JPH0579335B2 - - Google Patents

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 obtains results by transmitting and receiving ultrasonic waves from an ultrasonic probe to a subject. The received signal is converted into a digital signal by an A/D converter, and this data is written into the frame memory.
The present invention relates to an ultrasonic diagnostic apparatus that performs TV scan conversion and displays ultrasonic tomographic images 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 a plurality of ultrasonic transducers, a plurality of ultrasonic transducers is considered to be one unit, and the ultrasonic wave of this one unit is This is a method of transmitting an ultrasonic beam by exciting a sonic oscillator. For example, by sequentially shifting the pitch one oscillator at a time 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. The reflected ultrasonic waves are focused (electronic focus) using the phase difference between each sound wave generated by the ultrasonic transducer.
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 changes sequentially in a fan shape for each pulse of the ultrasonic beam for one unit of excited ultrasonic transducers. It changes according to the 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 within a 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, that is, clutter components. The signal passed through the filter is then subjected to frequency analysis.
Here, while scanning the ultrasound beam from one side to the other in correspondence with the sector scan screen,
By performing the above-described series of processes, information on two-dimensionally distributed blood flow can be detected. Then, the blood flow information such as the two-dimensional blood flow velocity image showing the direction and velocity of the blood flow mentioned above, and the B-mode image and M-mode image obtained with another system are converted to a DSC (digital scan converter). can be superimposed and displayed on a TV monitor.

Next, Figure 3 shows ultrasound raster #1 to
It is a figure showing #N. Conventionally, ultrasonic scanning has been performed as a non-interlace scan in which raster #1 is scanned sequentially to raster #N as shown in FIG. For this reason, it takes a considerable amount of time for one frame period, and phenomena caused by the time difference between rasters that occur when displaying a fast-moving organ such as the heart, such as the shape of the heart valve being distorted or the movement being aliased, can occur. It looks like a vine. The reason for this can be explained as follows. That is, if the ultrasonic transmission/reception cycle is T and the number of rasters is N, it takes NT time to generate one frame of image.
That is, since N=256 and T=250 μsec, NT=64
It becomes msec. On the other hand, the movement of heart valves is rapid 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 interlaced scan is an interlaced scan, e.g.
ODD field (raster #1, #3,...#N)
This method scans EVEN fields (rasters #2, #4, etc.). According to this, since one frame is composed of two fields, the image becomes smoother than the conventional image.

However, when there is movement in an organ in one field image, such as a heart, the raster between the left and right sides that are not scanned by the field becomes an image containing jagged noise, making the entire image look ugly.

Therefore, the purpose of the present invention is to obtain a good ultrasound image even when there is movement by changing the ultrasound scan when the object is not moving to another type of ultrasound scan when there is movement of the object. The purpose of the present invention is to provide an ultrasonic diagnostic device that can perform the following functions.

[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, claim 1
The invention relates to a wave transmitting/receiving circuit that drives and controls an ultrasonic probe to perform ultrasonic scanning on a subject using an ultrasonic raster from the ultrasonic probe, and converting an output signal from the wave transmitting/receiving circuit into a digital signal. a display system that temporarily writes data from the A/D converter into a frame memory and outputs the data from the frame memory using a TV scan method for display; a motion detection circuit that compares data from the converter with data from one frame before and detects the presence or absence of movement of the subject; and an odd number when the motion detection circuit determines that there is no movement of the subject; The wave transmitting/receiving circuit is controlled to perform interlaced scanning in which scanning is performed alternately using ultrasonic rasters of fields and even fields.On the other hand, when the motion detection circuit determines that there is movement in the subject, It is characterized by comprising a control means for controlling the wave transmitting/receiving circuit to perform acoustic wave scanning.

Another invention according to claim 2 provides, in addition to the same wave transmitting/receiving circuit, A/D converter, display system, and motion detection circuit as described above, when the motion detection circuit determines that there is no movement in the subject, The wave transmitting/receiving circuit is controlled to perform ultrasonic scanning at the predetermined number of transmission stages, and when the motion detection circuit determines that there is movement in the subject, the number of transmission stages is less than the predetermined number of transmission stages. The present invention is characterized by comprising a control means for controlling the wave transmitting/receiving circuit so as to perform ultrasonic scanning.

Still another invention according to claim 3 provides, in addition to the same wave transmitting/receiving circuit, A/D converter, display system, and motion detection circuit as described above, when the motion detection circuit determines that there is no movement in the subject. , the transmitter/receiver circuit is controlled to perform ultrasonic scanning at the predetermined raster density, and when the motion detection circuit determines that there is movement in the subject, The ultrasonic diagnostic apparatus is characterized by comprising a control means for controlling the wave transmitting/receiving circuit so as to perform ultrasonic scanning at raster density.

In addition, ultrasonic waves are transmitted and received from the ultrasonic probe to the subject using a wave transmitting/receiving circuit, and the received signal obtained by this is converted into a digital signal by an A/D converter, and this data is written into the frame memory. , in an ultrasonic diagnostic apparatus that performs TV scan conversion and displays it on a display system, a movement in which it is determined that there is movement when the difference data obtained by subtracting data from one frame before from the data from the A/D converter 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. It is equipped with the means and.

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. Increasing the raster density of the transmitter/receiver circuit,
and control means for controlling the raster density of the wave transmitting/receiving circuit to decrease when there is movement.

(Effects) By taking such measures, the following effects are achieved. According to the invention claimed in claim 1,
The motion detection circuit detects the presence or absence of movement without requiring operator intervention, and when there is movement in the subject,
Ultrasonic scanning changes from interlaced scanning when there is no movement to sequential scanning. According to this sequential scanning, since the time difference between adjacent scanning lines is small, the amount of movement of the object between adjacent scanning lines is small. Ultrasound images can now be obtained.

According to another invention according to claim 2, by detecting the presence or absence of movement and reducing the number of transmission stages when the object is moving than when the object is not moving, it is possible to increase the number of frames, for example. You can deal with the movement.

According to still another invention according to claim 3, the presence or absence of movement is detected, and when there is movement in the subject,
By making the raster density coarser than when the object is not moving, it is possible to increase the number of frames, for example, and to cope with movement.

(Example) FIG. 1 is a schematic block diagram showing an embodiment of an ultrasound diagnostic apparatus according to the present invention, FIG. 2a is a schematic diagram showing an ultrasound interlace scan to which the present invention is applied,
FIG. 2b is a diagram showing an ODD field and an EVEN field in one ultrasonic frame.
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 1 is driven to transmit by a wave transmitting/receiving circuit 2, whereby ultrasonic pulses are transmitted from the transducer of the ultrasonic probe 1 to the living body. The reflected ultrasonic waves are then received by the ultrasonic probe 1 and the wave transmitting/receiving circuit 2. Further, the signal is converted into a digital signal by an A/D converter 3 and input to a motion detection circuit 4 comprising a one-frame delay circuit 11, an absolute value circuit 12, and a comparator 13. That is, the data from the A/D converter 3 to the motion detection circuit 4 is input to the 1 frame delay circuit 11 which delays the data by 1 frame, and the absolute value circuit 12 receives data from the 1 frame previous from the 1 frame delay circuit 11. Data and A/D
Current data from converter 3 are input. Then, the absolute value circuit 12 subtracts the data one frame before from the current data, and the comparator 13 compares and determines the subtraction output with the threshold level TH. That is, the comparator 13 is
When the output P from the absolute value circuit 12 exceeds the threshold level TH, it is determined that there is movement, and a detection signal s0 is output to the controller 5 as a control means.

Here, if it is determined that there is no movement based on the detection result of the motion detection circuit 4, the detection signal s0 is not output to the controller 5. In this case, a reference signal s1 having a frequency f1 is input from the reference signal generation circuit 6 to the wave transmitting/receiving circuit 2, and the wave transmitting/receiving circuit 2 generates a second signal.
As shown in the figure, for each field scan, i.e.
ODD field scanning or EVEN field scanning is performed. Further, when the detection signal s0 is not output from the comparator 13 of the motion detection circuit 4, the switch 7 is switched to the contact point c. Then, ODD field scanning data or EVEN field scanning data from the A/D converter 3 is written into the field memory 8 via the switch 7. Then, when data for the next field scan is written to the field memory 8, the field data one field before is read out and written to the frame memory 9, and further TV scan converted and displayed as an image on the TV display unit 10. Ru.

Therefore, even when there is no movement, a good ultrasound image can be obtained, 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 the detection circuit s0 to the controller 5. Then, the reference signal generation circuit 6 inputting the control signal c0 from the controller 5 generates a reference signal s2 having a frequency f2 twice that of the reference signal s1 having the frequency f1. Then, the reference signal s2 from the reference signal generating circuit 6 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. Also, switch 7 is
The contact b is switched to write the data from the A/D converter 3, that is, the data for each frame, to the frame memory 10. Further data is read from the frame memory 10 and from the ultrasound scan.
The image is converted to a TV scan and displayed on the TV display section 11
will be displayed.

In this way, according to this embodiment, the motion detection circuit 4
Based on the results of , if there is no movement, ODD,
EVEN An interless scan is performed that scans the raster for each field, 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. Furthermore, when there is no movement, the number of ultrasonic frames is approximately twice that of a non-interlace scan.

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 s0. 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 c1 from the controller 5a 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, when there is movement, the motion detection circuit 4 outputs a detection signal s0 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 wave transmitting/receiving circuit 2
The number of transmission stages is reduced to, for example, one stage. 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, images between frames can be observed as 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.

Note 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 invention according to claim 1, the motion detection circuit detects the presence or absence of motion without requiring operator intervention, and when the subject moves, the ultrasonic wave Scanning changes from interlaced scanning when there is no movement to sequential scanning. According to this sequential scanning, since the time difference between adjacent scanning lines is small, the amount of movement of the object between adjacent scanning lines is small. It is possible to provide an ultrasound diagnostic device that can obtain ultrasound images.

According to another invention according to claim 2, by detecting the presence or absence of movement and reducing the number of transmission stages when the object is moving than when the object is not moving, it is possible to increase the number of frames, for example. Therefore, it is possible to provide an ultrasonic diagnostic apparatus that can deal with the movement of the surroundings.

According to still another invention according to claim 3, the presence or absence of movement is detected, and when there is movement in the subject,
By making the raster density coarser than when the object does not move, it is possible to increase the number of frames, for example, and provide an ultrasonic diagnostic apparatus that can cope with movement.

[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 interless scanning for each field, and FIG. 3 is a schematic diagram showing on-interless scanning to which the present invention is applied. , 4th
The figure is a schematic configuration diagram showing a second embodiment of the present invention. 1... Ultrasonic probe, 2... Transmission/reception circuit, 3...
...A/D converter, 4...Motion detection circuit, 5, 5a
... Controller, 6, 6a ... Reference signal generation circuit, 7 ... Switch, 8 ... Field memory,
9...Frame memory, 10...TV display section, 1
1...1 frame delay circuit, 12...absolute value circuit, 13...comparator.

Claims (1)

[Scope of Claims] 1. A wave transmitting/receiving circuit that drives and controls an ultrasonic probe to ultrasonically scan a subject with an ultrasonic raster from the ultrasonic probe; and an output signal from the wave transmitting/receiving circuit. an A/D converter that converts into a digital signal; a display system that temporarily writes data from the A/D converter into a frame memory and outputs the data from the frame memory using a TV scan method for display; a motion detection circuit that compares data from the /D converter with data from one frame before and detects the presence or absence of movement of the subject; and when the motion detection circuit determines that there is no movement of the subject; , the wave transmitter/receiver circuit is controlled to perform interlaced scanning in which scanning is performed alternately using ultrasonic rasters of odd-numbered fields and even-numbered fields; on the other hand, when the motion detection circuit determines that there is movement in the subject, An ultrasonic diagnostic apparatus comprising: a control means for controlling the wave transmitting/receiving circuit to sequentially perform ultrasonic scanning. 2. A wave transmitting/receiving circuit that drives and controls an ultrasonic probe to ultrasonically scan a subject in the depth direction at a predetermined number of transmission stages using the ultrasonic waves from the ultrasonic probe, and an output from the wave transmitting/receiving circuit. an A/D converter that converts a signal into a digital signal; a display system that temporarily writes data from the A/D converter into a frame memory and outputs the data from the frame memory using a TV scan method for display; a motion detection circuit that compares data from the A/D converter with data from one frame before and detects the presence or absence of movement of the subject; and the motion detection circuit determines that there is no movement of the subject. At this time, the wave transmitting/receiving circuit is controlled to perform ultrasonic scanning at the predetermined number of transmission stages;
and a control means for controlling the wave transmitting/receiving circuit to perform ultrasonic scanning with a number of transmission stages smaller than the predetermined number of transmission stages when the motion detection circuit determines that there is movement in the subject. Features of ultrasonic diagnostic equipment. 3. A wave transmitting/receiving circuit that drives and controls an ultrasonic probe to ultrasonically scan a subject at a predetermined ultrasonic raster density using the ultrasonic waves from the ultrasonic probe; and an output signal from the wave transmitting/receiving circuit. an A/D converter that converts into a digital signal; a display system that temporarily writes data from the A/D converter into a frame memory and outputs the data from the frame memory using a TV scan method for display; a motion detection circuit that compares data from the /D converter with data from one frame before and detects the presence or absence of movement of the subject; and when the motion detection circuit determines that there is no movement of the subject; , the transmitter/receiver circuit is controlled to perform ultrasonic scanning at the predetermined raster density, and when the motion detection circuit determines that there is movement in the subject, An ultrasonic diagnostic apparatus comprising: control means for controlling the wave transmitting/receiving circuit so as to perform ultrasonic scanning at raster density.