Vascular pressure calibration device and method

Abstract

A vascular pressure calibration method according to one embodiment may comprise the steps of: acquiring a blood vessel image including a relative positional difference with respect to the gravitational direction between a predetermined reference point of a target blood vessel of a patient and another point included in the target blood vessel; converting the relative positional difference with respect to the gravitational direction into a height difference by using a calibration factor of the acquired blood vessel image; and acquiring a calibrated pressure value for the other point by calibrating a pressure value measured in advance for the other point using a hydrostatic pressure corresponding to the height difference.

Description

Vascular pressure compensation device and method

[0001] Below, a technique for compensating for intravascular pressure differences is provided.

[0002] Angiography is a diagnostic procedure that uses X-rays to visualize blood vessels and their conditions, making it a useful tool for examining vascular diseases. For example, in coronary angiography, the presence of coronary artery stenosis is determined through visual assessment by a medical professional. However, if treatment is based on this visual assessment, surgical procedures such as percutaneous coronary intervention may be performed on coronary arteries that are stenotic but functionally normal. Therefore, fractional flow reserve (FFR) testing is performed to more accurately diagnose coronary artery stenosis. However, to improve the accuracy of FFR test results, it is necessary to accurately calculate the pressure difference before and after the lesion.

[0003] To improve the accuracy of fractional flow reserve (FFR) testing, it is necessary to more accurately measure the pressure difference between the pre- and post-lesion reference points. Specifically, in addition to pressure loss due to narrowing of the vessel lumen near the lesion, the pressure difference between the pre- and post-lesion reference points, depending on the vertical position, can be considered to improve FFR measurement accuracy.

[0004] However, technical challenges are not limited to the technical challenges described above, and other technical challenges may exist.

[0005] A method for correcting blood vessel pressure performed by a processor according to one embodiment may include the steps of: obtaining a blood vessel image including a relative position difference with respect to the direction of gravity between a predetermined reference point of a target blood vessel of a patient and another point included in the target blood vessel; converting the relative position difference with respect to the direction of gravity into a height difference using a calibration factor of the obtained blood vessel image; and obtaining a corrected pressure value with respect to the another point by correcting a hydrostatic pressure corresponding to the height difference to a pressure value measured in advance with respect to the another point.

[0006] The step of acquiring the blood vessel image may include a step of acquiring the blood vessel image by photographing the target blood vessel at an angle less than a predetermined critical angle with respect to the coronal plane of the patient.

[0007] The above vascular images can be obtained from C-arm.

[0008] The step of acquiring the blood vessel image may include: determining the predetermined reference point as a point where a catheter is inserted into the target blood vessel; and acquiring a blood vessel image including a relative positional difference in the direction of gravity between the point and a point other than the point.

[0009] The step of converting the relative position difference with respect to the gravity direction into a height difference may include the step of calculating the relative position difference with respect to the gravity direction based on the shooting angle information and the calibration factor based on the coronal plane of the patient for the acquired blood vessel image; and the step of converting the calculated relative position difference into a height difference on the blood vessel image acquired at the target shooting angle by transforming the shooting angle information into target shooting angle information with respect to the coronal plane of the patient.

[0010] The step of obtaining a corrected pressure value for the other point may include a step of calculating a hydrostatic pressure at the other point based on the converted height difference, gravitational acceleration, and blood density at the other point.

[0011] A blood vessel pressure compensation device according to one embodiment may include an image acquisition unit that acquires a blood vessel image including a relative positional difference with respect to the direction of gravity between a predetermined reference point of a target blood vessel of a patient and another point included in the target blood vessel; and a processor that converts the relative positional difference with respect to the direction of gravity into a height difference using a calibration factor of the acquired blood vessel image, and compensates a hydrostatic pressure corresponding to the height difference to a pressure value measured in advance for the other point, thereby acquiring a corrected pressure value for the other point.

[0012] The processor can adjust the position of the image acquisition unit so that the image acquisition unit acquires the blood vessel image by photographing the target blood vessel at an angle less than a predetermined critical angle with respect to the coronal plane of the patient.

[0013] The above image acquisition unit may include a C-arm.

[0014] The processor may determine the predetermined reference point as a point where a catheter is inserted into the target blood vessel, and adjust the position of the image acquisition unit so that the image acquisition unit acquires a blood vessel image including a relative positional difference in the direction of gravity between the point and a point other than the point.

[0015] The processor calculates a relative position difference with respect to the gravity direction based on the shooting angle information and the calibration factor based on the coronal plane of the patient for the acquired blood vessel image, and converts the shooting angle information into target shooting angle information for the coronal plane of the patient, thereby converting the calculated relative position difference into a height difference on the blood vessel image acquired at the target shooting angle.

[0016] The processor can calculate hydrostatic pressure at the other point based on the converted height difference, gravitational acceleration, and blood density at the other point, and obtain a corrected pressure value for the other point based on the calculated hydrostatic pressure.

[0017] FIG. 1 is a drawing illustrating the structure of a medical electronic device according to one embodiment.

[0018] FIG. 2 is a drawing illustrating a change in the projection angle of radiation according to the rotation of a C-arm included in an electronic device according to one embodiment.

[0019] FIG. 3 is a diagram illustrating a process by which an electronic device according to one embodiment calculates a straight-line distance from a radiation source to a target blood vessel.

[0020] FIG. 4 is a flowchart illustrating a method for compensating blood vessel pressure considering a height difference of blood vessels according to one embodiment.

[0021] Figures 5a to 5c are graphs showing the height difference between a blood vessel point and the entrance of the blood vessel.

[0022] Figure 6 is a diagram of an electronic device that calculates an approximate value of hydrostatic pressure based on a blood vessel image taken at a certain angle relative to the patient's coronal plane.

[0023] Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be modified and implemented in various forms. Therefore, the actual implementation is not limited to the specific embodiments disclosed, and the scope of this specification includes modifications, equivalents, or alternatives within the technical concepts described in the embodiments.

[0024] Although terms such as "first" or "second" may be used to describe various components, these terms should be interpreted solely to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

[0025] When it is said that a component is "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but there may also be other components in between.

[0026] Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "has" should be understood to indicate the presence of a described feature, number, step, operation, component, part, or combination thereof, but not to exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0027] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art. Terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0028] Hereinafter, embodiments will be described in detail with reference to the attached drawings. In the description with reference to the attached drawings, identical components are assigned the same reference numerals regardless of the drawing numbers, and redundant descriptions thereof will be omitted.

[0029] FIG. 1 is a drawing illustrating the structure of a medical electronic device according to one embodiment.

[0030] According to one embodiment, a medical electronic device (100) (hereinafter, “electronic device”) can compensate for pressure by considering a height difference at a target from a medical image. A medical image in which blood vessels of a subject are captured may also be referred to as a blood vessel image. The electronic device (100) can compensate for pressure by considering a height difference at each point of a blood vessel, and may also be referred to as a blood pressure compensation device for a blood vessel. The blood pressure value compensated by the electronic device (100) can be used to calculate an index related to blood flow (e.g., quantitative flow ratio (QFR), fractional flow reserve (FFR)). For example, the electronic device (100) can obtain relative heights at each point of a blood vessel from the blood vessel image. The electronic device (100) can compensate for pressure at each point of a blood vessel based on the obtained relative height information at each point of a blood vessel. The electronic device (100) may include a device that calculates a more accurate fractional blood flow reserve based on the pressure at each point of a blood vessel compensated according to the relative height information.

[0031] The electronic device (100) may include an image acquisition unit and a processor (110). In this specification, the image acquisition unit is mainly described as an imaging device, but is not limited thereto. The image acquisition unit may also be a device that receives medical images (e.g., blood vessel images) from an external imaging device based on wired and / or wireless communication.

[0032] The image acquisition unit may include a device that takes a blood vessel image by irradiating radiation to the blood vessels of the subject. The blood vessels may include, for example, the left main coronary artery (LM), the left anterior descending artery (LAD), the left circumflex artery (LCX), and the right cornary artery (RCA). The image acquisition unit may take a picture of the blood vessels using cornoary angiography. For example, the image acquisition unit may include a body (11), a C-arm (12), a radiation irradiation unit (13), and a radiation detection unit (14). An imaging device having a C-arm (12) may also be referred to as a C-arm imaging device.

[0033] The C-arm (12) may have a curved C-shaped arc shape with one side open. For example, when the C-arm (12) is vertically erected based on the floor on which the electronic device (100) is placed, the C-arm (12) may have a shape that is symmetrical based on a plane that is parallel to the floor and includes an isocenter (111). The isocenter (111) is a portion or point that serves as the center of a flux of radiation emitted from various positions despite the rotation of the C-arm, and may be defined as a point where the first rotation axis and the second rotation axis of the C-arm intersect. The isocenter (111) may indicate the center of the rotational orbit of the radiation irradiation unit (13) (or radiation source (not shown)) generated according to the rotation of the C-arm (12). The C-arm (12) may have a shape that is open toward the isocenter (111).

[0034] The body part (11) can be connected to the C-arm (12). The body part (11) can be mechanically coupled to the C-arm (12). The C-arm (12) can rotate with respect to the body part (11). The C-arm (12) can rotate within the YZ plane with respect to the body part (11). For example, a protrusion included in the body part (11) and a moving guide included in the C-arm (12) can be coupled to each other, and the C-arm (12) can rotate within the YZ plane along the moving guide with respect to a rotation axis that is parallel to the X-axis and passes through the isodose center point (111). In addition, the C-arm (12) can also rotate within the XZ plane with respect to the body part (11). For example, in a state where the point where the body part (11) and the C arm (12) contact each other is fixed, the C arm (12) can rotate within the XZ plane based on a rotation axis that is parallel to the Y axis and passes through the isocenter point (111).

[0035] The radiation irradiation unit (13) and the radiation detection unit (14) may be arranged to face each other with the isodose center point (111) interposed therebetween on the inner surface of the C-arm (12). Each of the radiation irradiation unit (13) and the radiation detection unit (14) may be connected to the C-arm (12). The radiation irradiation unit (13) may include one or more radiation sources and may emit radiation toward a subject through one or more radiation sources. The radiation detection unit (14) may include a radiation detection sensor and may detect radiation emitted from the radiation irradiation unit (13) and penetrating a blood vessel of the subject through the radiation detection sensor. Since the radiation irradiation unit (13) and the radiation detection unit (14) are connected through the C-arm (12) and rotate as one unit, when the radiation detection unit (14) moves, the radiation irradiation unit (13) may be positioned on the opposite side of the radiation detection unit (14) based on the isodose center point (111). As will be described later, the electronic device (100) can capture medical images (e.g., blood vessel images) at multiple capture locations while changing the location (e.g., capture location) of the radiation detection unit (14).

[0036] A subject can be laid down on the table (15). More specifically, the table (15) may include a table top (15-1) on which the subject can be laid down, and a table support (15-2) that supports the table top (15-1). The table support (15-2) may be fixed to a floor surface. For example, the table top (15-1) may be movably coupled to the table support (15-2). The electronic device (100) may further include an actuator (not shown) that changes the position of the table top (15-1) relative to the table support (15-2). The electronic device (100) may move the table top (15-1) relative to the table support (15-2) through the actuator (not shown). The actuator (not shown) may include a motor (e.g., an electric motor) and a power transmission structure.

[0037] The table top (15-1) can move left-right and up-down with respect to the table support (15-2). For example, the electronic device (100) can move the table top (15-1) left-right on a plane parallel to the surface of the table (e.g., XY plane). The surface of the table may refer to the upper surface of the table top (15-1). The electronic device (100) can also move the table top (15-1) up-down on an axis perpendicular to the plane parallel to the surface of the table (e.g., XY plane) (e.g., Z axis). In the following description, moving the table (15) may refer to moving the table top (15-1) with respect to the table support (15-2). For example, the electronic device (100) can move the table (15) in order to accurately irradiate radiation to a target blood vessel of a subject.

[0038] The electronic device (100) can control the C-arm (12) to rotate around the subject of the procedure positioned on the table (15). After fixing the C-arm (12), the electronic device (100) can irradiate the target blood vessel of the subject of the procedure on the table (15) with radiation through the radiation source of the radiation irradiation unit (13) connected to the C-arm (12). The radiation irradiated to the blood vessel of the subject of the procedure may be X-ray.

[0039] In one embodiment, a subject (120) may be positioned on a table top (15-1) of an electronic device (100). The electronic device (100) may generate a blood vessel image (130) of a target blood vessel (320) of the subject (120) using radiation emitted from a radiation source (131).

[0040] The processor (110) of the electronic device (100) can derive quantitative analysis results, such as the diameter of the target blood vessel (320) and the length of the lesion, from the generated blood vessel image (130). In order to derive quantitative analysis results related to the target blood vessel (320) from the blood vessel image (130), the processor (110) can convert the distance measured within the blood vessel image (130) into a real-world physical distance, such as μm, mm, or cm. For example, the processor (110) can convert the distance measured within the blood vessel image (130) into a physical distance by utilizing a calibration factor.

[0041] Specifically, the physical distance can be calculated by multiplying the number of pixels corresponding to the distance measured within the vascular image (130) by the correction factor. For example, the physical distance can be expressed as in Mathematical Expression 1 below.

[0042] [Mathematical Formula 1]

[0043]

[0044] Referring to mathematical expression 1, the correction coefficient may represent a physical distance corresponding to the length (e.g., horizontal length or vertical length) of one pixel constituting the vascular image (130). In order to accurately calculate the physical distance, it is necessary to accurately calculate the correction coefficient.

[0045] A correction factor can represent the spatial relationship between an object in a vascular image and an object in the real world. The correction factor can be calculated by multiplying the value obtained by dividing the distance from the radiation source to the target object (source-to-object distance (SOD)) by the distance from the radiation source to the image receiver (source-to-image receptor distance (SID)) by the imager pixel spacing. The imager pixel spacing can represent the length (e.g., horizontal length or vertical length) of one pixel constituting the vascular image. In other words, the correction factor can be expressed as in Mathematical Expression 2 below.

[0046] [Equation 2]

[0047]

[0048] In mathematical expression 2, SOD can represent the straight-line distance from the source (e.g., a radiation source) to the object to be photographed, and SID can represent the straight-line distance from the source to the image receiver. The distance from the source to the image receiver (SID) and the imager pixel interval can be extracted from the metadata of Digital Imaging and Communications in Medicine (DICOM). DICOM can represent a standard specification for storing and transmitting data related to images generated by medical electronic devices.

[0049] In one embodiment, the electronic device (100) can irradiate a target blood vessel (320) of a subject (120) positioned on a table top (15-1) with radiation using a radiation source (131) included in a radiation irradiation unit (13). The electronic device (100) can calculate a target distance from the radiation source (131) to the target blood vessel (320) based on a first vertical distance from the isodose center point (111) to the table (15) and a second vertical distance from the target blood vessel (320) to the table (15). Here, the first vertical distance from the isodose center point (111) to the table (15) may represent a vertical distance from the isodose center point (111) to the upper surface of the table top (15-1). Similarly, the second vertical distance from the target blood vessel (320) to the table (15) may represent a vertical distance from the target blood vessel (320) to the upper surface of the table top (15-1).

[0050] More specifically, the electronic device (100) can adjust the position of the target blood vessel (320) through the table (15) before irradiating the target blood vessel (320) with radiation using the radiation source (131). The electronic device (100) can move the table (15) so that the radiation source (131), the target blood vessel (320), and the isodose center point (111) are arranged in a straight line. In one embodiment, the electronic device (100) can arrange the radiation source (131), the target blood vessel (320), and the isodose center point (111) in a straight line by moving the table top (15-1) only in the left-right direction on the XY plane. In another embodiment, the electronic device (100) may move the table top (15-1) both left-right on the XY plane and up-down on the Z axis so that the radiation source (131), the target blood vessel (320), and the isodose center point (111) are arranged in a straight line.

[0051] In one embodiment, when the position of the radiation source (131) changes according to the rotation of the C arm (12), the table top (15-1) can be moved together so that the radiation source (131), the target blood vessel (320), and the isodose center point (111) are arranged in a straight line.

[0052] In one embodiment, the electronic device (100) can move the table (15) in the left-right direction on a plane including the surface of the table so that the isodose center point (111) is positioned on the same straight line as the radiation source (131) and the target blood vessel (320). The height of the table (15) may be fixed, but is not limited thereto and may be variable. For example, the electronic device (100) can calculate the height from the bottom surface of the target blood vessel (320). The electronic device (100) can calculate the height from the bottom surface of the target blood vessel (320) by adding the height of the target blood vessel (320) from the surface of the table and the height from the bottom surface of the table (15). However, the present invention is not limited thereto, and the electronic device (100) can also obtain the height from the table (15) (e.g., the surface of the table) to the target blood vessel (320). The electronic device (100) can generate a plane that is parallel to the floor (or XY plane) and includes a point corresponding to the target blood vessel (320) based on the position (e.g., height) of the target blood vessel (320). The electronic device (100) can calculate a point ('intersection point') that intersects the plane that is parallel to the floor and includes the target blood vessel (320) and a straight axis connecting the radiation source (131) and the isodose center point (111). The electronic device can move the table top (15-1) left and right on the XY plane so that the target blood vessel (320) is located at the calculated intersection point.

[0053] In one embodiment, the electronic device (100) can calculate a target distance representing a straight-line distance from the radiation source (131) to the target blood vessel (320) using a plurality of parameters after adjusting the position of the target blood vessel (320) by moving the table top (15-1). The plurality of parameters can include, for example, a position of the table (15), a position of the target blood vessel (320), and an irradiation angle of radiation emitted from the radiation source (131) (e.g., a projection angle (231) of radiation in FIG. 2). More specifically, the electronic device (100) can accurately calculate the target distance from the radiation source (131) to the target blood vessel (320) based on a first vertical distance from the isodose center point (111) to the table (15), a second vertical distance from the target blood vessel (320) to the table (15), and an irradiation angle of radiation emitted from the radiation source (131).

[0054] The electronic device (100) can store information related to the time of irradiating the target blood vessel as metadata of DICOM (Digital Imaging and Communications in Medicine). For reference, DICOM can represent a standard specification for storing and transmitting data related to images generated by medical electronic devices. For example, the electronic device (100) can generate an image of the DICOM standard based on information about radiation reaching the radiation detection unit (14) through the target blood vessel of the subject on the table (15) from the radiation source of the radiation irradiation unit (13) connected to the C arm (12). The electronic device (100) can store information as metadata about the distance from the radiation source to the target object (e.g., target blood vessel) at the time the DICOM standard image was generated (source to object distance, SOD), the distance from the radiation source to the radiation detector (14) (e.g., image receiver) (source to image receptor distance, SID), the distance from the radiation source to the isodose center point (111), and the left-right or up-down movement distance of the table (15). In addition, the electronic device (100) can store the physical distance, correction factor, and imager pixel spacing for the DICOM standard image described above. For example, the electronic device (100) can store a value of 0.3 mm for the row spacing between pixels and 0.25 mm for the column spacing as the imager pixel spacing corresponding to the scale factor of the camera as DICOM metadata.

[0055]

[0056] FIG. 2 is a drawing illustrating a change in the projection angle of radiation according to the rotation of a C-arm included in an electronic device according to one embodiment.

[0057] In one embodiment, the electronic device (100) can irradiate a target blood vessel of a subject positioned on a table (15) using a radiation source (131) included in the radiation irradiation unit (13).

[0058] An electronic device (100) according to one embodiment can rotate a radiation source based on the rotation of the C-arm, based on at least one of a first rotation axis (A-A') that is parallel to the table plane and includes the isodose center point (111) and a second rotation axis (B-B') that is different from the first rotation axis (A-A'). For example, the radiation source can be rotated in one of a plane that is perpendicular to the first rotation axis (A-A') that is parallel to the table plane and includes the isodose center point (111) or a plane that is perpendicular to the second rotation axis (B-B') that is different from the first rotation axis (A-A') and includes the isodose center point (111). The second rotation axis (B-B') can intersect the first rotation axis (A-A'), or, for example, can be orthogonal to each other at the isodose center point (111). For convenience of explanation, an example is described in which the C arm and the radiation source are rotated in one plane, but this is not limited to this and they may be rotated about two rotation axes (A-A', B-B') at the same time.

[0059] For example, the electronic device (100) can rotate the C-arm (12) with respect to the body (11) about the first rotation axis (A-A'). The first rotation axis (A-A') can represent an axis connecting the point where the C-arm (12) and the body (11) are coupled and the isodose center point (111). The position of the radiation source (131) can change according to the rotation of the C-arm (12). For example, according to the rotation of the C-arm (12) about the first rotation axis (A-A'), the radiation source (131) can rotate along a rotational orbit on a plane (190) that is perpendicular to the first rotation axis (A-A') and includes the isodose center point (111). In FIG. 2, the XZ plane is exemplarily illustrated as the plane (190) that is perpendicular to the first rotation axis (A-A').

[0060] The radiation source (131) can rotate in a rotational orbit similar to a circle on a plane (190) according to the rotation of the C arm (12). The rotational orbit along which the radiation source (131) moves when the C arm (12) rotates is not geometrically a circle, and may become a circle that is distorted to some extent due to deflection, vibration, etc. of the C arm (12).

[0061] In addition, the electronic device (100) can also rotate the C-arm (12) with respect to the body (11) about the second rotation axis (B-B'). The second rotation axis (B-B') may be an axis that intersects (e.g., is perpendicular to) the first rotation axis (A-A') while passing through the isodose center point (111). For example, according to the rotation of the C-arm (12) about the second rotation axis (B-B'), the radiation source (131) can rotate in a rotational orbit on a plane that includes the isodose center point (111) and is perpendicular to the second rotation axis (B-B'). For reference, FIG. 2 illustrates an example in which the C-arm rotates about the first rotation axis (A-A') and the second rotation axis (B-B') also rotates. However, when rotation of the C-arm (12) occurs based on the second rotation axis (B-B') while the radiation source (131) and the radiation detector (14) are positioned on the Z-axis, the second rotation axis (B-B') is parallel to the X-axis, and the radiation source (131) can be rotated in a rotational orbit on the YZ plane.

[0062] When the position of the radiation source (131) changes according to the rotation of the C-arm (12), the projection angle (231) of the radiation emitted from the radiation source (131) (e.g. ) can be changed. In other words, the projection angle (231) of radiation emitted from the radiation source can be changed according to the rotation of the C arm (12).

[0063] The projection angle (231) of the radiation may represent an angle between an axis (e.g., Z-axis) perpendicular to a plane including the surface of the table (15) and an axis (211) corresponding to the irradiation direction of the radiation emitted from the radiation source (131). The irradiation direction of the radiation may represent a direction from the radiation irradiation unit (13) (or the radiation source (131)) toward the radiation detection unit (14) (or the radiation detection sensor). The axis (211) corresponding to the irradiation direction of the radiation may represent an axis connecting the radiation irradiation unit (13) and the radiation detection unit (14). The projection angle (231) of the radiation may be an angle between -180 degrees and 180 degrees.

[0064] The isodose center point (111) can be defined in various ways based on the rotation of the C-arm (12). For example, the isodose center point (111) can represent a point where radiation irradiated from various locations of the radiation source according to the rotation of the C-arm (12) is concentrated. For another example, the isodose center point (111) can represent the geometric center of the rotational orbit of the radiation source (131). For another example, the isodose center point (111) can represent the rotational center of the C-arm (12).

[0065] As described in FIG. 1, the electronic device (100) can store angle information related to the rotation of the C-arm (12) as metadata of DICOM. For example, the electronic device (100) can store a first angle formed by the C-arm (12) rotating around the first rotation axis (A-A') and a second angle formed by the C-arm (12) rotating around the second rotation axis (B-B') as metadata of DICOM. For example, the electronic device (100) can store a radiation projection angle (231) as metadata of DICOM. The electronic device (100) can determine the position of the camera based on the intersection of the first rotation axis (A-A') and the second rotation axis (B-B') at the time of radiation irradiation by utilizing the metadata of DICOM. The electronic device (100) can obtain height information for a plurality of points of the target blood vessel based on the position of the camera (e.g., the direction of radiation irradiation to the target blood vessel at the time of photographing).

[0066] FIG. 3 is a diagram illustrating a process by which an electronic device according to one embodiment calculates a straight-line distance from a radiation source to a target blood vessel.

[0067] FIG. 3 is a side view of an electronic device (e.g., the electronic device (100) of FIG. 1) viewed from the XZ plane. Before the electronic device uses a radiation source (131) to irradiate a target blood vessel (320), the device can move the table top (15-1) to align the radiation source (131), the target blood vessel (320), and the isodose center point (111) in a straight line. As described above, the position of the radiation detection unit (14) (e.g., the photographing position) can be moved according to the rotation of the C-arm (12). For example, the radiation detection unit (14) and the radiation irradiation unit (13) can be moved in an area range (310) corresponding to the surface of a hemisphere according to the rotation of the C-arm (12).

[0068] In one embodiment, the electronic device may calculate a first value (d1-d2) by subtracting a second vertical distance (d2) from a subject (e.g., a target blood vessel) to the table (15) from a first vertical distance (d1) from the isodose center point (111) to the table (15). The first value (d1-d2) may represent a vertical distance from the isodose center point (111) to the target blood vessel (320). In addition, the electronic device may calculate the cosine value (cos( )) can be divided to calculate a second value. The second value can represent a straight-line distance from the isodose center point (111) to the target blood vessel (320). The electronic device can calculate the target distance (x) from the radiation source (131) to the target blood vessel (320) by subtracting the calculated second value (i.e., the straight-line distance from the isodose center point (111) to the target blood vessel (320)) from the straight-line distance (d3) from the radiation source (131) to the isodose center point (111). For example, the target distance from the radiation source (131) to the target blood vessel (320) can be calculated as in the following mathematical expression 3.

[0069] [Equation 3]

[0070]

[0071] In the above mathematical expression 3, SOD is the straight-line distance from the radiation source (131) to the target blood vessel (320), Source to Isocenter is the straight-line distance (d3) from the radiation source (131) to the isodose center point (111), Isocenter to table is the vertical distance (d1) from the isodose center point (111) to the table (15), Object height is the vertical distance (d2) from the target blood vessel (320) to the table (15), can represent the angle of irradiation of radiation.

[0072] In one embodiment, the electronic device may calculate a correction factor based on the calculated target distance after calculating the target distance. As described above, the electronic device may utilize the calculated correction factor to convert the distance in the vascular image (130) into a physical distance.

[0073] In one embodiment, the electronic device can calculate the distance from the position of the radiation detection unit (14) to the target blood vessel (320) based on the calculated target distance (x). For example, the electronic device can calculate the distance from a pixel on an image generated based on the radiation detected by the radiation detection unit (14) to a point corresponding to the pixel of the target blood vessel (320) along a straight line connecting the pixel and the radiation source (131) on the image. For reference, the electronic device can store the first vertical distance (d1), the second vertical distance (d2), the first value (d1-d2), the second value, the correction coefficient, the physical distance in the blood vessel image (130), and the distance from the position of the radiation detection unit (14) to the target blood vessel (320) as DICOM metadata. The description of the DICOM metadata stored by the electronic device is omitted as it is redundant.

[0074] The electronic device can generate a three-dimensional blood vessel model corresponding to the target blood vessel (320) from a single two-dimensional image by utilizing the distance from the pixel to the point corresponding to the pixel of the target blood vessel (320). A specific method by which the electronic device generates a three-dimensional blood vessel model from a two-dimensional image is described in detail below in FIG. 7.

[0075] In summary, as described in FIGS. 1 to 3, the electronic device can capture images of target blood vessels using a C-arm. In addition, the electronic device can store all of the capture information, distance information, and angle information when capturing images of the target blood vessels as DICOM metadata. Furthermore, the electronic device can generate a three-dimensional shape of the target blood vessels based on the stored DICOM metadata, and can obtain the relative heights between each point of the target blood vessels based on the generated three-dimensional shape. The electronic device can compensate for the blood vessel pressure by calculating the hydrostatic pressure according to the relative heights between each point of the target blood vessels. Based on the compensated blood vessel pressure, the electronic device can more accurately calculate the fractional blood flow reserve.

[0076] FIG. 4 is a flowchart illustrating a method for compensating blood vessel pressure considering a height difference of blood vessels according to one embodiment.

[0077] In step (410), an electronic device according to one embodiment (e.g., the electronic device (100) of FIG. 1) may acquire a blood vessel image including a relative positional difference in the direction of gravity between a predetermined reference point of a target blood vessel of a patient and another point included in the target blood vessel. For example, the predetermined reference point of the target blood vessel may correspond to a point where a catheter is inserted into the target blood vessel when treating a patient based on angiography. Accordingly, the electronic device may determine the point where the catheter is inserted into the target blood vessel as the predetermined reference point of the target blood vessel. For example, during a procedure using angiography, a catheter including a blood pressure measurement sensor may be inserted along the target blood vessel from the blood vessel entrance point to measure blood pressure at a specific point in the blood vessel. At this time, the electronic device may determine the point where the catheter including the blood pressure measurement sensor is inserted as the predetermined reference point of the target blood vessel. The electronic device may acquire a blood vessel image such that the predetermined reference point described above is distinguished from other points. For example, the electronic device may acquire a 2D image of the target blood vessel. At this time, the electronic device can acquire a blood vessel image such that a predetermined reference point of the target blood vessel and a point at which the blood vessel pressure is to be measured are revealed at different locations on the 2D image. For reference, when the electronic device photographs the target blood vessel, if the predetermined reference point of the target blood vessel and the point at which the blood vessel pressure is to be measured are located on the same photographing light (e.g., X-ray), the predetermined reference point and the point at which the blood vessel pressure is to be measured may overlap at the same pixel location of the photographed blood vessel image. Therefore, the electronic device can acquire a blood vessel image such that the predetermined reference point and another point included in the target blood vessel are revealed at different locations on the image. The blood vessel image acquired by the electronic device may include a relative position difference with respect to the direction of gravity between the predetermined reference point and the other point included in the target blood vessel.For example, the electronic device can obtain a blood vessel image by photographing the target blood vessel at an angle less than a predetermined critical angle with respect to the coronal plane of the patient (e.g., the subject (120) illustrated in FIG. 1). For example, the electronic device can obtain a blood vessel image by photographing the target blood vessel of the patient at a position of LAO 90 degrees or RAO 90 degrees of the patient.

[0078] For reference, the coronal plane can represent an imaginary plane that anatomically divides the human body into anterior and posterior. The coronal plane is a vertical plane that passes through the body when viewed from the front, and can be a plane that distinguishes the front (anterior) and posterior (posterior) without separating the left and right sides. For example, a 90-degree angle to the coronal plane can indicate an image of the body from the front or back. For another example, a 0-degree angle (or parallel to the coronal plane) can indicate an image of the body from the right or left side. Therefore, the angle at which the body is imaged can be defined relative to the coronal plane. For example, an electronic device can set a predetermined critical angle to a 90-degree angle to the coronal plane. An image obtained by the electronic device when imaging a target blood vessel at a 90-degree angle to the coronal plane can correspond to an image obtained based on light radiating in a direction parallel to the direction of gravity. Images acquired based on rays radiating in a direction parallel to the direction of gravity may not include relative positional differences with respect to the direction of gravity. Therefore, an electronic device can acquire a blood vessel image that includes relative positional differences with respect to the direction of gravity between a predetermined reference point and another point within the target blood vessel by photographing the target blood vessel at an angle less than 90 degrees to the coronal plane (e.g., obliquely with respect to the direction of gravity).

[0079] In step (420), an electronic device according to an embodiment may convert a relative position difference with respect to the direction of gravity into a height difference using a calibration factor of an acquired blood vessel image. The electronic device may calculate a physical distance as a relative position difference with respect to the direction of gravity between a predetermined point included in the blood vessel image and another point using the calibration factor described in FIG. 1. For example, the electronic device may calculate an actual distance between a predetermined point and another point based on a straight-line distance between a pixel corresponding to a predetermined point and a pixel corresponding to another point in a 2D blood vessel image and the calibration factor. The electronic device may convert a relative position difference with respect to the direction of gravity between the predetermined point and another point into a height difference based on the actual distance between the predetermined point and the another point. For example, assuming that the electronic device photographs a target blood vessel of a patient at a 0 degree angle (e.g., RAO 90 degrees, LAO 90 degrees) relative to the coronal plane of the patient, the acquired blood vessel image may be an image acquired in response to a photographing light (e.g., X-ray) perpendicular to the direction of gravity. Accordingly, the electronic device can determine the vertical distance between different straight lines parallel to the X-axis on the image and passing through each of the pixel points corresponding to a predetermined point and the pixel points corresponding to the other points in the blood vessel image taken at a 0 degree angle relative to the coronal plane, as the relative position difference with respect to the direction of gravity. Accordingly, the electronic device can calculate the actual height difference between the predetermined point and the other point of the target blood vessel based on the relative position difference and the correction coefficient.

[0080] In step (430), the electronic device according to one embodiment can obtain a corrected pressure value for another point by correcting the hydrostatic pressure corresponding to the height difference to the pressure value measured in advance for another point. For example, the electronic device can calculate the hydrostatic pressure based on the relative height of another point with respect to a predetermined reference point. For reference, the hydrostatic pressure can refer to the pressure of water (or liquid) acting in a stationary fluid. In the present specification, the hydrostatic pressure can refer to the pressure generated by the height difference between two different points of a blood vessel. The electronic device can calculate the hydrostatic pressure through the following mathematical equation 4 based on the relative height difference between the predetermined point and the other point.

[0081] [Equation 4]

[0082]

[0083] In the mathematical expression 4 above, represents the hydrostatic pressure based on the height difference between a predetermined reference point and another point in the target blood vessel. Blood density represents the density of blood flowing at the target point in the blood vessel. represents the relative height difference of another point of the blood vessel with respect to the reference point. For example, if the reference point corresponds to the entrance of the blood vessel, The hydrostatic pressure may be generated based on the relative height of another point of the blood vessel compared to the entrance of the blood vessel. In one embodiment, the electronic device may display the fractional flow reserve (FFR) at the blood vessel point on the display based on the pressure loss according to the width of the blood vessel at the blood vessel point for measuring the hydrostatic pressure and blood pressure. The electronic device may calculate the hydrostatic pressure at another point of the blood vessel based on Equation 4.

[0084] Figures 5a to 5c are graphs showing the height difference between a blood vessel point and the entrance of the blood vessel.

[0085] In the treatment of vascular disease, accurate measurement of intravascular pressure is crucial. In particular, blood pressure can be affected by vascular narrowing and the vessel's height relative to gravity. Blood pressure can increase as the vessel narrows and decrease as the vessel widens. Furthermore, blood pressure can decrease as the vessel is located higher than the heart and increase as the vessel is located lower than the heart. Therefore, to accurately measure intravascular pressure, it is crucial to accurately calculate hydrostatic pressure according to vessel height. Specifically, blood pressure is crucial for calculating fractional flow reserve. For example, when performing a procedure on a patient, assuming the patient is lying on their back on the operating table, the coronary arteries surrounding the heart may be located higher or lower than the heart, depending on the shape of the heart. The relative positions of the coronary arteries relative to the heart are described in detail below.

[0086] The graph (500a) of FIG. 5a shows the relative height of a sensor relative to a reference point, which changes depending on the distance at which the sensor is inserted, when a sensor (e.g., a catheter) for measuring blood pressure is inserted into a reference point of the left anterior descending artery (LAD). Specifically, in the graph (500a), the x-axis (510) may represent the distance from the reference point where the sensor is inserted into the blood vessel to the point where the sensor is located. Additionally, in the graph (500a), the y-axis (520) may represent the height in the direction of gravity of the point where the sensor is located relative to the reference point where the sensor is inserted into the blood vessel. For example, it is assumed that a catheter is inserted into the entrance of the left anterior descending artery (LAD) while the subject is lying on his back with his back facing the floor. The entrance of the left anterior descending artery may represent the point where the left anterior descending artery and the heart are connected, or may represent the point where the catheter is inserted. Therefore, the entrance of the left anterior descending artery is not a fixed value, and may include the point where a catheter is inserted for measuring vascular pressure. In graph (500a), since the left anterior descending artery is located in front of the heart, the catheter may be positioned at increasingly higher points compared to the reference point until it is inserted about 130 mm from the entrance of the left anterior descending artery (e.g., proximal to the heart). Therefore, graph (500a) may represent the relative height at which the catheter is positioned compared to the reference point within the left anterior descending artery, and each point within the left anterior descending artery may have a pressure difference due to the relative height difference. Therefore, when calculating the fractional flow reserve, the electronic device needs to consider the relative height difference at each vascular point within the left anterior descending artery. In particular, when obtaining blood pressure to measure fractional blood flow reserve, even if there is no pressure loss at all due to blood flow between the proximal / distal parts of the lesion, it can be measured as if a pressure loss occurred due to a pressure difference caused by a relative height difference.

[0087] The graph (500b) of Fig. 5b shows the relative height of the sensor relative to the reference point, which changes depending on the distance at which the sensor is inserted, when the sensor for measuring blood pressure is inserted into the reference point of the left circumflex artery (LCX). The x-axis (510) and y-axis (520) of the graph (500b) overlap with those described in Fig. 5a and are therefore omitted.

[0088] For example, assume that the subject is lying on his back with a catheter inserted into the entrance of the left circumflex artery. In the graph (500b), if the sensor is inserted about 150 mm from the entrance of the left circumflex artery (e.g., the proximal part close to the heart), the sensor may be positioned at a point with a relatively lower height compared to the entrance of the left circumflex artery. In the graph (500b), if the sensor is inserted deeper than about 150 mm from the entrance of the left circumflex artery, the sensor may be positioned at a point with a relatively higher height compared to the entrance of the left circumflex artery. Up to the point 150 mm on the x-axis of the graph (500b), since the sensor is positioned at a lower point compared to the reference point, even if there is no pressure loss due to blood flow between the proximal and distal parts of the lesion, the pressure loss may show a trend opposite to that of FIG. 5a due to the pressure difference due to the difference in relative height from the reference point.

[0089] The graph (500c) of Fig. 5c shows the relative height of the sensor relative to the reference point, which changes depending on the distance at which the sensor is inserted, when the sensor for measuring blood pressure is inserted into the reference point of the right coronary artery (RCA). In the graph (500c), the x-axis (510) and the y-axis (520) overlap with those described in Figs. 5a and 5b, and are therefore omitted.

[0090] For example, assume that a catheter is inserted into the entrance of the right coronary artery while the subject is lying on their back facing the floor. In graph (500c), if the sensor is inserted while extending from the entrance of the right coronary artery (e.g., proximal to the heart), the relative position of the sensor with respect to the reference point may change. The change in the relative position of the sensor with respect to the reference point overlaps with the description in FIGS. 5A and 5B and is therefore omitted.

[0091] Therefore, when the subject is lying on his back with his back facing the floor, the blood pressure measured by the catheter inserted into the reference point of the blood vessel may be affected by the relative height of the point compared to the reference point. If the blood pressure value due to the relative height difference at the blood vessel point is not considered, for example, the value may be overcalculated compared to the actual fractional flow reserve in the left anterior inferior artery, and the value may be undercalculated compared to the actual fractional flow reserve in the left circumflex artery and right coronary artery at points with lower heights compared to the reference point. Therefore, when calculating the fractional flow reserve, it is necessary to reflect the pressure correction value due to the height of the blood vessel point compared to the catheter insertion point.

[0092] Figure 6 is a diagram of an electronic device that calculates an approximate value of hydrostatic pressure based on a blood vessel image taken at a certain angle relative to the patient's coronal plane.

[0093] Fig. 6 may correspond to the side view of the electronic device illustrated in Fig. 3. At this time, the top-down direction with reference to Fig. 6 may correspond to the direction of gravity (g). In the following description, the direction of gravity (g) is fixed as the top-down direction of Fig. 6.

[0094] An electronic device (600) according to one embodiment can acquire blood vessel images of a patient (610) taken from various angles (630) based on a coronal plane (620) of the patient. For example, the radiation irradiation units (601, 603) and the radiation detection units (602, 604) can move according to the rotation of the C-arm. In this specification, the radiation irradiation unit (601) and the radiation detection unit (602) are described as being located on a plane parallel to the coronal plane (620) of the patient, and the radiation irradiation unit (603) and the radiation detection unit (604) are described as being located on a plane not parallel to the coronal plane (620). The coronal plane (620) can represent a virtual plane anatomically dividing the human body into front and back as described in FIG. 4. Since the coronal plane (620) has been described in detail in FIG. 4, a duplicate description will be omitted.

[0095] The electronic device (600) should utilize the radiation irradiation unit (601) and the radiation detection unit (602) as much as possible to obtain a blood vessel image including the relative position difference with respect to the direction of gravity (g) between a predetermined reference point (650a, 650b) and another point (660a, 660b) at which the blood vessel pressure is to be measured in the target blood vessel (605) of the patient (610). For example, as illustrated in FIG. 6, the blood vessel image captured based on the radiation irradiation unit (601) and the radiation detection unit (602) may correspond to a blood vessel image captured at 90 degrees to the left anterior oblique (LAO) with respect to the patient (610). In other words, the electronic device (600) can obtain an image captured perpendicular to the direction of gravity (g) by capturing the target blood vessel (605) of the patient (610) at 90 degrees to the LAO. Accordingly, on a blood vessel image acquired based on a radiation irradiation unit (601) and a radiation detection unit (602) positioned on a plane parallel to the coronal plane (620), the vertical positional difference between a predetermined point (650b) and another point (660b) may correspond to a height difference. However, when the electronic device (600) acquires a blood vessel image based on a radiation irradiation unit (603) and a radiation detection unit (604) positioned on a plane different from the coronal plane (620) at a certain angle (630), the vertical positional difference between a predetermined point (650a) and another point (660a) on the blood vessel image may not correspond to a height difference. In other words, the predetermined point (650a) and another point (660a) may be smaller or larger than a value corresponding to an actual height. Therefore, the electronic device (600) needs to approximate the blood vessel image obtained at a certain angle (630) with the coronal plane (620) to an image taken perpendicular to the direction of gravity (g).For example, the electronic device (600) can calculate the relative position difference (h1) with respect to the direction of gravity based on the information of the shooting angle (630) based on the patient's coronal plane (620) and the calibration factor for the acquired blood vessel image. For example, the electronic device (600) can acquire a blood vessel image captured at an angle (630) formed by the coronal plane (620) and a plane including the radiation irradiation unit (603) and the radiation detection unit (604). The electronic device (600) can extract parallel lines passing through each of a predetermined point (650a) and another point (660a) on the blood vessel image. The electronic device (600) can determine the shortest distance between the parallel lines passing through each of the predetermined point (650a) and the another point (660a) as the relative position difference (h1) with respect to the direction of gravity. The electronic device (600) can calculate the actual distance of the position difference (h1) based on the correction coefficient. Then, the electronic device (600) can convert the calculated relative position difference (h1) into a height difference (h2) on the blood vessel image acquired at the target shooting angle by transforming the shooting angle (630) to a target shooting angle with respect to the patient's coronal plane (620). For example, the electronic device (600) can treat the blood vessel image captured at the angle (630) as if it were a blood vessel image captured on a plane parallel to the coronal plane (620), such as LAO 90 degrees or RAO 90 degrees. For example, the electronic device (600) can transform a length value corresponding to a relative position difference (h1) in a blood vessel image captured at an angle (630) into a target shooting angle (e.g., LAO 90 degrees, RAO 90 degrees, or 0 degrees with respect to the coronal plane (620)) by orthogonally projecting the length value corresponding to the relative position difference (h1) onto a plane perpendicular to the coronal plane (620). In other words, the electronic device (600) can approximately calculate a relative height difference (h2) between a predetermined point (650b) and another point (660b) by orthogonally projecting the relative position difference (h1) onto a plane perpendicular to the coronal plane (620).The electronic device (600) can calculate an approximate hydrostatic pressure corresponding to the height difference (h2). Based on the approximate hydrostatic pressure, the electronic device (600) can compensate for the pressure at another point (660b).

[0096] The embodiments described above may be implemented using hardware components, software components, and / or a combination of hardware components and software components. For example, the devices, methods, and components described in the embodiments may be implemented using a general-purpose computer or a special-purpose computer, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding to them. The processing device may execute an operating system (OS) and software applications running on the operating system. Furthermore, the processing device may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing device is sometimes described as being used alone; however, one of ordinary skill in the art will recognize that the processing device may include multiple processing elements and / or multiple types of processing elements. For example, a processing unit may include multiple processors, or a processor and a controller. Other processing configurations, such as parallel processors, are also possible.

[0097] Software may include computer programs, codes, instructions, or a combination of one or more of these, which may configure a processing device to perform a desired operation or may independently or collectively command the processing device. The software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, or computer storage medium or device for interpretation by the processing device or for providing instructions or data to the processing device. The software may also be distributed over networked computer systems and stored or executed in a distributed manner. The software and data may be stored on a computer-readable recording medium.

[0098] The method according to the embodiment may be implemented in the form of program commands that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program commands, data files, data structures, etc., alone or in combination, and the program commands recorded on the medium may be those specially designed and configured for the embodiment or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program commands such as ROMs, RAMs, and flash memories. Examples of program commands include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0099] The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

[0100] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0101] Although the embodiments described above have been described with limited drawings, those skilled in the art will appreciate that various technical modifications and variations can be applied based on the described embodiments. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0102] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

Claims

1. In a method for correcting blood vessel pressure performed by a processor, A step of acquiring a blood vessel image including a relative position difference in the direction of gravity between a predetermined reference point of a target blood vessel of a patient and another point included in the target blood vessel; A step of converting the relative position difference with respect to the gravity direction into a height difference using the calibration factor of the acquired blood vessel image; and A step of obtaining a corrected pressure value for the other point by correcting the hydrostatic pressure corresponding to the height difference to the pressure value measured in advance for the other point. A method for correcting vascular pressure, comprising:

2. In paragraph 1, The step of acquiring the above blood vessel image is: A step of acquiring the blood vessel image by photographing the target blood vessel at an angle less than a predetermined critical angle based on the coronal plane of the patient. A method for correcting vascular pressure, comprising:

3. In paragraph 1, The above vascular images are obtained from C-arm, Method of compensating vascular pressure.

4. In paragraph 1, The step of acquiring the above blood vessel image is: A step of determining the predetermined reference point as the point where the catheter is inserted into the target blood vessel; and A step of acquiring a blood vessel image including a relative position difference in the direction of gravity between the above point and a point other than the above point A method for correcting vascular pressure, comprising:

5. In paragraph 1, The step of converting the relative position difference in the above gravity direction into a height difference is: A step of calculating a relative position difference with respect to the direction of gravity based on the shooting angle information based on the coronal plane of the patient and the calibration factor for the acquired blood vessel image; and A step of converting the above shooting angle information into target shooting angle information for the patient's coronal plane, thereby converting the calculated relative position difference into a height difference on a blood vessel image acquired at the target shooting angle. A method for correcting vascular pressure, comprising:

6. In paragraph 1, The step of obtaining the corrected pressure value for the above different points is: A step of calculating hydrostatic pressure at the different point based on the converted height difference, gravitational acceleration, and blood density at the different point. A method for correcting vascular pressure, comprising:

7. A computer program stored in a computer-readable recording medium to execute the method of claim 1 in combination with hardware.

8. In the vascular pressure compensation device, An image acquisition unit for acquiring a blood vessel image including a relative position difference in the direction of gravity between a predetermined reference point of a patient's target blood vessel and another point included in the target blood vessel; and A processor that converts the relative position difference with respect to the gravity direction into a height difference using the calibration factor of the acquired blood vessel image, and obtains a corrected pressure value for the other point by correcting the hydrostatic pressure corresponding to the height difference to the pressure value measured in advance for the other point. A vascular pressure compensation device comprising:

9. In paragraph 8, The above processor, The image acquisition unit adjusts the position of the image acquisition unit to acquire the blood vessel image by photographing the target blood vessel at an angle less than a predetermined critical angle based on the coronal plane of the patient. Vascular pressure compensation device.

10. In paragraph 8, The above image acquisition unit, A vascular pressure compensation device including a C-arm.

11. In paragraph 8, The above processor, The predetermined reference point is determined as the point where the catheter is inserted into the target blood vessel, and the image acquisition unit adjusts the position of the image acquisition unit to acquire a blood vessel image including a relative position difference in the direction of gravity between the point and a point other than the point. Vascular pressure compensation device.

12. In paragraph 8, The above processor, Based on the shooting angle information and the calibration factor based on the coronal plane of the patient for the acquired blood vessel image, a relative position difference with respect to the gravity direction is calculated, and the shooting angle information is transformed into target shooting angle information with respect to the coronal plane of the patient, thereby converting the calculated relative position difference into a height difference on the blood vessel image acquired at the target shooting angle. Vascular pressure compensation device.

13. In paragraph 8, The above processor, Based on the converted height difference, gravitational acceleration, and blood density at the other point, the hydrostatic pressure at the other point is calculated, and a corrected pressure value for the other point is obtained based on the calculated hydrostatic pressure. Vascular pressure compensation device.

Images