Electronic facebow angle accuracy testing method

Abstract

The present application relates to a kind of electronic face bow angle precision test methods, comprising: the test index for evaluating electronic face bow angle precision is established;With the set value of the preset test index, simulate the forward movement of mandible, backward movement, left lateral movement and right lateral movement;When simulating the forward movement of mandible, backward movement, left lateral movement and right lateral movement, the measurement value of test index is measured using electronic face bow;According to the set value and measurement value, calculate the measurement deviation value;Through multiple measurements under different set values, the measurement deviation value is counted, and the measurement precision of each test index of electronic face bow is estimated.The present application realizes the angle precision test of electronic face bow, and the test process is efficient and reliable.

Description

Technical Field

[0001] This invention belongs to the field of testing technology and oral medical devices, specifically relating to a method for testing the accuracy of electronic face bow angle. Background Technology

[0002] The electronic facebow is a precise tooth occlusion tracking and positioning device that can record mandibular movement trajectory and describe condylar mutation data. In conjunction with a digital CAD / CAM system, it provides dynamic data for digital treatment processes, effectively reducing clinical jaw adjustment time.

[0003] The electronic face bow consists of three parts: a transmitter and support, a mandibular fork and receiver, and a system host. The transmitter and support are installed on the patient's head and generate a stable magnetic field around the head after power-on. The receiver is installed on the patient's mandible via the mandibular fork to sense the spatial magnetic field. The system host is used for posture calculation and data output. During normal operation, the patient wearing the mandibular fork performs mandibular protrusion, retraction, leftward movement, rightward movement, and wide-opening movement. The receiver senses the magnetic field during the movement, and the system host calculates the movement trajectory, then calculates the angle between the trajectory and a reference plane, and finally outputs this angle for use in dental prosthesis restoration, etc.

[0004] When evaluating the accuracy of angle measurement using electronic face bow equipment, a reference plane is usually manually specified. The angle between the measurement trajectory and the reference plane varies depending on the reference plane. Testers cannot accurately control the position of the reference plane, making it difficult to precisely test the angle measurement accuracy of the electronic face bow in actual operation, thus failing to meet testing requirements. Therefore, existing methods cannot be used to complete the detection and screening of electronic face bow angle tests. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to disclose a method for testing the accuracy of electronic face bow angles, in order to solve the problem of testing electronic face bow angles.

[0006] This invention discloses a method for testing the accuracy of an electronic face bow angle, comprising: Establish test indicators for evaluating the angular accuracy of electronic face bows; The test indicators include the anterior tangential guide angle, the left lateral tangential guide angle, the right lateral tangential guide angle, the left condyle anterior condyle guide angle, the left condyle left lateral condyle guide angle, the right condyle anterior condyle guide angle, and the right condyle right lateral condyle guide angle. Using pre-set test index values, simulate the forward protrusion, backward movement, leftward movement, and rightward movement of the mandible; When simulating the forward, backward, leftward, and rightward movements of the mandible, the measured values ​​of the test indicators were obtained using an electronic face bow. The measurement deviation value is calculated based on the set value and the measured value; By taking multiple measurements at different set values, statistically analyzing the measurement deviations, and estimating the measurement accuracy of each test index of the electronic face bow.

[0007] Furthermore, when simulating the forward or backward movement of the mandible, the accuracy indicators of the tested electronic facebone include the forward protrusion guide slope, the left condyle protrusion guide slope, and the right condyle protrusion guide slope. When simulating left-lateral mandibular movement, the accuracy indicators of the tested electronic facebow include left-lateral tangential guide slope and left condylar guide slope. When simulating right-sided mandibular movement, the accuracy indicators of the tested electronic facebow include the right-sided tangential guide slope and the right condylar guide slope.

[0008] Furthermore, during the measurement process of simulating the forward movement, backward movement, and left or right side movement of the mandible, the transmitter of the electronic face bow remains in a fixed position relative to the mandible, while the receiver of the electronic face bow follows the movement of the maxilla and remains relatively fixed relative to the simulated incisor and the left and right condyles.

[0009] Furthermore, the testing process in simulating mandibular protrusion or retraction movements includes: When moving forward or backward, calculate the coordinates of the receiver in the transmitter coordinate system; Perform coordinate transformation to calculate the position coordinates of the simulated incisor in the mandibular coordinate system, and the coordinates of the left and right condyles in the maxillary coordinate system; When plotting protrusion or retraction movements, simulate the trajectory of the incisor in the mandibular coordinate system, and simulate the trajectories of the left and right condyles in the maxillary coordinate system; Based on the trajectory of the incisor in the mandibular coordinate system and the trajectories of the left and right condyles in the maxillary coordinate system, the measured values ​​of the incisor protrusion inclination, the left condyle protrusion inclination, and the right condyle protrusion inclination were calculated. , and .

[0010] Furthermore, the coordinates of the incision guide in the mandibular coordinate system are... ; This is the transformation matrix from the transmitter to the mandible. The transformation matrix from receiver to tangent; the coordinates of the forward-moving receiver in the transmitter coordinate system are... ; The coordinates of the left condyle in the maxillary coordinate system are: ; The coordinates of the right condyle in the maxillary coordinate system are: ; in, This is the transformation matrix from the receiver to the simulated left condyle. This is the transformation matrix from the receiver to the simulated right condyle. This is the transformation matrix from the left condyle to the maxilla in the simulation. This is the transformation matrix from the right condyle to the maxilla in the simulation.

[0011] Furthermore, the testing procedure for simulating left or right mandibular movements includes: When moving to the left or right, calculate the coordinates of the receiver in the transmitter coordinate system; Perform coordinate transformation to calculate the position coordinates of the incisor in the mandibular coordinate system and the coordinates of the left or right condyle in the maxillary coordinate system; When moving to the left, draw the trajectory curve of the incisor in the mandibular coordinate system and the trajectory curve of the left condyle in the maxillary coordinate system; The measured value of the left-side tangential slope is determined based on the tangential trajectory of the left-side motion. The measured value of the left condyle guide slope was determined based on the trajectory of the left condyle during left-side movement. ; When moving to the right side, draw the trajectory curve of the incisor in the mandibular coordinate system and the trajectory curve of the right condyle in the maxillary coordinate system; The measured value of the right-side tangential slope is determined based on the tangential trajectory of the right-side motion. The measured value of the right condyle guide slope was determined based on the trajectory of the right condyle during right-side movement. .

[0012] Furthermore, during left-side movement, Position coordinates of the tangent in the mandibular coordinate system ,in, This is the transformation matrix from the transmitter to the mandible. Let be the transformation matrix from receiver to tangent; the receiver's coordinates in the transmitter coordinate system are . ; The coordinates of the left condyle in the maxillary coordinate system are: , This is the transformation matrix from the left condyle to the maxilla. This is the transformation matrix from the receiver to the left condyle; When moving to the right, Position coordinates of the tangent in the mandibular coordinate system ; Let be the transformation matrix from receiver to tangent. The transformation matrix from transmitter to mandible; the receiver's coordinates in the transmitter coordinate system are... ; The coordinates of the right condyle in the maxillary coordinate system ; Let be the transformation matrix from the receiver to the right condyle. This is the transformation matrix from the right condyle to the maxilla.

[0013] Furthermore, through multiple measurements at different set values, the measurement deviation values ​​are statistically analyzed to estimate the measurement accuracy of each test index of the electronic face bow, including: statistically analyzing the angular deviation sequence of each angle in the test index. The value is set to the measurement accuracy of this angle; This is the root mean square value.

[0014] Furthermore, a medical jawbone frame was used to simulate mandibular protrusion, retraction, left lateral movement, and right lateral movement. The transmitter of the electronic face bow is fixed on the same plane as the medical jaw frame; the receiver of the electronic face bow is rigidly connected to the maxillary body of the medical jaw frame through a tooling, so that the receiver moves with the maxillary body; by measuring the receiver moving with the maxillary body through the electronic face bow, the simulated mandibular protrusion, retraction, left lateral movement and right lateral movement are measured through coordinate transformation.

[0015] Furthermore, before performing accuracy testing using the medical jawbone, the receiver parameters are calibrated using the medical jawbone; specifically including: Lock the central axis of the jawbone frame, lift the maxilla of the jawbone frame, and rotate it around the central axis within a certain angle range; record the sequence of receiver pose data during the rotation process. Based on the receiver pose data sequence and the relative pose relationship between the receiver and the left and right condyles of the jaw frame, the coordinate sequence of the left and right condyles of the jaw frame in the transmitter coordinate system is calculated; The coordinate sequence is corrected using an optimization method so that the deviation between the Euclidean distance calculated during the rotation of the corrected left and right condyles and the Euclidean distance obtained by the structural constraint on the jaw frame is less than the deviation threshold. During the correction process, the pose correction amount of the receiver in the transmitter coordinate system is obtained to form a correction coefficient matrix for calibrating the receiver pose parameters.

[0016] The present invention can achieve the following beneficial effects: The electronic facebow angle accuracy testing method of the present invention achieves trajectory measurement by simulating the movement of the human head and jaw, and finally evaluates the angle measurement accuracy through statistical methods, thus realizing the electronic facebow angle accuracy testing, and the testing process is efficient and reliable. Attached Figure Description

[0017] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0018] Figure 1This is a flowchart of the electronic face bow angle accuracy testing method in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the testing process during simulated mandibular protrusion or retraction movements in an embodiment of the present invention. Figure 3 This is a test flowchart illustrating the simulated left or right mandibular movement in an embodiment of the present invention. Figure 4 This is a schematic diagram of the medical jawbone structure in an embodiment of the present invention; Figure 5 This is a schematic diagram of an electronic facebow angle accuracy testing system constructed using a medical jaw frame, as described in an embodiment of the present invention. Figure 6 This is a schematic diagram of the position coordinate system of the receiver or transmitter of the electronic face bow in an embodiment of the present invention. Detailed Implementation

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0020] One embodiment of the present invention discloses a method for testing the accuracy of an electronic face bow angle, such as... Figure 1 As shown, it includes: Step S101: Establish test indicators for evaluating the accuracy of the electronic face bow angle; The test indicators include the anterior tangential guide angle, the left lateral tangential guide angle, the right lateral tangential guide angle, the left condyle anterior condyle guide angle, the left condyle left lateral condyle guide angle, the right condyle anterior condyle guide angle, and the right condyle right lateral condyle guide angle. Step S102: Simulate the forward protrusion, backward movement, leftward movement, and rightward movement of the mandible using the preset test index values; Simulators, including an extracorporeal simulator of the temporomandibular joint, can be used to simulate the forward, backward, leftward, and rightward movements of the mandible using pre-set test index values. Step S103: When simulating the forward, backward, leftward, and rightward movements of the mandible, the electronic face bow is used to measure the values ​​of the test indicators. Step S104: Calculate the measurement deviation value based on the set value and the measured value; Step S105: By taking multiple measurements under different set values, statistically analyze the measurement deviation values ​​and estimate the measurement accuracy of each test index of the electronic face bow.

[0021] Specifically, in the electronic face bow angle accuracy testing method of this embodiment, When simulating the forward or backward movement of the mandible, the electronic facial arch accuracy indicators tested include the forward protrusion guide slope, the left condyle forward protrusion guide slope, and the right condyle forward protrusion guide slope. When simulating left-lateral mandibular movement, the tested electronic facebow accuracy indicators include left-lateral tangential guide slope and left condylar guide slope. When simulating right-sided mandibular movement, the tested electronic facial bow accuracy indicators include right-sided tangential guide slope and right condylar guide slope.

[0022] Specifically, to improve the accuracy of the test, during the measurement process of simulating the forward movement, backward movement, and left or right side movement of the mandible, the position of the transmitter and the simulated mandible remains unchanged, and the receiver of the electronic face bow moves with the simulated maxilla, and the position of the simulated left and right condyles is relatively fixed.

[0023] Specifically, such as Figure 2 As shown, the test procedure in simulating mandibular protrusion or retraction includes: Step S201: During forward or backward movement, calculate the coordinates of the receiver in the transmitter coordinate system; Step S202: Perform coordinate transformation to calculate the position coordinates of the simulated incisor in the mandibular coordinate system and the coordinates of the simulated left and right condyles in the maxillary coordinate system. The coordinates of the incision guide in the mandibular coordinate system are: ; This is the transformation matrix from the transmitter to the mandible. The transformation matrix from receiver to tangent; the coordinates of the forward-moving receiver in the transmitter coordinate system are... ; The simulated left condyle has the following coordinates in the maxillary coordinate system: ; The simulated right condyle has the following coordinates in the maxillary coordinate system: ; in, This is the transformation matrix from the receiver to the simulated left condyle. This is the transformation matrix from the receiver to the simulated right condyle. This is the transformation matrix from the left condyle to the maxilla in the simulation. This is the transformation matrix from the right condyle to the maxilla in the simulation.

[0024] Step S203: When drawing the forward or backward movement, simulate the trajectory of the tangent in the mandibular coordinate system, and simulate the trajectory of the left and right condyles in the maxillary coordinate system. Step S204: Based on the trajectory of the incisor guide in the mandibular coordinate system and the trajectories of the left and right condyles in the maxillary coordinate system, calculate the measured values ​​of the protrusion incisor guide inclination, the protrusion condyle guide inclination of the left condyle, and the protrusion condyle guide inclination of the right condyle. , and ; Specifically, in the calculation method, the angles between the tangents of the three curves and the selected first reference plane are obtained, which are the measured values ​​of the anterior condyle tangential guide angle, the left condyle anterior condyle guide angle, and the right condyle anterior condyle guide angle, respectively. , and

[0025] The first reference plane can be a horizontal plane.

[0026] Specifically, such as Figure 3 As shown, the testing procedure for simulating left or right mandibular movements includes: Step S301: When moving to the left or right, calculate the coordinates of the receiver in the transmitter coordinate system; Step S302: Perform coordinate transformation to calculate the position coordinates of the simulated incisor in the mandibular coordinate system and the coordinates of the simulated left or right condyle in the maxillary coordinate system. When moving to the left, The simulated position coordinates of the tangent in the mandibular coordinate system ,in, Let be the transformation matrix from the transmitter to the simulated mandible. Let be the transformation matrix from receiver to analog tangent; the receiver's coordinates in the transmitter coordinate system are... ; The simulated left condyle has the following coordinates in the maxillary coordinate system: , This is the transformation matrix from the left condyle to the maxilla in the simulation. This is the transformation matrix from the receiver to the simulated left condyle; When moving to the right, The simulated position coordinates of the tangent in the mandibular coordinate system ; The transformation matrix from the receiver to the analog tangent. The transformation matrix from transmitter to simulated mandible; the receiver's coordinates in the transmitter coordinate system are... ; The simulated right condyle in the maxillary coordinate system ; This is the transformation matrix from the receiver to the simulated right condyle. This is the transformation matrix from the right condyle to the maxilla in the simulation.

[0027] Step S303: During the left-side movement, draw the simulated trajectory curve of the tangent in the mandibular coordinate system and the simulated trajectory curve of the left condyle in the maxillary coordinate system. Step S304: Determine the measured value of the left-side tangential slope based on the tangential trajectory of the left-side motion. The measured value of the left condyle guide slope was determined based on the trajectory of the left condyle during left-side movement. ; Specifically, during the leftward movement, the angle between the line connecting the starting and ending points of the tangential trajectory and the set second reference plane is measured as the leftward tangential slope. Calculate the angle between the line connecting the start and end points of the left condyle trajectory and the third reference plane, which is the measured value of the left condyle slope. .

[0028] The second reference plane can be a commonly used reference plane in existing methods, based on the measurement principle of tangential inclination. The third reference plane can be a simulated sagittal plane of the jawbone.

[0029] Step S305: During the right-side movement, draw the simulated trajectory curve of the incisor in the mandibular coordinate system and the simulated trajectory curve of the right condyle in the maxillary coordinate system. Step S306: Determine the measured value of the right-side tangential slope based on the tangential trajectory of the right-side motion. The measured value of the right condyle guide slope was determined based on the trajectory of the right condyle during right-side movement. .

[0030] Specifically, during the movement to the right, the angle between the line connecting the starting and ending points of the tangential trajectory and the set fourth reference plane is measured as the tangential slope on the right. Calculate the measured value of the guide slope of the right condyle, which is the angle between the line connecting the starting and ending points of the right condyle trajectory and the third reference plane. .

[0031] The fourth reference plane can be a commonly used reference plane in existing methods, based on the measurement principle of tangential inclination. The third reference plane can be a simulated sagittal plane of the jaw body.

[0032] Specifically, in step S105, through multiple measurements at different set values, the measurement deviation values ​​are statistically analyzed to obtain the angle deviation sequence for each angle in the test index, and the data of each angle deviation is collected. The value is set to the measurement accuracy of this angle; This is the root mean square value.

[0033] In this embodiment, as Figure 4 As shown, the temporomandibular joint extracorporeal simulation simulator used in steps S102-S102 is a medical jaw frame; preferably an average value jaw frame; A medical jawbone frame is used to simulate the forward protrusion, backward movement, leftward movement, and rightward movement of the mandible; like Figure 5 The diagram shows an electronic facebow angle accuracy testing system constructed using a medical jaw frame. The transmitter of the electronic facebow is fixed to the jaw frame on the same plane. The receiver of the electronic facebow is rigidly connected to the maxillary body of the jaw frame through a fixture, so that the receiver moves with the maxillary body. By measuring the receiver moving with the maxillary body through the electronic facebow, the simulated mandibular protrusion, retraction, left lateral movement, and right lateral movement are measured through coordinate transformation.

[0034] During the simulated mandibular movement, the pose data of the receiver is measured by the main unit of the electronic facebow; The test terminal is used to calculate the measured value of the test index and the measurement deviation value between the measured value and the set value based on the pose data; and to estimate the measurement accuracy of the electronic face bow by statistically analyzing the measurement deviation values ​​of multiple measurements under different set values.

[0035] The transmitter of the electronic face bow and the jaw frame are fixed on the same plane, which is the test fixture plane; the receiver of the electronic face bow is rigidly connected to the maxillary body of the jaw frame through a strip support plate; the receiver is glued to one end of the strip support plate; the other end of the strip support plate is fixed to the maxillary body; Preferably, after connection, the distance between the receiver and the front end of the jaw frame is 20cm.

[0036] The transmitter of the electronic face bow is bonded to the jaw support surface, and the distance between the center of the transmitter and the front end of the jaw support is maintained within a threshold range. Preferably, the threshold range is no more than 15cm.

[0037] The main unit of the electronic face bow measures the position data of the receiver, including three-axis position data of X, Y, and Z axes and three-axis attitude data including yaw angle, pitch angle, and roll angle.

[0038] like Figure 6 The figure shows a schematic diagram of the coordinate system of the receiver or transmitter position of the electronic face bow.

[0039] In the specific testing process of this embodiment, in accordance with Figure 5 After the system was set up as shown, it was powered on. The system was fault-free and preheated for 20 minutes.

[0040] Before conducting the accuracy test, in order to improve the accuracy of the test, this embodiment also uses a jaw frame to calibrate the receiver parameters. Specifically, it includes: 1) Lock the central axis of the jaw frame, lift the maxilla of the jaw frame, and rotate it around the central axis within a certain angle range; record the pose data sequence measured by the electronic face bow receiver during the rotation; the angle range is 30°~50°.

[0041] 2) Based on the receiver pose data sequence and the relative pose relationship between the receiver and the left and right condyles of the jaw frame, calculate the coordinate sequence of the left and right condyles of the jaw frame in the transmitter coordinate system; The calculation method is as follows: the three-dimensional coordinates of the left and right condyles in the receiver coordinate system are obtained by manual measurement. and Simultaneously, the three-dimensional coordinates of the receiver in the transmitter coordinate system are obtained through electronic face bow measurement. Then the coordinates of the left and right condyles of the jawbone in the launcher coordinate system can be calculated. , ; Once the relative position of the receiver and the jaw frame is determined, the relative pose relationship between the receiver and the left and right condyles of the jaw frame is determined. The relative pose relationship can be obtained by measurement, and the relative pose includes the relative position and the relative posture.

[0042] 3) The coordinate sequence is corrected using the simulated annealing optimization method so that the deviation between the Euclidean distance calculated by the corrected left and right condyles during rotation and the Euclidean distance (110mm) obtained by the structural limit on the jaw frame is less than the deviation threshold of 1mm; during the correction process, the pose correction amount of the receiver in the transmitter coordinate system is obtained to form a correction coefficient matrix for calibrating the pose parameters of the receiver.

[0043] The correction coefficient matrix ,in For receiver X-axis coordinate deviation, For receiver Y-axis coordinate deviation, For the Z-axis coordinate deviation of the receiver, For receiver heading angle deviation, For receiver pitch angle deviation, This refers to the receiver roll angle deviation.

[0044] The deviation threshold is 1 mm. This correction factor will be subtracted from all subsequent receiver measurements, and will not be discussed further thereafter.

[0045] After the system parameters are calibrated, jaw movement data are collected.

[0046] First, the test parameters were set. Multiple sets of jawbone parameters, each with 7 parameters, were randomly generated. The 7 parameters were the set values ​​for the incisor guide angle, the left side incisor guide angle, the right side incisor guide angle, the left condyle angle, the left side condyle angle, the right condyle angle, and the right side condyle angle. Table 1 shows the set values ​​for 20 sets of jawbone parameters.

[0047] Table 1. Cervical artery parameter settings / °

[0048] The jaw frame is set according to the set values ​​of the incisal guide angle and the condylar guide angle, including: Unlock the cervical artery center lock, loosen the left condyle side locking screw, and then tighten the locking screw after setting the left condyle protrusion guide slope and the left quadrangular condyle guide slope; Loosen the right condyle side locking screw, set the guide slope of the right anterior condyle and the guide slope of the right lateral condyle, and then tighten the locking screw; Loosen the guide pin locking screw, set the guide pin forward extension angle, left side guide angle, and right side guide angle, then tighten the locking screw.

[0049] During the simulated forward, backward, left, and right lateral movements of the mandible, the test terminal records trajectory data composed of receiver pose data during the movement.

[0050] Specifically, during the testing process, When simulating the forward or backward movement of the mandible Hold the incision guide pin with your hand and control the incision guide pin of the jaw frame to move forward or backward along the incision guide disc; at this time, the left and right condyles of the jaw frame will slide along the condylar fossa until they reach the structural limit, and then slowly return to the origin; repeat the above steps N times and record the receiver trajectory data during the process; When simulating leftward movement of the mandible, Hold the incision guide pin with your hand and control the incision guide pin of the jaw frame to move to the left side along the incision guide disc; at this time, the left condyle will slide laterally along the condylar fossa until it reaches the structural limit, and then slowly return to the origin; repeat the above steps N times and record the receiver trajectory data during the process; When simulating right-side movement of the mandible, Hold the incision guide pin with your hand and control the incision guide pin of the jaw frame to move to the right side along the incision guide plate; at this time, the right condyle will slide laterally along the condylar fossa until it reaches the structural limit, and then slowly return to the origin; repeat the above steps N times and record the receiver trajectory data during the process.

[0051] Preferably, the number of repetitions N=3.

[0052] The test indicators are measured based on the pose data in the test terminal. The data analysis process includes: When simulating the forward or backward movement of the mandible, the incision guide angle of the incision guide needle, the condyle guide angle of the left condyle, and the condyle guide angle of the right condyle are obtained based on the trajectory data of the receiver. When simulating the left-side movement of the mandible, the left-side incision guide angle of the incision guide needle and the left-side condyle guide angle of the left condyle are obtained based on the receiver trajectory data; When simulating the right-side movement of the mandible, the right-side incision guide angle and the right-side condyle guide angle are obtained based on the receiver trajectory data.

[0053] Specifically, based on the detailed scheme of steps S103-S104 above, multiple tests were conducted, and the angles obtained from the multiple sets of motion trajectories in the test terminal were as follows: ; In the test terminal, the set value is removed from the obtained angle sequence, and the resulting angle deviation sequence is: ; In step S105, through multiple measurements at different set values, the measurement deviation values ​​are statistically analyzed to obtain the angle deviation sequence for each angle in the test index, and the data for each angle deviation are collected. The value is set to the measurement accuracy of this angle. This is the root mean square value.

[0054] The accuracy of electronic face bow angle measurement is: .

[0055] The accuracy of the electronic face bow angle measurement enables the detection and screening of electronic face bows.

[0056] In summary, the electronic facebow angle accuracy testing method using a jaw frame in this embodiment of the invention can utilize the jaw frame to provide a stable reference plane, and combine the electronic facebow with the jaw frame. By simulating the movement of the human head's mandible, trajectory measurement is achieved. Then, the angle between the movement trajectory and the reference plane is calculated, and finally, the angle measurement accuracy is evaluated through statistical methods. This realizes the electronic facebow angle accuracy testing, and the testing process is efficient and reliable.

[0057] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for testing the accuracy of an electronic face bow angle, characterized in that, include: Establish test indicators for evaluating the angular accuracy of electronic face bows; The test indicators include the anterior tangential guide angle, the left lateral tangential guide angle, the right lateral tangential guide angle, the left condyle anterior condyle guide angle, the left condyle left lateral condyle guide angle, the right condyle anterior condyle guide angle, and the right condyle right lateral condyle guide angle. Using pre-set test index values, simulate the forward protrusion, backward movement, leftward movement, and rightward movement of the mandible; When simulating the forward, backward, leftward, and rightward movements of the mandible, the measured values ​​of the test indicators were obtained using an electronic face bow. The measurement deviation value is calculated based on the set value and the measured value; By taking multiple measurements under different set values, the measurement deviation values ​​are statistically analyzed, and the measurement accuracy of each test index of the electronic face bow is estimated. When simulating the forward or backward movement of the mandible, the accuracy indicators of the electronic facebow tested include the forward protrusion guide slope, the left condyle forward protrusion guide slope, and the right condyle forward protrusion guide slope. When simulating left-lateral mandibular movement, the accuracy indicators of the tested electronic facebow include left-lateral tangential guide slope and left condylar guide slope. When simulating right-sided mandibular movement, the accuracy indicators of the tested electronic facebow include the right-sided tangential guide slope and the right condylar guide slope.

2. The method for testing the accuracy of the electronic face bow angle according to claim 1, characterized in that, During the measurement process simulating the forward protrusion, backward movement, and left or right lateral movement of the mandible, the transmitter of the electronic face bow remains in a fixed position relative to the mandible, while the receiver of the electronic face bow follows the movement of the maxilla and remains relatively fixed relative to the simulated incisor and the left and right condyles.

3. The method for testing the accuracy of the electronic face bow angle according to claim 2, characterized in that, The testing procedure for simulating mandibular protrusion or retraction movements includes: When moving forward or backward, calculate the coordinates of the receiver in the transmitter coordinate system; Perform coordinate transformation to calculate the position coordinates of the simulated incisor in the mandibular coordinate system, and the coordinates of the left and right condyles in the maxillary coordinate system; When plotting protrusion or retraction movements, simulate the trajectory of the incisor in the mandibular coordinate system, and simulate the trajectories of the left and right condyles in the maxillary coordinate system; Based on the trajectory of the incisor in the mandibular coordinate system and the trajectories of the left and right condyles in the maxillary coordinate system, the measured values ​​of the incisor protrusion inclination, the left condyle protrusion inclination, and the right condyle protrusion inclination were calculated. , and .

4. The method for testing the accuracy of the electronic face bow angle according to claim 2, characterized in that, The coordinates of the tangent in the mandibular coordinate system are: ; This is the transformation matrix from the transmitter to the mandible. The transformation matrix from receiver to tangent; the coordinates of the forward-moving receiver in the transmitter coordinate system are... ; The coordinates of the left condyle in the maxillary coordinate system are: ; The coordinates of the right condyle in the maxillary coordinate system are: ; in, This is the transformation matrix from the receiver to the simulated left condyle. This is the transformation matrix from the receiver to the simulated right condyle. This is the transformation matrix from the left condyle to the maxilla in the simulation. This is the transformation matrix from the right condyle to the maxilla in the simulation.

5. The method for testing the accuracy of the electronic face bow angle according to claim 2, characterized in that, The testing procedure for simulating left or right mandibular movements includes: When moving to the left or right, calculate the coordinates of the receiver in the transmitter coordinate system; Perform coordinate transformation to calculate the position coordinates of the incisor in the mandibular coordinate system and the coordinates of the left or right condyle in the maxillary coordinate system; When moving to the left, draw the trajectory curve of the incisor in the mandibular coordinate system and the trajectory curve of the left condyle in the maxillary coordinate system; The measured value of the left-side tangential slope is determined based on the tangential trajectory of the left-side motion. The measured value of the left condyle guide slope was determined based on the trajectory of the left condyle during left-side movement. ; When moving to the right side, draw the trajectory curve of the incisor in the mandibular coordinate system and the trajectory curve of the right condyle in the maxillary coordinate system; The measured value of the right-side tangential slope is determined based on the tangential trajectory of the right-side motion. The measured value of the right condyle guide slope was determined based on the trajectory of the right condyle during right-sided movement. .

6. The method for testing the accuracy of the electronic face bow angle according to claim 5, characterized in that, When moving to the left, Position coordinates of the tangent in the mandibular coordinate system ,in, This is the transformation matrix from the transmitter to the mandible. Let be the transformation matrix from receiver to tangent; the receiver's coordinates in the transmitter coordinate system are . ; The coordinates of the left condyle in the maxillary coordinate system are: , This is the transformation matrix from the left condyle to the maxilla. This is the transformation matrix from the receiver to the left condyle; When moving to the right, Position coordinates of the tangent in the mandibular coordinate system ; Let be the transformation matrix from receiver to tangent. The transformation matrix from transmitter to mandible; the receiver's coordinates in the transmitter coordinate system are... ; The coordinates of the right condyle in the maxillary coordinate system ; Let be the transformation matrix from the receiver to the right condyle. This is the transformation matrix from the right condyle to the maxilla.

7. The method for testing the accuracy of the electronic face bow angle according to claim 4, characterized in that, By performing multiple measurements at different set values, statistically analyzing the measurement deviations, the measurement accuracy of each test index of the electronic face bow is estimated, including: the angular deviation sequence of each angle in the statistical test index. The value is set to the measurement accuracy of this angle; This is the root mean square value.

8. The method for testing the accuracy of the electronic face bow angle according to any one of claims 2-7, characterized in that, Using a medical jawbone frame to simulate mandibular protrusion, retraction, left lateral movement, and right lateral movement; The transmitter of the electronic face bow is fixed on the same plane as the medical jaw frame; the receiver of the electronic face bow is rigidly connected to the maxillary body of the medical jaw frame through a tooling, so that the receiver moves with the maxillary body; by measuring the receiver moving with the maxillary body through the electronic face bow, the simulated mandibular protrusion, retraction, left lateral movement and right lateral movement are measured through coordinate transformation.

9. The method for testing the accuracy of the electronic face bow angle according to claim 8, characterized in that, Before performing accuracy testing using the medical jawbone, the receiver parameters are calibrated using the medical jawbone; specifically including: Lock the central axis of the jawbone frame, lift the maxilla of the jawbone frame, and rotate it around the central axis within a certain angle range; record the sequence of receiver pose data during the rotation process. Based on the receiver pose data sequence and the relative pose relationship between the receiver and the left and right condyles of the jaw frame, the coordinate sequence of the left and right condyles of the jaw frame in the transmitter coordinate system is calculated; The coordinate sequence is corrected using an optimization method so that the deviation between the Euclidean distance calculated during the rotation of the corrected left and right condyles and the Euclidean distance obtained by the structural constraint on the jaw frame is less than the deviation threshold. During the correction process, the pose correction amount of the receiver in the transmitter coordinate system is obtained to form a correction coefficient matrix for calibrating the receiver pose parameters.

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