JPS58183147A - 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] [Technical Field of the Invention] The present invention relates to an ultrasonic diagnostic device, particularly an electronic scanning type ultrasonic diagnostic device using ultrasonic transducers arranged in an array. .

[Technical background and problems]

Temporary electronic scanning ultrasonic diagnostic equipment has two methods, depending on the purpose: a method in which the ultrasound beam is moved in parallel (linear scanning method) and a method in which the beam is deflected in a fan shape (sector scanning method).
There is. Among these, the linear scanning method uses an ultra-ta probe (also called a globe) that uses an electronic switch to arrange a large number of transducers on a plane and switch the transducers t-i at a time. ) is fixed at point F and the ultrasonic beam is scanned in parallel.0 In this case,
Since the scanning line spacing F1a is equal to the center distance of the contacting transducers, the scanning line spacing of machines with small transducers can also be narrowed, but as the transducer diameter becomes smaller, the directivity at long distances becomes dull and the azimuth resolution decreases. I will do it. However, in order to obtain sharp directivity, a somewhat large aperture (the diameter or area of the vibrator when it is partially manufactured) is required.

Therefore, conventional #i As shown in FIG. KL transmits an ultrasonic beam α by simultaneously driving the
At the same time, the receiving section 4 adopts a method of receiving ultra-fil echoes from a set of transducers and selecting the transducers by shifting them one by one using the selection switch 2 for transmission and reception. According to such a method, it is possible to obtain an aperture eight times larger than the transducer spacing, thereby improving directivity. By the way, in general, in order to improve the resolution, electronic focusing is used to focus during transmission and reception using slow speed. For example, considering the transmission focus, as shown in Fig. 2, the signal from the transmission s5 is
The ultrasonic waves emitted from the transducer group 1 with a time difference corresponding to e are made into a concave composite wavefront, so that the entire transmitted ultrasonic beam is focused at point C. Also,
The reception focus is carried out as follows.The reflected wavefront propagating from point C in the living body first reaches the transducers 1-4, Fi, and 1-5, and is successively fired. and reaches the vibrator 1-1 or 1-8. In this nKL, each vibrator generates electrical signals d that are delayed sequentially, but if these signals are simply added together, the phase angle (distance)
There is no consistency. Therefore, in the receiving section 4, the transducer group 1
The echo signal received at the buffer circuit group 44 is inputted to perform impedance conversion, and then sent to the next stage delay element group 4B.
Output to. Each of the delay element groups 4B has different delay time taps, and the taps are selected by the next-stage analog switch group. This analog switch group 4C
is controlled by a control signal m generated by an analog switch controller 6 which receives signals f and yk from a reference signal oscillation circuit 5. In this way, f
The ultrasonic original signal 1 is obtained by adding the obtained signals by an adder 4DK.

The control signal M from the analog switch controller 6 is designed to switch the analog switch #P4tit in order to move the focus point at the time of reception according to the depth of the living body. In this case, if the ultra-TV reflection echo #i is set to a near-distance area A, a middle-distance area B, and a far-distance area C according to the depth direction as shown in Fig. 3, the focus point is moved according to the distance. By doing so, it is possible to obtain ultrasonic waves gR with good resolution for all regions. Therefore, the fourth
As shown in the figure, first, the reference signal oscillator 5 generates a clock signal f and super ff! 1. A signal equivalent to a repetitive signal! A control signal A is generated from the analog switch controller 6, and pressure is applied to switch the focus point according to each area at each timing point Aa and Bα. As a result, as shown in FIG.
Beam pattern with focus point on 1! and the beam pattern J at the intermediate distance focus point at each timing Aa, Bα
By switching with n1, a beam pattern like ↓ as shown by the thick real image is obtained. Incidentally, FIG. 5 shows a beam pattern when focusing on one point without changing or moving the focus point.

However, in this unnatural switching operation, the switching noise of the analog switch becomes large and mixes into the obtained super-if echo, resulting in a severe deterioration of the image quality of the ultrasonic tomography. A problem arose.

[Purpose of the invention]

The present invention was developed in view of the above circumstances, and it is an object of the present invention to provide an ultra-f[diagnosis device] that can reduce switching noise and improve image quality.

[Summary of the invention]

In order to achieve the above object, the present invention provides a transducer group r′ in which a plurality of ultrasonic transducers are arranged in an array, and an arbitrary number of adjacent transducers are selected and driven, and six transducers are selected. It includes a transmitter that performs transmission focus by driving with a time difference, a delay element group, and an analog switch group, and the analog switch group is switched when receiving ultra-f waves, so that reception is performed according to the depth of the object. a first receiving section that moves a focus point;
A second receiver 5llt having a similar configuration to the above receiver and having a different switching timing of the analog switch group is provided in parallel with the receiver, and the first and second receivers amplify the outputs of the first and second receivers. The 20th amplifier is provided with a switching means for switching and outputting the output of each amplifier,
Install a controller to control this switching means,
This controller controls the switching of the switching means so as to derive the output of the first or second ceramic amplifier that is not affected by noise during the switching operation of the analog switch group in the first or second receiver. It is characterized by doing.

[Embodiments of the invention]

Hereinafter, the present invention will be specifically explained with reference to FIGS. 7 to 9! Figure 7 shows f! which is an embodiment of the present invention. 0 which is a block diagram of the Ii wave diagnostic device 0. In the figure, parts having the same functions as those shown in FIG.
The difference from the configuration shown in FIG. 2 is that a second receiving section 14 is provided in parallel to the receiving section 4, and the first and second amplifiers 10111i! Now, the changeover switch 17 for switching the outputs of the amplifiers 1o and ii is connected to -
In addition, a transducer selection switch controller 7 is provided, and a switch controller 9ft for controlling the analog switch in the second reception s14 is provided, and a switch controller 9ft for controlling the selector switch 171 is provided. Detector 18. Brightness modulation signal generator 1
9. - Although the signal generator 20 and display 21 are not shown in FIG. 2, they were also present in the conventional device 1t. Further, each of the controllers is controlled by control signals f, y, and q from the reference clock oscillator 5. Furthermore, the first reception s4. The second reception s14 is composed of a buffer circuit group, a slow-burning group, an analog switch group, and an adder, as shown in the second figure. In addition to referring to the cross section tit in FIG. 9, the operation 1 of #effi according to an embodiment of the present invention will be explained.

First, during the blanking period of the display, the analog switch in the first reception s4 is selected by the signal horse from the analog switch controller 6, and the focus point of the ultra-IT wave beam is placed in the area A in the fault line II in the diagram #I9. J1! by the lff1J11 signal of the second analog switch controller 16.
Select the analog switch in the receiver 14 of No. 2 to
The focus point of the ff beam is set to region B in the cross-section 1 in FIG.

A signal from the transducer selection switch controller 7 selects one set of transducers in the transducer group 1 via the switch group 2.0-order signal KL from the reference clock oscillator 5 and a signal # from the transmitter controller 8. The transducer drive pulse is sent to iB3 with a time difference to the transducer at -t'rt, and the focus point of the ultra-f temporary beam is set at a certain set point. 9. The reflected echo from a living body, etc. is received by a vibrator and converted into an electrical signal, which is sent to two receivers 4.14 via a switch 21.
Entered into. Next, at the timing Aα when transitioning from area A to area B in the first section of the fault l in FIG. 9, the signal from the switch controller 9 causes the first amplifier 10111i! From the point αl to the second amplifier va contact (
Switch to 2. At this time, the switching noise of the selector switch 17 will naturally be included in the signal, but since the gain of the first and second amplifiers 10 and 11 in the previous stage is set to 1llIi, the reflected echo 1v ignores the switching noise. The amplifier n should be as large as possible. Such an amplifier 10.11 may be a linear amplifier or a logarithmic amplifier.
I can think of s.

PfFI changeover switch 17 closes contact az- and increases
11, that is, the signal in the B% range in the fault line. - The focus point of the image is set at area C in the fault formation in FIG. Next, the timing Ba for transitioning from area 9B to area C in fault 1 in Fig. 9
The selector switch 17 is turned on, that is, the signal from the first amplifier 10 which amplifies the signal in the C region is selected. By sequentially repeating this operation sound, the signal of the superf-wave beam for multiple reception focus points (t-1) can be generated in one transmission pulse period. In this way, the t'Lfc signal obtained through the changeover switch 17f is detected by the PLT detector 18, and the luminance modulation signal generator 19 is used to display the XY display 2.
1 of 24M1K plus a signal corresponding to the ultrasonic repetition signal! A deflection signal for the XY display 21 is generated by the deflection signal generator 2 in the relationship between
Figure 9's construction is super f [fault IIl! get. As a result, there is no influence of the switching noise of the analog switch in the receiving section, and the switching noise of the changeover switch is also ignored.-The present invention is limited to the above-mentioned embodiment. Various modifications are possible. For example, in the embodiment described above, the detector 18 is provided after the selector switch 17, but a separate detector is provided after each amplifier 10, 11 so that selection can be made via the selector switch at the image display stage. Even so, it's L.

Although the above embodiment describes a linear scanning electronic scanner using a linear array transducer, the present invention is applicable to a sector scanning electronic scanner, a two-dimensional array transducer, or an annular array transducer. It goes without saying that this can be applied to everything that was created using the 6 focus method.

Furthermore, in addition to tap selection during reception focus, e.g.
t can also be used to remove switching noise when changing the number of vibrators such as a variable aperture.

〔Effect of the invention〕

By incorporating the present invention described in detail above, it is possible to avoid shadows caused by switching noise when the seven focus points are switched and moved in multiple stages according to the depth of the object during reception, and to achieve good image quality using ultrasonic waves. It is possible to provide an ultra-fine diagnostic device that can obtain ultra-fine data.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram for explaining the scanning method in the conventional electronic scanning ultrasonic dungeon disassembly award; The figure is a pattern diagram showing an example of the 1st fault of the seaside fault, the dark blue figure 4 is a time chart for explaining the operation of the second worst device, i! 5(s) and Figure 6 are beam pattern diagrams obtained using the electronic focusing method, Figure 7 is a block diagram of an embodiment of the device of the present invention, and Figure 8 is a time chart for explaining the operation. , FIG. 9 is a pattern diagram showing an example of one fault line obtained by the embodiment device. 1... Vibrator group, 2... Switch group, 6...
・Send member 4j-, buffer circuit, 4B...delay element section, 4C...analog switch group, 4...first
14... Second receiving unit, 5... Reference clock oscillator, 6... First analog switch controller, 16... Second analog switch controller, 9... Switch controller. , 10・
...First amplifier (- device, 11...Second amplifier, 1
7...Switch.

Claims (1)

[Claims] A group of transducers in which a plurality of ultra-ttM transducers are arranged in a play shape, and an arbitrary number of adjacent transducers are selected and driven, and each transducer is driven with a time difference. a transmitter unit that performs transmission focus by performing a transmission focus; and a first reception unit that includes a delay element group and an analog switch group and moves the reception focus point according to the depth of the object by switching the analog switch group at the time of ultra-ta reception. cleft with part and t
In parallel with the first receiving section, there is provided a receiving section @2 having a similar configuration but with different switching timings of the analog switch groups, and amplifying the outputs of crt, WAl and the second receiving section. Remove the 1st and WJ2 amplifiers.
A switching means for switching and outputting the output of each amplifier is provided, and a controller for controlling the switching means tm is provided, and this controller has a
(i) The switching means is controlled so as to derive the output of the first or second amplifier that is not affected by noise during the switching operation of the analog switch group in the second receiving section. Ultrasound [Diagnostic device〇]