JP6776766B2 - Ultrasonic measuring device and control method of ultrasonic measuring device - Google Patents

Description

The present invention relates to an ultrasonic measuring device or the like that performs ultrasonic measurement.

Conventionally, there has been known an ultrasonic measuring device that scans an ultrasonic beam using an ultrasonic probe in which a plurality of ultrasonic elements (ultrasonic vibrators) are arranged to image the inside of a living body. In imaging, beamforming (BF; Beam Forming) processing is performed in which received signals received for each ultrasonic element are added. Since the resolution of an image is low in a simple beamforming process, a technique for obtaining a higher resolution image has been developed. For example, the adaptive beamforming process described in Patent Document 1 is one of them.

By the way, the adaptive beamforming process has a problem that the amount of calculation increases while a higher resolution can be obtained as compared with the non-adaptive conventional beamforming process. Examples of the technique for solving this problem include the technique of Patent Document 2. The technique of Patent Document 2 adds echo detection data (received signals) from adjacent channels, thins out the data, and then executes adaptive signal processing (adaptive beamforming processing) to perform high-speed signal processing. It is intended to be converted.

JP-A-2015-77393 Japanese Unexamined Patent Publication No. 2011-5237

According to the technique of Patent Document 2, since the number of received signals to be processed by the adaptive beamforming process can be reduced, the amount of calculation can be reduced accordingly. However, as a result, the effect of the adaptive beamforming process for increasing the resolution is diminished, which may affect the image quality of the generated ultrasonic image.

The present invention has been made in view of these circumstances, and has been devised for the purpose of suppressing deterioration of the image quality of ultrasonic images while reducing the amount of calculation related to the execution of adaptive beamforming processing. is there.

The first invention for solving the above-mentioned problems is an ultrasonic probe in which a plurality of ultrasonic elements for transmitting and receiving ultrasonic waves are arranged, and beamforming processing and an adaptive beam for a received signal received for each ultrasonic element. A calculation processing unit that is multi-stage signal processing with forming processing, performs a plurality of the multi-stage signal processing having different setting conditions of the beam forming processing, and generates an ultrasonic image based on the average signal of the result of each multi-stage signal processing. It is an ultrasonic measuring device equipped with.

Another invention is a control method of an ultrasonic measuring device that performs ultrasonic measurement using an ultrasonic probe in which a plurality of ultrasonic elements for transmitting and receiving ultrasonic waves are arranged, and receives each ultrasonic element. It is a multi-stage signal processing of the beamforming process and the adaptive beamforming process for the received signal, and the multiple-stage signal processing having different setting conditions of the beamforming process is performed, and the result of the plurality of multi-stage signal processing. A control method may be configured that includes generating an ultrasonic image based on the average signal of.

According to the first invention and the like, since the multi-stage signal processing of the beamforming process and the adaptive beamforming process is performed, the amount of calculation related to the execution of the adaptive beamforming process can be reduced. Further, it is possible to perform a plurality of multi-stage signal processing having different setting conditions for the beamforming processing and generate an ultrasonic image by averaging the results of each multi-stage signal processing. According to this, it is possible to suppress the deterioration of the image quality of the ultrasonic image that may occur due to the execution of the beamforming process.

Further, as a second invention, the arithmetic processing unit may configure the ultrasonic measuring apparatus of the first invention, which performs the plurality of multi-stage signal processing in parallel.

According to the second invention, each multi-stage signal processing can be performed in parallel. Therefore, the signal processing can be speeded up.

Further, as a third invention, the arithmetic processing unit has the plurality of multistages under the setting condition in which the number of signals of the received signal to be processed by the beamforming process is different from each other and is not a multiple of each other. The ultrasonic measuring apparatus of the first or third invention which performs signal processing may be configured.

According to the third invention, in each multi-stage signal processing, beamforming processing can be executed for receiving signals having different numbers of signals that are not multiples of each other. As a result, deterioration of the image quality of the ultrasonic image due to multi-stage signal processing can be suppressed.

Further, as a fourth invention, the ultrasonic measuring apparatus of the third invention may be configured in which the number of signals under the setting conditions related to the plurality of multi-stage signal processing is a number that does not include a prime factor common to each other. Good.

According to the fourth invention, in each multi-stage signal processing, it is possible to execute a beamforming process for processing received signals having a number of signals that do not include a common prime factor. As a result, deterioration of the image quality of the ultrasonic image due to multi-stage signal processing can be suppressed.

Further, as a fifth invention, the arithmetic processing unit calculates the average signal by weight-averaging the results of the plurality of multi-stage signal processing, according to the ultrasonic measuring apparatus of any one of the first to fourth inventions. It may be configured.

According to the fifth invention, an ultrasonic image can be generated by weighted averaging the results of each multi-stage signal processing.

Further, as a sixth invention, the adaptive beamforming process is a process of calculating a weight based on a received signal for each ultrasonic element and weighting and adding the received signal using the weight. The ultrasonic measuring device of any one of the first to fifth inventions can be configured. By executing the adaptive beamforming process, the resolution (direction resolution) can be increased as compared with the non-adaptive beamforming process, so that the image quality of the ultrasonic image can be improved.

Further, as a seventh invention, the arithmetic processing unit constitutes an ultrasonic measuring apparatus according to any one of the first to sixth inventions, which includes an arithmetic circuit for executing the beamforming process for each of the multi-stage signal processes. You may.

According to the seventh invention, the beamforming process can be executed by using the arithmetic circuit provided for each multi-stage signal processing.

The figure which shows the system configuration example of the ultrasonic measuring apparatus. The figure which shows the processing block of BF processing. FIG. 2 is a diagram showing an example of reception sensitivity characteristics related to the BF process of FIG. The figure which shows the processing block of adaptive BF processing. The figure which shows the receiving sensitivity characteristic example which concerns on the BF process of FIG. The figure which shows the processing block example of multi-stage signal processing. The figure which shows another example of the processing block of multi-stage signal processing. FIG. 7 is a diagram showing an example of reception sensitivity characteristics related to multi-stage signal processing in FIG. 7. FIG. 8 is an enlarged view of the reception sensitivity characteristic of FIG. The figure which shows another example of the processing block of multi-stage signal processing. The figure which shows the receiving sensitivity characteristic example which concerns on the multi-stage signal processing of FIG. FIG. 11 is an enlarged view of the reception sensitivity characteristic of FIG. The figure which shows the processing block example at the time of executing the multi-stage signal processing of FIG. 7 and the multi-stage signal processing of FIG. FIG. 6 is a diagram showing an example of reception sensitivity characteristics related to parallel execution of multi-stage signal processing of FIG. FIG. 14 is an enlarged view of the reception sensitivity characteristic of FIG. The block diagram which shows the functional configuration example of an ultrasonic measuring apparatus. The figure which shows the data structure example of the setting condition table. The flowchart which shows the flow of the ultrasonic image generation processing.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and the embodiments to which the present invention can be applied are not limited to the following embodiments. Further, in the description of the drawings, the same parts are designated by the same reference numerals.

FIG. 1 is a diagram showing a system configuration example of the ultrasonic measuring device 10 according to the present embodiment. The ultrasonic measuring device 10 is for acquiring biological information of the subject 2 by using ultrasonic measurement, and also serves as a means for displaying a measurement result and an operation information as an image and a means for inputting an operation. It includes a touch panel 12, a keyboard 14 for inputting operations, an ultrasonic probe (probe) 16, and an image processing device 30.

The ultrasonic probe 16 has a plurality of ultrasonic elements (ultrasonic vibrators) arranged in rows at equal intervals on the sensor surface side thereof, and for example, the ultrasonic beam is arranged in the arrangement direction of the ultrasonic elements. Ultrasonic measurement is performed by a so-called linear scanning method in which ultrasonic beams are transmitted and received along a plurality of scanning lines parallel to each other while shifting the incident position. The ultrasonic probe 16 is used with the sensor surface in close contact with the biological surface (neck in FIG. 1) of the subject 2. The scanning method is not limited to the linear scanning method, and the present embodiment can be similarly applied when another scanning method such as a sector scanning method is adopted. The measurement site to which the ultrasonic probe 16 is applied is not limited to the neck, but is the site of the subject 2 such as the wrist, arm, and abdomen according to the purpose of measurement.

A control board 31 is mounted on the image processing device 30, and is connected to various parts of the device such as the touch panel 12, the keyboard 14, and the ultrasonic probe 16 so as to be able to transmit and receive signals. The control board 31 includes a CPU (Central Processing Unit) 32, various integrated circuits such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field-Programmable Gate Array), a storage medium 33 such as an IC memory and a hard disk, and an external device. It is equipped with a communication IC 34 that realizes data communication with the device. The ultrasonic measuring device 10 performs processing necessary for acquiring biological information including ultrasonic measurement by executing a program in which the CPU 32 or the like is stored in the storage medium 33 in the image processing device 30.

Specifically, the ultrasonic measuring device 10 transmits an ultrasonic beam from the ultrasonic probe 16 to the subject 2 under the control of the image processing device 30, receives the reflected wave, and performs ultrasonic measurement. Then, the received signal of the reflected wave is amplified and signal-processed to generate reflected wave data such as the position information of the in-vivo structure of the subject 2 and the change with time. The ultrasonic measurement is repeated at a predetermined cycle. The unit of measurement is called a "frame".

The reflected wave data includes images in so-called A mode, B mode, M mode, and color Doppler mode. In the A mode, the first axis is a sequence of sampling points of the received signal along the transmission / reception direction (direction of the scanning line) of the ultrasonic beam, and the second axis is the reception signal intensity of the reflected wave at each sampling point. This is a mode for displaying the amplitude (A mode image) of. Further, in the B mode, a two-dimensional ultrasonic image of the in-vivo structure is visualized by converting the reflected wave amplitude (A mode image) obtained while scanning the ultrasonic beam within a predetermined scanning range into a brightness value. This is a mode for displaying (B mode image).

[Overview]
When generating the reflected wave data, the ultrasonic measuring device 10 performs a process of phase-adjusting and adding the received signals from each ultrasonic element (hereinafter, also referred to as “channel”) at each sampling point (received beamforming). When a plurality of ultrasonic element groups form one channel to transmit and receive ultrasonic waves, the received signals obtained for each ultrasonic element group are phase-aligned and added. Hereinafter, the received signal from each channel composed of the ultrasonic element or the ultrasonic element group is referred to as a “channel signal”.

Specifically, after the reception focus processing (phase adjustment processing) that delays the channel signals from each channel, the beamforming processing that adds each channel signal after the reception focus processing is performed. Thereby, only the signal from the desired direction (direction of the scanning line) having the same phase can be amplified, and the desired wave from the direction of the scanning line can be extracted.

Here, in the following description, the beamforming process (BF process) refers to, for example, fixed beamforming with a fixed reception directivity, and is a non-adaptive beamforming process. That is, the BF process is a process of weighted addition of channel signals from each channel using a predetermined fixed addition weight (weight). FIG. 2 is a diagram showing a processing block P _ds for BF processing channel signals x _{1 to} x ₁₂ from ₁₂ channels, and FIG. 3 shows an example of reception sensitivity characteristics according to the BF processing P _ds of FIG. It is a figure. In FIG. 3, the front surface (direction of the scanning line) is set to 0 degrees, and the reception sensitivity in each direction when an unnecessary wave having the same signal strength as the desired wave from the front surface is received from an oblique direction is shown as a graph. There is.

As shown in FIG. 3, in the reception sensitivity characteristic of the BF processed P _ds , the main lobe ML1 appearing at 0 degrees has a wide width unlike the ideal steep shape. In addition, the levels of the side lobes SL11 and SL13 appearing in the diagonal direction off the front are not close to zero and are large. Here, the main lobe is the sensitivity to the desired wave, and the side lobe is the sensitivity to the unwanted wave. The narrower the width of the main lobe and the lower the level of the side lobes, the higher the resolution (direction resolution). However, in the BF processing P _ds , as described above, the width of the main lobe ML1 is wide and the side lobes SL11 and SL13 are also large. It is also sensitive to unwanted waves. This lowers the resolution and causes deterioration of the image quality of the ultrasonic image.

In contrast to this BF process, an adaptive beamforming process (adaptive BF process) that dynamically changes the addition weight used for adding channel signals according to the incoming wave is known. To briefly explain the adaptive BF processing procedure, the following processing is performed for each sampling point. First, the correlation matrix is calculated based on the channel signal of each channel after the reception focus processing. Subsequently, the addition weight to be multiplied by each channel signal is calculated from the calculated correlation matrix using the steering vector defined based on the direction of the scanning line. After that, the calculated addition weight is used, and the channel signal of each channel after the reception focus processing is weighted and added. Specific examples of the adaptive BF treatment include an MV (Minimum Variance) method, an APES (Amplitude and Phase Optimization) method, and the like, which may be appropriately adopted. According to this adaptive BF process, the channel signal can be weighted and added by constraining the direction so as to have sensitivity only to the desired wave from the direction of the scanning line and not to the unnecessary wave. And high resolution can be achieved.

FIG. 4 is a diagram showing a processing block P _mv for performing adaptive BF processing of channel signals x _{1 to} x ₁₂ from the same 12 channels as in FIG. Further, FIG. 5 is a diagram showing an example of reception sensitivity characteristics according to the adaptive BF processing P _mv of FIG. 4, and shows a graph of reception sensitivity in each direction under the same conditions as in FIG. As shown in FIG. 5, in the reception sensitivity characteristic of the adaptive BF processing P _mv , the width of the main lobe ML2 is narrow unlike the BF processing P _ds . On the other hand, the side lobes are barely visible and are kept small.

However, the adaptive BF process is a complicated process for calculating the addition weight to be multiplied by the channel signal each time as described above, so that there is a problem that the amount of calculation increases. The amount of calculation related to the execution of the adaptive BF process is determined by the number of channels M (the number of channel signals to be processed by the adaptive BF process) and the order of the calculation formula for calculating the addition weight, and is expressed in O notation as O. (M ^ 3) (M = 12 in FIG. 4).

Therefore, in the present embodiment, multi-stage signal processing of BF processing and adaptive BF processing is performed to reduce the amount of calculation while suppressing deterioration of the image quality of the ultrasonic image. FIG. 6 is a diagram showing a processing block example of multi-stage signal processing. As shown in FIG. 6, in the multi-stage signal processing, the BF processing P _ds is performed before the adaptive BF processing P _mv . Specifically, for each channel signal received by each ultrasonic element and converted from an analog signal to a digital signal (256 channels in FIG. 6), a predetermined number of ultrasonic elements (channels) are arranged in order. BF processing P _ds is applied (for example, 8 lines) at a time. As a result, a predetermined number of channel signals of each channel can be bundled.

Here, a channel signal of each channel after reception focusing processing and x _m, a channel signal adaptive BF process is processed to y _n. Then, in the case of performing BF processing by q with q as the application unit of BF processing (the number of signals processed by BF processing; hereinafter referred to as "the number of unit BF processing") (that is, the number of channel signals y _{n is} the number of channels). (When 1 / q of M), y _n is represented by the following equation (1). In the example of FIG. 6, the channel signal _x 1 _{~x 256} may be a channel signal _y 1 _{~y 32} of 32 channels of a 1/8 channel number M = 256 by BF process _{P ds,} adaptive BF process P _It is passed to _mv .

[principle]
The problem with multi-stage signal processing is that the effect of adaptive BF processing is diminished by performing BF processing and bundling channels. FIG. 7 is a diagram showing a processing block example of the multi-stage signal processing P11 when the number of channels is the same as that in FIG. 2 and the number of channels is 12 and the unit BF processing number q = 4. In the multi-stage signal processing of this configuration, each channel signal x _{1 to} x _{12 from 12} channels is bundled by 4 in the BF processing P _ds of the previous stage, and is adapted as ₃ channel signals y _{a1 to} y _a3. It is passed to the type BF process P _mv .

FIG. 8 is a diagram showing an example of reception sensitivity characteristics related to the multi-stage signal processing of FIG. 7, and shows a graph of reception sensitivity in each direction under the same conditions as in FIG. FIG. 9 is an enlarged view showing side lobes by narrowing the range of the vertical axis of FIG. In the reception sensitivity characteristic of the multi-stage signal processing of FIG. 7, side lobes appear at around ± 30 degrees and around ± 80 degrees as shown in FIGS. 8 and 9, and have sensitivity. Therefore, in the multi-stage signal processing, if unnecessary waves from each direction of around ± 30 degrees and around ± 80 degrees are received, the resolution is lowered and the image quality of the ultrasonic image is affected.

Further, FIG. 10 is a diagram showing an example of a processing block of the multi-stage signal processing P13 when the unit BF processing number q = 3. FIG. 11 is a diagram showing an example of reception sensitivity characteristics related to the multi-stage signal processing of FIG. 10, and FIG. 12 is an enlarged view in which the vertical axis of FIG. 11 is narrowed. In the multi-stage signal processing of this configuration, each channel signal x _{1 to} x _{12 from 12} channels is bundled by 3 in the BF processing P _ds of the previous stage, and is adapted as ₄ channel signals y _{b1 to} y _b4. It is passed to the type BF process P _mv . In the reception sensitivity characteristic of this multi-stage signal processing, as shown in FIGS. 11 and 12, side lobes appear at around ± 40 degrees and have sensitivity. Therefore, unnecessary waves from each direction near ± 40 degrees affect the image quality of the ultrasonic image.

By the way, the reception sensitivity characteristics of the multi-stage signal processing (FIGS. 7 to 9) when the unit BF processing number q = 4 and the multi-stage signal processing (FIGS. 10 to 12) when the unit BF processing number q = 3 According to this, in each case, a narrow main lobe appears at 0 degrees. On the other hand, the angle (direction) at which the side lobe appears, that is, the angle (direction) at which the side lobe appears and has sensitivity to unnecessary waves is different between the two. Therefore, by averaging the results of each multi-stage signal processing, the reception sensitivity characteristic can be modified so that the level of each side lobe becomes small.

From the above, in the present embodiment, a plurality of multi-stage signal processes having different settings of the unit BF processing number q as setting conditions are performed in parallel, and the average signal of each multi-stage signal processing result is calculated. FIG. 13 is a diagram showing an example of a processing block when the multi-stage signal processing P11 of FIG. 7 and the multi-stage signal processing P13 of FIG. 10 are executed in parallel. 13, averaging processing P2 in a subsequent stage of the multi-stage signal processing P11, P13 is the output signal _{f a} of the adaptive BF process _{P mv} in one of the multi-stage signal processing, adaptive BF process _{P mv} of the other multi-stage signal processing The average signal f with the output signal f _{b of} is calculated and output. The formula for calculating the average signal f is represented by the following formula (2).

Here, the specific value of the unit BF processing number q is not limited to the combination of “3” and “4” illustrated, but having sensitivity to unnecessary waves at the same angle has the effect of reducing the side lobe. Cannot be obtained. In the present embodiment, it is set as the number of signals that do not include the prime factors common to each other. As a result, the side lobes can be made to appear at different angles in the reception sensitivity characteristics related to each multi-stage signal processing.

FIG. 14 is a diagram showing reception sensitivity characteristics related to parallel execution of the two multi-stage signal processes P11 and P13 shown in FIG. 13, and FIG. 15 is an enlarged view in which the range of the vertical axis of FIG. 14 is narrowed. As shown in FIGS. 14 and 15, according to this configuration, side lobe levels near each angle of ± 30 degrees, ± 40 degrees, and ± 80 degrees are performed independently for each multi-stage signal processing P11 and P13. It can be kept smaller than the case where (see FIGS. 9 and 12 and the like). Therefore, it is possible to suppress the deterioration of the image quality of the ultrasonic image that may occur by executing the BF process.

Further, the amount of calculation related to the execution of the adaptive BF processing when the multi-stage signal processing is executed in parallel is O (M / 3 ^ 3 + M / 4 ^ 3). For example, when the calculation amount in the case of FIG. 13 where M = 13 is compared with the calculation amount O (M ^ 3) in the case of FIG. 4, the calculation amount can be reduced to about 1/19.

The multi-stage signal processing to be executed in parallel is not limited to two, and may be configured to execute three or more multi-stage signal processes in parallel. Even in that case, it is preferable that the number of unit BF processing related to each multi-stage signal processing is the number of signals that do not include the prime factors common to each other.

Further, the averaging process P2 is not limited to the process of calculating the output signals f _a and f _b by simple averaging according to the equation (2). For example, using the following equation (3) may be a process of calculating the average signal f with respect to the output signal f _a and the output signal f _b weighted average of.

Here, the ultrasonic beam transmitted from the ultrasonic probe 16 is mainly a radiation beam (called a main lobe) having a high sound pressure emitted along the direction of the scanning line (direction of 0 degrees). Therefore, the signal strength of the received signal is generally stronger as it is closer to 0 degrees and weaker as it is farther from 0 degrees. Therefore, it can be said that the multi-stage signal processing having a sensitivity at an angle close to 0 degrees in the reception sensitivity characteristic is more susceptible to the influence of unnecessary waves. Therefore, when calculating the weighted average, it is preferable to reduce the weight to be multiplied by the multi-stage signal processing result of the reception sensitivity characteristic in which the side lobe appears at an angle close to 0 degrees. In this example, the multi-stage signal processing P11 has sensitivity near ± 30 degrees and ± 80 degrees, and the multi-stage signal processing P13 has sensitivity near ± 40 degrees. Therefore, the weight α with respect to the output signal f _b . than _b, it is preferable to reduce the weight alpha _a of the output signal _{f a (α a <α b} ).

[Functional configuration]
FIG. 16 is a block diagram showing a functional configuration example of the ultrasonic measuring device 10. The ultrasonic measuring device 10 includes an image processing device 30 and an ultrasonic probe 16, and the image processing device 30 includes an operation input unit 310, a display unit 330, a communication unit 350, an arithmetic processing unit 370, and storage. A unit 500 is provided.

The ultrasonic probe 16 includes a plurality of ultrasonic elements (channels) arranged in an array, and ultrasonic waves are based on the pulse voltage from the image processing device 30 (more specifically, the ultrasonic measurement control unit 371 of the arithmetic processing unit 370). To send. Then, the reflected wave of the transmitted ultrasonic wave is received, and the channel signal from each channel is output to the ultrasonic measurement control unit 371.

The operation input unit 310 receives various operation inputs by the user and outputs an operation input signal corresponding to the operation input to the arithmetic processing unit 370. This can be achieved with button switches, lever switches, dial switches, trackpads, mice, etc. In FIG. 1, the touch panel 12 and the keyboard 14 correspond to this.

The display unit 330 is realized by a display device such as an LCD (Liquid Crystal Display), and performs various displays based on the display signal from the arithmetic processing unit 370. In FIG. 1, the touch panel 12 corresponds to this.

The communication unit 350 is a communication device for transmitting and receiving data to and from the outside under the control of the arithmetic processing unit 370. As the communication method of the communication unit 350, a form of wired connection via a cable conforming to a predetermined communication standard, a form of connecting via an intermediate device also used as a charger called a cradle, and wireless communication are used. Various methods such as a wireless connection format can be applied. In FIG. 1, the communication IC 34 corresponds to this.

The arithmetic processing unit 370 is realized by, for example, a microprocessor such as a CPU or GPU (Graphics Processing Unit), or an electronic component such as an ASIC, FPGA, or IC memory. Then, the arithmetic processing unit 370 performs input / output control of data with each functional unit, and determines a predetermined program and data, an operation input signal from the operation input unit 310, and a channel signal of each channel from the ultrasonic probe 16. The biological information of the subject 2 is calculated by executing various arithmetic processes based on the above. In FIG. 1, the CPU 32 corresponds to this. It should be noted that each unit constituting the arithmetic processing unit 370 may be configured by hardware such as a dedicated module circuit.

The arithmetic processing unit 370 includes an ultrasonic measurement control unit 371 and an image generation unit 400.

The ultrasonic measurement control unit 371 constitutes an ultrasonic measurement unit 20 together with the ultrasonic probe 16, and the ultrasonic measurement unit 20 performs ultrasonic measurement. The ultrasonic measurement control unit 371 can be realized by using a known technique. That is, the ultrasonic measurement control unit 371 controls the transmission timing of the ultrasonic pulse by the ultrasonic probe 16, generates a pulse voltage at the transmission timing, and outputs the pulse voltage to the ultrasonic probe 16. At that time, transmission delay processing is performed to adjust the output timing of the pulse voltage to each channel. Further, the channel signal of each channel from the ultrasonic probe 16 is amplified and filtered, and the processed channel signal (measurement result) of each channel is output to the image generation unit 400.

The image generation unit 400 generates an ultrasonic image based on the channel signal of each channel from the ultrasonic measurement control unit 371. The image generation unit 400 includes a reception focus processing unit 410 and a beamforming processing unit 420.

The reception focus processing unit 410 performs reception focus processing for delaying the channel signal of each channel by adding a predetermined delay time for the corresponding channel. The channel signal of each channel after the reception focus processing is output to each BF processing unit 431 included in the plurality of multi-stage signal processing units 430 in the beamforming processing unit 420.

The beam forming processing unit 420 includes a plurality of multi-stage signal processing units 430 (first multi-stage signal processing unit 430-1, second multi-stage signal processing unit 430-2, ...) And an averaging processing unit 440. Multi-stage signal processing by each multi-stage signal processing unit 430 is performed in parallel for each sampling point, and the average signal of each multi-stage signal processing result is calculated. Each of the plurality of multi-stage signal processing units 430 includes a BF processing unit 431 and an adaptive BF processing unit 433.

The storage unit 500 is realized by a storage medium such as an IC memory, a hard disk, or an optical disk. The storage unit 500 stores in advance a program for operating the ultrasonic measuring device 10 and realizing various functions included in the ultrasonic measuring device 10, data used during execution of the program, and the like. Or, it is temporarily stored each time it is processed. In FIG. 1, the storage medium 33 mounted on the control board 31 corresponds to this. The connection between the arithmetic processing unit 370 and the storage unit 500 is not limited to the connection by the internal bus circuit in the device, but may be realized by a communication line such as a LAN (Local Area Network) or the Internet. In that case, the storage unit 500 may be realized by an external storage device different from the ultrasonic measuring device 10.

Further, the storage unit 500 stores the ultrasonic measurement program 510, the received signal data 520, the reflected wave data 530, and the setting condition table 540.

The arithmetic processing unit 370 realizes functions such as the ultrasonic measurement control unit 371 and the image generation unit 400 by reading and executing the ultrasonic measurement program 510. When these functional parts are realized by hardware such as an electronic circuit, a part of the program for realizing the functions can be omitted.

The received signal data 520 stores the received signal (channel signal) of each ultrasonic element (channel) related to the scanning of each scanning line obtained as a result of the ultrasonic measurement.

The reflected wave data 530 stores the reflected wave data obtained by the ultrasonic measurement repeated for each frame. The reflected wave data 530 includes data of a B-mode image for each frame, which is an ultrasonic image.

The setting condition table 540 is a data table in which the unit BF processing number q is set. FIG. 17 is a diagram showing a data configuration example of the setting condition table 540. As shown in FIG. 17, in the setting condition table 540, a plurality of multi-stage signal processing units 430 (first multi-stage signal processing unit 430-1, second multi-stage signal processing unit 430-2,) constituting the beamforming processing unit 420 For each of (...), the unit BF processing number q of the BF processing executed by the BF processing unit 431 is set. In the present embodiment, the number of signals that does not include the prime factors common to each other is set in each unit BF processing number q.

[Processing flow]
FIG. 18 is a flowchart showing the flow of the ultrasonic image generation processing in the present embodiment. The process described here is started, for example, when the ultrasonic probe 16 is applied to the body surface of the subject 2 by the user and a predetermined measurement start operation is performed. This process can be realized by the arithmetic processing unit 370 reading the ultrasonic measurement program 510 from the storage unit 500 and executing the process to operate each part of the ultrasonic measurement device 10.

Prior to the ultrasonic measurement, the arithmetic processing unit 370 reads out from the setting condition table 540 and sets the unit BF processing number q of the BF processing executed by each BF processing unit 431 in the plurality of multi-stage signal processing units 430 (step). S1). After that, the processing after step S3 is repeated in frame units.

First, the ultrasonic measurement unit 20 performs ultrasonic measurement (step S3). By the processing here, the measurement result is stored in the received signal data 520.

After that, the beamforming processing unit 420 repeats the processing of the loop A for each scanning line while referring to the received signal data 520 (steps S5 to S17). Then, in loop A, sampling is performed for a certain period of time on the processing target line using the measurement result of the ultrasonic measurement in step S3, and loop B processing is performed for each sampling point (steps S7 to S15).

In loop B, first, the reception focus processing unit 410 performs reception focus processing for delaying the delay time on the channel signals from each channel (step S9). Subsequently, each of the plurality of multi-stage signal processing units 430 performs multi-stage signal processing in parallel (step S11). By the processing here, first, the BF processing unit 431 of each multi-stage signal processing unit 430 executes the BF processing with the different unit BF processing number q set in step S1, and the channel of each channel after the reception focus processing. Bundle q signals x _m at a time. Then, the adaptive BF processing unit 433 of each multi-stage signal processing unit 430 executes the adaptive BF processing with the channel signal y _n after the BF processing from the corresponding BF processing unit 431 as the processing target.

Subsequently, the averaging processing unit 440 averages the results of each multi-stage signal processing executed in parallel in step S11 and calculates the averaging signal f (step S13).

When the processing of the loop B is repeated and the sampling of the processing target line is completed, the processing of the loop A for the processing target line is completed. Then, when the loop A processing is performed with all the scanning lines as the processing targets, the average signal f obtained at each sampling point is subjected to the necessary processing to generate an ultrasonic image (step S19). The generated ultrasonic image is appropriately displayed and controlled on the display unit 330.

As described above, according to the present embodiment, in the multi-stage signal processing of the BF processing and the adaptive BF processing, a plurality of multi-stage signal processing having a different unit BF processing number q is executed in parallel as a setting condition of the BF processing. can do. Then, the ultrasonic image can be generated by averaging the results of each multi-stage signal processing. Therefore, it is possible to suppress the deterioration of the image quality of the ultrasonic image while reducing the amount of calculation related to the execution of the adaptive BF process.

The unit BF processing number q of the BF processing performed by each BF processing unit 431 in the plurality of multi-stage signal processing units 430 may be set as different signal numbers that are not multiples of each other. For example, in a configuration in which a large number of multi-stage signal processing units 430 are provided (for example, four, five, or more), the number of unit BF processing related to each multi-stage signal processing unit 430 is set as the number of signals that do not include a common prime factor. It may be difficult to configure. Since the output signals of each multi-stage signal processing unit 430 are finally average-processed, the same effect as that of the present embodiment can be obtained if the unit BF processing number can be configured as different signal numbers that are not multiples of each other. Because.

Further, in the image generation unit 400, the reception focus processing unit 410 receives and focuses the channel signal from each channel, and the BF processing unit 431 performs the BF processing of this by using hardware (arithmetic circuit) such as FPGA. It can be easily realized. On the other hand, the adaptive BF process performed by the adaptive BF processing unit 433 is a complicated process for calculating the addition weight, and therefore should be realized by software. Even in that case, since the number of signals to be processed by the adaptive BF processing can be set to 1 / q of the number of channels M as described above, the amount of data passed from the BF processing to the adaptive BF processing can also be reduced. , The amount of data transfer can be reduced.

10 ... Ultrasonic measuring device, 16 ... Ultrasonic probe, 20 ... Ultrasonic measuring unit, 30 ... Image processing device, 310 ... Operation input unit, 330 ... Display unit, 350 ... Communication unit, 370 ... Arithmetic processing unit, 371 ... Ultrasound measurement control unit, 400 ... image generation unit, 410 ... reception focus processing unit, 420 ... beamforming processing unit, 430 ... multi-stage signal processing unit, 431 ... BF processing unit, 433 ... adaptive BF processing unit, 440 ... average Chemical processing unit, 500 ... Storage unit, 510 ... Ultrasonic measurement program, 520 ... Received signal data, 530 ... Reflected wave data, 540 ... Setting condition table, 2 ... Subject

Claims (8)

An ultrasonic probe in which multiple ultrasonic elements that transmit and receive ultrasonic waves are arranged, and
It is a multi-stage signal processing of beamforming processing and adaptive beamforming processing for a received signal received for each ultrasonic element, and a plurality of the multi-stage signal processing having different setting conditions of the beamforming processing is performed, and each multi-stage signal is performed. An arithmetic processing unit that generates an ultrasonic image based on the average signal of the processing result,
Ultrasonic measuring device equipped with. The arithmetic processing unit performs the plurality of multi-stage signal processing in parallel.
The ultrasonic measuring device according to claim 1. The arithmetic processing unit performs the plurality of multi-stage signal processing under the setting conditions in which the number of signals of the received signals to be processed by the beamforming processing is different from each other and is not a multiple of each other.
The ultrasonic measuring device according to claim 1 or 2. The number of signals under the setting conditions related to the plurality of multi-stage signal processing is a number that does not include a prime factor common to each other.
The ultrasonic measuring device according to claim 3. The arithmetic processing unit calculates the average signal by weighted averaging the results of the plurality of multi-stage signal processing.
The ultrasonic measuring device according to any one of claims 1 to 4. The adaptive beamforming process is a process of calculating a weight based on a received signal for each ultrasonic element and weighting and adding the received signal using the weight.
The ultrasonic measuring device according to any one of claims 1 to 5. The arithmetic processing unit includes an arithmetic circuit for executing the beamforming processing for each multi-stage signal processing.
The ultrasonic measuring device according to any one of claims 1 to 6. It is a control method of an ultrasonic measuring device that performs ultrasonic measurement using an ultrasonic probe in which a plurality of ultrasonic elements for transmitting and receiving ultrasonic waves are arranged.
It is a multi-stage signal processing of beamforming processing and adaptive beamforming processing for a received signal received for each ultrasonic element, and a plurality of the multi-stage signal processing having different setting conditions of the beamforming processing is performed.
To generate an ultrasonic image based on the average signal as a result of the plurality of multi-stage signal processing,
Control method including.

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