A calcaneal measurement method and a method for digitizing and customizing an orthosis

Abstract

The invention relates to a calcaneal measurement method and a method for digitized custom-made orthosis. The method comprises the following steps: using an electronic camera to photograph the calcaneal of a foot to be measured on a collection platform to obtain a calcaneal image, and then using a halcon algorithm to extract the contour of the calcaneal image. Then, the range of the inner and outer ankles is marked in sequence, and a computer automatically identifies and calculates the inner and outer ankle heights, the inner and outer ankle distances, the inner and outer ankle inclinations, and the inner and outer valgus degrees of the calcaneal. The development of the calcaneal is determined by the identified data, and a calcaneal orthosis is digitized and designed according to the development of the calcaneal, so as to customize a matching orthosis for a person to be measured. The customized orthosis has a higher adaptability to the person to be measured, can more accurately control and adjust the ankle joint force line of the person to be measured, and shortens the treatment time of the person to be measured.

Description

Technical Field

[0001] The present invention relates to the technical field of image acquisition and orthosis production, and in particular to a calcaneus measurement method and a method for digitized custom orthosis. Background Art

[0002] With the continuous development of modern medicine, people are paying more and more attention to the healthy development of bones, especially the development of the bone structure of the lower limbs. As a common disease of lower limb structural abnormalities, calcaneal valgus has an incidence rate of about 7.1% of the population. Calcaneous valgus is common in young and middle-aged people, and some of it develops from improper treatment of postural flat feet. It mainly causes severe pain when standing or walking, and the gait may be in a figure eight gait. As a medical device installed and fixed on the ankle for correcting calcaneal valgus, the calcaneal orthosis uses a part of the human body's bony marker as a support point through its special material and structure, and uses an under-positioning method to apply torque to the joint that needs to be corrected, thereby achieving the correction function of calcaneal valgus. Its advantages include no surgery, no constraints on the ankle joint, fit to the lower limbs, and meet daily wear requirements. Summary of the invention

[0003] The object of the present invention is to provide a calcaneal measurement method and a method for digitizing and customizing an orthosis to solve the problems raised by the above-mentioned background technology.

[0004] To achieve the above object, a calcaneal measurement method is provided, the method comprising the following steps:

[0005] S1. The foot to be tested is placed flat on the acquisition platform of the evaluation equipment, and the person to be tested stands with his back to the calcaneal acquisition camera;

[0006] S2. Using an electronic camera to take pictures of the calcaneus of the foot to be measured on the acquisition table to obtain a calcaneus image, and the calcaneus image is transmitted to the image display processing device via USB;

[0007] S3. Using halcon to implement the algorithm to extract the calcaneal skin in the calcaneal image;

[0008] S4. Draw a contour map of the extracted calcaneal skin using the halcon implementation algorithm;

[0009] S5. Manually mark the inner and outer ankle ranges on the extracted calcaneal skin image, and based on this, the computer automatically identifies the key points of the most convex point A on the outer side of the ankle joint, the most convex point B on the inner side of the ankle joint, the center point C of the inner and outer ankle joints, the center point D of the Achilles tendon, and the lowest point E of the heel;

[0010] S6. Calculate the calcaneal data including medial malleolus height, lateral malleolus height, and medial malleolus inclination angles;

[0011] S7. Calculate the degree of calcaneal valgus and inside-out valgus. The Achilles tendon center point D, the inside-out malleolus center point C and the heel lowest point E form a triangle DCE. The supplementary angle of ∠DCE is the degree of calcaneal valgus and outside-in valgus. ∠DCE in the triangle DCE can be calculated using the cosine formula. The supplementary angle of ∠DCE = 180° - ∠DCE.

[0012] The electronic camera device is mainly composed of two high-definition image acquisition cameras, and the two cameras are responsible for acquiring images of the left and right heel bones respectively.

[0013] The step of using the halcon algorithm to extract the calcaneal skin in the calcaneal image is:

[0014] (1) Obtaining / setting grayscale value: Input the calcaneal image Image, first obtain the grayscale value Grayval of each pixel in the calcaneal image, and then set the grayscale value to 0.50000 * Grayval[0] - 0.41869 * Grayval[1] - 0.08131 * Grayval[2] + 128, complete the distinction between the calcaneal skin and background features, and obtain a black and white calcaneal image, in which the calcaneal part is displayed in white;

[0015] (2) Binarization: Binarize the grayscale image using the binary_threshold operator to find the segmentation threshold of the dark and light parts of the image, and then use the threshold to extract the light calcaneal image;

[0016] (3) Extracting the calcaneal skin: First, the connection operator is used to distinguish the image in the calcaneal image according to the contrast, thereby dividing it into several different area blocks; then the area_center operator is used to obtain the area and center of each area block, and the tuple_max operator is used to calculate the maximum area; after the above operations are performed, the select_shape operator is used to filter and extract the target area that meets the area range through the feature histogram according to the area feature, and a rough calcaneal image is obtained;

[0017] (4) Post-extraction processing: After extracting the rough calcaneal image, the calcaneal image is subjected to erosion and dilation operations to obtain a more detailed calcaneal image; wherein the erosion operation erosion_circle is an operation to shrink the selected area, which can eliminate edges and noise; the dilation operation dilation_circle operator is to expand the boundary points and fill the internal holes; and the fill_up operator is used to fill the holes inside the calcaneal image with a given shape;

[0018] (5) Draw the final image: After executing the above four steps, the calcaneal region to be extracted is obtained, and the difference between this region and the original calcaneal image is calculated. The operator used is: complement. The region region outside the calcaneal skin to be extracted is obtained, and the region region is filled with white.

[0019] The final interference-free calcaneal skin image is obtained using the overpaint_region operator.

[0020] The step of using the halcon implementation algorithm to draw the contour map of the extracted calcaneal skin is:

[0021] (1) Image grayscale: Load the calcaneal image whose contour is to be extracted, and then use the rgb1_to_gray operator to convert the calcaneal image from color to gray, which can simplify the matrix and improve the operation speed;

[0022] (2) Extracting contours: Use the edges_sub_pix operator to perform sub-pixel edge extraction on the grayscale calcaneal image to obtain the contour map of the calcaneal image. The parameter passed is edges_sub_pix(Image, Edges1, 'lanser1', 6, 30, 50), where Image is the input image, Edges1 is the output image, lanser1 is the filter, 6, 30, and 50 are the filter parameter, the lower limit of the hysteresis threshold, and the upper limit of the hysteresis threshold, respectively; then use the select_contours_xld operator to select the part of the contour whose contour length meets the range of (80, 99999) according to the feature, and filter out the surrounding noise and interference items; then use the union_adjacent_contours_xld operator to connect all contours so that the small line segments are spliced ​​together;

[0023] (3) Drawing the contour: Use the gen_region_contour_xld operator to convert the contour image after the above operation into a region, and then use the gen_image_proto operator to create an image with a specified grayscale value of 255, that is, white, and then draw the region onto the white image to obtain a contour image of the calcaneus image with a white background.

[0024] The steps of marking the medial and lateral malleolus range and identifying key points are:

[0025] (1) The most convex point on the outside of the ankle joint: first click on the upper and lower points (point a and point b) on the outside of the ankle joint of the left calcaneal image displayed on the image display processing device to determine the value range of the most convex point on the outside of the ankle joint, and then the computer identifies and takes out the point with the smallest horizontal coordinate among all the points within the range of point a and point b on the left calcaneal contour as the most convex point on the outside of the ankle joint (for the right calcaneal, take out the point with the largest horizontal coordinate among all the points within the range of point a and point b on the calcaneal contour as the most convex point on the outside of the ankle joint);

[0026] (2) The most convex point on the inner side of the ankle joint: first click on the upper and lower points (point c and point d) on the inner side of the ankle joint of the left calcaneal image displayed on the image display processing device to determine the value range of the most convex point on the inner side of the ankle joint. Then, the computer recognizes that the point with the largest horizontal coordinate among all the points within the range of point c and point d on the left calcaneal contour is the most convex point on the inner side of the ankle joint (for the right calcaneal, the point with the smallest horizontal coordinate among all the points within the range of point c and point d on the calcaneal contour is the most convex point on the inner side of the ankle joint);

[0027] (3) Center point of the medial and lateral malleolus: The center point of the medial and lateral malleolus can be obtained based on the most convex point on the lateral side of the ankle joint and the most convex point on the medial side of the ankle joint. That is, the coordinates of the center point of the medial and lateral malleolus are obtained by combining half of the sum of the horizontal coordinates of the most convex points of the medial and lateral malleolus and half of the sum of the vertical coordinates of the most convex points of the medial and lateral malleolus.

[0028] (4) Achilles tendon center point: Identify the pixel with the largest horizontal coordinate Max(X,Y) and the smallest pixel Min(X,Y) among all the pixels within the upper third of the calcaneus. The horizontal coordinate of the Achilles tendon center point is (MinX+MaxX) / 2, and the vertical coordinate of the Achilles tendon center point is MinY;

[0029] (5) The lowest point of the heel: The point with the largest vertical coordinate in the calcaneal image is identified as the lowest point of the heel.

[0030] The steps to calculate the calcaneal data are:

[0031] (1) Connect the coordinates (0, the ordinate of the lowest point of the heel), (the width of the calcaneal image, the ordinate of the lowest point of the heel) to form a heel horizontal line d;

[0032] (2) Calculating the scale: Determine the station for collecting the calcaneal image and then take a photo of the test reference object, mark a fixed distance on the image display device to obtain the distance A on the map, and then measure the actual measured distance B. The scale C=A / B between the distance on the map and the actual distance can be calculated;

[0033] (3) Medial malleolus height: the distance between the medial ankle joint marking point and the point where the medial ankle joint marking point and the heel horizontal line d intersect vertically is the medial malleolus height on the map, the medial malleolus height = the medial malleolus height on the map distance / the scale C;

[0034] (4) Lateral malleolus height: The distance between the lateral ankle joint marking point and the point where the lateral ankle joint marking point and the heel horizontal line d intersect vertically is the on-graph distance of the lateral malleolus height. The lateral malleolus height = the on-graph distance of the lateral malleolus height / the scale C.

[0035] (5) In-and-out ankle inclination angle: A triangle ABF is formed by the most convex point A on the outside of the ankle joint, the most convex point B on the inside of the ankle joint, the horizontal coordinate of point A and the vertical coordinate of point B. ∠ABF is the in-and-out ankle inclination angle, where ∠ABF can be calculated using the cosine formula in triangle ABF.

[0036] A method for digitizing and customizing a calcaneal orthosis, the method comprising the following steps:

[0037] S1, obtain the measurement data of both heels, including the calcaneal angle θ (same as ∠ABF), medial malleolus height H1, lateral malleolus height H2, medial malleolus distance l and heel width w, and use a tape measure to measure the arch length L from the first metatarsophalangeal joint point A to the most convex point B on the medial side of the calcaneus of both feet of the subject;

[0038] S2, obtain the plaster prototype of the subject's ankle and foot;

[0039] S3, repairing the plaster prototype of the subject's ankle and foot according to the measurement data of the calcaneus to obtain a standard ankle and foot plaster model of the subject.

[0040] S4, fabrication of calcaneal orthosis;

[0041] The fixing rod of the standard ankle-foot plaster model is fixed on the fixture, and a thermoplastic plate of appropriate size is heated and softened, and then covered on the outside of the standard ankle-foot plaster model. All openings are sealed by the self-adhesiveness of the thermoplastic plate, and then the negative pressure pump is turned on to extract the air between the ankle-foot plaster model and the high-temperature softened thermoplastic plate, so that the thermoplastic plate is adsorbed on the surface of the ankle-foot plaster model, and after cooling, a thermoplastic plate shell matching the ankle-foot plaster model is formed;

[0042] S4.1, use a marker to draw an L-shaped cutting area on the front of the thermoplastic shell, and use a jigsaw to cut the cutting area;

[0043] S4.2, use a marker to draw a dividing line on the thermoplastic shell at the ankle joint, and use a jigsaw to separate the thermoplastic shell into a foot shell and a calf shell at the dividing line;

[0044] S4.3, polish and grind all the cuts of the thermoplastic plate shell using a grinder;

[0045] S4.4, drilling through holes on both sides of the ankle joint incision using an electric drill, and then connecting the foot shell and the calf shell by hinges and rivets to obtain an ankle-foot orthosis;

[0046] S4.5, grinding and polishing the entire ankle-foot orthosis using a polishing wheel to obtain a finished ankle-foot orthosis.

[0047] The standard ankle-foot plaster model of the subject is obtained by repairing the ankle joint and the arch of the foot on the plaster prototype with tools such as plaster slurry, files, and gauze; the repairing is to adjust the shape of the ankle joint and the arch of the foot of the plaster prototype according to the obtained measurement data of the heel bones, including the calcaneal angle θ, the medial malleolus height H1, the lateral malleolus height H2, the medial malleolus distance l, the arch length L, and the heel width w;

[0048] The repair process of the ankle joint includes: using a marker pen to mark the corresponding heights of the inner and outer ankles of the plaster prototype to indicate the inner and outer ankle heights H1 and H2, and then using plaster slurry and a file to heighten the inner and outer ankles of the plaster prototype by 5-10 mm;

[0049] The repair process of the arch part includes: using a marker pen to file the arch area of ​​the plaster prototype, the filed part is a solid body consisting of a bottom surface O, a side surface Q and a top curved surface P, the bottom surface O area takes the first metatarsophalangeal joint as the starting point A, the most convex point on the inner side of the calcaneus as the end point B, draws the arch length line L, and draws a line near point A. Take point a at L, take straight line Aa as L1, straight line aB as L2, and draw a circle on one side of the arch with point a as the center and L1 as the radius. Circle, recorded as arc S1, and then move point a to the other side of arc S1 L to point b, with point b as the center and the end point of S1 as the starting point, L is the radius, draw below S1 The circle is recorded as arc S2, S1+S2 is recorded as curve S3. The bottom surface O of the arch part is composed of L+S3;

[0050] The side surface Q is based on point a, perpendicular to the bottom surface of the "D" shape, and upward, with a height of tanθ·L1, and the highest point is recorded as C. The top curve of the side surface Q is a perfect circle passing through points A, C, and B, recorded as S4, and the boundary points of the curve are points A and B, that is, the side surface Q is surrounded by the straight line AB and the curve S4;

[0051] The intersection of the top curved surface P and the vertical plane at point a on the straight line AB satisfies the quadratic function The function graph in the first quadrant, where: a<0, b=0, c=tanθ·L1, that is, the coordinates of the highest point are (0, tanθ·L1), and the coordinates of the intersection with the positive half axis of X are (L1, 0). When x=0, y=c, when y=0, a= , that is, the intersection of the top surface P and the vertical plane at point a on the straight line AB satisfies the function , the curvature of the top surface P is given by the function Curve S constraint in the first quadrant;

[0052] The L-shaped cutting area is composed of the instep area and the front tibia area.

[0053] The dividing line is the projection of the extended line connecting the inner and outer malleolus on the ankle joint.

[0054] The bottom surface O and the side surface Q are substantially in a "D-shape".

[0055] Compared with the prior art, the calcaneal measurement method and the method for selecting an orthosis according to the calcaneal bone of the present invention have the following beneficial effects: the calcaneal measurement method of the present invention can automatically and conveniently and quickly identify the degree of inversion and valgus of the calcaneal bone, and judge the development of the calcaneal bone, thereby avoiding the problems of poor measurement data accuracy, low measurement efficiency, and difficulty in promotion caused by manual measurement; and selecting a suitable orthosis according to the development of the calcaneal bone can provide the wearer with greater comfort and promote healthier development of the calcaneus. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a schematic diagram of the product appearance of the present invention;

[0057] Figure 2 is a schematic diagram of a calcaneus image collected by the present invention;

[0058] Figure 3 is a schematic diagram of the calcaneal skin automatically identified and extracted by the present invention;

[0059] Figure 4 is a schematic diagram of the calcaneal skin contour automatically identified and extracted by the present invention;

[0060] Figures 5 and 6 It is a schematic diagram of key points automatically identified and marked by the present invention;

[0061] Figure 7 is a schematic diagram of calcaneal value acquisition of the present invention;

[0062] Figure 8 It is a physical diagram of the arch area that needs to be repaired;

[0063] Fig. 9 This is a schematic diagram of the manufacturing process of the calcaneal orthosis. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] like Figure 1 The figure shows the appearance diagram of the product of the present invention. The product of the present invention is also called calcaneal image acquisition equipment, which is mainly composed of an acquisition table, a storage box and an electronic camera device, wherein the electronic camera is built into the measuring rod for acquiring heel images.

[0066] The calcaneal measurement method of the present invention mainly comprises the following steps:

[0067] S1. The foot to be tested is placed flat on the acquisition platform of the evaluation equipment, and the person to be tested stands with his back to the calcaneal acquisition camera;

[0068] S2. Using an electronic camera to take a picture of the calcaneus of the foot to be measured on the acquisition table to obtain a calcaneus image (as shown below) Figure 2 ), and transmitting the calcaneal image to an image display processing device via USB;

[0069] S3. Using halcon to implement the algorithm to extract the calcaneal skin in the calcaneal image (as shown below Figure 3 );

[0070] S4. Use halcon to implement the algorithm to draw the contour of the extracted calcaneal skin (as shown below Figure 4 );

[0071] S5. Manually mark the inner and outer ankle ranges on the extracted calcaneal skin image, and the computer automatically identifies the most convex point on the outer side of the ankle joint (as shown below) Figure 5 Point A), the most convex point on the inner side of the ankle joint (as shown below Figure 5 Point B), the center of the inner and outer ankles (as shown below Figure 5 Point C), Achilles tendon center (as shown below Figure 5 Point D) and the lowest point of the heel (as shown below Figure 5 Point E);

[0072] S6. Calculate the calcaneal data including medial malleolus height, lateral malleolus height, and medial malleolus inclination angles;

[0073] S7. Calculate the degree of calcaneal valgus. The Achilles tendon center point D, the medial and lateral malleolus center point C and the heel lowest point E form a triangle DCE. The supplementary angle of ∠DCE is the degree of calcaneal valgus (denoted as angle θ). ∠DCE in the triangle DCE can be calculated using the cosine formula. The supplementary angle of ∠DCE = 180° - ∠DCE.

[0074] The electronic camera device described in the present invention is mainly composed of two high-definition image acquisition cameras, and the two cameras are responsible for acquiring images of the left and right heel bones respectively.

[0075] The steps of using the halcon algorithm to extract the calcaneal skin in the calcaneal image described in the present invention are:

[0076] (1) Obtaining / setting grayscale value: Input the calcaneal image Image, first obtain the grayscale value Grayval of each pixel in the calcaneal image, and then set the grayscale value to 0.50000 * Grayval[0] - 0.41869 * Grayval[1] - 0.08131 * Grayval[2] + 128, complete the distinction between the calcaneal skin and background features, and obtain a black and white calcaneal image, in which the calcaneal part is displayed in white;

[0077] (2) Binarization: Binarize the grayscale image using the binary_threshold operator to find the segmentation threshold of the dark and light parts of the image, and then use the threshold to extract the light calcaneal image;

[0078] (3) Extracting the calcaneal skin: First, the connection operator is used to distinguish the image in the calcaneal image according to the contrast, thereby dividing it into several different area blocks; then the area_center operator is used to obtain the area and center of each area block, and the tuple_max operator is used to calculate the maximum area; after the above operations are performed, the select_shape operator is used to filter and extract the target area that meets the area range through the feature histogram according to the area feature, and a rough calcaneal image is obtained;

[0079] (4) Post-extraction processing: After extracting the rough calcaneal image, the calcaneal image is subjected to erosion and dilation operations to obtain a more detailed calcaneal image; wherein the erosion operation erosion_circle is an operation to shrink the selected area, which can eliminate edges and noise; the dilation operation dilation_circle operator is to expand the boundary points and fill the internal holes; and the fill_up operator is used to fill the holes inside the calcaneal image with a given shape;

[0080] (5) Draw the final image: After executing the above four steps, the calcaneal region to be extracted is obtained, and the difference between this region and the original calcaneal image is calculated. The operator used is: complement. The region region outside the calcaneal skin to be extracted is obtained, and the region region is filled with white.

[0081] The final interference-free calcaneal skin image is obtained using the overpaint_region operator.

[0082] In the present invention, the steps of marking the inner and outer ankle ranges and identifying key points are:

[0083] (1) The most convex point on the outside of the ankle joint: first click on the upper and lower points (point a and point b) on the outside of the ankle joint of the left calcaneal image displayed on the image display processing device to determine the value range of the most convex point on the outside of the ankle joint, and then the computer identifies and takes out the point with the smallest horizontal coordinate among all the points within the range of point a and point b on the left calcaneal contour as the most convex point on the outside of the ankle joint (for the right calcaneal, take out the point with the largest horizontal coordinate among all the points within the range of point a and point b on the calcaneal contour as the most convex point on the outside of the ankle joint);

[0084] (2) The most convex point on the inner side of the ankle joint: first click on the upper and lower points (point c and point d) on the inner side of the ankle joint of the left calcaneal image displayed on the image display processing device to determine the value range of the most convex point on the inner side of the ankle joint. Then, the computer recognizes that the point with the largest horizontal coordinate among all the points within the range of point c and point d on the left calcaneal contour is the most convex point on the inner side of the ankle joint (for the right calcaneal, the point with the smallest horizontal coordinate among all the points within the range of point c and point d on the calcaneal contour is the most convex point on the inner side of the ankle joint);

[0085] (3) Center point of the medial and lateral malleolus: The center point of the medial and lateral malleolus can be obtained based on the most convex point on the lateral side of the ankle joint and the most convex point on the medial side of the ankle joint. That is, the coordinates of the center point of the medial and lateral malleolus are obtained by combining half of the sum of the horizontal coordinates of the most convex points of the medial and lateral malleolus and half of the sum of the vertical coordinates of the most convex points of the medial and lateral malleolus.

[0086] (4) Achilles tendon center point: Identify the pixel with the largest horizontal coordinate Max(X,Y) and the smallest pixel Min(X,Y) among all the pixels within the upper third of the calcaneus. The horizontal coordinate of the Achilles tendon center point is (MinX+MaxX) / 2, and the vertical coordinate of the Achilles tendon center point is MinY;

[0087] (5) The lowest point of the heel: The point with the largest vertical coordinate in the calcaneal image is identified as the lowest point of the heel.

[0088] In the present invention, the steps of calculating the calcaneal data are:

[0089] (1) Connect the coordinates (0, the ordinate of the lowest point of the heel), (the width of the calcaneal image, the ordinate of the lowest point of the heel) to form a heel horizontal line d;

[0090] (2) Calculating the scale: Determine the position for collecting the calcaneal image and then take a photo of the test reference object, mark a fixed distance on the image display device to obtain the distance A on the map, and then measure the actual measured distance B. The scale C = A / B between the distance on the map and the actual distance can be calculated;

[0091] (3) Medial malleolus height: The distance between the medial ankle joint marking point and the point where the medial ankle joint marking point and the heel horizontal line d intersect vertically is the medial malleolus height on the map. The medial malleolus height = the medial malleolus height on the map distance / the scale C;

[0092] (4) Lateral malleolus height: The distance between the lateral ankle joint marking point and the point where the lateral ankle joint marking point and the heel horizontal line d intersect vertically is the on-graph distance of the lateral malleolus height. The lateral malleolus height = the on-graph distance of the lateral malleolus height / the scale C.

[0093] (5) Inner and outer ankle inclination angle: A triangle ABF is formed by the most convex point A on the outer side of the ankle joint, the most convex point B on the inner side of the ankle joint, the horizontal coordinate of point A and the vertical coordinate of point B. ∠ABF is the inner and outer ankle inclination angle, where ∠ABF can be calculated using the cosine formula in triangle ABF.

[0094] The above describes how the calcaneal measurement method of the present invention is implemented. The following describes how the calcaneal orthosis selection method is implemented.

[0095] A method for digitizing and customizing a calcaneal orthosis, the method comprising the following steps:

[0096] (1) Obtain measurement data of both heels, including calcaneal angle θ (same as ∠ABF), medial malleolus height H1, lateral malleolus height H2, medial malleolus distance l, and heel width w. At the same time, use a tape measure to measure the arch length L from the first metatarsophalangeal joint point A to the most convex point B on the medial side of the calcaneus of both feet of the subject.

[0097] (2) In the data-based customization method of the calcaneal orthosis, the plaster prototype of the subject's ankle and foot is made by wrapping a soaked plaster bandage around the subject's ankle and foot below the knee. After the plaster bandage solidifies, it is removed with a knife and then sealed with a soaked plaster bandage. After the opening solidifies, a negative mold with the same shape and size as the subject's ankle and foot is obtained. Finally, the mixed plaster slurry is injected into the negative mold and a fixing rod is inserted into the injection port. After the plaster slurry solidifies, the plaster bandage is peeled off to obtain a plaster prototype with the same shape and size as the subject's ankle and foot.

[0098] (3) The standard ankle-foot plaster model of the subject is made by repairing the ankle joint part of the plaster prototype according to the obtained measurement data of the heel bones of both feet using tools such as plaster slurry, files, and gauze: Use a marker to mark the corresponding heights of the inner and outer ankles of the plaster prototype to mark the inner and outer ankle heights H1 and H2, and then use plaster slurry and files to repair the inner and outer ankle parts of the plaster prototype to a height of 5-10 mm;

[0099] (3.1) The arch repair process is to use a marker pen to file the arch area of ​​the plaster prototype. The filed part is a solid body consisting of the bottom surface O, the side surface Q and the top surface P. The bottom surface O area takes the first metatarsophalangeal joint as the starting point A and the most convex point on the inner side of the calcaneus as the end point B. Connect AB to get the arch length line L. Take point a at L, take straight line Aa as L1, straight line aB as L2, and draw a circle on one side of the arch with point a as the center and L1 as the radius. Circle, recorded as arc S1, and then move point a to the other side of arc S1 L to point b, with point b as the center and the end point of S1 as the starting point, L is the radius, draw below S1 The circle is recorded as arc S2, S1+S2 is recorded as curve S3. The bottom surface O of the arch part is composed of L+S3;

[0100] (3.2) The side surface Q is based on point a, perpendicular to the bottom surface of the "D" shape and upward, with a height of tanθ·L1. The highest point is denoted by C. The top curve of the side surface Q is a perfect circle passing through points A, C, and B, denoted by S4. The boundary points of the curve are points A and B. That is, the side surface Q is surrounded by the straight line AB and the curve S4.

[0101] (3.3) The intersection of the top surface P and the perpendicular plane at point a on the line AB satisfies the quadratic function The function graph in the first quadrant, where: a<0, b=0, c=tanθ·L1, that is, the coordinates of the highest point are (0, tanθ·L1), and the coordinates of the intersection with the positive half axis of X are (L1, 0). When x=0, y=c, when y=0, a= , that is, the intersection of the top surface P and the vertical plane at point a on the straight line AB satisfies the function , the curvature of the top surface P is given by the function The curve S in the first quadrant is constrained. The plaster prototype is adjusted according to the ankle joint height parameters and the arch part parameters to produce a standard plaster model.

[0102] (4) To make a calcaneal orthosis, fix the fixed rod of the standard ankle-foot plaster model on the fixture, take a thermoplastic sheet of appropriate size, heat and soften it, and then wrap it around the outside of the standard ankle-foot plaster model. All openings are sealed by the self-adhesiveness of the thermoplastic sheet. Then, turn on the negative pressure pump to extract the air between the ankle-foot plaster model and the high-temperature softened thermoplastic sheet, so that the thermoplastic sheet is adsorbed on the surface of the ankle-foot plaster model. After cooling, a thermoplastic sheet shell matching the ankle-foot plaster model is formed.

[0103] (4.1) Use a marker to draw cutting lines on the dorsal area and anterior tibial area of ​​the thermoplastic shell and use a jigsaw to cut the cutting area;

[0104] (4.2) Use a marker pen to draw a cutting line at the ankle joint of the thermoplastic shell through the most convex points of the medial and lateral malleolus to divide the thermoplastic shell into two parts: the foot shell and the calf shell;

[0105] (4.3) Use a grinder to polish and grind all the cuts of the thermoplastic plate shell;

[0106] (4.4) Drilling through holes on both sides of the ankle joint incision using an electric drill, and then connecting the foot shell and the calf shell with hinges and rivets to obtain an ankle-foot orthosis;

[0107] (4.5) Use a polishing wheel to grind and polish the entire ankle-foot orthosis to obtain a finished ankle-foot orthosis.

[0108] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A calcaneal measurement method, characterized in that: The method comprises the following steps: S1. The foot to be tested is placed flat on the collection platform of the evaluation equipment, and the person to be tested stands with his back to the calcaneal collection electronic camera device; S2. Using an electronic camera to take a picture of the calcaneus of the foot to be measured on the acquisition platform to obtain a calcaneus image, and transmit the calcaneus image to the image display processing device via USB; S3. Using halcon to implement the algorithm to extract the calcaneal skin in the calcaneal image; S4. Use halcon to implement the algorithm to draw the contour of the extracted calcaneal skin; S5. Manually mark the inner and outer ankle ranges on the extracted calcaneal skin image, and based on this, the computer automatically identifies the key points: the most convex point A on the outer side of the ankle joint, the most convex point B on the inner side of the ankle joint, the center point C of the inner and outer ankle joints, the center point D of the Achilles tendon, and the lowest point E of the heel; S6. Calculate the medial malleolus height, lateral malleolus height, and medial malleolus inclination angles of the calcaneus data; S7. Calculate the degree of calcaneal valgus, the Achilles tendon center point D, the medial and lateral malleolus center point C and the heel lowest point E form a triangle DCE, the supplementary angle of ∠DCE is the degree of calcaneal valgus, wherein ∠DCE is calculated using the cosine formula in the triangle DCE, and the supplementary angle of ∠DCE = 180°-∠DCE; The electronic camera device is mainly composed of two high-definition image acquisition cameras, which are responsible for acquiring images of the left and right heel bones respectively; The step of using the halcon algorithm to extract the calcaneal skin in the calcaneal image is: (1) Obtaining / setting grayscale value: Input the calcaneal image Image, first obtain the grayscale value Grayval of each pixel in the calcaneal image, and then set the grayscale value to 0.50000*Grayval[0]-0.41869*Grayval[1]-0.08131*Grayval[2]+128, complete the distinction between the calcaneal skin and background features, and obtain a black and white calcaneal image, in which the calcaneal part is displayed in white; (2) Binarization: Use the binary_threshold operator to binarize the grayscale image, find the segmentation threshold of the dark and light parts of the image, and then use the threshold to extract the light calcaneal image; (3) Extracting the calcaneal skin: First, the connection operator is used to distinguish the image in the calcaneal image according to the contrast, thereby dividing it into several different area blocks; then the area_center operator is used to obtain the area and center of each area block, and the tuple_max operator is used to calculate the maximum area; after the above operations are performed, the select_shape operator is used to filter and extract the target area that meets the area range through the feature histogram according to the area feature, and a rough calcaneal image is obtained; (4) Post-extraction processing: After extracting the rough calcaneal image, the calcaneal image is subjected to erosion and dilation operations to obtain a more detailed calcaneal image; wherein the erosion operation erosion_circle is an operation to shrink the selected area, which can eliminate edges and noise; the dilation operation dilation_circle operator is to expand the boundary points and fill the internal holes; and the fill_up operator is used to fill the holes inside the calcaneal image with a given shape; (5) Draw the final image: After executing the above four steps, the calcaneal region to be extracted is obtained, and the difference between this region and the original calcaneal image is calculated. The operator used is: complement. The region region outside the calcaneal skin to be extracted is obtained, and the region region is filled with white. The final calcaneal skin image without interference items is obtained, and the operator used is: overpaint_region; The steps of using the halcon implementation algorithm to draw the contour map of the extracted calcaneal skin are: (1) Image grayscale: Load the calcaneal image whose contour is to be extracted, and then use the rgb1_to_gray operator to convert the calcaneal image from color to gray, which can simplify the matrix and improve the operation speed; (2) Extracting contours: Use the edges_sub_pix operator to perform sub-pixel edge extraction on the grayscale calcaneal image to obtain the contour map of the calcaneal image. The parameter passed is edges_sub_pix(Image, Edges1, 'lanser1', 6, 30, 50), where Image is the input image, Edges1 is the output image, lanser1 is the filter, 6, 30, and 50 are the filter parameter, the lower limit of the hysteresis threshold, and the upper limit of the hysteresis threshold, respectively; then use the select_contours_xld operator to select the part of the contour whose contour length meets the range of (80, 99999) according to the feature, and filter out the surrounding noise and interference items; then use the union_adjacent_contours_xld operator to connect all contours so that the small line segments are spliced ​​together; (3) Drawing the contour: using the gen_region_contour_xld operator to convert the contour image after the above operation into a region, and then using the gen_image_proto operator to create an image with a specified gray value of 255, that is, white, and then drawing the region onto the white image to obtain a contour image of the calcaneus image with a white background; The steps of marking the medial and lateral malleolus range and identifying key points are: (1) The most convex point on the outer side of the ankle joint: first click on the upper and lower points a and b on the outer side of the ankle joint of the left calcaneal image displayed on the image display processing device to determine the value range of the most convex point on the outer side of the ankle joint, and then the computer identifies and selects the point with the smallest horizontal coordinate among all the points within the range of point a and point b on the left calcaneal contour as the most convex point on the outer side of the ankle joint; (2) The most convex point on the inner side of the ankle joint: first click on the upper and lower points c and d on the inner side of the ankle joint of the left calcaneal image displayed on the image display processing device to determine the value range of the most convex point on the inner side of the ankle joint, and then the computer identifies and extracts the point with the largest horizontal coordinate among all the points within the range of point c and point d on the left calcaneal contour as the most convex point on the inner side of the ankle joint; (3) Center point of the medial and lateral malleolus: The center point of the medial and lateral malleolus can be obtained according to the most convex point on the lateral side of the ankle joint and the most convex point on the medial side of the ankle joint. That is, the coordinates of the center point of the medial and lateral malleolus are formed by half of the sum of the abscissas of the most convex points of the medial and lateral malleolus and half of the sum of the ordinates of the most convex points of the medial and lateral malleolus; (4) Achilles tendon center point: Identify the pixel with the largest horizontal coordinate Max(X, Y) and the smallest pixel Min(X, Y) among all the pixels within the upper third of the calcaneus. The horizontal coordinate of the Achilles tendon center point is (MinX+MaxX) / 2, and the vertical coordinate of the Achilles tendon center point is MinY; (5) The lowest point of the heel: the point with the largest ordinate in the calcaneal image is identified as the lowest point of the heel; The steps to calculate the calcaneal data are: (1) connecting the coordinates (0, the ordinate of the lowest point of the heel) and (the calcaneal image width, the ordinate of the lowest point of the heel) to form a heel horizontal line d; (2) Calculating the scale: Determine the position for collecting the calcaneal image and then take a photo of the test reference object, mark a fixed distance on the image display device to obtain the distance A on the image, and then measure the actual measured distance B. The scale C=A / B between the distance on the image and the actual distance can be calculated; (3) Medial malleolus height: the distance between the medial ankle joint marking point and the point where the medial ankle joint marking point and the heel horizontal line d intersect vertically is the medial malleolus height on the map, the medial malleolus height = the medial malleolus height on the map distance / the scale C; (4) Lateral malleolus height: the distance between the lateral ankle joint marking point and the perpendicular intersection of the lateral ankle joint marking point and the heel horizontal line d is the distance on the map of the lateral malleolus height, the lateral malleolus height = the distance on the map of the lateral malleolus height / the scale C; (5) In-and-out ankle inclination angle: A triangle ABF is formed by the most convex point A on the outside of the ankle joint, the most convex point B on the inside of the ankle joint, the horizontal coordinate of point A and the vertical coordinate of point B. ∠ABF is the in-and-out ankle inclination angle, where ∠ABF can be calculated using the cosine formula in triangle ABF.

2. A method for digitizing and customizing a calcaneal orthosis, characterized in that: The method comprises the following steps: S1, using the calcaneal measurement method as described in claim 1 to obtain measurement data of both heels, including medial and lateral malleolus inclination, medial malleolus height H1, lateral malleolus height H2, medial and lateral malleolus distance l and heel width w, and using a tape measure to measure the arch length L from the first metatarsophalangeal joint point A to the most convex point B on the inner side of the calcaneus of both feet of the subject; S2, obtain the plaster prototype of the subject's ankle and foot; S3, repairing the plaster prototype of the ankle and foot of the subject according to the measurement data of the calcaneus to obtain a standard ankle and foot plaster model of the subject, wherein the standard ankle and foot plaster model of the subject is obtained by repairing the ankle joint and the arch of the foot on the plaster prototype with plaster slurry, a file, and a gauze, and the standard ankle and foot plaster model of the subject is obtained; the repairing is to adjust the shape of the ankle joint and the arch of the foot of the plaster prototype according to the obtained measurement data of the double heel bones, including the inner and outer malleolus inclination angles, the inner and outer malleolus height H1, the outer malleolus height H2, the inner and outer malleolus distance l, the arch length L, and the heel width w; S4, fabrication of calcaneal orthosis; The fixing rod of the standard ankle-foot plaster model is fixed on the fixture, and a thermoplastic plate of appropriate size is heated and softened, and then covered on the outside of the standard ankle-foot plaster model. All openings are sealed by the self-adhesiveness of the thermoplastic plate, and then the negative pressure pump is turned on to extract the air between the ankle-foot plaster model and the high-temperature softened thermoplastic plate, so that the thermoplastic plate is adsorbed on the surface of the ankle-foot plaster model, and after cooling, a thermoplastic plate shell matching the ankle-foot plaster model is formed; S4.1, use a marker to draw an L-shaped cutting area on the front of the thermoplastic shell, and use a jigsaw to cut the cutting area; S4.2, use a marker to draw a dividing line on the thermoplastic shell at the ankle joint, and use a jigsaw to separate the thermoplastic shell into a foot shell and a calf shell at the dividing line; S4.3, polish and grind all the cuts of the thermoplastic plate shell using a grinder; S4.4, drilling through holes on both sides of the ankle joint incision using an electric drill, and then connecting the foot shell and the calf shell by hinges and rivets to obtain an ankle-foot orthosis; S4.5, grinding and polishing the entire ankle-foot orthosis using a polishing wheel to obtain a finished ankle-foot orthosis.

3. A method for digitizing and customizing a calcaneal orthosis according to claim 2, characterized in that: The repair process of the ankle joint includes: using a marker pen to mark the corresponding heights of the inner and outer ankles of the plaster prototype to indicate the inner and outer ankle heights H1 and H2, and then using plaster slurry and a file to heighten the inner and outer ankles of the plaster prototype by 5-10 mm; The repair process of the arch part includes: using a marker pen to file the arch area of ​​the plaster prototype, and the filed part is a solid body composed of a bottom surface O, a side surface Q and a top curved surface P.

4. The method for digitizing and customizing a calcaneal orthosis according to claim 2, characterized in that: The L-shaped cutting area is composed of the instep area and the front tibia area.

5. The method for digitizing and customizing a calcaneal orthosis according to claim 3, characterized in that: The dividing line is the projection of the extended line connecting the inner and outer ankles on the ankle joint, and the shape of the bottom surface O and the side surface Q is roughly "D-shaped".

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