JPH0542144A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To collect three-dimensional information by a simple constitution and at a low cost in a short time by arranging transmitting electrodes and receiving electrodes on one face and the other face opposed to each other, respectively of a transducer so that they are roughly orthogonal to each other. CONSTITUTION:On the surface 21a side and the reverse side 21b of a plate-like transducer 21, strip-like transmitting electrodes 22-1-22-4 of an array shape, and receiving electrodes 23-1-23-4 are attached, respectively. In this case, the transmitting electrodes 22-1-22-4 are arranged in the horizontal direction by aligning the longitudinal direction with the vertical direction, and the receiving electrodes 23-1-23-4 are arranged in the vertical direction by aligning the longitudinal direction with the horizontal direction, that is, so as to be orthogonal to the transmitting electrodes 22-1-22-4. Subsequently, the transmitting electrodes 22 and the receiving electrodes 23 are connected to transmitting circuits 27-1-27-4 and receiving circuits 28-1-28-4 through signal lines 26a, 26b, respectively. In such a way, three-dimensional information can be obtained by a small number of electrodes and the number of transmitting/receiving channels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe used for ultrasonic diagnosis in various fields, which is constituted by arranging a plurality of electro-acoustic conversion elements (piezoelectric elements, transducers). In particular, the present invention relates to an ultrasonic probe capable of acquiring three-dimensional data.

[0002]

2. Description of the Related Art An ultrasonic diagnostic method for radiating an ultrasonic pulse into a living body and obtaining biological information by a reflected wave from each tissue is known as an X-ray diagnostic method.
It has an advantage that there is no irradiation obstacle such as a line and the soft tissue can be diagnosed without a contrast agent. Then, the ultrasonic diagnostic method in recent years has come to see a dramatic spread particularly by the practical application of an electronic scanning type diagnostic apparatus.

The ultrasonic probe used in this electronic scanning type ultrasonic diagnostic apparatus is generally of an array type in which a plurality of transducers are arranged one-dimensionally in an ultrasonic probe. By giving a predetermined delay time to a drive signal and a received signal applied to a transducer, an ultrasonic beam is deflected or focused at a desired position to improve lateral resolution, and a tomographic image with excellent resolution is obtained.

FIG. 6 is a block diagram of a sector electronic scanning type ultrasonic diagnostic apparatus provided with such an ultrasonic probe.

Reference signal generator 1 mounted on the apparatus main body side
Is connected to N transmission delay circuits 2-1 to 2-N via the bus B, and each transmission delay circuit is also a pulser (transmission circuit) 3-.
Connect with 1 to 3-N. Then, each pulser is connected to each of N transducers 4-1 to 4-N arranged in a one-dimensional manner, which constitutes an ultrasonic probe in the probe.

The transducers 4-1 to 4-N are further connected to the preamplifiers 5-1 to 5-N on the apparatus main body side. Each preamplifier is connected to the receiving delay circuits 6-1 to 6-N, and each receiving circuit is connected to the adder 7. The logarithmic amplifier 8, the detection circuit 9, and the A / D converter 1 are sequentially output from the adder 7.
0, the image memory 11 and the CRT 12 are connected.

In the sector electronic scanning, first, when transmitting ultrasonic waves, the reference signal generator 1 determines the intervals of the ultrasonic pulses radiated into the living body, and the intervals are repeated under the determined pulse intervals. Delay circuit for pulse transmission 2-1 to 2-
Sent to N. Then, each of the transmission delay circuits 2-1 to 2-N is given a predetermined delay time determined by the radiation direction of the transmitted ultrasonic waves and the focusing point accompanying the sector scan. Focusing the ultrasonic beam is to increase the resolution of the ultrasonic image.

The repetitive pulse provided with the delay time is then sent to the pulsers 3-1 to 3-N to form a drive pulse. Then, the N pulses of transducers 4-1 to 4-N are driven by this drive pulse, and ultrasonic waves are radiated into the living body.

On the other hand, the reflected wave of the ultrasonic wave from each tissue of the living body is similarly received by the N transducers 4-1 to 4-N, converted into the received signal, and then the preamplifier on the apparatus main body side.
Enter in 5-1 to 5-N. The received signal is amplified by each preamplifier and then input to the receiving delay circuits 6-1 to 6-N.

The received signal is sent to the adder 7 after each receiving circuit is given a delay time substantially similar to that at the time of transmission, and all the received signals are added. By the way, the output signal of the adder 7 is actually divided into a tomographic image display processing circuit including the block described above and a blood flow information calculation processing circuit. Only the signal processing in the above will be described.

The output signal of the adder 7 is the logarithmic amplifier 8 first.
After the signal amplitude is amplified by logarithmic conversion at, the detection circuit 9
Envelope detection is performed at. After that, after A / D conversion is performed by the A / D converter 10, it is once input to the image memory 11. Then, necessary data is sent to the CRT 12 and an ultrasonic tomographic image is displayed.

[0012]

By the way, what is necessary for medical diagnosis is three-dimensional information in the body, but the images obtained by the ultrasonic diagnostic apparatuses that have been put into practical use are displayed only on the cross section of the living body ( It is only two-dimensional information). Therefore, the examiner (doctor, examiner) obtains a plurality of ultrasonic images, and builds a three-dimensional structure of the living body in the brain based on the obtained ultrasonic images.

However, it takes time to obtain a plurality of two-dimensional images, and some experience must be gained to construct a three-dimensional image in the brain. Furthermore, in the two-dimensional display, even if there is a subtle change in the shape of an organ due to a disease, there is a risk of overlooking.

Under such circumstances, it is expected that a diagnostic device that can directly obtain a three-dimensional ultrasonic image will be put into practical use. As a technique to meet the needs, (1)
A mechanical three-dimensional scanning method, (2) a method of rotating a one-dimensional array or moving it in a direction orthogonal thereto, and (3) an electronic scanning method using a two-dimensional array have been proposed, and they are already at the stage of research and development.

However, in the mechanical scanning of (1) and (2), the ultrasonic probe is large and heavy, and there is a difficulty in operability. Further, since parallel simultaneous reception in a plurality of directions is impossible, it takes a lot of time to collect three-dimensional information, and there is a drawback that a three-dimensional image cannot be displayed in real time.

On the other hand, in the two-dimensional array (3), the number of transducers increases and the signal lines have to be drawn out at extremely narrow intervals, making it difficult to manufacture an ultrasonic probe. Moreover, the same number of transmitting / receiving circuits as the number of transducers are required, which lowers cost performance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ultrasonic probe capable of collecting three-dimensional information in a short time with a simple structure and good cost performance. ..

[0018]

In order to solve the above-mentioned problems, the present invention connects a transducer and an ultrasonic transmitting circuit and an ultrasonic receiving circuit, respectively, via signal lines, and connects them to opposite surfaces of the transducer. An ultrasonic probe is provided that includes a plurality of strip-shaped transmission electrodes and reception electrodes that are respectively arranged, and these transmission electrodes and reception electrodes are arranged so as to be substantially orthogonal to each other.

[0019]

The ultrasonic probe of the present invention uses two opposite surfaces of a transducer to install electrodes, one surface for transmitting electrodes and the other surface for receiving electrodes. Are arranged so as to be substantially orthogonal to each other. Therefore,
In this ultrasonic probe, the transmitted ultrasonic beam and the received ultrasonic beam are substantially orthogonal to each other according to the arrangement of the electrodes, and even with a small number of electrodes, three-dimensional information can be acquired in the directions in which the two coincide.

According to the present invention, the signal line connecting each electrode to the transmitting circuit and the receiving circuit can be installed at the same interval as the conventional one-dimensional array ultrasonic probe on the two surfaces on which the electrodes are arranged, and the transmitting / receiving The number of channels can be reduced according to the number of electrodes.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view of an ultrasonic probe 20 according to the first embodiment of the present invention. The plate-shaped transducer 21 has a front surface 21a side (living body side or a medium side to be imaged) and a back surface 21b side (opposite the living body).
In addition, four strip-shaped transmission electrodes 22-1 to 22-
Four pieces of 22-4 and four pieces of receiving electrodes 23-1 to 23-4 are attached. Here, the four transmitting electrodes 22-1 to 22-4 are arranged in the horizontal direction with the longitudinal direction aligned with the vertical direction, and the four receiving electrodes 23-1 to 23-4 are aligned in the longitudinal direction. Vertically according to
That is, they are arranged orthogonally to the transmission electrodes 22-1 to 22-4.

On the opposite side of the transducers 21 to 22-4 and the receiving electrodes 23-1 to 23-4 from the transducer 21, a matching layer 24 for matching the acoustic impedances of the living body and the transducer, and A backing material 25 that absorbs unnecessary ultrasonic waves emitted in the direction opposite to the living body is attached. Further, from the transmission electrodes 22-1 to 22-4 and the reception electrodes 23-1 to 23-4, the signal lines 26a and 26b are respectively connected.
Are drawn out, and each signal line 26a is connected to the transmission circuit (pulsar) 27.
-1 to 27-4, the signal line 26b is the receiving circuit (preamplifier) 28
-1 to 28-4.

In this embodiment, the transducer is not separated, but only the electrodes are separated. At this time, a groove is cut in a portion between the electrodes of the transducer, or a composite piezoelectric body already put into practical use as a transducer is used. If used, it is possible to suppress cross talk due to acoustic coupling between adjacent signals.

On the other hand, FIG. 2 shows an ultrasonic probe 2 of this embodiment.
FIG. 3 is a block diagram of a three-dimensional imaging device that uses 0 for electronic sector scanning.

Reference signal generator 3 mounted on the apparatus main body side
Reference numeral 1 denotes four transmission delay circuits 32-1 to 32-4 via the bus B.
Connected with, each transmission delay circuit is also a pulsar (transmission circuit)
Connect with 27-1 to 27-4. Each pulser has four transducers (that is, four transmitting electrodes 22-1 to 22-) which are one-dimensionally arranged in the probe and constitute an ultrasonic probe.
4) Connect with each.

The four transducers (that is, the four receiving electrodes 23-1 to 23-4) are further connected to the preamplifiers 28-1 to 28-4 on the apparatus main body side. Each preamplifier is connected to the receiving delay circuits 39-1 to 39-4, and each receiving circuit is connected to the adder 40. Then, the logarithmic amplifier 41, the detection circuit 42, the A / D converter 43, the image memory 44, and the TV monitor 45 are sequentially connected from the adder 40.

In the sector electronic scanning, the reference signal generator 31 first determines the interval of the ultrasonic pulse radiated in the living body (or the medium in general) when transmitting the ultrasonic wave, and the determination is made. Repeated pulses are sent to the delay circuits for transmission 32-1 to 32-4 under the pulse interval. Then, each of the transmission delay circuits 32-1 to 32-4 is given a predetermined delay time determined by the emission direction of the transmitted ultrasonic waves and the focal point accompanying the sector scan. Focusing the ultrasonic beam is
This is to increase the resolution of the ultrasonic image.

The repetitive pulse provided with the delay time is then sent to the pulsers 27-1 to 27-4 to form a drive pulse. Then, four transducers are driven by this drive pulse, and ultrasonic waves are radiated into the living body.

On the other hand, the reflected wave of the ultrasonic wave from each tissue of the living body is similarly received by the four transducers, passes through the transducers, and the receiving electrodes 23-1 to 23-3 on the side opposite to the living body.
After being converted into a reception signal by 23-4, it is input to the preamplifiers 28-1 to 28-4 on the apparatus main body side. Then, the reception signal is amplified by each preamplifier and then input to the reception delay circuits 39-1 to 39-4.

The received signals are given a delay time in each receiving circuit similar to that at the time of transmission, and then sent to the adder 40 to add all the received signals. The output signal of the adder 40 is first subjected to signal compression by the logarithmic amplifier 41 and then subjected to envelope detection by the detection circuit 42. After that, A / D converter 4
After A / D conversion is performed in 3, the image is temporarily input to the image memory 44. Then, necessary data is sent to the TV monitor 45 and an ultrasonic tomographic image is displayed.

In this case, as shown in FIG. 3, the transmitted ultrasonic beam 50 traveling in the z direction can be deflected and focused in the x direction, but has no strong directivity in the y direction. Especially in the vicinity of the transducer 21, the transducer 2
The beam width is almost equal to the element width of 1.

On the other hand, the reception ultrasonic beam 51 obtained from the z direction can be deflected and focused in the y direction contrary to the transmission ultrasonic beam 50, but has a strong directivity in the x direction. do not do. In the vicinity of the transducer 21, the beam width is almost equal to the element width of the transducer 21.

Therefore, the reflection information in the medium obtained by the transmission / reception ultrasonic beam 52 is obtained from the direction in which the transmission ultrasonic beam 50 and the reception ultrasonic beam 51 intersect, and becomes three-dimensional information. The intersecting direction is determined by the x-direction beam deflection angle of the transmission beam and the y-direction beam deflection angle of the reception beam, and can be any direction.

As described above, according to the present embodiment, by adopting the crossed electrode type ultrasonic probe in which the transmission electrode and the reception electrode are arranged to cross each other on the front and back sides of the transducer, With such a configuration, three-dimensional scanning becomes possible. That is, since this ultrasonic probe only needs to have N-channel (four channels in this embodiment) transmitting circuits and receiving circuits (that is, the total number of channels is N + N), the two-dimensional array ultrasonic probe has been used so far. N as thought by the child
No need for × N transducers, electrodes and signal lines, it is almost the same as a conventional ultrasonic (two-dimensional) tomography device, and an ultrasonic three-dimensional device with excellent cost performance can be realized. In this case, the distance between the signal lines can be made the same as in the conventional one-dimensional array ultrasonic probe.

FIG. 4 is a block diagram of another three-dimensional imaging apparatus 50 that performs electronic sector scanning using the ultrasonic probe 20 described above. The transmission system is the same as that in the first embodiment, and is therefore omitted. The parts corresponding to those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

The reflected wave from the medium is captured by the transducer and then converted into an electric signal (received signal) by the four receiving electrodes 23-1 to 23-4 to be preamplifiers 28-1 to 28-4. Sent to. The received signal is subsequently digitized by the A / D converters 43-1 to 43-4 connected to the respective preamplifiers and then temporarily stored in the storage circuits 51-1 to 51-2.

Then, the four reception signals applied to the reception ultrasonic beam are combined (added) with a delay time so as to be deflected by a phasing adder 52 at a predetermined deflection angle in the y direction. In this embodiment, the received signal input to the phasing adder 52 is already digitized,
If the phasing adder 52 has, for example, m channels, it is possible to simultaneously receive signals in m directions (this is called “parallel simultaneous reception”).

Therefore, in the case where a three-dimensional image is formed by scanning n scans in the x direction and m scans in the y direction, the phasing adder 52 is provided for m channels to perform parallel signal processing. If so, the three-dimensional scanning will be completed by transmitting ultrasonic waves n times in the X direction. This number of transmissions has been considered in the conventional three-dimensional scanning, (n transmissions in the x direction) ×
This is a significant decrease compared to (m transmissions in the y direction), which is almost the same as the number of transmissions in the conventional two-dimensional tomography.

Therefore, in this embodiment, the output of the phasing adder 52 is once stored in the image memory 44, and then the necessary data is image-processed by the image processing circuit 53 according to a predetermined format, and the TV monitor is displayed. Although a three-dimensional image is displayed on 45, the system configuration of the three-dimensional imaging device 50 enables three-dimensional information to be displayed in real time.

From the viewpoint of hardware such as power consumption and device size, when it is difficult to perform parallel signal processing by installing the phasing adder in m channels for scanning in the y direction, reduce the number of channels and store. The output from the circuit may be sequentially phased and added for that channel.

FIG. 5 is a perspective view of an ultrasonic probe 60 according to the second embodiment of the present invention. In the curved plate-shaped transducer 61 convex in the x direction, five transmitting electrodes 62-1 to 62-5 are provided on the front surface 61a side, and four receiving electrodes 63-1 to 63- are provided on the rear surface 61b side. 4 is attached. 5 transmitter electrodes 62
-1 to 62-5 are arranged in the horizontal direction with the longitudinal direction aligned with the vertical direction, and the four reception electrodes 63-1 to 63-4 are arranged in the vertical direction with the longitudinal direction aligned with the horizontal direction. Then, the transmitting electrode 62-1
To 62-5 and the receiving electrodes 63-1 to 63-4, signal lines 64a and 64b are respectively drawn out. Connect to 66-1 to 66-4.

As shown in FIG. 3, in the planar transducer, x in the vicinity of the transducer
The beam width in the direction or the y direction is equal to the element width of the transducer, which also determines its three-dimensional display width in the x or y direction.

However, in this embodiment, since the transducer is convex in the x direction, the beam width in the x direction becomes wider than the element width of the transducer, and more three-dimensional information can be acquired. By making the transducer convex also in the y direction, the beam width in the y direction also becomes wider than the element width of the transducer, and more three-dimensional information can be collected.

Although the above embodiment has described the collection of three-dimensional information by sector electronic scanning, the ultrasonic probe of the present invention employs a linear scanning method, a convex scanning method, or a scanning method combining these methods (for example, transmission). It is also possible to perform convex scanning at the time, sector scanning at the time of reception, etc.).

The ultrasonic probe of the present invention can be used not only for medical diagnosis but also for ocean development, nondestructive inspection and the like.

[0047]

As described above, the ultrasonic probe of the present invention can acquire three-dimensional information with a simple structure having a small number of electrodes and channels for transmission and reception, and with good cost performance. Further, since it is electronic scanning, parallel simultaneous reception is possible and real-time three-dimensional display is also possible.

[Brief description of drawings]

FIG. 1 is a perspective view of an ultrasonic probe according to a first embodiment of the present invention.

FIG. 2 is an electronic sector scanning type 3 using the ultrasonic probe.
FIG. 3 is a block diagram of a three-dimensional imaging apparatus.

FIG. 3 is a schematic diagram of a transmission / reception ultrasonic beam by the ultrasonic probe.

FIG. 4 is a block diagram of another electronic sector scanning type three-dimensional imaging apparatus using the ultrasonic probe.

FIG. 5 is a perspective view of an ultrasonic probe according to a second embodiment of the present invention.

FIG. 6 is a block diagram of a sector electronic scanning ultrasonic diagnostic apparatus including a conventional ultrasonic probe.

[Explanation of symbols]

 21 Transducer 22-1 to 22-4 Transmitting electrode 23-1 to 23-4 Receiving electrode 24 Matching layer 25 Backing material 26a, 26b Signal line

Claims (1)

[Claims] 1. A transducer, a plurality of strip-shaped transmission electrodes and a plurality of strip-shaped transmission electrodes, which are connected to an ultrasonic transmission circuit and an ultrasonic reception circuit, respectively, through signal lines, and are arranged on opposite surfaces of the transducer, respectively. An ultrasonic probe including electrodes, and the transmitting electrodes and the receiving electrodes are arranged so as to be substantially orthogonal to each other.