Blood vessel detection system, electronic device, storage medium and computer program product

Abstract

The embodiment of the invention provides a blood vessel detection system, electronic equipment, a storage medium and a computer program product. The system comprises a catheter and a host, the catheter is provided with a first signal collector and a second signal collector, the first signal collector is used for collecting intravascular ultrasonic echo signals, and the second signal collector is used for collecting blood flow source signals; the host is used for generating an intravascular ultrasonic image according to the intravascular ultrasonic echo signal of the to-be-detected blood vessel, determining blood vessel blood flow information according to the blood flow source signal of the to-be-detected blood vessel, and registering the intravascular ultrasonic image and the blood vessel blood flow information on acquisition time; first blood vessel blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum expansion state and second blood vessel blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state are determined according to the registration result, and a blood flow reserve characteristic value is calculated according to the determined blood vessel blood flow information. Therefore, comprehensive evaluation of the morphology and the function of the blood vessel can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular, to a vascular detection system, an electronic device, a storage medium, and a computer program product. Background Art

[0002] In recent years, the incidence of cardiovascular diseases has been increasing day by day and has become one of the diseases with the highest mortality rate. Intravascular imaging techniques such as Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT) are of great significance for the identification of vascular lesions, the formulation of treatment methods, and the evaluation of treatment effects. IVUS is the clinical application of ultrasonic imaging in blood vessels. According to the acoustic impedance differences of tissues, it receives the echoes reflected by the tissues and analyzes them to generate grayscale images of the cross-section of blood vessels. However, IVUS is only limited to evaluating the morphological changes of blood vessels and cannot reflect functional change information such as changes in blood supply capacity caused by morphological changes of blood vessels. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed. Embodiments of the present invention provide a vascular detection system, an electronic device, a storage medium, and a computer program product. By adopting this solution, the signal collector required for collecting IVUS images can be integrated with the signal collector required for measuring the blood flow reserve characteristic value on the same catheter, so that the functions of collecting IVUS images and measuring the blood flow reserve characteristic value can be realized by using the same vascular detection system, realizing a comprehensive evaluation of vascular morphology and function, and at the same time achieving other technical effects such as improving the accuracy of measuring the blood flow reserve characteristic value.

[0004] According to one aspect of the present invention, there is provided a vascular detection system, including a catheter and a host. A first signal collector and a second signal collector are provided on the catheter. The first signal collector is used to collect intravascular ultrasound echo signals, and the second signal collector is used to collect blood flow source signals, where the blood flow source signal is a signal for determining blood flow; the host is respectively communicatively connected to the first signal collector and the second signal collector, and is used for: generating an intravascular ultrasound image of a blood vessel to be measured according to the intravascular ultrasound echo signal of the blood vessel to be measured collected by the first signal collector, determining the blood flow information of the blood vessel to be measured according to the blood flow source signal of the blood vessel to be measured collected by the second signal collector, registering the intravascular ultrasound image and the blood flow information in terms of acquisition time, determining the first blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in a resting state according to the registration result, and calculating a blood flow reserve characteristic value of the blood vessel to be measured according to the first blood flow information and the second blood flow information, where the blood flow information includes the blood flow of the blood vessel to be measured and / or intermediate blood flow information of the blood vessel to be measured for determining blood flow.

[0005] Exemplarily, the blood flow information includes intermediate blood flow information, where the intermediate blood flow information includes blood flow velocity or includes blood flow velocity and blood flow direction. The blood flow source signal includes an ultrasonic Doppler signal, and the second signal collector includes a first ultrasonic transducer for collecting the ultrasonic Doppler signal; or, the intermediate blood flow information includes blood flow velocity, the blood flow source signal includes a blood flow temperature signal, and the second signal collector includes a temperature sensor; or, the intermediate blood flow information includes blood flow pressure, the blood flow source signal includes a blood flow pressure signal, and the second signal collector includes a pressure sensor.

[0006] Exemplarily, the first signal collector includes a second ultrasonic transducer for collecting intravascular ultrasound echo signals. The element plane of the second ultrasonic transducer is parallel to the axis of the catheter, and the element plane of the first ultrasonic transducer forms a preset angle with the axis of the catheter.

[0007] Exemplarily, the first ultrasonic transducer is further used to transmit pulsed ultrasonic waves and receive corresponding echo signals as blood flow source signals, and the intermediate blood flow information further includes blood flow direction.

[0008] Exemplarily, when the intermediate blood flow information includes blood flow velocity or includes blood flow velocity and blood flow direction, the vascular detection system further includes a display. The host is communicatively connected to the display, and the host is further used to perform color coding on the intermediate blood flow information, and superimpose the color coding result on the intravascular ultrasound image matched with the intermediate blood flow information according to the registration result and output it to the display for display.

[0009] Exemplarily, the host specifically registers the intravascular ultrasound image and the intravascular blood flow information in terms of acquisition time in the following manner: determining at least the actual acquisition time difference between the intravascular ultrasound image and the intravascular blood flow information according to the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter and the retraction speed of the catheter; matching the scanned blood vessel positions corresponding to the intravascular ultrasound image and the scanned blood vessel positions corresponding to the intravascular blood flow information according to the actual acquisition time difference, and determining the intravascular ultrasound image and the intravascular blood flow information corresponding to the same blood vessel position scanned at the same theoretical acquisition time, so as to obtain a registration result, where the registration result includes the matching relationship between the intravascular ultrasound image and the intravascular blood flow information, and the intravascular ultrasound image and the intravascular blood flow information corresponding to the same blood vessel position scanned at the same theoretical acquisition time are mutually matching intravascular ultrasound image and intravascular blood flow information.

[0010] Exemplarily, the host specifically determines the actual acquisition time difference between the intravascular ultrasound image and the intravascular blood flow information in the following manner: determining the actual acquisition time difference between the intravascular ultrasound image and the intravascular blood flow information according to the preset angle between the element plane of the first ultrasonic transducer and the axis of the catheter, the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter, and the retraction speed of the catheter.

[0011] Exemplarily, the host specifically matches the scanned blood vessel positions corresponding to the intravascular ultrasound image and the scanned blood vessel positions corresponding to the intravascular blood flow information in the following manner: aligning the first scanned blood vessel region corresponding to the intravascular ultrasound image and the second scanned blood vessel region corresponding to the intravascular blood flow information on the time axis according to the actual acquisition time difference; deleting the non-overlapping regions in the aligned first and second scanned blood vessel regions, and determining the blood vessel positions in the overlapping region in the aligned first and second scanned blood vessel regions as the same blood vessel positions scanned at the same theoretical acquisition time, so as to determine the intravascular ultrasound image and the intravascular blood flow information corresponding to the same blood vessel position scanned at the same theoretical acquisition time.

[0012] Exemplarily, the host is further configured to: in response to user input information, determine a target blood vessel position, or determine the blood vessel position with the smallest lumen area as the target blood vessel position according to the intravascular ultrasound image; select a first intravascular ultrasound image and a second intravascular ultrasound image from the intravascular ultrasound images acquired at the target blood vessel position.

[0013] Exemplarily, the catheter includes a base body and a rotatable transmission shaft. The first signal collector is disposed on the transmission shaft, and the second signal collector is disposed on the base body. The host includes a retraction device and a rotation device. The retraction device is mechanically connected to the base body and the transmission shaft and is configured to drive the base body and the transmission shaft to retract. The rotation device is mechanically connected to the transmission shaft and is configured to drive the transmission shaft to rotate during retraction.

[0014] According to another aspect of the present invention, there is also provided an electronic device, including a processing device and a storage device. A computer program instruction is stored in the storage device. When the computer program instruction is run by the processing device, it is configured to perform the following operations: generating an intravascular ultrasound image of a blood vessel to be measured according to the intravascular ultrasound echo signal of the blood vessel to be measured collected by the first signal collector of the blood vessel detection system; determining the blood flow information of the blood vessel to be measured according to the blood flow source signal of the blood vessel to be measured collected by the second signal collector of the blood vessel detection system; registering the intravascular ultrasound image and the blood flow information in terms of the acquisition time; determining the first blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculating a blood flow reserve characteristic value of the blood vessel to be measured according to the first blood flow information and the second blood flow information. The blood flow information includes the blood flow volume of the blood vessel to be measured and / or the intermediate blood flow information for determining the blood flow volume of the blood vessel to be measured, and the blood flow source signal is a signal for determining the blood flow volume.

[0015] According to another aspect of the present invention, there is also provided a storage medium, on which a program instruction is stored. When the program instruction is run, it is configured to perform the following operations: generating an intravascular ultrasound image of a blood vessel to be measured according to the intravascular ultrasound echo signal of the blood vessel to be measured collected by the first signal collector of the blood vessel detection system; determining the blood flow information of the blood vessel to be measured according to the blood flow source signal of the blood vessel to be measured collected by the second signal collector of the blood vessel detection system; registering the intravascular ultrasound image and the blood flow information in terms of the acquisition time; determining the first blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculating a blood flow reserve characteristic value of the blood vessel to be measured according to the first blood flow information and the second blood flow information. The blood flow information includes the blood flow volume of the blood vessel to be measured and / or the intermediate blood flow information for determining the blood flow volume of the blood vessel to be measured, and the blood flow source signal is a signal for determining the blood flow volume.

[0016] According to another aspect of the present invention, there is also provided a computer program product, including computer program instructions which are used to perform the following operations when running: generating an intravascular ultrasound image of a blood vessel to be measured according to the intravascular ultrasound echo signal of the blood vessel to be measured collected by a first signal collector of a blood vessel detection system; determining the blood flow information of the blood vessel to be measured according to the blood flow source signal of the blood vessel to be measured collected by a second signal collector of the blood vessel detection system; registering the intravascular ultrasound image and the blood flow information in terms of the acquisition time; determining the first blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculating a blood flow reserve characteristic value of the blood vessel to be measured according to the first blood flow information and the second blood flow information, wherein the blood flow information includes the blood flow volume of the blood vessel to be measured and / or intermediate blood flow information of the blood vessel to be measured for determining the blood flow volume, and the blood flow source signal is a signal for determining the blood flow volume.

[0017] By adopting the above technical solution, the signal collector required for collecting IVUS images and the signal collector required for measuring the blood flow reserve characteristic value can be integrated on the same catheter, so that the functions of collecting IVUS images and measuring the blood flow reserve characteristic value can be realized by using the same blood vessel detection system, realizing the comprehensive evaluation of the morphology and function of blood vessels, so as to provide more comprehensive information for evaluating lesions and improving the accuracy of cardiovascular disease diagnosis. At the same time, the two types of detections can be completed simultaneously during a single catheter insertion process, which can shorten the operation time, relieve the patient's pain, and reduce the surgical risk. In addition, through this measurement method, the change of the blood vessel lumen area detected by IVUS can be combined with the stage change of the blood flow information of the blood vessel, that is, the accuracy of the blood flow volume when the blood vessel reaches the state required for calculating the blood flow reserve characteristic value can be determined more accurately, thereby contributing to improving the accuracy of measuring the blood flow reserve characteristic value.

[0018] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The above and other objects, features, and advantages of the present invention will become more apparent. The drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings, the same reference numerals generally represent the same components or steps.

[0020] Figure 1 A schematic diagram showing a blood vessel detection system according to an embodiment of the present invention;

[0021] Figure 2 and Figure 3 respectively show two different exemplary setting manners of a first signal collector and a second signal collector on a catheter according to an embodiment of the present invention;

[0022] Figure 4 An exemplary structural diagram showing a blood vessel detection system according to an embodiment of the present invention. Detailed implementation manners

[0023] In order to make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention. It should be understood that the present invention is not limited by the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] The measurement of fractional flow reserve (FFR) characteristic values is a method for the functional evaluation of blood vessels. This method can evaluate coronary artery lesions from different perspectives compared to intravascular ultrasound (IVUS), and is a good complement to IVUS. The FFR characteristic value can be a characteristic value used to represent the degree of influence of the stenosis of a blood vessel on its blood supply capacity, such as coronary flow reserve (CFR), etc. The following will be described taking CFR as an example. CFR is a measurement technique used to determine whether a coronary artery stenosis is functionally significant, and is defined as the ratio of the blood flow when the coronary artery is in a nearly maximally dilated state to the blood flow at rest. CFR is a good indicator for evaluating the function of coronary microvessels and is considered a strong predictor of cardiovascular death events. The CFR measurement techniques include positron emission tomography (PET), transthoracic echocardiographic coronary blood flow imaging, cardiovascular magnetic resonance imaging, intracoronary Doppler ultrasound, etc. The present invention proposes a blood vessel detection solution, which can integrate the signal collector required for collecting IVUS images and the signal collector required for measuring FFR characteristic values on the same catheter. In this way, the functions of collecting IVUS images and measuring FFR characteristic values can be realized using the same blood vessel detection system, achieving a comprehensive evaluation of the morphology and function of blood vessels, and other technical effects such as improving the accuracy of measuring FFR characteristic values can be achieved simultaneously.

[0025] To at least partially solve the above technical problems, an embodiment of the present invention provides a blood vessel detection system. Figure 1 The schematic diagram of a blood vessel detection system 100 according to an embodiment of the present invention is shown. As Figure 1As shown, the vascular detection system 100 includes a catheter 110 and a main unit 120. A first signal collector 112 and a second signal collector 114 are provided on the catheter 110. The first signal collector 112 is used to collect intravascular ultrasound echo signals, and the second signal collector 114 is used to collect blood flow source signals, where the blood flow source signals are signals for determining blood flow. The main unit 120 is respectively communicatively connected to the first signal collector 112 and the second signal collector 114. The communication connections described herein can be connected by any type of wired communication connection method and / or wireless communication connection method. The wired communication connection method can include electrical connection or include both electrical connection and mechanical connection. The main unit 120 is used to perform the following target processing operations: generate an intravascular ultrasound image of the blood vessel to be measured based on the intravascular ultrasound echo signals of the blood vessel to be measured collected by the first signal collector 112, determine the blood flow information of the blood vessel to be measured based on the blood flow source signals of the blood vessel to be measured collected by the second signal collector 114, register the intravascular ultrasound image and the blood flow information in terms of the acquisition time, determine the first blood flow information matched by the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched by the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculate the blood flow reserve characteristic value of the blood vessel to be measured based on the first blood flow information and the second blood flow information. The blood flow information includes the blood flow of the blood vessel to be measured and / or the intermediate blood flow information for determining the blood flow of the blood vessel to be measured. The blood vessel to be measured can be any type of blood vessel, including but not limited to coronary blood vessels. That is, although the blood vessel to be measured and the corresponding blood flow reserve characteristic value are described above with coronary arteries and CFR as examples, the vascular detection technology described herein can be applied to other blood vessels similar to coronary arteries as needed and can be used to measure blood flow reserve characteristic values similar to CFR of other blood vessels. Exemplarily, the main unit can include a processing device, and the processing device can be respectively communicatively connected to the first signal collector and the second signal collector, and the above target processing operations can be executed by the processing device of the main unit.

[0026] The first signal collector is used to collect intravascular ultrasound echo signals, and it may include a second ultrasonic transducer, i.e., an IVUS transducer. The IVUS transducer may be a single-element ultrasonic transducer or a multi-element ultrasonic transducer. When the IVUS transducer is a single-element ultrasonic transducer or, although it is a multi-element ultrasonic transducer but cannot scan the entire angle to be scanned (e.g., 360 degrees) simultaneously, the IVUS transducer can perform rotational scanning during the catheter withdrawal process. When the IVUS transducer is a multi-element ultrasonic transducer but can scan the entire angle to be scanned (e.g., 360 degrees) simultaneously, the IVUS transducer may also not rotate during the catheter withdrawal process. It can be understood that the IVUS transducer can follow the catheter into the blood vessel, emit ultrasonic waves towards the blood vessel wall, and collect the corresponding echo signals (referred to as intravascular ultrasound echo signals in this article). Those skilled in the art can understand the structure and working principle of the IVUS transducer, which will not be elaborated in this article.

[0027] The second signal collector is used to collect the blood flow source signal of the blood vessel, and the blood flow source signal is a signal used to determine the blood flow. The blood flow source signal can be any signal that can be used to determine the blood flow. Exemplarily, the blood vessel blood flow information of the blood vessel to be measured can be determined based on the blood flow source signal of the blood vessel to be measured. In one embodiment, the blood vessel blood flow information may include the blood flow of the blood vessel to be measured, and in this case, operations such as registration can be directly performed based on the blood flow. In another embodiment, the blood vessel blood flow information may include the intermediate blood flow information for determining the blood flow of the blood vessel to be measured. Based on the intermediate blood flow information, the blood flow can be further determined. In this case, when performing operations such as registration, it can be performed based on the intermediate blood flow information, and when finally calculating the blood flow reserve characteristic value of the blood vessel to be measured according to the first blood vessel blood flow information and the second blood vessel blood flow information, after calculating the blood flow corresponding to the first blood vessel blood flow information and the second blood vessel blood flow information respectively based on the intermediate blood flow information in the first blood vessel blood flow information and the intermediate blood flow information in the second blood vessel blood flow information, the blood flow reserve characteristic value is then calculated. The intermediate blood flow information can be information such as blood flow velocity and blood pressure.

[0028] In one embodiment, blood flow can be measured using ultrasound Doppler technology. For example, the vascular blood flow information includes intermediate blood flow information, and the intermediate blood flow information includes blood flow velocity or includes blood flow velocity and blood flow direction. The blood flow source signal includes an ultrasound Doppler signal, and the second signal collector includes a first ultrasound transducer for collecting the ultrasound Doppler signal. The first ultrasound transducer can emit ultrasonic waves towards the blood vessel wall and collect the returned echo signal (referred to herein as the ultrasound Doppler signal). Based on the ultrasound Doppler signal, the blood flow velocity can be determined, and then based on the blood flow velocity, the blood flow can be determined. In another embodiment, the blood flow can also be measured using the thermal dilution method. For example, the vascular blood flow information includes intermediate blood flow information, and the intermediate blood flow information includes blood flow velocity. The blood flow source signal includes a blood flow temperature signal, and the second signal collector includes a temperature sensor. The thermal dilution method is a technique for measuring blood flow velocity and cardiac output. This technique is based on the physical principle that when a liquid with a known temperature is injected into the blood, it will cause a local temperature change, and there is a certain mathematical relationship between this change and the blood flow. Therefore, a temperature sensor can be set on the catheter to measure the blood temperature, and then the blood flow can be determined. Exemplarily, the temperature sensor can include one or more of, but not limited to, a thermistor, a thermocouple, and an optical fiber temperature sensor, etc. In yet another embodiment, the blood flow can also be measured using the fractional flow reserve (FFR) technique. For example, the vascular blood flow information includes intermediate blood flow information, and the intermediate blood flow information includes blood flow pressure. The blood flow source signal includes a blood flow pressure signal, and the second signal collector includes a pressure sensor. Based on the FFR technique, the blood flow pressure in the blood vessel can be measured, and there is a certain relationship between the blood flow pressure and the blood flow. Therefore, based on the blood flow pressure, the blood flow can be determined. For the convenience of understanding, the following mainly describes the case where the second signal collector is the first ultrasound transducer. The setting method of other types of signal collectors and the method of registering with the IVUS image can refer to the first ultrasound transducer. The principle of determining the blood flow and the blood flow reserve characteristic value based on the blood flow source signal collected by the corresponding signal collector can be implemented using the determination method in the related technology.

[0029] Figure 2 And Figure 3 respectively show two different exemplary setting methods of the first signal collector and the second signal collector on the catheter according to the embodiments of the present invention. In Figure 2 And Figure 3 In the leftmost side, a left view of the catheter is shown, in the upper right side, a top view of the catheter is shown, and in the lower right side, a front view of the catheter is shown. Figure 2 And Figure 3 The end on the left side of the catheter shown in is the distal end of the catheter, and the end on the right side of the catheter is the proximal end of the catheter. In Figure 2 AndFigure 3 Among them, UT1 represents the first signal collector, and UT2 represents the second signal collector. UT1 and UT2 can be arranged staggeredly along the axial direction of the catheter. In Figure 2 Among them, UT1 is closer to the proximal end of the catheter than UT2. In Figure 3 Among them, UT1 is closer to the distal end of the catheter than UT2. The relative positional relationship between UT1 and UT2 can be set as needed, and the present invention does not limit this. Exemplarily, UT1 can be the second ultrasonic transducer (i.e., IVUS transducer) for collecting intravascular ultrasound echo signals, and UT2 can be the first ultrasonic transducer for collecting ultrasonic Doppler signals. UT1 can be arranged laterally, that is, the element plane of UT1 is parallel to the axis of the catheter. It can be understood that the IVUS transducer belongs to the ultrasonic transducer, and the element plane of the ultrasonic transducer can be perpendicular to the ultrasonic emission direction of the ultrasonic transducer. As described above, the IVUS transducer can be a single-element ultrasonic transducer or a multi-element ultrasonic transducer. Figure 2 and Figure 3 As shown in, UT1 is a single-element ultrasonic transducer. In this case, UT1 can be fixed on the drive shaft of the catheter, and UT1 can rotate with the rotation of the drive shaft of the catheter (with the axis of the catheter as the rotation axis) to perform 360-degree scanning of the blood vessel. UT1 can be responsible for both transmitting ultrasonic waves and receiving intravascular ultrasound echo signals. The received intravascular ultrasound echo signals can be reconstructed into a blood vessel cross-sectional image (i.e., the intravascular ultrasound image described herein) after signal and image processing.

[0030] When UT2 is the first ultrasonic transducer for collecting ultrasonic Doppler signals, the excitation and reception module of UT2 can be completely independent of UT1. Exemplarily, UT2 can be a single-element ultrasonic transducer or a multi-element ultrasonic transducer, and the number of elements in the multi-element ultrasonic transducer can be two or more. If UT2 has more than two elements, it can support both continuous ultrasonic waves (which can be simply referred to as continuous waves) and pulsed ultrasonic waves (which can be simply referred to as pulsed waves). If it is a single-element ultrasonic transducer, it only supports pulsed waves and does not support continuous waves. Taking a two-element ultrasonic transducer as an example, element 1 can be responsible for transmitting ultrasonic waves, and element 2 is responsible for receiving echo signals (i.e., ultrasonic Doppler signals). When UT2 is a single-element ultrasonic transducer, UT2 can be responsible for both transmitting ultrasonic waves and receiving echo signals. Therefore, UT2 can only transmit pulsed waves and cannot transmit continuous waves. When the number of elements of UT2 is greater than 2, by reasonably allocating the functions (transmitting or receiving) of each element and assigning corresponding delays to each element, simple transmit focusing or receive focusing can be achieved to improve the signal-to-noise ratio. When UT1 and UT2 are single-element ultrasonic transducers, the structures of UT1 and UT2 can be similar, except for differences in size and shape. However, the multi-element ultrasonic transducers corresponding to UT1 and UT2 are different and there are structural differences. Compared with the single element, the multi-elements of UT1 can change from a planar distribution to an annular distribution. For UT2, compared with the single element, the multi-elements can still maintain a planar distribution, just by dividing the single element into multiple coplanar elements. When UT2 is the first ultrasonic transducer for collecting ultrasonic Doppler signals, it can be placed forward, and the element plane of UT2 can form an arbitrary angle (i.e., a preset angle) with the axis of the catheter. UT2 can be non-rotating during the retraction process. It can be understood that when UT2 is replaced with a temperature sensor or a pressure sensor, it can still be staggeredly arranged with UT1 in the axial direction of the catheter, and the orientation of UT1 can be set according to the technical requirements of the corresponding technology.

[0031] Due to the limited installation location, there are differences in the vascular regions scanned (or swept) by the first signal collector and the second signal collector at the same actual acquisition time. Therefore, by retracting, the first signal collector and the second signal collector can have a common scanned vascular region. Exemplarily, the host may include a retraction device, which is mechanically connected to the catheter, and the catheter can be driven to retract through the retraction device. The retraction device may internally include a processor or be connected to the processing device of the host, and the retraction speed, etc. can be controlled through the processor inside the retraction device or the processing device of the host. During retraction, it can be controlled that the first signal collector and the second signal collector respectively complete the acquisition of intravascular ultrasound echo signals and blood flow source signals within a preset duration at a single vascular position (based on these two types of information, intravascular ultrasound images and vascular blood flow information can be obtained respectively, so this acquisition process can also be regarded as the acquisition of intravascular ultrasound images and vascular blood flow information). After that, the catheter can be retracted to the next vascular position under the drive of the retraction device. The above preset duration can be, for example, at least one complete cardiac cycle. The vascular positions described herein can be understood as the positions distributed along the axis direction of the catheter for any vascular cross-section, that is, different vascular positions are staggered along the axis direction of the catheter. The retraction method can include but is not limited to continuous retraction, stepwise retraction, etc. During continuous retraction, the retraction speed can be controlled so that the retraction speed is less than a certain preset speed, so that the retraction distance within the preset duration required to stay at a single vascular position can be ignored, that is, it is considered that the retraction distance of the catheter within the preset duration will not affect the acquisition accuracy and registration accuracy of the intravascular ultrasound image and vascular blood flow information at a single vascular position. During retraction, the continuous retraction method is relatively optional, which can speed up the measurement speed. The above retraction and signal acquisition process can be repeated until the acquisition of the intravascular ultrasound echo signals and blood flow source signals corresponding to the entire segment of the blood vessel to be measured is completed.

[0032] Since the intravascular ultrasound echo signal and the blood flow source signal are collected separately, that is, the intravascular ultrasound image and the blood vessel blood flow information are collected separately. Therefore, after all data collection is completed, a series of measured blood vessel blood flow information and intravascular ultrasound images can be matched one by one, that is, registration is performed in terms of acquisition time (which can be simply referred to as information registration). Information registration can be based on the following basic assumptions: 1. The cardiac cycle is basically stable during the entire retraction process; 2. Since the coronary artery has fewer branches and fewer influencing factors affecting blood flow, the blood flow is relatively stable. Therefore, it can be considered that the change patterns of blood flow distribution, blood flow velocity, etc. at the same position within each cardiac cycle remain unchanged in a short period of time. That is, it can be considered that the blood vessel blood flow information measured at the t-th moment of the N-th cardiac cycle is the same as that measured at the t-th moment of the (N + 1)-th cardiac cycle. Therefore, the intravascular ultrasound images and blood vessel blood flow information at the same actual acquisition time in different cardiac cycles collected at the same blood vessel position can be corresponding. In this article, the time corresponding to the same cardiac state in different cardiac cycles is called the same theoretical acquisition time. Since the system collects intravascular ultrasound images while also collecting blood vessel blood flow information, the intravascular ultrasound images and blood vessel blood flow information are strictly one-to-one corresponding in terms of actual acquisition time, which facilitates more accurate information registration.

[0033] After information registration is completed, the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second intravascular ultrasound image when the blood vessel lumen is in the resting state can be selected at any target blood vessel position. When the blood vessel blood flow information includes intermediate blood flow information, the lumen areas corresponding to the above two frames of images can be combined with the intermediate blood flow information to calculate their respective blood flow volumes, and then blood flow reserve characteristic values such as CFR can be obtained. When the blood vessel blood flow information includes blood flow volume, the blood flow reserve characteristic values such as CFR can be directly determined according to the blood flow volumes corresponding to the above two frames of images respectively. Exemplarily, the target blood vessel position can be default selected by the host according to a preset rule. For example, the minimum lumen area of the entire blood vessel to be measured is default calculated as the target blood vessel position. Alternatively, the target blood vessel position can also be manually selected by the user. For example, any blood vessel position is manually selected as the target blood vessel position according to the intravascular ultrasound image. Exemplarily, the frame with the largest lumen area can be selected from the intravascular ultrasound image corresponding to the target blood vessel position (since the lumen area at the same blood vessel position will also increase and decrease due to cardiac contraction and relaxation) as the first intravascular ultrasound image, and the frame with the smallest lumen area can be selected as the second intravascular ultrasound image.

[0034] By using the above-mentioned vascular detection system, the signal collector required for collecting IVUS images and the signal collector required for measuring the blood flow reserve characteristic value can be integrated on the same catheter. In this way, the functions of collecting IVUS images and measuring the blood flow reserve characteristic value can be realized by the same vascular detection system, so as to achieve a comprehensive evaluation of vascular morphology and function, in order to provide more comprehensive information for lesion evaluation and improve the accuracy of cardiovascular disease diagnosis. At the same time, the two types of detections can be completed simultaneously during a single catheter insertion process, which can shorten the operation time, relieve the patient's pain, and reduce the surgical risk. In addition, through this measurement method, the change of the vascular lumen area detected by IVUS can be combined with the stage change of vascular blood flow information, that is, the accuracy of the blood flow volume when the blood vessel reaches the state required for calculating the blood flow reserve characteristic value can be determined more accurately, which helps to improve the accuracy of measuring the blood flow reserve characteristic value.

[0035] According to an embodiment of the present invention, the vascular blood flow information includes intermediate blood flow information, wherein the intermediate blood flow information includes blood flow velocity or includes blood flow velocity and blood flow direction, the blood flow volume source signal includes an ultrasonic Doppler signal, and the second signal collector includes a first ultrasonic transducer for collecting the ultrasonic Doppler signal; or, the intermediate blood flow information includes blood flow velocity, the blood flow volume source signal includes a blood flow temperature signal, and the second signal collector includes a temperature sensor; or, the intermediate blood flow information includes blood flow pressure, the blood flow volume source signal includes a blood flow pressure signal, and the second signal collector includes a pressure sensor.

[0036] Several implementation schemes for measuring the blood flow reserve characteristic value and the corresponding second signal collector, intermediate blood flow information, and blood flow volume source signal have been described above, and will not be elaborated here. According to the above schemes, a variety of different hardware can be used to measure the blood flow reserve characteristic value. The scheme for measuring the blood flow reserve characteristic value by ultrasonic Doppler technology is relatively mature, with low hardware cost and high accuracy. The scheme for measuring the blood flow reserve characteristic value by thermodilution method has high accuracy and is convenient for simultaneously measuring other important hemodynamic parameters, such as stroke volume (SV), systemic vascular resistance (SVR), etc. The scheme for measuring the blood flow reserve characteristic value by FFR is convenient for further evaluating the patient's vascular condition in combination with the FFR index.

[0037] According to an embodiment of the present invention, the first signal collector includes a second ultrasonic transducer for collecting intravascular ultrasound echo signals, the element plane of the second ultrasonic transducer is parallel to the axis of the catheter, and the element plane of the first ultrasonic transducer forms a preset angle with the axis of the catheter.

[0038] Reference Figure 2 and Figure 3, an exemplary setting method is shown in which the element plane of the second ultrasonic transducer is parallel to the axis of the catheter and the element plane of the first ultrasonic transducer forms a preset angle with the axis of the catheter. Those skilled in the art can understand that in order to achieve measurement, there needs to be an angle between the acoustic beam axis of the first ultrasonic transducer and the axis of the catheter, and this angle is a non-90-degree angle. The acoustic beam axis is perpendicular to the element plane of the first ultrasonic transducer, that is to say, there also needs to be an angle (i.e., the preset angle) between the element plane of the first ultrasonic transducer and the axis of the catheter, and the preset angle is a non-zero angle. As Figure 3 shown, for the case where the first ultrasonic transducer is closer to the proximal end of the catheter than the second ultrasonic transducer, the setting methods of the first ultrasonic transducer and the second ultrasonic transducer can be: the second ultrasonic transducer is arranged on the side surface of the catheter close to the distal end of the catheter, and this side surface of the catheter is the surface parallel to the axis direction of the catheter, and the first ultrasonic transducer is arranged in a groove closer to the proximal end of the catheter. Specifically, two groove side surfaces are arranged in the axial direction of the catheter for this groove (that is, one of the two groove side surfaces is closer to the proximal end or the distal end of the catheter than the other), and the first ultrasonic transducer is arranged on the groove side surface closer to the proximal end of the catheter. Exemplarily, each of the two groove side surfaces arranged in the axial direction of the catheter for the groove can be arranged such that the plane passing through the normal line of this groove side surface and the catheter axis is perpendicular to this groove side surface. Further, the catheter main body structure can be arranged so as not to obstruct the scanning of the first ultrasonic transducer. Exemplarily, the length of the groove in the axial direction of the catheter is greater than a set value so that the groove side surface closer to the distal end of the catheter is not within the scanning field of view of the first ultrasonic transducer. Furthermore, the length of the groove can also be reasonably set in combination with the size of the angle between the element plane of the first ultrasonic transducer and the axis of the catheter, so that the first ultrasonic transducer can completely scan while the length of the groove is not too long, thereby shortening the overall length of the catheter. As described above, the second ultrasonic transducer can be designed to be rotatable or non-rotatable during catheter withdrawal. For the first ultrasonic transducer, during catheter withdrawal, it can be kept non-rotating, so that when collecting the blood flow source signal at a certain blood vessel position, the first ultrasonic transducer can repeatedly collect data at the same blood vessel position for about 8 to 10 times, for example, so that single-frame blood vessel blood flow information can be obtained through the data collected multiple times.

[0039] Through the above solutions, the second ultrasonic transducer and the first ultrasonic transducer can be arranged in a suitable orientation, and this setting method helps to accurately collect intravascular ultrasonic images and blood vessel blood flow information.

[0040] According to an embodiment of the present invention, the first ultrasonic transducer is further configured to emit pulsed ultrasonic waves and receive corresponding echo signals as blood flow source signals.

[0041] When the second signal collector includes a first ultrasonic transducer for collecting the ultrasonic Doppler signal, the intermediate blood flow information may include the blood flow velocity or may include both the blood flow velocity and the blood flow direction. In addition to the blood flow velocity, obtaining the blood flow direction additionally can provide users with more diverse blood vessel blood flow information, which helps to better assist users in evaluating the blood vessel conditions of patients. In the case where the first ultrasonic transducer emits continuous ultrasonic waves (which can be called continuous Doppler technology), the blood flow velocity can be determined based on the blood flow source signal, and the blood flow direction can also be determined. The advantage of continuous wave Doppler technology is high signal-to-noise ratio, but it requires multiple array elements to achieve, and the system complexity is high. In the case where the first ultrasonic transducer emits pulsed ultrasonic waves (which can be called pulsed Doppler technology), the blood flow velocity can also be determined based on the blood flow source signal, and the blood flow direction can also be determined. Pulsed Doppler technology can be achieved with only a single array element, with low system complexity and low hardware cost. Therefore, pulsed Doppler technology can be preferably adopted.

[0042] The host can process the ultrasonic Doppler signal received from the first ultrasonic transducer through the following signal processing methods to calculate the blood flow velocity or to calculate the blood flow velocity and the blood flow direction: According to the principle of the Doppler effect, based on the sound velocity of ultrasonic waves in the blood flow medium, the Doppler frequency shift of the ultrasonic Doppler signal, the central frequency of the emitted ultrasonic waves, and the angle between the sound beam axis and the axis of the catheter, the blood flow velocity or the blood flow velocity and the blood flow direction can be determined.

[0043] The above signal processing method for the ultrasonic Doppler signal can be expressed by the following formula:

[0044]

[0045] Among them, V is the blood flow velocity, f d is the Doppler frequency shift of the ultrasonic Doppler signal, f0 is the central frequency of the emitted ultrasonic waves, c is the sound velocity of ultrasonic waves in the blood flow medium, is the angle between the sound beam axis and the axis of the catheter. f0, c, and are preset parameters. V can optionally carry a positive or negative sign. At this time, this positive or negative sign can be used to represent the blood flow direction. For example, either the positive sign or the negative sign can be used to represent approaching the catheter, that is, flowing from the distal end to the proximal end of the catheter, and the other can be used to represent departing from the catheter, that is, flowing from the proximal end to the distal end of the catheter.

[0046] In the case where the first ultrasonic transducer emits pulsed ultrasonic waves, the upper limit of the measurement of the blood flow velocity is affected by the pulse repetition frequency, and the two satisfy the following relationship:

[0047]

[0048] Among them, V max$V_{max}$ is the maximum measurable blood flow velocity, PRF is the pulse repetition frequency, $f_0$ is the center frequency of the transmitted ultrasonic wave, $c$ is the sound velocity in the blood flow medium, and $\theta$ is the angle between the array element plane of the first ultrasonic transducer and the axis of the catheter. However, there is no such limitation for the first ultrasonic transducer to transmit continuous ultrasonic waves. Therefore, if the blood flow velocity is greater than the measurable velocity range when the first ultrasonic transducer transmits pulsed ultrasonic waves, the user can manually select to use continuous ultrasonic waves for measurement according to needs.

[0049] According to an embodiment of the present invention, when the intermediate blood flow information includes the blood flow velocity or includes the blood flow velocity and the blood flow direction, the blood vessel detection system further includes a display, and the host is communicatively connected to the display. The host can be used to control the visual display of the intermediate blood flow information. The visual display can, for example, display the intermediate blood flow information in the display by means of text, graphics, adding false colors, etc. Exemplarily, when visually displaying the intermediate blood flow information, the intermediate blood flow information can be fused on the intravascular ultrasound image matching the intermediate blood flow information and output to the display for display.

[0050] Further, the host is also used to perform color coding on the intermediate blood flow information, and superimpose the color coding result on the intravascular ultrasound image matching the intermediate blood flow information according to the registration result and output it to the display for display. If the intravascular ultrasound images are switched and displayed frame by frame, the corresponding color coding results of the intermediate blood flow information can also be switched and displayed correspondingly. For example, when playing a video containing intravascular ultrasound images, every time a frame of the intravascular ultrasound image is refreshed, the corresponding intermediate blood flow information is also updated in real time.

[0051] Exemplarily, in the case of determining the blood flow velocity or determining the blood flow velocity and the blood flow direction from the blood flow volume source signal collected by the first ultrasonic transducer, the host can perform color coding on the determined blood flow velocity or on the blood flow velocity and the blood flow direction and superimpose the color coding result on the intravascular ultrasound image for display. Exemplarily, different blood flow directions can be represented by different colors, and different blood flow velocities can be represented by different color depths of the same color. For example, red can be used to represent approaching the catheter, that is, flowing from the distal end to the proximal end of the catheter, and blue can be used to represent departing from the catheter, that is, flowing from the proximal end to the distal end of the catheter. Exemplarily, the darker the color, the faster the blood flow velocity can be represented. Since the information registration between the blood vessel blood flow information and the intravascular ultrasound image has been completed, the host can directly superimpose the color coding result on the corresponding intravascular ultrasound image and output the intravascular ultrasound image with the superimposed color coding result to the display for display. Exemplarily, the target processing operation can include the above operations of performing color coding on the intermediate blood flow information, and superimposing the color coding result on the intravascular ultrasound image matching the intermediate blood flow information according to the registration result and outputting it to the display for display.

[0052] Through the above solution, the intermediate blood flow information can be color-coded and the color-coded result can be superimposed on the corresponding intravascular ultrasound image for display, which facilitates the user to view the intermediate blood flow information while viewing the intravascular ultrasound image, and the user experience is relatively good.

[0053] According to an embodiment of the present invention, the host specifically registers the intravascular ultrasound image and the vascular blood flow information in terms of the acquisition time in the following manner: determining at least the actual acquisition time difference between the intravascular ultrasound image and the vascular blood flow information according to the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter and the retraction speed of the catheter; according to the actual acquisition time difference, matching the scanned vascular positions corresponding to the intravascular ultrasound image and the scanned vascular positions corresponding to the vascular blood flow information, and determining the intravascular ultrasound image and the vascular blood flow information corresponding to the same vascular position scanned at the same theoretical acquisition time to obtain a registration result, where the registration result includes the matching relationship between the intravascular ultrasound image and the vascular blood flow information, and the intravascular ultrasound image and the vascular blood flow information corresponding to the same vascular position scanned at the same theoretical acquisition time are mutually matching intravascular ultrasound image and vascular blood flow information.

[0054] The distance between the first signal collector and the second signal collector in the direction of the axis of the catheter can be represented by the distance between any first preset feature point on the first signal collector and any second preset feature point on the second signal collector in the direction of the axis of the catheter. The first preset feature point and the second preset feature point can be, for example, a geometric center point, a center of gravity, etc. The distance between the first signal collector and the second signal collector in the direction of the axis of the catheter can be pre-measured and stored in the storage device of the host after the catheter is assembled. The retraction speed of the catheter can be a default speed or can be determined according to the speed set by the user on the host during actual measurement.

[0055] If the vascular scanning regions scanned by the first signal collector and the second signal collector are completely coincident when they are located at the same vascular position, the actual acquisition time difference between the intravascular ultrasound image and the vascular blood flow information can be determined according to the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter and the retraction speed of the catheter. The absolute value of the actual acquisition time difference can be equal to the ratio of the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter to the retraction speed. If the vascular scanning regions scanned by the first signal collector and the second signal collector are not completely coincident when they are located at the same vascular position, the actual acquisition time difference between the intravascular ultrasound image and the vascular blood flow information can be determined according to the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter, the retraction speed of the catheter, and further in combination with the respective scanning directions of the first signal collector and the second signal collector. The temporal sequence of the intravascular ultrasound image and the vascular blood flow information at the same vascular position, which can be distinguished by the positive or negative sign of the actual acquisition time difference, can depend on the relative positional relationship between the first signal collector and the second signal collector. For example, if the first signal collector is closer to the proximal end of the catheter than the second signal collector, the actual acquisition time of the intravascular ultrasound image can be before the vascular blood flow information, and the actual acquisition time difference between the two can be positive. If the first signal collector is closer to the distal end of the catheter than the second signal collector, the actual acquisition time of the intravascular ultrasound image can be after the vascular blood flow information, and the actual acquisition time difference between the two can be negative.

[0056] After determining the actual acquisition time difference, the vascular positions scanned corresponding to the intravascular ultrasound image and the vascular positions scanned corresponding to the vascular blood flow information can be matched to determine the intravascular ultrasound image and the vascular blood flow information corresponding to the same vascular position scanned at the same theoretical acquisition time. For example, according to the actual acquisition time difference, either the vascular positions scanned corresponding to the intravascular ultrasound image or the vascular positions scanned corresponding to the vascular blood flow information can be moved on the time axis towards alignment with the other. Specifically, for example, if the intravascular ultrasound image is acquired Δt seconds earlier than the vascular blood flow information, the intravascular ultrasound image acquired at each t moment can be aligned with the vascular blood flow information acquired at the t - Δt moment, and it is considered that the vascular position corresponding to the intravascular ultrasound image acquired at the t moment and the vascular position corresponding to the vascular blood flow information acquired at the t - Δt moment are matched, that is, it is considered that they are the intravascular ultrasound image and the vascular blood flow information corresponding to the same vascular position scanned at the same theoretical acquisition time.

[0057] By adopting the above solution, the matching relationship between the intravascular ultrasound image and the intravascular blood flow information can be determined based on the actual acquisition time difference between the intravascular ultrasound image and the intravascular blood flow information. Since the intravascular ultrasound image and the intravascular blood flow information are set on the same catheter and their actual acquisition times strictly correspond to each other, the intravascular ultrasound image and the intravascular blood flow information can be registered very quickly and accurately through the actual acquisition time difference between the two.

[0058] According to an embodiment of the present invention, the host specifically determines the actual acquisition time difference between the intravascular ultrasound image and the intravascular blood flow information in the following manner: determining the actual acquisition time difference between the intravascular ultrasound image and the intravascular blood flow information according to a preset angle between the array plane of the first ultrasonic transducer and the axis of the catheter, the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter, and the retraction speed of the catheter.

[0059] When the first ultrasonic transducer scans at each vascular position, it emits ultrasonic waves along a preset direction. For the same scan line (i.e., the ultrasonic beam line emitted each time), a frame of ultrasonic Doppler signal can be acquired, and the host computer can correspondingly obtain a frame of vascular blood flow information based on this frame of ultrasonic Doppler signal. As described above, each vascular position is the position where the vascular cross-section is distributed along the axis direction of the catheter, that is, different vascular positions are staggered in the direction along the axis of the catheter. Exemplarily, each vascular position may include a plurality of position points distributed in the direction perpendicular to the axis of the catheter, that is, different position points included in the same vascular position are staggered in the direction perpendicular to the axis of the catheter. A frame of ultrasonic Doppler signal may include ultrasonic Doppler signals acquired at different depths (i.e., at the position points where the depths are located) on the same scan line. Correspondingly, a frame of vascular blood flow information may include vascular blood flow information corresponding to each depth (i.e., corresponding to the position point where the depth is located) determined one-to-one based on the ultrasonic Doppler signals acquired at different depths on the same scan line. Since there is a preset angle (which can be called the first preset angle) between the array element plane of the first ultrasonic transducer and the axis of the catheter, that is, there is a preset angle (which can be called the second preset angle) between the beam axis of the first ultrasonic transducer and the axis of the catheter, and the sum of the first preset angle and the second preset angle is 90 degrees. Therefore, when calculating the actual acquisition time difference between the vascular blood flow information obtained by scanning at each depth on the scan line through the first ultrasonic transducer and the intravascular ultrasound image acquired by the second ultrasonic transducer at the same time, the position points corresponding to the vascular blood flow information obtained by scanning at each depth on the scan line can be mapped to the direction along the axis of the catheter according to the trigonometric function relationship, and then summed with the distance between the first ultrasonic transducer and the second ultrasonic transducer in the direction along the axis of the catheter. The result of the summation can be regarded as the distance difference between the vascular position to which the position points corresponding to the vascular blood flow information obtained by scanning at each depth on the scan line belong and the vascular position corresponding to the intravascular ultrasound image acquired at the same time. Subsequently, the ratio of the result of the summation to the retraction speed can be calculated, and the ratio is used as the actual acquisition time difference. For example, assuming that the angle between the array element plane of the first ultrasonic transducer and the axis of the catheter is θ, the distance between the first signal collector and the second signal collector in the direction along the axis of the catheter is L, and the retraction speed of the catheter is v, then for the vascular blood flow information obtained at the depth d on the same scan line (i.e., the ultrasonic beam line emitted each time) through the first ultrasonic transducer, the actual acquisition time difference between it and the corresponding intravascular image is:

[0060] It can be understood that the scan line has different depths. For each scan line emitted each time, the closer it is to the array element plane of the first ultrasonic transducer, the smaller the depth d.

[0061] During registration, since information of at least one cardiac cycle is completely collected for each blood vessel position, the host can first automatically calculate the lumen area of all intravascular ultrasound images collected, and match the intravascular ultrasound images collected at different blood vessel positions according to the states in the cardiac cycle based on a preset algorithm to determine which cardiac phase each intravascular ultrasound image belongs to. Subsequently, based on parameters such as the preset angle between the array plane of the first ultrasound transducer and the axis of the catheter, the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter, and the retraction speed of the catheter, the host can calculate the actual acquisition time difference between the first signal collector and the second signal collector when scanning the same blood vessel position through trigonometric relations and the formula of distance / speed. Subsequently, the registration result of the intravascular ultrasound image and the blood flow information of the blood vessel can be determined in combination with the actual acquisition time difference.

[0062] Through the above solution, when the second signal collector includes the first ultrasound transducer, the preset angle between the array plane of the first ultrasound transducer and the axis of the catheter can be considered in the registration process of the intravascular ultrasound image and the blood flow information of the blood vessel, which helps to improve the accuracy of registration.

[0063] According to an embodiment of the present invention, the host specifically registers the intravascular ultrasound image and the blood flow information in terms of acquisition time in the following manner: according to the acquisition time difference, align the first blood vessel scanning area corresponding to the intravascular ultrasound image and the second blood vessel scanning area corresponding to the blood flow information on the time axis; delete the non-overlapping areas in the first blood vessel scanning area and the second blood vessel scanning area after alignment, and determine that the position points of the overlapping area in the first blood vessel scanning area and the second blood vessel scanning area after alignment are the position points of the intravascular ultrasound image and the position points of the blood flow information obtained by scanning at the same time.

[0064] The blood vessel scanning areas of the first signal collector and the second signal collector do not necessarily overlap. Here, an example is described where the first signal collector is the second ultrasound transducer and the second signal collector is the first ultrasound transducer. The projection of the area scanned by the second ultrasound transducer in a period of time on the cross-sectional image along the retraction direction is a rectangular area, and the projection of the area scanned by the first ultrasound transducer in the same period of time on the cross-sectional image along the retraction direction is a parallelogram area, and the overlapping area of the two is the common scanning area. Therefore, the first blood vessel scanning area corresponding to the intravascular ultrasound image and the second blood vessel scanning area corresponding to the blood flow information can be aligned on the time axis, the non-overlapping areas after alignment are deleted, and the overlapping areas are matched. The position points of the overlapping area in the first blood vessel scanning area and the second blood vessel scanning area after alignment are the position points of the intravascular ultrasound image and the position points of the blood flow information obtained by scanning at the same time.

[0065] Through the above solution, the non-overlapping areas in the first blood vessel scanning area and the second blood vessel scanning area can be deleted during registration, which can omit unnecessary information, reduce the subsequent information processing volume, and improve the accuracy of the registration result.

[0066] According to an embodiment of the present invention, the host is further configured to: in response to user input information, determine the target blood vessel position, or determine the blood vessel position with the smallest lumen area in the intravascular ultrasound image as the target blood vessel position; select a first intravascular ultrasound image and a second intravascular ultrasound image from the intravascular ultrasound images collected at the target blood vessel position.

[0067] As described above, the host can default to select the target blood vessel position according to a preset rule, or the user can manually select the target blood vessel position. The preset rule can include, for example, determining the blood vessel position with the smallest lumen area in the intravascular ultrasound image as the target blood vessel position. Exemplarily, any existing or future possible intima-media extraction algorithm (such as the deep learning U-Net algorithm or other algorithms) can be used to determine the lumen area corresponding to each intravascular ultrasound image. For example, the blood vessel and the background in the intravascular ultrasound image can be segmented by binarization, and then the number of pixels corresponding to the blood vessel is calculated. Since the spatial area corresponding to each pixel is known in advance, the lumen area can be obtained by multiplying the number of pixels by the spatial area corresponding to each pixel. The host can include any type of input device or be communicatively connected to an input device, and the input device can include, but is not limited to, a keyboard, a mouse, a touch panel, etc. The host can receive user input information through the input device. After determining the target blood vessel position, a first intravascular ultrasound image and a second intravascular ultrasound image can be selected from the intravascular ultrasound images collected at the target blood vessel position. For example, the intravascular ultrasound image with the largest lumen area can be selected as the first intravascular ultrasound image and the intravascular ultrasound image with the smallest lumen area can be selected as the second intravascular ultrasound image from the intravascular ultrasound images corresponding to the target blood vessel position.

[0068] The above target processing operation can include the operations of "in response to user input information, determining the target blood vessel position, or determining the blood vessel position with the smallest lumen area in the intravascular ultrasound image as the target blood vessel position; selecting a first intravascular ultrasound image and a second intravascular ultrasound image from the intravascular ultrasound images collected at the target blood vessel position".

[0069] According to the above solution, the host can automatically select or the user can select the target blood vessel position and obtain the corresponding first intravascular ultrasound image and second intravascular ultrasound image. The automatic selection scheme of the host can improve the automation and intelligence of the system, save user operations, and provide a better user experience. The user's selection of the target blood vessel position can facilitate the user to select a suitable blood vessel position for observation according to the needs and the patient's condition.

[0070] According to an embodiment of the present invention, the catheter includes a base body and a rotatable transmission shaft. The first signal collector is disposed on the transmission shaft, and the second signal collector is disposed on the base body. The host includes a retraction device and a rotation device. The retraction device is mechanically connected to the base body and the transmission shaft for driving the base body and the transmission shaft to retract. The rotation device is mechanically connected to the transmission shaft for driving the transmission shaft to rotate during retraction.

[0071] As described above, the first signal collector may rotate or not rotate during catheter retraction, and preferably, the second signal collector does not rotate during catheter retraction. When the first signal collector can rotate and the second signal collector does not rotate, the first signal collector and the second signal collector can be separately disposed. For example, the catheter includes a base body and a rotatable transmission shaft. The base body does not rotate during retraction, and the second signal collector is disposed on the base body. The first signal collector is disposed on the transmission shaft. The base body may be, for example, the outer shell of the catheter, and the transmission shaft may be disposed inside the outer shell. In addition, the retraction device may be mechanically connected to the base body and the transmission shaft, that is, integrally connected to the catheter, so as to drive the entire catheter to retract.

[0072] Through the above solution, the separate setting of the first signal collector and the second signal collector can be achieved, and this separate setting solution helps to independently control the rotation conditions of the first signal collector and the second signal collector during retraction.

[0073] Figure 4 An exemplary structural diagram of a blood vessel detection system according to an embodiment of the present invention is shown. As Figure 4 shown, the host may include a rotation device and a retraction device, and the rotation device and the retraction device are mechanically connected to the catheter. Figure 4 It is shown that the rotation device and the retraction device may be connected (which at least includes a communication connection), which is optional, and the two may also be independent of each other. In addition, as Figure 4As shown, the host may include a processing device, which may include an IVUS imaging excitation module, an IVUS signal processing module, an image processing module, a lumen area calculation module, an ultrasonic Doppler excitation module, an ultrasonic Doppler signal processing module, a blood flow velocity and direction calculation module, an information registration module, and a required frame extraction and CFR calculation module. Any one or more of the above modules in the processing device may be implemented by independent hardware, such as by using independent processing chips such as FPGAs or MCUs and their peripheral circuits, or may be implemented by software algorithm modules. The IVUS imaging excitation module may excite the first signal processor (i.e., the IVUS transducer) to emit ultrasonic waves. The IVUS signal processing module may receive the intravascular ultrasound echo signal from the first signal processor and perform signal processing. The image processing module may reconstruct the IVUS image based on the signal processing result of the IVUS signal processing module. The lumen area calculation module may calculate the lumen area corresponding to the IVUS image. The ultrasonic Doppler excitation module may excite the second signal processor (i.e., the first ultrasonic transducer) to emit ultrasonic waves. The ultrasonic Doppler signal processing module may receive the ultrasonic Doppler signal from the second signal processor and perform signal processing. The blood flow velocity and direction calculation module may calculate the blood flow velocity and blood flow direction based on the signal processing result of the ultrasonic Doppler signal processing module to obtain intermediate blood flow information. The information registration module may register the intermediate blood flow information and the IVUS image. The required frame extraction and CFR calculation module may determine the first blood vessel blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood vessel blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculate the CFR of the blood vessel to be measured based on the first blood vessel blood flow information and the second blood vessel blood flow information.

[0074] According to another aspect of the present invention, there is provided an electronic device, including a processing device and a storage device, wherein computer program instructions are stored in the storage device, and when the computer program instructions are run by the processing device, they are used to perform the following operations: generating an intravascular ultrasound image of a blood vessel to be measured based on the intravascular ultrasound echo signal of the blood vessel to be measured collected by the first signal collector of the blood vessel detection system; determining the blood flow information of the blood vessel to be measured based on the blood flow source signal of the blood vessel to be measured collected by the second signal collector of the blood vessel detection system; registering the intravascular ultrasound image and the blood flow information in terms of the acquisition time; determining the first blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculating the blood flow reserve characteristic value of the blood vessel to be measured based on the first blood flow information and the second blood flow information, wherein the blood flow information includes the blood flow volume of the blood vessel to be measured and / or the intermediate blood flow information for determining the blood flow volume of the blood vessel to be measured, and the blood flow source signal is a signal for determining the blood flow volume. The electronic device may be the above-mentioned host computer.

[0075] According to still another aspect of the present invention, there is also provided a storage medium, on which program instructions are stored, and when the program instructions are run by a computer or a processor, the computer or the processor is made to perform the following operations: generating an intravascular ultrasound image of a blood vessel to be measured based on the intravascular ultrasound echo signal of the blood vessel to be measured collected by the first signal collector of the blood vessel detection system; determining the blood flow information of the blood vessel to be measured based on the blood flow source signal of the blood vessel to be measured collected by the second signal collector of the blood vessel detection system; registering the intravascular ultrasound image and the blood flow information in terms of the acquisition time; determining the first blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculating the blood flow reserve characteristic value of the blood vessel to be measured based on the first blood flow information and the second blood flow information, wherein the blood flow information includes the blood flow volume of the blood vessel to be measured and / or the intermediate blood flow information for determining the blood flow volume of the blood vessel to be measured, and the blood flow source signal is a signal for determining the blood flow volume. The storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0076] According to another aspect of the present invention, there is also provided a computer program product, including computer program instructions which are used to perform the following operations when running: generating an intravascular ultrasound image of a blood vessel to be measured based on the intravascular ultrasound echo signal of the blood vessel to be measured collected by the first signal collector of the blood vessel detection system; determining the blood flow information of the blood vessel to be measured according to the blood flow source signal of the blood vessel to be measured collected by the second signal collector of the blood vessel detection system; registering the intravascular ultrasound image and the blood flow information in terms of the acquisition time; determining the first blood flow information matched with the first intravascular ultrasound image when the blood vessel lumen reaches the maximum dilation state and the second blood flow information matched with the second intravascular ultrasound image when the blood vessel lumen is in the resting state according to the registration result, and calculating the blood flow reserve characteristic value of the blood vessel to be measured according to the first blood flow information and the second blood flow information, wherein the blood flow information includes the blood flow of the blood vessel to be measured and / or the intermediate blood flow information for determining the blood flow of the blood vessel to be measured, and the blood flow source signal is a signal for determining the blood flow.

[0077] Those of ordinary skill in the art can understand the specific implementation and beneficial effects of the above-mentioned electronic device, storage medium and computer program product by reading the above specific description of the blood vessel detection system. For the sake of brevity, they will not be elaborated here.

[0078] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present invention thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as claimed in the appended claims.

[0079] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0080] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0081] In the description provided herein, numerous specific details are set forth. It will be understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0082] Similarly, it should be understood that in order to streamline the present invention and aid in understanding one or more of the various inventive aspects, in the description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, the methods of the present invention should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, the inventive point lies in that the corresponding technical problems can be solved by features less than all the features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate embodiment of the present invention.

[0083] Those skilled in the art will appreciate that, except where features are mutually exclusive, any combination may be employed of all the features disclosed in this specification (including the accompanying claims, abstract and drawings), as well as any of the processes or units of any method or apparatus so disclosed. Each feature disclosed in this specification (including the accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

[0084] In addition, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features of different embodiments are meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0085] Each component embodiment of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all of the functions of some modules in the blood vessel detection system according to the embodiments of the present invention. The present invention can also be implemented as a device program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0086] It should be noted that the above embodiments illustrate the present invention rather than limit the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several devices, several of these devices can be embodied by the same item of hardware. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

[0087] The above are only the specific embodiments of the present invention or the descriptions of the specific embodiments. The protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all of them should be covered by the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A blood vessel detection system, characterized in that: It comprises a catheter and a host, wherein the catheter is provided with a first signal collector and a second signal collector, wherein the first signal collector is used to collect intravascular ultrasonic echo signals, and the second signal collector is used to collect blood flow source signals, wherein the blood flow source signals are signals used to determine blood flow; The host is communicatively connected to the first signal collector and the second signal collector respectively, and is used to: generate an intravascular ultrasound image of the blood vessel to be measured according to the intravascular ultrasound echo signal of the blood vessel to be measured collected by the first signal collector, determine the vascular blood flow information of the blood vessel to be measured according to the blood flow source signal of the blood vessel to be measured collected by the second signal collector, align the intravascular ultrasound image and the vascular blood flow information in terms of acquisition time, determine the first vascular blood flow information matched by the first intravascular ultrasound image when the vascular lumen reaches the maximum expansion state and the second vascular blood flow information matched by the second intravascular ultrasound image when the vascular lumen is in a resting state according to the alignment result, and calculate the blood flow reserve characteristic value of the blood vessel to be measured according to the first vascular blood flow information and the second vascular blood flow information, the vascular blood flow information including the blood flow of the blood vessel to be measured and / or the intermediate blood flow information of the blood vessel to be measured for determining the blood flow.

2. The blood vessel detection system according to claim 1, characterized in that: The vascular blood flow information includes the intermediate blood flow information, wherein: The intermediate blood flow information includes blood flow velocity or blood flow velocity and blood flow direction, the blood flow source signal includes an ultrasonic Doppler signal, and the second signal collector includes a first ultrasonic transducer for collecting the ultrasonic Doppler signal; or, The intermediate blood flow information includes blood flow velocity, the blood flow source signal includes a blood flow temperature signal, and the second signal collector includes a temperature sensor; or, The intermediate blood flow information includes blood flow pressure, the blood flow source signal includes a blood flow pressure signal, and the second signal collector includes a pressure sensor.

3. The blood vessel detection system according to claim 2, characterized in that: The first signal collector includes a second ultrasonic transducer for collecting the intravascular ultrasonic echo signal, the array element plane of the second ultrasonic transducer is parallel to the axis of the catheter, and the array element plane of the first ultrasonic transducer forms a preset angle with the axis of the catheter.

4. The blood vessel detection system according to claim 2, characterized in that: The first ultrasonic transducer is also used to transmit pulsed ultrasonic waves and receive corresponding echo signals as the blood flow source signals.

5. The blood vessel detection system according to claim 2, characterized in that: When the intermediate blood flow information includes blood flow velocity or blood flow velocity and blood flow direction, the blood vessel detection system further includes a display, and the host is in communication connection with the display. The host is also used to color-code the intermediate blood flow information, and superimpose the color-coding result on the intravascular ultrasound image matching the intermediate blood flow information according to the registration result, and output it to the display for display.

6. The blood vessel detection system according to any one of claims 1 to 5, characterized in that: The host specifically registers the intravascular ultrasound image and the vascular blood flow information in terms of acquisition time in the following manner: Determine an actual acquisition time difference between the intravascular ultrasound image and the blood vessel blood flow information at least based on the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter and the withdrawal speed of the catheter; According to the actual acquisition time difference, the scanned blood vessel position corresponding to the intravascular ultrasound image and the scanned blood vessel position corresponding to the vascular blood flow information are matched, and the intravascular ultrasound image and vascular blood flow information corresponding to the same blood vessel position scanned at the same theoretical acquisition time are determined to obtain the registration result, which includes a matching relationship between the intravascular ultrasound image and the vascular blood flow information. The intravascular ultrasound image and vascular blood flow information corresponding to the same blood vessel position scanned at the same theoretical acquisition time are mutually matching intravascular ultrasound images and vascular blood flow information.

7. The blood vessel detection system according to claim 6 as referred to claim 3, characterized in that: The host determines the actual acquisition time difference between the intravascular ultrasound image and the vascular blood flow information in the following manner: The actual acquisition time difference between the intravascular ultrasound image and the vascular blood flow information is determined based on the preset angle between the array element plane of the first ultrasonic transducer and the axis of the catheter, the distance between the first signal collector and the second signal collector in the direction of the axis of the catheter, and the withdrawal speed of the catheter.

8. The blood vessel detection system according to claim 6, characterized in that: The host specifically matches the scanned blood vessel position corresponding to the intravascular ultrasound image with the scanned blood vessel position corresponding to the blood vessel blood flow information in the following manner: According to the actual acquisition time difference, aligning a first blood vessel scanned area corresponding to the intravascular ultrasound image with a second blood vessel scanned area corresponding to the blood vessel blood flow information on a time axis; The non-overlapping areas in the first blood vessel scanning area and the second blood vessel scanning area after alignment are deleted, and the blood vessel positions in the overlapping areas in the first blood vessel scanning area and the second blood vessel scanning area after alignment are determined as the same blood vessel position scanned at the same theoretical acquisition time, so as to determine the intravascular ultrasound image and vascular blood flow information corresponding to the same blood vessel position scanned at the same theoretical acquisition time.

9. The blood vessel detection system according to any one of claims 1 to 5, characterized in that: The host is also used to: In response to user input information, determining the target blood vessel position, or determining the blood vessel position with the smallest lumen area as the target blood vessel position according to the intravascular ultrasound image; The first intravascular ultrasound image and the second intravascular ultrasound image are selected from intravascular ultrasound images acquired at the target blood vessel position.

10. The blood vessel detection system according to any one of claims 1 to 5, characterized in that: The catheter comprises a base and a rotatable transmission shaft, the first signal collector is arranged on the transmission shaft, and the second signal collector is arranged on the base. The main machine includes a retracting device and a rotating device. The retracting device is mechanically connected to the base and the transmission shaft for driving the base and the transmission shaft to retract. The rotating device is mechanically connected to the transmission shaft for driving the transmission shaft to rotate during the retracting process.

11. An electronic device comprising a processing device and a storage device, characterized in that: The storage device stores computer program instructions, which are used by the processing device to perform the following operations when the processing device is running: generating an intravascular ultrasound image of the blood vessel to be detected according to the intravascular ultrasound echo signal of the blood vessel to be detected collected by the first signal collector of the blood vessel detection system; Determining blood flow information of the blood vessel to be detected based on the blood flow source signal of the blood vessel to be detected collected by the second signal collector of the blood vessel detection system; Registering the intravascular ultrasound image and the vascular blood flow information in terms of acquisition time; The first blood vessel blood flow information matched by the first intravascular ultrasound image when the blood vessel lumen reaches the maximum expansion state and the second blood vessel blood flow information matched by the second intravascular ultrasound image when the blood vessel lumen is in a resting state are determined according to the registration result, and the blood flow reserve characteristic value of the blood vessel to be measured is calculated according to the first blood vessel blood flow information and the second blood vessel blood flow information, the blood vessel blood flow information includes the blood flow rate of the blood vessel to be measured and / or the intermediate blood flow information of the blood vessel to be measured for determining the blood flow rate, and the blood flow source signal is a signal for determining the blood flow rate.

12. A storage medium having program instructions stored thereon, characterized in that: The program instructions are used to perform the following operations when running: generating an intravascular ultrasound image of the blood vessel to be detected according to the intravascular ultrasound echo signal of the blood vessel to be detected collected by the first signal collector of the blood vessel detection system; Determining blood flow information of the blood vessel to be detected based on the blood flow source signal of the blood vessel to be detected collected by the second signal collector of the blood vessel detection system; Registering the intravascular ultrasound image and the vascular blood flow information in terms of acquisition time; The first blood vessel blood flow information matched by the first intravascular ultrasound image when the blood vessel lumen reaches the maximum expansion state and the second blood vessel blood flow information matched by the second intravascular ultrasound image when the blood vessel lumen is in a resting state are determined according to the registration result, and the blood flow reserve characteristic value of the blood vessel to be measured is calculated according to the first blood vessel blood flow information and the second blood vessel blood flow information, the blood vessel blood flow information includes the blood flow rate of the blood vessel to be measured and / or the intermediate blood flow information of the blood vessel to be measured for determining the blood flow rate, and the blood flow source signal is a signal for determining the blood flow rate.

13. A computer program product comprising computer program instructions, characterized in that The computer program instructions are used to perform the following operations when executed: generating an intravascular ultrasound image of the blood vessel to be detected according to the intravascular ultrasound echo signal of the blood vessel to be detected collected by the first signal collector of the blood vessel detection system; Determining blood flow information of the blood vessel to be detected based on the blood flow source signal of the blood vessel to be detected collected by the second signal collector of the blood vessel detection system; Registering the intravascular ultrasound image and the vascular blood flow information in terms of acquisition time; The first blood vessel blood flow information matched by the first intravascular ultrasound image when the blood vessel lumen reaches the maximum expansion state and the second blood vessel blood flow information matched by the second intravascular ultrasound image when the blood vessel lumen is in a resting state are determined according to the registration result, and the blood flow reserve characteristic value of the blood vessel to be measured is calculated according to the first blood vessel blood flow information and the second blood vessel blood flow information, the blood vessel blood flow information includes the blood flow rate of the blood vessel to be measured and / or the intermediate blood flow information of the blood vessel to be measured for determining the blood flow rate, and the blood flow source signal is a signal for determining the blood flow rate.

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