close

Вход

Забыли?

вход по аккаунту

JPH0937377

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH0937377
[0001]
The present invention relates to an array type ultrasonic probe having an acoustic lens
(hereinafter referred to as an array type probe) as a technical field, and in particular, to suppress
unnecessary ultrasonic waves from the outer periphery of the acoustic lens. Array probe with a
reduced beam width.
[0002]
BACKGROUND OF THE INVENTION Arrayed probes are useful, for example, in medical diagnostic
ultrasound systems as ultrasound transducers. For example, strip-shaped small width
piezoelectric elements are arranged in the width direction (long axis direction), and linear or
sector drive is performed in the same direction. In such a device, in general, an acoustic lens is
provided in the longitudinal direction (short axis direction) of the piezoelectric element to
increase the resolution in the same direction.
[0003]
2. Description of the Related Art FIG. 8 is a diagram of an array-type probe for explaining a
conventional example of this kind, in which (a) is a schematic front sectional view, (b) is a side
sectional view, and (b) c) is an illustration of an acoustic lens. The arrayed probe is formed by
arranging strip-shaped piezoelectric elements 2 made of PZT (lead zirconate titanate) or the like
03-05-2019
1
on the backing material 1 in the long axis direction. Electrodes are provided on both main
surfaces, and a filler is embedded between the grooves (not shown). Then, on the front surface of
the piezoelectric element 2, a two-layer acoustic matching layer 3 (ab) is provided to measure the
matching of the acoustic impedance with the detection target (such as a living body) and to
improve the ultrasonic wave propagation efficiency. Furthermore, an acoustic lens 4 is provided
on the acoustic matching layer 3. In the piezoelectric element group, a flexible substrate or the
like to be connected to the electrode of each piezoelectric element 2 is provided (not shown), and
the molding material 5 is applied to the outer periphery thereof. Reference numeral 6 in the
figure is a base, and 7 is a case.
[0004]
The acoustic lens 4 generally has a silicon material whose sound velocity is slower than that of
the object to be detected as a main component. The piezoelectric element 2 has a curvature
convex in the longitudinal direction. Basically, as shown in FIG. 9, it may be provided on the
acoustic matching layer 3 with a length equal to that of the piezoelectric element 2. However, in
reality, its alignment and the like are difficult, and manufacturing is difficult. Then, when there is
a positional deviation or the like, ultrasonic waves are emitted directly from the end (exposed
portion) of the piezoelectric element 2. That is, the light is emitted also in the direction different
from the direction of convergence by the acoustic lens 4 to disturb the sound field characteristic
and increase the noise component.
[0005]
Because of this, usually, the length of the acoustic lens 4 is made larger than that of the
piezoelectric element 2. Then, for example, leg portions 4b are extended from both end sides of
the acoustic lens 4 (curvature portions 4a) so as to cover the piezoelectric element group "front 8
(bc)". In this way, even if there is a positional deviation, the ultrasonic waves from the
piezoelectric element 2 will surely pass through the acoustic lens, and will converge in a certain
direction. Therefore, the sound field characteristics can be improved. The acoustic lens 4 is
convex when the sound velocity is slower than that of the detection target, and concave when it
is faster. Further, the leg 4 b prevents the acoustic lens 4 from being separated from the
piezoelectric element group.
[0006]
03-05-2019
2
However, recently, with the increase in accuracy of diagnostic devices etc., ultrasonic waves
emitted from both end sides of the acoustic lens 4 broaden the beam width and adversely affect
the resolution etc. It has been found. That is, in the above configuration, as described above, the
acoustic lens 4 is set larger than the length of the piezoelectric element 2. Therefore, it has been
found that the ultrasonic wave from the piezoelectric element 2 propagates in the acoustic lens 4
or in the molding material 5 and leaks from the outer periphery of the acoustic lens 4 so that the
beam width is broadened.
[0007]
An object of the present invention is to provide an ultrasonic probe which eliminates
unnecessary ultrasonic waves from both end sides of an acoustic lens and reduces the beam
width to obtain a good image.
[0008]
In the present invention, it is a basic solution that both end sides of an acoustic lens are end
faces.
Hereinafter, examples of the present invention will be described with reference to experimental
results and the like.
[0009]
[First Embodiment] FIG. 1 is a side sectional view of an ultrasonic probe for explaining an
embodiment of the present invention. The same reference numerals are given to the same parts
as in the prior art example and the description will be simplified. In the array type probe, as
described above, the piezoelectric element 2 is arranged in the long axis direction on the backing
material 1 to provide the two acoustic matching layers 3 (ab), and the molding material 5 is
applied to the outer periphery, The acoustic lens 4 which the leg part 4b extended from the both
end side of 4a is provided in the short axis direction.
[0010]
03-05-2019
3
In this embodiment, the acoustic lens 4 has notches 8 at both ends of the curvature portion 4a.
The notch portion 8 cuts out both end sides of the curvature portion 4 a in an L shape to form a
step. That is, on both end sides of the curvature portion 4a, end faces substantially coinciding
with the transmission / reception direction of the ultrasonic wave (the direction perpendicular to
the piezoelectric element 2) are provided. The acoustic lens 4 (full length) before the ablation is
15 mm, and the curvature portion (after the ablation) 4a has the same center of the piezoelectric
element 2 and both are 11 mm.
[0011]
Fig. 2 (ab) is a sound field characteristic diagram compared with the conventional example of the
ultrasonic probe having such a configuration, and Fig. 2 (a) is the present embodiment, and Fig. 2
(b) is the conventional example. . However, the sound field characteristics are the reception level
characteristics at 40 mm in front of the ultrasonic probe, the vertical axis is the reception level
(dB) at which the central part of the ultrasonic probe is 0 dB, and the horizontal axis is It is the
distance (mm) from the center where the center is 0.
[0012]
As apparent from this figure, in the present embodiment, the distance width (ie, the beam width)
at each attenuation range of 3, 6, 12, 24 dB from the center of the ultrasonic probe is about 2, 4,
8, It will be 19 mm. On the other hand, in the prior art, the beam width in each attenuation
region is about 4, 7, 10, and 30 mm. As described above, according to this embodiment, the
beam width is narrower in any attenuation region as compared with the conventional example.
And it will become a sharp characteristic also in the whole.
[0013]
As described above, in the present embodiment, since the notches 8 are provided on both ends of
the curvature portion 4a of the acoustic lens 4 to form end faces, unnecessary ultrasonic waves
from the outer peripheral portion are eliminated, and the beam width is narrowed to sharpen
Ultrasonic waves could be obtained. That is, since the both end parts of the curvature part 4a
were made into the end surface, it is guessed that propagation of the ultrasonic wave was
interrupted ¦ blocked.
03-05-2019
4
[0014]
[Second Embodiment] FIG. 3 is a view of an ultrasonic probe for explaining another embodiment
of the present invention. The same parts as those in the previous embodiment are given the same
reference numerals and the explanation thereof is omitted. In this embodiment, the notch 8 of
the acoustic lens 4 is a V-shaped groove. The sound field characteristic similar to that described
above for such a device is shown in FIG. That is, the respective beam widths in the respective
attenuation ranges of 3, 6, 12, and 24 dB are approximately 2, 4, 8, and 15 mm. As described
above, even when the notches 8 are V-shaped grooves and the end faces are provided on both
ends of the curved portion 4a, the beam width in each attenuation region is reduced, and sharp
characteristics can be obtained.
[0015]
[Other Matters] In the above embodiment, the end face is formed by the L-shaped cut-out or Vshaped notch 8. However, the present invention is not limited to this and may be a simple cut. . In
addition, although the curvature portion 4a (remaining portion) of the acoustic lens has been
described as being equal to the length of the piezoelectric element 2, the same effect can be
obtained even if there is an error of about ± 1 mm with respect to the piezoelectric element 2.
be able to. Further, as shown in FIG. 5, the depth t of the notches 8 provided on both ends of the
curvature portion 4a may be designed to be reduced. In this case, the propagation loss is
prevented as the thickness becomes smaller compared to the above embodiment. Also, although
the acoustic lens 4 extends the leg 4b from the curvature portion 4a, it may be only the
curvature portion (FIG. 6). In the first embodiment, the tip of the case 7 may be fitted into the
notch 8. As described above, the present invention can be variously modified, and in short, if the
both end sides of the curvature portion 4a of the acoustic lens 4 have end faces by the notch
portion 8 or the like so as to block the propagation of ultrasonic waves. Good.
[0016]
According to the present invention, since both end sides of the curvature portion in the acoustic
lens are end faces, unnecessary ultrasonic waves from both ends of the acoustic lens are
eliminated, and the beam width is reduced to obtain a good image. An acoustic probe can be
provided.
03-05-2019
5
[0017]
Brief description of the drawings
[0018]
1 is a diagram for explaining an embodiment of the present invention, FIG. 1 (a) is a side
sectional view of an ultrasonic probe, FIG. 1 (b) is a diagram of an acoustic lens.
[0019]
2 is a diagram for explaining the effect of an embodiment of the present invention, the figure (a)
is an example of the embodiment, the figure (b) is a sound field characteristic diagram of the
conventional example.
[0020]
3 is a cross-sectional view of an ultrasound probe for explaining another embodiment of the
present invention.
[0021]
4 is a sound field characteristic diagram for explaining the effect of another embodiment of the
present invention.
[0022]
5 is a cross-sectional view of an acoustic lens illustrating still another embodiment of the present
invention.
[0023]
6 is a diagram of an acoustic lens illustrating yet another embodiment of the present invention.
[0024]
7 is a cross-sectional view of an ultrasound probe for explaining yet another embodiment of the
present invention.
[0025]
8A and 8B are diagrams for explaining the conventional example, wherein FIG. 8A is a front
03-05-2019
6
sectional view of the ultrasonic probe, FIG. 8B is a side sectional view, and FIG. 8C is a diagram of
an acoustic lens.
[0026]
9 is a side cross-sectional view of an ultrasound probe for explaining the conventional example.
[0027]
Explanation of sign
[0028]
1 backing material, 2 piezoelectric elements, 3 acoustic matching layers, 4 acoustic lenses, 4a
curvatures, 4b legs, 5 molds, 6 bases, 7 cases, 8 notches.
03-05-2019
7
1/--страниц
Пожаловаться на содержимое документа