Ultrasonic diagnostic apparatus

Abstract

To improve the image quality of ultrasound images obtained by using transducer element groups of the RCA structure.SOLUTION: An ultrasound diagnosis apparatus includes an ultrasound probe, a generator and a display controller. The ultrasound probe includes a plurality of transducer elements arranged two-dimensionally and includes a plurality of transducer element groups of a Row-Column Addressing type in which, when ultrasound transmission is to be performed, a plurality of first transducer elements arranged in the direction of one of two axes intersecting each other are connected in common to one another and in which, when ultrasound reception is to be performed, a plurality of second transducer elements arranged in the direction of the other of the two axes are connected in common to one another. The generator performs a beam forming process on a plurality of reception signals output from the plurality of second transducer elements for each of the transducer element groups and generates ultrasound image data on the basis of a signal obtained from the beam forming. The two axes corresponding to the plurality of transducer element groups of the Row-Column Addressing type are mutually different.SELECTED DRAWING: Figure 9A

Description

Technical Field

[0001] The embodiments disclosed in this specification and the drawings relate to an ultrasonic diagnostic apparatus.

Background Art

[0002] There is an ultrasonic diagnostic apparatus that electronically three-dimensionally scans a living body. As a method for the ultrasonic diagnostic apparatus to electronically three-dimensionally scan a living body, the following methods can be considered. FIG. 1A is a diagram showing an example of the configuration of a conventional ultrasonic diagnostic apparatus 200. As shown in FIG. 1A, the conventional ultrasonic diagnostic apparatus 200 includes an ultrasonic probe 201 and an apparatus main body 202.

[0003] The ultrasonic probe 201 includes a plurality of vibrators 203 arranged two-dimensionally and an electronic circuit 204. The plurality of vibrators 203 arranged two-dimensionally are also referred to as two-dimensional array vibrators. FIG. 1B is a diagram showing an example of the configuration of a conventional ultrasonic probe 201. As shown in FIG. 1B, in a two-dimensional coordinate system constituted by the x-axis and the y-axis, a vibrator row constituted by N (N is a natural number) vibrators 203 arranged along the x-axis is arranged in N rows along the y-axis. That is, in the example of FIG. 1B, the ultrasonic probe 201 has N 2 (N×N) vibrators 203. As shown in FIG. 1A, the N 2 vibrators 203 are classified so as to belong to any of a plurality of groups called sub-arrays constituted by M vibrators 203. M is a natural number smaller than N.

[0004] The electronic circuit 204 includes a plurality of blocks 205. One block 205 is provided corresponding to one sub-array. That is, the blocks 205 are provided for each sub-array. One block 205 causes the M vibrators 203 constituting the sub-array to perform transmission and reception of ultrasonic waves.

[0005] One block 205 includes 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 subarray beamformer 205f. Among these, the transmit system consists of the transmit beamformer 205a and the pulsers 205b, and the receive system consists of the LNAs 205d, the VGAs 205e, and the receive subarray beamformer 205f.

[0006] Corresponding to one oscillator 203, one pulser 205b, one transmit / receive switch 205c, one LNA 205d, and one VGA 205e are provided. Also, corresponding to one subarray, one set of receive subarray beamformers 205f is provided.

[0007] The operations of each block 205 of the ultrasonic probe 201 will be described. When transmitting ultrasonic waves, the transmission beamformer 205a causes a plurality (M) of vibrators 203 to transmit delay-controlled ultrasonic waves via the pulsar 205b. That is, the pulsar 205b supplies a delay-controlled drive signal to the vibrator 203. The transmit / receive switch 205c disconnects the receiving system from the transmitting system in order to suppress the application of voltage from the transmitting system to the receiving system during ultrasonic wave transmission. When receiving ultrasonic waves, the transmit / receive switch 205c disconnects the received signal transmitted from each vibrator 203 from the transmitting system. Then, the LNA 205d amplifies the received signal. Then, the VGA 205e performs gain adjustment on the amplified received signal according to depth. Then, the receive subarray beamformer 205f applies a receive delay to the M received signals after gain adjustment and adds the M received signals to which the receive delay has been applied. Then, the receive subarray beamformer 205f outputs the received signal obtained by the addition to the apparatus main body 202. That is, the receive subarray beamformer 205f applies a receive delay to the received signals in units of a group called a subarray and then adds them, and outputs the received signal obtained by the addition. Such beamforming for each subarray (receive beamforming) is referred to as subarray beamforming. In this way, the ultrasonic probe 201 outputs the number of received signals equal to the number of subarrays to the apparatus main body 202.

[0008] The apparatus main body 202 includes a receive beamformer 206. The receive beamformer 206 applies a receive delay to a plurality of received signals (the number of received signals equal to the number of subarrays) output by the ultrasonic probe 201 and adds the received signals to which the receive delay has been applied. Then, the apparatus main body 202 generates ultrasonic image data using the signal obtained by the addition.

[0009] Here, as shown in FIG. 1B, in the case of an N×N two-dimensional array of vibrators (N vibrators arranged in N rows in the row direction and N columns in the column direction), as shown in FIG. 1A, N 2 pulsars 205b, N 2 LNAs 205d, N 2 LNAs 205d, N 2N VGA205es 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 VGA205es 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 VGA205es are required. When one pulser 205b, one LNA 205d, and one VGA205e are regarded as one electronic circuit, 16,384 electronic circuits are required. Implementing 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 pulsers 205b, LNAs 205d, and VGA205es 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 the prior art RCA will be described. FIGS. 2A and 2B are diagrams for explaining an example of the RCA. FIG. 3 is a diagram showing an example of the configuration of a conventional ultrasonic diagnostic apparatus 300 having the structure of an example of the RCA described with reference to FIGS. 2A and 2B. As shown in FIG. 3, the ultrasonic diagnostic apparatus 300 includes an ultrasonic probe 301 and an apparatus main body 302.

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

[0015] The apparatus main body 302 includes N pulsers (Pulser) 304, a transmission beamformer 305, N LNAs 306, N VGAs 307, and a reception beamformer 308.

[0016] The operation of the ultrasonic diagnostic apparatus 300 will be described. When the ultrasonic diagnostic apparatus 300 transmits ultrasonic waves, as shown in FIG. 2A, one surface (for example, the front surface) of two surfaces of each of the N transducers 303 arranged in the column direction (y-axis direction) is commonly connected. That is, the ultrasonic diagnostic apparatus 300 commonly connects the N transducers 303 arranged in the column direction (y-axis direction). Thereby, a transducer group 303a constituted by 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 FIG. 3, one pulser 304 is provided for one transducer group 303a. Since the number of transducer groups 303a is N, N pulsers 304 are provided in the apparatus main body 302. Therefore, when one pulser 304 is regarded as one electronic circuit, when the ultrasonic diagnostic apparatus 300 transmits ultrasonic waves, the apparatus main body 302 requires N electronic circuits.

[0018] Then, the transmission beamformer 305 causes, via the pulsar 304, ultrasonic waves with a transmission delay applied in the row direction to be transmitted from the other surface (e.g., the back surface) of the N transducers 303 that make up the transducer group 303a. The transmission beamformer 305 performs such processing for each transducer group 303a.

[0019] Next, when the ultrasonic diagnostic apparatus 300 receives ultrasonic waves, as shown in FIG. 2B, the other surfaces (e.g., the back surfaces) of the two surfaces each of the N transducers 303 arranged in the row direction (x-axis direction) are commonly connected. That is, the ultrasonic diagnostic apparatus 300 commonly connects the N transducers 303 arranged in the row direction (x-axis direction). As a result, transducer groups 303b each composed of N transducers 303 that are connected in series and arranged in the row direction are arranged in N columns in the column direction (y-axis direction).

[0020] As shown in FIG. 3, one LNA 306 and one VGA 307 are provided for one transducer group 303b. Since the number of transducer groups 303b is N, N LNAs 306 and N VGAs 307 are provided in the apparatus main body 302.

[0021] The LNA 306 amplifies the received signal output from the transducer group 303b. Here, the received signal output from one transducer group 303b is a received signal obtained by adding (combining) M received signals output from the M transducers 303 that make up one transducer group 303b. Then, the VGA 307 performs gain adjustment on the amplified received signal according to the depth. Then, the A / D (Analog to Digital) converter converts the received signal, which is an analog signal in analog form after gain adjustment, into a digital signal in digital form. Then, the reception beamformer 308 applies a reception delay to the N received signals (digital signals) after gain adjustment and adds the N received signals with the reception delay applied. Then, the apparatus main body 302 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 transmit / receive 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] FIG. 4A is a diagram showing the PSF (Point Spread Function) of the ultrasonic diagnostic apparatus 200 of 2DA in contour lines at 6 dB intervals as viewed from the z-axis direction. However, in the case shown in FIG. 4A, reception apodization and transmission apodization are not performed. Here, reception apodization is, for example, a technique in which reception signals from the same sample point received by a plurality of vibrators constituting the reception aperture of an ultrasonic probe are weighted by an apodization function (aperture function) and then subjected to coherent addition processing. The apodization function is a function in which weights are set for each position of the vibrator. Also, transmission apodization is, for example, a technique in which the amplitude of ultrasonic waves transmitted by a plurality of vibrators constituting the transmission aperture of an ultrasonic probe is changed for each position of the vibrator.

[0026] FIGS. 4B and 4C are diagrams showing the PSF of the ultrasonic diagnostic apparatus 300 including the vibrator group of the RCA structure in contour lines at 6 dB intervals as viewed from the z-axis direction. However, in the case shown in FIG. 4B, reception apodization and transmission apodization are not performed, while in the case shown in FIG. 4C, reception apodization and transmission apodization are performed.

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

[0028] When comparing Image 210 and Image 310, it can be seen that in the ultrasonic diagnostic apparatus 300 without performing reception apodization and transmission apodization, the main lobe is slightly wider and the spatial resolution is slightly worse compared to the ultrasonic diagnostic apparatus 200. Also, when comparing Image 210 and Image 310, it can be seen that in the ultrasonic diagnostic apparatus 300 without performing reception apodization and transmission apodization, the side lobes along the x-axis and y-axis are larger and artifacts are more likely to occur compared to the ultrasonic diagnostic apparatus 200.

[0029] When comparing Image 210, Image 310, and Image 311, it can be seen that in the ultrasonic diagnostic apparatus 300 when performing reception apodization and transmission apodization, the main lobe is considerably wider and the spatial resolution is considerably worse compared to the ultrasonic diagnostic apparatus 200 and the ultrasonic diagnostic apparatus 300 without performing reception apodization and transmission apodization. Also, when comparing Image 210, Image 310, and Image 311, it can be seen that in the ultrasonic diagnostic apparatus 300 when performing reception apodization and transmission apodization, the side lobes along the x-axis and y-axis are smaller compared to the ultrasonic diagnostic apparatus 300 without performing reception apodization and transmission apodization. On the other hand, the side lobes along the x-axis and y-axis are larger compared to the ultrasonic diagnostic apparatus 200. For this reason, it can be seen that in the ultrasonic diagnostic apparatus 300 when performing reception apodization and transmission apodization, artifacts are more likely to occur compared to the ultrasonic diagnostic apparatus 200.

[0030] As described above, the ultrasonic diagnostic apparatus 300 having an oscillator group with an RCA structure has the advantage that the number of required electronic circuits can be reduced compared to the 2D ultrasonic diagnostic apparatus 200, but there is a problem of poor image quality.

Prior Art Documents

Patent Documents

[0031]

Patent Document 1

[0032] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to improve the image quality of ultrasonic images obtained using an oscillator group with an RCA structure. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. The problems corresponding to the respective effects of each configuration shown in the embodiments described later can also be regarded as other problems. [Means for Solving the Problems]

[0033] The ultrasonic diagnostic apparatus according to the embodiment includes an ultrasonic probe, a generation unit, and a display control unit. The ultrasonic probe includes a plurality of oscillators arranged two-dimensionally, and when transmitting ultrasonic waves, a first plurality of oscillators arranged in the direction of one of two axes intersecting each other are commonly connected, and when receiving ultrasonic waves, a second plurality of oscillators arranged in the direction of the other of the two axes are commonly connected, and includes a plurality of oscillator groups of a Row-Column Addressing type. The generation unit performs beamforming on a plurality of received signals output from the second plurality of oscillators for each of the plurality of oscillator groups, and generates ultrasonic image data based on the signals obtained by the beamforming. The display control unit causes a display unit to display an ultrasonic image based on the ultrasonic image data. The plurality of sets of the two axes corresponding to the plurality of oscillator groups of the Row-Column Addressing type are different from each other. [Brief Description of the Drawings]

[0034]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 5A

Figure 5B

Figure 5C

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Figure 7A

Figure 7B

Figure 7C

Figure 7D

Figure 8

Figure 9A

Figure 9B

Figure 9C

Figure 10

Figure 11

Figure 12A

Figure 12B

Figure 12C

Figure 13A

Figure 13B

Figure 13C

Figure 14A

Figure 14B

Figure 14C

Figure 15A

Figure 15B

Embodiments for Carrying Out the Invention

[0035] First, before explaining the ultrasonic diagnostic apparatus according to the embodiment, an example of a case where an ultrasonic diagnostic apparatus including a transducer group having an RCA structure generates ultrasonic image data while rotating the transducer group having the RCA structure will be described.

[0036] FIG. 6A is a diagram showing the PSF of the ultrasonic diagnostic apparatus 300 including the transducer group having the RCA structure as contour lines at 6 dB intervals as viewed from the z-axis direction.

[0037] FIG. 6B is a diagram showing the PSF of the ultrasonic diagnostic apparatus 300 as contour lines at 6 dB intervals as viewed from the z-axis direction, where the received signal obtained by beamforming the received signal obtained when the angle of the transducer group having the RCA structure is 0°, which is a predetermined reference angle, and the received signal obtained by beamforming the received signal obtained when the transducer group having the RCA structure is rotated 45° from the predetermined reference angle and the angle of the transducer group having the RCA structure is 45° are added. That is, FIG. 6B is a diagram showing the PSF of the ultrasonic diagnostic apparatus 300 as contour lines at 6 dB intervals as viewed from the z-axis direction, where the received signal obtained by beamforming the received signal obtained at each angle while rotating the transducer group having the RCA structure in the range of 0° or more and less than 90° at 45° intervals is added to obtain the received signal supplied to the signal processing circuit.

[0038] FIG. 6C is a diagram showing the PSF of the ultrasonic diagnostic apparatus 300 viewed from the z-axis direction, where the received signals obtained by beamforming the received signals obtained when the angle of the oscillator group of the RCA structure is 0°, which is a predetermined reference angle, the received signals obtained by beamforming the received signals obtained when the oscillator group of the RCA structure is rotated 22.5° from the predetermined reference angle and the angle of the oscillator group of the RCA structure is 22.5°, the received signals obtained by beamforming the received signals obtained when the oscillator group of the RCA structure is rotated 45° from the predetermined reference angle and the angle of the oscillator group of the RCA structure is 45°, and the received signals obtained by beamforming the received signals obtained when the oscillator group of the RCA structure is rotated 67.5° from the predetermined reference angle and the angle of the oscillator group of the RCA structure is 67.5° are added together to obtain the received signal supplied to the signal processing circuit. That is, FIG. 6C is a diagram showing the PSF of the ultrasonic diagnostic apparatus 300 viewed from the z-axis direction, where the received signals obtained by beamforming the received signals obtained at each angle while rotating the oscillator group of the RCA structure at 22.5° intervals in the range of 0° or more and less than 90° are added together to obtain the received signal supplied to the signal processing circuit, shown by contour lines at 6 dB intervals.

[0039] FIG. 6D is a diagram showing the PSF of the ultrasonic diagnostic apparatus 300 viewed from the z-axis direction, where the received signals obtained by beamforming the received signals obtained at each angle while rotating the oscillator group of the RCA structure at 11.25° intervals in the range of 0° or more and less than 90° are added together to obtain the received signal supplied to the signal processing circuit, shown by contour lines at 6 dB intervals.

[0040] In addition, in each of the cases shown in FIGS. 6A to 6D, reception apodization and transmission apodization are not performed.

[0041] FIG. 7A represents the content shown in FIG. 6A as an image 312 from the peak to -40 dB. FIG. 7B represents the content shown in FIG. 6B as an image 313 from the peak to -40 dB. FIG. 7C represents the content shown in FIG. 6C as an image 314 from the peak to -40 dB. FIG. 7D represents the content shown in FIG. 6D as an image 315 from the peak to -40 dB.

[0042] From image 312 to images 313, 314, and 315, the side lobes in the cross direction gradually decrease. Specifically, in image 312, the side lobes in the cross direction are clearly present, but in image 315, such side lobes are almost disappeared. In the examples of FIGS. 4C and 5C above, the case of reducing the side lobes by performing receive apodization and transmit apodization was described, but it can be seen from images 313 to 315 that the side lobes can be reduced or disappeared without applying such apodization. By not applying apodization, it becomes possible to reduce the side lobes while suppressing the increase of the main lobe, that is, while suppressing the degradation of the spatial resolution.

[0043] However, it is not realistic to rotate the oscillator group of the RCA structure. For example, since the oscillator group of the RCA structure is in contact with the subject, it may be difficult to rotate the oscillator of the RCA structure. Also, the subject may move while the oscillator group of the RCA structure is rotating. Therefore, the ultrasonic diagnostic apparatus according to each embodiment described below is configured to be able to reduce the side lobes while suppressing the degradation of the spatial resolution without rotating the oscillator group of the RCA structure. That is, the ultrasonic diagnostic apparatus according to each embodiment is configured so that the image quality of the ultrasonic image obtained using the oscillator group of the RCA structure can be improved.

[0044] Hereinafter, the ultrasonic diagnostic apparatus according to each embodiment will be described with reference to the drawings.

[0045] (First Embodiment) FIG. 8 is a block diagram showing a configuration example of the ultrasonic diagnostic apparatus 1 according to the first embodiment. As illustrated in FIG. 8, the ultrasonic diagnostic apparatus 1 according to the first embodiment includes an apparatus main body 100, an ultrasonic probe 101, an input device 102, and a display 103.

[0046] The ultrasonic probe 101 has, for example, a plurality of vibrators (piezoelectric elements). The plurality of vibrators generate ultrasonic waves based on a drive signal supplied from a transmission circuit 111 of a transmission / reception circuit 110 included in the apparatus main body 100. Specifically, the plurality of vibrators generate ultrasonic waves having a waveform corresponding to a transmission drive voltage when a voltage (transmission drive voltage) is applied by the transmission circuit 111. The waveform of the transmission drive voltage indicated by the drive signal is the waveform of the voltage applied to the plurality of vibrators. That is, the ultrasonic probe 101 transmits ultrasonic waves corresponding to the magnitude of the applied transmission drive voltage. Further, the ultrasonic probe 101 receives a reflected wave from the subject P, converts the reflected wave into a reflected wave signal (received signal) which is an electrical signal, and outputs the reflected wave signal to the apparatus main body 100. Further, the ultrasonic probe 101 has, for example, a matching layer provided on the vibrator and a backing material or the like that prevents the propagation of ultrasonic waves backward from the vibrator. Note that the ultrasonic probe 101 is detachably connected to the apparatus main body 100.

[0047] When ultrasonic waves are transmitted from the ultrasonic probe 101 to the subject P, the transmitted ultrasonic waves are successively reflected at discontinuous surfaces of acoustic impedance in the body tissues of the subject P and received by a plurality of vibrators included in the ultrasonic probe 101 as reflected waves. The amplitude of the received reflected wave depends on the difference in acoustic impedance at the discontinuous surface where the ultrasonic wave is reflected. Note that when the transmitted ultrasonic pulse is reflected at the surface of a moving blood flow, a heart wall, or the like, the reflected wave undergoes a frequency shift depending on the velocity component of the moving object with respect to the ultrasonic transmission direction due to the Doppler effect. Then, the ultrasonic probe 101 outputs the reflected wave signal to a reception circuit 112 of the transmission / reception circuit 110 described later.

[0048] The ultrasonic probe 101 is detachably provided on the apparatus main body 100. When performing a scan of a two-dimensional region (two-dimensional scan) within the subject P, the operator connects, for example, a 1D array probe in which a plurality of vibrators are arranged in a line to the apparatus main body 100 as the ultrasonic probe 101. Examples of the types of 1D array probes include linear ultrasonic probes, convex ultrasonic probes, sector ultrasonic probes, and the like. Further, when performing a scan of a three-dimensional region (three-dimensional scan) within the subject P, the operator connects, for example, a mechanical 4D probe or a 2D array probe to the apparatus main body 100 as the ultrasonic probe 101. The mechanical 4D probe can perform two-dimensional scanning using a plurality of vibrators arranged in a line like a 1D array probe, and can perform three-dimensional scanning by swinging a plurality of vibrators at a predetermined angle (swing angle). Also, the 2D array probe can perform three-dimensional scanning with a plurality of vibrators arranged in a matrix, and can perform two-dimensional scanning by focusing and transmitting ultrasonic waves.

[0049] FIGS. 9A to 9C are diagrams showing an example of the configuration of the ultrasonic probe 101 according to the first embodiment. As shown in FIG. 9A, the ultrasonic probe 101 includes a plurality of vibrators 104 constituting the first vibrator group 106 of the RCA structure, and a plurality of vibrators 105 constituting the second vibrator group 107 of the RCA structure. That is, the ultrasonic probe 101 includes two systems of vibrator groups (the first vibrator group 106 and the second vibrator group 107) as the vibrator groups of the RCA structure. For example, in a two-dimensional coordinate system constituted by the x-axis and the y-axis, the ultrasonic probe 101 has N vibrators 104 arranged in N rows in the x-axis direction and N columns in the y-axis direction, and N 2 vibrators 105 arranged in N rows in the x-axis direction and N columns in the y-axis direction. In the case shown in FIG. 9A, the value of N is 7. 2

[0050] The vibrators 104 and 105 are constituted by, for example, a MUT (Micromachined Ultrasound Transducer). Examples of such a MUT include a CMUT (Capacitive Micromachined Ultrasound Transducer). One cell of the MUT corresponds to one vibrator 104 or one vibrator 105.

[0051] As shown in FIG. 9A, the distance between two adjacent vibrators 104 in the x-axis direction is "a". Similarly, the distance between two adjacent vibrators 105 in the x-axis direction is also "a". Also, the distance between two adjacent vibrators 104 in the y-axis direction and the distance between two adjacent vibrators 105 in the y-axis direction are both "a".

[0052] The two-dimensional coordinate system constituted by the x-axis and y-axis shown in FIG. 9A corresponds to the first vibrator group 106 of the RCA structure. Also, the two-dimensional coordinate system constituted by the x2-axis and y2-axis shown in FIG. 9A corresponds to the second vibrator group 107 of the RCA structure. Here, the two-dimensional coordinate system constituted by the x2-axis and y2-axis is obtained by translating the two-dimensional coordinate system constituted by the x-axis and y-axis by a / 2 in the positive direction of the x-axis and -a / 2 in the negative direction of the y-axis, and then rotating the two-dimensional coordinate system constituted by the translated x-axis and y-axis by 45° around the origin of the two-dimensional coordinate system constituted by the translated x-axis and y-axis.

[0053] Therefore, as shown in FIG. 9A, the distance between two adjacent vibrators 105 in the x2-axis direction is "2 1 / 2 a". Similarly, the distance between two adjacent vibrators 104 in the x2-axis direction is also "2 1 / 2 a". Also, the distance between two adjacent vibrators 104 in the y2-axis direction and the distance between two adjacent vibrators 105 in the y2-axis direction are both "2 1 / 2 a".

[0054] When the first oscillator group 106 of the RCA structure transmits ultrasonic waves, as shown in FIG. 9A, the ultrasonic probe 101 commonly connects one of the two surfaces (for example, the front surface) of each of the N oscillators 104 arranged in the column direction (y-axis direction). That is, the ultrasonic probe 101 commonly connects the N oscillators 104 arranged in the column direction (y-axis direction). As a result, an oscillator group 104a composed of N oscillators 104 connected in series and arranged in the column direction is arranged in N columns in the row direction (x-axis direction). Note that the N oscillators 104 arranged in the column direction (y-axis direction) are an example of the first plurality of oscillators.

[0055] Also, when the first oscillator group 106 of the RCA structure receives ultrasonic waves (reflected waves), as shown in FIG. 9A, the ultrasonic probe 101 commonly connects the other of the two surfaces (for example, the back surface) of each of the N oscillators 104 arranged in the row direction (x-axis direction). That is, the ultrasonic probe 101 commonly connects the N oscillators 104 arranged in the row direction (x-axis direction). As a result, an oscillator group 104b composed of N oscillators 104 connected in series and arranged in the row direction is arranged in N columns in the column direction (y-axis direction). Note that the N oscillators 104 arranged in the row direction (x-axis direction) are an example of the second plurality of oscillators.

[0056] On the other hand, when the second oscillator group 107 of the RCA structure transmits ultrasonic waves, as shown in FIG. 9B, the ultrasonic probe 101 commonly connects one of the two surfaces (for example, the front surface) of each of the k (k = 2, 3, ···, N) oscillators 105 arranged in the column direction (y2-axis direction). That is, the ultrasonic probe 101 commonly connects the k oscillators 105 arranged in the column direction (y2-axis direction). As a result, an oscillator group 105a composed of k oscillators 105 connected in series and arranged in the column direction is arranged in (2N - 3) columns in the row direction (x2-axis direction). Note that the k oscillators 105 arranged in the column direction (y2-axis direction) are an example of the first plurality of oscillators.

[0057] Also, when the second oscillator group 107 of the RCA structure receives ultrasonic waves (reflected waves), as shown in FIG. 9C, the ultrasonic probe 101 commonly connects the other surfaces (for example, the back surfaces) of the k oscillators 105 arranged in the row direction (x2-axis direction). That is, the ultrasonic probe 101 commonly connects the k oscillators 105 arranged in the row direction (x2-axis direction). As a result, the oscillator group 105b composed of k oscillators 105 connected in series and arranged in the row direction will be arranged in (2N - 3) columns in the column direction (y2-axis direction). Note that the k oscillators 105 arranged in the row direction (x2-axis direction) are an example of the second plurality of oscillators.

[0058] As described above, the ultrasonic probe 101 according to the first embodiment includes a plurality of oscillators 104, 105 arranged two-dimensionally. And when the ultrasonic probe 101 transmits ultrasonic waves, it commonly connects N oscillators 104 or k oscillators 105 arranged in the direction of one of two axes (for example, the x-axis and the y-axis or the x2-axis and the y2-axis) that intersect each other (for example, the column direction described above). When receiving ultrasonic waves, it commonly connects N oscillators 104 or k oscillators 105 arranged in the direction of the other of the two axes (for example, the row direction described above). The ultrasonic probe 101 includes a plurality of oscillator groups (the first oscillator group 106 and the second oscillator group 107) of the Row-Column Addressing type.

[0059] And in the first embodiment, the plurality of pairs of two axes (for example, the pair of the x-axis and the y-axis and the pair of the x2-axis and the y2-axis) corresponding to the plurality of oscillator groups (the first oscillator group 106 and the second oscillator group 107) of the Row-Column Addressing type are different from each other. Specifically, for example, with respect to the pair of the x-axis and the y-axis, the pair of the x2-axis and the y2-axis is shifted by 45°.

[0060] In the first embodiment, the ultrasonic probe 101 includes a plurality of row-column addressing type oscillator groups (the first oscillator group 106 and the second oscillator group 107), and the product of the angular interval (e.g., 45°) between a plurality of pairs of two axes (e.g., the pair of the x-axis and the y-axis and the pair of the x2-axis and the y2-axis) corresponding to the plurality of row-column addressing type oscillator groups and the number of the plurality of row-column addressing type oscillator groups (e.g., 2) is 90°.

[0061] The input device 102 is realized by input means such as a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, a joystick, etc. The input device 102 receives various setting requests from the operator of the ultrasonic diagnostic apparatus 1 and transfers the received various setting requests to the apparatus main body 100.

[0062] The display 103 displays, for example, a GUI (Graphical User Interface) for the operator of the ultrasonic diagnostic apparatus 1 to input various setting requests using the input device 102, or displays an ultrasonic image or the like based on the ultrasonic image data generated in the apparatus main body 100. The display 103 is realized by a liquid crystal monitor, a CRT (Cathode Ray Tube) monitor, or the like. The display 103 is an example of a display unit.

[0063] The apparatus main body 100 generates ultrasonic image data based on the reflected wave signals transmitted from the ultrasonic probe 101. Note that the ultrasonic image data is an example of image data. The apparatus main body 100 can generate two-dimensional ultrasonic image data based on the reflected wave signals corresponding to the two-dimensional region of the subject P transmitted from the ultrasonic probe 101. Further, the apparatus main body 100 can generate three-dimensional ultrasonic image data based on the reflected wave signals corresponding to the three-dimensional region of the subject P transmitted from the ultrasonic probe 101. As shown in FIG. 1, the apparatus main body 100 includes a transmission / reception 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.

[0064] The transmission / reception circuit 110, under the control of the control circuit 170, causes the ultrasonic probe 101 to transmit ultrasonic waves and causes the ultrasonic probe 101 to receive the reflected waves of the ultrasonic waves. That is, the transmission / reception circuit 110 performs scanning via the ultrasonic probe 101. Note that the scanning is also referred to as a scan, an ultrasonic scan, or an ultrasonic scanning. The transmission / reception circuit 110 is an example of a transmission / reception unit. The transmission / reception circuit 110 includes a transmission circuit 111 and a reception circuit 112.

[0065] The transmission circuit 111, under the control of the control circuit 170, causes the ultrasonic probe 101 to transmit ultrasonic waves. The transmission 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 transmission circuit 111 causes the ultrasonic probe 101 to transmit an ultrasonic beam for scanning the two-dimensional region. Further, when scanning a three-dimensional region within the subject P, the transmission circuit 111 causes the ultrasonic probe 101 to transmit an ultrasonic beam for scanning the three-dimensional region. FIG. 10 is a diagram showing an example of the configuration of the transmission / reception system of the ultrasonic diagnostic apparatus 1 according to the first embodiment.

[0066] As shown in FIG. 10, the transmission circuit 111 includes a Pulser 181 and a transmission beamformer 182. The transmission beamformer 182 causes the ultrasonic waves with delayed control to be transmitted from each of the plurality of vibrators 104 constituting the vibrator group 104a and from each of the plurality of vibrators 105 constituting the vibrator group 105a via the Pulser 181.

[0067] The transmission beamformer 182 includes a rate pulser generation circuit and a transmission delay circuit. The rate pulser generation circuit repeatedly generates rate pulses for forming transmission ultrasonic waves (transmission beams) at a predetermined rate frequency (PRF: Pulse Repetition Frequency). When the rate pulses pass through the transmission delay circuit, voltages are applied to the Pulser 181 in a state having different transmission delay times. For example, the transmission delay circuit provides, for each rate pulse generated by the rate pulser generation circuit, the transmission delay time for each vibrator necessary for focusing the ultrasonic waves generated from the ultrasonic probe 101 into a beam shape and determining the transmission directivity.

[0068] The Pulser 181 supplies a drive signal (drive pulse) with delayed control to the vibrator. The Pulser 181 supplies a drive signal to the ultrasonic probe 101 at a timing based on the rate pulse. That is, the Pulser 181 applies a voltage (transmission drive voltage) having a waveform indicated by the drive signal to the ultrasonic probe 101 at a timing based on such a rate pulse. Note that the transmission delay circuit arbitrarily adjusts the transmission direction of the ultrasonic waves from the transmission surfaces of the vibrators 104 and 105 by changing the transmission delay time given to each rate pulse.

[0069] The drive pulse is transmitted from the pulsar 181 to the vibrators 104 and 105 in the ultrasonic probe 101 via a cable, and then is converted from an electrical signal into a mechanical vibration at the vibrators 104 and 105. That is, when a voltage is applied to the vibrators 104 and 105, the vibrators 104 and 105 vibrate mechanically. The ultrasonic waves generated by this mechanical vibration are transmitted into the inside of the subject P, that is, into the living body. Here, the ultrasonic waves having different transmission delay times for each of the vibrators 104 and 105 are focused and propagated in a predetermined direction.

[0070] Note that the transmission circuit 111 has a function of instantaneously changing the transmission frequency, the transmission drive voltage, etc. in order to execute a predetermined scanning sequence under the control of the control circuit 170. In particular, the change of the transmission drive voltage is realized by a linear amplifier type transmission circuit capable of instantaneously switching the value of the transmission drive voltage, or by a mechanism for electrically switching a plurality of power supply units.

[0071] Here, in the first embodiment, as shown in FIG. 10, one pulsar 181 is provided for each of the N vibrator groups 104a and the (2N - 3) vibrator groups 105a. Therefore, (3N - 3) pulsars 181 are provided in the apparatus main body 100. Thus, when treating one pulsar 181 as one electronic circuit, when the ultrasonic diagnostic apparatus 1 transmits ultrasonic waves, the apparatus main body 100 requires 2N electronic circuits.

[0072] When the first vibrator group 106 transmits ultrasonic waves, the transmission beamformer 182 causes the pulsar 181 to transmit ultrasonic waves with a transmission delay applied in the x-axis direction from the other surface (for example, the back surface) of the N vibrators 104 constituting the vibrator group 104a. The transmission beamformer 182 performs such processing for each of the vibrator groups 104a.

[0073] Also, when the second oscillator group 107 transmits ultrasonic waves, the transmission beamformer 182 causes, via the pulsar 181, ultrasonic waves with a transmission delay applied in the x2-axis direction to be transmitted from the other surface (e.g., the back surface) of the k oscillators 105 that make up the oscillator group 105a. The transmission beamformer 182 performs such processing for each oscillator group 105a.

[0074] The reflected waves of the ultrasonic waves transmitted by the ultrasonic probe 101 reach the oscillators inside the ultrasonic probe 101 and are then converted from mechanical vibrations into electrical signals (reflected wave signals) at the oscillators 104 and 105 and input to the receiving circuit 112. As shown in FIG. 10, the receiving circuit 112 includes an LNA 183, a VGA 184, an A / D (Analog to Digital) converter (not shown), a receiving beamformer 185, etc., and performs various processes on the reflected wave signals transmitted from the ultrasonic probe 101 to generate reflected wave data. The above-described reflected wave signals and reflected wave data are examples of received signals. The receiving circuit 112 generates two-dimensional reflected wave data from the two-dimensional reflected wave signals transmitted from the ultrasonic probe 101. Also, the receiving circuit 112 generates three-dimensional reflected wave data from the three-dimensional reflected wave signals transmitted from the ultrasonic probe 101. Then, the receiving circuit 112 stores the generated reflected wave data in the buffer memory 120.

[0075] When the first oscillator group 106 with an RCA structure receives ultrasonic waves (reflected waves), the LNA 183 amplifies the reflected wave signals output from the oscillator group 104b. Here, the reflected wave signals output from one oscillator group 104b are reflected wave signals (received signals) obtained by adding (combining) the N reflected wave signals output from the N oscillators 104 that make up one oscillator group 104b. In this way, by the first oscillator group 106 with an RCA structure transmitting and receiving ultrasonic waves, one oscillator group 104b outputs to the LNA 183 the reflected wave signals obtained by adding the N reflected wave signals.

[0076] Also, when the second oscillator group 107 of the RCA structure receives an ultrasonic wave (reflected wave), the LNA 183 amplifies the reflected wave signal output from the oscillator group 105b. Here, the reflected wave signal output from one oscillator group 105b is a reflected wave signal obtained by adding (combining) k reflected wave signals output from k oscillators 105 that make up one oscillator group 105b. In this way, when the second oscillator group 107 of the RCA structure transmits and receives ultrasonic waves, one oscillator group 105b outputs to the LNA 183 a reflected wave signal obtained by adding k reflected wave signals.

[0077] Then, the VGA 184 performs gain adjustment on the amplified reflected wave signal according to the depth. And the A / D (Analog to Digital) converter converts the reflected wave signal, which is an analog signal in analog form after gain adjustment, into a reflected wave signal in digital form (digital signal).

[0078] Then, the receiving beamformer 185 applies a reception delay to the N gain-adjusted reflected wave signals (digital signals) output from the N oscillator groups 104b, and adds the N reflected wave signals to which the reception delay has been applied. And the receiving beamformer 308 stores the reflected wave data obtained by adding the N reflected wave signals in the buffer memory 120. In this way, the reflected wave data obtained by transmitting and receiving ultrasonic waves by the first oscillator group 106 of the RCA structure may hereinafter be referred to as "first reflected wave data".

[0079] Also, the receiving beamformer 185 applies a reception delay to the (2N - 3) gain-adjusted reflected wave signals (digital signals) output from the (2N - 3) oscillator groups 105b, and adds the (2N - 3) reflected wave signals to which the reception delay has been applied. And the receiving beamformer 308 stores the reflected wave data obtained by adding the (2N - 3) reflected wave signals in the buffer memory 120. In this way, the reflected wave data obtained by transmitting and receiving ultrasonic waves by the second oscillator group 107 of the RCA structure may hereinafter be referred to as "second reflected wave data".

[0080] From the above, for each of the plurality of oscillator groups (the first oscillator group 106 and the second oscillator group 107), the receiving circuit 112 performs beamforming (receiving beamforming) on the plurality of reflected wave signals output from the plurality of oscillators 104 or the plurality of oscillators 105.

[0081] Here, in the first embodiment, as shown in FIG. 10, one LNA 183 and one VGA 184 are provided for each of the N oscillator groups 104b and the (2N - 3) oscillator groups 105b. Therefore, the apparatus main body 100 is provided with (3N - 3) LNAs 183 and (3N - 3) VGAs 184. Thus, when treating a set of one LNA 183 and one VGA 184 as one electronic circuit, when the ultrasonic diagnostic apparatus 1 transmits ultrasonic waves, the apparatus main body 100 requires (3N - 3) electronic circuits.

[0082] The buffer memory 120 is a memory that temporarily stores the reflected wave data generated by the transmission / reception circuit 110. For example, the buffer memory 120 is configured to be able to store the reflected wave data for a predetermined number of frames. And when the buffer memory 120 is storing the reflected wave data for a predetermined number of frames and new reflected wave data for one frame is generated by the receiving circuit 112, under the control of the receiving circuit 112, the reflected wave data for the oldest one frame in terms of the generated time is discarded, and the newly generated reflected wave data for one frame is stored. For example, the buffer memory 120 is realized by a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory.

[0083] The signal processing circuit 130 reads the first reflected wave data and the second reflected wave data from the buffer memory 120. Then, the signal processing circuit 130 adds the read second reflected wave data to the read first reflected wave data, performs various signal processes on the data (data after addition) obtained by the addition, and outputs the data after addition on which various signal processes have been performed to the image generation circuit 140 as B-mode data or Doppler data. The signal processing circuit 130 is realized by, for example, a processor. The signal processing circuit 130 is an example of a signal processing unit.

[0084] FIG. 11 is a flowchart showing an example of the flow of processing from when the reception circuit 112 and the signal processing circuit 130 according to the first embodiment generate the first reflected wave data and the second reflected wave data until the data after addition is obtained.

[0085] As shown in FIG. 11, the reception circuit 112 generates the first reflected wave data and stores the first reflected wave data in the buffer memory 120 (step S101). Then, the reception circuit 112 generates the second reflected wave data and stores the second reflected wave data in the buffer memory 120 (step S102).

[0086] 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 ends the processing shown in FIG. 11. Here, as described above, the signal processing circuit 130 generates B-mode data or Doppler data by performing various signal processes on the data after addition obtained by the addition.

[0087] For example, each time the first reflected wave data and the second reflected wave data for one frame are newly stored in the buffer memory 120, the signal processing circuit 130 reads out the first reflected wave data and the second reflected wave data for one frame newly stored in the buffer memory 120. Then, each time the first reflected wave data and the second reflected wave data for one frame are read out, the signal processing circuit 130 adds the second reflected wave data to the first reflected wave data to generate data after addition for one frame. Then, each time the data after addition for one frame is generated, the signal processing circuit 130 performs various signal processes on the data after addition to newly generate B-mode data or Doppler data for one frame. Then, each time the B-mode data or Doppler data for one frame is generated, the signal processing circuit 130 outputs the newly generated B-mode data or Doppler data for one frame to the image generation circuit 140. Hereinafter, an example of various signal processes executed by the signal processing circuit 130 will be described.

[0088] For example, the signal processing circuit 130 performs quadrature detection, logarithmic amplification, envelope detection processing, etc. on the data after addition to generate B-mode data in which the signal intensity (amplitude intensity) for each sample point is expressed by the brightness of the luminance. Then, the signal processing circuit 130 outputs the generated B-mode data to the image generation circuit 140.

[0089] Further, the signal processing circuit 130 performs signal processing for performing harmonic imaging that visualizes harmonic components on the data after addition. Examples of harmonic imaging include contrast harmonic imaging (CHI) and tissue harmonic imaging (THI). Also, in contrast harmonic imaging and tissue harmonic imaging, the following scanning methods are known as scanning methods. For example, as such a scanning method, phase modulation (PM) called amplitude modulation (AM), pulse subtraction method, or pulse inversion method, and AMPM in which both the effects of AM and PM can be obtained by combining AM and PM are known.

[0090] Further, the signal processing circuit 130 extracts motion information of a moving object (such as blood flow, tissue, contrast agent echo components, etc.) based on the Doppler effect from the data after addition by performing frequency analysis on the data after addition, and generates Doppler data indicating the extracted motion information. For example, the signal processing circuit 130 extracts, at multiple points, the average velocity, average dispersion value, average power value, etc. as the motion information of the moving object, and generates Doppler data indicating the extracted motion information of the moving object. The signal processing circuit 130 outputs the generated Doppler data to the image generation circuit 140.

[0091] Using the functions of the signal processing circuit 130 described above, the ultrasonic diagnostic apparatus 1 according to the embodiment can execute a color Doppler method, also called a color flow mapping (CFM) method. In the color flow mapping method, ultrasonic transmission and reception are performed multiple times on a plurality of scan lines. Then, in the color flow mapping method, by applying an MTI (Moving Target Indicator) filter to the data series at the same position, signals (clutter signals) derived from stationary tissues or tissues with slow movement are suppressed from the data series at the same position, and signals (blood flow signals) derived from blood flow are extracted. Then, in the color flow mapping method, blood flow information such as the velocity of blood flow, the dispersion of blood flow, and the power of blood flow is estimated from this blood flow signal. The signal processing circuit 130 outputs color image data indicating the blood flow information estimated by the color flow mapping method to the image generation circuit 140. Note that the color image data is an example of Doppler data.

[0092] The signal processing circuit 130 can process both the two-dimensional data after addition and the three-dimensional data after addition.

[0093] The image generation circuit 140 generates ultrasonic image data from the B-mode data or Doppler data output from the signal processing circuit 130. The image generation circuit 140 is realized by a processor.

[0094] For example, the image generation circuit 140 generates two-dimensional B-mode image data representing the intensity of the reflected wave as luminance from the two-dimensional B-mode data generated by the signal processing circuit 130. Also, the image generation circuit 140 generates two-dimensional Doppler image data in which motion information or blood flow information is visualized from the two-dimensional Doppler data generated by the signal processing circuit 130. Note that the two-dimensional Doppler image data in which motion information is visualized is velocity image data, dispersion image data, power image data, or image data combining these.

[0095] Here, the image generation circuit 140 generally converts (scanning conversion) the scanning line signal sequence of ultrasonic scanning into a scanning line signal sequence in a video format typified by a television or the like, and generates ultrasonic image data for display. For example, the image generation circuit 140 generates ultrasonic image data for display by performing coordinate conversion on the data output from the signal processing circuit 130 according to the scanning form of ultrasonic waves by the ultrasonic probe 101. In addition, as various image processes other than scanning conversion, the image generation circuit 140 performs, for example, an image process (smoothing process) of regenerating an average value image of luminance using a plurality of image frames after scanning conversion, an image process (edge enhancement process) using a differential filter within the image, and the like. Further, the image generation circuit 140 synthesizes character information, scales, body marks, and the like of various parameters on the ultrasonic image data.

[0096] Furthermore, the image generation circuit 140 generates three-dimensional B-mode image data by performing coordinate conversion on the three-dimensional B-mode data generated by the signal processing circuit 130. Also, the image generation circuit 140 generates three-dimensional Doppler image data by performing coordinate conversion on the three-dimensional Doppler data generated by the signal processing circuit 130. That is, the image generation circuit 140 generates "three-dimensional B-mode image data and three-dimensional Doppler image data" as "three-dimensional ultrasonic image data (volume data)". Then, the image generation circuit 140 performs various rendering processes on the volume data in order to generate various two-dimensional image data for displaying the volume data on the display 103.

[0097] Examples of the rendering process performed by the image generation circuit 140 include a process of generating MPR image data from volume data using a cross-sectional reconstruction method (MPR: Multi Planer Reconstruction). Also, examples of the rendering process performed by the image generation circuit 140 include a volume rendering (VR: Volume Rendering) process of generating two-dimensional image data reflecting three-dimensional information. The image generation circuit 140 is an example of an image generation unit.

[0098] The B-mode data and Doppler data are ultrasonic image data before scan conversion processing, and the data generated by the image generation circuit 140 is ultrasonic image data for display after scan conversion processing. Note that the B-mode data and Doppler data are also called raw data.

[0099] From the above, the reception circuit 112, the signal processing circuit 130, and the image generation circuit 140 perform beamforming on a plurality of reflected wave signals output from a plurality of vibrators 104 or a plurality of vibrators 105 for each of a plurality of vibrator groups (the first vibrator group 106 and the second vibrator group 107), and generate ultrasonic image data based on the reflected wave data obtained by beamforming. The reception circuit 112, the signal processing circuit 130, and the image generation circuit 140 are an example of a generation unit. Note that the reception circuit 112 performs beamforming on a plurality of reception signals output from a plurality of vibrators 104 or a plurality of vibrators 105 for each of a plurality of vibrator groups (the first vibrator group 106 and the second vibrator group 107) without performing apodization.

[0100] Also, the signal processing circuit 130 and the image generation circuit 140 add a plurality of reflected wave data (the first reflected wave data and the second reflected wave data) obtained by a plurality of beamformings generated for a plurality of vibrator groups (the first vibrator group 106 and the second vibrator group 107), and generate ultrasonic image data based on the data after addition. Here, the data after addition is an example of the signal after addition.

[0101] The image memory 150 is a memory that stores various image data generated by the image generation circuit 140. Also, the image memory 150 stores the data generated by the signal processing circuit 130. The B-mode data and Doppler data stored in the image memory 150 can be called by the operator after diagnosis, for example, and become ultrasonic image data for display via the image generation circuit 140. For example, the image memory 150 is realized by a semiconductor memory element such as a RAM or a flash memory, a hard disk, or an optical disk.

[0102] The storage circuit 160 stores control programs for performing scanning (ultrasonic transmission and reception), image processing, and display processing, diagnostic information (for example, patient ID, doctor's findings, etc.), diagnostic protocols, and various data such as various body marks. Also, the storage circuit 160 is used for storing the data stored in the image memory 150 as needed. For example, the storage circuit 160 is realized by a semiconductor memory element such as a flash memory, a hard disk, or an optical disk.

[0103] The control circuit 170 controls the entire processing of the ultrasonic diagnostic apparatus 1. Specifically, the control circuit 170 controls the processing of the transmission / reception 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 various data read from the storage circuit 160. Also, the control circuit 170 controls the display 103 to display an ultrasonic image based on the ultrasonic 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 the B-mode image data or a color image based on the color image data. Also, the control circuit 170 controls the display 103 to display a color image superimposed on the B-mode image. The control circuit 170 is an example of a display control unit or a control unit. The control circuit 170 is realized by a processor, for example. The ultrasonic image is an example of an image.

[0104] In addition, the control circuit 170 controls the ultrasonic probe 101 via the transmission / reception circuit 110 to perform ultrasonic scanning control.

[0105] The term "processor" used in the above description means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), or a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), or a field programmable gate array (FPGA)). The processor realizes its functions by reading out the program stored in the storage circuit 160 and executing the read program. Instead of storing the program in the storage circuit 160, the program may be directly incorporated into the circuit of the processor. In this case, the processor realizes its functions by reading out and executing the program incorporated in the circuit. Each processor of the present embodiment is not limited to being configured as a single circuit for each processor, and may be configured as one processor by combining a plurality of independent circuits to realize its functions. Further, a plurality of circuits in FIG. 1 (for example, the signal processing circuit 130, the image generation circuit 140, and the control circuit 170) may be integrated into one processor to realize its functions. That is, the signal processing circuit 130, the image generation circuit 140, and the control circuit 170 may be integrated into one processing circuit realized by a processor.

[0106] FIG. 12A is a diagram showing the PSF of the first oscillator group 106 of the RCA structure in the z-axis direction as contour lines at 6 dB intervals. FIG. 12B is a diagram showing the PSF of the second oscillator group 107 of the RCA structure in the z-axis direction as contour lines at 6 dB intervals. FIG. 12C is a diagram showing the addition of the content shown in FIG. 12B to the content shown in FIG. 12A.

[0107] FIG. 13A represents the content shown in FIG. 12A as an image 186 from the peak to -40 dB. FIG. 13B represents the content shown in FIG. 12B as an image 187 from the peak to -40 dB. FIG. 13C represents the content shown in FIG. 12C as an image 188 from the peak to -40 dB.

[0108] Comparing the image 188 shown in FIG. 13C with the image 310 shown in the previous FIG. 5B, it can be seen that in the ultrasonic diagnostic apparatus 1 according to the first embodiment, the side lobe is reduced as compared with the ultrasonic diagnostic apparatus 300 including the oscillator group of the RCA structure when reception apodization and transmission apodization are not performed.

[0109] Also, comparing the image 188 shown in FIG. 13C with the image 311 shown in the previous FIG. 5C, it can be seen that in the ultrasonic diagnostic apparatus 1 according to the first embodiment, the main lobe is steeper and has higher resolution as compared with the ultrasonic diagnostic apparatus 300 including the oscillator group of the RCA structure when reception apodization and transmission apodization are performed.

[0110] Here, in order to clearly explain the effects exhibited by the ultrasonic diagnostic apparatus 1 according to the first embodiment, images with a display dynamic range of 30 dB are shown in FIGS. 14A to 14C. FIG. 14A represents the content shown in the previous FIG. 4B as an image 189 from the peak to -30 dB. FIG. 14B represents the content shown in the previous FIG. 4C as an image 190 from the peak to -30 dB. FIG. 14C represents the content shown in the previous FIG. 12C as an image 191 from the peak to -30 dB.

[0111] When comparing the image 191 shown in FIG. 14C with the image 189 shown in FIG. 14A, it is clearly understood that in the ultrasonic diagnostic apparatus 1 according to the first embodiment, the side lobes are reduced as compared with the ultrasonic diagnostic apparatus 300 including the transducer group of the RCA structure when reception apodization and transmission apodization are not performed.

[0112] Also, when comparing the image 191 shown in FIG. 14C with the image 190 shown in FIG. 14B, it is clearly understood that in the ultrasonic diagnostic apparatus 1 according to the first embodiment, the main lobe is steeper and has higher resolution as compared with the ultrasonic diagnostic apparatus 300 including the transducer group of the RCA structure when reception apodization and transmission apodization are performed.

[0113] From the above, according to the ultrasonic diagnostic apparatus 1 according to the first embodiment, the image quality can be improved.

[0114] The ultrasonic diagnostic apparatus 1 according to the first embodiment has been described above. From the above description, according to the ultrasonic diagnostic apparatus 1 according to the first embodiment, the image quality of the ultrasonic image obtained by using the transducer group of the RCA structure can be improved.

[0115] (Second Embodiment) In the first embodiment, the case where the ultrasonic probe 101 includes two systems of transducer groups (the first transducer group 106 and the second transducer group 107) as the transducer group of the RCA structure has been described. However, the ultrasonic probe 101 may include three or more systems of transducer groups as the transducer group of the RCA structure. 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 the description of the configuration similar to that of the first embodiment may be omitted.

[0116] FIG. 15A and FIG. 15B are diagrams showing an example of the configuration of the ultrasonic probe 101 according to the second embodiment. As shown in FIG. 15A, the ultrasonic probe 101 according to the second embodiment includes a first vibrator group 192 of the RCA structure, a second vibrator group 193 of the RCA structure, a third vibrator group 194 of the RCA structure, and a fourth vibrator group 195 of the RCA structure. That is, the ultrasonic probe 101 includes four systems of vibrator groups as the vibrator groups of the RCA structure.

[0117] In the second embodiment, the ultrasonic probe 101 includes a plurality of vibrators 196, a plurality of vibrators 197, a plurality of vibrators 198, and a plurality of vibrators 199. For example, the vibrators 196, 197, 198, and 199 are assigned as four vibrators arranged in a 2×2 block with 2 rows in the x-axis direction and 2 columns in the y-axis direction. And such blocks are arranged in a two-dimensional manner in the x-axis direction and the y-axis direction.

[0118] The vibrators 196, 197, 198, and 199 are constituted by, for example, MUTs. Examples of such MUTs include CMUTs. One cell of the MUT corresponds to one vibrator 196, one vibrator 197, one vibrator 198, or one vibrator 199.

[0119] The two-dimensional coordinate system constituted by the x-axis and the y-axis shown in FIG. 15A corresponds to the first vibrator group 192 of the RCA structure. Also, the two-dimensional coordinate system constituted by the x3-axis and the y3-axis shown in FIG. 15A corresponds to the second vibrator group 193 of the RCA structure. Here, the two-dimensional coordinate system constituted by the x3-axis and the y3-axis is a coordinate system obtained by rotating the two-dimensional coordinate system constituted by the x-axis and the y-axis by 22.5° around the origin of the two-dimensional coordinate system constituted by the x-axis and the y-axis.

[0120] In addition, the two-dimensional coordinate system composed of the x4-axis and the y4-axis shown in FIG. 15A corresponds to the third oscillator group 194 of the RCA structure. Here, the two-dimensional coordinate system composed of the x4-axis and the y4-axis is a coordinate system obtained by rotating the two-dimensional coordinate system composed of the x-axis and the y-axis by 45° around the origin of the two-dimensional coordinate system composed of the x-axis and the y-axis.

[0121] In addition, the two-dimensional coordinate system composed of the x5-axis and the y5-axis shown in FIG. 15A corresponds to the fourth oscillator group 195 of the RCA structure. Here, the two-dimensional coordinate system composed of the x5-axis and the y5-axis is a coordinate system obtained by rotating the two-dimensional coordinate system composed of the x-axis and the y-axis by 67.5° around the origin of the two-dimensional coordinate system composed of the x-axis and the y-axis.

[0122] When the first oscillator group 192 of the RCA structure transmits ultrasonic waves, as shown in FIG. 15B, the ultrasonic probe 101 commonly connects one of the two surfaces (for example, the front surface) of each of the plurality of oscillators 196 arranged in the column direction (y-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 196 arranged in the column direction (y-axis direction). As a result, an oscillator group composed of a plurality of oscillators 196 connected in series and arranged in the column direction is arranged in a plurality of rows in the row direction (x-axis direction). Note that the plurality of oscillators 104 arranged in the column direction (y-axis direction) are an example of the first plurality of oscillators.

[0123] In addition, when the first oscillator group 192 of the RCA structure receives ultrasonic waves (reflected waves), as shown in FIG. 15B, the ultrasonic probe 101 commonly connects the other of the two surfaces (for example, the back surface) of each of the plurality of oscillators 196 arranged in the row direction (x-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 196 arranged in the row direction (x-axis direction). As a result, an oscillator group composed of a plurality of oscillators 196 connected in series and arranged in the row direction is arranged in a plurality of rows in the column direction (y-axis direction). Note that the plurality of oscillators 196 arranged in the row direction (x-axis direction) are an example of the second plurality of oscillators.

[0124] Also, when the second oscillator group 193 of the RCA structure transmits ultrasonic waves, as shown in FIG. 15B, the ultrasonic probe 101 commonly connects one of the two surfaces (for example, the front surface) of each of the plurality of oscillators 197 arranged in the column direction (y3-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 197 arranged in the column direction (y3-axis direction). Here, the plurality of oscillators 197 arranged in the column direction (y3-axis direction) does not mean a plurality of oscillators 197 arranged in a straight line in the column direction (y3-axis direction), but means a plurality of oscillators 197 included within a range having a certain width in the row direction (x3-axis direction). As a result, an oscillator group composed of a plurality of oscillators 197 connected in series and arranged in the column direction will be arranged in a plurality of rows in the row direction (x-axis direction). Note that the plurality of oscillators 197 arranged in the column direction (y-axis direction) is an example of the first plurality of oscillators.

[0125] Also, when the second oscillator group 193 of the RCA structure receives ultrasonic waves (reflected waves), as shown in FIG. 15B, the ultrasonic probe 101 commonly connects the other of the two surfaces (for example, the back surface) of each of the plurality of oscillators 197 arranged in the row direction (x3-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 197 arranged in the row direction (x3-axis direction). Here, the plurality of oscillators 197 arranged in the row direction (x3-axis direction) does not mean a plurality of oscillators 197 arranged in a straight line in the row direction (x3-axis direction), but means a plurality of oscillators 197 included within a range having a certain width in the column direction (y3-axis direction). As a result, an oscillator group composed of a plurality of oscillators 197 connected in series and arranged in the row direction will be arranged in a plurality of rows in the column direction (y3-axis direction). Note that the plurality of oscillators 197 arranged in the row direction (x3-axis direction) is an example of the second plurality of oscillators.

[0126] Also, when the third oscillator group 194 of the RCA structure transmits ultrasonic waves, as shown in FIG. 15B, the ultrasonic probe 101 commonly connects one of the two surfaces (e.g., the front surface) of each of the plurality of oscillators 198 arranged in the column direction (y4-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 198 arranged in the column direction (y4-axis direction). Here, the plurality of oscillators 198 arranged in the column direction (y4-axis direction) does not mean a plurality of oscillators 198 arranged in a straight line in the column direction (y4-axis direction), but means a plurality of oscillators 198 included within a range having a certain width in the row direction (x4-axis direction). As a result, an oscillator group composed of a plurality of oscillators 198 connected in series and arranged in the column direction will be arranged in a plurality of rows in the row direction (x4-axis direction). Note that the plurality of oscillators 198 arranged in the column direction (y4-axis direction) is an example of the first plurality of oscillators.

[0127] Also, when the third oscillator group 194 of the RCA structure receives ultrasonic waves (reflected waves), as shown in FIG. 15B, the ultrasonic probe 101 commonly connects the other of the two surfaces (e.g., the back surface) of each of the plurality of oscillators 198 arranged in the row direction (x4-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 198 arranged in the row direction (x4-axis direction). Here, the plurality of oscillators 198 arranged in the row direction (x4-axis direction) does not mean a plurality of oscillators 198 arranged in a straight line in the row direction (x4-axis direction), but means a plurality of oscillators 198 included within a range having a certain width in the column direction (y4-axis direction). As a result, an oscillator group composed of a plurality of oscillators 198 connected in series and arranged in the row direction will be arranged in a plurality of rows in the column direction (y4-axis direction). Note that the plurality of oscillators 198 arranged in the row direction (x4-axis direction) is an example of the second plurality of oscillators.

[0128] Also, when the fourth oscillator group 195 of the RCA structure transmits ultrasonic waves, as shown in FIG. 15B, the ultrasonic probe 101 commonly connects one of the two surfaces (e.g., the front surface) of each of the plurality of oscillators 199 arranged in the column direction (y5-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 199 arranged in the column direction (y5-axis direction). Here, the plurality of oscillators 199 arranged in the column direction (y5-axis direction) does not mean a plurality of oscillators 199 arranged in a straight line in the column direction (y5-axis direction), but means a plurality of oscillators 199 included within a range having a certain width in the row direction (x5-axis direction). As a result, an oscillator group composed of a plurality of oscillators 199 connected in series and arranged in the column direction will be arranged in a plurality of columns in the row direction (x5-axis direction). Note that the plurality of oscillators 199 arranged in the column direction (y5-axis direction) is an example of the first plurality of oscillators.

[0129] Also, when the fourth oscillator group 195 of the RCA structure receives ultrasonic waves (reflected waves), as shown in FIG. 15B, the ultrasonic probe 101 commonly connects the other of the two surfaces (e.g., the back surface) of each of the plurality of oscillators 199 arranged in the row direction (x5-axis direction). That is, the ultrasonic probe 101 commonly connects the plurality of oscillators 199 arranged in the row direction (x5-axis direction). Here, the plurality of oscillators 199 arranged in the row direction (x5-axis direction) does not mean a plurality of oscillators 199 arranged in a straight line in the row direction (x5-axis direction), but means a plurality of oscillators 199 included within a range having a certain width in the column direction (y5-axis direction). As a result, an oscillator group composed of a plurality of oscillators 199 connected in series and arranged in the row direction will be arranged in a plurality of columns in the column direction (y5-axis direction). Note that the plurality of oscillators 199 arranged in the row direction (x5-axis direction) is an example of the second plurality of oscillators.

[0130] Then, the ultrasonic diagnostic apparatus 1 according to the second embodiment performs the same processing as the processing performed by the ultrasonic diagnostic apparatus 1 according to the first embodiment using the four systems of oscillator groups (the first oscillator group 192, the second oscillator group 193, the third oscillator group 194, and the fourth oscillator group 195) described above.

[0131] As described above, the ultrasonic probe 101 according to the second embodiment includes a plurality of vibrators 196, 197, 198, 199 arranged two-dimensionally. When transmitting ultrasonic waves, the ultrasonic probe 101 commonly connects a plurality of vibrators 196, a plurality of vibrators 197, a plurality of vibrators 198, or a plurality of vibrators 199 arranged in the direction of one of two axes (for example, the x-axis and the y-axis, the x3-axis and the y3-axis, the x4-axis and the y4-axis, or the x5-axis and the y5-axis) that intersect each other (for example, the column direction described above). When receiving ultrasonic waves, the ultrasonic probe 101 commonly connects a plurality of vibrators 196, a plurality of vibrators 197, a plurality of vibrators 198, or a plurality of vibrators 199 arranged in the direction of the other of the two axes (for example, the row direction described above). The ultrasonic probe 101 includes a plurality of vibrator groups of the row-column addressing type (the first vibrator group 192, the second vibrator group 193, the third vibrator group 194, and the fourth vibrator group 195).

[0132] In the second embodiment, a plurality of pairs of two axes (for example, the pair of the x-axis and the y-axis, the pair of the x3-axis and the y3-axis, the pair of the x4-axis and the y4-axis, and the pair of the x5-axis and the y5-axis) corresponding to the plurality of vibrator groups of the row-column addressing type (the first vibrator group 192, the second vibrator group 193, the third vibrator group 194, and the fourth vibrator group 195) are different from each other.

[0133] Also, in the second embodiment, the ultrasonic probe 101 is configured such that the product of the angular interval (for example, 22.5°) of a plurality of pairs of two axes (for example, the pair of the x-axis and the y-axis, the pair of the x3-axis and the y3-axis, the pair of the x4-axis and the y4-axis, and the pair of the x5-axis and the y5-axis) corresponding to the plurality of vibrator groups of the row-column addressing type (the first vibrator group 192, the second vibrator group 193, the third vibrator group 194, and the fourth vibrator group 195) and the number of the plurality of vibrator groups of the row-column addressing type (for example, 4) is 90°. The ultrasonic probe 101 includes a plurality of vibrator groups of the row-column addressing type (the first vibrator group 192, the second vibrator group 193, the third vibrator group 194, and the fourth vibrator group 195).

[0134] The above describes the ultrasonic diagnostic apparatus 1 according to the second embodiment. According to the ultrasonic diagnostic apparatus 1 according to the second embodiment, the same effects as those achieved by the ultrasonic diagnostic apparatus 1 according to the first embodiment are achieved.

[0135] Note that the program executed by the processor is provided by being pre - incorporated into a ROM (Read Only Memory), a storage circuit, or the like. Note that this program may be recorded and provided on a computer - readable non - transitory storage medium such as a CD (Compact Disk) - ROM, FD (Flexible Disk), CD - R (Recordable), DVD (Digital Versatile Disk) in a form installable or executable on these devices. Further, this program may be stored on a computer connected to a network such as the Internet and provided or distributed by being downloaded via the network. For example, this program is composed of modules including the above - described respective processing functions. As actual hardware, the CPU reads the program from a storage medium such as a ROM and executes it, so that each module is loaded onto the main storage device and generated on the main storage device.

[0136] According to at least one of the embodiments described above, the image quality of the ultrasonic image obtained using the oscillator group with the RCA structure can be improved.

[0137] Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0138] 1 Ultrasonic diagnostic apparatus 112 Receiver circuit 130 Signal processing circuit 140 Image generation circuit 170 Control circuit

Claims

1. An ultrasonic probe comprising a plurality of first oscillator groups; a generation unit that performs beamforming on a plurality of received signals output from the plurality of first oscillator groups, and generates ultrasonic image data based on the signals obtained by the beamforming; a display control unit that causes a display unit to display an ultrasonic image based on the ultrasonic image data; comprising: each of the plurality of first oscillator groups includes a plurality of oscillators two-dimensionally arranged in a two-dimensional coordinate system defined by two intersecting axes, and when transmitting ultrasonic waves, a first plurality of oscillators arranged in the direction of one of the two axes are commonly connected, and when receiving ultrasonic waves, a second plurality of oscillators arranged in the direction of the other of the two axes are commonly connected, which is a Row-Column Addressing type oscillator group; the first plurality of oscillators arranged in the direction of one of the axes are a plurality of oscillators included within a range having a certain width in the direction of the other axis; the second plurality of oscillators arranged in the direction of the other axis are a plurality of oscillators included within a range having a certain width in the direction of one of the axes; each of the plurality of first oscillator groups, when receiving ultrasonic waves, comprises a plurality of second oscillator groups each including a second plurality of oscillators commonly connected; each of the plurality of configured second oscillator groups outputs a received signal obtained by adding signals output from the commonly connected second plurality of oscillators; the generation unit performs the beamforming on the plurality of received signals output from the plurality of second oscillator groups for each of the first oscillator groups, and generates the ultrasonic image data based on the signals obtained by the beamforming; for the plurality of first oscillator groups, the direction in which the first plurality of commonly connected oscillators included in one of the first oscillator groups of the plurality of first oscillator groups are arranged is different from the direction in which the first plurality of commonly connected oscillators included in another first oscillator group of the plurality of first oscillator groups are arranged; the direction in which the second plurality of commonly connected oscillators included in one of the first oscillator groups of the plurality of first oscillator groups are arranged is different from the direction in which the second plurality of commonly connected oscillators included in another first oscillator group of the plurality of first oscillator groups are arranged; an ultrasonic diagnostic apparatus.

2. The ultrasonic diagnostic apparatus according to claim 1, wherein the generation unit adds the plurality of signals obtained for the plurality of first oscillator groups, and generates the ultrasonic image data based on the signal after addition.

3. The ultrasonic diagnostic apparatus according to claim 1 or 2, wherein the generation unit performs beamforming on the plurality of reception signals output from the plurality of second oscillator groups without performing apodization for each of the first oscillator groups.

4. For each of the plurality of two-dimensional coordinate systems corresponding to the plurality of first oscillator groups, the angle formed by one of the two axes defining the two-dimensional coordinate system and one of the two axes defining another two-dimensional coordinate system is a natural multiple of a predetermined angle, and the plurality of two-dimensional coordinate systems are defined. The ultrasonic probe includes the plurality of first oscillator groups of the row-column addressing type configured such that the product of the predetermined angle and the number of the plurality of oscillator groups is 90°, and the ultrasonic diagnostic apparatus according to any one of claims 1 to 3.

5. The ultrasonic diagnostic apparatus according to any one of claims 1 to 4, wherein the ultrasonic probe includes the plurality of oscillators constituted by MUT (Micromachined Ultrasonic Transducer).

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