JPS6223829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a linear electronic scanning type ultrasonic imaging device.

BACKGROUND ART Conventionally, in an ultrasonic imaging apparatus, the following method has usually been adopted when attempting to obtain a high-resolution, high-quality image. That is, two types of transducer groups are formed, each consisting of M and M-1 transducers among a plurality of linearly arranged transducers (ultrasonic probes) capable of performing linear electronic scanning. , these transducer groups are sequentially scanned by shifting one pitch (interval between transducers), and when the echo reception signals obtained from both groups are displayed on a display device, the signals of both groups are interlaced, that is, between the scanning lines of each other. A tomographic image display method is used in which the number of scanning lines is increased and displayed through interpolation. According to this method, a high-resolution, high-quality image of 1/2 pitch scanning can be obtained in which one frame is composed of two fields scanned by M transducer groups and M-1 transducer groups. . Furthermore, it can be seen that when even higher resolution and quality are desired, finer interpolation scanning can be performed. However, as interpolation scanning increases, the number of fields per frame increases, the frame rate decreases, screen flickering becomes noticeable, and real-time performance is impaired.

In view of these points, an object of the present invention is to provide an ultrasonic imaging device that can perform finer interpolation scanning without lowering the frame rate and obtain high-resolution, high-quality images.

The present invention will be explained in detail below using the drawings. FIG. 1 is a diagram showing the main parts of an ultrasonic imaging apparatus according to the present invention. In FIG. 1, 1 is an ultrasonic probe, 2 is a multiplexer, 3a and 3b are electronic focus circuits, 4a and 4b are memories, 5a and 5b are buffer memories, and 6 is a switch. The ultrasound probe 1 includes a plurality of linearly arranged transducers (not shown), and these transducers are driven by well-known means similar to the pulse drive of the probe of a normal ultrasound tomographic imaging device. Therefore, the M number of vibrators are driven as a set while being shifted one pitch at a time. The reflected waves from the object are received again by these transducers. The received signals are selected by a multiplexer 2 and simultaneously guided to electronic focus circuits 3a and 3b. The figure shows a connection diagram when giving the output of the multiplexer 2 to the electronic focus circuit in the case of M=8, and the electronic focus circuit 3a shows the outputs m1 to m of the relevant transducer group for pulse wave emission (transmission).
8, and the focus circuit 3b receives the output m2~ of the group that is one pitch ahead of the relevant transducer group.
m9 is given. Electronic focus circuit 3a, 3
b electrically corrects a propagation time delay caused by receiving a spherical reflected wave with a flat probe, and the corrected signals are provided to memories 4a and 4b, respectively. This memory 4a, 4
b stores video signal data for one scan, which is one transmission/reception, and updates and stores the data for each scan. This memory 4a, 4b
The outputs of the buffer memories 5a and 5b are respectively transferred to buffer memories 5a and 5b, and the outputs of the buffer memories 5a and 5b are selectively selected at appropriate timing by a switch 6 and displayed on a display device (not shown) as a tomographic image signal.
It is now being sent to

The operation of the present invention in such a configuration is as follows: M=8
The case will be explained using as an example. Among the vibrators #1 to #n arranged at intervals d as shown in FIG.
First, pulse waves are emitted (transmitted) from group 1 of #1 to #8 at the timing shown in Figure 3 B and C.
Then, the reflected waves are transmitted to group 1 and oscillators #2 to #9, which are one pitch ahead of group 1, as shown in Figure 3D.
Group 2 (hereinafter particularly referred to as group 2' in this case) consisting of the above images is received at the same time to obtain a video signal related to the tomographic image. After completing the first transmission and reception in this way, the second transmission and reception begins, and this time it is transmitted in group 2 of #2 to #9, and this group 2 and group 3, which is one pitch ahead (hereinafter, in this case, especially group 3) ’) is received at the same time.
In the next transmission/reception cycle, group 3 transmits, and group 3 and group 4 (in this case, group 4') receive simultaneously. Similarly,
The operation of transmitting one group and receiving two groups is repeated for the last group. In this case, the video signal data from the first transmission/reception is transferred to the buffer memories 5a, 5b at the end of the scan, and the switch 6 is driven during the second transmission/reception cycle to transfer the video signal data from group 1 as shown in FIG. Following the transmission of the video signal of group 2', the video signal of group 2' is transmitted. In the next transmission/reception cycle, data of groups 2 and 3' are transmitted, and thereafter two sets of data are transmitted in the same manner during one transmission/reception cycle.

Here, assuming that the transmitting and receiving sensitivity characteristics of each transducer #1 to #n are substantially the same, the received data of groups 2', 3', and 4', which are one pitch ahead of the transmitting group, are relative to the transmitting group. This is equivalent to the reflected wave reception data at a position 1/2 pitch ahead.

Therefore, the data transmitted in the order of groups 1, 2', 2, 3', 3, 4', etc. as shown in Fig.
It is equivalent to the case obtained by moving and scanning with 2 pitches. Then, the scanning line numbers of the CRT screen are A, a, B, b, C, c, etc. from the top as shown in Figure 4, and the numbers corresponding to these scanning lines are as shown in Figure 3 C. If the video signals of groups 1, 2', 2, 3', 3, 4', etc. are displayed on a CRT, a 1/2 pitch scanning tomographic image can be obtained. In this case, there are two displays per transmission/reception cycle, so two screens can be displayed in the same frame time as the conventional frame time of one display per transmission/reception cycle without reducing the frame rate.

Although the case of 1/2 pitch scanning is illustrated above, the scanning method of the present invention can also be applied to cases of other divided pitch scanning. Fifth
The figure shows a specific example of 1/4 pitch scanning. That is, in the first transmission/reception cycle, the transducers #1 to #7 transmit, the two groups #1 to #7 and #1 to #8 receive simultaneously, and in the second transmission/reception cycle, the transducers #1 to #8 transmit. Send and #1~
It is received in two groups: #8 and #2 to #8. By sequentially scanning by shifting one pitch at a time in this mode, a 1/4 pitch scanning video signal can be obtained. In this case, if two displays are performed per one transmission/reception cycle, the frame time will be doubled compared to the case of 1/2 pitch scanning described above.

As explained above, according to the ultrasonic imaging device of the present invention, by transmitting with one transducer group and receiving simultaneously with two transducer groups,
It is possible to equivalently receive reflected waves at desired intervals such as pitch or 1/4 pitch, and moreover, it is possible to send out and scan and display two sets of video signals during one transmission/reception cycle. 1 hit
It is possible to obtain a high-resolution, high-quality tomographic image display with a high scanning line density at the same frame rate as the scanning display.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main parts of the ultrasonic imaging device of the present invention, FIG. 2 is a diagram for explaining a transducer group, FIG. 3 is a time chart, and FIG. 4 is a diagram showing scanning lines of a CRT. FIG. 5 is a diagram for explaining another transducer scanning method. 1... Ultrasonic probe, 2... Multiplexer,
3a, 3b...electronic focus circuit, 4a, 4b
...Memory, 5a, 5b...Buffer memory, 6
...Switch.

Claims (1)

[Claims] 1. Linear electronic scanning of a transducer group consisting of a plurality of adjacent transducers among a plurality of linearly arranged transducers, and reflected waves obtained from this transducer group. In an ultrasonic imaging device that obtains a video signal based on the signal and displays it on a display device to display a tomographic image of the object, there is a multiplexer for selecting a target transducer group, and a transducer selected by the multiplexer. Two sets of electronic focus circuits extract two sets of reflected wave signals from different transducer groups, including overlapping parts, from among the outputs of the groups, and perform electronic focusing on each set. It is equipped with two sets of storage means that are updated and stored in each transmission/reception cycle, and a switch that selectively selects and outputs the outputs of the two sets of storage means during one transmission/reception cycle, and upon reception, the outputs are sent via the multiplexer. Reflected wave signals from M (M is an integer) oscillators, which are the same as those at the time of transmission, and reflected wave signals from N (N is an integer) oscillators, including oscillators that overlap with these M oscillators. are simultaneously stored in the two sets of storage means via the two sets of electronic focus circuits, and a reflected wave signal with a scanning pitch finer than the pitch of the vibrator can be obtained from the switch. Sonic imaging device. 2. The ultrasonic imaging apparatus according to claim 1, wherein the M and N transducer groups are groups of the same number of transducers separated by one transducer. 3. The M number can be m (m is an integer) or m+1, and in the first transmission/reception cycle, the M number is set to m at the time of transmission, and the number M is set to m at the time of reception. At the same time, the N number is set to m+1, and in the second transmission/reception cycle, the M number is set to the m+1, and at the time of reception, the M number is set to m+1, and the N number is set to one oscillator pitch from the m number. m advanced transducers, and in subsequent transmission/reception cycles, the first and second transmission/reception are similarly repeated sequentially in a transducer group that is one transducer pitch advanced from the transducer group. The ultrasonic imaging device according to item 1.