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DESCRIPTION JPH09288095
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
ultrasonic probe, and more particularly, to a mirror reflection type ultrasonic probe used for
medical or non-destructive inspection or other ultrasonic diagnostic imaging apparatus. It relates
to the tip structure.
[0002]
2. Description of the Related Art An ultrasonic probe is a direct-view type that emits an ultrasonic
beam to an object to be observed and a mirror reflection that reflects an ultrasonic wave by a
mirror provided in a sheath and emits an ultrasonic beam to an object to be observed It can be
roughly divided into types.
[0003]
It is known that the mirror reflection type ultrasonic probe can make observation from the
immediate vicinity of the sheath because it can increase the time from transmitting an ultrasonic
pulse to reaching the object to be observed.
[0004]
The mirror reflection type ultrasonic probe shown in FIG. 7, which is a conventional example,
includes the mirror 15 alone, or the ultrasonic transducer 19 and the mirror 15 integrally, and is
rotatably provided, and these are extended from the rotation drive unit The mechanical scan is
performed while rotating through a flexible shaft or the like.
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[0005]
In this type of ultrasonic probe, an ultrasonic transducer 19 or a mirror 15 is supported via a
housing 11, and a flexible shaft is connected to one end of the housing 11, and this flexible shaft
together with a sheath 13 surrounding them is It extends to a connector portion located at the
rear end of the acoustic probe.
[0006]
Inside the sheath 13, liquid paraffin, propylene glycol, physiological saline, aqueous solution of
gelatin, aqueous solution of sodium derivative of carboxymethylcellulose, higher alcohol and the
like are filled as the ultrasonic transmission medium 14.
[0007]
The ultrasonic transmission medium 14 has both the function of efficiently transmitting
ultrasonic waves and the function of a lubricant so that the operation of the flexible shaft in the
sheath 13 becomes smooth.
The ultrasonic transmission medium 14 is enclosed from the front end or the rear end of the
sheath 13. The front end of the sheath 13 is a cylindrical sealing member 17 as shown in FIG. I
was trying to seal.
[0008]
This ultrasonic probe applies a drive pulse having a voltage of about 100 to several hundred
volts from a pulser (not shown) to the piezoelectric element 4 having the piezoelectric ceramic 1,
the surface electrode 2 and the surface electrode 3. The piezoelectric element 4 is deformed
rapidly by the inverse piezoelectric effect, and the ultrasonic pulse excited by this is transmitted
to the ultrasonic transmission medium 14 through the acoustic matching layer 5 or the acoustic
lens, and is reflected by the mirror 15 to be a path As shown at 20, it is transmitted out of the
sheath 13.
In FIG. 7, 7 and 8 are wires, 9 is a resin, and 10 is an adhesive.
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[0009]
Also, the transmitted ultrasonic pulse is reflected at the interface of each tissue in the body for
medical use and after being reflected from a discontinuous portion such as a flaw inside the
measured object for nondestructive testing, the above-mentioned mirror 15, The light is reincident on the piezoelectric element 4 through the acoustic matching layer 5 or the acoustic
lens to vibrate it.
The mechanical vibration piezoelectric effect is converted to an electrical signal and imaged by
an observation device (not shown).
[0010]
Among the ultrasonic probes of the mirror reflection type, in an ultrasonic probe of the type
emitted from the ultrasonic transducer 19 toward the tip of the sheath 13, an ultrasonic
transducer is used. Among the ultrasonic waves emitted from 19, an ultrasonic wave which
always passes through between the components in the housing 11 such as the sheath 13 and the
mirror 15 without being reflected by the mirror 15 necessarily exists.
[0011]
The ultrasonic wave leaked to the distal end portion is transmitted through the ultrasonic wave
transmission medium 14, partially reflected by the sealing member 17 at the distal end of the
sheath 13, partially transmitted, and reflected or contacted at the opposite end surface It is
transmitted into the member.
Then, it is reflected and passes again between the sheath 13 and components such as the mirror
15 and the like, and a part reaches the ultrasonic transducer 19.
[0012]
The ultrasonic wave reaching the ultrasonic transducer 19 has a problem that it appears as noise
when it is imaged.
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[0013]
Further, among the ones used as the ultrasonic wave transmission medium 14 in contact with the
acoustic radiation surface of the ultrasonic transducer 19, water and various aqueous solutions
damage the resin 9 constituting the ultrasonic transducer 19 and increase aging over time. It was
necessary to take waterproofing measures, which led to the price increase of the ultrasonic
probe.
[0014]
Then, the liquid paraffin and higher alcohol used in the above-mentioned cases have a high
attenuation rate, or an appropriate viscosity is obtained to improve the rotational property of the
ultrasonic probe, including water, physiological saline and the like. Furthermore, in order to
introduce the alkali metal or alkaline earth metal that degrades the piezoelectric ceramic in order
to make it water-soluble like an aqueous solution of sodium derivative of carboxymethylcellulose,
a piezoelectric element represented by PT system with age In 4, there was a failure that led to
destruction.
[0015]
SUMMARY OF THE INVENTION The present invention has been made to solve the abovementioned problems, and a mirror reflection type ultrasonic wave section in which deterioration
in image accuracy caused by a sheath tip member is minimized. The purpose is to provide a
feeler.
Another object of the present invention is to provide an ultrasonic probe provided with an
ultrasonic transmission medium which has an appropriate viscosity and can be improved in
rotational property.
[0016]
According to the first aspect of the present invention, an ultrasonic transducer is provided in a
flexible sheath and a mirror reflection type ultrasonic transducer is provided, an ultrasonic
transmission medium is filled around it, and an ultrasonic image is obtained by scanning the
ultrasonic wave In the probe, the end face shape of the sealing member on the ultrasonic
transducer side of the sheath tip end portion filled with the ultrasonic wave transmission medium
is a shape other than a plane perpendicular to the axis of the sheath. It is a thing.
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[0017]
The invention according to claim 2 is the ultrasonic probe according to claim 1, wherein both
end surfaces of the sealing member at the tip of the sheath filled with the ultrasonic transmission
medium are perpendicular to the axis of the sheath. It is characterized in that it has a shape other
than a flat surface.
[0018]
The invention according to claim 3 is the ultrasonic probe according to claim 1 or 2, wherein the
sealing member of the sheath distal end portion filled with the ultrasonic transmission medium
has an acoustic impedance of the ultrasonic transmission medium, It is characterized by
comprising a resin material having an acoustic impedance between the acoustic impedance of the
sheath and the sheath.
[0019]
The invention according to claim 4 is the ultrasonic probe according to claim 1 or 2, wherein the
acoustic impedance of the ultrasonic transmission medium is applied to the end face of the
sealing member at the tip of the sheath filled with the ultrasonic transmission medium. It is
characterized in that a resin having an acoustic impedance between the acoustic impedance of
the sealing member and the sealing member is applied.
[0020]
The invention according to claim 5 is an ultrasonic probe comprising an ultrasonic transducer
comprising at least a piezoelectric element, an acoustic matching layer, and a back load material,
and a sheath including the ultrasonic transducer and an ultrasonic transmission medium. A
mixture of a polyvinyl alcohol-based polymer or a crosslinked polymer of a polymer and water is
used as an ultrasonic wave transmission medium in contact with the acoustic radiation surface of
the ultrasonic transducer.
[0021]
The invention according to claim 5 is an ultrasonic probe comprising an ultrasonic transducer
comprising at least a piezoelectric element, an acoustic matching layer, and a back load material,
and a sheath including the ultrasonic transducer and an ultrasonic transmission medium. It is
characterized in that a mixture of polyvinyl pyrrolidone-based polymer or cross-linked polymer
and water is used as an ultrasonic wave transmission medium in contact with the acoustic
radiation surface of the ultrasonic transducer.
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[0022]
The invention according to claims 1 and 2 is characterized in that an ultrasonic transducer of
mirror reflection type is provided in a flexible sheath, an ultrasonic transmission medium is filled
around it, and an ultrasonic image is obtained by scanning an ultrasonic wave. In the ultrasonic
probe, the end face shape of the sealing member at the tip of the sheath filled with the ultrasonic
transmission medium is at least the ultrasonic transducer side is a shape other than a plane
perpendicular to the axis of the sheath Of the ultrasonic waves emitted from the body, the
ultrasonic waves that have escaped between the sheath and the housing component such as the
mirror without being reflected by the mirror are emitted to the outside of the sheath and
reflected by the sealing member The ultrasonic waves that pass between the components of the
sensor and reach the ultrasonic transducer are reduced, and components that appear as noise
when imaged are reduced.
[0023]
The invention according to claim 3 is that, in the ultrasonic probe, a sealing member of the
sheath distal end portion filled with the ultrasonic transmission medium has an acoustic
impedance of the ultrasonic transmission medium, and an acoustic impedance of the sheath. By
using a resin material having an acoustic impedance of between, the ultrasonic wave that has
leaked out to the sheath tip is efficiently radiated out of the sheath, reflected by the sealing
member, and again made up of components such as the sheath and mirror. The ultrasonic waves
reaching the ultrasonic transducer are reduced, and components that appear as noise when
imaging are reduced.
[0024]
The invention according to claim 4 is the ultrasonic probe according to claims 1 and 2, wherein
an acoustic wave of the ultrasonic transmission medium is applied to the end face of the sealing
member at the tip of the sheath filled with the ultrasonic transmission medium. A resin is coated
with an acoustic impedance between the beading and the acoustic impedance of the sealing
member, and the ultrasonic wave leaked to the tip of the sheath is efficiently radiated out of the
sheath and reflected by the sealing member. Again, the ultrasonic waves that pass between the
sheath and components such as mirrors and reach the ultrasonic transducer are reduced, and
noise components that appear as ring-shaped noise when imaging are reduced.
[0025]
The invention according to claim 5 is an ultrasonic probe comprising an ultrasonic transducer
comprising at least a piezoelectric element, an acoustic matching layer and a back load material,
and a sheath including the ultrasonic transducer and an ultrasonic transmission medium. Since
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viscosity adjustment is performed using a mixture of a polyvinyl alcohol-based polymer or a
polymer cross-linked body and water as an ultrasonic transmission medium in contact with the
acoustic radiation surface of the sound wave transducer, it is possible to achieve both rotation
and sensitivity at observation.
[0026]
The invention according to claim 6 is an ultrasonic probe comprising an ultrasonic transducer
comprising at least a piezoelectric element, an acoustic matching layer, and a back load material,
and a sheath including the ultrasonic truss inducer and an ultrasonic transmission medium. Since
viscosity adjustment is performed using a mixture of polyvinylpyrrolidone-based polymer or
cross-linked polymer and water as an ultrasonic transmission medium in contact with the
acoustic radiation surface of the ultrasonic transducer, it is possible to achieve both rotational
performance and sensitivity during observation. .
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the ultrasonic probe
according to the present invention will be described below with reference to the drawings.
[0028]
[First Embodiment] [Configuration] The first embodiment of the ultrasonic probe according to the
present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 is a schematic view showing the entire configuration of the ultrasonic probe according to
the first embodiment, FIG. 2 is a cross-sectional view showing a tip of the ultrasonic probe
according to the first embodiment, and FIG. It is explanatory drawing which shows the various
sealing members in an ultrasound probe.
In the first embodiment and the third to fourth embodiments described later, the same elements
as those of the conventional example shown in FIG. 7 are indicated by the same reference
numerals.
[0029]
In the ultrasonic probe according to the first embodiment, as shown in FIG. 1, a housing 11 with
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a mirror 15 in which an ultrasonic transducer 19 is incorporated in a sheath 13 made of a
polyethylene or Teflon tube is It is fitted in a state of being joined to a flexible shaft 23 for
transmitting rotation.
[0030]
An aqueous solution of 5 wt% polyvinyl alcohol is enclosed as an ultrasonic transmission medium
14 in the space such as the sheath 13, the housing 11, and the flexible shaft 23, and water
tightness is secured at the connector 24. There is.
[0031]
The observation of the actual image obtained by the ultrasonic probe is performed by connecting
a detachable connector 24 to an image observation device (not shown).
[0032]
As shown in FIG. 2, the structure of the distal end portion of the ultrasonic probe is provided with
a metal housing 11 having a role of a waveguide in a sheath 13, and the housing 11 is provided
with an acoustic matching layer 5 and a piezoelectric element 4. , And an ultrasonic transducer
19 having a backing material 6 etc. is adhesively fixed.
[0033]
The ultrasonic transducer 19 is composed of a piezoelectric ceramic plate 1, a GND side
electrode 3 provided on the piezoelectric ceramic plate 1, a piezoelectric element 4 composed of
a positive electrode 2, an acoustic matching layer 5, and a backing material 6. The wiring is
connected to the coaxial cable in the flexible shaft 23 by the wirings 7 and 8 applied to the side
surface portion of the ultrasonic transducer 19.
Incidentally, the polarity of the wires 7 and 8 is such that the acoustic radiation surface side with
the acoustic matching layer 5 is at GND.
The ultrasonic transducer 19 is fixed to the housing 11 with an adhesive 10, and a sealing
member 9 is applied to the periphery.
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[0034]
Ultrasonic waves are emitted from the acoustic matching layer 5 side of the ultrasonic transducer
19 in the direction of the distal end of the sheath 13 and ultrasonic pulses whose direction is
changed by the mirror 15 fixed to the housing 11 are notched parts of the housing 11 The light
is reflected from 18 to the observation object through a path 20.
[0035]
The tip of the sheath 13 encloses water, which is the ultrasonic wave transmission medium 14, in
the sheath 13, and then, after pressing and sealing the silicone rubber sealing member 17 having
a conical shape on the housing 11 side, The sheath 13 was produced by heating and welding.
[0036]
The flexible shaft 23 with the housing 11 incorporating the ultrasonic transducer 19 is inserted
into the sheath 13 subjected to such tip processing, and sealing is performed while securing
water tightness at the connector 24 portion to obtain an ultrasonic probe. Made.
[0037]
The piezoelectric element 4 used for the ultrasonic transducer 19 was made of a silver-baked
electrode and had a center frequency of 20 MHz and a size of 0.6 × 0.6 mm.
The acoustic matching layer 5 was made of resin as a matrix and the filler dispersed in this
matrix.
Specifically, calcia powder was used as the powder, and an epoxy thermosetting resin was used
as the matrix.
Moreover, what carried out dispersion of the zirconia powder in the epoxy resin was used for the
back load material 6.
[0038]
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[Operation] The transmission directions of the ultrasonic waves oscillated from the ultrasonic
probe of the above configuration are as shown by paths 20 and 21 shown in FIG.
The component emitted from the acoustic matching layer 5 of the ultrasonic transducer 19 and
reflected by the sheath 13 without being reflected by the mirror 15 travels toward the tip of the
sheath 13 as indicated by the path 21.
[0039]
However, since the ultrasonic transducer 19 side of the sealing member 17 has a conical shape,
the ultrasonic waves leaked to the distal end of the sheath 13 are reflected by the sealing
member 17 and go out of the sheath 13.
On the other hand, the ultrasonic wave component emitted from the ultrasonic transducer 19
and reflected by the mirror 15 goes out of the sheath 13 as shown by the path 20 and is
reflected at the interface of the object to be observed, etc. Returning to the acoustic transducer
19, the piezoelectric element 4 is vibrated and converted into an electrical signal, which is
imaged by the observation device.
[0040]
Further, in the aqueous solution of 5 wt% of polyvinyl alcohol, which is the ultrasonic
transmission medium 14, the hydroxyl groups in the polyvinyl alcohol attract water molecules, so
the penetration of water into the resin 9 constituting the ultrasonic transducer 19 is suppressed.
[0041]
Further, the addition of polyvinyl alcohol results in the ultrasonic wave transmission medium 14
having an appropriate viscosity, so that the rotational property can be improved when it is
rotationally driven.
[0042]
[Effect] According to the first embodiment, most of the components of the ultrasonic wave that
has leaked to the distal end of the sheath 13 and reflected by the sealing member 17 are out of
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the sheath 13 as in the prior art. The noise component reflected to the sealing member 17 and
returned to the ultrasonic transducer 19 is greatly reduced.
Therefore, the obtained image has a high resolution from the immediate vicinity of the sheath 13.
[0043]
In the first embodiment, although the ultrasonic transducer 19 and the mirror 15 are integrally
rotated in the example, the same applies to an ultrasonic transducer fixed type in which the
mirror 15 rotates to the distal end side of the sheath 13. It goes without saying that the effect
can be obtained.
[0044]
In the first embodiment, the shape of the sealing member 17 is conical on the ultrasonic
transducer 19 side, but the ultrasonic wave leaked to the tip of the sheath 13 is again used as the
ultrasonic transducer 19. It may be out of the sheath 13 in a direction in which it is difficult to
return, and its shape is not limited to the conical shape, and various types can be mentioned.
[0045]
For example, as shown in FIG. 3, a sealing member 17a of a combination of a cylinder and a
pyramid, a sealing member 17b of a combination of a cylinder and a cone, a sealing member 17c
of a combination of a cylinder and a hemisphere, a cylinder A sealing member 17d having a
shape that is cut obliquely, a sealing member 17e having a shape that is cut diagonally on both
sides of the diameter of the cylinder, a sealing member 17f having a shape in which hemispheres
are joined on both sides of the cylinder, and a cylinder The same effect as in the case of the
sealing member 17 can be obtained by using a sealing member 17g having a shape in which a
pyramid and a hemisphere are joined to each other and a sealing member 17h having a shape in
which a cone is joined to both surfaces of a cylinder. .
[0046]
Further, as the material of the sealing member 17, various resin materials, metals and various
composite materials can be used in addition to the above-mentioned silicone rubber, and the
same effect as in the first embodiment can be obtained even using these. Be
[0047]
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Furthermore, in the first embodiment, the ultrasonic transmission medium 14 is enclosed in the
sheath 13 and then the tip portion is sealed in the order of sealing the ultrasonic probe, but after
the ultrasonic transmission medium 14 is enclosed, It is also possible to manufacture by a
method of inserting the ultrasonic transducer 19 and finally sealing the tip of the sheath 13.
[0048]
In addition, since the hydroxyl group in the polymer attracts water molecules in the aqueous
solution of polyvinyl alcohol, which is the ultrasonic wave transmission medium 14, the
penetration of water into the resin constituting the ultrasonic transducer 19 is suppressed, and
the secular change is small. Can be manufactured inexpensively.
Furthermore, polyvinyl alcohol is added to form an ultrasonic transmission medium 14 having an
appropriate viscosity, so that the rotational property can be improved at the time of actual image
observation, and a highly accurate one with less image flow can be obtained.
[0049]
Although polyvinyl alcohol is used as the ultrasonic wave transmission medium 14 in the first
embodiment, the same effect can be obtained with a cross-linked product of polyvinyl alcohol or
various derivatives and copolymers having polyvinyl alcohol as a basic structure.
[0050]
Second Embodiment [Configuration] Next, a second embodiment will be described with reference
to FIG.
FIG. 4 shows the tip portion of the ultrasound probe according to the second embodiment.
In the description of the configuration and the drawings in the second embodiment shown in FIG.
4, the same elements as those in the first embodiment described above are denoted by the same
reference numerals, and redundant description will be omitted.
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[0051]
As in the first embodiment, the ultrasonic probe shown in FIG. 4 has a housing with a mirror 15
in which an ultrasonic transducer 19 is incorporated in a polyethylene (ρc = 2.1) tube
constituting the sheath 13. 11 are joined to the flexible shaft 23 for transmitting the rotation.
An acrylic resin 12 is coated by electrodeposition on the inner surface of the SUS304 housing 11
serving as a waveguide.
[0052]
The ultrasonic transducer 19 used in the second embodiment includes the piezoelectric ceramic
plate 1, the electrode 3 on the GND side provided on the piezoelectric ceramic plate 1, the
piezoelectric element 4 including the positive electrode 2, and the back load member 6. , An
acoustic matching layer 5 and an acoustic lens 22.
The acoustic matching layer 5 was formed using machinable ceramics, and the acoustic lens 22
was formed using an epoxy resin not mixed with a filler.
[0053]
In the distal end portion of the sheath 13, pure water (1.5c = 1.5) which is the ultrasonic wave
transmission medium 14 is enclosed in the sheath 13, then the housing 11 side is conical and the
distal end side of the sheath 13 is crushed in a hemisphere. After pressing and sealing the sealing
member 17 made of polyurethane () c = 1.9) in the shape of a square, the sheath 13 was
manufactured by heating and welding.
[0054]
[Operation] According to the second embodiment, as in the first embodiment, most of the
ultrasonic components leaked from between the sheath 13 and the housing 11 are transmitted
through the sealing member 17. Do.
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The transmitted ultrasonic wave comes out of the sheath 13 from the distal end of the sheath 13,
and the echo wave goes out in a direction in which it is difficult to return to the ultrasonic
transducer 19.
[0055]
In addition, although a part of the light is reflected at the interface between the sheath 13 and
the sealing member 17, this reflection surface also has a difference in angle depending on the
location, and therefore does not cause noise.
[0056]
[Effect] According to the second embodiment, since the acoustic impedance of the sealing
member 17 is in the middle between the acoustic impedance of the sheath 13 and the acoustic
impedance of the ultrasonic transmission medium 14, the ultrasonic waves leaked to the tip end
portion Most of them permeate the sealing member 17 and go out of the sheath 13 in the distal
direction of the sheath 13.
For this reason, the noise component that is reflected by the sealing member 17 and returned to
the ultrasonic transducer 19 as in the prior art is greatly reduced.
For this reason, the obtained image has high resolution from the immediate vicinity of the sheath.
[0057]
In the second embodiment, the mechanical scanning method in which the ultrasonic transducer
19 and the mirror 15 rotate integrally is described, but the same effect can be obtained even in
the transducer fixed type in which the rotating mirror is on the distal end side of the sheath 13
Needless to say.
[0058]
In the second embodiment, the shape of the sealing member 17 is a conical shape on the side of
the ultrasonic transducer 19 and a shape in which the tip of the sheath is squeezed into a
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hemisphere, but leakage to the tip of the sheath 13 The shape may be any shape that makes it
difficult for the ultrasonic waves to return to the ultrasonic transducer 19 at the same time, and
there are various shapes.
For example, as in the case of the first embodiment, the same effect as that of the first
embodiment can be obtained even if any of the sealing members 17a to 17h as shown in FIG. 3 is
used.
[0059]
In addition to the urethane rubber shown in the second embodiment, the material of the sealing
member 17 may be similar to the acoustic impedance of the sheath 13 and the ultrasonic wave
transmission medium 14.
However, a sealing member having an acoustic impedance value between the sheath 13 and the
ultrasonic transmission medium 14 is most effective.
In addition, welding of the sheath tip can also be performed using a U-shaped heater other than
welding using ultrasonic waves.
[0060]
Third Embodiment [Configuration] A third embodiment of the present invention will be described
with reference to FIG.
In the description of the configuration and the drawings, the same elements as those of the
second embodiment described above are denoted by the same reference numerals, and
redundant description will be omitted.
[0061]
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FIG. 5 is a schematic view of the ultrasonic probe tip produced in the third embodiment.
Similar to the second embodiment, a housing 11 with a mirror 15 in which an ultrasonic
transducer is incorporated in a Teflon (ρc = 4.5) tube called a sheath 13 is attached to a flexible
shaft 23 for transmitting rotation. Combined and in.
[0062]
A fluorine-modified acrylic resin 12 is coated by electrodeposition on the inner surface of the
SUS304 housing 11 serving as a waveguide.
The tip of the sheath encloses water (cc = 1.5) which is the ultrasonic transmission medium 14 in
the sheath 13 and then, the housing 11 side is formed into a conical shape, and the epoxy resin
25 containing no filler is approximately 1/1. The sheath 13 is heated after the sealing member
17 made of gel-like epoxy (ρc = 3.5) containing filler is formed with a thickness of 4λ and the
distal end side of the sheath is shaped like a hemispherical crushed shape; It welded and
produced.
[0063]
[Operation] According to the third embodiment, since the acoustic matching layer 25 is applied
to the sealing member 17, the ultrasonic wave leaked from between the sheath 13 and the
housing 11 as in the second embodiment. The components are most efficiently transmitted into
the sealing member 17.
The transmitted ultrasonic wave exits the sheath 13 from the sheath distal end, and the echo
wave exits in a direction in which it is difficult to return to the ultrasonic transducer 19.
In addition, although a part of the light is reflected at the interface between the sheath 13 and
the sealing member 17, the interface also has a difference in angle depending on the location,
and therefore does not cause noise.
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[0064]
[Effect] According to the third embodiment, since there is the acoustic impedance of the acoustic
matching layer 25 provided on the sealing member 17 between the acoustic impedance of the
ultrasonic transmission medium 14 and the acoustic impedance of the sealing member 17, the
sheath Most of the ultrasonic wave that has leaked to the distal end passes through the sealing
member 17 and is taken out of the sheath in the sheath distal direction.
[0065]
For this reason, the noise component which is reflected by the sealing member and returned to
the ultrasonic transducer 19 as in the prior art is greatly reduced, and the obtained image has a
good resolution from the immediate vicinity of the sheath 13.
[0066]
In the third embodiment, the shape of the sealing member 17 is a conical shape on the ultrasonic
transducer 19 side and a hemispherical shape on the sheath tip end side. Any shape may be used
as long as the sound waves are difficult to return to the ultrasonic transducer 19 at the same
time, and there are various shapes as in the case of the second embodiment.
Further, the material of the acoustic matching layer 25 provided on the surface of the sealing
member 17 is not limited to the epoxy resin shown in the third embodiment, and the acoustic
impedance between the ultrasonic wave transmission medium 14 and the sealing member 17 is
not limited. Any material can be used.
Furthermore, the thickness of the acoustic matching layer 25 provided on the surface of the
sealing member 17 may be approximately 1 / 4λ or (1/4 + 1 / 2n) λ (n is a natural number).
[0067]
[Fourth Embodiment] [Configuration] A fourth embodiment will be described with reference to
FIG.
In the description of the configuration and the drawings, the same components as those in the
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first embodiment described above are denoted by the same reference numerals, and redundant
description will be omitted.
FIG. 6 is a schematic view of a side-view type ultrasonic probe tip produced in the fourth
embodiment.
[0068]
In the fourth embodiment, as in the first embodiment, a housing in which an ultrasonic
transducer 19 having an acoustic emission surface on the side as shown in FIG. 6 is adhesively
fixed in a polyethylene tube called a sheath 13 as shown in FIG. 11 are coupled to and inserted
into a flexible shaft 23 for transmitting rotation.
Wired to the piezoelectric element 4 is performed directly on the + side by the solder 26 on the
folded electrode portion of the piezoelectric element 4 and on the GND side by dropping the
coaxial cable once into the housing 11. This is done by soldering the folded electrode portion of
the above with the lead wire 27.
[0069]
Thereafter, the portions other than the acoustic radiation surface were sealed with an epoxy resin
9 to produce an ultrasonic transducer 19.
A flexible shaft 23 with a housing 11 mounted with the ultrasonic transducer 19 is inserted as an
ultrasonic transmission medium 14 into a sheath 13 sealed with a 7 wt% polyvinylpyrrolidone
aqueous solution and sealed at the tip, and the connector is viewed from the attached side A type
of ultrasonic probe was produced.
[0070]
[Operation] In the side-view type ultrasonic probe in the fourth embodiment, as in the first
embodiment, when a voltage pulse is applied from the observation device, the piezoelectric
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element 4 vibrates, and the acoustic matching layer 5 is produced. The ultrasonic waves are
transmitted to the ultrasonic wave transmission medium 14 through the acoustic lens 22.
The ultrasonic waves pass through the sheath 13 and are emitted to the substance to be
observed, are reflected at the interface of the substance to be observed, etc., return to the
ultrasonic transducer 19 again, and are converted into electrical signals and imaged.
[0071]
In the fourth embodiment, as in the first embodiment described above, since the aqueous
solution of 7 wt% of polyvinyl pyrrolidone which is the ultrasonic transmission medium 14
attracts water molecules in the hydrophilic group in the polyvinyl pyrrolidone, the ultrasonic
transducer 19 is used. The entry of water into the constituent resin is suppressed.
Furthermore, the addition of polyvinyl pyrrolidone results in the ultrasonic transmission medium
14 having an appropriate viscosity, so that the rotational property can be improved when it is
rotationally driven.
[0072]
[Effect] According to the fourth embodiment, since the aqueous solution of polyvinyl pyrrolidone
which is the ultrasonic wave transmission medium 14 attracts water molecules by the
hydrophilic group in the polymer, the water in the resin constituting the ultrasonic transducer 19
is Infiltration is suppressed, and it becomes possible to inexpensively manufacture an ultrasonic
probe with a long life with little aging.
[0073]
Furthermore, since polyvinyl pyrrolidone is added to form an ultrasonic transmission medium 14
having a suitable viscosity, the rotational property can be improved at the time of actual image
observation, and a high-precision one without image flow can be obtained.
Although polyvinyl pyrrolidone is used in the fourth embodiment, the same effect can be
obtained with a cross-linked product of polyvinyl pyrrolidone or various derivatives and
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copolymers having polyvinyl pyrrolidone as a basic configuration.
[0074]
According to the inventions of claims 1 and 2, in the mirror reflection type ultrasonic probe, an
ultrasonic wave capable of obtaining a high resolution image with less noise over a wide range
from the immediate vicinity of the sheath can be obtained. It can provide a probe.
[0075]
According to the invention as set forth in claim 3, in the mirror reflection type ultrasonic probe,
by setting the impedance of the sealing member appropriately, high resolution with very little
noise over a wide range from the immediate vicinity of the sheath It is possible to provide an
ultrasound probe capable of obtaining an image of
[0076]
According to the invention of claim 4, in the mirror reflection type ultrasonic probe, by providing
the acoustic matching layer to the sealing member, the wide range from the immediate vicinity of
the sheath as in the invention according to claims 1 to 3 Thus, it is possible to provide an
ultrasonic probe capable of obtaining an image with very little noise and high resolution.
[0077]
According to the invention as set forth in claims 5 and 6, in the ultrasonic probe in which the
ultrasonic transmission medium is always in contact with the ultrasonic transducer, it is possible
to inexpensively manufacture the ultrasonic probe having a small aging and a long life. It
becomes.
Furthermore, since an ultrasonic transmission medium having an appropriate viscosity can be
easily manufactured, the rotational performance can be improved at the time of actual image
observation, and an ultrasonic search can be performed to obtain a good image with high
accuracy and no image flow. Can provide a tentacle.
[0078]
Brief description of the drawings
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20
[0079]
1 is a schematic view showing an ultrasonic probe according to Embodiment 1 of the present
invention.
[0080]
2 is a cross-sectional view showing the tip portion of the ultrasound probe of the embodiment 1
of the present invention.
[0081]
3 is an explanatory view showing various sealing members in the ultrasonic probe of the
embodiment 1 of the present invention.
[0082]
4 is a cross-sectional view showing the tip of the ultrasound probe of the second embodiment of
the present invention.
[0083]
5 is a cross-sectional view showing the tip portion of the ultrasonic probe of the embodiment 3
of the present invention.
[0084]
<Figure 6> It is the cross section diagram which shows the point section of the ultrasonic probe
of the form 4 of execution of this invention.
[0085]
7 is a cross-sectional view showing the tip of the conventional ultrasonic probe.
[0086]
Explanation of sign
[0087]
Reference Signs List 1 piezoelectric ceramic plate 2 surface electrode 3 surface electrode 4
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21
piezoelectric element 5 acoustic matching layer 6 backing material 7 wiring 8 wiring 9 resin 10
adhesive 11 housing 13 sheath 14 ultrasonic transmission medium 15 mirror 16 sheath welded
portion 17 sealing member 18 Notched portion 19 Ultrasonic transducer 20 Ultrasonic wave
path 21 Ultrasonic wave path 22 Acoustic lens 23 Flexible shaft 24 Connector 25 Sealing
member matching layer 27 Lead wire
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JPH02122290

JP2005062141

JPH03295545

JPH05146756

JPH0746695

JPH04215399

JPH0349760

JP2001330485

JPH0514997

JPH03274900