JPS58141139A - Ultrasonic wave transmitting and receiving system - 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 a receiving scissor straightener for a wide-field high-performance Hiroko scanning ultrasonic tomography system.

Conventionally, super ml! &, Ij=7 In the scanning method, the transmitting/receiving aperture is selected by the switching means from all the apertures of the array transducer, and the above-mentioned selection +#9. When the ultrasonic beam is scanned and a tomographic image is obtained by controlling the aperture, a single ultrasonic beam is obtained on the center set of the aperture at the selected transmitting/receiving aperture. For this reason, each end of the arrayed transducer has a portion that cannot be scanned by a width of 1/2 of the transmitting/receiving aperture, resulting in a disadvantage that the field of view becomes narrow.

In particular, when the transmitting aperture position is increased for the purpose of increasing the resolution, the above-mentioned drawbacks become noticeable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wide-field-of-view, high-resolution ultrasonic transmission/reception system.

The present invention obtains a plurality of parallel beams at the same number of beams selected by a switch, thereby making it possible to scan the entire diameter of the array transducer and obtain a wide-field ultrasonic tomographic image. It is a method.

In order to obtain a parallel receiving beam, the phase of the Ukekai Hakugo of each arrayed confectionery is controlled (2
)do. On the other hand, by moving the transmitting aperture backward to a position that matches the receiving aperture P3t - the receiving beam, the transmitting and receiving beam characteristics are optimized.

No. 1 μ Honchoaki Nori = 7 An explanatory diagram about running food.
, the visual field operator moves the receiving aperture for each scanning line, the phaser control data is a constant area (region of symmetrical reception), and the area ■ is the receiving aperture for each scanning line. This is a region (asymmetric reception region) in which the phaser control data is changed at the center of the radius.

In addition, 18.1. , 1. , 1. represents the flux line at the boundary of each region. Further, U indicates an array element (1 to N pieces), and RA indicates a receiving aperture.

FIG. 2 is an explanatory diagram of sector scanning of the present invention,
Areas I and I[ indicate areas similar to those in FIG.

In addition, in FIG. 2, 0 indicates the deflection angle. Here, in the case of linear scanning, the difference between regions I and I[ will be explained using FIG. 3. In the figure, P is the receiving aperture (array T,
1 to 14) on the center line -1P, ``is a reflected sound source other than the center line.

A, B, C, and D are equal phase planes VV, W! It is the intersection with

In region l, if the reflection band is always placed on the center line of the aperture, the constant phaser control data level should be constant for each scanning line. On the other hand, in region (2), it is assumed that a reflected sound source is located in a direction other than the center line of the front and back lines, and the phaser control data has true data for each scanning line.

+7 = In the case of 7 scans, is there a phaser in region l? ! 111j
The wholesale data is symmetrical IA (distance between array element and intersection point A) and -14B (distance between llel element array 14 and intersection point B) with respect to the center of the receiving aperture, and the area is 14D with asymmetrical dimensions.
becomes.

Although the directivity characteristics of asymmetrical reception are degraded compared to those of symmetrical reception, as shown in the table, it is at most 40%, which is not a practical problem.

In the case of sector scanning, deflection data is also required in area l. It is clear that the diameter is not symmetrical about the center of the diameter.

FIG. 4 is a block diagram showing the implementation of the first embodiment of the present invention, in which 1 is an array shifter consisting of 384% children, 2 is a transmitting/receiving switch, 3 is a transmitting drive circuit, and 4 is a front panel. Direct amplifier, 5 is receiver phaser, 6 is compression circuit, 7 is detection R jump, 8 is six indicator, 9
1 is a control unit, IO is an asymmetrical data memo IJ, and 11 is a symmetrical reception data memory.

In the case of linear scanning, the data memory is
In the case of Chi' and Light' running, it is 7''-force 7 theta and deflection data.

Since it is necessary to perform so-called die, namic focus, it is necessary to wait for multiple focusators depending on the depth. 12 is an inverting circuit, and 13 is a switch that is ON when a control signal is present and OFF when there is no control signal.

14 is a switch and when a control signal is present, the asymmetric reception memory 1
It is assumed that the symmetric reception memory 111all is ONN auditory sensation when there is no signal to OIIll.

A is a control signal for moving the transmitting aperture, and b is a control signal for moving the receiving aperture. C is symmetrical reception, asymmetrical reception is determined by ll11# polarization code,
When it is present, the reception is asymmetrical, and when it is absent, it is symmetrical reception.

In such a configuration, from a total of 384 elements in one array transducer, the switching device 2 switches between 48 elements and 1.
The receiving apertures of the 92 elements are selected by -M by control numbers a and b, respectively. The output of the 48-wire transmission drive circuit 3 having the dimension amplitude and phase t is sent to the switching device 21r to the array oscillator 1 t.
, l18m.

On the other hand, each receiving signal number of 192 elements is amplified by a preamplifier 4, and then phased and summed by a receiving phaser 5 controlled by a data memory 10 or 11. Thereafter, the ultrasonic reflection signal corresponding to one scanning line is displayed on the display 118 through the compression circuit 6 and the detection circuit 7t. Next, the control section 9
0 control flaw number a.

'b and C, scanning lines are sequentially obtained and a supersonic tomogram is displayed on the n1 display 8.

Here, 11111@ polarization codes a, b, and c will be further explained.

During symmetrical reception, the divider value C is 0, and the switch 14 turns on the data memory 11 for symmetrical reception.

At the same time, the output of the inverting circuit 12 is l, so the switch 13
becomes ON. Therefore, each run *Ii! The data memory of the receiving phaser is constant with respect to Sl, and the receiving aperture is moved by the switch 2.

On the other hand, 1 is asymmetrical and 1! The side 111Ll value C is l, and the switch 14 turns on the data memory 10 for asymmetric reception.
Therefore, the switch 13 is turned off. Therefore, the receiving aperture does not move with respect to the valley scanning range, and the data memory lO
The contents of this will be completely new.

Here, the configuration of the switching device 2 shown in FIG. 4 will be explained using FIGS. 5(a) and 5(b).

The first channel of the wave transmission drive circuit is the wave transmission switch 5vV.
Ti (i+=1.49.97.145...) f, ◆1°49.97,145. ... is connected to the array element.

In particular, the 24th channel of the drive circuit is 24.72°1
To the array element of 20,..., @48 channel is ◆48
,96,144. ...is connected to an array of sweets.

On the other hand, the array element passes through the wave receiving switch 8WRi 192
It is connected to the channel Mae Jokusai IIa.

Here, the control signals for the intermittent switch 8WTt and the wave receiving switch valley switches 8WTi and 8WRi are omitted in FIG. 5.

Only the switches T1 to 5WT48 for imagomi waves and the switches f9VVl-41 to 5WR192 for wave reception are set to the kON state, and the waves are transmitted by the array sweets 1 to 48, and the waves are transmitted by arrays 1 to 19.
Connect the received signal of 2 to the preamplifier. Next, the speed generation switches 8WT2 to 8WT49 and the wave reception switch SWR
, 2 to 8 Only WR193 is in the ON state, and the array sweets 2
-49 transmit the waves, and the received signals of N2-193 are connected to the preamplifier.

Here, the control signal generator of the switch 8WTi is, for example, a 384-bit ringing counter (48 bits only 1,
Otherwise, use 0), and when the control am number is set, switch 8WT< is set to 0.
It may be set to N state, and when it is 0, it may be set to OFF state.

The configuration of the switching device shown in FIG. 5 allows the transmitting and receiving aperture to be moved.

As shown in Fig. 6, as the mouth moves, the input and output channel signals of the switch change, so the amplitude weight and phase of the transmitting drive circuit and the phase of the receiving phaser are changed to change the array element. It is necessary to set the above value to the desired value. In other words, in the case of movement of the transmitting aperture having a triangular weighted amplitude distribution and a concave phase distribution, when the transmitting aperture of the array cables 1 to 48, the amplitude distribution and phase distribution are given as shown in the left side acupuncture needle. ,
When the transmitting aperture of the distribution system element 24 to ◆72 is used, it is necessary to control the output of the transmitting drive circuit so as to provide an amplitude distribution and a phase distribution as shown by the dotted line on the left side. The same applies to the receiving phaser.

The above explanation describes a method for obtaining multiple receiving beams by phase control.

By moving the transmitting aperture in a direction that partially coincides with the direction of the receiving beam, the optimum transmitting and receiving beam can be achieved.
To the answer, 6°, that is, the receiving aperture ts1 to s14 as shown in Figure 3.
Phase city IJ141L to converge to 21 points.
, the direction of the received beam obtained by dynamic focusing is t L t. On the other hand, the transmitting aperture is set to 9 to 13 as part of the receiving beam, and by making the center of the 22s wave opening part part of the receiving beam, an optimum transmitting beam can be obtained.

In other words, in Fig. w&4, when the control signal C is not present, the receiving aperture does not move, and when the control signal C is present, asymmetric reception occurs, but in that state, the position W of the received beam extended /L
The transmitting aperture is adjusted by controlling the transmitting port property moving wIIJ reference number ak so as to configure the transmitting beam in the direction that partially forms the transmitting aperture with the conductive state switch sFt of the switching device 2. Move the position of IIJJ and it will be fine.

The present invention has the effect of obtaining a plurality of receiving beams with an N-receiving aperture through asymmetric reception, and widening the field of view of the ultrasonic tomography apparatus 1 by moving the receiving aperture and the transmitting aperture.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are explanatory diagrams of the present invention.
Fig. 4 is a naprock diagram showing an example of an embodiment of the present invention, and Fig. 5 (a) and Φ) are examples of a part of a switching device.
l- Shoulder 1 Figure Shakuhachi City 2 Outer L it is Z & ) 5 5th 4th Zumon 5 Mouth (a) (b) : ; : = ? ! 6th mouth

Claims (1)

[Claims] 1. In an ultrasonic tomography apparatus which obtains a tomographic image by scanning an ultrasonic wave beam by selecting a transmitting and receiving aperture from all the apertures of the array transducer by a switching means and controlling the above-mentioned switching means, the An ultra-convertible transmitting/receiving device which obtains a plurality of parallel received beams by in-focusing by controlling the phase of the received signal of each array element in the radius. 2., %FF In the device according to claim 1, a part of the reception port is made into a transmitting aperture, and the position of the transmitting aperture is moved in accordance with the receiving beam forming position. A super-wave transmitter/receiver device with special features.