JPS5991950A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic diagnostic apparatus, and particularly to an ultrasonic diagnostic apparatus having a function of recording and reproducing ultrasonic echo signals in a video tail recorder (hereinafter referred to as ``TK'').

(1) In general, ultrasound diagnostic equipment diagnoses the internal tissue structure of the human body by applying ultrasound from an ultrasound transducer called a probe to the human body and displaying the reflected waves from various parts of the human body on a CRT screen. However, some of these ultrasonic diagnostic apparatuses have a function of displaying ultrasonic echoes on a CRT and recording and reproducing the echo signals on a VTR.

A conventional device of this kind is shown in FIG. In the figure, (1)
is an ultrasonic probe that emits ultrasonic waves toward the human body, (2) is a balsa that generates ultrasonic pulses to be emitted from this probe (1), and (3) is a balsa that is reflected from the human body and Tentacle (
1) is an amplification/detection circuit that amplifies and detects the received ultrasonic echo signal; 14) is a signal processing circuit that processes the output signal of this amplification/detection circuit (3); and (5) is the pulsar (2).
2.) A synchronization signal generation circuit that provides ultrasonic pulse generation timing to the VTR and generates a synchronization signal for recording and reproducing the echo signal on the VTR.

(6) is a synthesis circuit that synthesizes the output of the signal processing circuit (4) and the output of this synchronization signal generation circuit (5), and (7) is a VTR that records and plays back the output of this synthesis circuit (6). be.

(2) In addition, (8) is a digital scan converter (hereinafter referred to as DSC) that converts the ultrasonic echo signal obtained from the output of the signal processing circuit 14) or the output of the Me VTR171 into a signal that can be displayed on a television. omitted), (
9) is a TV monitor that displays the output of this oSCt81 on a CRT, and α1 inputs the output of the signal processing circuit 14) to the DSC (8), or the output of the VTR (7). This is a selector switch that switches between output and input.

Next, the operation will be explained.

Assume that the changeover switch aα is now in the state shown in Figure 1.O First, the synchronization signal generation circuit (5) creates a synchronization signal 3 as shown in Figure 3(a), and the timing is adjusted to this synchronization signal 3. The ultrasonic probe (1) emits ultrasonic waves based on the ultrasonic pulses from the balsa (2) and receives the reflected echo from the human body, and the echo signal is sent to the amplification/detection circuit (
The signal is amplified and detected in step 3), and then processed in signal processing circuit 14) to produce a signal as shown in FIG. 3(b). The echo signal is then converted into a television signal by the DSC (B) and displayed as an ultrasound echogram on the TV monitor (9). At the same time, the ultrasonic echo signal outputted from the signal processing circuit 14) is synthesized with the synchronization signal 3 by the 1 synthesis circuit (6),
As a video signal C as shown in the same figure (C), VTR
(Recorded in 71.

Next, when reproducing the video signal C recorded on the VTR (71), switch the changeover switch a from the state shown in FIG.
(So that it is input to 81. Then, the above V T
R (video signal C recorded in 71 is D S Cf
The signal is converted into a television signal by 81 and displayed as an ultrasound echogram on the TV monitor (9) in the same manner as above.

However, in such conventional devices, the echo signal is directly input to the VTR (7) regardless of its strength, so the peak value of the echo signal is
If the input upper limit value of 7) is exceeded, the waveform of the echo signal will be distorted, and the peak value of the echo signal will always be significantly lower than the input upper limit value of 71. , there is a problem that the dynamic range of the VTR (71) for the echo signal becomes narrow.

Generally, in the amplified and detected ultrasonic echo signal, in addition to the reflected echo signal from the human body, there is a leakage signal P at the time of transmission, and this leakage signal P is usually the detected echo signal. The medium quantity also shows a large value. When the leakage signal P is large, the echo signal reflected from the human body is also large, and when the leakage signal P is small, the echo signal is also small.

Therefore, this invention was made by focusing on the fact that the leakage signal has a large amount of detected echo signal, and the peak value of the leakage signal is held and the peak value is kept constant. To provide an ultrasonic diagnostic device capable of recording an ultrasonic echo signal on a video tape recorder with the most efficient and appropriate amplitude by controlling the gain of an amplifier that amplifies a detected echo signal so that the ultrasonic echo signal becomes The purpose is to

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

FIG. 2 shows an ultrasonic diagnostic apparatus according to an embodiment of the present invention.
0tsuk configuration diagram is shown. In the figure, the same reference numerals as in FIG. 1 indicate the same or equivalent ones, and Ql) is a voltage-controlled variable gain amplifier that appropriately amplifies the ultrasonic echo signal outputted from the signal processing circuit (4); +1? J is a peak hold circuit that holds the peak value of the ultrasonic echo signal (13 is this peak hold circuit (17J)
This is a control voltage generation circuit that obtains the output of and generates a voltage to control the gain of the voltage controlled variable gain amplifier a. The control voltage generation circuit αJ includes a reference voltage setter 11Φ that sets a predetermined reference voltage. .

a subtraction circuit that subtracts the reference voltage of the reference voltage setter (141) from the output of the peak hold circuit 117J;
A control voltage generator (previously constructed) generates a control voltage according to the output of the subtraction circuit a9.

Next, the operation will be explained.

In this embodiment, the output of the signal processing circuit] 4) is shown in Fig. 3 (b).
The operation is the same as that of the conventional device until the signal shown in ) is obtained. The output of this signal processing circuit (4) is:

It is input to the voltage controlled variable gain amplifier all, and
The peak value of the leakage signal P in the output signal is held by the peak hold circuit (1).The subtraction circuit (151) is the output signal d of the peak hold circuit d shown in FIG. 3(d). The value V set by the reference voltage setter is subtracted from the value V set by the reference voltage setter, and the control voltage generator α is the voltage that controls the gain of the voltage-controlled variable gain amplifier αD according to the output of this subtraction circuit (19). occurs.

That is, the control voltage generator 06) reduces the gain of the amplifier (111) according to the degree when the peak value is larger than the reference voltage V(, and the peak value is smaller than the reference voltage VO). In this case, a control voltage is generated to increase the gain of the amplifier (111) according to the degree of the change.

Therefore, the ultrasonic echo signal output from the signal processing circuit +41 is amplified by the voltage controlled variable gain amplifier (11) so that its peak value is constant, as shown in FIG. 3(e). .Furthermore, the signal e suitably amplified by this amplifier (Ill) is combined with the synchronization signal 3 created by the synchronization signal creation circuit (5) by the synthesis circuit 1 (6), and is appropriately amplified as shown in FIG. 3(f). A video signal f having a certain amplitude is recorded in V'I''Rf71.

Note that the peak hold circuit 113 is reset by the primary synchronization signal 3 and repeats the above operation.

Therefore, according to the present device, the ultrasonic echo signal is converted to V T
Before recording on Ri7), the echo signal is amplified with a gain corresponding to the peak value so that the peak value is always constant, so it is possible to record with the most efficient and appropriate amplitude. The recorded signal waveform will not be too large and be distorted, nor will the signal waveform be significantly lower than the input upper limit value, resulting in a narrow dynamic range.

As described above, according to the present invention, the peak value of the leakage signal is held and the gain of the amplifier that amplifies the detected echo signal is controlled so that the peak value becomes constant, so that the video tape recorder This has the effect of being able to record ultrasonic echo signals at the most efficient and appropriate amplitude.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional ultrasonic diagnostic device;
Figure 3 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. 3 is a signal waveform diagram showing the operation of the device of FIG. 2. FIG. (7)...Video tape recorder, αb...Voltage controlled variable gain amplifier, α2...Peak hold circuit, α
G... Control voltage generation circuit, a... Synchronization signal, b...
Ultrasonic echo signal. Agent Shin Kuzuno - Figure 1

Claims (1)

[Claims] (1) A voltage-controlled variable gain amplifier that appropriately amplifies the ultrasonic echo signal by applying a synchronization signal to the ultrasonic echo signal after detection, and sending it to the ultrasonic diagnostic equipment that has the function of recording and reproducing the video tape recorder. and a peak hold circuit that holds the peak value of the ultrasonic echo signal.
and a control voltage generation circuit that obtains the output of the peak hold circuit and generates a control voltage for controlling the gain of the voltage controlled variable gain amplifier so that the peak value of the output echo signal of the amplifier is constant. An ultrasonic diagnostic device featuring: