U.S. patent application number 14/604540 was filed with the patent office on 2015-05-14 for subject information acquiring apparatus.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Takaaki Nakabayashi.
Application Number | 20150133766 14/604540 |
Document ID | / |
Family ID | 49003645 |
Filed Date | 2015-05-14 |
United States Patent
Application |
20150133766 |
Kind Code |
A1 |
Nakabayashi; Takaaki |
May 14, 2015 |
SUBJECT INFORMATION ACQUIRING APPARATUS
Abstract
A subject information acquiring apparatus of the present
invention includes a subject-holding member which holds a subject
and a probe unit having a transducer which receives acoustic waves
from the subject through the subject-holding member, a housing
which accommodates the transducer, and a matching liquid-holding
member configured to hold a matching liquid between the transducer
and the subject-holding member, the probe unit being allowed to
move relative to the subject-holding member. The probe unit has a
guide which introduces the matching liquid to the subject-holding
member, the matching liquid having been spilled from a space
defined by the matching liquid-holding member, the transducer, and
the subject-holding member onto the upper surface of the hosing and
then flowed from the upper surface of the housing.
Inventors: |
Nakabayashi; Takaaki;
(Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
49003645 |
Appl. No.: |
14/604540 |
Filed: |
January 23, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13776200 |
Feb 25, 2013 |
8971987 |
|
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14604540 |
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Current U.S.
Class: |
600/407 |
Current CPC
Class: |
A61B 5/704 20130101;
A61B 2562/14 20130101; A61B 8/4281 20130101; A61B 5/708 20130101;
A61B 8/4444 20130101; A61B 8/403 20130101; A61B 8/406 20130101;
A61B 5/4312 20130101; A61B 8/4209 20130101; A61B 5/0095 20130101;
A61B 8/0825 20130101 |
Class at
Publication: |
600/407 |
International
Class: |
A61B 8/00 20060101
A61B008/00; A61B 8/08 20060101 A61B008/08; A61B 5/00 20060101
A61B005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 29, 2012 |
JP |
2012-043808 |
Claims
1. A subject information acquiring apparatus comprising: a subject
holding member which holds a subject; and a probe unit having a
housing having an opposing surface facing to the subject holding
member and an upper surface connected to an upper edge of the
opposing surface, a transducer provided on the opposing surface and
a matching liquid storing member secured to the opposing surface
and contacting the subject holding member so as to form a storing
space storing a matching liquid between the opposing surface and
the subject holding member, wherein the opposing surface has a
supply port being configured to supply the matching liquid to the
storing space and the matching liquid storing member has an opening
between the supply port and the upper surface, and wherein the
probe unit has a guide which directs the matching liquid overflowed
from the storing space via the opening to the subject holding
member.
2. The subject information acquiring apparatus according to claim
1, wherein the guide is provided to the housing and introduces the
matching liquid flowing from the upper surface to the subject
holding member.
3. The subject information acquiring apparatus according to claim
1, further comprising: a cable extending from the transducer toward
a direction in opposition to a direction toward the subject holding
member, wherein the guide restricts a flow of the matching liquid
to the cable in order to prevent the matching liquid from being
spilled on the cable.
4. The subject information acquiring apparatus according to claim
1, wherein the guide includes a groove formed in the housing.
5. The subject information acquiring apparatus according to claim
1, wherein at least part of the guide is deformed depending on the
shape of the subject holding member being in a state in which a
subject is held.
6. The subject information acquiring apparatus according to claim
1, wherein the opposing surface has a liquid level sensor detecting
a level of the matching liquid at the opposing surface.
7. The subject information acquiring apparatus according to claim
6, wherein the liquid level sensor is located higher than the
transducer so as to determine whether the storing space is filled
with the matching liquid or not.
8. The subject information acquiring apparatus according to claim
10, wherein the liquid level sensor is located lower than the
opening.
9. The subject information acquiring apparatus according to claim
6, wherein the liquid level sensor is located higher than the
transducer so as to determine whether the matching liquid is stored
enough to propagate acoustic waves from the subject to the
transducer or not.
10. The subject information acquiring apparatus according to claim
1, wherein the transducer receives acoustic waves from the subject
through the subject holding member and the matching liquid stored
in the storing space.
11. The subject information acquiring apparatus according to claim
1, wherein the probe unit is moved relative to the subject holding
member.
12. The subject information acquiring apparatus according to claim
1, wherein the opening is provided at an upper side of the opposing
surface so as to release an air bubble left in the matching liquid
stored in the storing space.
13. The subject information acquiring apparatus according to claim
1, wherein the upper edge is located at a highest end of the
opposing surface in a vertical direction.
14. The subject information acquiring apparatus according to claim
1 further comprising a bed on which a subject testee can be in a
prone position, wherein the bed has a through hole located above
the subject holding member such that the subject of the subject
testee is able to be inserted through the through hole
downwardly.
15. A subject information acquiring apparatus comprising: a subject
holding member which holds a subject; and a probe unit having a
base member having an opposing surface facing to the subject
holding member, a transducer provided on the opposing surface, a
matching liquid storing member secured to the opposing surface and
contacting the subject holding member so as to form a storing space
storing a matching liquid between the opposing surface and the
subject holding member and a supply port supplying the matching
liquid into the storing space, wherein the matching liquid storing
member has an opening above the supply port, and wherein the probe
unit has a guide which directs the matching liquid overflowed from
the storing space via the opening to the subject holding
member.
16. The subject information acquiring apparatus according to claim
15, further comprising: a cable extending from the transducer
toward a direction in opposition to a direction toward the subject
holding member, wherein the guide restricts a flow of the matching
liquid to the cable in order to prevent the matching liquid from
being spilled on the cable.
17. The subject information acquiring apparatus according to claim
15, wherein the probe unit has a liquid level sensor detecting a
level of the matching liquid stored in the storing space.
18. The subject information acquiring apparatus according to claim
18, wherein the liquid level sensor is located higher than the
transducer so as to determine whether the storing space is filled
with the matching liquid or not.
19. A subject information acquiring apparatus comprising: a bed
having a through hole; a holding member holding a subject below the
through hole; a probe unit facing and being scanned with respect to
the holding member comprising: a base member having an opposing
surface facing to and spaced apart from the holding member; a
matching liquid holder secured to the opposing surface so as to
form a storing space to be stored an acoustic matching liquid
within; a transducer secured to the opposing surface to receive an
acoustic wave from the subject via the acoustic matching liquid
stored within the storing space; and a supply port provided to the
opposing surface, and a matching liquid retrieving unit comprising:
a tank reserving the matching liquid from the probe unit; and a
pump connected to the tank and the supply port so as to supply the
matching liquid from the tank into the storing space, wherein the
matching liquid holder has an opening located closer to the bed
than the transducer, and wherein the probe unit has a guide which
directs the matching liquid overflowed from the storing space via
the opening toward the tank.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser.
No. 13/776,200 filed Feb. 25, 2013 which claims priority from
Japanese Patent Application No. 2012-043808 filed Feb. 29, 2012,
all of which are hereby incorporated by reference herein in their
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a subject information
acquiring apparatus which receives acoustic waves from a
subject.
[0004] 2. Description of the Related Art
[0005] Japanese Patent Laid-Open No. 2011-103913 discloses a
subject information acquiring apparatus which utilizes a
photoacoustic effect, in which acoustic waves from a subject
irradiated with light are received with a probe to create an image
representing information on the subject. In this apparatus, a
breast being the subject is held with two subject-holding members
facing each other, and the probe is two-dimensionally moved in
horizontal and vertical directions along the subject-holding
members to receive acoustic waves. A housing which accommodates the
probe (transducer) has an oil sealing portion which enables a
matching liquid such as oil to be held between the probe and the
subject-holding member for acoustic impedance matching. The upper
surface of the oil sealing portion has an opening to remove bubbles
contained in the matching liquid. The matching liquid which has
spilled or overflowed from the opening runs down the
subject-holding member and is then retrieved to a tank by a
retrieving mechanism.
[0006] The apparatus disclosed in Japanese Patent Laid-Open No.
2011-103913 gives no consideration to the case in which matching
liquid flows out of the opening onto the upper surface of the
housing (namely, the matching liquid on the upper surface of the
housing). Part of the matching liquid on the upper surface of the
housing runs down a side surface of the housing and the back
surface thereof (opposite side of the subject-holding member
relative to the probe). In particular, in the apparatus disclosed
in Japanese Patent Laid-Open No. 2011-103913, the matching liquid
which has spilled from the opening onto the upper surface of the
housing directly falls down from the lower part of the housing
without running down the subject-holding member. In the case where
the fallen matching liquid does not land on a tray provided below
the subject-holding member, the matching liquid cannot be
retrieved, leading to possible fear of a decrease in the total
amount of the matching liquid. Even in the case where the matching
liquid which has not run down the subject-holding member falls on
the tray, the matching liquid splashes, which leads to a decrease
in the total amount of the matching liquid and makes the interior
of the apparatus dirty in some cases.
SUMMARY OF THE INVENTION
[0007] The present invention provides a subject information
acquiring apparatus which enables a matching liquid flowing from
the upper surface of a housing to run down a subject-holding
member.
[0008] An aspect of the present invention provides a subject
information acquiring apparatus including a subject-holding member
which holds a subject and a probe unit having a transducer which
receives acoustic waves from the subject through the
subject-holding member, a housing which accommodates the
transducer, and a matching liquid-holding member configured to hold
a matching liquid between the transducer and the subject-holding
member, the probe unit being allowed to move relative to the
subject-holding member, wherein the probe unit has a guide which
introduces the matching liquid toward the subject-holding member,
the matching liquid having been spilled from a space defined by the
matching liquid-holding member, the transducer, and the
subject-holding member onto the upper surface of the hosing and
then flowed from the upper surface of the housing.
[0009] Such an aspect of the present invention enables the matching
liquid flowing from the upper surface of the housing to run down
the subject-holding member, which can prevent a reduction in the
amount of the matching liquid and contribute to keeping the
interior of the apparatus clean.
[0010] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic perspective view illustrating a
subject information acquiring apparatus according to an embodiment
of the present invention.
[0012] FIG. 2 is a schematic perspective view illustrating an
examination unit according to an aspect of the present
invention.
[0013] FIG. 3A is a schematic perspective view illustrating a probe
unit according to a first embodiment of the present invention.
[0014] FIG. 3B is a schematic top view illustrating the probe unit
according to the first embodiment of the present invention.
[0015] FIG. 4A is a schematic cross-sectional view illustrating a
groove of a housing according to the first embodiment of the
present invention.
[0016] FIG. 4B is a schematic cross-sectional view illustrating
modifications of the groove of the housing.
[0017] FIGS. 5A and 5B are schematic side views each illustrating a
change in a state of a guide sheet according to an embodiment of
the present invention.
[0018] FIG. 6 is a schematic view illustrating a moving route of a
probe unit according to an embodiment of the present invention.
[0019] FIG. 7A is a schematic front view illustrating a probe unit
according to a second embodiment of the present invention.
[0020] FIG. 7B is a schematic side view illustrating the probe unit
according to the second embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0021] In the present invention, a probe unit has a guide
configured to introduce a matching liquid from a housing to a
subject-holding member, so that the matching oil flowing down from
the upper surface of the housing is guided to the subject-holding
member.
[0022] In the present invention, acoustic waves include elastic
waves such as a sound wave, an ultrasonic wave, a photoacoustic
wave, and an optical ultrasonic wave, and the probe receives the
acoustic waves propagated inside a subject. The subject information
acquiring apparatus of the present invention includes an apparatus
in which a subject is irradiated with light beams (electromagnetic
waves including visible light beams and infrared rays) to generate
acoustic waves inside the subject and the acoustic waves are
received to acquire information on the subject.
[0023] Information on a subject to be acquired indicates
characteristic information reflecting a distribution of the initial
sound pressure of acoustic waves generated by irradiation with
light, a density distribution of light energy absorption derived
from a distribution of the initial sound pressure, a distribution
of an absorption coefficient, and concentration distributions of
substances constituting tissues. The concentration distributions of
substances are, for example, a distribution of oxygen saturation
and a concentration distribution of oxygenated or reduced
hemoglobin. The information on a subject may be acquired not only
as numerical data but as a distribution of information in different
sites of the subject. In particular, a distribution of information,
such as a distribution of an absorption coefficient or a
distribution of oxygen saturation, may be acquired in the form of
image data.
[0024] The subject information acquiring apparatus of the present
invention may be an apparatus utilizing an ultrasonic pulse-echo
technique, in which ultrasonic waves are transmitted to a subject
and waves reflected inside the subject are received to acquire
information on the subject. In the apparatus utilizing an
ultrasonic pulse-echo technique, information on a subject to be
acquired is characteristic information reflecting a difference in
acoustic impedance between internal tissues of the subject.
[0025] Embodiments of the present invention will now be described
with reference to the accompanying drawings. The same components
are basically denoted by the same reference symbols to omit the
repeated description thereof.
First Embodiment
[0026] The present embodiment herein discussed gives an example of
an apparatus in which a subject is irradiated with light beams and
acoustic waves generated in the subject are received with a probe
to acquire information on the subject. FIG. 1 is a schematic
perspective view illustrating a subject information acquiring
apparatus of the present embodiment. The subject information
acquiring apparatus includes a supporting member 201 as a bed for
supporting a test subject 1 and an examination unit 100 provided
under the supporting member 201. The supporting member 201 has an
opening 202 into which a subject such as a breast being body part
of the test subject 1 is inserted. The examination unit 100
provided under the supporting member 201 receives acoustic waves
from a subject.
Examination Unit
[0027] FIG. 2 is a perspective view illustrating the internal
configuration of the examination unit 100. The examination unit 100
has a probe unit 10, an optical unit 40, and a fixing member 22 and
movable holding member 32 being a subject-holding member. An oil
tray 52 is provided below the fixing member 22 to retrieve matching
oil spilled from a space (space 15 in FIG. 3B) formed between a
probe inside the probe unit 10 and the fixing member 22. The oil
tray 52 is disposed so as to catch matching oil running down the
fixing member 22.
[0028] The probe unit 10 is attached to a probe-moving mechanism 21
having two shafts of a horizontal shaft 21a and a vertical shaft
21b and can therefore two-dimensionally move along the fixing
member 22. The probe-moving mechanism 21 is controlled by a micro
controller or computer (not illustrated) being a control unit. In
the present embodiment, the supporting member 201 is provided as a
counter member so as to overlie the probe unit 10. In the present
invention, however, the counter member is not limited to the
supporting member 201 and includes a member provided so as to
overlie a region in which a probe can move, such as a reinforcing
member for enhancing the strength of the subject-holding member. A
direction in which gravity works (direction of gravity field)
herein indicates "being downward (lower side)", and the direction
opposite thereto herein indicates "being upward (upper side)".
Subject-Holding Member
[0029] A subject to be examined (not illustrated) is held so as to
be pressed from two sides by the fixing member 22 and the movable
holding member 32 provided relative to the fixing member 22. The
fixing member 22 is preferably formed from a resin in view of
acoustic impedance matching between a subject and the probe inside
the probe unit 10, and an especially preferred material is
polymethylpentene. The fixing member 22 is attached to a fixing
plate 23, and the movable holding member 32 is attached to movable
plates 33. The movable plates 33 are provided so as to be movable
along guide rods 34 in a direction in which a subject is pressed to
be held and are driven by a holding member-driving mechanism 35.
The holding member-driving mechanism 35 includes a motor 35a, a
ball screw 35b, and a nut 35c. Since component onto which the nut
35c is provided is connected to the movable plates 33, driving of
the motor 35a enables the movable holding member 32 to move.
Optical Unit
[0030] The optical unit 40 is disposed so as to face the probe unit
10 with the fixing member 22 interposed therebetween. Light is
introduced from a light source (not illustrated) to the optical
unit 40 via an optical system, such as a fiber or a lens, and the
light is emitted from a light emission end of an optical system
inside the optical unit 40 to a subject through the movable holding
member 32. A laser which generates pulsed light on the order of
nanoseconds is used as the light source. The optical unit 40 can be
two-dimensionally moved by an optical unit-moving mechanism 31
having two shafts of a horizontal shaft 31a and a vertical shaft
31b as in the probe driving unit 21. The optical unit-moving
mechanism 31 is controlled by a micro controller or a computer (not
illustrated) as in the probe-moving mechanism 21. The probe-moving
mechanism 21 and the optical unit-moving mechanism 31 are
controlled in synchronism, so that the optical unit 40 and probe
unit 10 symmetrically disposed with a subject interposed
therebetween can be always moved while being kept at symmetrical
positions.
[0031] In the present embodiment, the probe unit 10 is disposed on
the side of the fixing member 22, and the optical unit 40 is
disposed on the side of the movable holding member 32; however, the
present invention should not be limited to such a configuration.
The probe unit 10 may be provided on the side of the movable
holding member 32 or may be provided on the both sides of the
fixing member 22 and the movable holding member 32. The optical
unit 40 may be provided on the side of the fixing member 22 or may
be provided on the both sides of the fixing member 22 and the
movable holding member 32. Furthermore, a fiber or another
component may be inserted into the probe unit 10 to emit light from
the interior of the probe unit 10. The configuration of the probe
unit 10 will now be described in detail.
Probe Unit
[0032] FIG. 3A is a schematic perspective view illustrating the
probe unit 10, and FIG. 3B is a schematic top view illustrating the
probe unit 10. The probe unit 10 has a probe 11 which receives
acoustic waves from a subject through the fixing member 22. The
term "probe" herein refers to a transducer which receives acoustic
waves and then converts the acoustic waves into electric signals.
Any transducer which receives acoustic waves and then converts the
acoustic waves into electric signals can be used, such as
piezoelectric transducers utilizing a piezoelectric phenomenon,
transducers utilizing optical resonance, and transducers utilizing
a change in capacitance. Multiple transducers may be arrayed, or a
single transducer may be provided.
[0033] The probe 11 is accommodated in a housing 12 and fixed
thereto. The housing 12 has a sealing member 13 being a matching
liquid-holding member and provided so as to surround the probe 11.
A packing formed from rubber, a porous material (e.g., sponge),
leather, or resin can be used as the sealing member 13. The housing
12 is pressed against the fixing member 22 with the sealing member
13 interposed therebetween, so that a space 15 can be formed
between the fixing member 22 and the probe 11 to hold matching oil
being a matching liquid for acoustic impedance matching. The
matching oil is held in the space 15 defined by the fixing member
22, the probe 11, and the sealing member 13.
[0034] The upper side of the space 15 is opened to release air
contained in the matching oil. In other words, an opening is
provided to the upper side of the space 15. The subject-holding
member-side surface of the housing 12 has a supply port 14 formed
to supply the matching oil to the space 15. The matching oil is
supplied from a tank (not illustrated) by using a pump (not
illustrated). The pump is controlled by a micro controller or a
computer (not illustrated). The matching liquid is preferably
degased, and water or any other liquid than oil can be used. The
tank holds the matching oil in an amount enough to fill the space
between the fixing member 22 and the probe 11 from the beginning of
an examination to the end.
[0035] An oil fence 12a is provided at the rear edge of the upper
surface of the housing 12 (on the side of a cable 11a of the probe
11) and functions as a partition which prevents the matching oil on
the housing 12 from flowing to the cable 11a. The partition of the
present invention is preferably bent or formed from an elastic
material so as to be deformable in response to application of
stress. Since the partition is deformable, the probe unit 10 can be
moved in close proximity to the counter member (supporting member
201 or another component) even in the case where the partition
contacts the counter member.
[0036] The housing 12 has grooves 12b (side guide portion) and a
guide sheet 17 (front guide portion) each constituting a guide for
the matching oil. The guide sheet 17 is preferably deformable in
response to application of stress from the fixing member 22 and is
formed so as to allow the movement of the probe unit 10 even in a
state in which the guide sheet 17 contacts the fixing member 22. A
polyethylene terephthalate (PET) film can be used for the guide
sheet 17.
[0037] The sizes, materials, shapes, and relative arrangement of
the below-mentioned components of the guide should be appropriately
changed depending on a variety of configurations and requirements
of apparatuses to which the present invention is applied. The
present invention should not be limited to the configuration
described below.
[0038] Each groove 12b of the guide of the present embodiment is
configured so as to extend toward the lower part of the housing 12
as approaching the fixing member 22 from the side of the oil fence
12a. FIG. 4A illustrates the cross-sectional structure with the
groove 12b viewed in the direction indicated by an arrow IVA in
FIG. 3A. Arrows in FIG. 4A schematically indicate the flow of the
matching oil from the upper surface of the housing 12. The matching
oil runs down the side surface of the housing 12 and then reaches
the groove 12b. The groove 12b has an upper edge 12c with an obtuse
angle, so that the matching oil can run along the shape of the
groove 12b and then reaches a bottom 12d of the groove 12b. The
angle of the edge 12c and the cross-sectional structure of the
groove 12b are not limited to those of the present embodiment, and
any structure can be employed provided that the matching oil
running down the side surface can be caught and guided to the
subject-holding member without being spilled from the groove 12b to
the side surface of the housing 12.
[0039] FIG. 4B illustrates modifications of the side guide portion.
As illustrated in FIG. 4B, the side surface may have a step and a
protrusion in place of the groove.
[0040] FIG. 5A is a side view illustrating the probe unit 10 and
the fixing member 22 in a state in which a subject is not held, and
FIG. 5B is a side view illustrating the probe unit 10 and the
fixing member 22 in a state in which the fixing member 22 is bent
as a result of holding a subject. The guide sheet 17 of the guide
is bent obliquely downward from the housing 12. In particular, the
level of the guide sheet 17 becomes decreased as the guide sheet 17
extends from the housing 12 to the fixing member 22. The matching
oil to be guided by the guide sheet 17 thus flows on the upper
surface of the guide sheet 17 and then is introduced to the fixing
member 22. Even in the case where the fixing member 22 is deformed
toward the probe unit 10 by pressing a subject for holding when the
probe unit 10 is moved, force acts in a direction in which the
guide sheet 17 is bent. In particular, the guide sheet 17 is
deformable. Examples of a material of the guide sheet 17 include a
sheet of PET, a sheet of another resin such as polycarbonate (PC),
a plate having a spring property, and rubber.
[0041] The guide sheet 17 is bonded to the housing 12 with an
adhesive exhibiting high sealing properties to prevent the leakage
of the matching oil from the bonded portion. The guide sheet 17 and
the housing 12 may be connected such that rubber or a porous
material (e.g., sponge) is provided therebetween while being fixed
with another component. The guide sheet 17 preferably has a width
larger than a width A of the housing 12. The fixing member 22-side
tip of the guide sheet 17 may not necessarily contact the fixing
member 22 provided that the matching oil flowing on the upper
surface of the guide sheet 17 can be introduced to the fixing
member 22. A distance which enables the matching oil to be
introduced to the fixing member 22 even though the guide sheet 17
does not contact the fixing member 22 can be determined depending
on the physical properties of the matching oil to be used, such as
surface tension and viscosity. If highly viscous matching oil
flowing through each groove 12b directly contacts the fixing member
22 and then runs down the fixing member 22, the guide sheet 17 may
not be provided. In other words, the guide of the present invention
may have only the side guide portion without the front guide
portion.
[0042] The space 15 defined by the fixing member 22, the probe 11,
and the sealing member 13 (at least between the fixing member 22
and the probe 11) is filled with the matching oil during an
examination. The subject-holding member-side surface of the housing
12 has a liquid surface sensor 16 provided at a level higher than
that of the sensor 11. In the case where the liquid surface sensor
16 can detect the matching oil, it is determined that the space
between the fixing member 22 and the probe 11 is filled with the
matching oil.
[0043] In preparation for an examination, a result of detection by
the liquid surface sensor 16 is viewed to determine whether the
space 15 is filled with the matching oil or not. If a result of
detection shows that the space 15 is filled with matching oil,
preparation for the examination has been finished. Even in the case
where the matching oil is spilled or leaked by the movement of the
probe unit 10 during an examination, the matching oil is constantly
supplied to the space 15 to maintain the amount enough for the
examination.
Moving Route of Probe Unit
[0044] A moving route of the probe unit 10 will now be described.
FIG. 6 is a schematic view illustrating a moving route of the probe
unit 10 during an examination. Arrows 61 indicate a route of the
movement of the probe unit 10 during an examination.
[0045] The probe unit 10 is positioned at the uppermost position in
an examination region (scanning region) at the initial stage of an
examination. Once the examination has started, the probe unit 10
sequentially scans a subject in a horizontal direction in one scan
line as indicated by the arrow 61 while receiving acoustic waves;
then, the probe unit 10 moves below to the next scan line and scans
the subject in the opposite direction in this scan line. These
processes are repeated to scan the subject in every single line in
sequence from the top. The probe unit 10 finally reaches the end
position and then returns to the initial position to complete the
examination. The scan procedure is not limited to such a procedure;
the probe unit 10 may move from a lower position to an upper
position to scan a subject, or a step-and-repeat process in which
the probe unit 10 stops at receiving positions to receive acoustic
waves may be employed. Traditional techniques can be used to create
image data of information on a subject from electric signals output
from the probe 11 which has received acoustic waves.
Flow of Matching Liquid
[0046] The flow of matching oil from the upper surface of the
housing 12 will now be described. Arrows in FIGS. 5A and 5B
schematically indicate the flow of the matching oil. In the case
where the matching oil is leaked or spilled onto the upper surface
of the housing 12, the matching oil runs down side surfaces of the
housing 12 because the fixing member 22 and the oil fence 12a are
provided in front of and in the rear of the housing 12,
respectively. The matching oil runs down the side surfaces of the
housing 12 to the grooves 12b and then is introduced to the front
side (side of the fixing member 22) of the housing 12 along the
grooves 12b. After the matching oil has reached the front side of
the housing 12, the matching oil flows down to the guide sheet 17
along the housing 12.
[0047] Then, the matching oil flows down from two ends 17a of the
guide sheet 17 (see, FIG. 3B) or the space between the fixing
member 22 and the guide sheet 17 along the fixing member 22. In the
case where a subject is held, the fixing member 22 is deformed by
being bent, and the distance between the fixing member 22 and the
housing 12 is therefore changed. For instance, a distance t1 is
secured in FIG. 5A in which a subject is not held; on the other
hand, the distance t1 is decreased to a distance t2 in FIG. 5B in
which a subject is held.
[0048] The distance between the fixing member 22 and the housing 12
also changes depending on the position of the probe unit 10. As
described above, the guide sheet 17 can be deformed in response to
application of stress from the fixing member 22. In the case where
the distance between the fixing member 22 and the housing 12 is
decreased, the tip of the guide sheet 17 shifts in the direction
indicated by an arrow C. In the case where the distance
therebetween is increased, the guide sheet 17 starts to return to
the initial shape; thus, the tip of the guide sheet 17 shifts
toward the fixing member 22. Hence, even though the distance
between the fixing member 22 and the housing 12 is changed, the
matching oil can be always guided from the guide sheet 17 to the
fixing member 22. Consequently, even in the case where the fixing
member 22 is deformed as a result of holding a subject, the
matching oil can be guided to the fixing member 22.
[0049] Although the guide sheet 17 of the present embodiment is a
single component, the present invention should not be limited to
such a structure. The guide sheet 17 preferably has a structure
which can be deformed in synchronism with the deformation of the
fixing member 22; for example, a base may be formed from a rigid
material such as aluminum, and a rubber sheet may be used to form
only a portion which contacts the fixing member 22. Furthermore, a
spring may be used to urge the guide sheet 17 against the fixing
member 22.
[0050] In the configuration of the present embodiment, the matching
oil which has spilled onto the upper surface of the housing 12 can
be introduced to the fixing member 22 by the guide which includes
grooves (steps or protrusions) as the side guide portion provided
to the side surfaces of the housing 12 and the guide sheet as the
front guide portion. The guide sheet 17 can be deformed in response
to application of stress; thus, even in the case where the probe
unit 10 is moved in a state in which the fixing member 22 is
deformed as a result of holding a subject, the matching oil can be
guided to the fixing member 22.
Second Embodiment
[0051] The present embodiment is different from the first
embodiment in the configuration of the guide. FIG. 7A is a
schematic front view illustrating the probe unit 10 of a second
embodiment, and FIG. 7B is a schematic side view illustrating the
probe unit 10 of the second embodiment. In the second embodiment,
side guide sheets 18 are provided as the side guide portion on the
side surfaces of the housing 12 in place of the grooves. Each side
guide sheet 18 is formed from, for example, a PET film. Each side
guide sheet 18 has a bonded part 18a attached to the housing 12 and
a folded part 18b at which the side guide sheet 18 is folded in an
oblique direction. Each side guide sheet 18 is bonded to the
housing 12 at the bonded part 18a with an adhesive exhibiting
sealing properties to prevent the leakage of the matching oil
therefrom. The housing 12 and each side guide sheet 18 may be
connected such that rubber or a porous material (e.g., sponge) is
provided therebetween while being fixed with another component.
[0052] Arrows in FIG. 7B schematically indicate the flow of the
matching oil. The matching oil which has run down the side surfaces
of the housing 12 to the side guide sheets 18 is introduced to the
front side of the housing 12 (side of the fixing member 22) along
the folded portions 18b of the side guide sheets 18. The matching
oil which has reached the front side of the housing 12 falls down
to the guide sheet 17 along the housing 12. The guide sheet 17 of
the present embodiment functions as the front guide portion as in
the first embodiment.
[0053] The amount of the flowing matching oil increases in some
cases depending on the driving speed of the probe unit 10. In the
case where the probe unit 10 is driven at a high speed (fast), for
example, the amount of the matching oil to be spilled increases;
thus, the amount of the flowing matching oil becomes increased in
some cases. In the first embodiment, an increase in the amount of
the matching oil flowing from the housing 12 onto its side surface
causes the side guide portions, such as grooves or protrusions, to
have increased size adequate for the increased amount of the
flowing matching oil. In such a case, formation of the side guide
portion may fall into difficulty, or the size of the housing 12 may
be increased in proportion to an increase in the size of the
grooves. Hence, the side guide portion of the present embodiment
has a configuration effective to the matching oil flowing in a
large amount.
[0054] In the present embodiment, each side guide sheet 18 being
the side guide portion and the guide sheet 17 being the front guide
portion are separately provided; however, these components may be
integrally provided. In particular, each side guide sheet 18 may be
extended across the front surface (probe 11-side surface) of the
housing 12 to the side of the fixing member 22 and function also as
the front guide portion. The guide having such a configuration can
also introduce the matching oil to the fixing member 22.
[0055] Even in the case where each side guide sheet 18 has the
configuration illustrated in FIGS. 7A and 7B, the guide sheet 17
may not be formed, provided that highly viscous matching oil
running down each side guide sheet 18 can directly contact the
fixing member 22 and then run down the fixing member 22. In other
words, only the side guide portion can serve as the guide of the
present invention without use of the front guide portion.
[0056] As described above, in the present embodiment, each side
guide sheet 18 provided to the housing 12 as the side guide portion
can also introduce the matching oil flowing from the upper surface
of the housing 12 to the fixing member 22.
[0057] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
* * * * *