close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JP2007181060

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 JP2007181060
[Purpose] To achieve sufficient EMC measures while maintaining a simple structure without
changing the basic structure of the ultrasound probe. An ultrasonic probe in which a first layer
and a second layer of an acoustic matching layer are sequentially provided on a piezoelectric
plate, and the outer periphery of the piezoelectric plate is covered with a shield material, the
inside of the first layer of the acoustic matching layer The radio wave absorbing material is
dispersed therein, and the radio wave absorbing material is made of a resistive absorbing
material, an inductive absorbing material or a magnetic absorbing material. Further, a thin film
made of a radio wave absorbing material is provided between the first layer and the second layer
of the acoustic matching layer, and the first layer of the acoustic matching layer is glass, and the
second layer is a resin. [Selected figure] Figure 1
Ultrasound probe
[0001]
The present invention relates to an ultrasonic probe having EMC (Electro-Magnetic Compatibility,
electromagnetic environment compatibility) as a technical field, and in particular to an ultrasonic
probe using a radio wave absorbing material for an ultrasonic wave transmission / reception
wave front.
[0002]
BACKGROUND OF THE INVENTION An ultrasound probe is applied to, for example, a medical
ultrasound diagnostic apparatus as a transmission / reception unit of ultrasound.
14-04-2019
1
In recent years, it is required that the ultrasonic probe itself does not emit interfering radio
waves (so-called EMI) and that its operation is not inhibited by external electromagnetic waves
(the same EMS). In particular, in the case of a medical ultrasound probe, there is a concern that
the electromagnetic waves generated by itself may adversely affect the living body (human body).
[0003]
(Example of Prior Art) FIG. 3 is a cross-sectional view of an ultrasonic probe for explaining an
example of the prior art. The ultrasonic probe has an acoustic matching layer 3 on the
transmission / reception wavefront side (one main surface side) of a piezoelectric plate 2 made
of, for example, PZT (registered trademark) having drive electrodes 1 (ab) on both main surfaces.
The piezoelectric plate 2 is, for example, a circular single plate or a so-called single type in which
this is divided into two. The acoustic matching layer 3 has a two-layer structure in which a first
layer 3a and a second layer 3b are sequentially formed from one main surface of the
piezoelectric plate 2.
[0004]
The first layer 3a of the acoustic matching layer 3 is, for example, glass by adhesion, and the
second layer 3b is a resin by coating. The coating is formed by applying a molten resin, curing it
and polishing it. In the first layer 3a and the second layer 3b, an acoustic impedance value that
becomes smaller toward the living body (subject) is selected to reduce the propagation loss of the
ultrasonic wave emitted from the piezoelectric plate 2. Further, each of the first layer 3a and the
second layer 3b has, for example, a thickness of λ / 4 of the ultrasonic frequency.
[0005]
For example, a backing material 4 is provided on the other main surface of the piezoelectric plate
2 by pouring resin. The backing material 4 suppresses oscillation tailing (ringing) by the
piezoelectric plate 2. A shield case 6 grounded to the ground potential with the insulating plate 5
interposed therebetween is provided on the outer periphery of the piezoelectric plate 2. Then, a
probe casing 7 made of an insulator is provided on the outer periphery of the shield case 6. The
14-04-2019
2
second layer 3 b of the acoustic matching layer 3 is provided so as to cover the surface of one
surface and the open end faces of the shield case 6 and the probe casing 7.
[0006]
A pair of lead wires 8 are connected to the drive electrode 1 (ab) of the piezoelectric plate 2, and
the drive electrode 1 (ab) is led out from an open end on the other end side of the shield case 6
by a coaxial cable or the like (not shown). Generally, the drive pulse P is applied to the other
principal surface side with the drive electrode 1 (ab) on the transmission / reception wavefront
side as the ground potential. Thus, the outer periphery and the other main surface of the
piezoelectric plate 2 are surrounded by the shield case 6 by the drive electrode 1a in which the
transmission and reception wavefronts of the piezoelectric plate 2 are set to the ground potential,
thereby providing EMI measures including EMI and EMS. JP, 2004-57806, A JP, 2002-101496,
A No. of radio wave absorbers, Nikkan Kogyo Shimbun, published on June 29, 2001, P1 to P6.
[0007]
(Problems of the Prior Art) However, in the ultrasonic probe of the above configuration, although
the piezoelectric plate 2 with the drive electrode 1a of the transmission / reception wavefront as
the ground potential is accommodated in the shield case 6, the minuteness of the transmission /
reception wavefront There is a problem that can not be said that it is a sufficient EMC
countermeasure because it jumps from the gap of From this, for example, as disclosed in Patent
Document 1, there is a case where a shielding material is provided also on the transmission /
reception wavefront side to secure the EMC, but there is a problem that these complicate the
structure and make manufacturing difficult.
[0008]
(Object of the Invention) An object of the present invention is to provide an ultrasonic probe with
sufficient measures against EMC while maintaining a simple structure without changing the basic
structure.
[0009]
The present invention focuses on the radio wave absorbers shown in Patent Document 1 and
Non-patent Document 1, for example, and as shown in the claims (claim 1), the first and second
layers of the acoustic matching layer are piezoelectric In the ultrasonic probe which is
14-04-2019
3
sequentially provided on the plate and the outer periphery of the piezoelectric plate is covered
with a shield material, the radio wave absorbing material is dispersed in the first layer of the
acoustic matching layer.
[0010]
In the ultrasonic probe according to claim 3, the first layer and the second layer of the acoustic
matching layer are sequentially provided on the piezoelectric plate, and the outer periphery of
the piezoelectric plate is covered with a shield material. A thin film made of a radio wave
absorber is provided between the first and second layers.
[0011]
According to the configuration of claim 1 or 3 as described above, the electromagnetic wave
absorbing material dispersed in the first layer of the acoustic matching layer converts the
electromagnetic wave entering and exiting from the ultrasonic wave transmitting and receiving
surface into heat and absorbs it.
Therefore, no new shielding material is added to the transmission / reception wave front, and the
structure of the ultrasonic probe can be easily maintained, and sufficient EMC measures can be
taken.
[0012]
FIG. 1 is a cross-sectional view of an ultrasonic probe for explaining an embodiment of the
present invention.
The description of the same parts as in the prior art example is simplified or omitted.
[0013]
As described above, in the ultrasonic probe, the acoustic matching of the two-layer structure (the
first layer 3a and the second layer 3b) on the ultrasonic wave transmitting and receiving side of
14-04-2019
4
the piezoelectric plate 2 having the drive electrodes 1 (ab) on both main surfaces A layer 3 is
provided, and the other main surface side is fixed to the backing material 4.
Then, the outer periphery of the piezoelectric plate 2 is covered with the shield case 6 in the
probe housing 7 with the insulating plate 5 interposed therebetween, and a pair of lead wires 8
such as coaxial cables are led out from the other main surface of the piezoelectric plate 2.
[0014]
Here, in the first layer 3a made of glass of the acoustic matching layer 3, the radio wave absorber
8 indicated by black spots is dispersed. The radio wave absorber 8 is made of a resistive
absorber, an inductive absorber or a magnetic absorber. For example, ITO (indium tin oxide) may
be used as the resistive absorber, ferrite particles may be used as the magnetic absorber, carbon
rubber as the inductive absorber, foamed urethane containing the same, or polystyrene may be
used. The electromagnetic wave absorbing material 8 converts the electromagnetic wave into
heat and absorbs the energy. The second layer 3b of the acoustic matching layer 3 is formed of a
resin coating as described above.
[0015]
With such a configuration, the electromagnetic wave absorbing material 8 dispersed in the first
layer 3a of the acoustic matching layer 3 converts unnecessary electromagnetic waves from the
transmission / reception wavefront into heat. Therefore, the electromagnetic wave can be
prevented from entering and exiting from the transmission / reception wave front. Further,
electromagnetic waves from the outer periphery other than the transmission and reception
wavefronts are blocked by the shield case 6 as in the prior art. As a result, the electromagnetic
wave from the ultrasonic probe is completely shut off and the EMC measures are sufficiently
made.
[0016]
Then, since the first layer 3a of the acoustic matching layer 3 in which the radio wave absorber 8
is mixed (dispersed) is covered by the second layer 3b, the first layer 3a and the living body are
electrically isolated. Therefore, an adverse effect on the living body by the first layer 3a including
14-04-2019
5
the radio wave absorber 8 can be prevented.
[0017]
(Other Matters) In the above embodiment, although the first layer 3a of the acoustic matching
layer 3 is made of glass by adhesion, it is a matter of course that the first layer 3a may be coated
with resin as the second layer 3b. In this case, since the resin of the first layer 3a has flexibility as
compared to glass, it absorbs, for example, the difference in thermal expansion coefficient with
the radio wave absorber 8 to prevent breakage or cracking. Although the ultrasonic probe is a
single type, the present invention is not limited to this, and can be applied to an array type in
which rectangular piezoelectric elements are arranged in the width direction.
[0018]
Further, instead of the shield case 6 covering the outer periphery of the piezoelectric plate 2, for
example, a shield material formed by winding copper foil or the like around the outer periphery
may be used. What is necessary. Further, not only the acoustic matching layer 3 but also the
backing material 4 may be dispersed (mixed) in the backing material 4 as shown in Patent
Document 2.
[0019]
In addition, although the radio wave absorber 8 is a resistive absorber, a magnetic absorber, or
an inductive absorber, the inductive absorber has a large attenuation of ultrasonic waves, so a
resistive absorber or a magnetic absorber is preferable for practical use. . Also, although the
radio wave absorber 8 is dispersed in the acoustic matching layer 3, for example, as shown in
FIG. 3, the first layer 3a, the second layer 3b, and the side of the first layer are made by using the
radio wave absorber 8 as a resistance absorber. A thin film sufficiently smaller than the thickness
of the first layer 3a and the second layer 3b (usually at λ / 4 of the ultrasonic frequency) may be
provided between them by vapor deposition or the like. In addition, it forms also in the outer
peripheral side of 1st layer 3a.
[0020]
14-04-2019
6
It is a sectional view of an ultrasound probe explaining one embodiment of the present invention.
It is sectional drawing of the ultrasound probe explaining other embodiment of this invention. It
is sectional drawing of the ultrasound probe which demonstrates a prior art example.
Explanation of sign
[0021]
DESCRIPTION OF SYMBOLS 1 drive electrode, 2 piezoelectric plate, 3 acoustic matching layer, 3a
1st layer, 3b 2nd layer, 4 backing material, 5 insulating plate, 6 shield case, 7 probe case, 8 lead
wire, 9 electric wave absorber.
14-04-2019
7
Документ
Категория
Без категории
Просмотров
0
Размер файла
15 Кб
Теги
description, jp2007181060
1/--страниц
Пожаловаться на содержимое документа