JPH02200255A - Ultrasonic diagnostic device - Google Patents

Abstract

PURPOSE:To improve ultrasonic resolution, to improve an ultrasonic frame speed and to obtain a satisfactory picture smoothly connected by changing the density of a raster according to cases that there is motion and there is no motion. CONSTITUTION:When the absence of the motion is decided based on the detected result of a motion detection circuit 4, a detection signal s0 is not outputted to a controller 5. In such a case, a reference signal s1, for which a frequency f1 is provided, is inputted from a reference signal generation circuit 6 to a transmission/reception circuit 2. Then, scanning is executed for each field by the transmission/reception circuit 2, namely, QDD field scanning or EVEN field scanning is executed. Even there is no motion, a satisfactory ultrasonic picture can be obtained and an ultrasonic frame number is made almost double to non-inductance scan. Since non-interlace scan is successively executed to scan all the rasters for each frame when there is the motion, a notched noise can be removed even when there is the motion. Then, the satisfactory ultrasonic picture can be obtained.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention transmits and receives ultrasonic waves from an ultrasonic probe to a subject using a wave transmitting/receiving circuit, and the reception obtained thereby. Signal A/
The present invention relates to an ultrasonic diagnostic apparatus that converts the data into a digital signal using a D converter, writes this data into a frame memory, converts it into a TV scan, and displays an ultrasonic tomographic image on a display system.

(Prior art) Ultrasonic diagnostic methods use anatomical information, typically represented by B-mode images, movement information of in-vivo organs, typically represented by M-mode images, and the Doppler effect, typically represented by blood flow imaging. The functional information associated with the movement of moving objects within the living body is used for diagnosis.

Further, a typical example of a method of scanning an inside of a living body using ultrasound waves is electronic scanning and mechanical scanning. Here, the electronic scanning method will be explained.

In other words, in the case of linear electronic scanning using an array-type ultrasonic probe (probe) equipped with multiple ultrasonic transducers, a plurality of ultrasonic transducers is regarded as one unit, and this one unit of ultrasonic wave This is a method of transmitting an ultrasonic beam by exciting a vibrator. For example, by sequentially shifting the pitch by one vibrator and excitation so that the position of one unit of element changes one after another, This is a method of electronically shifting the transmission point position of the ultrasound beam.

Then, so that the ultrasound beam is focused as a beam, the excited ultrasound transducers are shifted in excitation timing between those located in the center of the beam and those located on the sides, and the ultrasonic transducers generated thereby The reflected ultrasound waves are focused (electronically focused) using the phase difference between the sound waves generated by the vibrator.

The reflected ultrasound is then received by the same vibrator that was excited and converted into an electrical signal, and the echo information from each transmitted and received wave is formed, for example, as a tomographic image, and the image is displayed on a cathode ray tube or the like.

In addition, in the case of sector scanning, the excitation timing of each transducer is set so that the transmission direction of the ultrasonic beam sequentially changes into a fan shape for every l pulse of the ultrasonic beam for one unit of excited ultrasonic transducer group. It is changed in accordance with a desired direction, and the subsequent processing is basically the same as the linear electronic scanning described above.

In addition to the above-mentioned linear and sector electronic scanning, there is also mechanical scanning in which a transducer (probe) is attached to a scanning mechanism and ultrasonic scanning is performed by moving the scanning mechanism.

On the other hand, in addition to B-mode images in which signals based on ultrasonic transmission and reception are combined to form a tomographic image, typical imaging methods include M-mode images based on fixed scanning in the same direction. This represents the temporal change in the ultrasonic wave transmitting/receiving site, and is particularly suitable for diagnosing moving organs such as the heart.

Further, the ultrasonic Doppler method, of which blood flow imaging is a typical example, is a method of obtaining functional information accompanying the movement of a moving object within a living body and visualizing it, and this will be described in detail below. That is, the ultrasonic Doppler method utilizes the ultrasonic Doppler effect in which when an ultrasonic wave is reflected by a moving object, the frequency of the reflected wave shifts in proportion to the moving speed of the object.

Specifically, if an ultrasonic rate pulse (or continuous wave) is transmitted into a living body and the frequency shift due to the Doppler effect is obtained from the phase change of the reflected wave echo, the Motion information of moving objects can be obtained. According to this, it is possible to know the state of blood flow such as the direction of blood flow at a certain position in the living body, the state of the flow (disturbed or regular), the flow pattern, the velocity value, etc.

Next, the device will be explained. That is, in order to obtain blood flow information from ultrasonic echoes, ultrasonic pulses are repeatedly transmitted a predetermined number of times in a certain predetermined direction, and phase information is extracted by phase-detecting the received echoes. This signal is digitized and passed through a digital filter to remove non-moving or slow-moving components, or clutter components. Then, the signal that has passed through the filter is subjected to frequency analysis.

Here, by performing the above-described series of processes while scanning the ultrasound beam from one side to the other in correspondence with the sector scan screen, information on blood flow distributed two-dimensionally can be detected. Then, the blood flow information such as the two-dimensional blood flow velocity image showing the direction and velocity of blood flow, and the B-mode image and M-mode image obtained with another system are converted to a DSC (digital scan converter). Tv
It can be displayed on Tanabata.

Next, Figure 3 shows ultrasound image 1 obtained by conventional ultrasound scanning.
It is a diagram showing ultrasonic rasters #l to #N forming a frame. Conventionally, ultrasonic scanning has been performed as a non-interlace scan in which raster #1 is sequentially scanned to raster #N as shown in FIG. For this reason, it takes a considerable amount of time for one frame period, and the phenomenon caused by the time difference between rasters that occurs when displaying a fast-moving organ such as the heart, that is, the shape of the heart valve may become distorted.1. The movement appears to be reversed. The reason for this can be explained as follows. In other words, if the ultrasonic transmission/reception cycle is T and the number of rasters is N, it takes NT to generate one frame of image.
time is required.

That is, from N-258, T = 250 μsec, N
It becomes T-64ssec. On the other hand, the movement of the heart valves is faster in abnormal cases and newborns, resulting in poor temporal resolution and, as mentioned above, the problem that images between frames are not connected smoothly in time.

(Problem to be Solved by the Invention) On the other hand, there is also a method of employing interlace scanning in order to make the frame image smooth.

This interlace scan is an interlaced scan, for example, scans the ODD field (rasters #l, #3...#N), and then scans the EVEN field (rasters #2, #4...).
This is a method of scanning. According to this, since one frame is composed of two fields, the image becomes smoother than the conventional image.

However, when an organ in a single field image is in motion, such as a heart, the raster in the gaps that are not scanned by the field becomes an image containing jagged noise, making the entire image unreliable.

Therefore, it is an object of the present invention to improve ultrasonic resolution by changing the raster density depending on whether there is movement or no movement, and to increase the ultrasonic frame speed, thereby achieving smooth and well-connected ultrasonic waves. An object of the present invention is to provide an ultrasonic diagnostic device that obtains sonic images.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems and achieve the objects, the present invention takes the following measures. That is, the present invention transmits and receives ultrasonic waves from an ultrasound probe to a subject using a wave transmitting/receiving circuit, converts the received signal obtained thereby into a digital signal using an A/D converter, and stores this data in a frame memory. write to T
In an ultrasonic diagnostic apparatus that performs V-scan conversion and displays it on a display system, motion detection determines that there is movement if the difference data obtained by subtracting the data from the A/D converter and the data one frame before exceeds a predetermined value. Based on the results of this motion detection circuit, if there is no movement, interlace scanning is performed to scan the raster for each ODD or EVEN filtrate, and if there is movement, non-interlace scanning is performed to sequentially scan all the rasters. and control means for controlling the wave transmitting/receiving circuit to perform the following.

In addition, ultrasonic waves are transmitted and received from the ultrasonic probe to the subject by a wave transmitting/receiving circuit, the received signal obtained by this is converted into a digital signal by an A/D converter, and this data is written to the frame memory, and the TV In an ultrasonic diagnostic apparatus that scan-converts and displays on a display system, a motion detection circuit that determines that there is movement when differential data obtained by subtracting data from one frame before from the data from the A/D converter exceeds a predetermined value. and a control means for increasing the number of transmission stages of the wave transmitting and receiving circuit when there is no movement and decreasing the number of transmission stages of the wave transmitting and receiving circuit when there is movement based on the result of the motion detection circuit. It is equipped with the following.

Furthermore, there is a motion detection circuit that determines that there is movement if the difference data obtained by subtracting the data from the A/D converter and the data one frame before exceeds a predetermined value, and if there is no motion based on the result of this motion detection circuit. and control means for increasing the raster density of the wave transmitting/receiving circuit and decreasing the raster density of the wave transmitting/receiving circuit when there is movement.

(Effects) By taking such measures, the following effects are achieved. Based on the results of the motion detection circuit, if there is no movement, an interlace scan is performed that scans the rasters of each ODD and EVEN field, and if there is movement, a non-interlace scan is performed that sequentially scans all the rasters. Even when there is movement, jagged noise can be removed and good ultrasound images can be obtained. In addition, when there is no movement, the number of ultrasonic frames is approximately twice that of non-interlace scanning.

Based on the results of the motion detection circuit, if there is no movement, the number of transmission stages of the transceiver circuit is increased, so a high-resolution ultrasonic image can be obtained, and if there is movement, the number of transmission stages of the transceiver circuit is increased. , the number of frames can be increased. Furthermore, based on the results of the motion detection circuit, when there is no movement, increasing the raster density by increasing the number of rasters in the transmitting/receiving circuit can similarly obtain high-resolution ultrasound images; The number of frames can be increased by reducing the raster density of the transmitter/receiver circuit. As a result, even when measuring and displaying fast-moving organs, images between frames can be viewed as smoothly connected.

(Example) FIG. 1 is a schematic block diagram showing an embodiment of an ultrasound diagnostic apparatus according to the present invention, FIG. 2(a) is a schematic diagram showing an ultrasound interlace scan to which the present invention is applied, Figure (b) shows the ODD field and EVE in one ultrasonic frame.
FIG. 3 is a diagram showing an N field. FIG. 3 is a schematic diagram showing an ultrasonic non-interlace scan. The ultrasonic diagnostic apparatus will be described below with reference to the drawings.

The ultrasonic probe l is driven to transmit by a wave transmitting/receiving circuit 2,
As a result, ultrasonic pulses are transmitted from the vibrator of the ultrasonic probe l to the living body. And the reflected ultrasound waves are transmitted by an ultrasound probe l.
and is received by the wave transmitting/receiving circuit 2. Furthermore, the signal is A
/D converter 3 converts the signal into a digital signal and sends it to a one-frame delay circuit 11. Absolute value circuit 12. The signal is input to a motion detection circuit 4 composed of a comparator 13. That is, the data from the A/D converter 3 to the motion detection circuit 4 is input to a one-frame delay circuit 11 that delays the data by one frame, and the absolute value circuit 12 receives data one frame before from the one-frame delay circuit 11. data and current data from the A/D converter 3 are input. Then, the absolute value circuit 12 subtracts the data from the previous frame from the current data, and the comparator 18 compares and determines the subtraction output with the reset register hold level TH.

That is, when the output P from the absolute value circuit 12 exceeds the threshold level TH, the comparator 13 determines that there is movement, and outputs the detection signal SO to the controller 5 as a control means.

If it is determined that there is no movement based on the detection result of the motion detection circuit 4, the controller 5 receives a detection signal SO.
is not output. In this case, a reference signal s1 having a frequency f1 is input from the reference signal generation circuit B to the wave transmitting/receiving circuit 2, and the wave transmitting/receiving circuit 2 performs each field scan as shown in FIG. will be carried out. Further, when the detection signal SO is not output from the comparator 13 of the motion detection circuit 4, the switch 7 is switched to the contact point C. Then, A
ODD field scanning data or EVEN field scanning data from the /D converter 3 is written into the field memory 8 via the switch 7. When data for the next field scan is written into the field memory 8, the field data one field before is read out and written into the frame memory 9, and then converted into a TV scan and displayed as an image on the TV display section IO. Ru.

Therefore, a good ultrasound image can be obtained even when there is no movement, and the number of ultrasound frames is approximately twice that of a non-interlace scan.

On the other hand, if there is movement, the motion detection circuit 4 inputs a detection signal SO to the controller 5.

When the reference signal generation circuit B receives the control signal CO from the controller 5, a reference signal S2 having a frequency f2 twice that of the reference signal sl having the frequency fl is generated. Then, the reference signal S2 from the reference signal generation circuit B is input to the wave transmitting/receiving circuit 2, and the scanning of the wave transmitting/receiving circuit 2 is doubled as compared to the field scanning. That is, a non-interlace scan is performed in which all rasters are scanned as shown in FIG. Further, the switch 7 is switched to the contact position, and the data from the A/D converter 3, that is, the data for each frame is written into the frame memory IO. Furthermore, the data is stored in the frame memory l.
The ultrasonic scan is converted into a TV scan, and the image is displayed on the TV display unit 11.

As described above, according to this embodiment, based on the result of the motion detection circuit 4, if there is no motion, ODD is detected.

An interlace scan is performed that scans the raster for each EVEN fill route, and when there is movement, a non-interlace scan is performed that sequentially scans all rasters frame by frame, so even when there is movement, jagged noise is removed. It is possible to obtain good ultrasound images. In addition, when there is no movement, the number of ultrasonic frames is approximately twice that of non-interlace scanning.

Next, a second embodiment of the present invention will be described with reference to FIG. Note that the same parts as those shown in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

The feature of this embodiment is that based on the result of the motion detection circuit 4, the controller 5a as a control means increases the number of transmission stages of the wave transmitting/receiving circuit 2 when there is no motion, and when there is motion. The number of transmission stages of the wave transmitting/receiving circuit 2 is controlled to be reduced. That is, based on the result of the motion detection circuit 4, if there is no motion, the comparator 13 of the motion detection circuit 4 will not output the detection signal SO.

In this case, the controller 5a determines that the correlation between the frames is high, determines the diagnostic region, interprets this to mean that breathing is being held, and outputs a control signal cl to the wave transmitting/receiving circuit 2. Then, the number of transmission stages is increased by the wave transmitting/receiving circuit 2 to, for example, four stages. Therefore, when there is no movement, an ultrasonic image with high resolution can be obtained by increasing the number of transmission stages of the wave transmitting/receiving circuit 2.

Next, if there is movement, the motion detection circuit 4 outputs the detection signal SO from the comparator 13 to the controller 5a. Then, the controller 5a determines that the correlation between frames is low, interprets this as screening by moving the ultrasound probe, and outputs a control signal C2 from the controller 5a to the wave transmitting/receiving circuit 2. Then, the number of transmission stages is reduced to, for example, one stage by the wave transmitting/receiving circuit 2.

Therefore, when there is movement, the number of frames can be increased by reducing the number of transmission stages of the wave transmitting/receiving circuit 2. As a result, even when measuring and displaying fast-moving organs,
It can be observed that the images between frames appear to be smoothly connected.

Further, the controller 5a controls the raster density of the wave transmitting/receiving circuit 2 to increase when there is no movement, and to decrease the raster density of the wave transmitting/receiving circuit 2 when there is movement. In this case, based on the result of the motion detection circuit 4, when there is no movement, the number of rasters in the wave transmitting/receiving circuit 2 increases and the raster density increases. When an ultrasonic image is obtained and there is movement, the number of rasters in the wave transmitting/receiving circuit 2 decreases and the raster density decreases, so the number of frames can be increased.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] According to the present invention, based on the results of the motion detection circuit, when there is no movement, interlace scanning is performed to scan the rasters for each ODD and EVEN filtrate, and when there is movement, all rasters are scanned sequentially. Since non-interlace scanning is performed to scan the raster, even if there is movement, jagged noise can be removed and a good ultrasound image can be obtained; It is approximately twice that of the previous year. Also, based on the results of the motion detection circuit,
When there is no movement, the number of transmission stages of the transmitting/receiving circuit is increased or the raster density is increased, so a high resolution ultrasonic image can be obtained, and when there is movement, the number of transmitting stages of the transmitting/receiving circuit is decreased. The number of frames can be increased by increasing the number of frames and reducing the raster density. As a result, even when measuring and displaying a fast-moving organ, it is possible to provide an ultrasonic diagnostic apparatus that allows images between frames to be observed as if they are smoothly connected.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing an ultrasonic diagnostic apparatus according to the present invention, FIG. 2 is a schematic diagram showing interlace scanning for each field, and FIG. 3 is a schematic diagram showing non-interlace scanning to which the present invention is applied. , FIG. 4 is a schematic diagram showing a second embodiment of the present invention. l... Ultrasonic probe, 2... Transmission/reception circuit, 3...
A/D converter, 4...Motion detection circuit, 5, 5a...
Controller, 8.6a... Reference signal generation circuit, 7.
...Switch, 8...Field memory, 9...Frame memory, IO...TV display unit, 11...1 frame delay circuit, 12...Absolute value circuit, 13...Comparator.

Claims (3)

[Claims] (1) Ultrasonic waves are transmitted and received from the ultrasound probe to the subject using the transmitter/receiver circuit, the received signal obtained by this is converted into a digital signal by the A/D converter, and this data is written to the frame memory. , in an ultrasonic diagnostic apparatus converted to a TV scan and displayed on a display system, a movement in which it is determined that there is movement when the difference data obtained by subtracting the data from the A/D converter and the data one frame before exceeds a predetermined value. Based on the results of the motion detection circuit and the motion detection circuit, if there is no movement, interlace scanning is performed to scan the rasters for each ODD and EVEN filtrate, and if there is movement, non-interlace scanning is performed to sequentially scan all rasters. An ultrasonic diagnostic apparatus comprising: control means for controlling the wave transmitting/receiving circuit to perform scanning. (2) Ultrasonic waves are transmitted and received from the ultrasound probe to the subject using a wave transmitting/receiving circuit, the received signal obtained by this is converted into a digital signal by an A/D converter, and this data is written to the frame memory. , in an ultrasonic diagnostic apparatus converted to a TV scan and displayed on a display system, a movement in which it is determined that there is movement when the difference data obtained by subtracting the data from the A/D converter and the data one frame before exceeds a predetermined value. a detection circuit; and control for increasing the number of transmission stages of the wave transmitting/receiving circuit when there is no movement and decreasing the number of transmission stages of the wave transmitting/receiving circuit when there is movement based on the result of the motion detecting circuit. An ultrasonic diagnostic apparatus comprising: means. (3) Ultrasonic waves are transmitted and received from the ultrasound probe to the subject using a wave transmitting/receiving circuit, the received signal obtained by this is converted into a digital signal by an A/D converter, and this data is written to the frame memory. , in an ultrasonic diagnostic apparatus converted to a TV scan and displayed on a display system, a movement in which it is determined that there is movement when the difference data obtained by subtracting the data from the A/D converter and the data one frame before exceeds a predetermined value. a detection circuit; and control for increasing the raster density of the transmitting and receiving circuit when there is no movement and decreasing the raster density of the transmitting and receiving circuit when there is movement based on the results of the motion detecting circuit. An ultrasonic diagnostic apparatus comprising: means.