JPS62698B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic diagnostic apparatus having a function of not only displaying a tomographic image but also displaying a reference signal waveform at the same time as displaying the tomographic image.

In a so-called real-time ultrasound diagnostic device, for example, when observing a cardiac tomogram, the waveform of a biological signal such as an electrocardiogram signal or a pulse wave is displayed in the same manner as the tomogram as a reference signal for observing an ultrasound tomogram (B-mode image). Conventionally, information has been displayed on the screen using a memory display method called non-fade display. In non-fade display, biological signals etc. sampled at a certain period are sequentially written to a certain capacity memory, and after storing the sampled biological signals to the full capacity of the memory, the oldest data is sequentially erased from the memory and new sampled data is written. is written to update the contents of memory. The sampling data is displayed by repeatedly reading out the contents of the memory at high speed (time compressed) in the order in which the data was stored and displaying them on the display device while performing the sampling operation on the memory. Therefore, the biological signal waveform is displayed on the display screen of the display device without fading (non-fading) of the old part of the waveform, as if it were flowing on a recording paper on which the waveform was recorded.

On the other hand, in order to closely observe ultrasonic tomographic images of biological parts that move quickly, such as the heart, we can capture any time phase in the electrocardiogram waveform and photograph the cardiac tomographic image in synchronization with the electrocardiogram. A so-called freezing display of image display images is also practiced. Freezing display is a display method in which image data at a certain timing of a continuously changing display image is stored and held in a storage means, and the image is repeatedly read out and displayed, thereby freezing the image and displaying it as a still image. The timing of freezing is not limited to the electrocardiogram synchronization, but may also be controlled by an external manual switch. At the time of this freezing display, it is desirable that the above-mentioned reference signal, which is displayed in a non-fade manner on the same display screen as the tomographic image, is also frozen at the same time. This is because by freezing the reference signal, it becomes easy to understand at which time phase on the reference signal waveform the timing of freezing of the tomographic image occurs, which is extremely effective for analyzing and diagnosing tomographic images. This is because information can be obtained. Freezing of this non-fade display of the reference signal waveform can be achieved by canceling writing to the memory for non-fade display, but if you do this, the reference signal will be displayed in real-time non-fade display as soon as the freeze is released. When the reference signal waveform returns to (and will never match except by chance), causing a discontinuous portion on the non-fade display waveform. In other words, the newest waveform data stored in the non-fade display memory during the freeze state and the first data stored in the memory after the freeze is released are displayed consecutively on the display screen immediately after the freeze is released. Since the time phases are not continuous between these waveform data, the displayed waveform becomes discontinuous at this point. In this way, if the non-fade display becomes discontinuous when the freeze is released, it becomes difficult to grasp the time phase from the non-fade waveform for a while after the freeze is released (until the waveform after the freeze is displayed for approximately one period or more). occurs.

The present invention was made based on such circumstances, and regardless of the time phase on the waveform at the timing of freezing and unfreezing,
It is an object of the present invention to provide an ultrasonic diagnostic apparatus that can perform non-fade display so that the time phase can be easily grasped immediately after freezing is released.

That is, the feature of the present invention is that a tomographic image of a subject is obtained by scanning using an ultrasound beam,
In an ultrasonic diagnostic apparatus that can display this tomographic image as a moving image, simultaneously display an analog waveform of a reference signal obtained from the same subject, and display the tomographic image statically in a required display frame of the moving image. , a sampling means for sampling a reference signal from the subject at a cycle shorter than a scanning cycle of the ultrasound beam, and two memories each capable of storing waveform data corresponding to at least one cycle of an analog waveform of the reference signal. and one of these storage sections is updated by writing the data sampled by the sampling means, and the storage section to which the writing is updated is alternately switched each time the static display mode of the tomographic image is set, and the Waveform data is read and displayed in synchronization with the display cycle of the tomographic image from the storage section on the side where the writing update is being performed when displaying a moving image, and from the storage section on the side where the writing update is not being performed when the static display is performed. The present invention also includes a storage unit control means for providing the information.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is an amplifier for amplifying a biological signal consisting of an analog waveform signal such as an electrocardiogram signal induced from a subject P to display the waveform as a reference signal; sampler for sampling,
3 is a sampling pulse generator for giving sampling pulses of a preset constant period to the sampler 2 to perform sampling operations at scheduled timing; 4 is a sampling pulse generator for generating biosignal data in the form of analog values sampled by the sampler 2; An A/D (analog-digital) converter converts into a digital value; 5 and 6 are changeover switches whose switching is controlled when switching the operating mode of the system; and 7 to 12 whose switching is controlled when switching the operating mode of the system. 13 is a first memory having a storage capacity for one screen of digital waveform data;
4 is a first ring counter used for addressing the first memory 13; 15 is a second memory having a storage capacity for one screen of digital waveform data;
6 is a second ring counter used for addressing the second memory 15; 17 is a write pulse generator that generates write pulses for the first and second memories 13 and 15; 18 is a write pulse generator for the first and second memories 13 and 15; memory 13,
15 is a read pulse generator that generates read pulses, 19 and 20 are OR gates, and 21 is a D/A that converts the digital waveform data read from the first and second memories 13 and 15 into an analog waveform signal. (digital-to-analog) converter, 22
2 is an X signal generator that generates a sweep signal for displaying a reference signal (biological signal); 23 is a Z signal generator that generates a Z signal (luminance signal) for displaying a reference signal;
4 is an ultrasonic imaging device (equipped with a freezing function) that captures an ultrasonic tomographic image of the subject P, that is, a B-mode echo image, and outputs it as an image signal; 25
is the D/A converter 21, the X signal generator 22 and the Z
A time-division synthesis device for time-division synthesis of the reference signal display image signal from the signal generator 23 and the tomographic image display image signal from the ultrasound imaging device 24; 26 is a composite image synthesized by the time-division synthesis device 25; A monitor such as a CRT (cathode ray tube) monitor for displaying signals; 27 is a mode changeover switch for switching the operating mode of the system by external manual operation; 28 is a mode changeover switch for switching the operating mode of the system by a signal from 27 or in case of freezing. Detect the time phase on the biosignal waveform set in advance from the biosignal output from amplifier 1 (the timing to freeze is determined based on the time phase on the biosignal waveform, that is, actually the detected time on the biosignal waveform) It is meaningful for diagnosis to easily set the time from a specific time phase, and is often done.) By doing so, each switch 5...12, each memory 13, 15, and the ultrasound imaging device 24 can be controlled at a predetermined timing. This is a control device that performs system operation timing control and system operation mode switching control.

Next, the operation in such a configuration will be explained.

A biological signal induced from the subject P is amplified by an amplifier 1 and sampled by a sampler 2. The sampler 2 supplies the amplifier 1 with the sampling pulse from the sampling pulse generator 3.
The output of is sampled at a preset constant period. The output of the sampler 2 is converted into a digital signal by an A/D converter 4. System mode switching, namely, the first display mode (hereinafter referred to as
This is referred to as the "real-time mode") and a second display mode (hereinafter referred to as "freeze mode") in which reference signals and B-mode echo images are displayed in a frozen manner (hereinafter referred to as "freeze mode") can be switched by operating the switch 5. ~12, memory 13, 15
and the ultrasonic imaging device 24 is controlled. The mode switching operation of the control device 28 is performed in response to the switching operation of the mode changeover switch 27 or based on the output of the amplifier 1.

In the real-time mode, the changeover switches 5 and 6 are both connected to the side a in the figure, the switches 9 and 10 are both closed, and the switches 7, 8, 11, and 12 are all open.
The output waveform data of the A/D converter 4 passes through the changeover switch 5 and is stored in the first memory 13. This operation of sampling→A/D conversion→memory storage is repeatedly performed at the cycle of the sampling pulse of the sampling pulse generator 3 according to the timing control of the control device 28. The storage address of the waveform data in the first memory 13 is specified by the output of the first ring counter 14, and each time the waveform data is stored in the specified address of the first memory 13, the write pulse generator 17 The first ring counter 14 becomes 1 due to the pulse output from the
The sample data storage address in the first memory 13 is incremented by one. By this writing, the oldest data in the first memory 13 is erased and updated to the latest data. Next, pulses from the read pulse generator 18 are outputted by the control device 28 when the first memory 13 is in the read state (i.e., during write intervals), and this pulse train sequentially causes the first ring counter 14 to is incremented by 1 at high speed, and all of the waveform data stored in the first memory 13 for one screen is read out in the order of the oldest. In this way, the waveform data read out from the first memory 13 is converted into an analog value by the D/A converter 21 and sent to the X signal generator 22 and the Z signal generator 2.
It is given to the time division synthesizer 25 along with the output of 3,
In the time division synthesis device 25, the ultrasonic imaging device 2
It is time-division synthesized with the real-time B-mode echo image signal from 4 and displayed on the monitor 26 as a synthesized image.

When freeze is applied based on the operation of the mode changeover switch 27 or the output of the amplifier 1, the control device 28 is immediately operated and the changeover switches 5 and 6 are brought into an open state in which they are not connected to either. At this time, under the control of the control device 28, the switches 8, 10, 12 are closed, the switches 9, 11 are opened, the first memory 13 is in the read state, the second memory 15 is in the write state, and the A pulse from a read pulse generator 18 is applied to one ring counter 14, and a pulse from a write pulse generator 17 is applied to a second ring counter 16, respectively. In this case, the output pulse train from the write pulse generator 17 is a high-speed pulse train synchronized with the output pulse train from the read pulse generator 18, and all the data stored in the first memory 13 is transferred to the second memory 15. Transferred at high speed. Immediately after the data transfer is completed, the switch 8 is opened, the changeover switch 5 is connected to the side b in the figure, and the changeover switch 6 is connected to the side a in the figure, thereby entering the freeze mode. In this freeze mode, new sample data is
Data is sequentially written and updated from the converter 4 to the second memory 15 (in the same manner as in the case of the first memory 13 described above). On the other hand, since no new writing is performed in the first memory 13, the same contents as transferred to the second memory 15 are stored as they are, and this is repeated by signals from the control device 28 and the read pulse generator 18. The signal is read out, converted into an analog signal by the D/A converter 21, and supplied to the time division synthesizer 25, so that a frozen waveform is displayed on the monitor 26. Further, at the same time as freezing is applied, the ultrasonic imaging device 24 also enters the freeze mode and the tomographic image display is also frozen. During this time, sampling of biological signals by the sampler 2 continues, and new sample data is written into the memory 15 of the sampler 2 one after another.

Next, when the freeze is released, the control device 28 switches the changeover switch 6 to the side b in the figure, so that the switches 9 and 10 are both opened and the switches 11 and 12 are closed. For this reason,
New data after freezing is updated in the second memory 15 in the same way as during freezing, and data to be displayed is also read out from the second memory 15, and the non-fade display using the second memory 15 is performed. Real-time mode with display.

The above operation will be further explained in a supplementary manner with reference to timing charts shown in FIGS. 2a to 2k.

FIG. 2a shows the time-division control timing in the control device 28 for time-division synthesis of the B-mode echo image and the reference biological signal waveform in the time-division synthesis device 25 as a waveform. indicates the B-mode echo image display period, and the low level period indicates the biological signal display period. That is, during the time phase period indicated by the low level in this waveform, the first memory 13 or the second memory 13
The biological signal waveform is displayed by performing high-speed reading of the memory 15. Figure b shows the output waveform of the sampling pulse generator 3, which is periodically output even during the B-mode echo image display period. For example, c in the same figure is the first
This is the input waveform of the first ring counter 14 when the memory 13 is in the real-time mode in which the memory 13 is provided for non-fade display, and RP shown in the figure is a read pulse and WP is a write pulse. This write pulse
After the sampling pulse shown in FIG.
is output from. That is, in the state shown in FIG. 3C, since reading is being performed while writing is being performed, the biological signal waveform is not frozen and is displayed in real time without fading. d in the figure is a write/read control signal from the control device 28 for the first memory 13, and the write pulse
Only in the time phase corresponding to WP, the level becomes low and the first memory 13 becomes writable. During the high level period in this waveform, the first memory 13 is in a readable state.

Further, FIG. 2e shows a time-division control timing waveform similar to that in FIG. At this time, in order to prevent the system from malfunctioning, the control device 28 resets the time-division timing control at the time the freeze is applied, and the system displays biological signals no matter the timing when the freeze is applied. Works from period. When the freeze is applied, the first ring counter 1 shown in FIG.
4 and the input waveform of the second ring counter 16 _shown in _FIG . memory 13 to second memory 15
Data transfer is performed. Data transfer occurs before the next write pulse WP occurs. When the data transfer is completed, the system enters the freeze mode, and only the read pulse RP is input to the first ring counter 14 and only the write pulse WP is input to the second ring counter 16, as shown in f and g in the figure. Therefore, the biological signal waveform display is frozen. h and i in the same figure are f and g in the same figure, respectively.
The first memory 13 at a timing corresponding to
and a write/read control signal for the second memory 15, in which a high level indicates a readable state and a low level indicates a writable state.

When the freeze is released, the input waveform of the second ring counter 16 shown in FIG.
The second ring counter 16 receives the read pulse that was previously applied to the first ring counter 14.
As soon as RP is given, a write pulse WP is given continuously from the previous freeze state, and the latest data is sequentially read from the second memory 15, and real-time non-fade using the second memory 15 is performed. Display is performed. The write/read control signal for the second memory 15 at this time is shown in FIG. Note that data transfer when freezing is applied next time is from the second memory 15 to the first memory 13.

In this way, each time freezing is applied, the first memory 13 and the second memory 15 alternately change their functions, and the freeze mode and real-time mode are displayed.

That is, at the time of freezing, the contents of one memory that had been used for sample data are all transferred to the other memory.
New sample data is successively stored in the other memory, updating the contents of the memory. At this time, the waveform display is performed by repeatedly reading out the contents of one of the memories, and since new sample data is not stored in the memory and the stored contents are not updated, the displayed waveform is frozen. . Next, when the freeze is released, the waveform display will be based on the contents of the other memory, and new sample data will continue to be stored in the memory from the freeze state, resulting in a real-time non-fade display. . In this way, while frozen, the latest data is always stored in the memory on the side that is not displayed, and the contents of that memory are updated sequentially. Immediately, one screen worth of sampling data up to that point is displayed, and then a non-fade display is performed continuously. Regardless of the timing of unfreezing, the waveform can be displayed without discontinuities, making it easy to read and understand the waveform. This becomes possible immediately after the freeze is released.

Note that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications without changing the gist thereof.

For example, the switches 5 to 12 in FIG. 1 may have a configuration in which the signal lines are bus lines and these are controlled by logic signals. In addition, by reading out the data from the memories of two systems during the freeze mode and dividing the screen of two displays or one display into two and displaying each separately, freezing display and real-time display can be performed simultaneously. You can also do it. Furthermore, two systems of memory can be connected in cascade as necessary to perform non-fade display with twice the sample length.
In addition, as a display means, a so-called X-Y monitor,
Any TV monitor will do.

As detailed above, according to the present invention, it is possible to provide an ultrasonic diagnostic apparatus that can perform non-fade display that makes it easy to understand the time phase immediately after freezing, regardless of the time phase of freezing and unfreezing. can.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIGS. 2a to 2k are timing charts for explaining the embodiment. 1...Amplifier, 2...Sampler, 3...Sampling pulse generator, 4...A/D converter, 5,
6... Selector switch, 7... 12... Switch,
13, 15...first and second memory, 14, 16
...First and second ring counters, 17...Write pulse generator, 18...Read pulse generator,
19, 20... OR gate, 21... D/A converter, 22... X signal generator, 23... Z signal generator, 24... Ultrasonic imaging device, 25... Time division synthesis device, 26... ... Monitor, 27 ... Mode changeover switch, 28 ... Control device.

Claims (1)

[Claims] 1 Obtain a tomographic image of a subject by scanning with an ultrasound beam, display this tomographic image as a moving image, simultaneously display an analog waveform of a reference signal obtained from the same subject, and display the tomographic image as a moving image. In an ultrasonic diagnostic apparatus capable of statically displaying an image in a required display frame, a sampling means for sampling a reference signal from the subject at a cycle shorter than a scanning cycle of the ultrasound beam, and at least an analog of the reference signal, respectively. Two storage sections capable of storing waveform data corresponding to one cycle of the waveform; one of these storage sections is updated by writing the data sampled by the sampling means, and the storage section to be written and updated is used as the tomographic image. Each time the still display mode is set, the data is switched alternately, and when the moving image is displayed, the data is stored from the storage unit on the side where the writing update is being performed, and when the static display is performed, the data is stored from the storage unit on the side where the writing update is not performed. 1. An ultrasonic diagnostic apparatus comprising: storage unit control means for reading and displaying waveform data in synchronization with the display cycle of each tomographic image.