JP2707448B2 - Ultrasound diagnostic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus that obtains a tomographic image of a diagnostic part of a subject using ultrasonic waves, and more particularly, to improving a frame rate of a tomographic image. The present invention relates to an ultrasonic diagnostic apparatus capable of improving image quality in an apparatus provided with a plurality of echo signal receiving systems.

[Conventional technology]

A conventional ultrasonic diagnostic apparatus of this kind is disclosed in JP-B-56-20017.
5, a plurality of transducer elements 1a, 1b,... 1n are arranged in a line and transmit and receive ultrasonic waves. A transmission pulse generator 3 for applying a predetermined delay time to 1a to 1n to apply a driving pulse for ultrasonic launch, a transmission phase control circuit 4 for controlling the phase of the pulse of the transmission pulse generator 3, Probe 2
An amplifier 5 for amplifying the reflected echo signal received by the above, and a plurality of amplifiers which give a predetermined delay time to the echo signal received by each of the transducer elements 1a to 1n of the probe 2, align the phases thereof, add and output the same. Receiving phasing circuits 6a, 6b, and these receiving phasing circuits 6a, 6b
And a display device 7 for displaying an output signal from the device as an image. In FIG. 5, reference numeral 8 denotes a switch for sequentially selecting a specific plurality of transducer element groups of the probe 2 and switching the connection to the transmission pulse generator 3 and the amplifier 5 to perform, for example, linear electronic scanning. Reference numeral 9 denotes a circuit, which is a control device for controlling each of the above components.

A drive pulse for ultrasonic launch is generated by the transmission phase control circuit 4 and the transmission pulse generator 3, and the transducer elements 1a to 1n of the probe 2 are sequentially switched and selected by the switching circuit 8, and An ultrasonic beam is transmitted from the probe 2, an echo signal reflected from a diagnostic part of the subject is received by the probe 2, and the received signal is received via the switching circuit 8 and the amplifier 5. Wave phasing circuits 6a and 6b capture the received signals, give a predetermined delay time to the received signals, align and add the phases, and output the signals. Output signals S ₁ and S ₂ from these received phasing circuits 6a and 6b Was input to the display device 7 and displayed as an image.

In general, the directivity of the ultrasonic beam of the ultrasonic diagnostic apparatus having such a configuration is determined by the product of the directivity of the transmitting unit and the directivity of the receiving unit. Thus, by slightly displacing the directivity of the transmitter and the directivity of the receiver, the overall directivity can be positioned between the two. This indicates that the reflected echoes in the directions slightly shifted from each other can be received at the same time by receiving with a plurality of receivers whose directions are slightly shifted from the directivity of one transmitter. ing. FIG. 6 schematically shows this state. That is, transducer elements 1a~1e of the probe 2 when excited, transmit beam is usually in the direction of arrow T ₁ of the dashed line on the middle axis of the transducer elements 1a~1e used. At this time, the group of the transducer elements 1a~1e used to receive the reflected echoes, and a group of 1 a - 1 f, one oscillator element group 1a~1e dashed on the middle axis of the arrow R ₁ Direction and the other transducer element group 1a
To have a directivity of the receivers in the two directions of dashed direction of the arrow R ₂ on the middle axis of the ～1F. Accordingly, the directivity of the wave transceiver overall is in both the solid arrow TR ₁ and TR _2. That is,
With respect to the emission of one ultrasonic beam, reflected echo signals from _two directions of TR ₁ and TR ₂ are obtained by two receiving phasing circuits 6a and 6b, each of which has a slightly shifted directivity in FIG. Can be received simultaneously. In this way, the complete image time derived from the conventional sound speed can be halved, and the frame rate of the tomographic image has been improved.

[Problems to be solved by the invention]

In such a conventional ultrasonic diagnostic apparatus, reflected echo signals from two directions can be simultaneously received by a plurality of reception phasing circuits 6a and 6b, each of which has a slight shift in directivity, and a tomographic image is obtained. However, since the output signals S ₁ and S ₂ output from the respective reception phasing circuits 6a and 6b are directly input to the display device 7 and displayed as images, Variations in the receiving sensitivities of the respective wave receiving and phasing circuits 6a and 6b affect images. That is, the above-described variation in the receiving sensitivity causes a difference in contrast, brightness, and the like between the scanning lines forming the tomographic image, thereby deteriorating the image quality. Therefore, the image becomes difficult to see, and good diagnostic information may not be obtained.

To cope with this, in the conventional device, selection was performed so that the characteristics of the circuit components such as the respective reception phasing circuits 6a and 6b were aligned, or the gain was trimmed at a specific operating point and the like was performed. . However, in the case of selecting to make the characteristics of the circuit components uniform or trimming the gain,
TGC (Tim) that increases the gain over time to compensate for the weaker the reflected echo signal from the deeper part of the subject
It has been practically impossible to remove or reduce the variation in the gain of all the received signals of different magnitudes in the (e Gain Control) operation.
In order for this to be practically effective, a large amount of adjustment man-hour is required, which causes a cost increase.

Therefore, an object of the present invention is to provide an ultrasonic diagnostic apparatus that can solve such a problem.

[Means for solving the problem]

The above-described object is to provide a probe in which a plurality of transducer elements are arranged in a line to transmit and receive ultrasonic waves, and a transmission means for applying a predetermined delay time to each of the transducer elements and applying a driving pulse for ultrasonic emission. A wave pulse generator, a predetermined delay time is given to the echo signal received by each transducer element of the probe, the phases are aligned and added, and the phased signal is detected. A plurality of receiving systems that simultaneously receive echo signals with a slight shift in the directivity of receiving an echo signal with respect to one emission direction of a sound wave, and a display device that displays output signals from these receiving systems as images. In the ultrasonic diagnostic apparatus provided, output signals from the plurality of receiving systems are respectively input to generate a control signal for adjusting the receiving sensitivity of the other receiving system to the receiving sensitivity of one receiving system as a reference. And a controller to send A variable gain amplifier that adjusts the gain so that the signal level of the output signal of the other receiving system becomes equal to the output signal of the other receiving system by a control signal from the controller of the plurality of receiving systems; When comparing the reception sensitivities of the output signals, the echo signals received by the probe are cut off, and a pseudo echo signal for calibration is used for each reception system in a state where the directivity of each reception system is the same. And a pseudo-echo signal generator for generating and transmitting the same.

(Operation)

The ultrasonic diagnostic apparatus configured as described above uses a controller provided on the output side of a plurality of receiving systems to input output signals from each of the receiving systems and refer to the receiving sensitivity of one of the receiving systems as a reference. A control signal for matching the receiving sensitivity of the other receiving system is generated and transmitted, and a control signal from this controller is input to a variable gain amplifier provided on the output side of one of the receiving systems. The variable gain amplifier adjusts the gain so that the signal level of the output signal of one receiving system becomes equal to the output signal of the other receiving system. By inputting output signals from a plurality of receiving systems in which the gain has been adjusted and the difference in receiving sensitivity has been compensated for to the display device, the frame rate of the tomographic image can be improved and the image quality can be improved. Can be improved. When comparing the receiving sensitivities of the output signals from the plurality of receiving systems by the pseudo echo signal generator, the echo signals received by the probe are cut off and the directivity of each receiving system is made the same. In this state, a pseudo echo signal for calibration is generated and transmitted to each receiving system. Thereby, the operation of the plurality of receiving systems can be easily calibrated.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention. This ultrasonic diagnostic apparatus obtains a tomographic image of a diagnostic part of a subject using ultrasonic waves,
As shown in FIG. 1, a probe 2 and a transmission pulse generator 3
, A plurality of receiving systems 10 a and 10 b, a display device 7, and a control device 9.

The probe 2 transmits and receives ultrasonic waves to and from a diagnosis site of a subject. For example, a plurality of strip-shaped transducer elements 1a, 1b,... 1n are arranged in a line. . In addition,
The probe 2 may include an electronic switch for performing an operation of switching signals from the transducer elements 1a to 1n to perform linear electronic scanning, or may include an electronic switch for performing a sector electronic operation. It may not be. The transmission pulse generator 3 applies a predetermined delay time to each of the transducer elements 1a to 1n of the probe 2 to apply a driving pulse for launching an ultrasonic wave. And the convergence point can be arbitrarily controlled.

The first and second receiving systems 10a and 10b are provided in parallel on the output side of the received signal of the probe 2, and the probe 2
A predetermined delay time is given to the echo signal received by each of the transducer elements 1a to 1n, the phases are aligned, the phases are added and the phase is adjusted, and the phased signal is detected, and in one emission direction of the ultrasonic wave, On the other hand, the directivity of the reception of the echo signal is shifted at the same time by a very small amount, and it is received at the same time.
11a and 11b, phasing circuits 12a and 12b, and detection circuits 13a and 13b are provided. The amplifiers 11a and 11b amplify the reflected echo signals received by the probe 2, and
A multi-channel amplifier is used to respond to echo signals from multiple transducer elements, and a TGC operation that increases the gain over time to compensate for weaker echo signals reflected from deeper into the subject is possible Variable gain amplifiers are often used. The phasing circuits 12a and 12b are provided on the output sides of the amplifiers 11a and 11b, respectively, and give a predetermined delay time to the echo signals received by the transducer elements of the probe 2 to align the phases. The output is added, and the directivity of the ultrasonic beam is given in a specific direction, and the convergence of the ultrasonic beam is given to a specific depth. The detection circuits 13a and 13b are provided on the output side of each of the phasing circuits 12a and 12b, respectively, and detect the signals phasified by the phasing circuits 12a and 12b after logarithmic compression. And the first and second receiving systems 10a, 10
In b, the directivity and the convergence point of the ultrasonic beam are controlled by the control device 9 in the same manner as in the transmission pulse generator 3.

As shown in FIG. 2, the first and second receiving systems 10a and 10b respectively move left and right with respect to the direction θ of the ultrasonic beam T emitted from the probe 2 toward the subject. Directivity is provided in a direction deflected by a small angle Δθ, that is, in a direction of (θ + Δθ) and (θ−Δθ), and after transmitting the ultrasonic beam T, simultaneously reflected echo signals in the two directions are provided.
By receiving R ₁ and R ₂ , the frame rate of the tomographic image is to be improved. Furthermore, in these two receiving systems 10a and 10b, the portion where the reflected echo is generated becomes deeper as the ultrasonic wave propagates through the subject, so that the dynamic focus that sequentially moves the convergence point can be performed accordingly. It has become.

The display device 7 receives the output signals S ₁ and S ₂ output from the first and second receiving systems 10 a and 10 b and displays them as an image. For example, a digital scan converter composed of a semiconductor memory and a standard scan System and a television monitor. The control device 9 controls the operation of each of the above components.

Here, in the present invention, a controller 14 is provided in common on the output side of the first and second receiving systems 10a and 10b, and for example, the controller 14 is variable between the second receiving system 10b and the display device 7. A gain amplifier 15 is provided, and a pseudo echo signal generator 17 is provided.
Is provided. The controller 14 receives the output signals S ₁ and S ₂ output from the first and second receiving systems 10a and 10b, respectively, and receives the output signals S ₁ and S ₂ from the other receiving system 10b based on the receiving sensitivity of one receiving system 10a. Control signal S ₃ for adjusting the receiving sensitivity to it
Is generated and transmitted, and is connected to the first receiving system 10a via a signal line 16a, and is connected to the second receiving system 10b via a signal line 16b. This control unit 14 is adapted to store the control signal S ₃ which is the product.
The variable gain amplifier 15 inputs a control signal S ₃ sent from the controller 14, for example, the output signal S of the first receiving system 10a
For _one in which the second output signal S ₂ of the signal level of the receiving system 10b is adjusted its gain to be equal, the output signal S ₂ of the gain-adjusted 'from the first reception system 10a has become such that the output signals S ₁ and the same level. When comparing the reception sensitivities of the output signals S ₁ and S ₂ output from the two reception systems 10 a and 10 b, the pseudo echo signal generator 17 blocks the echo signal received by the probe 2. In FIG. 2, the two receiving systems are set with a small angle Δθ = 0.
With the directivity of 10a and 10b being the same,
A pseudo echo signal for calibration is generated and transmitted to a and 10b.

Next, the operation of the ultrasonic diagnostic apparatus thus configured will be described. First, the transmission pulse generator 3 is operated by the control device 9 to apply a driving pulse for ultrasonic emission to each of the transducer elements 1a to 1n of the probe 2. Thereby, the directivity and the convergence point of the ultrasonic beam are determined in a specific state,
An ultrasonic beam is emitted from the probe 2 toward the subject. Next, the echo signal reflected from the diagnostic part of the subject is received by the probe 2 and input to the first and second receiving systems 10a and 10b, respectively. At this time, as shown in FIG. 2, the first and second receiving systems 10a and 10b direct the reception in directions deflected by a small angle Δθ to the left and right with respect to the reflection direction θ of the ultrasonic beam T, respectively. After transmitting the ultrasonic beam T, the two-way reflected echo signals R ₁ and R ₂ are received at the same time. Then, for example, a first echo signal R ₁ is input to the first receiving system 10a, matched phase giving a predetermined delay time phasing circuit 12a while being amplified by the amplifier 11a summed and the detection circuit 13a in is detected, is transmitted as an output signal S _1. At the same time, the second echo signal
R ₂ is input to the second receiving system 10b, in the amplifier 11b and the phasing circuit 12b and detector 13b is the same reception processing as described above, is transmitted as an output signal S _2. Next, the output signals S ₁ and S ₂ from the first and second receiving systems 10a and 10b are input to the controller 14 via signal lines 16a and 16b, respectively. Then, the controller 14, the output signals S ₁ and S ₂ which is the input relative to each other, with respect to the reception sensitivity of one of the receiving system 10a if there is a difference in the signal level of the other receiving system 10b and sends to the variable gain amplifier 15 receiving sensitivity by generating a control signal S ₃ to match it. Then, the variable gain amplifier 15, the control signal S ₃ inputted from the controller 14, the first receiving system 10
It adjusts its gain so that the signal level of the output signal S ₂ are equal from the second receiving system 10b for the output signals S ₁ from a, and outputs an output signal S ₂ 'as a result. At this time, the output signals S ₁ from the first receiving system 10a, the gain adjusted output signal S ₂ 'in the second variable gain amplifier 15 is output from the receiving system 10b of the signal level is the same Become. Thereafter, the output signals S ₁ and S ₂ 'are displayed as an image input to the display device 7. As a result, it is possible to prevent a difference in contrast and brightness between scanning lines forming a tomographic image, thereby improving image quality.

Here, when comparing the receiving sensitivities of the output signals S ₁ and S _{2 from} the two receiving systems 10a and 10b, the directivity of the first and second receiving systems 10a and 10b is set to be the same. Instead of the operation of generating the control voltage so that the echo signals received by the probe 2 become equal, the echo signal is cut off, and a pseudo echo signal for calibration is generated from the pseudo echo signal generator 17. The signals may be input to the first and second receiving systems 10a and 10b. Further, since the control signal S ₃ which is generated by the controller 14 is temporarily stored in the controller 14 generates a pseudo echo signal from the echo replica generator 17 and the output signals S ₁ with stops operation of comparing S ₂ is not performed, may be controlled variable gain amplifier 15 with the control signal S ₃ which is above storage.

FIG. 3 is a block diagram showing another embodiment of the present invention. In this embodiment, inside the first receiving system 10a,
Two reception processing systems including an amplifier 11a, a phasing circuit 12a, and a detection circuit 13a are provided and these are switched.
In the second receiving system 10b, the amplifier 11b, the phasing circuit 12b, and the detection circuit
Two reception processing systems 13b are provided, and these are switched by a changeover switch 18b.
The output signals S ₁ and S ₂ ′ sent from the first and second receiving systems 10a and 10b to the display device 7 are output from the A / D converter 19
The digital signals are converted into digital signals by a and 19b, and are temporarily stored in the line memories 20a and 20b. Further, the controller 14 shown in FIG. 1 is built in the control device 9. The changeover switches 18a and 18b do not generate noise when switching.

Next, the embodiment of FIG. 3 will be described in more detail. First, in the first receiving system 10a or the second receiving system 10b shown in FIG. 1, a convergence point is sequentially determined in response to a deepening of a portion where a reflected echo is generated as an ultrasonic wave propagates through a subject. Although dynamic focusing can be performed by moving, as a method of performing dynamic focusing by giving an appropriate delay to a received echo signal, in the phasing circuit 12a or 12b shown in FIG. Are switched using an analog switch. However, if the analog switch is switched while the above-described tapped electromagnetic delay line is operating, in a normal switch in which the analog switch is made of, for example, a MOS FET, noise generated from the switch at the time of the switching is output signal S _1. , mixed in S _2, which may affect the tomographic images obtained. In contrast, in the embodiment shown in FIG. 3, 11a ₁ + 12a ₁ + 13a ₁ , 11a ₂ + 12a ₂ + 13a ₂ ; 11b ₁ + 12b ₁ + inside the first and second receiving systems 10a and 10b.
_Two reception processing systems such as 13b ₁ , 11b ₂ + 12b ₂ + 13b ₂ are provided, and these are switched by the changeover switches 18a, 18b. Next, the operation of these receiving systems 10a and 10b will be described using the first receiving system 10a as an example. First, in the first reception processing system consisting of amplifiers 11a ₁ and phasing circuit 12a ₁ and the detection circuit 13a ₁ Tokyo, as shown in 4 (a), the depth converges to a depth z ₁ of the diagnostic region of 0
To receive the reflected echo region I to z ₂ from,
And sets narrow the aperture of the amplifier 11a ₁ of the probe by controlling the gain probe 2, and appropriately setting the delay time of a tapped electromagnetic delay line of the phasing circuit 12a _1, and conducting a change-over switch 18a to the contact A side Let it. During this reception, the area of the second reception processing system consisting of the other amplifier 11a ₂ and phasing circuit 12a ₂ and the detection circuit 13a ₂ Metropolitan from depth z ₂ in FIG. 4 (a) to z ₄ to perform the preparation for receiving a reflected echo of II, with the diameter of the probe 2 by controlling the gain of the amplifier 11a ₂ is set to be slightly wider, phasing circuits 12a ₂ taps electromagnetic delay line with taps by switching appropriately set the delay time so as to converge at a depth z _3. In this case, even if the noise from the analog switch for switching the tap of the phasing circuits 12a ₂ of the electromagnetic delay line with taps is generated, the change-over switch 18a is connected to the contact A side for receiving a signal of the first reception processing system Therefore, the noise from the analog switch does not mix with the signal of the first reception processing system.

Next, ultrasonic waves emitted toward the patient is propagated through the body, from FIG. 4 (a) is reached when the depth z ₂ to the depth z ₂ in
To observe the region II to z _4, the change-over switch 18a is connected to the contact point B at time t ₁ shown in FIG. 4 (b), receiving a signal of the second reception processing system. During this reception, the first reception processing system, in order to prepare to receive the reflected echo region III from depth z ₄ in FIG. 4 (a) to z _6, the gain of the amplifier 11a ₁ Control to set the diameter of the probe 2 to be the widest,
appropriately switched depth taps electromagnetic delay line with taps a ₁
to set the delay time so as to converge to z _5. In this case, even if the noise from the analog switch for switching the tap of the phasing circuits 12a ₁ of the electromagnetic delay line with taps is generated, the change-over switch 18a is connected to the contact B side for receiving a signal of the second reception processing system Therefore, the noise from the analog switch does not mix into the signal of the second reception processing system.

Next, ultrasonic waves emitted toward the patient is propagated through the body, from FIG. 4 (a) reaches the depth z ₄ in the depth z ₄
To observe the region III to the z _6, the changeover switch 18a is again connected to the contact A side at time t ₂ shown in FIG. 4 (b), receiving a signal of the first reception processing system. As described above, the phasing circuit 12 of the first and second reception processing systems
The dynamic focus can be executed without being affected by noise at the time of tap switching of the tapped electromagnetic delay line in a ₁ and 12a ₂ .

Next, a procedure for adjusting the reception sensitivity of the other reception system 10b to the reception sensitivity of one reception system 10a in the embodiment of FIG. 3 will be described. First, in the first and second receiving systems 10a and 10b, the small angle Δθ shown in FIG.
= 0, the reflected echo signals from the probe 2 are cut off, and a pseudo echo signal for calibration is generated from the pseudo echo signal generator 17 to produce the first and second signals. Input to the second receiving systems 10a and 10b. next,
The output signals S ₁ and S ₂ from the respective receiving systems 10a and 10b are input to the control device 9 and compared therein. Then, if there is a signal level difference between the respective output signals S ₁ and S ₂ , for example, the signal of the output signal S ₂ from the second receiving system 10b with respect to the output signal S ₁ from the first receiving system 10a level and sends a control signal S ₃ that are equal. The control signal S ₃ is inputted to the variable gain amplifier 15 adjusts the gain of the variable gain amplifier 15. Thereby, the output signal S ₂ from the second reception system 10b
Is adjusted and output as an output signal S ₂ ′ having the same level as the output signal S ₁ from the first receiving system 10 a. Therefore, the first A / D converter 19a connected to the output side of the first receiving system 10a, and the second A / D converter 19b connected to the output side of the second receiving system 10b The levels of the input signals are the same. The first and second receiving systems 10
a, when there is no difference in the reception sensitivity between 10b, the control voltage of the control signal S ₃ to be input to the variable gain amplifier 15, a constant value as indicated by the straight line V ₀ in FIG. 4 (c). However, normally, as shown by the curve Vc in the figure, the value changes with time t. Then, store the control signal S ₃ of such contents in the control device 9. The above operation is referred to as a calibration mode I here.

The above-described calibration mode I is performed, for example, immediately after the power switch of the ultrasonic diagnostic apparatus is turned on, every time the operation switch for the calibration mode is operated, at a certain time interval, The method may be appropriately adopted such that the method is carried out every time the data is exchanged.

In the above-mentioned calibration mode I, a pseudo echo signal is used. However, when dynamic focus for changing the aperture of the probe 2 and changing the convergence point is performed on an echo signal from a living body, the ultrasonic living body It is desirable that the difference between the receiving sensitivities of the first and second receiving systems 10a and 10b be compensated for, including the characteristics affected by the biological action such as attenuation in the inside. In response to such a request, the first and second receiving systems 10a,
The directivity of 10b is set to the small angle Δθ = 0 shown in FIG. 2 as in the case of the calibration mode I, and the beam deflection angle θ is set to 0 in both cases by the control device 9 in FIG. 4 (c).
To generate a control signal S ₃ of the control voltage as shown by the curve Vc, it may be stored the control signal S _3. Here, in a specific case where the beam deflection angle θ is constant, the acquired control voltage
The difference between the receiving sensitivities of the first and second receiving systems 10a and 10b may be compensated by Vc. Alternatively, the control voltage Vc may be fetched every time the beam deflection angle θ is changed, and the control voltage may be sequentially changed each time the beam deflection angle θ is changed for sector scanning. As described above, the reflected echo signals from the living body first and second receiving systems 10a, simultaneously captures at 10b, and calibration mode II the mode for generating a control signal S ₃ of the variable gain amplifier 15 as compared with one another Call.

In this calibration mode II, a tomographic image of the subject is obtained at the same time, but the first and second receiving systems 10a, 10b
Both have directivity in the same direction, so that the frame rate of the tomographic image decreases. Therefore, the calibration mode II is preferably executed only when a decrease in the frame rate is allowed.

Furthermore, in order to strictly compensate for the difference between the receiving sensitivities of the first and second receiving systems 10a and 10b, the directivity of the two receiving systems 10a and 10b is set to (θ +
Δθ), (θ-Δθ) and then, calibrated using a phantom for generating a uniform reflection echo Despite these directional, it is sufficient to generate a control signal S _3. This mode is called calibration mode III.

Above calibration mode I, II, in III, the first and second receiving system 10a, as a method for compensating for differences in the reception sensitivity 10b, store the control signal S ₃ to be sent to the variable gain amplifier 15 data was assumed that, instead of the control signal S ₃ described above were compared and stores the output signals S _1, S ₂ itself from the receiving systems 10a, 10b, or two of the output signals S _1, S ₂ May be stored.

Next, when the above calibration mode is completed, in the calibration mode I, the generation of the pseudo echo signal from the pseudo echo signal generator 17 is stopped, and the first and second receiving systems 10a, 10a,
The directivity of 10b is set to (θ + Δθ) and (θ−Δθ), and the transmission pulse generator 3 is operated to transmit the ultrasonic beam from the probe 2 and receive the reflected echo from the subject. In FIG. 2, the electron deflection is performed, for example, by changing the beam deflection angle θ every time a transmission pulse is generated. At this time, the echo signals received by the probe 2 are input to first and second receiving systems 10a and 10b, respectively, and output signals S ₁ and S ₂ are output from these receiving systems 10a and 10b, respectively. Is output.
In this case, the read control signal S ₃ which has already been stored in the control device 9 by the above calibration mode I, to adjust the gain of the variable gain amplifier 15 by the control signal S _3. Thus, the output signal S ₂ of the signal level from the second receiving system 10b is adjusted, the output signal S from the first receiving system 10a
It is output as an output signal S ₂ ′ having the same signal level as ₁ .
Thereafter, the output signals S ₁ , S ₂ ′ are first and second A, respectively.
The signals are input to the / D converters 19a and 19b, converted into digital signals, and simultaneously stored in the first and second line memories 20a and 20b. The stored data is alternately read in a short time, input to the display device 7, and displayed as an image.
This operation is here called a diagnostic mode.

In this diagnostic mode, if the control voltage curve Vc shown in FIG. 4C hardly changes with the passage of time t due to the characteristic variation of the circuit components, the average value Vcmean of the curve Vc is used. The control voltage may be constant with time. On the other hand, if the curve Vc of the control voltage changes every time the beam deflection angle θ changes by the electron sector scanning, the beam deflection angle θ is changed to θ ₁ , θ ₂ ,. The control voltage Vcθ may be stored for each, and the control voltage Vcθ corresponding to each of the different beam deflection angles θ ₁ , θ ₂ ,.

In the third diagram, an example of controlling the magnitude of the second signal level of the output signal S ₂ from the receiving system 10b of the variable gain amplifier 15, in place of the variable gain amplifier 15, the The control may be performed by changing the reference voltage of the two A / D converters 19b, or the gains of the amplifiers 11b ₁ and 11b ₂ may be controlled by being superimposed on the TGC operation.

〔The invention's effect〕

Since the present invention is configured as described above, the output signals S ₁ and S ₂ from the plurality of receiving systems 10a and 10b are respectively input to the controller 14 and the other receiving system 10a is used as a reference with respect to the receiving sensitivity of one receiving system 10a. Control signal S ₃ for adjusting the reception sensitivity of the
And sends the control signal S ₃ to the variable gain amplifier 15.
Enter by the output signal S ₂ of the signal level of the other of the receiving system 10b for the output signals S ₁ of one of the receiving system 10a to adjust its gain to be equal to, from one of the receiving system 10a above and the output signal S _1, a gain adjusted output signal by the variable gain amplifier 15 is output from the other receiving system 10b
The signal level with S ₂ ′ can be the same. Accordingly, it becomes that said plurality of receiving systems 10a, is S ₂ 'and the output signals S ₁ of the same signal level difference has been compensated for their reception sensitivity from 10b to enter the display device 7, to form a tomographic image It is possible to prevent a difference in contrast and brightness from occurring between scanning lines, to improve a frame rate of a tomographic image, and to improve the image quality.
In addition, a pseudo echo signal generator 17 is provided to cut off the echo signal received by the probe 2 and compare each reception signal when comparing the reception sensitivities of the output signals from the plurality of reception systems 10a and 10b. By generating and sending a calibration echo signal to each of the receiving systems 10a and 10b with the directivity of the systems 10a and 10b being the same, the operation of a plurality of receiving systems can be easily calibrated. Can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an ultrasonic diagnostic apparatus according to the present invention, FIG. 2 is an explanatory view showing the directivity of reflected echo reception by a plurality of receiving systems, and FIG. FIG. 4 is a block diagram showing the operation of another embodiment, FIG. 5 is a block diagram showing a conventional ultrasonic diagnostic apparatus, and FIG. 6 is a plurality of receivers. FIG. 7 is an explanatory diagram showing a state in which reflected echoes in directions slightly deviated by the above are simultaneously received. 1a to 1n: vibrator element, 2: probe, 3: transmitting wave pulse generator, 7, display device, 9: control device, 10a, 10b
...... Reception system, 14 ... Controller, 15 ... Variable gain amplifier, 17
…… Pseudo echo signal generator, S ₁ , S ₂ , S ₂ ′ …… Output signal,
S ₃ … Control signal.

Continuation of the front page (72) Inventor Shinji Kishimoto 2-1 Shinjuyo Kashiwa, Chiba Pref. Hitachi Medical Research Institute, Ltd. (56) References JP-A-61-135641 (JP, A) JP-A-62-64343 (JP, A) JP-A-54-7786 (JP, A)

Claims (1)

(57) [Claims] 1. A probe in which a plurality of transducer elements are arranged in a line to transmit and receive an ultrasonic wave, and a transmission means for applying a predetermined delay time to each of the transducer elements to apply a driving pulse for ultrasonic emission. A wave pulse generator, a predetermined delay time is given to the echo signal received by each transducer element of the probe, the phases are aligned and added, and the phased signal is detected. A plurality of receiving systems that simultaneously receive echo signals with a slight shift in the directivity of receiving an echo signal with respect to one emission direction of a sound wave, and a display device that displays output signals from these receiving systems as images. In the ultrasonic diagnostic apparatus provided, output signals from the plurality of receiving systems are respectively input to generate a control signal for adjusting the receiving sensitivity of the other receiving system to the receiving sensitivity of one receiving system as a reference. Controller to send A variable gain amplifier for adjusting a gain so that a signal level of an output signal of one receiving system becomes equal to an output signal of the other receiving system by a control signal from a controller; and outputs from the plurality of receiving systems. When comparing the signal reception sensitivity, the echo signal received by the probe is cut off, and a pseudo echo signal for calibration is supplied to each reception system with the same directivity of each reception system. An ultrasonic diagnostic apparatus, comprising: a pseudo echo signal generator for generating and transmitting.