JP2000005169A - Ultrasonic transmit-receive circuit, and ultrasonograph having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic transmit-receive circuit which can drive one ultrasonic oscillator in a small-diameter ultrasonic probe by means of successive plural driving pulse signals independently of load even when a pulse width of the driving pulse signal is narrow or when period of the driving pulse signal is short, and provide an ultrasonograph having the ultrasonic transmit-receive circuit. SOLUTION: According to control pulse signals from pulsar drivers 40, 41, driving pulse signals A2, A4 with high voltage are outputted by high voltages VH1, VH2 from a pulsar high voltage supply circuit 42. The driving pulse signals A2, A4 are outputted to a signal cable 2 respectively through diodes D3, D6, and impressed on an ultrasonic oscillator 3a. Thus, the ultrasonic oscillator 3a generates ultrasonic wave to transmit the ultrasonic wave toward a desired portion of an object to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic transmission / reception circuit for driving a small-diameter ultrasonic probe for use in a body cavity, which is used in combination with an endoscope inserted into a subject such as a patient and the like. The present invention relates to an ultrasonic diagnostic apparatus including an ultrasonic transmission / reception circuit.

[0002]

2. Description of the Related Art Conventionally, the digestive tract and blood vessels of a subject are examined by an ultrasonic diagnostic apparatus having a small-diameter ultrasonic probe for use in a body cavity used in combination with an endoscope inserted into a subject such as a patient. When performing ultrasound diagnosis in a body cavity such as inside,
The ultrasonic transducer disposed at the distal end of the insertion portion of the small-diameter ultrasonic probe is mechanically radially scanned. In this case, the ultrasonic vibrator disposed at the distal end of the insertion portion is provided on a rotating body, and the periphery of the rotating body is covered by an acoustic window formed of an acoustic lens or the like. By filling the gap with an acoustic transmission medium, ultrasonic waves can be emitted to the subject, and ultrasonic waves are obtained by converting reflected waves from the subject into electric signals and processing the signals. . Based on this ultrasonic image, a doctor performs ultrasonic diagnosis.

FIGS. 1 and 2 show an example of the configuration of a conventional ultrasonic transmitting / receiving circuit for driving a small-diameter ultrasonic probe having an ultrasonic transducer for transmitting / receiving ultrasonic waves to / from a subject. It is. As shown in FIG. 1, a conventional ultrasonic transmission / reception circuit 51 is connected to an ultrasonic transducer 53 for transmitting / receiving ultrasonic waves to / from a subject via a signal cable 52 such as a coaxial cable or a shielded cable. .

In the ultrasonic transmitting / receiving circuit 51, a control pulse signal generated by a pulser driver 54 in response to a clock signal is supplied to the gate of a transistor 55.
Note that the pulser driver 54 outputs a low (L) level signal only when a high-voltage driving pulse signal is applied to the ultrasonic vibrator 53 in order to transmit an ultrasonic wave to the subject. Sometimes, a high (H) level signal is output.

When the pulsar driver 54 outputs an H-level signal, the transistor 55 is turned on but the transistor 56 is turned off. Therefore, a high-voltage driving pulse by a high voltage VH from a power source (not shown) is used. The signal is not applied to the ultrasonic transducer 53 via the signal cable 52.

On the other hand, when an L-level signal is output from the pulser driver 54, the transistor 55 is turned off.
When the transistor 56 is turned on, a high-voltage drive pulse signal based on the high voltage VH from the power supply is applied to the ultrasonic transducer 53 via the signal cable 52. The ultrasonic transducer 53 generates an ultrasonic wave by the applied high-voltage drive pulse signal, and the generated ultrasonic wave is transmitted toward a desired part of the subject.

[0007] A reflected wave reflected from a desired portion of the subject in response to the transmitted ultrasonic wave is received as an echo signal by an ultrasonic transducer 53, and the received echo signal is transmitted and received via a signal cable 52. The signal is sent to the circuit 51. At this time, since the pulser driver 54 outputs an H-level signal, the transistor 55 is turned on,
Transistor 56 is off. On the other hand, the signal level of the received echo signal is weak,
Is below the threshold level required to turn on, diode 57 remains off. Therefore, the echo signal is not supplied to the transistor 55 but is supplied to the preamplifier 59 via the limiter 58.

The received weak echo signal is amplified to a required signal level by a preamplifier 59 and then output to a signal processing circuit (not shown) to perform necessary signal processing. Thereby, an ultrasonic image is obtained. The limiter 58 is used to limit the signal level of the echo signal supplied to the preamplifier 59 to a constant level.
9 is prevented from being directly input, and protection against breakage of the preamplifier 59 is achieved.

An ultrasonic transmitting / receiving circuit 61 shown in FIG.
Has the same configuration as the ultrasonic transmission circuit 51 shown in FIG. 1 except that the coils 60 and 61 are provided, and operates in the same manner as described above to transmit and receive ultrasonic waves to and from the subject.

[0010]

In the case of a small-diameter ultrasonic probe, it is necessary to reduce the diameter of the portion where the ultrasonic transducer is disposed. The effective area also becomes small, and the distance resolution and the reception sensitivity of the echo signal decrease. Therefore,
It is desired to improve the distance resolution and the reception sensitivity of the echo signal, and for that purpose, it is necessary to narrow the pulse width of the drive pulse signal or shorten the cycle of the drive pulse signal.

FIG. 3 is a diagram showing a driving pulse signal applied to the ultrasonic vibrator to drive the ultrasonic vibrator and its spectrum. In the conventional ultrasonic transmitting and receiving circuits 51 and 61 as shown in FIGS. 1 and 2, when a driving pulse signal as shown in FIG. 3A is applied to the ultrasonic vibrator 53, the spectrum is as shown in FIG. ), The reception sensitivity of the received echo signal is reduced. On the other hand, when a drive pulse signal having positive and negative polarities as shown in FIG. 3B is applied to the ultrasonic transducer 53, the spectrum becomes as shown by a curve B in FIG. The reception sensitivity of the echo signal is higher than that of the case A, but the reception sensitivity of the echo signal is lower at the center frequency.

Therefore, when a plurality of (for example, two) continuous drive pulse signals having a positive polarity as shown in FIG. 3C are applied to the ultrasonic transducer 53, the spectrum thereof becomes as shown in FIG.
As shown by the curve C in (e), the reception sensitivity of the echo signal can be increased at the center frequency as compared with the case of the curve B.

When an ultrasonic diagnosis is performed in a deep part of a subject, a drive pulse signal having a spectrum whose center frequency is shifted to a lower frequency side according to the depth as shown in FIG. When applied to the ultrasonic transducer 53, the reception sensitivity of the echo signal at the center frequency can be maintained satisfactorily.

However, the output terminals of the conventional ultrasonic transmission / reception circuits 51 and 61 as shown in FIGS. 1 and 2 are connected to an ultrasonic transducer 53 via a signal cable 52. Therefore, for example, when the load on the ultrasonic transmission / reception circuits 51 and 61 is increased by increasing the cable length of the signal cable 52 or using the ultrasonic transducer 53 having a large capacity, the pulse width of the drive pulse signal is small. In the case where the period of the driving pulse signal is short or the like, FIG.
As shown in (d), the second drive pulse signal of the two continuous drive pulse signals cannot be applied to the ultrasonic transducer 53 in some cases. As a result, the ultrasonic vibrator 53 could not be driven sufficiently, and the high-frequency ultrasonic vibrator could not be driven.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the diameter of a drive pulse signal regardless of load even when the pulse width of the drive pulse signal is narrow or the cycle of the drive pulse signal is short. An ultrasonic transmitting and receiving circuit capable of driving one ultrasonic transducer in an ultrasonic probe with a plurality of driving pulse signals that are continuously connected by a plurality of driving circuits connected in common, and an ultrasonic diagnostic apparatus including the ultrasonic transmitting and receiving circuit. To provide.

[0016]

According to a first aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves. An ultrasonic transmission / reception circuit for processing a reception signal received by a plurality of ultrasonic transducers includes a plurality of drive circuits commonly connected to one ultrasonic transducer.

According to another aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves, and the plurality of ultrasonic waves are transmitted. In an ultrasonic transmitting and receiving circuit that processes a received signal received by the transducer, a plurality of driving units that are commonly connected to one ultrasonic transducer and generate a plurality of driving signals,
Means for giving a predetermined delay time to the plurality of drive signals generated by the plurality of drive means, performing phasing addition, and outputting the phasing-added drive signal to the one ultrasonic transducer. And

According to another aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves, and the plurality of ultrasonic waves are transmitted. In an ultrasonic transmitting and receiving circuit that processes a received signal received by the transducer, a plurality of driving units that are commonly connected to one ultrasonic transducer and generate a plurality of driving signals,
Switching means for switching the timing of supplying the plurality of drive signals to the one ultrasonic transducer.

According to another aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves, and the plurality of ultrasonic waves are transmitted. In an ultrasonic transmitting and receiving circuit that processes a received signal received by the transducer, a plurality of driving units that are commonly connected to one ultrasonic transducer and generate a plurality of driving signals,
Switching means for switching the timing of supplying the plurality of drive signals to the one ultrasonic transducer; and a resonance means capable of changing a resonance frequency, wherein the plurality of drive signals are in accordance with a resonance frequency of the resonance means. Each of them has a desired transmission characteristic.

According to another aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves, and the plurality of ultrasonic transducers are transmitted. In an ultrasonic diagnostic apparatus having an ultrasonic transmission / reception circuit for processing a reception signal received by a transducer, the ultrasonic transmission / reception circuit includes a plurality of drive circuits commonly connected to one ultrasonic transducer. It is characterized by the following.

According to another aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves, and the plurality of ultrasonic waves are transmitted. In an ultrasonic diagnostic apparatus having an ultrasonic transmission / reception circuit that processes a reception signal received by a transducer, the ultrasonic transmission / reception circuit is commonly connected to one ultrasonic transducer and generates a plurality of drive signals. A plurality of drive units, a plurality of drive signals generated by the plurality of drive units, a predetermined delay time is given to perform phasing addition, and a phasing-added drive signal is output to the one ultrasonic transducer. It is characterized by having.

According to another aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves, and the plurality of ultrasonic transducers are transmitted. In an ultrasonic diagnostic apparatus having an ultrasonic transmission / reception circuit that processes a reception signal received by a transducer, the ultrasonic transmission / reception circuit is commonly connected to one ultrasonic transducer and generates a plurality of drive signals. A plurality of driving means, and switching means for switching timing of supplying the plurality of driving signals to the one ultrasonic transducer are provided.

According to another aspect of the present invention, a plurality of ultrasonic transducers in a small-diameter ultrasonic probe are driven to transmit ultrasonic waves, and the plurality of ultrasonic waves are transmitted. In an ultrasonic diagnostic apparatus having an ultrasonic transmission / reception circuit that processes a reception signal received by a transducer, the ultrasonic transmission / reception circuit is commonly connected to one ultrasonic transducer and generates a plurality of drive signals. A plurality of driving units; a switching unit configured to switch a timing of supplying the plurality of driving signals to the one ultrasonic transducer; and a resonance unit capable of changing a resonance frequency. Are characterized by having desired transmission characteristics in accordance with the resonance frequencies of

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a diagram showing a schematic configuration of an ultrasonic diagnostic apparatus having an ultrasonic transmitting / receiving circuit according to an embodiment of the present invention. In FIG. 4, an ultrasonic diagnostic apparatus according to an embodiment of the present invention includes an ultrasonic transmitting and receiving circuit 1 for performing various diagnoses based on information obtained from a subject such as a patient using ultrasonic waves.
, 3n for transmitting ultrasonic waves to the subject and receiving reflected waves from the subject, and a plurality of ultrasonic transducers 3a, 3b,. Ultrasonic probe 3, ultrasonic diagnostic apparatus body 1, and ultrasonic probe 2
And a signal cable 2 for connecting the ultrasonic diagnostic apparatus main body 1 and the ultrasonic probe 2 to transmit and receive electric signals to and from the ultrasonic diagnostic apparatus.

The ultrasonic transducers 3a, 3b,..., 3n
Is connected to an ultrasonic transmitting / receiving circuit 1a of the ultrasonic diagnostic apparatus 1 via a signal cable 2 such as a coaxial cable and a shielded cable.

The ultrasonic transducers 3a, 3b,...
Although 3n is shown using a representative symbol in FIG. 4, it is generally shown by an equivalent circuit as shown in FIG. 5, and includes a series connection of a capacitance C1, an inductance L1, and a resistor R1, and This is shown by a circuit in which a capacitor C3 is connected in parallel with a capacitor C3 connected in series with a capacitor C2, an inductance L2, and a resistor R2.

FIG. 6 is a diagram showing a schematic configuration of an ultrasonic transmitting / receiving circuit according to an embodiment of the present invention. Here, an ultrasonic transmission / reception circuit using an isolation transformer for isolation required for a small-diameter ultrasonic probe will be described.

As shown in FIG. 6, an ultrasonic transmission / reception circuit 1a according to an embodiment of the present invention generates a transmission timing for generating a control pulse signal for determining a transmission timing of an ultrasonic wave to a subject with a predetermined delay time. Circuits 10, 11, 12
A high-voltage control circuit 16 for generating a high-voltage drive pulse signal; and a high-voltage pulse for outputting a drive pulse signal generated by the high-voltage control circuit 16 in response to the control pulse signal generated by the transmission timing generation circuit. Transmission circuit 1
3, 14, 15 and switch elements 17, 18, 1 for switching the supply of the drive pulse signal to the ultrasonic transducer 3a.
9, 31; an element switching circuit 20 for performing switching control of the switching elements 17, 18, 19, 31; and a variable capacitor that is used to change the resonance frequency of a resonance circuit described later, and that changes its capacity according to voltage. Diode (varicap) 2
And a voltage supply circuit 27 for supplying a predetermined voltage to change the capacitance of the variable capacitance diodes 21 to 26
And the ultrasonic transducer 3a of the small-diameter ultrasonic probe 3 are kept in a physical non-contact state.
Isolation transformers 28, 29, and 30 that maintain electrical connection during the rotational movement of the ultrasonic wave, a limiter 32 for limiting the signal level of the echo signal to a constant level, And a preamplifier 33 for amplifying to a signal level.

Transmission timing generation circuits 10, 11, 12
Are control pulse signals P having different delay times.
1, P2 and P3 are generated. The generated control pulse signal P
1, P2, and P3, the high-voltage control circuit 16
The high voltage pulse transmission circuits 13, 14, 15 output high voltage drive pulse signals.

The element switching circuit 20 includes a switch element 17,
18 and 19 are switched at a predetermined timing to drive the drive pulse signal to one of the isolation transformers 28, 29 and 30.
Supply to the next side. Further, the element switching circuit 20 switches the switch element 31 at a predetermined timing, performs phasing addition of the drive pulse signals generated on the secondary side of the isolation transformers 28, 29, 30, and outputs the phasing-added drive pulse signal. The signal is applied to the ultrasonic transducer 3a via the signal cable 2 having a predetermined capacity 2a. The ultrasonic transducer 3a vibrates according to the applied drive pulse signal to generate ultrasonic waves. The generated ultrasonic waves are transmitted to the subject.

The ultrasonic wave transmitted toward the subject is reflected on a discontinuous surface of acoustic impedance inside the subject, and vibrates the ultrasonic transducer 3a as an echo signal. As a result, a weak electric signal is generated in the ultrasonic transducer 3a. This electric signal is guided to the limiter 32 through the signal cable 2 and the like, amplified by the preamplifier 33, delayed by a predetermined time by a reception delay circuit (not shown), and added by an adder (not shown) to obtain one reception signal. Can be
Various ultrasonic images are generated by performing signal processing based on the received signals.

The ultrasonic transmitting / receiving circuit 1a shown in FIG. 6 shows a case where one ultrasonic transducer is driven by three driving circuits. That is, the first drive circuit includes the transmission timing generation circuit 10, the high-voltage pulse transmission circuit 13, and the high-voltage control circuit 16,
Is composed of a transmission timing generation circuit 11, a high-voltage pulse transmission circuit 14, and a high-voltage control circuit 16, and the third drive circuit includes a transmission timing generation circuit 12,
High voltage pulse transmission circuit 15 and high voltage control circuit 16
It consists of. However, in the embodiment of the present invention, one ultrasonic transducer is not limited to being driven by three driving circuits, and one ultrasonic transducer is driven by two or four or more driving circuits. It is also possible. Thereby, it becomes possible to drive an ultrasonic transducer having a higher frequency or an ultrasonic transducer having a larger capacity.

FIG. 7 is a diagram showing a specific configuration of the ultrasonic transmitting / receiving circuit according to the embodiment of the present invention shown in FIG. The ultrasonic transmission / reception circuit 1a shown in FIG.
31, the element switching circuit 20, and the variable capacitance diode 2
1, 22, 24, 25, voltage supply circuit 27, isolation transformers 28, 29, limiter 32, preamplifier 33, pulser drivers 40, 41, pulser high voltage supply circuit 42, resistors R3, R4 , Capacitors C4 and C5, diodes D1 to D6, and transistors TR1 to TR4.

The ultrasonic transmitting / receiving circuit shown in FIG. 7 shows a case where one ultrasonic transducer is driven by two driving circuits. That is, the first driving circuit includes:
A pulse driver 40, transistors TR1 and TR2, and a pulsar high voltage supply circuit 42;
Is a pulse driver 41, a transistor TR
3, TR4, and a pulsar high voltage supply circuit 42.

Next, the operation of the ultrasonic transmission / reception circuit according to the embodiment of the present invention will be described.

In the ultrasonic transmission / reception circuit 1a shown in FIG. 7, the pulser driver 40 generates a control pulse signal A1 and transmits the generated control pulse signal A1 to the transistor TR2.
Supply to the gate. In the pulsar driver 40,
A low (L) level control pulse signal is output only when a high voltage drive pulse signal is applied to the ultrasonic transducer 3a to transmit an ultrasonic wave to the subject, and otherwise high (H). Outputs a level control pulse signal.

When the pulsar driver 40 outputs a control pulse signal of H level, the transistor TR2 is on but the transistor TR1 is off, so that the high voltage supplied from the pulsar high voltage supply circuit 42 is high. The high-voltage drive pulse signal A2 by VH1 is not applied to the ultrasonic transducer 3a.

On the other hand, when an L-level control pulse signal is output from the pulser driver 40, the transistor TR2 is turned off, but the transistor TR1 is turned on, so that the driving pulse by the high voltage VH1 from the pulser high voltage supply circuit 42 is output. The signal A2 is output to the signal cable 2 via the diode D3 and the like, and is applied to the ultrasonic transducer 3a. Thereby, the ultrasonic transducer 3a generates an ultrasonic wave and transmits the ultrasonic wave toward a desired part of the subject.

A reflected wave reflected from a desired portion of the subject in response to the transmitted ultrasonic wave is received as an echo signal by the ultrasonic transducer 3a, and the received echo signal is transmitted and received through the signal cable 2 to the ultrasonic wave. It is sent to the circuit 1a.
At this time, since the pulser driver 40 outputs the control pulse signal of H level, the transistor TR1 is turned off and the transistor TR2 is turned on. On the other hand, since the received echo signal is weak, the diode D
2, due to the presence of D3, is not supplied to the transistor TR2. Therefore, the received echo signal is supplied to the preamplifier 33 via the limiter 32.

The received weak echo signal is amplified to a required signal level by the preamplifier 33, and then output to a signal processing circuit (not shown) to perform necessary signal processing. Thereby, an ultrasonic image is obtained. The limiter 32 is used to limit the signal level of the echo signal supplied to the preamplifier 33 to a constant level.
3 is prevented from being directly input, thereby protecting the preamplifier 33 from being damaged.

On the other hand, the pulser driver 41 generates a control pulse signal A3 obtained by giving an arbitrary delay time to the control pulse signal A1 generated by the pulser driver 40. Thereafter, the same operation as described above is performed, and the drive pulse signal A4 is generated.

The high-voltage drive pulse signals A2 and A4 generated by the pulsar drivers 40 and 41 are used for the braking capacity of the ultrasonic transducer 3a, the capacity 2a of the signal cable 2, the isolation transformers 28 and 29, the variable capacity diode 21, 2
The signals are output to two resonance circuits composed of 2, 24 and 25, respectively, and are converted into drive pulse signals having desired transmission characteristics in these two resonance circuits. In this case, it is possible to adjust the constant of each element constituting the resonance circuit so as to be the same in both of the above-described two resonance circuits, and to resonate, depending on the region of interest (for example, depth) of the subject. It can be arbitrarily adjusted so that the resonance frequency changes.

FIG. 8 is a sectional view showing a configuration of a rotary transformer as an isolation transformer in the ultrasonic transmitting / receiving circuit according to the embodiment of the present invention. A rotary transformer as the isolation transformer 28 shown in FIG.
a and a rotor portion 28b on the rotating side that is physically in non-contact but electrically in contact with each other, and is provided with a coil 28d. By rotating the rotor portion 28b about the axis 28c, the ultrasonic transducer 3a rotates. In addition, the isolation transformer 2
9 and 30 are configured similarly to the isolation transformer 28.

As shown in FIG. 8, when the isolation transformer 28 is constituted by a rotary transformer having a desired number of channels, the number of parts can be reduced. The inductance of each channel is
It is necessary to set to satisfy the following conditions.

(1) Self-inductance of each channel,
Braking capacity of ultrasonic transducer 3a, capacity 2 of signal cable 2
The cut-off frequency of the low-pass filter constituted by a and its inductance is higher than a desired frequency. That is, the frequency characteristics of the low-pass filter are not deteriorated.

(2) Variable capacitance diodes 21, 22, 2
The variable capacitance diodes 21, 22, 24, 2
The optimum resonance can be obtained at the frequency where the reception sensitivity of the echo signal is desired to be improved by the capacitance of 5 and its inductance.

If the isolation transformer 28 is provided in the small-diameter ultrasonic probe 3, the constant of each element constituting the resonance circuit is adjusted in advance so as to obtain an optimum resonance for each connected small-diameter ultrasonic probe. It's easy to do,
It is also possible to fix the isolation transformer 28 to the ultrasonic transmission / reception circuit 1a of the ultrasonic diagnostic apparatus 1.

When the element constant of each resonance circuit is set to be the same, the variable capacitance diode can be provided on the secondary side of the isolation transformer 28 instead of the primary side.

The isolation transformer 28
If the drive pulse signal is phased and added on the next side, it becomes possible to apply a drive pulse signal as indicated by A5 to the ultrasonic transducer 3a.

When the echo signal is received, the reception range of the echo signal can be widened by setting the same element constants of the two resonance circuits as in the transmission of the ultrasonic wave. It is also possible. Also,
By setting the element constants of the two resonance circuits to be different from each other in accordance with the depth of the subject and distinguishing the reception system of the echo signal, the sensitivity of the echo signal can be increased.

Although the embodiments of the present invention have been described with respect to the two-system resonance circuit, the present invention is not limited to the configuration of the two-system resonance circuit, but includes three or more systems each having the same element constant. A resonance circuit can be formed, or three or more resonance circuits each having a different element constant can be formed.

[0053]

As described above, according to the present invention, a plurality of (n) drive circuits are commonly connected to one load such as an ultrasonic vibrator and a plurality of continuous drive pulse signals are applied. The ultrasonic vibrator is being driven. Therefore, as compared with the conventional case, the current output capability of the drive circuit for driving one ultrasonic transducer becomes n times, and the output resistance becomes 1 / n. Therefore, an ultrasonic transducer having a higher frequency or an ultrasonic transducer having a larger capacity can be connected and driven.

Also, by changing the resonance frequency of the resonance circuit according to the center frequency of the echo signal which is a reflected wave that changes with the passage of time, highly sensitive echoes can be obtained over a wide area from the shallow part to the deep part of the subject. A signal can be obtained.

Further, by appropriately delaying the high-voltage driving pulse signals applied to the ultrasonic vibrator and then adding them to each other or controlling the phases thereof, the driving pulse signals having various transmission characteristics, which have been difficult in the past, can be obtained. It becomes possible to drive the ultrasonic vibrator.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a configuration of a conventional ultrasonic transmission / reception circuit.

FIG. 2 is a diagram illustrating an example of another configuration of a conventional ultrasonic transmission / reception circuit.

FIG. 3 is a diagram showing a drive pulse signal applied to the ultrasonic vibrator to drive the ultrasonic vibrator and a spectrum thereof.

FIG. 4 is a diagram illustrating a schematic configuration of an ultrasonic diagnostic apparatus including an ultrasonic transmitting / receiving circuit according to an embodiment of the present invention.

FIG. 5 is a diagram showing a general equivalent circuit of an ultrasonic transducer.

FIG. 6 is a diagram illustrating a schematic configuration of an ultrasonic transmission / reception circuit according to an embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of an ultrasonic transmission / reception circuit according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating a configuration of a rotary transformer as an isolation transformer in the ultrasonic transmission / reception circuit according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus main body 1a Ultrasonic transmission / reception circuit 2 Signal cable 3 Small-diameter ultrasonic probe 3a, 3b, 3n Ultrasonic transducer 4 Ultrasonic diagnostic apparatus 10, 11, 12 Transmission timing generation circuit 13, 14, 15 High voltage Pulse transmission circuit 16 High voltage control circuit 17, 18, 19, 31 Switching element 20 Element switching circuit 21, 22, 23, 24, 25, 26 Variable capacitance diode 27 Voltage supply circuit 28, 29, 30 Isolation transformer 32 Limiter 33 Preamplifier

Claims (8)

[Claims] An ultrasonic transmitting and receiving circuit for driving a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processing a received signal received by the plurality of ultrasonic transducers, An ultrasonic transmission / reception circuit comprising a plurality of drive circuits commonly connected to one ultrasonic transducer. 2. An ultrasonic transmission / reception circuit for driving a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processing received signals received by the plurality of ultrasonic transducers, A plurality of driving units connected in common to the two ultrasonic transducers to generate a plurality of driving signals; and a plurality of driving signals generated by the plurality of driving units are given a predetermined delay time to perform phasing addition. Means for outputting the phasing-added drive signal to the one ultrasonic vibrator. 3. An ultrasonic transmitting / receiving circuit for driving a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processing a reception signal received by the plurality of ultrasonic transducers, A plurality of driving units that are commonly connected to one ultrasonic transducer and generate a plurality of driving signals; and a switching unit that switches timing of supplying the plurality of driving signals to the one ultrasonic transducer. An ultrasonic transmission / reception circuit, characterized in that: 4. An ultrasonic transmission / reception circuit that drives a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processes a received signal received by the plurality of ultrasonic transducers. A plurality of driving units that are commonly connected to one ultrasonic transducer and generate a plurality of driving signals; a switching unit that switches a timing of supplying the plurality of driving signals to the one ultrasonic transducer; An ultrasonic transmission / reception circuit, comprising: resonance means capable of changing a frequency, wherein the plurality of drive signals have desired transmission characteristics according to a resonance frequency of the resonance means. 5. An ultrasonic wave transmitting / receiving circuit for driving a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processing a reception signal received by the plurality of ultrasonic transducers. In the ultrasonic diagnostic apparatus, the ultrasonic transmitting and receiving circuit includes a plurality of driving circuits commonly connected to one ultrasonic transducer. 6. An ultrasonic wave transmitting / receiving circuit for driving a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processing a reception signal received by the plurality of ultrasonic transducers. In the ultrasonic diagnostic apparatus, the ultrasonic transmission / reception circuit is commonly connected to one ultrasonic transducer and generates a plurality of driving signals, and a plurality of driving units generates a plurality of driving signals. Means for phasing and adding the signals with a predetermined delay time, and outputting the phasing-added drive signal to the one ultrasonic vibrator. 7. An ultrasonic transmission / reception circuit for driving a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processing a reception signal received by the plurality of ultrasonic transducers. In the ultrasonic diagnostic apparatus, the ultrasonic transmission / reception circuit is connected to one ultrasonic transducer in common, generates a plurality of drive signals, and a plurality of driving units, and the plurality of driving means for the one ultrasonic transducer An ultrasonic diagnostic apparatus comprising: switching means for switching a timing of supplying a drive signal. 8. An ultrasonic transmission / reception circuit that drives a plurality of ultrasonic transducers in a small-diameter ultrasonic probe to transmit ultrasonic waves and processes a reception signal received by the plurality of ultrasonic transducers. In the ultrasonic diagnostic apparatus, the ultrasonic transmission / reception circuit is connected to one ultrasonic transducer in common, generates a plurality of drive signals, and a plurality of driving units, and the plurality of driving means for the one ultrasonic transducer Switching means for switching the timing of supply of the drive signal; and resonance means capable of changing the resonance frequency, wherein the plurality of drive signals have desired transmission characteristics according to the resonance frequency of the resonance means. Ultrasonic diagnostic equipment.