JPS61135641A - Parallel receiving type ultrasonic 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] The present invention relates to a technique for creating a tomographic image of a subject (living body) in an ultrasonic device, and in particular, the present invention relates to a technique for creating a tomographic image of a subject (living body) in an ultrasonic device. The present invention relates to a technique that is effective when applied to a technique for removing blurring of a displayed image caused by a difference in the level of receiving sensitivity of each channel and a difference in noise.

[Background technology] In order to increase the frame rate of tomographic images inside a subject (living body), an ultrasound diagnostic device uses an ultrasonic beam emitted into a subject (biological body) based on the directional characteristics of the ultrasound beam at the time of transmission and the receiving wave. By placing the ultrasonic beam at a point where the receiving directional characteristics of the ultrasound beam are different, a two-channel receiving device is used to receive internally reflected waves in two directions at the same time (for example,
-Refer to Publication No. 20017).

However, since the conventional ultrasonic diagnostic apparatus uses a two-channel receiving device, there is a problem in that the displayed image is blurred due to differences in sensitivity and noise between the respective channels. Conventional devices have not taken measures to remove this blurred image from the displayed image.

[Purpose of the invention]

An object of the present invention is to remove blurring of a display image caused by differences in reception sensitivity level and noise between channels of each receiving device used for parallel reception in a parallel reception type ultrasonic device. The objective is to provide a technology that makes it possible to obtain high-quality images.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of one typical invention disclosed in this application is as follows.

That is, in the parallel reception type ultrasound apparatus, a first calculation means performs a weighting calculation of the received signals obtained by simultaneously receiving the reflected waves of the ultrasound beams emitted into the subject in parallel, and the simultaneous reception signals and the received signals. and a second calculation means that performs a weighting calculation based on the received signal according to the adjacent scanning timing, and calculates the level difference in receiving sensitivity and the noise difference between each channel of each receiving device used for parallel wave reception. This method removes the smearing of the displayed image caused by this, making it possible to obtain a high-quality image.

[Configuration of 5rs Light] Hereinafter, the configuration of the present invention will be explained using the drawings together with an embodiment in which the present invention is applied to a parallel reception type ultrasonic diagnostic apparatus.

In addition, in all the figures for explaining the embodiment, parts having the same functions are given the same reference numerals, and repeated explanations thereof will be omitted.

1 to 7 are diagrams for explaining a parallel wave receiving type ultrasonic diagnostic apparatus according to an embodiment of the present invention, and FIG. 1 is an overall schematic diagram of the parallel wave receiving type ultrasonic diagnostic apparatus. FIG. 2 is a block diagram showing the detailed configuration of the parallel wave receiving section, FIG. 3 is an explanatory diagram for explaining the principle of the parallel wave receiving section, and FIGS. 4 to 6 7 is an explanatory diagram for explaining the principle of the correction calculation of the embodiment, and FIG. 7 is a block diagram showing the configuration of another embodiment of the arithmetic processing circuit shown in FIG. 1.

1 and 1, 1 is a probe for transmitting and receiving ultrasonic beams, and as shown in FIG. 2, n strip-shaped transducers (hereinafter referred to as elements #1 to #n) ) are arranged in an array to form a transducer. Each element #l to #n of the probe 1 is connected to a switching circuit 2. The switching circuit 2 sequentially selects elements from the n elements, and selects the transmitting pulsers 3A (P+ to p5) and the receiving pulsers of the transmitting circuit 3.
Doubling [This is to perform the operation of connecting to the superior AMP (Rt to R5). The transmitting pulser 3A includes a transmitting circuit 3
is connected to the transmission phase control circuit 3B.

Create a phase-controlled pulse. The output of the reception amplifier AMP is guided to reception phasing circuits 4 and 5.

These receiving wave phasing circuits! By controlling the phase of the signals from each element, the receiving directivity of each element can be shifted.

Next, the parallel reception method will be explained using FIG. 3.

When elements #1 to #5 of the probe 1 are excited, the transmitted beam is normally located in the direction of the axis Tl (indicated by a dashed-dotted line arrow) in the middle of the used transducer. At this time, to receive the reflected echo in the R1 direction, use elements #1 to #5,
To receive the reflected echo in the R2 direction, element #1
~ Using #6.

The receiver has directional characteristics in two directions. As a result, the overall directionality of transmission and reception is in both directions of TRI and TR2. That is, one ultrasound signal can be received at the same time.

In reality, two-way simultaneous ultrasonic signals S1 and 82 in the Al and At' directions, for example, are obtained by the reception phasing circuits 4 and 5 whose directivity is slightly shifted from each other as shown in FIG.

6 and 7 are detection circuits, and the receiving phasing circuits 4 and 5
The ultrasonic reception signal 81 (PastPaa H
Pas ed + etc.) and S 2 (Pb2- P
ba.

This is for extracting ultrasonic tomographic image signals from Pbs, etc.). The detection circuits 6 and 7 each include an analog-to-digital converter that converts the extracted ultrasonic tomographic image signal into a digital signal.

8 is an arithmetic processing circuit; a first arithmetic unit 9 performs a weighting operation on the received 4FJ signals obtained by simultaneously receiving in parallel the reflected waves of the ultrasonic beam emitted into the living body; It consists of a line memory 10 and a second arithmetic unit 11 that performs a weighting calculation based on the simultaneously received signal and a received signal based on the scanning timing adjacent to this received signal.

This arithmetic processing circuit 8 performs a correction calculation for the distortion of the five displayed images in order to remove the distortion of the display image caused by the difference in reception sensitivity level and noise difference between the channels of each receiving device used for parallel wave reception. This is what we do. Reference numeral 12 denotes an image memory for storing the ultrasonic tomographic image signal which has been subjected to arithmetic processing for correcting drooping of the displayed image by the arithmetic processing circuit 8.

Reference numeral 13 denotes an address generation circuit, which generates write and read addresses for the image memory 12. 14
1 is a display device such as a tIi or m-tube (CRT) monitor that reads out and displays the ultrasonic tomographic image signal stored in the image memory 12. Control of each section is performed by a control circuit 15.

In addition, in FIGS. 4 and 5, P is the intensity of the received signal, X is the distance in the scanning pitch direction of the ultrasound beam at a certain depth of the object, and the scanning timing t in the scanning pitch direction is Proportional.

In FIG. 5, the blanks are the received signals of the A channel, and the shaded ones are the received signals of the B channel.

Next, a description will be given of the computation for correcting the blurring of the display image performed in the arithmetic processing circuit 8.

Each channel of the receiving device (hereinafter, one is called the A channel,
The other channel is called the B channel) If the receiving sensitivity level is the same (if the received signal is correct) 1 For example,
As shown in FIG.
The strength value of the received signal received at ...) is PL, P3
．． It becomes P5...

However, when the receiving sensitivity level of the A channel and the receiving sensitivity level of the B channel are different.

For example, as shown in FIG. 5, the received signals Pa+, Pa3 . Paq ... becomes,
The strength of the received signal received on the B channel is Pb2.
Pb4. Pbs..., which differs from the value when the receiving sensitivity level between each channel of the receiving apparatus shown in FIG. 4 is the same. This error causes blurring in the displayed image. In addition.

The A channel and the B channel are respectively transmitted and received simultaneously. That is, the above A and B1. A2 and B2
, A3 and Bs, . . . are received simultaneously.

Therefore, in this embodiment, in order to correct the difference in reception sensitivity between the A channel and the B channel, the blurring of the displayed image is corrected based on the experimental correlation equation shown in the following correlation equation (1). It is.

In this correlation equation (1), M is an arbitrary real number set from experimental results, D is sensitivity-corrected reception data, and Dn is the operation of the element that receives the ultrasound reflected at a certain depth of the subject. The received data at a certain time t when the received signals are arranged rightward (in chronological order), DO is the received data one place to the right of the received data Dn. When there is a large difference in the level of receiving sensitivity, M is set to rlJ (M=1). Furthermore, when the receiving sensitivity levels of both signals are approximately equal, M approaches infinity.

The received data calculated by the above equation (1).

When arranged in the following order in time series and for each channel, as shown in FIG. 6, Dl, D2. Ds... becomes.

For example, when the difference between the reception sensitivity of channel A and the reception sensitivity of channel B is large, an example of calculating equation (1) with M=1 will be explained using FIGS. 5 and 6. 6 A certain time t Multiply the received data P a t of the A channel (AI) received data Pa The sensitivity-corrected value D1 is
As shown in Figure 6.

This is the data received by AI. Reception data Pa3 of the A channel (A2) and reception data Pba of the B channel (B2) received at the same time at time t+i are detected, but reception data Pb2 of the B channel (B, ) at the time t is detected.
Multiply it by "1", add the received data Pa3 to this value, and get "
Divide by 2.

The sensitivity-corrected value D2 is taken as the received data of B+.

Further, the received data Pa3 is multiplied by rlJ, the received data Pb4 is added to this value, and the result is divided by "2", and the sensitivity-corrected value D3 is set as the received data of A2. If the received data D 4 , D @ . . . which have been subjected to sensitivity correction in the same manner are calculated and are arranged in chronological order, the result will be as shown in FIG.

In this way, by correcting the blurring of the display image using correlation equation (1), it is possible to smooth the received data that includes the level difference in reception sensitivity between each channel.

Note that the first arithmetic unit 9 and the second arithmetic unit I are as follows.

A ROM (read only m
It is also possible to use e.g.

Next, the operation of the parallel reception type ultrasonic diagnostic apparatus of this embodiment will be explained with reference to FIG.

First, the transducer selection signal (a) from the control circuit 15 switches the switching circuit 2 to the transmitter side. An ultrasonic beam is emitted from 1 toward the subject. Before the ultrasound beam reflected from the subject (hereinafter simply referred to as an echo) returns to the probe 1, the control circuit 15 changes the transducer selection signal (a) and switches the switching circuit 2 to the receiving side.

The reception phasing circuits 4 and 5 are controlled by the delivery control signals (b) and (c) from the control circuit 15, and echoes are captured. This echo is detected by the detection circuits 6 and 7 and then converted into an analog signal.
converted to digital. This operation is controlled by the control circuit 1
This is done by control signals (E) and (E) from 5.

The received signals of the two channels, the A channel and the B channel, obtained in this way are input to the first arithmetic unit 9 or the line memory 10, respectively.

In the first arithmetic unit 9, the input received signal is applied to Dn and DO of the correlation equation (1), and the received data DI, Ds, D are corrected for the blurring of the display image shown in FIG.
s... are calculated and stored in the image memory 12.

On the other hand, the received signal input to the line memory IO and the next A
The received signal of the channel is input to the second arithmetic unit ll,
The reception data D2-B4. which is applied to Dn and Do of the correlation formula (1) and whose reception sensitivity is corrected as shown in FIG. Ds
... are calculated and stored in the image memory 12. These calculations are controlled by control signals (g), (ch), and (su).

Writing and reading of the calculated result into and from the image memory 12 is performed by a control signal (N). The write and read address at that time is commanded by the address generated by the address generation circuit 13.The received signal (ultrasonic tomographic image signal) stored in the image memory 12 and corrected for reception sensitivity is read out and displayed. device ff1
14.

As can be seen from the above description, according to this embodiment, by providing the arithmetic processing circuit 8 that corrects the blurring of the displayed image, it is possible to correct the deviation of the displayed image, so that a high-quality image can be obtained. be able to.

Moreover, various image restorations can be performed by arbitrarily selecting the value of M in correlation equation (1) so as to obtain a desired image display state.

FIG. 7 is a block diagram showing the configuration of an arithmetic processing circuit 8A of another embodiment of the arithmetic processing circuit of this embodiment, in which the first arithmetic unit 9 and the second arithmetic unit 11 of FIG. It is something.

In FIG. 7, 20 is a buffer memory for storing the A channel received signal Pa and the B channel received signal pb. 21 is a gate circuit, and 22 is a line memory, which has a capacity sufficient to store signals for -scanning lines.

23 is a write/read counter.

This is for generating write and read addresses for the buffer memory 20 and line memory 22. 24 is a latch circuit for temporarily holding the received signal. Reference numeral 25 denotes a computing unit, which is used to compute the above-mentioned correlation equation (1). 26 is a latch circuit, and the control circuit 15 controls each section.

Next, the seventh section will discuss the operation of the arithmetic processing circuit 8A of this embodiment.
This will be explained using figures.

The received signals received in parallel are stored in the buffer memory 20 through the A channel and the B channel. The stored reception signal is transferred to the A channel by using the write/read counter 23 and the gate circuit 21.
The B channel, A channel, B channel, etc. are read out in the order of input (scanning order). Each received signal read out is input to the calculator 25, and the correlation equation (
”) is calculated. That is, the first received signal Pa1 shown in FIG. 5 is input to the arithmetic unit 25 and is also input to the line memory 22 and stored therein. Next, when the second received signal Pb2 is input, the line memory 22 is put into a read state and the above-mentioned Pa+ is outputted, and after being latched by the latch circuit 24, the line memory 22 is immediately put into a write state and Pb2 is stored. . The arithmetic unit 25 uses the output signal Pat of the latch circuit 24 and the received signal Pb that has just been input.
2, the corrected received data DI is obtained.

The next third received signal Pa3 is input, and in the same manner as above, corrected received data D2 is obtained using the received signals Pbz and Pa3. 6. Received data D3 corrected in the same way
．． D4. Corrected reception data DI, D2, D3, D4, etc. obtained as follows: D5...
... are respectively connected to the image memory 1 via the latch circuit 26.
Written to 2. Note that the arithmetic unit 25 may use a ROM that includes a table configured by calculating the value of M in the correlation equation (1) experimentally determined in advance to obtain a correction value.

The present invention has been specifically explained above using examples.
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the gist thereof.

For example, it goes without saying that the present invention can be applied to parallel reception type ultrasound devices other than ultrasound diagnostic yt devices.

〔effect〕

As explained above, according to the present invention, the following effects can be obtained.

(1) In a receiving device using a parallel reception method, by providing an arithmetic processing circuit that corrects image information deviation according to the difference in reception sensitivity between reception channels, it is possible to correct the level difference in reception sensitivity between each reception channel. Since the deviation of the displayed image due to the noise difference can be corrected, a high quality image can be obtained.

(2) Various image restorations can be performed by selecting the value of M in correlation equation (1) so as to obtain the desired image display state.

(3) According to (1) and (2) above, good diagnostic materials can be provided.

[Brief explanation of the drawing]

1 to 7 are diagrams for explaining a parallel reception type ultrasonic diagnostic apparatus according to an embodiment of the present invention. Figure 1 is a block diagram showing the overall schematic configuration of the parallel wave receiving type ultrasound diagnostic device, Figure 2 is a block diagram showing the detailed configuration of the parallel wave receiving unit, and Figure 3 is the parallel wave receiving unit. 4 to 6 are explanatory diagrams for explaining the principle of the correction calculation of the embodiment. FIG. 7 is an explanatory diagram for explaining the principle of the correction calculation of the embodiment. FIG. 2 is a block diagram showing the configuration of an embodiment. In the figure, 1... Probe, 2... Switching circuit, 3... Ultrasonic wave transmitting circuit, AMP... Receiving amplifier, 4, 5...
Receiving phasing circuit, 6, 7...detection circuit, 8... arithmetic processing circuit. 9... first arithmetic unit, 10... line memory, 11.
... second arithmetic unit, 12 ... image memory, 13 ... address generation circuit, 14 ... display device, 15 ... control circuit.

Claims (1)

[Claims] (1) A probe and a receiving circuit that receive the ultrasound beam reflected waves emitted into the subject in parallel, an amplifier that amplifies the output received signal of this receiving circuit, and a memory that stores this amplified received signal. , in a parallel reception type ultrasound device that has an image processing device that performs image processing and a display device that displays the image processed image signal, reception in which the reflected waves of the ultrasound beam launched into the subject are simultaneously received in parallel. The present invention is characterized in that it is provided with an arithmetic processing mechanism consisting of a first arithmetic means that performs a weighting operation on signals, and a second arithmetic means that performs a weighting operation based on the simultaneously received signal and a received signal based on a scanning timing adjacent to this received signal. Ultrasonic device.