A flow rate detection method, system and storage medium

Abstract

The present specification discloses a flow velocity detection method, comprising: acquiring image data; determining parameters related to phase change of at least one detection point based on the image data; determining a first flow velocity of at least one detection point based on the parameters related to phase change and a positional relationship between at least one detection point and at least one transmitting point and multiple receiving points.

Description

Technical Field

[0001] The present invention relates to the field of flow rate detection, and in particular to a flow rate detection method and system. Background Art

[0002] Flow velocity detection can detect the movement speed of the target object based on the image data of the target object. The image data of the target object can be obtained based on the phase change of the echo data at the same position of the target object at different times. However, due to the limitation of the scanning mode, the system can only detect the phase change along the transmission direction. In order to obtain the accurate flow velocity of the target object, it is necessary to adjust the transmission angle of the scanning signal or manually adjust the position of the scanning probe.

[0003] Therefore, it is desired to provide a flow velocity detection method and system, which can automatically detect the flow velocity of a target object in any direction and improve the frame rate of imaging. Summary of the invention

[0004] One aspect of the present specification provides a flow velocity detection method, the method comprising: acquiring image data; determining parameters related to phase change of at least one detection point based on the image data; determining a first flow velocity of at least one detection point based on the parameters related to phase change and a positional relationship between at least one detection point and at least one transmitting point and multiple receiving points.

[0005] One aspect of the present specification provides a flow velocity detection system, the system comprising: at least one storage medium storing at least one set of instructions; and at least one processor configured to communicate with the at least one storage medium, wherein, when executing the at least one set of instructions, the at least one processor is instructed to cause the system to: acquire image data; determine parameters related to phase change of at least one detection point based on the image data; determine a first flow velocity of at least one detection point based on the parameters related to phase change and a positional relationship between the at least one detection point and at least one transmitting point and a plurality of receiving points.

[0006] One aspect of the present specification provides a flow rate detection system, the system comprising: an image data acquisition module for acquiring image data; a parameter determination module for determining parameters related to phase change of at least one detection point based on the image data; a first flow rate determination module for determining a first flow rate of at least one detection point based on the parameters related to phase change and a positional relationship between at least one detection point and at least one transmitting point and multiple receiving points.

[0007] Another aspect of the present specification provides a computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the flow rate detection method.

[0008] Some embodiments of the present specification group the array elements, and use the positional relationship between the emission point (emission focus), the receiving point (array element) and / or the detection point, combined with the phase change to determine the two-dimensional flow velocity of each detection point. Compared with the multi-angle emission mode, a single emission can obtain the phase change of the reflected signal at multiple angles, and the flow velocity of the target object perpendicular to the emission direction can be detected, which improves the system's utilization of data and is conducive to improving the accuracy of the system frame rate and speed evaluation; the use of the full-aperture emission mode can improve the imaging efficiency, and the non-focused wave mode can be used, so that the emitted scanning signal can point to the same The focus position can not only improve the signal-to-noise ratio, but also increase the frame rate of the system, thereby improving the system's time resolution capability; based on the image data, the optical flow method is used to calculate the second flow velocity of at least one detection point, and the flow velocity of the detection point in the three-dimensional motion field can be converted into a two-dimensional motion field for calculation and acquisition; the first flow velocity and the second flow velocity are obtained based on the system's time resolution capability (phase change) and spatial resolution capability (pixel point intensity), respectively, so that they can verify and / or correct each other; the pixel beam synthesis method is utilized, and GPU parallel computing is used based on the array element grouping mode, which can improve computing efficiency and reduce hardware and time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0010] Figure 1 is a schematic diagram of an application scenario of a flow rate detection system according to some embodiments of this specification;

[0011] Figure 2 is an exemplary module diagram of a flow rate detection system according to some embodiments of this specification;

[0012] Figure 3 is an exemplary flow chart of a method for determining a first flow velocity of at least one detection point according to some embodiments of the present specification;

[0013] Figure 4a is an exemplary schematic diagram of diverging waves according to some embodiments of the present specification;

[0014] Figure 4b is an exemplary schematic diagram of a plane wave according to some embodiments of the present specification;

[0015] Figure 5a is an exemplary schematic diagram of full aperture transmission in a diverging wave mode according to some embodiments of the present specification;

[0016] Figure 5bis an exemplary schematic diagram of full aperture transmission in plane wave mode according to some embodiments of the present specification;

[0017] Figure 6 is an exemplary schematic diagram of image data according to some embodiments of the present specification;

[0018] Figure 7 is an exemplary flow chart of a method for determining a first flow velocity of at least one detection point based on parameters related to phase change and a positional relationship between at least one detection point and at least one transmitting point and a plurality of receiving points according to some embodiments of this specification;

[0019] Figure 8 is an exemplary flow chart of a method for determining a second flow rate of at least one detection point according to some embodiments of the present specification;

[0020] Fig. 9 is an exemplary flow chart of a flow rate correction method according to some embodiments of the present specification. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0022] It should be understood that the "system", "device", "unit" and / or "module" used in this specification is a method for distinguishing different components, elements, parts, parts or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0023] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0024] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0025] Figure 1 It is a schematic diagram of an application scenario of a flow rate detection system according to some embodiments of this specification.

[0026] The flow velocity detection system 100 can determine the two-dimensional flow velocity by implementing the method and / or process disclosed in this specification.

[0027] like Figure 1 As shown, the flow rate detection system 100 may include: a scanning device 110, a processing device 120, a terminal device 130, a network 140 and / or a storage device 150, etc.

[0028] The components of the flow rate detection system 100 may be connected in one or more of a variety of ways. For example, Figure 1 As shown, the scanning device 110 can be connected to the processing device 120 via the network 140. For another example, the scanning device 110 can be directly connected to the processing device 120 (as shown by the dotted double-headed arrow connecting the scanning device 110 and the processing device 120). As a further example, the storage device 150 can be connected to the processing device 120 directly or via the network 140. As a further example, the terminal device 130 can be connected to the processing device 120 directly (as shown by the dotted double-headed arrow connecting the terminal device 130 and the processing device 120) and / or via the network 140.

[0029] The scanning device 110 can scan the target object to obtain scanning data. In some embodiments, the scanning device 110 can transmit a signal to the target object or a portion thereof (e.g., transmit an ultrasonic wave), and receive a reflected signal from the target object or a portion thereof (e.g., reflect an ultrasonic wave). In some embodiments, the scanning device 110 can include a scanning device. The scanning device can be used to transmit a signal and / or receive a signal. The scanning device can include, but is not limited to, an ultrasonic probe and a radar probe.

[0030] The processing device 120 can process data and / or information obtained from the scanning device 110, the terminal device 130 and / or the storage device 150. For example, the processing device 120 can determine the first flow rate of at least one detection point based on the image data. For another example, the processing device 120 can determine the first flow rate of at least one detection point based on the image data. For another example, the processing device 120 can determine the target flow rate of at least one detection point based on the first flow rate and the second flow rate of at least one detection point. In some embodiments, the processing device 120 may include a central processing unit (CPU), a digital signal processor (DSP), a system on a chip (SoC), a microcontroller unit (MCU), etc. and / or any combination thereof. In some embodiments, the processing device 120 may include a computer, a user console, a single server or a server group, etc. The server group may be centralized or distributed. In some embodiments, the processing device 120 may be local or remote. For example, the processing device 120 can access information and / or data stored in the scanning device 110, the terminal device 130 and / or the storage device 150 via the network 140. For another example, the processing device 120 can be directly connected to the scanning device 110, the terminal device 130 and / or the storage device 150 to access the stored information and / or data. In some embodiments, the processing device 120 can be implemented on a cloud platform. As an example only, the cloud platform can include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an inter-cloud, a multi-cloud, etc., or any combination thereof. In some embodiments, the processing device 120 or a portion of the processing device 120 can be integrated into the scanning device 110.

[0031] The terminal device 130 can receive instructions (e.g., ultrasound inspection mode), and / or display flow rate detection results and / or images to the user. The terminal device 130 may include a mobile device 131, a tablet computer 132, a notebook computer 133, etc., or any combination thereof. In some embodiments, the terminal device 130 may be part of the processing device 120.

[0032] The network 140 may include any suitable network that facilitates information and / or data exchange of the flow velocity detection system 100. In some embodiments, one or more components of the flow velocity detection system 100 (e.g., the scanning device 110, the processing device 120, the storage device 150, the terminal device 130) may communicate information and / or data with one or more other components of the flow velocity detection system 100 via the network 140. For example, the processing device 120 may receive user instructions from the terminal device via the network. For another example, the scanning device 110 may obtain ultrasonic emission parameters from the processing device 120 via the network 140. The network 140 may be and / or include a public network (e.g., the Internet), a private network (e.g., a local area network (LAN), a wide area network (WAN)), a wired network (e.g., an Ethernet network), a wireless network (e.g., an 802.11 network, a Wi-Fi network), a cellular network (e.g., a long term evolution (LTE) network), a frame relay network, a virtual private network ("VPN"), a satellite network, a telephone network, a router, a hub, a switch, a server computer, and / or any combination thereof. By way of example only, the network 140 may include a cable network, a wired network, a fiber optic network, a telecommunication network, an intranet, a wireless local area network (WLAN), a metropolitan area network (MAN), a public switched telephone network (PSTN), a Bluetooth TM Network, ZigBee TM In some embodiments, the network 140 may include one or more network access points. For example, the network 140 may include a wired and / or wireless network access point such as a base station and / or an Internet exchange point, and one or more components of the flow rate detection system 100 may be connected to the network 140 through these access points to exchange data and / or information.

[0033] The storage device 150 may store data, instructions and / or any other information. In some embodiments, the storage device 150 may store data obtained from the scanning device 110, the terminal device 130 and / or the processing device 120. In some embodiments, the storage device 150 may store data and / or instructions, and the processing device 120 may execute or use the data and instructions to execute the exemplary method / system described in the present application. In some embodiments, the storage device 150 may include a large capacity memory, a removable memory, a volatile read-write memory, a read-only memory (ROM), etc. or any combination thereof. Exemplary large capacity memory may include a disk, an optical disk, a solid-state disk, etc. Exemplary removable memory may include a flash drive, a floppy disk, an optical disk, a memory card, a compressed disk, a tape, etc. Exemplary volatile read-write memory may include a random access memory (RAM). Exemplary RAM may include a dynamic random access memory (DRAM), a double data rate synchronous dynamic random access memory (DDR SDRAM), a static random access memory (SRAM), a thyristor random access memory (T-RAM), and a zero capacitance random access memory (Z-RAM), etc. Exemplary ROMs may include mask read-only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), compact disk read-only memory (CD-ROM), and digital versatile disk read-only memory, etc. In some embodiments, the storage device 150 may be executed on a cloud platform. By way of example only, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-layer cloud, etc., or any combination thereof.

[0034] In some embodiments, the storage device 150 can be connected to the network 140 to communicate with one or more other components of the flow velocity detection system 100 (e.g., the scanning device 110, the processing device 120, the terminal device 130). One or more components of the flow velocity detection system 100 can access data or instructions stored in the storage device 150 through the network 140. In some embodiments, the storage device 150 can be directly connected to or communicate with one or more other components of the flow velocity detection system 100 (e.g., the scanning device 110, the processing device 120, the storage device 150, the terminal device 130). In some embodiments, the storage device 150 can be part of the processing device 120.

[0035] Figure 2 is an exemplary module diagram of a flow rate detection system according to some embodiments of the present specification.

[0036] In some embodiments, the processing device 120 may include an image data acquisition module 210 , a parameter determination module 220 , and / or a first flow rate determination module 230 , a second flow rate determination module 240 , and / or a flow rate correction module 250 .

[0037] The image data acquisition module 210 may be used to acquire image data. In some embodiments, the image data may be data obtained by scanning in a B mode.

[0038] In some embodiments, the image data acquisition module 210 may acquire image data using full aperture transmission. In some embodiments, the full aperture transmission may include full aperture transmission in a non-focused wave transmission mode.

[0039] In some embodiments, the image data acquisition module 210 may group the array elements of the scanning probe to obtain multiple groups of array elements. Each group of array elements in the multiple groups of array elements may include one or more array elements. In some embodiments, the scanning probe may include any one of a linear array probe, a convex array probe, and / or a phased array probe. In some embodiments, the image data may include multiple groups of image data. In some embodiments, each group of image data in the multiple groups of image data may correspond to a group of array elements in the multiple groups of array elements. In some embodiments, a group of image data may be obtained by demodulating and / or beamforming the reflected signals received by the corresponding group of array elements.

[0040] The parameter determination module 220 may be used to determine a parameter related to phase change of at least one detection point based on the image data. In some embodiments, the parameter related to phase change may include a phase change rate. In some embodiments, the parameter determination module 220 may be used to perform one or more of the following: determining at least two image data segments that are temporally adjacent to each other and received by each group of array elements in the image data; determining a phase change rate of at least one detection point corresponding to each group of array elements based on the at least two temporally adjacent image data segments.

[0041] The first flow rate determination module 230 can be used to determine the first flow rate of one or more detection points. In some embodiments, the first flow rate determination module 230 can determine the first flow rate of at least one detection point based on parameters related to phase change and the positional relationship between at least one detection point and at least one transmitting point and multiple receiving points. In some embodiments, the first flow rate determination module 230 can determine the first flow rate of at least one detection point by GPU parallel computing.

[0042] In some embodiments, the first flow rate determination module 230 can calculate the characteristic matrix for multiple groups of array elements respectively based on parameters related to phase change and the positional relationship between at least one detection point and at least one transmitting point and multiple receiving points, and integrate the calculation results of the multiple groups of array elements to obtain the first flow rate of at least one detection point.

[0043] In some embodiments, the first flow rate determination module 230 can be used to perform one or more of the following: determine the total spatial displacement vector corresponding to each group of array elements based on the positional relationship between at least one detection point and at least one transmitting point and multiple receiving points; determine the first characteristic matrix corresponding to each group of array elements based on the total spatial displacement vector corresponding to each group of array elements; determine the first flow rate of at least one detection point based on the phase change rate of at least one detection point corresponding to each group of array elements and the first characteristic matrix corresponding to each group of array elements.

[0044] In some embodiments, the first flow rate determination module 230 can be used to perform one or more of the following: determine a first auxiliary calculation matrix corresponding to each group of array elements based on a phase change rate of at least one detection point corresponding to each group of array elements and a resultant spatial displacement vector corresponding to each group of array elements; determine a second auxiliary calculation matrix corresponding to each group of array elements based on a first characteristic matrix corresponding to each group of array elements; accumulate the first auxiliary calculation matrices corresponding to each group of array elements to obtain a third auxiliary calculation matrix; accumulate the second auxiliary calculation matrices corresponding to each group of array elements to obtain a fourth auxiliary calculation matrix; and determine a first flow rate of at least one detection point based on the third auxiliary calculation matrix and the fourth auxiliary calculation matrix.

[0045] In some embodiments, the first flow rate determination module 230 may be used to perform one or more of the following: determine the spatial displacement vector corresponding to each receiving point based on the positional relationship between at least one detection point, at least one transmission point, and each receiving point in a plurality of receiving points; determine the summed spatial displacement vector corresponding to each group of array elements based on the spatial displacement vector corresponding to each receiving point and the weight corresponding to each receiving point. In some implementations, the first flow rate determination module 230 may use the weight of each receiving point in each group of array elements to perform weighted summation on the spatial displacement vector of each receiving point in each group of array elements to obtain the summed spatial displacement vector corresponding to each group of array elements. In some embodiments, the weight corresponding to each receiving point may be determined based on the distance between each receiving point and at least one detection point.

[0046] The second flow rate determination module 240 may be used to determine the second flow rate of one or more detection points. In some embodiments, the second flow rate determination module 240 may determine the temporal intensity gradient and / or spatial intensity gradient of at least one detection point based on the image data; and / or determine the second flow rate of at least one detection point based on the temporal intensity gradient and / or spatial intensity gradient of at least one detection point.

[0047] The flow rate correction module 250 can be used to correct the flow rate of one or more detection points to obtain a target flow rate. In some embodiments, the flow rate correction module 250 can perform a speed correction based on the first flow rate and / or the second flow rate of at least one detection point to obtain a target flow rate of at least one detection point. In some embodiments, the flow rate correction module 250 can be used to perform one or more of the following: determining the difference between the first flow rate and the second flow rate of at least one detection point; in response to the difference being not greater than a threshold, determining the target flow rate of at least one detection point based on the first flow rate and the second flow rate of at least one detection point; in response to the difference being greater than a threshold, determining the target flow rate of at least one adjacent detection point adjacent to the at least one detection point, and interpolating the target flow rates of at least two detection points to obtain the target flow rate of at least one detection point.

[0048] Figure 3 is an exemplary flow chart of a method for determining a first flow velocity of at least one detection point according to some embodiments of the present specification.

[0049] In some embodiments, process 300 may be performed by scanning device 110 and / or processing device 120. In some embodiments, process 300 may be stored in a storage device (such as storage device 150) in the form of a program or instruction. When flow rate detection system 100 (such as processing device 120) executes the program or instruction, process 300 may be implemented. In some embodiments, process 300 may be performed by scanning device 110 and / or processing device 120. Figure 2 One or more modules in the Figure 3 As shown, process 300 may include:

[0050] In operation 310 , image data (eg, image data of a target object) may be acquired. In some embodiments, operation 310 may be performed by the image data acquisition module 210 .

[0051] An image may be a carrier describing visual information of a target object. Image data may be data used to generate an image. In some embodiments, the image data acquisition module 210 may acquire image data through a scanning probe. Specifically, the scanning probe may transmit a scanning signal to the target object or a portion thereof, receive a reflection signal from the target object or a portion thereof, and then acquire image data based on the reflection signal.

[0052] In some embodiments, the target object may be a human body, an organ, a damaged part, a tumor, an organism, an object, etc. For example, the target object may be one or more diseased tissues of the heart, and the image may be a medical image of one or more diseased tissues of the heart. For another example, the target object may be an obstacle during the flight of an airplane, and the image may be a flight radar map. For another example, the target object may be a fluid, and the image may be a flow pattern map.

[0053] In some embodiments, the format of the image may include but is not limited to Joint Photographic Experts Group (JPEG) image format, Tagged Image File Format (TIFF) image format, Graphics Interchange Format (GIF) image format, Kodak Flash PiX (FPX) image format, Digital Imaging and Communications in Medicine (DICOM) image format, etc.

[0054] In some embodiments, the type of image may include but is not limited to an ultrasonic image and / or an electromagnetic wave image. Corresponding to the type of image, the scanning probe may include but is not limited to a combination of one or more of an ultrasonic probe and / or a radar probe. In some embodiments, the scanning signal may include but is not limited to a combination of one or more of ultrasonic waves and / or electromagnetic waves. In some embodiments, the reflection signal may include but is not limited to a combination of one or more of an ultrasonic reflection signal and / or an electromagnetic wave reflection signal.

[0055] In some embodiments, the image data corresponding to the ultrasonic image may be data obtained by scanning in B mode. In some embodiments, the ultrasonic image obtained by scanning in B mode may be a two-dimensional ultrasonic image in which the amplitude of the ultrasonic reflection signal corresponding to one ultrasonic emission is represented by brightness.

[0056] In some embodiments, the scanning probe may include an array element, which may be a component on the scanning probe for transmitting a scanning signal and / or receiving a reflected signal.

[0057] In some embodiments, based on the arrangement of array elements on the scanning probe, the scanning probe may include any one or more combinations of a linear array probe, a convex array probe and / or a phased array probe. The array elements of the linear array probe, the convex array probe and / or the phased array probe may be arranged in a straight line segment (such as Figure 4a ), an arc segment (such as Figure 4b ) and / or a square matrix (not shown).

[0058] In some embodiments, the array elements of the scanning probe may include piezoelectric materials. For example, the array elements of the ultrasound probe and / or radar probe may include barium titanate, lead titanate, lead zirconate titanate, etc.

[0059] In some embodiments, the scanning probe may include array elements of multiple frequencies and a control circuit corresponding to each array element. The scanning probe may stimulate array elements at different positions through pulse signals to generate scanning signals of different frequencies.

[0060] Exemplarily, the scanning ultrasound probe can convert electrical signal pulses into ultrasound signals through array elements to transmit to the target object or a part thereof, and can also convert reflected ultrasound signals of the target object or a part thereof into electrical signals (ie, image data).

[0061] In some embodiments, each control circuit can excite an array element. Specifically, the scanning probe can send each pulse signal to the corresponding control circuit, and each control circuit excites the corresponding array element based on the pulse signal, thereby emitting scanning signals of different or same frequencies at different or same times.

[0062] In some embodiments, the image data acquisition module 210 may acquire image data using full array element (also called full aperture) transmission.

[0063] Full aperture transmission may be a transmission mode that uses all array elements of the scanning probe to transmit scanning signals. It is understood that the image data acquisition module 210 may acquire an image frame corresponding to the entire detection area (i.e., the target object or a portion thereof) based on one full aperture transmission. In some embodiments, the image data acquisition module 210 may acquire an image sequence (or video) corresponding to the detection area (i.e., the target object or a portion thereof) based on multiple image frames corresponding to multiple full aperture transmissions.

[0064] In some embodiments, full aperture transmission may include full aperture transmission in a non-focused wave transmission mode, such as a diverging wave transmission mode and / or a plane wave transmission mode.

[0065] The divergent wave transmission mode may be a transmission mode in which the focus is above the scanning probe during transmission. Figure 4a As shown in the figure, when the divergent wave is transmitted, the focus A is above the scanning probe, and all array elements ab on the scanning probe can transmit scanning signals. The plane wave transmission mode can be a transmission mode in which the focus is at infinity during transmission. Figure 4b As shown, when the plane wave is emitted, the focus is at infinity, and all array elements cd on the scanning probe can emit scanning signals.

[0066] In some embodiments, the image data acquisition module 210 can divide multiple full-aperture transmissions in the divergent wave transmission mode into multiple transmission groups, each of which can include at least two adjacent full-aperture transmissions. In some embodiments, the focal positions corresponding to the full-aperture transmissions in each transmission group can be the same.

[0067] For example, the image data acquisition module 210 can divide 40 full-aperture transmissions in the divergent wave mode into 20 transmission groups, each transmission group containing two adjacent full-aperture transmissions: the first transmission group includes the 1st full-aperture transmission and the 2nd full-aperture transmission, and the focal positions corresponding to the 1st and 2nd full-aperture transmissions are both the first focus; the second transmission group includes the 3rd full-aperture transmission and the 4th full-aperture transmission, and the focal positions corresponding to the 3rd and 4th full-aperture transmissions are both the second focus;…; the twentieth transmission group includes the 39th full-aperture transmission and the 40th full-aperture transmission, and the focal positions corresponding to the 39th and 40th full-aperture transmissions are both the twentieth point.

[0068] In some embodiments, the image data acquisition module 210 may group the array elements of the scanning probe to obtain multiple groups of array elements, and each group of array elements in the multiple groups of array elements may include one or more array elements.

[0069] In some embodiments, each group of array elements may include the same number of array elements. Figure 5a As shown, the image data acquisition module 210 can divide the 128 array elements of the scanning probe into 16 groups of array elements, and each group of array elements can include 8 array elements.

[0070] In some embodiments, any two groups of array elements may include different numbers of array elements. Exemplarily, the image data acquisition module 210 may reduce the number of array elements in the array element group corresponding to the non-interest area, and increase the number of array elements in the array element group corresponding to the interest area. For example, the center position of the detection area is the interest area, and the positions on both sides are the non-interest area. The image data acquisition module 210 may divide the 128 array elements of the scanning probe into 8 groups of array elements, and the number of array elements included in the 8 groups of array elements may be 8, 8, 8, 8, 16, 16, 16, 8, 8, 8, 8, respectively.

[0071] In some embodiments, the image data may include multiple groups of image data, and each group of image data in the multiple groups of image data may correspond to a group of array elements in the multiple groups of array elements.

[0072] In some embodiments, the array element group corresponding to each set of image data may be the array element group that receives the reflection signal corresponding to the set of image data. Figure 5aAs shown, based on the scanning signal transmitted by the third group of array elements, the first group of array elements can receive the corresponding reflection signal, and the image data acquisition module 210 can generate a group of image data (e.g., the first group of image data) based on the reflection signal received by the first group of array elements, and the first group of array elements can be the array element group corresponding to the group of image data. Similarly, the second group of array elements, the third group of array elements, ... the 16th group of array elements can correspond to the second group of image data, the third group of image data, ... the 16th group of image data, respectively.

[0073] In some embodiments, each set of image data corresponding to each array element group may correspond to an image area (eg, a portion of an image). Figure 5a As shown, the image data acquisition module 210 can generate the first image area (e.g., the image of the detection area within the range of CK and CE) based on the first group of image data. Similarly, the image data acquisition module 210 can generate the second image area, the third image area, ... the sixteenth image area based on the second group of image data, the third group of image data, ... the sixteenth group of image data, respectively. In some embodiments, the first image area, the second image area, the third image area, ... the sixteenth image area can be different from each other and constitute the detection area. It can be understood that the image data acquisition module 210 can spatially divide the image data corresponding to the detection area into multiple groups of image data corresponding to multiple image areas based on array element grouping.

[0074] In some embodiments, each set of image data may be obtained by demodulating and / or beamforming reflected signals received by a corresponding set of array elements.

[0075] Demodulation can be the process of restoring a digital frequency band signal to a digital baseband signal.

[0076] Beamforming can be a process of weighted synthesis of multiple reflected signals. In some embodiments, the image data acquisition module 210 can weighted synthesize the reflected signals received by two or more array elements in each array element group, thereby determining the image data group corresponding to the multiple reflected signals received by the array element group.

[0077] Exemplarily, the image data acquisition module 210 may generate the first group of image data, the second group of image data, ... the sixteenth group of image data based on the reflection signals received by the first group of array elements, the second group of array elements, ... the sixteenth group of array elements, respectively.

[0078] Operation 320 , determining a parameter related to the phase change of at least one detection point based on the image data. In some embodiments, operation 320 may be performed by parameter determination module 220 .

[0079] The detection point can be a spatial point on the detection area (i.e., the target object or a part of it). Figure 5aAs shown, the detection point may be a spatial point D on the detection area.

[0080] The parameter related to phase change may be a parameter characterizing the time-dependent change of the phase of the reflected signal returned from the detection point. In some embodiments, the parameter related to phase change may include a phase change rate.

[0081] The phase change rate can be the change in the phase of the reflected signal returned from the detection point in a unit time. It can be understood that the reflected signal can be affected by the direction of the scanning signal and / or the movement of the detection point. Therefore, in order to obtain the movement speed of the detection point based on the phase change rate, the phase change rate can be the change in the phase of the reflected signal corresponding to the scanning signal in the same direction in a unit time. In some embodiments, the direction of the scanning signal can be determined based on the position of the transmitting focus. In some embodiments, the focus corresponding to the same scanning signal can be the same.

[0082] Exemplarily, the phase change rate in the plane wave mode with the focus at infinity can be the change in the phase of the reflected signal corresponding to any two adjacent transmitted scanning signals per unit time.

[0083] In another exemplary embodiment, the phase change rate in the diverging wave mode may be the change in the phase of the reflected signal corresponding to any two adjacent transmitted scanning signals in the same transmission group within a unit time. For example, the phase change rate may be the change in the phase of the reflected signal corresponding to the first full-aperture transmission and the second full-aperture transmission in the first transmission group within a unit time, wherein the focal positions corresponding to the first and second full-aperture transmissions may both be point C.

[0084] In some embodiments, the parameter determination module 220 may determine at least two image data segments that are temporally adjacent to each other and received by each group of array elements in the image data.

[0085] The image data segment may be a portion of the image data corresponding to each image frame.

[0086] In some embodiments, the processing device can generate an image frame based on the image data corresponding to the scanning signal emitted by the scanning probe, and then generate an image based on multiple image frames. Exemplarily, in the full-aperture transmission mode of the scanning probe, each image frame can be acquired based on the image data corresponding to one scanning signal, and each image can be acquired based on 40 image frames. For example, in the full-aperture transmission mode, based on the 1st scanning signal, the 2nd scanning signal, ... the 40th scanning signal, the 1st image frame, the 2nd image frame, ... the 40th image frame can be generated respectively, and further, based on the transmission order of the scanning signal corresponding to each image frame, the 1st image frame, the 2nd image frame, ... the 40th image frame can be compounded to acquire an image.

[0087] As mentioned above, each group of image data corresponding to each group of array elements may correspond to an image region. Further, based on multiple image regions corresponding to multiple array element groups, the parameter determination module 220 may divide the image data corresponding to each image frame into multiple image data segments. Figure 6 As shown, the image data corresponding to the 1st image frame can be divided into corresponding 1-1th image data segments (i.e., the first image data segment of the 1st frame image), 1-2th image data segments (i.e., the second image data segment of the 1st frame image), … 1-16th image data segments (i.e., the sixteenth image data segment of the 1st frame image) based on the 1st image area, the 2nd image area, … the 16th image area; … the image data corresponding to the 40th image frame can be divided into corresponding 40-1th image data segments (i.e., the first image data segment of the 40th frame image), 40-2th image data segments (i.e., the second image data segment of the 40th frame image), … 40-16th image data segments (i.e., the sixteenth image data segment of the 40th frame image) based on the 1st image area, the 2nd image area, … the 16th image area.

[0088] It can be understood that each image data segment may correspond to a part of the image data corresponding to each image frame in space, and may correspond to a part of each image data group in time.

[0089] In some embodiments, multiple image data segments may be first composited based on spatial relationships to obtain multiple image frames, and then image data of the detection area may be obtained based on time sequence. Figure 6 As shown, based on the image data of the 16 image areas corresponding to the 1st image frame, the image data of the detection area corresponding to the 1st image frame can be obtained. Similarly, based on the image data of the 16 image areas corresponding to the 40th image frame, the image data of the entire detection area corresponding to the 40th image frame can be obtained. Furthermore, based on 40 image frames (each image frame corresponds to the image data of the entire detection area), the image data of the entire detection area can be obtained.

[0090] In some embodiments, multiple frames of image data segments may be first compounded based on the time relationship to obtain multiple sets of image data, and then image data of the detection area may be obtained based on the spatial relationship. Figure 6 As shown, the first group of image data corresponding to the first image area can be obtained based on the first image data segment of each image frame in the 40 image frames corresponding to the first image area. Similarly, the 16th group of image data corresponding to the 16th image area can be obtained based on the 16th image data segment of each image frame in the 40 image frames corresponding to the 16th image area. Furthermore, the image data of the entire detection area can be obtained based on the 16 groups of image data of the 16 image areas.

[0091] In some embodiments, the at least two image data segments that are adjacent in time and received by each group of array elements may be at least two image data segments that are adjacent in sequence and have the same focal position in the transmission scanning signal received by each group of array elements. For example, the at least two image data segments that are adjacent in time and have the same focal position in the transmission scanning signal received by each group of array elements may be two consecutive image data segments corresponding to the scanning signal in the same transmission group in the divergent wave transmission mode, such as the first image data segment received by the first group of array elements when the transmission focal point is C. and the second image data segment For another example, at least two image data segments that are adjacent in time and have the same focal position and are received by each group of array elements may be a plurality of continuous image data segments in the plane wave transmission mode, such as the second image data segment received by the first group of array elements. The third image data segment and the 4th image data segment

[0092] In some embodiments, the parameter determination module 220 may determine the phase change rate of at least one detection point corresponding to each group of array elements based on at least two image data segments that are temporally adjacent.

[0093] As mentioned above, each set of image data may correspond to a portion of the image of the detection area (i.e., an image area), and each image data segment may include image data of at least one detection point. Figure 5a As shown, the image data segment (or image data group) corresponding to the first group of array elements may include image data of detection points within the range of CK and CE.

[0094] In some embodiments, the parameter determination module 220 may determine a phase change rate of at least one detection point of each group of array elements based on two temporally adjacent image data segments by using formula (1):

[0095]

[0096] in, represents the phase change rate of at least one detection point received by the kth group of array elements, and They represent the i+1th frame and the ith image data segment received by the kth group of array elements based on the scanning signal corresponding to the same focus, and They respectively represent the emission time of the scanning signal corresponding to the i+1th frame and the i-th image data segment received by the k-th group of array elements.

[0097] For example, the second frame and the first image data segment received by the first group of array elements based on the scanning signal corresponding to the same focus C are respectively and Then, during the time interval between the second frame received by the first group of array elements and the transmission of the scanning signal corresponding to the first image data segment, the phase change rate of at least one detection point received by the first group of array elements is

[0098] Similarly, the parameter determination module 220 may determine multiple phase change rates of at least one detection point of each group of array elements based on multiple image data segments that are adjacent in time. Specifically, the parameter determination module 220 may first obtain multiple corresponding phase change rates based on any two adjacent image data segments in the multiple image data segments that are adjacent in time by using formula (1), and then obtain a final phase change rate based on the multiple phase change rates. In some embodiments, the parameter determination module 220 may calculate an average value, a weighted average value, a variance, etc. of the multiple phase change rates to obtain a final phase change rate.

[0099] For example, for the scanning signal of the first group of array elements based on the same transmit focus, the second image data segment received The third image data segment and the 4th image data segment The parameter determination module 220 may be based on the second image data segment and the third image data segment Get the phase change rate Based on the third image data segment and the 4th image data segment Get the phase change rate Then calculate the phase change rate and the phase change rate The average value of the phase change rate of at least one detection point of the first group of array elements is obtained.

[0100] In operation 330, a first flow velocity of at least one detection point may be determined based on parameters related to the phase change and a positional relationship between at least one detection point and at least one transmitting point and a plurality of receiving points.

[0101] In some embodiments, operation 330 may be performed by first flow rate determination module 230 .

[0102] The transmitting point can be any array element in the array element group that transmits the scanning signal to the detection point. Figure 5a As shown, the second array element in the third group of array elements that transmit scanning signals to the detection point D can be the transmitting point 3-2 corresponding to the detection point D.

[0103] The receiving point can be any element in the array element group that receives the reflected signal from the detection point. Figure 5aAs shown, the fifth array element in the first group of array elements that receives the scanning signal from the detection point D can detect the receiving points 1-5 corresponding to the detection point D.

[0104] The first flow velocity may be a flow velocity at a detection point determined based on a phase change of a reflection signal.

[0105] In some embodiments, the first flow rate determination module 230 can calculate the characteristic matrix for multiple groups of array elements respectively based on parameters related to phase change and the positional relationship between at least one detection point and at least one transmitting point and multiple receiving points, and integrate the calculation results of the multiple groups of array elements to obtain the first flow rate of at least one detection point.

[0106] For a detailed description of obtaining the first flow rate, please refer to Figure 7 And the related description will not be repeated here.

[0107] Figure 7 This is an exemplary flow chart of a method for determining a first flow velocity of at least one detection point based on parameters related to phase changes and a positional relationship between at least one detection point and at least one transmitting point and multiple receiving points as shown in some embodiments of this specification. In some embodiments, process 700 can be performed by the scanning device 110 and / or the processing device 120. In some embodiments, process 700 can be stored in a storage device (such as storage device 150) in the form of a program or instruction, and when the flow velocity detection system 100 (such as processing device 120) executes the program or instruction, process 700 can be implemented. In some embodiments, process 700 can be performed by the first flow velocity determination module 230. Figure 7 As shown, process 700 may include one or more of the following operations.

[0108] In operation 710, a combined spatial displacement vector corresponding to each group of array elements may be determined based on a positional relationship between at least one detection point and at least one transmission point and a plurality of reception points.

[0109] In some embodiments, each transmitting point may transmit a scanning signal to at least one detection point. Specifically, each transmitting point may transmit a scanning signal to a detection point in a corresponding transmitting direction in the detection area.

[0110] In some embodiments, the transmission direction of each transmission point can be determined based on the corresponding focal position when the transmission point transmits the scanning signal. For example, the transmission direction can be directed from the focal position to the transmission point position. Figure 5a As shown, the emission direction of the emission point 3-2 (the second array element in the third group of array elements) in the divergent wave mode can be directed from the emission focus C to the detection point D (i.e. direction), the transmitting point 3-2 can be directed to the detection area The detection point in the direction (i.e., the detection point on the line segment FG) emits a scanning signal. Figure 5b As shown, the emission direction of the reflection point in the plane wave mode can be a vertical direction.

[0111] In some embodiments, each receiving point may receive a reflection signal obtained from at least one detection point based on a scanning signal of at least one detection point. Specifically, each receiving point may receive a reflection signal from a detection point in a corresponding receiving direction in the detection area. In some embodiments, the receiving direction of each receiving point may be determined based on the receiving point position and the detection point position. For example, the receiving direction may be directed from the receiving point position to the detection point position. Figure 5a As shown, the receiving direction of the receiving point 1-5 (the fifth array element in the first group of array elements) can be directed from the position J of the receiving point 1-5 to the detection point D (i.e. direction), receiving points 1-5 can be detected in the detection area The detection point in the direction (ie, the detection point on line segment HI) receives the reflected signal.

[0112] The summed spatial displacement vector corresponding to each group of array elements may be the unit flow velocity of at least one detection point detected by each group of array elements, and may characterize the flow velocity direction of at least one detection point detected by each group of array elements. In some embodiments, the summed spatial displacement vector corresponding to each group of array elements may be the summed vector of the spatial displacement vectors corresponding to all array elements (i.e., receiving points) in each group of array elements.

[0113] In some embodiments, the first flow rate determination module 230 may determine a spatial displacement vector corresponding to each receiving point based on a positional relationship between at least one detection point, at least one emission point, and / or each receiving point in a plurality of receiving points.

[0114] The spatial displacement vector of a receiving point corresponding to a certain detection point can be the sum of the unit vector of the detection point in the receiving direction of the receiving point and the unit vector of the detection point in the transmitting direction. Figure 5a As shown, the spatial displacement vector of receiving points 1-5 corresponding to detection point D can be the detection point D in the receiving direction The unit vector on the direction of emission The resultant vector of the unit vectors on

[0115] In some embodiments, the first flow rate determination module 230 may determine the spatial displacement vector of each receiving point corresponding to a detection point based on formula (2):

[0116]

[0117] in, is the spatial displacement vector of the mth array element (i.e., the mth receiving point) in the kth group of receiving array elements corresponding to a certain detection point, x is the position of the detection point, x T is the location of the emission focus, is the position of the mth array element in the kth group of receiving array elements.

[0118] Further, in some embodiments, the first flow rate determination module 230 may determine a combined spatial displacement vector corresponding to each group of array elements based on the spatial displacement vector corresponding to each receiving point and the weight corresponding to each receiving point.

[0119] The weight of each receiving point may be a representation of the importance of each receiving point to the at least one detection point. In some embodiments, the weight of each receiving point may be different for different detection points.

[0120] In some embodiments, the weight of each reception point may be determined based on the distance of each reception point from at least one detection point.

[0121] In some embodiments, the weight of each receiving point may be positively correlated with the distance between each receiving point and at least one detection point. For example, the closer the distance between a receiving point and a detection point is, the smaller the weight of the receiving point relative to the detection point is. Figure 5a As shown, the distances of receiving points 1-1, 1-5, ..., 2-5 from the detection point D are getting closer and closer, and the weights corresponding to receiving points 1-1, 1-5, ..., 2-5 are getting smaller and smaller.

[0122] In some embodiments, the first flow rate determination module 230 can determine the weight of each receiving point based on the distance between each receiving point and the detection point. Exemplarily, the first flow rate determination module 230 can use the ratio of the distance between each receiving point and the detection point to the sum of the distances between all receiving points and the detection points as the weight of each receiving point. For example, the distances from receiving point 1-1, receiving point 1-2, ... receiving point 16-8 to detection point D are 20mm, 25mm, ... 50mm, respectively, and the sum of the distances is 3840mm, then the weights of receiving point 1-1, receiving point 1-2, ... receiving point 16-8 are 20 / 3840=0.0052, 25 / 3840=0.0065, ..., 50 / 3840=0.0130, respectively.

[0123] Some embodiments of the present specification set the weight of each receiving point to be positively correlated with the distance between each receiving point and at least one detection point, which can improve the resolution of the image.

[0124] In some embodiments, the weight of each receiving point may be negatively correlated with the distance between each receiving point and the at least one detection point. For example, the closer the distance between a receiving point and a certain detection point is, the greater the weight of the receiving point relative to the detection point is. Figure 5a As shown, the distances of receiving points 1-1, 1-5, ..., 2-5 from the detection point D are getting closer and closer, and the corresponding weights of receiving points 1-1, 1-5, ..., 2-5 are getting larger and larger.

[0125] In some embodiments, the first flow rate determination module 230 can determine the weight of each receiving point based on the reciprocal value of the distance between each receiving point and the detection point. Exemplarily, the first flow rate determination module 230 can use the ratio of the reciprocal value of the distance between each receiving point and the detection point to the sum of the reciprocal values ​​of the distances between all receiving points and the detection points as the weight of each receiving point. For example, the distances of receiving point 1-1, receiving point 1-2, ... receiving point 16-8 from detection point D are 20mm, 25mm, ... 50mm, respectively, and the reciprocals of the corresponding distances are 0.05, 0.04, ... 0.02, respectively, and the sum of the reciprocals of the distances is 3.2, then the weights of receiving point 1-1, receiving point 1-2, ... receiving point 16-8 are 0.05 / 3.2 = 0.015625, 0.04 / 3.2 = 0.0125, ..., 0.02 / 3.2 = 0.00625, respectively.

[0126] Some embodiments of the present specification set the weight of each receiving point to be negatively correlated with the distance between each receiving point and at least one detection point, which can reduce image artifacts.

[0127] In some embodiments, the first flow rate determination module 230 may use the weight of each receiving point in each group of array elements to perform weighted summation on the spatial displacement vector of each receiving point in each group of array elements to obtain a combined spatial displacement vector corresponding to each group of array elements.

[0128] In some embodiments, the first flow rate determination module 230 may determine the summed spatial displacement vector corresponding to each group of array elements by formula (3):

[0129]

[0130] Among them, p k is the sum of the spatial displacement vectors of the kth array elements,

[0131] The spatial displacement vector of the mth receiving point of the kth group of array elements. is the weight of the mth receiving point of the kth array element, yes

[0132] Continuing with the above example, the first flow rate determination module 230 may be based on the spatial displacement vectors of the receiving points 1-1, 1-2, ..., 1-16 in the first array element corresponding to the detection point D. and weight Determine the sum spatial displacement vector p1 of the first group of array elements corresponding to the detection point D. Similarly, the first flow rate determination module 230 can determine the sum spatial displacement vectors p2, p3, ... p16 of the second group of array elements, the third group of array elements, ... p27 of the 16th group of array elements corresponding to the detection point D respectively. 16 .

[0133] In operation 720, a first characteristic matrix corresponding to each group of array elements may be determined based on the resultant spatial displacement vector corresponding to each group of array elements.

[0134] The first characteristic matrix of each group of array elements may be a matrix obtained based on the components of the phase change of the reflected signal corresponding to two adjacent scanning signals received by each group of array elements in the horizontal and vertical axis directions in the coordinate system of the waveform diagram of the reflected signal.

[0135] In some embodiments, the first flow rate determination module 230 may determine the components of the unit phase change rate in the X-axis and the Z-axis based on the summed spatial displacement vector corresponding to each group of array elements, wherein the X-axis and the Z-axis may be parallel to the horizontal direction and the vertical direction of the detection area, respectively.

[0136] Specifically, the first flow rate determination module 230 may obtain the first characteristic matrix of each group of array elements based on formula (4):

[0137]

[0138] in, and can represent the X-axis component and the Z-axis component of the unit phase change rate corresponding to the k-th array element, ω0 is the angular frequency of the transmitted pulse, c is the speed of the scanning signal, and p kx T and p kz T are the transpose p of the sum of spatial displacement vectors of the kth group of array elements respectively. T The component on the X-axis and the component on the Z-axis may be determined based on the positional relationship between at least one detection point and at least one transmitting point and a plurality of receiving points.

[0139] In operation 730, a first flow velocity of at least one detection point may be determined based on a phase change rate of at least one detection point corresponding to each group of array elements and / or a first characteristic matrix corresponding to each group of array elements.

[0140] In some embodiments, the relationship between the first flow velocity and the phase change rate of at least one detection point can be expressed by formula (5):

[0141]

[0142] in, is the phase change rate, v is the first flow velocity of at least one detection point, and pT is the transpose of the resultant spatial displacement vector.

[0143] In some embodiments, the first flow velocity v can be decomposed into components v on the horizontal axis x and the component v on the vertical axis z , and based on formula (6), the right side of (5) is decomposed into the product of the first matrix and the first flow rate on the horizontal axis:

[0144]

[0145] To facilitate calculation, we can Thus, formula (6) is simplified to formula (7):

[0146] a k v=b k (7)

[0147] In some embodiments, the first flow rate determination module 230 may determine a first auxiliary calculation matrix corresponding to each group of array elements based on a phase change rate of at least one detection point corresponding to each group of array elements and / or a first characteristic matrix corresponding to each group of array elements.

[0148] In some embodiments, the first auxiliary calculation matrix may be the product of the transposed matrix of the first characteristic matrix of each group of array elements and the phase change rate: k T b k .

[0149] In some embodiments, the first flow rate determination module 230 may determine a second auxiliary calculation matrix corresponding to each group of array elements based on the first characteristic matrix corresponding to each group of array elements. In some embodiments, the second auxiliary matrix may be the product of the transpose of the first characteristic matrix of each group of array elements and the first characteristic matrix: k T a k .

[0150] In some embodiments, the first flow rate determination module 230 may accumulate the first auxiliary calculation matrix corresponding to each group of array elements to obtain a third auxiliary calculation matrix. Specifically, the third auxiliary matrix may be determined based on formula (8):

[0151] A T B=∑ k a k T b k (8)

[0152] In some embodiments, the first flow rate determination module 230 may accumulate the second auxiliary calculation matrix corresponding to each group of array elements to obtain a fourth auxiliary calculation matrix. Specifically, the fourth auxiliary matrix may be determined based on formula (9):

[0153] A T A=∑ k a k T a k (9)

[0154] In some embodiments, the first flow rate determination module 230 may determine the first flow rate of at least one detection point based on the third auxiliary calculation matrix and the fourth auxiliary calculation matrix.

[0155] In some embodiments, the first flow rate can be determined based on formula (10):

[0156] v=(A T A) -1 (A T b) (10)

[0157] In some embodiments, the first flow rate determination module 230 may determine the first flow rate of at least one detection point by GPU parallel computing.

[0158] Specifically, the GPU can calculate the phase change rate, the resultant spatial displacement vector, the first characteristic matrix and the first auxiliary calculation matrix corresponding to each group of array elements in parallel, thereby improving the calculation efficiency.

[0159] Figure 8 is an exemplary flow chart of a method for determining a second flow rate of at least one detection point according to some embodiments of the present specification. In some embodiments, process 800 can be performed by scanning device 110 and / or processing device 120. In some embodiments, process 800 can be stored in a storage device (such as storage device 150) in the form of a program or instruction. When the flow rate detection system 100 (such as processing device 120) executes the program or instruction, process 800 can be implemented. In some embodiments, process 800 can be performed by second flow rate determination module 240. Figure 8 As shown, process 800 may include one or more of the following operations:

[0160] In operation 810 , a temporal intensity gradient and / or a spatial intensity gradient of at least one detection point may be determined based on the image data.

[0161] The optical flow field can be a projection image of the motion field on a two-dimensional plane. It can be understood that the motion field can be used to describe motion, and the optical flow field can reflect the grayscale distribution of different projection images in the projection image sequence, thereby transferring the motion field in the three-dimensional space to the two-dimensional plane. Therefore, the optical flow field can correspond to the motion field in an ideal state.

[0162] The optical flow may be the instantaneous motion speed of the projection point corresponding to the detection point on the projection image. In some embodiments, the optical flow may be represented by the change trend of the grayscale value of the pixel point in the optical flow field. The length and direction of the arrow in the optical flow field may respectively represent the size and direction of the optical flow at each point.

[0163] In some embodiments, the second flow rate determination module 240 may acquire an optical flow field based on image data. Specifically, the second flow rate determination module 240 may determine all optical flows based on changes in grayscale values ​​of all pixels in a plurality of consecutive image frames, thereby acquiring an optical flow field.

[0164] In some embodiments, the second flow velocity determination module 240 may acquire a temporal intensity gradient and / or a spatial intensity gradient based on the optical flow field.

[0165] The temporal intensity gradient can be the rate at which the grayscale value of a pixel in the optical flow field changes based on time, and can be represented by the partial derivative of the pixel in the projected image with respect to the time (t) direction.

[0166] In some embodiments, the second flow rate determination module 240 may determine the time intensity gradient of at least one detection point based on formula (11):

[0167]

[0168] in, is the time intensity gradient of at least one detection point, I is the optical flow field, and t is the inter-frame interval time corresponding to multiple optical flow field frames that constitute the optical flow field.

[0169] The spatial intensity gradient can be the gradient of the gray value of the pixel point in the optical flow field based on the position change, which can be represented by the partial derivatives of the pixel point along the X-axis and the Z-axis in the projected image. In some embodiments, the second flow rate determination module 240 can determine the spatial intensity gradient of at least one detection point based on formula (12):

[0170]

[0171] in, is the spatial intensity gradient of at least one detection point, I is the optical flow field, x is the unit distance of the optical flow field on the horizontal axis, and z is the unit distance of the optical flow field on the vertical axis.

[0172] In operation 820, a second flow velocity of at least one detection point may be determined based on a temporal intensity gradient and / or a spatial intensity gradient of the at least one detection point.

[0173] The second flow rate may be a flow rate of a detection point determined based on a temporal change and / or spatial change of the intensity of a pixel point of an image, and may be represented by an instantaneous speed of an optical flow.

[0174] Specifically, assuming that the pixel point I(x, z, t) corresponding to the detection point moves a distance (dx, dz) in two adjacent image frames in dt time, based on the assumption that the gray value of the same pixel point remains unchanged before and after the movement, the basic constraint equation (13) can be obtained:

[0175] I(x,z,t)=I(x+dx,z+dz,t+dt) (13)

[0176] Furthermore, the right side of (13) can be expanded based on Taylor's formula to obtain formula (14):

[0177]

[0178] Among them, ε represents the second-order infinitesimal term and can be ignored.

[0179] Furthermore, the second flow rate determination module 240 can simultaneously subtract I(x, z, t) from both ends of (14), and then divide them by dt to obtain formula (15):

[0180]

[0181] in, and are the velocity vector v of the second flow velocity v along the X-axis x and the velocity vector v along the Z axis z , and The spatial intensity gradient Components along the X and Z axes, is the time intensity gradient

[0182] In some embodiments, the relationship between the second flow velocity, the spatial intensity gradient, and the temporal intensity gradient at at least one detection point can be expressed by formula (16):

[0183]

[0184] In some embodiments, formula (16) can be transformed into formula (17):

[0185]

[0186] Where i represents the i-th image frame, and They represent the position change rate of the optical flow corresponding to the detection point of the i-th image frame along the X-axis and Z-axis components, respectively. Represents the time rate of change of the optical flow corresponding to the detection point.

[0187] In some embodiments, you can Convert formula (17) into formula (18):

[0188] Mv=N (18)

[0189] Among them, M can represent the spatial intensity gradient matrix corresponding to at least a plurality of consecutive image frames, v can represent the second flow velocity of the detection point, and N can represent the temporal intensity gradient matrix corresponding to at least a plurality of consecutive image frames.

[0190] Furthermore, the second flow rate determination module 240 can be based on multiplying both ends of formula (18) by the transpose M of the matrix M: T , get M T Mv=M T N.

[0191] In some embodiments, the second flow rate determination module 240 may simplify and / or calculate based only on the real part of the data: real(M T Mv)=real(M T N).

[0192] Furthermore, the second flow rate determination module 240 can obtain the second flow rate (19) of the detection point based on formula (18):

[0193] v=(M T M) -1 (M T N) (19)

[0194] in,

[0195] Some embodiments of the present specification use an optical flow method to calculate a second flow velocity of at least one detection point based on image data, and can convert the flow velocity of the detection point in a three-dimensional motion field into a two-dimensional motion field for calculation and acquisition.

[0196] Fig. 9is an exemplary flow chart of a flow rate correction method according to some embodiments of the present specification. In some embodiments, process 900 can be performed by scanning device 110 and / or processing device 120. In some embodiments, process 900 can be stored in a storage device (such as storage device 150) in the form of a program or instruction. When flow rate detection system 100 (such as processing device 120) executes the program or instruction, process 900 can be implemented. In some embodiments, process 900 can be performed by flow rate correction module 250. Fig. 9 As shown, process 900 may include one or more of the following operations.

[0197] As mentioned above, the first flow velocity may be the flow velocity of the detection point determined based on the phase change of the reflection signal of the detection point; the second flow velocity may be the flow velocity of the detection point determined based on the time change and spatial change of the pixel intensity of the image. The first flow velocity and the second flow velocity use the same image data and are respectively obtained based on the time resolution capability (phase change) and spatial resolution capability (pixel intensity) of the system, so that they can be verified and / or corrected with each other.

[0198] In operation 910 , a difference between a first flow rate and a second flow rate at at least one detection point may be determined.

[0199] The difference between the first flow velocity and the second flow velocity at at least one detection point may represent the difference in speed and direction between the first flow velocity and the second flow velocity at at least one detection point.

[0200] In some embodiments, the flow rate correction module 250 can obtain the rate difference between the first flow rate and the second flow rate based on the difference, difference percentage, etc. between the first flow rate and the second flow rate of at least one detection point. For example, if the first flow rate of detection point Q is 20 and the second flow rate is 22, then the rate difference between the first flow rate and the second flow rate can be 22-20=2. For another example, if the first flow rate of detection point D is 20 and the second flow rate is 30, then the rate difference between the first flow rate and the second flow rate can be (30-20) / 20×100%=50%.

[0201] In some embodiments, the flow rate correction module 250 can obtain the direction difference between the first flow rate and the second flow rate based on the size of the angle between the first flow rate and the second flow rate at at least one detection point. For example, if the angle between the first flow rate and the X-axis at the detection point Q is 30°, and the angle between the second flow rate and the X-axis is 40°, then the direction difference between the first flow rate and the second flow rate can be 40-30=10.

[0202] In some embodiments, the flow rate correction module 250 can obtain the difference between the first flow rate and the second flow rate based on the magnitude of the vector difference between the first flow rate and the second flow rate at at least one detection point. For example, the first flow rate of the detection point Q is The second flow rate is Then the rate difference between the first flow rate and the second flow rate can be

[0203] In operation 920 , in response to the difference being not greater than the threshold, a target flow rate of the at least one detection point may be determined based on the first flow rate and the second flow rate of the at least one detection point.

[0204] The threshold value may be a value used to evaluate the difference between the first flow rate and the second flow rate of at least one detection point. In some embodiments, the threshold value may be manually set in advance.

[0205] In some embodiments, the threshold may include a first threshold and a second threshold. The first threshold may be a value for evaluating the difference between the first flow velocity rate and the second flow velocity rate of at least one detection point. The second threshold may be a value for evaluating the difference in direction between the first flow velocity and the second flow velocity of at least one detection point. Continuing with the above example, the first threshold is 5, the second threshold is 20°, the difference between the first flow velocity rate and the second flow velocity rate of detection point Q is 2, and the difference in direction between the first flow velocity and the second flow velocity of detection point Q is 10, then the target flow velocity of detection point Q can be determined to be the average value 21 of the first flow velocity rate 20 and the second flow velocity rate 22 of detection point Q, and the direction is 35° with the X-axis.

[0206] In some embodiments, the threshold value may further include a third threshold value. The third threshold value may be a value for evaluating the difference in speed and direction between the first flow velocity and the second flow velocity of at least one detection point. Continuing with the above example, the third threshold value is 6, and the first flow velocity of the detection point Q is and the second flow rate The difference is Then the target flow rate at the detection point Q can be determined as the average of the first flow rate and the second flow rate. The direction is the sum of the first and second flow velocities. direction.

[0207] In operation 930, in response to the difference being greater than a threshold, a target flow rate of at least one adjacent detection point adjacent to the at least one detection point may be determined, and the target flow rate of the at least one adjacent detection point may be interpolated to obtain the target flow rate of the at least one detection point.

[0208] It can be understood that when the difference between the first flow rate and the second flow rate of at least one detection point is large, the image data corresponding to the at least one detection point may have errors, and the flow rate correction module can obtain the target flow rate of the at least one detection point based on the target flow rates of other adjacent detection points.

[0209] Continuing with the above example, the first threshold is 10%, and the difference between the first flow rate and the second flow rate at the detection point D is 50%. Then, the target flow rate at the detection point D can be obtained by interpolation.

[0210] In some embodiments, interpolation may include but is not limited to at least one of the adaptive interpolation algorithms such as nearest neighbor interpolation, quadratic interpolation, cubic interpolation, etc. In some embodiments, the flow rate correction module 250 may select at least one adjacent detection point adjacent to at least one detection point based on different interpolation algorithms.

[0211] For example, the flow rate correction module 250 may use the target flow rate of the adjacent detection point closest to the detection point as the target flow rate of the detection point based on the nearest neighbor interpolation algorithm.

[0212] In another exemplary embodiment, the velocity correction module 250 can select the left and right detection points that are most adjacent to the detection point in the horizontal direction, and the upper and lower detection points that are most adjacent to the detection point in the vertical direction as the adjacent detection points of the detection point based on the quadratic interpolation algorithm. Further, the average value of the horizontal component of the target flow velocity of the most adjacent left and right detection points is obtained as the horizontal target flow velocity of the detection point; the average value of the vertical component of the target flow velocity of the most adjacent upper and lower detection points is obtained as the vertical target flow velocity of the detection point; based on the horizontal target flow velocity and the vertical target flow velocity of the detection point, the target flow velocity of the detection point is obtained.

[0213] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: (1) grouping array elements, and using the positional relationship between the emission point (emission focus), the receiving point (array element) and / or the detection point, combined with the phase change to determine the two-dimensional flow velocity of each detection point. Compared with the multi-angle emission mode, a single emission can obtain the phase change of the reflected signal at multiple angles, and the flow velocity of the target object perpendicular to the emission direction can be detected, thereby improving the system's utilization of data and facilitating the improvement of the system's frame rate and the accuracy of speed assessment; (2) using the full-aperture emission mode can improve the imaging efficiency, and at the same time, the divergent wave mode can be used so that the emitted scanning signal can be Pointing to the same focal position can not only improve the signal-to-noise ratio, but also increase the frame rate of the system, thereby improving the system's temporal resolution capability; (3) Based on the image data, the optical flow method is used to calculate the second flow velocity of at least one detection point, and the flow velocity of the detection point in the three-dimensional motion field can be converted to the two-dimensional motion field for calculation and acquisition; (4) The first flow velocity and the second flow velocity are obtained based on the system's temporal resolution capability (phase change) and spatial resolution capability (pixel point intensity), respectively, so that they can be verified and / or corrected with each other; (5) The pixel beam synthesis method is utilized, and GPU parallel calculation is used based on the array element grouping mode, which can improve the computing efficiency and reduce the hardware and time costs. It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0214] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0215] At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of this specification can be appropriately combined.

[0216] In addition, it will be understood by those skilled in the art that various aspects of this specification may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of this specification may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of this specification may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0217] A computer storage medium may include a propagated data signal containing computer program code, for example, in baseband or as part of a carrier wave. The propagated signal may be in a variety of forms, including electromagnetic, optical, etc., or a suitable combination. A computer storage medium may be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, device or apparatus to communicate, propagate or transmit the program for use. The program code on the computer storage medium may be transmitted via any suitable medium, including radio, cable, fiber optic cable, RF, or similar media, or any combination of the above media.

[0218] The computer program code required for the operation of each part of this specification can be written in any one or more programming languages, including object-oriented programming languages ​​such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python, etc., conventional procedural programming languages ​​such as C language, Visual Basic, Fortran2003, Perl, COBOL2002, PHP, ABAP, dynamic programming languages ​​such as Python, Ruby and Groovy, or other programming languages, etc. The program code can be run entirely on the user's computer, or run on the user's computer as an independent software package, or run partially on the user's computer and partially on a remote computer, or run entirely on a remote computer or processing device. In the latter case, the remote computer can be connected to the user's computer through any network form, such as a local area network (LAN) or a wide area network (WAN), or connected to an external computer (e.g., via the Internet), or in a cloud computing environment, or used as a service such as software as a service (SaaS).

[0219] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this specification, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing processing device or mobile device.

[0220] Similarly, it should be noted that in order to simplify the description disclosed in this specification and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this specification, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the subject matter of this specification are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0221] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0222] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, documents, etc., cited in this specification are hereby incorporated by reference in their entirety. Except for application history documents that are inconsistent with or conflicting with the contents of this specification, documents that limit the broadest scope of the claims of this specification (currently or later attached to this specification) are also excluded. It should be noted that if the descriptions, definitions, and / or use of terms in the materials attached to this specification are inconsistent or conflicting with the contents described in this specification, the descriptions, definitions, and / or use of terms in this specification shall prevail.

[0223] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A flow velocity detection method, comprising: Get image data; determining a rate of change of phase of at least one detection point based on the image data; Based on the positional relationship between the at least one detection point, the at least one transmission point, and each of the multiple reception points, a spatial displacement vector corresponding to each reception point is determined; the spatial displacement vector corresponding to each reception point is a sum of a unit vector of the detection point in a reception direction of the reception point and a unit vector of the detection point in a transmission direction; Grouping array elements of the scanning probe to obtain multiple groups of array elements; Determine a combined spatial displacement vector corresponding to each group of array elements based on the spatial displacement vector corresponding to each receiving point and the weight corresponding to each receiving point; Determine a first characteristic matrix corresponding to each group of array elements based on the resultant spatial displacement vector corresponding to each group of array elements; Based on the phase change rate of at least one detection point corresponding to each group of array elements and a first characteristic matrix corresponding to each group of array elements, a first flow velocity of the at least one detection point is determined.

2. The method according to claim 1, wherein acquiring image data comprises: The image data is acquired using full aperture transmission.

3. The method of claim 2, wherein the full-aperture transmission comprises full-aperture transmission in a non-focused wave transmission mode.

4. According to the method of claim 1, the scanning probe comprises any one of a linear array probe, a convex array probe, and a phased array probe.

5. The method as claimed in claim 1, wherein the image data comprises multiple groups of image data, each group of image data in the multiple groups of image data corresponds to a group of array elements in the multiple groups of array elements, and each group of image data is obtained by demodulating and beamforming reflected signals received by a corresponding group of array elements.

6. The method of claim 5, wherein determining the phase change rate of at least one detection point based on the image data comprises: Determine at least two frames of image data segments that are temporally adjacent and received by each group of array elements in the image data; Based on the at least two image data segments that are adjacent in time, a phase change rate of the at least one detection point corresponding to each group of array elements is determined.

7. The method according to claim 1, wherein determining the first flow velocity of the at least one detection point based on the phase change rate of the at least one detection point corresponding to each group of array elements and the first characteristic matrix corresponding to each group of array elements comprises: Determine a first auxiliary calculation matrix corresponding to each group of array elements based on a phase change rate of the at least one detection point corresponding to each group of array elements and a first characteristic matrix corresponding to each group of array elements; Determine a second auxiliary calculation matrix corresponding to each group of array elements based on the first characteristic matrix corresponding to each group of array elements; Accumulating the first auxiliary calculation matrix corresponding to each group of array elements to obtain a third auxiliary calculation matrix; Accumulating the second auxiliary calculation matrix corresponding to each group of array elements to obtain a fourth auxiliary calculation matrix; Based on the third auxiliary calculation matrix and the fourth auxiliary calculation matrix, a first flow velocity of the at least one detection point is determined.

8. The method according to claim 1, wherein determining the combined spatial displacement vector corresponding to each group of array elements based on the spatial displacement vector corresponding to each receiving point and the weight corresponding to each receiving point comprises: The weight of each receiving point in each group of array elements is used to perform weighted summation on the spatial displacement vector of each receiving point in each group of array elements to obtain a combined spatial displacement vector corresponding to each group of array elements.

9. The method of claim 1, wherein the weight corresponding to each receiving point is determined based on a distance between each receiving point and the at least one detection point.

10. The method of claim 1, further comprising: Determining a temporal intensity gradient and a spatial intensity gradient of the at least one detection point based on the image data; A second flow velocity of the at least one detection point is determined based on the temporal intensity gradient and the spatial intensity gradient of the at least one detection point.

11. The method of claim 10, further comprising: Based on the first flow rate and the second flow rate of the at least one detection point, a velocity correction is performed to obtain a target flow rate of the at least one detection point.

12. The method of claim 11, wherein the speed correction comprises: determining a difference between a first flow rate and a second flow rate at the at least one detection point; In response to the difference being not greater than a threshold, determining a target flow rate for the at least one detection point based on the first flow rate and the second flow rate for the at least one detection point; In response to the difference being greater than a threshold, a target flow rate of at least one adjacent detection point adjacent to the at least one detection point is determined, and the target flow rate of the at least one adjacent detection point is interpolated to obtain the target flow rate of the at least one detection point.

13. The method according to claim 1, wherein the image data is data obtained by scanning in B mode.

14. The method of claim 1, wherein determining the first flow rate of the at least one detection point comprises: The first flow velocity of the at least one detection point is determined by GPU parallel computing.

15. A flow rate detection system, comprising: at least one storage medium storing at least one set of instructions; as well as at least one processor configured to communicate with the at least one storage medium, wherein when executing the at least one set of instructions, the at least one processor is instructed to cause the system to: Get image data; determining a rate of change of phase of at least one detection point based on the image data; Based on the positional relationship between the at least one detection point, the at least one transmission point, and each of the multiple reception points, a spatial displacement vector corresponding to each reception point is determined; the spatial displacement vector corresponding to each reception point is a sum of a unit vector of the detection point in a reception direction of the reception point and a unit vector of the detection point in a transmission direction; Grouping array elements of the scanning probe to obtain multiple groups of array elements; Determine a combined spatial displacement vector corresponding to each group of array elements based on the spatial displacement vector corresponding to each receiving point and the weight corresponding to each receiving point; Determine a first characteristic matrix corresponding to each group of array elements based on the resultant spatial displacement vector corresponding to each group of array elements; A first flow velocity of the at least one detection point is determined based on a phase change rate of the at least one detection point corresponding to each group of array elements and a first characteristic matrix corresponding to each group of array elements.

16. A flow rate detection system, comprising: An image data acquisition module, used for acquiring image data; a parameter determination module, configured to determine a phase change rate of at least one detection point based on the image data; A first flow rate determination module is used to Based on the positional relationship between the at least one detection point, the at least one transmission point, and each of the multiple reception points, a spatial displacement vector corresponding to each reception point is determined; the spatial displacement vector corresponding to each reception point is a sum of a unit vector of the detection point in a reception direction of the reception point and a unit vector of the detection point in a transmission direction; Grouping array elements of the scanning probe to obtain multiple groups of array elements; Determine a combined spatial displacement vector corresponding to each group of array elements based on the spatial displacement vector corresponding to each receiving point and the weight corresponding to each receiving point; Determine a first characteristic matrix corresponding to each group of array elements based on the resultant spatial displacement vector corresponding to each group of array elements; A first flow velocity of the at least one detection point is determined based on a phase change rate of the at least one detection point corresponding to each group of array elements and a first characteristic matrix corresponding to each group of array elements.

17. A non-transitory computer-readable storage medium comprising at least one set of instructions, wherein: When executed by at least one processor of a computer device, the at least one set of instructions instructs the at least one processor to: Get image data; determining a rate of change of phase of at least one detection point based on the image data; Based on the positional relationship between the at least one detection point, the at least one transmission point, and each of the multiple reception points, a spatial displacement vector corresponding to each reception point is determined; the spatial displacement vector corresponding to each reception point is a sum of a unit vector of the detection point in a reception direction of the reception point and a unit vector of the detection point in a transmission direction; Grouping array elements of the scanning probe to obtain multiple groups of array elements; Determine a combined spatial displacement vector corresponding to each group of array elements based on the spatial displacement vector corresponding to each receiving point and the weight corresponding to each receiving point; Determine a first characteristic matrix corresponding to each group of array elements based on the resultant spatial displacement vector corresponding to each group of array elements; A first flow velocity of the at least one detection point is determined based on a phase change rate of the at least one detection point corresponding to each group of array elements and a first characteristic matrix corresponding to each group of array elements.

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