decision point, used to determine whether the system is in the high-speed approach phase. If the determination is yes (path Y1), the process will enter module F, and the system will execute the high-speed drilling strategy (V_fast, R_fast); if the determination is no (path N1), the process will enter modules I and H, indicating that the system has entered and executed a deceleration or fine control strategy.

[0045] Module I serves as the identifier or preprocessing step for entering the fine-grained control phase; Module H represents the actual execution of the low-speed (V_slow) or pecking mode strategy. Here, the system performs core cross-validation. Fine-grained control mode is only confirmed when both conditions are met: RT_current ≤ 20% RT_initial and HFER_current > 1.5 HFER_base. The AE signal then becomes the primary criterion for this decision.

[0046] Module K is the final stop condition judgment point that is consistent throughout the entire process (corresponding to step S500). All execution paths (from the high-speed strategy of module F and the fine-grained strategy of module H) eventually converge into module K.

[0047] The final stopping conditions include the following items; any two of them must be met to trigger the process: RT_current < the set absolute safety limit value (e.g., 0.1mm); ESS_current has dropped by more than 50% compared to the previous time. SCS_current experiences a drastic frequency shift compared to SCS_base.

[0048] Redundant decision-making is performed at the judgment module K: If the judgment result is yes (path Y2), the stopping condition is met, the process enters module L (execute stop and backtrack, corresponding to step S600), the central control unit 17 immediately stops all motors and controls the Z-axis motor 2 to move in the opposite direction, and finally terminates at module M (algorithm end).

[0049] If the judgment result is negative (path N2), meaning the stopping condition is not met, the process will return to module C / D along this feedback path to obtain new real-time data and start the next control cycle, thus forming a complete adaptive closed-loop control.

[0050] Figure 4 Explanation of Chinese markings: Y1, Y2: Represent the (Yes) path of the corresponding judgment module.

[0051] N1, N2: Represent the No path of the corresponding judgment module.

[0052] M: Algorithm ends, overall process ends.

[0053] This embodiment employs a dual-mode sensing + fusion decision mechanism to achieve cross-verification of information, which can solve the defects of single sensors that may fail or misjudge in complex biological environments, thus raising the safety of surgery to a new level. Moreover, this method has a high degree of intelligence and adaptability: individualized self-calibration and a four-stage predictive control algorithm enable the equipment to adapt to the physiological differences of different animals and dynamically adjust the control strategy according to the real-time progress of drilling, thus achieving intelligent adaptive control.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive control system for directly measuring the depth of skull drilling, characterized in that, The system includes the following units: A drilling execution unit is used to perform skull drilling; the drilling execution unit includes a sliding guide rail, a drill bit holder and a drill bit, the drill bit holder holding the drill bit and moving it on the sliding guide rail; An integrated dual-mode sensing unit is used to measure skull thickness and analyze changes in the microstructure of bone. The integrated dual-mode sensing unit includes a coaxial pulse-echo ultrasound module and a structural acoustic emission analysis module. The coaxial pulse-echo ultrasound module is used to measure the skull thickness under the drill bit in real time, and the structural acoustic emission analysis module is used to collect the structural vibrations and sound waves generated during the drill bit's cutting of bone. The coaxial pulse-echo ultrasound module is fitted around the drill bit and measures the skull thickness under the drill bit by emitting ultrasound waves. The coaxial pulse echo ultrasound module measures and stores the initial total skull thickness RT_initial; the drill bit drills into the skull at an extremely low speed, and the structural acoustic emission analysis module collects the signals during the drilling process, establishes the baseline acoustic model AE_baseline, and calculates two baseline parameters: the initial baseline high-frequency energy ratio HFER_base and the initial baseline spectral centroid SCS_base. The integrated dual-mode sensing unit is coaxially integrated into the drilling execution unit, and the integrated dual-mode sensing unit is used to provide the drilling execution unit with accurate drilling data; The central control unit receives signals from the integrated dual-mode sensing unit and issues control commands according to the algorithm to control the drilling execution unit to move. The central control unit synchronously acquires raw data from the coaxial pulse echo ultrasonic module and the structural acoustic emission analysis module, and performs digital filtering and preprocessing; based on the preprocessed data, four characteristic parameters are calculated: The remaining skull thickness RT_current is calculated based on the ultrasound flight time. Echo intensity ESS_current represents the reflected energy of ultrasound waves at the intracranial interface. HFER_current is the ratio of high-frequency energy to total energy in the acoustic emission signal calculated in the structural acoustic emission analysis module. The spectral centroid SCS_current is used to reflect the concentrated frequency point of the acoustic emission signal spectral energy. Its drastic changes are used to predict abrupt changes in material properties. The central control unit will perform core cross-validation. Only when both conditions are met simultaneously, such as RT_current≤20%RT_initial and HFER_current>1.5HFER_base, can it be confirmed that the fine control mode has been entered, and the drilling execution unit will execute the extremely low speed V_slow or the pecking drill mode.

2. The adaptive control system for directly measuring the depth of skull drilling according to claim 1, characterized in that, The drilling execution unit is driven by a drilling drive unit, which includes a Z-axis motor and a drilling motor. The Z-axis motor is connected to the drill bit and drill bit holder of the drilling execution unit and drives the drill bit and drill bit holder to move on the sliding guide rail. The drilling motor is connected to the drill bit and drives the drill bit to perform rotary cutting.

3. The adaptive control system for directly measuring the depth of skull drilling according to claim 2, characterized in that, The structural acoustic emission analysis module is installed on the drilling execution unit. The structural acoustic emission analysis module collects the structural vibrations and sound waves generated during the process of the drill bit cutting bone, and analyzes the microstructural changes of the skull.

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