JP7645692B2 - Ultrasound diagnostic equipment and medical analysis equipment - Google Patents

Description

The embodiments disclosed in this specification and the drawings relate to ultrasound diagnostic devices and medical analysis devices.

Conventionally, in ultrasound diagnostic devices, techniques such as color Doppler are known that express information on the power and velocity of blood flow by changes in color on ultrasound image data. In such techniques, blood flow information such as the power, velocity, and direction of blood flow is extracted by suppressing unnecessary signals (clutter) contained in the ultrasound data obtained from the received reflected waves using a wall filter.

In this type of technology, increasing the accuracy of extracting information related to the power of blood flow in the wall filter can result in over-extraction of changes in the speed and direction of blood flow, resulting in an uneven display of blood flow in the ultrasound image data.

JP 2019-103919 A

One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to improve the uniformity of the display of the blood flow speed and direction while maintaining the extraction accuracy regarding the power of the blood flow. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems. The first filter is an eigenvalue expansion type wall filter. The second filter is a fixed-length type wall filter.

The ultrasound diagnostic device according to the embodiment includes an acquisition unit, a first filter processing unit, a second filter processing unit, and an image generation unit. The acquisition unit acquires reflected wave ultrasound data. The first filter processing unit applies a first filter to the reflected wave ultrasound data to extract intensity information related to blood flow. The second filter processing unit applies a second filter to the reflected wave ultrasound data to extract phase change information. The image generation unit generates blood flow image data based on the intensity information and the phase change information.

FIG. 1 is a block diagram showing an example of an ultrasonic diagnostic apparatus according to the first embodiment. FIG. 2 is a diagram showing an example of functions of the Doppler processing circuitry according to the first embodiment. FIG. 3 is a diagram showing an example of Doppler image data according to a comparative example. FIG. 4 is a diagram showing an example of Doppler image data according to the first embodiment. FIG. 5 is a flowchart showing an example of the flow of a generation process of Doppler image data according to the first embodiment. FIG. 6 is a diagram showing an example of the functions of the Doppler processing circuitry according to the second embodiment. FIG. 7 is a flowchart showing an example of the flow of a generation process of Doppler image data according to the second embodiment. FIG. 8 is a flowchart showing an example of the flow of a generation process of Doppler image data according to the first modification.

Below, we will explain in detail the embodiments of the ultrasound diagnostic device and medical analysis device with reference to the drawings.

First Embodiment
Fig. 1 is a block diagram showing an example of an ultrasound diagnostic apparatus 100 according to the first embodiment. As shown in Fig. 1, the ultrasound diagnostic apparatus 100 includes a device main body 10, an ultrasound probe 1, an input device 3, and a display 2.

The device main body 10 includes a transmission/reception circuit 101, a buffer memory 102, a B-mode processing circuit 103, a Doppler processing circuit 104, an output interface 105, an input interface 106, an image generation circuit 107, a display control circuit 108, an image memory 109, a memory circuit 110, a control circuit 111, and a NW (network) interface 112. The device main body 10 is also connected to an external device 400 via a network NW.

The ultrasonic probe 1 has a number of elements, such as piezoelectric transducers. These elements generate ultrasonic waves based on a drive signal supplied from a transmission/reception circuit 101 in the device body 10. The ultrasonic probe 1 also receives reflected waves from the subject P and converts them into electrical signals. The ultrasonic probe 1 also has, for example, a matching layer provided on the piezoelectric transducer and a backing material that prevents ultrasonic waves from propagating backward from the piezoelectric transducer. The ultrasonic probe 1 is detachably connected to the device body 10.

When ultrasound waves are transmitted from the ultrasound probe 1 to the subject P, the transmitted ultrasound waves are reflected successively by discontinuous surfaces of acoustic impedance in the tissues of the subject P, and are received as reflected wave signals by multiple elements of the ultrasound probe 1. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuous surfaces where the ultrasound waves are reflected. When the transmitted ultrasound pulse is reflected by the surface of a moving blood flow or heart wall, the reflected wave signal undergoes a frequency shift due to the Doppler effect, depending on the velocity component of the moving body in the direction of ultrasound transmission. The ultrasound probe 1 then outputs the reflected wave signal to the transmission/reception circuit 101 of the device main body 10.

In this embodiment, the ultrasound probe 1 is a one-dimensional array probe in which multiple ultrasound transducers are arranged in a predetermined direction. However, without being limited to this example, the ultrasound probe 1 may be a two-dimensional array probe (a probe in which multiple ultrasound transducers are arranged in a two-dimensional matrix) or a mechanical 4D probe (a probe that can perform ultrasound scanning by mechanically moving an ultrasound transducer array in a direction perpendicular to the array direction) capable of acquiring volume data.

The input device 3 is realized by input means such as a mouse, keyboard, button, panel switch, touch command screen, foot switch, trackball, joystick, etc. The input device 3 accepts various setting requests from the operator of the ultrasound diagnostic device 100 and transfers the accepted various setting requests to the device main body 10.

The display 2 displays, for example, a GUI (Graphical User Interface) that allows the operator of the ultrasound diagnostic device 100 to input various setting requests using the input device 3, and displays ultrasound images and the like that are shown based on ultrasound image data generated in the device body 10. The display 2 is realized by a liquid crystal monitor, a CRT (Cathode Ray Tube) monitor, or the like. The display 2 is an example of a display unit.

Under the control of the control circuit 111, the transmission/reception circuit 101 causes the ultrasonic probe 1 to transmit ultrasonic waves and causes the ultrasonic probe 1 to receive ultrasonic waves (ultrasonic reflected waves). In other words, the transmission/reception circuit 101 executes ultrasonic scanning via the ultrasonic probe 1.

More specifically, the transmission/reception circuit 101, under the control of the control circuit 111, causes the ultrasonic probe 1 to transmit ultrasonic waves. The transmission/reception circuit 101 has, for example, a trigger generation circuit, a delay circuit, and a pulser circuit, which are not shown. The trigger generation circuit repeatedly generates trigger pulses to form a transmission ultrasonic wave at a predetermined rate frequency fr Hz. In addition, the delay circuit provides each trigger pulse with a delay time required to focus the ultrasonic waves into a beam for each channel and determine the transmission directivity. The pulser circuit applies a drive pulse to the ultrasonic probe 1 at a timing based on this trigger pulse.

The transmission/reception circuit 101 also generates reflected wave ultrasonic data, which is ultrasonic data based on the reflected wave signal received by the ultrasonic probe 1. The transmission/reception circuit 101 then stores the generated reflected wave ultrasonic data in the buffer memory 102.

More specifically, the reflected wave of the ultrasound transmitted by the ultrasound probe 1 reaches the piezoelectric transducer inside the ultrasound probe 1, where it is converted from mechanical vibration to an electrical signal (reflected wave signal) and input to the transmission/reception circuit 101. The transmission/reception circuit 101 has, for example, a preamplifier, an A/D (Analog to Digital) converter, a quadrature detection circuit, etc., and performs various processes on the reflected wave signal received by the ultrasound probe 1 to generate reflected wave ultrasound data. In this embodiment, "acquiring ultrasound data" includes obtaining ultrasound data by transmitting and receiving ultrasound. The transmission/reception circuit 101 is an example of an acquisition unit in this embodiment.

Reflected wave ultrasound data is two-dimensional data in which multiple data from multiple sample points lined up in the depth direction on a scan line (hereafter referred to as a raster) are lined up in the raster direction, the number of times being the number of rasters.

The preamplifier amplifies the reflected wave signal for each channel and performs gain adjustment (gain correction). The A/D converter converts the gain-corrected reflected wave signal into a digital signal by A/D converting the gain-corrected reflected wave signal. The quadrature detection circuit converts the A/D converted reflected wave signal into an in-phase signal (I signal, I: In-phase) and a quadrature signal (Q signal, Q: Quadrature-phase) in the baseband.

Then, the quadrature detection circuit stores the I signal and the Q signal as reflected ultrasonic data in the buffer memory 102. Hereinafter, the I signal and the Q signal are collectively referred to as the IQ signal. In addition, since the IQ signal is A/D converted digital data, it is also referred to as IQ data.

The buffer memory 102 at least temporarily stores the reflected ultrasound data (IQ data) generated by the transmission/reception circuit 101. For example, the buffer memory 102 stores the reflected ultrasound data acquired by transmitting and receiving ultrasound multiple times per raster. Here, multiple pieces of reflected ultrasound data for the same raster are acquired by transmitting and receiving ultrasound multiple times per raster. Hereinafter, the number of pieces of reflected ultrasound data for the same raster will be referred to as the ensemble number, and the data itself will be referred to as ensemble data. The buffer memory 102 stores the ensemble data arranged in the time direction for the number of ensembles in raster order. The buffer memory 102 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory.

The B-mode processing circuit 103 performs processes such as logarithmic amplification, envelope detection, and logarithmic compression on the reflected ultrasound data read from the buffer memory 102 to generate data (B-mode data) in which the signal strength is expressed as luminance.

The Doppler processing circuit 104 performs frequency analysis on the reflected ultrasound data stored in the buffer memory 102 to generate data (Doppler data) that extracts motion information based on the Doppler effect of a moving object within a region of interest (ROI) set in the scan area. An example of a moving object is blood. For example, the Doppler processing circuit 104 can execute a color Doppler method, also known as a color flow mapping (CFM) method. Details of the processing by the Doppler processing circuit 104 will be described later.

The output interface 105 outputs the electrical signal from the control circuit 111 to the outside. The output interface 105 is connected to the control circuit 111 via a bus, for example, and outputs the electrical signal from the control circuit 111 to the display 2.

The input interface 106 accepts various instructions from the operator via the input device 3. The input interface 106 is connected to the control circuit 111 via, for example, a bus, converts the operation instructions input by the operator into electrical signals, and outputs the electrical signals to the control circuit 111. Note that the input interface 106 is not limited to being connected to physical operation components such as a mouse and keyboard. For example, an example of an input interface also includes a circuit that receives an electrical signal corresponding to an operation instruction input from an external input device provided separately from the ultrasound diagnostic device 100 and outputs this electrical signal to the control circuit 111.

The image generation circuit 107 generates ultrasound image data based on the data generated by the B-mode processing circuit 103 and the Doppler processing circuit 104. The image generation circuit 107 stores the generated ultrasound image data in the image memory 109.

More specifically, the image generation circuitry 107 generates B-mode image data based on the B-mode data generated by the B-mode processing circuitry 103.

The image generation circuit 107 also generates Doppler image data based on the Doppler data generated by the Doppler processing circuit 104. The Doppler image data is an example of blood flow image data in this embodiment. The image generation circuit 107 generates Doppler image data based on the intensity information and phase change information contained in the Doppler data generated by the Doppler processing circuit 104.

Doppler image data is, for example, velocity image data, variance image data, power image data, or image data that combines these. For example, the image generation circuit 107 generates blood flow image data in which blood flow information is displayed in color as Doppler image data from Doppler data as blood flow information. In this case, the image generation circuit 107 visualizes the blood flow as Doppler image data by determining the depiction position based on the signal power of the blood flow and the display color based on the speed and direction of the blood flow. The image generation circuit 107 is an example of an image generation unit in this embodiment.

The display control circuit 108 causes the display 2 to display ultrasound images based on various ultrasound image data generated by the image generation circuit 107. The display control circuit 108 may also cause the display 2 to display a GUI that allows the operator to input various setting requests using the input device 3.

The image memory 109 stores various image data generated by the control circuit 111. For example, the image memory 109 is realized by a semiconductor memory element such as a RAM or a flash memory, a hard disk, or an optical disk.

The memory circuit 110 is realized by, for example, a magnetic or optical storage medium, a semiconductor memory element such as a flash memory, a hard disk, or a processor-readable storage medium such as an optical disk. The memory circuit 110 stores a program for realizing ultrasonic transmission and reception, various data, and the like. The program and various data may be stored in the memory circuit 110 in advance, for example. Also, for example, the program and various data may be stored in a non-transient storage medium and distributed, and may be read from the non-transient storage medium and installed in the memory circuit 110. The memory circuit 110 may be an example of a memory unit in this embodiment.

The control circuit 111 controls the overall operation of the ultrasound diagnostic device 100. For example, the control circuit 111 controls ultrasound scanning by controlling the ultrasound probe 1 via the transmission/reception circuit 101.

The NW interface 112 is connected to an external device 400, for example, via a network NW, and performs data communication with the external device 400.

The external device 400 is, for example, a workstation that performs post-processing of various data generated by the ultrasound diagnostic device 100 and processing such as displaying ultrasound image data. The external device 400 includes, for example, a processing circuit such as a processor, a storage device, a display, an input device, and a NW interface that can be connected to the ultrasound diagnostic device 100 via a network NW. The external device 400 may also be a tablet terminal, etc.

Next, we will explain the details of the Doppler processing circuit 104.

Figure 2 is a diagram showing an example of the functions of the Doppler processing circuit 104 according to the first embodiment. As shown in Figure 2, the Doppler processing circuit 104 includes a power WF (Wall Filter) function 141, a power estimation function 142, a velocity/direction WF function 143, an autocorrelation processing function 144, a velocity/direction estimation function 145, and a packing function 146.

The power WF function 141 and the speed/direction WF function 143 each apply a wall filter to the ensemble data 600 stored in the buffer memory 102.

More specifically, the power WF function 141 extracts intensity information related to blood flow by applying a wall filter for power (intensity) information to the ensemble data 600. The power WF function 141 uses an eigenvalue expansion type wall filter. The power WF function 141 is an example of a first filter processing unit in this embodiment. The eigenvalue expansion type wall filter applied to the ensemble data 600 by the power WF function 141 is an example of a first filter in this embodiment.

The eigenvalue expansion type wall filter is, for example, an adaptive MTI (Moving Target Indicator) filter that changes coefficients according to an input signal using an eigenvector. The eigenvector is calculated from a correlation matrix. Specifically, the power WF function 141 calculates a correlation matrix of the scanning range from a data string of reflected wave ultrasound data at the same position collected over multiple frames. In this embodiment, the reflected wave ultrasound data at the same position is ensemble data 600. The power WF function 141 calculates an eigenvector from the correlation matrix, and determines the coefficients to be used in the MTI filter based on the calculated eigenvector. Note that the adaptive MTI filter using the eigenvector is an example of an eigenvalue expansion type wall filter, and other methods may be adopted.

In an eigenvalue expansion type wall filter, components with large energy in the eigenvector dimension of the ensemble data 600 are detected as principal components, and Doppler shifts that are spatially similar to the principal components are suppressed as clutter components. Such eigenvalue expansion type wall filters are excellent in the ability to suppress clutter and extract power components of blood flow.

The power estimation function 142 estimates blood flow intensity information from the components extracted from the ensemble data 600 by the power WF function 141. The power estimation function 142 is an example of a power estimation unit.

The WF function for velocity and direction 143 extracts phase change information by applying a wall filter for velocity and direction to the ensemble data 600. The WF function for velocity and direction 143 uses a fixed-length wall filter. The phase change information includes blood flow velocity information and direction information. The WF function for velocity and direction 143 is an example of a second filter processing unit in this embodiment. The fixed-length wall filter used by the WF function for velocity and direction 143 is an example of a second filter in this embodiment.

More specifically, in this embodiment, the speed/direction WF function 143 uses a polynomial approximation type wall filter. In a polynomial approximation type wall filter, fitting is performed with a predetermined polynomial, and clutter components are removed by a polynomial fitting technique that identifies low-order components as clutter components. Note that fixed-length wall filters other than polynomial approximation type wall filters may also be used. For example, the speed/direction WF function 143 may use an IIR (Infinite Impulse Response) filter.

Fixed-length wall filters treat components with low Doppler shift frequencies as clutter and suppress them. The Doppler shift frequency is low in reflected ultrasound data from stationary or slow-moving tissue. Fixed-length wall filters may have lower separation capabilities between clutter and blood flow than eigenvalue expansion wall filters. However, fixed-length wall filters can stably extract changes in blood flow speed and direction information.

As a comparative example, when the above-mentioned eigenvalue expansion type wall filter is used to extract blood flow velocity and direction information, blood flow velocity and direction information that is spatially similar to the principal component is also suppressed, so phase changes between frames are likely to be extracted. For this reason, in Doppler image data based on the extraction results of the eigenvalue expansion type wall filter, changes in blood flow velocity and direction information may be emphasized. For this reason, when the phase change between frames is large, the uniformity of the display of blood flow velocity and direction may decrease in Doppler image data based on blood flow velocity and direction information extracted by the eigenvalue expansion type wall filter.

Figure 3 is a diagram showing an example of Doppler image data 80a, 80b according to a comparative example. The Doppler image data 80a and Doppler image data 80b in Figure 3 are color Doppler image data in which blood flow is represented based on blood flow information extracted by an eigenvalue expansion type wall filter. The Doppler image data 80a and Doppler image data 80b show changes in blood flow over time.

In the Doppler image data 80a and 80b, the depiction positions of the blood flows 70a and 70b are determined based on the blood flow intensity information contained in the blood flow information. In addition, in the Doppler image data 80a and 80b, the colors of the blood flows 70a and 70b are determined based on the information on the speed and direction of the blood flow. As shown in FIG. 3, in the Doppler image data 80a and 80b of the comparative example, the changes in the speed and direction of the blood flow between frames are emphasized, and the display of the blood flows 70a and 70b is uneven. As a result, the color changes in the blood flows 70a and 70b are large, and the blood flows 70a and 70b are not displayed smoothly.

Figure 4 is a diagram showing an example of Doppler image data 90a, 90b according to the first embodiment. The Doppler image data 90a and the Doppler image data 90b show time-series changes in blood flow. In this embodiment, blood flow intensity information is extracted by an eigenvalue expansion type wall filter, while blood flow velocity and direction information is extracted by a fixed-length type wall filter. Therefore, as shown in Figure 4, the color changes in the blood flows 71a, 71b depicted on the Doppler image data 90a, 90b are smooth, and the uniformity is improved compared to Figure 3.

In the following, in this embodiment, when there is no particular distinction between the individual Doppler image data 90a and 90b, they will be referred to as Doppler image data 90.

Returning to FIG. 2, the autocorrelation processing function 144 performs autocorrelation processing on the data extracted from the ensemble data 600 by the speed/direction WF function 143. The autocorrelation processing function 144 is an example of an autocorrelation processing unit.

The speed/direction estimation function 145 estimates the speed and direction information of the blood flow based on the result of the autocorrelation processing by the autocorrelation processing function 144. The speed/direction estimation function 145 is an example of a speed/direction estimation unit. The speed/direction estimation function 145 may also estimate the variance of the blood flow.

The packing function 146 generates Doppler data including blood flow intensity, velocity, and direction information by combining the blood flow intensity information estimated by the power estimation function 142 and the blood flow velocity and direction information estimated by the velocity and direction estimation function 145. From the Doppler data generated by the packing function 146, the image generation circuit 107 generates Doppler image data 90. The packing function 146 is an example of a packing section.

The B-mode processing circuit 103, the Doppler processing circuit 104, the image generation circuit 107, the display control circuit 108, and the control circuit 111 are realized by a processor. For example, computer-executable programs that define the processes to be executed by these circuits are stored in the memory circuit 110. These circuits realize the functions corresponding to each program by reading the programs from the memory circuit 110 and executing them. In addition, although FIG. 1 illustrates a single memory circuit 110 storing programs corresponding to each processing function, multiple memory circuits may be distributed and arranged, and each circuit may read a corresponding program from an individual memory circuit.

In the above description, an example in which the "processor" reads out and executes a program corresponding to each function from the storage circuit 110 has been described, but the embodiment is not limited to this. The term "processor" refers to circuits such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). When the processor is, for example, a CPU, the processor reads out and executes a program stored in the storage circuit 110 to realize each function shown in FIG. 1 and FIG. 2. On the other hand, when the processor is an ASIC, instead of storing a program in the storage circuit 110, the function is directly incorporated as a logic circuit in the circuit of the processor. Note that each processor in this embodiment is not limited to being configured as a single circuit for each processor, and may be configured as a single processor by combining multiple independent circuits to realize its function. Furthermore, multiple components in Figures 1 and 2 may be integrated into a single processor to achieve the functions.

Next, we will explain the flow of the process of generating Doppler image data 90 executed by the ultrasound diagnostic device 100 in this embodiment configured as described above.

Figure 5 is a flowchart showing an example of the flow of the process for generating Doppler image data 90 according to the first embodiment.

First, the transmission/reception circuit 101 causes the ultrasonic probe 1 to transmit ultrasonic waves and causes the ultrasonic probe 1 to receive the reflected waves of the transmitted ultrasonic waves (S101). The transmission/reception circuit 101 generates reflected wave ultrasonic data, which is ultrasonic data based on the reflected wave signal received by the ultrasonic probe 1, and stores it in the buffer memory 102.

Next, the power WF function 141 of the Doppler processing circuit 104 applies an eigenvalue expansion type wall filter to the ensemble data 600 (S102).

Then, the power estimation function 142 of the Doppler processing circuit 104 estimates blood flow intensity (power) information from the components extracted from the ensemble data 600 by the power WF function 141 (S103).

In addition, the velocity/direction WF function 143 of the Doppler processing circuit 104 applies a polynomial approximation type wall filter to the ensemble data 600 (S104).

Next, the autocorrelation processing function 144 of the Doppler processing circuit 104 performs autocorrelation processing on the data extracted from the ensemble data 600 by the speed/direction WF function 143 (S105).

Next, the velocity/direction estimation function 145 of the Doppler processing circuit 104 estimates the velocity and direction information of the blood flow based on the results of the autocorrelation processing by the autocorrelation processing function 144 (S106).

Then, the packing function 146 of the Doppler processing circuit 104 combines the blood flow intensity information estimated by the power estimation function 142 with the blood flow velocity and direction information estimated by the velocity and direction estimation function 145 to generate Doppler data including blood flow intensity, velocity, and direction information (S107).

Next, the image generation circuitry 107 generates Doppler image data 90 based on the Doppler data generated by the Doppler processing circuitry 104 (S108).

Next, the display control circuit 108 causes the display 2 to display a Doppler image based on the Doppler image data 90 generated by the image generation circuit 107 (S109). At this point, the processing of this flowchart ends.

In this way, the ultrasound diagnostic device 100 of this embodiment generates Doppler image data based on blood flow intensity information based on data extracted from the reflected wave ultrasound data by a wall filter for extracting intensity information, and on blood flow velocity and direction information based on data extracted from the reflected wave ultrasound data by a wall filter for velocity and direction.

In this embodiment, the power of blood flow and information on the speed and direction of blood flow are obtained from separate filtering results suited to the respective characteristics, thereby improving the uniformity of the display of the speed and direction of blood flow while maintaining the extraction accuracy of the power of blood flow.

In addition, in the ultrasound diagnostic device 100 of this embodiment, the power of the blood flow is obtained from data extracted by an eigenvalue expansion type wall filter. In addition, in the ultrasound diagnostic device 100 of this embodiment, information on the speed and direction of the blood flow is obtained from data extracted by a fixed-length type wall filter. Therefore, according to the ultrasound diagnostic device 100 of this embodiment, it is possible to separate the power of the blood flow and clutter with high accuracy, and to display the changes in the speed and direction of the blood flow smoothly.

In addition, in the ultrasound diagnostic device 100 of this embodiment, information on the velocity and direction of blood flow is obtained from data extracted by a polynomial approximation type wall filter. This allows the ultrasound diagnostic device 100 of this embodiment to stably extract information on the velocity and direction of blood flow.

Second Embodiment
In the first embodiment described above, a fixed-length wall filter is always used for the information on the velocity and direction of blood flow. In the present embodiment, an eigenvalue expansion type wall filter and a fixed-length type wall filter are used depending on the phase change.

The overall configuration of the ultrasound diagnostic device 100 of this embodiment is the same as that of the first embodiment described in FIG. 1. The ultrasound diagnostic device 100 includes a device main body 10, an ultrasound probe 1, an input device 3, and a display 2. The device main body 10 also includes a transmission/reception circuit 101, a buffer memory 102, a B-mode processing circuit 103, a Doppler processing circuit 104, an output interface 105, an input interface 106, an image generation circuit 107, a display control circuit 108, an image memory 109, a memory circuit 110, a control circuit 111, and a NW interface 112.

The ultrasound probe 1, input device 3, display 2, transmission/reception circuitry 101, buffer memory 102, B-mode processing circuitry 103, output interface 105, input interface 106, image generation circuitry 107, display control circuitry 108, image memory 109, memory circuitry 110, control circuitry 111, and NW interface 112 have the same functions as those in the first embodiment.

Figure 6 is a diagram showing an example of the functions of the Doppler processing circuit 104 according to the second embodiment. The Doppler processing circuit 104 of this embodiment includes a power WF function 141, a power estimation function 142, a first velocity/direction WF function 143a, a second velocity/direction WF function 143b, a first autocorrelation processing function 144a, a second autocorrelation processing function 144b, a first velocity/direction estimation function 145a, a second velocity/direction estimation function 145b, a packing function 146, a phase change detection function 147, and a selection function 148.

The power WF function 141 and the power estimation function 142 are the same functions as in the first embodiment. The power WF function 141 uses an eigenvalue expansion type wall filter, as in the first embodiment. The eigenvalue expansion type wall filter is an example of a first filter in this embodiment. Also, the power WF function 141 is an example of a first filter processing unit in this embodiment.

The first WF function for velocity and direction 143a extracts first phase change information related to blood flow by applying the first WF for velocity and direction to the ensemble data 600. The first WF function for velocity and direction 143a is an example of a second filter processing unit in this embodiment. The first WF for velocity and direction is an example of a second filter in this embodiment. The first WF for velocity and direction is a fixed-length type wall filter, in particular a polynomial approximation type wall filter.

The second velocity/direction WF function 143b extracts second phase change information related to blood flow by applying the second velocity/direction WF to the ensemble data 600. The second velocity/direction WF function 143b is an example of a third filter processing unit in this embodiment. The second velocity/direction WF is an example of a third filter in this embodiment. The second velocity/direction WF is an eigenvalue expansion type wall filter.

The first phase change information and the second phase change information are velocity information and direction information of blood flow.

The first autocorrelation processing function 144a performs autocorrelation processing on the data extracted from the ensemble data 600 by the first speed/direction WF function 143a. The first autocorrelation processing function 144a is an example of a first autocorrelation processing unit.

The second autocorrelation processing function 144b performs autocorrelation processing on the data extracted from the ensemble data 600 by the second speed/direction WF function 143b. The second autocorrelation processing function 144b is an example of a second autocorrelation processing unit.

The first speed/direction estimation function 145a estimates the speed and direction information of the blood flow based on the result of the autocorrelation processing by the first autocorrelation processing function 144a. For example, the first speed/direction estimation function 145a calculates the speed of the blood flow based on the result of the autocorrelation processing by the first autocorrelation processing function 144a. The first speed/direction estimation function 145a is an example of a first speed/direction estimation unit and a first speed calculation unit.

The second speed/direction estimation function 145b estimates the speed and direction information of the blood flow based on the result of the autocorrelation processing by the second autocorrelation processing function 144b. For example, the second speed/direction estimation function 145b calculates the speed of the blood flow based on the result of the autocorrelation processing by the second autocorrelation processing function 144b. The second speed/direction estimation function 145b is an example of a second speed/direction estimation unit and a second speed calculation unit.

The phase change detection function 147 detects a phase change in the reflected wave ultrasound data based on at least one of the first phase change information or the second phase change information. In this embodiment, the phase change detection function 147 detects a phase change faster than a specified criterion based on the difference between the filtering results of a fixed-length wall filter and an eigenvalue expansion type wall filter. The difference between the filtering results of a fixed-length wall filter and an eigenvalue expansion type wall filter becomes large when the phase change is fast. Therefore, the phase change detection function 147 uses this difference to detect a phase change faster than a specified criterion.

More specifically, the phase change detection function 147 determines the similarity between the first blood flow velocity calculated by the first velocity/direction estimation function 145a and the second blood flow velocity calculated by the second velocity/direction estimation function 145b. Based on the calculation result of the similarity, if the difference between the first blood flow velocity and the second blood flow velocity is greater than a threshold, the phase change detection function 147 determines that the phase change is faster than a specified criterion. Furthermore, if the difference between the first blood flow velocity and the second blood flow velocity is equal to or less than the threshold, the phase change detection function 147 determines that the phase change is equal to or less than the specified criterion. Note that the threshold for the difference between the first blood flow velocity and the second blood flow velocity is not particularly limited.

Note that the method of detecting a phase change is not limited to this. For example, the phase change detection function 147 may detect a sudden phase change by utilizing the dispersion of blood flow based on the first phase change information or the second phase change information. The phase change detection function 147 is an example of a phase change detection unit.

The selection function 148 selects either the first phase change information or the second phase change information based on the phase change of the reflected wave ultrasound data. More specifically, the selection function 148 selects either the data extracted from the ensemble data 600 by the first WF function for velocity and direction 143a or the data extracted from the ensemble data 600 by the second WF function for velocity and direction 143b as data to be used to generate Doppler data. The selection function 148 is an example of a selection unit.

Specifically, the selection function 148 selects the first phase change information when the phase change is faster than a specified criterion, and selects the second phase change information when the phase change is equal to or smaller than the specified criterion. The degree of phase change that serves as the specified criterion is not particularly limited.

In other words, when the phase change detection function 147 detects a phase change faster than a specified criterion, the selection function 148 selects the blood flow velocity and direction information based on the data extracted from the ensemble data 600 by a fixed-length wall filter as the data to be used for generating Doppler data. Also, when the phase change is equal to or smaller than the specified criterion, the selection function 148 selects the blood flow velocity and direction information based on the data extracted from the ensemble data 600 by an eigenvalue expansion wall filter as the data to be used for generating Doppler data.

The packing function 146 generates Doppler data including blood flow intensity, velocity, and direction information by combining the blood flow intensity information estimated by the power estimation function 142 with the blood flow velocity and direction information estimated by the first velocity/direction estimation function 145a and the second velocity/direction estimation function 145b, which is selected by the selection function 148.

The image generation circuit 107 generates Doppler image data 90 from the Doppler data generated by the packing function 146. In other words, the image generation circuit 107 of this embodiment generates blood flow image data based on the intensity information and either the first phase change information or the second phase change information selected by the selection function 148.

Next, we will explain the flow of the process of generating Doppler image data 90 executed by the ultrasound diagnostic device 100 in this embodiment configured as described above.

Figure 7 is a flowchart showing an example of the flow of the process for generating Doppler image data 90 according to the second embodiment.

The process from the ultrasonic transmission/reception process in S101 to the power estimation process in S103 is the same as in the first embodiment.

In addition, the first velocity/direction WF function 143a of the Doppler processing circuit 104 applies a polynomial approximation type wall filter to the ensemble data 600 (S201).

Next, the first autocorrelation processing function 144a performs autocorrelation processing on the data extracted from the ensemble data 600 by the first speed/direction WF function 143a (S202).

Next, the first speed/direction estimation function 145a estimates the speed and direction information of the blood flow based on the results of the autocorrelation processing by the first autocorrelation processing function 144a (S203).

The second speed/direction WF function 143b also applies an eigenvalue expansion type Wall filter to the ensemble data 600 (S204).

Next, the second autocorrelation processing function 144b performs autocorrelation processing on the data extracted from the ensemble data 600 by the second speed/direction WF function 143b (S205).

Next, the second speed/direction estimation function 145b estimates the speed and direction information of the blood flow based on the results of the autocorrelation processing by the second autocorrelation processing function 144b (S206).

Then, the phase change detection function 147 determines whether or not an abrupt phase change has been detected (S207). If the phase change is faster than a specified criterion, the phase change detection function 147 determines that an abrupt phase change has been detected. More specifically, the phase change detection function 147 calculates the similarity between the first blood flow velocity calculated by the first velocity/direction estimation function 145a and the second blood flow velocity calculated by the second velocity/direction estimation function 145b, and if the difference between the first blood flow velocity and the second blood flow velocity is greater than a threshold, it determines that the phase change is faster than the specified criterion.

If a sudden phase change is detected (S207 "Yes"), the selection function 148 selects the processing result by the first velocity/direction WF function 143a (S208). In other words, the selection function 148 selects the blood flow velocity and direction information based on the data extracted from the ensemble data 600 by the polynomial approximation type wall filter as the data to be used to generate Doppler data.

Also, if no sudden phase change is detected (S207 "No"), the selection function 148 selects the processing result by the second velocity/direction WF function 143b (S209). In other words, the selection function 148 selects the blood flow velocity and direction information based on the data extracted from the ensemble data 600 by the eigenvalue expansion type wall filter as the data to be used for generating Doppler data.

Then, the packing function 146 generates Doppler data including the blood flow intensity, velocity, and direction information by combining the blood flow intensity information estimated by the power estimation function 142 with the blood flow velocity and direction information selected by the selection function 148 (S107). The image generation process in S108 to the image display process in S109 are the same as in the first embodiment.

In this way, according to the ultrasound diagnostic device 100 of this embodiment, by dynamically changing the type of wall filter for velocity and direction based on the phase change of the reflected wave ultrasound data, it is possible to extract appropriate blood flow information according to the phase change while maintaining the effects of the first embodiment.

For example, in Doppler image data 80 based on data extracted by an eigenvalue expansion type wall filter, generally, when the phase change is fast, the display of the blood flow velocity and direction tends to be non-uniform, as in the comparative example described in FIG. 3. For this reason, in the ultrasound diagnostic device 100 of this embodiment, when the phase change is fast, a fixed-length wall filter is used to extract information on the blood flow velocity and phase, thereby reducing the non-uniformity of the display of the blood flow velocity and direction. In addition, in the ultrasound diagnostic device 100 of this embodiment, when the phase change is slow, an eigenvalue expansion type wall filter is used to extract information on the blood flow velocity and direction, thereby making it possible to utilize the excellent clutter separation ability of the eigenvalue expansion type wall filter.

In addition, in the ultrasound diagnostic device 100 of this embodiment, whether or not the phase change is faster than a specified standard is determined based on the difference between the first blood flow velocity calculated based on the data extracted by the fixed-length wall filter and the second blood flow velocity calculated based on the data extracted by the eigenvalue expansion wall filter. Therefore, in the ultrasound diagnostic device 100 of this embodiment, it is possible to easily detect a phase change faster than a specified standard by utilizing the difference between the filtering results of the fixed-length wall filter and the eigenvalue expansion wall filter.

(Variation 1)
In each of the above-described embodiments, the generation process of color Doppler image data 90 using the color flow mapping method is taken as an example, but the ultrasound diagnostic device 100 may be provided with a mode for generating other types of ultrasound image data.

For example, the ultrasound diagnostic device 100 may generate ultrasound image data called a monochromatic map, which represents the velocity of blood flow by changes in the density of a single color.

For example, the input device 3 accepts a user operation to select either a generation mode of color Doppler image data 90 that indicates the velocity and direction of blood flow by changing multiple colors as exemplified in each of the above-mentioned embodiments, or a generation mode of a monochromatic map. The input device 3 is an example of a reception unit.

Furthermore, the color Doppler image data 90 is an example of first blood flow image data in this modified example. The monochromatic map is an example of second blood flow image data in this modified example.

The Doppler processing circuit 104 of the ultrasound diagnostic device 100 of this modified example includes, for example, a power WF function 141, a power estimation function 142, a first velocity/direction WF function 143a, a second velocity/direction WF function 143b, a first autocorrelation processing function 144a, a second autocorrelation processing function 144b, a first velocity/direction estimation function 145a, a second velocity/direction estimation function 145b, a packing function 146, a phase change detection function 147, and a selection function 148, similar to the second embodiment.

In a monochromatic map, there is no change in color according to the speed and direction of blood flow, so there is no need to consider non-uniformity in the display of the speed and direction of blood flow.

For this reason, the selection function 148 of this modified example has the functionality of the second embodiment, and when a monochrome map is selected as the blood flow image data to be generated, it selects the second phase change information regardless of the magnitude of the phase change.

Figure 8 is a flowchart showing an example of the flow of the Doppler image data generation process related to variant example 1.

The process from the ultrasound transmission/reception process in S101 to the power estimation process in S103, and the process from the first velocity/direction wall filter process in S201 to the blood flow velocity and direction estimation process in S206 are the same as in the second embodiment.

Then, the selection function 148 of this modified example determines whether or not a monochromatic map has been selected as the blood flow image data to be generated (S301). If a monochromatic map has been selected as the blood flow image data to be generated (S301 "Yes"), the selection function 148 selects the processing result by the second velocity/direction WF function 143b (S209). In other words, the selection function 148 selects the blood flow velocity and direction information based on the data extracted from the ensemble data 600 by an eigenvalue expansion type wall filter as the data to be used to generate Doppler data.

If a monochrome map is not selected as the blood flow image data to be generated (S301 "No"), the selection function 148 proceeds to the processing of S207, and selects either the data extracted by the eigenvalue expansion type wall filter or the data extracted by the polynomial approximation type wall filter according to the phase change, as in the second embodiment. The subsequent processing is the same as in the second embodiment.

In this way, according to the ultrasound diagnostic device 100 of this modified example, when a monochromatic map is selected as the blood flow image data to be generated, an eigenvalue expansion type wall filter is adopted, and the excellent clutter separation ability of the eigenvalue expansion type wall filter can be utilized except when a color display is performed.

The timing of the process of determining whether or not a monochromatic map is selected as the blood flow image data to be generated is not limited to the example shown in FIG. 8. For example, the process of determining whether or not a monochromatic map is selected may be executed before the wall filter process. In this case, if a monochromatic map is selected as the blood flow image data to be generated, the processes of S201 to S203 may not be executed.

In addition, in this modified example, the determination is made based on both whether a monochromatic map is selected and the phase change, but a configuration in which the wall filter is not used according to the phase change may be adopted. In this case, the selection function 148 uses an eigenvalue expansion type wall filter and a fixed-length type wall filter depending on whether a monochromatic map is selected. In other words, when a monochromatic map is selected as the blood flow image data to be generated, the selection function 148 selects the blood flow velocity and direction information based on the data extracted by the eigenvalue expansion type wall filter as the data to be used for generating the Doppler data. When a monochromatic map is not selected, the selection function 148 selects the data extracted by the fixed-length type wall filter as the data to be used for generating the Doppler data.

The configuration of this modified example may also be combined with the first embodiment. For example, if a monochromatic map is selected by the user as the target for generation, a single eigenvalue expansion type wall filter may be used without separating a wall filter for power and a wall filter for velocity and direction. When this configuration is adopted, if the user selects color Doppler image data 90 as the target for generation, an eigenvalue expansion type wall filter for power and a fixed-length type wall filter for velocity and direction are used.

The ultrasound diagnostic device 100 may also have a mode for generating other types of ultrasound image data. For example, the ultrasound diagnostic device 100 may generate ultrasound image data that represents power and variance without displaying the blood flow velocity. The ultrasound diagnostic device 100 may also have a Shear Wave Elastography (SWE) function that displays a stiffness image by measuring the propagation speed of shear waves generated by a push pulse. The ultrasound diagnostic device 100 may also use a fixed-length wall filter and an eigenvalue expansion wall filter when generating ultrasound image data other than color Doppler image data.

(Variation 2)
In the above-described embodiments, the ultrasound diagnostic device 100 has been described as performing the process of generating color Doppler image data 90 using the color flow mapping method, but for example, the external device 400 connected to the ultrasound diagnostic device 100 may perform this process. When this configuration is adopted, the processing circuit of the external device 400 may have the same function as the Doppler processing circuit 104 described in Fig. 2 or 6. The external device 400 is an example of a medical analysis device in this modified example.

In this case, the network interface of the external device 400 acquires the ensemble data 600 from the ultrasound diagnostic device 100. The network interface is an example of an acquisition unit in this modified example. Note that some or all of the functions of the external device 400 may be realized in a cloud environment.

The various data discussed in this specification are typically digital data.

According to at least one of the embodiments described above, it is possible to improve the uniformity of the display of the blood flow speed and direction while maintaining the extraction accuracy of the blood flow power.

Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations of embodiments can be made without departing from the spirit of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and spirit of the invention.

With regard to the above embodiment, the following notes are disclosed as one aspect and optional feature of the invention.

(Appendix 1)
An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract phase change information;
an image generating unit that generates blood flow image data based on the intensity information and the phase change information;
An ultrasound diagnostic device comprising:

(Appendix 2)
The first filter may be an eigenvalue expansion type wall filter, and the second filter may be a fixed length type wall filter.

(Appendix 3)
The second filter may be a polynomial approximation type wall filter.

(Appendix 4)
An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract first phase change information;
a third filter processing unit that applies a third filter to the reflected ultrasonic data to extract second phase change information;
A selection unit that selects either the first phase change information or the second phase change information based on a phase change of the reflected wave ultrasonic data;
an image generating unit that generates blood flow image data based on the intensity information and the first phase change information or the second phase change information selected by the selecting unit;
An ultrasound diagnostic device comprising:

(Appendix 5)
The first filter and the third filter may be eigenvalue expansion type wall filters.
The second filter may be a fixed-length wall filter.

(Appendix 6)
The selection unit may select the first phase change information when the phase change of the reflected wave ultrasound data is faster than a specified criterion, and select the second phase change information when the phase change of the reflected wave ultrasound data is equal to or less than the specified criterion.

(Appendix 7)
a first autocorrelation processing unit that performs autocorrelation processing on the first phase change information;
a second autocorrelation processing unit that performs autocorrelation processing on the second phase change information;
a first velocity calculation unit that calculates a first blood flow velocity based on the first autocorrelation processing unit;
a second velocity calculation unit that calculates a second blood flow velocity based on a processing result of the second phase change information;
The apparatus may further include a phase change detection unit that determines that the phase change is faster than the specified standard when a difference between the first blood flow velocity and the second blood flow velocity is greater than a threshold value.

(Appendix 8)
The image data may further include a receiving unit that receives a user's selection as to whether the blood flow image data is first blood flow image data that represents the speed and direction of the blood flow by changes in multiple colors, or second blood flow image data that represents the speed of the blood flow by changes in density of a single color.
The selection unit may select the first phase change information when the second blood flow image data is selected.

(Appendix 9)
An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract phase change information;
an image generating unit that generates blood flow image data based on the intensity information and the phase change information;
Medical analysis equipment.

(Appendix 10)
An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract first phase change information;
a third filter processing unit that applies a third filter to the reflected ultrasonic data to extract second phase change information;
A selection unit that selects either the first phase change information or the second phase change information based on a phase change of the reflected wave ultrasonic data;
an image generating unit that generates blood flow image data based on the intensity information and the first phase change information or the second phase change information selected by the selecting unit;
Medical analysis equipment.

1 Ultrasonic probe 2 Display 3 Input device 10 Device main body 90, 90a, 90b Doppler image data 100 Ultrasonic diagnostic device 101 Transmitting and receiving circuit 102 Buffer memory 103 B-mode processing circuit 104 Doppler processing circuit 105 Output interface 106 Input interface 107 Image generation circuit 108 Display control circuit 109 Image memory 110 Memory circuit 111 Control circuit 112 NW interface 141 Power WF function 142 Power estimation function 143 Speed/direction WF function 143a First speed/direction WF function 143b Second speed/direction WF function 144 Autocorrelation processing function 144a First autocorrelation processing function 144b Second autocorrelation processing function 145 Speed/direction estimation function 145a First speed/direction estimation function 145b Second speed/direction estimation function 146 Packing function 147 Phase change detection function 148 Selection function 400 External device 600 Ensemble data P Subject

Claims (10)

An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract phase change information;
an image generating unit that generates blood flow image data based on the intensity information and the phase change information;
Equipped with
the first filter is an eigenvalue expansion type wall filter,
The second filter is a fixed-length wall filter.
Ultrasound diagnostic equipment. The second filter is a wall filter that considers components with low Doppler shift frequencies as clutter and suppresses them.
The ultrasonic diagnostic apparatus according to claim 1 . the second filter is a polynomial approximation type wall filter;
3. The ultrasonic diagnostic apparatus according to claim 1. An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract first phase change information;
a third filter processing unit that applies a third filter to the reflected ultrasonic data to extract second phase change information;
A selection unit that selects either the first phase change information or the second phase change information based on a phase change of the reflected wave ultrasonic data;
an image generating unit that generates blood flow image data based on the intensity information and the first phase change information or the second phase change information selected by the selecting unit;
An ultrasound diagnostic device comprising: the first filter and the third filter are eigenvalue expansion type wall filters,
The second filter is a fixed-length wall filter.
The ultrasonic diagnostic apparatus according to claim 4. The selection unit selects the first phase change information when the phase change of the reflected ultrasonic data is faster than a specified criterion, and selects the second phase change information when the phase change of the reflected ultrasonic data is equal to or smaller than the specified criterion.
6. The ultrasonic diagnostic apparatus according to claim 4 or 5. a first autocorrelation processing unit that performs autocorrelation processing on the first phase change information;
a second autocorrelation processing unit that performs autocorrelation processing on the second phase change information;
a first velocity calculation unit that calculates a first blood flow velocity based on the first autocorrelation processing unit;
a second velocity calculation unit that calculates a second blood flow velocity based on a processing result of the second phase change information;
and a phase change detection unit that determines that the phase change is faster than the specified criterion when a difference between the first blood flow velocity and the second blood flow velocity is greater than a threshold value.
The ultrasonic diagnostic apparatus according to claim 6. a reception unit that receives a user's selection as to whether the blood flow image data is first blood flow image data that represents a velocity and a direction of the blood flow by a change in a plurality of colors, or second blood flow image data that represents the velocity of the blood flow by a change in density of a single color,
the selection unit selects the first phase change information when the second blood flow image data is selected.
The ultrasonic diagnostic apparatus according to any one of claims 4 to 7. An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract phase change information;
an image generating unit that generates blood flow image data based on the intensity information and the phase change information ,
the first filter is an eigenvalue expansion type wall filter,
The second filter is a fixed-length wall filter.
Medical analysis equipment. An acquisition unit for acquiring reflected ultrasonic data;
a first filter processing unit that applies a first filter to the reflected ultrasound data to extract intensity information related to blood flow;
A second filter processing unit that applies a second filter to the reflected wave ultrasound data to extract first phase change information;
a third filter processing unit that applies a third filter to the reflected ultrasonic data to extract second phase change information;
A selection unit that selects either the first phase change information or the second phase change information based on a phase change of the reflected wave ultrasonic data;
an image generating unit that generates blood flow image data based on the intensity information and the first phase change information or the second phase change information selected by the selecting unit;
A medical analysis device comprising :

Images