Ultrasound diagnostic equipment

Abstract

To improve the quality of an ultrasonic image acquired by using an oscillator group of an RCA structure.SOLUTION: An ultrasonic probe includes a plurality of oscillators disposed in a two-dimensional shape. The plurality of oscillators are a plurality of row column addressing type oscillators that cause a first oscillator group lined up in a direction of one of two axes intersecting each other and composed of a plurality of oscillators connected in common to transmit a first ultrasonic wave, cause a second oscillator group lined up in a direction of the other of the two axes and composed of a plurality of oscillators connected in common to receive a reflection wave of the first ultrasonic wave, cause the second oscillator group to transmit a second ultrasonic wave, and cause the first oscillator group to receive a reflection wave of the second ultrasonic wave. A generation unit generates ultrasonic image data on the basis of a first reception signal acquired by causing the second oscillator group to receive the reflection wave of the first ultrasonic wave, and a second reception signal acquired by causing the first oscillator group to receive the reflection wave of the second ultrasonic wave.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] Embodiments disclosed herein and in the drawings relate to ultrasound diagnostic devices. [Background technology]

[0002] There are ultrasound diagnostic devices that electronically scan living organisms in three dimensions. The following methods are possible for ultrasound diagnostic devices to electronically scan living organisms in three dimensions. Figure 1A shows an example of the configuration of a conventional ultrasound diagnostic device 200. As shown in Figure 1A, a conventional ultrasound diagnostic device 200 comprises an ultrasound probe 201 and a device body 202.

[0003] The ultrasonic probe 201 comprises a plurality of transducers 203 arranged in two dimensions and an electronic circuit 204. The plurality of transducers 203 arranged in two dimensions are also called a two-dimensional array transducer. Figure 1B shows an example of the configuration of a conventional ultrasonic probe 201. As shown in Figure 1B, in a two-dimensional coordinate system composed of the x and y axes, there are N (N is a natural number) transducer rows, each composed of N transducers 203 arranged along the x-axis, and N rows arranged along the y-axis. That is, in the example in Figure 1B, the ultrasonic probe 201 is N 2 It has (N × N) oscillators 203. As shown in Figure 1A, N 2 Each of the M oscillators 203 is classified to belong to one of several groups called subarrays, which are composed of M oscillators 203. M is a natural number less than N.

[0004] The electronic circuit 204 comprises multiple blocks 205. Each block 205 corresponds to one subarray. That is, there is a block 205 for each subarray. Each block 205 causes the M transducers 203 that make up the subarray to perform ultrasonic transmission and reception.

[0005] Each block 205 comprises one transmit beamformer 205a, M pulsers 205b, M transmit / receive switches (T / R switches) 205c, M low noise amplifiers (LNAs) 205d, M variable gain amplifiers (VGAs) 205e, and one receive sub-array beamformer 205f. Of these, the transmit system consists of the transmit beamformer 205a and pulser 205b, while the receive system consists of the LNA 205d, VGA 205e, and receive sub-array beamformer 205f.

[0006] Each oscillator 203 is associated with one pulser 205b, one transmit / receive switch 205c, one LNA 205d, and one VGA 205e. Additionally, each subarray is associated with one set of receiving subarray beamformers 205f.

[0007] The operation of each block 205 of the ultrasonic probe 201 will be described below. When transmitting ultrasound, the transmitting beamformer 205a causes each of the multiple (M) transducers 203 to transmit delayed ultrasound via the pulser 205b. That is, the pulser 205b supplies delayed drive signals to the transducers 203. The transmit / receive switch 205c disconnects the receiving system from the transmitting system to suppress the application of voltage to the receiving system by the transmitting system when transmitting ultrasound. When receiving ultrasound, the transmit / receive switch 205c disconnects the received signals transmitted from each transducer 203 from the transmitting system. The LNA 205d then amplifies the received signals. The VGA 205e then adjusts the gain of the amplified received signals according to the depth. The receiving subarray beamformer 205f then applies a reception delay to the M received signals after the gain adjustment and adds the M received signals with the reception delay applied. The receiving sub-array beamformer 205f then outputs the received signal obtained by summing to the main unit 202 of the device. That is, the receiving sub-array beamformer 205f multiplies the received signal by a reception delay in units of sub-arrays, adds them together, and outputs the received signal obtained by summing. This type of beamforming (receiving beamforming) for each sub-array is called sub-array beamforming. In this way, the ultrasonic probe 201 outputs a number of received signals equal to the number of sub-arrays to the main unit 202 of the device.

[0008] The main unit 202 of the device is equipped with a receiving beamformer 206. The receiving beamformer 206 multiplies the reception delay of multiple received signals (the number of received signals corresponding to the number of sub-arrays) output by the ultrasonic probe 201 and adds the received signals with the reception delay multiplied. The main unit 202 then generates ultrasonic image data using the signal obtained by the addition.

[0009] Here, as shown in Figure 1B, an N×N two-dimensional array oscillator (N rows in the row direction and N columns in the column direction) is arranged in this way. 2 In the case of (a number of oscillators), as shown in Figure 1A, N 2 Individual Pulsar 205b, N 2 Individual LNA205d, N 2N VGA205e are used. Such a configuration is hereinafter referred to as "2DA". 2 N pulsers 205b 2 N LNAs 205d 2 The electronic circuits of N VGA205e are arranged inside the ultrasonic probe 201, for example, as shown in FIG. 1A.

[0010] Here, as the value of N increases, the amount of electronic circuits increases exponentially. For this reason, problems occur from the viewpoints of mounting area, heat generation, etc. For example, when the value of N is 128, 16,384 pulsers 205b, 16,384 LNAs 205d, and 16,384 VGA205e are required. When one pulser 205b, one LNA 205d, and one VGA205e are regarded as one electronic circuit, 16,384 electronic circuits are required. Mounting such a number of electronic circuits inside the ultrasonic probe 201 is difficult from the viewpoints of mounting area, heat generation, etc.

[0011] By performing reception beamforming inside the ultrasonic probe 201 for every M vibrators 203 by the subarray beamforming which is the above-described conventional technique, the number of cables connecting the ultrasonic probe 201 and the apparatus main body 202 becomes (1 / M) times the number of cables in the case where subarray beamforming is not performed. Therefore, the number of cables can be reduced by subarray beamforming. However, the number of electronic circuits such as the pulser 205b, the LNA 205d, and the VGA205e is not reduced.

[0012] Here, as a conventional method for reducing the number of electronic circuits, a conventional technique called RCA (Row-Column Addressing) described in Patent Document (U.S. Patent No. 9,855,022) etc. is known.

[0013] An example of a conventional RCA will be described. Figures 2A and 2B are diagrams illustrating an example of an RCA. Figure 3 is a diagram showing an example configuration of a conventional ultrasound diagnostic apparatus 300 having the structure of the example RCA described with reference to Figures 2A and 2B. As shown in Figure 3, the ultrasound diagnostic apparatus 300 comprises an ultrasound probe 301 and an apparatus body 302.

[0014] The ultrasonic probe 301 is equipped with an N×N two-dimensional array transducer. That is, as shown in Figures 2A and 2B, the ultrasonic probe 301 is an RCA structure transducer group (transducer array) with N rows in the row direction (x-axis direction) and N columns in the column direction (y-axis direction). 2 It is equipped with a transducer 303. Thus, the ultrasound diagnostic apparatus 300 shown in Figure 3 is equipped with a group of transducers with an RCA structure.

[0015] The main unit 302 of the device comprises N pulsers 304, a transmitting beamformer 305, N LNAs 306, N VGAs 307, and a receiving beamformer 308.

[0016] The operation of the ultrasound diagnostic device 300 will now be described. When the ultrasound diagnostic device 300 transmits ultrasound, as shown in Figure 2A, one of the two faces (e.g., the surface) of each of the N transducers 303 arranged in the column direction (y-axis direction) is connected in common. In other words, the ultrasound diagnostic device 300 connects the N transducers 303 arranged in the column direction (y-axis direction) in common. As a result, the transducer group 303a, which consists of N transducers 303 connected in series and arranged in the column direction, is arranged in N columns in the row direction (x-axis direction).

[0017] As shown in Figure 3, one pulser 304 is provided for each transducer group 303a. Since there are N transducer groups 303a, the main body 302 is equipped with N pulsers 304. Therefore, if we treat one pulser 304 as one electronic circuit, the main body 302 requires N electronic circuits when the ultrasound diagnostic device 300 transmits ultrasound.

[0018] The transmitting beamformer 305 then causes the pulser 304 to transmit ultrasonic waves with a transmission delay applied in the row direction from the other side (e.g., the back surface) of the N transducers 303 that make up the transducer group 303a. The transmitting beamformer 305 performs this process for each transducer group 303a.

[0019] Next, when the ultrasound diagnostic device 300 receives ultrasound, as shown in Figure 2B, the other face (for example, the back face) of each of the N transducers 303 arranged in the row direction (x-axis direction) is connected in common. That is, the ultrasound diagnostic device 300 connects the N transducers 303 arranged in the row direction (x-axis direction) in common. As a result, the transducer group 303b, which consists of N transducers 303 connected in series and arranged in the row direction, is arranged in N columns in the column direction (y-axis direction).

[0020] As shown in Figure 3, one LNA 306 and one VGA 307 are provided for each oscillator group 303b. Since there are N oscillator groups 303b, the main body of the device 302 is provided with N LNA 306s and N VGA 307s.

[0021] LNA306 amplifies the received signal output from the transducer group 303b. Here, the received signal output from one transducer group 303b is obtained by adding (combining) the M received signals output from the M transducers 303 that make up one transducer group 303b. VGA307 then adjusts the gain of the amplified received signal according to the depth. The A / D (Analog to Digital) converter converts the received signal, which is an analog signal after gain adjustment, into a digital signal. The receiving beamformer 308 multiplies the N received signals (digital signals) after gain adjustment by a reception delay and adds the N received signals with the reception delay applied. The main unit 302 then generates ultrasonic image data using the received signal obtained by the addition.

[0022] As shown in FIG. 3, one LNA 306 and one VGA 307 are provided for one oscillator group 303b. Since the number of oscillator groups 303b is N, the apparatus main body 302 is provided with N LNAs 306 and N VGAs 307. Therefore, when one LNA 306 and one VGA 307 are treated as one electronic circuit, when the ultrasonic diagnostic apparatus 300 receives ultrasonic waves, N electronic circuits are required in the apparatus main body 302. From the above, when the ultrasonic diagnostic apparatus 300 transmits and receives ultrasonic waves, 2N electronic circuits are required in the apparatus main body 302. For example, when the value of N is 128, in the ultrasonic diagnostic apparatus 200, 16384 electronic circuits are required as described above, but in the ultrasonic diagnostic apparatus 300, only 256 (2×128) electronic circuits are needed. In this case, the number of electronic circuits required in the ultrasonic diagnostic apparatus 300 is 1 / 64 times the number of electronic circuits required in the ultrasonic diagnostic apparatus 200. Therefore, the ultrasonic diagnostic apparatus 300 can significantly reduce the number of required electronic circuits.

[0023] Also, the receiving system and the transmitting system are originally separated, and a transmission / reception switch for separating the receiving system and the transmitting system is not required. From this point as well, compared with the ultrasonic diagnostic apparatus 200, the ultrasonic diagnostic apparatus 300 can reduce the number of electronic circuits.

[0024] However, the image quality of the ultrasonic image based on the ultrasonic image data generated by the ultrasonic diagnostic apparatus 300 is significantly lower than the image quality of the ultrasonic image based on the ultrasonic image data generated by the ultrasonic diagnostic apparatus 200.

[0025] Figure 4A shows the Point Spread Function (PSF) of a 2DA ultrasound diagnostic device 200 as viewed from the z-axis direction, with contour lines at 6 dB intervals. However, in the case shown in Figure 4A, neither receive apodization nor transmit apodization is performed. Here, receive apodization is a technique in which, for example, received signals from the same sample point received by multiple transducers constituting the receiving aperture of an ultrasound probe are weighted by an apodization function (aperture function) and then subjected to phase-correcting summation. The apodization function is a function in which a weight is set for each transducer position. Transmit apodization is a technique in which, for example, the amplitude of the ultrasound transmitted by multiple transducers constituting the transmitting aperture of an ultrasound probe is changed for each transducer position.

[0026] Figures 4B and 4C show the PSF (Psycho-Sensitivity Field) of an ultrasound diagnostic device 300 equipped with an RCA-structured transducer group, viewed from the z-axis direction, as contour lines at 6 dB intervals. However, in the case shown in Figure 4B, neither receive apodization nor transmit apodization is performed, while in the case shown in Figure 4C, both receive apodization and transmit apodization are performed.

[0027] Figure 5A represents the content shown in Figure 4A as image 210 from the peak to -40dB. Figure 5B represents the content shown in Figure 4B as image 310 from the peak to -40dB. Figure 5C represents the content shown in Figure 4C as image 311 from the peak to -40dB.

[0028] Comparing image 210 and image 310, it can be seen that the ultrasound diagnostic device 300, when receiving and transmitting apodization is not performed, has a slightly wider main lobe and slightly worse spatial resolution compared to the ultrasound diagnostic device 200. Furthermore, comparing image 210 and image 310, it can be seen that the ultrasound diagnostic device 300, when receiving and transmitting apodization is not performed, has larger side lobes along the x and y axes compared to the ultrasound diagnostic device 200, making it more prone to artifacts.

[0029] Comparing images 210, 310, and 311, it can be seen that when receiving and transmitting apodization is performed, the main lobe of the ultrasound diagnostic device 300 is considerably wider and the spatial resolution is considerably worse compared to the ultrasound diagnostic device 200 and the ultrasound diagnostic device 300 when receiving and transmitting apodization is not performed. Furthermore, comparing images 210, 310, and 311, the side lobes along the x and y axes are smaller when receiving and transmitting apodization is performed in the ultrasound diagnostic device 300 compared to the ultrasound diagnostic device 300 when receiving and transmitting apodization is not performed, but the side lobes along the x and y axes are larger compared to the ultrasound diagnostic device 200. Therefore, it can be seen that artifacts are more likely to occur in the ultrasound diagnostic device 300 when receiving and transmitting apodization is performed compared to the ultrasound diagnostic device 200.

[0030] As mentioned above, the ultrasound diagnostic device 300, which has a group of transducers with an RCA structure, has the advantage of requiring fewer electronic circuits compared to the ultrasound diagnostic device 200 with 2DA, but it has the problem of poor image quality.

[0031] Furthermore, there is a technique in which, when ultrasound is transmitted in the row direction (e.g., the x-axis direction), the ultrasound (reflected wave) is received by multiple transducers arranged in the row direction and multiple transducers arranged in the column direction (e.g., the y-axis direction), and then when ultrasound is transmitted in the column direction, the ultrasound (reflected wave) is received by multiple transducers arranged in the row direction and multiple transducers arranged in the column direction, and the two envelope signals are multiplied. However, this technique is only feasible if the objects being scanned are non-overlapping point reflectors. For this reason, for example, a dilute contrast agent is used.

[0032] Here, we further consider the reasons why the image quality of ultrasound images based on ultrasound image data generated by the ultrasound diagnostic device 300, which is equipped with a group of transducers with an RCA structure, is significantly lower than the image quality of ultrasound images based on ultrasound image data generated by the ultrasound diagnostic device 200, which is equipped with 2DA transducers.

[0033] Figures 6A to 6F illustrate an example of how ultrasound is transmitted and received by a conventional ultrasound diagnostic device 300. For example, consider the case where the ultrasound diagnostic device 300 transmits ultrasound as shown in Figures 6A to 6C and receives ultrasound (reflected waves) as shown in Figures 6D to 6F.

[0034] As shown in Figures 6A to 6C, when the ultrasound diagnostic device 300 transmits ultrasound, it applies focus (transmission focus) in the x-axis direction and transmits a plane wave without applying focus in the y-axis direction. For example, the ultrasound diagnostic device 300 performs a process for each transducer group 303a, in which it transmits ultrasound with a transmission delay applied in the row direction (x-axis direction) from the N transducers 303 that make up the transducer group 303a.

[0035] Furthermore, as shown in Figures 6D to 6F, when the ultrasound diagnostic device 300 receives ultrasound, it applies focus in the y-axis direction (receiving focus) and receives plane waves without applying focus in the x-axis direction. The ultrasound diagnostic device 300 then applies a reception delay to the received signals (digital signals) based on the received signals (analog signals) output from the N transducer group 303b, and adds up the N received signals with the reception delay applied. The ultrasound diagnostic device 300 then generates ultrasound image data using the received signals obtained by the addition.

[0036] When approximating the sound field at the focus point with a sinc function, the sound field for both transmission and reception of ultrasound in the ultrasound diagnostic device 300 is expressed as sinc(x)sinc(y). On the other hand, in the 2DA ultrasound diagnostic device 200, both transmission and reception of ultrasound can be focused, so it is (sinc(x)sinc(y)). 2 This is expressed as follows. As a result, the image quality of ultrasound images based on ultrasound image data generated by the ultrasound diagnostic device 300 equipped with an RCA structure transducer group is significantly lower than the image quality of ultrasound images based on ultrasound image data generated by the ultrasound diagnostic device 200 with 2DA transducers. [Prior art documents] [Patent Documents]

[0037] [Patent Document 1] U.S. Patent No. 9855022 [Patent Document 2] U.S. Patent Application Publication No. 2020 / 0064468 [Non-patent literature]

[0038] [Non-Patent Document 1] H. Bouzari, M. Engholm, MB Stuart, EV Thomsen, JA Jensen, “Improved Focusing Method for 3-D Imaging using Row-Column-Addressed 2-D Arrays” in Proc. IEEE Ultrasonics Symp., 2017 [Overview of the project] [Problems that the invention aims to solve]

[0039] One of the problems that the embodiments disclosed in this specification and drawings aim to solve is to improve the image quality of ultrasonic images obtained using a group of transducers with an RCA structure. However, the problems that the embodiments disclosed in this specification and drawings aim to solve are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems. [Means for solving the problem]

[0040] The ultrasonic diagnostic apparatus of this embodiment comprises an ultrasonic probe, a generation unit, and a display control unit. The ultrasonic probe comprises a plurality of transducers arranged in two dimensions. The generation unit generates ultrasonic image data based on the received signal obtained by the ultrasonic probe. The display control unit causes the ultrasonic image based on the ultrasonic image data to be displayed on the display unit. The plurality of transducers are a row-column addressing type plurality of transducers, which, when transmitting a first ultrasonic wave, are arranged in the direction of one of two intersecting axes and are connected in common to transmit the first ultrasonic wave; when receiving the reflected wave of the first ultrasonic wave, are arranged in the direction of the other of the two axes and are connected in common to receive the reflected wave of the first ultrasonic wave; when transmitting a second ultrasonic wave, are caused to transmit the second ultrasonic wave to the second transducer group; and when receiving the reflected wave of the second ultrasonic wave, are caused to receive the reflected wave of the second ultrasonic wave to the first transducer group. The generation unit generates ultrasonic image data based on a first received signal obtained by having the second group of transducers receive the reflected waves of the first ultrasonic wave, and a second received signal obtained by having the first group of transducers receive the reflected waves of the second ultrasonic wave. [Brief explanation of the drawing]

[0041] [Figure 1A] Figure 1A shows an example of the configuration of a conventional ultrasound diagnostic device. [Figure 1B] Figure 1B shows an example of the configuration of a conventional ultrasound probe. [Figure 2A] Figure 2A is a diagram illustrating an example of RCA. [Figure 2B] Figure 2B is a diagram illustrating an example of RCA. [Figure 3] Figure 3 shows an example of the configuration of a conventional ultrasound diagnostic device having the structure of an example RCA described with reference to Figures 2A and 2B. [Figure 4A] Figure 4A shows the Point Spread Function (PSF) of a 2DA ultrasound diagnostic device as viewed from the z-axis direction, with contour lines at 6 dB intervals. [Figure 4B] Figure 4B shows the PSF (Psycho-Sensitivity Field) as viewed from the z-axis direction of an ultrasound diagnostic device performing RCA (Radio Cross-Analysis), with contour lines at 6 dB intervals. [Figure 4C] Figure 4C shows the PSF (Psycho-Surface Field) as viewed from the z-axis direction of an ultrasound diagnostic device performing RCA (Radio Cross Acquisition), with contour lines at 6 dB intervals. [Figure 5A] Figure 5A shows the content of Figure 4A as an image from the peak down to -40 dB. [Figure 5B] Figure 5B shows the content of Figure 4B as an image ranging from the peak to -40 dB. [Figure 5C] Figure 5C shows the content of Figure 4C as an image ranging from the peak to -40 dB. [Figure 6A] Figure 6A is a diagram illustrating an example of how ultrasound is transmitted and received by a conventional ultrasound diagnostic device. [Figure 6B] Figure 6B is a diagram illustrating an example of how ultrasound is transmitted and received by a conventional ultrasound diagnostic device. [Figure 6C] Figure 6C is a diagram illustrating an example of how ultrasound is transmitted and received by a conventional ultrasound diagnostic device. [Figure 6D] Figure 6D is a diagram illustrating an example of how ultrasound is transmitted and received by a conventional ultrasound diagnostic device. [Figure 6E] Figure 6E is a diagram illustrating an example of how ultrasound is transmitted and received by a conventional ultrasound diagnostic device. [Figure 6F] Figure 6F is a diagram illustrating an example of how ultrasound is transmitted and received by a conventional ultrasound diagnostic device. [Figure 7] Figure 7 is a block diagram showing an example configuration of an ultrasound diagnostic apparatus according to the first embodiment. [Figure 8] Figure 8 shows an example of the configuration of an ultrasonic probe according to the first embodiment. [Figure 9A] Figure 9A is a diagram illustrating an example of ultrasonic transmission and reception when obtaining first reflected wave data according to the first embodiment. [Figure 9B] Figure 9B is a diagram illustrating an example of ultrasonic transmission and reception when obtaining the first reflected wave data according to the first embodiment. [Figure 9C] Figure 9C is a diagram illustrating an example of ultrasonic transmission and reception when obtaining the first reflected wave data according to the first embodiment. [Figure 9D] Figure 9D is a diagram illustrating an example of ultrasonic transmission and reception when obtaining the first reflected wave data according to the first embodiment. [Figure 9E] Figure 9E is a diagram illustrating an example of ultrasonic transmission and reception when obtaining the first reflected wave data according to the first embodiment. [Figure 9F] Figure 9F is a diagram illustrating an example of ultrasonic transmission and reception when obtaining the first reflected wave data according to the first embodiment. [Figure 10A] Figure 10A is a diagram illustrating an example of ultrasonic transmission and reception when obtaining second reflected wave data according to the first embodiment. [Figure 10B] Figure 10B is a diagram illustrating an example of ultrasonic transmission and reception when obtaining second reflected wave data according to the first embodiment. [Figure 10C] Figure 10C is a diagram illustrating an example of ultrasonic transmission and reception when obtaining second reflected wave data according to the first embodiment. [Figure 10D] Figure 10D is a diagram illustrating an example of ultrasonic transmission and reception when obtaining second reflected wave data according to the first embodiment. [Figure 10E] Figure 10E is a diagram illustrating an example of ultrasonic transmission and reception when obtaining second reflected wave data according to the first embodiment. [Figure 10F] Figure 10F is a diagram illustrating an example of ultrasonic transmission and reception when obtaining second reflected wave data according to the first embodiment. [Figure 11] Figure 11 is a flowchart illustrating an example of the processing flow from when the transmission circuit and signal processing circuit according to the first embodiment generate the first reflected wave data and the second reflected wave data, until the data after summation is obtained. [Figure 12A] Figure 12A shows the PSF (Pressure Saturation Field) of an ultrasound diagnostic device equipped with an RCA-structured transducer group, viewed from the z-axis direction, represented as contour lines at 6 dB intervals, with the image extending from the peak to -30 dB. [Figure 12B] Figure 12B shows the PSF of the ultrasound diagnostic apparatus according to the first embodiment, viewed from the z-axis direction, represented as contour lines at 6 dB intervals, with the image ranging from the peak to -30 dB. [Figure 12C] Figure 12C shows the PSF of a 2DA ultrasound diagnostic device as viewed from the z-axis direction, represented by contour lines at 6 dB intervals, with the image ranging from the peak to -30 dB. [Figure 13] Figure 13 shows an example of a trained model according to the third embodiment. [Figure 14] Figure 14 is a diagram illustrating an example of a method for generating a trained model according to the third embodiment. [Modes for carrying out the invention]

[0042] The ultrasound diagnostic apparatus according to each embodiment will be described below with reference to the drawings.

[0043] (First Embodiment) Figure 7 is a block diagram showing an example configuration of an ultrasound diagnostic apparatus 1 according to the first embodiment. As illustrated in Figure 7, the ultrasound diagnostic apparatus 1 according to the first embodiment includes a main body 100, an ultrasound probe 101, an input device 102, and a display 103.

[0044] The ultrasonic probe 101 has, for example, multiple transducers (piezoelectric elements). The multiple transducers generate ultrasound based on a drive signal supplied from the transmitting circuit 111 of the transmitting / receiving circuit 110 of the device body 100. Specifically, the multiple transducers generate ultrasound with a waveform corresponding to the transmitting drive voltage when a voltage (transmitting drive voltage) is applied by the transmitting circuit 111. The waveform of the transmitting drive voltage indicated by the drive signal is the waveform of the voltage applied to the multiple transducers. In other words, the ultrasonic probe 101 transmits ultrasound to the subject P according to the magnitude of the applied transmitting drive voltage. The ultrasonic probe 101 also receives reflected waves from the subject P, converts the reflected waves into reflected wave signals (received signals) which are electrical signals, and outputs the reflected wave signals to the device body 100. The ultrasonic probe 101 also has, for example, a matching layer provided on the transducer and a backing material that prevents the propagation of ultrasound backward from the transducer. The ultrasonic probe 101 is detachably connected to the device body 100.

[0045] When ultrasound is transmitted from the ultrasound probe 101 to the subject P, the transmitted ultrasound is reflected one after another by discontinuities in the acoustic impedance of the subject P's internal tissues, and the reflected waves are received by multiple transducers of the ultrasound probe 101. The amplitude of the received reflected waves depends on the difference in acoustic impedance at the discontinuities where the ultrasound is reflected. Furthermore, when the transmitted ultrasound pulse is reflected by a moving blood flow or the surface of the heart wall, the reflected wave undergoes a frequency shift due to the Doppler effect, depending on the velocity component of the moving object relative to the ultrasound transmission direction. The ultrasound probe 101 then outputs the reflected wave signal to the receiving circuit 112 of the transmitting / receiving circuit 110, which will be described later.

[0046] The ultrasonic probe 101 is detachably attached to the main unit 100 of the device. When scanning a two-dimensional area within the subject P (two-dimensional scanning), the operator connects a 1D array probe, for example, in which multiple transducers (ultrasonic elements) are arranged in a row, to the main unit 100 as the ultrasonic probe 101. Examples of 1D array probes include linear ultrasonic probes, convex ultrasonic probes, and sector ultrasonic probes. When scanning a three-dimensional area within the subject P (three-dimensional scanning), the operator connects a mechanical 4D probe or a 2D array probe to the main unit 100 as the ultrasonic probe 101. A mechanical 4D probe can perform two-dimensional scanning using multiple transducers arranged in a row, similar to a 1D array probe, and can also perform three-dimensional scanning by oscillating the multiple transducers at a predetermined angle (oscillation angle). A 2D array probe can perform three-dimensional scanning using multiple transducers arranged in a matrix, and can also perform two-dimensional scanning by focusing and transmitting ultrasound. The following explanation describes the case where the ultrasound probe 101 is a 2D array probe.

[0047] Figure 8 shows an example of the configuration of an ultrasonic probe 101 according to the first embodiment. As shown in Figure 8, the ultrasonic probe 101 comprises a plurality of transducers 104 that constitute a group of transducers with an RCA structure. For example, in a two-dimensional coordinate system composed of the x and y axes, the ultrasonic probe 101 has N rows in the x-axis direction and N columns in the y-axis direction. 2 The ultrasonic probe 101 comprises a plurality of transducers 104 arranged in two dimensions. In the case shown in Figure 8, the value of N is 3, but the value of N is not limited to this.

[0048] The oscillator 104 is composed of, for example, MUTs (Micromachined Ultrasound Transducers). Examples of such MUTs include CMUTs (Capacitive Micromachined Ultrasound Transducers). One cell of the MUT corresponds to one oscillator 104.

[0049] The transducer 104 transmits ultrasonic waves based on drive signals supplied by pulsers 105_1 and 105_2 provided in the transmitting circuit 111. When the transducer 104 receives a reflected wave, it outputs a reflected wave signal corresponding to the received reflected wave to amplifiers 106_1 and 106_2 provided in the receiving circuit 112.

[0050] A pulser 105_1 is provided for each oscillator group 104a (see Figure 9A), which consists of N oscillators 104 arranged in a row (y-axis direction). That is, each of the multiple pulsers 105_1 corresponds to one oscillator group 104a. An amplifier 106_1 is also provided for each oscillator group 104a. That is, each of the multiple amplifiers 106_1 corresponds to one oscillator group 104a.

[0051] A pulser 105_2 is provided for each oscillator group 104b (see Figure 9D), which consists of N oscillators 104 arranged in the row direction (x-axis direction). That is, each of the multiple pulsers 105_2 is provided corresponding to one oscillator group 104b. An amplifier 106_2 is also provided for each oscillator group 104b. That is, each of the multiple amplifiers 106_2 is provided corresponding to one oscillator group 104b.

[0052] Furthermore, as shown in Figure 8, the ultrasonic probe 101 is equipped with one multiplexer 107_1, one demultiplexer 107_2, one electrode contact (element electrode contact) 108 for the transducer 104 which is the ultrasonic element, and one switch 109, corresponding to one transducer 104. In other words, for each transducer 104, the ultrasonic probe 101 is equipped with one multiplexer 107_1, one demultiplexer 107_2, one electrode contact 108 for the transducer 104 which is the ultrasonic element, and one switch 109.

[0053] One pulser 105_1 is connected to the first input terminal 107_1_a of the N multiplexers 107_1 of the N oscillators 104 that constitute one oscillator group 104a. Another pulser 105_2 is connected to the second input terminal 107_1_b of the N multiplexers 107_1 of the N oscillators 104 that constitute one oscillator group 104b.

[0054] Furthermore, the multiplexer 107_1 receives control signals from the control circuit 170 of the main unit 100. Based on the input control signals, the multiplexer 107_1 supplies the drive signal supplied by the pulser 105_1 and input to the first input terminal 107_1_a, or the drive signal supplied by the pulser 105_2 and input to the second input terminal 107_1_b, to the vibrator 104 via the electrode contact 108. For example, the multiplexer 107_1 supplies the drive signal to the vibrator 104 by outputting the drive signal from the output terminal 107_1_c of the multiplexer 107_1.

[0055] The electrode contact 108 is connected to the input terminal 107_2_a of the demultiplexer 107_2 via the switch 109. As a result, the reflected wave signal from the oscillator 104 is input to the input terminal 107_2_a of the demultiplexer 107_2.

[0056] Furthermore, one amplifier 106_1 is connected to the first output terminal 107_2_b of the N demultiplexers 107_2 of the N oscillators 104 that constitute one oscillator group 104a. Also, one amplifier 106_2 is connected to the second output terminal 107_2_c of the N demultiplexers 107_2 of the N oscillators 104 that constitute one oscillator group 104b.

[0057] Furthermore, the demultiplexer 107_2 receives control signals from the control circuit 170 of the main unit 100. Based on the input control signals, the demultiplexer 107_2 outputs the reflected wave signal input to input terminal 107_2_a to amplifier 106_1 by outputting it from the first output terminal 107_2_b, or to amplifier 106_2 by outputting it from the second output terminal 107_2_c.

[0058] Returning to the explanation of Figure 7, the input device 102 is implemented by input means such as a mouse, keyboard, buttons, panel switches, touch command screen, foot switch, trackball, joystick, etc. The input device 102 receives various setting requests from the operator of the ultrasound diagnostic device 1 and transmits the received setting requests to the main unit 100 of the device.

[0059] The display 103 may, for example, display a GUI (Graphical User Interface) for the operator of the ultrasound diagnostic device 1 to input various setting requests using the input device 102, or display ultrasound images based on ultrasound image data generated by the device body 100. The display 103 is implemented using an LCD monitor, a CRT (Cathode Ray Tube) monitor, or the like. The display 103 is an example of a display unit.

[0060] The device body 100 generates ultrasonic image data based on reflected wave signals transmitted from the ultrasonic probe 101. The ultrasonic image data shown is an example of image data. The device body 100 can generate two-dimensional ultrasonic image data based on reflected wave signals corresponding to the two-dimensional region of the subject P transmitted from the ultrasonic probe 101. Furthermore, the device body 100 can generate three-dimensional ultrasonic image data based on reflected wave signals corresponding to the three-dimensional region of the subject P transmitted from the ultrasonic probe 101. As shown in Figure 1, the device body 100 includes a transmit / receive circuit 110, a buffer memory 120, a signal processing circuit 130, an image generation circuit 140, an image memory 150, a storage circuit 160, and a control circuit 170.

[0061] The transmitting / receiving circuit 110, under the control of the control circuit 170, causes the ultrasonic probe 101 to transmit ultrasonic waves and the ultrasonic probe 101 to receive reflected ultrasonic waves. In other words, the transmitting / receiving circuit 110 performs scanning via the ultrasonic probe 101. Scanning is also referred to as scanning, ultrasonic scanning, or ultrasonic scanning. The transmitting / receiving circuit 110 is an example of a transmitting / receiving unit. The transmitting / receiving circuit 110 has a transmitting circuit 111 and a receiving circuit 112.

[0062] The transmitting circuit 111, under the control of the control circuit 170, causes the ultrasonic probe 101 to transmit ultrasound. The transmitting circuit 111, under the control of the control circuit 170, supplies a drive signal to the ultrasonic probe 101. When scanning a two-dimensional region within the subject P, the transmitting circuit 111 causes the ultrasonic probe 101 to transmit an ultrasonic beam for scanning the two-dimensional region. When scanning a three-dimensional region within the subject P, the transmitting circuit 111 causes the ultrasonic probe 101 to transmit an ultrasonic beam for scanning the three-dimensional region.

[0063] The transmitting circuit 111 includes pulsers 105_1 and 105_2 (see Figure 8) and a transmitting beamformer (not shown). The transmitting beamformer causes each of the multiple transducers 104 constituting transducer group 104a and each of the multiple transducers 104 constituting transducer group 104b to transmit delayed ultrasonic waves via pulsers 105_1 and 105_2.

[0064] The transmitting beamformer includes a rate pulser generation circuit and a transmit delay circuit. The rate pulser generation circuit repeatedly generates rate pulses at a predetermined rate frequency (PRF: Pulse Repetition Frequency) to form the transmitting ultrasonic waves (transmitting beam). As the rate pulses pass through the transmit delay circuit, voltages are applied to pulsers 105_1 and 105_2 with different transmit delay times. For example, the transmit delay circuit provides each rate pulse generated by the rate pulser generation circuit with a transmit delay time for each transducer necessary to focus the ultrasonic waves generated from the ultrasonic probe 101 into a beam and determine the transmit directivity.

[0065] Pulsors 105_1 and 105_2 supply a delayed drive signal (drive pulse) to the transducer 104. Pulsors 105_1 and 105_2 supply a drive signal to the ultrasonic probe 101 at a timing based on the rate pulse. That is, pulsers 105_1 and 105_2 apply a voltage (transmit drive voltage) of the waveform represented by the drive signal to the ultrasonic probe 101 at a timing based on the rate pulse. The transmit delay circuit arbitrarily adjusts the direction of ultrasonic wave transmission from the transmitting surface of the transducer 104 by changing the transmit delay time applied to each rate pulse.

[0066] The drive pulse is transmitted from pulsers 105_1 and 105_2 via a cable to the transducer 104 in the ultrasound probe 101, where it is converted from an electrical signal to a mechanical vibration. That is, when a voltage is applied to the transducer 104, the transducer 104 vibrates mechanically. The ultrasound generated by this mechanical vibration is transmitted into the inside of the subject P, i.e., into the living body. Here, the ultrasound, which has a different transmission delay time for each transducer 104, is focused and propagates in a predetermined direction.

[0067] Furthermore, the transmitting circuit 111, under the control of the control circuit 170, has the function of instantaneously changing the transmitting frequency, transmitting drive voltage, etc., in order to execute a predetermined scanning sequence. In particular, the change in the transmitting drive voltage is achieved by a linear amplifier type oscillator circuit that can instantly switch the value of the transmitting drive voltage, or by a mechanism that electrically switches multiple power supply units.

[0068] The ultrasonic waves transmitted by the ultrasonic probe 101 reach the transducer 104 inside the ultrasonic probe 101. There, the transducer 104 converts the mechanical vibrations into an electrical signal (reflected wave signal) and inputs it to the receiving circuit 112. The receiving circuit 112 includes amplifiers 106_1 and 106_2, an A / D (Analog to Digital) converter (not shown), a receiving beamformer (not shown), etc., and performs various processing on the reflected wave signal transmitted from the ultrasonic probe 101 to generate reflected wave data. The reflected wave signal and reflected wave data described above are examples of received signals. The receiving circuit 112 generates two-dimensional reflected wave data from the two-dimensional reflected wave signal transmitted from the ultrasonic probe 101. The receiving circuit 112 also generates three-dimensional reflected wave data from the three-dimensional reflected wave signal transmitted from the ultrasonic probe 101. The receiving circuit 112 then stores the generated reflected wave data in the buffer memory 120.

[0069] Amplifiers 106_1 and 106_2 amplify the reflected wave signals output from either the oscillator group 104a or the oscillator group 104b. Here, the reflected wave signal output from one oscillator group 104a or one oscillator group 104b is a reflected wave signal (received signal) obtained by adding (combining) the N reflected wave signals output from the N oscillators 104 that make up one oscillator group 104a or one oscillator group 104b.

[0070] The A / D converter then converts the reflected wave signal, which is an amplified analog signal, into a digital reflected wave signal (digital signal).

[0071] The receiving beamformer then generates first reflected wave data by multiplying the reception delay on the N digital reflected wave signals obtained by A / D conversion of the N analog reflected wave signals output from the N oscillator group 104b, and adding the N reflected wave signals multiplied by the reception delay. In other words, the receiving beamformer generates first reflected wave data by beamforming the N digital reflected wave signals based on the N analog reflected wave signals output from the N oscillator group 104b.

[0072] Furthermore, the receiving beamformer generates second reflected wave data by multiplying the reception delay on the N digital reflected wave signals obtained by A / D conversion of the N analog reflected wave signals output from the N oscillator group 104a, and then adding the N reflected wave signals multiplied by the reception delay. In other words, the receiving beamformer generates second reflected wave data by beamforming the N digital reflected wave signals based on the N analog reflected wave signals output from the N oscillator group 104a.

[0073] The receiving beamformer then stores the generated reflected wave data (first reflected wave data and second reflected wave data) in the buffer memory 120.

[0074] Here, an example of a method for generating the first reflected wave data and the second reflected wave data will be described with reference to Figures 9A to 9F and Figures 10A to 10F. Figures 9A to 9F are diagrams illustrating an example of ultrasonic transmission and reception when obtaining the first reflected wave data according to the first embodiment.

[0075] As shown in Figures 9A to 9C, when the ultrasound diagnostic device 1 transmits ultrasound (first ultrasound), it applies focus (transmission focus) in the x-axis direction and transmits a plane wave without applying focus in the y-axis direction. For example, the ultrasound diagnostic device 1 performs a process for each transducer group 104a in which it causes the N transducers 104 that make up the transducer group 104a to transmit ultrasound with a transmission delay applied in the row direction (x-axis direction). That is, when the ultrasound diagnostic device 1 transmits the first ultrasound, it causes the transducer group 104a, which is composed of multiple transducers 104 that are aligned in the y-axis direction (direction of one axis) of the two intersecting x and y axes and are commonly connected, to transmit the first ultrasound. The transducer group 104a is an example of the first transducer group. The N transducer group 104a are aligned in the x-axis direction (direction of the other axis).

[0076] Then, as shown in Figures 9D to 9F, when the ultrasound diagnostic device 1 receives the reflected wave of ultrasound (first ultrasound), it focuses (receives focus) in the y-axis direction, but does not focus in the x-axis direction and receives the plane wave. That is, when the ultrasound diagnostic device 1 receives the reflected wave of the first ultrasound, it causes a group of transducers 104b, which consists of multiple transducers 104 that are aligned in the x-axis direction (direction of the other axis) and are commonly connected, to receive the reflected wave of the first ultrasound. The group of transducers 104b is an example of a second group of transducers. The N transducers 104b are aligned in the y-axis direction (direction of one axis).

[0077] In this case, the control circuit 170 inputs a control signal to the multiplexer 107_1 to cause the drive signal supplied by the pulser 105_1, which is input to the first input terminal 107_1_a of the multiplexer 107_1, to be output from the output terminal 107_1_c of the multiplexer 107_1. As a result, the multiplexer 107_1 supplies the drive signal supplied by the pulser 105_1 to the vibrator 104.

[0078] Furthermore, the control circuit 170 inputs a control signal to the demultiplexer 107_2 to cause the reflected wave signal input from the oscillator 104 to the input terminal 107_2_a of the demultiplexer 107_2 to be output from the second output terminal 107_2_c of the demultiplexer 107_2 to the amplifier 106_2 connected to this second output terminal 107_2_c. As a result, the demultiplexer 107_2 outputs the reflected wave signal output from the oscillator 104 to the amplifier 106_2.

[0079] In this way, as shown in Figures 9A to 9F, the transmission and reception of ultrasonic waves yields N reflected wave signals (analog signals) output from the N transducer group 104b, resulting in N reflected wave signals (digital signals). These N reflected wave signals are then input to the receiving beamformer.

[0080] Then, as described above, the receiving beamformer generates the first reflected wave data by performing beamforming on the obtained N reflected wave signals (digital signals). A specific example of the beamforming process performed by the receiving beamformer will be explained below.

[0081] The receiving beamformer performs adaptive beamforming on the obtained N reflected wave signals (digital signals) to improve azimuth resolution. For example, the receiving beamformer performs beamforming on the obtained N reflected wave signals (digital signals) using the MV (Minimum Variance) method. The MV method reduces the response from unwanted directions by setting a null for the response in the unwanted direction with high power. Below is an example of when the receiving beamformer performs beamforming using the MV method. For example, when R is the covariance matrix, the receiving beamformer uses the MV method to determine the weighting coefficient W of oscillator 104. MV This is calculated using the following formula (1).

[0082]

number

[0083] Here, "a" in equation (1) is the steering vector in the desired direction. The receiving beamformer calculates the covariance matrix R using the following equations (2) and (3), with respect to the time average from "-k" to "k" and a subarray of length "l".

[0084]

number

number

[0085] In equation (2), "n" is the number of oscillators 104. Also, "x" is the oscillator direction and "z" is the depth direction. Furthermore, the term on the left side of equation (3) is the received signal vector at the position (z,x) of the i-th subarray.

[0086] Then, to ensure that the inverse of the covariance matrix R exists, the receiving beamformer adds noise to the diagonal elements of the covariance matrix R using equations (4) and (5) below.

[0087]

number

number

[0088] However, in equation (4), "I" is the identity matrix.

[0089] Then, the receiving beamformer calculates the first reflected wave data s as a result of the beamforming process according to equation (6) below. MV Calculate.

[0090]

number

[0091] In the manner described above, the receiving beamformer performs beamforming using the MV method, and the first reflected wave data s MV Generates.

[0092] Figures 10A to 10F illustrate an example of ultrasonic transmission and reception when obtaining second reflected wave data according to the first embodiment.

[0093] As shown in Figures 10A to 10C, when the ultrasound diagnostic device 1 transmits ultrasound (second ultrasound), it applies focus (transmission focus) in the y-axis direction and transmits a plane wave without applying focus in the x-axis direction. For example, the ultrasound diagnostic device 1 performs a process for each transducer group 104b, causing the N transducers 104 that make up the transducer group 104b to transmit ultrasound with a transmission delay applied in the column direction (y-axis direction). That is, when the ultrasound diagnostic device 1 transmits the second ultrasound, it causes the transducer group 104b to transmit the second ultrasound.

[0094] Then, as shown in Figures 10D to 10F, when the ultrasound diagnostic device 1 receives the reflected wave of the ultrasound (second ultrasound), it focuses (receives focus) in the x-axis direction, but does not focus in the y-axis direction and receives the plane wave. In other words, when the ultrasound diagnostic device 1 receives the reflected wave of the second ultrasound, it causes the transducer group 104a to receive the reflected wave of the second ultrasound.

[0095] The multiple oscillators 104 arranged in a two-dimensional manner according to this embodiment are multiple row-column addressing type oscillators capable of the operation described above.

[0096] In this case, the control circuit 170 inputs a control signal to the multiplexer 107_1 to cause the drive signal supplied by the pulser 105_2, which is input to the second input terminal 107_1_b of the multiplexer 107_1, to be output from the output terminal 107_1_c of the multiplexer 107_1. As a result, the multiplexer 107_1 supplies the drive signal supplied by the pulser 105_2 to the vibrator 104.

[0097] Furthermore, the control circuit 170 inputs a control signal to the demultiplexer 107_2 to cause the reflected wave signal input from the oscillator 104 to the input terminal 107_2_a of the demultiplexer 107_2 to be output from the first output terminal 107_2_b of the demultiplexer 107_2 to the amplifier 106_1 connected to this first output terminal 107_2_b. As a result, the demultiplexer 107_2 outputs the reflected wave signal output from the oscillator 104 to the amplifier 106_1.

[0098] In this way, by transmitting and receiving ultrasonic waves as shown in Figures 10A to 10F, N reflected wave signals (digital signals) are obtained based on N reflected wave signals (analog signals) output from the N transducer group 104a, and the obtained N reflected wave signals are input to the receiving beamformer.

[0099] The receiving beamformer then generates the second reflected wave data in the same manner as the first reflected wave data generation method described above. Although the case where the receiving beamformer performs beamforming using the MV method has been described, any beamforming method can be used by the receiving beamformer, as long as it is adaptive beamforming that can obtain ultrasonic image data close to that of focused transmission from plane wave transmission. For example, the receiving beamformer may perform beamforming using the APES (Amplitude and Phase Estimation) method, the FC (Coherence Factor) method, or the SCF (Sign Coherence) method. The receiving beamformer may also perform beamforming using a modified version of any one of these methods. For example, the receiving beamformer may perform beamforming using an advanced form of the CF method such as the united sign coherence factor. Furthermore, the receiving beamformer may perform beamforming using methods such as inverse problem solving or deep learning.

[0100] The buffer memory 120 is a memory that temporarily stores reflected wave data generated by the transmitting and receiving circuit 110. For example, the buffer memory 120 is configured to store a predetermined number of frames of reflected wave data. When the buffer memory 120 has stored a predetermined number of frames of reflected wave data, and a new frame of reflected wave data is generated by the receiving circuit 112, the buffer memory 120, under the control of the receiving circuit 112, discards the oldest frame of reflected wave data generated and stores the newly generated frame of reflected wave data. For example, the buffer memory 120 can be implemented using semiconductor memory elements such as RAM (Random Access Memory) or flash memory.

[0101] The signal processing circuit 130 reads the first reflected wave data and the second reflected wave data from the buffer memory 120. The signal processing circuit 130 then adds the read second reflected wave data to the read first reflected wave data, applies various signal processing to the resulting data (added data), and outputs the processed added data as B-mode data or Doppler data to the image generation circuit 140. The signal processing circuit 130 can be implemented, for example, by a processor. The signal processing circuit 130 is an example of a signal processing unit.

[0102] Figure 11 is a flowchart showing an example of the processing flow from when the receiving circuit 112 and signal processing circuit 130 of the first embodiment generate the first reflected wave data and the second reflected wave data, until the data after summation is obtained.

[0103] As shown in Figure 11, the receiving circuit 112 generates first reflected wave data and stores the first reflected wave data in the buffer memory 120 (step S101). Then, the receiving circuit 112 generates second reflected wave data and stores the second reflected wave data in the buffer memory 120 (step S102).

[0104] Then, the signal processing circuit 130 reads the first reflected wave data and the second reflected wave data from the buffer memory 120, adds the second reflected wave data to the first reflected wave data (step S103), and finishes the process shown in Figure 11.

[0105] The sound field for ultrasonic transmission and reception shown in Figures 9A to 9F above is, for example, sinc(x)sinc 2 (y) is represented as (y). Also, the sound field of ultrasonic transmission and reception shown in Figures 10A to 10F above is, for example, sinc 2 This is expressed as (x)sinc(y). Therefore, the sound field when the second reflected wave data is added to the first reflected wave data is expressed as sinc(x)sinc(y)(sinc(x)+sinc(y)). In the conventional ultrasonic diagnostic device 300 equipped with a group of transducers with an RCA structure, as described above, the sound field for transmitting and receiving ultrasound is expressed as sinc(x)sinc(y). Therefore, according to the ultrasonic diagnostic device 1 of the first embodiment, the directivity can be improved by (sinc(x)+sinc(y)) times compared with the ultrasonic diagnostic device 300.

[0106] Figure 12A shows the PSF of an ultrasound diagnostic device 300 equipped with an RCA structure transducer group, viewed from the z-axis direction, represented as contour lines at 6 dB intervals, from the peak to -30 dB, as image 180. Figure 12B shows the PSF of an ultrasound diagnostic device 1 according to the first embodiment, viewed from the z-axis direction, represented as contour lines at 6 dB intervals, from the peak to -30 dB, as image 181. Figure 12C shows the PSF of a 2DA ultrasound diagnostic device 200, viewed from the z-axis direction, represented as contour lines at 6 dB intervals, from the peak to -30 dB, as image 182.

[0107] As can be seen by comparing image 180 and image 181, the ultrasound diagnostic apparatus 1 according to the first embodiment significantly reduces side lobes compared to the conventional ultrasound diagnostic apparatus 300. Furthermore, as can be seen by comparing image 181 and image 182, the ultrasound diagnostic apparatus 1 according to the first embodiment can approach the image quality of image data generated by the 2DA ultrasound diagnostic apparatus 200. Therefore, the ultrasound diagnostic apparatus 1 according to the first embodiment improves the image quality of ultrasound images obtained using a group of transducers with an RCA structure.

[0108] As described above, the signal processing circuit 130 generates B-mode data or Doppler data by applying various signal processing to the added data obtained by addition. For example, each time that a new frame's worth of first and second reflected wave data is stored in the buffer memory 120, the signal processing circuit 130 reads out the newly stored frame's worth of first and second reflected wave data from the buffer memory 120. Then, each time that frame's worth of first and second reflected wave data is read out, the signal processing circuit 130 adds the second reflected wave data to the first reflected wave data to generate a frame's worth of added data. Then, each time that frame's worth of added data is generated, the signal processing circuit 130 applies various signal processing to the added data to generate a new frame's worth of B-mode data or Doppler data. The signal processing circuit 130 then outputs the newly generated B-mode data or Doppler data for one frame to the image generation circuit 140 each time it generates one frame's worth of B-mode data or Doppler data. The following describes some examples of the various signal processing operations performed by the signal processing circuit 130.

[0109] For example, the signal processing circuit 130 performs quadrature detection on the summed data, logarithmic amplification, and envelope detection processing to generate B-mode data in which the signal strength (amplitude strength) of each sample point is expressed as brightness. The signal processing circuit 130 then outputs the generated B-mode data to the image generation circuit 140.

[0110] Furthermore, the signal processing circuit 130 performs signal processing on the summed data to perform harmonic imaging, which visualizes the harmonic components. Examples of harmonic imaging include contrast harmonic imaging (CHI) and tissue harmonic imaging (THI). In addition, the following scanning methods are known for contrast harmonic imaging and tissue harmonic imaging. For example, such scanning methods include amplitude modulation (AM), phase modulation (PM) called pulse subtraction or pulse inversion, and AMPM, which combines AM and PM to obtain the effects of both AM and PM.

[0111] Furthermore, the signal processing circuit 130 performs frequency analysis on the summed data to extract motion information of moving objects (blood flow, tissue, contrast agent echo components, etc.) based on the Doppler effect from the summed data, and generates Doppler data showing the extracted motion information. For example, the signal processing circuit 130 extracts average velocity, average variance, and average power value, etc., from multiple points as motion information of moving objects, and generates Doppler data showing the extracted motion information of moving objects. The signal processing circuit 130 outputs the generated Doppler data to the image generation circuit 140.

[0112] Using the functions of the signal processing circuit 130 described above, the ultrasound diagnostic apparatus 1 according to this embodiment can perform a color Doppler method, also known as color flow mapping (CFM). In the color flow mapping method, ultrasound is transmitted and received multiple times on multiple scan lines. In the color flow mapping method, an MTI (Moving Target Indicator) filter is applied to the data sequence at the same location to suppress signals originating from stationary or slow-moving tissue (clutter signals) and extract signals originating from blood flow (blood flow signals). The color flow mapping method then estimates blood flow information such as blood flow velocity, blood flow dispersion, and blood flow power from this blood flow signal. The signal processing circuit 130 outputs color image data showing the blood flow information estimated by the color flow mapping method to the image generation circuit 140. The color image data is an example of Doppler data.

[0113] The signal processing circuit 130 is capable of processing both two-dimensional summed data and three-dimensional summed data.

[0114] The image generation circuit 140 generates ultrasound image data from B-mode data or Doppler data output from the signal processing circuit 130. The image generation circuit 140 is implemented by a processor.

[0115] For example, the image generation circuit 140 generates two-dimensional B-mode image data from the two-dimensional B-mode data generated by the signal processing circuit 130, representing the intensity of reflected waves in terms of brightness. The image generation circuit 140 also generates two-dimensional Doppler image data from the two-dimensional Doppler data generated by the signal processing circuit 130, which visualizes motion information or blood flow information. The two-dimensional Doppler image data that visualizes motion information may be velocity image data, dispersion image data, power image data, or a combination of these.

[0116] Here, the image generation circuit 140 generally converts the scan line signal sequence of the ultrasonic scan into a scan line signal sequence of a video format, such as that used in televisions (scan conversion), and generates ultrasonic image data for display. For example, the image generation circuit 140 generates ultrasonic image data for display by performing a coordinate transformation on the data output from the signal processing circuit 130 according to the scanning pattern of the ultrasonic probe 101. In addition to scan conversion, the image generation circuit 140 also performs various image processing tasks, such as image processing that regenerates an average brightness image using multiple image frames after scan conversion (smoothing process), and image processing that uses a differential filter within the image (edge ​​enhancement process). Furthermore, the image generation circuit 140 synthesizes various parameter text information, scales, body marks, etc., with the ultrasonic image data.

[0117] Furthermore, the image generation circuit 140 generates 3D B-mode image data by performing a coordinate transformation on the 3D B-mode data generated by the signal processing circuit 130. The image generation circuit 140 also generates 3D Doppler image data by performing a coordinate transformation on the 3D Doppler data generated by the signal processing circuit 130. In other words, the image generation circuit 140 generates "3D ultrasound image data (volume data)" from the "3D B-mode image data and 3D Doppler image data". Then, the image generation circuit 140 performs various rendering processes on the volume data to generate various 2D image data for display on the display 103.

[0118] The rendering process performed by the image generation circuit 140 includes, for example, generating MPR image data from volume data using the Multi-Planer Reconstruction (MPR) method. Another rendering process performed by the image generation circuit 140 is volume rendering (VR), which generates 2D image data that reflects 3D information. The image generation circuit 140 is an example of an image generation unit.

[0119] B-mode data and Doppler data are ultrasound image data before scan conversion processing, while the data generated by the image generation circuit 140 is ultrasound image data for display after scan conversion processing. B-mode data and Doppler data are also referred to as raw data.

[0120] Based on the above, in the first embodiment, the receiving circuit 112, the signal processing circuit 130, and the image generation circuit 140 generate ultrasonic image data based on the reflected wave signal obtained by the ultrasonic probe 101. For example, the receiving circuit 112, the signal processing circuit 130, and the image generation circuit 140 generate ultrasonic image data based on the reflected wave signal (first received signal) obtained by having the transducer group 104b receive the reflected wave of the first ultrasonic wave, and the reflected wave signal (second received signal) obtained by having the transducer group 104a receive the reflected wave of the second ultrasonic wave.

[0121] Furthermore, the receiving circuit 112, signal processing circuit 130, and image generation circuit 140 generate ultrasonic image data based on the summed data (fifth received signal) obtained by adding first reflected wave data (third received signal) obtained by beamforming multiple first received signals output from multiple (N) transducer group 104b, and second reflected wave data (fourth received signal) obtained by beamforming multiple second received signals output from multiple (N) transducer group 104a. The receiving circuit 112, signal processing circuit 130, and image generation circuit 140 are examples of the generation unit.

[0122] The image memory 150 is a memory that stores various image data generated by the image generation circuit 140. The image memory 150 also stores data generated by the signal processing circuit 130. The B-mode data and Doppler data stored in the image memory 150 can be retrieved by the operator after a diagnosis, for example, and become ultrasound image data for display via the image generation circuit 140. For example, the image memory 150 can be implemented using semiconductor memory elements such as RAM or flash memory, a hard disk, or an optical disk.

[0123] The memory circuit 160 stores control programs for scanning (transmission and reception of ultrasound), image processing, and display processing, as well as various data such as diagnostic information (e.g., patient ID, physician's findings, etc.), diagnostic protocols, and various body marks. The memory circuit 160 is also used, if necessary, to store data stored in the image memory 150. For example, the memory circuit 160 can be implemented using semiconductor memory elements such as flash memory, a hard disk, or an optical disk. The memory circuit 160 is an example of a memory unit.

[0124] The control circuit 170 controls the entire process of the ultrasound diagnostic device 1. Specifically, the control circuit 170 controls the processing of the transmitting / receiving circuit 110, the signal processing circuit 130, and the image generation circuit 140 based on various setting requests input from the operator via the input device 102, and various control programs and data read from the memory circuit 160. The control circuit 170 also controls the display 103 to display an ultrasound image based on ultrasound image data for display stored in the image memory 150. For example, the control circuit 170 controls the display 103 to display a B-mode image based on B-mode image data or a color image based on color image data. The control circuit 170 also controls the display 103 to display a color image superimposed on a B-mode image. The control circuit 170 is an example of a display control unit or a control unit. The control circuit 170 is implemented, for example, by a processor. An ultrasound image is an example of an image.

[0125] Furthermore, the control circuit 170 controls the ultrasonic scanning by controlling the ultrasonic probe 101 via the transmitting and receiving circuit 110.

[0126] In the above description, the term "processor" refers to circuits such as a CPU (Central Processing Unit), GPU (Graphics Processing Unit), Application Specific Integrated Circuit (ASIC), or programmable logic device (e.g., Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), or Field Programmable Gate Array (FPGA)). The processor performs its functions by reading a program stored in the memory circuit 160 and executing the read program. Alternatively, instead of storing the program in the memory circuit 160, the processor may be configured to directly incorporate the program into its circuitry. In this case, the processor performs its functions by reading and executing the program incorporated into the circuitry. In this embodiment, each processor is not limited to being configured as a single circuit; multiple independent circuits may be combined to form a single processor, and its functions may be realized in this way. Furthermore, the multiple circuits shown in Figure 7 (for example, the transmitting / receiving circuit 110, the signal processing circuit 130, the image generation circuit 140, and the control circuit 170) may be integrated into a single processor to realize their functions. In other words, the transmitting / receiving circuit 110, the signal processing circuit 130, the image generation circuit 140, and the control circuit 170 may be integrated into a single processing circuit realized by the processor.

[0127] The ultrasound diagnostic apparatus 1 according to the first embodiment has been described above. As described above, the ultrasound diagnostic apparatus 1 according to the first embodiment can improve the image quality of ultrasound images obtained using a group of transducers with an RCA structure.

[0128] (Second embodiment) In the first embodiment, a case was described in which the ultrasound diagnostic device 1 adds two reflected wave data obtained by separately beamforming each of the two reflected wave signals obtained by transmitting and receiving ultrasound twice. However, the ultrasound diagnostic device 1 may also beamform the two reflected wave signals obtained by transmitting and receiving ultrasound twice together at one time. Therefore, such an embodiment will be described as the second embodiment. In the description of the second embodiment, mainly the differences from the first embodiment will be described, and descriptions of configurations similar to the first embodiment may be omitted.

[0129] In the second embodiment, the receiving beamformer extends the MV method to two dimensions. In the second embodiment, for the sake of simplicity, we will explain using the case where there is no subarray, i.e., when l=n. In the second embodiment, the receiving beamformer sets l=n in equation (2). The receiving beamformer then uses equation (7) below and performs beamforming according to equations (4) to (6), similar to the first embodiment.

[0130]

number

[0131] In equation (7), "u" is the received signal vector (reflected wave signal vector) obtained by receiving the first ultrasonic reflected wave shown in Figures 6D to 6F. "v" is the received signal vector (reflected wave signal vector) obtained by receiving the second ultrasonic reflected wave shown in Figures 9D to 9F. In equation (7), "u" and "v" are concatenated into a single vector. In the second embodiment, the signal (reflected wave data) s obtained by equation (6) is... MV This is the result of performing beamforming on two reflected wave signals simultaneously using the MV method.

[0132] In other words, the receiving circuit 112, the signal processing circuit 130, and the image generation circuit 140 combine the multiple reflected wave signals (first received signals) output from the multiple oscillator group 104b and the multiple reflected wave signals (second received signals) output from the multiple oscillator group 104a, and perform beamforming on the multiple first received signals and the multiple second received signals to obtain reflected wave data s MV Based on this, ultrasonic image data is generated. Reflected wave data s MV This is an example of a third received signal.

[0133] The ultrasound diagnostic apparatus 1 according to the second embodiment has been described above. The ultrasound diagnostic apparatus 1 according to the second embodiment can achieve the same effects as the ultrasound diagnostic apparatus 1 according to the first embodiment.

[0134] (Third embodiment) The ultrasound diagnostic device 1 may use a trained model to estimate the signal (reflected wave data) obtained by beamforming. Therefore, such an embodiment will be described as the third embodiment. Note that in the description of the third embodiment, the differences from the first embodiment will be mainly explained, and descriptions of configurations similar to the first embodiment may be omitted.

[0135] Figure 13 shows an example of a trained model 400 according to the third embodiment. In the third embodiment, the memory circuit 160 stores the trained model 400 shown in Figure 13. The receiving beamformer then retrieves the trained model 400 from the memory circuit 160 and uses the retrieved trained model 400 to estimate the signal (reflected wave data) obtained by beamforming.

[0136] The trained model 400 is generated by training using machine learning. An example of how to generate this trained model 400 is shown in Figure 14. Figure 14 is a diagram illustrating an example of how to generate the trained model 400 according to the third embodiment. Here, for example, the case in which an external device generates the trained model 400 is described. The trained model 400 takes a delayed x-direction received signal 401 (see Figure 14) and a delayed y-direction received signal 402 (see Figure 14) as inputs, and outputs the result of multiplying the signals from each element by weights and adding them together as the beamforming result. Here, the delayed x-direction received signal 401 is, for example, multiple delayed reflected wave signals (first received signal) output from a group of multiple (N) oscillators 104a, and the delayed y-direction received signal 402 is, for example, multiple delayed reflected wave signals (second received signal) output from a group of multiple (N) oscillators 104b. The trained model 400 generates a first beamformed signal by weighted summing the delayed x-direction received signal 401 and the delayed y-direction received signal 402, and outputs the generated first beamformed signal.

[0137] Here, as shown in Figure 14, the external device calculates the optimal weights by deep learning so that the first signal output from the trained model 400 is close to the 2DA training data 403 (so that the first signal is similar to the 2DA training data 403), and trains the trained model 400 with the optimal weights. Here, the 2DA training data 403 is, for example, the second signal after beamforming obtained by a 2DA ultrasound diagnostic device 200 used as training data. The external device may, for example, create the delayed x-direction received signal 401, the delayed y-direction received signal 402, and the 2DA training data 403 using an ultrasound simulator such as "Field II". Alternatively, the external device may use actual data obtained using an RCA probe and a 2DA probe.

[0138] For example, a trained model 400 generated by an external device is stored in the memory circuit 160. Here, the external device generates the trained model 400 by, for example, learning the relationship between a combination of a delayed x-direction received signal 401 and a delayed y-direction received signal 402 and 2DA training data 403.

[0139] In this way, the external device generates a trained model 400 by learning by associating the combination of the delayed x-direction received signal 401 and the delayed y-direction received signal 402 with the 2DA training data 403.

[0140] For example, an external device takes a combination of a delayed x-direction received signal 401 and a delayed y-direction received signal 402 as input data, and inputs 2DA training data 403 as training data into the machine learning engine to perform machine learning. For example, the machine learning engine performs machine learning using various algorithms such as deep learning, neural networks, logistic regression analysis, nonlinear discriminant analysis, support vector machines (SVM), random forests, and naive Bayes.

[0141] An external device generates a trained model 400 as a result of this machine learning. The trained model 400 receives signals corresponding to the combination of the delayed x-direction received signal 401 and the delayed y-direction received signal 402 as input, estimates (generates) a signal corresponding to the 2DA training data 403, and outputs it.

[0142] Then, during inference, when inferring the signal corresponding to the 2DA training data 403, the receiving beamformer acquires the trained model 400 from the memory circuit 160. The receiving beamformer then inputs the combination of the delayed x-direction received signal 401 and the delayed y-direction received signal 402 to the acquired trained model 400, and acquires the signal corresponding to the 2DA training data 403 output from the trained model 400. The receiving beamformer then stores the acquired signal corresponding to the 2DA training data 403 in the buffer memory 120.

[0143] The signal processing circuit 130 then reads the signal corresponding to the 2DA training data 403 stored in the buffer memory 120, performs various signal processing on the read signal corresponding to the 2DA training data 403, and outputs the signal corresponding to the 2DA training data 403, which has undergone various signal processing, to the image generation circuit 140 as B-mode data or Doppler data.

[0144] The ultrasound diagnostic apparatus 1 according to the third embodiment has been described above. In the third embodiment, the memory circuit 160 stores a learned model 400 that, upon input of a combination of a delayed x-direction received signal 401 and a delayed y-direction received signal 402, outputs a signal corresponding to a beamformed second signal obtained by beamforming a plurality of reflected wave signals (received signals) output from a plurality of transducers 203 arranged in two dimensions.

[0145] In the third embodiment, the receiving circuit 112, signal processing circuit 130, and image generation circuit 140 generate a combination of a delayed x-direction received signal 401 and a delayed y-direction received signal 402. The receiving circuit 112, signal processing circuit 130, and image generation circuit 140 then input the generated combination of the delayed x-direction received signal 401 and the delayed y-direction received signal 402 to the trained model 400 and acquire a signal corresponding to the 2DA training data 403 output from the trained model 400. The receiving circuit 112, signal processing circuit 130, and image generation circuit 140 then generate ultrasonic image data based on the acquired signal corresponding to the 2DA training data 403.

[0146] The ultrasound diagnostic apparatus 1 according to the third embodiment can achieve the same effects as the ultrasound diagnostic apparatus 1 according to the first embodiment.

[0147] The program executed by the processor is provided pre-installed in ROM (Read Only Memory) or memory circuits. This program may also be provided as a file in an installable or executable format on a computer-readable, non-transient storage medium such as a CD (Compact Disk)-ROM, FD (Flexible Disk), CD-R (Recordable), or DVD (Digital Versatile Disk). Furthermore, this program may be stored on a computer connected to a network such as the Internet and provided or distributed by downloading it via the network. For example, this program consists of modules containing the processing functions described above. In actual hardware, the CPU reads the program from a storage medium such as ROM and executes it, loading each module onto the main memory and generating it in the main memory.

[0148] According to at least one embodiment described above, the image quality of ultrasonic images obtained using a group of transducers with an RCA structure can be improved.

[0149] While several embodiments have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0150] 1. Ultrasound diagnostic equipment 112 Receiving Circuit 130 Signal Processing Circuits 140 Image generation circuit 170 Control circuits

Claims

1. An ultrasonic probe equipped with multiple transducers arranged in a two-dimensional manner, A generation unit that generates ultrasonic image data based on the received signal obtained by the ultrasonic probe, A display control unit that displays an ultrasonic image based on the aforementioned ultrasonic image data on a display unit, Equipped with, The aforementioned plurality of oscillators are, When transmitting the first ultrasonic wave, the first ultrasonic wave is transmitted to a group of transducers, which consists of a plurality of transducers arranged in the direction of one of two intersecting axes and connected in common. When receiving the reflected wave of the first ultrasonic wave, the reflected wave of the first ultrasonic wave is received by a second group of transducers, which consists of a plurality of transducers arranged in the direction of the other of the two axes and connected in common. When transmitting the second ultrasonic wave, the second group of transducers is made to transmit the second ultrasonic wave. When receiving the reflected wave of the second ultrasonic wave, the first group of transducers is configured to receive the reflected wave of the second ultrasonic wave using a row-column addressing method. The generation unit generates the ultrasonic image data based on a first received signal obtained by having the second group of transducers receive the reflected waves of the first ultrasonic wave, and a second received signal obtained by having the first group of transducers receive the reflected waves of the second ultrasonic wave. The generation unit inputs a signal based on the first received signal output from the second group of transducers and the second received signal output from the first group of transducers into a trained model, thereby obtaining a signal from the trained model that corresponds to the signal on which beamforming has been performed on the received signals output from the plurality of transducers, and generates the ultrasonic image data based on the obtained signal. Ultrasound diagnostic equipment.

2. The generation unit inputs a signal combining a first delayed signal obtained by delaying the first received signal output from the second group of transducers and a second delayed signal obtained by delaying the second received signal output from the first group of transducers to the trained model, thereby obtaining a signal from the trained model that corresponds to a signal on which beamforming has been performed on the received signals output from the plurality of transducers, and generates the ultrasonic image data based on the obtained signal. The ultrasound diagnostic apparatus according to claim 1.

3. The first group of oscillators constitutes a first row of oscillators, The second group of oscillators constitutes a second oscillator array, The first row of oscillators is arranged in the direction of the other axis, The second row of oscillators is arranged in the direction of the first axis, The ultrasound diagnostic apparatus according to claim 1.

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