Positioning method, electronic equipment and positioning system

Abstract

The invention provides a positioning method, electronic equipment and a positioning system, and relates to the technical field of medical treatment, in particular to the technical field of tumor positioning. According to the specific implementation scheme, an imaging device is used for obtaining a projection image of a target object at the current moment, and an optical tracking device is used for obtaining the position offset of the target object deviating in at least one direction of a preset three-dimensional coordinate system at the current moment; and determining the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment based on the projection image, the reference image at the imaging angle corresponding to the projection image and the position offset of at least one direction of the preset three-dimensional coordinate system. Wherein the projection image is obtained by the imaging device at any imaging angle. Through the method, the three-dimensional offset of the patient can be accurately determined.

Description

Technical Field

[0001] The present disclosure relates to the field of medical technology, in particular to the field of tumor localization technology, and specifically to a positioning method, electronic equipment and a positioning system. Background Art

[0002] During radiotherapy, accurate positioning of the tumor is one of the key technologies of radiotherapy. At present, when accurately positioning the tumor, the imaging device can be rotated by the frame to obtain a two-dimensional projection image (i.e., KV image) at two orthogonal or nearly orthogonal angles, and then the two two-dimensional projection images are respectively registered with the electronic computed tomography (CT) image to determine the three-dimensional offset of the tumor, thereby completing the accurate positioning of the tumor.

[0003] However, there is a time interval between when the gantry rotates to the first angle to take the first 2D projection image and when the gantry rotates to the second angle to take the second 2D projection image, that is, it is difficult to obtain the two 2D projection images under the same tumor motion state. Therefore, there is a lack of consistency between the two 2D projection images, which leads to inaccurate results of the determined 3D offset. Summary of the invention

[0004] The present disclosure provides a positioning method, an electronic device and a positioning system, which can accurately determine the three-dimensional offset of a patient.

[0005] In a first aspect, the present disclosure provides a positioning method, the method comprising: using an imaging device to obtain a projection image of a target object at the current moment, and using an optical tracking device to obtain a position offset of the target object at the current moment in at least one direction of a preset three-dimensional coordinate system, and based on the projection image, a reference image at an imaging angle corresponding to the projection image, and the position offset in at least one direction of the preset three-dimensional coordinate system, determining the position offset of the target object at the current moment in other directions of the preset three-dimensional coordinate system. The projection image is a projection image obtained by the imaging device at any imaging angle.

[0006] In some embodiments, based on the projection image, the reference image at the imaging angle corresponding to the projection image, and the position offset in at least one direction of the preset three-dimensional coordinate system, determining the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment includes:

[0007] The projected image is registered with the reference image at the imaging angle corresponding to the projected image to obtain the image offset of the target object, and the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment is determined based on the image offset, the position offset in at least one direction of the preset three-dimensional coordinate system and the imaging parameters of the imaging device. The image offset of the target object is the two-dimensional offset of the target object in the image coordinate system corresponding to the detector of the imaging device.

[0008] In some embodiments, the position offset in at least one direction of the preset three-dimensional coordinate system is a first position offset in a first direction of the preset three-dimensional coordinate system, and the position offsets in other directions of the preset three-dimensional coordinate system include a second position offset in a second direction of the preset three-dimensional coordinate system and a third position offset in a third direction of the preset three-dimensional coordinate system; the image offset includes a first image offset in the first direction of the image coordinate system and a second image offset in the second direction of the image coordinate system, and the first direction of the image coordinate system is parallel to the second direction of the preset three-dimensional coordinate system; based on the image offset, the position offset in at least one direction of the preset three-dimensional coordinate system and the imaging parameters of the imaging device, determining the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment includes: determining the second position offset based on the first image offset and the first imaging parameter of the imaging device, and determining the third position offset based on the second image offset, the first position offset and the second imaging parameter of the imaging device.

[0009] In some embodiments, the first imaging parameter includes a distance between a detector of the imaging device and a radiation source of the imaging device, and a distance between the radiation source of the imaging device and an isocenter of the imaging device.

[0010] In some embodiments, the second imaging parameter includes an angle between a first direction of a preset three-dimensional coordinate system and a second direction of the image coordinate system; or an angle between a third direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system.

[0011] In some embodiments, the first direction of the preset three-dimensional coordinate system is the X-axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y-axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the Z-axis of the IEC coordinate system; or, the first direction of the preset three-dimensional coordinate system is the Z-axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y-axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the X-axis of the IEC coordinate system.

[0012] In some embodiments, the imaging device is a CBCT device.

[0013] In some embodiments, the optical tracking device is a body surface optical tracking device or an infrared optical tracking device.

[0014] In a second aspect, the present disclosure further provides an electronic device, comprising: a processor and a memory configured to store processor executable instructions; wherein the processor is configured to execute the instructions to implement any one of the optional positioning methods in the first aspect above.

[0015] In a third aspect, the present disclosure further provides a positioning system, which includes: an imaging device, an optical tracking device and an electronic device; the imaging device is used to obtain a projection image of the target object at a current moment, the optical tracking device is used to obtain a position offset of the target object at a current moment in at least one direction of a preset three-dimensional coordinate system, and the electronic device is used to execute any one of the optional positioning methods in the above-mentioned first aspect.

[0016] The positioning method provided by the present disclosure can directly determine the position offset of the target object in other directions of the preset three-dimensional coordinate system based on the above-mentioned projection image and position offset, as well as the reference image at the imaging angle corresponding to the projection image, after obtaining the projection image of the target object at any imaging angle at the current moment by using an imaging device, and obtaining the position offset of the target object in at least one direction of the preset three-dimensional coordinate system by using an optical tracking device, without the need to drive the imaging device to rotate by the frame to collect projection images at multiple angles. It can be seen that, compared with the related art, the positioning method provided by the present disclosure is based on the position offset of the target object in the preset three-dimensional coordinate system determined based on the same tumor motion state, and there is no time interval. Therefore, the above-mentioned positioning method can accurately determine the patient's three-dimensional offset. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.

[0018] Figure 1 A schematic diagram of a scene of a positioning system provided by an embodiment of the present disclosure;

[0019] Figure 2 A flowchart of a positioning method provided by an embodiment of the present disclosure;

[0020] Figure 3 A schematic structural diagram of an imaging device provided by an embodiment of the present disclosure;

[0021] Figure 4 A schematic plan view of an imaging device provided by an embodiment of the present disclosure;

[0022] Figure 5 A schematic block diagram of an electronic device provided in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0024] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "first", "second", and "third" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0025] In the description of the present disclosure, the word "exemplary" is used to mean "used as an example, illustration, or illustration". Any embodiment described in the present disclosure as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present disclosure. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present disclosure can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present disclosure with unnecessary details. Therefore, the present disclosure is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present disclosure.

[0026] It should be noted that since the method of the embodiment of the present disclosure is executed in an electronic device, the processing objects of the electronic device exist in the form of data or information. For example, time is actually time information. It can be understood that if size, quantity, position, etc. are mentioned in subsequent embodiments, they are all corresponding data, so that the electronic device can process them. The details will not be repeated here.

[0027] Radiotherapy is a method of treating tumors using radiation emitted by radiotherapy equipment. Radiotherapy can cause complete necrosis of cancer cells or apoptosis of cancer cells, and is one of the main means of treating malignant tumors. During radiotherapy, precise positioning of the tumor is one of the key technologies of radiotherapy. Deviation in the location of the tumor will not only result in the inability to effectively kill tumor cells, but also lead to the risk of secondary cancer.

[0028] The radiotherapy equipment may include a rotating gantry, and a treatment source and an imaging device arranged on the rotating gantry, and both the treatment source and the imaging device may rotate with the rotation of the rotating gantry. The treatment source may emit radiation for treating the patient's lesions. The imaging device (such as a cone beam computed tomography (CBCT) device) may include an imaging source (such as a tube) and an imager (such as a flat panel detector), wherein the imaging source and the imager are arranged relative to each other, and the imaging source may emit imaging lines, which pass through the patient's lesions and are received by the imager to generate projection data.

[0029] At present, image guided radiation therapy (IGRT) is usually used to accurately locate tumors. Specifically, the imaging device is rotated by the frame to obtain a two-dimensional projection image (i.e., KV image) at two orthogonal or nearly orthogonal angles, and then the two two-dimensional projection images are registered with the computed tomography (CT) image to determine the three-dimensional offset of the tumor, thereby completing the precise positioning of the tumor.

[0030] However, there is a time interval between when the gantry rotates to the first angle to take the first 2D projection image and when the gantry rotates to the second angle to take the second 2D projection image, that is, it is difficult to obtain the two 2D projection images under the same tumor motion state. Therefore, there is a lack of consistency between the two 2D projection images, which leads to inaccurate results of the determined 3D offset.

[0031] Based on the above technical problems, the embodiments of the present disclosure provide a positioning method, after using an imaging device to obtain the projection image of the target object at any imaging angle at the current moment, and using an optical tracking device to obtain the position offset of the target object at the current moment in at least one direction of the preset three-dimensional coordinate system, the position offset of the target object in other directions of the preset three-dimensional coordinate system can be directly determined based on the above projection image and position offset, as well as the reference image at the imaging angle corresponding to the projection image, without the need to drive the imaging device to rotate by the frame to collect projection images at multiple angles. It can be seen that, compared with the related art, the positioning method provided by the present disclosure is based on the position offset of the target object in the preset three-dimensional coordinate system determined based on the same tumor motion state, and there is no time interval. Therefore, the above positioning method can accurately determine the three-dimensional offset of the tumor.

[0032] Figure 1 A schematic diagram of a scene of a positioning system provided by an embodiment of the present disclosure, such as Figure 1 As shown, the positioning system is applied to a radiotherapy device 100 , and the positioning system may include an imaging device 200 , an optical tracking device 300 and an electronic device 400 .

[0033] In some embodiments, the radiotherapy device 100 may include a gantry 101 and a positioning support device 102. The gantry 101 may be a ring gantry, a C-arm gantry, a drum gantry, a multi-layer bowl-shaped / cylindrical structure gantry, etc. The positioning support device 102 may support and position a target object, which may be a patient or a phantom simulating a patient. Exemplarily, the positioning support device 102 may be a three-dimensional, four-dimensional, five-dimensional, or six-dimensional treatment bed or treatment chair, etc.

[0034] It is understood that the radiotherapy device 100 may also include a radiotherapy head ( Figure 1 (not shown in the figure), which can be set on the gantry 101 and rotate with the rotation of the gantry 101. The radiotherapy head can be a focusing therapy head or a conformal therapy head. Specifically, when the radiotherapy head is a focusing therapy head, the ray focus of the focusing therapy head is located on the rotation axis of the gantry 101 and coincides with the device isocenter O1 of the radiotherapy device 100. When the radiotherapy head is a conformal therapy head, the intersection of the central ray of the conformal beam emitted by the conformal therapy head and the rotation axis of the gantry 101 coincides with the device isocenter O1 of the radiotherapy device 100. Here, the therapeutic ray emitted by the radiotherapy head may include a particle beam (for example, a neutron beam, a proton beam, an electron beam, etc.), a photon beam (for example, X-rays, gamma rays), etc., or a combination of a particle beam and a photon beam.

[0035] In some embodiments, the imaging device 200 may include a ray source 201 and a detector 202. The ray source 201 may emit imaging rays, and the detector 202 may receive an imaging beam that passes through a target object to generate a projection image. Here, the ray source 201 may be a tube, and the detector 202 may be a flat panel detector or a curved surface detector. The imaging device composed of the tube and the flat panel detector is a cone beam CT, i.e., CBCT. The embodiments of the present disclosure do not specifically limit the ray source 201 and the detector 202.

[0036] The ray source 201 and the detector 202 may also be disposed on the gantry 101 and rotate along with the rotation of the gantry 101 . Thus, the imaging device 200 may image the target object at different imaging angles and generate projection images at corresponding imaging angles.

[0037] In some embodiments, the body surface optical tracking device 300 may include at least one camera. Exemplarily, the optical tracking device 300 may include a first camera 301 and a second camera 302, which project light beams toward the virtual isocenter O2 (having a preset position relationship with the device isocenter O1) and the device isocenter O1, respectively, and receive light beams reflected by the target object and / or the optical markers set on the target object, thereby generating corresponding optical tracking images. Among them, the first camera 301 can be used to position the target object to move the position of the target object to a preset position, and the second camera 302 can be used to monitor the real-time position of the target object during radiotherapy. Optionally, the first camera 301 and the second camera 302 can be connected to the ceiling S of the radiotherapy room via a telescopic rod.

[0038] In the case where the optical tracking device 300 is a body surface optical tracking device, the first camera 301 and the second camera 302 are both structured light cameras. After the target object is located on the positioning support device 102, the structured light camera can emit structured light to the target object on the positioning support device, and receive the structured light reflected back by the body surface of the target object, thereby obtaining a three-dimensional image of the body surface of the target object. Before the target object is treated with the radiotherapy device 100 and / or during the treatment of the target object with the radiotherapy device 100, the target object can be positioned or its real-time position monitored by the obtained three-dimensional image of the body surface of the target object. The optical tracking device 300 can also be an infrared optical tracking device, and accordingly, the first camera 301 and the second camera 302 are both infrared cameras. Of course, the optical tracking device 300 can also be other optical tracking devices different from the imaging device for tracking and monitoring the target object, which are not specifically limited here.

[0039] The electronic device 400 is communicatively connected to the optical tracking device 300 and the imaging device 200 respectively.

[0040] In some embodiments, the electronic device 400 is a server with an image processing function, and the electronic device 400 may include: one or more processors, a memory, and one or more applications. For example, the electronic device 400 may include an image guidance system (IGS) application, and the processor of the electronic device 400 executes the IGS application to achieve: using the imaging device 200 to obtain the projection image of the target object at the current moment, and using the optical tracking device 300 to obtain the position offset of the target object at the current moment in at least one direction of the preset three-dimensional coordinate system, and then based on the projection image, the reference image at the imaging angle corresponding to the projection image, and the position offset in at least one direction of the preset three-dimensional coordinate system, determine the position offset of the target object at the current moment in other directions of the preset three-dimensional coordinate system.

[0041] In the embodiment of the present disclosure, the electronic device 400 may be an independent server, or a server network or server cluster composed of servers. For example, the electronic device described in the embodiment of the present disclosure includes but is not limited to a computer, a network host, a single network server, a plurality of network server sets or a cloud server composed of a plurality of servers. The cloud server is composed of a large number of computers or network servers based on cloud computing.

[0042] Figure 2 A flow chart of a positioning method provided in an embodiment of the present disclosure, which can be applied to Figure 1 The electronic equipment in the positioning system shown, such as Figure 2 As shown, the method includes:

[0043] S201, using an imaging device to obtain a projection image of a target object at a current moment.

[0044] The projection image is a projection image obtained by the imaging device at any imaging angle.

[0045] Specifically, after receiving a capture instruction for capturing a projection image of a target object, the electronic device sends the capture instruction to the imaging device, wherein the capture instruction may be generated by the electronic device in response to a capture operation of a user (medical staff) for capturing a projection image of a target object.

[0046] The imaging device can respond to the acquisition instruction. At any imaging angle, the ray source emits imaging rays to the target object. Correspondingly, the detector receives the imaging rays and generates a projection image. The electronic device obtains the projection image of the target object at the current moment from the detector, wherein the projection image is a two-dimensional image.

[0047] In the embodiments of the present disclosure, the target object can be used to refer to the patient, including the target area of ​​the patient, such as a lesion (such as a tumor), and can also be used to refer to the phantom, including the simulated target area in the phantom. The embodiments of the present disclosure do not specifically limit the target object.

[0048] In the embodiment of the present disclosure, the imaging device may include but is not limited to a cone beam CT device, and the embodiment of the present disclosure does not specifically limit the imaging device.

[0049] S202: Using an optical tracking device, obtain a position offset of a target object in at least one direction of a preset three-dimensional coordinate system at a current moment.

[0050] In the embodiments of the present disclosure, the optical tracking device may be a body surface optical tracking device or an infrared optical tracking device. The embodiments of the present disclosure do not specifically limit the optical tracking device.

[0051] In the embodiment of the present disclosure, the preset three-dimensional coordinate system may include but is not limited to the International Electrotechnical Commission (IEC) coordinate system, and the embodiment of the present disclosure does not specifically limit the preset three-dimensional coordinate system.

[0052] Among them, the IEC coordinate system may include but is not limited to three coordinate axes, for example, an X-axis (or simply the X-axis), a Y-axis (or simply the Y-axis) and a Z-axis (or simply the Z-axis). The embodiment of the present application does not specifically limit the number of coordinate axes in the IEC coordinate system. The following is an example of an IEC coordinate system containing three coordinate axes.

[0053] In the embodiment of the present disclosure, at least one direction may include one direction or multiple directions. For example, assuming that the preset three-dimensional coordinate system is the IEC coordinate system, at least one direction may include at least one of the direction where the X-axis is located, the direction where the Y-axis is located, and the direction where the Z-axis is located. Accordingly, the position offset amount of the target object offset in at least one direction of the preset three-dimensional coordinate system may include at least one of the position offset amount of the target object offset in the X-axis of the IEC coordinate system, the position offset amount of the target object offset in the Y-axis of the IEC coordinate system, and the position offset amount of the target object offset in the Z-axis of the IEC coordinate system.

[0054] Specifically, while using the imaging device to obtain the projection image of the target object at the current moment, the optical tracking device can also respond to the above-mentioned acquisition instruction to obtain the optical tracking image of the target object at the current moment, such as the surface optical tracking image or the infrared optical tracking image, and align the optical tracking image of the target image with the pre-stored target optical tracking image to obtain the position offset of the target object in one direction or multiple directions of the preset three-dimensional coordinate system.

[0055] S203, determining the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment based on the projection image, the reference image at the imaging angle corresponding to the projection image, and the position offset in at least one direction of the preset three-dimensional coordinate system.

[0056] The electronic device obtains a reference image at an imaging angle corresponding to the projection image based on the imaging angle corresponding to the projection image of the target object at the current moment. The reference image at the corresponding imaging angle may be a digitally reconstructed radiograph (DRR) image generated by digitally reconstructing a planned image, such as a CT image.

[0057] In this way, the electronic device can determine the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment based on the projected image, the reference image at the imaging angle corresponding to the projected image, and the position offset of the target object in at least one direction of the preset three-dimensional coordinate system.

[0058] In the embodiment of the present disclosure, other directions are relative to at least one direction in S202. For example, in the case where at least one direction includes the direction where the X-axis of the IEC coordinate system is located, the other directions may include the direction where the Y-axis of the IEC coordinate system is located and the direction where the Z-axis of the IEC coordinate system is located. Accordingly, the position offset of the target object in other directions of the preset three-dimensional coordinate system may include the position offset of the target object in the Y-axis of the IEC coordinate system and the position offset of the target object in the Z-axis of the IEC coordinate system. In the case where at least one direction includes the direction where the Z-axis of the IEC coordinate system is located, the other directions may include the direction where the Y-axis of the IEC coordinate system is located and the direction where the X-axis of the IEC coordinate system is located. Accordingly, the position offset of the target object in other directions of the preset three-dimensional coordinate system may include the position offset of the target object in the Y-axis of the IEC coordinate system and the position offset of the target object in the X-axis of the IEC coordinate system.

[0059] Through the above technical solution, the position offset of the target object in other directions of the preset three-dimensional coordinate system can be determined directly based on the projection image at any imaging angle, the position offset obtained by the optical tracking device, and the reference image at the imaging angle corresponding to the projection image, without the need to drive the imaging device to rotate by the frame to collect projection images at multiple angles. Therefore, compared with the related art, the positioning method provided by the present disclosure is based on a single projection image combined with the position offset of the target object in the preset three-dimensional coordinate system determined by the optical tracking device, which gets rid of the limitation of the related art that two mutually orthogonal projection images are required to determine the position offset of the target object, which can not only effectively improve the utilization rate of the projection image, but also enhance the real-time performance of determining the position offset of the target object, so that during the radiotherapy process, the position of the target object can be monitored in real time according to the position offset of the target object.

[0060] In an application example, the positioning method in the embodiment of the present disclosure can be used to obtain the position offset of the target object in each direction of the preset three-dimensional coordinate system at the current moment during the positioning process, so that the control device of the radiotherapy equipment adjusts the position of the positioning support device that supports the positioning target object based on the position offset of the target object in each direction of the preset three-dimensional coordinate system at the current moment, and repeats the aforementioned steps until it is determined that the position offset of the target object in each direction of the preset three-dimensional coordinate system at the current moment is within the preset position offset range, thereby completing the positioning of the target object before radiotherapy.

[0061] In another application example, the positioning method in the embodiment of the present disclosure can be used to continuously obtain the position offset of the target object in each direction of the preset three-dimensional coordinate system at the current moment during the radiotherapy process, so that the control device of the radiotherapy equipment, when determining that the average value of the position offset of the target object in each direction of the preset three-dimensional coordinate system at the current moment is within the preset position offset range, continues to return to repeat the aforementioned steps until the radiotherapy is completed; and when the control device of the radiotherapy equipment determines that at least one of the position offsets of the target object in each direction of the preset three-dimensional coordinate system at the current moment is not within the preset position offset range, controls the radiotherapy head of the radiotherapy equipment to stop emitting beams and stops monitoring, thereby completing real-time monitoring of the target object during the radiotherapy process.

[0062] It can be seen that the positioning method in the embodiment of the present disclosure can be used for positioning the target object before radiotherapy and / or for real-time monitoring of the target object during radiotherapy.

[0063] Whether in the positioning process, the radiotherapy process, or the whole radiotherapy process (including the positioning process and the radiotherapy process), the electronic device can also use the optical tracking device to obtain the position offset of the target object in each direction of the preset three-dimensional coordinate system at the current moment. In this way, by comparing the position offset of the target object in each direction of the preset three-dimensional coordinate system obtained by the positioning method in the embodiment of the present disclosure with the position offset of the target object in each direction of the preset three-dimensional coordinate system obtained by the optical tracking device at the current moment, the position offsets obtained by both are mutually verified. If the comparison result is not within the preset deviation range, it indicates that at least one of the position offsets obtained by the two is inaccurate, and at least one of the two needs to re-acquire the position offset; if the comparison result is within the preset deviation range, it indicates that the position offsets obtained by both are relatively accurate, and there is no need to re-acquire the position offset.

[0064] Exemplarily, when an optical tracking device is used to position the target object, and the positioning method in the embodiment of the present invention is used to monitor the target object in real time during radiotherapy treatment, during the positioning process, the electronic device can also use the positioning method in the embodiment of the present invention to obtain the position offset of the target object in each direction of the preset three-dimensional coordinate system, thereby verifying the position offset of the target object in each direction of the preset three-dimensional coordinate system obtained by the optical tracking device. During radiotherapy, the electronic device can also use the optical tracking device to obtain the position offset of the target object in each direction of the preset three-dimensional coordinate system, thereby verifying the position offset of the target object in each direction of the preset three-dimensional coordinate system obtained by the positioning method in the embodiment of the present invention.

[0065] Exemplarily, when the positioning method in the embodiment of the present invention is used to position the target object, and an optical tracking device is used to monitor the target object in real time during radiotherapy treatment, during the positioning process, the electronic device can also use the optical tracking device to obtain the position offset of the target object in each direction of the preset three-dimensional coordinate system, thereby verifying the position offset of the target object in each direction of the preset three-dimensional coordinate system obtained by the positioning method in the embodiment of the present invention. During radiotherapy, the electronic device can also use the positioning method in the embodiment of the present invention to obtain the position offset of the target object in each direction of the preset three-dimensional coordinate system, thereby verifying the position offset of the target object in each direction of the preset three-dimensional coordinate system obtained by the optical tracking device.

[0066] In an optional embodiment, during the execution of the above S203, the electronic device may first align the projected image with the reference image at the imaging angle corresponding to the projected image to obtain the image offset of the target object, and then determine the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment based on the image offset, the position offset in at least one direction of the preset three-dimensional coordinate system and the imaging parameters of the imaging device.

[0067] The image offset of the target object is a two-dimensional offset of the target object in the image coordinate system corresponding to the detector of the imaging device.

[0068] Specifically, the electronic device aligns the projection image of the target object with the DRR image at the corresponding imaging angle to obtain the image offset of the target object in the image coordinate system, and finally determines the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment based on the image offset, the position offset in at least one direction of the preset three-dimensional coordinate system, and the imaging parameters of the imaging device stored in advance.

[0069] In an optional embodiment, it is assumed that the position offset occurring in at least one direction of a preset three-dimensional coordinate system is a first position offset in a first direction of the preset three-dimensional coordinate system, and the position offsets in other directions of the preset three-dimensional coordinate system include a second position offset in a second direction of the preset three-dimensional coordinate system and a third position offset in a third direction of the preset three-dimensional coordinate system; the image offset includes a first image offset in the first direction of the image coordinate system and a second image offset in the second direction of the image coordinate system, and the first direction of the image coordinate system is parallel to the second direction of the preset three-dimensional coordinate system.

[0070] When determining the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment based on the image offset, the position offset in at least one direction of the preset three-dimensional coordinate system and the imaging parameters of the imaging device, the second position offset can be determined based on the first image offset and the first imaging parameter of the imaging device, and the third position offset can be determined based on the second image offset, the first position offset and the second imaging parameter of the imaging device.

[0071] In an optional implementation, each direction in the preset three-dimensional coordinate system may include but is not limited to the following two situations:

[0072] Case 1: The first direction of the preset three-dimensional coordinate system is the X-axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y-axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the Z-axis of the IEC coordinate system. The position offset of the target object on the X-axis of the IEC coordinate system is obtained by an optical tracking device.

[0073] Case 2: The first direction of the preset three-dimensional coordinate system is the Z axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the X axis of the IEC coordinate system. The position offset of the target object on the Z axis of the IEC coordinate system is obtained by an optical tracking device.

[0074] The positioning method provided by the embodiment of the present disclosure is described below using the above two situations as examples.

[0075] Case 1: The first direction of the preset three-dimensional coordinate system is the X-axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y-axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the Z-axis of the IEC coordinate system.

[0076] In an optional implementation, the first imaging parameter may include the distance between the detector of the imaging device and the ray source of the imaging device, and the distance between the ray source of the imaging device and the isocenter mentioned above.

[0077] The central imaging ray emitted by the radiation source passes through the isocenter, and the intersection with the detector is the center point of the detector.

[0078] Accordingly, when the second position offset is determined based on the first image offset and the first imaging parameter of the imaging device, the second position offset of the target object in the second direction of the preset three-dimensional coordinate system can be determined according to the first image offset, the distance between the detector of the imaging device and the ray source of the imaging device, and the distance between the ray source of the imaging device and the isocenter.

[0079] The second position offset is negatively correlated with the distance between the detector of the imaging device and the ray source of the imaging device, and the second position offset is positively correlated with the distance between the ray source of the imaging device and the isocenter.

[0080] For example, in one embodiment, Figure 3 A schematic diagram of the structure of an imaging device provided in an embodiment of the present disclosure is shown in FIG. Figure 3 As shown in the figure, X represents the X axis of the IEC coordinate system, Z represents the Z axis of the IEC coordinate system, and Y represents the Y axis of the IEC coordinate system. The direction of the Y axis is the direction of the patient's head and feet. V represents the first direction of the image coordinate system, and U represents the second direction of the image coordinate system. The V axis is parallel to the Y axis. Therefore, when the target object is located at the position of the isocenter O, the coordinates of the target object in the image coordinate system are the coordinate origin (0, 0). When the target object is offset from the isocenter O, the coordinates of the target object in the image coordinate system are the offset of the target object relative to the isocenter O in the IEC coordinate system.

[0081] Continue to see Figure 3, SID represents the distance between the detector of the imaging device and the ray source of the imaging device, SAD represents the distance between the ray source of the imaging device and the isocenter O. After the electronic device determines the first image offset in the above manner, it can determine the second position offset according to the following formula 1, that is, the position offset of the target object on the Y axis of the IEC coordinate system.

[0082]

[0083] Wherein, v1 represents the first image offset, and ΔY represents the second position offset.

[0084] Through the above technical solution, the position offset of the target object on the Y-axis of the IEC coordinate system can be determined directly based on the projection image at one imaging angle, the positions of the ray source and the detector in the imaging device, and the isocenter, without the need to determine it through the projection images at two orthogonal imaging angles. Therefore, the limitation of the related art that two mutually orthogonal projection images are required to determine the position offset of the target object is eliminated, and the real-time performance of determining the position offset of the target object on the Y-axis of the IEC coordinate system can be improved.

[0085] In an optional embodiment, the second imaging parameter may include but is not limited to any one of the following (1) and (2):

[0086] (1) The angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, that is, the angle between the X-axis of the IEC coordinate system and the second direction of the image coordinate system.

[0087] (2) The angle between the third direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, that is, the angle between the Z axis of the IEC coordinate system and the second direction of the image coordinate system.

[0088] The positioning method provided by the embodiment of the present disclosure will be described below by taking the second imaging parameter as the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system as an example.

[0089] When the third position offset is determined based on the second image offset, the first position offset and the second imaging parameter of the imaging device, the third position offset of the target object in the third direction of the preset three-dimensional coordinate system can be determined according to the second image offset, the first position offset, and the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system.

[0090] Specifically, the electronic device can determine the third position offset of the target object in the third direction of the preset three-dimensional coordinate system, that is, the position offset of the target object on the Z axis of the IEC coordinate system based on the sine value and cosine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, as well as the second image offset and the first position offset.

[0091] The third position offset is negatively correlated with the sine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, and the third position offset is positively correlated with the cosine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system.

[0092] For example, in one embodiment, Figure 4 A schematic diagram of an imaging device provided in an embodiment of the present disclosure is shown in FIG. Figure 4 As shown, X represents the X axis of the IEC coordinate system, Z represents the Z axis of the IEC coordinate system, U represents the second direction of the image coordinate system, that is, the direction of the U axis of the image coordinate system, Z' is parallel to U, and α is the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system. Because the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, the second image offset, the first position offset of the target object in the first direction of the preset three-dimensional coordinate system, and the third position offset of the target object in the third direction of the preset three-dimensional coordinate system meet the conditions shown in Formula 2, therefore, after the electronic device determines the second image offset, it can determine the third position offset of the target object in the third direction of the preset three-dimensional coordinate system according to the following Formula 3, that is, the position offset of the target object on the Z axis of the IEC coordinate system.

[0093] Δzsinα-Δxcosα=u1 (Formula 2)

[0094]

[0095] Among them, u1 represents the first image offset, ΔZ represents the position offset of the target object on the Z axis of the IEC coordinate system, that is, the third position offset, Δx represents the first position offset of the target object in the first direction of the preset three-dimensional coordinate system, that is, the position offset of the target object on the X axis of the IEC coordinate system, sinα represents the sine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, and cosα represents the cosine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system.

[0096] Through the above technical scheme, the position offset of the target object on the Z axis of the IEC coordinate system can be directly determined based on the position offset of the target object on the X axis of the IEC coordinate system obtained by the optical tracking device, the second image offset and the angle between the X axis of the IEC coordinate system and the second direction of the image coordinate system, that is, there is no need to determine the position offset of the target object through projection images at two orthogonal imaging angles, thus getting rid of the limitation of the related art that two mutually orthogonal projection images are required to determine the position offset of the target object, and the real-time performance of determining the position offset of the target object on the Z axis of the IEC coordinate system can be improved.

[0097] Case 2: The first direction of the preset three-dimensional coordinate system is the Z axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the X axis of the IEC coordinate system.

[0098] In the second case, the process of determining the position offset of the target object on the Y axis of the IEC coordinate system (i.e., the second position offset) is the same as the process of determining the position offset of the target object on the Y axis of the IEC coordinate system in the first case mentioned above, and will not be repeated here.

[0099] The following will take the second imaging parameter as the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system as an example to illustrate the process of determining the position offset of the target object on the X-axis of the IEC coordinate system (ie, the third position offset).

[0100] Specifically, the electronic device can determine the third position offset of the target object in the third direction of the preset three-dimensional coordinate system, that is, the position offset of the target object on the Z axis of the IEC coordinate system based on the sine value and cosine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, as well as the second image offset and the first position offset.

[0101] The third position offset is positively correlated with the sine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, and the third position offset is negatively correlated with the cosine value of the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system.

[0102] For example, in one embodiment, continue to refer to Figure 4As shown, α is the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system. Because the angle between the first direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system, the second image offset, the first position offset of the target object in the first direction of the preset three-dimensional coordinate system, and the third position offset of the target object in the third direction of the preset three-dimensional coordinate system meet the conditions shown in the above formula 2, therefore, after the electronic device determines the second image offset, it can determine the third position offset of the target object in the third direction of the preset three-dimensional coordinate system according to the following formula 4, that is, the position offset of the target object on the X-axis of the IEC coordinate system.

[0103]

[0104] Through the above technical scheme, the position offset of the target object on the X-axis of the IEC coordinate system can be directly determined based on the position offset of the target object on the Z-axis of the IEC coordinate system obtained by the optical tracking device, the second image offset and the angle between the X-axis of the IEC coordinate system and the second direction of the image coordinate system, that is, there is no need to determine the position offset of the target object through projection images at two orthogonal imaging angles, thus getting rid of the limitation of the related art that two mutually orthogonal projection images are required to determine the position offset of the target object, and the real-time performance of determining the position offset of the target object on the X-axis of the IEC coordinate system can be improved.

[0105] In the embodiment of the present disclosure, after the position offset of the target object in other directions of the preset three-dimensional coordinate system is confirmed by the above method, the position offset of the target object in other directions of the preset three-dimensional coordinate system obtained by the optical tracking device can be used to verify the confirmed position offset of the target object in other directions. If the verification is successful, the position offset of the target object in other directions of the preset three-dimensional coordinate system confirmed by the above method is used to determine the position of the target object.

[0106] Specifically, the electronic device can first determine the difference between the position offset of the target object in other directions of the preset three-dimensional coordinate system obtained by using the optical tracking device and the confirmed position offset of the target object in other directions. If the difference is within the preset difference range, the position of the target object is determined by using the position offset of the target object in other directions of the preset three-dimensional coordinate system confirmed by the above method. If the difference is outside the preset difference range, the position offset of the target object in other directions of the preset three-dimensional coordinate system is reconfirmed by the positioning method provided in the embodiment of the present disclosure.

[0107] By the above method, after determining the position offset of the target object in other directions of the preset three-dimensional coordinate system, the position offset can be further verified to ensure the accuracy of the confirmed position offset, thereby effectively improving the accuracy of the determined position of the target object.

[0108] Figure 5 A schematic block diagram of an example electronic device 500 that can be used to implement an embodiment of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or claimed herein. In some embodiments, the electronic device may be the above-mentioned Figure 1 The electronic device shown in .

[0109] like Figure 5 As shown, the electronic device 500 includes a computing unit 501, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory 502 or a computer program loaded from a storage unit 508 to a random access memory 503. In the random access memory (RAM) 503, various programs and data required for the operation of the electronic device 500 can also be stored. The computing unit 501, the read-only memory (ROM) 502 and the RAM 503 are connected to each other via a bus 504. An input / output interface 505 is also connected to the bus 504.

[0110] Multiple components in the electronic device 500 are connected to the input / output (I / O) interface 505, including: an input unit 506, such as a keyboard, a mouse, etc.; an output unit 1007, such as various types of displays, speakers, etc.; a storage unit 508, such as a disk, an optical disk, etc.; and a communication unit 509, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 509 allows the electronic device 500 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0111] The computing unit 501 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 501 include, but are not limited to, a central processing unit, a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors, and any appropriate processors, controllers, microcontrollers, etc. The computing unit 501 performs the various methods and processes described above, such as the positioning method. For example, in one embodiment, the positioning method may be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 508. In one embodiment, part or all of the computer program may be loaded and / or installed on the electronic device 500 via ROM 502 and / or a communication unit 509. When the computer program is loaded into RAM 503 and executed by the computing unit 501, one or more steps of the positioning method described above may be performed. Alternatively, in other embodiments, the computing unit 501 may be configured to perform the positioning method in any other appropriate manner (e.g., by means of firmware).

[0112] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays, application specific integrated circuits, application specific standard parts (ASSP), system on chip systems (System On Chip, SOC), complex programmable logic devices (Complex Programmable Logic Device, CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include: being implemented in one or more computer programs, which can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor, which can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0113] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0114] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. More specific examples of machine-readable storage media may include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories, read-only memories, erasable programmable read-only memories, optical fibers, portable compact disk read-only memories, optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0115] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user, such as a cathode ray tube (CRT) or a liquid crystal display (LCD) monitor; and a keyboard and a pointing device (e.g., a mouse or a trackball), through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and the input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0116] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: Local Area Networks (LANs), Wide Area Networks (WANs), and the Internet.

[0117] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0118] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of this disclosure can be achieved, and this document is not limited here.

[0119] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A positioning method, characterized in that: The method comprises: Acquire a projection image of the target object at the current moment by using an imaging device, wherein the projection image is a projection image acquired by the imaging device at any imaging angle; Using an optical tracking device to obtain a position offset of the target object in at least one direction of a preset three-dimensional coordinate system at the current moment; Based on the projection image, the reference image at the imaging angle corresponding to the projection image and the position offset in at least one direction of the preset three-dimensional coordinate system, the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment is determined.

2. The method according to claim 1, characterized in that The determining, based on the projection image, the reference image at an imaging angle corresponding to the projection image, and the position offset in at least one direction of the preset three-dimensional coordinate system, the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment comprises: Registering the projection image with a reference image at an imaging angle corresponding to the projection image to obtain an image offset of the target object, where the image offset of the target object is a two-dimensional offset of the target object in an image coordinate system corresponding to a detector of the imaging device; Based on the image offset, the position offset in at least one direction of the preset three-dimensional coordinate system and the imaging parameters of the imaging device, the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment is determined.

3. The method according to claim 2, characterized in that The position offset occurring in at least one direction of the preset three-dimensional coordinate system is a first position offset in a first direction of the preset three-dimensional coordinate system, the position offsets in other directions of the preset three-dimensional coordinate system include a second position offset in a second direction of the preset three-dimensional coordinate system and a third position offset in a third direction of the preset three-dimensional coordinate system, the image offset includes a first image offset in the first direction of the image coordinate system and a second image offset in the second direction of the image coordinate system, and the first direction of the image coordinate system is parallel to the second direction of the preset three-dimensional coordinate system; The determining, based on the image offset, the position offset in at least one direction of the preset three-dimensional coordinate system and the imaging parameter of the imaging device, the position offset of the target object in other directions of the preset three-dimensional coordinate system at the current moment comprises: determining the second position offset based on the first image offset and a first imaging parameter of the imaging device; The third position offset is determined based on the second image offset, the first position offset and a second imaging parameter of the imaging device.

4. The method according to claim 3, characterized in that The first imaging parameter includes a distance between a detector of the imaging device and a ray source of the imaging device, and a distance between the ray source of the imaging device and an isocenter of the imaging device.

5. The method according to claim 3, characterized in that: The second imaging parameter includes an angle between a first direction of the preset three-dimensional coordinate system and a second direction of the image coordinate system; or an angle between a third direction of the preset three-dimensional coordinate system and the second direction of the image coordinate system.

6. The method according to claim 1, characterized in that The first direction of the preset three-dimensional coordinate system is the X-axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y-axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the Z-axis of the IEC coordinate system; or, The first direction of the preset three-dimensional coordinate system is the Z axis of the IEC coordinate system, the second direction of the preset three-dimensional coordinate system is the Y axis of the IEC coordinate system, and the third direction of the preset three-dimensional coordinate system is the X axis of the IEC coordinate system.

7. The method according to claim 1, characterized in that The imaging device is a cone beam computer tomography (CBCT) device.

8. The method according to claim 1, characterized in that The optical tracking device is a body surface optical tracking device or an infrared optical tracking device.

9. An electronic device, characterized in that: The electronic device comprises: processor; a memory configured to store instructions executable by the processor; The processor is configured to execute the instructions to implement the positioning method as described in any one of claims 1-8.

10. A positioning system, characterized in that: The system includes: an imaging device, an optical tracking device and an electronic device; The imaging device is used to obtain a projection image of the target object at a current moment; The optical tracking device is used to obtain the position offset of the target object in at least one direction of the preset three-dimensional coordinate system at the current moment; The electronic device is used to execute the positioning method as described in any one of claims 1-8.

Images