JPS61253049A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ultrasonic diagnostic apparatus, and particularly to a method for creating a B-mode image. - (Prior Art) In an 8-mode ultrasonic diagnosis 1lli device, when obtaining an image finer than the element pitch of the probe, the following method is usually used.

(1) The number of driving elements of the probe is switched between an even number and an odd number, and an image is created based on adjacent sound rays. That is, as shown in FIG. 4, when the number is even, the sound ray is a solid line A, and when it is an odd number, the sound ray is a broken line B.

(2) The number of driving elements is nine, and the position is not switched, but the focus is switched between transmission and reception. That is, as shown in FIG. 5, both transmission and reception are focused on the solid line A
, the transmission is Fl and the reception is F2 (or vice versa)
A method to obtain an image as a sound ray of dashed line B.

(Problems to be Solved by the Invention) However, such conventional systems have the following problems. In both methods (1) and (2), the tonic line (
The image characteristics such as gain and resolution are different between the solid line) and the subtone line (broken line), and there is a considerable difference between the methods (1) and (2). For this reason, when a B-mode image is created, especially when an enlarged image is created, this difference becomes noticeable, resulting in what is commonly called a grid pattern, which appears as a vertical striped pattern as shown in FIG. This stems from the following points.

In the case of method (1), the difference in gain, etc. due to the change in the number of driving elements.

In the method of pasting (2), the focus of transmission and reception is intentionally shifted, so that each appears as a difference in gain.

It is an object of the present invention to improve the tonic rays without increasing or decreasing the number of tonic rays without causing a grid pattern.

It is an object of the present invention to provide an ultrasonic diagnostic apparatus which can obtain images finer than the element pitch of a probe using sub-sound rays.

<Means for Solving the Problems> The present invention solves these problems by changing the focus of the transmitting and receiving beams for transmission and reception without changing the drive element to create a main sound ray and a sub-sound ray, In ultrasonic diagnostic equipment that obtains images using sound rays that are finer than the drive element pitch, one of the focal points when creating the main sound ray and sub sound rays is positioned on the central axis of the drive element, and the main sound ray and The subtone lines are symmetrical about this central axis, and a grid pattern is not generated on the image.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

First, the principle of the system of the present invention will be described with reference to FIG. Although the figure shows a case where the number of drive elements is six, the number is not limited to six. The transmission focus is set at Fl on the central axis of the group of drive elements 1, the reception focus is set to F2 to create a main sound line to the solid line, and the reception focus to F3 to create a sub sound line to the broken line B, and an image is obtained. In addition, by reversing the transmission and reception, that is, the transmission focal point is F2 and the reception focal point is Fl, and the transmission focal point is F3 and the reception focal point is Fl.
and subtone ray B may be obtained.

By making the main sound ray and the sub-tone rays symmetrical with respect to the central axis of the drive element in this manner, the gain, beam width, etc. of both sound rays are made equal, and the generation of the grid pattern 9 can be prevented.

-3-' FIG. 2 is a block diagram of the main parts of a transmitting focus circuit for generating the sound rays shown in FIG. 1 and obtaining echo signals. In the figure,
10 is a probe having a plurality of driving elements. 11
A transmission focus circuit generates drive pulses with drive timings of each element adjusted so that the transmission beam is focused on the transmission focus F1.

12 is a transmitting/receiving switching circuit, and when transmitting, the transmitting focus circuit 11
A high voltage pulse is generated by the driving pulse given by the
This is added to the corresponding element of the probe, and at the time of reception, the echo signal received by each element is sent to the cross point switch circuit 1.
It is configured to send to 3. The cross-point switch circuit 13 appropriately switches the connections of the output signals from each element and guides them to the delay line 14. delay line 14
The echo signals from each element are delayed by a predetermined time, and are aggregated onto one signal line and output. The reception focus can be selected as F2 or F3 by controlling this delay time and the connection relationship with the crosspoint switch.

By adding the output of this delay line 14 to a signal processing circuit (not shown) and processing it appropriately, an image can be obtained.

A control circuit 15 controls the timing and functions of each part. In addition, the control circuit is J5, and the connection relationship at the cross point switch is the focus F2. The data that is the basis for switching using F3 is normally stored in a memory (for example, ROM), and the data is read and used using F2 and F3. However, by using the configuration shown in Figure 3, the memory capacity can be reduced. You can save money.

That is, the configuration is such that the output of the counter 21 indicating the number of driven elements is applied to the ROM 23 via the exclusive OR circuit 22 to read out the received focus data. The same data can be used by simply applying a control signal C (1 or O) for switching the tonic line and sub-tone line to each of the exclusive OR circuits 22 and switching the reading direction, so the memory capacity is small. I'm done.

(Effect of the invention) As explained above, according to the present invention, the tonic line.

The relationship between the sub sound rays can be made bilaterally symmetrical, and essentially no difference in gain or the like is produced between the two sound rays. Therefore, a grid pattern essentially does not occur.

Further, the focus data for the tonic ray and the sub-tone rays are normally read out from the memory, but the same focus data can be used by simply changing the reading direction, so the memory can be saved.

[Brief explanation of the drawing]

Figure 1 is a diagram for explaining the principle of the method of the present invention, Figure 2 is a diagram for explaining the principle of the method of the present invention.
The figure is a main part configuration diagram showing an embodiment of the ultrasonic diagnostic apparatus according to the present invention, FIG. 3 is a configuration diagram of the focus data readout circuit part, and FIGS. 4 and 5 are for explaining the conventional system. FIG. 6 is a schematic diagram illustrating the grid pattern. 1... Drive element 10... Probe 11.
...Transmission focus circuit 12...Transmission/reception switching circuit 13.
・・Cross point switch circuit 14 ・・Delay line 15 ・・Control circuit 21 ・・Counter 22 ・・Exclusive OR circuit 23 ・・Memory

Claims (1)

[Claims] In an ultrasonic diagnostic system that creates a main sound ray and sub-sound rays by changing the focus of the transmitting and receiving beams for transmission and reception without changing the drive element, the main sound ray When creating the tonic and sub-tone lines, one of the focal points should both be located on the central axis of the drive element, and the tonic and sub-tone lines should be symmetrical about this central axis, so that a grid pattern is created on the image. An ultrasonic diagnostic apparatus characterized by being configured to prevent such occurrence.