Vascular lumen area measuring device

Abstract

This application provides a device for measuring the lumen area of ​​blood vessels. The device includes a control unit, an angiography unit, a magnetic field generating unit, a scanning probe, a magnetic field receiving unit, and a lifting platform. The control unit controls a first magnetic field group and a second magnetic field group to generate magnetic signals and receives magnetic signals. Based on the generated and received magnetic signals, the probe position is determined, and angiography images and intravascular images are acquired simultaneously. Based on the angiography images and the probe position, the blood vessel orientation is determined. The original blood vessel area is obtained based on the intravascular image. A spatial orientation vector is determined based on the first and second received signals, a first reference magnetic field vector, a second reference magnetic field vector, and a direction vector. The original blood vessel area is corrected based on the blood vessel orientation and the spatial orientation vector to obtain the corrected blood vessel area. This application eliminates measurement deviations caused by probe tilt and improves the accuracy of blood vessel lumen area measurement.

Description

Technical Field

[0001] This application relates to the field of vascular measurement technology, and more specifically, to a device for measuring the area of ​​a blood vessel lumen. Background Technology

[0002] Optical coherence tomography (OCT) is a core high-resolution imaging tool in cardiovascular interventional diagnosis and treatment for assessing vascular morphology and the degree of stenosis. It is often used in conjunction with digital subtraction angiography (DSA) to provide precise imaging support for interventional procedures for diseases such as coronary artery disease. OCT involves inserting a catheter probe into the blood vessel, emitting probe light perpendicular to the probe axis, and acquiring tomographic images of the lumen to calculate the lumen size.

[0003] In existing technologies, OCT lumen size measurement defaults to the probe direction being parallel to the direction of the blood vessel centerline, and the measurement result perpendicular to the probe is directly used as the actual lumen size of the blood vessel.

[0004] However, when the blood vessel is curved or the probe is not aligned with the center line of the blood vessel, the lumen size measured by the probe light perpendicular to the probe may be larger than the true value, resulting in inaccurate measurement results. Summary of the Invention

[0005] The purpose of this application is to provide a blood vessel lumen area measuring device to address the shortcomings of the prior art and solve the problem of inaccurate lumen size measurement in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, this application provides a vascular lumen area measurement device, the device including a control component, an angiography component, a magnetic field generating component, a scanning probe, a magnetic field receiving component, and a lifting platform. The magnetic field generating component includes a first magnetic field group and a second magnetic field group. The first magnetic field group includes a first magnetic field module and a second magnetic field module arranged in parallel. The second magnetic field group includes a third magnetic field module and a fourth magnetic field module arranged in parallel. The first magnetic field module and the third magnetic field module are located on a first side of the lifting platform, and the second magnetic field module and the fourth magnetic field module are located on a second side of the lifting platform. The scanning probe is rigidly fixedly connected to the magnetic field receiving component. The control component is used to control the first magnetic field group and the second magnetic field group to alternately generate magnetic generation signals in the form of a preset gradient, and to receive magnetic receiving signals from the magnetic field receiving component. Based on the magnetic generation signals and the magnetic receiving signals, the probe position of the scanning probe is determined. The magnetic receiving signals include a first receiving signal corresponding to the first magnetic field group and a second receiving signal corresponding to the second magnetic field group. The control unit is used to simultaneously acquire angiography images and intravascular images, determine the vascular direction corresponding to the probe position based on the angiography images and the probe position, and obtain the original vascular area based on the intravascular images. The control component is used to determine the spatial orientation vector of the scanning probe based on the first received signal, the second received signal, the first reference magnetic field vector corresponding to the first magnetic field group, the second reference magnetic field vector corresponding to the second magnetic field group, and the orientation vector of the probe relative to the magnetic field receiving component. The control component is used to correct the original blood vessel area based on the blood vessel direction and the spatial direction vector of the scanning probe, so as to obtain the corrected blood vessel area of ​​the blood vessel region to be tested.

[0007] The magnetic generation signal includes a first generation signal corresponding to the first magnetic field group and a second generation signal corresponding to the second magnetic field group; The control component is specifically used for: If the difference between the first gradient intensity of the first received signal and the first generated signal is less than a preset difference threshold, then the first current cross-section corresponding to the first generated signal is taken as the first face where the scanning probe is located, and the first current cross-section is the cross-section where the first magnetic field group generates the first generated signal; If the difference between the second gradient intensity of the second received signal and the second generated signal is less than the preset difference threshold, then the second current cross-section corresponding to the second generated signal is taken as the second face where the scanning probe is located, and the second current cross-section is the cross-section where the second magnetic field group generates the second generated signal; The intersection of the first surface, the second surface, and the preset horizontal plane is taken as the probe position of the scanning probe.

[0008] The control component is specifically used for: The probe position is projected into the angiographic image to determine the blood vessel where the scanning probe is located; The tangent direction at the center line of the blood vessel corresponding to the probe position is taken as the direction of the blood vessel.

[0009] The control component is specifically used for: Based on the first reference magnetic field vector and the second reference magnetic field vector, determine the world orthogonal axis vector in the world coordinate system; Based on the first received magnetic field vector in the first received signal and the second received magnetic field vector in the second received signal, determine the local orthogonal axis vector in the local coordinate system; The rotation matrix is ​​determined based on the world orthogonal axis vector and the local orthogonal axis vector; The spatial orientation vector of the scanning probe is determined based on the orientation vector of the probe relative to the magnetic field receiving component and the rotation matrix.

[0010] The control component is specifically used for: The first reference magnetic field vector is normalized to obtain the first world vector; The first reference magnetic field vector and the second reference magnetic field vector are subjected to Schmitt orthogonalization to obtain a second world vector that is perpendicular to the first world vector. Perform a vector product operation on the first world vector and the second world vector to obtain the third world vector; The first world vector, the second world vector, and the third world vector are used as the world orthogonal axis vectors.

[0011] The control component is specifically used for: The first received magnetic field vector is normalized to obtain the first local vector; The first received magnetic field vector and the second received magnetic field vector are subjected to Schmitt orthogonalization to obtain a second local vector that is perpendicular to the first local vector. Perform a vector product operation on the first local vector and the second local vector to obtain the third local vector; The first local vector, the second local vector, and the third local vector are used as the local orthogonal axis vectors.

[0012] The control component is specifically used for: The rotation matrix is ​​the dot product of the world orthogonal axis vector and the local orthogonal axis vector.

[0013] The control component is specifically used for: The dot product of the rotation matrix and the direction vector of the probe relative to the magnetic field receiving component is used as the spatial direction vector of the scanning probe.

[0014] The control component is specifically used for: The absolute value of the dot product of the blood vessel direction and the spatial direction vector of the scanning probe is used as the correction coefficient. The product of the original blood vessel area and the correction coefficient is used as the corrected blood vessel area of ​​the blood vessel region to be tested.

[0015] Optionally, the first magnetic field module and the third magnetic field module are arranged close together at a preset angle, and the second magnetic field module and the fourth magnetic field module are arranged close together at the preset angle.

[0016] The beneficial effects of this application are as follows: After the subject lies flat on the lifting platform, the control unit acquires the angiographic image and the original blood vessel area. It then uses the alternating decrease of the first and second magnetic field groups to generate magnetic signals, thereby accurately positioning the scanning probe based on the correspondence between magnetic field strength and spatial position. The blood vessel direction is determined based on the position of the angiographic image and the scanning probe. The spatial direction vector of the scanning probe is determined based on the first received signal, the second received signal, the first reference magnetic field vector, the second reference magnetic field vector, and the direction vector of the probe relative to the magnetic field receiving component. Finally, the original blood vessel area is corrected according to the blood vessel direction and the probe direction to obtain the corrected blood vessel area. This device can eliminate measurement deviations caused by probe tilt and improve the accuracy of blood vessel lumen area measurement. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a scanning probe and a blood vessel provided in an embodiment of this application; Figure 2 This is a schematic diagram of the planar structure of a blood vessel lumen area measuring device provided in an embodiment of this application; Figure 3 This is a three-dimensional structural schematic diagram of a blood vessel lumen area measuring device provided in an embodiment of this application; Figure 4 This is a schematic diagram of a connection structure between a scanning probe and a magnetic field receiving component provided in an embodiment of this application; Figure 5 This is a schematic diagram of a control component performing a blood vessel lumen area measurement according to an embodiment of this application; Figure 6 This is a schematic diagram of an alternating operation of a magnetic field group provided in this embodiment; Figure 7 This is a schematic diagram showing a decrease in magnetic field strength between a first magnetic field group and a second magnetic field group, as provided in an embodiment of this application. Figure 8 This is a schematic diagram of a blood vessel area provided in an embodiment of this application; Figure 9 This is a schematic diagram of a control component determining the probe position of a scanning probe according to an embodiment of this application; Figure 10 This is a schematic flowchart illustrating how a control component determines the spatial orientation vector of a scanning probe, as provided in an embodiment of this application. Figure 11 This is a schematic diagram of a world coordinate system and a local coordinate system provided in an embodiment of this application; Figure 12 This is a schematic diagram of a control component determining the magnitude of the world orthogonal axis, provided in an embodiment of this application. Figure 13 This is a schematic diagram of a control component determining a local orthogonal axial quantity, provided in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0020] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0022] Figure 1 This is a schematic diagram of a scanning probe and a blood vessel provided in an embodiment of this application. Figure 1As shown, the direction of the probe inserted into the blood vessel does not coincide with the direction of the blood vessel's centerline, which causes the lumen size measured by the probe to be larger than the true value.

[0023] To address the problem of inaccurate measurement of lumen dimensions by probes in existing technologies, this application proposes a vascular lumen area measurement device. In this device, the control unit determines the vascular direction and original vascular area based on angiographic images and intravascular images. Simultaneously, it determines the probe position based on the gradient magnetic generation signals alternately generated by the first and second magnetic field groups and the corresponding magnetic reception signals received by the magnetic field receiving unit. Then, based on the magnetic reception signals, a pre-established reference magnetic field vector, and the probe's direction vector relative to the magnetic field receiving unit, it determines the spatial direction vector of the scanning probe. Finally, it uses the vascular direction and the spatial direction vector of the scanning probe to correct the original vascular area obtained by the scanning probe, thus obtaining the corrected vascular area. This device compensates for measurement deviations caused by vascular curvature and probe tilt, ensuring that the measurement results closely match the actual cross-sectional dimensions of the vascular vessel, thereby improving the accuracy and reliability of lumen area measurement.

[0024] Next, refer to Figure 2 and Figure 3 This section introduces equipment for measuring the lumen area of ​​blood vessels. Among other things, Figure 2 This is a schematic diagram of the planar structure of a blood vessel lumen area measuring device provided in an embodiment of this application. Figure 2 The upper part is a side view of the system, and the lower part is a top view of the system. Figure 3 This is a three-dimensional structural schematic diagram of a blood vessel lumen area measuring device provided in an embodiment of this application.

[0025] The vascular lumen area measurement device includes a control unit, an angiography unit, a magnetic field generating unit, a scanning probe, a magnetic field receiving unit, and a lifting platform. The magnetic field generating unit includes a first magnetic field group and a second magnetic field group arranged in parallel. The first magnetic field group includes a first magnetic field module and a second magnetic field module arranged in parallel. The second magnetic field group includes a third magnetic field module and a fourth magnetic field module arranged in parallel. The first and third magnetic field modules are located on the first side of the lifting platform and are arranged close together at a preset angle. The second and fourth magnetic field modules are located on the second side of the lifting platform and are also arranged close together at a preset angle. The first and second sides are opposite sides of the lifting platform. Optionally, when the object to be measured lies flat on the lifting platform, the first and second sides can be located on the left and right sides of the object. The angle formed between the first and third magnetic field modules is the same as the angle formed between the second and fourth magnetic field modules, for example, an angle greater than 90 degrees and less than 180 degrees.

[0026] The scanning probe is an OCT probe, which can be inserted into the blood vessel of the object to be tested through a catheter, emit near-infrared light to collect vascular tomographic images, and calculate the cross-sectional area of ​​the blood vessel perpendicular to the probe axis through a built-in algorithm.

[0027] The first magnetic field module, the second magnetic field module, the third magnetic field module, and the fourth magnetic field module can each be composed of multiple sets of coils. They can generate magnetic fields with preset strength and preset direction under the drive of the control component. The position, direction, and intensity distribution of the two sets of magnetic fields can all be pre-calibrated.

[0028] Optionally, the control component can be connected to the scanning probe and the magnetic field receiving component via wires; the control component can be, for example, a trolley.

[0029] The contrast-enhancing unit, also known as the DSA device, includes an X-ray emitter and an X-ray receiver. The X-ray emitter is located on the third side of the lifting platform, such as the upper side, and the X-ray receiver is located on the fourth side of the lifting platform, such as the lower side. The X-ray emitter and X-ray receiver are connected by a C-arm. The contrast-enhancing unit generates a clear image of the blood vessel by injecting a contrast agent into the blood vessel, using X-ray imaging, and subtracting background interference from bones, soft tissues, etc.

[0030] Figure 2 and Figure 3 The shapes of the first, second, third, and fourth magnetic field modules are only shown in the illustration; their specific shapes and magnetic field generation methods are not limited in this embodiment.

[0031] Figure 4 This is a schematic diagram of a connection structure between a scanning probe and a magnetic field receiving component provided in an embodiment of this application. Figure 4 As shown, the scanning probe and the magnetic field receiving component are rigidly fixedly connected. The magnetic field receiving component can be a composite magnetic field sensor composed of three orthogonal Hall elements, such as an X-axis direction sensor, a Y-axis direction sensor, and a Z-axis direction sensor. Optionally, the connection between the scanning probe and the magnetic field receiving component can be as follows: one end of the magnetic field receiving component is connected to one end of the scanning probe, and the other end of the scanning probe is connected to a conduit. Alternatively, one end of the scanning probe can be connected to one end of the magnetic field receiving component, and the other end of the magnetic field receiving component is connected to a conduit. The positional relationship between the scanning probe and the magnetic field receiving component can be set according to actual conditions, and this embodiment does not limit it.

[0032] Figure 5 This is a schematic diagram illustrating the process of a control component performing a blood vessel lumen area measurement, as provided in an embodiment of this application. (Refer to...) Figure 5 As shown, the specific steps for the control component to measure the area of ​​the blood vessel lumen will be introduced next.

[0033] S501. Control the first magnetic field group and the second magnetic field group to alternately generate magnetic generation signals in the form of preset gradients, and receive magnetic receiving signals from the magnetic field receiving component. Determine the probe position of the scanning probe based on the magnetic generation signals and magnetic receiving signals. The magnetic receiving signals include a first receiving signal corresponding to the first magnetic field group and a second receiving signal corresponding to the second magnetic field group.

[0034] Optionally, before controlling the first and second magnetic field groups to alternately generate magnetic signals in the form of a preset gradient, the subject lies flat on the lifting platform, and the height of the lifting platform is adjusted so that the area of ​​the blood vessel to be measured is aligned with the imaging range of the angiography component. Simultaneously, the subject's body is fixed to prevent movement during the measurement process. The scanning probe is guided into the area of ​​the blood vessel to be measured, ready to acquire an image. The subject can be a human or an animal, etc., and this embodiment does not impose any limitations on this.

[0035] Subsequently, the control unit can control the first magnetic field group and the second magnetic field group to work alternately according to a preset timing sequence using time-division multiplexing. Specifically, the first magnetic field group is started first, and the second magnetic field group is turned off. After the first magnetic field group has worked for a preset time, it is turned off again, and the second magnetic field group is started. After the second magnetic field group has worked for a preset time, it is turned off again, and the first magnetic field group is started again, and this process is repeated cyclically to avoid mutual interference between the two magnetic field signals. For example, Figure 6 This is a schematic diagram illustrating the alternating operation of a magnetic field group provided in this embodiment. For example... Figure 6 As shown, the first magnetic field group and the second magnetic field group are activated alternately, and the activation time is the same.

[0036] Simultaneously, during the activation of each magnetic field group, the control unit drives the first or second magnetic field group to output a preset magnetic generation signal with decreasing or increasing intensity. The magnetic field strength is pre-calibrated, and the magnetic field strength corresponds one-to-one with the spatial position of the magnetic field group. At this time, the magnetic field receiving unit collects the magnetic field signal, generates a first receiving signal containing real-time magnetic field strength information, and sends it to the control unit. For example, Figure 7 This is a schematic diagram illustrating the decreasing magnetic field strength of a first magnetic field group and a second magnetic field group, as provided in an embodiment of this application. Figure 7 As shown, the positions where the first and second magnetic field modules in the first magnetic field group emit magnetic signals correspond to the magnetic field strength of the emitted magnetic field. Similarly, the positions where the third and fourth magnetic field modules in the second magnetic field group emit magnetic signals correspond to the magnetic field strength of the emitted magnetic field. Furthermore, the magnetic field strength follows the direction shown in the figure. Figure 7The arrows shown indicate a decreasing direction. For example, the first and second magnetic field modules in the first magnetic field group emit a magnetic field of intensity 100 at position A, and a magnetic field of intensity 90 at position B, decreasing in that gradient. At this time, the second magnetic field group is turned off. After a preset time, the third and fourth magnetic field modules in the second magnetic field group emit a magnetic field of intensity 100 at position a, and a magnetic field of intensity 90 at position b. At this time, the first magnetic field group is turned off, and this process is repeated sequentially. In this embodiment, the decreasing direction of the magnetic fields in the first and second magnetic field groups can be set according to actual needs; this embodiment does not impose any restrictions on this.

[0037] Optionally, the control unit, based on the timing of the alternating signals generated by the first magnetic field group and the second magnetic field group, and according to a preset mapping relationship between magnetic field strength and spatial position, matches the magnetic field strength of the first received signal with the magnetic signal strength of the first magnetic field group to obtain the position plane where the scanning probe is located. Then, it matches the magnetic field strength of the second received signal with the magnetic signal strength of the second magnetic field group to obtain another position plane where the scanning probe is located. The intersection of the position plane where the scanning probe is located and the preset horizontal plane is used as the coordinate position of the scanning probe.

[0038] S502. Simultaneously acquire angiography images and intravascular images. Based on the angiography images and probe position, determine the vascular direction corresponding to the probe position, and acquire the original vascular area based on the intravascular images.

[0039] Optionally, the control unit sends imaging commands to the angiography unit, injects contrast agent into the blood vessels of the subject, acquires vascular images via an X-ray emitter and X-ray receiver, and removes bone and soft tissue background through digital subtraction processing to generate a clear angiographic image. The angiography unit then sends the angiographic image to the control unit.

[0040] Optionally, the doctor manipulates a catheter to insert a scanning probe into the blood vessel to be tested. The control unit sends a scanning command to the scanning probe, which emits near-infrared light to acquire a vascular tomographic image. A built-in algorithm calculates the cross-sectional area of ​​the blood vessel perpendicular to the probe's axis, i.e., the original blood vessel area, and sends this data to the control unit in real time. Specifically, since the angiographic image contains the complete outline and macroscopic direction of the blood vessel, and the probe position is the specific coordinate of the scanning probe in three-dimensional space, projecting the probe position onto the angiographic image allows for precise matching of the specific blood vessel segment where the probe is located. The blood vessel centerline is the central axis of the blood vessel, and its tangent direction represents the actual direction of the blood vessel at that location. By extracting the tangent direction of the blood vessel segment's centerline, the direction of the blood vessel where the scanning probe is located can be determined—that is, the tangent direction of the centerline at the probe's location on the blood vessel's centerline.

[0041] It is worth noting that the execution order of the steps of controlling the first magnetic field group and the second magnetic field group to generate magnetic signals to determine the probe position and the steps of acquiring angiographic images and intravascular images is not limited in this embodiment.

[0042] S503. Determine the spatial orientation vector of the scanning probe based on the first received signal, the second received signal, the first reference magnetic field vector corresponding to the first pre-established magnetic field group, the second reference magnetic field vector corresponding to the second pre-established magnetic field group, and the pre-set orientation vector of the probe relative to the magnetic field receiving component.

[0043] The first and second reference magnetic field vectors are the magnetic field vectors of the first and second magnetic field groups in the world coordinate system, respectively, and are obtained by calibrating the fixed installation position and magnetic field direction of each magnetic field group. The direction vector of the probe relative to the magnetic field receiving component is the vector of the scanning probe's own axis in the local coordinate system, calibrated by the rigid fixed relationship between the scanning probe and the magnetic field receiving component. This direction vector remains unchanged and represents the fixed orientation of the probe itself.

[0044] Specifically, the first reference magnetic field vector and the second reference magnetic field vector are fixed and pre-calibrated. A world coordinate system based on the imaging component can be constructed using the first reference magnetic field vector and the second reference magnetic field vector.

[0045] The first and second received signals are signals received by the magnetic field receiving component. Since the magnetic field receiving component is very close to the scanning probe, its error can be ignored. Therefore, the local coordinate system constructed based on the first and second received signals received by the magnetic field receiving component is a local coordinate system constructed with the scanning probe itself as the reference.

[0046] The relative relationship between the world coordinate system and the local coordinate system can be represented by a rotation matrix. Based on the pre-set direction vector of the probe relative to the magnetic field receiving component and the rotation matrix, the orientation of the scanning probe in the blood vessel in the world coordinate system can be obtained.

[0047] S504. Based on the direction of the blood vessel and the spatial direction vector of the scanning probe, the original blood vessel area is corrected to obtain the corrected blood vessel area of ​​the blood vessel region to be tested.

[0048] Since the original blood vessel area is measured by the probe along its perpendicular direction, when the probe is tilted, the probe direction is not parallel to the blood vessel direction. Therefore, the measured blood vessel area will be larger than the actual blood vessel area, which is equivalent to measuring a slanted section of the blood vessel instead of a normal section. Thus, the original blood vessel area is corrected based on the blood vessel direction and the spatial direction vector of the scanning probe to obtain the true area of ​​the normal blood vessel section, i.e., the corrected blood vessel area.

[0049] Figure 8 This is a schematic diagram of a blood vessel area provided in an embodiment of this application, such as... Figure 8 As shown, based on the direction of the blood vessel and the spatial direction vector of the scanning probe, the original blood vessel area can be corrected to obtain the corrected blood vessel area.

[0050] In this embodiment, after the subject lies flat on the lifting platform, the control unit acquires the angiographic image and the original blood vessel area. It then uses the first and second magnetic field groups to alternately generate magnetic signals, thereby accurately positioning the scanning probe based on the correspondence between magnetic field strength and spatial position. The blood vessel direction is determined based on the angiographic image and the position of the scanning probe. The spatial direction vector of the scanning probe is determined based on the first received signal, the second received signal, the first reference magnetic field vector, the second reference magnetic field vector, and the probe's direction vector relative to the magnetic field receiving component. Finally, the original blood vessel area is corrected based on the blood vessel direction and the probe direction to obtain the corrected blood vessel area. This device can eliminate measurement deviations caused by probe tilt and improve the accuracy of blood vessel lumen area measurement.

[0051] Optionally, the magnetic generation signal includes a first generation signal corresponding to the first magnetic field group and a second generation signal corresponding to the second magnetic field group.

[0052] The first generating signal corresponds to the magnetic field signal output by the control component when the first magnetic field group is working. The second generating signal corresponds to the magnetic field signal output by the control component when the second magnetic field group is working.

[0053] Figure 9 This is a schematic flowchart illustrating how a control component determines the probe position of a scanning probe, as provided in an embodiment of this application. Figure 9 As shown, the specific process of determining the probe position of the scanning probe based on the magnetic generation signal and the magnetic reception signal in step S502 of the control unit will be described next.

[0054] S901. If the difference between the first gradient intensity of the first received signal and the first generated signal is less than a preset difference threshold, then the first current cross-section corresponding to the first generated signal is taken as the first face where the scanning probe is located, and the first current cross-section is the cross-section where the first magnetic field group generates the first generated signal.

[0055] Optionally, since the magnetic field has a gradient distribution in space, the difference between the received magnetic field strength and the signal strength transmitted by the magnetic field group at any point within the same magnetic field cross-section is basically the same and less than a preset difference threshold. Therefore, by determining whether the intensity difference between the first received signal and the first generated signal is less than the preset difference threshold, it is determined whether the probe is located on the first current cross-section where the first generated signal is emitted by the first magnetic field group. If so, the first current cross-section is taken as the first spatial reference plane of the positioning scanning probe, i.e., the first plane.

[0056] Specifically, the control unit receives the first received signal sent by the magnetic field receiving unit, extracts the magnetic field strength of the first received signal, calculates the difference between the magnetic field strength of the first received signal and the magnetic field strength of the first generated signal to obtain the first gradient intensity difference, compares the first gradient intensity difference with a preset difference threshold, and if the first gradient intensity difference is less than the preset difference threshold, it indicates that the scanning probe is within the first current cross-section of the first generated signal output by the first magnetic field group, and the control unit determines this plane as the first surface where the scanning probe is located.

[0057] If the first gradient intensity difference is not less than the preset difference threshold, the control unit continues to calculate the first generation signal of the next face and recalculates the intensity difference until the condition is met to determine the first face.

[0058] S902. If the difference between the second gradient intensity of the second received signal and the second generated signal is less than a preset difference threshold, then the second current cross-section corresponding to the second generated signal is taken as the second surface where the scanning probe is located, and the second current cross-section is the cross-section where the second magnetic field group generates the second generated signal.

[0059] The principle for determining the second face is the same as that for determining the first face, and will not be repeated here.

[0060] S903. The intersection of the first surface, the second surface, and the preset horizontal plane is taken as the probe position of the scanning probe.

[0061] The preset horizontal plane is a spatial plane pre-set by the control components, which is parallel to the plane where the lifting platform is located.

[0062] Specifically, the first and second planes, as two magnetic field tangents, intersect to form a straight line. Points on this line satisfy the condition of the difference in strength between the two magnetic fields. Combined with a preset horizontal plane, the three planes intersect to obtain a unique intersection point, which is the three-dimensional spatial coordinate of the scanning probe.

[0063] In this embodiment, by comparing the magnetic generation signal and the received signal, the first and second surfaces where the scanning probe is located are determined. Then, the position of the scanning probe is determined by combining the preset horizontal plane, thereby improving the accuracy and efficiency of probe position positioning.

[0064] Next, the specific implementation method of determining the blood vessel direction corresponding to the scanning probe based on the angiographic image and the probe position in step S503 of the above-mentioned control component will be introduced.

[0065] Optionally, the probe position can be projected onto the angiographic image to determine the blood vessel where the scanning probe is located.

[0066] Specifically, the control unit converts the three-dimensional coordinates of the probe position into two-dimensional coordinates corresponding to the angiography image, thus projecting the probe position onto the angiography image. Contour recognition is performed on the angiography image to extract the contour information of all blood vessels in the image. The positional relationship between the probe position projection point and the contours of each blood vessel is compared, and the blood vessel whose projection point falls within the contour range or is the closest is identified as the blood vessel where the scanning probe is located.

[0067] Optionally, the tangent direction at the center line of the blood vessel corresponding to the probe position can be taken as the direction of the blood vessel.

[0068] Specifically, the control component fits a smooth and continuous centerline along the middle of the blood vessel's contour, extracts the tangent direction of the centerline corresponding to the probe position, and this direction is the true direction of the blood vessel at the location of the scanning probe. The direction of this centerline is converted into a vector form in the world coordinate system, which is the direction of the blood vessel.

[0069] In this embodiment, the probe position is projected onto the angiographic image to locate the blood vessel where the probe is located, and the direction of the blood vessel's centerline is used as the blood vessel direction, thereby improving the accuracy and efficiency of blood vessel direction determination.

[0070] Figure 10 This is a schematic flowchart illustrating how a control component determines the spatial orientation vector of a scanning probe, as provided in an embodiment of this application. Next, refer to... Figure 10 The step of determining the spatial orientation vector of the scanning probe based on the first received signal, the second received signal, the first reference magnetic field vector corresponding to the first magnetic field group, the second reference magnetic field vector corresponding to the second magnetic field group, and the pre-set direction vector of the probe relative to the magnetic field receiving component in step S504 of the above-mentioned control component will be described.

[0071] Figure 11 This is a schematic diagram of a world coordinate system and a local coordinate system provided in an embodiment of this application. For example... Figure 11 As shown, taking the first magnetic field group as an example, the magnetic field generated by the first magnetic field group corresponds to the first reference magnetic field vector. This vector is a vector in the world coordinate system (x, y, z), and the spatial direction vector of the scanning probe corresponds to the direction vector of the probe relative to the magnetic field receiving component, which is a vector in the local coordinate system (x', y', z').

[0072] S1001. Determine the world orthogonal axis vector in the world coordinate system based on the first reference magnetic field vector and the second reference magnetic field vector.

[0073] Specifically, the control unit can normalize the first reference magnetic field vector to obtain the first world vector. Then, using the Schmitt orthogonalization algorithm, the first and second reference magnetic field vectors are processed to obtain the second world vector, which is perpendicular to the first world vector. Finally, the vector product of the first and second world vectors is calculated to obtain the third world vector, which is perpendicular to both of the first two vectors. The first, second, and third world vectors together form the world orthogonal axis vectors in the world coordinate system, which provide a spatial reference for coordinate system transformation.

[0074] S1002. Determine the local orthogonal axis vector in the local coordinate system based on the first received magnetic field vector in the first received signal and the second received magnetic field vector in the second received signal.

[0075] Specifically, the control unit can extract a first received magnetic field vector from a first received signal and a second received magnetic field vector from a second received signal. As an optional implementation, the first and second received signals can be filtered during the extraction process before extracting the magnetic field vectors to ensure accurate vector data.

[0076] Optionally, the first received magnetic field vector is normalized to obtain a first local vector. Then, the Schmitt orthogonalization algorithm is used to process the first and second received magnetic field vectors to obtain a second local vector perpendicular to the first local vector. Finally, the vector product of the first and second local vectors is calculated to obtain a third local vector perpendicular to both of the first two vectors. The first, second, and third local vectors together form the local orthogonal axis vectors in the local coordinate system.

[0077] S1003. Determine the rotation matrix based on the world orthogonal axis vector and the local orthogonal axis vector.

[0078] Specifically, the dot product of the first world vector in the world orthogonal axis vectors and the first local vector in the local orthogonal axis vectors is calculated and used as the element of the first row and first column of the rotation matrix. The dot products of each axis of the world orthogonal axis vectors and each axis of the local orthogonal axis vectors are calculated in turn, and all elements of the 3×3 matrix are filled to obtain the rotation matrix.

[0079] As an optional implementation, the obtained rotation matrix is ​​orthogonalized to avoid calculation errors.

[0080] S1004. Determine the spatial orientation vector of the scanning probe based on the orientation vector of the probe relative to the magnetic field receiving component and the rotation matrix.

[0081] Specifically, the direction vector of the probe relative to the magnetic field receiving component is multiplied by the rotation matrix to convert the vector in the local coordinate system into a vector in the world coordinate system, thus obtaining the spatial direction vector of the scanning probe.

[0082] As an alternative implementation, the spatial orientation vector of the scanning probe can be normalized to ensure that the vector represents only the orientation.

[0083] In this embodiment, by determining the world orthogonal axis vector, the local orthogonal axis vector, and the rotation matrix, the spatial direction vector of the scanning probe is finally determined, thereby realizing the coordinate system transformation of the direction vector of the probe relative to the magnetic field receiving component. The calculation process is simple and improves the accuracy of probe direction determination.

[0084] Figure 12 This is a schematic diagram illustrating the process of a control component determining the magnitude of the world orthogonal axis, as provided in an embodiment of this application. Figure 12 As shown, the following describes the specific implementation steps of the control unit in performing step S1001 above to determine the world orthogonal axis vector in the world coordinate system based on the first reference magnetic field vector and the second reference magnetic field vector.

[0085] S1201. Normalize the first reference magnetic field vector to obtain the first world vector.

[0086] For example, the process of obtaining the first world vector is as follows: (1) (1) in, , as well as These are the x-axis, y-axis, and z-axis components of the first world vector, respectively. , as well as These are the x-axis, y-axis, and z-axis components of the first reference magnetic field vector, respectively. It is the square of the magnitude of the first reference magnetic field vector. .

[0087] S1202. Perform Schmitt orthogonalization on the first reference magnetic field vector and the second reference magnetic field vector to obtain the second world vector that is perpendicular to the first world vector.

[0088] For example, the process of obtaining the second world vector is as follows: (2) (2) in, , as well as These are the x-axis, y-axis, and z-axis components of the second world vector, respectively. , and In the world coordinate system, the intermediate vector obtained after orthogonalization of the second reference magnetic field vector is the x-axis component, y-axis component, and z-axis component. The method for determining this intermediate vector is shown in the following formula (3): (3) in, , as well as These are the x-axis, y-axis, and z-axis components of the second reference magnetic field vector, respectively. It is the dot product of the first reference magnetic field vector and the second reference magnetic field vector in the world coordinate system. .

[0089] It is the square of the magnitude of the second reference magnetic field vector after orthogonalization of the world coordinate system. , It is the square of the magnitude of the second receiving magnetic field vector after the local coordinate system is orthogonalized. , It is the square of the magnitude of the second reference magnetic field vector.

[0090] S1203. Perform a vector product operation on the first world vector and the second world vector to obtain the third world vector.

[0091] For example, the process of obtaining the third-world vector is as follows: (4) (4) in, , as well as These are the x-axis, y-axis, and z-axis components of the third world vector, respectively.

[0092] S1204. Take the first world vector, the second world vector, and the third world vector as world orthogonal axis vectors.

[0093] Optionally, the first world vector, the second world vector, and the third world vector can be used as world orthogonal axis vectors to construct a complete and accurate world coordinate system reference.

[0094] In this embodiment, a complete and accurate world orthogonal axis vector is constructed to provide a spatial reference for probe orientation calculation.

[0095] Figure 13 This is a schematic flowchart illustrating a control component determining a local orthogonal axial quantity according to an embodiment of this application. Figure 13As shown, the following describes the specific implementation method of the control unit determining the local orthogonal axis vector in the local coordinate system based on the first received magnetic field vector in the first received signal and the second received magnetic field vector in the second received signal in step S1002: S1301. Normalize the first received magnetic field vector to obtain the first local vector.

[0096] For example, the process of obtaining the first local vector is as follows: (5) (5) in, , as well as These are the x-axis component, y-axis component, and z-axis component of the first local vector, respectively. , as well as These are the x-axis, y-axis, and z-axis components of the first received magnetic field vector, respectively. It is the square of the magnitude of the first received magnetic field vector. .

[0097] S1302. Perform Schmitt orthogonalization on the first and second received magnetic field vectors to obtain a second local vector that is perpendicular to the first local vector.

[0098] For example, the process of obtaining the second local vector is as follows: (6) (6) in, , as well as These are the x-axis component, y-axis component, and z-axis component of the second local vector, respectively. , and In the local coordinate system, the intermediate vector obtained after orthogonalization of the second receiving magnetic field vector is the x-axis component, y-axis component, and z-axis component. The method for determining this intermediate vector is shown in the following formula (7): (7) in, , as well as These are the x-axis, y-axis, and z-axis components of the second receiving magnetic field vector, respectively. It is the dot product of the first and second receiving magnetic field vectors in the local coordinate system. .

[0099] It is the square of the magnitude of the second receiving magnetic field vector after local coordinate system orthogonalization. , It is the square of the magnitude of the second reference magnetic field vector after the world coordinate system is orthogonalized. .

[0100] S1303. Perform a vector product operation on the first local vector and the second local vector to obtain the third local vector.

[0101] For example, the process of obtaining the third local vector is as follows: (8) (8) in, , as well as These are the x-axis component, y-axis component, and z-axis component of the third local vector, respectively.

[0102] S1304. Use the first local vector, the second local vector, and the third local vector as local orthogonal axis vectors.

[0103] Optionally, the first local vector, the second local vector, and the third local vector can be used as local orthogonal axis vectors to construct a complete and accurate local coordinate system reference.

[0104] In this embodiment, a complete and accurate local orthogonal axis vector is constructed to provide a spatial reference for probe orientation calculation.

[0105] Next, we will introduce the process of determining the rotation matrix based on the world orthogonal axis vector and the local orthogonal axis vector in step S1003 above.

[0106] Specifically, the dot product of the world orthogonal axis vector and the local orthogonal axis vector is used as the rotation matrix.

[0107] For example, the rotation matrix is ​​as shown in equations (9) and (10) below: (9) (10) in, , , , , , , , as well as These represent the projections of the x-axis, y-axis, and z-axis in the local coordinate system onto the x-axis, y-axis, and z-axis in the world coordinate system, respectively.

[0108] Furthermore, in step S1204 above, the specific method for determining the spatial direction vector of the scanning probe based on the direction vector of the probe relative to the magnetic field receiving component and the rotation matrix is ​​as follows: the dot product of the rotation matrix and the direction vector of the probe relative to the magnetic field receiving component is taken as the spatial direction vector of the scanning probe.

[0109] For example, the spatial orientation vector of the scanning probe can be obtained by the following formula (11): (11) Wherein, the spatial direction vector of the scanning probe is ( The direction vector of the probe relative to the magnetic field receiving component is ( ).

[0110] Next, we will introduce the step in step S505 where the control unit corrects the original blood vessel area based on the blood vessel direction and the spatial direction vector of the scanning probe to obtain the corrected blood vessel area of ​​the blood vessel region to be tested.

[0111] Optionally, the absolute value of the dot product of the blood vessel direction and the spatial direction vector of the scanning probe can be used as a correction coefficient.

[0112] Optionally, if the spatial direction vector of the scanning probe is parallel to the direction of the blood vessel, the correction coefficient is 1, and the original blood vessel area measured by the scanning probe is the true area of ​​the blood vessel.

[0113] Optionally, the product of the original blood vessel area and the correction coefficient can be used as the corrected blood vessel area of ​​the blood vessel region to be tested.

[0114] For example, the method for determining the corrected blood vessel area is as follows: (12) (12) in, This is the corrected blood vessel area. It is the original blood vessel area. It is the spatial orientation vector of the scanning probe. It's in the direction of the blood vessels.

[0115] In this embodiment, the original blood vessel area is corrected by a correction coefficient, thereby eliminating the measurement deviation caused by probe tilt.

[0116] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A device for measuring the area of ​​a blood vessel lumen, characterized in that, The device includes a control unit, an imaging unit, a magnetic field generating unit, a scanning probe, a magnetic field receiving unit, and a lifting platform. The magnetic field generating unit includes a first magnetic field group and a second magnetic field group. The first magnetic field group includes a first magnetic field module and a second magnetic field module arranged in parallel. The second magnetic field group includes a third magnetic field module and a fourth magnetic field module arranged in parallel. The first magnetic field module and the third magnetic field module are located on the first side of the lifting platform, and the second magnetic field module and the fourth magnetic field module are located on the second side of the lifting platform. The scanning probe is rigidly fixedly connected to the magnetic field receiving unit. The control component is used to control the first magnetic field group and the second magnetic field group to alternately generate magnetic generation signals in the form of a preset gradient, and to receive magnetic receiving signals from the magnetic field receiving component. Based on the magnetic generation signals and the magnetic receiving signals, the probe position of the scanning probe is determined. The magnetic receiving signals include a first receiving signal corresponding to the first magnetic field group and a second receiving signal corresponding to the second magnetic field group. The control unit is used to simultaneously acquire angiography images and intravascular images, determine the vascular direction corresponding to the probe position based on the angiography images and the probe position, and obtain the original vascular area based on the intravascular images. The control component is used to determine the spatial orientation vector of the scanning probe based on the first received signal, the second received signal, the first reference magnetic field vector corresponding to the first magnetic field group, the second reference magnetic field vector corresponding to the second magnetic field group, and the orientation vector of the probe relative to the magnetic field receiving component. The control component is used to correct the original blood vessel area based on the blood vessel direction and the spatial direction vector of the scanning probe, so as to obtain the corrected blood vessel area of ​​the blood vessel region to be tested.

2. The vascular lumen area measuring device according to claim 1, characterized in that, The magnetic generation signal includes a first generation signal corresponding to the first magnetic field group and a second generation signal corresponding to the second magnetic field group; The process of determining the probe position of the scanning probe based on the magnetic generation signal and the magnetic reception signal includes: If the difference between the first gradient intensity of the first received signal and the first generated signal is less than a preset difference threshold, then the first current cross-section corresponding to the first generated signal is taken as the first face where the scanning probe is located, and the first current cross-section is the cross-section where the first magnetic field group generates the first generated signal; If the difference between the second gradient intensity of the second received signal and the second generated signal is less than the preset difference threshold, then the second current cross-section corresponding to the second generated signal is taken as the second face where the scanning probe is located, and the second current cross-section is the cross-section where the second magnetic field group generates the second generated signal; The intersection of the first surface, the second surface, and the preset horizontal plane is taken as the probe position of the scanning probe.

3. The vascular lumen area measuring device according to claim 1, characterized in that, The process of determining the blood vessel direction corresponding to the probe position based on the angiography image and the probe position includes: The probe position is projected into the angiographic image to determine the blood vessel where the scanning probe is located; The tangent direction at the center line of the blood vessel corresponding to the probe position is taken as the direction of the blood vessel.

4. The vascular lumen area measuring device according to claim 1, characterized in that, The process of determining the spatial orientation vector of the scanning probe based on the first received signal, the second received signal, the first reference magnetic field vector corresponding to the pre-established first magnetic field group, the second reference magnetic field vector corresponding to the pre-established second magnetic field group, and the pre-set orientation vector of the probe relative to the magnetic field receiving component includes: Based on the first reference magnetic field vector and the second reference magnetic field vector, determine the world orthogonal axis vector in the world coordinate system; Based on the first received magnetic field vector in the first received signal and the second received magnetic field vector in the second received signal, determine the local orthogonal axis vector in the local coordinate system; The rotation matrix is ​​determined based on the world orthogonal axis vector and the local orthogonal axis vector; The spatial orientation vector of the scanning probe is determined based on the orientation vector of the probe relative to the magnetic field receiving component and the rotation matrix.

5. The vascular lumen area measuring device according to claim 4, characterized in that, The process of determining the world orthogonal axis vector in the world coordinate system based on the first reference magnetic field vector and the second reference magnetic field vector includes: The first reference magnetic field vector is normalized to obtain the first world vector; The first reference magnetic field vector and the second reference magnetic field vector are subjected to Schmitt orthogonalization to obtain a second world vector that is perpendicular to the first world vector. Perform a vector product operation on the first world vector and the second world vector to obtain the third world vector; The first world vector, the second world vector, and the third world vector are used as the world orthogonal axis vectors.

6. The vascular lumen area measuring device according to claim 4, characterized in that, The process of determining the local orthogonal axis vector in the local coordinate system based on the first received magnetic field vector in the first received signal and the second received magnetic field vector in the second received signal includes: The first received magnetic field vector is normalized to obtain the first local vector; The first received magnetic field vector and the second received magnetic field vector are subjected to Schmitt orthogonalization to obtain a second local vector that is perpendicular to the first local vector. Perform a vector product operation on the first local vector and the second local vector to obtain the third local vector; The first local vector, the second local vector, and the third local vector are used as the local orthogonal axis vectors.

7. The vascular lumen area measuring device according to claim 4, characterized in that, The process of determining the rotation matrix based on the world orthogonal axis vector and the local orthogonal axis vector includes: The rotation matrix is ​​the dot product of the world orthogonal axis vector and the local orthogonal axis vector.

8. The vascular lumen area measuring device according to claim 4, characterized in that, The process of determining the spatial orientation vector of the scanning probe based on the orientation vector of the probe relative to the magnetic field receiving component and the rotation matrix includes: The dot product of the rotation matrix and the direction vector of the probe relative to the magnetic field receiving component is used as the spatial direction vector of the scanning probe.

9. The vascular lumen area measuring device according to claim 1, characterized in that, The process of correcting the original blood vessel area based on the blood vessel direction and the spatial direction vector of the scanning probe to obtain the corrected blood vessel area of ​​the region to be tested includes: The absolute value of the dot product of the blood vessel direction and the spatial direction vector of the scanning probe is used as the correction coefficient. The product of the original blood vessel area and the correction coefficient is used as the corrected blood vessel area of ​​the blood vessel region to be tested.

10. The vascular lumen area measuring device according to claim 1, characterized in that, The first magnetic field module and the third magnetic field module are arranged close together at a preset angle, and the second magnetic field module and the fourth magnetic field module are arranged close together at the preset angle.

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