JP2001238882A - Ultrasound diagnostic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ultrasound diagnostic equipment which can produce images by using probes with a large element pitch while simultaneceously satisfying in terms of high resolution, super sensitivity, and low grating lobe. SOLUTION: When transmitting beams or receiving beams are formed by making multiple bundles of subdiced elements 3 at a part 4 for binding elements, patterns for binding subdiced elements must be altered by receiving beams to differentiate from patterns for binding transmitting beams so that the positions of grating lobe for transmitting beams can meet the positions where the strength of the receiving beams are small, and the positions of grating lobe for receiving beams can meet the positions where the strength of the transmitting beams are small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ultrasonic diagnostic apparatus for forming an ultrasonic beam having a small grating lobe using a probe having a large element pitch.

[0002]

2. Description of the Related Art Ultrasound used for ultrasonic diagnosis is generated from thickness vibration of an element provided on a probe. Therefore, although it is ideal that the element performs only the thickness vibration, unnecessary vibrations other than the thickness vibration actually occur as shown in FIG. Therefore, as schematically shown in FIG. 2B, the element is cut more finely, and unnecessary vibration is suppressed while maintaining thickness vibration. This fine cutting of the element is called a sub die. A conventional ultrasonic diagnostic apparatus uses a probe in which each element is sub-diced in order to suppress unnecessary vibrations other than thickness vibrations. (1985) pages 188-189).

In a probe used in a conventional ultrasonic diagnostic apparatus, a minimum unit independently connected to a drive circuit and a delay circuit is each element, and a common electrode is provided for each sub-die element after a sub-die. It is attached (see the above-mentioned “Medical Ultrasound Equipment Handbook”, page 187).

[0004]

In an ultrasonic diagnostic apparatus, an undesired virtual image called a grating lobe appears on a tomographic image according to the element pitch. This will be described with reference to FIG. In the drawing, reference numeral 1 denotes a probe, D1 denotes a direction in which an ultrasonic main beam is formed, D2 denotes a direction in which a grating lobe appears, and θ denotes an angle between the two directions D1 and D2. If the wavelength of the ultrasonic wave is λ and the element pitch of the probe is d,
θ, λ, and d have a relationship represented by the following equation (1).

[0005] sin θ = λ / d (1)

That is, as the wavelength λ becomes shorter (as the frequency becomes higher) and as the element pitch d becomes larger, the angle θ becomes smaller, and a grating lobe appears near D1.
Therefore, in the ultrasonic diagnostic apparatus, the element pitch must be reduced in order to keep the grating lobe as far away from the ultrasonic main beam as possible. An example of the reference formula for determining the element pitch is disclosed in the aforementioned “Medical Ultrasound Equipment Handbook”, page 191.

On the other hand, the ultrasonic diagnostic apparatus gives a drive pulse to each element independently at the time of transmission for beam forming.
At the time of reception, a delay is given independently to the reception signal of each element. Assuming that the number of elements that can be controlled independently is N, the diameter D of the probe used for one ultrasonic transmission / reception is D = N · d. Here, the azimuth resolution of the device is inversely proportional to the aperture length D,
The transmission / reception sensitivity is proportional to the aperture length D. Therefore, the larger the value of N or d, the higher the resolution of the device and the higher the transmission / reception sensitivity. However, from the viewpoint of the circuit scale, N cannot be increased without limit, and many devices currently set N = 64 or N = 128. Therefore, in order to maintain the resolution and sensitivity of the device, it is necessary to increase the element pitch d.

That is, in the conventional ultrasonic diagnostic apparatus,
When the element pitch d is increased while giving priority to the resolution and sensitivity when N is constant, a problem arises in that the appearance position of the grating lobe is close to the ultrasonic main beam. And degradation of sensitivity. An object of the present invention is to solve the above problems and provide an ultrasonic diagnostic apparatus capable of performing imaging simultaneously satisfying high resolution, high sensitivity, and low grating lobe using a probe having a large element pitch. is there.

[0009]

To achieve the above object, an ultrasonic diagnostic apparatus according to the present invention includes a sub-diced element sub-diced to suppress unnecessary vibration other than thickness vibration, and transmits and receives ultrasonic waves to and from a subject. Probe, an element bundling control section, an element bundling section that bundles sub-die elements into a plurality of groups based on a control signal from the element bundling control section, and a sub-die element that is bundled into the same group by the element bundling section. On the other hand, a drive unit for giving the same transmission pulse, a delay unit for giving the same delay time required for ultrasonic beam formation to the received signals from the sub-die elements bundled in the same group by the element bundling unit, and a delay unit An adder for adding the outputs of the adder, a display for displaying the output of the adder as a tomographic image, and a transmission / reception separator for switching the device-side signal line of the element bundling unit to a drive or a delay for connection. The element bundling control unit determines the bundling pattern of the sub dice elements independently at the time of transmission and reception of the ultrasonic wave, and is generated by the grating lobe position of the transmission beam generated by the bundling pattern at the time of transmission and the bundling pattern at the time of reception. It is characterized in that the grating lobe position of the receiving beam is controlled independently.

[0010] The grating lobe intensity of the transmitted / received beam obtained by independently determining the bundle pattern of the sub dice elements at the time of transmission and reception of the ultrasonic wave is the same when the same bundle pattern of the sub dice elements as at the time of transmission is used at the time of reception. And the grating lobe intensity of the transmission / reception beam when the same bundle pattern of the sub dice elements is used during transmission as during reception. The bundle pattern of the sub dice elements may be determined such that the grating lobe position of the transmission beam matches the position where the reception beam intensity is low, and the grating lobe position of the reception beam matches the position where the transmission beam intensity is low.

When the ultrasonic beam deflection angle is smaller than a predetermined angle, the element bundling control unit sets the sub dice element bundling pattern at the time of transmission and the sub dice element bundling pattern at the time of reception to be the same, and the ultrasonic beam deflection angle becomes the predetermined angle. When the angle is larger than the above angle, the sub-die element bundling pattern at the time of transmission and the sub-die element bundling pattern at the time of reception can be made different. The predetermined angle may be substantially equal to the smaller one of the absolute value θt of the first grating lobe appearance angle of the transmission beam and the absolute value θr of the first grating lobe appearance angle of the reception beam.
According to the present invention, using a probe having a large element pitch,
It is possible to realize an ultrasonic diagnostic apparatus that performs imaging that simultaneously satisfies high resolution, high sensitivity, and low grating lobe.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing an example of an ultrasonic diagnostic apparatus according to the present invention. In the figure, 1 is a probe,
2 is an element, 3 is a sub die element, 4 is an element bundling section, 5 is an element bundling control section, 6 is a transmission / reception separation section, 7 is a driving section, 8 is a delay section, 9 is an addition section, 10 is a display section, and 20 controls. It is a control unit. The probe 1 is a set of sub-diced elements (micro piezoelectric materials) 2 as shown in FIG. That is, the piezoelectric material that is physically cut to the finest is the sub-die element 3, and the set of sub-die elements that are subjected to signal processing independently when transmitting or receiving ultrasonic waves is the element 2. Some or all of the elements of the probe 1 are selected and used for transmitting and receiving an ultrasonic beam. The portion of the selected probe is called the caliber.

The transmission / reception separating unit 6, the driving unit 7, the delay unit 8, and the adding unit 9 constitute a beam forming unit. When transmitting the ultrasonic beam,
The drive unit 7 of the beam forming unit controls the drive timing of each element located within the aperture of the probe 1 so that the transmission beam converges to the transmission focus point. Also, when receiving the ultrasonic beam,
The delay unit 8 and the addition unit 9 of the beam forming unit perform delay addition processing (phasing addition processing) of the reception signals of the respective elements located within the aperture of the probe 1, and amplify the reception signal from the reception focus point. . One raster on a tomographic image is formed by receiving a reception signal while sequentially changing the reception focus point in one ultrasonic transmission / reception. The transmitting and receiving beams are moved, a raster is formed at each beam position, and an ultrasonic tomographic image is formed. The tomographic image is displayed on the display unit 10. The general control section 20 comprehensively controls the beam forming section and the element control section. In the digital ultrasonic diagnostic apparatus, the CPU controls the entire apparatus.
Can be shared.

There are two methods for moving the transmitting and receiving beams.
In other words, as schematically shown in FIG. 5A, the aperture position in the probe is moved for each beam to form a raster along the probe, and linear scanning is schematically shown in FIG. 5B. Thus, sector scanning is performed in which the aperture position in the probe is fixed for all beams, the drive timing for transmission and the delay processing for reception are changed for each beam, and a raster is formed in a fan shape from the fixed aperture. The present invention can be applied to any of the transmission and reception beam moving methods.

In the following, for convenience of explanation, it is assumed that the number of elements of the probe is 4, each element 2 is divided into three sub-die elements 3, and the number of elements that can be controlled independently by the drive unit 7 and the delay unit 8 The following description is based on the assumption that (the number of channels) is 4. However,
This is for the sake of convenience for the sake of simplicity and ease of understanding, and does not mean that the application of the present invention is limited to such a specific probe.

First, the element bundling control unit 5 shown in FIG. 1 determines a sub dice element bundling pattern at the time of transmission. This example is shown in FIG. At the time of transmission, the element bundling unit 4 bundles the three sub dice elements 3 according to the control signal from the element bundling control unit 5 and treats them as one independent element (channel). If the width of the sub-die element 3 in the diameter direction is set to δ, the probe 1
Has an element pitch of 3δ, which matches the original element pitch. Each channel is driven by the applied voltage from the drive unit 7 through the transmission / reception separation unit 6, and as a result, the probe 1 irradiates the subject with ultrasonic pulses.

The irradiated ultrasonic pulse is reflected in the subject, and the reflected pulse is received by the probe 1. After the transmission processing of the device is completed, the element bundling unit 4 changes the bundling pattern of the sub dice elements 3 according to a control signal from the element bundling control unit 5. Here, if the time required for the element bundling unit 4 to switch the bundling of the sub dice elements 3 from the transmission pattern to the reception pattern is τ, and the sound velocity in the subject is c, the depth h of the subject that cannot be imaged is It is given by the following equation (2).

H = τc / 2 (2)

In actual living body imaging, 1
Since it is not necessary to image a depth range within mm, high-speed switching in which τ is 1.3 μs or less does not cause any practical problem. FIG. 7 shows an example of a sub-die element bundling pattern at the time of reception. At the time of reception, the two sub-die elements 3 are bundled and treated as one independent element (channel). If the width of the sub die element 3 is set to δ, the apparent element pitch of the probe 1 is 2δ, which is ２ of the original element pitch. Each channel is connected to the delay unit 8 through the transmission / reception separation unit 6. The combination conditions of the sub-die element bundling patterns at the time of transmission and at the time of reception can be unique for each probe. In this case, the combination conditions of the binding pattern are set in the device memory at the time of shipment from the factory, for example, and the probe 1
It is sufficient that the element bundling control unit 5 reads out from the memory at the time when is connected. Note that the element bundling unit 4 in FIGS. 6 and 7 determines a method of connecting the sub die element 3 and the transmission / reception separation unit 6. The delay unit 8 gives a delay for reception focusing to each channel signal and aligns the phases of all the signals. The signals having the same phase are added by the adder 9, and only the signal from the target direction (focus point) is amplified and displayed on the display 10 after being subjected to luminance modulation.

In the present invention, at the time of transmission and at the time of reception, the element bundling section 4 changes the bundling pattern of the sub dice elements 3 to reduce the grating lobe in a probe having a large element pitch. This utilizes that an ultrasonic transmission / reception beam is represented by a product of a transmission beam and a reception beam. If the bundle pattern is common for transmission and reception, the appearance position of the grating lobe is also common for the transmission beam and the reception beam. Therefore, also in the transmission / reception beam which is the product of the transmission beam and the reception beam, the grating lobe appears at the same position as the transmission beam and the reception beam. Where the transmit beam is
The ultrasonic waves generated from the elements to which the voltage is independently applied by the drive unit 7 are the intensity distribution of the ultrasonic waves generated in the subject. The reception beam has a sensitivity distribution that indicates from which part of the subject the reception signal is strongly received by the amplification processing of the reception signal by the phasing addition in the delay unit 8 and the addition unit 9.
In the reception beam, it is assumed that a reception signal is uniformly returned from each part of the subject. In addition, the transmission and reception beams, for a received signal having an intensity distribution from the subject irradiated with the transmission beam,
This is a sensitivity distribution indicating from which part of the subject the received signal is strongly received when the phasing addition processing is performed.

On the other hand, when the binding pattern is changed in transmission and reception, by devising a combination of the binding patterns,
Matching the grating lobe position of the transmit beam to a position where the receive beam intensity is low (ideally zero), and matching the grating lobe position of the receive beam to a position where the transmit beam intensity is low (ideally zero) Is possible. This gives the product transmit and receive beam:
The grating lobe intensity can be reduced.
That is, grating lobes appear in each of the transmission beam and the reception beam, but the intensity of the grating lobe decreases in the transmission / reception beam which is the product of the transmission beam and the reception beam. Further, in the present invention, the apparent element pitch is changed by focusing on the sub dice elements of each element and changing the way of bundling the sub dice elements.

FIG. 8 is an explanatory diagram showing the effect of matching the grating lobe position of the transmission beam with the position where the reception beam intensity is low and matching the grating lobe position of the reception beam with the position where the transmission beam intensity is low. . 8A shows a transmission beam, FIG. 8B shows a reception beam, and FIG. 8C shows a transmission and reception beam. In each figure, the horizontal axis is the azimuth direction sin (γ), and the vertical axis is the beam intensity (d
B). MB represents an ultrasonic main beam, and GL
Represents a grating probe. As shown in FIGS. 8A and 8B, the grating lobe position of the transmission beam was matched with the position where the intensity of the reception beam was small, and the grating lobe position of the reception beam was matched with the position where the intensity of the transmission beam was small. In this case, as shown in FIG. 8C, the grating lobe intensity of the transmission / reception beam is greatly reduced.

The effectiveness of the device operation described above was verified by computer simulation. The results of the computer simulation will be described below. In computer simulation,
The width of the sub-die element 3 in FIG. 1 in the probe diameter direction is 0.12 mm, the number of elements (the number of channels) that can be independently controlled by the drive unit 7 and the delay unit 8 is 64, and the transmitted ultrasonic pulse is 7.5 MHz. Four sin pulses (the envelope is in a Hanning shape) and the focus point was 50 mm in front of the center of the transmission and reception aperture. Here, the four sin pulse waves having the Hanning-shaped envelope are, as shown in FIG.
It is a pulse wave with four in carriers.

FIG. 10A shows transmission / reception beams when both the transmission bundle pattern and the reception bundle pattern are shown in FIG. The vertical axis represents the beam intensity obtained by standardizing the maximum value of the beam to 0 dB, and the horizontal axis represents the azimuthal direction of the beam (in units of mm). In the figure, MB is an ultrasonic main beam, and GL is a grating lobe. Although the total number of channels is assumed to be 4 in FIG. 6, the total number of channels is set to 64 in the actual computer simulation as described above. FIG. 10B shows transmitted / received beams when the transmission bundle pattern is shown in FIG. 7 and the reception bundle pattern is shown in FIG. 6 (similar transmission / reception beams are obtained when the transmission bundle pattern is shown in FIG. 6 and the reception bundle pattern is shown in FIG. 7). ).

FIG. 10A shows a conventional ultrasonic beam having a common element pitch for transmission and reception, and FIG. 10B shows an ultrasonic beam of the present invention for changing an apparent element pitch for transmission and reception. In the transmission / reception beam of FIG. 10B, the grating lobe intensity is lower than the transmission / reception beam of FIG. 10A by about 20 dB, and the effectiveness of the present invention can be proved.
However, in FIG. 10B, the receiving aperture is 2 in FIG.
Therefore, when the maximum value of the beam is compared with the amplitude before the standardization, the maximum amplitude in FIG. 10B is lower than that in FIG. 10A by 4 dB, which is almost equal to the aperture ratio (decreased by 3.5 dB). .

The apparent element pitch of the probe is shown in FIG.
7 is 0.26 mm, and the bundling pattern in FIG. 7 is 0.24 mm, which correspond to 1.75 wavelengths and 1.17 wavelengths at a frequency of 7.5 MHz, respectively. The element pitch at which the grating lobe can be completely removed is generally set to be equal to or less than a half wavelength. Therefore, FIG.
The reduction of the grating lobe intensity shown in FIG.
It is considered that this was not caused by the apparent element pitch becoming sufficiently small with respect to the wavelength, but caused by the cancellation of grating lobes in transmission and reception. To confirm this,
Transmission and reception beams were obtained when both the transmission bundle pattern and the reception bundle pattern were as shown in FIG. The results are shown in FIG. In the calculation of FIG. 10C, the number of channels is set to 96 for convenience in order to make the sensitivity almost equal to that of FIG.

A grating lobe also occurs in the transmission / reception beam of FIG.
It was confirmed that 4 mm was not fine enough to eliminate grating lobes. More notably, Figure 1
The transmission / reception beam of 0 (b) has a grating lobe intensity reduced by about 10 dB as compared with the transmission / reception beam of FIG. 10 (c). That is, in FIG. 10C, the grating lobe intensity is large even though the apparent element pitch at the time of reception is smaller than that in FIG. The result is that if the number of channels is limited in terms of the circuit scale and the element pitch cannot be made sufficiently small (1/2 wavelength or less) in order to maintain sensitivity and resolution, the element pitch is reduced to some extent by transmitting and receiving. It is shown that changing the element pitch in transmission / reception has higher sensitivity, higher resolution, and lower grating lobe strength than in the transmission / reception in which the element pitch remains large, rather than aligning.

FIG. 11 shows a bundling pattern of the elements shown in FIG.
(A) to (c) show the results of calculating transmission and reception beams with continuous wave beams in the same manner as in (a) to (c). The directivity of each element was ignored.
In each figure, the horizontal axis represents the azimuth direction sin (γ), and the vertical axis represents the beam intensity (dB). Further, MB represents an ultrasonic main beam, and GL represents grating probe. FIG.
(A) is a transmission / reception beam when both the transmission bundle pattern and the reception bundle pattern are shown in FIG. 6, and FIG. 11 (b) is a transmission / reception beam when the transmission bundle pattern is shown in FIG. 7 and the reception bundle pattern is FIG. FIG. 11C shows the transmission and reception beams when both the transmission bundle pattern and the reception bundle pattern are shown in FIG. As is clear from the comparison of the figures, FIG.
In FIGS. 11A and 11C, the grating probe has the same intensity as the main beam, but in FIG. 11B, the grating probe is significantly reduced. in this way,
It can be seen that grating lobes can be greatly reduced by changing the bundle pattern of elements between the transmission beam and the reception beam not only in the pulse beam but also in the continuous wave beam.

Next, under the same conditions as those shown in FIGS.
The ultrasonic beam tilted at 0 ° is shown in FIG.
(A), (b) and (c) show.

FIG. 12 shows a conventional ultrasonic beam.
FIG. 12 shows an ultrasonic beam according to the present invention as compared with FIG.
In (b), the grating lobe intensity is reduced by about 35 dB. The transmission / reception beam of FIG.
The grating lobe intensity is reduced by about 20 dB as compared with the transmission / reception beam of (c). Further, FIG.
Although the receiving aperture is 2/3 of that in FIG. 12A, when the beam maximum value is compared with the amplitude before the standardization, the maximum amplitude is 2.2 dB higher. In other words, when the beam is deflected, both the grating lobe intensity and the sensitivity
The present invention is superior to the conventional method. Generally, it is considered that the influence of the grating lobe increases as the deflection angle of the ultrasonic beam increases. Therefore, the present invention, which is effective for reducing the grating lobe, has a more remarkable effect on an ultrasonic beam having a large deflection angle and a large influence of the grating lobe.

FIG. 12 shows the calculation using the pulse beam. FIG. 13 shows the calculation result using the continuous wave beam. The directivity of each element was ignored. In each figure, the horizontal axis is the azimuth direction sin
(Γ), the vertical axis is the beam intensity (dB). Also, MB
Represents an ultrasonic main beam, and GL represents a grating probe. FIG. 13 (a) corresponds to FIG. 12 (a), and FIG.
FIG. 12B corresponds to FIG. 12B, and FIG. 13C corresponds to FIG. Also in this case, it can be seen that grating lobes can be greatly reduced by changing the bundle pattern of elements between the transmission beam and the reception beam.

FIG. 14 is a schematic explanatory view of another example of the ultrasonic diagnostic apparatus according to the present invention. This ultrasonic diagnostic apparatus corresponds to the apparatus shown in FIG. 1 in which a beam deflection angle output unit 11 is added. In FIG. 14, the same functional portions as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and duplicate description will be omitted.

From FIGS. 10 and 12, the effect of changing the apparent element pitch of the probe to reduce the grating lobe becomes more significant as the deflection angle of the ultrasonic beam increases. In FIG. 10, when the apparent element pitch is changed in transmission and reception, the grating lobe intensity decreases but the sensitivity also decreases. Therefore, when it is desired to give priority to sensitivity, it is desirable that the bundle pattern of the sub dice elements 3 be both the transmission pattern and the reception pattern shown in FIG. 6 when the focus point is located in front of the center (deflection angle 0 °). On the other hand, when the deflection angle is 30 ° and the sensitivity is prioritized, the bundle pattern of the sub dice elements 3 is as shown in FIG.
(Or FIG. 6 for transmission and FIG. 7 for reception).

Therefore, in the ultrasonic diagnostic apparatus shown in FIG. 14, the beam deflection angle output unit 11 outputs the deflection angle of the ultrasonic beam, and when the deflection angle is smaller than a predetermined value, the beam is transmitted and received by the sub dice element 3. An element bundling control unit 5 controls the element bundling unit 4 so that the bundling pattern is common, and when the deflection angle is equal to or more than a predetermined value, the element bundling control unit 5 changes the bundling pattern of the sub dice elements 3 in transmission and reception. 5 controls the element bundling unit 4. For example, the absolute value of the first grating lobe appearance angle of the transmission beam is θt,
The absolute value of the grating lobe appearance angle is θr, and θt
Θg is the smaller of θr and θr. At this time, θg is used as the predetermined value, and the element bundling control unit 5 transmits and receives the bundle pattern of the sub dice element 3 when the absolute value of the deflection angle of the ultrasonic beam output from the beam deflection angle output unit 11 is equal to or more than θg. Is controlled so that the absolute value of the deflection angle of the ultrasonic beam output from the beam deflection angle output unit 11 is smaller than θg. The bundle pattern of the sub dice elements 3 is common in transmission and reception. The element bundling unit 4 may be controlled as described above.

[0035]

As described above, according to the present invention, it is possible to realize an ultrasonic diagnostic apparatus for performing imaging simultaneously satisfying high resolution, high sensitivity, and low grating lobe using a probe having a large element pitch.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an example of an ultrasonic diagnostic apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a thickness vibration of an element and other unnecessary vibrations.

FIG. 3 is an explanatory diagram of a grating lobe.

FIG. 4 is a schematic diagram showing a relationship among a probe, elements constituting the probe, and an aperture.

FIG. 5 is a diagram illustrating a method of moving a transmission / reception beam.

FIG. 6 is a diagram showing an example of a sub-die element bundling pattern at the time of transmission.

FIG. 7 is a diagram showing an example of a sub-die element bundling pattern at the time of reception.

FIG. 8 is an explanatory diagram showing the effect of matching the grating lobe position of the transmission beam with a position where the reception beam intensity is small and matching the grating lobe position of the reception beam with a position where the transmission beam intensity is small.

FIG. 9 is a diagram showing a waveform example of an ultrasonic pulse to be transmitted.

FIG. 10 is a diagram showing an example of an ultrasonic beam pattern when the deflection angle is 0 °.

FIG. 11 is a diagram corresponding to FIG. 10 and showing a result of calculating a transmission / reception beam using a continuous wave beam;

FIG. 12 is a diagram showing an example of an ultrasonic beam pattern when the deflection angle is 30 °.

FIG. 13 is a diagram corresponding to FIG. 12, showing a result of calculating a transmission / reception beam using a continuous wave beam;

FIG. 14 is a schematic explanatory view showing another example of the ultrasonic diagnostic apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Element, 3 ... Sub die element, 4 ... Element bundling part, 5 ... Element bundling control part, 6 ... Transmission / reception separation part, 7 ... Driving part, 8 ... Delay part, 9 ... Addition part, 10 ... Display unit, 11 ...
Deflection angle output unit, 20: general control unit, D1: ultrasonic main beam forming direction, D2: emergence direction of grating lobe, ML: ultrasonic main beam, GL: grating lobe

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichiro Umemura 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Inventor Hiroshi Kanda 1-1-14 Uchikanda, Chiyoda-ku, Tokyo Hitachi Medical Co., Ltd. (72) Inventor Minoru Yoshi ▼ T. 1-114 Uchikanda, Chiyoda-ku, Tokyo F-term (reference) 2G047 CA01 EA07 GB02 GF17 4C301 AA02 EE02 EE07 GB04 HH13 HH37 HH38 JB50

Claims (4)

[Claims] A probe for transmitting and receiving an ultrasonic wave to and from a subject, comprising a sub-diced element sub-diced to suppress unnecessary vibration other than thickness vibration, an element bundling control unit, An element bundling unit that bundles the sub dice elements into a plurality of groups based on a control signal; a driving unit that supplies the same transmission pulse to the sub dice elements bundled into the same group by the element bundling unit; A delay unit that gives the same delay time required for ultrasonic beam formation to the reception signals from the sub-die elements bundled in the same group, an addition unit that adds the outputs of the delay units, A display unit that displays an output as a tomographic image; and a transmission / reception separation unit that switches and connects a device-side signal line of the element bundling unit to the driving unit or the delay unit. The bundle pattern of the sub dice element is determined independently at the time of wave transmission and at the time of reception, the grating lobe position of the transmission beam generated by the bundle pattern at the time of transmission and the grating lobe position of the receive beam generated by the bundle pattern at the time of reception An ultrasonic diagnostic apparatus characterized by independently controlling the parameters. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the grating lobe intensity of the transmission / reception beam obtained by independently determining the bundling pattern of the sub dice elements at the time of transmission and reception of the ultrasonic wave is at the time of reception. Grating lobe intensity of the transmitted / received beam when using the same bundle pattern of sub dice elements as during transmission, and lower than the grating lobe intensity of the transmitted / received beam when using the same bundle pattern of sub dice elements as during reception during transmission. An ultrasonic diagnostic apparatus characterized by the above-mentioned. 3. An ultrasonic diagnostic apparatus according to claim 1, wherein said element bundling control section includes a sub-dice element bundling pattern at the time of transmission and a sub-dice at the time of reception when a deflection angle of an ultrasonic beam is smaller than a predetermined angle. An ultrasonic diagnostic apparatus characterized in that the element bundling patterns are the same, and when the deflection angle of the ultrasonic beam is larger than the predetermined angle, the sub dice element bundling pattern during transmission and the sub dice element bundling pattern during reception are made different. 4. The ultrasonic diagnostic apparatus according to claim 3, wherein said predetermined angle is an absolute value θt of a first grating lobe appearance angle of a transmission beam and an absolute value θr of a first grating lobe appearance angle of a reception beam. An ultrasonic diagnostic apparatus characterized by being substantially equal to a smaller angle among them.