Calibration method and device, three-marker calibration system and storage medium

Abstract

According to the calibration method and device, the three-marker calibration system and the storage medium, a first marker and a second marker are fixedly arranged on medical imaging equipment and are arranged in a mirror image mode at intervals, and a third marker is used for marking the operation position of a patient, movably arranged on a diagnostic bed and adjacent to the operation position; the calibration method comprises the following steps: according to a relative position relation matrix of a first marker and a second marker which are initially and secondarily positioned by the binocular measuring instrument, obtaining the variation of the relative positions of the two markers, and calibrating the relative position relation of the first marker and the third marker by utilizing the combination of the first marker and the second marker, according to the binocular measuring instrument, the position of the first marker is changed, the relative position relation between the third marker and any coordinate in the image space coordinate system is determined, whether the position of the binocular measuring instrument is changed or not can be accurately found, the coordinates of the third marker can be calibrated, and the relative position relation between the third marker and the image space is ensured. The precision of the whole operation system is ensured.

Description

Technical Field

[0001] The present invention relates to the field of medical equipment, and more particularly to a calibration method, a device, a three-marker calibration system and a storage medium. Background Art

[0002] Interventional therapy is a general term for a series of technologies that use surgical robots to carry interventional equipment to introduce minimally invasive treatments into the lesions of the human body under the guidance and monitoring of medical imaging equipment. The entire process of interventional therapy is carried out under the guidance and monitoring of imaging equipment, and can accurately and directly reach the lesions without major trauma. It has now become the preferred treatment method for some diseases. In order to ensure the surgical accuracy of interventional therapy, it is necessary to ensure the accuracy of the mapping matrix between the image space and the patient marker space, that is, the positional accuracy and angular accuracy of the coordinate system of the patient's diagnostic image and the coordinate system of the patient's marker.

[0003] In the prior art, the position shift of medical imaging equipment is usually detected by the markers set on the patient's body. However, the markers on the patient's body will deform with human breathing or movement, causing the markers to fail, or the position and angle of the markers to change, thereby introducing large errors. Therefore, there is an urgent need for a calibration method that can accurately and quickly detect whether the mapping matrix between the image space and the patient's marker space needs to be calibrated, and accurately calibrate the position of the patient's markers, thereby ensuring the accuracy of the entire surgical system. Summary of the invention

[0004] The present application provides a calibration method, device, three-marker calibration system and storage medium. Regardless of whether the position of the binocular measuring instrument changes, it is possible to accurately detect whether the position of the first marker changes, and to calibrate the coordinates of the third marker, thereby ensuring the relative position relationship between the third marker and the image space, and ensuring the accuracy of the entire surgical system.

[0005] On the one hand, an embodiment of the present application provides a calibration method, which is applied to a calibration system including three markers, wherein a first marker Fix and a second marker XFix are fixedly mounted on a medical imaging device and spaced apart from each other, and are arranged in a mirror image with the center line of the medical imaging device; a third marker Bed is used to mark a surgical position of a patient, and is movably arranged on a diagnostic bed and adjacent to the surgical position; the first marker Fix is ​​used to mark the origin of a coordinate system of the medical imaging device, and is used to mark an image space coordinate system of the medical imaging device, and the calibration method includes:

[0006] According to the relative position relationship matrix between the first marker and the second marker when the binocular measuring instrument is initially positioned and the relative position relationship matrix between the first marker and the second marker during the secondary positioning of the binocular measuring instrument determining an amount of change in the relative position between the first marker and the second marker;

[0007] When the change amount is less than or equal to a preset threshold, a relative position relationship matrix between the first marker and the third marker is obtained. and a relative position relationship matrix between the second marker and the third marker

[0008] according to and Calculate the relative position relationship matrix between the first marker and the third marker in,

[0009] according to and Obtaining the relative position relationship matrix between the first marker and the third marker after calibration in, Used to determine the relative position relationship between the third marker and any coordinate in the image space coordinate system;

[0010] The coordinate system of the binocular measuring instrument during initial positioning is the binocular measuring instrument primary positioning coordinate system, the coordinate system of the binocular measuring instrument during secondary positioning is the binocular measuring instrument secondary positioning coordinate system, and the binocular measuring instrument secondary positioning coordinate system is the same as or different from the binocular measuring instrument primary positioning coordinate system.

[0011] On the other hand, an embodiment of the present application provides a calibration device, including a processor and a memory, wherein the memory is used to store a calibration program; the processor is used to read the calibration program and perform the calibration method described in the above embodiment.

[0012] On the other hand, an embodiment of the present application provides a three-marker calibration system, including: a binocular measuring instrument, a medical imaging device, three markers, and the calibration device described in the above embodiment;

[0013] The medical imaging device is provided with a diagnostic bed, and the three markers include a first marker Fix, a second marker XFix and a third marker Bed;

[0014] The first marker Fix and the second marker XFix are fixedly mounted on the medical imaging device and spaced apart from each other, and are arranged in a mirror image with the center line of the medical imaging device; the third marker Bed is used to mark the surgical position of the patient, and is movably arranged on the diagnostic bed and adjacent to the surgical position;

[0015] The first marker Fix is ​​used to mark the origin of the coordinate system of the medical imaging device and to mark the image space coordinate system of the medical imaging device;

[0016] The second marker XFix is ​​used to measure the relative position relationship with the first marker Fix, and determine whether the relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated;

[0017] The combination of the first marker Fix and the second marker XFix is ​​used to calibrate the relative position relationship between the first marker Fix and the third marker Bed, and to determine the relative position relationship between the third marker and any coordinate in the image space coordinate system;

[0018] The binocular measuring instrument is used to obtain the coordinates of the three markers and upload the coordinates of the three markers to the calibration device.

[0019] On the other hand, an embodiment of the present application provides a non-transitory computer storage medium storing a computer program, and when the computer program is executed by a processor, the calibration method described in the above embodiment can be implemented.

[0020] Compared with the related art, a calibration method, device, three-marker calibration system and storage medium in the embodiments of the present application can detect the coordinates of the three markers in real time through a binocular measuring instrument. Regardless of whether the position of the binocular measuring instrument itself changes, it can quickly detect whether the relative position relationship between the first marker and the second marker changes. The probability that both the first marker and the second marker change in position and change in the same direction is extremely low. Therefore, it is possible to accurately and quickly detect whether the position of the first marker on the medical imaging device changes, and determine whether the relative position relationship between the medical imaging device and the first marker needs to be calibrated. In addition, the relative position relationship between the first marker and the second marker can be used to determine whether the relative position relationship between the first marker and the third marker needs to be calibrated, thereby ensuring the accuracy of the relative position relationship between the marker used to mark the patient's surgical position and the medical imaging device, further ensuring the accuracy of the relative position relationship between the marker used to mark the patient's surgical position and the image space of the medical imaging device, and ensuring the accuracy of the entire surgical system.

[0021] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0023] Figure 1 is a flow chart of the calibration method of an embodiment of the present application;

[0024] Figure 2 is a flow chart of a calibration method specifically illustrated in an embodiment of the present application;

[0025] Figure 3 is a schematic diagram of a calibration device according to an embodiment of the present application;

[0026] Figure 4 Schematic diagram of a three-marker calibration system according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0028] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0029] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0030] Interventional therapy is an emerging discipline that has developed rapidly in recent years and integrates imaging diagnosis and clinical treatment. It is a general term for a series of technologies that use surgical robots to carry puncture needles, catheters and other interventional equipment to introduce specific instruments into the lesion site of the human body through natural channels or tiny incisions under the guidance and monitoring of medical imaging equipment such as digital subtraction angiography, CT, ultrasound and magnetic resonance imaging. The whole process of interventional therapy is carried out under the guidance and monitoring of imaging equipment, and can accurately and directly reach the lesion site without major trauma. Therefore, it has the advantages of accuracy, safety, efficiency, wide adaptability and few complications. It has become the preferred treatment method for some diseases. However, in the current interventional treatment process, due to the high cost of medical imaging equipment and the limited number of medical imaging equipment in hospitals, it is often necessary to move the surgical robot to the side of the medical imaging equipment to complete the interventional treatment. The image space coordinate system inside these medical imaging equipment cannot be directly matched with the coordinate system of the patient's marker. At the same time, the position and angle of the marker used to represent the image space coordinate system are prone to change in daily medical activities, which makes it impossible to achieve accurate mapping of the image space coordinate system, further increasing the error of the surgical robot in surgery. ,Therefore, there is an urgent need for a calibration method that can timely and ,accurately detect whether the mapping relationship between the patient’s surgical position and the ,image space coordinate system of the medical imaging equipment requires position calibration, ,so as to provide accurate medical image navigation during ,surgery and ensure the accuracy of the surgery.

[0031] The present application provides a calibration method, which is applied to a calibration system including three markers, wherein a first marker Fix and a second marker XFix are fixedly mounted on a medical imaging device and spaced apart from each other, and are arranged in a mirror image with the center line of the medical imaging device; a third marker Bed is used to mark the surgical position of the patient, and is movably arranged on a diagnostic bed and adjacent to the surgical position; the first marker Fix is ​​used to mark the origin of the coordinate system of the medical imaging device, and is used to mark the image space coordinate system of the medical imaging device, and the calibration method includes steps S100-S400, such as Figure 1As shown:

[0032] S100: Calculating the relative position relationship matrix between the first marker and the second marker during initial positioning of the binocular measuring instrument and the relative position relationship matrix between the first marker and the second marker during the secondary positioning of the binocular measuring instrument determining an amount of change in the relative position between the first marker and the second marker;

[0033] S200: When the change amount is less than or equal to a preset threshold, obtaining a relative position relationship matrix between the first marker and the third marker and a relative position relationship matrix between the second marker and the third marker

[0034] S300: According to and Calculate the relative position relationship matrix between the first marker and the third marker in,

[0035] S400: According to and Obtaining the relative position relationship matrix between the first marker and the third marker after calibration in, Used to determine the relative position relationship between the third marker and any coordinate in the image space coordinate system.

[0036] In this embodiment, the coordinate system of the binocular measuring instrument during initial positioning is the binocular measuring instrument primary positioning coordinate system, and the coordinate system of the binocular measuring instrument during secondary positioning is the binocular measuring instrument secondary positioning coordinate system. The binocular measuring instrument secondary positioning coordinate system is the same as or different from the binocular measuring instrument primary positioning coordinate system.

[0037] In this embodiment, the medical imaging device may be, but is not limited to, a computerized tomography (CT) device, a magnetic resonance imaging (MRI) device, an ultrasonic B-ultrasound device or a color Doppler ultrasound device.

[0038] In this embodiment, the first marker is represented by Fix, the second marker is represented by XFix, the third marker is represented by Bed, and the binocular measuring instrument is represented by Track.

[0039] In this embodiment, when the binocular measuring instrument Track is facing the first marker with Fix, it can provide accurate viewing angle and depth perception ability, and can obtain accurate position information of the first marker, thereby obtaining accurate position information of the medical imaging device. However, in actual operation, it is quite time-consuming to accurately adjust the binocular measuring instrument Track to a position facing the first marker Fix. Therefore, the second marker XFix is ​​introduced, and the first marker Fix and the second marker XFix are fixed on the medical imaging device at the same time. The probability that both the first marker and the second marker change their positions and change their positions in the same direction is extremely low. By judging the relative position relationship between the first marker Fix and the second marker XFix, it can be determined whether the relative position relationship between the first marker Fix and the medical imaging device has changed, and there is no need to adjust the spatial position of the binocular measuring instrument.

[0040] In this embodiment, since the change in the relative position between the first marker and the second marker is obtained in step S100, that is, the spatial position of the binocular measuring instrument may remain unchanged or may change when the secondary positioning is compared with the initial positioning.

[0041] In this embodiment, the first marker Fix is ​​located at the origin of the first marker coordinate system, the first marker coordinate system and the coordinate system of the medical imaging device are the same coordinate system, and the origin of the first marker coordinate system is the origin of the coordinate system of the medical imaging device; the second marker XFix is ​​located at the origin of the second marker coordinate system; the third marker Bed is located at the origin of the third marker coordinate system; during initial positioning, the binocular measuring instrument Track is located at the origin of the first positioning coordinate system of the binocular measuring instrument; during secondary positioning, the binocular measuring instrument Track is located at the origin of the secondary positioning coordinate system of the binocular measuring instrument.

[0042] In this embodiment, the relative position relationship matrix between the first marker and the second marker during initial positioning is and the relative position relationship matrix between the first marker and the second marker during secondary positioning Both are transformation matrices for transforming the second marker coordinate system into the first marker coordinate system.

[0043] In this embodiment, are transformation matrices for transforming the third marker coordinate system into the first marker coordinate system, is a transformation matrix for transforming the third marker coordinate system into the second marker coordinate system.

[0044] In this embodiment, the first marker and the second marker can be fixed on the front protective cover of the scanning frame of the medical imaging device, and the third marker can be movably set on the diagnostic bed and adjacent to the patient's surgical position, and can be used to mark the patient's surgical position, avoiding the defect of failure of the patient's external markers due to human breathing and movement.

[0045] In this embodiment, the third marker is not limited to being set on the diagnostic bed. The third marker can be set on any device that requires position calibration in the surgical system, and can be located together with the first marker and the second marker within the visual measurement range of the binocular measuring instrument.

[0046] In this embodiment, during the initial positioning of the binocular measuring instrument, the binocular measuring instrument can display and record the coordinates of the first marker and the second marker within the field of view in real time; during the secondary positioning of the binocular measuring instrument, the binocular measuring instrument can display and record the coordinates of the first marker, the second marker and the third marker within the field of view in real time.

[0047] In this embodiment, the binocular measuring instrument can detect the coordinates of the three markers in real time. Regardless of whether the position of the binocular measuring instrument itself changes, it can quickly detect whether the relative position relationship between the first marker and the second marker changes. The probability that both the first marker and the second marker change in position and change in the same direction is extremely low. Therefore, it is possible to accurately and quickly find out whether the position of the first marker on the medical imaging device changes, and determine whether the relative position relationship between the medical imaging device and the first marker needs to be calibrated. In addition, the relative position relationship between the first marker and the second marker can be used to determine whether the relative position relationship between the first marker and the third marker needs to be calibrated, thereby ensuring the accuracy of the relative position relationship between the marker used to mark the patient's surgical position and the medical imaging device, further ensuring the accuracy of the relative position relationship between the marker used to mark the patient's surgical position and the image space of the medical imaging device, and ensuring the accuracy of the entire surgical system.

[0048] In an exemplary embodiment, before step S100, steps S010-S020 may also be included:

[0049] S010: Obtaining a relative position relationship matrix between the first marker and the second marker during initial positioning of the binocular measuring instrument

[0050] S020: Obtaining a relative position relationship matrix between the first marker and the second marker during secondary positioning of the binocular measuring instrument

[0051] In an exemplary embodiment, step S010 may include steps S011-S013:

[0052] S011: When the binocular measuring instrument is initially positioned, the coordinates of the first marker obtained by the binocular measuring instrument are received, and a conversion matrix is ​​calculated to convert the coordinate system of the first marker into the primary positioning coordinate system of the binocular measuring instrument.

[0053] S012: When the binocular measuring instrument is initially positioned, receiving the coordinates of the second marker obtained by the binocular measuring instrument, and calculating a transformation matrix for transforming the coordinate system of the second marker into the primary positioning coordinate system of the binocular measuring instrument

[0054] S013: Calculate the relative position relationship matrix of the second marker in the first marker coordinate system as the relative position relationship matrix between the first marker and the second marker in,

[0055] In an exemplary embodiment, the r1 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t1 is a 3*1 column vector representing the displacement relationship between the first marker and the second marker;

[0056] or; r1 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t1 is a 3*1 row vector representing the displacement relationship between the first marker and the second marker.

[0057] In an exemplary embodiment, step S020 may include steps S021-S023:

[0058] S021: During the secondary positioning of the binocular measuring instrument, receiving the coordinates of the first marker obtained by the binocular measuring instrument, and calculating the conversion matrix of the first marker coordinate system to the secondary positioning coordinate system of the binocular measuring instrument

[0059] S022: During the secondary positioning of the binocular measuring instrument, receiving the coordinates of the second marker obtained by the binocular measuring instrument, and calculating the transformation matrix of the second marker coordinate system to the secondary positioning coordinate system of the binocular measuring instrument

[0060] S023: Calculate the relative position relationship matrix of the second marker in the first marker coordinate system as the relative position relationship matrix between the first marker and the second marker in,

[0061] In an exemplary embodiment, the r2 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t2 is a 3*1 column vector representing the displacement relationship between the first marker and the second marker;

[0062] or; r2 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t2 is a 3*1 row vector representing the displacement relationship between the first marker and the second marker.

[0063] In this embodiment, when When, accordingly,

[0064] In this embodiment, when When, accordingly,

[0065] In an exemplary embodiment, the determining of the change in the relative position between the first marker and the second marker in step S100 may include steps S101-S103:

[0066] S101: Calculate the rotation relative position change matrix R1, where:

[0067] S102: Calculate the relative position change vector r1 (θx1, θy1, θz1) of the Euler angle, where:

[0068] θx1=|tan -1 2(-r32, r33)|,

[0069]

[0070] θz1=|tan -1 2(-r31, r11)|;

[0071] S103: Calculate the displacement relative position change S1, where: Among them, x2, y2 and z2 are the three elements of t2, and x1, y1 and z1 are the three elements of t1.

[0072] In this embodiment, in the calculation formulas of θx1, θy1, θz1 and S1, absolute values ​​are taken, and the calculation results are greater than or equal to zero.

[0073] In an exemplary embodiment, step S100 may further include steps S110-S111:

[0074] S110: Determine the preset threshold, including the preset Euler angle threshold vector r t1 (θx t1 ,θy t1 ,θz t1 ) and the preset displacement threshold S t1 , the θx t1 ,θy t1 and θz t1 is the Euler angle threshold element and is greater than zero and less than The preset displacement threshold S t1 is a positive number;

[0075] S111: Determine the relationship between the change amount and the preset threshold.

[0076] In an exemplary embodiment, step S111 may further include steps S1111-S1114:

[0077] S1111: Compare the displacements of S1 and S t1 By contrast, if S1 is greater than S t1 , execute step S1113; if S1 is less than or equal to S t1 , execute step S1112;

[0078] S1112: Compare the Euler angles and compare θx1 and θx t1 For comparison, θy1 and θy t1 For comparison, θz1 and θz t1 For comparison, as long as there is an element in r1 that is greater than r t1 , executing step S1113; otherwise, determining that the change amount is less than or equal to the preset threshold, executing steps S200 and S1114;

[0079] S1113: Determine that a relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated;

[0080] S1114: Determine that the relative positional relationship between the medical imaging device and the first marker Fix does not require calibration.

[0081] In this embodiment, if the judgment result is S1113, it is determined that the relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated, then the operation cannot be continued. The operation can only be performed after the relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated.

[0082] In this embodiment, if the judgment result is S1114, it is determined that the relative position relationship between the medical imaging device and the first marker Fix does not need to be calibrated, then step S200 can be executed.

[0083] In an exemplary embodiment, step S200 may further include steps S201-S203:

[0084] S201: During the secondary positioning of the binocular measuring instrument, receiving the coordinates of the third marker obtained by the binocular measuring instrument, and calculating the transformation matrix of the third marker coordinate system to the secondary positioning coordinate system of the binocular measuring instrument

[0085] S202: Calculate the transformation matrix of the third marker coordinate system to the first marker coordinate system as the relative position relationship matrix between the first marker and the third marker in, Obtained by step S021 in the above embodiment;

[0086] S203: Calculate the transformation matrix of the third marker coordinate system to the second marker coordinate system as the relative position relationship matrix between the second marker and the third marker in, Obtained by step S022 in the above embodiment.

[0087] In this embodiment, through steps S202 and S203, the third marker can establish a relative position relationship with the first marker and the second marker respectively, laying a foundation for using the first marker and the second marker to calibrate the relative position relationship between the first marker Fix and the third marker Bed.

[0088] In this embodiment, after executing step S203, step S300 is executed. and Calculate the relative position relationship matrix between the first marker and the third marker in, In step S300, the second marker XFix is ​​used to calculate the relative position relationship between the first marker and the third marker. Theoretically, and should be consistent, but due to the existence of systematic errors, in actual situations, and is inconsistent.

[0089] In an exemplary embodiment, step S400 may further include step S410:

[0090] S410: and Perform interpolation calculation, mean calculation or least squares calculation to obtain a relative position relationship matrix between the first marker and the third marker after calibration

[0091] In this embodiment, and Perform interpolation calculation to obtain the relative position relationship matrix between the first marker and the third marker after calibration The interpolation calculation methods used include but are not limited to Lagrange interpolation method and two-dimensional interpolation method; the values ​​obtained after interpolation calculation, mean calculation or least square calculation Some system errors can be eliminated by using The matrix representing the relative position relationship between the third marker and the first marker is more accurate.

[0092] The calibration method is described in detail below using a specific example, which includes the following steps: Figure 2 As shown:

[0093] S1: During initial positioning, the relative position relationship matrix between the first marker and the second marker is calculated according to the conversion matrix of the first marker coordinate system converted to the binocular measuring instrument primary positioning coordinate system and the conversion matrix of the second marker coordinate system converted to the binocular measuring instrument primary positioning coordinate system.

[0094] S2: During the secondary positioning, the relative position relationship matrix between the first marker and the second marker is calculated according to the conversion matrix of the first marker coordinate system converted to the binocular measuring instrument secondary positioning coordinate system and the conversion matrix of the second marker coordinate system converted to the binocular measuring instrument secondary positioning coordinate system.

[0095] S3: According to and Obtaining a change in the relative position between the first marker and the second marker;

[0096] S4: Determine the relationship between the change amount and the preset threshold; if the change amount is less than or equal to the preset threshold, execute step S5; if the change amount is greater than the preset threshold, execute step S8;

[0097] S5: Determine that the relative position relationship between the medical imaging device and the first marker Fix does not require calibration; and obtain a relative position relationship matrix between the first marker and the third marker and a relative position relationship matrix between the second marker and the third marker

[0098] S6: According to and Calculate the relative position relationship matrix between the first marker and the third marker in,

[0099] S7: According to and Perform interpolation calculation to obtain the relative position relationship matrix between the first marker and the third marker after calibration

[0100] S8: Determine that calibration is required for the relative positional relationship between the medical imaging device and the first marker Fix.

[0101] The present application also provides a calibration device, including a processor and a memory. Figure 3 As shown, the memory is used to store the calibration program; the processor is used to read the calibration program and perform the calibration method described in the above embodiment.

[0102] The present application also provides a three-marker calibration system, such as Figure 4 As shown, it includes: a binocular measuring instrument, a medical imaging device, three markers and the calibration device described in the above embodiment; Figure 4 The circle filled with left slashes represents the first marker, the circle filled with right slashes represents the second marker, and the circle filled with dense dots represents the third marker.

[0103] In this embodiment, the medical imaging device is provided with a diagnostic bed, and the three markers include a first marker Fix, a second marker XFix and a third marker Bed.

[0104] In this embodiment, the first marker Fix and the second marker XFix are fixed to the medical imaging device and are spaced apart from each other, and are mirror-set with the center line of the medical imaging device. The third marker Bed is used to mark the surgical position of the patient, and is movably set on the diagnostic bed and adjacent to the surgical position.

[0105] In this embodiment, the first marker Fix is ​​used to mark the origin of the coordinate system of the medical imaging device, and is used to mark the image space coordinate system of the medical imaging device.

[0106] In this embodiment, the second marker XFix is ​​used to measure the relative position relationship with the first marker Fix, and determine whether the relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated.

[0107] In this embodiment, the combination of the first marker Fix and the second marker XFix is ​​used to calibrate the relative position relationship between the first marker Fix and the third marker Bed, and to determine the relative position relationship between the third marker and any coordinate in the image space coordinate system.

[0108] In this embodiment, the binocular measuring instrument is used to obtain the coordinates of the three markers, and upload the coordinates of the three markers to the calibration device.

[0109] In this embodiment, the diagnostic bed can carry a patient when the medical imaging device is performing a scan.

[0110] In this embodiment, the third marker Bed may also be arranged at other locations in the operating room where the medical imaging device is located, as long as it can be detected by the binocular measuring instrument during the secondary positioning.

[0111] In this embodiment, the first marker, the second marker, and the third marker can all be rigid bodies including four reflective balls.

[0112] The embodiment of the present application further provides a non-transitory computer storage medium storing a computer program. When the computer program is executed by a processor, the calibration method described in the above embodiment can be implemented.

[0113] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A calibration method, characterized in that: Applicable to a calibration system including three markers, wherein a first marker Fix and a second marker XFix are fixedly mounted on a medical imaging device and spaced apart from each other, and are arranged in a mirror image with the center line of the medical imaging device; a third marker Bed is used to mark the surgical position of the patient, and is movably arranged on a diagnostic bed and adjacent to the surgical position; The first marker Fix is ​​used to mark the origin of the coordinate system of the medical imaging device and to mark the image space coordinate system of the medical imaging device. The calibration method includes: According to the relative position relationship matrix between the first marker and the second marker when the binocular measuring instrument is initially positioned and the relative position relationship matrix between the first marker and the second marker during the secondary positioning of the binocular measuring instrument determining an amount of change in the relative position between the first marker and the second marker; When the change amount is less than or equal to a preset threshold, a relative position relationship matrix between the first marker and the third marker is obtained. and a relative position relationship matrix between the second marker and the third marker according to and Calculate the relative position relationship matrix between the first marker and the third marker in, according to and Obtaining the relative position relationship matrix between the first marker and the third marker after calibration in, Used to determine the relative position relationship between the third marker and any coordinate in the image space coordinate system; The coordinate system of the binocular measuring instrument during initial positioning is the binocular measuring instrument primary positioning coordinate system, the coordinate system of the binocular measuring instrument during secondary positioning is the binocular measuring instrument secondary positioning coordinate system, and the binocular measuring instrument secondary positioning coordinate system is the same as or different from the binocular measuring instrument primary positioning coordinate system.

2. The calibration method according to claim 1, characterized in that: Before determining the change in the relative position between the first marker and the second marker, the method further includes: Obtaining a relative position relationship matrix between the first marker and the second marker when the binocular measuring instrument is initially positioned Obtaining a relative position relationship matrix between the first marker and the second marker during secondary positioning of the binocular measuring instrument 3. The calibration method according to claim 2, characterized in that: The relative position relationship matrix between the first marker and the second marker when the binocular measuring instrument is initially positioned is obtained. include: When the binocular measuring instrument is initially positioned, the coordinates of the first marker obtained by the binocular measuring instrument are received, and a conversion matrix is ​​calculated for converting the coordinate system of the first marker to the coordinate system of the binocular measuring instrument for primary positioning. When the binocular measuring instrument is initially positioned, the coordinates of the second marker obtained by the binocular measuring instrument are received, and a conversion matrix is ​​calculated for converting the coordinate system of the second marker to the primary positioning coordinate system of the binocular measuring instrument. Calculate the relative position relationship matrix of the second marker in the first marker coordinate system as the relative position relationship matrix between the first marker and the second marker in, 4. The calibration method as claimed in claim 3, characterized in that : Said r1 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t1 is a 3*1 column vector representing the displacement relationship between the first marker and the second marker; or; r1 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t1 is a 3*1 row vector representing the displacement relationship between the first marker and the second marker.

5. The calibration method as claimed in claim 2, characterized in that , the relative position relationship matrix between the first marker and the second marker when obtaining the secondary positioning of the binocular measuring instrument include: During the secondary positioning of the binocular measuring instrument, the coordinates of the first marker obtained by the binocular measuring instrument are received, and a conversion matrix for converting the first marker coordinate system to the secondary positioning coordinate system of the binocular measuring instrument is calculated. During the secondary positioning of the binocular measuring instrument, the coordinates of the second marker obtained by the binocular measuring instrument are received, and a conversion matrix is ​​calculated for converting the coordinate system of the second marker to the secondary positioning coordinate system of the binocular measuring instrument. Calculate the relative position relationship matrix of the second marker in the first marker coordinate system as the relative position relationship matrix between the first marker and the second marker in, 6. The calibration method according to claim 5, characterized in that: Said r2 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t2 is a 3*1 column vector representing the displacement relationship between the first marker and the second marker; or; r2 is a 3*3 matrix representing the rotation relationship between the first marker and the second marker, and t2 is a 3*1 row vector representing the displacement relationship between the first marker and the second marker.

7. The calibration method according to claim 4 or 6, characterized in that: The determining the change in the relative position between the first marker and the second marker comprises: Calculate the rotation relative position change matrix R1, where Calculate the relative position change vector r1 (θx1, θy1, θz1) of the Euler angle, where: <h2 style=";text-align:left;direction:ltr">θx1 = tan<h2 style=";text-align:left;direction:ltr"> -1 <h2 style=";text-align:left;direction:ltr"> 2(-r32,r33)|, θz1=|tan -1 2(-r31,r11)|; Calculate the relative position change S1, where: Among them, x2, y2 and z2 are the three elements of t2, and x1, y1 and z1 are the three elements of t1.

8. The calibration method according to claim 7, characterized in that: After determining the change in the relative position between the first marker and the second marker, the method further includes: Determine the preset threshold, including the preset Euler angle threshold vector r t1 (θx t1 ,θy t1 ,θz t1 ) and the preset displacement threshold S t1 , the θx t1 ,θy t1 and θz t1 is the Euler angle threshold element and is greater than zero and less than The preset displacement threshold S t1 is a positive number; Determine the relationship between the change amount and the preset threshold.

9. The calibration method according to claim 8, characterized in that: The determining the relationship between the change amount and the preset threshold value includes: Compare the displacements and compare S1 with S t1 In contrast, if S1 is greater than S t1 , determine that the relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated; if S1 is less than or equal to S t1 , compare the Euler angles; The Euler angle comparison includes: comparing θx1 with θx t1 For comparison, θy1 and θy t1 For comparison, θz 1 and θz t1 For comparison, as long as there is an element in r1 that is greater than r t1 The corresponding Euler angle threshold element in determines that the relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated; otherwise, the change is less than or equal to the preset threshold, determining that the relative position relationship between the medical imaging device and the first marker Fix does not need to be calibrated.

10. The calibration method according to claim 9, characterized in that: When the change amount is less than or equal to a preset threshold, obtaining a relative position relationship matrix between the first marker and the third marker and a relative position relationship matrix between the second marker and the third marker include: During the secondary positioning of the binocular measuring instrument, the coordinates of the third marker obtained by the binocular measuring instrument are received, and a conversion matrix is ​​calculated for converting the third marker coordinate system to the binocular measuring instrument secondary positioning coordinate system. Calculate the transformation matrix of the third marker coordinate system to the first marker coordinate system as the relative position relationship matrix between the first marker and the third marker in, Calculate the transformation matrix of the third marker coordinate system to the second marker coordinate system as the relative position relationship matrix between the second marker and the third marker in, 11. The calibration method according to claim 10, characterized in that: The basis and Obtaining the relative position relationship matrix between the first marker and the third marker after calibration include: Will and Perform interpolation calculation, mean calculation or least squares calculation to obtain a relative position relationship matrix between the first marker and the third marker after calibration 12. A calibration device, comprising a processor and a memory, characterized in that: The memory is used to store the calibration program; The processor is used to read the calibration program and perform the calibration method as described in any one of claims 1-11.

13. A three-marker calibration system, characterized in that: include: A binocular measuring instrument, a medical imaging device, a three-marker, and a calibration device as claimed in claim 12; The medical imaging device is provided with a diagnostic bed, and the three markers include a first marker Fix, a second marker XFix and a third marker Bed; The first marker Fix and the second marker XFix are fixedly mounted on the medical imaging device and spaced apart from each other, and are arranged in a mirror image with the center line of the medical imaging device; the third marker Bed is used to mark the surgical position of the patient, and is movably arranged on the diagnostic bed and adjacent to the surgical position; The first marker Fix is ​​used to mark the origin of the coordinate system of the medical imaging device and to mark the image space coordinate system of the medical imaging device; The second marker XFix is ​​used to measure the relative position relationship with the first marker Fix, and determine whether the relative position relationship between the medical imaging device and the first marker Fix needs to be calibrated; The combination of the first marker Fix and the second marker XFix is ​​used to calibrate the relative position relationship between the first marker Fix and the third marker Bed, and to determine the relative position relationship between the third marker and any coordinate in the image space coordinate system; The binocular measuring instrument is used to obtain the coordinates of the three markers and upload the coordinates of the three markers to the calibration device.

14. A non-transitory computer storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the calibration method according to any one of claims 1 to 11 can be implemented.

Images