JP5019561B2 - Ultrasonic probe and ultrasonic diagnostic apparatus - Google Patents

Description

  The present invention relates to an ultrasonic probe and an ultrasonic diagnostic apparatus incorporating a transmission circuit.

  An ultrasonic probe having a 1.5-dimensional array or a two-dimensional array having more elements than the number of channels (for example, 128 channels) of the ultrasonic diagnostic apparatus main body has been developed. Regarding such an ultrasonic probe, Patent Document 1 describes an example in which ultrasonic transducers are grouped into a plurality of subarrays to perform signal processing.

  In these ultrasonic probes, a transmitting circuit and a receiving circuit corresponding to each transducer are arranged in the probe handle part, and the received signals are grouped into a plurality of subarrays within the probe handle to bundle the received signals. There is a device that does not increase the number of connection signals.

  For example, with a 2200 array two-dimensional array probe, if 25 receiving elements are grouped into one group, 3200 elements can be controlled by 128 groups and can be directly connected to the main body of 128 channels. Within a group, electronic scanning can be performed by performing minute delay time control in accordance with the direction of the received beam.

  The transmission circuit controls the delay time with a transmission beam former provided in the probe handle, and generates a high voltage pulse with the transmission circuit provided for each element. By using a serial bus, delay data and waveform data can be transferred from the main unit to the transmission beamformer using several control lines.

  By the way, since the ultrasonic probe having the transmission / reception circuit in the probe handle in this manner cannot avoid the heat generation due to the conversion loss of the ultrasonic transducer and the heat generation due to the power consumption of the electronic circuit itself, these reductions are required. The Also, the size and weight of the probe handle is required to be held small for a long time so as not to get tired. For this reason, a small and low-power circuit is used for the electronic circuit in the probe, and the transmission circuit is configured by a simple unipolar pulse driving circuit.

  On the other hand, there is a high demand for high-resolution harmonic imaging clinically, and methods such as a pulse inversion video method are preferred and used. In the pulse inversion video method, the phase is shifted twice by 180 degrees, and the two echo signals based on these two transmissions are added to extract only the harmonic component and form an image.

  However, since a unipolar pulse drive circuit cannot generally output a bipolar waveform, a technique such as a pulse inversion video method cannot be used. For this reason, when the transmission circuit is configured by a single-pole pulse drive circuit, harmonic imaging using a filter method that removes the fundamental wave with a high-pass filter is used. In the filter method, the fundamental wave of transmission cannot be removed, and the image quality is inferior to that of the pulse inversion video method.

  Patent Document 2 proposes a configuration that enables a pulse inversion image method even in a unipolar pulse driving circuit by connecting a receiving circuit to the opposite side of the electrode to which the transmitting circuit of the ultrasonic transducer is connected. Yes.

However, the configuration of Patent Document 2 has a problem that the symmetry of the positive and negative waveforms is poor because the rise time and the fall time are different due to the characteristic difference between the Pch transistor and the Nch transistor.
JP2000-33087A JP 2004-89694 A

  As described above, conventionally, when unipolar pulse driving is adopted, a bipolar waveform cannot be output, or even if it can be output, the waveform is not symmetrical and a high-quality image can be obtained by the pulse inversion image method. It was difficult.

The present invention has been made in consideration of such circumstances, and its purpose is as follows:
An object of the present invention is to provide an ultrasonic probe and an ultrasonic diagnostic apparatus capable of transmitting a bipolar waveform having good positive / negative symmetry.

In order to achieve the above object, the present invention provides an ultrasonic transducer having first and second electrodes and a plurality of voltages having different magnitudes in any direction between the first and second electrodes. An ultrasonic probe comprising: a voltage application circuit for applying the voltage to the first electrode; and a control circuit for controlling the application circuit so as to change the voltage application state between the first and second electrodes in a predetermined pattern. And a plurality of first switching elements configured to open and close connections between the first electrodes and the plurality of first potential points having potentials corresponding to the plurality of voltages, respectively. And the plurality of second switching elements that respectively open and close the connection between each of the plurality of first potential points and the second electrode, and the plurality of first potential points are different and substantially equal to each other. Two with potential And a third switching element for opening and closing a connection between one of the two potential points and the first electrode and a connection between the other of the two second potential points and the second electrode, respectively. Further, the control circuit does not simultaneously close two of the plurality of first switching elements and the plurality of second switching elements, and closes one of the plurality of first switching elements. The third switching element is closed when the second switching element is closed, and the fourth switching element is closed when any of the plurality of second switching elements is closed .

In order to achieve the above object, another aspect of the present invention provides an ultrasonic transducer having first and second electrodes and a plurality of voltages having different magnitudes between the first and second electrodes. Ultrasonic diagnosis comprising: a voltage application circuit for applying a voltage in a direction; and a control circuit for controlling the application circuit so as to change a voltage application state between the first and second electrodes in a predetermined pattern. The voltage application circuit includes a plurality of first potentials for opening and closing a connection between each of a plurality of first potential points having a potential corresponding to each of the plurality of voltages and the first electrode. The switching elements, the plurality of second switching elements that respectively open and close the connection between each of the plurality of first potential points and the second electrode, and the plurality of first potential points are different from each other, and Two with almost equal potential Third and fourth switching elements for opening and closing a connection between one of the second potential points and the first electrode and a connection between the other of the two second potential points and the second electrode, respectively. And the control circuit does not simultaneously close two of the plurality of first switching elements and the plurality of second switching elements, and closes any one of the plurality of first switching elements. The third switching element is closed when the second switching element is closed, and the fourth switching element is closed when any of the plurality of second switching elements is closed .

  According to the present invention, it is possible to transmit a bipolar waveform with good positive / negative symmetry.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing the configuration of the ultrasonic diagnostic apparatus according to the first embodiment.

  The ultrasonic diagnostic apparatus according to the first embodiment includes an apparatus main body 100 and an ultrasonic probe 200.

  The apparatus main body 100 further includes a system controller 1, a beam former 2, a scan converter 3, and a display device 4. The ultrasonic probe 200 further includes a transmission beamformer 5, a subarray beamformer 6, and a plurality of transducer sets 7.

  The system controller 1 transfers delay data and transmission waveform data to the transmission beamformer 5. The transmission beam former 5 controls each of the plurality of transducer sets 7 so as to form a required ultrasonic beam based on the delay data and the transmission waveform data.

  The subarray beamformer 6 adds a small delay to echo signals output from each of the plurality of transducer sets 7 within a subgroup formed by grouping the plurality of transducer sets 7 into a plurality of groups. The subarray beamformer 6 sends the added echo signal obtained for each subgroup to the beamformer 2. The beam former 2 delays and adds all of the added echo signals obtained for each subgroup to obtain an echo signal related to a required reception beam. Further, the beam former 2 performs a process of extracting a harmonic component from the echo signal when the pulse inversion video method is to be applied. That is, the beamformer 2 extracts a harmonic component by adding two echo signals based on two transmissions whose phases are shifted by 180 degrees as described later and canceling the fundamental component. The scan converter 3 converts the echo signal obtained by the beamformer 2 into data suitable for display on the display device 4. Thereby, the display device 4 displays an ultrasonic image based on the data converted by the scan converter 3.

  Now, the plurality of transducer sets 7 all have the same configuration. In other words, the transducer set 7 includes an ultrasonic transducer 71, first to eighth transistors 72-1 to 72-8, control circuits 74-1 and 74-2, and first to fourth diodes 73-1. To 73-4 and a receiving amplifier 75.

  The ultrasonic transducer 71 includes first and second electrodes 71a and 71b, and emits ultrasonic waves according to a change in voltage applied between the electrodes. The first electrode 71a is located on the ultrasonic radiation surface side, and the second electrode 71b is located on the back surface of the ultrasonic radiation surface. The ultrasonic transducers 71 included in each of the plurality of transducer sets 7 are arranged to form a 1.5-dimensional array or a two-dimensional array.

  The first transistor 72-1 is interposed between the potential point P1 whose voltage is Vpp1 and the first electrode 71a. The second transistor 72-2 is interposed between the potential point P2 whose voltage is Vpp2 and the first electrode 71a. The third transistor 72-3 is interposed between the potential point P3 whose voltage is Vpp3 and the first electrode 71a. The fourth transistor 72-4 is interposed between the potential point P4, which is the ground potential, and the first electrode 71a. The fifth transistor 72-5 is interposed between the potential point P1 whose voltage is Vpp1 and the second electrode 71b. The sixth transistor 72-6 is interposed between the potential point P2 where the voltage is Vpp2 and the second electrode 71b. The seventh transistor 72-7 is interposed between the potential point P3 whose voltage is Vpp3 and the second electrode 71b. The eighth transistor 72-8 is interposed between the potential point P5, which is the ground potential, and the second electrode 71b. The gates of the first to fourth transistors 72-1 to 72-4 are connected to the control circuit 74-1. The gates of the fifth to eighth transistors 72-5 to 72-8 are connected to the control circuit 74-2. As the first to eighth transistors 72-1 to 72-8, the same kind of element is used. That is, the first to eighth transistors 72-1 to 72-8 all have the same characteristics. Here, the same type p-channel transistor is employed. The voltages Vpp1, Vpp2, and Vpp3 are all the same polarity and have different sizes. Here, it is assumed that Vpp1> Vpp2> Vpp3.

  Both the first and second diodes 73-1 and 73-2 are interposed between the potential point P4 and the fourth transistor 72-4. The first and second diodes 73-1 and 73-2 are arranged in parallel in opposite directions. The third and fourth diodes 73-3 and 73-4 are both interposed between the potential point P5 and the eighth transistor 72-8. The third and fourth diodes 73-3 and 73-4 are arranged in parallel in opposite directions.

  A control signal output from the transmission beam former 5 is input to the control circuits 74-1 and 74-2. The control circuit 74-1 sends drive signals S1 to S4 to the first to fourth transistors 72-1 to 72-4, respectively, based on the control signal. The control circuit 74-2 sends drive signals S5 to S8 to the fifth to eighth transistors 72-5 to 72-8, respectively, based on the control signal.

  The above control circuit 74-1 and transistors 72-1 to 72-4 constitute one unipolar pulser. The control circuit 74-2 and the transistors 72-5 to 72-8 constitute another single pole pulser.

  The reception amplifier 75 is a differential amplifier circuit and includes two input terminals. One input terminal is connected to the first electrode 71a via the fourth transistor 72-4. The other input terminal is connected to the second electrode 71b via the eighth transistor 72-8. That is, the echo signal received by the ultrasonic transducer 71 is input to the reception amplifier 75 via the fourth and eighth transistors 72-4 and 72-8. The receiving amplifier 75 amplifies this echo signal and sends it to the subarray beamformer 6.

  Next, the operation of the ultrasonic diagnostic apparatus configured as described above will be described. The operation of this ultrasonic diagnostic apparatus is different from the conventional operation in the operation related to the driving of the ultrasonic transducer 71 at the time of ultrasonic transmission. The description of the operation is omitted.

  In this ultrasonic diagnostic apparatus, a complex transmission sound is obtained by arbitrarily applying a 7-level transmission voltage including voltages + Vpp1, + Vpp2, + Vpp3, -Vpp1, -Vpp2, -Vpp3 and a ground level to the ultrasonic transducer 71. An ultrasonic wave with a pressure change can be transmitted. Hereinafter, a specific example of driving the ultrasonic transducer 71 with five levels of transmission voltages including + Vpp2, + Vpp3, -Vpp2, -Vpp3 and the ground level will be described in detail.

  FIG. 2 is a timing chart showing an example of a sequence related to one ultrasonic transmission.

  The control circuits 74-1 and 74-2 set the drive signals S1 to S3 and S5 to S7 to the low level and the drive signals S4 and S8 to the high level during the period in which transmission is not performed.

  In the period Pa, the control circuits 74-1 and 74-2 set the drive signal S3 to the high level and the drive signal S4 to the low level. Then, the third transistor 72-3 is turned on, and the fourth transistor 72-4 is turned off. Thus, only the third transistor 72-3 and the eighth transistor 72-8 among the first to eighth transistors 72-1 to 72-8 are turned on. In this state, as shown in FIG. 3, the pulse current passes through the third transistor 72-3, the ultrasonic transducer 71, the eighth transistor 72-8, and the fourth diode 73-4 from the potential point P3. It flows into the point P5. That is, the voltage Vpp3 is applied in the direction from the first electrode 71a to the second electrode 71b.

  In the period Pb following the period Pa, the control circuits 74-1 and 74-2 return the drive signal S3 to the low level, the drive signal S4 to the high level, the drive signal S6 to the high level, and the drive signal S8 to the low level. Level. Then, only the sixth transistor 72-6 and the fourth transistor 72-4 are turned on among the first to eighth transistors 72-1 to 72-8. In this state, as shown in FIG. 4, the pulse current passes through the sixth transistor 72-6, the ultrasonic transducer 71, the fourth transistor 72-4, and the first diode 73-1 from the potential point P2. It flows into the point P4. That is, the voltage Vpp2 is applied in the direction from the second electrode 71b toward the first electrode 71a. This is equivalent to the voltage −Vpp2 being applied to the ultrasonic transducer 71 when the state of the period Pa is considered as a reference.

  In the period Pc following the period Pb, the control circuits 74-1 and 74-2 return the drive signal S6 to the low level, the drive signal S8 to the high level, the drive signal S2 to the high level, and the drive signal S4 to the low level. Level. Then, only the second transistor 72-2 and the eighth transistor 72-8 are turned on among the first to eighth transistors 72-1 to 72-8. In this state, as shown in FIG. 5, the pulse current passes through the second transistor 72-2, the ultrasonic transducer 71, the eighth transistor 72-8, and the fourth diode 73-4 from the potential point P2. It flows into the point P5. That is, the voltage Vpp2 is applied in the direction from the first electrode 71a to the second electrode 71b. This is equivalent to the voltage + Vpp2 being applied to the ultrasonic transducer 71 when the state of the period Pa is considered as a reference.

  In the period Pd following the period Pc, the control circuits 74-1 and 74-2 return the drive signal S2 to the low level, the drive signal S8 to the high level, the drive signal S7 to the high level, and the drive signal S4 to the low level. Level. Then, only the seventh transistor 72-7 and the eighth transistor 72-8 are turned on among the first to eighth transistors 72-1 to 72-8. In this state, as shown in FIG. 6, the pulse current passes through the seventh transistor 72-7, the ultrasonic transducer 71, the eighth transistor 72-8, and the first diode 73-1 from the potential point P3. It flows into the point P4. That is, the voltage Vpp3 is applied in the direction from the second electrode 71b toward the first electrode 71a. This is equivalent to the voltage −Vpp3 being applied to the ultrasonic transducer 71 when the state of the period Pa is considered as a reference.

  In this way, the voltage applied to the ultrasonic transducer 71, that is, the transmission voltage changes as shown in FIG. As a result, the ultrasonic transducer 71 transmits ultrasonic waves whose transmission sound pressure changes as shown in FIG.

  When the pulse inversion imaging method is applied, as shown in FIG. 2, the ultrasonic wave whose transmission sound pressure changes is different from the ultrasonic wave having a phase difference of 180 degrees with respect to the change of the transmission sound pressure. Send each. For ultrasonic waves having a phase difference of 180 degrees, voltages Vpp1, Vpp2, and Vpp3 are selected in the same order as described above, and the selected voltages are applied to the ultrasonic transducer from the opposite direction to the above. Thus, transmission can be performed by driving the first to eighth transistors 72-1 to 72-8. That is, when transmitting an ultrasonic wave having a phase difference of 180 degrees, the first transistor 72-1 and the fifth transistor 72-5, the second transistor and the sixth transistor 72-6, and the third transistor 72- The third and seventh transistors 72-7, the fourth transistor 72-4, and the eighth transistor 72-8 are paired, and the driving pattern in FIG. 2 for the paired transistors is applied to each transistor. That is, for example, the second transistor 72-2 is driven by a drive signal having the same pattern as the drive signal S6, and the sixth transistor 72-6 is driven by a drive signal having the same pattern as the drive signal S2.

  As described above, the control circuits 74-1 and 74-2 set the drive signals S1 to S3 and S5 to S7 to the low level and set the drive signals S4 and S8 to the high level during the period in which transmission is not performed. deep. Then, only the fourth transistor 72-4 and the eighth transistor 72-8 are turned on among the first to eighth transistors 72-1 to 72-8. In this state, as shown in FIG. 7, the echo signal generated by the ultrasonic transducer 71 receiving the ultrasonic echo is sent to the reception amplifier 75 via the fourth transistor 72-4 or the eighth transistor 72-8. Entered. The first to fourth diodes 73-1 to 73-4 input the echo signal from the ultrasonic transducer 71 to the reception amplifier 75 with high impedance. That is, the first to fourth diodes 73-1 to 73-4 function as T / R switches.

  As described above, according to the present embodiment, the drive signals S1 to S8 output from the control circuits 74-1 and 74-2 are pulses having the same polarity, but + Vpp1, + Vpp2, + Vpp3, -Vpp1, -Vpp2, -The ultrasonic transducer 71 is driven by arbitrarily combining seven levels of transmission voltages including Vpp3 and the ground level, and for example, ultrasonic waves whose transmission sound pressure changes in a complicated and diverse manner as shown in FIG. 2 are transmitted. can do. Since + Vpp1 and -Vpp1, + Vpp2 and -Vpp2, or + Vpp3 and -Vpp3 are applied to the ultrasonic transducer 71 from the same potential point P1, potential point P2 or P3, respectively, the symmetry of the positive and negative waveforms is increased. Are better.

  In the video method in which harmonic imaging is performed by two transmissions / receptions, the symmetry of the transmission waveform when inverted 180 degrees greatly affects the image quality performance. The two ultrasonic signals having a phase difference of 180 degrees transmitted as described above by the ultrasonic diagnostic apparatus of the present embodiment are signals in which only the polarities are inverted from each other, and the symmetry of the positive and negative waveforms is excellent. Therefore, the symmetry of the waveform is very good. For this reason, the image quality of harmonic imaging can be improved.

  Furthermore, for example, in order to output the transmission voltage 100Vp-p with a conventional single-pole control circuit, the power supply voltage 100V is necessary, but in this embodiment, the power supply voltage may be 50V. Similarly, in order to output 100 Vp-p in the bipolar control circuit, two types of voltage sources of +50 V and −50 V are necessary, but in this embodiment, only one type of voltage source of +50 V is sufficient. That is, according to the first embodiment, the voltage output of the power supply circuit may be ½ of the peak value of the transmission voltage.

  Further, when the maximum value of the transmission voltage is 100 Vp-p, the withstand voltage of the transistor is required to be 100 V or more in order to make a conventional single-pole control circuit. In this embodiment, the first to eighth transistors are used. The maximum withstand voltage of 72-1 to 72-8 may be 50V. That is, according to the present embodiment, the withstand voltages of the first to eighth transistors 72-1 to 72-8 may be 1/2 of the peak value of the transmission voltage. When the power supply voltage is halved, the current is also halved. Therefore, inexpensive and small elements can be used as the first to eighth transistors 72-1 to 72-8.

  Each of the above embodiments can be modified in various ways as follows.

  Only one input terminal of the receiving amplifier 75 is connected to the first electrode 71a via the fourth transistor 72-4, or connected to the second electrode 71b via the eighth transistor 72-8. The output of the reception amplifier 75 may be fed back to one input terminal of the reception amplifier 75. At this time, the side where the input terminal of the receiving amplifier 75 of the first and second diodes 73-1 and 73-2 and the third and fourth diodes 73-3 and 73-4 is not connected may be omitted. good.

  Between the input terminal of the receiving amplifier 75 and the fourth transistor 72-4 and between the input terminal of the receiving amplifier 75 and the eighth transistor 72-8, an AC coupling circuit composed of a capacitor and a resistor is provided. It may be inserted.

  A part of the circuit mounted on the ultrasonic probe 200 may be provided on the apparatus main body 100 side. For example, it is possible to draw signals from both poles of the ultrasonic vibrator 71 and connect them to the main body, and to provide all the circuits other than the ultrasonic vibrator 71 on the apparatus main body 100 side.

  Both the first and fifth transistors 72-1 and 72-5 may be connected to different potential points whose voltage is Vpp1. Both the second and sixth transistors 72-2 and 72-6 may be connected to different potential points whose voltage is Vpp2. The third and seventh transistors 72-3 and 72-7 may be connected to different potential points whose voltage is Vpp3.

  The potential points P4 and P5 may be any potential other than the ground potential as long as they are different from Vpp1, Vpp2, and Vpp3.

  One of the potential points P1 to P3 and the transistor connected to the potential point may be omitted, or four or more sets of potential points corresponding to the potential points P1 to P3 and the potential point may be connected. It is also good.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in each embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a diagram showing a configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The timing chart which showed an example of the sequence regarding one time ultrasonic transmission. The figure which shows the path | route of the pulse current in the period Pa in FIG. The figure which shows the path | route of the pulse current in the period Pb in FIG. The figure which shows the path | route of the pulse current in the period Pc in FIG. The figure which shows the path | route of the pulse current in the period Pd in FIG. The figure which shows the path | route through which an echo signal flows in the vibrator | oscillator set 7 shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... System controller, 2 ... Beam former, 3 ... Scan converter, 4 ... Display apparatus, 5 ... Transmission beam former, 6 ... Subarray beam former, 7, 8, 9, 10 ... Vibrator set, 71 ... Ultrasonic transducer , 71a ... first electrode, 71b ... second electrode, 72-1 ... first transistor, 72-2 ... second transistor, 72-3 ... third transistor, 72-4 ... fourth transistor 72-5 ... fifth transistor, 72-6 ... sixth transistor, 72-7 ... seventh transistor, 72-8 ... eighth transistor, 73-1 ... first diode, 73-2 ... Second diode, 73-3 ... third diode, 73-4 ... fourth diode, 74-1, 74-2 ... control circuit, 75 ... receiving amplifier 100 ... main body, 200 ... ultrasonic probe, P1 , P2, P3, P4, P5 ... potential points.

Claims (6)

An ultrasonic transducer having first and second electrodes;
A voltage application circuit for applying a plurality of voltages of different magnitudes in any direction between the first and second electrodes;
A control circuit that controls the application circuit to change the application state of the voltage between the first and second electrodes in a predetermined pattern ;
The voltage application circuit includes:
A plurality of first switching elements that respectively open and close a connection between each of a plurality of first potential points having potentials respectively corresponding to the plurality of voltages and the first electrode;
A plurality of second switching elements that respectively open and close a connection between each of the plurality of first potential points and the second electrode;
The connection between one of the two second potential points, which is different from the plurality of first potential points and having substantially the same potential, and the first electrode, and the other of the two second potential points, A third and a fourth switching element for opening and closing the connection with the second electrode, respectively.
Further, the control circuit does not simultaneously close two of the plurality of first switching elements and the plurality of second switching elements, and closes any one of the plurality of first switching elements. An ultrasonic probe that sometimes closes the third switching element and closes the fourth switching element when any of the plurality of second switching elements is closed . An ultrasonic transducer having first and second electrodes;
A voltage application circuit for applying a plurality of voltages of different magnitudes in any direction between the first and second electrodes;
A control circuit that controls the application circuit to change the application state of the voltage between the first and second electrodes in a predetermined pattern ;
The voltage application circuit includes:
A plurality of first switching elements that respectively open and close a connection between each of a plurality of first potential points having potentials respectively corresponding to the plurality of voltages and the first electrode;
A plurality of second switching elements that respectively open and close a connection between each of the plurality of first potential points and the second electrode;
The connection between one of the two second potential points, which is different from the plurality of first potential points and having substantially the same potential, and the first electrode, and the other of the two second potential points, A third and a fourth switching element for opening and closing the connection with the second electrode, respectively.
Further, the control circuit does not simultaneously close two of the plurality of first switching elements and the plurality of second switching elements, and closes any one of the plurality of first switching elements. An ultrasonic diagnostic apparatus that sometimes closes the third switching element and closes the fourth switching element when any of the plurality of second switching elements is closed .   The ultrasonic diagnostic apparatus according to claim 2, wherein the predetermined pattern includes two sets of patterns in which the selection order of the plurality of voltages is the same and the application directions are reversed.   And further comprising image generation means for generating an image based on signals obtained by adding or subtracting echo signals relating to two sets of ultrasonic pulses respectively transmitted from the ultrasonic transducers according to the two sets of patterns. The ultrasonic diagnostic apparatus according to claim 3. An amplifier having an input terminal connected to the first electrode or the second electrode via the third switching element or the fourth switching element, and amplifying a signal input to the input terminal;
Wherein the control means, the reception period, is opened all the plurality of first switching elements and the plurality of second switching elements, according to claim 2, characterized in that closing said third and fourth switching elements An ultrasonic diagnostic apparatus according to 1. Two rectifying elements that are opposite and parallel to each other and are interposed between the third switching element and one of the two second potential points;
3. The rectifying device according to claim 2 , further comprising two rectifying elements interposed in a direction opposite to each other and parallel to each other between the fourth switching element and the other of the two second potential points. The ultrasonic diagnostic apparatus according to claim 5 .

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