JP2009284941A - Ultrasonic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic device for acquiring a signal of high S/N even in a deep part of an object to be examined. <P>SOLUTION: A transmission circuit supplies a first and a second ultrasonic probes with signals so that an observation axis 3a of a first ultrasonic beam transmitted by the first ultrasonic probe and an observation axis 3b of a second ultrasonic beam transmitted by the second ultrasonic probe intersect at an intersection point and a time when a pulse wave transmitted by the first ultrasonic probe passes the intersection point and a time when a pulse wave transmitted by the second ultrasonic probe passes the intersection point at least overlap at one part. Thus, a third ultrasonic beam is formed on an axis 3c different from observation axes 3a and 3b. A receiving processing circuit extracts and processes a signal corresponding to a reflection wave from a point on the axis 3c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic apparatus that acquires a tomographic image or a three-dimensional image of a sample using ultrasonic waves, and particularly relates to an ultrasonic apparatus that performs imaging using a plurality of probes.

  A conventional apparatus for obtaining a tomographic image using general ultrasonic waves includes a transmission unit that transmits ultrasonic waves to an inspection object (sample), a reception unit that receives reflected waves, and a scan for scanning transmitted / received waves. And means for converting and visualizing the received reflected signal into a luminance signal. And the inside of a sample is observed using the time-sequential tomographic image acquired by these means. In one form of the above apparatus, a three-dimensional image is obtained by scanning ultrasonic waves vertically and horizontally by the scanning means.

  A living body can be mentioned as an object to be observed by ultrasonic waves. It is well known that ultrasonic waves are often used for observing the inside of a living body because the real-time property, simplicity, and non-invasiveness of an ultrasonic device are advantageous.

  Ultrasound used for observing the inside of a living body is transmitted and received by a plurality of electromechanical transducers (mainly piezoelectric elements). The transmission unit matches the phase of the ultrasonic wave transmitted from each element at the focus position by shifting the timing at which the electric signal (drive signal) is applied to each element. As a result, it is possible to generate an ultrasonic wave that converges at the focus position. Such a region through which the ultrasonic wave passes is a region centered on a straight line connecting the center of the plurality of driven elements (the center of the opening) and the focus position. This region is called a transmission beam (ultrasonic beam). On the other hand, the receiving unit receives the electrical signal generated from the reflected wave received by each element, corrects the time delay corresponding to the focus position, and then adds the signal of each element. Thereby, an ultrasonic reflection signal at the focus position is acquired. Note that the focus position at the time of reception can be changed in real time. In addition, a region where a reflected signal is acquired at the time of reception with respect to the previous transmission beam may be referred to as a reception beam.

  By performing such transmission / reception control, the ultrasonic apparatus can focus the ultrasonic wave on a portion to be observed, and image the inside of the living body by the reflected wave intensity.

  The reason why it is necessary to form a transmission / reception beam is that the reflection intensity of the ultrasonic wave inside the living body is low and the attenuation due to propagation is very large.

  The attenuation by propagation will be described. In general, attenuation of ultrasonic waves in a living body is 0.5 to 1 dB / (MHz · cm). For example, when a site having a depth of 10 cm is observed with 3 MHz ultrasonic waves, attenuation of 30 to 60 dB occurs only by reciprocating. Further, assuming that the reflectance is about 1% (equivalent to −40 dB), the attenuation is 70 to 100 dB in total. In order to suppress the decrease in the S / N ratio of the received signal due to such attenuation, the transmission / reception beam is formed as described above.

Patent Document 1 describes a technique for improving the S / N ratio by using a goal ray code that matches the frequency band of an ultrasonic transducer.
Japanese Patent No. 3423935 (Japanese Patent Laid-Open No. 2001-299750)

  However, since the magnitude of attenuation depends on the distance, it is difficult to ensure the SN ratio particularly when observing a portion far from the ultrasonic probe. Nonetheless, since safety standards are provided for ultrasonic power that can be input to a living body, there is a limit to the method of increasing the input power to improve the SN ratio.

In addition, the half-width of the transmit / receive beam that determines the azimuth resolution of the image is
Δy = d / 2≈1.22λ / D × X
(D: beam width, D: aperture width, X: depth)
It is represented by If the size of the aperture is constant, the beam width becomes wider when observing a deeper part, and the S / N ratio decreases when considered by the reflection intensity per unit volume of the observed part. . Note that the opening here refers to a region formed by an element that actually performs transmission and reception.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an ultrasonic apparatus capable of acquiring a signal having a high S / N ratio even in a deep part of an inspection object.

  In order to achieve the above object, an ultrasonic apparatus according to the present invention includes a first ultrasonic probe having a plurality of transducers, a second ultrasonic probe having a plurality of transducers, and ultrasonic waves to be transmitted. A transmission circuit for supplying signals to the first and second ultrasonic probes, a reception processing circuit for processing signals obtained from the ultrasonic waves received by the first and second ultrasonic probes, and the reception processing circuit An image processing unit that forms image information using information output from the control unit, and a control unit that controls the transmission circuit and the reception processing circuit. The transmission circuit transmits from the first ultrasonic probe. A first axis that is an axis of the first ultrasonic beam to be intersected with a second axis that is an axis of the second ultrasonic beam transmitted from the second ultrasonic probe, and Transmitted from the first ultrasonic probe. The first and second ultrasonic waves so that the time when the pulse wave passes through the intersection and the time when the pulse wave transmitted from the second ultrasonic probe passes through the intersection overlap at least partially. By supplying a signal to the probe, a third ultrasonic beam is formed on a third axis different from the first and second axes, and the reception processing circuit has a point on the third axis. The signal corresponding to the reflected wave from is extracted and processed.

  According to the present invention, it is possible to form a third ultrasonic beam, thereby obtaining a signal having a high S / N ratio even in the deep part of the inspection object.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. Although an example of a medical ultrasonic diagnostic apparatus is shown here as an example of an ultrasonic apparatus, the present invention is preferably applicable to various ultrasonic inspection apparatuses that use an object other than a living body as an inspection object. .

<Example 1>
FIG. 1 is a system schematic diagram of an ultrasonic apparatus according to Embodiment 1 of the present invention.

  The ultrasonic apparatus includes a plurality of ultrasonic probes 1a and 1b. Each of the ultrasonic probes 1a and 1b includes a plurality of transducers (not shown). The vibrator is an element that performs mutual conversion between an electric signal and mechanical vibration (ultrasound), and for example, a piezoelectric element is used. Position sensors 5a and 5b are attached to the probes 1a and 1b, respectively.

Here, for convenience, the ultrasonic probe 1a is referred to as a first ultrasonic probe, and the ultrasonic probe 1b is referred to as a second ultrasonic probe. An ultrasonic beam formed by ultrasonic waves transmitted from the first ultrasonic probe is called a first ultrasonic beam or a first transmission beam, and the central axis of the beam is a first observation axis or a first transmission beam. This is called the 1 axis. Similarly, an ultrasonic beam formed by an ultrasonic wave transmitted from the second ultrasonic probe is called a second ultrasonic beam or a second transmission beam, and the central axis of the beam is a second observation axis or This is called the second axis.

  The ultrasonic apparatus includes a transmission circuit 6, a reception processing circuit 7, a probe position processing unit 8, an image processing unit 11, an image display unit 12, and a system control unit 13. The transmission circuit 6 is a circuit that supplies an electrical signal (drive signal) for transmitting ultrasonic waves to the ultrasonic probes 1a and 1b. The reception processing circuit 7 is a circuit that processes signals obtained from ultrasonic waves (reflected waves) received by the ultrasonic probes 1a and 1b. The probe position processing unit 8 is a circuit that acquires three-dimensional position information of the ultrasonic probes 1a and 1b based on outputs from the position sensors 5a and 5b. The image processing unit 11 is a circuit that forms image information (for example, a B mode image, an M mode image, and the like) using information output from the reception processing circuit 7. The image display unit 12 is a display device that displays an image signal output from the image processing unit 11. The image display unit 12 may be configured separately from the ultrasonic apparatus main body. The system control unit 13 is a circuit that controls the transmission circuit 6, the reception processing circuit 7, the probe position processing unit 8, the image processing unit 11, and the like.

  The signal flow will be described with reference to FIG. In FIG. 1, the probe position processing unit 8 acquires position information of the ultrasonic probes 1 a and 1 b and sends the information to the system control unit 13. Based on the position information, the system control unit 13 determines the transmission direction of each ultrasonic probe so that the observation axes of the ultrasonic beams transmitted from the respective ultrasonic probes intersect in the inspection object. The system control unit 13 sends information on the transmission direction and the separately set focus depth to the transmission circuit 6. Based on the information, the transmission circuit 6 determines the time delay and intensity of each transducer of each ultrasonic probe, and supplies an electrical signal for driving each transducer to the ultrasonic probes 1a and 1b.

  The formation of the transmission beam in the inspection object will be described with reference to FIGS. 2 and 3 are plots obtained by calculating and plotting the maximum sound pressure after the ultrasonic wave transmitted from one ultrasonic probe passes. FIG. 4 is a plot of the maximum sound pressure after the ultrasonic waves transmitted from the two ultrasonic probes have passed. The portion with the higher sound pressure is shown in a darker color.

  Paying attention to FIG. 2, the ultrasonic wave transmitted from the opening 2a of the first ultrasonic probe 1a forms a first transmission beam along the first observation axis 3a. When attention is paid to FIG. 3, the ultrasonic wave transmitted from the opening 2b of the second ultrasonic probe 1b forms a second transmission beam along the second observation axis 3b. In the calculation, attenuation due to propagation of ultrasonic waves is taken into account.

  In FIG. 4, the first observation axis 3a and the second observation axis 3b intersect, and the ultrasonic wave (pulse wave) transmitted from the opening 2a and the ultrasonic wave transmitted from the opening 2b are observed in the observation axes 3a, 3b. The maximum sound pressure distribution is shown when the intersections are simultaneously reached. When the transmission beam of each probe is controlled in this way, a region with a high sound pressure is formed along an axis 3c different from the first observation axis 3a and the second observation axis 3b. Hereinafter, this high sound pressure region is referred to as a third ultrasonic beam or a third transmission beam, and the axis 3c is referred to as a third observation axis or a third axis. The position of the third observation axis 3c can be calculated from the positions of the first and second observation axes 3a and 3b and the transmission timing (phase difference) of the ultrasonic waves from the openings 2a and 2b. In the example of FIG. 4, the third observation axis 3c is formed so as to pass through the intersection of the observation axes 3a and 3b and bisect the angle formed by the observation axes 3a and 3b.

As can be seen from FIG. 4, the third transmission beam is converged in a deeper part of the inspection object than the first and second transmission beams, and the half-value width thereof is that of the first and second transmission beams. It is narrower than the full width at half maximum. Therefore, by using the reflected wave by the third transmission beam, it is possible to obtain a signal having a high reflection intensity per unit volume and a high SN ratio even in the deep part of the inspection object.

  Further, different forms of transmission beam formation will be described with reference to FIGS. 5 to 8, as in FIG. 4, the first observation axis 3a and the second observation axis 3b intersect, and the ultrasonic wave transmitted from the opening 2a and the ultrasonic wave transmitted from the opening 2b are observed. In this example, the transmission beam is controlled so as to reach the intersection of the axes 3a and 3b at the same time. However, in FIGS. 5 to 8, the positional relationship between the intersection of the observation axes 3a and 3b and the focus points 4a and 4b on the observation axes 3a and 3b is changed. That is, FIG. 5 is an example in which the focus point is set at a position sufficiently closer to the opening than the intersection of the observation axes. 6 and 7 are examples in which the focus point is set near the intersection of the observation axes. FIG. 6 is an example in which the focus point is closer to the opening, and FIG. 7 is an example in which the intersection is closer to the opening. FIG. 8 shows an example in which the focus point is set sufficiently far from the intersection of the observation axes. In either case, it can be seen that a third transmission beam having a narrow half-value width is formed in a portion deeper than the first and second transmission beams.

  Returning to FIG. 1, reception will be described. The ultrasonic probes 1a and 1b receive reflected waves from the object to be inspected by a plurality of vibrators. The received reflected waves are converted into electric signals and input to the reception processing circuit 7. Further, the system control unit 13 uses the position information from the probe position processing unit 8 to generate information on the positional relationship between the ultrasonic probes 1a and 1b and the observation point on the third observation axis 3c. , It is transmitted to the reception processing circuit 7. Specifically, the system control unit 13 determines the position at which the third observation axis 3c is formed from the positions of the first and second observation axes 3a and 3b and the transmission timings of the ultrasonic probes 1a and 1b. Calculate and set an observation point on the third observation axis 3c. In this embodiment, the observation point is set on a straight line passing through the intersection of the first and second observation axes 3a and 3b, and the ultrasonic wave transmitted from the two openings 2a and 2b is the same as passing through the intersection. It is set to pass the intersection at the timing.

  Using this positional relationship information, the reception processing circuit 7 performs time delay processing on the input time-series electrical signals, and then adds them to reflect from the designated observation point. Extract signals related to waves. Next, the reception processing circuit 7 detects the envelope of the extracted signal and transmits the electric signal to the image processing unit 11. The image processing unit 11 uses the position information of the observation point transmitted from the system control unit 13 and the electrical signal transmitted from the reception processing circuit 7 to generate a luminance signal at each position in the observation region, and Output to the display unit 12.

  By sequentially performing the above processing while changing the transmission direction, an image in the observation region can be formed. Note that it is possible to form an image using not only a reflected wave from a point on the third axis but also a reflected wave from a point on the first axis and a point on the second axis. Preferred for enlargement. In that case, it is desirable to perform synthesis or filtering processing so that the boundary of the image data obtained on each observation axis is not conspicuous.

  By using the ultrasonic diagnostic apparatus as described above, a signal having a high SN ratio can be acquired even in the deep part.

  In the present embodiment, the case where there are two ultrasonic probes has been described, but the same effect can be obtained even when three or more probes are used. Furthermore, in the present embodiment, the explanation was made on a plane, but the effect can be obtained by the same processing even in a three-dimensional space.

Moreover, the structure by which the some ultrasonic probe is being fixed to the jig | tool is also preferable. In this case, since the relative positions between the probes are known and do not change, it is not necessary to acquire probe position information for the calculation of the observation axes 3a to 3c. Therefore, the position sensor and the probe position processing unit can be omitted.

  In this embodiment, the aperture is used to mean a region formed by a plurality of transducers that transmit or receive. For example, in an ultrasonic probe for linear scanning composed of 128 transducers, when transmission / reception is performed using 32 transducers, the size of the opening is 32 elements. In an ultrasonic probe for sector scanning composed of 64 transducers, when 64 transducers are used, there are openings for 64 elements.

<Example 2>
Next, a second embodiment of the present invention will be described. In the first embodiment, the transmission timing is controlled so that the ultrasonic wave transmitted from the opening 2a and the ultrasonic wave transmitted from the opening 2b reach the intersection of the observation axes 3a and 3b at the same time. On the other hand, in the second embodiment, the transmission timing is shifted so that the ultrasonic waves do not reach the intersection of the observation axes 3a and 3b at the same time.

  FIG. 9 shows the maximum sound pressure distribution when ultrasonic waves are transmitted from the two openings 2a and 2b. FIG. 10 shows the time of the sound pressure waveform 20a on the time axis of the ultrasonic wave (pulse wave) transmitted from the opening 2a and the time of the ultrasonic wave (pulse wave) transmitted from the opening 2b at the intersection of the two observation axes 3a and 3b. A sound pressure waveform 20b on the axis is shown. In the sound pressure waveform 20a, the ultrasonic waveform 21a transmitted from the opening 2a is plotted, and in the sound pressure waveform 20b, the ultrasonic waveform 21b transmitted from the opening 2b is plotted. Actually, a sound pressure in which these two sound pressure waveforms are overlapped is observed, but is separated into two for the sake of explanation. These two ultrasonic waveforms 21 a and 21 b are overlapped by the length of the overlap time 22.

  As shown in FIG. 10, if the time for the ultrasonic wave transmitted from the opening 2a to pass through the intersection and the time for the ultrasonic wave transmitted from the opening 2b to pass through the intersection are at least partially overlapped, As shown in FIG. 9, the third transmission beam is formed. However, the third observation axis 3c in this case does not pass through the intersection of the two observation axes 3a and 3b.

  The ultrasonic apparatus of the present embodiment uses a signal related to a reflected wave from a designated observation point on the third observation axis 3c. In the present embodiment, since the third observation axis 3c does not pass through the intersection, it is necessary to separately calculate the formation position. Therefore, as shown in FIG. 11, the ultrasonic apparatus of this embodiment includes a beam position calculation unit 14.

  Prior to transmission / reception control, the system control unit 13 transmits information on the transmission direction, the depth of focus, and the position of the probe to the beam position calculation unit 14. The beam position calculation unit 14 calculates at what timing and where the third observation axis 3c is formed. The calculation result is stored in a storage unit (memory) in the beam position posting unit 14 in the form of a table. In this calculation, it is possible to use a method such as the Rayleigh integration method from the transmitted sound pressure on the aperture, the sound pressure distribution estimation by the Green function, and the calculation using the spatial response function.

  Since the method of transmitting ultrasonic waves performs the same processing as in the first embodiment, description thereof is omitted. At the time of reception, the reception processing circuit 7 refers to the calculation result on the memory of the beam position calculation unit 14 to extract the reception signal from the observation point on the third axis. At that time, the reception processing circuit 7 performs reception signal processing using a signal obtained by a probe having a shorter distance between the observation point and the aperture among the ultrasonic probes 1a and 1b. By performing such processing, it is possible to perform reception at a place closer to the observation point, and it is possible to prevent a reduction in the intensity of the reflected wave. In FIG. 9, since the opening 2b is close to the observation point, image information is formed using the received signal from the ultrasonic probe 1b.

Note that the beam position calculation unit 14 has an MI (mechanical index) value and a TI (thermal index).
It is also possible to calculate values and display these values on the image display unit 12 via the system control unit 13. When the MI value or TI value exceeds the allowable range with respect to a predetermined reference, it is better to perform processing such as stopping transmission, displaying a warning on the display screen, or reducing transmission intensity.

  By performing the processing as described above, it is possible to acquire a signal with a high S / N ratio even in the deep part.

  The signal processing system can perform the above processing by using the same system as that of the first embodiment.

<Example 3>
Next, a third embodiment of the present invention will be described.

  FIG. 12 shows the maximum sound pressure distribution when ultrasonic waves are transmitted from the two openings 2a and 2b. In this embodiment, the openings 2a and 2b are installed in a positional relationship that is not parallel. When a plurality of ultrasonic probes are actually used, it is possible that the opening surfaces of the probes are not parallel to each other. Even in such a positional relationship, the third transmission beam is formed, and its half-value width is narrower than that of the first transmission beam and the second transmission beam.

  By the way, there is an angle dependency in ultrasonic transmission / reception sensitivity. Due to the small projection component of the opening area and the fact that each vibrator has an angle dependency, the sensitivity tends to be high in the front direction of the opening, and the sensitivity tends to be low in other directions.

  Because of such angle dependence, it is desirable that the reflected wave can be acquired in the vertical direction of the opening as much as possible. Therefore, in the present embodiment, when the reception processing circuit 7 acquires the reflected wave from the observation point (10a, 10b) on the third observation axis 3c, the angle (9a, 9b) with respect to the vertical direction of the openings 2a, 2b. , 9c, 9d), which ultrasonic probe received signal is used is determined.

  For example, when acquiring the reflected wave from the observation point 10a, the reception processing circuit 7 observes the angle 9a that the straight line connecting the center of the opening 2a and the observation point 10a becomes a straight line perpendicular to the opening 2a, and the center of the opening 2b. An angle 9d formed by a straight line connecting the points 10a and a straight line perpendicular to the opening 2b is compared. In the example of FIG. 12, since the angle 9a is smaller, image information corresponding to the reflected wave from the observation point 10a is formed using the signal obtained by the ultrasonic probe 2a. On the other hand, when acquiring the reflected wave from the observation point 10b, similarly, the angle 9b and the angle 9c are compared, and the signal obtained by the ultrasonic probe 1b having the smaller angle is used.

  By performing the processing as described above, it is possible to efficiently receive the reflected wave from the third axis.

  Note that the processing of this embodiment can be executed by the system of FIG. 11 described in the second embodiment.

  The present invention has been described with reference to a plurality of examples. However, these are merely examples of the present invention. The scope of the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea. In addition, the configurations described in the embodiments can be appropriately combined.

FIG. 1 is a block diagram of the ultrasonic apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of a first ultrasonic beam transmitted from the first ultrasonic probe. FIG. 3 is a diagram illustrating an example of a second ultrasonic beam transmitted from the second ultrasonic probe. FIG. 4 is a diagram illustrating an example of a third ultrasonic beam formed by the first ultrasonic beam and the second ultrasonic beam according to the first embodiment. FIG. 5 is a diagram illustrating an example of a third ultrasonic beam according to the first embodiment. FIG. 6 is a diagram illustrating an example of a third ultrasonic beam according to the first embodiment. FIG. 7 is a diagram illustrating an example of a third ultrasonic beam according to the first embodiment. FIG. 8 is a diagram illustrating an example of a third ultrasonic beam according to the first embodiment. FIG. 9 is a diagram illustrating an example of a third ultrasonic beam according to the second embodiment. FIG. 10 is a diagram for explaining the transmission timing of the ultrasonic waves according to the second embodiment. FIG. 11 is a block diagram of the ultrasonic apparatus according to the second and third embodiments. FIG. 12 is a diagram illustrating an example of a third ultrasonic beam according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Ultrasonic probe 2a, 2b Opening of ultrasonic probe 3a, 3b, 3c Observation axis 5a, 5b Position sensor 6 Transmission circuit 7 Reception processing circuit 8 Probe position processing part 11 Image processing part 12 Image display part 13 System control part 14 Beam position calculator

Claims (7)

A first ultrasonic probe having a plurality of transducers;
A second ultrasonic probe having a plurality of transducers;
A transmission circuit for supplying signals for transmitting ultrasonic waves to the first and second ultrasonic probes;
A reception processing circuit for processing signals obtained from the ultrasonic waves received by the first and second ultrasonic probes;
An image processing unit that forms image information using information output from the reception processing circuit;
A control unit for controlling the transmission circuit and the reception processing circuit,
The transmission circuit includes:
A first axis that is an axis of a first ultrasonic beam transmitted from the first ultrasonic probe and a second axis that is an axis of a second ultrasonic beam transmitted from the second ultrasonic probe. The time when the pulse wave transmitted from the first ultrasonic probe passes through the intersection point and the time when the pulse wave transmitted from the second ultrasonic probe passes through the intersection point. By supplying signals to the first and second ultrasonic probes such that at least a part of
Forming a third ultrasonic beam on a third axis different from the first and second axes;
The reception processing circuit extracts and processes a signal corresponding to a reflected wave from a point on the third axis;
An ultrasonic device characterized by that. A probe position processing unit for acquiring position information of each of the first ultrasonic probe and the second ultrasonic probe;
The control unit calculates the positions of the first, second, and third axes based on the position information of the first and second ultrasonic probes acquired by the probe position processing unit.
The ultrasonic apparatus according to claim 1. The transmission circuit includes:
A signal is sent to the first and second ultrasonic probes so that the pulse wave transmitted from the first ultrasonic probe and the pulse wave transmitted from the second ultrasonic probe simultaneously reach the intersection. By supplying
Forming the third ultrasonic beam such that the third axis passes through the intersection;
The ultrasonic apparatus according to claim 1 or 2, wherein The reception processing circuit includes:
Extracting and processing signals corresponding to reflected waves from points on the first axis and / or points on the second axis;
The ultrasonic apparatus according to any one of claims 1 to 3. The image processing unit
Corresponding to image information formed from a signal corresponding to a reflected wave from a point on the third axis and a reflected wave from a point on the first axis and / or a point on the second axis Combining image information formed from the signal,
The ultrasonic apparatus according to claim 4. The reception processing circuit includes:
Of the first ultrasonic probe and the second ultrasonic probe, the third axis is obtained by using a signal obtained by an ultrasonic probe having a shorter distance from a point on the third axis. Extract the signal corresponding to the reflected wave from the upper point,
The ultrasonic apparatus according to any one of claims 1 to 5, wherein The reception processing circuit includes:
Of the first ultrasonic probe and the second ultrasonic probe, the angle formed by the straight line connecting the center of the opening of the ultrasonic probe and the point on the third axis is a straight line perpendicular to the opening. A signal corresponding to a reflected wave from a point on the third axis is extracted using a signal obtained by the other ultrasonic probe;
The ultrasonic apparatus according to any one of claims 1 to 5, wherein

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