close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JPS5695038

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 JPS5695038
Description 1, title of the invention
Ultrasound diagnostic probe
3. Detailed Description of the Invention The present invention is an ultrasonic diagnostic probe,
and more particularly, an improved ultrasound system capable of obtaining an arbitrary focusing
action of an ultrasonic beam with respect to a lateral direction orthogonal to the scanning
direction of the probe. The present invention relates to an ultrasonic diagnostic probe. An
ultrasonic diagnostic apparatus is known which emits an ultrasonic beam into a subject and
displays an image of a living tissue such as an organ based on a reflection echo generated from a
difference in acoustic impedance. The transducer for transmitting and receiving the ultrasonic
beam is excited by the electric signal of the ultrasonic frequency, but the transducer composed of
the electroacoustic transducer such as PZT is excited by the electric signal of ultrasonic
frequency, but the ultrasonic beam emitted from the probe travels in the radiation direction It is
known that the beam diffuses and the resolution of the image obtained is reduced. Various
improvements have conventionally been made in order to suppress the diffusion of the abovementioned ultrasonic beam and obtain a sharp directivity induced sound beam. FIG. 1 shows the
arrangement of the transducer elements in the conventional probe, and n transducer elements 0
0 are arranged in the scanning direction (X axis). Each vibrating element 10 has a vibrating
element length of 21-1 in the lateral direction (Y axis) orthogonal to the scanning direction, and
when the vibrating element 10 is excited, the scanning direction (X axis) and the transverse
direction (Y axis) The scanning plane of the X2 plane can be obtained by emitting an ultrasonic
beam in the radiation direction (Z axis) orthogonal to both of) and electronically controlling the
scanning of the excitation of each transducer 10. EndPage: FIG. 2 shows the electronic scanning
action using the above-mentioned conventional probe, and the number of transducer elements
14-04-2019
1
arbitrarily selected from the plurality of transducer elements 10, five in FIG. The scanning action
of the plurality of ultrasonic beams 200 can be obtained by switching control of the vibrating
element group by repetitive pulse 100 and sequentially exciting to obtain the tomogram 300 of
FIG. 0 As described above j7, the ultrasonic beam has a diffusing action, and the resolution of the
tomographic image 300 decreases as the depth in the radial direction (Z axis) increases, but in
the conventional apparatus, each vibration By delay-controlling the timing of transmission and
reception to and from the element 10, the emitted ultrasonic beam is focused to a desired
radiation depth to prevent a decrease in image resolution. According to such electronic delay
control, any focusing action can be obtained with respect to the scanning plane, ie, the X2 plane,
and furthermore, the focusing point is automatically moved from a short distance to a far
distance to a wide range. It is also possible to obtain a high resolution ultrasonic beam, and it is
possible to maintain good directivity in the scanning plane. However, the above-mentioned
focusing action is performed only on the X2 plane, and the conventional apparatus can not
prevent the diffusion of the ultrasonic beam in the YZ plane orthogonal to the scanning plane,
which is not good enough. Image quality is degraded.
For example, assuming that the vibration element length 2b is 10 mWL そ i and the wavelength
λ of the ultrasonic wave is 0.5 mm, the first zero angle (zero radiation angle) α of the ultrasonic
beam is one α-5 in. The length of the directional sound field of the ultrasonic beam emitted from
the vibration element 10 at this time is shown in FIG. As apparent from FIG. 3, as the radiation
depth is increased, the directivity of the ultrasonic beam in the lateral direction is reduced, so
that the resolution of the image is significantly reduced, making it difficult to secure a good
image quality. As a conventional improved probe, a probe having a laterally concave ultrasonic
beam emitting surface has been proposed, and it has become possible to obtain a lateral focusing
action by means of the probe. FIG. 4 shows a probe for forming a concave radiation surface by
the arc-shaped vibration element 10, and FIG. 5 adheres an acoustic lens 12 having a concave
radiation surface to the vibration element 10 of FIG. A fixed configuration is shown. In any of the
probes, the concave radiation surface has a curvature of R. In this improved conventional device,
focusing in the lateral direction is obtained, and a D constant represented by the following
equation is used to show this focusing characteristic. The D constant of represents the strength
of focusing, and the sound pressure at the curvature point is as follows: ■ = πD (3) For example,
assuming that the D constant is 2, It becomes possible to obtain three times the sound pressure
as compared with the conventional probe of FIG. 1 which does not converge. Therefore,
according to the conventional apparatus of FIG. 4 and FIG. 5, it is possible to obtain three-fold
sharp directivity. FIG. 6 shows the sound pressure distribution characteristics in the probe of λ =
0.5 mm, R = 75 mm and 2b = 13 mm5, the D constant at this time is D-11, and the maximum
point of the sound pressure is the radiation Although it is located approximately 45 mm from the
surface, as is apparent from the figure, in the conventional device, a good focusing action can not
be obtained except at the desired focusing point, which limits the probe. There is a disadvantage
that it can be used only for the use modes described above. That is, a conventional probe having
14-04-2019
2
a concave radiation surface has a problem that the probe must be converted whenever the depth
of focus is changed because the focusing point is determined from its shape, and the handling is
inconvenient. The The present invention has been made in view of the above-described
conventional problems, and its object is to make it possible to arbitrarily change the lateral
focusing characteristics of an ultrasonic beam, and to cover various diagnostic depths with a
single probe. It is an object of the present invention to provide an improved ultrasonic diagnostic
probe capable of
In order to achieve the above object, the present invention includes a plurality of vibratory
elements arranged along a scanning direction, each vibratory element obtaining an ultrasonic
beam focusing action in a lateral direction orthogonal to the scanning direction In the ultrasonic
diagnostic probe having an ultrasonic beam emission surface which is concave 6-EndPage in two
lateral directions, the lateral width of the emission surface can be arbitrarily changed in the
ultrasonic beam emission surface of the transducer. An acoustic mask of the present invention is
detachably mounted so that the lateral focusing characteristics of the ultrasonic beam can be
arbitrarily selected. The present invention is characterized in that, even if the curvature R is the
same, the D constant can be changed if the vibration element length 2b changes, and the
focusing point can be changed by the change of the D constant. Attention is focused, and desired
focusing characteristics are obtained by arbitrarily adjusting the lateral effective length of the
transducer with the acoustic mask. According to the present invention, as the shielding amount
by the acoustic mask is increased and the effective length of the vibrating element is shortened,
the focusing point approaches the radiation surface, and conversely, the effective length of the
magnetic moving element is increased. Thus, the focusing point can be set at a long distance
from the radiation surface, and by arbitrarily selecting the mounting position of the acoustic
mask on the vibrating element, it is possible to obtain a desired focusing action. Hereinafter,
preferred embodiments of the present invention will be described based on the drawings. FIG. 7
shows an embodiment in which the present invention is applied to the conventional apparatus of
FIG. 4, and shows a state in which an acoustic mars 14 is mounted on the ultrasonic beam
radiation surface 10a. FIG. 5 shows an embodiment in which the acoustic mask 14 is mounted on
the concave radiation surface 12a of the acoustic lens 12 in the conventional apparatus of FIG.
The acoustic mask I4 is made of a rubber plate, foamed polyethylene or the like having a
thickness of about 0.7 mm, and is detachably fixed to each of the radiation surfaces 10a and 12a
at an optional mounting position by a holding device (not shown). The acoustic mask 14 absorbs
the ultrasonic imaging kinetic energy with high efficiency, and from the radiation surface on
which the acoustic mask 14 is mounted, the ultrasound beam is not emitted into the subject, and
as a result, each radiation surface 10 a 12a has a short effective length when the acoustic mask
14 is attached, and it becomes possible to change the D constant shown in the equation (2) to an
arbitrary value. FIG. 9 shows the change of the sound pressure distribution characteristic when
the acoustic mask according to the present invention is attached to the probe of 2b = 14 mm, λ
= 0.5 mm and R-80, and the characteristic 401 is the acoustic. At this time, the D constant is
14-04-2019
3
approximately 12, and the sound pressure maximum point, ie, the focusing point, occurs at a
position approximately 52 degrees from the radiation surface.
On the other hand, in the characteristic 402, the acoustic mask 14 with a width of 3 is mounted
on both sides of the radiation surface, and the effective length of the vibrating element 1o is
reduced to 8 mrft. As a result, it is understood that the sound pressure maximum point or
focusing point moves to a position of about 24 朋. As apparent from the characteristic of FIG. 9,
the mounting of the acoustic mask 14 makes it possible to obtain a good focusing action at a
short diagnostic depth, which is why the radiation mask is adjusted by the acoustic mask 14 in
the present invention. It becomes possible to obtain arbitrary sound pressure distribution
characteristics. As described above, according to the present invention, by mounting the acoustic
mask on the ultrasonic beam emission surface at a desired position, it is possible to arbitrarily
select the lateral focusing characteristics of the ultrasonic beam, and it is possible to use a single
device. The probe can be used to deliver ultrasound beam radiation with the desired focusing
characteristics for a wide range of diagnostic depths, significantly increasing the application
range of the 9-ultrasound diagnostic device, high quality images with high resolution It is
possible to obtain
4. Brief description of the drawings Fig. 1 is a perspective view showing a conventional probe
without lateral focusing, Fig. 2 is an explanatory view showing a linear electronic scanning action
using the probe of Fig. 1, Fig. 2 3 is an explanatory view showing the lateral ultrasonic beam
diffusion action in the probe of FIG. 1, and FIG. 4 is a perspective view of a conventional
improved probe capable of performing a radial focusing action; FIG. 5 is a perspective view
showing another conventional probe capable of performing focusing operation in the radial
direction by an acoustic lens, and FIG. 6 is a sound pressure distribution characteristic of the
conventional probe of FIGS. FIG. 7 is a perspective view showing a preferred embodiment of the
present invention applied to the conventional apparatus shown in FIG. 4, and FIG. 8 shows a
preferred embodiment applied to the conventional apparatus shown in FIG. FIG. 9 is a
characteristic diagram showing the focusing characteristic adjustment operation in the
embodiment of FIG. 7 and FIG. A. 10 ... Vibration element 10a ... Radiation surface 14 ... Acoustic
mask applicant Aroka Co., Ltd. 11-212 years old 3TeU o 6 EndPage: 4
14-04-2019
4
Документ
Категория
Без категории
Просмотров
0
Размер файла
13 Кб
Теги
description, jps5695038
1/--страниц
Пожаловаться на содержимое документа