Non-invasive positioning method for pelvis and lower limb in hip replacement

Abstract

The invention discloses a non-invasive positioning method for pelvis and lower limbs in hip replacement. The non-invasive positioning method comprises the following steps: 1, calibrating a flexible multi-array strain sensor at pelvis skin; 2, acquiring strain intensity information, attitude information and space information of the sensor; 3, standardizing the timestamps of the collected information; 4, setting a data acquisition time interval; 5, calculating a strain tensor change rate, a relative displacement change rate and an attitude difference angle; 6, the trend degree and the dispersion degree of the sum are obtained; 7, calculating a skin sliding index SI and a skin deformation index DI; 8, respectively setting an SI threshold value and a DI threshold value and comparing; 9, calculating the length variation between the nodes of the sensor array; 10, performing spatial position compensation according to the step 8; and 11, repeating the steps 2-10 to carry out space information compensation on the femur until positioning is stopped. According to the invention, the identification and compensation of the motion artifacts of the optical marker in the operation are realized, and the accuracy and stability of navigation in the operation are improved.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to a non-invasive positioning method for the pelvis and lower limbs during hip replacement surgery. Background Art

[0002] During hip replacement surgery, accurate prosthesis positioning directly determines postoperative joint stability, functional recovery, and prosthesis lifespan. During surgery, surgeons utilize an orthopedic navigation robot and an infrared binocular camera to capture optical landmarks on the patient's body to assist in locating the spatial position of the pelvis and femur. Therefore, accurate identification of the optical landmarks' spatial location is crucial.

[0003] Fixing markers on the patient's bones through surgical operation is a reliable and accurate means of navigation and tracking. However, since it is an invasive procedure, it increases the patient's pain and risk of infection. Using non-invasive markers that are not attached to the patient's skin surface does not require any form of bone surface treatment. However, there is slippage between the skin and bone tissue, and the markers cannot always accurately reflect the true movement of the bones, forming the so-called "skin motion artifact." Traditional methods have difficulty in identifying and correcting this error in real time, affecting the accuracy of intraoperative judgment and postoperative evaluation. Therefore, there is an urgent need for a method that can monitor, identify and dynamically compensate for skin sliding artifacts in real time, and non-invasively locate the pelvis and lower limbs in real time. Summary of the Invention

[0004] The present invention aims to address the deficiencies of the above-mentioned prior art and proposes a non-invasive positioning method for the pelvis and lower limbs during hip replacement surgery, in order to achieve the recognition and compensation of motion artifacts of optical markers during surgery, thereby improving the accuracy and stability of intraoperative navigation.

[0005] In order to achieve the above-mentioned object, the present invention adopts the following technical solutions: The present invention provides a non-invasive positioning method for the pelvis and lower limbs during hip replacement surgery, which is characterized in that it is applied to a scene composed of a flexible multi-array strain sensor and an optical positioning camera, wherein the flexible multi-array strain sensor is respectively set at the pelvic skin and the femoral skin, so that there are M×N nodes on the flexible multi-array strain sensor, wherein M and N respectively represent the total number of rows and the total number of columns of the flexible multi-array strain sensor, and a posture sensor and an optical marker directly above it are respectively set on I nodes, and I nodes are nodes in an asymmetric position, and the distance between I optical markers is greater than twice the volume of the optical marker itself; the optical marker is in the field of view of the optical positioning camera, so that any i-th posture sensor and its optical marker are at the m-th position on the flexible multi-array strain sensor. i row and nth i On the column node; where m i ∈[1,M],n i∈ [1, N], i ∈ [1, I], I represents the total number of posture sensors, I ≥ 4; the non-invasive positioning method comprises the following steps: Step 1: initial strain calibration is performed on the flexible multi-array strain sensor, so that the stress of all nodes on the calibrated flexible multi-array strain sensor is 0; Step 2: x-direction strain intensity information of the mth row and nth column node on the calibrated flexible strain sensor array at the skin of the pelvis at time t is obtained , y-direction strain intensity information , and xy-direction strain intensity information , wherein m ∈ [1, M], n ∈ [1, N]; obtaining posture information of the ith posture sensor on the calibrated flexible strain sensor array at the skin of the pelvis at time t ; acquiring spatial position information of the ith optical marker on the calibrated flexible strain sensor array at the skin of the pelvis at time t by using an optical positioning camera ; Step 3: setting the number of standard frames as , for , , , and , to obtain synchronized spatial position information of the ith posture sensor at time t , synchronized strain tensor of the mth row and nth column node at time t , and synchronized posture information of the ith posture sensor at time t ; Step 4: setting the time interval of data acquisition as , if , then is assigned to t, and the step 2 is returned, otherwise, the step 5 is executed; Step 5: respectively calculating strain tensor change rate of the mth row and nth column node on the calibrated flexible strain sensor array at the skin of the pelvis at time t , relative displacement change rate of the ith optical marker at time t , and posture difference angle of the optical marker corresponding to the ith posture sensor at time t ; Step 6: based on , calculating trend degree and dispersion degree of the strain tensor change rate of the calibrated flexible strain sensor array at the skin of the pelvis at time t , calculate the trend of the relative displacement change rate of all posture sensors on the calibrated flexible strain sensor array at the pelvic skin at time t and dispersion ; based on , calculate the trend of the posture difference angle of all optical markers on the calibrated flexible strain sensor array at the pelvic skin at time t and dispersion ; Step 7: Calculate the skin sliding index of the pelvic skin at time t and skin deformation index ,in, w 1, w 2, w 3 is 3 weights, and ; Step 8: Set 2 thresholds for the skin slip index 、 and two thresholds for skin deformation and ; When 0< < And 0< < , it means that the skin at the pelvis has neither slipped nor deformed. No correction is required, and proceed to step 12. when < or < When t is reached, it means that the skin at the pelvis is slipping or deforming significantly and cannot be corrected. After discarding the data at time t, Assign the value to t and return to step 2 to execute sequentially; Otherwise, go to step 9; Step 9: Based on Calculate the length of the node in the mth row and nth column of the calibrated flexible strain sensor array at the pelvic skin at time t and The change in length between moments , and get the mth i row and nth i Transformation matrix of the i-th optical marker of the column node ; Step 10: Right Compensation is performed to obtain the mth position of the flexible multi-array strain sensor after calibration at the pelvic skin. i row and nth i The spatial position of the i-th optical marker of the column node after compensation at time t , used to locate the pelvis at time t, where represents the mth flexible strain sensor array on the pelvic skin after calibration i row and nth i Column at time t and The change in length between moments; Step 11: Following the process of steps 2 to 10, the compensated spatial position of the i-th optical marker on the calibrated flexible multi-array strain sensor at the femoral skin at time t is obtained and used to locate the lower limb at time t; Step 12: After assigning the value to t, return to step 2 and execute sequentially until the hip replacement surgery is completed.

[0006] The non-invasive positioning method for the pelvis and lower limbs during hip replacement surgery according to the present invention is also characterized in that step 5 comprises: Step 5.1: Calculate the rate of change of the strain tensor at the node in the mth row and nth column of the calibrated flexible strain sensor array at the pelvic skin at time t ;in, The calibrated flexible strain sensor array on the pelvic skin is shown in The synchronized strain tensor at the node in the mth row and nth column at the time instant; Step 5.2: Calculate the relative displacement difference of the i-th optical marker on the calibrated flexible strain sensor array at the pelvic skin at time t , thus obtaining the relative displacement change rate of the i-th optical marker at time t ;in, represents the position of the i-th posture sensor on the calibrated flexible strain sensor array at the pelvic skin. The spatial location information after synchronization at the moment; Step 5.3: Calculate the posture information of the i-th optical marker on the calibrated flexible strain sensor array at the pelvic skin at time t , thus obtaining the attitude difference angle of the optical marker corresponding to the i-th attitude sensor at time t ;in, express The reciprocal of represents the position of the i-th posture sensor on the calibrated flexible strain sensor array at the pelvic skin. The posture information after synchronization at the moment.

[0007] Furthermore, the step 6 includes: Step 6.1: Calculate the trend of the rate of change of the strain tensor of the calibrated flexible strain sensor array at the pelvic skin at time t and dispersion ; Step 6.2: Calculate the trend degree of the relative displacement rate of all posture sensors on the calibrated flexible strain sensor array at the pelvis skin at time t and dispersion ; Step 6.3: Calculate the trend degree of the posture difference angle of all optical markers on the calibrated flexible strain sensor array at the pelvis skin at time t and dispersion .

[0008] Further, the step 9 comprises: Step 9.1: Calculate the length of the mth row and nth column node on the calibrated flexible strain sensor array at the pelvis skin at time t , wherein, represents the initial length of the mth row and nth column node; wherein, is the synchronized x-direction strain intensity information of the mth row and nth column node at time t, is the synchronized y-direction strain intensity information of the mth row and nth column node at time t; Step 9.2: Calculate the length change amount of the mth row and nth column node on the calibrated flexible strain sensor array at the pelvis skin between time t and time t , wherein, represents the length of the mth row and nth column node at time t ; Step 9.3: Based on , calculate the rotation matrix of the i th optical marker at the m th row and n th column node on the calibrated flexible multi-array strain sensor at the pelvis skin i , i , , thereby constructing the transformation matrix of the i th optical marker at the m th row and n th column node at time t i , i . .

[0009] The electronic device comprises a memory and a processor, wherein the memory is used to store a program supporting the processor to execute the non-invasive positioning method, and the processor is configured to execute the program stored in the memory.

[0010] The computer readable storage medium stores a computer program, wherein the computer program is executed by the processor to execute the steps of the non-invasive positioning method.

[0011] Compared with the prior art, the present application has the following advantages: The application adopts a non-invasive positioning method for the pelvis and lower limbs in hip arthroplasty, which can identify and compensate for the false displacement of markers caused by skin sliding in real time without increasing invasiveness, realizes high-precision identification and compensation of motion artifacts, has strong real-time performance, can be dynamically corrected, improves the identification precision of spatial position information of optical markers, and improves the accuracy and stability of intraoperative navigation, so that the positioning method has good clinical applicability and engineering realizability, and is suitable for intraoperative navigation and postoperative functional evaluation. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a system result schematic diagram of a non-invasive positioning method for the pelvis and lower limbs in hip arthroplasty of the application; Figure 2 is a flexible multi-array strain sensor structure schematic diagram of the application; Figure 3 is a positioning step flowchart of the pelvis skin in a non-invasive positioning method for the pelvis and lower limbs in hip arthroplasty of the application; Figure 4 is a strain sensor strain strength detection device schematic diagram in the application; In the figure, 1 is a binocular camera; 2 is a capture card; 3 is a terminal; 4 is a flexible multi-array strain sensor at the pelvis skin; 5 is a flexible multi-array strain sensor at the femur skin; 6 is a foot pedal; 7 is an optical marker; 8 is a strain sensor; 9 is an adhesive; and 10 is a posture sensor. DETAILED DESCRIPTION

[0013] In this embodiment, a non-invasive positioning method for the pelvis and lower limbs in hip arthroplasty, as shown in Figure 1 , is applied to a scene composed of a flexible multi-array strain sensor and an optical positioning camera, wherein the flexible multi-array strain sensor is arranged at the pelvis skin and the femur skin, respectively, so that there are MxN nodes on the flexible multi-array strain sensor, wherein M and N respectively represent the total number of rows and the total number of columns of the flexible multi-array strain sensor, I posture sensors are arranged on I nodes, respectively, and optical markers are arranged directly above the I posture sensors, the I nodes are nodes in asymmetric positions, and the distance between the I optical markers is greater than 2 times the volume of the optical markers themselves; the optical markers are in the field of view of the optical positioning camera, so that any ith posture sensor and its optical marker are on the m i th row and the nth i column node on the flexible multi-array strain sensor; wherein m i ∈[1,M], n i ∈[1,N], i∈[1,I], I represents the total number of posture sensors, and I≥4; when I is 4, the positions of the posture sensors and the optical markers on the flexible multi-array strain sensor are arranged as shown inFigure 2 The non-invasive positioning method includes the following steps as shown in the figure: Figure 3 The non-invasive positioning method includes the following steps as shown in the figure: Step 1: After the surgical selection of the posterolateral approach, the patient is in a lateral body position, the flexible multi-array strain sensor at the skin of the pelvis is pasted on the pelvis and towards the binocular camera, the lower limbs are shaken, and the position of the binocular camera is adjusted so that all the optical markers are within the field of view of the binocular camera during the shaking process; due to the influence of body size and skin tightness, after the completion of the pasting of the flexible multi-array strain sensor at the skin of the pelvis, the static stress is also different, so it is necessary to calibrate the initial strain of the flexible multi-array strain sensor at the skin of the pelvis, so that the stress of all nodes on the calibrated flexible multi-array strain sensor at the skin of the pelvis is 0.

[0014] Step 2: During hip arthroplasty, the doctor operates with both hands, and can use the pedal for operation. After the pedal is stepped on, the acquisition card can convert the resistance change of each node on the flexible strain sensor array at the skin of the pelvis into strain intensity information to obtain the x-direction strain intensity information of the mth row and nth column node on the calibrated flexible strain sensor array at the skin of the pelvis at time t , y-direction strain intensity information and xy-direction strain intensity information , wherein m∈[1,M] and n∈[1,N]; The Euler angle collected by the posture sensor can be converted into attitude quaternion by using the acquisition card to obtain the attitude information of the ith posture sensor on the calibrated flexible strain sensor array at the skin of the pelvis at time t ; The spatial position information of the ith posture sensor on the calibrated flexible strain sensor array at the skin of the pelvis at time t is obtained by using the optical positioning camera ; the ith optical marker and the ith posture sensor are rigidly connected, and the spatial information of the ith optical marker can be shared with the attitude information of the ith posture sensor.

[0015] Step 3: The acquisition frame rate of the infrared binocular camera is generally fixed at several frequencies, and the data acquisition card acquisition frequency may be greater than or less than the above-mentioned infrared camera acquisition frame rate. A standard frequency is set, and the spatial information data frequency collected by the infrared camera and the strain information and attitude information collected by the data acquisition card are unified to a standard frame by interpolation and frame selection.

[0016] The number of digits of the standard frame is set to , which is used to , , , and Perform time stamp standardization; determine the frequency of data collection Are they the same? If they are, the data structure is unified into the format of data + time; if the collection frequency is , then data is extracted from the collected data at equal intervals as new data, making its frequency equal to the standard frame number ;if , then insert data frames at equal intervals in the sampled data, and the inserted data is the average of the 5 frames before and after the current frame; obtain the spatial position information of the i-th attitude sensor after synchronization at time t , the synchronized strain tensor at the node in the mth row and nth column at time t The attitude information after synchronization with the i-th attitude sensor at time t ;in, is the x-direction strain intensity information after synchronization on the node in the mth row and nth column at time t, is the y-direction strain intensity information of the node in the mth row and nth column after synchronization at time t, is the synchronized xy-direction strain intensity information of the node in the mth row and nth column at time t.

[0017] Step 4: In this embodiment, all the change rates are calculated by finding the difference between the current moment and the previous moment. In order to avoid the calculation dilemma at the initial moment (t=0), the time interval for data collection is set to ,and ,like , then After assigning the value to t, return to step 2, otherwise, execute step 5; Step 5: Calculate the rate of change of the strain tensor at the node in the mth row and nth column of the calibrated flexible strain sensor array at the pelvic skin at time t ;in, The calibrated flexible strain sensor array on the pelvic skin is shown in The synchronized strain tensor at the node in the mth row and nth column at the time instant; Calculate the relative displacement difference of the i-th optical marker on the calibrated flexible strain sensor array at the pelvic skin at time t , thus obtaining the relative displacement change rate of the i-th optical marker at time t ;in, represents the position of the i-th posture sensor on the calibrated flexible strain sensor array at the pelvic skin. The spatial location information after synchronization at the moment; Calculate the posture information of the i-th optical marker on the calibrated flexible strain sensor array on the pelvic skin at time t , thereby obtaining the posture difference angle of the i-th posture sensor corresponding to the optical marker at time t ; wherein, represents the reciprocal of represents the synchronized posture information of the i-th posture sensor on the flexible strain sensor array at the pelvis skin at time t.

[0018] Step 6: Calculate the trend degree and the dispersion degree of the strain tensor change rate of the flexible strain sensor array at the pelvis skin at time t after calibration. Calculate the trend degree and the dispersion degree of the relative displacement change rate of all posture sensors on the flexible strain sensor array at the pelvis skin at time t after calibration. Calculate the trend degree and the dispersion degree of the posture difference angle of all optical markers on the flexible strain sensor array at the pelvis skin at time t after calibration. Step 7: Calculate the skin sliding index and the skin deformation index at the pelvis skin at time t, wherein, w 1, w 2, w 3 are three weights, and .

[0019] Step 8: Set two threshold values , for the skin sliding index and two threshold values and for the skin deformation index; the skin sliding index threshold and the skin deformation index threshold are the embodiment of the system's tolerance to the degree of skin sliding and skin deformation, and their sizes can be fine-tuned according to actual application.

[0020] When 0 < and 0 < , the degree of skin sliding and deformation at the pelvis is within the error tolerance range, and it is considered that the skin at the pelvis neither slides nor deforms, and no correction is needed, and step 12 is performed.

[0021] When < or < , it indicates that the skin at the pelvis slides or deforms significantly and cannot be corrected, and after discarding the data at time t, ​Assign the value to t and return to step 2 to execute sequentially; Otherwise, go to step 9.

[0022] Step 9: Calculate the length of the node in the mth row and nth column of the calibrated flexible strain sensor array at the pelvic skin at time t ,in, Indicates the initial length of the node at row m and column n; Figure 4 As shown in the figure, when m and n are 2 and 4 respectively, the node in the 2nd row and 4th column is the intersection of the bold black lines in the figure. The initial length of the strain gauge resistor after calibration is shown in the 2nd row and 4th column. When the skin stretches or slides, the length of the strain gauge resistor will also change.

[0023] Calculate the relationship between the node in the mth row and the nth column of the calibrated flexible strain sensor array at the pelvic skin and the The change in length between moments ,in, Indicates that the node in row m and column n is Length of the moment; based on , calculate the mth strain on the calibrated flexible multi-array strain sensor at the pelvic skin i row and nth i The rotation matrix of the i-th optical marker of the column node , combined with the length change , construct the mth i row and nth i Transformation matrix of the i-th optical marker of the column node ,in The flexible multi-array strain sensor at the pelvic skin after calibration is located at the mth i row and nth i The column node at time t is The change in length between moments.

[0024] Step 10: The pelvis is a rigid object. Any point on it will move with the body. In this embodiment, it is positioned. Since the optical marker is attached to the pelvic skin, the skin sliding and muscle tissue deformation during human movement will seriously affect the positioning of the pelvis. The motion artifact error can be effectively eliminated by the transformation matrix. Compensation is performed to obtain the mth position of the flexible multi-array strain sensor after calibration at the pelvic skin. i row and nth i The spatial position of the i-th optical marker of the column node after compensation at time t , used to locate the pelvis at time t, where represents the length variation of the mth optical marker on the calibrated flexible multi-array strain sensor at the skin of the thigh at time t. i i represents the length variation of the mth optical marker on the calibrated flexible multi-array strain sensor at the skin of the thigh at time t.

[0025] Step 11: obtaining the compensated spatial position of the i th optical marker on the calibrated flexible multi-array strain sensor at the skin of the thigh at time t according to the process of steps 2-10, and using the same to position the lower limb at time t; After assigning t to t, returning to step 2 for sequential execution until the hip arthroplasty is completed.

[0026] In this embodiment, an electronic device includes a memory for storing a program supporting the processor to execute the above method, and a processor configured to execute the program stored in the memory.

[0027] In this embodiment, a computer readable storage medium has a computer program stored thereon, and the computer program is executed by a processor to perform the steps of the above method.​​​

Claims

1. A method of non-invasive positioning of the pelvis and lower extremities in hip arthroplasty, characterized in that, The application is applied to a scene composed of a flexible multi-array strain sensor and an optical positioning camera, wherein the flexible multi-array strain sensor is arranged at a pelvis skin and a femur skin respectively, and there are M*N nodes on the flexible multi-array strain sensor, wherein M and N respectively represent the total row number and the total column number of the flexible multi-array strain sensor, I attitude sensors and optical markers above the I attitude sensors are arranged on I nodes respectively, the I nodes are nodes in asymmetric positions, and the distance between the I optical markers is greater than 2 times the volume of the optical markers; the optical markers are in the visual range of the optical positioning camera, so that any ith attitude sensor and the optical marker thereof are on the m i th row node and the n i th column node on the flexible multi-array strain sensor; wherein m i ∈[1,M], n i ∈[1,N], i∈[1,I], I represents the total number of the attitude sensors, and I≥4; the non-invasive positioning method comprises the following steps: Step 1: initial strain calibration is performed on the flexible multi-array strain sensor, so that the stress of all nodes on the calibrated flexible multi-array strain sensor is 0; Step 2: Obtain the x-direction strain intensity information of the node at the mth row and the nth column of the calibrated flexible strain sensor array at the t time point at the pelvic skin , y-direction strain intensity information and xy-direction strain intensity information , wherein m ∈ [1, M], n ∈ [1, N] Obtain the posture information of the i-th posture sensor on the calibrated flexible strain sensor array at the pelvis skin at time t ; acquire the spatial position information of the i-th optical marker on the calibrated flexible strain sensor array at the pelvis skin at time t by using an optical positioning camera ; Step 3: set the number of standard frames to , for the timestamp standardization of , , , and , to obtain the synchronized spatial position information of the i-th attitude sensor at time t , the synchronized strain tensor on the m-th row and n-th column node at time t , and the synchronized attitude information of the i-th attitude sensor at time t ; Step 4: Set the time interval of data collection as , if , then assign to t, and return to Step 2, otherwise, execute Step 5; Step 5: Calculate the strain tensor change rate of the mth row and nth column node on the calibrated flexible strain sensor array at the t time point at the pelvic skin respectively , the relative displacement change rate of the i th optical marker at the t time point ; the attitude difference angle of the optical marker corresponding to the i th attitude sensor at the t time point ; Step 6: Based on , the trend degree of the rate of change of the strain tensor of the calibrated flexible strain sensor array at the skin of the pelvis at time t is calculated and the dispersion ; Based on , the trend degree of the relative displacement rate of all posture sensors on the calibrated flexible strain sensor array at the pelvis skin at time t and the dispersion ; Based on , the trend degree and dispersion degree of the pose difference angle of all optical markers on the calibrated flexible strain sensor array at the pelvis skin at time t are calculated ; Step 7: Calculate the skin sliding index at the pelvis skin at time t and the skin deformation index wherein, w 1, w 2, w 3 are 3 weights, and ; Step 8: Setting 2 thresholds for skin slip index , and 2 thresholds for skin deformation and ; When 0 < x < 0.5 and 0 < y < 0.5, it means that the skin at the pelvis neither slides nor deforms, no correction is needed, and step 12 is performed; When 0 < x < 0.5 and 0 < y < 0.5, it means that the skin at the pelvis neither slides nor deforms, no correction is needed, and step 12 is performed; ​​​ when < or < When t is reached, it means that the skin at the pelvis is slipping or deforming significantly and cannot be corrected. After discarding the data at time t, Assign the value to t and return to step 2 to execute sequentially; Otherwise, step 9 is performed; Step 9: Based on Calculate the length of the node in the mth row and nth column of the calibrated flexible strain sensor array at the pelvic skin at time t and its The change in length between moments , and get the mth i row and nth i Transformation matrix of the i-th optical marker of the column node ; Step 10: Right Compensation is performed to obtain the mth position of the flexible multi-array strain sensor after calibration at the pelvic skin. i row and nth i The spatial position of the i-th optical marker of the column node after compensation at time t , used to locate the pelvis at time t, where represents the mth flexible strain sensor array on the pelvic skin after calibration i row and nth i Column at time t and The change in length between moments; Step 11: the compensated spatial position of the i-th optical marker on the calibrated flexible multi-array strain sensor at the femoral skin at time t is obtained according to the process of steps 2-10, and is used for positioning the lower limb at time t; Step 12: Assigning the value to t, the process returns to step 2 and continues sequentially until the hip replacement procedure is complete. After assigning the value to t, the process returns to step 2 and continues sequentially until the hip replacement procedure is complete.

2. The non-invasive positioning method of the pelvis and lower extremities in hip arthroplasty according to claim 1, characterized in that, The step 5 comprises: Step 5.1: Calculate the strain tensor rate of the mth row and nth column node on the calibrated flexible strain sensor array at the tth time on the skin of the pelvis ; wherein, represents the synchronized strain tensor of the calibrated flexible strain sensor array at the tth time on the skin of the pelvis the mth row and nth column node. Step 5.2: Calculate the relative displacement difference of the i-th optical marker on the calibrated flexible strain sensor array at time t at the pelvis skin , thereby obtaining the relative displacement rate of the i-th optical marker at time t ; wherein, represents the synchronized spatial position information of the i-th posture sensor on the calibrated flexible strain sensor array at time t at the pelvis skin ​ Step 5.3: Calculate the posture information of the i-th optical marker on the calibrated flexible strain sensor array at the pelvic skin at time t , thus obtaining the attitude difference angle of the optical marker corresponding to the i-th attitude sensor at time t ;in, express The reciprocal of represents the position of the i-th posture sensor on the calibrated flexible strain sensor array at the pelvic skin. The posture information after synchronization at the moment.

3. The non-invasive positioning method of the pelvis and lower extremities in hip arthroplasty according to claim 2, characterized in that, The step 6 comprises: Step 6.1: Calculate the trend of the rate of change of the strain tensor of the calibrated flexible strain sensor array at the pelvis skin at time t and dispersion ; Step 6.2: Calculate the trend of the relative displacement rate of all posture sensors on the calibrated flexible strain sensor array at the pelvis skin at time t and dispersion ; Step 6.3: Calculate the trend of the difference in the pose angle of all optical markers on the calibrated flexible strain sensor array at the time t at the pelvic skin and dispersion .

4. The non-invasive positioning method of the pelvis and lower extremities in hip arthroplasty according to claim 3, characterized in that, The step 9 comprises: Step 9.1: Calculate the length of the mth row and nth column node on the calibrated flexible strain sensor array at the t time at the pelvic skin wherein, represents the initial length of the mth row and nth column node; wherein, is the synchronized x-direction strain intensity information of the mth row and nth column node at the t time, is the synchronized y-direction strain intensity information of the mth row and nth column node at the t time; Step 9.2: Calculate the length change of the mth row and nth column node on the calibrated flexible strain sensor array at the pelvis skin at time t and time t + Δt wherein, Lm,n(t) represents the length of the mth row and nth column node at time t Lm,n(t + Δt) represents the length of the mth row and nth column node at time t + Δt Lm,n(t + Δt) represents the length of the mth row and nth column node at time t + Δt Step 9.3: Based on , calculate the mth strain on the calibrated flexible multi-array strain sensor at the pelvic skin i row and nth i The rotation matrix of the i-th optical marker of the column node , thus constructing the mth i row and nth i Transformation matrix of the i-th optical marker of the column node .

5. An electronic device comprising a memory and a processor, characterized in that The memory is configured to store a program supporting the processor to execute the non-invasive positioning method of any one of claims 1-4, and the processor is configured to execute the program stored in the memory.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to perform the steps of the non-invasive positioning method of any one of claims 1-4.

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