JPH0771555B2 - Ultrasonic diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an ultrasonic diagnostic apparatus capable of displaying a B-mode image and a Doppler mode image.

(Prior Art) When simultaneously displaying a B-mode image and a Doppler mode image in real time by an ultrasonic diagnostic apparatus, improving the sensitivity of the Doppler mode image without degrading the image quality of the B-mode image improves the diagnostic ability. It is necessary to plan.

In this case, conventionally, in order to improve the sensitivity of the Doppler mode image, for example, as shown in FIG. 3A, the drive circuit 30 for generating the drive pulse and the ultrasonic probe 31 are directly connected to each other, and the ultrasonic vibration is generated. A method of performing simultaneous burst drive in B mode and Doppler mode at a cycle 1 / f ₀ of the center frequency f ₀ of the child,
As shown in FIG. 3 (b), the center frequency f _{0 of the} ultrasonic transducer
The resonance element 32 that resonates with the drive circuit 30 and the ultrasonic probe 31
A method for performing simultaneous burst drive in B mode and Doppler mode with a period 1 / f ₀ of the center frequency f ₀ is also used.

By the way, in order to improve the sensitivity of the Doppler mode image by performing the transmission / reception resonance drive as shown in FIG. 3 (b), the pulse convergence time of the ultrasonic echo signal at the resonance drive shown in FIG. 4 (b). Since t ₂ is longer than the pulse convergence time t ₁ at the time of non-resonance shown in FIG. 4A, there is a problem that the distance resolution of the B-mode image is reduced. This is because the continuous wave of the ultrasonic echo signal of frequency f ₀ repeats vibration for a long time during resonance drive.

Further, the spectrum of the transmission power at the time of both non-resonance drive and resonance drive is as shown in FIGS. 5 (a) and 5 (b). That is, since the transmission power during resonance drive becomes narrower than that during non-resonance drive, considering the attenuation of ultrasonic waves in the subject, the received echo signal at this time causes a decrease in the S / N ratio in the deep part of the subject. there is a possibility.

On the other hand, in order to improve the sensitivity of the Doppler mode image while performing burst driving with an arbitrary number of waves as shown in FIG. 3 (a), a large transmission power is required, and as a result, the safety of the subject is taken into consideration. There is a problem that the specified transmission power regulation cannot be observed.

(Problems to be Solved by the Invention) As described above, in the conventional device, when simultaneous real-time display of the B-mode image and the Doppler mode image is performed, there is a problem that the resolution of the B-mode image and the sensitivity at a deep portion are lowered. Inclusive.

Therefore, according to the present invention, when the B-mode image and the Doppler mode image are simultaneously displayed in real time, ultrasonic wave transmission is performed within the transmission power regulation to prevent the image quality deterioration of the B-mode image and improve the sensitivity of the Doppler mode. It is an object of the present invention to provide an ultrasonic diagnostic apparatus.

[Configuration of Invention] (Means for Solving Problems) In order to achieve the above object, the present invention performs ultrasonic scanning on a subject and displays an ultrasonic image based on the obtained echo data. In the ultrasonic diagnostic apparatus to be provided, an ultrasonic probe provided with a plurality of transducers for transmitting and receiving ultrasonic waves,
Driving means for transmitting / receiving and driving the plurality of oscillators in a resonant or non-resonant state, driving the plurality of oscillators in a non-resonant state at the B-mode transmission / reception timing, and driving the plurality of oscillators at the Doppler mode transmitting / receiving timing. A drive control circuit for controlling the drive of the drive means so as to drive the oscillator in the resonance state, and a display means for simultaneously displaying the B mode image and the Doppler mode image based on the echo data.

(Operation) The operation of the apparatus configured as described above will be described below.

The drive control circuit drives the ultrasonic transducer in a non-resonant state at the transmission / reception timing in the B mode, and drives the ultrasonic transducer in a resonant state at the transmission / reception timing in the Doppler mode.

As a result, the ultrasonic echo convergence time is short and the range resolution does not deteriorate at the B-mode transmission / reception timing, so that the Doppler sensitivity can be improved and the reception sensitivity can be increased by the reception resonance, so that the sensitivity can be increased with low transmission power. Becomes Further, at the transmission / reception timing of the Doppler mode image, the reception sensitivity due to resonance can be improved.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG.

The apparatus shown in FIG. 1 includes an ultrasonic probe 1 having a large number of ultrasonic transducers for transmitting and receiving ultrasonic waves, and a drive for performing burst drive of one wave or several waves on the ultrasonic probe 1. A drive circuit unit 2 that generates a pulse and a drive control circuit unit 3 that controls the generation of a drive pulse in the drive circuit unit 2 and that controls the vibration state of the ultrasonic transducer to a non-resonant or resonant state. It is configured to have.

The drive control circuit unit 3 includes a drive wave controller 4 that controls the generation of drive pulses in the drive circuit unit 2, and a, b, and c provided between the drive circuit unit 2 and the ultrasonic probe 1, respectively. First and second changeover switches 5A, 5B having three terminals, a switch controller 6 for controlling the first and second changeover switches 5A, 5B at the same time, and first and second changeover switches 5A, 5B, The resonance element 7 resonates at the center frequency f ₀ of the ultrasonic transducer connected between both terminals b of 5B. Further, both a terminals of the first and second changeover switches 5A and 5B are directly connected, the c terminal of the first changeover switch 5A is driven by the ultrasonic probe 1, and the c terminal of the second changeover switch 5B is driven. Each is connected to the circuit unit 2.

Next, the operation of the device having the above configuration will be described.

When a B-mode image is to be obtained with this device, the switch controller 6 is used to provide the first and second changeover switches 5
Both A and 5B are switched so that the a terminal and the c terminal are connected. Then, in this state, the drive circuit controller 2 controls the drive circuit section 2 to generate a drive pulse of one wave. This drive pulse is sent to each ultrasonic transducer element of the ultrasonic probe 1 via the second switch 5B and the first switch 5A. As a result, each ultrasonic transducer is excited in a non-resonant state, and transmits ultrasonic waves toward a subject (not shown).
The ultrasonic echo from the subject is received by each of the ultrasonic transducers, converted into an electric signal and subjected to subsequent processing, but since the reception processing of this ultrasonic echo is also performed in a non-resonant state, it has already been described. As shown in FIG. 4 (a), since the convergence time t ₁ of the ultrasonic echo signal is short, the resolution of the B-mode image does not deteriorate.

Next, when the Doppler mode image is to be obtained, the switch controller 6 causes the first and second changeover switches 5A and 5B.
Are switched so that the b terminal and the c terminal are connected.

Then, in this state, the drive circuit controller 2 controls the drive circuit section 2 to generate a drive pulse of one wave or several waves.

This drive pulse is applied to the second switch 5B, the resonance element 7, the first
Is sent to each ultrasonic vibration element of the ultrasonic probe 1 via the changeover switch 5A. As a result, each ultrasonic vibration element is excited in the resonance state of the center frequency f ₀ and transmits the ultrasonic waves toward the subject (not shown).

The ultrasonic echo from the subject is received by each of the ultrasonic vibration elements, converted into an electric signal, and then subjected to a process for obtaining a Doppler mode image. Since the processing is also performed in the resonance state, it has a high reception sensitivity, and thus a good Doppler mode image can be obtained without increasing the transmission power.

Next, with reference to FIG. 2, a specific circuit configuration example of the device shown in FIG. 1 will be described. Incidentally, in the device shown in FIG.
Components having the same functions as those shown in the drawings are designated by the same reference numerals, and detailed description thereof will be omitted.

The apparatus shown in FIG. 2 has n ultrasonic transducers 11a, 11b, ... 11n as the ultrasonic probe 1 and n ultrasonic transducers 11a, 11b ,. , 12n are provided respectively, and the drive control circuit section 3 corresponds to the ultrasonic transducers 11a, 11b, ..., 11n and the drive circuits 12a, 12b, ..., 12n, respectively. N switches 15a ₁ , 15a ₂ , ..., 15an, 15b ₁ , 15b ₂ ,
, 15bn and n resonant elements 7a, 7b, ..., 7n, and the switch controller 6 causes the changeover switches 15a to 15a to be provided.
n, 15b _{1 to} 15bn are controlled to be switched.

Also in the case of this device, as in the case of the device shown in FIG. 1, when the B-mode image is obtained, the changeover switches 15a _{1 to} 15an, 15b _{1 to} 15bn are switched to the a terminal side by the switch controller 6 so that no resonance occurs. Each ultrasonic transducer 11a, 11b,
, 11n to improve the resolution of the B-mode image by transmitting and receiving, and when obtaining the Doppler mode image, the changeover switches 15a _{1 to} 15an, 15b _{1 to} 15bn are switched to the b terminal side, and the resonance state is obtained. By driving each ultrasonic transducer to transmit and receive, the receiving sensitivity of the Doppler mode image can be increased without increasing the transmission power.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist thereof.

For example, in the device shown in FIG. 2, the drive circuit and the ultrasonic vibration element have a one-to-one correspondence,
The present invention is not limited to this, and can be applied to an apparatus having a configuration in which a smaller number of drive circuits than the ultrasonic vibration elements are used and the ultrasonic vibration elements to be driven are controlled by switches.

[Effects of the Invention] As described in detail above, according to the present invention, at the transmission / reception timing of the B mode, the ultrasonic echo reception processing is performed in a non-resonant state, so that the convergence time of the ultrasonic echo is short, and It is possible to prevent deterioration of the image quality of the mode image, and conversely, at the transmission / reception timing of the Doppler mode, the reception processing of the ultrasonic echo is performed in a resonance state, so high reception sensitivity is obtained.
A good Doppler mode image can be obtained with low transmission power.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a concrete circuit configuration example of the apparatus shown in FIG.
FIG. 3 (a) is a block diagram showing a conventional non-resonant driving state, FIG. 3 (b) is a block diagram showing a conventional resonant driving state, and FIGS. 4 (a) and 4 (b) are non-resonant driving states, respectively. Waveform diagrams showing the converged state of the ultrasonic echo signal at the time of resonance and at the time of resonance, and FIGS. 5A and 5B are frequency spectra of ultrasonic power at the time of non-resonance and at the time of resonance, respectively. 1 ... Ultrasonic probe, 2 ... Drive circuit section, 3 ... Drive control circuit section.

Claims (2)

[Claims] 1. An ultrasonic diagnostic apparatus for ultrasonically scanning a subject and displaying an ultrasonic image based on the obtained echo data, the ultrasonic diagnostic apparatus comprising a plurality of transducers for transmitting and receiving ultrasonic waves. A sound wave probe, a driving unit that drives the plurality of transducers to transmit and receive in a resonance or non-resonance state, and drives the plurality of transducers in a non-resonance state in B mode transmission / reception timing, and in a Doppler mode transmission / reception timing. A drive control circuit for controlling the drive of the drive means so as to drive the plurality of vibrators in a resonance state; and a display means for simultaneously displaying a B mode image and a Doppler mode image based on the echo data. And ultrasonic diagnostic equipment. 2. The drive control circuit has a resonance element that resonates at a center frequency of the vibrator, and a resonance state and a non-resonance state of transmission / reception driving are switched by connecting the resonance element. 1. The ultrasonic diagnostic apparatus according to 1.