close

Вход

Забыли?

вход по аккаунту

?

JPH07193895

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 JPH07193895
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
ultrasonic transducer used for medical or nondestructive inspection ultrasonic diagnostic
equipment.
[0002]
2. Description of the Related Art Generally, the tip of an ultrasonic probe of a mechanical drive
system is as described in "Ultrasonic microendoscope for gastrointestinal tract" (Proceedings of
the Proceedings of the Japan Ultrasonic Medical Association, November 1991, p.793). It is
configured. As shown in FIG. 7, this ultrasonic probe comprises an ultrasonic transducer 30 and
an acoustic mirror 31 for bending an ultrasonic beam constituted by an ultrasonic pulse train
oscillated from the ultrasonic transducer 30. It mounts and is comprised in the cylindrical
housing 32 which is. By applying a pulse voltage to the ultrasonic transducer 30 from an
ultrasonic oscillator (not shown), an ultrasonic pulse is oscillated from the ultrasonic transducer
30, reflected by the acoustic mirror 31, and output to the outside of the ultrasonic probe. Ru.
Then, the ultrasonic pulse reflected by the observation target is changed in direction by the
acoustic mirror 31 and enters the ultrasonic transducer 30.
[0003]
03-05-2019
1
The purpose of such a configuration is to provide an ultrasonic pulse transmission section
between the ultrasonic transducer 30 and the acoustic mirror 31 to set a time interval between
the ultrasonic beam and the object to be observed. With this time interval, it becomes possible to
receive the ultrasonic pulse reflected in the immediate vicinity of the ultrasonic probe after the
oscillation pulse applied to the ultrasonic transducer 30 has no influence on the observation
device, and observation of a close distance is possible. It will be possible.
[0004]
However, in the above configuration, first, the cross-sectional area of the ultrasonic probe
regulates the outer shape of the ultrasonic transducer 30, and secondly, the ultrasonic
transducer 30 and the acoustic mirror Since the ultrasonic beam diverges in the transmission
interval between 31 and 31, the gain of the ultrasonic probe as a whole is reduced due to the fact
that the acoustic mirror 31 can not reflect all the beams in both transmission and reception. I
will. For this reason, the ultrasonic probe of the above-mentioned structure can only perform
observation at a close distance, and the application range is very limited.
[0005]
The present invention has been made in view of such conventional problems, and provides an
ultrasonic transducer for an ultrasonic probe that is suitable for close-range observation and is
also applicable to longer-distance observation. The purpose is
[0006]
SUMMARY OF THE INVENTION In order to solve the above problems, according to the present
invention, a piezoelectric element, an acoustic matching layer formed on one side of the
piezoelectric element, and the other side of the piezoelectric element are provided. And an
ultrasonic transducer having a low acoustic impedance and low attenuation material as its basic
component, and a waveguide member provided with a member made of a high acoustic
impedance material around the member made of a low acoustic impedance material, Integrally
formed.
[0007]
The ultrasonic beam emitted from the ultrasonic transducer of the present invention having the
above-mentioned configuration is transmitted into the above-mentioned waveguide member.
03-05-2019
2
Since the ultrasonic beam is reflected by the high acoustic impedance member which is the outer
wall of the waveguide member, it is transmitted to the end of the waveguide member while being
confined within the low acoustic impedance and low attenuation region inside the waveguide
member. Then, it is oscillated to the outside of the waveguide member.
[0008]
1 and 2 show a perspective view and a longitudinal sectional view of an ultrasonic transducer
according to the present embodiment, respectively.
(Configuration) In the ultrasonic transducer 10, the acoustic matching layer 11 is integrally
formed on one surface of the piezoelectric element 1 in which the front surface electrode 2 and
the back surface electrode 3 are formed on both sides of the piezoelectric body 4 of PZT
piezoelectric ceramic. The surface of the acoustic matching layer 11 is an acoustic radiation
surface 19, and the back load member 7 is integrally formed on the other surface. The front
surface electrode 2 and the back surface electrode 3 are electrically connected to the lead wires
14 and 15, respectively, and are connected to a pulser (not shown) and an observation device
(not shown) via the lead wires 14 and 15, respectively. ing.
[0009]
The waveguide member 5 is composed of a stainless steel cylindrical reflection member 13
whose cross-sectional area is equal to or larger than the area of the piezoelectric element 1 and a
transmission member 12 made of agarten filled inside. The reflecting member 13 is fixed to the
outer peripheral portion of the ultrasonic transducer 10 via the sealing member 17 made of
silicone rubber at one end thereof, and a stainless steel circle having a bevel on the end face at
the other end. A mirror block 18 which is a columnar member is integrally fixed, and constitutes
the ultrasonic probe tip 20 as a whole. Further, the transmission member 12 is completely in
close contact with the acoustic radiation surface 19, the mirror block 18 and the inner wall of the
reflection member 13. Furthermore, the ultrasonic transducer 10 is mounted on a drive member
(not shown) such as a rotation mechanism and a linear motion mechanism. The periphery is
covered with a protective sheath (not shown) made of a polyethylene tube, and an ultrasonic
medium (not shown) is filled between the ultrasonic transducer 10 and the inner wall of the
protective sheath. .
03-05-2019
3
[0010]
(Operation) A pulse voltage is applied from the pulsar to both electrodes 2 and 3 via the lead
wires 14 and 15 to excite the piezoelectric element 1. Then, the vibration of the piezoelectric
element 1 is oscillated as an ultrasonic pulse. At this time, vibration is suppressed by the load on
the surface on which the back load member 7 is formed, and thus the oscillated ultrasonic pulse
is transmitted from the acoustic radiation surface 19 to the transmission member 12 only
through the acoustic matching layer 11. Ru. Then, the ultrasonic pulse transmitted in the
transmission member 12 is transmitted in the transmission member 12. Of the ultrasonic beam,
the energy component 8 oscillated from the vicinity of the center of the acoustic emission
surface 19 directly reaches the acoustic reflection surface 6 and is reflected there to change its
direction. It oscillates to the outside.
[0011]
The ultrasonic pulse component 9 oscillated from the edge of the acoustic emission surface 19
diffuses outward, but the transmission member 12 and the reflection member 13 provided in
close contact with the transmission member 12 It is incident on the interface. At this time, the
difference in acoustic impedance between the transmission member 12 and the reflection
member 13 is very large, and the incident angle of the ultrasonic pulse component 9 on the inner
wall of the reflection member 13 is shallow, so that the incident ultrasonic waves The pulse
component 9 is transmitted through the transmission member 12 while being totally reflected.
The transmitted ultrasonic pulse component 9 finally reaches the acoustic reflection surface 6
and is reflected to change its direction, like the component 8 oscillated from near the center, and
the outside of the ultrasonic probe tip 20 Is oscillated. By driving the ultrasonic probe tip 20 by a
drive mechanism (not shown), an ultrasonic beam consisting of an oscillated ultrasonic pulse
train is scanned along an arbitrary path. Similarly, the ultrasonic pulse reflected from the
observation target is transmitted to the piezoelectric element 1 through the waveguide member 5
along the path (energy component 8 and ultrasonic pulse 9) to vibrate it. The voltage generated
by the vibration of the piezoelectric element 1 is transmitted to the observation device via the
lead wires 14 and 15.
[0012]
03-05-2019
4
(Effect) All energy of the ultrasonic pulse oscillated from the ultrasonic transducer 10 can be
transmitted to the outside, and at the same time, all energy incident on the ultrasonic probe can
be received by the ultrasonic transducer 10, and transmission and reception sensitivity Improve.
In addition, since there is no part where there is a risk that air bubbles, foreign matter and the
like intervene before the ultrasonic beam is oscillated to the outside, high-reliability observation
can always be performed.
[0013]
Further, in the present embodiment, the case of using PZT as the piezoelectric body 4 has been
exemplified, but piezoelectric ceramics such as PT and PLZT and piezoelectric crystals such as
LiNbO can be used. Similarly, as the material of the reflection member 13, other metal materials
such as titanium, nickel and copper alloy, and ceramic materials such as alumina, machinable
ceramics and zirconia can also be used. As for the shape, in addition to the cylindrical shape as
illustrated, it is also possible to make the cross section a polygon such as an ellipse or a
quadrangle, to add a taper, to change the cross sectional shape, or the like. Also, the material of
the transmission member 12 is not limited to austenite, but in particular, the transmission
member 12 is an ultrasonic transmission medium such as water, saline, ultrasonic jelly,
ultrasonic gel, etc. It is also possible to virtually omit the transmission medium by using the same
material as the ultrasonic medium described in the above. Furthermore, the angle of the slope of
the acoustic reflection surface 6 is not limited to 45 °, and an arbitrary angle can be set
depending on the scanning direction of the ultrasonic beam. Needless to say, it is easy to omit the
slope and use only the transmission effect of the waveguide member 5.
[0014]
Embodiment 2 FIGS. 3 and 4 show a perspective view and a longitudinal sectional view,
respectively, of the ultrasonic probe tip 20 of this embodiment. Since the basic configuration is
the same as that of the first embodiment, the same members as those of the first embodiment are
denoted by the same reference numerals, and the description thereof will be omitted.
(Configuration) In the present embodiment, the reflecting member 13 of the waveguide member
5 is formed as a rectangular tube whose cross section is a square, and the convex spherical
acoustic lens 16 made of silicone rubber is fixed to the opening 21 thereof. There is. The acoustic
reflection surface 6 is integrally formed on the end face of the waveguide member 5. Here, the
transmission member 12 is in close contact with the acoustic lens 16 in addition to the members
shown in the first embodiment.
03-05-2019
5
[0015]
The ultrasonic beam transmitted by the transmission member 12 is reflected by the acoustic
reflection surface 6, passes through the acoustic lens 16, and is then oscillated to the outside of
the ultrasonic probe tip 20. At this time, the ultrasonic beam is a focused beam focused by the
lens.
[0016]
(Effect) Since an ultrasonic beam can be focused, a thinner beam can be obtained. Therefore, it is
possible to obtain an observation image with high resolution in the direction orthogonal to the
traveling direction of the beam. In the present embodiment, the acoustic lens 16 is a convex
spherical surface made of silicone rubber, but the material and the shape are not limited to this.
For example, as the shape, in addition to a spherical surface, an aspheric surface or a cylindrical
surface represented by a paraboloid can be used. As a material, polyethylene, epoxy resin, etc.
can be used. Here, when the sound velocity of the lens material is equal to or higher than that of
the ultrasonic wave medium, the lens surface needs to be concave, and in the opposite case, it
needs to be convex. In addition, it is possible to make the outer side flat and the inner side
curved, and to make both sides curved. In addition, since the transmission member 12 inside the
waveguide member 5 can be isolated from the outside and protected by the lens, the degree of
freedom in selecting the material of the transmission member 12 is increased. For example, it is
possible to use a liquid of a material different from that of the above-mentioned ultrasonic
medium covering the ultrasonic probe tip 20.
[0017]
[Third Embodiment] FIG. 5 shows a longitudinal sectional view of the ultrasonic probe tip 20 of
this embodiment. Since the basic configuration is the same as in the first and second
embodiments, the same members as those in the first and second embodiments are indicated by
the same reference numerals, and the description thereof is omitted. (Constitution) In the present
embodiment, a convex spherical acoustic lens 16 made of silicone rubber was fixed to the inside
of the tip of the waveguide member 5.
[0018]
03-05-2019
6
(Operation) The ultrasonic pulse is focused by the acoustic lens 16 and then reaches the acoustic
reflection surface 6, and is oscillated to the outside as a focused beam.
[0019]
(Effects) Compared to the structure shown in Example 2, the following advantages are obtained.
That is, according to this embodiment, the outer shape of the acoustic lens 16 can be made the
same as the cross-sectional shape of the transmission member 12. For this reason, the shape of
the transmission member 12 can be set arbitrarily, and a transducer of the largest size possible
in design can be used, so high gain can be achieved.
[0020]
[Embodiment 4] FIG. 6 shows a longitudinal sectional view of the ultrasonic probe tip 20 of this
embodiment. Since the basic configuration is the same as that of the first embodiment, the same
members as those of the first embodiment are denoted by the same reference numerals, and the
description thereof will be omitted. (Configuration) In this embodiment, the acoustic reflection
surface 6 formed on the mirror block 18 is formed as a spherical concave surface.
[0021]
The ultrasonic beam transmitted by the transmission member 12 is reflected by the acoustic
reflection surface 6 and then oscillated to the outside of the ultrasonic probe tip 20. At this time,
the ultrasonic beam is a focused beam focused by the lens.
[0022]
(Effects) Compared with the structures shown in Examples 2 and 3, there are the following
advantages. That is, since the ultrasonic beam is focused by mirror reflection only, the
transmission loss due to the acoustic impedance mismatch between the acoustic lens 16 and the
transmission member 12 and the acoustic lens 16 is eliminated, and the sensitivity can be further
03-05-2019
7
enhanced. It is also possible to combine the mirror shown in this embodiment with the lens
shown in Embodiment 2 or 3. In this case, although the aforementioned loss occurs, the gain can
be secured to the same level as that of the second or third embodiment.
[0023]
As described above, according to the ultrasonic transducer of the present invention, it is possible
to realize an ultrasonic transducer for an ultrasonic probe which is suitable for close-range
observation and is also applicable to long-distance observation. be able to.
03-05-2019
8
Документ
Категория
Без категории
Просмотров
0
Размер файла
17 Кб
Теги
jph07193895
1/--страниц
Пожаловаться на содержимое документа