Alveolar bone surface tooth root detection method and detector

Abstract

The invention relates to an alveolar bone surface tooth root detection method and detector, and the method comprises the following steps: obtaining age data and bone density data of a testee according to CT data and imaging data of the testee, and matching corresponding ultrasonic parameters and acoustic impedance correction parameters; constructing a multi-layer medium acoustic impedance model comprising a tooth root layer of the bone surface of the alveolar bone; configuring transmitted ultrasonic waves based on the ultrasonic wave parameters; receiving an echo signal corresponding to the transmitted ultrasonic wave, and performing adaptive correction on parameters of each layer in the multilayer medium acoustic impedance model based on the acoustic impedance correction parameters by taking minimization of the difference between the echo signal and a theoretical reflection signal obtained by the multilayer medium acoustic impedance model as a target; and based on the multi-layer medium acoustic impedance model after self-adaptive correction, realizing detection of the tooth root on the bone surface of the alveolar bone. Compared with the prior art, the method has the advantages of accurate detection of the tooth root on the bone surface of the alveolar bone, high adaptability and the like.

Description

Technical Field

[0001] The invention relates to the technical field of face detection, in particular to a method and a detector for detecting tooth roots on alveolar bone surfaces. Background Art

[0002] The position of the teeth in the jaw is not clearly perceived on the mucosal surface and bone surface due to the wrapping of the alveolar bone. When performing maxillary segmentation surgery, anchorage nail implantation, and fixation of maxillary and mandibular fractures with titanium nails, even if there is a basis of imaging data, the sub-bone anatomy at the precise site cannot be detected and the root position cannot be accurately located. Therefore, root damage is common in clinical practice.

[0003] Due to the large variation in the position of tooth roots, the complex operation angles, and the close proximity of many tooth roots, it is difficult to accurately locate the tooth roots. Currently, the main bone and tooth detection technologies in clinical practice are X-ray and computed tomography (CT) technology. However, the instruments used in the above methods are large in size, fixed in position, expensive, and have ionizing radiation. They are not suitable for daily high-frequency detection of bone and tooth conditions, nor for emergency detection.

[0004] In summary, there is currently a lack of a method and instrument for detecting teeth in the jaw to perform rapid and accurate position calibration to fully protect the jaw surface and perform operations that cannot be performed under direct visual observation. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method and a detector for detecting tooth roots on the alveolar bone surface, so as to solve or partially solve the problem of inaccurate detection of tooth roots on the alveolar bone surface.

[0006] The purpose of the present invention can be achieved by the following technical solutions: One aspect of the present invention provides a method for detecting alveolar bone surface tooth root, comprising the following steps: Obtain age data and bone density data, and match corresponding ultrasonic parameters and acoustic impedance correction parameters; Construct a multi-layer dielectric acoustic impedance model including the alveolar bone surface and tooth root layer; configuring the emitted ultrasonic wave based on the ultrasonic wave parameters; receiving an echo signal corresponding to the transmitted ultrasonic wave, and adaptively correcting the parameters of each layer in the multi-layer medium acoustic impedance model based on the acoustic impedance correction parameter with the goal of minimizing the difference between the echo signal and a theoretical reflection signal obtained by the multi-layer medium acoustic impedance model; Based on the adaptively corrected multi-layer dielectric acoustic impedance model, the detection of tooth roots on the alveolar bone surface is achieved.

[0007] As a preferred technical solution, the multi-layer dielectric acoustic impedance model is modeled as follows: Z layer =ρ layer· c layer Among them, Z layer , layer 、c layer Respectively i Acoustic impedance, density, and sound wave propagation speed of the layer medium.

[0008] As a preferred technical solution, the process of adaptively correcting the parameters of each layer in the multi-layer medium acoustic impedance model comprises the following steps: Start a new round of calibration, calculate the reflection signals of each layer in the multi-layer medium acoustic impedance model, and obtain the total theoretical reflection signal; Calculating the difference between the theoretical reflection signal and the actually received echo signal; Based on the difference, with the goal of minimizing the difference between the actually received echo signal and the theoretical reflection signal, the acoustic impedance of at least one layer in the multi-layer medium acoustic impedance model is updated based on the acoustic impedance correction parameter to complete a round of correction; Repeat multiple rounds of calibration until the actual received echo signal matches the theoretical reflection signal.

[0009] As a preferred technical solution, the summed theoretical reflection signal is calculated using the following formula:

[0010]

[0011] in, is the initial sum of the theoretical reflection signals, It is i Layer and i +1 layer of reflection coefficient between the media, is the number of dielectric layers, , They are i Layer and i +1 layer of acoustic impedance.

[0012] As a preferred technical solution, updating the acoustic impedance of the layer in the multi-layer medium acoustic impedance model based on the acoustic impedance correction parameter is implemented by the following formula: Z new =Z old +α·E E=|R measured- R expected ∣ Among them, Z new, Z old is the acoustic impedance before and after the update, E is the difference between the echo signal and the theoretical reflection signal, α is the acoustic impedance correction parameter, and E is the echo signal R measured and the theoretical reflection signal R expected The difference between , || means taking the absolute value.

[0013] As a preferred technical solution, the multi-layer dielectric acoustic impedance model further includes at least one of an alveolar bone layer, an enamel layer, a dentin layer, and a gingival soft tissue layer.

[0014] As a preferred technical solution, the corresponding acoustic impedance correction parameters are matched based on the age data.

[0015] As a preferred technical solution, based on the ultrasonic parameters corresponding to the bone density data, the ultrasonic parameters include the proportion of low-frequency components in the emitted ultrasonic waves, and the larger the bone density data, the larger the proportion of the low-frequency components.

[0016] As a preferred technical solution, the process of detecting the alveolar bone surface and tooth root based on the adaptively corrected multi-layer dielectric acoustic impedance model includes: Based on the acoustic impedance size corresponding to the alveolar bone surface and root layer in the multi-layer medium acoustic impedance model, it is determined whether there is an alveolar bone surface and root at the location of the currently emitted ultrasonic wave.

[0017] Another aspect of the present invention provides an alveolar bone surface tooth root detector for implementing the aforementioned alveolar bone surface tooth root detection method, the detector comprising: An ultrasonic probe, comprising a shell with an acoustic insulation layer, wherein the shell includes a damping sound absorbing layer, an electrode connected with an electrode wire, a piezoelectric crystal, an acoustic matching layer and a protective layer; The host is connected to the ultrasonic probe through the electrode line, and the host includes a housing, a display, a synchronization circuit, a horizontal scanning circuit, a transmitting channel and a receiving channel, wherein the transmitting channel includes a power supply, a signal generator and a transmitting circuit, and the receiving channel includes a receiving circuit.

[0018] Compared with the prior art, the present invention has at least one of the following beneficial effects: (1) Accurate detection of tooth roots on the alveolar bone surface: The present invention first matches the corresponding parameters based on age information and bone density information, then constructs a multi-layer dielectric acoustic impedance model, and adaptively corrects the model based on the echo. Finally, the corrected model is used to accurately detect the root.

[0019] (2) Strong adaptability: The present invention adjusts the proportion of low-frequency components in the emitted ultrasonic waves and the acoustic impedance correction coefficient in the calibration process according to the differences in age and bone density, thereby ensuring the accuracy of detection when there are differences in age and bone density.

[0020] (3) Fast detection: After adaptive correction, the present invention realizes the detection of the tooth root on the alveolar bone surface based on the adaptively corrected multi-layer dielectric acoustic impedance model. It can complete a single detection in a short time (1s) and provide accurate data, with a fast detection speed.

[0021] (4) Non-destructive detection: The application principle of the present invention is ultrasonic detection, not imaging fluoroscopy, and there is no need to cause damage to bone tissue and surrounding tissues. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Flow chart of the alveolar bone surface tooth root detection method in the embodiment; Figure 2 This is a schematic diagram of the appearance of the detector in the embodiment; Figure 3 It is a structural schematic diagram of the probe in the embodiment; Figure 4 is a schematic diagram of an electronic device in an embodiment, Among them, 1. main unit, 2. ultrasonic probe, 3. electrode wire, 4. shell, 5. acoustic insulation layer, 6. damping sound absorption layer, 7. electrode, 8. acoustic matching layer, 9. protective layer, 10. piezoelectric crystal. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] Example 1 Regarding the problems existing in the above prior art, see Figure 1 This embodiment provides a method for detecting tooth roots on an alveolar bone surface, comprising the following steps: Step S1, according to the CT data and imaging data of the subject, the age data and bone density data of the subject are obtained, and the corresponding ultrasonic parameters and acoustic impedance correction parameters are matched, wherein the imaging data may include panoramic films and / or anteroposterior and lateral skull X-ray films. Preferably, the subject may be a human or an in vitro animal other than a human.

[0026] Taking into account the bone density and tooth development stage of different subjects, if fixed parameters are used for detection, it is easy to cause inaccurate detection results. In this step, the ultrasonic parameters of the ultrasonic wave and the acoustic impedance correction coefficient used for subsequent adaptive correction are matched according to the bone density and tooth development stage of the subjects.

[0027] Specifically, step S1 may include steps S101 - S102 .

[0028] Step S101, bone density change matching: Taking into account the large differences in bone density between different subjects (for example, the alveolar bone density between the elderly and the young is quite different), the bone density of the subjects is measured by imaging means (such as X-ray, CT, etc.) to obtain the bone density. For subjects with higher bone density, the proportion of low-frequency ultrasound is increased to ensure the accuracy of detection by enhancing the penetration of the signal.

[0029] Step S102, tooth development stage matching: considering that the development degree of tooth roots and enamel of young subjects is different from that of adults, which affects the propagation speed and density of sound waves, the corresponding impedance correction coefficient α is matched according to the age of the subject.

[0030] In order to adapt to different age groups and tooth development status, this method introduces an age-based correction factor α in the acoustic impedance calculation. Since the teeth and roots of children and adolescents are still in the developmental stage, their density and mineralization are lower than those of adults, resulting in weaker sound wave reflection; and elderly subjects often have osteoporosis or enamel wear, which will also affect the impedance measurement results. To ensure accuracy, the subject's age or tooth age is automatically identified according to the preset "tooth development stage database", and the corresponding correction factor α is selected: 1. Adolescent stage.

[0031] The tooth root is not fully developed and the mineralization is low. Moderately increase α to compensate for the low reflection value, thereby reducing the measurement deviation.

[0032] 2. Middle-aged stage.

[0033] The teeth and alveolar bones are relatively stable, the system keeps α in the neutral range, and the measurement results are highly consistent with the actual values.

[0034] 3. Old age stage.

[0035] The decrease in alveolar bone density and enamel thickness can easily lead to an overestimation of the impedance measurement; at this time, reduce α to avoid overestimation of the impedance value.

[0036] The above correction mechanism can be expressed by the formula Z final =Z raw ×α (age) This ensures that more accurate root impedance measurements can be obtained at different ages and developmental stages, thereby effectively reducing the risk of misjudgment and damage to the root.

[0037] Among them, α (age) is a correction factor that matches the age or developmental stage of the subject. For children or adolescents whose teeth are not fully developed, α (age) Relatively high; for elderly subjects whose bones may have degenerated, α (age) Relatively low.

[0038] In the application, according to the actual situation of the subject (dental age, bone age and basic information of oral X-ray, etc.), the appropriate α(age) and α (age) The value range is (0.8~1.2) to ensure the measurement accuracy of different populations.

[0039] Step S2, constructing a multi-layer dielectric acoustic impedance model including the alveolar bone surface and root layer.

[0040] The multi-layer medium acoustic impedance model takes into account the acoustic impedance differences of alveolar bone, tooth root, cementum, dentin, enamel and surrounding soft tissues (such as gums). Each medium has a different acoustic impedance, and these differences directly affect the propagation, reflection and energy transfer of ultrasound at the interface. Accurately calculating the acoustic impedance of each layer of medium is crucial to improving the resolution and positioning accuracy of the detector.

[0041] The formula for acoustic impedance is modeled as: Z = ρ·c Where: Z is the acoustic impedance of the medium (unit: Rayl, kg / (m²·s)); ρ is the density of the medium (unit: kg / m³); c is the speed of sound waves in the medium (unit: m / s).

[0042] In the application of alveolar bone and related structures, the acoustic impedance value of each layer of medium can be calculated by the physical properties of the medium (density and sound velocity). The medium is a multi-layer structure (such as alveolar bone, tooth root, enamel, etc.), and the following formula can be used to describe the acoustic impedance of each layer of medium: Z layer =ρ layer· c layer Where: Zlayer It is i The acoustic impedance of the layer medium (unit: Rayl, kg / (m²·s)) represents the acoustic impedance characteristics of each layer (such as alveolar bone, tooth root, enamel, etc.); ρ layer It is i Density of the layer medium; c layer It is i The speed of sound waves in a layered medium.

[0043] In this step, the density and propagation speed parameters of each layer of the model are initialized to the preset parameter values, as shown in Table 1.

[0044] Table 1 Initial values ​​of parameters of multilayer dielectric acoustic impedance model

[0045] Step S3, configuring the transmitted ultrasonic wave based on the ultrasonic wave parameters.

[0046] Considering that the design of ultrasonic waveform has a huge impact on detection accuracy, especially in the process of alveolar bone surface and tooth root detection, the selection and optimization of waveform will directly affect the transmission and reflection effect of the signal. In order to ensure that the ultrasonic wave can better penetrate the alveolar bone and accurately locate the root position, this step makes the following improvements: Low-frequency broadband pulse waveform: Considering the influence of the jaw when detecting the alveolar bone surface and tooth root, the ultrasonic wave emitted by the probe adopts a low-frequency broadband pulse waveform to ensure the ultrasonic wave's ability to penetrate the alveolar bone. Compared with high-frequency ultrasonic waves, low-frequency waves can more effectively penetrate the high-density jawbone and cementum. Through the design of broadband pulse waves, reflected signals can be generated in a multi-frequency range, thereby improving detection accuracy, especially in the high-density alveolar bone area.

[0047] Step S4, receiving the echo signal corresponding to the transmitted ultrasonic wave, with the goal of minimizing the difference between the echo signal and the theoretical reflection signal obtained by the multi-layer medium acoustic impedance model, and adaptively correcting the parameters of each layer in the multi-layer medium acoustic impedance model based on the acoustic impedance correction parameters.

[0048] The adaptive correction algorithm provided in this step makes the ultrasonic detection results more accurate by adjusting the acoustic impedance model and parameters in real time. This algorithm can dynamically adjust the impedance calculation according to the actual conditions of different subjects (such as bone density, tooth type, etc.) and optimize the detection process.

[0049] Specifically, this step may include steps S401-S403: Step S401, preliminary impedance calculation.

[0050] The preliminary acoustic impedance calculation is based on the initialized multi-layer medium acoustic impedance model to calculate the reflection signal strength of each layer:

[0051]

[0052] in is the total number of dielectric layers, is the reflection coefficient between layers, Z i and Z i+1 They are i Layer and i +1 layer of acoustic impedance.

[0053] Step S402: feedback adjustment.

[0054] During the measurement process, the device will receive the reflected signal in real time and compare it with the preset standard signal. If the strength of the reflected signal is significantly different from the expected value, it indicates that the impedance model calculated initially may not fully conform to the actual situation. At this time, feedback adjustment is performed.

[0055] The feedback adjustment process is based on the following principles: Step 1: Calculate the difference between the real-time reflection signal and the preset standard reflection signal, and define the error term E: E=|R measured- R expected ∣ Where: R measured is the actual measured reflection signal; R expected is the reflected signal calculated according to the expected model.

[0056] Step 2: Adjust the corresponding medium acoustic impedance value according to the error E. Assuming that the adjustment is made for a certain layer (such as alveolar bone or tooth root), update the acoustic impedance: Z new =Z old +α·E Among them, Z new is the updated acoustic impedance, Z old is the initially calculated acoustic impedance, and α is the impedance correction factor, which controls the magnitude of the correction.

[0057] Step S403, multiple iterations of optimization.

[0058] Through multiple iterations, the accuracy of the acoustic impedance calculation is adjusted each time, and the error is gradually reduced until the error meets the set accuracy requirements. In this process, the algorithm continuously optimizes the impedance value of each dielectric layer so that the final reflection signal is highly matched with the actual measurement result.

[0059] Step S5, based on the multi-layer medium acoustic impedance model after adaptive correction, realize the detection of the alveolar bone surface tooth root. The specific execution steps include steps S501-S506: Step S501, prepare the corrected model output data.

[0060] Calibrate acoustic impedance reference value: extract the model data after adaptive correction, clarify the acoustic impedance characteristic value of multi-layer media (alveolar bone, bone surface, tooth root, etc.); record the acoustic impedance value of each layer of media and its allowable error range to provide accurate matching standards for subsequent detection.

[0061] Verify model error correction: Confirm that the calibrated model has compensated for factors such as environmental noise and detection bias to ensure the reliability and accuracy of the output data.

[0062] Step S502, detection signal transmission and reception.

[0063] Design ultrasonic signal parameters: According to the model requirements, design the appropriate ultrasonic signal emission frequency and intensity to cover the specific acoustic impedance range of the target medium layer; Step S503, transmitting a signal: transmitting a preset signal to a target area through an ultrasonic transmitting device.

[0064] Echo signal reception: Through a high-sensitivity sensor, the echo signal returned by the ultrasonic wave after passing through multiple layers of media is collected to extract the time delay and amplitude characteristics.

[0065] Step S504: data processing and feature extraction.

[0066] Time delay and amplitude analysis: Calculate the time delay and amplitude changes of the echo signal, and combine it with the acoustic impedance model to deduce the distance and intensity attenuation of the ultrasonic wave passing through each layer of the medium.

[0067] Acoustic impedance inversion calculation: Using the corrected multi-layer medium acoustic impedance model, the acoustic impedance value of each layer of medium is determined through the inversion algorithm.

[0068] Step S505, target position determination.

[0069] Layer identification: Match the acoustic impedance value extracted from the echo signal with the acoustic impedance characteristic values ​​of the alveolar bone, bone surface and root layer in the model to identify whether the propagation path of the current detection signal is consistent with the target layer.

[0070] Target confirmation: Based on the multi-layer dielectric acoustic impedance model, determine whether the current signal corresponds to the alveolar bone surface or tooth root position. For example: Alveolar bone: The acoustic impedance value is significantly greater than that of the root layer and is continuous.

[0071] Root layer: The acoustic impedance value is relatively low and shows a certain degree of non-uniformity.

[0072] If the detection result does not match the target layer, the detection position or parameters can be adjusted according to the model feedback.

[0073] Step S506: visualization and data output.

[0074] Visualization of detection results: Generate two-dimensional or three-dimensional images to intuitively present the distribution of alveolar bone, bone surface and tooth root, and provide clinical decision support.

[0075] Data output: record the acoustic impedance value of each detection, the corresponding medium layer name and the target position status, to facilitate subsequent data archiving and analysis.

[0076] Based on the acoustic impedance size corresponding to the alveolar bone surface and root layer in the multi-layer medium acoustic impedance model, it is determined whether there is an alveolar bone surface and root at the location of the currently emitted ultrasonic wave.

[0077] Example 2 Based on Example 1, see Figure 2 and Figure 3 This embodiment provides an alveolar bone surface tooth root detector, which is used to implement the alveolar bone surface tooth root detection method as described in Example 1. The detector includes: An ultrasonic probe, comprising a shell with an acoustic insulation layer, wherein the shell includes a damping sound absorbing layer, an electrode connected with an electrode wire, a piezoelectric crystal, an acoustic matching layer and a protective layer; The host is connected to the ultrasonic probe through an electrode line. The host includes a plastic shell, a display, a synchronization circuit, a horizontal scanning circuit, a transmitting channel and a receiving channel, wherein the transmitting channel includes a power supply, a signal generator and a transmitting circuit, and the receiving channel includes a receiving circuit.

[0078] Among them, the ultrasonic probe is arranged at one end of the plastic shell, and its working end is a pen-shaped tip with a diameter of 1mm. The tip of the probe is the ultrasound emitting end; there is a red laser indicator light on each side of the plastic connecting handle above the ultrasonic probe, which is projected obliquely on the tip of the probe to mark the ultrasound site; the display shows the corresponding numerical value, and the displayed data is impedance conversion, and the data range value is 1~100dd.

[0079] When working, the probe is coated with coupling agent, and the transmitting circuit is triggered by the synchronization pulse signal input by the synchronization circuit, which generates a high-frequency electrical pulse signal to excite the chip, generate high-frequency vibration, and generate ultrasonic waves in the bone-tooth medium. Considering that ultrasound usually cannot penetrate bones, but the alveolar bone has a relatively low density, and low-frequency ultrasound has stronger permeability than high-frequency ultrasound, it can still partially penetrate the jawbone.

[0080] The ultrasonic transducer in the ultrasonic probe uses the piezoelectric effect to realize the mutual conversion between electrical energy and acoustic energy. The ultrasonic probe is the electrical load of the transmitter, requiring electrical impedance matching; the human tissue and organs (medium) are the mechanical load of the ultrasonic probe, requiring acoustic characteristic impedance matching.

[0081] The display shows different impedance values ​​according to the strength of the sound wave reflection. When the acoustic impedance value is greater than that of normal jawbone, it indicates that there are tooth roots or cementum in the area. When the acoustic impedance value is smaller, it indicates that the area is pure bone.

[0082] Example 3 This embodiment provides an electronic device, including: one or more processors and a memory, wherein the memory stores one or more programs, and the one or more programs include instructions for executing the alveolar bone surface root detection method as described in Example 1.

[0083] like Figure 4 As mentioned above, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 Of course, in addition to the software implementation, the present invention does not exclude other implementations, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0084] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for detecting tooth roots on alveolar bone surface, characterized in that: The steps include: According to the CT data and imaging data of the subject, the age data and bone density data of the subject are obtained, and the corresponding ultrasonic parameters and acoustic impedance correction parameters are matched; Construct a multi-layer dielectric acoustic impedance model including the alveolar bone surface and tooth root layer; configuring the emitted ultrasonic wave based on the ultrasonic wave parameters; receiving an echo signal corresponding to the transmitted ultrasonic wave, and adaptively correcting the parameters of each layer in the multi-layer medium acoustic impedance model based on the acoustic impedance correction parameter with the goal of minimizing the difference between the echo signal and a theoretical reflection signal obtained by the multi-layer medium acoustic impedance model; Based on the adaptively corrected multi-layer dielectric acoustic impedance model, the detection of tooth roots on the alveolar bone surface is achieved.

2. The alveolar bone surface tooth root detection method according to claim 1, characterized in that: The multi-layer dielectric acoustic impedance model is modeled as: Z layer =ρ layer· c layer， Among them, Z layer , layer 、c layer Respectively i Acoustic impedance, density, and sound wave propagation speed of the layer medium.

3. The alveolar bone surface tooth root detection method according to claim 1, characterized in that: The process of adaptively correcting the parameters of each layer in the multi-layer medium acoustic impedance model comprises the following steps: Start a new round of calibration, calculate the reflection signals of each layer in the multi-layer medium acoustic impedance model, and obtain the total theoretical reflection signal; Calculating the difference between the theoretical reflection signal and the actually received echo signal; Based on the difference, with the goal of minimizing the difference between the actually received echo signal and the theoretical reflection signal, the acoustic impedance of at least one layer in the multi-layer medium acoustic impedance model is updated based on the acoustic impedance correction parameter to complete a round of correction; Repeat multiple rounds of calibration until the actual received echo signal matches the theoretical reflection signal.

4. The alveolar bone surface tooth root detection method according to claim 3, characterized in that: The theoretical reflection signal of the sum is calculated using the following formula: ， ， in, is the initial sum of the theoretical reflection signals, It is i Layer and i +1 layer of reflection coefficient between the media, is the number of dielectric layers, , They are i Layer and i +1 layer of acoustic impedance.

5. The alveolar bone surface tooth root detection method according to claim 3, characterized in that: Updating the acoustic impedance of the layer in the multilayer medium acoustic impedance model based on the acoustic impedance correction parameter is achieved by the following formula: WITH new =Z old +α E, E=∣R measured- R expected ∣, Among them, Z new , Z old is the acoustic impedance before and after the update, E is the difference between the echo signal and the theoretical reflection signal, α is the acoustic impedance correction parameter, and E is the echo signal R measured and the theoretical reflection signal R expected The difference between , || means taking the absolute value.

6. The alveolar bone surface tooth root detection method according to claim 1, characterized in that: The multi-layer dielectric acoustic impedance model also includes at least one of an alveolar bone layer, an enamel layer, a dentin layer, and a gingival soft tissue layer.

7. The alveolar bone surface tooth root detection method according to claim 1, characterized in that: The corresponding acoustic impedance correction parameters are matched based on the age data.

8. The alveolar bone surface tooth root detection method according to claim 1, characterized in that: Based on the ultrasound parameters corresponding to the bone density data, the ultrasound parameters include the proportion of low-frequency components in the emitted ultrasound, and the larger the bone density data, the larger the proportion of the low-frequency components.

9. The alveolar bone surface tooth root detection method according to claim 1, characterized in that: Based on the adaptively corrected multi-layer dielectric acoustic impedance model, the process of detecting the alveolar bone surface and tooth root includes: Based on the acoustic impedance size corresponding to the alveolar bone surface and root layer in the multi-layer medium acoustic impedance model, it is determined whether there is an alveolar bone surface and root at the location of the currently emitted ultrasonic wave.

10. An alveolar bone surface tooth root detector, characterized in that: Used to implement the alveolar bone surface tooth root detection method according to any one of claims 1 to 9, the detector comprises: An ultrasonic probe, comprising a shell with an acoustic insulation layer, wherein the shell includes a damping sound absorbing layer, an electrode connected with an electrode wire, a piezoelectric crystal, an acoustic matching layer and a protective layer; The host is connected to the ultrasonic probe through the electrode line, and the host includes a housing, a display, a synchronization circuit, a horizontal scanning circuit, a transmitting channel and a receiving channel, wherein the transmitting channel includes a power supply, a signal generator and a transmitting circuit, and the receiving channel includes a receiving circuit.

Images