JPH0226544A - Ultrasonic diagnosing device - 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 [Object of the Invention] (Industrial Application Field) The present invention relates to ultrasonic diagnosis that uses ultrasound to obtain diagnostic information such as B-mode information and Doppler mode information and displays this information. Regarding equipment.

(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. Diagnosis is performed using functional information associated with the movement of moving objects within the living body.

Further, typical methods for scanning inside a living body using ultrasound waves include 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 made up of a plurality of ultrasonic transducers arranged in parallel, a plurality of ultrasonic transducers is considered to be one unit, and this one unit is This is a method of transmitting an ultrasonic beam by exciting an ultrasonic transducer. For example, the pitch is sequentially shifted by one transducer and the position of each unit of element is sequentially changed. This is scanning in which the transmission point position of the ultrasonic beam is electronically shifted.

Then, so that the ultrasonic beam is focused, the excited ultrasonic transducers are shifted in excitation timing between those located in the center of the beam and those located on the sides, and the ultrasonic vibrations generated by this are shifted. The reflected ultrasonic waves are focused (electronic focusing) using the phase difference between the respective generated sound waves. The reflected ultrasonic waves are then received by the same transducer used for excitation and converted into electrical signals (however, the number of transducers used for transmission and reception is not necessarily the same). The echo information generated by the waves is formed as a tomographic image, for example, and displayed on TV.
Display the image on a monitor, etc.

In addition, in the case of sector electronic scanning, as shown in Fig. 4,
One unit of excited ultrasonic transducer group (ultrasonic probe 1
), the excitation timing of each transducer is changed according to the desired direction so that the transmission direction of the ultrasonic beam changes sequentially in a fan shape every one pulse of the ultrasonic beam, as shown in Fig. 4. As shown, one frame is formed by ultrasonic rasters #1 to #N. 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, transducer (
There is also mechanical scanning in which ultrasonic scanning is performed by attaching a probe (probe) to a scanning mechanism and moving the scanning mechanism.

On the other hand, in the imaging method, in addition to a B-mode image in which signals accompanying ultrasound transmission and reception are combined to form a tomographic image, an M-mode image based on fixed scanning in the same direction is typical. 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 moving 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 moving object at the position where the echo was obtained. You can obtain exercise information. According to this, it is possible to know the state of blood flow, such as the direction of the flow of blood, the state of the flow (disturbed or regular), the flow pattern, the velocity value, etc., at a certain position in the living body.

Next, the device will be explained. That is, in Doppler mode, in order to obtain blood flow information from ultrasound echoes, ultrasound pulses are repeatedly transmitted in a given direction a given number of times.
Phase information is extracted by phase detection of the received echo. 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.

As a result, the analyzed frequency is a Doppler shift frequency caused by the movement of a moving object, and can be used alone or in a B-mode image or M-mode image as blood flow information such as a CFM image that shows the direction and velocity of blood flow. Display in superimposed manner.

On the other hand, in B-mode and Doppler mode scans,
Single-stage transmit focus, -stage receive focus, and multi-stage transmit focus to improve resolution.

Multi-stage reception focusing is performed. That is,
Transmission or reception focus is realized by controlling the aperture of the vibrator and controlling the amount of delay.

Therefore, when forming a B-mode image as a two-dimensional ultrasonic image, one ultrasonic raster can be obtained by transmitting and receiving ultrasonic waves once if the focus is 1 step, and n times if the focus is 9 steps. One ultrasonic raster can be obtained by transmitting and receiving ultrasonic waves. Also, as a two-dimensional ultrasound image, C
When forming an FM image, if the focus is 1 stage, one ultrasonic wave can be obtained by transmitting and receiving p ultrasound waves (p is about 10), and if the focus is 0 stages, the rlX
One ultrasonic raster can be obtained by transmitting and receiving p ultrasonic waves.

(Problem to be Solved by the Invention) As described above, in the conventional technology, the number of ultrasonic transmissions and receptions to obtain one ultrasonic raster is p times the number of times for a B-mode image in the case of a CFM image. shall be. Therefore, under a constant ultrasound rate, the number of frames of a CFM image decreases, which causes problems such as not being displayed smoothly, especially when diagnosing a moving object such as the heart.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ultrasonic diagnostic apparatus suitable for diagnosing moving objects.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a structure in which the following means are taken to solve the above problems and achieve the objects.

That is, the present invention provides an ultrasonic diagnostic apparatus that transmits an ultrasonic beam for each ultrasonic rate pulse and generates an ultrasonic image from received echoes thereof. A second reception delay circuit is provided, and for each ultrasonic rate pulse, after transmitting the first ultrasonic beam, the second ultrasonic beam is transmitted in a direction shifted by a predetermined angle from the first ultrasonic beam. During reception, a first reception echo corresponding to the first ultrasound beam is received by the first reception delay circuit, and a second reception echo is received by the first reception delay circuit.
A second received echo corresponding to the ultrasound beam of
It is characterized in that two ultrasonic rasters are obtained with one ultrasonic rate pulse.

(Function) According to such a configuration, two ultrasonic rasters can be obtained with one ultrasonic rate pulse, and the number of frames can be increased. Therefore, under the same ultrasonic rate, CF
The number of frames of the M image can be increased, which is particularly suitable for diagnosing moving objects such as the heart, as smooth display can be achieved.

(Embodiment) An embodiment of the ultrasonic diagnostic apparatus according to the present invention will be described below with reference to the drawings.

Fig. 1 is a block diagram of the ultrasonic diagnostic apparatus of this embodiment, Fig. 2
The figure shows the form of an ultrasonic beam for each ultrasonic rate in this embodiment, and FIG. 2 is a diagram showing the form of an ultrasonic beam in one frame of ultrasonic raster in this embodiment.

As shown in FIG. 1, for example, an ultrasonic probe 1 for sector scanning, which is made up of a large number of micro transducers arranged side by side, is applied to the body surface of a subject (not shown), and is driven to transmit by a balsa 2. The number of balsers 2 is equal to the number of vibrators, and these are driven by a transmission delay circuit 3. That is, the application timing of the excitation pulse in the balsa 2 is shifted for each transducer by the transmission delay circuit 3 according to the swing angle, focus depth, etc. of the transmitted ultrasound beam.

The preamplifier 4 amplifies the received echo signal due to the reflected ultrasound received by each transducer of the ultrasound probe 10, and this amplified echo is transmitted to the first reception delay circuit 5A or the second reception delay circuit 5A.
The received signal is taken into the reception delay circuit 5B, where it is delayed for each vibrator according to the swing angle, focus depth, etc., and phase adjustment is performed.

This transmission delay circuit 3, the first reception delay circuit 5A, and the second
Delay data for setting the beam swing direction is given to the reception delay circuit 5B by the first transmission/reception raster generator 6A and the first transmission/reception raster generator 6B. Then, a transmitting/receiving raster generator 6A and a first transmitting/receiving raster generator 6
B is operated by ultrasonic rate pulses given from the transmission/reception control system 7.

On the other hand, the phase-adjusted echo data output from the first reception delay circuit 5A and the second reception delay circuit 5B is processed as a B-mode image or a CFM image by the display system 8, and is displayed on the TV.
Displayed on a monitor, etc.

Here, ultrasonic beam control in this embodiment will be explained. That is, FIG. 2 shows the form of ultrasonic transmission and reception in one of the ultrasonic rate pulses, and after transmitting the first ultrasonic beam ■, a predetermined angle θ deviation from this first ultrasonic beam ■ is shown. The second ultrasonic beam ■ is transmitted in the direction of the
The first reception echo ■corresponding to the first reception delay circuit 5
A second reception echo ■ corresponding to the second ultrasonic beam ■ is received by the second reception delay circuit 5B,
Two ultrasonic rasters are obtained with one ultrasonic rate pulse.

Here, it is assumed that the second ultrasonic beam ■ is transmitted immediately after the first ultrasonic beam ■ is transmitted, and the angle θ between the first ultrasonic beam ■ and the second ultrasonic beam ■ is teeth,
The angle is set to about 45 degrees, for example, in consideration of the fact that the two beams do not interfere and the field of view angle of the sector scan is 90 degrees.

FIGS. 3(a) and 3(b) show the combination of two ultrasonic beams in this example, and FIG. 3(a) is a diagram showing the relationship between the ultrasonic rate and the ultrasonic raster. , FIG. 3(b) is a diagram showing the timing of ultrasound transmission in FIG. 3(a).

In FIG. 3, the transmitting/receiving raster generator 6A shown in FIG.
and the first transmission/reception raster generator 6B is connected to the transmission/reception control system 7.
The second
In the form of the ultrasound beam shown in the figure, as shown in Figure 3(a), the rate URI creates ultrasound rasters #1 and #n, and the rate UR2 creates ultrasound rasters #2 and #n+1. , at rate UR3, ultrasonic raster #3 and #n+2 are created, and at rate U RN/2, ultrasonic raster #3 is created.
Make n-1 and #N. To explain this with reference to FIG. 3(b), in the rate URL, the ultrasonic wave is transmitted in the direction #1, and then the ultrasonic wave is transmitted in the direction #n. This is continued until the angle is shifted little by little until the direction #n-1 is reached, and the operation is repeated again by returning to the rate URI.

As described above, according to this embodiment, two ultrasonic rasters can be obtained with one ultrasonic rate pulse, and the number of frames can be increased. Therefore, at the same ultrasound rate, the number of frames for B-mode images and CF M images can be doubled compared to conventional methods, especially when diagnosing moving objects such as the heart. , the display is smooth and suitable.

As mentioned above, in order to form one ultrasonic raster of a B-mode image as a two-dimensional ultrasonic image, one step of focus requires one ultrasound transmission/reception, and one step of focus requires one ultrasonic transmission/reception. If there is, n times of ultrasonic transmission and reception is required.

In addition, when forming one ultrasonic raster of a CFM image as an ultrasonic two-dimensional image, if one stage focus is used, p
(p is about 10) times (p is about 10), and for 0-stage focus, nXp times of ultrasound transmission and reception are required.

The present invention is not limited to the above embodiments, but can be implemented with various modifications without departing from the gist of the present invention.

[Effects of the Invention] As described above, the present invention has the following advantages. A second reception delay circuit is provided, and for each ultrasonic rate pulse, after transmitting the first ultrasonic beam, the second ultrasonic beam is transmitted in a direction shifted by a predetermined angle from the first ultrasonic beam. During reception, a first reception echo corresponding to the first ultrasound beam is received by the first reception delay circuit, and a second reception echo corresponding to the second ultrasound beam is received by the second reception delay circuit. By receiving the circuit so that two ultrasonic rasters are obtained with one ultrasonic rate pulse, two ultrasonic rasters can be obtained with one ultrasonic rate pulse,
The number of frames can be increased.

Therefore, the number of frames of CFM images can be increased under the same ultrasound rate, and especially when diagnosing moving objects such as the heart, the display is smooth and the diagnosis can be performed well. effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of an ultrasonic diagnostic apparatus according to the present invention, FIGS. 2 and 3 are diagrams showing the form of an ultrasound beam in the embodiment, and FIG. 4 is a sector scan FIG. DESCRIPTION OF SYMBOLS 1... Ultrasonic probe, 2... Pulser, 3... Transmission delay circuit, 4... Preamplifier, 5A, 5B... 1st. second reception delay circuit, 6A, 6B...first. Second
7. Transmission/reception control system; 8. Surface water system.

Claims (1)

[Claims] An ultrasonic diagnostic apparatus that transmits an ultrasonic beam for each ultrasonic rate pulse and generates an ultrasonic image based on received echoes thereof, which includes first and second reception delay circuits and transmits an ultrasonic beam for each ultrasonic rate pulse. , after transmitting the first ultrasonic beam, a second ultrasonic beam is transmitted in a direction shifted by a predetermined angle from the first ultrasonic beam, and upon reception, the first ultrasonic beam is
The first received echo corresponding to the ultrasound beam of
A second reception echo corresponding to the second ultrasonic beam is received by the second reception delay circuit, so that two ultrasonic rasters are obtained with one ultrasonic rate pulse. An ultrasonic diagnostic device characterized by: