Method for determining hemodynamic parameters based on vector velocity and ultrasonic device

Abstract

A method for determining hemodynamic parameters based on vector velocity and an ultrasonic device. The method for determining hemodynamic parameters based on vector velocity includes: emitting an ultrasonic beam to a target area, the target area including a blood vessel (S110); receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal (S120); determining the vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal (S130); determining a scalar value corresponding to the hemodynamic parameter according to the vector velocity (S140); and obtaining the hemodynamic parameter according to the scalar value (S150). It can be seen that the method for determining hemodynamic parameters based on vector velocity can determine various hemodynamic parameters based on the vector velocity of blood flow, including not only hemodynamic parameters based on scalar values, but also hemodynamic parameters based on direction, so as to provide more abundant reference parameters for the dynamic condition of blood flow and provide a more accurate basis for subsequent blood flow analysis.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of ultrasonic detection, and more specifically, to a method for determining hemodynamic parameters based on vector velocity and an ultrasonic device. Background Art

[0002] In the process of measuring hemodynamic parameters, the velocity based on traditional methods such as pulsed wave doppler (PW) is the velocity corrected by angle, and the blood flow velocity obtained is the projection component in the direction of ultrasound emission. Such velocity is only scalar information, so the measured value is inaccurate in the area of ​​blood flow angle disorder. As a result, the hemodynamic parameters further determined based on the blood flow velocity are also inaccurate. Summary of the invention

[0003] On the one hand, an embodiment of the present invention provides a method for determining hemodynamic parameters based on vector velocity, the method comprising:

[0004] transmitting an ultrasound beam to a target area, wherein the target area includes a blood vessel;

[0005] receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal;

[0006] determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal;

[0007] determining a scalar value corresponding to the hemodynamic parameter based on the vector velocity;

[0008] The hemodynamic parameter is obtained according to the scalar value.

[0009] On the other hand, an embodiment of the present invention further provides a method for determining hemodynamic parameters based on vector velocity, the method comprising:

[0010] transmitting an ultrasound beam to a target area, wherein the target area includes a blood vessel;

[0011] receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal;

[0012] determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal;

[0013] determining a velocity direction corresponding to the hemodynamic parameter according to the vector velocity;

[0014] According to the velocity direction, the direction-based hemodynamic parameter is obtained.

[0015] In another aspect, an embodiment of the present invention further provides an ultrasonic device, comprising:

[0016] Ultrasound probe;

[0017] a transmit / receive selection switch, used to stimulate the ultrasound probe to transmit an ultrasonic beam to a target area via a transmitting circuit, and to receive an ultrasonic echo of the ultrasonic beam returned from the target area, wherein the target area includes a blood vessel;

[0018] A memory, used to store a program executed by the processor;

[0019] Processor for:

[0020] obtaining an ultrasonic echo signal based on the ultrasonic echo;

[0021] determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal;

[0022] determining a scalar value corresponding to the hemodynamic parameter based on the vector velocity;

[0023] The hemodynamic parameter is obtained according to the scalar value.

[0024] In another aspect, an embodiment of the present invention further provides an ultrasonic device, comprising:

[0025] Ultrasound probe;

[0026] a transmit / receive selection switch, used to stimulate the ultrasound probe to transmit an ultrasonic beam to a target area via a transmitting circuit, and to receive an ultrasonic echo of the ultrasonic beam returned from the target area, wherein the target area includes a blood vessel;

[0027] A memory, used to store a program executed by the processor;

[0028] Processor for:

[0029] obtaining an ultrasonic echo signal based on the ultrasonic echo;

[0030] determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal;

[0031] determining a velocity direction corresponding to the hemodynamic parameter according to the vector velocity;

[0032] According to the velocity direction, the direction-based hemodynamic parameter is obtained.

[0033] In addition, an embodiment of the present invention further provides a computer storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for determining hemodynamic parameters based on vector velocity described in the above aspect are implemented.

[0034] It can be seen that the embodiments of the present invention can determine various hemodynamic parameters based on the vector velocity of blood flow, including not only hemodynamic parameters based on the scalar value of the vector velocity, but also hemodynamic parameters based on the direction of the vector velocity. This can provide more abundant reference parameters for the dynamic condition of blood flow and provide a more accurate basis for subsequent blood flow analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 It is a block diagram of the structure of an ultrasonic device;

[0037] Figure 2 is a schematic flow chart of a method for determining hemodynamic parameters based on vector velocity;

[0038] Figure 3 It is a schematic diagram of the vector velocity of blood flow in a blood vessel;

[0039] Figure 4 is a schematic flow chart of a method for determining hemodynamic parameters based on vector velocity according to an embodiment of the present invention;

[0040] Figure 5 It is a schematic diagram of the cardiac cycle;

[0041] Figure 6 is a schematic diagram of a cross section of a blood vessel and the position of a velocity center in an embodiment of the present invention;

[0042] Figure 7 is a schematic diagram of velocity distribution at the cross section AB of a blood vessel in an embodiment of the present invention;

[0043] Figure 8 is a schematic diagram of the velocity magnitude at the cross section AB of the blood vessel in an embodiment of the present invention;

[0044] Fig. 9 It is a schematic flow chart of a method for determining hemodynamic parameters based on vector velocity according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The embodiment of the present invention provides an ultrasonic device that can obtain more accurate hemodynamic parameters.

[0046] like Figure 1 1 is a block diagram of a structure of an ultrasonic device. The ultrasonic device 10 includes an ultrasonic probe 110, a transmit / receive selection switch 120, a memory 130, a processor 140, and a display 150. The transmit / receive selection switch 120 can stimulate the ultrasonic probe 110 to transmit an ultrasonic beam to a target area, and receive an ultrasonic echo of the ultrasonic beam returned from the target area through the ultrasonic probe 110. The processor 140 can obtain an ultrasonic echo signal based on the ultrasonic echo of the ultrasonic beam, and process the ultrasonic echo signal.

[0047] Exemplarily, the transmit / receive selection switch 120 can stimulate the ultrasound probe 110 to transmit an ultrasonic beam to a target area, the target area including a blood vessel, and receive an ultrasonic echo of the ultrasonic beam returned from the target area through the ultrasound probe 110. The processor 140 can obtain an ultrasonic echo signal based on the ultrasonic echo; and determine the vector velocity of the blood flow in the blood vessel according to the ultrasonic echo signal; and then obtain a hemodynamic parameter based on the vector velocity.

[0048] The vector velocity may be calculated by any method such as a speckle tracking method, a transverse wave oscillation method, or a multi-angle deflection transmission / reception method.

[0049] Taking the method of obtaining the vector velocity by multi-angle deflection transmission / reception as an example, the transmission / reception selection switch 120 can excite the ultrasound probe 110 to transmit an ultrasonic beam to a target area along at least two directions, the target area including a blood vessel, and receive an ultrasonic echo of the ultrasonic beam returned from the target area through the ultrasound probe 110. The processor 140 can obtain an ultrasonic echo signal along each of the at least two directions based on the ultrasonic echo; determine the velocity component of the blood flow in the blood vessel along each of the at least two directions according to the ultrasonic echo signal along each of the at least two directions; and determine the vector velocity of the blood flow in the blood vessel according to the velocity component in each of the at least two directions.

[0050] The hemodynamic parameters may be currently available parameters of interest, or may include other parameters that can represent the fluid dynamics of blood flow. For a more detailed description, please refer to the subsequent embodiments of this specification.

[0051] Exemplarily, the processor 140 may also obtain an ultrasonic echo signal based on the ultrasonic echo; and obtain an ultrasonic image of the target area according to the ultrasonic echo signal. For example, the ultrasonic echo signal may be processed by beamforming, orthogonal demodulation, wall filtering, etc. The ultrasonic image obtained by the processor 140 may be stored in the memory 130. Furthermore, the ultrasonic image may be displayed on the display 150. Optionally, the display 150 may also display hemodynamic parameters of the blood vessel, etc.

[0052] Optionally, the display 150 in the ultrasound device 10 may be a touch screen, a liquid crystal display, etc.; or the display 150 may be an independent display device such as a liquid crystal display, a television, etc. that is independent of the ultrasound device 10; or the display 150 may be a display screen of an electronic device such as a smart phone, a tablet computer, etc. The number of the displays 150 may be one or more.

[0053] Optionally, the memory 130 in the ultrasound device 10 may be a flash memory card, a solid-state memory, a hard disk, etc. It may be a volatile memory and / or a non-volatile memory, a removable memory and / or a non-removable memory, etc.

[0054] Optionally, the processor 140 in the ultrasound device 10 can be implemented by software, hardware, firmware or any combination thereof, and can use circuits, single or multiple application specific integrated circuits (ASICs), single or multiple general purpose integrated circuits, single or multiple microprocessors, single or multiple programmable logic devices, or any combination of the aforementioned circuits and / or devices, or other suitable circuits or devices, so that the processor 140 can execute the corresponding steps of the methods in the various embodiments of the present specification.

[0055] It should be understood that Figure 1 The components included in the ultrasonic device 10 shown are only schematic, and it may include more or fewer components. For example, the ultrasonic device 10 may also include input devices such as a keyboard, a mouse, a roller, a trackball, and / or may include output devices such as a printer. The corresponding external input / output port may be a wireless communication module, or a wired communication module, or a combination of the two. The external input / output port may also be implemented based on USB, bus protocols such as CAN, and / or wired network protocols, etc. The present invention is not limited to this.

[0056] The embodiment of the present invention provides a method for determining hemodynamic parameters based on vector velocity. A flow chart of the method is shown in FIG. Figure 2 As shown, the method includes:

[0057] S101, obtaining the vector velocity of blood flow;

[0058] S102: Determine hemodynamic parameters according to the vector velocity, wherein the hemodynamic parameters include parameters associated with the scalar value of the vector velocity and / or parameters associated with the direction of the vector velocity.

[0059] In the embodiment of the present invention, the vector velocity of the blood flow can represent the actual flow state of the blood flow, such as Figure 3As shown. Vector velocity includes not only magnitude but also direction. The direction of the vector velocity of blood flow at different locations in the blood vessel is generally different; at the same location, the direction of the vector velocity of blood flow at different times is likely to be different.

[0060] As an example, the vector velocity can be obtained based on a vector blood flow imaging method of speckle tracking, wherein the speckle tracking can be realized by using the sum of absolute differences, wherein the calculation can be performed based on plane wave emission and speckle tracking method.

[0061] As an example, the vector velocity can be obtained by a vector blood flow imaging method based on the transverse wave oscillation method, wherein the longitudinal velocity is obtained by a traditional calculation method based on the Doppler principle, the transverse velocity is calculated by generating a transverse oscillating ultrasonic sound field based on the autocorrelation method, and then the transverse and longitudinal velocities are combined to obtain the vector velocity.

[0062] As an example, the vector velocity can be obtained by multi-angle deflection transmission and reception. Each angle is calculated using the traditional Doppler principle to obtain the velocity component at that angle. The velocity measurement results at multiple different angles are synthesized by angle to obtain the magnitude and direction of the actual velocity, that is, the vector velocity.

[0063] The blood flow velocity obtained by traditional PW is based on the velocity after angle correction. The above method for determining the vector velocity of blood flow does not require angle correction and can obtain a more actual velocity magnitude and direction of blood flow. It can more accurately represent the actual flow state of blood flow than the traditional velocity after angle correction.

[0064] The vector velocity mentioned in this application refers to the actual velocity of the blood flow (such as the red blood cells in the blood flow), or closer to the actual velocity of the blood flow (such as the red blood cells in the blood flow); the direction of the velocity refers to the actual flow direction of the blood flow (such as the red blood cells in the blood flow), or closer to the actual flow direction of the blood flow (such as the red blood cells in the blood flow); Figure 3 As shown, the direction of the vector velocity can be in the range of 0° to 360° in the imaging plane, and its direction can represent the actual flow direction of the blood flow.

[0065] For example, the vector velocity may be obtained by an ultrasonic device, such as Figure 4 A schematic flow chart of a method for determining hemodynamic parameters based on vector velocity is shown, comprising:

[0066] S110, transmitting an ultrasonic beam to a target area, where the target area includes a blood vessel;

[0067] S120, receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal;

[0068] S130, determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal;

[0069] S140, determining a scalar value corresponding to the hemodynamic parameter according to the vector velocity;

[0070] S150: Obtain the hemodynamic parameter according to the scalar value.

[0071] Combination Figure 2 , it can be considered Figure 2 S101 in includes S110 to S130, Figure 2 S102 in includes S140 to S150. Figure 4 In the flowchart shown, the vector velocity of the blood flow can be determined through S110 to S130, wherein the vector velocity can be calculated by any method such as speckle tracking method, transverse wave oscillation method, multi-angle deflection transmission / reception, etc.

[0072] In S140, the scalar value may refer to the absolute value of the vector velocity, or may refer to the velocity component of the vector velocity in a preset direction. That is, S140 may include: determining the absolute value of the vector velocity as the scalar value; or S140 may include: determining the velocity component of the vector velocity in a preset direction as the scalar value.

[0073] The absolute value of the vector velocity can be obtained by mathematically calculating the mode of the vector. For example, the absolute value of the vector velocity is equal to the square root of the sum of the squares of the components of the vector velocity on each coordinate axis of the orthogonal Cartesian coordinate system.

[0074] The preset direction may be any of the following directions: the long axis direction of the blood vessel, the X-axis direction of the coordinate system, the Y-axis direction of the coordinate system, the ultrasound emission direction, a user-defined direction, etc. Of course, the preset direction may also be any other direction, such as a direction that forms a certain angle (e.g., 45°, 60°, etc.) with the long axis direction of the blood vessel, etc., which is not limited in the present invention. The velocity component of the vector velocity in the preset direction may be obtained by projecting the vector velocity in the preset direction.

[0075] In one implementation, the hemodynamic parameter may include at least one of the following: a systolic velocity peak value within a heart rate cycle, a diastolic velocity trough value within a heart rate cycle, and an average velocity within a heart rate cycle.

[0076] A schematic diagram of a cardiac cycle is as follows Figure 5 The interval between two adjacent velocity troughs can be defined as a cardiac cycle. It is understandable that other methods can also be used to define a cardiac cycle, such as between two adjacent wave peaks, etc. The present invention is not limited to this.

[0077] The systolic velocity peak value within the heart rate cycle may be the peak value of the absolute value of the systolic vector velocity within the heart rate cycle, expressed as |PS|. Alternatively, the systolic velocity peak value within the heart rate cycle may be the peak value of the velocity component of the systolic vector velocity in a preset direction within the heart rate cycle, expressed as PS M , M represents the preset direction.

[0078] The trough value of the end-diastolic velocity in the heart rate cycle may be the trough value of the absolute value of the end-diastolic vector velocity in the heart rate cycle, expressed as |ED|. Alternatively, the trough value of the end-diastolic velocity in the heart rate cycle may be the trough value of the velocity component of the end-diastolic vector velocity in the heart rate cycle in a preset direction, expressed as ED M , M represents the preset direction.

[0079] The average speed in the heart rate cycle may be the average value of the absolute value of the vector speed in the heart rate cycle, expressed as |TAMean|. Alternatively, the average speed in the heart rate cycle may be the average value of the speed component of the vector speed in a preset direction in the heart rate cycle, expressed as TAMean M , M represents the preset direction.

[0080] Optionally, the average speed in the heart rate cycle can be calculated based on multiple vector speeds at multiple different time points in the heart rate cycle. Assume that the number of the multiple vector speeds is V Num , V Num is a positive integer. Then: Among them, HeartBeat represents a cardiac cycle, and the value range of t is 1 to V Num It should be noted that V Num V t Can be evenly distributed along time, that is, every two adjacent V t The time intervals between are consistent. Alternatively, V Num V t It can be unevenly distributed along time, that is, two different V t The time intervals between them may not be equal.

[0081] In one implementation, the hemodynamic parameter may include at least one of the following: a pulsatility index, a resistance index, a systolic-to-diastolic ratio, and a diastolic-to-systolic ratio.

[0082] Exemplarily, the hemodynamic parameters include a pulsatility index (PI), and S140 may include: determining, based on the vector velocity: a systolic velocity peak value within a heart rate cycle, a diastolic velocity trough value within a heart rate cycle, and an average velocity within a heart rate cycle.

[0083] That is to say, combined Figure 4 The pulsatility index (PI) can be obtained through the following process: emitting an ultrasonic beam to a target area, the target area including a blood vessel; receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal; determining the vector velocity of the blood flow in the blood vessel according to the ultrasonic echo signal; determining the peak systolic velocity within the heart rate cycle, the trough value of the end-diastolic velocity within the heart rate cycle, and the average velocity within the heart rate cycle according to the vector velocity; obtaining the pulsatility index (PI) according to the peak systolic velocity, the trough value of the end-diastolic velocity and the average velocity within the heart rate cycle.

[0084] Among them, the systolic velocity peak value within the heart rate cycle is the peak value of the absolute value of the systolic vector velocity within the heart rate cycle, the diastolic end velocity trough value within the heart rate cycle is the trough value of the absolute value of the diastolic end vector velocity within the heart rate cycle, and the average velocity within the heart rate cycle is the average value of the absolute value of the vector velocity within the heart rate cycle. In other words, the change of the absolute value of the vector velocity (expressed as |V|) along the entire heart rate cycle can be obtained, and based on this, the peak value of the absolute value of the vector velocity (|V|) in the systolic period (expressed as |PS|), the trough value at the end of diastole (expressed as |ED|), and the average value within the heart rate cycle (expressed as |TAMean|, as listed in the above embodiment) can be obtained. Furthermore, in S150, the pulsatility index can be obtained based on the above three values ​​by the following formula:

[0085]

[0086] Or, the systolic velocity peak value in the heart rate cycle is the peak value of the velocity component of the systolic vector velocity in the heart rate cycle in the preset direction, the diastolic end velocity trough value in the heart rate cycle is the trough value of the velocity component of the diastolic end vector velocity in the heart rate cycle in the preset direction, and the average velocity in the heart rate cycle is the average value of the velocity component of the vector velocity in the heart rate cycle in the preset direction. In other words, the velocity component of the vector velocity in the preset direction (expressed as V M , M can represent the preset direction) along the change of the entire heart rate cycle, and based on this, the velocity component of the vector velocity (V M ) at the peak of the systolic period (denoted as PS M ), the trough value at the end of diastole (expressed as ED M ), the average value within the heart rate cycle (expressed as TAMean M , as listed in the above embodiment). Further, in S150, the pulsatility index can be obtained based on the above three values ​​by the following formula:

[0087]

[0088] Exemplarily, the hemodynamic parameter includes at least one of a resistance index (RI), a systolic to diastolic ratio (S / D), and a diastolic to systolic ratio (D / S). S140 may include: determining, according to the vector velocity: a systolic velocity peak value within a heart rate cycle, and a diastolic end velocity trough value within a heart rate cycle.

[0089] That is to say, combined Figure 4 The resistance index (RI) can be obtained through the following process: emitting an ultrasonic beam to a target area, the target area including a blood vessel; receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal; determining the vector velocity of the blood flow in the blood vessel according to the ultrasonic echo signal; determining a systolic velocity peak value within a heart rate cycle and a diastolic velocity trough value within the heart rate cycle according to the vector velocity; and obtaining the resistance index (RI) according to the systolic velocity peak value and the diastolic velocity trough value within the heart rate cycle.

[0090] That is to say, combined Figure 4 , the systolic-to-diastolic ratio (S / D) can be obtained by the following process: emitting an ultrasonic beam to a target area, the target area including a blood vessel; receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal; determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal; determining a systolic velocity peak value within a heart rate cycle and a diastolic end-velocity trough value within the heart rate cycle according to the vector velocity; obtaining the systolic-to-diastolic ratio (S / D) according to the systolic velocity peak value and the diastolic end-velocity trough value within the heart rate cycle.

[0091] The systolic velocity peak value in the heart rate cycle is the peak value of the absolute value of the systolic vector velocity in the heart rate cycle, and the diastolic end velocity trough value in the heart rate cycle is the trough value of the absolute value of the diastolic end vector velocity in the heart rate cycle, which are respectively expressed as |PS| and |ED|. Then, in S150, at least one of the resistance index (RI), the systolic to diastolic ratio (S / D), or the diastolic to systolic ratio (D / S) can be obtained based on the above two values ​​by the following formula:

[0092]

[0093] S / D=|PS| / |ED|,

[0094] D / S=|ED| / |PS|.

[0095] The systolic velocity peak value in the heart rate cycle is the peak value of the velocity component of the systolic vector velocity in the heart rate cycle in the preset direction, and the diastolic velocity trough value in the heart rate cycle is the trough value of the velocity component of the diastolic vector velocity in the heart rate cycle in the preset direction, which are respectively expressed as PS M and ED M , M represents a preset direction. Then, in S150, at least one of the resistance index (RI), the systolic-to-diastolic ratio (S / D), or the diastolic-to-systolic ratio (D / S) can be obtained based on the above two values ​​by the following formula:

[0096]

[0097] S / D=PS M / ED M ,

[0098] D / S=ED M / PS M .

[0099] In one implementation, the hemodynamic parameter may include a velocity time integral (Velocity Time Integral, VTI).

[0100] Exemplarily, S140 may include: determining the absolute value of the vector velocity as the scalar value; or S140 may include: determining the velocity component of the vector velocity in a preset direction as the scalar value. Accordingly, S150 may include: determining the integral of the scalar value over the time period between the first moment and the second moment as the velocity time integral.

[0101] That is to say, the velocity time integral can be the integral of the absolute value of the vector velocity over the time period between the first moment and the second moment, expressed as follows:

[0102]

[0103] In the above formula, |VTI| represents the velocity time integral in absolute value form, |v(t)| represents the absolute value of the vector velocity at time t, T1 represents the first time, and T2 represents the second time. And, it can be understood that if the first time to the second time constitutes a cardiac cycle, the velocity time integral is the velocity time integral within a cardiac cycle.

[0104] That is to say, the velocity time integral can be the integral of the velocity component of the vector velocity in the preset direction over the time period between the first moment and the second moment, which can be expressed as follows:

[0105]

[0106] In the above formula, VTI M represents the velocity time integral of the velocity component in the preset direction, v(t) M represents the velocity component of the vector velocity at time t in the preset direction, M represents the preset direction, T1 represents the first moment, and T2 represents the second moment. And, it can be understood that if the first moment to the second moment constitute a cardiac cycle, the velocity time integral is the velocity time integral within a cardiac cycle.

[0107] In one implementation, the hemodynamic parameter may include an average velocity over a specific time period, for example, the specific time period may be a time period between a first moment and a second moment. Furthermore, it is understood that if the first moment to the second moment constitutes a cardiac cycle, the average velocity over the specific time period is the average velocity within a cardiac cycle. In other words, the hemodynamic parameter may include an average velocity within a cardiac cycle.

[0108] Exemplarily, S140 may include: determining an absolute value of the vector velocity as the scalar value; or, S140 may include: determining a velocity component of the vector velocity in a preset direction as the scalar value.

[0109] Accordingly, S150 may include: calculating the integral of the scalar value over the time period between the first moment and the second moment, and dividing the integral by the time period to obtain the average speed. This may be expressed as follows:

[0110] or

[0111] Alternatively, S150 may include: calculating the average speed according to multiple scalar values ​​at multiple different time points between the first moment and the second moment. It can be expressed as follows:

[0112] or

[0113] In which, it is assumed that the number of multiple vector velocities is V Num , V Num is a positive integer. The value range of t is 1 to V Num It should be noted that V Num V t Can be evenly distributed along time, that is, every two adjacent V t The time intervals between are consistent. Alternatively, V Num V t It can be unevenly distributed along time, that is, two different V t The time intervals between them may not be equal.

[0114] Optionally, in the above embodiment, the time period between the first moment and the second moment may be a cardiac cycle, such as Figure 5 shown.

[0115] In one implementation, the hemodynamic parameter may include minimum diastolic velocity (Min-Diastolic Velocity, MD).

[0116] Exemplarily, S140 may include: determining the absolute value of the vector velocity as the scalar value; or, S140 may include: determining the velocity component of the vector velocity in a preset direction as the scalar value. Accordingly, S150 may include: determining the minimum value of the scalar value in the diastole of the cardiac cycle as the diastole minimum velocity. It can be seen that the diastole minimum velocity may be the minimum value of the absolute value of the vector velocity in the diastole, or the minimum value of the velocity component of the vector velocity in the preset direction in the diastole.

[0117] In one implementation, the hemodynamic parameter may include early systolic acceleration (Acceleration, AC).

[0118] For example, S140 may include: determining the absolute value of the vector velocity as the scalar value; or S140 may include: determining the velocity component of the vector velocity in a preset direction as the scalar value. Accordingly, S150 may include: determining the first-order gradient of the scalar value to time in the early systolic period of the cardiac cycle as the early systolic acceleration.

[0119] That is, the early contraction acceleration may be the minimum absolute value of the vector velocity in the early contraction period, or the minimum velocity component of the vector velocity in a preset direction in the early contraction period.

[0120] The early contraction acceleration can be understood as being obtained by calculating the absolute value of the vector velocity or the slope of a curve of the velocity component of the vector velocity in a preset direction varying with time during the rising period of the early contraction spectrum.

[0121] In one implementation, the hemodynamic parameter may include an offset between a velocity centerline and a vessel centerline.

[0122] Specifically, the hemodynamic parameter may be the offset between the position of the velocity center at a certain cross section of the blood vessel and the center point of the cross section. Figure 6 , showing a section of a blood vessel, taking cross section AB as an example, the center point of the cross section (or simply the center of the cross section) is the geometric midpoint of AB, that is, Figure 6 If the position of the velocity center obtained by determination is D, then the offset of D relative to C can be further obtained.

[0123] The position of the velocity center may be the position of the center of the velocity distribution on the cross section. Optionally, the velocity distribution may be the distribution of the vector velocity or the distribution of the velocity component of the vector velocity in a preset direction. Accordingly, S140 may include: determining the position of the physical center of the vector velocity at each position along the cross section of the blood vessel; or, S140 may include: determining the position of the physical center of the velocity component of the vector velocity in a preset direction at each position along the cross section of the blood vessel. Figure 7 , assuming that the velocity distribution along the cross section AB of the blood vessel is in the range EF, that is, Figure 7 If there is blood flow on the line segment EF shown in FIG, then the physical center of EF (i.e., the midpoint D of EF) can be determined as the position of the velocity center. It can be understood that Figure 7 The arrow shown in FIG. 1 may be a vector velocity or may be a vector velocity in a preset direction (eg, Figure 7 The preset direction shown is the velocity component in the direction perpendicular to the cross section AB.

[0124] Alternatively, the position of the velocity center may be the position of the maximum value of the velocity on the cross section. Optionally, the maximum value of the velocity may be the maximum value of the absolute value of the vector velocity or may be the maximum value of the velocity component of the vector velocity in a preset direction. Accordingly, S140 may include: determining the absolute value of the vector velocity at each position along the cross section of the blood vessel; determining the position of the cross section of the blood vessel corresponding to the maximum value of the absolute value. Alternatively, S140 may include: determining the velocity component of the vector velocity at each position along the cross section of the blood vessel in a preset direction; determining the position of the cross section of the blood vessel corresponding to the maximum value of the velocity component. Reference Figure 8 , assuming that the position of the maximum velocity along the cross section AB of the blood vessel is D, that is, Figure 8 The length of the arrow shown in the figure can represent the magnitude of the speed, so the arrow with the longest length is the position with the highest speed. It can be understood that Figure 8 The arrow shown in FIG. 1 may be a vector velocity or may be a vector velocity in a preset direction (eg, Figure 8 The preset direction shown is the velocity component in the direction perpendicular to the cross section AB.

[0125] For example, the offset between the velocity centerline and the blood vessel centerline may represent the distance between the position of the velocity center and the center point of the cross section at a certain cross section of the blood vessel. Figure 6 , the distance can be Figure 6 The distance between the midpoint D and point C.

[0126] Exemplarily, the offset between the velocity centerline and the blood vessel centerline can represent the distance between the position of the velocity center and the center point of the cross section and the direction of the position of the velocity center relative to the center point of the cross section at a certain cross section of the blood vessel. For example, if the position of the velocity center is located in a first direction from the center of the cross section, the offset can be represented as a positive value. If the position of the velocity center is located in a second direction from the center of the cross section, the offset can be represented as a negative value. The first direction and the second direction are opposite directions. Figure 6 , assuming that D is located on AC, it is located in the first direction of C, and the offset is positive, |CD|. On the other hand, if D is located on BC, it is located in the second direction of C, and the offset is negative, -|CD|. Where |CD| represents the distance between point D and point C.

[0127] For example, the offset between the velocity centerline and the blood vessel centerline can represent the percentage of the velocity center position offset from the center point of the cross section at a certain cross section of the blood vessel. If the velocity center position coincides with the center point of the cross section, the offset percentage can be considered to be 0; if the velocity center position is located at the blood vessel wall, the offset percentage can be considered to be 100%. Accordingly, the offset can be defined as:

[0128]

[0129] Combination Figure 6 It can be seen that if point D is located at point A, the offset is 100%; if point D is located at point B, the offset is -100%; if point D is located at point C, the offset is 0. Considering that the diameters of different cross-sections of the blood vessel may be different, expressing the offset in this percentage way can more accurately reflect the dynamic performance of blood flow, thereby providing a more effective reference for blood flow analysis.

[0130] Return now Figure 2 The hemodynamic parameter in S102 may be a parameter associated with the direction of the vector velocity, or may also be referred to as a direction-based hemodynamic parameter or an angle-based hemodynamic parameter. For example, the vector velocity in S101 may be obtained by an ultrasonic device, such as Fig. 9 A schematic flow chart of a method for determining hemodynamic parameters based on vector velocity is shown, comprising:

[0131] S210, transmitting an ultrasonic beam to a target area, where the target area includes a blood vessel;

[0132] S220, receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal;

[0133] S230, determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal;

[0134] S240, determining a velocity direction corresponding to the hemodynamic parameter according to the vector velocity;

[0135] S250: Obtain hemodynamic parameters according to the velocity direction.

[0136] Combination Figure 2 , it can be considered Figure 2 S101 in includes S210 to S230, Figure 2 S102 in includes S240 to S250. Fig. 9 In the flowchart shown, the vector velocity of the blood flow can be determined through S210 to S230, wherein the vector velocity can be calculated by any method such as speckle tracking method, transverse wave oscillation method, multi-angle deflection transmission / reception, etc.

[0137] In one implementation, the direction-based hemodynamic parameter may include the angle between the direction of the vector velocity of the blood flow at a certain location of the blood vessel at two different times.

[0138] For example, in S240, a first direction of the vector velocity of the first position of the blood vessel at a first moment may be determined, and a second direction of the vector velocity of the first position of the blood vessel at a second moment may be determined. In S250, an angle between the first direction and the second direction may be obtained based on the two directions.

[0139] Alternatively, the angle may be expressed as:

[0140] ΔAngle time =Angle t1 -Angle t2

[0141] Wherein, t1 represents the first moment, and t2 represents the second moment. t1 It can represent the first direction, and can be represented as the angle between the first direction and the preset direction. t2 The second direction can be represented, and exemplarily can be represented as the angle between the second direction and the preset direction. The preset direction here can be any direction, such as the long axis direction of the blood vessel, the X-axis direction, etc.

[0142] Optionally, if the first moment is the moment corresponding to the peak value of the systolic velocity in the heart rate cycle, and the second moment is the moment corresponding to the trough value of the diastolic velocity in the heart rate cycle. Or, similarly, the first moment is the moment corresponding to the trough value of the diastolic velocity in the heart rate cycle, and the second moment is the moment corresponding to the peak value of the systolic velocity in the heart rate cycle. Then, the above formula can be:

[0143] ΔAngle time =Angle PS -Angle ED or ΔAngle time =Angle ED -Angle PS .

[0144] In one implementation, the direction-based hemodynamic parameter may include an average velocity direction of a vector velocity of blood flow at a certain location of a blood vessel within a preset time period.

[0145] Exemplarily, S240 may include: determining multiple directions of multiple vector velocities within a preset time period; S250 may include: determining an average of the multiple directions to obtain an average velocity direction.

[0146] Alternatively, the average velocity direction can be expressed by:

[0147] Wherein, AngleNum represents the number of multiple directions.

[0148] It is understandable that if the preset time period is a cardiac cycle, the above can be:

[0149]

[0150] In one implementation, the direction-based hemodynamic parameter may include the angle between the directions of the vector velocities of the blood flow at two different locations of the blood vessel at the same moment.

[0151] For example, in S240, a first direction of a vector velocity of a first position of a blood vessel at a first moment may be determined, and a second direction of a vector velocity of a second position of a blood vessel at the first moment may be determined. In S250, an angle between the first direction and the second direction may be obtained based on the two directions.

[0152] Alternatively, the angle may be expressed as:

[0153] ΔAngle position =Angle p1 -Angle p2 ;

[0154] Where p1 represents the first position and p2 represents the second position. p1 It can represent the first direction, and can be represented as the angle between the first direction and the preset direction. p2The second direction can be represented, and exemplarily can be represented as the angle between the second direction and the preset direction. The preset direction here can be any direction, such as the long axis direction of the blood vessel, the X-axis direction, etc.

[0155] In one implementation, the direction-based hemodynamic parameter may include the directional angle between the vector velocities of blood flow at two different locations of the blood vessel at the same moment, and the average value of the angle difference within a preset time period.

[0156] Exemplarily, multiple first directions of multiple vector velocities at the first position within a preset time period and multiple second directions of the second position at the corresponding moment can be determined, and then the mean of the angle difference can be determined, which can be obtained by the following formula:

[0157]

[0158] In one implementation, the direction-based hemodynamic parameter may include an angle between a velocity direction of a vector velocity of blood flow at a certain location of a blood vessel and a centerline direction of the blood vessel.

[0159] For example, the angle determined in S250 may be expressed by the following formula:

[0160] ΔAngle centerline =Angle-Angle centerline ;

[0161] Among them, Angle centerline Indicates the centerline direction of the blood vessel.

[0162] In one implementation, the direction-based hemodynamic parameter may include the angle between the velocity direction of the vector velocity of the blood flow at a certain position of the blood vessel and the centerline direction of the blood vessel, and the average value of the angle within a preset time period.

[0163] For example, the velocity directions of multiple vector velocities within a preset time period and the corresponding centerline directions of multiple blood vessels can be determined, and then the mean angle can be determined, which can be obtained by the following formula:

[0164]

[0165] It should be understood that although the above combination Figures 2 to 9 The process of determining each hemodynamic parameter is described, but in the embodiment of the present invention, some or all of the above-listed hemodynamic parameters can be determined at the same time. And optionally, after the hemodynamic parameter is determined, the hemodynamic parameter can also be displayed on a display so that the user can view it intuitively. Optionally, the hemodynamic parameter can be displayed while displaying the ultrasound image. The present invention is not limited to this.

[0166] It can be seen that the embodiments of the present invention can determine various hemodynamic parameters based on the vector velocity of blood flow, including not only hemodynamic parameters based on scalar values, but also hemodynamic parameters based on direction. This can provide more abundant reference parameters for the dynamic condition of blood flow and provide a more accurate basis for subsequent blood flow analysis.

[0167] Now return to Figure 1 The ultrasound device 10 is shown.

[0168] In one implementation, the transmit / receive selection switch 120 can stimulate the ultrasound probe 110 to transmit an ultrasonic beam to a target area via a transmitting circuit, the target area including a blood vessel, and receive an ultrasonic echo of the ultrasonic beam returned from the target area. The processor 140 can obtain an ultrasonic echo signal based on the ultrasonic echo; determine the vector velocity of the blood flow in the blood vessel according to the ultrasonic echo signal; determine a scalar value corresponding to the hemodynamic parameter according to the vector velocity; and obtain the hemodynamic parameter according to the scalar value.

[0169] For example, the transmit / receive selection switch 120 can excite the ultrasound probe 110 to transmit an ultrasonic beam to a target area via a transmitting circuit along at least two directions, the target area including a blood vessel, and receive an ultrasonic echo of the ultrasonic beam returned from the target area. The processor 140 can obtain an ultrasonic echo signal along each of the at least two directions based on the ultrasonic echo; determine a velocity component of the blood flow velocity in the blood vessel along each of the at least two directions according to the ultrasonic echo signal along each of the at least two directions; determine a vector velocity of the blood flow in the blood vessel according to the velocity component in each of the at least two directions; determine a scalar value corresponding to the hemodynamic parameter according to the vector velocity; and obtain the hemodynamic parameter according to the scalar value.

[0170] In one implementation, the transmit / receive selection switch 120 can stimulate the ultrasound probe 110 to transmit an ultrasonic beam to a target area via a transmitting circuit, the target area including a blood vessel, and receive an ultrasonic echo of the ultrasonic beam returned from the target area. The processor 140 can obtain an ultrasonic echo signal based on the ultrasonic echo; determine the vector velocity of the blood flow in the blood vessel according to the ultrasonic echo signal; determine the velocity direction corresponding to the hemodynamic parameter according to the vector velocity; and obtain the direction-based hemodynamic parameter according to the velocity direction.

[0171] In addition, an embodiment of the present invention further provides a computer storage medium on which a computer program is stored. When the computer program is executed by a computer or a processor, the aforementioned Figure 2 or Figure 4 or Fig. 9The steps of any method for determining hemodynamic parameters based on vector velocity shown in any one of the above. For example, the computer storage medium is a computer readable storage medium.

[0172] In one embodiment, the computer program instructions, when executed by a computer or a processor, cause the computer or the processor to perform the following steps: transmitting an ultrasonic beam to a target area, the target area including a blood vessel; receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal; determining a vector velocity of blood flow in the blood vessel based on the ultrasonic echo signal; determining a scalar value corresponding to the hemodynamic parameter based on the vector velocity; and obtaining the hemodynamic parameter based on the scalar value.

[0173] In one embodiment, the computer program instructions, when executed by a computer or a processor, cause the computer or processor to perform the following steps: transmitting an ultrasonic beam to a target area, the target area including a blood vessel; receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal; determining a vector velocity of blood flow in the blood vessel based on the ultrasonic echo signal; determining a velocity direction corresponding to the hemodynamic parameter based on the vector velocity; and obtaining a direction-based hemodynamic parameter based on the velocity direction.

[0174] Computer storage media may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. A computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0175] In addition, an embodiment of the present invention further provides a computer program product, which includes instructions. When the instructions are executed by a computer, the computer executes the above Figure 2 or Figure 4 or Fig. 9 Any of the steps in the method for determining hemodynamic parameters based on vector velocity shown.

[0176] It can be seen that the embodiments of the present invention can determine various hemodynamic parameters based on the vector velocity of blood flow, including not only hemodynamic parameters based on scalar values, but also hemodynamic parameters based on direction. This can provide more abundant reference parameters for the dynamic condition of blood flow and provide a more accurate basis for subsequent blood flow analysis.

[0177] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as required by the appended claims.

[0178] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0179] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0180] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0181] Similarly, it should be understood that in order to streamline the present invention and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0182] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0183] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0184] The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all of the functions of some modules in the article analysis device according to an embodiment of the present invention. The present invention may also be implemented as a device program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0185] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

[0186] The above is only a specific embodiment of the present invention or an explanation of a specific embodiment. The protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for determining hemodynamic parameters based on vector velocity, characterized in that: The method comprises: transmitting an ultrasound beam to a target area, wherein the target area includes a blood vessel; receiving an ultrasonic echo of the ultrasonic beam returned from the target area to obtain an ultrasonic echo signal; determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal; determining a scalar value corresponding to the hemodynamic parameter based on the vector velocity; Obtaining the hemodynamic parameter according to the scalar value; The hemodynamic parameter includes the offset between the position of the velocity center at a certain cross section of the blood vessel and the center point of the cross section. And wherein the position of the velocity center is determined by any one of the following methods: Determine the absolute value of the vector velocity at each position along the cross section of the blood vessel, and determine the position of the cross section of the blood vessel corresponding to the maximum value of the absolute value as the position of the velocity center; Determine the velocity component of the vector velocity at each position along the cross section of the blood vessel in a preset direction, and determine the position of the cross section of the blood vessel corresponding to the maximum value of the velocity component as the position of the velocity center; determining the position of the physical center of the vector velocity at each position along the cross section of the blood vessel as the position of the velocity center; The position of the physical center of the velocity component of the vector velocity in a preset direction at each position along the cross section of the blood vessel is determined as the position of the velocity center.

2. The method according to claim 1, characterized in that Determining a scalar value corresponding to the hemodynamic parameter according to the vector velocity includes: The absolute value of the vector velocity is determined as the scalar value.

3. The method according to claim 1, characterized in that Determining a scalar value corresponding to the hemodynamic parameter according to the vector velocity includes: A velocity component of the vector velocity in a preset direction is determined as the scalar value.

4. The method according to any one of claims 1 to 3, characterized in that The hemodynamic parameter includes a pulsatility index, and determining a scalar value corresponding to the hemodynamic parameter according to the vector velocity includes: The peak value of the systolic velocity in the heart rate cycle, the trough value of the diastolic velocity in the heart rate cycle, and the average velocity in the heart rate cycle are determined according to the vector velocity.

5. The method according to claim 4, characterized in that The systolic velocity peak value in the heart rate cycle is the peak value of the absolute value of the systolic vector velocity in the heart rate cycle, the diastolic end velocity trough value in the heart rate cycle is the trough value of the absolute value of the diastolic end vector velocity in the heart rate cycle, and the average velocity in the heart rate cycle is the average value of the absolute value of the vector velocity in the heart rate cycle; or, The peak systolic velocity within the heart rate cycle is the peak value of the velocity component of the systolic vector velocity in the heart rate cycle in the preset direction, the trough value of the end-diastolic velocity within the heart rate cycle is the trough value of the velocity component of the end-diastolic vector velocity in the heart rate cycle in the preset direction, and the average velocity within the heart rate cycle is the average value of the velocity component of the vector velocity in the preset direction within the heart rate cycle.

6. The method according to any one of claims 1 to 3, characterized in that The hemodynamic parameters include a resistance index, a systolic-to-diastolic ratio or a diastolic-to-systolic ratio, and determining a scalar value corresponding to the hemodynamic parameter according to the vector velocity includes: A systolic velocity peak value in a heart rate cycle and a diastolic velocity trough value in the heart rate cycle are determined based on the vector velocity.

7. The method according to claim 6, characterized in that The systolic velocity peak value in the heart rate cycle is the peak value of the absolute value of the systolic vector velocity in the heart rate cycle, and the diastolic end velocity trough value in the heart rate cycle is the trough value of the absolute value of the diastolic end vector velocity in the heart rate cycle; or, The systolic velocity peak value within the heart rate cycle is the peak value of the velocity component of the systolic vector velocity in the heart rate cycle in a preset direction, and the diastolic end-velocity trough value within the heart rate cycle is the trough value of the velocity component of the diastolic end-velocity vector velocity in the heart rate cycle in a preset direction.

8. The method according to any one of claims 1 to 3, characterized in that The hemodynamic parameters include velocity time integral, The hemodynamic parameter is obtained according to the scalar value, including: The integral of the scalar value over a time period between the first moment and the second moment is determined as the velocity time integral.

9. The method according to claim 8, characterized in that The hemodynamic parameters include mean velocity, The hemodynamic parameter is obtained according to the scalar value, including: The average speed is determined by integrating the scalar value over a period of time between a first moment and a second moment and dividing the integral by the period of time.

10. The method according to any one of claims 1 to 3, characterized in that The hemodynamic parameters include mean velocity, The hemodynamic parameter is obtained according to the scalar value, including: The average speed is determined by calculating the average of multiple scalar values ​​at multiple different time points between the first moment and the second moment.

11. The method according to claim 8, characterized in that The first moment to the second moment constitutes a cardiac cycle.

12. The method according to any one of claims 1 to 3, characterized in that The hemodynamic parameters include the minimum diastolic velocity, The hemodynamic parameter is obtained according to the scalar value, including: The minimum value of the scalar value in the diastolic period of the cardiac cycle is determined as the diastolic minimum velocity.

13. The method according to any one of claims 1 to 3, characterized in that The hemodynamic parameters include early systolic acceleration, The hemodynamic parameter is obtained according to the scalar value, including: The first order gradient of the scalar value with respect to time in the early systolic period of the cardiac cycle is determined as the early systolic acceleration.

14. The method according to any one of claims 3, 5 and 7, characterized in that: The preset direction is any one of the following: the long axis direction of the blood vessel, a direction specified by a user, and an emission direction of the ultrasonic beam.

15. The method according to claim 1, characterized in that If the position is in a first direction from the center of the cross section, representing the offset as a positive value; If the position is in a second direction from the center of the cross section, representing the offset as a negative value; The first direction and the second direction are two opposite directions.

16. The method according to any one of claims 1 to 3, characterized in that The vector velocity is calculated by at least one of a speckle tracking method, a transverse wave oscillation method, and a multi-angle deflection transmission / reception method.

17. An ultrasonic device, characterized in that: include: Ultrasound probe; a transmit / receive selection switch, used to stimulate the ultrasound probe to transmit an ultrasonic beam to a target area via a transmitting circuit, and to receive an ultrasonic echo of the ultrasonic beam returned from the target area, wherein the target area includes a blood vessel; a memory for storing programs executed by the processor; Processor for: obtaining an ultrasonic echo signal based on the ultrasonic echo; determining a vector velocity of blood flow in the blood vessel according to the ultrasonic echo signal; determining a scalar value corresponding to a hemodynamic parameter based on the vector velocity; Obtaining the hemodynamic parameter according to the scalar value; Wherein, the hemodynamic parameter includes the offset between the position of the velocity center at a certain cross section of the blood vessel and the center point of the cross section; And wherein the position of the velocity center is determined by any one of the following methods: Determine the absolute value of the vector velocity at each position along the cross section of the blood vessel, and determine the position of the cross section of the blood vessel corresponding to the maximum value of the absolute value as the position of the velocity center; Determine the velocity component of the vector velocity at each position along the cross section of the blood vessel in a preset direction, and determine the position of the cross section of the blood vessel corresponding to the maximum value of the velocity component as the position of the velocity center; determining the position of the physical center of the vector velocity at each position along the cross section of the blood vessel as the position of the velocity center; The position of the physical center of the velocity component of the vector velocity in a preset direction at each position along the cross section of the blood vessel is determined as the position of the velocity center.

18. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 16 are implemented.

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