JP6182241B1 - Ultrasonic diagnostic equipment - Google Patents

Abstract

An improved technique for obtaining a beam signal of an ultrasonic beam is provided. A phasing processor 32 obtains a phasing signal for each oscillating element of a plurality of oscillating elements by phasing processing corresponding to a basic beam line. The correction processing unit 34 obtains a correction signal corresponding to the correction beam line from the phasing signal corresponding to the basic beam line for each vibration element of the plurality of vibration elements by the correction process based on the plane wave model. The addition processing unit 36 obtains a beam signal of a correction beam line based on correction signals corresponding to a plurality of vibration elements. [Selection] Figure 1

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to a technique for obtaining a beam signal of an ultrasonic beam.

  An ultrasonic diagnostic apparatus is an apparatus that forms and displays an ultrasonic image based on reception data obtained by transmitting and receiving ultrasonic waves. For example, an ultrasonic image is formed based on reception data obtained from a cross section including a diagnosis target by scanning an ultrasonic beam. As an ultrasound image, for example, a B-mode image is well known.

  There are various modes of transmission / reception processing using an ultrasonic beam. For example, in addition to basic transmission / reception processing for obtaining one reception beam from one transmission beam, transmission / reception processing called multidirectional simultaneous reception for obtaining a plurality of reception beams from one transmission beam is also known. For example, Patent Document 1 describes an invention for obtaining a plurality of ultrasonic reception beams substantially simultaneously. According to the invention of Patent Document 1, it is possible to form a plurality of reception beams that are shifted from the center beam direction (transmission beam direction) by a displacement angle (Δθ / 2) substantially simultaneously.

Japanese Patent No. 2933361

  By the way, when obtaining a beam signal of an ultrasonic beam, the amount of data and the amount of computation required for computation may become enormous. For example, in the invention of Patent Document 1, a phase rotation amount Δφ corresponding to the depth (distance R) is used (see Patent Document 1, page 4, right column (1) (1a) (1b). ). Therefore, in the invention of Patent Document 1, in order to obtain a beam signal corresponding to a plurality of depths for each reception beam, for example, a plurality of phase rotation amounts Δφ corresponding to a plurality of depths for each reception beam. Must be prepared in advance, or a plurality of phase rotation amounts Δφ corresponding to a plurality of depths must be calculated for each depth, and at least one of the data amount and the calculation amount becomes enormous. End up.

  Under such circumstances, the appearance of improved technology for obtaining a beam signal of an ultrasonic beam has been desired.

  An object of the present invention is to provide an improved technique for obtaining a beam signal of an ultrasonic beam.

  An ultrasonic diagnostic apparatus suitable for the above object obtains a phasing signal for each vibration element of the plurality of vibration elements by a plurality of vibration elements that transmit and receive ultrasonic waves and a phasing process corresponding to the basic beam line. A phasing processing unit and a correction processing unit that obtains a correction signal corresponding to the correction beam line from the phasing signal corresponding to the basic beam line for each vibration element of the plurality of vibration elements by correction processing based on a plane wave model. And obtaining a beam signal of the correction beam line based on correction signals corresponding to the plurality of vibration elements.

  In the above configuration, the basic beam line is a reference line (main line or parent line) for forming an ultrasonic reception beam, and follows the transmission beam in, for example, a two-dimensional plane or a three-dimensional space. Scanned. Although the basic beam line is preferably in the same direction as the transmission beam, it does not necessarily have to coincide with the transmission beam, for example. The phasing processing unit obtains a phasing signal for each oscillating element of the plurality of oscillating elements by phasing processing corresponding to the basic beam line. The phasing processing unit executes the phasing processing of the phasing addition processing in, for example, ultrasonic beam forming. Note that, based on the phasing signals corresponding to the plurality of vibration elements, for example, the phasing signals corresponding to the plurality of vibration elements may be added to form the beam signal corresponding to the basic beam line.

  In the above configuration, the correction beam line is a line (secondary line or child line) obtained based on the basic beam line, for example, in the vicinity of the basic beam line scanned in a two-dimensional plane or a three-dimensional space. It is formed. For example, one or more correction beam lines are formed for each scanning position (each scanning direction) of the basic beam line. Realizing multi-directional simultaneous reception (including general parallel reception, synthetic aperture, spatial compound, etc.), for example, by forming a plurality of correction beam lines for each scanning position (each scanning direction) of the basic beam line Can do.

  In the above configuration, the correction processing unit obtains a correction signal corresponding to the correction beam line from the phasing signal corresponding to the basic beam line for each vibration element of the plurality of vibration elements by the correction process based on the plane wave model. . As the plane wave model (plane wave approximation), for example, a model using two plane waves of a plane wave corresponding to the basic beam line and a plane wave corresponding to the correction beam line is preferable. That is, for each beam line of the basic beam line and the correction beam line, a model using plane waves assuming that the ultrasonic convergence point (focus point) is at an infinite depth (infinite depth) is preferable. Although a flat plane wave is suitable, for example, a plane wave having a curvature (desirably small) according to the shape of the transducer surface composed of a plurality of vibration elements may be used. .

  According to the above configuration, by using the plane wave model, it is possible to realize a relatively simple correction process assuming that the convergence point of the ultrasonic wave is at an infinite depth. For example, correction processing independent of depth is realized. Thereby, for example, the load of the correction process is reduced as compared with a case where a different correction process is executed for each depth over a plurality of depths. For example, at least one of the data amount and the calculation amount required for the correction process is reduced. On the other hand, in the phasing process corresponding to the basic beam line, for example, it is desirable to perform the phasing process corresponding to each depth over a plurality of depths. That is, it is desirable to combine high-precision phasing processing for the basic beam line and low-load correction processing for the correction beam line. As a result, it is possible to obtain the beam signal of the corrected beam line with a relatively high accuracy while performing a process with a relatively low load.

  In a desirable specific example, the correction processing unit performs correction processing based on the plane wave model using two plane waves of a plane wave corresponding to the basic beam line and a plane wave corresponding to the correction beam line, for each vibration element. The correction signal is obtained from the phasing signal.

  In a desirable specific example, the correction processing unit corrects the phasing signal with a correction amount corresponding to a distance between the two plane waves at a position corresponding to each vibration element for each vibration element. A correction signal is obtained.

  In a preferred embodiment, the phasing processing unit outputs the phasing signal corresponding to a plurality of depths for each vibration element by the phasing process based on a delay pattern corresponding to the depth of the basic beam line. The correction processing unit corrects the phasing signal corresponding to a plurality of depths with a correction amount that does not depend on the depth based on the plane wave model, for each of the vibration elements, thereby adjusting the phasing signals to a plurality of depths. A corresponding correction signal is obtained.

  The present invention provides an improved technique for obtaining a beam signal of an ultrasonic beam. For example, according to a preferred aspect of the present invention, a combination of high-accuracy phasing processing for the basic beam line and low-load correction processing for the correction beam line enables relatively low-load processing. It is possible to obtain the beam signal of the correction beam line with relatively high accuracy.

It is a figure which shows the specific example of a suitable ultrasonic diagnostic apparatus in implementation of this invention. It is a figure which shows the specific example of multidirectional simultaneous reception. It is a figure which shows the specific example of a plane wave model. It is a figure which shows the suitable example 1 of a receiving beam forming part. It is a figure which shows the suitable structural example 2 of a receiving beam forming part. It is a figure which shows the specific example of the B mode image formed by 4-way parallel reception.

  FIG. 1 is a diagram showing a specific example of an ultrasonic diagnostic apparatus suitable for implementing the present invention. The array transducer 10 includes a plurality of vibration elements that transmit and receive ultrasonic waves. In the specific example shown in FIG. 1, for example, a sector scanning type is suitable as the array transducer 10. However, the array transducer 10 having a scanning mode different from the sector scanning type may be used, or the array transducer 10 capable of three-dimensionally scanning the ultrasonic beam may be used.

  The transmission beam forming unit 20 has a function as a transmission beam former, and forms and scans a transmission beam by controlling transmission of a plurality of vibration elements included in the array transducer 10. The reception beam forming unit 30 has a function as a reception beam former, and forms a reception beam by processing signals obtained from a plurality of vibration elements. The ultrasonic diagnostic apparatus of FIG. 1 has a function of executing multidirectional simultaneous reception.

  FIG. 2 is a diagram illustrating a specific example of multidirectional simultaneous reception. With reference to FIG. 2, description will be given of four-way parallel reception, which is a preferred specific example of multi-directional simultaneous reception.

  FIG. 2 shows a fan-shaped scanning surface obtained by sector scanning. The transmission beam TB is scanned like a fan in a two-dimensional plane. For example, the transmission beam TB is formed for each angle (each azimuth) while changing the angle (azimuth) stepwise with the main position of the fan on the scanning surface as the scanning origin.

  In the four-way parallel reception, every time one transmission beam TB is formed for each direction, four reception beams RB are formed. For example, as in the specific example shown in FIG. 2, a total of four reception beams RB are formed, two on the right side and two on the left side of the transmission beam TB. Then, one transmission beam TB and four reception beams RB are formed for each angle (each direction) while changing the angle (direction) in stages, so that a large number of reception beams RB constituting the scanning plane are formed. Is formed.

  The ultrasonic diagnostic apparatus in FIG. 1 performs two-way parallel reception in which two reception beams RB are formed every time one transmission beam TB is formed for each direction, and one transmission for each direction. Multidirectional parallel reception may be performed in which more than four receive beams RB are formed each time the beam TB is formed.

  Returning to FIG. 1, the reception beam forming unit 30 includes a phasing processing unit 32, a correction processing unit 34, and an addition processing unit 36, and outputs a beam signal obtained by multidirectional simultaneous reception. The beam signal processing unit 40 performs various processes on the beam signal, and the image forming unit 50 forms an ultrasonic image.

  For example, when a B-mode image is formed in the image forming unit 50, the beam signal processing unit 40 performs detection processing, logarithmic compression processing, or the like on the beam signal. When forming a Doppler image in the image forming unit 50, the beam signal processing unit 40 performs Doppler processing such as orthogonal detection processing or autocorrelation processing on the beam signal. An ultrasonic image (B-mode image, Doppler image, etc.) formed in the image forming unit 50 is displayed on the display unit 60.

  The control unit 100 generally controls the inside of the ultrasonic diagnostic apparatus in FIG. The overall control by the control unit 100 also reflects an instruction received from a user such as a doctor or a laboratory technician via the operation device 70.

  In the configuration shown in FIG. 1 (each part given a reference numeral), the transmission beam forming unit 20, the reception beam forming unit 30, the beam signal processing unit 40, and the image forming unit 50 are, for example, hardware such as an electric / electronic circuit or a processor. It can be realized using hardware, and a device such as a memory may be used as necessary in the realization. In addition, at least some of the functions corresponding to the above-described units may be realized by a computer. That is, at least a part of the functions corresponding to the above-described units may be realized by cooperation between hardware such as a CPU, a processor, and a memory and software (program) that defines the operation of the CPU and the processor.

  A preferred specific example of the display unit 60 is a liquid crystal monitor or the like. The operation device 70 can be realized by at least one of a mouse, a keyboard, a trackball, a touch panel, and other switches, for example. And the control part 100 is realizable by cooperation with hardwares, such as CPU, a processor, a memory, and the software (program) which prescribes | regulates operation | movement of CPU, a processor, for example.

  The overall configuration of the ultrasonic diagnostic apparatus in FIG. 1 is as described above. Next, functions and the like related to the formation of a reception beam realized by the ultrasonic diagnostic apparatus of FIG. 1 will be described in detail. In addition, about the structure (part) shown in FIG. 1, the code | symbol of FIG. 1 is utilized in the following description. In forming a reception beam, the ultrasonic diagnostic apparatus of FIG. 1 uses a plane wave model.

  FIG. 3 is a diagram illustrating a specific example of a plane wave model. In FIG. 3, the array transducer 10 is configured by M (M is an integer of 2 or more) vibrating elements arranged in a straight line. The array transducer 10 is preferably composed of a large number of vibration elements, for example, several tens to several hundreds. In FIG. 3, the number of vibrating elements (number of aperture elements) is simplified to four (M = 4).

  The basic beam line is a reference line for forming an ultrasonic reception beam. In the specific example of FIG. 3, the basic beam line is inclined at an angle SxA with respect to the array transducer 10 with the center position of the array transducer 10 as the origin. The correction beam line is a line near the basic beam line. In the specific example of FIG. 3, the correction beam line is inclined by an angle RxA with respect to the array transducer 10 with the center position of the array transducer 10 as the origin. The angle difference between the basic beam line and the correction beam line is dA (RxA−SxA).

  Further, FIG. 3 shows a plane wave corresponding to the basic beam line and a plane wave corresponding to the correction beam line. That is, the plane wave orthogonal to the basic beam line and the plane wave orthogonal to the correction beam line at the center position (origin point) of the array transducer 10 are respectively shown by dashed straight lines.

  In forming an ultrasonic reception beam, first, a phasing signal is generated for each oscillating element of the plurality of oscillating elements by phasing processing corresponding to the reference beam line. For example, a phasing signal α (m, r) corresponding to a plurality of depths r is generated for each vibration element by a phasing process based on a delay pattern corresponding to a plurality of depths r on the basic beam line. . Note that the element number m of each vibration element is m = n− (M−1) / 2. Here, n is an integer associated with each vibration element, and n = 0 to (M−1).

  Next, a correction signal corresponding to the correction beam line is generated from the phasing signal corresponding to the basic beam line for each vibration element of the plurality of vibration elements by the correction process based on the plane wave model. For example, the phasing signal α (m, r) is corrected with a correction amount corresponding to the distance dZ (m) between two plane waves at the position corresponding to the vibration element (element number m) for each vibration element. A preferred specific example of the correction amount according to the distance dZ (m) is the phase correction amount ω (m) calculated by the equation (1). In Equation 1, an element interval pitch of a plurality of vibration elements, an ultrasonic sound velocity V, and an ultrasonic center frequency fc are used.

  Based on the correction signals corresponding to the plurality of vibration elements, a beam signal of the correction beam line is formed. For example, by adding a correction signal (corrected phasing signal α (m, r)) corresponding to a plurality of vibration elements (element number m), the beam of the correction beam line can be expressed by Equation (2) or Equation (3). Signal B (RxA, r) is formed. Formula 2 is a calculation formula when the phasing signal α (m, r) is a real number, and Formula 3 is a calculation formula when the phasing signal α (m, r) is a complex number.

  The ultrasonic diagnostic apparatus of FIG. 1 forms a reception beam using the plane wave model described with reference to FIG. For example, when 4-way parallel reception is realized, a basic beam line is associated with the scanning direction of one transmission beam TB (FIG. 2) scanned in the scanning plane, and four reception beams RB are further associated. (FIG. 2) is associated with the correction beamline. That is, four correction beam lines having different angle differences dA (FIG. 3) from the basic beam line are formed and associated with the four reception beams RB. Then, the four beam signals corresponding to the four correction beam lines obtained using the plane wave model described with reference to FIG. 3 are used as the reception beam signals of the four reception beams RB.

  FIG. 4 is a diagram illustrating a preferred configuration example 1 of the reception beam forming unit 30. FIG. 4 illustrates a preferred specific example 1 of the phasing processing unit 32, the correction processing unit 34, and the addition processing unit 36 included in the reception beam forming unit 30.

  The phasing processor 32 obtains a phasing signal for each oscillating element of the plurality of oscillating elements by phasing processing corresponding to the basic beam line. For example, the direction of the transmission beam is a basic beam line, and after transmitting an ultrasonic wave corresponding to the transmission beam, the signal obtained from each vibration element (element number m) is subjected to analog-digital conversion (A / D conversion). Delay processing is performed. The delay processing is the same processing as that for forming a reception beam in the direction of the basic beam line. That is, a phasing signal α (m, r) corresponding to a plurality of depths r is obtained for each vibration element (element number m) by phasing processing based on a delay pattern corresponding to the depth of the basic beam line. Stored in the signal memory.

  Note that delay data (table) that defines a delay pattern for each vibration element of the plurality of vibration elements is stored in advance in a delay data memory. The delay data memory stores delay data (table) corresponding to a plurality of depths for each direction of the basic beam line.

  The correction processing unit 34 obtains a correction signal corresponding to the correction beam line from the phasing signal corresponding to the basic beam line for each vibration element of the plurality of vibration elements by the correction process based on the plane wave model. For each vibration element (element number m), the correction processing unit 34 corresponds to a plurality of depths r by a correction amount that does not depend on the depth based on the plane wave model, that is, the phase correction amount ω (m) of Formula 1. The phasing signal α (m, r) thus corrected is delayed.

  Note that the phase correction amount ω (m) corresponding to each vibration element (element number m) is preferably calculated in advance based on Equation 1 and stored in the correction amount memory. For example, although the phase correction amount ω (m) of Equation 1 is calculated for each vibration element (element number m), it does not depend on the depth, and therefore, a plurality of phase correction amounts ω (m) for each vibration element (element number m). The same phase correction amount ω (m) can be used in the depth. Of course, at the stage of the correction process, the correction processing unit 34 may calculate the phase correction amount ω (m) using Equation (1).

  The addition processing unit 36 obtains a beam signal of a correction beam line based on correction signals corresponding to a plurality of vibration elements. The addition processing unit 36 adds the correction signal (corrected phasing signal α (m, r)) corresponding to the plurality of vibration elements (element number m), thereby correcting the beam signal B (RxA, r).

  Configuration example 1 in FIG. 4 is a specific example when the phasing signal α (m, r) is a real number, and the beam signal B (RxA, r) is formed based on the equation (2). Further, in the configuration example 1 in FIG. 4, a post-processing unit 38 is provided at the subsequent stage of the addition processing unit 36.

  The post-processing unit 38 performs a known Hilbert transform on the beam signal B (RxA, r) obtained from the addition processing unit 36. FIG. 4 shows a specific example of Hilbert transform using FIR. For the Hilbert transform by FIR, for example, the coefficient shown in the following equation is used.

  The beam signal processing unit 40 performs a detection process on the beam signal B (RxA, r) of the corrected beam line that has been subjected to the Hilbert transform obtained from the post-processing unit 38, and performs echo intensity (for example, detection) on the corrected beam line. Line data (beam data) indicating the absolute value of the processed signal) is obtained.

  The processing from the phasing processing unit 32 to the beam signal processing unit 40 shown in FIG. 4 corresponds to the basic beam line in the scanning direction of the transmission beam TB every time the transmission beam TB (FIG. 2) is formed in the scanning plane. To be executed. Each time a transmission beam TB is formed in the scanning plane, four correction beam lines having different angle differences dA (FIG. 3) from the basic beam line are output for each correction beam line. (RxA, r) is formed.

  As a result, line data of a large number of correction beam lines corresponding to the large number of reception beams RB constituting the scanning plane can be obtained. The image forming unit 50 (FIG. 1) forms a B-mode image based on a large number of line data obtained from the scanning plane. When forming a Doppler image in the image forming unit 50, the beam signal processing unit 40 performs Doppler processing such as orthogonal detection processing or autocorrelation processing on the beam signal. In the post-processing unit 38, quadrature detection processing may be executed instead of Hilbert transform.

  FIG. 5 is a diagram illustrating a preferred configuration example 2 of the reception beam forming unit 30. FIG. 5 illustrates a preferred specific example 2 of the phasing processing unit 32, the correction processing unit 34, and the addition processing unit 36 included in the reception beam forming unit 30.

  The phasing processor 32 obtains a phasing signal for each oscillating element of the plurality of oscillating elements by phasing processing corresponding to the basic beam line. For example, the direction of the transmission beam is a basic beam line, and after transmitting an ultrasonic wave corresponding to the transmission beam, the signal obtained from each vibration element (element number m) is subjected to analog-digital conversion (A / D conversion). Delay processing is performed. The delay processing is the same processing as that for forming a reception beam in the direction of the basic beam line. That is, a phasing signal α (m, r) corresponding to a plurality of depths r is obtained for each vibration element (element number m) by phasing processing based on a delay pattern corresponding to the depth of the basic beam line. Stored in the signal memory.

  Note that delay data (table) that defines a delay pattern for each vibration element of the plurality of vibration elements is stored in advance in a delay data memory. The delay data memory stores delay data (table) corresponding to a plurality of depths for each direction of the basic beam line.

  In the configuration example 2 of FIG. 5, the phasing signal α (m, r) is subjected to quadrature detection processing. That is, the phasing signal α (m, r) obtained as a real number is converted into a complex format composed of the in-phase component I and the quadrature component Q by quadrature detection. Also, it is desirable to reduce the amount of data by executing sampling data thinning processing on the in-phase component I and the quadrature component Q after quadrature detection. In addition, after performing quadrature detection on the signal after analog-digital conversion obtained from each vibration element (element number m), delay processing is performed on each of the in-phase component I and quadrature component Q after quadrature detection. May be.

  The correction processing unit 34 obtains a correction signal corresponding to the correction beam line from the phasing signal corresponding to the basic beam line for each vibration element of the plurality of vibration elements by the correction process based on the plane wave model. For each vibration element (element number m), the correction processing unit 34 corresponds to a plurality of depths r by a correction amount that does not depend on the depth based on the plane wave model, that is, the phase correction amount ω (m) of Formula 1. The phasing signal α (m, r) thus corrected is delayed.

  Note that the phase correction amount ω (m) corresponding to each vibration element (element number m) is preferably calculated in advance based on Equation 1 and stored in the correction amount memory. For example, although the phase correction amount ω (m) of Equation 1 is calculated for each vibration element (element number m), it does not depend on the depth, and therefore, a plurality of phase correction amounts ω (m) for each vibration element (element number m). The same phase correction amount ω (m) can be used in the depth. Of course, at the stage of the correction process, the correction processing unit 34 may calculate the phase correction amount ω (m) using Equation (1).

  The addition processing unit 36 obtains a beam signal of a correction beam line based on correction signals corresponding to a plurality of vibration elements. The addition processing unit 36 adds the correction signal (corrected phasing signal α (m, r)) corresponding to the plurality of vibration elements (element number m), thereby correcting the beam signal B (RxA, r).

  In the configuration example 2 in FIG. 5, the phasing signal α (m, r) is separated into the in-phase component I and the quadrature component Q by the quadrature detection processing. That is, the phasing signal α (m, r) is a complex number. Therefore, the correction processing unit 34 performs delay correction on each of the in-phase component I and the quadrature component Q of the phasing signal α (m, r), and the addition processing unit 36 performs the in-phase component based on the equation (3). The addition for each of I and the orthogonal component Q is executed to form a beam signal B (RxA, r) consisting of a real part and an imaginary part. In addition, in the configuration example 2 in FIG. 5, since the quadrature detection process is performed, the Hilbert transform (the post-processing unit 38 in FIG. 4) can be omitted.

  The beam signal processing unit 40 performs filter processing (BPF processing) on the beam signal B (RxA, r) of the correction beam line obtained from the addition processing unit 36, and line data indicating echo intensity on the correction beam line (Beam data) is obtained.

  The processing from the phasing processing unit 32 to the beam signal processing unit 40 shown in FIG. 5 corresponds to the basic beam line in the scanning direction of the transmission beam TB every time the transmission beam TB (FIG. 2) is formed in the scanning plane. To be executed. Each time a transmission beam TB is formed in the scanning plane, four correction beam lines having different angle differences dA (FIG. 3) from the basic beam line are output for each correction beam line. (RxA, r) is formed.

  As a result, line data of a large number of correction beam lines corresponding to the large number of reception beams RB constituting the scanning plane can be obtained. The image forming unit 50 (FIG. 1) forms a B-mode image based on a large number of line data obtained from the scanning plane. When the Doppler image is formed in the image forming unit 50, the beam signal processing unit 40 uses the beam signal B (RxA, r) that has already been orthogonally detected and separated into the real part and the imaginary part. Doppler processing such as correlation processing is performed.

  FIG. 6 is a diagram illustrating a specific example of a B-mode image formed by four-way parallel reception. FIG. 6A is an image example of a B-mode image formed by four-way parallel reception using a plane wave model, that is, a B-mode image obtained by the ultrasonic diagnostic apparatus of FIG. FIG. 6B shows a B-mode image formed by executing a reception beam forming process corresponding to each direction of four directions, that is, a phasing addition process based on a delay pattern corresponding to the depth. Comparative Example 1). FIG. 6C is a B-mode image (Comparative Example 2) formed by executing phasing addition processing based on the same delay pattern for all four directions.

  In FIG. 6B, the reception beam forming process corresponding to each of the four directions is performed, so that the image closest to the ideal state is realized in the specific example shown in FIG. ing. However, since a delay pattern corresponding to the depth is used for each direction, the calculation load of the beam forming process is the largest among the specific examples shown in FIG. Further, in FIG. 6C, the phasing addition process based on the same delay pattern is executed for all four directions, so that the calculation load of the beam forming process is the highest in the specific example shown in FIG. small. However, substantially the same beam signal is obtained in all four directions, and the image state (image quality, etc.) is the worst among the specific examples shown in FIG.

  On the other hand, in FIG. 6A, since the plane wave model is used, compared to the case where the reception beam forming process corresponding to each direction is performed for each of the four directions, that is, FIG. 6B. Compared with the case of obtaining the image of Comparative Example 1, the calculation load of the beam forming process is small. Moreover, an image state comparable to that of the comparative example 1 in FIG. 6B can be realized.

  As described above, according to the ultrasonic diagnostic apparatus of FIG. 1 using the plane wave model, it is possible to realize an ultrasonic image close to an ideal state while suppressing the calculation load of the beam forming processing in multidirectional simultaneous reception.

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above is only a mere illustration in all the points, and does not limit the scope of the present invention. The present invention includes various modifications without departing from the essence thereof.

  10 array transducers, 20 transmit beam forming unit, 30 receive beam forming unit, 32 phasing processing unit, 34 correction processing unit, 36 addition processing unit, 40 beam signal processing unit, 50 image forming unit, 60 display unit, 70 operation Device, 100 control unit.

Claims (4)

A plurality of vibration elements for transmitting and receiving ultrasonic waves;
A phasing processor that obtains a phasing signal for each oscillating element of the plurality of oscillating elements by phasing processing corresponding to a basic beam line;
A correction processing unit that obtains a correction signal corresponding to a correction beam line from a phasing signal corresponding to the basic beam line for each vibration element of the plurality of vibration elements by a correction process based on a plane wave model;
Have
Obtaining a beam signal of the correction beam line based on correction signals corresponding to the plurality of vibration elements;
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1,
The correction processing unit performs correction processing based on the plane wave model using two plane waves, a plane wave corresponding to the basic beam line and a plane wave corresponding to the correction beam line, from the phasing signal for each vibration element. Obtaining the correction signal;
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 2,
The correction processing unit obtains the correction signal by correcting the phasing signal with a correction amount corresponding to a distance between the two plane waves at a position corresponding to each vibration element for each of the vibration elements.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3,
The phasing processing unit derives the phasing signal corresponding to a plurality of depths for each vibration element by the phasing processing based on the delay pattern according to the depth of the basic beam line,
The correction processing unit corresponds to a plurality of depths by correcting the phasing signal corresponding to a plurality of depths with a correction amount independent of the depth based on the plane wave model for each of the vibration elements. Obtaining the correction signal;
An ultrasonic diagnostic apparatus.