Self-calibration method for measuring parameters of measuring device, electronic device and storage medium

Abstract

The present invention discloses a self-calibration method for measuring parameters of a measuring device, an electronic device and a storage medium. The method determines the relative distance between a displacement zero point and the photoelectric switch by using a photoelectric switch with a fixed position as an absolute position reference, and converts the displacement zero point whose position does not drift into the value obtained by the relative distance. Each time a baffle blocks the photoelectric switch during each use, the accumulated value of the number of pulses is recalibrated, thereby ensuring the accuracy and stability of the measurement, providing reliable measurement parameters for clinical use and ensuring clinical safety.

Description

Technical Field

[0001] The present invention relates to the field of artificial intelligence technology, and in particular to a self-calibration method for measuring parameters of a measuring device, an electronic device, and a storage medium. Background Art

[0002] Knee replacement surgery is a procedure that replaces part of a patient's knee joint with an artificial part. When problems develop in the knee joint, pain, swelling, stiffness, or difficulty moving the knee properly can occur. Knee problems can be caused by a variety of conditions, one of the most common causes being osteoarthritis. Knee replacement surgery can effectively relieve knee pain and improve the way the knee joint works, making it a commonly performed orthopedic procedure.

[0003] The surface of the human knee joint is covered with cartilage. With age, the cartilage gradually wears away, and the bones and ligaments surrounding the knee joint also degenerate, ultimately causing knee pain, deformity, and mobility problems. Many people misunderstand that knee replacement surgery involves replacing the entire knee. However, this is not the case. Knee replacement surgery primarily replaces the cartilage on the surface of the knee joint, which has become worn and pitted, with a metal prosthesis and a wear-resistant polyethylene gasket.

[0004] During knee replacement surgery, correct ligament laxity and soft tissue balance are key indicators of surgical success. Therefore, during surgery, the knee joint space and soft tissue tension must be measured to tailor a surgical plan to the patient's needs. However, these values ​​are often estimated based on the surgeon's experience, which is inaccurate and can lead to inaccurate osteotomy, compromising both surgical effectiveness and safety.

[0005] The measurement accuracy of the measuring device is extremely important. In order to ensure the accuracy of the gap value measurement, the measurement parameters of the measuring device need to be calibrated. The existing technology lacks a measurement parameter calibration method for such products. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and provide a self-calibration method for measuring parameters of a measuring device, an electronic device and a storage medium, so as to solve the technical problem that there is no measurement parameter correction method for a balance measuring device for knee joint soft tissue in the related art.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] According to a first aspect of the present invention, there is provided a method for self-calibration of a measurement parameter of a measuring device, comprising:

[0009] Step S1, recording the first pulse number detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, where the first pulse number corresponds to the displacement zero point;

[0010] Step S2, recording the second pulse number detected by the displacement sensor from the moment the push-up plate is opened to the moment when the photoelectric switch is not blocked;

[0011] Step S3, calculating the difference between the second pulse number and the first pulse number, and determining the relative distance between the displacement zero point and the photoelectric switch according to the difference;

[0012] Step S4: calibrating the zero point of the displacement sensor according to the relative distance;

[0013] Wherein, the measuring device comprises:

[0014] The first upper push plate, the second upper push plate, and the lower push plate, each of the two upper push plates is driven by a set of independent drive components; the drive component of the upper push plate on each side includes: a drive screw, which is relatively rotatably connected to the fixed shell; a transmission nut, which is threadedly connected to the drive screw; a guide slider, which is connected to the fixed shell; a linear guide rail, one end of the linear guide rail is connected to the transmission nut, and the other end passes through the guide slider and the fixed shell and is connected to the upper push plate on the corresponding side.

[0015] Preferably, in step S1, recording the first pulse number detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps includes:

[0016] After powering on, determine whether the photoelectric switch is blocked. If so, expand the upper push plate and then retract it. Otherwise, retract the upper push plate directly until the photoelectric switch is blocked.

[0017] When the photoelectric switch is blocked, it is determined whether the motor is blocked. If so, the contraction is stopped, the motor rotates a specific number of steps, and the upper push plate is opened to a specific displacement. The current number of pulses is recorded as the first pulse number. Otherwise, the upper push plate continues to be contracted until the motor is blocked.

[0018] Preferably, in step S2, recording the second pulse number detected by the displacement sensor from the moment the push-up plate is extended to the moment when the photoelectric switch is not blocked includes:

[0019] After recording the first pulse number, push the upper push plate open, and when the photoelectric switch is not blocked, record the current pulse number as the second pulse number.

[0020] Preferably, the method further comprises:

[0021] Place the measuring device at any angle. When no load is applied to the upper push plate, the first and second upper push plates are extended to the maximum travel point and then return to the origin.

[0022] When the first push plate returns to the origin from the maximum stroke point, the displacement value detected by the displacement sensor is recorded as The pressure value detected by the force sensor is recorded as The rotation angle of the moving part is recorded as θ 1 ;

[0023] When the second push plate returns to the origin from the maximum stroke point, the displacement value detected by the displacement sensor is recorded as The pressure value detected by the force sensor is recorded as The rotation angle of the moving part is recorded as θ 2 ;

[0024] The θ 1 ,θ 2 Substitute into the first force balance calculation formula to calculate the tension F2 of the elastic seal.

[0025] Preferably, the first force balance calculation formula includes:

[0026] F4=F2+Gcosθ=ks3+b+Gcosθ (1);

[0027]

[0028] Where G represents the gravity value of the moving part, S3 represents the actual value measured by the displacement sensor, F2 = ks3 + b, k is the elastic coefficient, b is the initial tension value, k and b are unknowns; Formula (1) represents that the pressure value F4 collected by the force sensor is equal to the sum of the tension F2 of the elastic seal and the gravity component of the moving part in the direction of the tension F2.

[0029] Preferably, the method further comprises:

[0030] Calculate the friction force F3 generated by the bending moment on the slider after the push plate applies a load to generate the downward thrust F1;

[0031] Measure the rotation angle θ of the moving part after the push plate applies a load to generate a downward thrust F1;

[0032] The tension F2 of the elastic seal, the friction force F3, and the pressure value F4 collected by the force sensor are substituted into the second force balance calculation formula to calculate the thrust F1 of the upper push plate on the femoral condyle.

[0033] Preferably, the calculation of the friction force F3 generated by the bending moment on the slider after the thrust F1 is generated by the end of the upper push plate is specifically:

[0034] The friction force F3 generated by the bending moment of the slider is calculated according to the following formula, including:

[0035] F3=μ(F1L1+F4L2) (4);

[0036] Where μ is the ratio of friction to torque between the slider and the linear guide, L1 is the torque from the thrust F1 to the linear guide, and L2 is the torque from the force sensor to the linear guide. (F1L1 + F4L2) represents the torque generated by the interaction between the slider and the linear guide after the thrust F1 is applied at the end of the upper push plate.

[0037] Preferably, the second force balance calculation formula includes:

[0038] F4=F1+F2+F3+Gcosθ=F1+ks3+b+μ(F1L1+F4L2)+Gcosθ (3).

[0039] Preferably, the method further comprises:

[0040] When the push plate is subjected to force, the end will produce elastic deformation. The deformation variable Δs is calculated according to the following formula:

[0041] Δs=mF1(4);

[0042] The displacement sensor's measured value S3 is corrected according to the following formula to output the gap value S1 between the femur and tibia:

[0043]

[0044] Where m is the elastic coefficient of the deformation of the upper push plate end under the action of F1.

[0045] According to a second aspect of the present invention, there is provided a self-calibration device for measuring parameters of a measuring device, comprising:

[0046] a recording module, configured to record a first pulse number detected by the displacement sensor at the moment when the linear guide rail moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, wherein the first pulse number corresponds to a displacement zero point;

[0047] It is also used to record the second pulse number detected by the displacement sensor from the moment the push-up plate is opened to the moment the photoelectric switch is unblocked;

[0048] a calculation module, configured to calculate a difference between the second pulse number and the first pulse number, and determine a relative distance between the displacement zero point and the photoelectric switch according to the difference;

[0049] The correction module is used to correct the displacement zero point of the displacement sensor according to the relative distance.

[0050] According to a third aspect of the present invention, there is provided an electronic device, comprising:

[0051] A processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus;

[0052] Memory for storing computer programs;

[0053] The processor is used to implement the above method when executing the program stored in the memory.

[0054] According to a fourth aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause a computer to execute the above method.

[0055] The technical solutions provided by the embodiments of the present invention may have the following beneficial effects:

[0056] By using the photoelectric switch with a fixed position as an absolute position reference, the relative distance between the displacement zero point and the photoelectric switch is determined, and the displacement zero point with no position drift is converted through the relative distance. Each time the baffle blocks the photoelectric switch during each use, the accumulated value of the number of pulses will be recalibrated, ensuring the accuracy and stability of the measurement, providing reliable measurement parameters for clinical practice, and ensuring clinical safety.

[0057] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 is a rear view of a measuring device according to an exemplary embodiment;

[0059] Figure 2 is a side view of a measuring device according to an exemplary embodiment;

[0060] Figure 3 is a cross-sectional view of a measuring device according to an exemplary embodiment;

[0061] Figure 4 is a cross-sectional view of a measuring device according to an exemplary embodiment;

[0062] Figure 5 is a flow chart showing a method for self-calibration of measurement parameters of a measurement device according to an exemplary embodiment;

[0063] Figure 6 This is a flow chart showing the overall concept of a self-calibration method for measuring parameters of a measuring device according to an exemplary embodiment;

[0064] Figure 7 is a schematic block diagram of a self-calibration device for measuring parameters of a measuring device according to an exemplary embodiment;

[0065] Figure 8 It is a schematic block diagram of an electronic device shown in an exemplary embodiment. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0067] As described in the background art above, the related art does not address the technical problem of a method for correcting measurement parameters of a balance measurement device for knee joint soft tissue.

[0068] In order to effectively solve the problems in the related art, the present invention provides a self-calibration method for measuring parameters of a measuring device, an electronic device and a storage medium, which are described in detail below.

[0069] It should be noted that the technical solutions provided in the following embodiments are based on Figures 1 to 4 The applicant has realized this on the basis of the utility model patent (application number: 202321985230.9) previously applied for. In order to facilitate the understanding of the technical solution of this application, Figures 1 to 4 The relevant operating principle of the measuring device shown is explained below:

[0070] See also Figure 1 The measurement device includes two upper push plates: a first upper push plate A1 and a second upper push plate A2, and a lower push plate B. Lower push plate B is stationary during use, while the two upper push plates push upward against the lateral and medial condyles of the femur, respectively. Each upper push plate is driven by an independent drive assembly, allowing it to operate independently.

[0071] See also Figure 3 and Figure 4 Taking the upper push plate on either side as an example, the drive assembly of the upper push plate includes: a drive screw 81, which is relatively rotatably connected to the fixed shell 7; a transmission nut 82, which is threadedly connected to the drive screw 81; a guide slider 83, which is connected to the fixed shell 7; a linear guide rail 84, which is connected to the transmission nut 82, one end of the linear guide rail 84 is connected to the transmission nut 82, and the other end of the linear guide rail 84 passes through the guide slider 83 and the fixed shell 7, and is connected to the upper push plate 2.

[0072] The linear guide rail 84 can slide up and down in the fixed shell 7 through the guide slider 83, avoiding interference from external factors during sliding. Moreover, the movement distance of the push plate 2 can be transmitted to the internal structure of the measuring device through this movement mode of the linear guide rail 84.

[0073] First, the lower push plate 1 is brought into contact with the tibia 11, and then the drive motor 91 and the reducer 92 are adjusted. The drive bolt 81 rotates under the action of the drive motor 91 and the reducer 92, and the transmission nut 82 cooperates with the thread of the drive bolt 81 to drive the transmission nut 82 to move up and down. The first connecting member 65 and the second connecting member 66 connected to the transmission nut 82 drive the linear guide rail 84 to move up and down until the upper push plate 2 contacts the femur 21. At this time, the force sensor 68 can accurately measure the tension value of the soft tissue of the knee joint. The displacement of the linear guide rail 84 is the gap value between the soft tissues of the knee joint. The magnetic scale 61 is fixedly connected to the linear guide rail 84. The reading component 63 can accurately measure the gap value between the soft tissues of the knee joint by detecting the displacement of the magnetic scale 61.

[0074] An elastic seal 841 is sleeved on the linear guide rail 84, one end of the elastic seal 841 is connected to the fixed shell 7, and the other end of the elastic seal 841 is connected to the upper push plate 2; the elastic seal 841 serves as a direct mechanism for driving the upper push plate 2, and can convert the force of the elastic component into a soft tissue tension value, and convert the displacement of the linear guide rail 84 through the displacement of the elastic component, and can further seal the fixed shell 7 to prevent external impurities from entering, thereby ensuring the normal operation of the detection device.

[0075] The drive motor 91 and the reducer 92 can drive the push plate 2 to move to a suitable measurement position via the drive screw 81 and the linear guide 84. The measuring assembly 6 (i.e., the displacement sensor mentioned in the following embodiments) includes: a magnetic scale 61, which is connected to the linear guide 84; a collection board 62, which is disposed on the fixed housing 7; a reading component 63, which is disposed on the collection board 62 and corresponds to the magnetic scale 61 to record the movement distance of the magnetic scale 61; and a photoelectric switch 64 for sensing the position of the magnetic scale 61. The photoelectric switch 64 is disposed on the collection board 62 and is spaced apart from the reading component 63.

[0076] Using the above device, the magnetic scale 61 is connected to the linear guide 84, ensuring that the movement distance of the magnetic scale 61 is consistent with the movement distance of the second support component 2 or the third support component 3. The reading component 63 can measure the movement distance of the magnetic scale 61, and the photoelectric switch 64 can determine the displacement zero point of the magnetic scale 61. By using the displacement zero point and the movement distance, the gap value between the femur and tibia at different extension and flexion angles can be accurately measured. This balance measurement device can measure the gap value and soft tissue tension value between the femur and tibia at different extension and flexion angles to achieve good soft tissue balance, thereby reducing the number of osteotomy adjustments or ligament damage to the patient, and also reducing surgical time.

[0077] For ease of reference, the parameters involved in the following implementations are summarized below, including:

[0078] F1—thrust on the femoral condyle, which is the actual load value to be output after compensation;

[0079] F2—Tension force generated when the elastic seal is stretched;

[0080] F3—After the upper push plate generates thrust, the friction force generated by the bending moment on the slider can be obtained through calculation;

[0081] F4—Force sensor value, which is the force value directly collected by the force sensor and is a known quantity collected in real time;

[0082] G—The weight of the moving parts, which is determined by the structure and material and is a known constant;

[0083] s1—the actual gap between the femoral condyle and the tibial plateau, which is the actual gap value after compensation;

[0084] Δs—The deformation between the upper push plates when the upper push plates are subjected to load, which needs to be calculated based on the load and the elastic coefficient of the push plates;

[0085] s3—the measured value of the displacement sensor (magnetic scale), which is a known quantity acquired in real time;

[0086] μ—The ratio between the friction force and torque between the slider and the linear guide, similar to the friction coefficient, is a known constant;

[0087] m—The elastic coefficient of the deformation of the upper push plate end under the action of F1, which is a known constant.

[0088] Example 1

[0089] Figure 5 is a flow chart showing a method for self-calibration of a measurement parameter of a measurement device according to an exemplary embodiment. Figure 5 , the method comprising:

[0090] Step S1, recording the first pulse number detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, where the first pulse number corresponds to the displacement zero point;

[0091] Step S2, recording the second pulse number detected by the displacement sensor from the moment the push-up plate is opened to the moment when the photoelectric switch is not blocked;

[0092] Step S3, calculating the difference between the second pulse number and the first pulse number, and determining the relative distance between the displacement zero point and the photoelectric switch according to the difference;

[0093] Step S4: calibrating the zero point of the displacement sensor according to the relative distance;

[0094] Among them, see Figure 1 、 Figure 3 and Figure 4 , the measuring device comprises:

[0095] The first upper push plate A1 and the second upper push plate A2, and the lower push plate B, each of the two upper push plates is driven by a set of independent drive components; the drive component of the upper push plate on each side includes: a drive screw 81, which is relatively rotatably connected to the fixed shell 7; a transmission nut 82, which is threadedly connected to the drive screw 81; a guide slider 83, which is connected to the fixed shell 7; a linear guide rail 84, one end of which is connected to the drive nut 82, and the other end passes through the guide slider 83 and the fixed shell 7, and is connected to the upper push plate 2 on the corresponding side.

[0096] It should be noted that the technical solution provided in this embodiment is applicable to Figures 1 to 4 In the measuring device shown in the figure, since the displacement sensor in this measuring device has no memory function (it does not record the initial point position after each calibration), the linear guide movement distance is calculated by accumulating pulses, so displacement zero point calibration is required every time the device is turned on.

[0097] Each time the machine is turned on, regardless of the operating status of the measuring device (for example, the upper push plate is extended or retracted), the motor must first drive the linear guide rail to reset to the position where the photoelectric switch is blocked, and then perform displacement zero point calibration.

[0098] Due to the characteristics of the displacement sensor, after each reset, it is necessary to control the motor to rotate a specific number of steps and expand the push plate a certain distance to prevent the motor from being blocked when the linear guide displacement is reset during normal use, making it impossible to read the value normally. (From the time the photoelectric switch is blocked to the time the motor is blocked, the structural design of the measuring device ensures that the photoelectric switch is always blocked.) This specific number of steps is a random number, because the displacement sensor is a cumulative count. If the moment the linear guide is reset and the motor rotates a specific number of steps, the magnetic scale reading head detects and records the first pulse number as 58, then the next time it is used, due to the different number of steps the motor rotates, the first pulse number detected and recorded by the magnetic scale reading head may be 100. Since the magnetic scale reading head calculates the distance the magnetic scale moves by counting the increase or decrease of pulses, the starting point position is different each time, which will not affect the normal use of the displacement sensor.

[0099] Theoretically, each time the measuring device is used after powering on, the linear guide should be reset to the position with the previously recorded pulse number of 58 or 100. However, due to the possibility of step-out of the pulse number collected by the magnetic scale reading head, it will not be completely reset to the previously calibrated position each time. The photoelectric switch is set on a fixed housing, and the position of the photoelectric switch is unchanged. Therefore, the photoelectric switch can be used as an absolute position reference, and the displacement zero point can be found by the relative distance from the photoelectric switch.

[0100] Under the guidance of the above-mentioned inventive concept, after completing step S1 to record the first pulse number P1 detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, it is necessary to continue to expand the upper push plate, execute step S2 to record the second pulse number P2 detected by the displacement sensor at the moment when the upper push plate is expanded to the point where the photoelectric switch is not blocked, and then execute step S3 to calculate the difference P2-P1 between the second pulse number P2 and the first pulse number P1, and determine the relative distance between the displacement zero point and the photoelectric switch based on the difference. Since the position of the photoelectric switch is fixed, the displacement zero point whose position will not drift can be converted into the relative distance.

[0101] After calibrating the displacement zero point, the magnetic scale reading head will detect and record the number of pulses during normal use (the number of pulses can be converted into the measurement value S3 of the displacement sensor (magnetic scale)). The number of pulses will accumulate during the push-out movement and decrease during the contraction process.

[0102] It can be understood that the technical solution provided in this embodiment determines the relative distance between the displacement zero point and the photoelectric switch by taking the photoelectric switch with a fixed position as an absolute position reference, and converts the displacement zero point whose position will not drift by using the relative distance. Each time the baffle blocks the photoelectric switch during each use, the accumulated value of the number of pulses will be recalibrated, thereby ensuring the accuracy and stability of the measurement, providing reliable measurement parameters for clinical practice, and ensuring clinical safety.

[0103] Specifically, in step S1, recording the first pulse number detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps includes:

[0104] After powering on, determine whether the photoelectric switch is blocked. If so, expand the upper push plate and then retract it. Otherwise, retract the upper push plate directly until the photoelectric switch is blocked (if the photoelectric switch is blocked, it means that the upper push plate was retracted when it was last used, and it can be retracted to reset it. If the photoelectric switch is not blocked, it means that the upper push plate was expanded when it was last used, and it can be retracted to reset it directly).

[0105] When the photoelectric switch is blocked, determine whether the motor is stalled. If so, stop contracting, and the motor rotates a specific number of steps to expand the push plate to a specific displacement. The current number of pulses is recorded as the first pulse number. Otherwise, continue to contract the push plate until the motor is stalled (motor stalling indicates a successful reset. The specific number of rotation steps is determined by the usage characteristics of the displacement sensor. In order to ensure the normal use of the displacement sensor, the specific number of steps and specific displacement here are random numbers, as long as they do not exceed the threshold).

[0106] Specifically, in step S2, the second pulse number detected by the displacement sensor from the moment the push-up plate is extended to the moment when the photoelectric switch is not blocked is recorded, includes:

[0107] After recording the first pulse number, push the upper push plate open, and when the photoelectric switch is not blocked, record the current pulse number as the second pulse number.

[0108] It is understood that the position corresponding to the second pulse number is the position of the photoelectric switch. The technical solution provided in this embodiment first locates the position of the displacement zero point, then finds the position of the photoelectric switch. The relative distance between the displacement zero point and the photoelectric switch ensures that the displacement zero point determined at power-on can be accurately found during subsequent use, thereby ensuring measurement accuracy.

[0109] Preferably, the method further comprises:

[0110] During the self-calibration process, the measuring device is placed at any angle. When no load force F1 is applied to the push plate, that is, F1 is 0, the friction force generated by the slider on the linear guide is very small, and the friction force of the slider can be ignored at this time.

[0111] Expand the first and second upper push plates to their maximum travel points and then return to their origins;

[0112] When the first push plate returns to the origin from the maximum stroke point, the displacement value detected by the displacement sensor is recorded as The pressure value detected by the force sensor is recorded as The rotation angle of the moving part is recorded as θ1 ;

[0113] When the second push plate returns to the origin from the maximum stroke point, the displacement value detected by the displacement sensor is recorded as The pressure value detected by the force sensor is recorded as The rotation angle of the moving part is recorded as θ 2 ;

[0114] The θ 1 ,θ 2 Substitute into the first force balance calculation formula to calculate the tension F2 of the elastic seal.

[0115] The first force balance calculation formula includes:

[0116] F4=F2+Gcosθ=ks3+b+Gcosθ(1);

[0117]

[0118] Among them, G represents the gravity value of the moving part, S3 represents the actual value measured by the displacement sensor, F2=ks3+b, k is the elastic coefficient, b is the initial tension value, k and b are unknown numbers, and the rest are known numbers. Solving the equation can determine the values ​​of k and b, which are only used for this startup; Formula (1) is obtained from force analysis, which represents that the pressure value F4 collected by the force sensor is equal to the sum of the tension F2 of the elastic seal and the gravity component of the moving part in the direction of the tension F2.

[0119] It should be noted that the moving parts mentioned in this embodiment refer to Figure 3 and Figure 4 The push plate 2, linear guide rail 84, elastic seal 841, magnetic scale 61, baffle, first connecting member 65, second connecting member 66, connecting pin 67, and force sensor 68 are included.

[0120] Preferably, the method further comprises:

[0121] Calculate the friction force F3 generated by the bending moment on the slider after the upper push plate applies a load to generate the downward thrust F1. After the upper push plate applies a load to generate the thrust F1 and the upward pull F4 of the force sensor, the slider and the linear guide will generate an interactive torque (F1L1+F4L2), which in turn generates a downward friction force F3 on the linear guide. The friction force and torque between the slider and the linear guide are linearly related, that is:

[0122] F3=μ(F1L1+F4L2) (4);

[0123] Where μ is the ratio of friction to torque between the slider and the linear guide, L1 is the torque from the thrust F1 to the linear guide, and L2 is the torque from the force sensor to the linear guide. (F1L1 + F4L2) represents the torque generated by the interaction between the slider and the linear guide after the thrust F1 is applied at the end of the upper push plate.

[0124] Measure the rotation angle θ of the moving part after the push plate applies a load to generate a downward thrust F1;

[0125] The tension F2 of the elastic seal, the friction force F3, and the pressure value F4 collected by the force sensor are substituted into the second force balance calculation formula to calculate the thrust F1 of the upper push plate on the femoral condyle.

[0126] The second force balance calculation formula includes:

[0127] F4=F1+F2+F3+Gcosθ=F1+ks3+b+μ(F1L1+F4L2)+Gcosθ (3).

[0128] The solution is:

[0129] Preferably, the method further comprises:

[0130] When the upper push plate is subjected to force, elastic deformation will occur at the end. The elastic coefficient m is a constant. Δs can be calculated based on F1 calculated by the previous compensation calculation. The lower push plate is designed to be strong enough so that the deformation caused by it can be ignored. This ensures that the two upper push plates can be measured simultaneously without affecting each other's measurement accuracy. Compensation is calculated based on the following formula, including:

[0131] When the push plate is subjected to force, the end will produce elastic deformation. The deformation variable Δs is calculated according to the following formula:

[0132] Δs=mF1(4);

[0133] The displacement sensor's measured value S3 is corrected according to the following formula to output the gap value S1 between the femur and tibia:

[0134]

[0135] Where m is the elastic coefficient of the deformation of the upper push plate end under the action of F1.

[0136] The measuring device outputs the actual load value F1 and gap value S1 after the above measurement, calculation and compensation, that is, the soft tissue tension and gap value of the knee joint. The overall solution is as follows: Figure 6 shown.

[0137] It can be understood that the technical solution provided in this embodiment has designed a self-calibration and compensation method for the measurement parameters to ensure the accuracy of the gap value measurement. Self-calibration is performed each time the equipment is turned on, which reduces the dependence of the measurement accuracy on structural stability, provides more accurate gap information, and improves the safety of the operation.

[0138] Example 2

[0139] Figure 7 is a schematic block diagram of a self-calibration device 100 for measuring parameters of a measuring device according to an exemplary embodiment. Figure 7 , the apparatus 100 comprises:

[0140] A recording module 101 is configured to record a first pulse number detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, wherein the first pulse number corresponds to a displacement zero point;

[0141] It is also used to record the second pulse number detected by the displacement sensor from the moment the push-up plate is opened to the moment the photoelectric switch is unblocked;

[0142] a calculation module 102 for calculating a difference between the second pulse number and the first pulse number, and determining a relative distance between the displacement zero point and the photoelectric switch according to the difference;

[0143] The correction module 103 is configured to correct a zero point of the displacement sensor according to the relative distance.

[0144] It should be noted that the technical solution provided in this embodiment is applicable to Figures 1 to 4 In the measuring device shown in the figure, since the displacement sensor in this measuring device has no memory function (it does not record the initial point position after each calibration), the linear guide movement distance is calculated by accumulating pulses, so displacement zero point calibration is required every time the device is turned on.

[0145] It should be noted that the implementation methods and beneficial effects of the above modules can be found in the introduction of the above embodiments, and will not be repeated in this embodiment.

[0146] It can be understood that the technical solution provided in this embodiment determines the relative distance between the displacement zero point and the photoelectric switch by taking the photoelectric switch with a fixed position as an absolute position reference, and converts the displacement zero point whose position will not drift by using the relative distance. Each time the baffle blocks the photoelectric switch during each use, the accumulated value of the number of pulses will be recalibrated, thereby ensuring the accuracy and stability of the measurement, providing reliable measurement parameters for clinical practice, and ensuring clinical safety.

[0147] Example 3

[0148] See also Figure 8According to an exemplary embodiment, an electronic device includes:

[0149] Processor 701, communication interface 702, memory 703 and communication bus 704, wherein the processor 701, communication interface 702, and memory 703 communicate with each other via the communication bus 704;

[0150] Memory 703, for storing computer programs;

[0151] The processor 701 is configured to implement the above method when executing a program stored in the memory.

[0152] It can be understood that the technical solution provided in this embodiment determines the relative distance between the displacement zero point and the photoelectric switch by taking the photoelectric switch with a fixed position as an absolute position reference, and converts the displacement zero point whose position will not drift by using the relative distance. Each time the baffle blocks the photoelectric switch during each use, the accumulated value of the number of pulses will be recalibrated, thereby ensuring the accuracy and stability of the measurement, providing reliable measurement parameters for clinical practice, and ensuring clinical safety.

[0153] Example 4

[0154] According to an exemplary embodiment, a non-transitory computer-readable storage medium storing computer instructions is shown, where the computer instructions are used to enable a computer to execute the above method.

[0155] It can be understood that the technical solution provided in this embodiment determines the relative distance between the displacement zero point and the photoelectric switch by taking the photoelectric switch with a fixed position as an absolute position reference, and converts the displacement zero point whose position will not drift by using the relative distance. Each time the baffle blocks the photoelectric switch during each use, the accumulated value of the number of pulses will be recalibrated, thereby ensuring the accuracy and stability of the measurement, providing reliable measurement parameters for clinical practice, and ensuring clinical safety.

[0156] Of course, those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program. The program can be stored in a computer-readable storage medium, and when executed, the program can include the processes in the above-described method embodiments. The storage medium can be a memory, a magnetic disk, an optical disk, etc.

[0157] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A self-calibration method for measuring parameters of a measuring device, characterized in that: include: Step S1, recording the first pulse number detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, where the first pulse number corresponds to the displacement zero point; Step S2, recording the second pulse number detected by the displacement sensor from the moment the push-up plate is opened to the moment when the photoelectric switch is not blocked; Step S3, calculating the difference between the second pulse number and the first pulse number, and determining the relative distance between the displacement zero point and the photoelectric switch according to the difference; Step S4: calibrating the zero point of the displacement sensor according to the relative distance; Wherein, the measuring device comprises: The first upper push plate, the second upper push plate, and the lower push plate, each of the two upper push plates is driven by a set of independent drive components; the drive component of the upper push plate on each side includes: a drive screw, which is relatively rotatably connected to the fixed shell; a transmission nut, which is threadedly connected to the drive screw; a guide slider, which is connected to the fixed shell; a linear guide rail, one end of the linear guide rail is connected to the transmission nut, and the other end passes through the guide slider and the fixed shell and is connected to the upper push plate on the corresponding side.

2. The method according to claim 1, characterized in that The step S1 records the first pulse number detected by the displacement sensor at the moment when the linear guide moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, including: After powering on, determine whether the photoelectric switch is blocked. If so, expand the upper push plate and then retract it. Otherwise, retract the upper push plate directly until the photoelectric switch is blocked. When the photoelectric switch is blocked, it is determined whether the motor is blocked. If so, the contraction is stopped, the motor rotates a specific number of steps, and the upper push plate is opened to a specific displacement. The current number of pulses is recorded as the first pulse number. Otherwise, the upper push plate continues to be contracted until the motor is blocked.

3. The method according to claim 2, characterized in that The second pulse number detected by the displacement sensor at the moment when the push-up plate is opened and the photoelectric switch is not blocked in step S2 includes: After recording the first pulse number, push the upper push plate open, and when the photoelectric switch is not blocked, record the current pulse number as the second pulse number.

4. The method according to any one of claims 1 to 3, characterized in that Also includes: Place the measuring device at any angle. When no load is applied to the upper push plate, the first and second upper push plates are extended to the maximum travel point and then return to the origin. When the first push plate returns to the origin from the maximum stroke point, the displacement value detected by the displacement sensor is recorded as The pressure value detected by the force sensor is recorded as The rotation angle of the moving part is recorded as θ 1 ; When the second push plate returns to the origin from the maximum stroke point, the displacement value detected by the displacement sensor is recorded as The pressure value detected by the force sensor is recorded as The rotation angle of the moving part is recorded as θ 2 ; The θ 1 ,θ 2 Substitute into the first force balance calculation formula to calculate the tension F2 of the elastic seal.

5. The method according to claim 4, characterized in that The first force balance calculation formula includes: F4=F2+Gcosθ=ks3+b+Gcosθ(1); Where G represents the gravity value of the moving part, S3 represents the actual value measured by the displacement sensor, F2 = ks3 + b, k is the elastic coefficient, b is the initial tension value, k and b are unknowns; Formula (1) represents that the pressure value F4 collected by the force sensor is equal to the sum of the tension F2 of the elastic seal and the gravity component of the moving part in the direction of the tension F2.

6. The method according to claim 5, characterized in that Also includes: Calculate the friction force F3 generated by the bending moment on the slider after the push plate applies a load to generate the downward thrust F1; Measure the rotation angle θ of the moving part after the push plate applies a load to generate a downward thrust F1; The tension F2 of the elastic seal, the friction force F3, and the pressure value F4 collected by the force sensor are substituted into the second force balance calculation formula to calculate the thrust F1 of the upper push plate on the femoral condyle.

7. The method according to claim 6, characterized in that The calculation of the friction force F3 generated by the bending moment on the slider after the thrust F1 is generated by the end of the push plate is specifically: The friction force F3 generated by the bending moment of the slider is calculated according to the following formula, including: F3=μ(F1L1+F4L2) (4); Where μ is the ratio of friction to torque between the slider and the linear guide, L1 is the torque from the thrust F1 to the linear guide, and L2 is the torque from the force sensor to the linear guide. (F1L1 + F4L2) represents the torque generated by the interaction between the slider and the linear guide after the thrust F1 is applied at the end of the upper push plate.

8. The method according to claim 7, characterized in that The second force balance calculation formula includes: F4=F1+F2+F3+Gcosθ=F1+ks3+b+μ(F1L1+F4L2)+Gcosθ (3).

9. The method according to claim 6, characterized in that Also includes: When the push plate is subjected to force, the end will produce elastic deformation. The deformation variable Δs is calculated according to the following formula: Δs=mF1 ​​(4); The displacement sensor's measured value S3 is corrected according to the following formula to output the gap value S1 between the femur and tibia: Where m is the elastic coefficient of the deformation of the upper push plate end under the action of F1.

10. A self-calibration device for measuring parameters of a measuring device, characterized in that: include: a recording module, configured to record a first pulse number detected by the displacement sensor at the moment when the linear guide rail moves to the point where the photoelectric switch is blocked and the motor rotates a specific number of steps, wherein the first pulse number corresponds to a displacement zero point; It is also used to record the second pulse number detected by the displacement sensor from the moment the push-up plate is opened to the moment the photoelectric switch is unblocked; a calculation module, configured to calculate a difference between the second pulse number and the first pulse number, and determine a relative distance between the displacement zero point and the photoelectric switch according to the difference; The correction module is used to correct the displacement zero point of the displacement sensor according to the relative distance.

11. An electronic device, characterized in that: include: A processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus; Memory for storing computer programs; A processor, configured to implement the method according to any one of claims 1 to 9 when executing a program stored in a memory.

12. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 9.

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