JP4468136B2 - Ultrasonic transceiver - Google Patents

Description

  The present invention relates to an ultrasonic transmission / reception apparatus used for observing an organ or the like in a living body by transmitting / receiving ultrasonic waves.

  Conventionally, in order to acquire a three-dimensional image by transmitting and receiving ultrasonic waves, a two-dimensional image related to a cross section in the depth direction is obtained by electrically steering the ultrasonic waves to be transmitted and received using a one-dimensional transducer array with a position sensor. Further, a three-dimensional image is created by synthesizing a plurality of two-dimensional images acquired by mechanically moving the one-dimensional transducer array. However, according to this method, since there is a time lag in the mechanical movement of the one-dimensional transducer array, a plurality of two-dimensional images at different times are synthesized, so that the synthesized image is blurred. End up. Therefore, this method is not suitable for imaging a subject with movement, such as a living body.

  In order to eliminate such drawbacks, it is more advantageous to acquire a three-dimensional image using a two-dimensional transducer array. Non-Patent Document 1 below uses a two-dimensional transducer array to transmit an ultrasonic beam to one area and simultaneously receive and process ultrasonic echoes reflected from 16 directions in the area. Beam reception is disclosed. Patent Document 1 below discloses multi-beam transmission in which ultrasonic beams are simultaneously transmitted to a plurality of regions.

  Further, in Patent Document 2 below, by generating a plurality of transmission signals having different frequency bands for one transmission, it is possible to simultaneously generate a plurality of ultrasonic transmission beams having different frequency bands, focal regions, and directions. An ultrasonic diagnostic apparatus is disclosed. However, since the maximum amplitude of the transmission signal is increased by combining multiple frequency signals, it is necessary to increase the withstand voltage of the ultrasonic transducer or increase the maximum output voltage of the transmission signal generation circuit, and the power consumption also increases. Resulting in.

  On the other hand, Patent Document 3 below discloses an ultrasonic diagnostic apparatus that simultaneously forms a plurality of transmission beams without requiring a special driver or the like. In order to form a plurality of transmission beams in one transmission, this ultrasonic diagnostic apparatus divides a plurality of vibration elements into a plurality of transmission groups, and a plurality of transmissions that supply transmission signals having different transmission frequencies for each transmission group. Includes circuitry.

  Similarly, Patent Document 4 below discloses an ultrasonic underwater detector including an ultrasonic transducer that does not increase an occupied area even though a plurality of circular vibration surfaces can be separately arranged. In this ultrasonic underwater detector, a plurality of ultrasonic transducers are arranged side by side so that their vibration planes are all located within the first circle along the horizontal plane, thereby constituting a transducer. These ultrasonic transducers are grouped into first to sixth ultrasonic transducer groups by second to fifth circles having the same diameter smaller than the first circle and inscribed in the first circle. By appropriately driving the transducer group appropriately, a desired beam can be formed while reducing the area occupied by the vibration surface of the ultrasonic transducer.

However, as disclosed in Patent Literature 3 and Patent Literature 4, when a plurality of transducers are divided into a plurality of groups and multi-beam transmission is performed, there is a problem that the intensity of each transmission beam decreases.
Richard E. Davidsen et al. “TWO-DIMENSIONAL RANDOM ARRAYS FOR REAL TIME VOLUMETRIC IMAGING”, ULTRASONIC IMAGING, Vol.16 (USA) Academic Press ( Academic Press), 1994, p. 143-163 US Pat. No. 6,179,780 (Column 2, FIG. 3) JP-A-8-38473 (first page, FIG. 1) Japanese Patent No. 3356996 (2nd page, FIG. 1) Japanese Patent No. 3255815 (second page, FIG. 1)

  Therefore, in view of the above points, an object of the present invention is to suppress an increase in the pressure resistance of an ultrasonic transducer and an increase in power consumption accompanying an increase in the number of transmission beams in an ultrasonic transmission / reception apparatus that performs multi-beam transmission. .

  In order to solve the above problems, an ultrasonic transmission / reception apparatus according to the present invention forms an ultrasonic beam according to a plurality of drive signals and transmits the ultrasonic beam to a subject, and receives a plurality of ultrasonic echoes reflected from the subject. An ultrasonic probe including a plurality of ultrasonic transducers that respectively output detection signals, and a plurality of ultrasonic beams transmitted simultaneously from the ultrasonic probe in a plurality of different directions. Drive waveform synthesizing means for generating information related to a synthesized drive waveform obtained by synthesizing a plurality of drive waveforms for the transducer, and a plurality of ultrasonic transducers by generating a plurality of drive signals according to the information generated by the drive waveform synthesizing means A plurality of transmission circuits each supplying a maximum voltage of a drive signal supplied to each ultrasonic transducer Correspondingly, a plurality of transmission circuits in which a plurality of types of maximum output voltages are determined, and a plurality of reception circuits that respectively process a plurality of detection signals output from a plurality of ultrasonic transducers that have received ultrasonic echoes. .

  According to the ultrasonic transmission / reception apparatus that performs multi-beam transmission according to the present invention, a plurality of types of maximum output voltages are determined for a plurality of transmission circuits corresponding to the maximum voltage of the drive signal supplied to each ultrasonic transducer. The increase in the pressure resistance of the ultrasonic transducer and the increase in power consumption accompanying the increase in the number of transmission beams can be suppressed. In the present application, the transducer for one element constituting the transducer array is referred to as “ultrasonic transducer”.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.
FIG. 1 is a block diagram showing a configuration of an ultrasonic transmission / reception apparatus according to an embodiment of the present invention. As shown in FIG. 1, this ultrasonic transmission / reception apparatus includes an ultrasonic probe (probe) 1 used in contact with a subject and an ultrasonic transmission / reception apparatus connected to the ultrasonic probe 1. And a main body 2.

The ultrasonic probe 1 incorporates a transducer array (also referred to as “array transducer”) including N ² ultrasonic transducers 11 arranged in a two-dimensional matrix. These ultrasonic transducers 11 are connected to the ultrasonic transmission / reception apparatus body 2 via signal lines.

  Each ultrasonic transducer 11 is, for example, a piezoelectric ceramic represented by PZT (Pb (lead) zirconate titanate) or a polymer piezoelectric element represented by PVDF (polyvinylidene difluoride). It is comprised with the vibrator | oscillator which formed the electrode in the both ends of materials (piezoelectric element) which have piezoelectricity, such as. In addition, in recent years, a piezoelectric element including PZNT (an oxide containing lead, zinc, niobium, and titanium), which is expected to contribute to the improvement of sensitivity and bandwidth of an ultrasonic transducer, may be used.

  When a voltage is applied to the electrodes of such a vibrator by sending a pulsed or continuous wave electrical signal, the piezoelectric element expands and contracts. By this expansion and contraction, pulsed or continuous wave ultrasonic waves are generated from the respective vibrators, and an ultrasonic beam is formed by synthesizing these ultrasonic waves. Each vibrator expands and contracts by receiving propagating ultrasonic waves and generates an electrical signal. These electric signals are output as ultrasonic detection signals.

The ultrasonic transmission / reception apparatus main body 2 includes a plurality of switching circuits 20, a plurality of transmission circuits 21, a plurality of reception circuits 22, a computer 30, a recording unit 40, and a display unit 50.
The plurality of switching circuits 20 respectively connect the plurality of ultrasonic transducers 11 built in the ultrasonic probe 1 to the plurality of transmission circuits 21 when transmitting ultrasonic waves, and when receiving ultrasonic waves, A plurality of ultrasonic transducers 11 built in the ultrasonic probe 1 are respectively connected to a plurality of receiving circuits 22.

  Each of the plurality of transmission circuits 21 includes a signal generator and a class A power amplifier. The signal generator generates a drive signal having a delay amount corresponding to the arrangement or the like of each ultrasonic transducer 11 according to the information regarding the drive waveform supplied from the computer 30. The power amplifier amplifies this drive signal and supplies it to the ultrasonic probe 1.

  Each of the plurality of receiving circuits 22 includes a preamplifier, a TGC (time gain compensation) amplifier, and an A / D (analog / digital) converter. The detection signals output from the respective ultrasonic transducers 11 are amplified by a preamplifier, and the TGC amplifier corrects the attenuation due to the distance that the ultrasonic wave has reached in the subject.

  The detection signal output from the TGC amplifier is converted into a digital signal by an A / D converter. The sampling frequency of the A / D converter needs to be at least about 10 times the frequency of the ultrasonic wave, and is preferably 16 times or more the frequency of the ultrasonic wave. The resolution of the A / D converter is preferably 10 bits or more.

  The computer 30 controls transmission / reception of ultrasonic waves based on software (control program) recorded in the recording unit 40. As the recording unit 40, a recording medium such as a hard disk, a flexible disk, MO, MT, RAM, CD-ROM, or DVD-ROM can be used. The computer 30 and software implement a scanning control unit 31, a drive waveform synthesis unit 32, a phase matching calculation unit 34, and a display image calculation unit 35 as functional blocks. The computer 30 has a reception memory 33.

  The scanning control unit 31 sequentially sets the transmission direction of the ultrasonic beam and the reception direction of the ultrasonic echo. For example, the scanning control unit 31 sets the directions of the plurality of ultrasonic beams transmitted from the ultrasonic probe 1 with a predetermined offset amount according to a predetermined scanning method or according to a predetermined beam scanning order. The drive waveform synthesizer 32 is controlled so as to be changed. Under the control of the scanning control unit 31, the drive waveform synthesizing unit 32 generates information related to a synthesized drive waveform obtained by synthesizing a plurality of drive waveforms for each ultrasonic transducer 11. Based on this information, the transmission circuit 21 generates a plurality of drive signals, whereby transmission focus processing is performed, and a plurality of ultrasonic beams are simultaneously emitted from the ultrasonic probe 1 in a plurality of different directions. Sent.

  The reception memory 33 stores digital detection signals output from the A / D converters of the plurality of reception circuits 22 in time series for each ultrasonic transducer. The phase matching calculation unit 34 selects a predetermined pattern from a plurality of reception delay patterns recorded in the recording unit 40 based on the reception direction set in the scanning control unit 31, and a plurality of patterns based on the pattern are selected. A reception focus process is performed by adding a delay to the detection signal of. By this reception focus processing, sound ray data in which the focus of the ultrasonic echo is narrowed down is formed. Note that the reception focus process may be performed before A / D conversion or before correction by the TGC amplifier.

  The display image calculation unit 35 generates image data based on the sound ray data formed by the phase matching calculation unit 34. The display unit 50 includes a display device such as a CRT or LCD, for example, and displays an ultrasonic image based on the image data generated by the display image calculation unit 35.

Next, reduction of drive voltage in multi-beam transmission, which is a feature of the present invention, will be described. As a premise of the concept of the present invention, a two-dimensional transducer array for transmission and reception as shown in FIG. 2 will be described as an example. In this example, the number of ultrasonic transducers (elements) is 42 elements × 42 elements, and substantially circular portions excluding the four corners of the transducer array are used for transmitting and receiving ultrasonic waves. The element pitch d is 0.35 mm, and when the ultrasonic frequency f _C is 2.5 MHz (wavelength λ = 0.6 mm), the element pitch corresponds to about 0.58λ. Therefore, the opening of the ultrasonic probe 1 is a circle having a diameter of 0.35 mm × 42 elements = 14.7 mm or more.

  FIG. 3 is a schematic diagram showing a state in which an ultrasonic beam is transmitted from a two-dimensional transducer array to a certain point within a scanning range. Point A and point B are the focal positions of the spatial region that is sector-scanned by the ultrasonic beam. Here, using the azimuth angle θ and the elevation angle φ, the direction of the focal point in the spatial region is represented by (θ, φ), and the directions of the points A and B are (0 °, 0 °) and (30 °, respectively). , 30 °). In this example, the ultrasonic scanning range is set to −30 ° ≦ θ ≦ 30 ° and −30 ° ≦ φ ≦ 30 °. Also, 16 ultrasonic beams are transmitted simultaneously, and the angle differences Δθ and Δφ between these ultrasonic beams are each 15 °. These ultrasonic beams are sequentially steered at a scanning step δθ = δφ = 1 °. FIG. 4 schematically shows 16 ultrasonic beams directed in the initial transmission direction and 16 ultrasonic beams steered downward by a scanning step.

  FIG. 5 is a diagram illustrating a relationship between a driving waveform applied to a plurality of ultrasonic transducers and an ultrasonic beam generated thereby. FIG. 5A shows that an ultrasonic beam is transmitted toward an azimuth angle θ = −15 ° by applying a plurality of drive signals having different phases to the respective ultrasonic transducers. FIG. 5B shows that an ultrasonic beam is transmitted toward an azimuth angle θ = 0 ° by applying a plurality of drive signals having the same phase to the respective ultrasonic transducers. FIG. 5C shows an ultrasonic beam directed to an azimuth angle θ = −15 ° and an azimuth angle θ = 0 ° by synthesizing the drive signals shown in FIGS. 5A and 5B. The ultrasonic beam is transmitted at the same time.

  As shown in FIG. 5C, two ultrasonic beams can be transmitted simultaneously by synthesizing two types of drive waveforms. However, the height of the peak is doubled where the peaks of the drive waveforms overlap. Generally, in order to transmit M ultrasonic beams at the same time, the peak height of the drive waveform may be M times, so that the pressure resistance of the ultrasonic transducer can be increased or the maximum output voltage of the transmission circuit can be increased. It is necessary to enlarge. In particular, when a class A power amplifier is used in the transmission circuit, power is consumed even when a drive signal is not output, so that power consumption increases in proportion to the maximum output voltage. Therefore, the ultrasonic transmission / reception apparatus according to the present invention is characterized in that, even when M ultrasonic beams are transmitted simultaneously, the peak height of the drive waveform is made smaller than M times as much as possible.

  Next, a simulation that supports the present invention will be described. In this simulation, in order to obtain the delay amount to be given to the drive signal based on the distance from each ultrasonic transducer to the focal point, and to transmit 16 ultrasonic beams simultaneously toward the 16 focal points, 16 types of driving are performed. The maximum amplitude (maximum value of one-side amplitude (zero-to-peak amplitude)) when signals are superimposed is calculated. Here, a burst signal having a wave run length of 2 is assumed as the drive signal, and the accuracy of the delay amount given to the drive signal is 10 nsec.

Consider a two-dimensional transducer array having an xy plane as a transmission surface, and the center of the transmission surface of this transducer array is the origin, and the distance from the origin to the focal point is r. The delay amount to be given to the drive signal in order to transmit the ultrasonic beam from the ultrasonic transducer at the position (x, y, 0) of the transducer array toward the focal point at the position (x _FOCUS , y _FOCUS , z _FOCUS ) τ is expressed by the following equation. Here, c is the speed of sound in the subject.

The focal point position is expressed as follows using the azimuth angle θ and the elevation angle φ.
x _FOCUS = r · cosφsinθ
y _FOCUS = r · sinφ
z _FOCUS = r · cosφcosθ

  FIG. 6A shows a case in which the reference ultrasonic beam among the 16 ultrasonic beams is transmitted in the direction (0 °, 0 °). A scanning area scanned by a sound beam is shown. 6B to 6D show the waveforms of drive signals applied to three ultrasonic transducers as an example. FIG. 7A shows a case in which a reference ultrasonic beam among the 16 ultrasonic beams is transmitted in the direction (0 °, 14 °), and FIG. (D) shows the waveforms of the drive signals applied to the three ultrasonic transducers as an example at that time.

  FIG. 8A shows a case where a reference ultrasonic beam is transmitted in the direction (14 °, 0 °) among the 16 ultrasonic beams, and FIGS. ) Shows the waveforms of the drive signals applied to the three ultrasonic transducers as an example. FIG. 9A shows a case in which the reference ultrasonic beam among the 16 ultrasonic beams is transmitted in the direction (7 °, 7 °), and FIG. (D) shows the waveforms of the drive signals applied to the three ultrasonic transducers as an example at that time.

  FIG. 10 is a histogram showing the maximum amplitude of the drive signal applied to each ultrasonic transducer to transmit 16 ultrasonic beams. In the histogram of FIG. 10, the horizontal axis indicates the maximum amplitude, and the vertical axis indicates the appearance frequency. Here, the maximum amplitude is expressed as a relative value with respect to the maximum amplitude for transmitting one ultrasonic beam. Further, the four bars in each maximum amplitude value on the horizontal axis correspond to the respective cases shown in FIGS. This is tabulated in FIG.

  As shown in FIGS. 10 and 11, the state in which the maximum amplitude exceeds 12 does not appear in any direction in which 16 ultrasonic beams are transmitted. Based on this simulation result, it is understood that the maximum output voltages of the plurality of transmission circuits may be set in a plurality of ranks corresponding to the maximum amplitudes 1 to 12 applied to the respective ultrasonic transducers. . In this way, by setting a plurality of types of maximum output voltages for a plurality of transmission circuits corresponding to the maximum voltage of the drive signal supplied to each ultrasonic transducer, power consumption in multi-beam transmission can be reduced. Can do.

  Furthermore, in any direction in which 16 ultrasonic beams are transmitted, the frequency at which the maximum amplitude is 8 or more is extremely small. From this, when the maximum amplitude is 8 or more, it can be said that even if the maximum amplitude is replaced with 7, the transmission beam is hardly affected. Alternatively, for each of the ultrasonic transducers 11, information on one drive waveform is obtained by superimposing a plurality of drive waveforms while shifting the transmission timing for a part of the plurality of ultrasonic beams having the same ultrasonic transmission timing. You may make it produce | generate. By synthesizing a plurality of drive waveforms in this way, the power consumption in multi-beam transmission can be further reduced.

FIG. 12 is a diagram for explaining an example of power consumption reduction in multi-beam transmission. In this example, when the maximum amplitude of the drive signal is 1 or 2, the maximum output of the transmission circuit is 2, and when the maximum amplitude of the drive signal is 3 or 4, the maximum output of the transmission circuit is 4. The maximum output of the transmission circuit is 7 when the maximum amplitude is 5 to 7, and the maximum output of the transmission circuit is 12 when the maximum amplitude of the drive signal is 12. Assuming that the power consumption of the transmission circuit is proportional to the square of the maximum output voltage, and assuming that the proportionality constant is 1 for simplicity, the power consumption of the transmission circuit is obtained as follows.
2 ² × (128 + 627) +4 ² × (378 + 191) +7 ² × (16 + 33 + 19)
+12 ² × 4≈1.60 × 10 ⁴
On the other hand, when the maximum output of all the transmission circuits is 12, the power consumption of the transmission circuit is obtained as follows.
12 ² × 1396 ≒ 2.01 × 10 ⁵
Therefore, the effect of reducing power consumption is as follows.
1.60 × 10 ⁴ /2.01×10 ⁵ ≒ 8%
In the above, when the maximum amplitude of the drive signal exceeds 7, if the maximum output of the transmission circuit is 7, power consumption can be further reduced.

  Next, an example of a drive waveform when the maximum amplitude of the drive waveform is replaced with a predetermined maximum amplitude will be described with reference to FIGS. Here, consider a case in which a space of 60 ° × 60 ° is scanned by 15 × 15 transmissions by simultaneously transmitting 4 × 4 = 16 transmission beams. In addition, the vertical axis of (a) to (d) in FIG. 15 indicates the relative amplitude of the driving waveform of each element, and the amplitude when transmitting in only one direction is 1. Further, the broken lines in FIGS. 15A to 15D are lines indicating amplitude = 4.

  For example, the result of obtaining the frequency of the maximum amplitude of the driving waveform of each element (ultrasonic transducer 11) of the two-dimensional transducer array during the entire transmission period of 15 × 15 times is the result as shown in FIG. Suppose that In this case, since the frequency at which the maximum amplitude is 5 or more is extremely less than the frequency at which the maximum amplitude is 4 or less, each element having a maximum amplitude of 5 or more as shown in FIG. The maximum amplitude of the drive waveform is replaced with 4.

  As shown in FIG. 14, the position of each element of the 42-element × 42-element two-dimensional transducer array shown in FIG. 2 is set to the coordinates (x, x) with the azimuth direction as the x axis and the elevation direction as the y axis. y). At this time, the drive waveform of the element located at the coordinates (20, 1) has a maximum amplitude of 4 or less as shown on the left side of FIG. 15A, so the drive waveform of this element is shown on the right side of the figure. Thus, the maximum amplitude is not replaced. On the other hand, the driving waveforms of the three elements located at the coordinates (14, 22), the coordinates (15, 16), and the coordinates (21, 21) are shown on the left side of FIGS. Thus, since the maximum amplitude exceeds 4, the drive waveforms of these elements are corrected to drive waveforms in which the maximum amplitude is replaced with 4 as shown on the right side of (b) to (d) of FIG. Specifically, for a drive waveform whose maximum amplitude exceeds 4, the maximum amplitude max of this drive waveform is obtained, and the maximum amplitude is obtained by multiplying the amplitude of this drive waveform by a coefficient (= 4 / max). 4 is corrected to the drive waveform replaced with 4.

  Next, an example of a drive waveform when the transmission timing is shifted for a part of a plurality of ultrasonic beams having overlapping ultrasonic transmission timings will be described with reference to FIGS. Here, as shown in FIG. 16A, each transmission beam is directed to the center of the scanning area of each subdivided transmission beam. Further, as shown in FIGS. 16B to 16E, consider a case where four transmission beams in the elevation direction are set as one set and are divided into four transmissions at intervals of 2.5 μs. That is, at time t = 0, four transmission beams in the elevation direction at the left end in FIG. 16B are transmitted as one set, and then the elevation is divided into four times while changing the azimuth direction at intervals of 2.5 μs. Four transmit beams in the direction are transmitted as one set.

  The position of each element (ultrasonic transducer) of the two-dimensional transducer array consisting of 42 elements × 42 elements shown in FIG. 2 is represented by coordinates (x, y) as shown in FIG. At this time, the transmission timings of the drive waveforms of the four elements positioned at the coordinates (20, 1), the coordinates (14, 22), the coordinates (15, 16) and the coordinates (21, 21) are shown in FIG. The maximum amplitude of the drive waveform of each element is reduced by shifting from the transmission timing shown on the left side of (d) to the transmission timing shown on the right side. Note that the horizontal axis of FIGS. 17A to 17D indicates the number of clocks, and the actual time is obtained by multiplying the horizontal axis by 100 ns. In addition, the vertical axis of (a) to (d) in FIG. 17 indicates the relative amplitude of the drive waveform of each element, and the amplitude when transmitting in only one direction is 1. Furthermore, the broken lines in FIGS. 17A to 17D are lines indicating the amplitude 4.

  Referring again to FIG. 1, the drive waveform synthesizer 32 uses a plurality of drives used to individually transmit ultrasonic beams in a plurality of different directions from the ultrasonic probe 1 for each ultrasonic transducer 11. By superimposing the waveforms, information on the composite drive waveform is generated. Further, when the amplitude of the drive waveform obtained as a result exceeds a predetermined value, the drive waveform synthesis unit 32 generates information related to the composite drive waveform by replacing the amplitude with a predetermined value. good.

  In the plurality of transmission circuits 21, a plurality of types of maximum output voltages are set corresponding to the maximum voltage of the drive signal supplied to each ultrasonic transducer. Thereby, the power consumption in these transmission circuits 21 is reduced. By the way, the maximum output voltage of each transmission circuit 21 is determined by the power supply voltage supplied to the transmission circuit 21. Accordingly, a plurality of types of power supply voltages are required, and these power supply voltages can be generated by adding a plurality of power supplies.

  For example, the minimum supply voltage for each transmission circuit 21 is the minimum necessary for outputting the maximum value of the drive signal corresponding to the combined drive waveform obtained by superimposing a plurality of drive waveforms in a plurality of different transmission directions. If the voltage is set, a plurality of types of values exist for the plurality of transmission circuits 21, and power consumption in the transmission circuit 21 in which the maximum supply voltage is set to a small value is reduced.

  INDUSTRIAL APPLICABILITY The present invention can be used in an ultrasonic transmission / reception apparatus that is used for transmitting / receiving ultrasonic waves and observing an organ or the like in a living body.

It is a block diagram which shows the structure of the ultrasonic transmitter / receiver which concerns on one Embodiment of this invention. It is a figure which shows the two-dimensional transducer array for transmission / reception used in the ultrasonic transmission / reception apparatus of FIG. 1 as an example. It is a schematic diagram showing a mode that an ultrasonic beam is transmitted to a certain point in a scanning range from a two-dimensional transducer array. It is a figure which shows typically the multi beam transmitted from a two-dimensional transducer array. It is a figure which shows the relationship between the drive waveform applied to a some ultrasonic transducer, and the ultrasonic beam generated by it. (A) is a figure which shows the position of a scanning area | region and a focus in the case of transmitting the ultrasonic beam used as a reference | standard in a direction (0 degree, 0 degree), (b)-(d) is a super It is a figure which shows the waveform of the drive signal in the case of transmitting a sound wave beam in a direction (0 °, 0 °). (A) is a figure which shows the scanning area | region and the position of a focus in the case of transmitting the ultrasonic beam used as a reference | standard in a direction (0 degree, 14 degrees), (b)-(d) is the super It is a figure which shows the waveform of a drive signal in the case of transmitting a sound wave beam in a direction (0 °, 14 °). (A) is a figure which shows the position of a scanning area | region and a focus in the case of transmitting the ultrasonic beam used as a reference | standard in a direction (14 degrees, 0 degree), (b)-(d) is a super It is a figure which shows the waveform of the drive signal in the case of transmitting a sound wave beam in a direction (14 °, 0 °). (A) is a figure which shows the scanning area | region and the position of a focus in the case of transmitting the ultrasonic beam used as a reference | standard in a direction (7 degrees, 7 degrees), (b)-(d) are the super It is a figure which shows the waveform of the drive signal in the case of transmitting a sound beam in a direction (7 °, 7 °). It is a histogram which shows the maximum amplitude of the drive signal applied to each ultrasonic transducer in order to transmit 16 ultrasonic beams. It is a table | surface which shows the maximum amplitude of the drive signal applied to each ultrasonic transducer in order to transmit 16 ultrasonic beams. It is a figure for demonstrating the example of the power consumption reduction in multibeam transmission. (A) is a figure which shows an example of the result of having calculated | required the frequency of the maximum amplitude of the drive waveform of each element (ultrasonic transducer), (b) shows the maximum amplitude of 5 or more shown in (a) to 4 or more. It is a figure which shows the frequency of the maximum amplitude of the drive waveform of each element when it replaces with. It is a figure for demonstrating expressing the position of each element of the two-dimensional transducer array which consists of 42 elements x 42 elements shown in FIG. 2 by a coordinate (x, y). It is a figure which shows an example of a drive waveform when the maximum amplitude of the drive waveform of each element is replaced with a predetermined maximum amplitude. It is a figure for demonstrating the transmission method when transmitting four transmission beams of an elevation direction as a set at intervals of 2.5 microseconds. It is a figure which shows an example of the drive waveform of each element when transmission timing is shifted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Ultrasonic transmitter / receiver main body 11 Ultrasonic transducer 20 Switching circuit 21 Transmission circuit 22 Reception circuit 30 Computer 31 Scan control part 32 Drive waveform synthetic | combination part 33 Reception memory 34 Phase matching calculation part 35 Display image calculation part 40 Recording unit 50 Display unit

Claims (6)

Ultrasound includes a plurality of ultrasonic transducers that form an ultrasonic beam according to a plurality of drive signals and transmit the ultrasonic beam to the subject and receive an ultrasonic echo reflected from the subject and output a plurality of detection signals, respectively. With a probe,
In order to simultaneously transmit a plurality of ultrasonic beams in a plurality of different directions from the ultrasonic probe, information on a combined drive waveform obtained by combining a plurality of drive waveforms for each ultrasonic transducer is generated. Drive waveform synthesis means;
A plurality of transmission circuits for generating a plurality of drive signals according to the information generated by the drive waveform synthesis means and supplying the drive signals to the plurality of ultrasonic transducers, respectively, wherein the maximum of the drive signals supplied to the respective ultrasonic transducers A plurality of transmission circuits in which a plurality of types of maximum output voltages are determined corresponding to the voltage;
A plurality of receiving circuits that respectively process a plurality of detection signals output from the plurality of ultrasonic transducers that have received the ultrasonic echo;
An ultrasonic transmission / reception apparatus comprising:   The drive waveform synthesizing unit synthesizes a plurality of drive waveforms used for individually transmitting ultrasonic beams in a plurality of different directions from the ultrasonic probe for each ultrasonic transducer. The ultrasonic transmission / reception apparatus according to claim 1, which generates information related to a drive waveform.   The minimum supply voltage for each of the plurality of transmission circuits is the minimum necessary for outputting the maximum value of the drive signal corresponding to the combined drive waveform obtained by superimposing the plurality of drive waveforms in a plurality of different transmission directions. The ultrasonic transmission / reception apparatus according to claim 2, wherein a plurality of types of values exist for the plurality of transmission circuits.   The drive waveform synthesizing unit superimposes a plurality of drive waveforms used to individually transmit ultrasonic beams in a plurality of different directions from the ultrasonic probe for each ultrasonic transducer, and obtains a result thereof. The ultrasonic transmission / reception apparatus according to claim 1, wherein when the amplitude of a drive waveform to be generated exceeds a predetermined value, information on the combined drive waveform is generated by replacing the amplitude with a predetermined value.   The drive waveform synthesis means superimposes a plurality of drive waveforms on each of the ultrasonic transducers while superimposing a plurality of drive waveforms while shifting the transmission timing of a part of the plurality of ultrasonic beams having the same ultrasonic transmission timing. The ultrasonic transmission / reception apparatus according to claim 1, wherein information relating to the generation is generated.   The scanning control means for controlling the drive waveform synthesizing means so as to change directions of a plurality of ultrasonic beams transmitted from the ultrasonic probe in accordance with a predetermined beam scanning order. The ultrasonic transmission / reception apparatus of any one of 1-5.

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