Wound model construction method and system, flap planning, and visualization projection method

Abstract

The present invention belongs to the field of digital medical technology, and discloses a wound model construction method and system, flap planning, and visualization projection method. The wound model construction method includes: step one, obtaining a skin model by processing the original CTA image; step two, extracting the wound model according to the test wound on the skin model; step three, obtaining a second target plane according to the vertices in all vertex groups in the wound model, projecting the vertices into the second target plane to obtain projection points and dividing the projection point groups; selecting edge points from the projection points, calculating the flattening points of the edge points and dividing the flattening point groups, and obtaining a flattened wound model according to the projection point groups and the flattening point groups. The present invention reduces the difficulty of operation by selecting key points on the skin model to obtain the wound surface; processing the wound surface in groups to improve the operation speed; orthogonally projecting each group and calculating the difference between the group and the projection area to flatten the group in sequence, thereby reducing the error value of the wound surface after flattening.

Description

Technical Field

[0001] The present invention belongs to the field of digital medical technology, and specifically relates to a wound surface model construction method and system, skin flap planning, and a visualization projection method. Background Art

[0002] At present, in the anterolateral thigh free flap transplantation surgery, doctors generally use gauze to cover the patient's wound to obtain the wound shape, and then flatten the gauze to obtain the size and shape of the skin tissue to be obtained from the donor area, and then put the gauze in the donor area, combined with the roughly located perforator blood vessel position before the operation to determine the scope of the incision and skin harvesting. This method has the following shortcomings:

[0003] 1. The gauze is too soft and has poor adhesion to the wound surface, which makes it impossible to achieve accurate measurement, resulting in a large error in the final measured defect area.

[0004] 2. Some wound surfaces have many irregular concave or convex surfaces, and the gauze cannot be perfectly attached. Even if the operator pays attention to these problems, accurate measurement data cannot be obtained, resulting in significantly low measurement accuracy.

[0005] 3. The gauze and paper may shift or be damaged during the process of attaching the gauze to the wound, requiring re-measurement, which wastes time and is inefficient.

[0006] 4. The wound area is an open and bacterially contaminated area. Using a copied wound morphology to attach it to the donor area for flap design will bring bacteria to the surgical area, increase the chance of infection in the surgical area, and even cause infection of the transplanted flap, leading to failure of the operation.

[0007] 5. From the moment the patient enters the operating room, the wound flap is measured, the flap is planned and designed, and the perforating blood vessels are located. There are many manual operation steps, and the system error increases significantly, which will lead to a longer operation time and a significantly increased risk of surgical failure. Summary of the invention

[0008] The purpose of the present invention is to provide a wound surface model construction method and system, flap planning, and visualization projection method to solve the main problems of large errors and low efficiency in the prior art.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a method for creating a wound surface model, which specifically comprises the following steps:

[0011] Step 1: obtaining a skin model of the person under test by processing the original CTA image of the person under test, wherein the original CTA image of the person under test includes a test wound surface;

[0012] Step 2, extracting a wound surface model according to the test wound surface on the skin model of the tested person; specifically comprising the following sub-steps:

[0013] Step 21, arbitrarily select multiple points along the edge of the test wound surface on the skin model as key points, and the plane polygon formed by all the key points is used as the first target plane;

[0014] Step 22, taking the operator's position as the center point, taking the direction of the main viewing angle as the normal vector and the plane passing through the center point as the reference plane, selecting reference points evenly along the x and y axes on the reference plane at intervals of half the original CTA image layer thickness, and calculating the index of each reference point; grouping the reference points according to the indexes of the reference points to obtain multiple reference point groups;

[0015] Step 23, taking each reference point as a starting point and the direction of the operator's main viewing angle as a vector to perform ray detection, taking the collision position of the ray that collides with the first target plane and the skin layer of the skin model at the same time and the skin layer as the vertex corresponding to the current reference point, and storing all the obtained vertices in the array PList, with the index of the vertex being consistent with its corresponding reference point;

[0016] Step 24, when the vertices obtained from the four reference points in the reference point group are less than four, the vertices obtained from the reference point group are deleted from the array PList; all the remaining vertices in the array PList are grouped to obtain multiple vertex groups, and the vertex grouping rules are consistent with their corresponding reference points;

[0017] Step 25, weaving triangles for the vertices in each vertex group, and the triangles obtained from all vertex groups together form a wound surface model;

[0018] Step three, obtain the second target plane according to the vertices in all vertex groups in the wound surface model obtained in step two, project all vertices into the second target plane to obtain projection points and divide the projection point groups; select edge points from the projection points, calculate the flattened points of the edge points and divide them into flattened point groups, and obtain the flattened wound surface model according to the projection point groups and the flattened point groups.

[0019] In a second aspect, the present invention provides a wound surface model creation system, comprising the following modules:

[0020] A skin model acquisition module is used to obtain a skin model of the person under test by processing the original CTA image of the person under test, where the original CTA image of the person under test includes a test wound surface;

[0021] The wound surface model extraction module is used to extract the wound surface model according to the test wound surface on the skin model of the tested person; specifically, the following operations are included:

[0022] A plurality of points are randomly selected along the edge of the test wound surface on the skin model as key points, and the plane polygon formed by all the key points is used as the first target plane;

[0023] Taking the operator's position as the center point, the direction of the main viewing angle as the normal vector and the plane passing through the center point as the reference plane, and half the thickness of the original CTA image layer as the interval, evenly select reference points along the x and y axes on the reference plane, and calculate the index of each reference point; group the reference points according to the index of the reference points to obtain multiple reference point groups;

[0024] Take each reference point as the starting point and the direction of the operator's main view as the vector to perform ray detection, and take the collision position of the ray that collides with the first target plane and the skin layer of the skin model at the same time as the vertex corresponding to the current reference point, and store all the obtained vertices in the array PList, with the index of the vertex being consistent with its corresponding reference point;

[0025] When the vertices obtained from the four reference points in the reference point group are less than four, the vertices obtained from the reference point group are deleted from the array PList; all the remaining vertices in the array PList are grouped to obtain multiple vertex groups, and the vertex grouping rules are consistent with their corresponding reference points;

[0026] Weave triangles for the vertices in each vertex group, and the triangles obtained from all vertex groups together form a wound surface model;

[0027] The flattened wound surface model acquisition module is used to obtain a second target plane based on the vertices in all vertex groups in the wound surface model obtained by the wound surface model extraction module, project all vertices into the second target plane to obtain projection points and divide the projection point groups; select edge points from the projection points, calculate the flattened points of the edge points and divide them into flattened point groups, and obtain a flattened wound surface model based on the projection point groups and the flattened point groups.

[0028] In a third aspect, the present invention provides a flap planning method, comprising the following operations:

[0029] The flattened wound model obtained by the wound model creation method provided in the first aspect is moved to the vicinity of the flap donor area in the skin model, and multiple sets of flap planning schemes are obtained and saved in combination with the distribution of each perforating blood vessel in the vascular model. The flap planning scheme includes the skin model and the corresponding vascular model.

[0030] In a fourth aspect, the present invention provides a visualization projection method, comprising the following operations:

[0031] The first optical positioning capture device and the second optical positioning capture device that have been calibrated and aligned are respectively fixed at a position near the test supply area of ​​the tested person and on the projector, and the positions of the test supply area of ​​the tested person and the projector are respectively obtained by a binocular camera;

[0032] A projector is used to project the multiple sets of flap planning schemes obtained by the flap planning method of the present invention provided in the third aspect onto the test donor area of ​​the tested person.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The wound surface model construction method of the present invention is based on the skin model and blood vessel model reconstructed by CTA of the tested person, extracts the selected wound surface model and flattens it to obtain the flattened wound surface model, wherein the wound surface is obtained by selecting key points on the skin model, which is simple and easy, and reduces the difficulty of operation; the wound surface is cut into groups for processing, which greatly improves the calculation speed; orthogonal projection is performed on each group and the difference between each group and the projection area is calculated to flatten the groups in turn, thereby reducing the error value of the wound surface after flattening.

[0035] (2) The flap planning method of the present invention moves the flattened wound surface model obtained by the wound surface model construction method to the flap donor area of ​​the tested person, and determines multiple surgical plans in combination with the position of the perforating blood vessels in the blood vessel model.

[0036] (3) The visualization projection method of the present invention can accurately obtain the positions of the test donor area and the projector of the tested person by installing optical positioning devices on the test donor area of ​​the tested person and the projector respectively, and identify the positioning devices through a binocular optical positioning camera, and then project the flap planning scheme obtained by the flap planning method to the corresponding position of the test donor area of ​​the tested person. The method can adjust the projection image in real time according to the position of the projector and the position of the test donor area of ​​the tested person to ensure that the relationship between the projection position and the actual position of the test donor area of ​​the tested person is correct, so as to guide the operator to select a more appropriate plan or conduct subsequent research. It can help doctors design and plan surgical plans more intuitively and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the effect diagram of the extracted wound surface model;

[0038] Figure 2 A flattened wound model;

[0039] Figure 3 The simulated display effect of the flattened wound surface model on the human body;

[0040] Figure 4 Take a screenshot of the planning scheme effect. DETAILED DESCRIPTION

[0041] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Embodiment 1:

[0043] The wound surface model creation method provided in this embodiment specifically includes the following steps:

[0044] Step 1: Processing the original CTA image of the person under test to obtain a skin model of the person under test, wherein the original CTA image of the person under test includes a test wound surface; specifically, the test wound surface is a wound surface designated for research or a real wound surface.

[0045] Specifically, the skin model of the person being tested can be obtained by using mimics software.

[0046] Step 2, extracting a wound surface model according to the test wound surface on the skin model of the tested person, specifically includes the following sub-steps:

[0047] Step 21, arbitrarily select multiple points along the edge of the test wound on the skin model as key points (such as Figure 1 As shown in Figure 2), the plane polygon formed by all key points is used as the first target plane;

[0048] Step 22, taking the operator's position as the center point, taking the direction of the main viewing angle as the normal vector and the plane passing through the center point as the reference plane, taking half the slice thickness of the original CTA image as the interval, uniformly selecting reference points along the x and y axes on the reference plane, and calculating the index of each reference point; grouping the reference points according to the index of the reference points to obtain multiple reference point groups;

[0049] Specifically, the index (xindex, yindex) of the reference point is calculated as follows:

[0050] xindex = x-coordinate of the base point rounded down;

[0051] yindex = y coordinate of the base point rounded down;

[0052] Specifically, grouping the reference points according to their indexes means grouping the four reference points whose indexes satisfy points A, B, C, and D into one group, and each reference point appears in only one group:

[0053] Point A index: xindex, yindex;

[0054] Point B index: xindex+1, yindex;

[0055] Point C index: xindex+1, yindex+1;

[0056] Point D index: xindex, yindex+1.

[0057] For example: the reference point with index xindex = 1 and yindex = 1 is point A, then: the index of point B is: xindex = 2, yindex = 1; the index of point C is: xindex = 2, yindex = 2; the index of point D is: xindex = 1, yindex = 2.

[0058] Step 23, perform ray detection with each reference point as the starting point and the direction of the operator's main viewing angle as the vector, and use the collision position of the ray that collides with the first target plane and the skin layer of the skin model at the same time as the vertex corresponding to the current reference point, and store all the obtained vertices in the array PList, and the index of the vertex is consistent with its corresponding reference point.

[0059] Step 24, when the vertices obtained from the four reference points in the reference point group are less than four, the vertices obtained from the reference point group are deleted from the array PList; all the remaining vertices in the array PList are grouped to obtain multiple vertex groups, and the vertex grouping rules are consistent with their corresponding reference points.

[0060] Step 25, weaving triangles for the vertices in each vertex group, and the triangles obtained from all vertex groups together form a wound surface model;

[0061] Specifically, two triangles are drawn using the four vertices in each vertex group. The vertex order of the first triangle is ABC; the vertex order of the second triangle is DAC.

[0062] Step three, obtain the second target plane according to the vertices in all vertex groups in the wound surface model obtained in step two, project all vertices into the second target plane to obtain projection points and divide the projection point groups; select edge points from the projection points, calculate the flattened points of the edge points and divide them into flattened point groups, and obtain the flattened wound surface model according to the projection point groups and the flattened point groups.

[0063] Step 3 specifically includes the following sub-steps:

[0064] Step 31, calculating the average coordinate values ​​of all vertices included in all vertex groups obtained in step 2, and taking it as the coordinate value of the center of mass of the test wound surface, recorded as Center;

[0065] Step 32, taking the direction of the operator's main viewing angle as the normal vector and the plane whose direction passes through the centroid as the second target plane, project all vertices contained in all vertex groups into the second target plane, and the obtained projection points form an array PList0, and the index of the projection point is consistent with the corresponding vertex;

[0066] Step 33, process each vertex group in turn, record the four points A, B, C, D in each vertex group and the corresponding projection points of these four points in the array PList0 as A`, B`, C`, D`, calculate the distance between each vertex group and each point of its projection point group, record them as: AB, CD, AD, BC, AB`, CD`, AD`, BC`;

[0067] Step 34, for each vertex group, calculate the difference xdis in the x direction and the difference ydis in the y direction between each vertex group and its projection point group, and the calculation formula is as follows:

[0068] xdis =((AB+DC)-(AB`+DC`)) / 2;

[0069] ydis =((AD+BC)-(AD`+BC`)) / 2;

[0070] Step 35, sum up all the ydis with the same xindex in the indexes of vertices in all vertex groups, and store them in the array ydislist with xindex as the index, sum up all the xdis with the same yindex in the indexes of vertices in all vertex groups, and store them in the array xdislist with yindex as the index.

[0071] Step 36, find the maximum and minimum points of yindex among all the points with the same xindex in array PList0 as edge points, and put them into array yminlist and array ymaxlist respectively; find the maximum and minimum points of xindex among all the points with the same yindex in array PList0 as edge points, and put them into array xminlist and array xmaxlist respectively;

[0072] Step 37, for all edge points stored in the arrays yminlist, ymaxlist, xminlist, and xmaxlist, calculate the coordinate values ​​of four flattened points spoint1, spoint2, spoint3, and spoint4 obtained by flattening each edge point in the x and y directions;

[0073] Specifically, the calculation process of the flattened points spoint1, spoint2, spoint3, and spoint4 is as follows:

[0074] The x and y coordinate values ​​of the 1st to 4th flattened points of the i-th edge point in the array yminlist:

[0075] spoint1.x = yminlist[i].x -intervel / 2;

[0076] spoint1.y = yminlist[i].y;

[0077] spoint2.x = yminlist[i].x + intervel / 2;

[0078] spoint2.y = yminlist[i].y;

[0079] spoint3.x = yminlist[i].x - intervel / 2;

[0080] spoint3.y = yminlist[i].y - ydislist[i];

[0081] spoint4.x = yminlist[i].x + intervel / 2;

[0082] spoint4.y = yminlist[i].y - ydislist[i];

[0083] Wherein, interval is the interval obtained by step 22;

[0084] Spoint1.x represents the x coordinate of the first flattened point;

[0085] Spoint1.y represents the y coordinate of the first flattened point;

[0086] xdislist[i] represents the value in the array xdislist, indexed by the yindex of the i-th edge point in the array yminlist;

[0087] ydislist[i] represents the value in the array ydislist, indexed by the xindex of the i-th edge point in the array yminlist;

[0088] The x and y coordinate values ​​of the 1st to 4th flattened points of the i-th edge point in the array ymaxlist:

[0089] spoint1.x = ymaxlist[i].x - intervel / 2;

[0090] spoint1.y = ymaxlist[i].y;

[0091] spoint2.x = ymaxlist[i].x + intervel / 2;

[0092] spoint2.y = ymaxlist[i].y;

[0093] spoint3.x = ymaxlist[i].x - intervel / 2;

[0094] spoint3.y = ymaxlist[i].y + ydislist[i];

[0095] spoint4.x = ymaxlist[i].x + intervel / 2;

[0096] spoint4.y = ymaxlist[i].y + ydislist[i];

[0097] Among them, ydislist[i] represents the value in the array ydislist, which is stored with the xindex of the i-th edge point in the array ymaxlist as the index;

[0098] The x and y coordinate values ​​of the 1st to 4th flattened points of the i-th edge point in the array xminlist:

[0099] spoint1.x = xminlist[i].x;

[0100] spoint1.y = xminlist[i].y - intervel / 2;

[0101] spoint2.x = xminlist[i].x;

[0102] spoint2.y = xminlist[i].y + intervel / 2;

[0103] spoint3.x = xminlist[i].x -xdislist[i];

[0104] spoint3.y = xminlist[i].y - intervel / 2;

[0105] spoint4.x = xminlist[i].x - xdislist[i];

[0106] spoint4.y = xminlist[i].y + intervel / 2;

[0107] Among them, xdislist[i] represents the value in the array xdislist, which is stored with the yindex of the i-th edge point in the array xminlist as the index;

[0108] The x and y coordinate values ​​of the 1st to 4th flattened points of the i-th edge point in the array xmaxlist:

[0109] spoint1.x = xmaxlist[i].x;

[0110] spoint1.y = xmaxlist[i].y - intervel / 2;

[0111] spoint2.x = xmaxlist[i].x;

[0112] spoint2.y = xmaxlist[i].y + intervel / 2;

[0113] spoint3.x = xmaxlist[i].x +xdislist[i];

[0114] spoint3.y = xmaxlist[i].y - intervel / 2;

[0115] spoint4.x = xmaxlist[i].x + xdislist[i];

[0116] point4.y = xmaxlist[i].y + intervel / 2.

[0117] Among them, xdislist[i] represents the value in the array xdislist, which is stored with the yindex of the i-th edge point in the array xmaxlist as the index;

[0118] Step 38, save the four flattened points spoint1, spoint2, spoint3, and spoint4 of all edge points obtained in step 37 after the projection points in PList0 in the order obtained.

[0119] In step 39, the four flattened points corresponding to each edge point obtained in step 37 are grouped into one group, and the first to fourth flattened points are recorded as points A, B, C, and D respectively.

[0120] Step 310, all points in the array PList0 (including projection points and flattened points) are knitted into triangles in groups, and all the obtained triangles together form a flattened wound surface model (see Figure 2), the simulation display of the flattened wound surface model on the human body is shown in Figure 3 .

[0121] Specifically, two triangles are drawn using the four vertices in each flattened point group, the vertex order of the first triangle is ABC; the vertex order of the second triangle is DAC.

[0122] Embodiment 2:

[0123] This embodiment provides a flap planning method based on the flattened wound surface model obtained by the wound surface model creation method of Embodiment 1, including the following operations:

[0124] Step 4: Move the flattened wound surface model obtained in step 3 to the vicinity of the flap donor area in the skin model obtained in step 1, and obtain and save multiple sets of flap planning schemes in conjunction with the distribution of the perforating blood vessels in the vascular model (in this embodiment, the vascular model is obtained using mimics software). The flap planning scheme includes the skin model and the corresponding vascular model, see Figure 4 ;

[0125] Embodiment 3:

[0126] This embodiment provides a visualization projection method based on multiple sets of flap planning schemes obtained by the flap planning method of Embodiment 2, which specifically includes the following steps:

[0127] Step five, respectively fix the calibrated and aligned first optical positioning capture device and second optical positioning capture device near the test area of ​​the person under test and on the projector, and respectively obtain the positions of the test area of ​​the person under test and the projector through the binocular camera.

[0128] It should be noted that the first optical positioning capture device and the second optical positioning capture device do not adopt the same structure, and the same structure is not conducive to the identification of the optical locator.

[0129] Step six, using a projector to project the multiple sets of flap planning schemes obtained in step four onto the test donor area of ​​the tested person.

[0130] Since both the projector and the test donor area of ​​the person being tested are positioned and tracked by the binocular camera, the flap planning scheme projected by the projector will be matched and displayed with the test donor area of ​​the person being tested in real time during movement as long as it is within the projection range.

[0131] In summary, the visualization projection method of the present invention can project and display each set of flap planning schemes on the test donor area of ​​the tested person, allowing researchers to select the most suitable flap planning scheme.

[0132] Embodiment 4:

[0133] The wound surface model creation system provided in this embodiment includes the following modules:

[0134] A skin model acquisition module is used to obtain a skin model of a tested person by processing an original CTA image, wherein the original CTA image includes a test wound surface;

[0135] The wound surface model extraction module is used to extract the wound surface model according to the test wound surface on the skin model; specifically, the following operations are included:

[0136] A plurality of points are randomly selected along the edge of the test wound surface on the skin model as key points, and the plane polygon formed by all the key points is used as the first target plane;

[0137] Taking the operator's position as the center point, the direction of the main viewing angle as the normal vector and the plane passing through the center point as the reference plane, and half the thickness of the original CTA image layer as the interval, evenly select reference points along the x and y axes on the reference plane, and calculate the index of each reference point; group the reference points according to the index of the reference points to obtain multiple reference point groups;

[0138] Take each reference point as the starting point and the direction of the main view as the vector to perform ray detection, and take the collision position of the ray that collides with the first target plane and the skin layer of the skin model as the vertex corresponding to the current reference point, and store all the obtained vertices in the array PList, with the index of the vertex being consistent with its corresponding reference point;

[0139] When the vertices obtained from the four reference points in the reference point group are less than four, the vertices obtained from the reference point group are deleted from the array PList; all the remaining vertices in the array PList are grouped to obtain multiple vertex groups, and the vertex grouping rules are consistent with their corresponding reference points;

[0140] Weave triangles for the vertices in each vertex group, and the triangles obtained from all vertex groups together form a wound surface model;

[0141] The flattened wound surface model acquisition module is used to obtain a second target plane based on the vertices in all vertex groups in the wound surface model obtained by the wound surface model extraction module, project all vertices into the second target plane to obtain projection points and divide the projection point groups; select edge points from the projection points, calculate the flattened points of the edge points and divide them into flattened point groups, and obtain a flattened wound surface model based on the projection point groups and the flattened point groups.

Claims

1. A method for creating a wound surface model, characterized in that: The specific steps include: Step 1: obtaining a skin model by processing the original CTA image, wherein the original CTA image includes a test wound surface; Step 2: extracting a wound surface model according to the test wound surface on the skin model; specifically including the following sub-steps: Step 21, arbitrarily select multiple points along the edge of the test wound surface on the skin model as key points, and the plane polygon formed by all the key points is used as the first target plane; Step 22, taking the operator's position as the center point, taking the direction of the main viewing angle as the normal vector and the plane passing through the center point as the reference plane, selecting reference points evenly along the x and y axes on the reference plane at intervals of half the original CTA image layer thickness, and calculating the index of each reference point; grouping the reference points according to the indexes of the reference points to obtain multiple reference point groups; Step 23, perform ray detection with each reference point as the starting point and the direction of the main view as the vector, and use the collision position of the ray that collides with the first target plane and the skin layer of the skin model at the same time as the vertex corresponding to the current reference point, and store all the obtained vertices in the array PList, and the index of the vertex is consistent with its corresponding reference point; Step 24, when the vertices obtained from the four reference points in the reference point group are less than four, the vertices obtained from the reference point group are deleted from the array PList; all the remaining vertices in the array PList are grouped to obtain multiple vertex groups, and the vertex grouping rules are consistent with their corresponding reference points; Step 25, weaving triangles for the vertices in each vertex group, and the triangles obtained from all vertex groups together form a wound surface model; Step 3, obtaining a second target plane according to the vertices in all vertex groups in the wound surface model obtained in step 2, projecting all vertices into the second target plane to obtain projection points and dividing the projection point groups; selecting edge points from the projection points, calculating the flattening points of the edge points and dividing the flattening point groups, and obtaining a flattened wound surface model according to the projection point groups and the flattening point groups; specifically comprising the following sub-steps: Step 31, calculating the average coordinate values ​​of all vertices included in all vertex groups obtained in step 2, and taking it as the coordinate value of the center of mass of the test wound surface, recorded as Center; Step 32, taking the direction of the main viewing angle as the normal vector and the plane whose direction passes through the centroid as the second target plane, project all vertices contained in all vertex groups into the second target plane, and the obtained projection points form an array PList0, and the index of the projection point is consistent with the corresponding vertex; Step 33, process each vertex group in turn, record the four points A, B, C, D in each vertex group and the corresponding projection points of these four points in the array PList0 as A`, B`, C`, D`, calculate the distance between each vertex group and each point of its projection point group, record them as: AB, CD, AD, BC, AB`, CD`, AD`, BC`; Step 34, for each vertex group, calculate the difference xdis in the x-direction distance and the difference ydis in the y-direction distance between each vertex group and its projection point group; Step 35, sum up all ydis with the same xindex in the indexes of vertices in all vertex groups, and store them in the array ydislist with xindex as the index; sum up all xdis with the same yindex in the indexes of vertices in all vertex groups, and store them in the array xdislist with yindex as the index; Step 36, find the maximum and minimum points of yindex among all the points with the same xindex in array PList0 as edge points, and put them into array yminlist and array ymaxlist respectively; find the maximum and minimum points of xindex among all the points with the same yindex in array PList0 as edge points, and put them into array xminlist and array xmaxlist respectively; Step 37, for all edge points stored in the arrays yminlist, ymaxlist, xminlist, and xmaxlist, calculate the coordinate values ​​of four flattened points spoint1, spoint2, spoint3, and spoint4 obtained by flattening each edge point in the x and y directions; Step 38, save the four flattened points spoint1, spoint2, spoint3, and spoint4 of all edge points obtained in step 37 after the projection points in PList0 in the order obtained; Step 39, grouping the four flattened points corresponding to each edge point obtained in step 37 into a group, and recording the first to fourth flattened points as points A, B, C, and D, respectively; Step 310: Weave all points in the array PList0 into triangles in groups, and all obtained triangles together form a flattened wound surface model.

2. The wound surface model creation method according to claim 1, characterized in that: In step 1, the skin model is obtained by using mimics software.

3. The wound surface model creation method according to claim 1, characterized in that: In step 22, the calculation formula of the index of the reference point is: xindex = x-coordinate of the base point rounded down; yindex = y coordinate of the base point rounded down; Grouping the reference points according to their indices means grouping the four reference points whose indices satisfy points A, B, C, and D into one group, and each reference point appears in only one group: Point A index: xindex, yindex; Point B index: xindex+1, yindex; Point C index: xindex+1, yindex+1; Point D index: xindex, yindex+1.

4. The wound surface model creation method according to claim 3, characterized in that: In step 25, two triangles are drawn using the four vertices in each vertex group. The vertex order of the first triangle is ABC; the vertex order of the second triangle is DAC.

5. A wound surface model creation system, characterized in that: Includes the following modules: A skin model acquisition module is used to obtain a skin model of a tested person by processing an original CTA image, wherein the original CTA image includes a test wound surface; The wound surface model extraction module is used to extract the wound surface model according to the test wound surface on the skin model; specifically, the following operations are included: A plurality of points are randomly selected along the edge of the test wound surface on the skin model as key points, and the plane polygon formed by all the key points is used as the first target plane; Taking the operator's position as the center point, the direction of the main viewing angle as the normal vector and the plane passing through the center point as the reference plane, and half the thickness of the original CTA image layer as the interval, evenly select reference points along the x and y axes on the reference plane, and calculate the index of each reference point; group the reference points according to the index of the reference points to obtain multiple reference point groups; Take each reference point as the starting point and the direction of the main view as the vector to perform ray detection, and take the collision position of the ray that collides with the first target plane and the skin layer of the skin model as the vertex corresponding to the current reference point, and store all the obtained vertices in the array PList, with the index of the vertex being consistent with its corresponding reference point; When the vertices obtained from the four reference points in the reference point group are less than four, the vertices obtained from the reference point group are deleted from the array PList; all the remaining vertices in the array PList are grouped to obtain multiple vertex groups, and the vertex grouping rules are consistent with their corresponding reference points; Weave triangles for the vertices in each vertex group, and the triangles obtained from all vertex groups together form a wound surface model; The flattened wound surface model acquisition module is used to obtain the second target plane according to the vertices in all vertex groups in the wound surface model obtained by the wound surface model extraction module, project all vertices into the second target plane to obtain projection points and divide the projection point groups; select edge points from the projection points, calculate the flattened points of the edge points and divide the flattened point groups, and obtain the flattened wound surface model according to the projection point groups and the flattened point groups; specifically includes the following operations: Calculate the average coordinate value of all vertices contained in all vertex groups obtained in step 2, and use it as the coordinate value of the center of mass of the test wound surface, denoted as Center; The direction of the main viewing angle is taken as the normal vector and the plane whose direction passes through the centroid is taken as the second target plane. All vertices contained in all vertex groups are projected into the second target plane. The obtained projection points form an array PList0. The index of the projection point is consistent with the corresponding vertex. Process each vertex group in turn, record the four points A, B, C, D in each vertex group and the corresponding projection points of these four points in the array PList0 as A`, B`, C`, D`, calculate the distance between each vertex group and each point of its projection point group, record them as: AB, CD, AD, BC, AB`, CD`, AD`, BC`; For each vertex group, the difference xdis in the x-direction distance and the difference ydis in the y-direction distance between each vertex group and its projection point group are calculated; Sum all the ydis with the same xindex in the index of vertices in all vertex groups, and store them in the array ydislist with xindex as the index. Sum all the xdis with the same yindex in the index of vertices in all vertex groups, and store them in the array xdislist with yindex as the index. In the array PList0, find the maximum and minimum points of yindex among all the points with the same xindex as edge points, and put them into the array yminlist and array ymaxlist respectively; in PList0, find the maximum and minimum points of xindex among all the points with the same yindex as edge points, and put them into the array xminlist and array xmaxlist respectively; For all edge points stored in the arrays yminlist, ymaxlist, xminlist, and xmaxlist, calculate the coordinate values ​​of the four flattened points spoint1, spoint2, spoint3, and spoint4 obtained by flattening each edge point in the x and y directions; Save the four flattened points spoint1, spoint2, spoint3, and spoint4 of all edge points after the projection points in PList0 in the order obtained; The four flattening points corresponding to each edge point are divided into a group, and the first to fourth flattening points are recorded as points A, B, C, and D respectively; All points in the array PList0 are weaved into triangles in groups, and all the obtained triangles together form a flattened wound surface model.

6. A flap planning method, characterized in that: The following operations are included: The flattened wound model obtained by the wound model creation method described in any one of claims 1 to 4 is moved to the vicinity of the flap donor area in the skin model, and multiple sets of flap planning schemes are obtained and saved in combination with the distribution of each perforator vessel in the vascular model. The flap planning scheme includes the skin model and the corresponding vascular model.

7. A visualization projection method, characterized in that: The following operations are included: The first optical positioning capture device and the second optical positioning capture device that have been calibrated and aligned are respectively fixed at a position near the test supply area of ​​the tested person and on the projector, and the positions of the test supply area of ​​the tested person and the projector are respectively obtained by a binocular camera; A projector is used to project the multiple sets of flap planning schemes obtained by the flap planning method of claim 6 onto the test donor area of ​​the tested person.

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