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

Abstract

The invention discloses a self-calibration method for measurement parameters of a measurement device, electronic equipment and a storage medium, and the method comprises the steps: taking a photoelectric switch with a fixed position as an absolute position reference, determining the relative distance between a displacement zero point and the photoelectric switch, converting the displacement zero point with a non-drifting position through the relative distance, and carrying out the self-calibration of the measurement parameters of the measurement device. And in each use process, the accumulated value of the pulse number can be recalibrated when the baffle shields the photoelectric switch each time, so that the accuracy and the stability of measurement are ensured, reliable measurement parameters are provided for clinical use, and the clinical safety is ensured.

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] A knee replacement is a procedure that replaces part of a patient's knee joint with an artificial part. When there is a problem with the knee joint, the knee may become painful, swollen, stiff, or have difficulty moving normally. Knee problems can be caused by a variety of different conditions, one of the most common causes is osteoarthritis. Knee replacements are an effective way to reduce knee pain and improve the way the knee joint works, and have become a common orthopedic procedure.

[0003] The surface of the human knee joint is covered by cartilage. As people age, the cartilage gradually wears away, and the bones and ligaments around the knee joint also degenerate, eventually causing knee pain, deformity, and movement disorders. Many people have a misunderstanding that knee replacement surgery is to replace the entire knee, but this is not the case. Knee replacement surgery mainly replaces the cartilage on the surface of the knee joint that has been worn into pits and pits with a metal prosthesis and a wear-resistant gasket made of high-molecular polyethylene.

[0004] During knee replacement surgery, correct ligament relaxation and soft tissue balance are key indicators of surgical success. Therefore, during the operation, it is necessary to measure the knee joint gap and soft tissue tension values ​​in order to develop a more suitable surgical plan for the patient. However, in general, during the operation, the doctor's experience is mainly relied on to roughly determine the knee joint gap and soft tissue tension values, which is not accurate enough, resulting in the inability to accurately perform osteotomy, affecting the surgical effect 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 prior art 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 to solve the technical problem that there is no measurement parameter correction method for a balance measuring device of the 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 self-calibration method for measuring parameters 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, wherein the first pulse number corresponds to the displacement zero point;

[0010] Step S2, recording the second pulse number detected by the displacement sensor when the push-up plate is opened until 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 displacement 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 driving components; the driving component of the upper push plate on each side includes: a driving screw, which is relatively rotatably connected to the fixed shell; a transmission nut, which is threadedly connected to the driving screw; a guide slider, which is connected to the fixed shell; a linear guide, one end of the linear guide 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 starting up, 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, determine whether the motor is blocked. If so, stop retracting, rotate the motor a specific number of steps, open the push plate a specific displacement, and record the current number of pulses as the first pulse number. Otherwise, continue to retract the push plate until the motor is blocked.

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

[0019] After recording the first pulse number, push open the upper push plate, 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 force is applied to the upper push plate, the first upper push plate and the second upper push plate are extended to the maximum stroke point and then return to the origin;

[0022] When the first push plate is returned from the maximum stroke point to the origin, 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 denoted as θ 1 ;

[0023] When the second push plate returns from the maximum stroke point to the origin, 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 denoted 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] Wherein, 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 at 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] Among them, μ is the ratio of the friction force to the 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 of 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 upper push plate is subjected to force, elastic deformation will occur at the end. The deformation variable Δs is calculated according to the following formula:

[0041] Δs=mF1(4);

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

[0043]

[0044] Wherein, m is the elastic coefficient of 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, used to record 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, wherein the first pulse number corresponds to the displacement zero point;

[0047] It is also used to record the second pulse number detected by the displacement sensor from the moment when the push-up plate is opened to the moment when the photoelectric switch is not blocked;

[0048] A calculation module, used for 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;

[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, used to store 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 solution provided by the embodiments of the present invention may have the following beneficial effects:

[0056] By taking the photoelectric switch with a fixed position as the absolute position reference, the relative distance between the displacement zero point and the photoelectric switch is determined, and the displacement zero point whose position will not drift is converted through the relative distance. Each time the baffle blocks the photoelectric switch during each use, the accumulated value of the pulse number will be recalibrated, thus 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 of a method for self-calibration of measuring parameters of a measuring device according to an exemplary embodiment;

[0063] Figure 6 is a flow chart of 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 solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 foregoing background art, the related art does not address the technical problem of a method for correcting measurement parameters of a balance measurement device for soft tissue of a knee joint.

[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 Figure 1 to Figure 4 The applicant has implemented the invention on the basis of the utility model patent previously applied for (application number: 202321985230.9). In order to facilitate the understanding of the technical solution of this application, Figure 1 to Figure 4 The relevant operating principle of the measuring device shown is explained as follows:

[0070] See also Figure 1 The measuring 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. When in use, the lower push plate B is fixed, and the two upper push plates push the lateral condyle and medial condyle of the femur upward respectively. The two upper push plates are each driven by a set of independent driving components, and when in use, the two upper push plates can work independently.

[0071] See also Figure 3 and Figure 4 Taking the upper push plate on either side as an example, the driving assembly of the upper push plate includes: a driving screw 81, which is relatively rotatably connected to the fixed shell 7; a transmission nut 82, which is threadedly connected to the driving 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 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, and the displacement of the linear guide 84 is the gap value between the soft tissues of the knee joint. The magnetic scale 61 is fixedly connected to the linear guide 84, and 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 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 the soft tissue tension value, and convert the displacement of the linear guide 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 driving motor 91 and the reducer 92 can drive the push plate 2 to move to a suitable measuring position through the driving 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 arranged on the fixed housing 7; a reading component 63, which is arranged on the collection board 62, and the reading component 63 is arranged corresponding to the magnetic scale 61 to record the moving distance of the magnetic scale 61; a photoelectric switch 64, which is used to sense the position of the magnetic scale 61, and the photoelectric switch 64 is arranged on the collection board 62, and the photoelectric switch 64 and the reading component 63 are arranged at intervals.

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

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

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

[0079] F2—Tensile force generated by the elastic seal being stretched;

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

[0081] F4—the value of the force sensor, 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—Measurement value of 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 end of the push plate under the action of F1, which is a known constant.

[0088] Embodiment 1

[0089] Figure 5 is a flow chart of a self-calibration method for measuring parameters of a measuring 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, wherein the first pulse number corresponds to the displacement zero point;

[0091] Step S2, recording the second pulse number detected by the displacement sensor when the push-up plate is opened until 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 displacement 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 driving components; the driving components of the upper push plate on each side include: a driving screw 81, the driving screw 81 is relatively rotatably connected to the fixed shell 7; a transmission nut 82, the transmission nut 82 is threadedly connected to the driving screw 81; a guide slider 83, the guide slider 83 is connected to the fixed shell 7; a linear guide rail 84, one end of the linear guide rail 84 is connected to the transmission 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 Figure 1 to Figure 4 In the measuring device shown in the figure. Since the displacement sensor in the measuring device has no memory function (it will not record the initial point position after each calibration), the moving distance of the linear guide is calculated by accumulating pulses, so the displacement zero point calibration is required every time the machine is turned on.

[0097] Each time the machine is turned on, regardless of the use status of the measuring device (for example, the upper push plate is open, or the upper push plate is retracted), the motor must first drive the linear guide 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 prop up the push plate for a certain displacement to avoid the motor being blocked when the linear guide displacement is reset during normal use, and unable to read normally (from the photoelectric switch being blocked to the motor being blocked, the structural design of the measuring device ensures that the photoelectric switch is always in a blocked state). The specific number of steps is a random number, because the displacement sensor is a cumulative count. If the current 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 moving distance of the magnetic scale 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 of the previously recorded pulse number of 58 or 100. However, due to the possibility of loss of step in the number of pulses 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 to 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 when the linear guide moves to the moment when the photoelectric switch is blocked and the motor rotates a specific number of steps, it is necessary to continue to open the upper push plate, execute step S2 to record the second pulse number P2 detected by the displacement sensor when the upper push plate is opened to the moment when 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 determined, the displacement zero point whose position will not drift can be converted through 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 the number of pulses will 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 the absolute position reference, and converts the displacement zero point whose position will not drift by 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, 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 in step S1 includes:

[0104] After starting up, determine whether the photoelectric switch is blocked. If so, expand the upper push plate and then retract it again. 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 used last time, and expand the upper push plate again to reset it; if the photoelectric switch is not blocked, it means that the upper push plate was expanded when it was used last time, and it can be directly retracted and reset);

[0105] When the photoelectric switch is blocked, determine whether the motor is blocked. 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 blocked (motor blockage indicates a successful reset. The specific number of rotation steps is determined by the use 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, the second pulse number detected by the displacement sensor when the push-up plate is opened to the moment when the photoelectric switch is not blocked in step S2 includes:

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

[0108] It can be 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, and then finds the position of the photoelectric switch. Through the relative distance between the displacement zero point and the photoelectric switch, it is ensured that the displacement zero point determined when the machine is turned on can be accurately found through the relative distance during subsequent use, thereby ensuring the accuracy of the measurement.

[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 upper 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] The first upper push plate and the second upper push plate are extended to the maximum travel point and then return to the origin;

[0112] When the first push plate is returned from the maximum stroke point to the origin, 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 denoted as θ1 ;

[0113] When the second push plate returns from the maximum stroke point to the origin, 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 denoted 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] Wherein, 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. The values ​​of k and b can be determined by solving the equation and are only used for this startup. Formula (1) is obtained by 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, the linear guide 84, the elastic seal 841, the magnetic scale 61, the baffle, the first connecting member 65, the second connecting member 66, the connecting pin 67, and the force sensor 68.

[0120] Preferably, the method further comprises:

[0121] Calculate the friction 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 pulling force 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 F3 on the linear guide. The friction between the slider and the linear guide is linearly related to the torque, that is:

[0122] F3=μ(F1L1+F4L2) (4);

[0123] Among them, μ is the ratio of the friction force to the 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 of 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] Solving for this yields:

[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 obtained by the previous compensation calculation. The lower push plate is designed to have high enough strength so that the deformation produced can be ignored. This ensures that the two upper push plates can be measured at the same time without affecting each other's measurement accuracy. Compensation is calculated based on the following formula, including:

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

[0132] Δs=mF1(4);

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

[0134]

[0135] Wherein, m is the elastic coefficient of 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 scheme 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 the structural stability, provides more accurate gap information, and improves the safety of the operation.

[0138] Embodiment 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 device 100 comprises:

[0140] A recording module 101, used to record 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, wherein the first pulse number corresponds to the displacement zero point;

[0141] It is also used to record the second pulse number detected by the displacement sensor from the moment when the push-up plate is opened to the moment when the photoelectric switch is not blocked;

[0142] A calculation module 102, used for 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;

[0143] The correction module 103 is used to correct the displacement 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 Figure 1 to Figure 4 In the measuring device shown in the figure. Since the displacement sensor in the measuring device has no memory function (it will not record the initial point position after each calibration), the moving distance of the linear guide is calculated by accumulating pulses, so the displacement zero point calibration is required every time the machine 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 described in detail 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 the absolute position reference, and converts the displacement zero point whose position will not drift by 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] Embodiment 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, memory 703 communicate with each other via the communication bus 704;

[0150] Memory 703, used for storing computer programs;

[0151] The processor 701 is used to implement the above method when executing the 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 the absolute position reference, and converts the displacement zero point whose position will not drift by 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] Embodiment 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 the absolute position reference, and converts the displacement zero point whose position will not drift by 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 can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the program can be stored in a computer-readable storage medium, and the program can include the processes of the above-mentioned method embodiments when executed. The storage medium can be a memory, a disk, an optical disk, etc.

[0157] The specific implementation of the present invention described above does not constitute a limitation on the protection scope 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 protection scope 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, wherein the first pulse number corresponds to the displacement zero point; Step S2, recording the second pulse number detected by the displacement sensor when the push-up plate is opened until 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 displacement 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 driving components; the driving component of the upper push plate on each side includes: a driving screw, which is relatively rotatably connected to the fixed shell; a transmission nut, which is threadedly connected to the driving screw; a guide slider, which is connected to the fixed shell; a linear guide, one end of the linear guide 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 starting up, 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, determine whether the motor is blocked. If so, stop retracting, rotate the motor a specific number of steps, open the push plate a specific displacement, and record the current number of pulses as the first pulse number. Otherwise, continue to retract the push plate until the motor is blocked.

3. The method according to claim 2, characterized in that The second pulse number detected by the displacement sensor from the moment when the push-up plate is opened to the moment when the photoelectric switch is not blocked in step S2 includes: After recording the first pulse number, push open the upper push plate, 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 force is applied to the upper push plate, the first upper push plate and the second upper push plate are extended to the maximum stroke point and then return to the origin; When the first push plate is returned from the maximum stroke point to the origin, 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 denoted as θ 1 ; When the second push plate returns from the maximum stroke point to the origin, 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 denoted 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); Wherein, 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 at 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); Among them, μ is the ratio of the friction force to the 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 of 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 upper push plate is subjected to force, elastic deformation will occur at the end. The deformation variable Δs is calculated according to the following formula: Δs=mF1 ​​(4); The measured value S3 of the displacement sensor is corrected according to the following formula, and the gap value S1 between the femur and tibia is output: Wherein, m is the elastic coefficient of 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, used to record 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, wherein the first pulse number corresponds to the displacement zero point; It is also used to record the second pulse number detected by the displacement sensor from the moment when the push-up plate is opened to the moment when the photoelectric switch is not blocked; A calculation module, used for 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; 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, used to store computer programs; A processor, for implementing 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 make a computer execute the method according to any one of claims 1 to 9.

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