Calibration method, system and calibrator for surgical instruments

Abstract

The application relates to the technical field of surgical instruments, in particular to a calibration method and system of a surgical instrument and a calibrator. The method comprises the following steps: projecting at least five mark points on the calibrator in at least one scanning body position, obtaining the projected mark points and the first projection positions of the mark points in a projection coordinate system; acquiring the first space positions of the mark points in an optical camera coordinate system; converting the first space positions to obtain the second projection positions of the mark points in the projection coordinate system according to the projection transformation relationship and the coordinate system transformation relationship between a ray light source tracker and a ray receiving plate tracker and the optical camera; inputting the first projection positions and the second projection positions into a first loss function and performing optimization processing to obtain the positions of light source particles in the ray light source tracker coordinate system and the first conversion matrix of the ray receiving plate tracker coordinate system and the projection coordinate system. The method can realize efficient development of a surgical process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of surgical instruments, in particular to a calibration method and system of surgical instruments and a calibrator. BACKGROUND

[0002] The current 2D surgical navigation system usually fixes a sleeve calibrator on the X-ray machine device, and an empty film is shot before each surgery to obtain the intraoperative space position of the X-ray machine device, and then the calibration of the surgical navigation system is completed. Due to the complex structure of the sleeve calibrator, it occupies a limited surgical operation space; and calibration is required before each surgery, which is a cumbersome process and increases the preoperative operation process, which is not conducive to the efficient development of the surgery process. SUMMARY

[0003] Therefore, a calibration method, system and calibrator of surgical instruments are provided to realize the efficient development of the surgery process.

[0004] In a first aspect, a calibration method of surgical instruments is provided, comprising:

[0005] In at least one scanning body position, the ray light source end of the scanning device projects at least five marker points on the calibrator to the ray receiving plate to obtain corresponding projection marker points and first projection positions of the projection marker points in the projection coordinate system corresponding to the ray receiving plate;

[0006] An optical camera obtains first spatial positions of each of the marker points in the optical camera coordinate system;

[0007] The projection transformation relationship of the scanning device, the first coordinate system transformation relationship between the ray light source tracker and the optical camera, and the second coordinate system transformation relationship between the ray receiving plate tracker and the optical camera are obtained;

[0008] According to the projection transformation relationship, the first coordinate system transformation relationship and the second coordinate system transformation relationship, the first spatial positions are converted to obtain second projection positions of the projection marker points in the projection coordinate system;

[0009] The first projection positions and the second projection positions are input into a preset first loss function, and the first loss function is optimized to obtain an optimization result to complete the calibration between the ray light source tracker and the ray light source end and between the ray receiving plate tracker and the ray receiving plate;

[0010] The optimization result includes the position of the light source particle emitted by the ray light source end in the ray light source tracker coordinate system, and a first conversion matrix between the ray receiving plate tracker coordinate system and the projection coordinate system.

[0011] With reference to the first aspect, in a first implementation form of the first aspect, the step of obtaining the first spatial position of each of the marker points in the optical camera coordinate system comprises:

[0012] obtaining calibration parameters of the calibrator, wherein the calibration parameters comprise second spatial positions of the at least three optical spheres in a calibrator coordinate system of the calibrator, and third spatial positions of each of the marker points in the calibrator coordinate system;

[0013] collecting fourth spatial positions of each of the optical spheres in the optical camera coordinate system;

[0014] calculating a second conversion matrix between the calibrator coordinate system and the optical camera coordinate system according to the fourth spatial positions of each of the optical spheres and the second spatial positions;

[0015] performing coordinate system conversion processing on the third spatial positions of each of the marker points according to the second conversion matrix, to obtain the first spatial positions of each of the marker points in the optical camera coordinate system.

[0016] With reference to the first implementation form of the first aspect, in a second implementation form of the first aspect, before the step of obtaining the calibration parameters of the calibrator, the method further comprises:

[0017] recognizing the calibrator in the first body position by the optical camera, and collecting fifth spatial positions of each of the optical spheres in the optical camera coordinate system;

[0018] recognizing the calibrator in the second body position by the optical camera, and collecting sixth spatial positions of each of the optical spheres in the optical camera coordinate system at least once;

[0019] constructing an initialization coordinate system according to the sixth spatial positions of each of the optical spheres collected at least once, and generating the calibrator coordinate system based on the initialization coordinate system;

[0020] performing coordinate system conversion processing on the fifth spatial positions of each of the optical spheres, to obtain the second spatial positions of each of the optical spheres in the calibrator coordinate system.

[0021] With reference to the second implementation form of the first aspect, in a third implementation form of the first aspect, the step of constructing the initialization coordinate system according to the sixth spatial positions of each of the optical spheres collected at least once comprises:

[0022] generating a coordinate system origin and a coordinate axis direction according to the sixth spatial positions of each of the optical spheres collected at least once, to construct the initialization coordinate system;

[0023] According to the coordinate system origin and the coordinate axis direction, a coordinate system conversion calculation is performed to obtain a third conversion matrix of the optical camera coordinate system to the initialization coordinate system;

[0024] According to the third conversion matrix, a coordinate system conversion processing is performed on each of the sixth spatial positions of the optical balls collected at least once to obtain a seventh spatial position of the corresponding optical ball in the initialization coordinate system;

[0025] A second loss function is constructed according to the seventh spatial position, and a second loss value of the second loss function is calculated, wherein the mathematical expression of the second loss function comprises:

[0026]

[0027]

[0028] N is the total number of times of collecting the sixth spatial position, and N≥1; n1∈{1,2,…,M1}, M1 is the total number of the optical balls, and M1≥3; is the seventh spatial position corresponding to the m1th optical ball collected for the nth time in the initialization coordinate system; represents the mean of the sum of the seventh spatial positions corresponding to the m1th optical ball collected for n times;

[0029] It is judged whether the second loss value is lower than a preset loss threshold value, if yes, the initialization coordinate system is successfully constructed; if no, the step of identifying the calibrator in the first body position by the optical camera is returned.

[0030] In a fourth implementable manner of the first aspect, in combination with the second or third implementable manner of the first aspect, before the step of obtaining the calibration parameters of the calibrator pre-calibrated, the method further comprises:

[0031] The optical camera identifies the calibrator in a third body position, and collects at least once the eighth spatial position of each of the optical balls in the optical camera coordinate system, wherein the third body position represents a body position when the calibrator is irregularly rotated with any one of the marker points as a rotation center;

[0032] According to the second spatial position and the eighth spatial position of each of the optical balls, a fourth conversion matrix of the calibrator coordinate system to the optical camera coordinate system is calculated;

[0033] The ninth spatial position of the marker point as the rotation center in the optical camera coordinate system is obtained;

[0034] According to the fourth conversion matrix, a coordinate system conversion process is performed on the ninth spatial position to obtain a third spatial position of a marker point serving as a rotation center in the calibrator coordinate system;

[0035] The body position of the calibrator after irregular rotation with other marker points as the rotation center is taken as a third body position, and the step of identifying the calibrator in the third body position by the optical camera is returned to obtain a third spatial position of the other marker points in the calibrator coordinate system.

[0036] In combination with the fourth implementable manner of the first aspect, in a fifth implementable manner of the first aspect, the step of obtaining the ninth spatial position of the marker point serving as the rotation center in the optical camera coordinate system comprises:

[0037] The ninth spatial position of the marker point serving as the rotation center in the optical camera coordinate system is preset;

[0038] According to the ninth spatial position and the eighth spatial position collected at least once, a corresponding mapping relationship is constructed, and a mathematical expression of the mapping relationship comprises:

[0039]

[0040] and The eighth spatial position of the m1th optical sphere collected for the kth time in the X axis, Y axis and Z axis is respectively xk, yk and zk, and the preset ninth spatial position in the X axis, Y axis and Z axis is respectively x1, y1 and z1, is a rotation radius of the m1th optical sphere, k∈{1, 2, …, K}, K is the number of collection of the eighth spatial position, and K≥1, m1∈{1, 2, …, M1}, M1 is the total number of the optical spheres, and M1≥3;

[0041] According to each mapping relationship, a third loss function is established, and a mathematical expression of the third loss function comprises:

[0042]

[0043] The third loss function is solved to obtain the values of the ninth spatial position in the X axis, Y axis and Z axis.

[0044] In a second aspect, a calibrator system of a surgical instrument is provided, which is placed in at least one scanning body position.

[0045] The scanning device comprises a ray source end and a ray receiving plate, and is used for projecting at least five marker points on a marker under the at least one scanning body position to the ray receiving plate through the ray source end to obtain corresponding projection marker points and first projection positions of the projection marker points in a projection coordinate system corresponding to the ray receiving plate;

[0046] A ray source tracker is rigidly connected with the ray source end;

[0047] A ray receiving plate tracker is rigidly connected with the ray receiving plate;

[0048] An optical camera is used for acquiring first spatial positions of each of the marker points in an optical camera coordinate system;

[0049] A transformation relationship acquisition module is used for acquiring a projection transformation relationship of the scanning device, a first coordinate system transformation relationship between the ray source tracker and the optical camera, and a second coordinate system transformation relationship between the ray receiving plate tracker and the optical camera;

[0050] A spatial position conversion module is used for converting the first spatial positions according to the projection transformation relationship, the first coordinate system transformation relationship and the second coordinate system transformation relationship to obtain second projection positions of the projection marker points in the projection coordinate system;

[0051] A first calibration module is used for inputting the first projection positions and the second projection positions into a preset first loss function, performing optimization processing on the first loss function to obtain an optimization result, so as to complete calibration between the ray source tracker and the ray source end and between the ray receiving plate tracker and the ray receiving plate;

[0052] The optimization result comprises a position of a light source point emitted by the ray source end in a ray source tracker coordinate system and a first conversion matrix between a ray receiving plate tracker coordinate system and the projection coordinate system.

[0053] In a third aspect, a marker is provided, which is applied to the surgical instrument calibration method of the first aspect or any one of the implementable manners in combination with the first aspect, and the surgical instrument calibration system of the second aspect, and the marker comprises:

[0054] A body, wherein at least three optical balls and at least five marker points for optical camera recognition are uniformly distributed on the body, and the five marker points are located in different planes respectively;

[0055] The base, the body and the base are connected in up-down sliding mode in vertical direction, and the body is detachably connected with the base, and the body is connected with the base at one end in axial direction of the body, or the body is connected with the base at one end in radial direction of the body;

[0056] The locking member is arranged on the connecting block and is used for limiting the up-down sliding of the body and fixing the height of the body on the base.

[0057] In combination with the third aspect, in a first implementation manner of the third aspect, the body comprises:

[0058] The connecting block is provided with a protruding block, and the axial direction of the protruding block is perpendicular to the axial direction of the connecting block, and the connecting block and the protruding block are respectively provided with a through hole in the axial direction thereof, and the at least three optical balls are arranged on the connecting block;

[0059] The at least one mounting block is fixedly connected with the connecting block, and the at least five mark points are arranged on the at least one mounting block, and the mark points are in the shape of the tip of the conical column;

[0060] The base comprises a bottom block, a mounting strip and an adjusting rod, two ends of the mounting strip are fixedly connected with the top wall of the bottom block and one end of the adjusting rod respectively, and the radial length of the adjusting rod is matched with the inner diameter size of the through hole;

[0061] The locking member is arranged on the connecting block.

[0062] In combination with the third aspect, in a second implementation manner of the third aspect, the body comprises:

[0063] The connecting block is provided with a protruding block, and the axial direction of the protruding block is perpendicular to the axial direction of the connecting block, and the connecting block and the protruding block are respectively provided with a through hole in the axial direction thereof, and the at least three optical balls are arranged on the connecting block;

[0064] The at least one mounting block is fixedly connected with the connecting block, and the at least five mark points are arranged on the at least one mounting block, and the mark points are in the shape of the tip of the conical column;

[0065] The base comprises a bottom block and a mounting strip, one end of the mounting strip is fixedly connected with the top wall of the bottom block, and the other end is provided with a mounting hole in the vertical direction, and the inner diameter of the mounting hole is matched with the radial length size of the supporting rod;

[0066] The locking member is arranged on the mounting strip.

[0067] The calibration method, system and calibrator of the surgical instrument are characterized in that, in at least one scanning position, at least five mark points on the calibrator are projected to a radiation receiving plate through a radiation light source end of a scanning device to obtain corresponding projection mark points and first projection positions of the projection mark points in a projection coordinate system corresponding to the radiation receiving plate; first space positions of the mark points in an optical camera coordinate system are obtained through an optical camera; a projection transformation relationship of the scanning device, a first coordinate system transformation relationship between a radiation light source tracker and the optical camera, and a second coordinate system transformation relationship between a radiation receiving plate tracker and the optical camera are obtained; the first space positions are converted according to the projection transformation relationship, the first coordinate system transformation relationship and the second coordinate system transformation relationship to obtain second projection positions of the projection mark points in the projection coordinate system; the first projection positions and the second projection positions are input into a preset first loss function and are subjected to optimization processing to obtain an optimization result, so as to complete calibration between the radiation light source tracker and the radiation light source end and between the radiation receiving plate tracker and the radiation receiving plate; wherein the optimization result includes a position of a light source particle emitted by the radiation light source end in a radiation light source tracker coordinate system and a first conversion matrix between the radiation receiving plate tracker coordinate system and the projection coordinate system. The calibration method of the surgical instrument provided in the application does not need to fix the calibrator on the surgical instrument, but only needs to place the calibrator in a range that can be recognized by the optical camera and the scanning device, and only needs to perform a calibration process once to realize permanent calibration of the surgical instrument, so that the surgical instrument does not need to be calibrated before each surgical operation, and therefore, compared with the prior art, the calibration method of the surgical instrument provided in the application can reduce a preoperative operation process and realize efficient surgical operation. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 It is a schematic diagram of the overall structure of the calibrator in the first embodiment.

[0069] Figure 2 It is a schematic diagram of the overall structure of the calibrator in the first embodiment.

[0070] Figure 3 It is a schematic diagram of the overall structure of the calibrator in the first embodiment.

[0071] Figure 4 It is a schematic diagram of the overall structure of the calibrator in the first embodiment.

[0072] Figure 5 It is a schematic diagram of the calibration method of the surgical instrument in the second embodiment.

[0073] Figure 6 It is a structural block diagram of the calibration system of the surgical instrument in the third embodiment.

[0074] Figure 7 It is a structural block diagram of the optical camera in the third embodiment.

[0075] Figure 8 a structure diagram of the second calibration module in the third embodiment;

[0076] Figure 9 a structure diagram of the second calibration module in the third embodiment.

[0077] Explanation of reference numerals:

[0078] 1. calibrator; 11. body; 111. optical ball; 112. mark point; 113. connecting block; 114. convex block; 115. through hole; 116. mounting block; 117. supporting rod; 118. supporting rod; 119. support; 12. base; 121. bottom block; 122. mounting strip; 123. adjusting rod; 124. mounting hole; 13. locking member. DETAILED DESCRIPTION

[0079] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0080] It should be noted that the diagrams provided in the embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the diagrams, not the number, shape and size of the components when actually implemented. The shape, number and proportion of each component when actually implemented can be arbitrarily changed, and the layout pattern of the components can also be more complex.

[0081] The structures, proportions, sizes, etc. shown in the diagrams attached to the present specification are only used to cooperate with the content disclosed in the specification for understanding and reading by those skilled in the art, and do not define the limiting conditions for the implementation of the present application, so they do not have technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that the present application can produce, should still fall within the scope of the technical content disclosed by the present application.

[0082] The orientations or positional relationships indicated by terms such as "upper", "lower", "left", "right", "intermediate", "vertical", "horizontal", "inner", "outer", "radial", "circumferential", etc. as used in this specification are based on the orientations or positional relationships shown in the drawings, and are only used to simplify the description, and cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0083] Since physical deformation occurs between the ray light source and the ray receiving plate during the rotation or movement of the scanning device, navigation and positioning errors are caused, so by installing a ray light source tracker near the ray light source end of the scanning device and a ray receiving plate tracker near the ray receiving plate of the scanning device, the spatial positions of the ray light source particles emitted by the ray light source end and the ray receiving plate are positioned respectively, thereby providing technical support for subsequent scanning image navigation and improving the phenomenon of navigation and positioning errors caused by physical deformation.

[0084] Before using the above positioning method or system, the spatial positions of the ray light source particles and the ray receiving plate need to be calibrated to obtain calibrated parameters, so that the spatial positions of the ray light source particles and the ray receiving plate are positioned according to the calibrated parameters. Therefore, the present application proposes a calibration method, system and calibrator for surgical instruments, which can realize the calibration of the spatial positions of the ray light source particles and the ray receiving plate. Next, the calibration method, system and calibrator for surgical instruments of the present application will be described in detail through the following embodiments.

[0085] In the first embodiment, as shown in Figure 1 , Figure 2 a calibrator 1 is provided, which is applied to the calibration method and system for surgical instruments, and comprises:

[0086] a body 11, at least three optical balls 111 and at least five marker points 112 for optical camera recognition are uniformly distributed on the body 11, and the five marker points 112 are located on different planes respectively;

[0087] a base 12, the body 11 and the base 12 are connected in an up-down sliding manner along the vertical direction, and the body 11 and the base 12 are detachably connected, one end of the body 11 along the axial direction thereof is connected with the base 12, or one end of the body 11 along the radial direction thereof is connected with the base 12;

[0088] a locking member 13 for limiting the up-down sliding of the body 11 and fixing the height of the body 11 on the base 12.

[0089] It should be noted that the marker points 112 are provided as the tips of conical columns, which can make the identification and positioning of the marker points 112 by the optical camera more accurate, and is beneficial to the calibration accuracy of the surgical instruments. The distance between any two marker points 112 can be set to 30mm. The type of the calibrator 1 can be passive or active, wherein the passive type means that the optical balls 111 do not actively emit light, but are identified and positioned by the optical camera through the reflection of infrared light; the active type is opposite to the passive type, and the optical balls 111 are identified and positioned by the optical camera through active light emission.

[0090] Preferably, the calibrator 1 needs to meet some unique geometric constraints: the distance between two marking points 112 in the same calibrator 1 is a segment length; generally, the difference between two segment lengths is at least 5 mm, and two segments with a difference within 5 mm are similar segments; two segments in the same calibrator 1 are a segment pair; two segment pairs on different calibrators 1 or different planes of the same calibrator 1, the segments in one segment pair and the similar segments in another segment pair are similar segment pairs; the included angle between two segments is a segment angle.

[0091] More specifically, the calibrator 1 also needs to meet some compatibility constraints: for two calibrators 1 of the same type, the segment angles of any two similar segment pairs differ by at least 2 degrees; passive calibrators 1 can have the same geometric shape as active calibrators 1, but the geometric shapes are mirror images, so they cannot be used together.

[0092] The number of optical spheres 111 on the calibrator 1 can be increased according to the application, but as the number of optical spheres 111 increases, the number of segments in the calibrator 1 also needs to increase; if multiple calibrators 1 are to be used simultaneously, the number of segment pairs also needs to increase; the minimum value of the maximum segment length of the calibrator 1 will be larger, and the number of segment angles will also increase.

[0093] In a specific embodiment, as shown in Figure 1 , Figure 3 The body 11 includes a connecting block 113, the connecting block 113 is provided with a protruding block 114, the axial direction of the protruding block 114 is perpendicular to the axial direction of the connecting block 113, the connecting block 113 and the protruding block 114 are respectively provided with a through hole 115 along the axial direction thereof, and the at least three optical spheres 111 are distributed on the connecting block 113; at least one mounting block 116 is fixedly connected with the connecting block 113, and the at least five marking points 112 are distributed on the at least one mounting block 116, the marking points 112 are in the shape of the tip of a conical column; the base 12 includes a bottom block 121, a mounting strip 122, and an adjusting rod 123, both ends of the mounting strip 122 are fixedly connected with the top wall of the bottom block 121 and one end of the adjusting rod 123, respectively, and the radial length of the adjusting rod 123 is adapted to the inner diameter size of the through hole 115; the locking member 13 is arranged on the connecting block 113.

[0094] In the embodiment, the number of the mounting blocks 116 is two, and the two mounting blocks 116 are fixedly connected with two ends of the connecting block 113 respectively; the convex block 114 is located between the two mounting blocks 116, the optical balls 111 are distributed between the two mounting blocks 116, and the locking member 13 can be arranged on the convex block 114; the number of the mark points 112 on one mounting block 116 can be 3-6, preferably, 4, which satisfies that the total number of the mark points on the calibrator 1 is 5 or more.

[0095] It should be noted that, for the convenience of operation, the locking member 13 can be a locking screw or other locking structure, and the present application does not limit this. When the height of the calibrator 1 is adjusted, the locking screw is loosened, then the body 11 is slid up and down along the vertical direction until the body 11 is moved to the desired height, and the locking screw is tightened to fix the height of the calibrator 1. For the calibrator 1 as shown in Figure 1 , the body 11 can also be taken off from the base 12, the through hole 115 on the convex block 114 is aligned with the adjusting rod 123, the adjusting rod 123 is inserted into the through hole 115, so that the calibrator 1 assumes a transverse body position as shown in Figure 3 . In the transverse body position, the height of the calibrator 1 can also be adjusted by sliding the body 11 up and down.

[0096] In another specific embodiment, as shown in Figure 2 , Figure 4 , the body 11 comprises: a connecting block 113, one end of the connecting block 113 and a place along the radial direction of the connecting block 113 are fixedly connected with a support rod 117 respectively, a support rod 118 is also fixedly connected with the place along the radial direction of the connecting block 113, one end of the support rod 118 away from the connecting block 113 is also fixedly connected with a support 119, and at least three optical balls 111 are distributed on the support 119; at least one mounting block 116 is fixedly connected with the connecting block 113, and at least five mark points 112 are distributed on the at least one mounting block 116, and the mark points 112 assume the shape of the tip of a conical column; the base 12 comprises a bottom block 121 and a mounting strip 122, one end of the mounting strip 122 is fixedly connected with the top wall of the bottom block 121, and the other end is provided with a mounting hole 124 along the vertical direction, and the inner diameter of the mounting hole 124 is adapted to the radial length dimension of the support rod 117; and the locking member 13 is arranged on the mounting strip 122.

[0097] As an example, in this embodiment, there are two mounting blocks 116, which are fixedly connected to both ends of the connecting block 113. The support rod 118 and the support rod 117 located at a point along the radial direction of the connecting block 113 can be located between the two mounting blocks 116. The optical ball 111 is distributed between the two mounting blocks 116. There can be 3-6 marking points 112 on one mounting block 116, preferably 4, so that the total number of marking points on the calibrator 1 is 5 or more.

[0098] Similarly, the locking member 13 in this embodiment can also be a locking screw. When adjusting the height of the calibrator 1, the locking screw is loosened, and then the body 11 is slid up and down in the vertical direction until the body 11 moves to the desired height. The locking screw is then tightened to fix the height of the calibrator 1. For example, Figure 2 The calibrator 1 shown can also have its body 11 removed from the base 12, and the support rod 117 located at a point along its own radial direction aligned with the mounting hole 124, so that the support rod 117 is inserted into the mounting hole 124, thereby making the calibrator 1 appear as shown. Figure 4 The lateral body position is shown; in the lateral body position, the height of the calibrator 1 can also be adjusted by sliding the body 11 up and down.

[0099] It should be noted that the number of mounting blocks 116 can be one or more, and this application uses... Figures 1-4 The number of mounting blocks 116 shown is two, used as an example. The mounting blocks 116 are set to distribute at least five marker points 112 on different planes, so that the spatial positions of marker points 112 on multiple different planes can be obtained as much as possible during subsequent calibration, thus making the calibration results more accurate. In the first and second embodiments, since the protrusion 114 in the first embodiment occupies less space than the support rod 118 and bracket 119 in the second embodiment, the calibrator 1 in the first embodiment, i.e., Figure 1 , Figure 3 The calibrator 1 shown is preferred. The calibrator 1 as a whole can be fixed by tenon and mortise joints with nylon screws and glue.

[0100] In summary, the calibrator of this application does not need to be fixed on the surgical instrument. It only needs to be placed in the recognizable space of the optical camera. After the surgical instrument is calibrated, it can be directly removed from the surgical operating space. This is more convenient than the prior art, which requires removing it from the surgical instrument, or compared to the prior art, which keeps it on the surgical instrument, thus reducing the space occupied in the surgical operating space.

[0101] In the second embodiment, as Figure 5As shown, a calibration method of a surgical instrument is provided, which applies the calibrator of the first embodiment described above, comprising:

[0102] S101: Under at least one scanning body position, the ray source end of the scanning device projects at least five marker points on the calibrator to the ray receiving plate to obtain corresponding projection marker points and first projection positions of the projection marker points in the projection coordinate system corresponding to the ray receiving plate.

[0103] For example, the scanning device can be a 2D X-ray machine, specifically a C-arm, O-arm or G-arm. The calibrator only needs to be located within the scanning range of the scanning device and the optical camera, and does not need to be fixed with the scanning device; and the calibrator is provided with at least five marker points that can be recognized by the scanning device and the optical camera, each of which is located in a different plane; in order to more accurately position the positions of the marker points, the shape of the marker points can be set as the tip of a conical column. The projection coordinate system corresponding to the ray receiving plate refers to: taking the plane where the ray receiving plate is located as the coordinate system plane, specifically the plane formed by the coordinate system origin, X-axis and Y-axis, taking the direction upward along the vertical direction as the coordinate system Z-axis, and forming the coordinate system according to the coordinate system plane and the coordinate system Z-axis as the projection coordinate system.

[0104] S102: The optical camera obtains the first spatial positions of each of the marker points in the optical camera coordinate system.

[0105] In a specific implementation, the optical camera can directly position the marker points to obtain the first spatial positions. In another preferred embodiment, the optical camera can obtain the first spatial positions of each of the marker points in the optical camera coordinate system according to the calibration parameters of the calibrator pre-calibrated, and the specific steps include: obtaining the calibration parameters of the calibrator pre-calibrated, wherein the calibration parameters include the second spatial positions of at least three optical balls on the calibrator in the calibrator coordinate system of the calibrator, and the third spatial positions of each of the marker points in the calibrator coordinate system; collecting the fourth spatial positions of each of the optical balls in the optical camera coordinate system; calculating the second conversion matrix between the calibrator coordinate system and the optical camera coordinate system according to the fourth spatial positions and the second spatial positions of each of the optical balls; and performing coordinate system conversion processing on the third spatial positions of each of the marker points according to the second conversion matrix to obtain the first spatial positions of each of the marker points in the optical camera coordinate system.

[0106] The second conversion matrix can be calculated by using a least square method. The coordinate system conversion process specifically refers to: calculating an inverse matrix of the second conversion matrix, calculating a transposed matrix of the inverse matrix, multiplying the transposed matrix with the third spatial positions of the marker points, and obtaining the first spatial positions of the marker points in the optical camera coordinate system.

[0107] Further, before the step of obtaining the calibration parameters previously calibrated by the calibrator, the calibrator needs to be calibrated to generate the calibration parameters, wherein the calibration parameters include the second spatial positions of the optical spheres in the calibrator coordinate system of the calibrator and the third spatial positions of the marker points in the calibrator coordinate system.

[0108] Specifically, the step of generating the second spatial positions includes: the optical camera recognizing the calibrator in the first body position and collecting the fifth spatial positions of the optical spheres in the optical camera coordinate system; the optical camera recognizing the calibrator in the second body position and collecting the sixth spatial positions of the optical spheres in the optical camera coordinate system at least once; constructing an initialization coordinate system according to the collected sixth spatial positions of the optical spheres at least once, generating a calibrator coordinate system based on the initialization coordinate system; and performing coordinate system conversion processing on the fifth spatial positions of the optical spheres to obtain the second spatial positions of the optical spheres in the calibrator coordinate system.

[0109] It should be noted that the first body position refers to: the calibrator is placed in the recognizable range of the optical camera, and the body 11 of the calibrator is connected to the base 12 along the axial end of the body 11 to form a longitudinal body position, as shown in Figure 1 or Figure 2 indicated, or the body 11 is connected to the base 12 along the radial end of the body 11 to form a transverse body position, as shown in Figure 3 or Figure 4 indicated.

[0110] In the first body position, the optical camera can effectively recognize and obtain the fifth spatial positions of the optical spheres on the calibrator: wherein, represents a set of the fifth spatial positions of all the optical spheres, represents the fifth spatial position of the m1th optical sphere in the optical camera coordinate system, m1∈{1,2,…,M1}, M1 is the total number of optical spheres, and M1≥3.

[0111] Within the recognizable range of the optical camera, the first body position is adjusted to form a second body position. The second body position refers to one of the following: a position formed by rotating, translating, or adjusting the height of the calibrator. For example, taking the first body position as a longitudinal position formed by connecting one end of the calibrator along its own axis to the base, if the calibrator is rotated to form the second body position, for example... Figure 1 The calibrator 1 shown can be removed from the base 12 by removing the body 11, and then inserting the through hole 115 on the protrusion 114 into the adjusting rod 123, so that one end of the body 11 along its own radial direction is connected to the base 12, and the calibrator 1 is presented as shown. Figure 3 The lateral body position shown; or, for example, Figure 2 The calibrator 1 shown can be detached from the base 12 by removing the body 11, and then inserting the support rod 117 located at a point along its own radial direction into the mounting hole 124, so that one end of the body 11 along its own radial direction is connected to the base 12, and the calibrator 1 is presented as follows. Figure 4 The indicated transverse body position.

[0112] If the calibrator is translated to form a second body position, then directly apply the following: Figure 1 Alternatively, the calibrator 1 shown in Figure 2 can be translated in any direction, as long as the translated calibrator 1 remains within the recognizable range of the optical camera. If the height of the calibrator is adjusted to form a second body position, for example... Figures 1-4 The calibrator 1 shown in any of the figures can slide up and down in the vertical direction to arbitrarily change the height of the body 11 on the base 12, and then the locking member 13 is used to restrict the sliding of the body 11 to fix the height of the calibrator 1.

[0113] For the calibrator in the second position, the optical camera continuously acquires at least one sixth spatial position of each optical sphere in the optical camera coordinate system over a period of time: Among them, P cam This represents the set of sixth spatial locations that have been collected at least once. This represents the sixth spatial position of each optical sphere in the nth acquisition. Let m1 represent the sixth spatial position of the m1-th optical sphere in the nth acquisition; n∈{1,2,…,N}, N represents the total number of acquisitions of the sixth spatial position, and N≥1; m1∈{1,2,…,M1}, M1 is the total number of optical spheres, and M1≥3.

[0114] Further, the step of constructing an initial coordinate system according to the sixth spatial positions of the optical balls collected at least once includes: generating a coordinate system origin and a coordinate axis direction according to the sixth spatial positions of the optical balls collected at least once to construct an initial coordinate system; performing coordinate system conversion calculation according to the coordinate system origin and the coordinate axis direction to obtain a third conversion matrix of the optical camera coordinate system to the initial coordinate system; performing coordinate system conversion processing on the sixth spatial positions of the optical balls collected at least once according to the third conversion matrix to obtain the seventh spatial positions of the optical balls in the initial coordinate system; and constructing a second loss function according to the seventh spatial positions and calculating a second loss value of the second loss function, wherein the mathematical expression of the second loss function includes:

[0115]

[0116]

[0117] N is the total number of collecting the sixth spatial positions, and N≥1; m1∈{1,2,…,M1}, M1 is the total number of the optical balls, and M1≥3; is the seventh spatial position corresponding to the sixth spatial position of the m1th optical ball collected for the nth time in the initial coordinate system; represents the mean of the sum of the seventh spatial positions corresponding to the m1th optical ball collected for n times; it is judged whether the second loss value is lower than a preset loss threshold value, if yes, the initial coordinate system is successfully constructed; if no, the step of identifying the marker in the first body position by the optical camera is returned.

[0118] It should be noted that the step of generating a coordinate system origin and a coordinate axis direction according to the sixth spatial positions of the optical balls collected at least once specifically includes: calculating the center of mass position of the marker when collecting each time according to the sixth spatial positions of the optical balls collected for N times: wherein C cam represents a set of the center of mass positions of the marker corresponding to N times of position collection, represents the center of mass position of the marker when collecting for the nth time, n∈{1,2,…,N}, N represents the total number of collecting the sixth spatial positions, and N≥1; m1∈{1,2,…,M1}, M1 is the total number of the optical balls, and M1≥3.

[0119] The centroid position is taken as the origin of the coordinate system, and then two sixth space positions of the optical spheres are arbitrarily selected. According to the centroid position as the origin of the coordinate system and the two sixth space positions of the optical spheres, the Z-axis direction of the coordinate system and the unit vector thereof, and the Y-axis direction and the unit vector thereof are calculated. Since the two sixth space positions of the optical spheres are selected to randomly initialize a coordinate system, and the initialization coordinate system is constructed to calculate the third conversion matrix of the optical camera coordinate system to the initialization coordinate system, the directions of the coordinate axes of the initialization coordinate system are not limited, and the two sixth space positions of the optical spheres can be arbitrarily selected.

[0120] For example, assuming that the optical spheres on the calibrator are labeled in an arbitrary order, the sixth space positions of the first optical sphere and the second optical sphere are selected, the Z-axis direction of the initialization coordinate system and the unit vector thereof are determined according to the centroid position and the sixth space position of the first optical sphere, the unit normal vector of the plane formed by the centroid position, the sixth space positions of the first optical sphere and the second optical sphere is taken as the Y-axis direction and the unit vector of the initialization coordinate system, and the X-axis direction is determined based on the centroid position, the Z-axis direction and the Y-axis direction by using the right-hand coordinate system rule.

[0121] The specific steps include: taking the vector direction formed by the centroid position and the sixth space position of the first optical sphere as the Z-axis direction of the initialization coordinate system, and the corresponding unit vector includes: the unit vector of the Z-axis corresponding to the n-th position acquisition, the centroid position corresponding to the n-th position acquisition, the sixth space position of the first optical sphere during the n-th position acquisition, the space vector formed by the centroid position corresponding to the n-th position acquisition and the first optical sphere, f norm (*) represents a vector modulo function.

[0122] Then, based on the space plane formed by the centroid position, the sixth space position of the first optical sphere and the sixth space position of the second optical sphere, the unit normal vector of the space plane is taken as the Y-axis direction of the initialization coordinate system, and the corresponding unit vector includes: the unit vector of the Y-axis corresponding to the n-th position acquisition, the sixth space position of the second optical sphere during the n-th position acquisition, the space vector formed by the centroid position corresponding to the n-th position acquisition and the first optical sphere, f cross (*,*) represents a normal vector solving function of two space vectors.

[0123] After the Z-axis direction and the Y-axis direction of the initialization coordinate system are obtained, the X-axis direction is determined by using the right-hand coordinate system rule. Specifically, the right hand is placed at the origin position of the initialization coordinate system, i.e., the centroid position, the thumb, the index finger and the middle finger are perpendicular to each other, the index finger points to the positive direction of the Y-axis, and the middle finger points to the positive direction of the Z-axis, and then the direction of the thumb is the positive direction of the X-axis. After the origin position of the coordinate system and the coordinate axis direction are determined, the construction of the initialization coordinate system is preliminarily completed.

[0124] After the step of preliminarily completing the construction of the initialization coordinate system, a second loss function of the initialization coordinate system needs to be constructed and a second loss value is calculated. When the second loss value is less than a preset loss threshold, it is considered that the initialization coordinate system is successfully constructed, otherwise the step of recognizing the calibrator in the first body position needs to be returned to reconstruct the initialization coordinate system. Specifically, it includes:

[0125] Based on the origin position of the initialization coordinate system, the unit vector of the Z-axis and the unit vector of the Y-axis, the third conversion matrix from the optical camera coordinate system to the initialization coordinate system is obtained by using the coordinate system conversion function, and the mathematical expression includes: is the third conversion matrix, is the centroid position corresponding to the n-th position acquisition, is the unit vector of the Z-axis corresponding to the n-th position acquisition, is the unit vector of the Y-axis corresponding to the n-th position acquisition, and f trans (*, *, *) represents the coordinate system conversion function.

[0126] The sixth spatial position of each optical sphere in the optical camera coordinate system is converted into the initialization coordinate system by using the third conversion matrix to obtain the corresponding seventh spatial position, and the mathematical expression includes: is the seventh spatial position corresponding to the sixth spatial position of the m1-th optical sphere acquired for the n-th time, n ∈ {1, 2, …, N}, N represents the total number of acquisition of the sixth spatial position, and N ≥ 1, m1 ∈ {1, 2, …, M1}, M1 is the total number of the optical spheres, and M1 ≥ 3.

[0127] Since the sixth spatial position of each optical sphere is collected N times, and N≥1, there are N seventh spatial positions corresponding to each optical sphere, and the total number of optical spheres is M1, and M1≥3. According to the mean of the sum of the N seventh spatial positions belonging to the same optical sphere and each seventh spatial position, the above-mentioned second loss function is constructed based on each optical sphere as a grouping basis, and the second loss value of the second loss function is calculated, if the second loss value is less than the preset loss threshold, the initialization coordinate system is established, otherwise, the spatial position acquisition step of the calibrator is repeated, and the initialization coordinate system is reconstructed, the second loss value of the initialization coordinate system is calculated, and so on, until the second loss value is less than the loss threshold.

[0128] After the initialization coordinate system is successfully established, the calibrator coordinate system can be generated, and the specific information of the coordinate system includes: cal = [O x ,O y ,O z ,1], Wherein, O cal represents the origin position of the calibrator coordinate system, represents the Z-axis unit vector of the calibrator coordinate system, represents the Y-axis unit vector of the calibrator coordinate system.

[0129] After the calibrator coordinate system is constructed, the fifth spatial position of each optical sphere is subjected to coordinate system conversion processing to obtain the second spatial position of each optical sphere in the calibrator coordinate system, and the specific steps include: according to the origin position, the Z-axis unit vector and the Y-axis unit vector of the calibrator coordinate system, the fifth conversion matrix of the initialization coordinate system to the calibrator coordinate system is obtained through the coordinate system conversion function, and the mathematical expression includes: is the fifth conversion matrix, f trans (*,*,*) represents the coordinate system conversion function.

[0130] Then, the transpose matrix of the third conversion matrix, the transpose matrix of the fifth conversion matrix and the fifth spatial position of each optical sphere are multiplied to obtain the second spatial position of each optical sphere in the calibrator coordinate system, and the mathematical expression includes: is the second spatial position of the m1th optical sphere, and the set of the second spatial position of each optical sphere in the calibrator coordinate system is n∈{1,2,…,N}, N represents the total number of times of collecting the sixth spatial position, and N≥1, m1∈{1,2,…,M1}, M1 is the total number of optical spheres, and M1≥3.

[0131] In the step of determining the second spatial positions of the optical balls in the calibrator coordinate system, the sixth spatial positions are collected multiple times to more accurately construct an initial coordinate system and then generate the calibrator coordinate system; the third conversion matrix of the optical camera coordinate system to the initial coordinate system and the fifth conversion matrix of the initial coordinate system to the calibrator coordinate system are calculated; and then the fifth spatial positions are converted according to the third conversion matrix and the fifth conversion matrix, so that the third spatial positions are more accurate.

[0132] After the second spatial positions are generated, third spatial positions of the marker points on the calibrator in the calibrator coordinate system also need to be generated, and the specific steps include: the optical camera recognizes the calibrator in a third body position, collects at least once the eighth spatial positions of the optical balls in the optical camera coordinate system, wherein the third body position represents a body position of the calibrator when the calibrator is irregularly rotated with any one of the marker points as a rotation center; a fourth conversion matrix of the calibrator coordinate system to the optical camera coordinate system is calculated according to the second spatial positions and the eighth spatial positions of the optical balls; a ninth spatial position of the marker point as the rotation center in the optical camera coordinate system is obtained; the ninth spatial position is processed by coordinate system conversion according to the fourth conversion matrix, so that the third spatial position of the marker point as the rotation center in the calibrator coordinate system is obtained; and the steps of recognizing the calibrator in the third body position by the optical camera are returned to obtain the third spatial positions of the other marker points in the calibrator coordinate system, with the other marker points as the rotation centers and the body positions of the calibrator after irregular rotation as the third body positions.

[0133] Specifically, during the irregular rotation of the calibrator, the eighth spatial positions of the optical balls are collected K times continuously: a set of the eighth spatial positions collected K times, the eighth spatial position of the m1th optical ball collected for the kth time, K≥1.

[0134] Then, the fourth conversion matrix between the calibrator coordinate system and the optical camera coordinate system is calculated by the least square method according to the second spatial positions and the eighth spatial positions of the optical balls, and the mathematical expression includes: a set of the fourth conversion matrices calculated according to the eighth spatial positions collected K times, a set of the eighth spatial positions of all the optical balls, P cal′ a set of the second spatial positions of all the optical balls, f lsm (*,*) represents a least square method function.

[0135] Then a ninth spatial position of the marker point as the rotation center in the optical camera coordinate system is acquired, specifically including: the ninth spatial position of the marker point as the rotation center in the optical camera coordinate system is preset as According to the ninth spatial position and the eighth spatial position acquired at least once, a corresponding mapping relationship is constructed, wherein a mathematical expression of the mapping relationship includes:

[0136]

[0137] And The eighth spatial position of the m1th optical sphere acquired for the kth time in the X axis, Y axis and Z axis is respectively xk, yk and zk, x1, y1 and z1 are respectively the values of the preset ninth spatial position in the X axis, Y axis and Z axis, r m1 The rotation radius of the m1th optical sphere is r, k∈{1,2,…,K}, K is the number of acquisition of the eighth spatial position, and K≥1, m1∈{1,2,…,M1}, M1 is the total number of the optical spheres, and M1≥3; according to each mapping relationship, a third loss function is established, wherein a mathematical expression of the third loss function includes:

[0138]

[0139] The third loss function is solved and processed to obtain the values of the ninth spatial position in the X axis, Y axis and Z axis.

[0140] After the specific value of the ninth spatial position is obtained, a fourth conversion matrix is used for coordinate system conversion to obtain a third spatial position of the marker point as the rotation center in the calibrator coordinate system, and a mathematical expression thereof includes:

[0141]

[0142] The third spatial position is The ninth spatial position is K is the number of acquisition of the eighth spatial position, and K≥1.

[0143] Then, the body position of the calibrator after irregular rotation with other marker points as the rotation center is taken as a third body position, and the step of identifying the calibrator in the third body position through the optical camera is returned to obtain the third spatial position of the other marker points in the calibrator coordinate system.

[0144] In the step of determining the third spatial position of each marker point in the calibrator coordinate system, the eighth spatial position is collected multiple times so that multiple fourth conversion matrices can be calculated in the subsequent step, and then the ninth spatial position is multiplied by the fourth conversion matrices respectively and the average value is calculated to obtain a more accurate third spatial position.

[0145] S103: Obtain a projection conversion relationship of the scanning device, a first coordinate system conversion relationship between a ray light source tracker and the optical camera, and a second coordinate system conversion relationship between a ray receiving plate tracker and the optical camera.

[0146] S104: Convert the first spatial position according to the projection conversion relationship, the first coordinate system conversion relationship, and the second coordinate system conversion relationship to obtain a second projection position of the projection marker point in the projection coordinate system.

[0147] The ray light source emitted by the ray light source end of the scanning device is regarded as an ideal light source point, and the homogeneous coordinate position of the light source point in the ray light source tracker coordinate system is assumed to be The first conversion matrix from the ray receiving plate tracker coordinate system to the projection coordinate system is assumed to be It can be represented by left multiplication of a quaternion rotation conversion matrix, and the mathematical expression is as follows:

[0148]

[0149] Wherein, a, b, c and d represent rotation parameters, T x , T y and T z represent translation parameters.

[0150] The projection conversion relationship refers to the coordinate conversion matrix of the marker point projected to the ray receiving plate under the projection of the ray light source emitted by the scanning device. Under a certain scanning position, the first spatial position of the marker point in the optical camera coordinate system can be converted to the second projection position in the projection coordinate system according to the projection conversion relationship, and the mathematical expression thereof is as follows:

[0151]

[0152] Wherein, The first spatial position of the marker point in the optical camera coordinate system can be converted to the second projection position in the projection coordinate system, and the mathematical expression thereof is as follows:

[0153]

[0154] The first coordinate system transformation relationship of the optical camera coordinate system to the ray receiving plate tracker coordinate system can be calculated according to the spatial positions of the optical balls in the ray receiving plate tracker coordinate system and the optical camera coordinate system respectively.

[0155] Similarly, The second coordinate system transformation relationship of the ray light source tracker coordinate system to the optical camera coordinate system can be calculated according to the positions of the optical balls in the ray light source tracker coordinate system and the optical camera coordinate system respectively.

[0156] The third projection position of the jth marker point in the i th scanning position in the projection coordinate system can be obtained by converting the first spatial position of the marker point into position information in the projection coordinate system. The second projection position of the jth marker point in the i th scanning position in the projection coordinate system can be obtained by converting the first spatial position of the marker point into position information in the projection coordinate system.

[0157] Therefore, according to the above projection transformation relationship, the first coordinate system transformation relationship and the second coordinate system transformation relationship, the second projection position can be obtained by the above steps.

[0158] S105: input the first projection position and the second projection position into a preset first loss function and perform optimization processing to obtain an optimization result, so as to complete the calibration between the ray light source tracker and the ray light source end, and between the ray receiving plate tracker and the ray receiving plate.

[0159] The optimization result includes the position of the light source particle emitted by the ray light source end in the ray light source tracker coordinate system, and the first conversion matrix between the ray receiving plate tracker coordinate system and the projection coordinate system.

[0160] Specifically, according to the first projection position and the second projection position, a Euclidean distance loss function can be established, which is mathematically expressed as follows:

[0161]

[0162] Wherein, i represents the index of the scanning position, and j represents the index of the marker point.

[0163] By establishing the above Euclidean distance loss function, optimization algorithms such as but not limited to Conjugate Gradient, Principal Axis, Levenberg Marquardt, Newton, Quasi Newton, Interior Point, and Linear Programming are selected to optimize the above loss function, so as to reduce the loss value of the above loss function. Preferably, when the loss value reaches the minimum value, the optimization result is the optimal result, that is, the homogeneous coordinate position S lig of the light source particle in the ray light source tracker coordinate system The optimal solution of the first conversion matrix from the ray receiving plate tracker coordinate system to the projection coordinate system

[0164] After obtaining the above optimization result, the calibration between the ray light source tracker and the ray light source end, and the ray receiving plate tracker and the ray receiving plate is completed. In specific applications, the conversion relationship from the optical camera coordinate system to the projection coordinate system can be obtained according to the product of the first coordinate system transformation relationship and the first conversion matrix The position S ndi of the light source particle in the optical camera coordinate system can be obtained according to the product of the second coordinate system transformation relationship from the ray light source tracker coordinate system to the optical camera coordinate system lig and the homogeneous coordinate position S ndi of the light source particle in the ray light source tracker coordinate system ; and the position of the light source particle in the projection coordinate system can be obtained according to the product of the conversion relationship from the optical camera coordinate system to the projection coordinate system and the position S ndi of the light source particle in the optical camera coordinate system; thereby realizing the positioning of the ray light source particle emitted by the ray light source end and the spatial position of the ray receiving plate, respectively, providing technical support for subsequent scan image navigation, and improving the phenomenon of navigation and positioning errors caused by physical deformation.

[0165] The present application obtains the first projection position and the second projection position under multiple scan body positions, and then establishes a Euclidean distance loss function, and optimizes the loss function to make the optimization result after calibration more accurate, thereby improving the accuracy of scan image spatial positioning.

[0166] In summary, the calibration method of the surgical instrument provided in the application, by obtaining the first projection position of the marker point in the projection coordinate system, through the coordinate system conversion relationship of the optical camera coordinate system, the ray light source tracker coordinate system and the ray receiving plate tracker coordinate system, and the conversion combined with the projection conversion relationship, the second projection position of the marker point is obtained; the first loss function is established based on the first projection position and the second projection position and optimization is performed to obtain the position of the light source particle in the ray light source tracker coordinate system and the first conversion matrix between the ray receiving plate tracker coordinate system and the projection coordinate system, so as to complete the calibration of the ray light source tracker, the ray receiving plate tracker and the scanning device; and then when the scanning device provided with the ray light source tracker and the ray receiving plate tracker is applied to realize navigation positioning, the phenomenon that the ray light source end of the scanning device and the ray receiving plate have errors in navigation and positioning due to physical deformation can be improved. Moreover, in the above calibration process, the calibrator does not need to be fixed on the surgical instrument, but only needs to be placed in the range that can be recognized by the optical camera and the scanning device, and only one calibration process is needed to realize the permanent calibration of the surgical instrument, so the surgical instrument does not need to be calibrated before each surgical operation, and therefore compared with the prior art, the calibration method of the surgical instrument provided in the application can reduce the preoperative operation process and realize efficient surgical operation.

[0167] It should be understood that, although Figure 5 the steps in the flowchart of the calibration method of the surgical instrument provided in the application are displayed in sequence according to the arrows, these steps are not necessarily executed in sequence according to the arrows. Unless otherwise specified in this article, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other sequences. Moreover, Figure 5 at least part of the steps in the calibration method of the surgical instrument provided in the application can include multiple sub-steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of these sub-steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least part of other steps or sub-steps or stages of other steps.

[0168] In the third embodiment, as shown in Figure 6 , a calibration system of a surgical instrument is provided, which applies the calibrator described in the first embodiment, comprising:

[0169] the calibrator placed in at least one scanning body position;

[0170] a scanning device including a ray light source end and a ray receiving plate, for projecting at least five marker points on the calibrator to the ray receiving plate through the ray light source end at the at least one scanning body position to obtain corresponding projection marker points and the first projection position of the projection marker points in the projection coordinate system corresponding to the ray receiving plate;

[0171] a ray source tracker rigidly connected with the ray source end;

[0172] a ray receiving plate tracker rigidly connected with the ray receiving plate;

[0173] an optical camera configured to acquire a first spatial position of each of the mark points in an optical camera coordinate system;

[0174] a transformation relationship acquisition module configured to acquire a projection transformation relationship of the scanning device, a first coordinate system transformation relationship between the ray source tracker and the optical camera, and a second coordinate system transformation relationship between the ray receiving plate tracker and the optical camera;

[0175] a spatial position conversion module configured to convert the first spatial position according to the projection transformation relationship, the first coordinate system transformation relationship, and the second coordinate system transformation relationship, to obtain a second projection position of the projection mark point in the projection coordinate system;

[0176] a first calibration module configured to input the first projection position and the second projection position into a preset first loss function, and perform optimization processing on the first loss function to obtain an optimization result, so as to complete calibration between the ray source tracker and the ray source end, and between the ray receiving plate tracker and the ray receiving plate;

[0177] The optimization result includes a position of a light source particle emitted by the ray source end in a ray source tracker coordinate system, and a first conversion matrix between the ray receiving plate tracker coordinate system and the projection coordinate system.

[0178] Specifically, as shown in Figure 7 the optical camera includes: a calibration parameter acquisition unit configured to acquire calibration parameters previously calibrated by the calibrator, wherein the calibration parameters include second spatial positions of at least three optical balls in a calibrator coordinate system of the calibrator, and third spatial positions of each of the mark points in the calibrator coordinate system; a spatial position acquisition unit configured to acquire fourth spatial positions of each of the optical balls in the optical camera coordinate system; a conversion matrix calculation unit configured to calculate a second conversion matrix between the calibrator coordinate system and the optical camera coordinate system according to the fourth spatial positions of each of the optical balls and the second spatial positions; and a spatial position calculation unit configured to perform coordinate system conversion processing on the third spatial positions of each of the mark points according to the second conversion matrix, to obtain the first spatial positions of each of the mark points in the optical camera coordinate system.

[0179] Specifically, as shown in Figure 8As shown, the system further comprises a second calibration module for generating calibration parameters, comprising: a first acquisition unit for identifying the calibrator in the first body position through the optical camera, and acquiring the fifth spatial position of each optical ball in the optical camera coordinate system; a second acquisition unit for identifying the calibrator in the second body position through the optical camera, and acquiring the sixth spatial position of each optical ball in the optical camera coordinate system at least once; a coordinate system construction unit for constructing an initialization coordinate system according to the sixth spatial position of each optical ball acquired at least once, and generating a calibrator coordinate system based on the initialization coordinate system; and a calibration parameter generation unit for performing coordinate system conversion processing on the fifth spatial position of each optical ball, and obtaining the second spatial position of each optical ball in the calibrator coordinate system.

[0180] Specifically, the coordinate system construction unit is configured to construct an initialization coordinate system according to the sixth spatial position of each optical ball acquired at least once, comprising: generating a coordinate system origin and a coordinate axis direction according to the sixth spatial position of each optical ball acquired at least once, to construct an initialization coordinate system; performing coordinate system conversion calculation according to the coordinate system origin and the coordinate axis direction, to obtain a third conversion matrix from the optical camera coordinate system to the initialization coordinate system; performing coordinate system conversion processing on the sixth spatial position of each optical ball acquired at least once according to the third conversion matrix, to obtain the seventh spatial position of the corresponding optical ball in the initialization coordinate system; constructing a second loss function according to the seventh spatial position, and calculating a second loss value of the second loss function, wherein the mathematical expression of the second loss function comprises:

[0181]

[0182]

[0183] N is the total number of times of acquiring the sixth spatial position, and N≥1; m1∈{1,2,…,M1}, M1 is the total number of optical balls, and M1≥3; is the seventh spatial position corresponding to the sixth spatial position of the m1th optical ball acquired for the nth time in the initialization coordinate system; represents the mean of the sum of the seventh spatial positions corresponding to the m1th optical ball acquired for n times; it is judged whether the second loss value is lower than a preset loss threshold value, if yes, the initialization coordinate system is successfully constructed; if no, the step of identifying the calibrator in the first body position through the optical camera is returned.

[0184] Specifically, as Figure 9As shown, the second calibration module further comprises a third acquisition unit, configured to identify the marker under a third body position through the optical camera, and acquire at least one eighth spatial position of each optical sphere in the optical camera coordinate system, wherein the third body position represents a body position of the marker when the marker is irregularly rotated with any one of the marker points as a rotation center; the calibration parameter generation unit is further configured to calculate a fourth conversion matrix from the marker coordinate system to the optical camera coordinate system according to the second spatial position and the eighth spatial position of each optical sphere, acquire a ninth spatial position of the marker point as the rotation center in the optical camera coordinate system, perform coordinate system conversion processing on the ninth spatial position according to the fourth conversion matrix to obtain a third spatial position of the marker point as the rotation center in the marker coordinate system, and take the body position of the marker after irregular rotation with other marker points as the rotation center as the third body position, and return to the step of identifying the marker under the third body position through the optical camera to obtain the third spatial position of the other marker points in the marker coordinate system.

[0185] Specifically, the calibration parameter generation unit is configured to acquire the ninth spatial position of the marker point as the rotation center in the optical camera coordinate system, including: presetting the ninth spatial position of the marker point as the rotation center in the optical camera coordinate system; and constructing a corresponding mapping relationship according to the ninth spatial position and the eighth spatial position acquired at least once, wherein the mathematical expression of the mapping relationship includes:

[0186]

[0187] and are numerical values of the eighth spatial position of the m1th optical sphere acquired for the kth time on the X-axis, the Y-axis and the Z-axis, respectively, x1, y1 and z1 are numerical values of the ninth spatial position on the X-axis, the Y-axis and the Z-axis, respectively, is the rotation radius of the m1th optical sphere, k ∈ {1, 2, …, K}, K is the number of acquisition of the eighth spatial position, and K ≥ 1, m1 ∈ {1, 2, …, M1}, M1 is the total number of the optical spheres, and M1 ≥ 3; a third loss function is established according to each mapping relationship, wherein the mathematical expression of the third loss function includes:

[0188]

[0189] The third loss function is solved to obtain numerical values of the ninth spatial position on the X-axis, the Y-axis and the Z-axis, respectively.

[0190] The specific limitations of the calibration system of the surgical instrument can refer to the limitations of the calibration method of the surgical instrument described above, which will not be repeated here. Each module in the calibration system of the surgical instrument described above can be implemented by software, hardware and their combinations. The above-mentioned modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to call and execute the operations corresponding to each module by the processor.

[0191] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of each method. In the embodiments provided in the present application, any reference to memory, storage, database or other medium can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM) and memory bus dynamic RAM (RDRAM) and the like.

[0192] The technical features of the above embodiments can be combined in any way. In order to make the description simple, not all possible combinations of the technical features in the above embodiments are described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0193] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for calibrating surgical instruments, characterized in that, include: In at least one scanning position, the X-ray source end of the scanning device projects at least five marker points on the calibrator onto the X-ray receiving plate to obtain the corresponding projection marker points and the first projection position of the projection marker points in the projection coordinate system corresponding to the X-ray receiving plate. The optical camera acquires the first spatial position of each of the marked points in the optical camera coordinate system; Obtain the projection transformation relationship of the scanning device, the first coordinate system transformation relationship between the ray source tracker and the optical camera, and the second coordinate system transformation relationship between the ray receiving plate tracker and the optical camera; Based on the projection transformation relationship, the projection marker point is transformed from the first spatial position in the optical camera coordinate system to the second projection position in the projection coordinate system; The projection transformation relationship refers to the coordinate transformation matrix of the projection mark point projected onto the ray receiving plate under the projection of the ray light source emitted by the scanning device; The first projection position and the second projection position are input into a preset first loss function and optimized to obtain the optimization result, so as to complete the calibration between the ray source tracker and the ray source end, and between the ray receiving plate tracker and the ray receiving plate; The optimization result includes the position of the light source particle emitted by the ray source end in the ray source tracker coordinate system, and the first transformation matrix between the ray receiver plate tracker coordinate system and the projection coordinate system.

2. The calibration method for surgical instruments according to claim 1, characterized in that, The step of acquiring the first spatial position of each of the marker points in the optical camera coordinate system includes: Obtain the calibration parameters that the calibrator has been pre-calibrated, wherein the calibration parameters include the second spatial positions of at least three optical spheres on the calibrator in the calibrator coordinate system, and the third spatial positions of each of the marker points in the calibrator coordinate system; Collect the fourth spatial position of each optical sphere in the optical camera coordinate system; Based on the fourth spatial position and the second spatial position of each optical sphere, calculate the second transformation matrix between the calibrator coordinate system and the optical camera coordinate system; The third spatial position of each of the marker points is transformed according to the second transformation matrix to obtain the first spatial position of each of the marker points in the optical camera coordinate system.

3. The calibration method for surgical instruments according to claim 2, characterized in that, Before the step of obtaining the pre-calibrated calibration parameters of the calibrator, the method further includes: The optical camera identifies the calibrator in the first body position and collects the fifth spatial position of each optical sphere in the optical camera coordinate system; The optical camera identifies the calibrator in the second body position and acquires at least one sixth spatial position of each optical sphere in the optical camera coordinate system. An initial coordinate system is constructed based on the sixth spatial position of each of the optical spheres acquired at least once, and a calibrator coordinate system is generated based on the initial coordinate system; The fifth spatial position of each optical sphere is transformed by a coordinate system to obtain the second spatial position of each optical sphere in the coordinate system of the calibrator.

4. The calibration method for surgical instruments according to claim 3, characterized in that, The step of constructing an initial coordinate system based on the sixth spatial position of each of the optical spheres acquired at least once includes: Based on the sixth spatial position of each optical sphere acquired at least once, the origin and coordinate axis directions of the coordinate system are generated to construct an initial coordinate system; Based on the origin and coordinate axis directions of the coordinate system, a coordinate system transformation calculation is performed to obtain the third transformation matrix from the optical camera coordinate system to the initialized coordinate system; According to the third transformation matrix, the sixth spatial position of each optical sphere acquired at least once is transformed to obtain the corresponding seventh spatial position of the optical sphere in the initialized coordinate system. A second loss function is constructed based on the seventh spatial location, and a second loss value of the second loss function is calculated, wherein the mathematical expression of the second loss function includes: ； ； To collect the total number of times the sixth spatial location is located, and ; , The total number of the optical spheres, and ; For the first The first collection The sixth spatial position of each optical sphere corresponds to the seventh spatial position in the initialized coordinate system; express The first collection The average of the sum of the seventh spatial positions corresponding to each optical sphere; Determine whether the second loss value is lower than a preset loss threshold. If yes, the initial coordinate system is successfully constructed; otherwise, return to the step of the optical camera recognizing the calibrator in the first body position.

5. The calibration method for surgical instruments according to claim 3 or 4, characterized in that, Before the step of obtaining the pre-calibrated calibration parameters of the calibrator, the method further includes: The optical camera identifies the calibrator in the third position and acquires at least one eighth spatial position of each optical sphere in the optical camera coordinate system, wherein the third position refers to the position of the calibrator when it rotates randomly with any of the marked points as the rotation center; Based on the second and eighth spatial positions of each optical sphere, calculate the fourth transformation matrix from the calibrator coordinate system to the optical camera coordinate system; Obtain the ninth spatial position of the marker point, which serves as the center of rotation, in the optical camera coordinate system; Based on the fourth transformation matrix, the ninth spatial position is subjected to coordinate system transformation to obtain the third spatial position of the marker point, which serves as the rotation center, in the calibrator coordinate system. The body position after randomly rotating the calibrator with other marker points as rotation centers is taken as the third body position, and the step of identifying the calibrator in the third body position by the optical camera is returned to obtain the third spatial position of the other marker points in the coordinate system of the calibrator.

6. The calibration method for surgical instruments according to claim 5, characterized in that, The step of obtaining the ninth spatial position of the marker point, which serves as the center of rotation, in the optical camera coordinate system includes: The preset mark point, serving as the center of rotation, is located at the ninth spatial position in the optical camera coordinate system. A corresponding mapping relationship is constructed based on the ninth spatial location and the eighth spatial location acquired at least once, wherein the mathematical expression of the mapping relationship includes: ； , and The first The first collection The values ​​of the eighth spatial position of the optical sphere on the X, Y, and Z axes. , and These are the preset values ​​of the ninth spatial position on the X-axis, Y-axis, and Z-axis, respectively. For the first The radius of rotation of the optical spheres K is the number of times the data is collected at the eighth spatial location, and K , , The total number of the optical spheres, and ; A third loss function is established based on each of the aforementioned mapping relationships, wherein the mathematical expression of the third loss function includes: ； The third loss function is solved to obtain the values ​​of the ninth spatial position on the X-axis, Y-axis and Z-axis respectively.

7. A calibration system for surgical instruments, characterized in that, include: A calibrator placed in at least one scanning position; A scanning device, including a radiation source end and a radiation receiving plate, is used to project at least five marker points on a calibrator onto the radiation receiving plate through the radiation source end under the at least one scanning position, so as to obtain the corresponding projection marker points and the first projection position of the projection marker points in the projection coordinate system corresponding to the radiation receiving plate. A ray source tracker is rigidly connected to the ray source end; A radiation receiving plate tracker is rigidly connected to the radiation receiving plate; An optical camera is used to acquire the first spatial position of each of the marked points in the optical camera coordinate system; The transformation relationship acquisition module is used to acquire the projection transformation relationship of the scanning device, the first coordinate system transformation relationship between the ray source tracker and the optical camera, and the second coordinate system transformation relationship between the ray receiving plate tracker and the optical camera; A spatial position transformation module is used to obtain, according to the projection transformation relationship, the transformation of the projection marker point from the first spatial position in the optical camera coordinate system to the second projection position in the projection coordinate system; The projection transformation relationship refers to the coordinate transformation matrix of the projection mark point projected onto the ray receiving plate under the projection of the ray light source emitted by the scanning device; The first calibration module is used to input the first projection position and the second projection position into a preset first loss function, perform optimization processing on the first loss function to obtain the optimization result, so as to complete the calibration between the ray source tracker and the ray source end, and between the ray receiving plate tracker and the ray receiving plate; The optimization result includes the position of the light source particle emitted by the ray source end in the ray source tracker coordinate system, and the first transformation matrix between the ray receiver plate tracker coordinate system and the projection coordinate system.

8. A calibrator, characterized in that, The calibrator is applied to the calibration method of the surgical instrument as described in any one of claims 1-6 and the calibration system of the surgical instrument as described in claim 7, wherein the calibrator comprises: The body has at least three optical spheres and at least five marker points evenly distributed on it for optical camera recognition, the five marker points being located on different planes; The base, the body and the base are slidably connected vertically, and the body and the base are detachably connected. One end of the body along its own axial direction is connected to the base, or one end of the body along its own radial direction is connected to the base. A locking element is used to restrict the vertical sliding of the body and fix the height of the body on the base.

9. The calibrator according to claim 8, characterized in that, The body includes: A connecting block is provided with a protrusion, and the axis of the protrusion is perpendicular to the axis of the connecting block. The connecting block and the protrusion are respectively provided with through holes along their own axes. The at least three optical balls are distributed on the connecting block. At least one mounting block is fixedly connected to the connecting block, and at least five marking points are distributed on the at least one mounting block, the marking points being in the shape of the tip of a conical column; The base includes a base block, a mounting strip, and an adjusting rod. The two ends of the mounting strip are fixedly connected to the top wall of the base block and one end of the adjusting rod, respectively. The radial length of the adjusting rod is adapted to the inner diameter of the through hole. The locking element is mounted on the connecting block.

10. The calibrator according to claim 8, characterized in that, The body includes: A connecting block, wherein a support rod is fixedly connected to one end of the connecting block and another point along its own radial direction, and a support rod is also fixedly connected to another point along its own radial direction. A bracket is also fixedly connected to the end of the support rod away from the connecting block, and the at least three optical balls are distributed on the bracket. At least one mounting block is fixedly connected to the connecting block, and at least five marking points are distributed on the at least one mounting block, the marking points being in the shape of the tip of a conical column; The base includes a base block and a mounting strip. One end of the mounting strip is fixedly connected to the top wall of the base block, and the other end has a mounting hole in the vertical direction. The inner diameter of the mounting hole is adapted to the radial length of the support rod. The locking element is mounted on the mounting strip.

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