JP3274194B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus in which saturation of a preamplifier caused by differences in biological attenuation of a subject is prevented by gain control.

[0002]

2. Description of the Related Art As shown in FIG. 6, an ultrasonic diagnostic apparatus transmits a driving pulser from a driving circuit 30 to a transducer 31 of a probe, and transmits an ultrasonic wave from the transducer 31 to a target portion. Then, each transducer 31 receives the echo signal from the target part and amplifies the signal by the preamplifier 32. The amplified echo signal is supplied to each preamplifier 32 in a delay circuit 33.
After an appropriate delay is given to the output signal from, and added by the adder 34, log compression for widening the dynamic range is performed by the log amplifier 35a of the log amplifier 35,
The detection circuit 35b changes the brightness of the monitor image to obtain image data, and sends this image data to a monitor (not shown) via a display-system DSC (digital scan converter) 36 so that a desired diagnostic image is displayed on the monitor. It is displayed. When the echo signal is received, a gain control signal is sent from the preamplifier gain signal control circuit 37 to the preamplifier 32 for each ultrasonic rate so as to avoid saturation of the preamplifier 32 at a short distance, and the gain of the preamplifier 32 increases with time. Controlled. Such a gain control signal is uniquely determined by the probe used and the observation mode, as shown in FIG.

An operation panel has a Sensitivity Time Command (STC) for correcting attenuation during propagation of ultrasonic waves.
An ontrol) volume 38 and a GAIN (gain) volume 39 are provided, and the gain control of the log amplifier unit 35 at the subsequent stage is performed within the range of the hatched portion in FIG. It can be adjusted uniformly in the depth direction of the specimen.

[0004]

However, in the ultrasonic diagnostic apparatus, the pattern of the preamplifier gain control signal is uniquely determined by the probe and the observation mode as shown in FIG. The gain control may not be properly performed due to the difference in attenuation or the difference in attenuation at the diagnosis target portion, and saturation may occur in the first-stage preamplifier. When such saturation occurs, the original echo signal cannot be reproduced even if the gain is reduced in the log amplifier unit at the subsequent stage, and the layer structure of the abdominal wall of the tomographic image drawn on the monitor may be crushed or blurred. There is a problem that the removal of the cavity becomes worse, the resolution is deteriorated, and the diagnostic ability is reduced clinically.

The present invention has been made to solve these problems, and an object of the present invention is to provide an ultrasonic diagnostic apparatus capable of finely adjusting a gain control signal of a preamplifier in response to a difference in living body attenuation. I do.

According to the first aspect of the present invention, there is provided an ultrasonic diagnostic apparatus comprising: a preamplifier for amplifying a signal received by a transducer; delay / addition means for performing a delay / addition process on an output signal of the preamplifier; An amplifier for amplifying the output signal of the delay / addition means, a means for controlling the gain of the preamplifier in accordance with the arrival time of the echo signal, and a GAIN setting means for adjusting the brightness of the monitor image. A means for generating a gain control signal for adjusting the gain of the preamplifier and the gain of the amplifier based on the set value is provided.

According to a third aspect of the present invention, there is provided an ultrasonic diagnostic apparatus comprising: a preamplifier for amplifying a signal received by a transducer; a delay / addition unit for performing a delay / addition process on an output signal of the preamplifier; An amplifier for amplifying the output signal of the delay / addition means, a means for controlling the gain of the preamplifier corresponding to the arrival time of the echo signal, and an STC setting means for adjusting the brightness of the monitor image for each depth of the subject. And a means for generating a gain control signal for adjusting the gain of the preamplifier and the gain of the amplifier based on the set value by the STC setting means.

[0008]

The ultrasonic diagnostic apparatus of the above means can change the pattern of the reference preamplifier gain control signal selected by the probe or the observation mode by operating the STC volume or the GAIN volume provided on the operation panel. For example, in accordance with the ultrasonic rate signal, the pattern of the preamplifier gain control signal is rapidly changed from a state where the gain is narrowed to a state where the gain is narrowed down to a state where the gain is sharply reduced, or the aperture of the gain is reduced within a range of hatching shown in FIG. The gain can be gradually increased from the state. As a result, the gain control signal of the preamplifier can be finely adjusted according to the difference in the attenuation of the living body of the subject or the difference in the attenuation of the diagnosis target portion. In addition, when observing a subject or a diagnosis site where the biological attenuation of the signal is small, the S / N of the diagnosis image can be improved by increasing the gain of the preamplifier.

By providing setting means for arbitrarily setting a range in which the adjustment operation of the STC volume and the GAIN volume and the gain control operation of the preamplifier are interlocked, it is necessary and sufficient to prevent saturation as shown by the oblique lines in FIG. The gain of the preamplifier can be controlled within a proper range, and the gain control of the log amplifier can be effectively performed outside the range. The hatched range in FIG. 5 is a variable range of the preamplifier gain control signal or a variable range of the log amplifier unit gain control signal.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an ultrasonic diagnostic apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main part of the ultrasonic diagnostic apparatus, and FIG. 2 is a block diagram showing a transport path of a gain control signal.

This ultrasonic diagnostic apparatus has a large number of transducers 1a.
, A driving circuit 2 for transmitting a driving pulser to the transducers 1a, a preamplifier 3 for amplifying each echo signal received by each transducer 1a, and an appropriate signal for the signals transmitted from each preamplifier 3. A delay circuit 4 for giving a long delay to focus a tomographic image obtained in a subsequent stage, an adder 5 for adding a delayed signal to obtain a tomographic image, a log amplifier 6a for widening a dynamic range, and a monitor A log amplifier unit 6 configured by a detection circuit 6b that changes the brightness of an image, and a DSC that performs various hardware processes such as zooming on the image data and sends the image data to a monitor at a subsequent stage.
(Digital scan converter) 7, a reference preamplifier gain signal generating circuit 8 for generating a gain control signal for controlling the gain of the preamplifier 3, and the ST shown in FIG.
An operation panel 11 having a C volume 9 and a GAIN volume 10;
A distributor 12 for distributing a gain control signal obtained by operating the volume 10 to a gain control signal of the preamplifier 3 or a gain control signal of the log amplifier unit based on a set value. In the distributor 12, a set value serving as a reference for signal distribution can be variably set to an arbitrary value by operating a switch (not shown) provided on the operation panel 11. Next, a circuit operation for transmitting a gain control signal to the preamplifier 3 or the log amplifier unit 6 will be described with reference to FIG.

First, when the STC volume 9 or the GAIN volume 10 on the operation panel 11 is operated, these S
The operation signals of the TC volume 9 and the GAIN volume 10 are output as an analog polygonal waveform voltage and a DC voltage signal, respectively. These analog signals are added to the adder 13
Are added to obtain a gain control signal. Then, the gain control signal is input to an AD converter (ADC) 14, which converts the gain control signal into a digital signal.
The signal is sent to the comparator 15.

The comparator 15 reads the variable range data of the preamplifier gain set by operating a switch on the operation panel 11 from a predetermined ROM 16 and compares the variable range data of the preamplifier gain with the gain control signal. Then, it is determined whether or not the gain control signal is a signal within a variable range for each unit in the depth direction of the living body of the subject. Then, the distributor 12 sends a partial signal within the variable range to the preamplifier side, and sends a partial signal outside the variable range to the log amplifier side.

The gain control signal distributed to the preamplifier side is added to the reference preamplifier gain control signal output from the ROM 8a of the reference preamplifier gain signal generation circuit 8 by the adder 17 and transferred to the RAM 18. The data transfer to the RAM 18 is performed by the STC volume 9 or G
It is performed every time the AIN volume 10 is adjusted. As the gain control signal of the preamplifier, for example, a digital signal in which 48 pieces of information are held in a range of 0 to 24 cm in time lapse when a polygonal line approximation is performed at intervals of 5 mm in the depth direction of a living body. These signals are stored in RAM for each ultrasonic rate.
The data D1, D2,.
D3,... And a low-pass filter (L
After passing through a PF) 20 to make a smooth control waveform signal, the signal is sent to the preamplifier 3.

On the other hand, the gain control signal distributed to the log amplifier side is similarly once stored in the RAM 21 and read out to the accumulator 22 for each ultrasonic rate. The data is filtered through the LPF 23 and sent to the log amplifier 6.

[0016]

According to the ultrasonic diagnostic apparatus of the present invention, the ST
Since the gain of the preamplifier is adjusted according to the adjustment of C or the gain, the saturation of the preamplifier can be avoided,
The resolution and resolution of the monitor image can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of an embodiment of an ultrasonic diagnostic apparatus to which the present invention is applied.

FIG. 2 is a block diagram showing main details of the embodiment.

FIG. 3 is a diagram showing main switches on an operation panel of the ultrasonic diagnostic apparatus.

FIG. 4 is a diagram showing polygonal line data obtained by cumulatively adding gain control signals.

FIG. 5 is a diagram showing a gain control signal of the ultrasonic diagnostic apparatus to which the present invention is applied.

FIG. 6 is a partial block diagram of a conventional ultrasonic diagnostic apparatus.

FIG. 7 is a diagram showing a gain control signal of a conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Probe 2 Drive circuit 3 Preamplifier 4 Delay circuit 5 Adder 6 Log amplifier part 7 DSC 8 Reference preamplifier gain signal generation circuit 9 STC volume 10 GAIN volume 11 Operation panel 12 Distributor

Continuation of front page (56) References JP-A-1-204652 (JP, A) JP-A-56-51684 (JP, A) JP-A-6-105839 (JP, A) JP-A-62-64343 (JP, A) JP-A-63-46139 (JP, A) JP-A-2-291843 (JP, A) JP-A-63-300745 (JP, A) JP-A-1-84616 (JP, U) JP-A 62-9411 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 8/00-8/15 G01N 29/00-29/28

Claims (4)

(57) [Claims] 1. A preamplifier for amplifying a signal received by a vibrator, a delay / addition unit for performing a delay / addition process on an output signal of the preamplifier, and an amplifier for amplifying an output signal of the delay / addition unit. Means for controlling the gain of the preamplifier in accordance with the arrival time of the echo signal; and GAIN setting means for adjusting the brightness of the monitor image. The gain of the preamplifier and the gain based on the set value by the GAIN setting means are provided. An ultrasonic diagnostic apparatus comprising: means for generating a gain control signal for adjusting a gain of an amplifier. 2. An STC setting means for adjusting the brightness of a monitor image for each depth of a subject, wherein the gain control signal is obtained based on a set value by the STC setting means and the GAIN setting means. Ultrasound diagnostic device. 3. A setting means for setting a variable range of a variable range of the gain of the preamplifier in accordance with a set value of the STC setting means and the GAIN setting means, and wherein the gain control signal is set by the variable range setting means. 3. The ultrasonic diagnostic apparatus according to claim 2, wherein the ultrasonic diagnostic apparatus is obtained based on a value. 4. A preamplifier for amplifying a signal received by an oscillator, a delay / addition unit for performing a delay / addition process on an output signal of the preamplifier, and an amplifier for amplifying an output signal of the delay / addition unit. Means for controlling the gain of the preamplifier according to the arrival time of the echo signal; and STC for adjusting the brightness of the monitor image for each depth of the subject.
An ultrasonic diagnostic apparatus comprising: a setting unit; and a unit that generates a gain control signal for adjusting a gain of the preamplifier and a gain of the amplifier based on a setting value of the STC setting unit.