JPH0244539B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for easily and easily determining the display start position from the outside when displaying an ultrasonic tomographic image displayed in a fixed display frame on a CRT display screen. The present invention relates to an ultrasonic diagnostic apparatus that can be set variably and whose display start position is displayed as a numerical value together with an ultrasonic tomographic image.

[Conventional technology] In ultrasonic diagnostic equipment, on the CRT monitor,
The reflected ultrasonic waves for each ultrasonic wave transmitted from the transducer into the subject are A mode method, B mode method,
Although it has come to be displayed as an image using M mode etc., until now, the display start depth on the display screen has been fixed,
Based on this, only images within a certain range can be displayed. Incidentally, examples related to this type of technology include, for example, Japanese Utility Model Publication No. 19037/1983 and Japanese Patent Application Laid-open No. 779/1983.

[Problem to be Solved by the Invention] Therefore, even if the display magnification of the image is variable, if the viewer sets the display magnification in the direction of enlarging the image, the size of the display screen will change. By being constant, the display range is restricted and there are parts of the image that cannot be displayed, and if you try to display the entire image, the entire image will be displayed in a reduced state and the image will be displayed in a small size. Such display has become impossible.

On the other hand, the former of the above-mentioned publications relates to selective display of an image part by mask control within a fixed display image, and the latter relates to a fixed display image in which a DC bias is added to the deflection voltage. This makes it possible to move vertically and horizontally. However, no matter which method is used, images other than fixed display images cannot be displayed at all.

An object of the present invention is to enable a display start position to be set externally and to display images within a certain range from the variably set display start position within a fixed display frame on the display screen. An object of the present invention is to provide an ultrasonic diagnostic apparatus in which a display start position can be displayed at a predetermined position within a fixed display frame.

[Means for Solving the Problems] In order to achieve this object, the present invention transmits ultrasonic waves from an ultrasonic transducer into the subject, and displays the echo signals at a normal display magnification higher than that displayed on the screen of the display device. Sequentially capturing the echo signals, the signal of the contact surface between the ultrasonic transducer and the subject can be displayed by the display frame by substantially matching the display frame fixedly set on the display screen of the display device. In the ultrasonic diagnostic apparatus, the display start signal setting means arbitrarily sets a signal to be started to be supplied for displaying the echo signal captured on the display on the display, and the display start signal means for matching the echo signal set by the setting means with a fixed display frame on the display screen and sequentially displaying the set echo signal by the fixed display frame; and setting means for setting the display start signal. and a means for displaying the echo signal supply start position as a numerical value in a specific area within the fixed display frame. The image can be moved and displayed arbitrarily.

[Function] The display start signal setting means is an echo signal for the ultrasonic waves transmitted from the ultrasound transducer to the subject, and is sequentially captured in an area larger than the fixed display frame of the display unit in normal magnification display. The display means allows the operator to arbitrarily set the signal to be started to be supplied for displaying the echo signal on the display device, and the display means is configured to set the signal set by the display start signal setting means. Match the fixed display frame on the display screen,
The fixed display frames are sequentially displayed from that signal. Therefore, although the echo signal is captured by an ultrasonic transducer, if there is a part that is not actually displayed in a certain display state and the operator wishes to observe that part, the above-mentioned By operating the display start signal setting means so that a desired portion is displayed, the displayed image moves in a scrolling manner, and the previously invisible portion appears as an image. be. Moreover, at that time, the echo signal supply start position set by the display start signal setting means is displayed as a numerical value in a specific area within the fixed display frame, so as a result,
While displaying the display start position of the currently displayed echo signal, it is possible to arbitrarily move and display the ultrasound image at the normal display magnification.

[Example] The present invention will be described below with reference to FIGS. 1, 2, and 3 a and b.
This is explained by:

FIG. 1 shows the basic configuration of an example of the ultrasonic diagnostic apparatus according to the present invention. In this example, a monostable multivibrator is commonly used in the X and Y directions as display start signal setting means. It has become something that has been done.

That is, the display start signal is set by adjusting the time constant of a time constant circuit forming a part of the monostable multivibrator 1. As shown in the figure, a monostable multivibrator main body 1a as an IC is externally connected with a capacitor 1b, a fixed resistor 1c, and a variable resistor 1d that constitute a time constant circuit. The vibrator 1 is designed to function as a display start signal setting means.

By the way, as shown in FIG. 2a, the synchronization signal generation circuit 4 generates a synchronization signal in a so-called low level state (in the Y direction) in terms of synchronization _Ts , and the monostable multivibrator 1 shifts to the low level state. It is set to be triggered at this point. As a result, a high-level pulse signal is obtained from the Q output terminal of the monostable multivibrator 1 as shown in Figure 2c, but the pulse width
T _MW is at least equal to or greater than the pulse width T _SW of the synchronization signal. When the resistance value of the variable resistor 1d is zero, T _MW =T _SW , and when the resistance value is other than zero, T _MW > T _SW . by the way,
The NAND gate 2 and the inverter 3 are used to detect the difference in pulse width, that is, T _MW - T _SW as shown in Figure 2d, and depending on the magnitude of the detected difference in pulse width, The XY sweep circuit 11 controls the start of sweeping the CRT 15 in the X and Y directions. That is, if the difference is zero, the display start position is zero, that is, assuming that there is no delay in the start of the sweep, the Y direction sweep is almost synchronized with the time when the synchronization signal transitions to the high level state, and the X direction sweep is This is done in synchronization with a direction synchronization signal. However, if the difference is other than zero, both sweeps are started at the same time with a time delay depending on the magnitude of the deviation. Figure 2e shows Y controlled as above.
A directional sweep signal is shown. In addition, CRT
In this case, 15 is in a state where the normal posture is rotated by 90 degrees, so the sweep in the Y direction is performed periodically T _S , and the sweep in the X direction is performed using the ultrasonic wave of one displayed image. The scanning is performed at a period of n·Ts, where the number of scanning lines is n.

On the other hand, ultrasonic waves are emitted to the living tissue 16 in Fig. 2b.
As shown in FIG. 2, this is carried out for a certain period of time in synchronization with the time when the synchronization signal (in the Y direction) shifts to a high level state. At that point, the high voltage pulse generating circuit 5 generates a high voltage pulse for a certain period of time, and this is applied to the vibrator 7 as a reversible electro-mechanical transducer through the switch 6, so that the high voltage pulse is Living tissue 16
Ultrasonic waves are emitted towards the target for a certain period of time. If the switch 6 is switched at the same time as the application of the high voltage pulse ends, reflected ultrasound is obtained from the living tissue 16 in a time-sequential manner until the next high voltage pulse is applied, and this is transmitted to the transducer 7 and the switch. 6, amplifier 8,
Since it is input to the CRT 15 as a luminance modulation signal via the detection circuit 9 and the video signal synthesis circuit 10,
A fixed display frame on the CRT display screen (in this case, the CRT
(The entire display screen becomes a fixed display frame) is a B mode display, that is, an ultrasonic tomographic image is displayed based on the X and Y direction setting display start signals. Note that in this case, the vibrator 7 may be used to remove the biological tissue 16 by an appropriate method.
Of course, scanning is performed using, for example, linear scan or sector scan. Furthermore, it is clear that the time _TV in FIG. 2e corresponds to the Y-direction displayable range of the fixed display frame. Here, the range of time T in which the display can be changed is T=T _S -T _V =T _MW -T _SW +T' in the Y direction. Therefore, the capacity of the reflected ultrasound signal in the time width TV during the display period is smaller than that of the reflected ultrasound signal obtained in the interval T _S , and as a result, the capacity of the reflected ultrasound signal in the time width T _V is smaller than that of the reflected ultrasound signal obtained in the interval T _S.
By setting the falling start point of T as a reference point (the point at which the Y-direction synchronization signal transitions to a high level) and changing it within the range of T above, a required image area that cannot normally be displayed can be obtained. Even images can be moved and displayed in a fixed display frame. To specifically explain this display example with reference to Figure 3 a and b, Figure 3 a
3 shows an example of a display in which A is the subject surface position and B is the normal display start position. As shown in the figure, only the image near the object surface is displayed within the fixed display frame (solid line display frame), and the image further away from the object surface indicates that the corresponding reflected ultrasound signal actually exists. Despite this, it has become impossible to display it. However, when the display start position is set as C, an image further away from the surface of the subject can be newly displayed, as shown in FIG. 3b. This is, so to speak,
This is similar to scrolling the displayed image in the vertical direction, and with such a display, it is possible to diagnose parts that cannot be diagnosed with normal displays for the first time.

Now, by appropriately adjusting the variable resistor 1d as described above, the display start position in the X and Y directions can be set arbitrarily.
5. The Y-direction setting display start position is displayed as a numerical value in a specific display area on the display screen. Video signal synthesis circuit 1 converts numerical data into a brightness modulation signal within a specific period of the X direction sweep period and within a specific period of the Y direction sweep period.
0 to the CRT 15, the setting display start position can be displayed as a numerical value in the specific display area. Of course, the displayed numerical value in this case corresponds to the pulse width deviation T _MW - T _SW . This display numerical value is generated by measuring the difference in pulse width over time using a clock pulse with a period corresponding to the depth unit. In this example, as shown in the figure, the counter 14 is reset by using the signal output from the XY sweep circuit 11 as a reset signal (R) prior to the X direction sweep, while the XY sweep circuit 11
A certain time T _S for the first Y-direction synchronization signal
Under gate control based on the output signal and the pulse width difference signal obtained from the inverter 3, clock pulses from the synchronizing signal generating circuit 4 are counted by a counter 14 via an AND gate 13. If the period of the clock pulse is made to correspond to the depth unit, the count value of the counter 14 will indicate the setting display start position. Therefore, under the control of the XY sweep circuit 11, if numerical data is generated from the count value in the display numerical data generation circuit and sent to the CRT 15 via the video signal synthesis circuit 10, the specific display area will be displayed in the Y direction. This means that the setting display start position can be displayed. In this example, this display start position is also the X-direction setting display start position.

As a result of the above, the image display mode is as follows.

In other words, the X sweep on the display screen is from left to right, Y
If the sweep is performed from top to bottom and the image is displayed within a fixed display frame on the display screen, if T _MW = T _SW , the surface of the transducer 7 as the Y direction display start position. A cross-sectional image of the biological tissue 16 within a certain distance from is displayed in the fixed display frame at the top of the display screen. However, if T _MW = T _SW , the Y-direction display start position is shifted in the depth direction of the living tissue 16 by a distance corresponding to the difference, and the cross section of the living tissue 16 within a certain distance from that position is shifted. The image is displayed in a fixed display frame on the display screen. No matter how the Y-direction display start position is set within a certain range, the image display start position will be at the top of the fixed display frame, so by setting the Y-direction display start position large, ,
A cross section at the deepest part of the biological tissue 16 can also be displayed. Note that if the X-direction sweep is actively delayed independently of the Y-direction sweep, the X-direction display start position will also be set in a largely variable manner.

This embodiment is as described above, but X, Y
Various other types of direction display start signal setting means are conceivable. An example is a digital switch. The Y direction setting display start position is displayed based on the binary value set by the digital switch, while the sweep in the X and Y directions is started when the count value of the counter that counts clock pulses matches the above binary value. That's fine.

[Effects of the Invention] As explained above, according to the present invention, the display start position can be set externally, and images within a certain range from the variably set display start position are fixedly displayed on the display screen. Since it can be displayed within the frame, even if the ultrasonic reflection site protrudes from the fixed display frame, the site and its vicinity can now be moved and displayed within the fixed display frame for diagnosis. In addition, since the display start position can be displayed at a predetermined position within the fixed display frame, the tomographic image can be easily recorded and managed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic general configuration of an example of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 2 is an input/output signal waveform diagram of an example of the main part of the configuration.
FIGS. 3a and 3b are diagrams for explaining moving display of a display image. 1... Monostable multivibrator, 4... Synchronization signal generation circuit, 10... Video signal synthesis circuit, 1
1...XY sweep circuit, 12...Display numerical data generation circuit, 14...Counter, 15...CRT.

Claims (1)

[Claims] 1. Send ultrasonic waves from the ultrasonic transducer into the subject, capture the echo signals one after another at a normal display magnification above the screen display of the display, and transmit the echo signals between the ultrasonic transducer and the subject. In an ultrasonic diagnostic apparatus in which a signal from a contact surface is made to substantially match a display frame fixedly set on a display screen of the display device and can be displayed by the display frame, an echo signal captured beyond the screen display. a display start signal setting means for arbitrarily setting a signal to be supplied to the display for display on the display; and a display start signal setting means for fixing the echo signal set by the display start signal setting means on the display screen. Means for sequentially displaying the set echo signal for the fixed display frame in accordance with the display frame, and a means for displaying the supply start position of the echo signal set by the display start signal setting means as a numerical value within the fixed display frame. means for displaying in a specific area, while displaying the display start position of the echo signal currently being displayed;
An ultrasonic diagnostic apparatus characterized in that an ultrasonic image can be arbitrarily moved and displayed at a normal display magnification.