A method for calibrating a medical dental performance testing phantom

Abstract

The application discloses a medical dental performance detection phantom calibration method, and belongs to the technical field of medical instrument calibration. The method comprises the following steps: S1, setting the required environmental conditions for calibration; S2, preparing a measurement standard with valid traceability after verification or calibration; S3, performing appearance conformity inspection on the medical dental performance detection phantom; S4, measuring the thickness of the additional attenuation layer of the phantom by using a length measurement standard; S5, horizontally placing the phantom on an X-ray imaging system test platform; S6, measuring the width of each line pair of the spatial resolution module in the imaging mode of step S5; and S7, recording the calibration conditions, measurement data and calculation results. The calibration method and equipment of the application solve the problems of lack of unified standards, non-standard operation and low result reliability in the existing dental performance detection phantom calibration, and the standardized process, precise measurement and high adaptability equipment design provide data support for the daily maintenance and performance optimization of dental X-ray imaging equipment.

Description

Technical Field

[0001] This invention belongs to the field of medical instrument calibration technology, specifically relating to a calibration method for a medical dental performance testing phantom. Background Technology

[0002] Dental performance testing phantoms are crucial metrological tools for verifying the core performance characteristics of dental X-ray imaging systems (such as dental CT scanners and panoramic X-ray machines), including imaging accuracy and resolution. The accuracy of their parameters directly affects the performance evaluation results of medical equipment, and consequently, the reliability of clinical dental disease diagnosis. With the continuous development of dental medical technology, the requirements for the detection accuracy of X-ray imaging systems are increasing, leading to a sustained growth in the demand for testing phantom calibration.

[0003] However, the industry currently lacks unified and standardized technical standards and operating procedures for calibrating medical dental performance testing phantoms. On the one hand, the control range of calibration environmental conditions (temperature, humidity, air pressure, vibration, etc.) is unclear, and the traceability requirements of measurement standards are not clear, leading to significant differences in calibration results between different laboratories and operators, resulting in low data reliability. On the other hand, the measurement methods for core parameters (such as the thickness of the additional attenuation layer, the diameter of the circular hole in the low-contrast resolution module, and the line pair width of the spatial resolution module) lack unified standards. A scientific error calculation and uncertainty assessment system has not been established, making it difficult to accurately quantify phantom parameter deviations. Furthermore, the special adaptation scenarios of sealed, non-removable phantom structures are not considered, resulting in insufficient versatility. Simultaneously, existing calibration equipment suffers from unreasonable structural design: some equipment lacks multi-dimensional adjustment functions, making it unable to adapt to testing phantoms of different specifications and sizes; the phantom-bearing mechanism of some equipment lacks stability, easily causing displacement and vibration during calibration, further introducing measurement errors; in addition, the adjustment accuracy of the equipment's X-ray emission and detection components is limited, making it difficult to meet the positioning requirements of high-precision calibration.

[0004] The aforementioned problems result in inconsistent and untraceable calibration results for dental performance testing phantoms, failing to provide reliable evidence for the performance verification of dental X-ray imaging systems. This not only affects the routine maintenance and performance optimization of medical equipment but may also lead to clinical diagnostic risks due to equipment testing deviations, thus hindering the standardized development of the dental medical equipment metrology and calibration industry. Therefore, there is an urgent need for a standardized, high-precision, and versatile calibration method and supporting equipment for dental performance testing phantoms to address the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] To address the problems mentioned in the background section, the present invention adopts the following technical solution.

[0007] A method for calibrating a medical dental performance testing phantom includes the following steps: S1. Set the environmental conditions required for calibration; S2. Prepare measurement standards that have been verified or calibrated for effective traceability; S3. Conduct an appearance conformity inspection on the medical dental performance testing mold; S4. The thickness of the additional attenuation layer of the phantom is measured using a length measurement standard. Measurements are taken at three locations, and the average value is calculated according to the formula: Calculate the measurement error. If the additional attenuation layer is a sealed, non-removable structure, this calibration step can be omitted. In the formula: — Measurement error of the additional attenuation layer (unit: mm) — Nominal value of the additional attenuation layer (unit: mm). —Average of three measurements taken for the additional attenuation layer (unit: mm); S5. Place the phantom horizontally on the X-ray imaging system test platform. After selecting the appropriate conditions for scanning and imaging, use the system software to measure the nominal diameter holes of each low-contrast resolution module. For each calibration point, select three locations for measurement and take the average value. According to the formula: Calculate the relative error of the diameter of the circular hole, where: —Relative error of the i-th circular hole diameter calibration point (unit: %) — The nominal value of the diameter calibration point of the i-th circular hole (unit: mm). —The average value of three measurements of the diameter of the i-th circular hole calibration point (unit: mm); S6. Following the imaging method of step S5, measure the width of each line pair of the spatial resolution module. For each calibration point, select three locations for measurement and take the average value. Then, use the formula: Calculate the relative error of line pair width, where: —Relative error of the width calibration point of the i-th line pair (unit: %) — The nominal value of the width calibration point of the i-th line pair (unit: mm). —The average value of three measurements taken at the width calibration point of the i-th line pair (unit: mm); S7. Record calibration conditions, measurement data and calculation results, assess measurement uncertainty and issue calibration certificate.

[0008] Preferably, the environmental conditions described in step S1 are: ambient temperature of 15-35℃, relative humidity ≤85%, atmospheric pressure of 80-106kPa, and the calibration area is free from factors that may affect the calibration results, such as significant vibration or electromagnetic interference.

[0009] Preferably, the measurement standards in step S2 include: a length measurement standard with a measurement range of 0 to 300 mm and a maximum permissible error of ±0.01 mm, and an X-ray imaging system with a maximum permissible error of ±0.01 mm, and all of the measurement standards must be verified or calibrated to achieve effective traceability.

[0010] Preferably, the specific requirements for appearance conformity inspection in step S3 are: the mold body is clean and free of stains, each functional module is free of structural defects such as cracks and damage, and the mold body is clearly marked with its name, model, factory number and manufacturer in a prominent position.

[0011] Preferably, the nominal value of the additional attenuation layer in step S4 The thickness is 6mm, and the maximum permissible error for the additional attenuation layer thickness is no more than ±0.05mm.

[0012] Preferably, the nominal value of the circular hole of the low contrast resolution module in step S5 is... The relative error of any circular hole diameter calibration point, including 1mm, 1.5mm, 2mm, and 2.5mm. Not exceeding ±10%.

[0013] Preferably, the relative error of any line to the width calibration point in step S6 does not exceed ±10%.

[0014] Preferably, the method for evaluating the measurement uncertainty in step S7 is as follows: taking a circular hole with a nominal diameter of 1.5 mm as an example, (1) Calculate the uncertainty introduced by measurement repeatability using the Type A evaluation method. According to the formula: In the formula: R is the range of the three measurements of the circular hole (maximum value minus minimum value, unit: mm). 1.69 is the range coefficient when the number of measurements is 3; (2) Calculate the uncertainty introduced by the standard resolution of the measurement. According to the formula: Where: 0.01 is the resolution of the measurement standard (unit: mm); (3) Calculate the uncertainty introduced by the average value of the calibration point measurements. According to the formula: ; (4) Calculate the combined standard uncertainty According to the formula: ; (5) Calculate the relative expanded uncertainty Let the coverage factor k=2, according to the formula: .

[0015] A medical dental performance testing phantom calibration device is provided, which is calibrated by the above-mentioned medical dental performance testing phantom calibration method. The calibration device includes a base, on which uprights are symmetrically slidably connected. One upright is equipped with a longitudinally movable X-ray tube, and the other upright is equipped with a longitudinally movable linear array detector. A receiving groove is centrally located on the base, and a fixing block is centrally located in the receiving groove. A magnetically driven rodless slide is mounted on the upper surface of the fixing block. A first slider is provided on the magnetically driven rodless slide, and a workpiece stage is mounted on the first slider. The phantom is placed on the workpiece stage.

[0016] Preferably, the receiving groove contains a first screw, and the threads on the first screw are arranged opposite each other with its center as the base point. Each pair of uprights has a protrusion at the bottom. The uprights are mounted on the upper surface of the base, and their protrusions extend to the receiving groove and are threadedly connected to the first screw. A motor is provided at the upper end of the uprights, and the drive end of the motor is connected to a second screw. A mounting plate is provided on the front surface of the uprights, and the rear surface of the mounting plate is threadedly connected to the second screw. A second track is symmetrically provided on the front surface of the uprights, and a groove is opened on the rear surface of the mounting plate to slide and connect with the second track. A sliding groove is symmetrically opened on the lower surface of the uprights, and a first track is correspondingly provided on the base to match the sliding groove.

[0017] Preferably, the workpiece table includes a scissor-type support rod, which is raised and lowered by a screw handwheel assembly. Multiple limit rods are provided around the scissor-type support rod. A first slide is connected to the upper surface of the scissor-type support rod. The first slide is slidably sleeved on the limit rods. A second slide is mounted on the first slide, and a workpiece plate is installed on the upper surface of the second slide.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The calibration method and equipment of the present invention specifically address the problems of lack of unified standards, non-standard operation, and low reliability of results in the calibration of existing dental performance testing phantoms. Its standardized process, precise measurement, and highly adaptable equipment design not only improve the efficiency and quality of phantom calibration, but also provide data support for the daily maintenance and performance optimization of dental X-ray imaging equipment. It is of great significance to promote the standardized development of the dental medical equipment metrology calibration industry and has broad application prospects. Furthermore, by clarifying the traceability requirements of calibration environment conditions and measurement standards, the core indicators such as the thickness of the additional attenuation layer, the diameter of the circular hole of the low contrast resolution module, and the width of the line pair of the spatial resolution module are measured using the "three-point measurement and average value" method and a standardized error calculation model. The maximum allowable error of each indicator is strictly limited, and a scientific measurement uncertainty evaluation process is established, including the Type A evaluation method and the calculation of the combined standard uncertainty. This effectively avoids the influence of environmental interference and measurement random errors on the results, ensures the accuracy and reliability of calibration data, and provides a reliable basis for the performance verification of medical dental X-ray imaging systems.

[0019] (2) This invention constructs a seven-step standardized calibration process of “environment setting - standard preparation - appearance inspection - parameter measurement - result evaluation - certificate issuance”. Each step has a clear operating procedure and judgment standard to reduce the impact of human operation differences. At the same time, for the special case of the additional attenuation layer being a sealed and non-removable structure, a calibration step omission mechanism is designed to adapt to different structural types of test phantoms, broaden the scope of application of the technology, improve the flexibility and practicality of operation, and facilitate its promotion and application in medical testing institutions, metrological calibration laboratories and other scenarios. Moreover, this invention requires that the measurement standard be verified or calibrated to achieve effective traceability, and fully record the calibration conditions, measurement data, error calculation results and uncertainty evaluation process, and finally issue a standardized calibration certificate to ensure that the entire calibration process is traceable and verifiable, which meets the compliance requirements of medical equipment metrological calibration, provides indirect guarantee for the accuracy of clinical dental diagnosis, and reduces the diagnostic risk caused by equipment performance deviation.

[0020] (3) The calibration equipment adopts a symmetrical sliding stand and base adaptation design. The stand is adjusted laterally by the first screw, and the motor cooperates with the second screw to realize the vertical lifting of the X-ray tube and the linear array detector. Combined with the magnetic drive rodless slide to drive the workpiece stage to move, a multi-dimensional adjustment mechanism is formed, which can accurately adapt to medical dental performance testing molds of different specifications and sizes. The workpiece stage adopts a lifting structure of scissor support rod + screw handwheel group, combined with the limit rod and the limit and fine adjustment design of double-layer slide, which not only ensures the horizontal stability of the mold placement, but also realizes the accurate positioning of the mold position, reduces the interference of displacement and vibration on the measurement results during the calibration process, and improves the smoothness and consistency of the calibration process. Attached Figure Description

[0021] Figure 1 The overall structure of the calibration device in this invention Figure 1 ; Figure 2 The overall structure of the calibration device in this invention Figure 2 ; Figure 3 This is a structural diagram of the calibration device in this invention; Figure 4 This is a top view of the calibration device in this invention; Figure 5 This is a perspective view of the base of the calibration device in this invention; Figure 6 This is a perspective view of the workpiece stage in this invention.

[0022] The correspondence between the labels and component names in the attached figures is as follows: 101. Base; 101a. First track; 101b. Receiving groove; 101c. First screw; 101d. Magnetic drive rodless slide; 101e. First slider; 102. Stand; 102a. Protrusion; 102b. Slide groove; 102c. Motor; 102d. Second screw; 102e. Mounting plate; 102f. Second track; 103. Workpiece stage; 103a. Scissor-type support rod; 103b. Screw handwheel assembly; 103c. Limiting rod; 103d. First slide; 103e. Second slide; 103f. Placement plate; 200. X-ray tube; 300. Linear array detector. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments. The present invention provides the following embodiments.

[0026] Example 1 The medical dental performance testing phantom calibration method in this embodiment achieves the calibration of the phantom's core performance indicators through standardized process design and precise parameter control. Before formal calibration, the following steps are first performed: Step S1: Set environmental conditions: Adjust the ambient temperature of the calibration area to 15–35°C, control the relative humidity to ≤85% using dehumidification equipment, and ensure that the atmospheric pressure is maintained within the range of 80–106 kPa. The calibration area should be far away from vibration sources (such as large mechanical equipment) and strong electromagnetic interference sources (such as high-voltage lines and high-frequency equipment). Further reduction of the impact of environmental factors on calibration results and ensuring the stability of the calibration process can be achieved by installing auxiliary facilities such as vibration damping pads and electromagnetic shielding covers. Step S2: Prepare the measurement standards: For length measurement, select a digital micrometer with a range of 0–300 mm, a maximum permissible error of ±0.01 mm, and ensure it is certified by a legal metrology institution and within its validity period to guarantee the effective traceability of the measurement standards. The X-ray imaging system needs to be calibrated in advance, with its maximum permissible error controlled within ±0.01 mm. Simultaneously, debug the system software's measurement functions to ensure the accuracy of data acquisition and calculation. All measurement standards must be preheated before use to acclimatize to the ambient temperature and avoid measurement errors caused by temperature changes. Step S3: Perform an appearance conformity inspection. Use a combination of visual inspection and tactile examination to check whether the mold body is clean, free of stains, and without obvious scratches. If stains are present, gently wipe them clean with a special cleaning cloth. Pay special attention to checking each functional module (low contrast resolution module, spatial resolution module, additional attenuation layer, etc.) for structural defects such as cracks, damage, or deformation, ensuring that the modules are firmly connected and not loose. Simultaneously verify that the mold body is clearly marked with its name, model number, serial number, and manufacturer's identification. Mold bodies with incomplete or unclear markings must have their identification information verified before calibration to avoid confusion regarding calibration targets. Step S4: Measure the thickness of the additional attenuation layer: For a non-sealed, detachable mold structure, use the prepared length measurement standard to select three evenly distributed measurement positions in different areas of the additional attenuation layer. Ensure the measurement standard is perpendicular to the attenuation layer surface at each position to avoid measurement deviation due to tilting. Record the three measurement data, calculate the average value, and then... In the formula: — Measurement error of the additional attenuation layer (unit: mm) — Nominal value of the additional attenuation layer (unit: mm). —Calculate the measurement error by averaging the three measurements of the additional attenuation layer (unit: mm). If the absolute value of the error does not exceed 0.05 mm, the thickness of the additional attenuation layer is deemed to meet the requirements. If the phantom is a sealed and non-removable structure, this step can be omitted and the subsequent calibration process can proceed. Step S5: Measuring the diameter of the circular holes in the low-contrast resolution module: Place the phantom stably on the placement plate 103f of the workpiece stage 103. Adjust the lifting, translation, and fine-tuning functions of the workpiece stage 103 to ensure the phantom is horizontal and the low-contrast resolution module is directly facing the X-ray tube 200 and the linear array detector 300. Based on the phantom's specifications, set appropriate scanning conditions in the X-ray imaging system (e.g., tube voltage 60kV, tube current 8mA, exposure time 0.1s), and start the system for scanning imaging. After imaging, use the system software's measurement tools to measure the circular holes on the low-contrast resolution module with nominal diameters of 1mm, 1.5mm, 2mm, and 2.5mm. Select three measurement points at different orientations for each hole, record the data at each point, and calculate the average value. Then, follow the formula... In the formula: —Relative error of the i-th circular hole diameter calibration point (unit: %) — The nominal value of the diameter calibration point of the i-th circular hole (unit: mm). —Calculate the relative error of each hole by taking the average of three measurements (unit: mm) of the diameter calibration point of the i-th hole. If the absolute value of the relative error of all holes does not exceed 10%, the low contrast resolution module is deemed to meet the requirements. Step S6: Measure the line pair width of the spatial resolution module: Using the imaging method and scanning parameters from step S5, without readjusting the phantom position, directly measure the width of each line pair of the spatial resolution module using the system software. Three locations are selected for measurement at each line pair width calibration point. After recording the data, calculate the average value according to the formula. In the formula: —Relative error of the width calibration point of the i-th line pair (unit: %) — The nominal value of the width calibration point of the i-th line pair (unit: mm). —Calculate the relative error using the average of three measurements (in mm) at the i-th line pair width calibration point, ensuring that the absolute value of the relative error at all line pair width calibration points does not exceed 10%; Step S7 Recording and Evaluation: Record in detail the environmental conditions (temperature, humidity, air pressure), measurement standard information (model, verification certificate number), measurement data for each step (raw data, average value, error value), and calculation results during the calibration process, ensuring the information is complete, accurate, and traceable. The measurement uncertainty evaluation uses a 1.5mm nominal diameter circular hole as an example. First, the Type A evaluation method is used, based on the range R of the three measurements, according to the formula... Calculate the uncertainty introduced by measurement repeatability Then, based on the standard resolution of 0.01 mm, according to the formula... Calculate the uncertainty u2 introduced by the standard resolution of the measurement; then follow the formula Calculate the uncertainty u3 introduced by the average value of the calibration point measurements; then use the formula for combined standard uncertainty. Calculate the combined standard uncertainty Finally, take the coverage factor k=2, and follow the formula. Calculate the relative expanded uncertainty. After completing all evaluations, issue a standardized calibration certificate based on the calibration data and uncertainty results, clarifying whether the phantom is qualified and its relevant technical parameters, providing a basis for the use and maintenance of the phantom.

[0027] Example 2 See Figure 1 , Figure 2 as well as Figure 4 The medical dental performance testing phantom calibration device of this embodiment is primarily used to achieve high-precision and standardized calibration operations in conjunction with the calibration method. Its overall structure is designed around the stable support of the phantom and the precise adjustment of X-ray emission and detection. The base 101, as the basic support component of the device, is integrally formed using high-strength alloy material to ensure the rigidity and stability of the overall structure and avoid errors caused by base deformation during calibration. The first track 101a symmetrically arranged on the upper surface of the base 101 forms a precise sliding fit with the sliding groove 102b opened on the lower surface of the stand 102. The first screw 101c in the receiving groove 101b realizes the lateral position adjustment of the stand 102. The first screw 101c is driven by a servo motor, and its surface threads are set relative to each other with the center as the base point. When the motor is started, a pair of stands 102 can move synchronously in opposite directions along the first track 101a, thereby precisely adjusting the distance between the X-ray tube 200 and the linear array detector 300 to adapt to the imaging requirements of phantoms of different sizes.

[0028] See Figure 3In this embodiment, a motor 102c is fixedly installed on the upper end of the support frame 102. The motor 102c is a stepper motor with high-precision speed control capability. Its drive end is rigidly connected to the second screw 102d to ensure the stability of power transmission. The second track 102f, which is symmetrically arranged on the front surface of the support frame 102, slides and adapts to the groove on the rear surface of the mounting plate 102e, providing guidance and limiting for the longitudinal movement of the mounting plate 102e. When the motor 102c drives the second screw 102d to rotate, the mounting plate 102e moves along the second track 102d under the action of thread transmission. The track 102f rises and falls smoothly, thereby driving the X-ray tube 200 or the linear array detector 300 mounted on the mounting plate 102e to adjust its longitudinal position, ensuring the coaxiality of X-ray emission and detection and improving imaging accuracy. The X-ray tube 200 is a medical-grade dental X-ray tube that supports the adjustment of various tube voltage and tube current parameters and can be matched with appropriate scanning conditions according to the phantom calibration requirements. The linear array detector 300 uses a high-resolution detector chip and has fast signal acquisition and transmission capabilities to ensure the clarity and detail reproduction of the image.

[0029] See Figure 5 and Figure 6 In this embodiment, within the centrally located receiving slot 101b of the base 101, a magnetically driven rodless slide 101d is mounted on the upper surface of the fixing block. This slide features contactless transmission, smooth operation, and high positioning accuracy. Its sliding stroke can be flexibly set according to actual calibration requirements. The first slider 101e is slidably connected to the magnetically driven rodless slide 101d, driving the workpiece stage 103 above to move horizontally along the slide direction. This facilitates the precise delivery of the mold to the area directly opposite the X-ray tube 200 and the linear array detector 300. The scissor-type support rod 103a of the workpiece stage 103 is made of high-strength aluminum alloy and is raised and lowered via a screw handwheel assembly 103b. When the operator rotates the handwheel, the opening and closing angle of the scissor-type support rod 103a can be changed through the screw's thread transmission. The height of the mounting plate 103f is smoothly adjusted to ensure that the mold is always horizontal and perpendicular to the direction of X-ray emission. Multiple limiting rods 103c, which are set around the scissor-type support rod 103a, are evenly distributed around the support rod and play a guiding and limiting role for the first slide 103d to avoid deviation during the lifting process. The first slide 103d and the second slide 103e are connected by a precision guide rail, which can realize bidirectional fine adjustment of the mold on the horizontal plane, further improving the positioning accuracy of the mold and ensuring that each measurement point is accurately centered in the imaging area during the calibration process. The upper surface of the mounting plate 103f is covered with anti-slip rubber pads and adjustable elastic limiting blocks are set to firmly fix the molds of different shapes and sizes and prevent the molds from shifting or shaking during the calibration process.

[0030] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A method for calibrating a medical dental performance testing phantom, characterized in that, Includes the following steps: S1. Set the environmental conditions required for calibration; S2. Prepare measurement standards that have been verified or calibrated for effective traceability; S3. Conduct an appearance conformity inspection on the medical dental performance testing mold; S4. The thickness of the additional attenuation layer of the phantom is measured using a length measurement standard. Measurements are taken at three locations, and the average value is calculated according to the formula: Calculate the measurement error. If the additional attenuation layer is a sealed, non-removable structure, then this calibration step can be omitted. S5. Place the phantom horizontally on the X-ray imaging system test platform. After selecting the appropriate conditions for scanning and imaging, use the system software to measure the nominal diameter holes of each low-contrast resolution module. For each calibration point, select three locations for measurement and take the average value. According to the formula: Calculate the relative error of the diameter of the circular hole; S6. Following the imaging method of step S5, measure the width of each line pair of the spatial resolution module. For each calibration point, select three locations for measurement and take the average value. Then, use the formula: Calculate the relative error of line pair width; S7. Record calibration conditions, measurement data and calculation results, assess measurement uncertainty and issue calibration certificate.

2. The calibration method for a medical dental performance testing phantom according to claim 1, characterized in that: The environmental conditions described in step S1 are as follows: ambient temperature 15-35℃, relative humidity ≤85%, atmospheric pressure 80-106kPa, and the calibration area is free from factors that may affect the calibration results, such as significant vibration or electromagnetic interference.

3. The calibration method for a medical dental performance testing phantom according to claim 1, characterized in that: The measurement standards mentioned in step S2 include: a length measurement standard with a measurement range of 0 to 300 mm and a maximum permissible error of ±0.01 mm, and an X-ray imaging system with a maximum permissible error of ±0.01 mm. All of the measurement standards must be verified or calibrated to achieve effective traceability.

4. The calibration method for a medical dental performance testing phantom according to claim 1, characterized in that: The specific requirements for appearance conformity inspection in step S3 are as follows: the mold body is clean and free of stains, each functional module is free of structural defects such as cracks and damage, and the name, model, serial number and manufacturer are clearly marked in a prominent position on the mold body.

5. The calibration method for a medical dental performance testing phantom according to claim 1, characterized in that: The nominal value of the additional attenuation layer in step S4 The thickness is 6mm, and the maximum permissible error for the additional attenuation layer thickness is no more than ±0.05mm.

6. The calibration method for a medical dental performance testing phantom according to claim 1, characterized in that: The nominal value of the circular hole in the low contrast resolution module in step S5 The relative error of any circular hole diameter calibration point, including 1mm, 1.5mm, 2mm, and 2.5mm. The relative error of any line to the width calibration point in step S6 shall not exceed ±10%. Not exceeding ±10%.

7. The calibration method for a medical dental performance testing phantom according to claim 1, characterized in that: The evaluation method for measurement uncertainty in step S7 is as follows: taking a circular hole with a nominal diameter of 1.5 mm as an example, the uncertainty introduced by measurement repeatability is calculated using the Type A evaluation method. Combined with the uncertainty introduced by the measurement standard resolution, the relative expanded uncertainty is obtained by calculating according to the formula for combined standard uncertainty and taking the coverage factor k=2.

8. A medical dental performance testing phantom calibration device, calibrated using the medical dental performance testing phantom calibration method according to any one of claims 1-8, characterized in that, The calibration device includes a base (101), on which symmetrically sliding frames (102) are connected. One of the frames (102) is equipped with a longitudinally movable X-ray tube (200), and the other frame (102) is equipped with a longitudinally movable linear array detector (300). A receiving groove (101b) is centrally located on the base (101), and a fixing block is centrally located in the receiving groove (101b). A magnetic drive rodless slide (101d) is mounted on the upper surface of the fixing block. A first slider (101e) is provided on the magnetic drive rodless slide (101d), and a workpiece stage (103) is installed on the first slider (101e). The mold is placed on the workpiece stage (103).

9. The medical dental performance testing phantom calibration device according to claim 8, characterized in that, The receiving groove (101b) houses a first screw (101c), and the threads on the first screw (101c) are arranged opposite each other with their center as the base point. Each pair of uprights (102) has a protrusion (102a) at its bottom. The uprights (102) are mounted on the upper surface of the base (101), and their protrusions (102a) extend into the receiving groove (101b) and are threadedly connected to the first screw (101c). A motor (102c) is located at the upper end of each upright (102), and the drive end of the motor (102c) is connected to a second screw. (102d) The front surface of the upright (102) is provided with a mounting plate (102e), the rear surface of the mounting plate (102e) is threadedly connected to the second screw (102d), the front surface of the upright (102) is symmetrically provided with a second track (102f), the rear surface of the mounting plate (102e) is provided with a groove that is slidably connected to the second track (102f), the lower surface of the upright (102) is symmetrically provided with a sliding groove (102b), and the base (101) is correspondingly provided with a first track (101a) that is adapted to the sliding groove (102b).

10. The medical dental performance testing phantom calibration device according to claim 8, characterized in that, The workpiece stage (103) includes a scissor-type support rod (103a), which is raised and lowered by a screw handwheel assembly (103b). Multiple limit rods (103c) are provided around the scissor-type support rod (103a). A first slide (103d) is connected to the upper surface of the scissor-type support rod (103a). The first slide (103d) is slidably sleeved on the limit rods (103c). A second slide (103e) is assembled on the first slide (103d), and a workpiece plate (103f) is installed on the upper surface of the second slide (103e).

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