U.S. patent application number 14/600955 was filed with the patent office on 2015-05-14 for magnetically guiding system and magnetically guiding method.
This patent application is currently assigned to OLYMPUS MEDICAL SYSTEMS CORP.. The applicant listed for this patent is OLYMPUS MEDICAL SYSTEMS CORP.. Invention is credited to Atsushi Chiba, Atsushi Kimura, Hidetake Segawa.
Application Number | 20150133730 14/600955 |
Document ID | / |
Family ID | 41110961 |
Filed Date | 2015-05-14 |
United States Patent
Application |
20150133730 |
Kind Code |
A1 |
Segawa; Hidetake ; et
al. |
May 14, 2015 |
MAGNETICALLY GUIDING SYSTEM AND MAGNETICALLY GUIDING METHOD
Abstract
A magnetically guiding system includes: a capsule medical device
that has a magnet provided therein; an information acquiring unit
that acquires physical information about magnetic guiding of the
capsule medical device; a magnetic field generating unit that
generates a magnetic field for magnetically guiding the capsule
medical device; and a control unit that sets a magnetic field
condition based on the physical information acquired by the
information acquiring unit and controls the magnetic field
generating unit to generate a magnetic field corresponding to the
magnetic field condition.
Inventors: |
Segawa; Hidetake; (Tokyo,
JP) ; Chiba; Atsushi; (Tokyo, JP) ; Kimura;
Atsushi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OLYMPUS MEDICAL SYSTEMS CORP. |
Tokyo |
|
JP |
|
|
Assignee: |
OLYMPUS MEDICAL SYSTEMS
CORP.
Tokyo
JP
|
Family ID: |
41110961 |
Appl. No.: |
14/600955 |
Filed: |
January 20, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13796163 |
Mar 12, 2013 |
8968185 |
|
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14600955 |
|
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|
13617839 |
Sep 14, 2012 |
8419620 |
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13796163 |
|
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12486399 |
Jun 17, 2009 |
8303485 |
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13617839 |
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Current U.S.
Class: |
600/109 |
Current CPC
Class: |
A61B 1/00036 20130101;
A61B 5/065 20130101; A61B 1/00016 20130101; A61B 1/00158 20130101;
A61B 1/041 20130101; A61B 34/73 20160201; A61B 5/062 20130101; A61B
5/073 20130101; A61B 2034/732 20160201 |
Class at
Publication: |
600/109 |
International
Class: |
A61B 1/00 20060101
A61B001/00; A61B 1/04 20060101 A61B001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 19, 2008 |
JP |
2008160807 |
Oct 17, 2008 |
JP |
2008269048 |
Claims
1. A magnetically guiding system comprising: a capsule medical
device that has a magnet; an information acquiring device that
acquires physical information about magnetic guiding of the capsule
medical device; a magnetic field generating unit that generates a
magnetic field for magnetically guiding the capsule medical device;
a control unit that sets a magnetic field condition based on the
physical information acquired by the information acquiring device
and controls the magnetic field generating unit to generate the
magnetic field corresponding to the magnetic field condition; and a
receiving unit that receives a transmission signal from the capsule
medical device, the transmission signal containing an image
captured by the capsule medical device and the physical
information; wherein the capsule medical device stores the physical
information in advance and transmits the image together with the
stored physical information; and the information acquiring device
extracts the physical information from the transmission signal
received by the receiving unit from the capsule medical device.
2. A magnetically guiding system comprising: a capsule medical
device that has a magnet; an information acquiring device that
acquires physical information about magnetic guiding of the capsule
medical device; a magnetic field generating unit that generates a
magnetic field for magnetically guiding the capsule medical device;
a control unit that sets a magnetic field condition based on the
physical information acquired by the information acquiring device
and controls the magnetic field generating unit to generate the
magnetic field corresponding to the magnetic field condition; and
an image member that has a reference direction and has an image
drawn thereon; wherein the capsule medical device includes: an
image capturing unit that captures an image of the image member in
such a manner that the reference direction of the image member is
coincident with a magnetization direction of the magnet, the image
capturing unit having a reference direction; and a transmission
unit that radio-transmits the image captured by the image capturing
unit; the information acquiring device acquires image data of the
image of the image member captured by the image capturing unit when
the reference direction of the image member is coincident with the
magnetization direction of the magnet; and the information
acquiring device calculates an angle between the reference
direction of the image capturing unit and the magnetization
direction of the magnet, based on the image data and reference
image data of an image captured when the reference direction of the
image capturing unit is coincident with the reference direction of
the image member.
3. A magnetically guiding system comprising: a capsule medical
device that has a magnet; an information acquiring device that
acquires physical information about magnetic guiding of the capsule
medical device; a magnetic field generating unit that generates a
magnetic field for magnetically guiding the capsule medical device;
a control unit that sets a magnetic field condition based on the
physical information acquired by the information acquiring device
and controls the magnetic field generating unit to generate the
magnetic field corresponding to the magnetic field condition; and
an image member that has a reference direction and has an image
drawn thereon; wherein the magnetic field generating unit generates
a magnetic field that causes the capsule medical device to rotate
in such a manner that a reference direction of an image acquired by
the information acquiring device is coincident with the reference
direction of the image member, the capsule medical device includes:
an image capturing unit that captures an image of the image member;
and a transmission unit that radio-transmits the image captured by
the image capturing unit; and the information acquiring device
calculates an angle between a magnetization direction of the magnet
and the reference direction of the image member, based on a
direction of the magnetic field generated from the magnetic field
generating unit.
4. A magnetically guiding system comprising: a medical device that
has a magnet; an information acquiring device that acquires
physical information about magnetic guiding of the medical device;
a magnetic field generating unit that generates a magnetic field
for magnetically guiding the medical device; and a control unit
that sets a magnetic field condition based on the physical
information acquired by the information acquiring device and
controls the magnetic field generating unit to generate the
magnetic field corresponding to the magnetic field condition;
wherein the medical device further includes a resonance circuit;
and the magnetically guiding system further comprises a resonance
characteristics measuring unit that measures resonance
characteristics of the medical device by detecting an induced
magnetic field generated from the resonance circuit.
5. The magnetically guiding system according to claim 4, wherein
the medical device is a capsule medical device.
6. A magnetically guiding system comprising: a medical device that
has a magnet; an information acquiring device that acquires
physical information about magnetic guiding of the medical device;
a magnetic field generating unit that generates a magnetic field
for magnetically guiding the medical device; and a control unit
that sets a magnetic field condition based on the physical
information acquired by the information acquiring device and
controls the magnetic field generating unit to generate the
magnetic field corresponding to the magnetic field condition;
wherein the information acquiring device includes a supporting unit
that supports the medical device.
7. The magnetically guiding system according to claim 6, wherein
the medical device is a capsule medical device.
8. The magnetically guiding system according to claim 6, wherein
the medical device is housed in a package, and the supporting unit
supports the medical device via the package.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation application of U.S. Ser.
No. 13/796,163, filed on Mar. 12, 2013, which is a Continuation
application of U.S. Ser. No. 13/617,839, filed on Sep. 14, 2012,
which is a Divisional application of U.S. Ser. No. 12/486,399,
filed on Jun. 17, 2009, which is based upon and claims the benefit
of priority from Japanese Patent Applications No. 2008-160807,
filed on Jun. 19, 2008, and No. 2008-269048, filed on Oct. 17,
2008, the entire contents of each of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a magnetically guiding
system and a magnetically guiding method for magnetically guiding a
medical device that is introduced into the body of a test
subject.
[0004] 2. Description of the Related Art
[0005] In the field of endoscopes, there have been capsule medical
devices having image capturing functions and radio communication
functions. A capsule medical device is introduced into the body of
a test subject such as a patient via the oral route, to check the
inside of an internal organ of the test subject. The capsule
medical device inside the body of the test subject sequentially
captures images of the inside of the internal organ (hereinafter
also referred to as in-vivo images) at predetermined intervals,
while moving in the internal organ through peristaltic movement.
The capsule medical device then sequentially radio-transmits the
in-vivo images to the outside. The capsule medical device inside
the body of the test subject sequentially repeats the capture and
radio transmission of the in-vivo images until it is excreted from
the body of the test subject. In the end, the capsule medical
device is excreted from the body of the test subject.
[0006] Each of the in-vivo images captured by the capsule medical
device is received by a receiving device outside the body of the
test subject, and is input to an image display device via the
receiving device. The image display device displays each of the
in-vivo images on its display screen. A user such as a medical
doctor or a nurse observes the inside of the internal organ of the
test subject through each of the in-vivo images displayed on the
image display device. Based on the observation result, the user can
make a diagnosis on the test subject.
[0007] In recent years, systems that magnetically guide a capsule
medical device inside the body of a test subject have been
proposed. As an example of such a magnetically guiding system,
there is a system that magnetically guides a video capsule inside a
human body located in an operating space surrounded by fourteen
individual coils (see Japanese Patent Application Laid-open No.
2005-81147).
[0008] In a medical device guiding system disclosed in Japanese
Patent Application Laid-open No. 2004-255174, a capsule medical
device that has an image capturing function and a magnet enclosed
inside a capsule-like casing is introduced into a digestive tract
of a test subject, and a rotating magnetic field is applied to the
capsule medical device inside the body of the test subject, so as
to magnetically guide the capsule medical device to a desired
position inside the body of the test subject. In this case, the
capsule medical device inside the body of the test subject moves,
as the magnet inside the capsule-like casing follows the rotating
magnetic field applied from the outside.
SUMMARY OF THE INVENTION
[0009] A magnetically guiding system according to an aspect of the
present invention includes a medical device that has a magnet; an
information acquiring device that acquires physical information
about magnetic guiding of the medical device; a magnetic field
generating unit that generates a magnetic field for magnetically
guiding the medical device; and a control unit that sets a magnetic
field condition based on the physical information acquired by the
information acquiring device and controls the magnetic field
generating unit to generate the magnetic field corresponding to the
magnetic field condition.
[0010] A magnetically guiding method according to another aspect of
the present invention includes acquiring physical information about
magnetic guiding of a medical device that includes a magnet;
setting a magnetic field condition for a magnetic field to be
applied to the medical device based on the acquired physical
information; and applying the magnetic field corresponding to the
set magnetic field condition to the medical device inside a test
subject, so as to magnetically guide the medical device.
[0011] The above and other features, advantages and technical and
industrial significance of this invention will be better understood
by reading the following detailed description of presently
preferred embodiments of the invention, when considered in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with a
first embodiment of the present invention;
[0013] FIG. 2 schematically shows a specific example of a magnetic
field condition table;
[0014] FIG. 3 is a schematic cross-sectional view showing an
example structure of a capsule medical device to be magnetically
guided;
[0015] FIG. 4 is a flowchart illustrating an example of a
magnetically guiding method in accordance with the first embodiment
of the present invention;
[0016] FIG. 5 is a schematic view showing an example of the capsule
medical device that is floating in a liquid, with an image viewing
field facing vertically upward;
[0017] FIG. 6 is a schematic view showing an example of an image
captured by the capsule medical device that is floating in the
liquid, with an image viewing field facing vertically upward;
[0018] FIG. 7 is a schematic view showing an example of a container
in which the capsule medical device floats on the liquid
surface;
[0019] FIG. 8 is a schematic view showing a situation where the
capsule medical device is floating in the liquid in the container,
with an image viewing field facing vertically downward;
[0020] FIG. 9 is a schematic view showing an example of an image
captured by the capsule medical device that is floating in the
liquid, with an image viewing field facing vertically downward;
[0021] FIG. 10 is a schematic view showing an example of the
capsule medical device that is floating in the liquid while
tilting;
[0022] FIG. 11 is a schematic view showing an example of an image
captured by the capsule medical device that is floating in the
liquid while tilting;
[0023] FIG. 12 is a schematic view showing a situation where the
capsule medical device introduced into the body of a test subject
is magnetically guided;
[0024] FIG. 13 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with a
second embodiment of the present invention;
[0025] FIG. 14 is a schematic view showing an example case where a
sheet-like member is put on the liquid surface in a container;
[0026] FIG. 15 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with a
third embodiment of the present invention;
[0027] FIG. 16 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with a
fourth embodiment of the present invention;
[0028] FIG. 17 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with a
fifth embodiment of the present invention;
[0029] FIG. 18 is a block diagram schematically showing an example
structure of a checking device in accordance with a sixth
embodiment of the present invention;
[0030] FIG. 19 is a schematic view showing an example structure of
a capsule medical device to be checked by the checking device in
accordance with the sixth embodiment of the present invention;
[0031] FIG. 20 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with the
sixth embodiment of the present invention;
[0032] FIG. 21 is a schematic view showing an example case where
the magnetic moment of a magnet inside the capsule medical device
is measured by the checking device in accordance with the sixth
embodiment of the present invention;
[0033] FIG. 22 is a block diagram schematically showing an example
structure of a checking device in accordance with a seventh
embodiment of the present invention;
[0034] FIG. 23 is a schematic view showing an example case where
the magnetic moment of a magnet inside a capsule medical device is
measured by the checking device in accordance with the seventh
embodiment of the present invention;
[0035] FIG. 24 is a block diagram schematically showing an example
structure of a checking device in accordance with an eighth
embodiment of the present invention;
[0036] FIG. 25 is a schematic view showing an example of an image
drawn on an image member;
[0037] FIG. 26 is a schematic view illustrating an operation by the
checking device in accordance with the eighth embodiment of the
present invention to measure the angle between the reference
direction of a magnet provided in a capsule medical device and the
reference direction of an image capturing unit;
[0038] FIG. 27 is a block diagram schematically showing an example
structure of a checking device in accordance with a ninth
embodiment of the present invention;
[0039] FIG. 28 is a schematic view illustrating an operation by the
checking device in accordance with the ninth embodiment of the
present invention to calculate the angle between the reference
direction of a magnet provided in a capsule medical device and the
reference direction of an image capturing unit; and
[0040] FIG. 29 is a block diagram schematically showing an example
structure of a checking device in accordance with a tenth
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] The following is a description of preferred embodiments of
magnetically guided systems and magnetically guiding methods
according to the present invention, with reference to the
accompanying drawings. It should be noted that the present
invention is not limited by the following embodiments. In the
accompanying drawings, like components are denoted by like
reference numerals.
[0042] FIG. 1 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with a
first embodiment of the present invention. The magnetically guiding
system in accordance with the first embodiment is a system that
magnetically guides a capsule medical device 10 to be introduced
into an internal organ of a test subject. As shown in FIG. 1, the
magnetically guiding system includes a magnetically guiding unit 2,
a receiving unit 3, an information acquiring unit 4, an input unit
5, a display unit 6, a storage unit 7, and a control unit 8.
[0043] The magnetically guiding unit 2 magnetically guides the
capsule medical device 10 introduced into the internal organ of the
test subject. The magnetically guiding unit 2 includes a magnetic
field generating unit 2a that outputs a guiding magnetic field, and
a power supply unit 2b that supplies electric power to the magnetic
field generating unit 2a.
[0044] The magnetic field generating unit 2a may be embodied with
the use of an electromagnet such as a Helmholtz coil. The magnetic
field generating unit 2a outputs a guiding magnetic field based on
the electric power supplied from the power supply unit 2b, and
applies the guiding magnetic field to the capsule medical device
10. The magnetic field generating unit 2a magnetically guides the
capsule medical device 10 by virtue of the action (such as magnetic
attraction, magnetic repulsion, magnetic gradient, or magnetic
torque) of the guiding magnetic field.
[0045] The power supply unit 2b supplies the electric power
required for generating the guiding magnetic field to be applied to
the capsule medical device 10, to the magnetic field generating
unit 2a. More specifically, the power supply unit 2b includes one
or more current signal generating unit(s) (not shown) corresponding
to one or more electromagnet(s) (coil(s)) that configure the
magnetic field generating unit 2a. Under the control of the control
unit 8, the power supply unit 2b generates current signals of
various patterns to apply the signals to the magnetic field
generating unit 2a, and supplies alternating currents of various
patterns to the magnetic field generating unit 2a. In accordance
with the patterns of the current signals supplied from the power
supply unit 2b, the magnetic field generating unit 2a applies
guiding magnetic fields of various output patterns to the capsule
medical device 10.
[0046] The receiving unit 3 receives an image that is captured by
the capsule medical device 10. More specifically, the receiving
unit 3 includes receiving antennas 3a, and receives a radio signal
from the capsule medical device 10 via at least one of the
receiving antennas 3a. The receiving unit 3 performs predetermined
communication processing such as demodulation on the radio signal
received from the capsule medical device 10, so as to demodulate
the radio signal to an image signal. The image signal contains at
least the data of the image captured by the capsule medical device
10. The receiving unit 3 then transmits the image signal from the
capsule medical device 10 to the information acquiring unit 4 and
the control unit 8.
[0047] Based on the image received by the receiving unit 3 from the
capsule medical device 10, the information acquiring unit 4
acquires physical information about the magnetic guiding of the
capsule medical device 10. More specifically, from the receiving
unit 3, the information acquiring unit 4 obtains the image signal
demodulated by the receiving unit 3 (that is, the image signal
transmitted from the capsule medical device 10). The information
acquiring unit 4 performs predetermined image processing on the
image signal, so as to generate the image captured by the capsule
medical device 10. Based on the generated image captured by the
capsule medical device 10, the information acquiring unit 4
calculates the physical information about the magnetic guiding of
the capsule medical device 10. In this manner, the information
acquiring unit 4 acquires the physical information about the
magnetic guiding of the capsule medical device 10. The information
acquiring unit 4 then transmits the physical information to the
control unit 8.
[0048] The physical information about the magnetic guiding of the
capsule medical device 10 relates to the field conditions of the
guiding magnetic field to be applied to the capsule medical device
10 when the capsule medical device 10 is magnetically guided. For
example, the physical information contains the information
indicating the density of the capsule medical device 10 or the
position of the center of gravity of the capsule medical device
10.
[0049] The input unit 5 may be embodied with the use of input
devices such as a mouse and a keyboard, and inputs various kinds of
information into the control unit 8 in accordance with input
operations by users. More specifically, the input unit 5 inputs
instruction information directed to the control unit 8 and physical
information and the likes required for calculating the physical
information about the magnetic guiding of the capsule medical
device 10. The physical information to be input by the input unit 5
includes the volume and mass of the capsule medical device 10, the
curvature radius of the dome-like part of the capsule medical
device 10, the density of the liquid to be introduced together with
the capsule medical device 10 into the test subject, and the
likes.
[0050] The display unit 6 may be embodied with the use of a display
device such as a CRT display or a liquid crystal display. The
display unit 6 displays various kinds of information instructed by
the control unit 8. Under the control of the control unit 8, the
display unit 6 displays the input information supplied from the
input unit 5, the image that is captured by the capsule medical
device 10 and is received by the receiving unit 3, the physical
information acquired by the information acquiring unit 4 (that is,
the physical information about the magnetic guiding of the capsule
medical device 10), the information indicating the magnetically
guided state of the capsule medical device 10, or the like.
[0051] The storage unit 7 may be embodied with the use of a storage
medium that stores information in a rewritable fashion, such as a
RAM, an EEPROM, a flash memory, or a hard disk. The storage unit 7
stores various kinds of information instructed to store by the
control unit 8, and transmits information among the stored various
kinds of information to the control unit 8 in accordance with a
read instruction issued from the control unit 8. More specifically,
under the control of the control unit 8, the storage unit 7
appropriately stores or updates the physical information that is
input by the input unit 5, the image captured by the capsule
medical device 10, the physical information about the magnetic
guiding of the capsule medical device 10, or the like.
[0052] The storage unit 7 also stores beforehand a magnetic field
condition table 7a designed for setting the magnetic field
conditions for the guiding magnetic field. FIG. 2 is a schematic
view showing a specific example of the magnetic field condition
table. The magnetic field condition table 7a is a data table that
associates the physical information about the magnetic guiding of
the capsule medical device 10 with the magnetic field conditions
for the guiding magnetic field. More specifically, the magnetic
field condition table 7a stores the density ranges R1 through Rn of
the density .rho..sub.CP of the capsule medical device 10, and the
output patterns A1 through An as the magnetic field conditions for
the guiding magnetic field, as shown in FIG. 2. In this case, the
density ranges R1 through Rn of the density .rho..sub.CP are
associated with the output patterns A1 through An of the guiding
magnetic field, respectively. The density .rho..sub.CP is an
example of the physical information about the magnetic guiding of
the capsule medical device 10, and is calculated by the information
acquiring unit 4. The output patterns A1 through An each associated
with the density ranges R1 through Rn of the density .rho..sub.CP
represent the optimum conditions (the optimum output patterns) for
the guiding magnetic field that varies with the density range of
the capsule medical device 10.
[0053] The control unit 8 controls the operations of the
magnetically guiding unit 2, the receiving unit 3, the information
acquiring unit 4, the input unit 5, the display unit 6, and the
storage unit 7, which are components of the magnetically guiding
system 1. The control unit 8 also controls signal inputs and
outputs between those components. More specifically, in accordance
with the instruction information that is input from the input unit
5, the control unit 8 controls the receiving operation of the
receiving unit 3, the information acquiring operation of the
information acquiring unit 4, the displaying operation of the
display unit 6, the storing operation of the storage unit 7, and
the likes. In this case, the control unit 8 stores various kinds of
information such as the information acquired by the information
acquiring unit 4 (that is, the physical information about the
magnetic guiding of the capsule medical device 10) or the
information input from the input unit 5, into the storage unit 7.
The control unit 8 then causes the display unit 6 to display the
various kinds of information, when appropriate. The control unit 8
also has an image processing function, and performs predetermined
image processing on the image signal acquired from the receiving
unit 3 so as to generate the image captured by the capsule medical
device 10. The control unit 8 then causes the display unit 6 to
display the generated image, and stores the generated image into
the storage unit 7. The control unit 8 reads out the various kinds
of information stored in the storage unit 7, when necessary.
[0054] The control unit 8 also includes a magnetic field condition
setting unit 8a that sets the magnetic field conditions for the
guiding magnetic field. The magnetic field condition setting unit
8a obtains the information acquired by the information acquiring
unit 4, that is, the physical information about the magnetic
guiding of the capsule medical device 10, from the information
acquiring unit 4. Based on the physical information, the magnetic
field condition setting unit 8a sets the magnetic field conditions
for the guiding magnetic field. In this case, the magnetic field
condition setting unit 8a selects the magnetic field condition
corresponding to the obtained physical information from the
magnetic field condition table 7a stored in the storage unit 7, and
sets the selected magnetic field condition as the magnetic field
condition for the guiding magnetic field. The control unit 8
controls the magnetically guiding unit 2 to apply the guiding
magnetic field satisfying the set magnetic field condition to the
capsule medical device 10. In this manner, the capsule medical
device 10 is magnetically guided. In this case, the control unit 8
controls the power supply unit 2b to apply the current signal of
the pattern satisfying the magnetic field condition to the magnetic
field generating unit 2a, and controls the guiding magnetic field
generating operation of the magnetic field generating unit 2a by
controlling the power supply unit 2b. After that, the control unit
8 uses the set magnetic field condition as the initial condition
for the guiding magnetic field. In accordance with the instruction
information that is input from the input unit 5, the control unit 8
controls the current signal to be applied from the power supply
unit 2b to the magnetic field generating unit 2a, and controls the
guiding magnetic field generating operation of the magnetic field
generating unit 2a by controlling the current signal. In this
manner, the control unit 8 continuously controls the magnetic
guiding of the capsule medical device 10, starting from controlling
the magnetically guided state of the capsule medical device 10
following the guiding magnetic field satisfying the initial
condition.
[0055] Next, the structure of the capsule medical device 10 to be
magnetically guided will be described. FIG. 3 is a schematic
cross-sectional view showing an example structure of the capsule
medical device to be magnetically guided. As shown in FIG. 3, the
capsule medical device 10 includes a capsule-like casing 11 that is
the exterior packaging designed in such a size as to be easily
introduced into an internal organ of a test subject such as a
patient, illuminating units 12 and 13 that illuminate different
photographic subjects in different directions, and image capturing
units 14 and 15 that capture images of the different photographic
subjects. The capsule medical device 10 also includes a radio
communication unit 16 that radio-transmits images captured by the
image capturing units 14 and 15 to the outside, a control unit 17
that controls the components of the capsule medical device 10, and
a power source unit 18 that supplies electric power to each of the
components of the capsule medical device 10. The capsule medical
device 10 further includes a magnet 19 for operating in accordance
with the guiding magnetic field applied by the magnetic field
generating unit 2a.
[0056] The capsule-like casing 11 is an exterior casing that is
formed in such a size as to be easily introduced into an internal
organ of a test subject such as a patient. The capsule-like casing
11 includes a cylindrical casing 11a having both opening ends
closed by dome-like casings 11b and 11c. The dome-like casings 11b
and 11c are dome-like optical members that are transparent to
illuminating light such as visible light emitted from the
illuminating units 12 and 13. The cylindrical casing 11a is a
colored casing that is substantially not transparent to visible
light. The capsule-like casing 11 formed with the cylindrical
casing 11a and the dome-like casings 11b and 11c encloses the
illuminating units 12 and 13, the image capturing units 14 and 15,
the radio communication unit 16, the control unit 17, the power
source unit 18, and the magnet 19 in a liquid-tight manner.
[0057] The illuminating units 12 and 13 may be embodied with the
use of light emitting devices such as LEDs, and illuminate the
respective image viewing fields D1 and D2 of the image capturing
units 14 and 15 that capture images in different directions from
each other. More specifically, the illuminating unit 12 emits
illuminating light onto the image viewing field D1 of the image
capturing unit 14, and illuminates the subject of the image
capturing unit 14 through the dome-like casing 11b. The
illuminating unit 13 emits illuminating light onto the image
viewing field D2 of the image capturing unit 15, and illuminates
the subject of the image capturing unit 15 through the dome-like
casing 11c.
[0058] The image capturing units 14 and 15 capture images in
different directions from each other. More specifically, the image
capturing unit 14 includes a solid-state image sensor 14a such as a
CMOS image sensor or a CCD, and an optical system 14b such as a
lens that forms an image of the subject located in the image
viewing field D1 on the light receiving face of the solid-state
image sensor 14a. The image capturing unit 14 captures an image of
the subject located in the image viewing field D1 illuminated by
the illuminating unit 12. The image capturing unit 15 includes a
solid-state image sensor 15a such as a CMOS image sensor or a CCD,
and an optical system 15b such as a lens that forms an image of the
subject located in the image viewing field D2 on the light
receiving face of the solid-state image sensor 15a. The image
capturing unit 15 captures an image of the subject located in the
image viewing field D2 illuminated by the illuminating unit 13.
[0059] In a case where the capsule medical device 10 is a twin-lens
capsule medical device that captures images from the front side and
the rear side in the long axis direction, as shown in FIG. 3, the
optic axes of the image capturing units 14 and 15 are substantially
parallel to or identical to a long axis CL that is the central axis
of the capsule-like casing 11 in the longitudinal direction. The
image viewing fields D1 and D2 of the image capturing units 14 and
15 extend in the opposite directions from each other.
[0060] The radio communication unit 16 has an antenna 16a, and
sequentially radio-transmits images captured by the image capturing
units 14 and 15 through the antenna 16a. More specifically, the
radio communication unit 16 obtains the image signal of an image
captured by the image capturing unit 14 or 15 from the control unit
17. The radio communication unit 16 performs modulation or the like
on the image signal, so as to generate a radio signal formed by
modulating the image signal. The radio communication unit 16 then
transmits the radio signal to the external receiving unit 3 (see
FIG. 1) through the antenna 16a.
[0061] The control unit 17 controls the illuminating units 12 and
13, the image capturing units 14 and 15, and the radio
communication unit 16, and also controls inputs and outputs of
signals among those components. More specifically, the control unit
17 causes the image capturing unit 14 to capture an image of the
subject located in the image viewing field D1 illuminated by the
illuminating unit 12, and causes the image capturing unit 15 to
capture an image of the subject located in the image viewing field
D2 illuminated by the illuminating unit 13. The control unit 17
also causes the radio communication unit 16 to sequentially
radio-transmit images captured by the image capturing units 14 and
15 in chronological order.
[0062] The control unit 17 also includes a signal processing unit
17a. The signal processing unit 17a obtains the image data about
the image viewing field D1 from the image capturing unit 14. Every
time the image data is obtained, the signal processing unit 17a
performs predetermined signal processing on the image data, so as
to generate an image signal containing the image data about the
image viewing field D1. Likewise, the signal processing unit 17a
obtains the image data about the image viewing field D2 from the
image capturing unit 15. Every time the image data is obtained, the
signal processing unit 17a performs predetermined signal processing
on the image data, so as to generate an image signal containing the
image data about the image viewing field D2. Each of the image
signals generated by the signal processing unit 17a is sequentially
transmitted to the radio communication unit 16.
[0063] The power source unit 18 includes a storage unit such as a
button-type battery cell or a capacitor, and a switching unit such
as a magnetic switch. The power source unit 18 switches the power
source on and off in accordance with a magnetic field applied from
the outside. When the power source is switched on, the power source
unit 18 appropriately supplies the power from the storage unit to
the components (the illuminating units 12 and 13, the image
capturing units 14 and 15, the radio communication unit 16, and the
control unit 17) of the capsule medical device 10. When the power
source is switched off, the power source unit 18 stops the power
supply to the components of the capsule medical device 10.
[0064] The magnet 19 is provided to enable the magnetic guiding of
the capsule medical device 10 by a magnetic field applied from the
outside. More specifically, the magnet 19 is placed in a
predetermined position inside the capsule-like casing 11, and forms
a magnetic field in a predetermined direction (such as the long
axis direction or the radial direction of the capsule-like casing
11). This magnet 19 operates in accordance with a magnetic field
induced from outside of the capsule-like casing 11, or the guiding
magnetic field applied by the magnetic field generating unit 2a
shown in FIG. 1. As a result, the capsule medical device 10 is
magnetically guided. In this case, the capsule medical device 10
makes at least one of a posture changing action and a displacement
action, by virtue of the effect of the magnet 19. Alternatively,
the capsule medical device 10 is maintained in a stopped state at a
predetermined position, by virtue of the effect of the magnet
19.
[0065] Next, the operation of the magnetically guiding system 1 in
accordance with the first embodiment of the present invention will
be described. FIG. 4 is a flowchart showing an example of a
magnetically guiding method in accordance with the first embodiment
of the present invention. The magnetically guiding system 1 in
accordance with the first embodiment magnetically guides the
capsule medical device 10, according to the procedures shown in
FIG. 4.
[0066] As shown in FIG. 4, the control unit 8 of the magnetically
guiding system 1 determines whether there is an instruction to set
a magnetic field condition for magnetically guiding the capsule
medical device 10 (step S101). In a case where the input unit 5 has
input instruction information to instruct the setting of a magnetic
field condition, the control unit 8 determines from the instruction
information that there is an instruction to set a magnetic field
condition in step S101. In a case where such instruction
information has not been input, the control unit 8 determines that
there is not an instruction to set a magnetic field condition.
[0067] If the control unit 8 determines in step S101 that there is
an instruction to set a magnetic field condition (step S101, Yes),
the control unit 8 obtains the physical information about the
magnetic guiding of the capsule medical device 10 to be
magnetically guided (step S102). In step S102, the control unit 8
controls the receiving unit 3 to receive an image captured by the
capsule medical device 10 in a floating or sunken state in a
liquid. The control unit 8 also controls the information acquiring
unit 4 to calculate the physical information about the magnetic
guiding of the capsule medical device 10, based on the image that
is captured by the capsule medical device 10 and is received by the
receiving unit 3. Under the control of the control unit 8, the
information acquiring unit 4 calculates the physical information
about the magnetic guiding of the capsule medical device 10, and
transmits the calculated physical information to the control unit
8. In this manner, the control unit 8 obtains the physical
information about the magnetic guiding of the capsule medical
device 10.
[0068] The control unit 8 then determines whether the physical
information obtained in step S102 is within a predetermined range
(step S103). In step S103, if the physical information is the
density .rho..sub.CP of the capsule medical device 10, the magnetic
field condition setting unit 8a reads the magnetic field condition
table 7a from the storage unit 7, and determines whether the
density .rho..sub.CP falls into one of the density ranges R1
through Rn.
[0069] If the physical information obtained in step S102 is within
the predetermined range (step S103, Yes), the control unit 8 sets a
magnetic field condition for magnetically guiding the capsule
medical device 10 (step S104). In step S104, the magnetic field
condition setting unit 8a sets the magnetic field condition for
magnetically guiding the capsule medical device 10, based on the
physical information about the magnetic guiding of the capsule
medical device 10 obtained from the information acquiring unit
4.
[0070] More specifically, in a case where the physical information
is the density .rho..sub.CP of the capsule medical device 10, the
magnetic field condition setting unit 8a reads the magnetic field
condition table 7a from the storage unit 7. While referring to the
magnetic field condition table 7a, the magnetic field condition
setting unit 8a sets the magnetic field condition suited for the
capsule medical device 10 having the density .rho..sub.CP. In this
case, the magnetic field condition setting unit 8a determines
whether the density .rho..sub.CP falls into one of the density
ranges R1 through Rn in the magnetic field condition table 7a. The
magnetic field condition setting unit 8a then selects the output
pattern of the magnetic field (one of the output patterns A1
through An) associated with the determined density range as the
magnetic field condition. For example, if the density .rho..sub.CP
falls into the density range R1, the magnetic field condition
setting unit 8a selects the output pattern A1 as the magnetic field
condition. If the density .rho..sub.CP falls into the density range
Rn, the magnetic field condition setting unit 8a selects the output
pattern An as the magnetic field condition.
[0071] In a case where the physical information is the position of
the center of gravity of the capsule medical device 10, the
magnetic field condition setting unit 8a sets a magnetic field
condition suited for the capsule medical device 10 having the
position of the center of gravity. In this case, the magnetic field
condition setting unit 8a sets the initial magnetic field direction
and the initial field intensity of the magnetic field to be applied
to the capsule medical device 10, based on the relative shift
amount and direction of the position of the center of gravity with
respect to the long axis CL of the capsule medical device 10 shown
in FIG. 3. Although the position of the center of gravity is
shifted from the long axis CL, the capsule medical device 10
subjected to the guiding magnetic field having the initial magnetic
field direction and the initial field intensity floats upright in
the liquid (or stands in such a manner that the long axis CL is
substantially parallel to the vertical direction of the capsule
medical device 10).
[0072] If the control unit 8 determines that the physical
information obtained in step S102 is not within the predetermined
range (step S103, No), the magnetic field condition setting unit 8a
determines that the density .rho..sub.CP is outside the density
ranges R1 through Rn defined in the magnetic field condition table
7a, for example. After that, the control unit 8 causes the display
unit 6 to display error information (step S105), and ends this
operation. In step S105, the control unit 8 causes the display unit
6 to display the error information indicating that the density pop
is outside the density ranges R1 through Rn defined in the magnetic
field condition table 7a.
[0073] After setting the magnetic field condition for magnetically
guiding the capsule medical device 10 in step S104 as described
above, the control unit 8 determines whether there is an
instruction to magnetically guide the capsule medical device 10
(step S106). In a case where instruction information to
magnetically guide the capsule medical device 10 has been input by
the input unit 5, the control unit 8 determines that there is an
instruction to magnetically guide the capsule medical device 10,
based on the instruction information in step S106. In a case where
such instruction information has not been input, the control unit 8
determines that there is not an instruction to magnetically guide
the capsule medical device 10.
[0074] If the control unit 8 determines that there is an
instruction to magnetically guide the capsule medical device 10 in
step S106 (step S106, Yes), the control unit 8 controls the
magnetically guiding unit 2 to output a guiding magnetic field to
the capsule medical device 10 to be magnetically guided (step
S107). In step S107, the control unit 8 controls the magnetic field
generating unit 2a and the current supply unit 2b to apply the
guiding magnetic field satisfying the magnetic field condition (an
output pattern, field intensity, a magnetic field direction, or the
like) set in step S104 to the capsule medical device 10. As a
result, the capsule medical device 10 in the liquid is magnetically
guided in the initial state, according to the guiding magnetic
field. The control unit 8 then controls the magnetic field
generating unit 2a and the current supply unit 2b to further apply
the guiding magnetic field based on the instruction information
input from the input unit 5 to the capsule medical device 10 in the
initial magnetically guided state. In this manner, the control unit
8 continuously controls the magnetic guiding of the capsule medical
device 10, starting from the initial magnetically guided state of
the capsule medical device 10.
[0075] After that, the control unit 8 determines whether to end the
magnetically guiding control operation for the capsule medical
device 10 (step S108). In a case where instruction information to
end the operation has been input by the input unit 5, the control
unit 8 determines to end the operation based on the instruction
information (step S108, Yes), and then ends this operation. In a
case where such instruction information to end the operation has
not been input, the control unit 8 determines not to end the
operation (step S108, No). The control unit 8 then returns to step
S101, and repeats the procedures of step S101 and steps that
follow.
[0076] If the control unit 8 determines that there is not an
instruction to set a magnetic field condition in the above step
S101 (step S101, No), the control unit 8 skips steps S102 through
S105, and moves on to step S106. The control unit 8 then repeats
the procedures of step S106 and steps that follow. If the control
unit 8 determines that there is not an instruction to magnetically
guide the capsule medical device 10 in step S106 (step S106, No),
the control unit 8 returns to step S101, and repeats the procedures
of step S101 and steps that follow.
[0077] Next, a specific operation of the magnetically guiding
system 1 during the procedure of the above step S102 will be
described by taking an example case where the physical information
about the magnetic guiding of the capsule medical device 10 is at
least one of the density .rho..sub.CP and the gravity center
position GP of the capsule medical device 10.
[0078] The following is a detailed description of the acquirement
of the density .rho..sub.CP of the capsule medical device 10
observed in a case where the capsule medical device 10 can float on
the liquid surface, with an image viewing field facing vertically
upward. FIG. 5 is a schematic view showing the capsule medical
device floating in a liquid, with an image viewing field facing
vertically upward. FIG. 6 is a schematic view showing an image
captured by the capsule medical device that is floating on the
liquid, with an image viewing field facing vertically upward.
[0079] As shown in FIG. 5, where the capsule medical device 10 is
floating on the liquid surface 100a of a liquid 100, the gravity
force Mg acting on the capsule medical device 10 equals the buoyant
force f acting on the capsule medical device 10 from the liquid
100. In short, the gravity force Mg is equal to the buoyant force
f. Here, the gravity force Mg is the product of the density
.rho..sub.CP and volume V.sub.CP of the capsule medical device 10.
The buoyant force f is the product of the density .rho..sub.LIQ of
the liquid 100 and the volume V.sub.B of the portion of the capsule
medical device 10 under the liquid surface 100a. Accordingly, the
following equation (1) is established:
.rho..sub.CP=(V.sub.B/V.sub.CP).times..rho..sub.LIQ (1)
[0080] The volume V.sub.B of the portion of the capsule medical
device 10 under the liquid surface 100a is calculated by
subtracting the volume V.sub.A of the protruding portion 10a (the
shaded area in FIG. 5) protruding from the liquid surface 100a from
the total volume V.sub.CP of the capsule medical device 10.
Accordingly, the following equation (2) is established:
V.sub.B=V.sub.CP-V.sub.A (2)
[0081] Also, the volume V.sub.A of the protruding portion 10a can
be calculated by the formula expressed by the following equation
(3):
V.sub.A=1/3.times..pi..times.X.sub.A.sup.2.times.(3.times.r-X.sub.A)
(3)
[0082] In the equation (3), X.sub.A represents the distance from
the liquid surface 100a to the top P of the dome-like protruding
portion 10a, and is equivalent to the protruding amount of the
capsule medical device 10 above the liquid surface 100a, as shown
in FIG. 5. Meanwhile, r represents the curvature radius of both
dome-like end portions (the dome-like casings 11b and 11c shown in
FIG. 3) of the exterior of the capsule medical device 100. The
curvature radius r is input as one kind of physical information
about the capsule medical device 10 by the input unit 5.
[0083] The capsule medical device 10 floating in the liquid 100
captures the image 101 shown in FIG. 6, with an image viewing field
facing vertically upward. The image 101 captured by the capsule
medical device 10 includes the boundary portion B between the
liquid surface 100a of the liquid 100 and the exterior of the
capsule medical device 10 as the subject. The boundary portion B
has a circular shape as shown in FIG. 6, when the capsule medical
device 10 floating in the liquid 100 floats upright as shown in
FIG. 5. If the liquid 100 is a colored liquid, the boundary portion
B is more clearly shown in the image 101.
[0084] The information acquiring unit 4 acquires the image signal
of the image 101 captured by the capsule medical device 10 from the
receiving unit 3. Based on the acquired image 101, the information
acquiring unit 4 calculates the density .rho..sub.CP as an example
of the physical information about the magnetic guiding of the
capsule medical device 10. In this case, the information acquiring
unit 4 first calculates a radius r.sub.A of the boundary portion B
in the image 101, based on a preset scale equivalent to one pixel.
The information acquiring unit 4 then calculates the protruding
amount X.sub.A of the capsule medical device 10 above the liquid
surface 100a, based on the calculated radius r.sub.A of the
boundary portion B and the curvature radius r of the capsule
medical device 10. More specifically, using the radius r.sub.A of
the boundary portion B and the curvature radius r, the information
acquiring unit 4 calculates the difference (r-X.sub.A) between the
curvature radius r and the protruding amount X.sub.A, according to
the Pythagorean theorem. The information acquiring unit 4 then
subtracts the difference (r-X.sub.A) from the curvature radius r,
to calculate the protruding amount X.sub.A calculated in this
manner. Using the protruding amount X.sub.A, the volume V.sub.CP of
the capsule medical device 100 input beforehand by the input unit
5, and the density .rho..sub.LIQ of the liquid 100, the information
acquiring unit 4 calculates the density .rho..sub.CP of the capsule
medical device 10, according to the equations (1) through (3). The
information acquiring unit 4 acquires the density .rho..sub.CP of
the capsule medical device 10 calculated in this manner as the
physical information about the magnetic guiding of the capsule
medical device 10.
[0085] By performing the above operation to calculate the density
of the capsule medical device 10, the information acquiring unit 4
can acquire the density .rho..sub.CP as the physical information
about the magnetic guiding of the capsule medical device 10 in both
situations where the capsule medical device 10 has already been
introduced into an internal organ of the test subject and where the
capsule medical device 10 has not been introduced thereinto.
[0086] More specifically, in a case where the density .rho..sub.CP
of the capsule medical device 10 is acquired before the capsule
medical device 10 is introduced into an internal organ of the test
subject, the capsule medical device 10 and an appropriate amount of
liquid 100 are put into a predetermined container, so that the
capsule medical device 10 floats on the liquid surface 100a of the
liquid 100 in the container. In this situation, the receiving unit
3 receives the image 101 captured by the capsule medical device 10
floating in the liquid 100 in the container. Based on the image 101
received by the receiving unit 3, the information acquiring unit 4
calculates the density .rho..sub.CP of the capsule medical device
10. After that, the liquid 100 and the capsule medical device 10
are introduced into an internal organ of the test subject.
[0087] In this operation to calculate the density of the capsule
medical device 10, this container is a hollow container that has an
internal diameter that is greater than the external diameter of the
capsule medical device 10, and has a depth that is greater than the
length of the capsule medical device 10 in its long axis direction.
The liquid 100 is a liquid that has higher density than the capsule
medical device 10. For example, the liquid 100 is a liquid harmless
to humans, such as water or isotonic sodium chloride solution in
which the capsule medical device 10 can float within an internal
organ of a test subject.
[0088] In a case where the density .rho..sub.CP of the capsule
medical device 10 is acquired after the capsule medical device 10
is introduced into an internal organ of the test subject, the
capsule medical device 10 and an appropriate amount of liquid 100
are introduced into an internal organ of the test subject via the
oral route, so that the capsule medical device 10 floats on the
liquid surface 100a of the liquid 100 in the internal organ of the
test subject. In this situation, the receiving unit 3 receives the
image 101 captured by the capsule medical device 10 floating in the
liquid 100 in the internal organ. Based on the image 101 received
by the receiving unit 3, the information acquiring unit 4
calculates the density .rho..sub.CP of the capsule medical device
10 in the above described manner.
[0089] The following is a detailed description of the acquirement
of the density .rho..sub.CP of the capsule medical device 10
observed in a case where the capsule medical device 10 can float on
the liquid surface, with an image viewing field facing vertically
downward. FIG. 7 is a schematic view showing an example of the
container in which the capsule medical device floats on the liquid
surface. FIG. 8 is a schematic view illustrating a situation where
the capsule medical device is floating in a liquid in the
container, with an image viewing field facing vertically downward.
FIG. 9 is a schematic view showing an example of an image captured
by the capsule medical device that is floating in the liquid, with
an image viewing field facing vertically downward.
[0090] As shown in FIG. 7, the container 110 is a cylindrical
hollow container, for example. The container 110 has an internal
diameter that is greater than the external diameter of the capsule
medical device 10, and has a depth that is greater than the length
of the capsule medical device 10 in the long axis direction. The
container 110 also has marks 111 drawn on the bottom. The marks 111
are formed with concentric circles combined as shown in FIG. 7. The
number of concentric circles forming the marks 111 is more than
one, and is not particularly limited to three.
[0091] The capsule medical device 10 and an appropriate amount of
liquid 100 are introduced into the container 110. In this case, the
capsule medical device 10 in the container 110 floats on the liquid
surface of the liquid 100, with an image viewing field facing
vertically downward, as shown in FIG. 8. The amount of the liquid
100 to be introduced into the container 110 is adjusted so that the
level of the liquid 100 (the distance from the bottom surface of
the container 110 to the liquid surface of the liquid 100) is fixed
while the capsule medical device 10 is floating on the liquid
surface.
[0092] The capsule medical device 10 floating in the liquid 100
captures the image 102 shown in FIG. 9, catching the bottom surface
of the container 110 within the image viewing field. The image 102
captured by the capsule medical device 10 includes the marks 111
formed on the bottom surface of the container 110 as the subject.
The marks 111 in the image 102 are more clearly shown, if the
liquid 100 is transparent and colorless.
[0093] The receiving unit 3 receives the image signal of the image
102 captured by the capsule medical device 10 floating in the
liquid 100 in the container 110. The information acquiring unit 4
acquires the image signal of the image 102 captured by the capsule
medical device 10 from the receiving unit 3. Based on the acquired
image 102, the information acquiring unit 4 calculates the density
.rho..sub.CP as an example of the physical information about the
magnetic guiding of the capsule medical device 10. In this case,
the information acquiring unit 4 calculates the density
.rho..sub.CP, based on the captured state of the marks 111 in the
image 102.
[0094] Here, the floating level of the capsule medical device 10 in
the liquid 100 becomes higher and lower in accordance with the
density .rho..sub.CP of the capsule medical device 10. Therefore,
if the angle of view of the capsule medical device 10 is fixed, the
range in which the marks 111 can be captured within the image
viewing field of the capsule medical device 10 (hereinafter
referred to as the capture allowing range of the marks 111) varies
with the floating level of the capsule medical device 10 or the
density .rho..sub.CP of the capsule medical device 10. More
specifically, the capture allowing range of the marks 111 becomes
narrower as the density .rho..sub.CP of the capsule medical device
10 becomes higher. The capture allowing range of the marks 111
becomes wider as the density .rho..sub.CP of the capsule medical
device 10 becomes lower. The captured state of the marks 111 in the
image 102 captured by the capsule medical device 10 varies as the
capture allowing range of the marks 111 varies.
[0095] The information acquiring unit 4 calculates the density
.rho..sub.CP of the capsule medical device 10, based on the
captured state of the marks 111 in the image 102 captured by the
capsule medical device 10, e.g., the number of concentric circles
or the sizes of the concentric circles of the marks 111 included in
the image 102. By performing this operation to calculate the
density of the capsule medical device 10, the information acquiring
unit 4 can acquire the density .rho..sub.CP as the physical
information about the magnetic guiding of the capsule medical
device 10, before the capsule medical device 10 is introduced into
an internal organ of the test subject.
[0096] In a case where the capsule medical device 10 sinks below
the liquid surface of the liquid 100, the information acquiring
unit 4 calculates the density .rho..sub.CP of the capsule medical
device 10, based on the physical information that is input by the
input unit 5. More specifically, the input unit 5 inputs the weight
W1 of the capsule medical device 10 in air, the weight W2 of the
capsule medical device 10 in the liquid 100, and the density
.rho..sub.LIQ of the liquid 100, into the control unit 8. The
control unit 8 transmits each piece of the physical information
that is input from the input unit 5 to the information acquiring
unit 4, and controls the information acquiring unit 4 to calculate
the density .rho..sub.CP of the capsule medical device 10.
Acquiring the physical information from the control unit 8, the
information acquiring unit 4 calculates the density .rho..sub.CP of
the capsule medical device 10, under the control of the control
unit 8. Based on the weights W1 and W2 of the capsule medical
device 10 and the density .rho..sub.LIQ of the liquid 100, the
information acquiring unit 4 calculates the density .rho..sub.CP of
the capsule medical device 10, according to the following equation
(4):
.rho..sub.CP=.rho..sub.LIQ.times.W1/(W1-W2) (4)
[0097] By performing the operation to calculate the density of the
capsule medical device 10 according to the equation (4), the
information acquiring unit 4 can acquire the density .rho..sub.CP
as the physical information about the magnetic guiding of the
capsule medical device 10, before the capsule medical device 10 is
introduced into an internal organ of the test subject.
[0098] The following is a detailed description of the acquirement
of the gravity center position GP of the capsule medical device 10
observed in a case where the capsule medical device 10 can float on
the liquid surface, with an image viewing field facing upward. FIG.
10 is a schematic view showing an example case where the capsule
medical device is floating in the liquid, while tilting. FIG. 11 is
a schematic view showing an example of an image that is captured by
the capsule medical device floating in the liquid while
tilting.
[0099] In a case where the gravity center position GP of the
capsule medical device 10 that can float in the liquid 100 deviates
in the radial direction from the long axis CL, the capsule medical
device 10 in such a gravity state tilts while floating on the
liquid surface 100a of the liquid 100, as shown in FIG. 10. The
tilting state of the capsule medical device 10 here refers to a
state in which the long axis CL of the capsule medical device 10 is
tilted relative to the vertical direction.
[0100] The capsule medical device 10 that is floating while tilting
in the liquid 100 captures the image 101 shown in FIG. 11, with the
image viewing field facing upward. The image 101 captured by the
capsule medical device 10 in such a tilting state includes the
boundary portion B between the liquid surface 100a of the liquid
100 and the exterior of the capsule medical device 10. In this
case, the center C2 of the boundary portion B in the image 101 is
shifted from the center C1 of the image 101, as shown in FIG. 11.
The shift amount from the center C1 of the image 101 to the center
C2 of the boundary portion B varies as the amount of tilt of the
capsule medical device 10 relative to the vertically upward
direction varies. Also, the relative shift direction of the center
C2 of the boundary portion B with respect to the center C1 of the
image 101 varies as the direction of tilt of the capsule medical
device 10 relative to the vertically upward direction varies.
[0101] In this situation, the receiving unit 3 receives the image
signal of the image 101 captured by the capsule medical device 10
in such a tilting state. The information acquiring unit 4 acquires
the image signal of the image 101 captured by the capsule medical
device 10 in the tilting state from the receiving unit 3. Based on
the acquired image 101, the information acquiring unit 4 acquires
the gravity center position GP as an example of the physical
information about the magnetic guiding of the capsule medical
device 10. In this case, the information acquiring unit 4
calculates a shift vector E that extends between the center C1 of
the image 101 and the center C2 of the boundary portion B (see FIG.
11). The shift vector E is the vector that indicates the shift
amount and shift direction of the center C2 of the boundary portion
B relative to the center C1 of the image 101. The information
acquiring unit 4 transmits the vector components information about
the vector E to the control unit 8, with the vector components
information indicating the relative shift amount and relative shift
direction of the gravity center position GP of the capsule medical
device 10 with respect to its long axis direction CL.
[0102] By performing the above operation to calculate the gravity
center position of the capsule medical device 10, the information
acquiring unit 4 can acquire the gravity center position GP as the
physical information about the magnetic guiding of the capsule
medical device 10, in both situations where the capsule medical
device 10 has already been introduced into an internal organ of a
test subject and where the capsule medical device 10 has not been
introduced thereinto.
[0103] More specifically, in a case where the gravity center
position GP of the capsule medical device 10 is acquired before the
capsule medical device 10 is introduced into an internal organ of a
test subject, the capsule medical device 10 and an appropriate
amount of liquid 100 are introduced to a predetermined container,
so that the capsule medical device 10 floats on the liquid surface
100a of the liquid 100 in the container. In this situation, the
receiving unit 3 receives the image 101 captured by the capsule
medical device 10 that is floating in the liquid 100 in the
container. Based on the image 101 received by the receiving unit 3,
the information acquiring unit 4 calculates the shift vector E of
the boundary portion B in the above described manner. After that,
the liquid 100 and the capsule medical device 10 are introduced
into an internal organ of the test subject.
[0104] In this operation to calculate the gravity center position
of the capsule medical device 10, the container is a hollow
container that has an internal diameter that is greater than the
external diameter of the capsule medical device 10, and has a depth
that is greater than the length of the capsule medical device 10 in
its long axis direction, as in the above described operation to
calculate the density of the capsule medical device 10.
[0105] In a case where the gravity center position GP of the
capsule medical device 10 is acquired after the capsule medical
device 10 is introduced into an internal organ of the test subject,
the capsule medical device 10 and an appropriate amount of liquid
100 are introduced into an internal organ of the test subject via
the oral route, so that the capsule medical device 10 floats on the
liquid surface 100a of the liquid 100 in the internal organ of the
test subject. In this situation, the receiving unit 3 receives the
image 101 captured by the capsule medical device 10 floating in the
liquid 100 in the internal organ. Based on the image 101 received
by the receiving unit 3, the information acquiring unit 4
calculates the shift vector E of the boundary portion B in the
above described manner.
[0106] In a case where the capsule medical device 10 in a tilting
state has an image viewing field facing downward, the receiving
unit 3 receives the image 102 captured by the capsule medical
device 10 floating in the liquid 100 in the above described
container 110. In this case, the information acquiring unit 4
calculates the shift vector of the marks 111 in the image 102 (the
vector indicating the shift amount and shift direction of the
center of the marks 111 relative to the center of the image 102),
instead of the shift vector E of the boundary portion B. The
information acquiring unit 4 then transmits the vector components
information about the calculated shift vector to the control unit
8, with the vector components information indicating the relative
shift amount and the relative shift direction of the gravity center
position GP of the capsule medical device 10 with respect to its
long axis direction CL.
[0107] By combining the density calculating operation and the
gravity center calculating operation, the information acquiring
unit 4 can also calculate both the density .rho..sub.CP and the
gravity center position GP (more specifically, the vector
components information about the shift vector) of the capsule
medical device 10, based on the image 101 and the image 102
captured by the capsule medical device 10. The information
acquiring unit 4 can transmit both the density .rho..sub.CP and the
gravity center position GP of the capsule medical device 10 as the
physical information about the magnetic guiding of the capsule
medical device 10, to the control unit 8.
[0108] The following is a detailed description of the magnetic
guiding of the capsule medical device 10 in accordance with the
magnetic field condition set by the above described magnetic field
condition setting unit 8a. FIG. 12 is a schematic view showing an
example case where the capsule medical device introduced into the
body of a test subject is magnetically guided. As shown in FIG. 12,
the capsule medical device 10 introduced into an internal organ of
the test subject 120 is floating in the liquid 100 also introduced
into the internal organ. In this case, the capsule medical device
10 has the image viewing field of the image capturing unit 14
facing upward in the vertical direction, and the image viewing
field of the image capturing unit 15 facing downward in the
vertical direction. The image capturing units 14 and 15
sequentially capture in-vivo images of the test subject 120.
[0109] Based on the density .rho..sub.CP and the gravity center
position GP of the capsule medical device 10 acquired by the
information acquiring unit 4 in the above described manner, the
magnetic field condition setting unit 8a sets the magnetic field
conditions for the guiding magnetic field to be applied to the
capsule medical device 10. The control unit 8 controls the magnetic
field generating unit 2a and the power supply unit 2b to apply the
guiding magnetic field satisfying the set magnetic field condition
(field intensity, a field direction, a field gradient, or the like)
to the capsule medical device 10 in the body of the test subject
120. Under the control of the control unit 8, the magnetic field
generating unit 2a applies the guiding magnetic field satisfying
the magnetic field condition to the capsule medical device 10
inside the body of the test subject 120.
[0110] More specifically, the magnetic field generating unit 2a
applies a canceling magnetic field H to the magnet 19 of the
capsule medical device 10 inside the body of the test subject 120,
as shown in FIG. 12. Here, the canceling magnetic field H is an
example of the guiding magnetic field satisfying the magnetic field
condition that is set by the magnetic field condition setting unit
8a. The canceling magnetic field H is a magnetic field having
magnetic force PW (magnetic attraction or magnetic repulsion) that
acts in such a direction as to cancel the difference between the
gravity force and the buoyant force acting on the capsule medical
device 10 in the liquid 100, as shown in FIG. 12. In FIG. 12, the
canceling magnetic field H forms a magnetic gradient in such a
vertical direction as to compensate for the shortage of the buoyant
acting on the capsule medical device 10. Based on the density
.rho..sub.CP of the capsule medical device 10, the magnetic field
condition setting unit 8a sets the size of the magnetic gradient of
the canceling magnetic field H.
[0111] In a case where instruction information to magnetically
guide the capsule medical device 10 has not been input from the
input unit 5, the magnetic field generating unit 2a applies the
canceling magnetic field H to the capsule medical device 10 inside
the body of the test subject 120, so that the difference between
the gravity force and the buoyant force acting on the capsule
medical device 10 is canceled. As a result, the capsule medical
device 10 inside the body of the test subject 120 becomes free from
the gravity force and the buoyant force in the liquid 100. In a
case where the instruction information to magnetically guide the
capsule medical device 10 has been input from the input unit 5, the
magnetic field generating unit 2a applies the canceling magnetic
field H to the capsule medical device 10 inside the body of the
test subject 120, and further applies a guiding magnetic field
according to the instruction information to the capsule medical
device 10. As a result, the magnetic field generating unit 2a can
magnetically guide the capsule medical device 10 inside the body of
the test subject 120, continuously from the state in which the
capsule medical device 10 is free from the gravity force and the
buoyant force. In this manner, the capsule medical device 10 being
magnetically guided can move slowly in the liquid 100, following
the guiding magnetic field. As a result, users can more easily
handle the capsule medical device 10 being magnetically guided by
operating the input unit 5.
[0112] As described so far, in the magnetically guiding system and
the magnetically guiding method in accordance with the first
embodiment of the present invention, the physical information about
the magnetic guiding of the capsule medical device is acquired,
based on the image captured by the capsule medical device in a
liquid. The magnetic field condition suitable for the acquired
physical information is set, and the guiding magnetic field
satisfying the set magnetic field condition is applied to the
capsule medical device in the liquid. In this manner, the capsule
medical device is magnetically guided. Accordingly, the optimum
magnetic field condition can be set in accordance with the physical
information such as the density or gravity center position of the
capsule medical device, and the guiding magnetic field satisfying
the optimum magnetic field condition is output so as to control the
magnetic guiding of the capsule medical device. Thus, the optimum
magnetic field is applied to the capsule medical device, and the
capsule medical device inside the body of a test subject can be
magnetically guided with high precision.
[0113] Next, a second embodiment of the present invention will be
described. In the first embodiment, the physical information (the
density .rho..sub.CP, the gravity center position GP, or the like)
about the magnetic guiding of the capsule medical device 10 is
acquired based on images captured by the capsule medical device 10
in a liquid. In the second embodiment, on the other hand, the
density .rho..sub.CP of the capsule medical device 10 is acquired
based on the temperature of the liquid 100 measured when the
capsule medical device 10 starts floating up or sinking down in the
liquid 100.
[0114] FIG. 13 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with the
second embodiment of the present invention. As shown in FIG. 13,
the magnetically guiding system 21 in accordance with the second
embodiment differs from the magnetically guiding system 1 of the
first embodiment in that the information acquiring unit 4 is
replaced with an information acquiring unit 24, and the control
unit 8 is replaced with a control unit 28. The magnetically guiding
system 21 further includes a container 25 into which the capsule
medical device 10 and the liquid 100 are to be introduced, a liquid
temperature adjusting unit 22 that adjusts the temperature of the
liquid 100 in the container 25, and a temperature measuring unit 23
that measures the temperature of the liquid 100 adjusted by the
liquid temperature adjusting unit 22. The other configurations of
this embodiment are the same as those of the first embodiment, and
the same components as those of the first embodiment are denoted by
the same reference numerals used in the first embodiment.
[0115] The container 25 is designed so that the capsule medical
device 10 can float up or sink down in the liquid 100. More
specifically, the container 25 has an internal diameter that is
greater than the external diameter of the capsule medical device
10, and has a depth that is greater than the length of the capsule
medical device 10 in its long axis direction. The capsule medical
device 10 and an appropriate amount of liquid 100 are introduced
into the container 25.
[0116] The liquid temperature adjusting unit 22 may be embodied
with the use of at least one of a heating device and a cooling
device, and is placed in the container 25. Under the control of the
control unit 28, the liquid temperature adjusting unit 22 heats up
or cools down the liquid 100 in the container 25, to adjust the
temperature of the liquid 100.
[0117] The liquid temperature measuring unit 23 may be embodied
with the use of a temperature sensor or the like, and is placed in
the container 25. Under the control of the control unit 28, the
liquid temperature measuring unit 23 measures the temperature of
the liquid 100 in the container 25, and transmits the measured
value of the temperature of the liquid 100 to the information
acquiring unit 24.
[0118] Based on the temperature of the liquid 100 measured when the
capsule medical device 10 starts floating up or sinking down in the
liquid 100, the information acquiring unit 24 measures the density
.rho..sub.CP as the physical information about the magnetic guiding
of the capsule medical device 10. More specifically, under the
control of the control unit 28, the information acquiring unit 24
sequentially acquires each image captured by the capsule medical
device 10 in the liquid 100 from the receiving unit 3, and also
sequentially acquires the measured values of the temperature of the
liquid 100 from the liquid temperature measuring unit 23. Based on
each image captured by the capsule medical device 10, the
information acquiring unit 24 determines the timing when the
capsule medical device 10 starts floating up or sinking down in the
liquid 100. Based on the temperature of the liquid 100 measured by
the liquid temperature measuring unit 23 when the capsule medical
device 10 starts floating up or sinking down, the information
acquiring unit 24 measures the density .rho..sub.CP of the capsule
medical device 10. At the timing when the capsule medical device 10
in the liquid 100 starts floating up or sinking down in accordance
with the temperature change of the liquid 100, the density
.rho..sub.CP of the capsule medical device 10 is substantially the
same as the density .rho..sub.LIQ of the liquid 100. Based on this
fact, the information acquiring unit 24 converts the temperature of
the liquid 100 measured at such timing into the density
.rho..sub.CP of the capsule medical device 10, which is
substantially the same as the density .rho..sub.LIQ of the liquid
100. In this manner, the information acquiring unit 24 acquires the
density .rho..sub.CP. Except for the function to measure the
density of the capsule medical device 10, the information acquiring
unit 24 has the same functions as those of the information
acquiring unit 4 of the magnetically guiding system 1 in accordance
with the first embodiment.
[0119] Based on instruction information that is input by the input
unit 5, the control unit 28 controls each of the operations of the
liquid temperature adjusting unit 22, the liquid temperature
measuring unit 23, and the information acquiring unit 24. The
control unit 28 also controls signal inputs and outputs between the
liquid temperature measuring unit 23 and the information acquiring
unit 24. In this case, the control unit 28 controls the liquid
temperature adjusting unit 22 to adjust the temperature of the
liquid 100 in the container 25 through a heating process or a
cooling process. The control unit 28 also controls the liquid
temperature measuring unit 23 to measure the temperature of the
liquid 100 adjusted by the liquid temperature adjusting unit 22,
and sequentially transmit the measured values of the temperature of
the liquid 100 to the information acquiring unit 24. The control
unit 28 further controls the information acquiring unit 24 to
measure the density .rho..sub.CP of the capsule medical device 10,
using each image captured by the capsule medical device 10 and the
temperature of the liquid 100 measured by the liquid temperature
measuring unit 23. The control unit 28 obtains the physical
information such as the density .rho..sub.CP about the magnetic
guiding of the capsule medical device 10, from the information
acquiring unit 24. Except for the functions to control the liquid
temperature adjusting unit 22, the liquid temperature measuring
unit 23, and the information acquiring unit 24, the control unit 28
has the same functions as those of the control unit 8 of the
magnetically guising system 1 in accordance with the first
embodiment.
[0120] Next, the operation by the magnetically guiding system 21 in
accordance with the second embodiment of the present invention will
be described. The magnetically guiding system 21 in accordance with
the second embodiment operates in the same manner as the
magnetically guiding system 1 of the first embodiment, except for
an operation when the density .rho..sub.CP as one kind of physical
information about the magnetic guiding of the capsule medical
device 10 is obtained. In other words, the control unit 28 of the
magnetically guiding system 21 carries out the same procedures as
those of steps S101 through S108 shown in FIG. 4. In this case, the
control unit 28 acquires the density PCP of the capsule medical
device 10 by a different technique from that utilized in step S102
by the control unit 8 of the first embodiment.
[0121] More specifically, in the above step S102, the control unit
28 controls the receiving unit 3 to receive images captured by the
capsule medical device 10 in the liquid 100. The control unit 28
also controls the liquid temperature adjusting unit 22 to change
the temperature of the liquid 100 having the capsule medical device
10 introduced thereinto. If the capsule medical device 10 is
stabilized while floating in the liquid 100 at this point, the
control unit 28 controls the liquid temperature adjusting unit 22
to gradually increase the temperature of the liquid 100 through a
heating process. If the capsule medical device 10 is stabilized in
a sunken state in the liquid 100 at this point, the control unit 28
controls the liquid temperature adjusting unit 22 to gradually
lower the temperature of the liquid 100 through a cooling process.
The control unit 28 also controls the liquid temperature measuring
unit 23 to sequentially measure the temperature of the liquid 100
adjusted by the liquid temperature adjusting unit 22, and
sequentially transmit the measured values of the temperature of the
liquid 100 to the information acquiring unit 24.
[0122] The control unit 28 controls the information acquiring unit
24 to acquire physical information about the magnetic guiding of
the capsule medical device 10, using each image captured by the
capsule medical device 10 and received by the receiving unit 3, and
the measured values of the temperature of the liquid 100 measured
by the liquid temperature measuring unit 23. Under the control of
the control unit 28, the information acquiring unit 24 acquires the
physical information such as the density .rho..sub.CP about the
magnetic guiding of the capsule medical device 10, and transmits
the physical information to the control unit 28.
[0123] More specifically, the information acquiring unit 24
sequentially acquires each image captured by the capsule medical
device 10 from the receiving unit 3, and calculates the motion
vector between each two images. Based on the acquired motion vector
between the images, the information acquiring unit 24 determines
the timing when the capsule medical device 10 in the liquid 100
starts floating up or sinking down. The information acquiring unit
24 holds a data table indicating the density conversion data about
the liquid 100 at each temperature. The information acquiring unit
24 measures the density .rho..sub.CP of the capsule medical device
10, based on the data table and the temperature of the liquid 100
measured by the liquid temperature measuring unit 23 at the timing
when the capsule medical device 10 starts floating up or sinking
down.
[0124] If the capsule medical device 10 is stabilized while
floating in the liquid 100 at this point, the capsule medical
device 10 in the floating state starts sinking down as the density
.rho..sub.LIQ of the liquid 100 becomes lower due to an increase in
the temperature of the liquid 100. When the capsule medical device
10 starts sinking down, the density PCP of the capsule medical
device 10 becomes substantially equal to the density .rho..sub.LIQ
of the liquid 100. If the capsule medical device 10 is stabilized
in a sunken state in the liquid 100, the capsule medical device 10
in the sunken state starts floating up as the density .rho..sub.LIQ
of the liquid 100 becomes higher due to a decrease in the
temperature of the liquid 100. When the capsule medical device 10
starts sinking down, the density .rho..sub.CP of the capsule
medical device 10 becomes substantially equal to the density
.rho..sub.LIQ of the liquid 100.
[0125] Based on the relationship between the density .rho..sub.LIQ
of the liquid 100 and the density .rho..sub.CP of the capsule
medical device 100, and the data table in terms of the conversion
of the density of the liquid 100, the information acquiring unit 24
converts the value of the temperature of the liquid 100 measured at
the timing when the capsule medical device 10 starts floating up or
sinking down, into the density .rho..sub.CP of the capsule medical
device 10, which is substantially equal to the density
.rho..sub.LIQ of the liquid 100. As a result, the information
acquiring unit 24 acquires the density .rho..sub.CP, which is one
kind of physical information about the magnetic guiding of the
capsule medical device 10. The information acquiring unit 24
acquires the other physical information about the magnetic guiding
of the capsule medical device 10, such as the gravity center
position GP of the capsule medical device 10, in the same manner as
the first embodiment in which the information acquiring unit 4
acquires the physical information.
[0126] In a case where the density .rho..sub.CP of the capsule
medical device 10 floating in the liquid 100 is measured in the
second embodiment, a sheet-like member may be put on the liquid
100, so as to eliminate the surface tension acting on the capsule
medical device 10 in the floating state. FIG. 14 is a schematic
view showing an example case where a sheet-like member is placed on
the liquid surface in the container. As shown in FIG. 14, the
sheet-like member 26 is placed on the liquid surface 100a of the
liquid 100 in the container 25. The sheet-like member 26 floats on
the liquid surface 100a, and prevents the capsule medical device 10
protruding from the liquid surface 100a of the liquid 100.
Accordingly, the sheet-like member 26 can eliminate the influence
of surface tension acting on the capsule medical device 10. In
other words, the capsule medical device 10 in the liquid 100 can
start sinking down as the density .rho..sub.LIQ becomes lower due
to an increase in the temperature of the liquid 100, without being
affected by the surface tension at the liquid surface 100a. As a
result, the liquid temperature measuring unit 23 can accurately
measure the temperature of the liquid 100 when the density
.rho..sub.CP of the capsule medical device 10 becomes substantially
equal to the density .rho..sub.LIQ of the liquid 100. Using the
accurately measured temperature of the liquid 100, the information
acquiring unit 24 can measure the density .rho..sub.CP of the
capsule medical device 10 with high precision.
[0127] As described above, in the magnetically guiding system and
the magnetically guiding method in accordance with the second
embodiment of the present invention, the temperature of the liquid
into which the capsule medical device is introduced is adjusted so
as to change the density of the liquid. By doing so, the capsule
medical device in the liquid is caused to float up or sink down.
When the capsule medical device starts floating up or sinking down
in the liquid, the temperature of the liquid is measured. Based on
the temperature of the liquid, the density of the capsule medical
device is measured. The other configurations of this embodiment are
the same as those of the first embodiment. Accordingly, not only
the same effects as those of the first embodiment can be achieved,
but also the capsule medical device can be magnetically guided with
higher precision, as the density of the capsule medical device can
be measured with high precision, and the magnetic field condition
is set based on the highly precise density of the capsule medical
device.
[0128] Next, a third embodiment of the present invention will be
described. In the first embodiment, the physical information (the
density .rho..sub.CP, the gravity center position GP, or the like)
about the magnetic guiding of the capsule medical device 10 is
acquired based on images captured by the capsule medical device 10
in a liquid. In the third embodiment, on the other hand, a gradient
magnetic field is applied to the capsule medical device 10 in the
liquid 100, and the density .rho..sub.CP of the capsule medical
device 10 is acquired based on the magnetic force of the gradient
magnetic field that is being applied when the capsule medical
device 10 starts floating up or sinking down in the liquid 100.
[0129] FIG. 15 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with the
third embodiment of the present invention. As shown in FIG. 15, the
magnetically guiding system 31 in accordance with the third
embodiment differs from the magnetically guiding system 1 of the
first embodiment in that the information acquiring unit 4 is
replaced with an information acquiring unit 34, and the control
unit 8 is replaced with a control unit 38. The magnetically guiding
system 31 further includes a magnetic field detecting unit 32 that
detects the gradient magnetic field applied to the capsule medical
device 10 in the liquid 100. In the third embodiment, the capsule
medical device 10 and the liquid 100 are put into the container 25
as in the above described second embodiment. The other
configurations of this embodiment are the same as those of the
first embodiment, and the same components as those of the first
embodiment are denoted by the same reference numerals used in the
first embodiment.
[0130] The magnetic field detecting unit 32 may be embodied with
the use of detector coils, and detects the magnetic gradient of the
gradient magnetic field applied to the capsule medical device 10 in
the liquid 100. The magnetic field detecting unit 32 transmits the
detected magnetic gradient of the gradient magnetic field to the
information acquiring unit 34. The gradient magnetic field to be
detected by the magnetic field detecting unit 32 is applied to the
capsule medical device 10 in the liquid 100 by the magnetic field
generating unit 2a. Under the control of the control unit 38, the
magnetic field generating unit 2a applies the gradient magnetic
field to the capsule medical device 10 in the liquid 100, while
gradually changing the magnetic gradient.
[0131] Based on the magnetic gradient of the gradient magnetic
field detected at the timing when the capsule medical device 10 in
the liquid 100 starts floating up or sinking down in accordance
with the gradient magnetic field generated from the magnetic field
generating unit 2a, the information acquiring unit 34 acquires the
density .rho..sub.CP as one kind of the physical information about
the magnetic guiding of the capsule medical device 10. More
specifically, under the control of the control unit 38, the
information acquiring unit 34 sequentially acquires each image
captured by the capsule medical device 10 in the liquid 100 from
the receiving unit 3, and also sequentially acquires magnetic
gradients of the gradient magnetic field applied to the capsule
medical device 10. Based on each of the images captured by the
capsule medical device 10, the information acquiring unit 34
determines the timing when the capsule medical device 10 starts
floating up or sinking down in the liquid 100. The information
acquiring unit 34 acquires the magnetic gradient of the gradient
magnetic field detected by the magnetic field detecting unit 32 at
the timing when the capsule medical device 10 starts floating up or
sinking down. The information acquiring unit 34 then converts the
acquired magnetic gradient into the magnetic force of the gradient
magnetic field detected at this timing. Using the mass W1 of the
capsule medical device 10 that is input beforehand by the input
unit 5, the density .rho..sub.LIQ of the liquid 100, and the
magnetic force of the gradient magnetic field, the information
acquiring unit 34 calculates the density .rho..sub.CP of the
capsule medical device 10. Except for the function to measure the
density of the capsule medical device 10, the information acquiring
unit 34 has the same functions as those of the information
acquiring unit 4 of the magnetically guiding system 1 in accordance
with the first embodiment.
[0132] The control unit 38 controls the information acquiring unit
34, instead of the information acquiring unit 4. In this case, the
control unit 38 controls the information acquiring unit 34 to
calculate the density .rho..sub.CP of the capsule medical device
10, using each of the images captured by the capsule medical device
10 and the result of the magnetic gradient detection performed on
the gradient magnetic field by the magnetic field detecting unit
32. The control unit 38 acquires the physical information about the
magnetic guiding of the capsule medical device 10, such as the
density .rho..sub.CP, from the information acquiring unit 34. Based
on instruction information that is input by the input unit 5, the
control unit 38 also controls the gradient magnetic field
generating operation of the magnetic field generating unit 2a by
controlling the power supply unit 2b. In this case, the control
unit 38 controls the magnetic field generating unit 2a to apply the
gradient magnetic field to the capsule medical device 10 in the
liquid 100, while gradually changing the magnetic gradient. Except
for the functions to control the magnetic field generating unit 2a
and the information acquiring unit 34, the control unit 38 has the
same functions as those of the control unit 8 of the magnetically
guising system 1 in accordance with the first embodiment.
[0133] Next, the operation by the magnetically guiding system 31 in
accordance with the third embodiment of the present invention will
be described. The magnetically guiding system 31 in accordance with
the third embodiment operates in the same manner as the
magnetically guiding system 1 of the first embodiment, except for
an operation when the density .rho..sub.CP as one kind of physical
information about the magnetic guiding of the capsule medical
device 10 is obtained. In other words, the control unit 38 of the
magnetically guiding system 31 carries out the same procedures as
those of steps S101 through S108 shown in FIG. 4. In this case, the
control unit 38 acquires the density .rho..sub.CP of the capsule
medical device 10 by a different technique from that utilized in
step S102 by the control unit 8 of the first embodiment.
[0134] More specifically, in the above step S102, the control unit
38 controls the receiving unit 3 to receive images captured by the
capsule medical device 10 in the liquid 100. The control unit 38
also controls the magnetic field generating unit 2a to apply a
gradient magnetic field to the capsule medical device 10 in the
liquid 100, while changing the magnetic gradient. If the capsule
medical device 10 is stabilized while floating in the liquid 100 at
this point, the control unit 38 controls the change of the magnetic
gradient of the gradient magnetic field generated from the magnetic
field generating unit 2a, so that the capsule medical device 10 in
the floating state gradually sinks down in the liquid 100. If the
capsule medical device 10 is stabilized in a sunken state in the
liquid 100 at this point, the control unit 38 controls the change
of the magnetic gradient of the gradient magnetic field generated
from the magnetic field generating unit 2a, so that the capsule
medical device 10 in the sunken state gradually floats up in the
liquid 100.
[0135] The control unit 38 also controls the information acquiring
unit 34 to acquire physical information about the magnetic guiding
of the capsule medical device 10, appropriately using each image
captured by the capsule medical device 10 and received by the
receiving unit 3, and the result of the magnetic gradient detection
performed on the gradient magnetic field by the magnetic field
detecting unit 32. Under the control of the control unit 38, the
information acquiring unit 34 acquires the physical information
such as the density .rho..sub.CP about the magnetic guiding of the
capsule medical device 10, and transmits the acquired physical
information to the control unit 38.
[0136] More specifically, the information acquiring unit 34
sequentially acquires each image captured by the capsule medical
device 10 from the receiving unit 3, and calculates the motion
vector between each image. Based on the motion vector between the
images, the information acquiring unit 34 determines the timing
when the capsule medical device 10 in the liquid 100 starts
floating up or sinking down.
[0137] The information acquiring unit 34 also acquires the magnetic
gradient of the gradient magnetic field detected by the magnetic
field detecting unit 32 at the timing when the capsule medical
device 10 starts floating up or sinking down. The information
acquiring unit 34 then converts the magnetic gradient into the
magnetic force (magnetic attraction or magnetic repulsion) of the
gradient magnetic field. Based on the magnetic force of the
gradient magnetic field obtained through the conversion process and
the mass W1 of the capsule medical device 10 in air, the
information acquiring unit 34 calculates the buoyant force f acting
on the capsule medical device 10 in the liquid 100. The information
acquiring unit 34 then divides the calculated buoyant force f by
the density .rho..sub.LIQ of the liquid 100, to calculate the
volume V.sub.CP of the capsule medical device 10. The information
acquiring unit 34 further divides the mass W1 of the capsule
medical device 10 by the volume V.sub.CP, to calculate the density
.rho..sub.CP of the capsule medical device 10. As a result, the
information acquiring unit 34 acquires the density .rho..sub.CP as
one kind of physical information about the magnetic guiding of the
capsule medical device 10.
[0138] The information acquiring unit 34 acquires the other
physical information about the magnetic guiding of the capsule
medical device 10, such as the gravity center position GP of the
capsule medical device, in the same manner as the manner in which
the information acquiring unit 4 of the first embodiment acquires
the physical information. The mass W1 of the capsule medical device
10 and the density .rho..sub.LIQ of the liquid 100 that are used in
the above operation by the information acquiring unit 34 to
calculate the density of the capsule medical device 10 are input
beforehand by the input unit 5.
[0139] In a case where the density .rho..sub.CP of the capsule
medical device 10 floating in the liquid 100 is measured in the
third embodiment, the sheet-like member 26 may be put on the liquid
surface of the liquid 100 in the container 25, so as to eliminate
the surface tension acting on the capsule medical device 10 in the
floating state, as in the second embodiment. Accordingly, the
capsule medical device 10 in the liquid 100 can start sinking down
in accordance with the gradient magnetic field generated from the
magnetic field generating unit 2a, without being affected by the
surface tension at the liquid surface 100a. As a result, the
magnetic field detecting unit 32 can detect the minimum magnetic
gradient of the gradient magnetic field required for the capsule
medical device 10 to start sinking in the liquid 100. Using the
minimum magnetic gradient of the gradient magnetic field, the
information acquiring unit 34 can measure the density .rho..sub.CP
of the capsule medical device 10 with high precision. Also, since
the liquid 100 in the container 25 is maintained at a fixed
temperature, the information acquiring unit 34 can more accurately
measure the density .rho..sub.CP of the capsule medical device 10
with higher precision.
[0140] In the third embodiment, the information acquiring unit 34
acquires the physical information such as the density .rho..sub.CP
of the capsule medical device 10 in the container 25, before the
capsule medical device 10 is introduced into an internal organ of a
test subject. However, the information acquiring unit 34 may
acquire the physical information such as the density .rho..sub.CP
of the capsule medical device 10, after the capsule medical device
10 is introduced into the internal organ of the test subject. In
such a case, the capsule medical device 10 and an appropriate
amount of liquid 100 are introduced into an internal organ of the
test subject via the oral route, so that the capsule medical device
10 is in a floating state or a sunken state in the liquid 100
inside the internal organ of the test subject. In this situation,
the magnetic field generating unit 2a applies a gradient magnetic
field to the capsule medical device 10 inside the body of the test
subject, and the receiving unit 3 receives images captured by the
capsule medical device 10 inside the body of the test subject. The
magnetic field detecting unit 32 detects the magnetic gradient of
the gradient magnetic field applied by the magnetic field
generating unit 2a to the capsule medical device 10 inside the body
of the test subject. In the same manner as in the case where the
information acquiring unit 34 acquires the physical information
before the capsule medical device 10 is introduced into the body of
the test subject, the information acquiring unit 34 acquires the
physical information such as the density .rho..sub.CP about the
magnetic guiding of the capsule medical device 10, appropriately
using each image captured by the capsule medical device 10 and
received by the receiving unit 3, and the result of the magnetic
gradient detection performed on the gradient magnetic field by the
magnetic field detecting unit 32.
[0141] As described above, in the magnetically guiding system and
the magnetically guiding method in accordance with the third
embodiment of the present invention, a gradient magnetic field is
applied to the capsule medical device in the liquid, and the
magnetic gradient of the gradient magnetic field is detected when
the capsule medical device in the liquid starts floating up or
sinking down in accordance with the gradient magnetic field. Based
on the detected magnetic gradient, the density of the capsule
medical device is calculated. The other configurations of this
embodiment are the same as those of the first embodiment.
Accordingly, not only the same effects as those of the first
embodiment can be achieved, but also the capsule medical device can
be magnetically guided with higher precision, as the density of the
capsule medical device can be calculated with high precision, and
the magnetic field condition is set based on the highly precise
density of the capsule medical device.
[0142] Next, a fourth embodiment of the present invention will be
described. In the above described third embodiment, the density
.rho..sub.CP of the capsule medical device 10 is calculated, based
on the magnetic gradient of a gradient magnetic field detected by
the magnetic field detecting unit 32 when the capsule medical
device 10 in the liquid 100 starts floating up or sinking down. In
the fourth embodiment, on the other hand, the magnetic gradient of
a gradient magnetic field detected by the magnetic field detecting
unit 32 at the timing when the capsule medical device 10 starts
floating up or sinking down in the liquid 100 is acquired as one
kind of physical information about the magnetic guiding of the
capsule medical device 10.
[0143] FIG. 16 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with the
fourth embodiment of the present invention. As shown in FIG. 16,
the magnetically guiding system 41 in accordance with the fourth
embodiment differs from the magnetically guiding system 31 of the
third embodiment in that the information acquiring unit 34 is
replaced with an information acquiring unit 44, and the control
unit 38 is replaced with a control unit 48. The control unit 48
includes a magnetic field condition setting unit 48a, instead of
the magnetic field condition setting unit 8a. In the fourth
embodiment, the storage unit 7 does not hold the magnetic field
condition table 7a. The other configurations of this embodiment are
the same as those of the third embodiment, and the same components
as those of the third embodiment are denoted by the same reference
numerals used in the third embodiment.
[0144] The information acquiring unit 44 acquires the magnetic
gradient of the gradient magnetic field at the timing when the
capsule medical device 10 in the liquid 100 starts flowing up or
sinking down following the gradient magnetic field. The information
acquiring unit 44 uses the magnetic gradient as the physical
information about the magnetic guiding of the capsule medical
device 10. More specifically, under the control of the control unit
48, the information acquiring unit 44 sequentially acquires each
image captured by the capsule medical device 10 in the liquid 100
from the receiving unit 3, and sequentially acquires the magnetic
gradients of the gradient magnetic field applied to the capsule
medical device 10 from the magnetic detecting unit 32. Based on
each of the images captured by the capsule medical device 10, the
information acquiring unit 44 determines the timing when the
capsule medical device 10 starts floating up or sinking down in the
liquid 100. The information acquiring unit 44 acquires the magnetic
gradient of the gradient magnetic field detected by the magnetic
field detecting unit 32 when the capsule medical device 10 starts
floating up or sinking down. The information acquiring unit 44
acquires the magnetic gradient as the physical information about
the magnetic guiding of the capsule medical device 10. The
information acquiring unit 44 transmits the acquired magnetic
gradient of the gradient magnetic field to the control unit 48. As
a result, the magnetic gradient of the gradient magnetic field as
the physical information about the magnetic guiding of the capsule
medical device 10 is fed back to the control unit 48.
[0145] The control unit 48 controls the information acquiring unit
44, instead of the information acquiring unit 34. In this case, the
control unit 48 controls the information acquiring unit 44 to
acquire the magnetic gradient of the gradient magnetic field
detected by the magnetic field detecting unit 32 at the timing when
the capsule medical device 10 starts floating up or sinking down,
and use the magnetic gradient of the gradient magnetic field as the
physical information about the magnetic guiding of the capsule
medical device 10. In this manner, the control unit 48 acquires the
magnetic gradient of the gradient magnetic field as the physical
information about the magnetic guiding of the capsule medical
device 10, from the information acquiring unit 44.
[0146] The control unit 48 includes a magnetic field condition
setting unit 48a. The magnetic field condition setting unit 48a
sets a magnetic field condition for the guiding magnetic field to
be applied to the capsule medical device 10. Here, the magnetic
gradient acquired as the physical information about the magnetic
guiding of the capsule medical device 10 by the information
acquiring unit 44 is set as the magnetic field condition. In other
words, as the magnetic field condition for the guiding magnetic
field, the magnetic field condition setting unit 48a sets the
magnetic gradient of the gradient magnetic field fed back by the
information acquiring unit 44. Except for the function to control
the information acquiring unit 44 and the function to set the
magnetic field condition, the control unit 48 has the same
functions as those of the control unit 38 of the magnetically
guiding system 31 in accordance with the third embodiment.
[0147] Next, the operation by the magnetically guiding system 41 in
accordance with the fourth embodiment of the present invention will
be described. The magnetically guiding system 41 in accordance with
the fourth embodiment operates in the same manner as the
magnetically guiding system 31 of the third embodiment, except for
an operation when the physical information about the magnetic
guiding of the capsule medical device 10 is obtained, and when the
magnetic field condition is set. In other words, the control unit
48 of the magnetically guiding system 41 carries out the same
procedures as those of steps S101 through S108 shown in FIG. 4. In
this case, the control unit 48 acquires the physical information
about the magnetic guiding of the capsule medical device 10 by a
different technique from that utilized in step S102 by the control
unit 38 in the third embodiment. Also, the control unit 48 sets the
magnetic field condition for magnetically guiding the capsule
medical device 10 by a different technique from that utilized in
step S103 by the control unit 38 in the third embodiment.
[0148] More specifically, in step S102, the control unit 48
controls the receiving operation of the receiving unit 3 and the
gradient magnetic field generating operation of the magnetic field
generating unit 2a, as in the third embodiment. The control unit 48
also controls the information acquiring unit 44 to acquire physical
information about the magnetic guiding of the capsule medical
device 10, using each image captured by the capsule medical device
10 and received by the receiving unit 3, and the result of the
magnetic gradient detection performed on the gradient magnetic
field by the magnetic field detecting unit 32. Under the control of
the control unit 48, the information acquiring unit 44 acquires the
physical information about the magnetic guiding of the capsule
medical device 10, and transmits the acquired physical information
to the control unit 48.
[0149] More specifically, the information acquiring unit 44
determines the timing when the capsule medical device 10 in the
liquid 100 starts floating up or sinking down, based on the motion
vector between the images captured by the capsule medical device
10, as in the third embodiment. The information acquiring unit 44
also acquires the magnetic gradient of the gradient magnetic field
detected by the magnetic field detecting unit 32 when the capsule
medical device 10 starts floating up or sinking down, among the
magnetic gradients of the gradient magnetic field sequentially
detected by the magnetic field detecting unit 32. The information
acquiring unit 44 acquires the magnetic gradient as the physical
information about the magnetic guiding of the capsule medical
device 10. The information acquiring unit 44 then transmits the
magnetic gradient of the gradient magnetic field in that timing as
the physical information about the magnetic guiding of the capsule
medical device 10, to the control unit 48.
[0150] In the above step S103, the control unit 48 acquires the
magnetic gradient of the gradient magnetic field as the physical
information about the magnetic guiding of the capsule medical
device 10, from the information acquiring unit 44. The magnetic
field condition setting unit 48a sets the magnetic gradient
acquired from the information acquiring unit 44, as the magnetic
field condition for the magnetically guiding magnetic field to be
applied to the capsule medical device 10.
[0151] In a case where the magnetic gradient of the gradient
magnetic field for causing the capsule medical device 10 in a
floating state to start sinking down in the fourth embodiment, the
sheet-like member 26 may be put on the liquid surface of the liquid
100 in the container 25, so as to eliminate the surface tension
acting on the capsule medical device 10 in the floating state, as
in the second embodiment. Accordingly, the capsule medical device
10 in the liquid 100 can start sinking down in accordance with the
gradient magnetic field generated from the magnetic field
generating unit 2a, without being affected by the surface tension
at the liquid surface 100a. As a result, the magnetic field
detecting unit 32 can accurately detect the magnetic gradient of
the gradient magnetic field required for causing the capsule
medical device 10 to start sinking in the liquid 100. Thus, the
information acquiring unit 44 can acquire the accurate magnetic
gradient as the physical information about the magnetic guiding of
the capsule medical device 10.
[0152] In the fourth embodiment, the information acquiring unit 44
acquires the physical information about the magnetic guiding of the
capsule medical device 10 in the container 25, before the capsule
medical device 10 is introduced into an internal organ of a test
subject. However, the information acquiring unit 44 may acquire the
physical information about the magnetic guiding of the capsule
medical device 10, after the capsule medical device 10 is
introduced into the internal organ of the test subject. In such a
case, the capsule medical device 10 and an appropriate amount of
liquid 100 are introduced into the internal organ of the test
subject via the oral route, so that the capsule medical device 10
is in a floating state or a sunken state in the liquid 100 inside
the internal organ of the test subject. In this situation, the
magnetic field generating unit 2a applies a gradient magnetic field
to the capsule medical device 10 inside the body of the test
subject, and the receiving unit 3 receives images captured by the
capsule medical device 10 inside the body of the test subject. The
magnetic field detecting unit 32 detects the magnetic gradient of
the gradient magnetic field applied by the magnetic field
generating unit 2a to the capsule medical device 10 inside the body
of the test subject. In the same manner as in the case where the
information acquiring unit 44 acquires the physical information
before the capsule medical device 10 is introduced into the body of
the test subject, the information acquiring unit 44 acquires the
magnetic gradient of the gradient magnetic field detected by the
magnetic field detecting unit 32 when the capsule medical device 10
starts floating up or sinking down inside the body of the test
subject. The information acquiring unit 44 acquires the magnetic
gradient as the physical information about the magnetic guiding of
the capsule medical device 10.
[0153] As described above, in the magnetically guiding system and
the magnetically guiding method in accordance with the fourth
embodiment of the present invention, a gradient magnetic field is
applied to the capsule medical device in the liquid, and the
magnetic gradient of the gradient magnetic field is detected when
the capsule medical device in the liquid starts floating up or
sinking down in accordance with the applied gradient magnetic
field. The detected magnetic gradient is obtained as the physical
information about the magnetic guiding of the capsule medical
device, and the obtained physical information (the magnetic
gradient) is set as the magnetic field condition for magnetically
guiding the capsule medical device. The other configurations of
this embodiment are the same as those of the third embodiment.
Accordingly, not only the same effects as those of the third
embodiment can be achieved, but also the magnetic gradient of the
gradient magnetic field generated for magnetically guiding the
capsule medical device in the liquid can be fed back to the control
system for the magnetic guiding. As a result, the magnetic guiding
of the capsule medical device can be more practically
controlled.
[0154] Next, a fifth embodiment of the present invention will be
described. In the first embodiment, the physical information (the
density .rho..sub.CP, the gravity center position GP, or the like)
about the magnetic guiding of the capsule medical device 10 is
calculated based on images captured by the capsule medical device
10 in a liquid. In the fifth embodiment, on the other hand, the
physical information about the magnetic guiding of the capsule
medical device 10 is stored beforehand in the capsule medical
device 10 after the manufacture, and the physical information that
is radio-transmitted together with images from the capsule medical
device 10 to the outside is to be obtained.
[0155] FIG. 17 is a block diagram schematically showing an example
structure of a magnetically guiding system in accordance with the
fifth embodiment of the present invention. As shown in FIG. 17, the
magnetically guiding system 51 in accordance with the fifth
embodiment differs from the magnetically guiding system 1 of the
first embodiment in that the information acquiring unit 4 is
replaced with an information acquiring unit 54, and the control
unit 8 is replaced with a control unit 58. In the fifth embodiment,
the physical information about the magnetic guiding of the capsule
medical device 10, such as the density .rho..sub.CP and the gravity
center position GP, is stored beforehand in an internal memory (not
shown) of the capsule medical device 10. The capsule medical device
10 radio-transmits the physical information together with captured
images to the outside. The other configurations of this embodiment
are the same as those of the first embodiment, and the same
components as those of the first embodiment are denoted by the same
reference numerals used in the first embodiment.
[0156] The information acquiring unit 54 acquires the physical
information about the magnetic guiding of the capsule medical
device 10 via the receiving unit 3. More specifically, under the
control of the control unit 58, the receiving unit 3 receives image
signals that contain data about images captured by the capsule
medical device 10 in the liquid 100 and the physical information
about the magnetic guiding of the capsule medical device 10. The
receiving unit 3 then transmits the image signals from the capsule
medical device 10 to the information acquiring unit 54 and the
control unit 58. Under the control of the control unit 58, the
information acquiring unit 54 acquires the image signals from the
capsule medical device 10 via the receiving unit 3. From the
acquired image signals, the information acquiring unit 54 extracts
the physical information about the magnetic guiding of the capsule
medical device 10. In this manner, the information acquiring unit
54 acquires the physical information about the magnetic guiding of
the capsule medical device 10, and transmits the acquired physical
information to the control unit 58.
[0157] As shown in FIG. 3, the capsule medical device 10 includes
the control unit 17. The control unit 17 may be embodied with the
use of a CPU that executes processing programs, and a memory that
stores various kinds of information. After the manufacture of the
capsule medical device 10, the memory of the control unit 17 stores
the physical information about the magnetic guiding of the capsule
medical device 10. The control unit 17 controls the radio
communication unit 16 to radio-transmit the image signals
containing the data about images captured by the image capturing
units 14 and 15, and the physical information stored in the memory
(the physical information about the magnetic guiding of the capsule
medical device 10) to the outside. The image signals
radio-transmitted from the radio communication unit 16 are received
by the receiving unit 3 as described above.
[0158] Based on instruction information that is input from the
input unit 5, the control unit 58 controls the operation of the
information acquiring unit 54. In this case, the control unit 58
controls the information acquiring unit 54 to extract the physical
information about the magnetic guiding of the capsule medical
device 10 from the image signals that are transmitted from the
capsule medical device 10 and are received by the receiving unit 3.
The control unit 58 obtains the physical information about the
magnetic guiding of the capsule medical device 10, such as the
density .rho..sub.CP, from the information acquiring unit 54.
Except for the function to control the information acquiring unit
54, the control unit 58 has the same functions as those of the
control unit 8 of the magnetically guising system 1 in accordance
with the first embodiment.
[0159] Next, the operation by the magnetically guiding system 51 in
accordance with the fifth embodiment of the present invention will
be described. The magnetically guiding system 51 in accordance with
the fifth embodiment operates in the same manner as the
magnetically guiding system 1 of the first embodiment, except for
an operation when the physical information about the magnetic
guiding of the capsule medical device 10 is obtained. In other
words, the control unit 58 of the magnetically guiding system 51
carries out the substantially same procedures as those of steps
S101 through S108 shown in FIG. 4. In this case, the control unit
58 acquires the physical information about the magnetic guiding of
the capsule medical device 10 by a different technique from that
utilized in step S102 by the control unit 8 of the first
embodiment.
[0160] More specifically, in step S102, the control unit 58
controls the receiving unit 3 to receive image signals captured by
the capsule medical device 10 in the liquid 100. The control unit
58 also controls the information acquiring unit 54 to acquire image
signals from the capsule medical device 10 via the receiving unit
3. The control unit 58 further controls the information acquiring
unit 54 to acquire the physical information about the magnetic
guiding of the capsule medical device 10 contained in the image
signals.
[0161] Under the control of the control unit 58, the information
acquiring unit 54 acquires the image signals from the capsule
medical device 10 via the receiving unit 3, and extracts the
physical information about the magnetic guiding of the capsule
medical device 10 from the acquired image signals. In this manner,
the information acquiring unit 54 acquires the physical information
about the magnetic guiding of the capsule medical device 10, and
transmits the acquired physical information to the control unit
58.
[0162] The information acquiring unit 54 of the fifth embodiment
can acquire the physical information about the magnetic guiding of
the capsule medical device 10, in both situations where the capsule
medical device 10 has already been introduced into an internal
organ of a test subject and where the capsule medical device 10 has
not been introduced thereinto. More specifically, the receiving
unit 3 receives image signals from the capsule medical device 10
that has not been introduced to an internal organ of a test
subject. The information acquiring unit 54 extracts the physical
information about the magnetic guiding of the capsule medical
device 10 from the image signals received by the receiving unit 3.
Alternatively, the receiving unit 3 receives image signals from the
capsule medical device 10 that has been introduced into an internal
organ of a test subject, and the information acquiring unit 54
extracts the physical information about the magnetic guiding of the
capsule medical device 10 from the image signals received by the
receiving unit 3.
[0163] As described above, in the magnetically guiding system and
the magnetically guiding method in accordance with the fifth
embodiment of the present invention, the physical information about
the magnetic guiding of the capsule medical device is stored
beforehand in an internal memory of the capsule medical device, and
the stored physical information is included in image signals
captured by the capsule medical device and is then
radio-transmitted. The image signals from the capsule medical
device are received, and the physical information about the
magnetic guiding of the capsule medical device is extracted from
the received image signals. The other configurations of this
embodiment are the same as those of the first embodiment.
Accordingly, not only the same effects as those of the first
embodiment can be achieved, but also the physical information about
the magnetic guiding of the capsule medical device can be readily
obtained, in both situations where the capsule medical device has
been introduced into an internal organ of a test subject and where
the capsule medical device has not been introduced thereinto.
[0164] In each of the second through fourth embodiments, the timing
when the capsule medical device 10 starts floating up or sinking
down in the liquid 100 is determined, based on the motion vector
between images sequentially captured by the capsule medical device
10 in the liquid 100. However, the present invention is not limited
to that arrangement, and the timing when the capsule medical device
10 starts floating up or sinking down may be determined based on
the location information about the capsule medical device 10 in the
liquid 100. In such a case, each of the magnetically guiding
systems of the second through fourth embodiments further includes a
position detecting unit that detects the position of the capsule
medical device 10 in the liquid 100. Based on the location
information about the capsule medical device 10 detected by the
position detecting unit, the information acquiring unit determines
the timing when the capsule medical device 10 in the liquid 100
starts floating up or sinking down. The position detecting unit may
detect the position of the capsule medical device 10, based on the
reception field intensity of the receiving antennas 3a detected
when the receiving unit 3 receives an image signal from the capsule
medical device 10. Alternatively, the position detecting unit may
detect the position of the capsule medical device 1, based on the
intensity of the magnetic field generated from the magnet 19
provided inside the capsule medical device 10, or may detect the
position of the capsule medical device 10 by some other
techniques.
[0165] In each of the second through fourth embodiments, the timing
when the capsule medical device 10 starts floating up or sinking
down in the liquid 100 is determined with the use of images
captured by the capsule medical device 10. However, the present
invention is not limited to that arrangement. For example, images
of the capsule medical device 10 in the liquid 100 may be captured
by a camera independent of the capsule medical device 10, and the
timing when the capsule medical device 10 starts floating up or
sinking down in the liquid 100 may be determined with the use of
the images captured by the camera independent of the capsule
medical device 10.
[0166] Also, in each of the first through fifth embodiments, the
physical information about the magnetic guiding of the capsule
medical device is obtained by the information acquiring unit.
However, the present invention is not limited to that arrangement,
and the physical information about the magnetic guiding of the
capsule medical device may be input through the input unit.
[0167] In the first embodiment, the mark 111 formed with concentric
circles is provided at the bottom of the container 110. However,
the present invention is not limited to that arrangement, and the
mark to be provided at the bottom of the container 110 may have any
desired shape such as an oval shape or a rectangular shape.
Alternatively, the mark to be provided at the bottom of the
container 110 may be scaled at predetermined intervals, or may be
colored in different colors at predetermined intervals. The mark to
be provided at the bottom of the container 110 may have different
kinds of line at predetermined intervals. It is also possible to
form the mark by combining selected two or more of the above
mentioned types of mark.
[0168] In each of the first through fifth embodiments, the capsule
medical device 10 is of a twin-lens type that has two image
capturing units provided therein. However, the present invention is
not limited to that arrangement, and the capsule medical device to
be magnetically guided by a magnetically guiding system of the
present invention may be a capsule medical device of a single-lens
type that includes a single image capturing unit, or may be a
capsule medical device of multi-lens type that includes three or
more image capturing units. The image capturing direction of such a
capsule medical device of a twin-lens or multi-lens type may be the
direction of the long axis CL of the capsule medical device as
described above, or may be the radial direction of the capsule-like
casing 11 or a direction tilted with respect to the long axis
CL.
[0169] In each of the first through fifth embodiments, the
magnetically guiding system of the present invention guides the
capsule medical device 10 with magnetic force. However, the
magnetically guiding system of the present invention is not limited
thereto and is applicable to magnetically guide a medical device
that includes at least one magnet. For example, the magnetically
guiding system of the present invention may magnetically guide a
catheter including a magnet or may magnetically guide an
endoscope.
[0170] In each of the first through fifth embodiments, the
magnetically guiding system of the present invention guides the
capsule medical device 10 with magnetic force. However, the present
invention is not limited to that arrangement, and the present
invention may be applied to a checking device that checks the
characteristics of the magnet 19 in the capsule medical device
10.
[0171] The following is a description of such a checking device and
a magnetically guiding system that uses the checking device. In the
following description, a checking device that checks a capsule
medical device housed in a predetermined package and a magnetically
guiding system that magnetically guides the capsule medical device
checked by the checking device and introduced into the body of a
test subject are taken as examples. However, this embodiment does
not limit the present invention.
[0172] FIG. 18 is a block diagram schematically showing an example
structure of a checking device in accordance with a sixth
embodiment of the present invention. As shown in FIG. 18, the
checking device 201 in accordance with the sixth embodiment
includes: a housing unit 204 that houses a capsule medical device
202 to be magnetically guided by a predetermined magnetically
guiding device 304 together with the package 203 of the capsule
medical device 202; a magnet characteristics measuring unit 205
that measures the characteristics of a magnet 227 provided inside
the capsule medical device 202; and a resonance characteristics
measuring unit 206 that measures the characteristics of a resonance
circuit 228 provided inside the capsule medical device 202. The
checking device 201 also includes: an input unit 207 that inputs
various kinds of information; a display unit 208 that displays
various kinds of information such as the conditions for operating
the magnetically guiding device 304; an output unit 209 that
outputs operating condition information and the likes to the
magnetically guiding device 304; a storage unit 210 that stores
various kinds of information; and a control unit 211 that controls
the respective components of the checking device 201.
[0173] The capsule medical device 202 is a capsule-like medical
device that obtains in-vivo images of a test subject, and has an
image capturing function and a radio communication function inside
a capsule-like casing. The capsule medical device 202 can be
magnetically guided by the predetermined magnetically guiding
device 304, and has the magnet 227 and the resonance circuit 228
provided inside the capsule-like casing. The capsule medical device
202 is subjected to a sterilizing treatment after its manufacture,
and is then put into the package 203. After shipped to users such
as medical doctors and nurses, the capsule medical device 202 is
kept inside the package 203 until it is introduced into the body of
a test subject.
[0174] The package 203 has such a structure that can accommodate
the capsule medical device 202 therein, and has such an external
shape that the long axis direction of the housed capsule medical
device 202 can be visually recognized. The package 203 supports the
sterilized capsule medical device 202 therein in a detachable
manner, and houses the capsule medical device 202 in a sealed
state. The capsule medical device 202 housed (supported) inside the
package 203 cannot move freely inside the package 203 (that is,
cannot change its relative position and direction with respect to
the package 203).
[0175] The housing unit 204 functions as a supporting unit that
supports the capsule medical device 202 to be checked. More
specifically, the housing unit 204 has a concave portion (the
shaded portion in FIG. 18) that can accommodate the package 203
while defining the direction of the package 203. The housing unit
204 supports the package 203 fitted with the concave portion in
such a manner that a bearing structure allows the package 203 to
rotate. The housing unit 204 houses and supports the capsule
medical device 202 in a rotative manner via the package 203. In
this case, the package 203 housed in the housing unit 204 can
rotate about the central axis CL1 of the package 203. It is
desirable that the central axis CL1 of the package 203 is parallel
to the long axis of the capsule medical device 202 inside the
package 203 (or the central axis CL2 of the later described
capsule-like housing 220 in the longitudinal axis), and it is more
desirable that the central axis CL1 of the package 203 is
coincident with the long axis of the capsule medical device
202.
[0176] The magnet characteristics measuring unit 205 measures the
characteristics of the magnet 227 provided in the capsule medical
device 202. More specifically, the magnet characteristics measuring
unit 205 measures the magnetic moment that is part of the
characteristics of the magnet 227. The magnet characteristics
measuring unit 205 includes a magnetic moment measuring unit 213
that measures the magnetic moment of the magnet 227 in the capsule
medical device 202 housed in the housing unit 204, and a
magnetization direction control unit 214 that magnetically controls
the magnetization direction of the magnet 227.
[0177] The magnetic moment measuring unit 213 measures the magnetic
moment of the magnet 227 through the measurement of the residual
flux density of the magnet 227 inside the capsule medical device
202. The magnetic moment measuring unit 213 includes a flux density
measuring unit 213a that measures the residual flux density of the
magnet 227, and a magnetic moment calculating unit 213b that
calculates the magnetic moment of the magnet 227 based on the
result of the measurement carried out on the residual flux density
by the flux density measuring unit 213.
[0178] The flux density measuring unit 213a is placed in the
vicinity of the housing unit 204, and is located near the capsule
medical device 202 in the package 203 housed in the housing unit
204. Under the control of the control unit 211, the flux density
measuring unit 213a measures the residual flux density of the
magnet 227 indicating the maximum intensity of the magnetic field
(the maximum magnetic force) that can be generated from the magnet
227 in the capsule medical device 202 at that time. The flux
density measuring unit 213a transmits the result of the measurement
of the residual flux density of the magnet 227 to the magnetic
moment calculating unit 213b.
[0179] Based on the result of the measurement carried out by the
flux density measuring unit 213a, the magnetic moment calculating
unit 213b calculates the magnetic moment of the magnet 227 in the
capsule medical device 202. More specifically, the magnetic moment
calculating unit 213b obtains the residual flux density of the
magnet 227 in the capsule medical device 202 from the flux density
measuring unit 213a. The magnetic moment calculating unit 213b
obtains magnet volume information 210a that is read from the
storage unit 210 by the control unit 211. Under the control of the
control unit 211, the magnetic moment calculating unit 213b
multiplies the residual flux density (the measured value) of the
magnet 227 by the magnet volume information 210a (the volume of the
magnet 227), so as to calculate the magnetic moment of the magnet
227. The magnetic moment calculating unit 213b then transmits the
magnetic moment of the magnet 227 calculated in this manner as the
result of the measurement of the magnetic moment of the magnet 227,
to the control unit 211.
[0180] The magnetization direction control unit 214 applies a
magnetic field to the capsule medical device 202, to control the
magnetization direction of the magnet 227 inside the capsule
medical device 202. More specifically, the magnetization direction
control unit 214 includes a magnetic field generating coil 214a, a
signal generating unit 214b, and a driving unit 214c. The
magnetization direction control unit 214 magnetically rotates the
capsule medical device 202 in the package 203 housed in the housing
unit 204 together with the package 203. By doing so, the
magnetization direction control unit 214 controls the magnetization
direction of the magnet 227 in the capsule medical device 202 to be
in the direction suited for the flux density measuring unit 213a to
measure the residual flux density of the magnet 227.
[0181] Based on a current supplied from the driving unit 214c, the
magnetic field generating coil 214a generates a guiding magnetic
field M1, and applies the generated guiding magnetic field M1 to
the capsule medical device 202 in the package 203. The guiding
magnetic field M1 of the magnetic field generating coil 214a is a
magnetic field for guiding the capsule medical device 202, and acts
on the magnet 227 inside the capsule medical device 202.
Accordingly, the capsule medical device 202 changes the
magnetization direction of the magnet 227 toward the flux density
measuring unit 213a, while rotating in accordance with the guiding
magnetic field M1. In other words, the magnetic field generating
coil 214a causes the magnetization direction of the magnet 227 in
the capsule medical device 202 to be coincident with the
magnetization direction of the guiding magnetic field M1 applied to
the capsule medical device 202.
[0182] The signal generating unit 214b generates a current signal,
under the control of the control unit 211. The signal generating
unit 214b then transmits the current signal to the driving unit
214c. The driving unit 214c amplifies the current signal generated
from the signal generating unit 214b, and transmits the amplified
current signal to the magnetic field generating coil 214a. In this
manner, the driving unit 214c supplies the power (the current)
required for generating the guiding magnetic field M1 to the
magnetic field generating coil 214a.
[0183] The resonance characteristics measuring unit 206 measures
the resonance characteristics of the resonance circuit 228 provided
inside the capsule medical device 202. More specifically, the
resonance characteristics measuring unit 206 includes a magnetic
field generating unit 215 that applies a magnetic field to the
resonance circuit 228 inside the capsule medical device 202 housed
in the housing unit 204, and an induced magnetic field measuring
unit 216 that measures the intensity of an induced magnetic field
generated from the resonance circuit 228.
[0184] The magnetic field generating unit 215 causes the resonance
circuit 228 in the capsule medical device 202 to generate an
induced magnetic field. The magnetic field generating unit 215
includes a magnetic field generating coil 215a, a signal generating
unit 215b, and a driving unit 215c. Based on a current supplied
from the driving unit 215c, the magnetic field generating coil 215a
generates a magnetic field M2 while changing frequencies, and
sequentially applies the magnetic field M2 of different frequencies
to the capsule medical device 202 in the package 203. The magnetic
field M2 generated from the magnetic field generating coil 215a
acts on the resonance circuit 228 inside the capsule medical device
202. In this case, upon receipt of the magnetic field M2, the
resonance circuit 228 is put into a resonant state and generates an
induced magnetic field. The induced magnetic field generated from
the resonance circuit 228 is a magnetic field that is output (as a
response) from the resonance circuit 228 that has received the
magnetic field M2 from the magnetic field generating coil 215a.
[0185] Under the control of the control unit 211, the signal
generating unit 215b generates a frequency sweep signal, and
transmits the generated frequency sweep signal to the driving unit
215c. The driving unit 215c electrically amplifies the frequency
sweep signal generated from the signal generating unit 215b, and
transmits the electrically amplified frequency sweep signal to the
magnetic field generating coil 215a. In this manner, the driving
unit 215c supplies the electric power (the current) required for
generating the magnetic field M2 to the magnetic field generating
coil 215a. Under the control of the control unit 211, the signal
generating unit 215b may generate a signal of at least one
frequency, and may transmit the generated signal of at least one
frequency to the driving unit 215c. In other words, the frequency
of the signal generated from the signal generating unit 215b (the
electric signal to be applied to the magnetic field generating coil
215a) may be one frequency or continuous frequencies.
[0186] The induced magnetic field measuring unit 216 is designed to
measure the intensity of the induced magnetic field generated from
the resonance circuit 228 inside the capsule medical device 202.
The induced magnetic field measuring unit 216 includes; a magnetic
field sensor 216a that detects an induced magnetic field that is
generated from the resonance circuit 228 in the capsule medical
device 202 in response to the magnetic field M2 generated from the
magnetic field generating coil 215a; and an induced magnetic field
calculating unit 216b that performs predetermined signal processing
on the results of the detection performed by the magnetic field
sensor 216a.
[0187] The magnetic field sensor 216a may be embodied with the use
of a coil or the like. The magnetic field sensor 216a detects the
induced magnetic field generated from the resonance circuit 228
inside the capsule medical device 202, and converts the detected
induced magnetic field into a voltage signal. The magnetic field
sensor 216a then transmits the voltage signal as the result of the
detection performed on the induced magnetic field from the
resonance circuit 228, to the induced magnetic field calculating
unit 216b.
[0188] The induced magnetic field calculating unit 216b may be
embodied with the use of an A-D converting unit, an FFT processing
unit, and the likes. The induced magnetic field calculating unit
216b obtains the voltage signal as the result of the detection
performed on the induced magnetic field from the magnetic field
sensor 216a, and performs a digital conversion on the obtained
voltage signal. After that, the induced magnetic field calculating
unit 216b performs a fast Fourier transform (FTT processing) on the
digitized voltage signal, and transmits the result of the FFT
processing (or the measured value of the induced magnetic field
generated from the resonance circuit 228) to the control unit 211.
The induced magnetic field calculating unit 216b may set the field
intensity information about the magnetic field M2 from the magnetic
field generating coil 215a as the operating parameter in advance,
or may obtain the field intensity information from the control unit
211. In this case, the induced magnetic field calculating unit 216b
may subtract the field intensity information (the set value of the
field intensity) about the magnetic field M2 from the result (the
measured value of the field intensity) of the magnetic field
detection performed by the magnetic field sensor 216a, so as to
obtain the measured value of the field intensity of the induced
magnetic field generated from the resonance circuit 228.
[0189] The input unit 207 may be embodied with the use of input
devices such as a keyboard, a mouse, and the likes. The input unit
207 inputs various kinds of information to the control unit 211, in
accordance with input operations performed by a user such as a
medical doctor, a nurse, or the like. The various kinds of
information to be input to the control unit 211 from the input unit
207 include: magnet information that indicates the volume of the
magnet 227 provided inside the capsule medical device 202; magnetic
guiding information that indicates the magnetic torque required for
the magnetically guiding device 304 to magnetically guide the
capsule medical device 202 inside the body of a test subject;
frequency information that indicates an alternating magnetic field
of a position detecting device 305 that detects a position of the
capsule medical device 202 in the body of the test subject; and
various kinds of instruction information for issuing instructions
to the control unit 211, for example.
[0190] The display unit 208 may be embodied with the use of a CRT
display, a liquid crystal display, or the like. The display unit
208 displays various kinds of information instructed to display by
the control unit 211. More specifically, the display unit 208
displays the result of the measurement of the residual flux density
of the magnet 227 inside the capsule medical device 202 (the result
of the measurement carried out by the flux density measuring unit
213a), the measured value of the induced magnetic field generated
from the resonance circuit 228 inside the capsule medical device
202 (the result of the measurement carried out by the induced
magnetic field measuring unit 216), the operating condition
information about each of the magnetically guiding device 304 and
the position detecting device 305, and the likes.
[0191] Under the control of the control unit 211, the output unit
209 performs an information communication with the magnetically
guiding device 304, and transmits the information instructed to
output by the control unit 211 (to be specific, the information
about the conditions for operating the magnetically guiding device
304) to the magnetically guiding device 304. Under the control of
the control unit 211, the output unit 209 also performs an
information communication with the position detecting device 305,
and transmits the information instructed to output by the control
unit 211 (to be specific, the information about the conditions for
operating the position detecting device 305) to the position
detecting device 305. The output unit 209 may perform radio
communications or wire communications with the magnetically guiding
device 304 and the position detecting device 305.
[0192] The storage unit 210 may be embodied with the use of a
storage medium that stores information in a rewritable fashion,
such as a RAM, an EEPROM, a flash memory, or a hard disk. The
storage unit 210 stores various kinds of information instructed to
store by the control unit 211. Among the various kinds of stored
information, the storage unit 210 transmits information instructed
to read out by the control unit 211, to the control unit 211. Under
the control of the control unit 211, the storage unit 210 stores
the magnet volume information 210a that indicates the volume of the
magnet 227 in the capsule medical device 202, and magnetic torque
information 210b that indicates the torque required for
magnetically guiding the capsule medical device 202 introduced into
the body of a test subject. In addition to the magnet volume
information 210a and the magnetic torque information 210b, the
storage unit 210 also stores the result of the measurement carried
out by the magnetic moment measuring unit 213, the result of the
measurement carried out by the induced magnetic field measuring
unit 216, the information about the conditions for operating the
magnetically guiding device 304, the information about the
conditions for operating the position detecting device 305, and the
likes.
[0193] The control unit 211 controls the operations of the
components (the magnet characteristics measuring unit 205, the
resonance characteristics measuring unit 206, the input unit 207,
the display unit 208, the output unit 209, and the storage unit
210) of the checking device 201, and also controls signal inputs
and outputs among those components. More specifically, the control
unit 211 controls the display unit 208 to display various kinds of
information such as the results of the measurements and the
information about the conditions for operating the magnetically
guiding device 304. The control unit 211 also controls the output
unit 209 to output the information about the operating conditions
to the magnetically guiding device 304. The control unit 211
further controls the output unit 209 to output the information
about the conditions for operating the position detecting device
305. The control unit 211 controls the storage unit 210 to store
the various kinds of information such as the results of the
measurements and the information about the conditions for operating
the magnetically guiding device 304.
[0194] Based on instruction information that is input from the
input unit 207, the control unit 211 also controls the magnet
characteristics measuring unit 205 to measure the characteristics
of the magnet 227 inside the capsule medical device 202. In this
case, the control unit 211 controls the signal generating unit 214b
to generate the current signal required for generating the guiding
magnetic field M1. By controlling the signal generating unit 214b,
the control unit 211 controls the magnetic field generating
operation of the magnetic field generating coil 214a. The control
unit 211 controls the magnetic field generating coil 214a to apply
the guiding magnetic field M1 to the capsule medical device 202 for
a predetermined period of time. By doing so, the control unit 211
directs the magnetization direction of the magnet 227 inside the
capsule medical device 202 toward the flux density measuring unit
213a. After that, the control unit 211 controls the signal
generating unit 214b to stop generating the current signal. By
doing so, the control unit 211 stops the generation of the guiding
magnetic field M1 from the magnetic field generating coil 214a (the
application of a magnetic field to the capsule medical device 202).
The control unit 211 controls the flux density measuring unit 213a
to measure the residual flux density of the magnet 227 at the
timing when the generation of the magnetic field is stopped, and
then controls the magnetic moment calculating unit 213b to
calculate the magnetic moment of the magnet 227 based on the
measured value of the residual flux density. In this manner, the
control unit 211 obtains the value calculated by the magnetic
moment calculating unit 213b or the value measured by the magnetic
moment measuring unit 213.
[0195] Based on instruction information that is input from the
input unit 207, the control unit 211 further controls the resonance
characteristics measuring unit 206 to measure the resonance
characteristics of the resonance circuit 228 inside the capsule
medical device 202. In this case, the control unit 211 controls the
signal generating unit 215b to generate the current signal required
for generating the magnetic field M2. By controlling the signal
generating unit 215b, the control unit 211 controls the magnetic
field generating operation of the magnetic field generating coil
215a. The control unit 211 also controls the induced magnetic field
calculating unit 216b to calculate the measurement value of the
induced magnetic field generated from the resonance circuit 228. In
this manner, the control unit 211 obtains the measurement value of
the induced magnetic field from the induced magnetic field
calculating unit 216b.
[0196] The control unit 211 includes an operating condition setting
unit 212 that sets the conditions for operating the magnetically
guiding device 304 and the position detecting device 305. Based on
the result of the measurement carried out by the magnet
characteristics measuring unit 205 or the result of the measurement
carried out by the resonance characteristics measuring unit 206,
the operating condition setting unit 212 sets the conditions for
operating the magnetically guiding device 304 to magnetically guide
the capsule medical device 202 inside the body of a test subject,
and the conditions for operating the position detecting device 305
to detect the position of the capsule medical device 202 being
magnetically guided by the magnetically guiding device 304 inside
the body of the test subject. The operating condition setting unit
212 includes a field intensity calculating unit 212a that
calculates the field intensity condition for the magnetically
guiding device 304, and a frequency calculating unit 212b that
calculates the frequency condition for the position detecting
device 305.
[0197] The field intensity calculating unit 212a calculates the
field intensity condition for the magnetically guiding device 304,
based on the result of the measurement carried out by the magnetic
moment measuring unit 213. More specifically, the field intensity
calculating unit 212a obtains the magnetic moment of the magnet 227
inside the capsule medical device 202 from the magnetic moment
calculating unit 213b. The field intensity calculating unit 212a
also obtains the magnetic torque information 210b that is read from
the storage unit 210 under the control of the control unit 211. The
field intensity calculating unit 212a divides the magnetic torque
information 210b (the torque required for the magnetic guiding) by
the magnetic moment (the measurement value) of the magnet 227, so
as to calculate the field intensity. The field intensity calculated
by the field intensity calculating unit 212a is the field intensity
condition for the magnetically guiding device 304 to magnetically
guide the capsule medical device 202 inside the body of the test
subject. The operating condition setting unit 212 sets the result
(the field intensity) of the calculation performed by the field
intensity calculating unit 212a as the field intensity condition
for the magnetically guiding device 304.
[0198] The frequency calculating unit 212b calculates the frequency
condition for the position detecting device 305, based on the
result of the FFT processing performed by the induced magnetic
field calculating unit 216b. More specifically, the frequency
calculating unit 212b obtains the measurement value of the induced
magnetic field generated from the resonance circuit 228 (or the
result of the FFT processing), from the induced magnetic field
calculating unit 216b. The frequency calculating unit 212b then
calculates the frequency at which the measurement value of the
induced magnetic field becomes the local maximum and the frequency
at which the measurement value of the induced magnetic field
becomes the local minimum (or calculates each frequency before and
after the resonance point of the resonance circuit 228). The
frequencies calculated by the frequency calculating unit 212b
represent the frequency condition for the position detecting device
305 to detect the magnetic field (the induced magnetic field)
generated from the capsule medical device 202. The operating
condition setting unit 212 sets the results (the frequencies) of
the calculations performed by the frequency calculating unit 212b
as the frequency condition for the position detecting device 305.
Meanwhile, the frequency calculating unit 212b may calculate the
resonance frequency of the resonance circuit 228, based on the
result of the FFT processing performed by the induced magnetic
field calculating unit 216b, and sets the resonance frequency as
the frequency condition for the position detecting device 305.
[0199] The magnetically guiding device 304 is an external device
for magnetically guiding the capsule medical device 202 introduced
into the body of a test subject. The magnetically guiding device
304 performs an information communication with the output unit 209,
to obtain the operating condition information that indicates the
results of the condition setting operation by the operating
condition setting unit 212. The operating condition setting
information obtained from the operating condition setting unit 212
includes the field intensity condition calculated by the field
intensity calculating unit 212a. The magnetically guiding device
304 sets the field intensity condition as the initial field
intensity condition for magnetically guiding the capsule medical
device 202 inside the body of a test subject. After that, the
magnetically guiding device 304 adjusts the intensity of the
magnetic field to be applied to the capsule medical device 202,
when necessary. The magnetically guiding device 304 uses the field
intensity condition set by the operating condition setting unit 212
as the maximum intensity value of the magnetic field required for
magnetically guiding the capsule medical device 202 inside the body
of the test subject.
[0200] The position detecting device 305 is an external device for
detecting the position of the capsule medical device 202 introduced
into the body of the test subject. The position detecting device
305 performs an information communication with the output unit 209,
to obtain the operating condition information that indicate the
result of the condition setting operation by the operating
condition setting unit 212. The operating condition information
obtained from the operating condition setting unit 212 includes the
frequency condition calculated by the frequency calculating unit
212b. The position detecting device 305 appropriately selects one
of the frequencies represented by the obtained frequency condition
(to be more specific, the frequency equivalent to the local maximum
value of the detected intensity of the induced magnetic field and
the frequency equivalent to the local minimum value). The position
detecting device 305 applies the magnetic field of the selected
frequency to the capsule medical device 202 in the body of the test
subject. By doing so, the position detecting device 305 detects the
intensity of the magnetic field (the induced magnetic field)
generated from the capsule medical device 202. Based on the
detected intensity value of the induced magnetic field generated
from the capsule medical device 202, the position detecting device
305 calculates (detects) the position of the capsule medical device
202 in the body of the test subject. Using the result of the
position detecting operation by the position detecting device 305
to detect the position of the capsule medical device 202, the
magnetically guiding device 304 magnetically guides the capsule
medical device 202.
[0201] The frequency indicated by the frequency condition set by
the operating condition setting unit 212 (or the result of the
operation by the frequency calculating unit 212b) may be the
resonance frequency of the resonance circuit 228 inside the capsule
medical device 202. The position detecting device 305 may apply a
magnetic field of the resonance frequency to the capsule medical
device 202 inside the body of the test subject, so as to detect the
position of the capsule medical device 202 inside the body of the
test subject.
[0202] Next, the structure of the capsule medical device 202 to be
checked by the checking device 201 in accordance with the sixth
embodiment of the present invention will be described. FIG. 19 is a
schematic view showing an example structure of the capsule medical
device to be checked by the checking device in accordance with the
sixth embodiment of the present invention. As shown in FIG. 19, the
capsule medical device 202 to be checked includes the capsule-like
casing 220 formed with a cylindrical casing 220a and a dome-like
casing 220b, an illuminating unit 221 such as LEDs, and an image
capturing unit 222 that captures images of a subject illuminated by
the illuminating unit 221. The capsule medical device 202 also
includes a signal processing unit 223 that generates the image
signals of the image data captured by the image capturing unit 222,
a transmission unit 224 that radio-transmits the image signals to
the outside, a control unit 225 that controls the components of the
capsule medical device 202, and a power source unit 226 such as a
battery. The capsule medical device 202 further includes the magnet
227 that operates following an external magnetic field, and the
resonance circuit 228 formed with a coil and a capacitor.
[0203] The capsule-like casing 220 has such a size as to be
introduced into an internal organ of a test subject. One end (the
opening end) of the cylindrical casing 220a having the other end in
a dome-like shape is covered with the dome-like casing 220b. The
dome-like casing 220b is a dome-like optical material that is
transparent to light in a predetermined wavelength band (visible
light, for example). The cylindrical casing 220a is a casing that
is substantially not transparent to visible light. The illuminating
unit 221, the image capturing unit 222, the signal processing unit
223, the transmission unit 224, the control unit 225, the power
source unit 226, the magnet 227, and the resonance circuit 228 are
housed in a liquid-tight manner in the capsule-like casing 220
formed with the cylindrical casing 220a and the dome-like casing
220b.
[0204] The illuminating unit 221 and the image capturing unit 222
form a function executing unit for capturing in-vivo images of a
test subject when the capsule medical device 202 is introduced into
the body of the test subject. More specifically, the illuminating
unit 221 may be embodied with the use of a light emitting element
such as LEDs, and illuminates the subject of the image capturing
unit 222 through the dome-like housing 220b.
[0205] The image capturing unit 222 includes an optical system 222a
such as a condenser lens, and a solid-state image sensor 222b such
as a CCD or a CMOS image sensor. The image capturing unit 222 is
fixed inside the capsule-like casing 220 in such a manner that the
reference direction (the vertical direction of the light receiving
face, for example) of the solid-state image sensor 222b is
substantially coincident with the radial direction of the
capsule-like casing 220. The optical system 222a gathers the light
reflected from the subject illuminated by the illuminating unit
221, and forms an optical image of the subject on the light
receiving face of the solid-state image sensor 222b. The
solid-state image sensor 222b captures optical images of the
subject or images (in-vivo images, for example) of the subject
illuminated by the illuminating unit 221.
[0206] The signal processing unit 223 obtains signals that are
photoelectrically converted by the solid-state image sensor 222b of
the image capturing unit 222. The signal processing unit 223
performs predetermined signal processing on the obtained signals,
so as to generate image signals that contain the image data (the
in-vivo images and the likes) of the subject captured by the image
capturing unit 222. The transmission unit 224 includes a coil-like
antenna 224a, and performs radio communications with an external
device through the antenna 224a. More specifically, the
transmission unit 224 obtains the image signals generated from the
signal processing unit 223, and performs modulation or the like on
the obtained image signals, so as to generate radio signals
including the image signals. The transmission unit 224 then
radio-transmits the radio signals including the image signals to
the outside through the antenna 224a.
[0207] The control unit 225 controls the components (the
illuminating unit 221, the image capturing unit 222, the signal
processing unit 223, and the transmission unit 224) of the capsule
medical device 202, and also controls signal inputs and outputs
among those components. More specifically, the control unit 225
controls the illuminating unit 221 and the image capturing unit 222
to operate in such timing that the image capturing unit 222
captures an image of the subject when the illuminating unit 221
illuminates the subject of the image capturing unit 222. The
control unit 225 controls the illuminating unit 221 and the image
capturing unit 222 to repeat the image capturing operation at
predetermined time intervals (every 0.5 seconds, for example). The
control unit 225 also controls the signal processing unit 223 and
the transmission unit 224 to radio-transmit the image signals
including the image data captured by the image capturing unit 222,
to the outside.
[0208] The power source unit 226 may be embodied with the use of a
switch circuit and a button battery or the like. When switched on
by the switch circuit, the power source unit 226 supplies electric
power to the illuminating unit 221, the image capturing unit 222,
the signal processing unit 223, the transmission unit 224, and the
control unit 225. When switched off by the switch circuit, the
power source unit 226 stops the supply of electric power to those
components. The switch circuit of the power source unit 226 may be
a magnetic switch that switches on and off the power source unit
226 by virtue of the actions of a magnetic field applied from the
outside, or may be an optical switch that switches on and off the
power source unit 226 by virtue of optical signals such as infrared
rays entering from the outside.
[0209] The magnet 227 may be a permanent magnet, for example, and
is placed at a predetermined position inside the capsule-like
casing 220 (placed in the vicinity of the center portion of the
capsule-like casing 220, for example). In this case, the magnet 227
is fixed in the capsule-like casing 220 in such a manner that the
direction perpendicular to the central axis CL2 of the longitudinal
direction of the capsule-like casing 220 (or the radial direction
of the capsule-like casing 220) is substantially coincident with
the magnetization direction. The magnet 227 operates in accordance
with the magnetic field generated from the magnetically guiding
device 304 located outside, so as to move the capsule medical
device 202 or stop the capsule medical device 202 at a desired
location inside the body of a test subject. Accordingly, the
capsule medical device 202 having the magnet 227 provided therein
can be magnetically guided by the magnetically guiding device 304
located outside.
[0210] The resonance circuit 228 may be embodied by connecting a
coil and a capacitor, and may be fixed inside the capsule-like
casing 220 in such a manner that the axial direction of the coil is
substantially coincident with the longitudinal direction of the
capsule-like casing 220, for example. The resonance circuit 228 has
a predetermined resonance frequency, and generates an induced
magnetic field in response to a magnetic field applied from the
outside (to be more specific, the magnetic field M2 of the magnetic
field generating coil 215a or the magnetic field of the position
detecting device 305).
[0211] Next, a magnetically guiding system in accordance with the
sixth embodiment of the present invention will be described. FIG.
20 is a block diagram schematically showing an example structure of
the magnetically guiding system in accordance with the sixth
embodiment of the present invention. As shown in FIG. 20, the
magnetically guiding system 301 in accordance with the sixth
embodiment includes: the checking device 201 that checks the
capsule medical device 202 to be introduced into the body of a test
subject; the capsule medical device 202 to be introduced into the
body of the test subject; a receiving device 303 that receives
in-vivo image groups captured by the capsule medical device 202
inside the body of the test subject; the magnetically guiding
device 304 that magnetically guides the capsule medical device 202
inside the body of the test subject; the position detecting device
305 that detects the position and orientation of the capsule
medical device 202 inside the body of the test subject; and an
image display device 306 that displays various kinds of information
such as the in-vivo images captured by the capsule medical device
202 inside the body of the test subject.
[0212] The capsule medical device 202 has the image capturing
function and the radio communication function, as shown in FIG. 19
described above. When introduced into an internal organ of a test
subject via the oral route, the capsule medical device 202
sequentially captures in-vivo images of the test subject, and
sequentially radio-transmits the obtained in-vivo images to the
receiving device 303. The capsule medical device 202 also includes
the magnet 227 and the resonance circuit 228, as described above.
The capsule medical device 202 is magnetically guided by the
magnetically guiding device 304, and the position of the capsule
medical device 202 is detected by the position detecting device
305.
[0213] The receiving device 303 has receiving antennas 303a, and
receives the in-vivo images of the test subject from the capsule
medical device 202 via the receiving antennas 303a. More
specifically, the receiving antennas 303a are scattered on the
surface of the body of the test subject having the capsule medical
device 202 being introduced into patient's digestive tract. The
receiving antennas 303a catch radio signals transmitted from the
capsule medical device 202 that is moving (or is magnetically
guided) through the digestive tract. The receiving device 303
receives radio signals from the capsule medical device 202 via the
receiving antennas 303a. The receiving device 303 then performs a
predetermined demodulating operation or the like on the received
radio signals, to extract the image signals contained in the radio
signals. The image signals extracted by the receiving device 303
contain the in-vivo images captured by the capsule medical device
202. The receiving device 303 then sequentially transmits the image
signals from the capsule medical device 202 to the image display
device 306.
[0214] The magnetically guiding device 304 is designed to
magnetically guide the capsule medical device 202 inside the body
of the test subject. The magnetically guiding device 304 includes:
a guiding magnetic field generating unit 304a that generates a
guiding magnetic field for magnetically guiding the capsule medical
device 202 inside the body of the test subject; a coil power source
unit 304b that supplies a current to the coil of the guiding
magnetic field generating unit 304a; an operating unit 304c that is
designed for starting the magnetic guiding of the capsule medical
device 202; and a magnetic-guiding control unit 304d that controls
the components of the magnetically guiding device 304.
[0215] The guiding magnetic field generating unit 304a may be
embodied with a combination of electromagnets such as Helmholtz
coils, and generates a guiding magnetic field that allows the
magnetic guiding of the capsule medical device 202 inside the body
of the test subject. More specifically, the guiding magnetic field
generating unit 304a has a triaxial orthogonal coordinate system
defined by three axes (X-axis, Y-axis, and Z-axis) perpendicular to
one another (hereinafter referred to as the absolute coordinate
system), and generates a magnetic field of desired intensity in
each of the axis directions (the X-axis direction, the Y-axis
direction, and the Z-axis direction) of the absolute coordinate
system. The guiding magnetic field generating unit 304a generates a
guiding magnetic field that is a three-dimensional rotating
magnetic field or gradient magnetic field formed by the magnetic
fields of the respective axis directions of the absolute coordinate
system inside the three-dimensional space S of the absolute
coordinate system (or inside the space surrounded by the
electromagnets of the guiding magnetic field generating unit 304a).
The guiding magnetic field generating unit 304a applies the guiding
magnetic field to the magnet 227 inside the capsule medical device
202 located inside the body of the test subject (not shown) on a
bed moved to the inside of the three-dimensional space S. Using the
guiding magnetic field, the guiding magnetic field generating unit
304a magnetically guides the capsule medical device 202.
[0216] The coil power source unit 304b supplies the current
required for the guiding magnetic field generating unit 304a to
generate the guiding magnetic field to be applied to the capsule
medical device 202 inside the body of the test subject. More
specifically, the coil power source unit 304b has power source
units for the respective coils (not shown) of the guiding magnetic
field generating unit 304a. Under the control of the
magnetic-guiding control unit 304d, the coil power source unit 304b
supplies an alternating current to each of the coils of the guiding
magnetic field generating unit 304a. By doing so, the coil power
source unit 304b causes the guiding magnetic field generating unit
304a to generate the guiding magnetic field.
[0217] The operating unit 304c may be embodied with the use of an
input device such as a joystick and an input button. In accordance
with an input operation by a user such as a medical doctor or a
nurse, the operating unit 304c inputs instruction information to
the magnetic-guiding control unit 304d, so that the capsule medical
device 202 is magnetically guided.
[0218] The magnetic-guiding control unit 304b controls the amount
of current to be supplied from the coil power source unit 304b to
the guiding magnetic field generating unit 304a, based on the
instruction information that is input from the operating unit 304c.
By controlling the coil power source unit 304b, the
magnetic-guiding control unit 304d controls the guiding magnetic
field generating operation of the guiding magnetic field generating
unit 304a. In this case, the magnetic-guiding control unit 304d
obtains the location information (hereinafter referred to as the
capsule location information) and the direction information
(hereinafter referred to as the capsule direction information)
about the capsule medical device 202 inside the body of the test
subject, from the position detection control unit 305d of the
position detecting device 305 described later. Based on the capsule
location information and the capsule direction information, the
magnetic-guiding control unit 304d controls the field intensity and
the field direction of the guiding magnetic field to be applied to
the capsule medical device 202. By controlling the field intensity
and the field direction of the guiding magnetic field, the
magnetic-guiding control unit 304d controls the magnetic guiding of
the capsule medical device 202 to be directed toward the desired
location or in the desired direction in accordance with the
instruction information input from the operating unit 304c. The
magnetic-guiding control unit 304d transmits magnetic-guiding
information to the image display device 306, with the
magnetic-guiding information including the information about the
field intensity and field direction of the guiding magnetic field
observed when the magnetic guiding of the capsule medical device
202 is controlled.
[0219] As described above, the magnetic-guiding control unit 304d
obtains the operating condition information that is set by the
operating condition setting unit 212, from the checking device 201.
The magnetic-guiding control unit 304d sets the field intensity
condition included in the obtained operating condition information
as the initial field intensity condition for magnetically guiding
the capsule medical device 202 inside the body of the test subject.
In this case, the magnetic-guiding control unit 304d sets the field
intensity condition at the maximum intensity value of the guiding
magnetic field required for magnetically guiding the capsule
medical device 202 inside the body of the test subject. The
magnetic-guiding control unit 304d controls the guiding magnetic
field within a range under the field intensity condition that is
initially set.
[0220] The position detecting device 305 detects at least one of
the position and the orientation of the capsule medical device 202
inside the body of the test subject located in the
three-dimensional space S as described above. More specifically,
the position detecting device 305 includes: a detection magnetic
field generating unit 305a that applies a detection magnetic field
to the resonance circuit 228 inside the capsule medical device 202;
a coil power source unit 305b that supplies a current to the
detection magnetic field generating unit 305a; a magnetic field
detecting unit 305c that detects an induced magnetic field
generated from the resonance circuit 228; and a position detection
control unit 305d that controls the components of the position
detecting device 300, and obtains the capsule location information
and the capsule direction information.
[0221] The detection magnetic field generating unit 305a may be
embodied with the use of one or more coil(s), and generates a
detection magnetic field that is an alternating magnetic field for
detecting at least one of the position and the orientation of the
capsule medical device 202 inside the body of the test subject.
Based on the current supplied from the coil power source unit 305b,
the detection magnetic field generating unit 305a generates a
detection magnetic field having the optimum intensity and
orientation for the position of the resonance circuit 228 and the
coil axis direction in the three-dimensional space S. The detection
magnetic field generating unit 305a then applies the detection
magnetic field to the resonance circuit 228 inside the capsule
medical device 202. By virtue of the action of the detection
magnetic field, the detection magnetic field generating unit 305a
causes the resonance circuit 228 to generate an induced magnetic
field.
[0222] The coil power source unit 305b includes one or more power
source unit(s) corresponding to the number of coils in the
detection magnetic field generating unit 305a. Under the control of
the position detection control unit 305d, the coil power source
unit 305b supplies an alternating current to the coils of the
detection magnetic field generating unit 305a. By doing so, the
coil power source unit 305b causes the detection magnetic field
generating unit 305a to generate the detection magnetic field.
[0223] The magnetic field detecting unit 305c detects the induced
magnetic field generated from the resonance circuit 228 as the
magnetic field required for detecting at least one of the position
and the orientation of the capsule medical device 202 inside the
body of the test subject. The magnetic field detecting unit 305c
transmits the result of the operation performed to detect the
induced magnetic field generated from the resonance circuit 228, to
the position detection control unit 305d.
[0224] When at least one of the position and orientation of the
capsule medical device 202 inside the body of the test subject is
detected, the position detection control unit 305d controls the
detection magnetic field generating unit 305a, the coil power
source unit 305b, and the magnetic field detecting unit 305c as
described above. More specifically, the position detection control
unit 305d obtains the operating condition information set by the
operating condition setting unit 212 from the checking device 201,
as described above. The position detection control unit 305d sets
the frequency condition included in the obtained operating
condition information as the operating condition for generating the
detection magnetic field. The position detection control unit 305d
controls the detection magnetic field generating unit 305a to apply
a detection magnetic field of the frequency defined by the set
frequency condition, to the resonance circuit 228 of the capsule
medical device 202 inside the body of the test subject. In this
case, the position detection control unit 305d controls the amount
of current to be supplied from the coil power source unit 305b to
the detection magnetic field generating unit 305a. By controlling
the amount of current, the position detection control unit 305d
controls the detection magnetic field generating operation of the
detection magnetic field generating unit 305a.
[0225] The position detection control unit 305d includes a position
calculating unit 305e. By controlling inputs and outputs of signals
from the magnetic field detecting unit 305c, the position detection
control unit 305d obtains the result of the detecting operation by
the magnetic field detecting unit 305c to detect the guiding
magnetic field generated from the resonance circuit 228. Based on
the result of the induced magnetic field detection obtained from
the magnetic field detecting unit 305c, the position calculating
unit 305e calculates at least one of the positional coordinates and
the directional vector of the capsule medical device 202 inside the
body of the test subject. The positional coordinates calculated by
the position calculating unit 305e are the capsule location
information that indicates the position of the capsule medical
device 202 in the three-dimensional space S. The directional vector
calculated by the position calculating unit 305e is the capsule
direction information that indicates the orientation of the capsule
medical device 202 in the three-dimensional space S. The position
detection control unit 305d transmits the capsule location
information and the capsule direction information calculated (or
detected) in the above manner to the magnetic-guiding control unit
304d. The capsule location information and the capsule direction
information calculated by the position detection control unit 305d
are then transmitted together with the magnetic guiding information
from the magnetic-guiding control unit 304d to the image display
device 306.
[0226] The image display device 306 has a structure similar to a
workstation that displays various kinds of information such as the
in-vivo images captured by the capsule medical device 202. More
specifically, the image display device 306 sequentially obtains the
image signals received by the receiving device 303. Based on the
obtained image signals, the image display device 306 generates the
images captured by the capsule medical device 202 or the in-vivo
images of the test subject. The image display device 306
sequentially displays the generated in-vivo images of the test
subject on its display, and sequentially stores the data about the
in-vivo images into a storage medium.
[0227] The image display device 306 also obtains the magnetic
guiding information from the magnetic-guiding control unit 304d,
and further obtains the capsule location information and the
capsule direction information from the position detection control
unit 305d via the magnetic-guiding control unit 304d. Based on the
magnetic guiding information, the capsule location information, and
the capsule direction information, the image display device 306
displays various kinds of information that is useful in
magnetically guiding the capsule medical device 202. The various
kinds of information includes the information about the position at
which the currently displayed in-vivo image is captured, the
movement locus of the capsule medical device 202 inside the body of
the test subject, the direction and intensity of the guiding
magnetic field applied to the capsule medical device 202 to be
magnetically guided. A user (an operator) such as a medical doctor
or a nurse performs the magnetic guiding of the capsule medical
device 202 by referring to the various kinds of information
displayed on the image display device 306, while observing the
in-vivo image of the test subject shown on the image display device
306.
[0228] Next, the operation of the checking device 201 in accordance
with the sixth embodiment of the present invention will be
described. FIG. 21 is a schematic view illustrating an example case
where the checking device in accordance with the sixth embodiment
of the present invention measures the magnetic moment of the magnet
inside the capsule medical device. Referring to FIG. 21, the
operation by the checking device 201 to measure the magnetic moment
of the magnet 227 inside the capsule medical device 202 will be
described in detail.
[0229] As described above, the capsule medical device 202 to be
checked is accommodated in the package 203 that is housed in the
concave portion of the housing unit 204 (see FIG. 18). The housing
unit 204 rotatably supports the capsule medical device 202 via the
package 203. With this arrangement, the capsule medical device 202
housed in the housing unit 204, as well as the package 203, can
rotate about the central axis CL1 of the package 203. The capsule
medical device 202 has an external shape that is rotationally
symmetrical with respect to the central axis CL2 of the
capsule-like casing 220. Therefore, it is difficult to visually
recognize the magnetization direction of the magnet 227 inside the
capsule medical device 202.
[0230] Under the control of the control unit 211, the magnetic
field generating coil 214a generates the guiding magnetic field M1,
and applies the guiding magnetic field M1 to the capsule medical
device 202 inside the package 203 housed in the housing unit 204.
In this case, the guiding magnetic field M1 acts on the magnet 227
inside the capsule medical device 202, and the magnet 227 operates
in accordance with the guiding magnetic field M1. The capsule
medical device 202 as well as the package 203 rotates about the
central axis CL1 by the action of the magnet 227. Accordingly, the
magnetization direction of the magnet 227 shifts toward the flux
density measuring unit 213a of the magnetic moment measuring unit
213. As a result, the magnet 227 has its magnetization direction
shifting toward the flux density measuring unit 213a (state
A1).
[0231] In a state where the capsule medical device 202 directs the
magnetization direction of the magnet 227 toward the flux density
measuring unit 213a, the magnetic field generating coil 214a stops
generating the guiding magnetic field M1, under the control of the
control unit 211. With this arrangement, the flux density measuring
unit 213a can receive the magnetic field from the magnet 227,
without receiving the guiding magnetic field M1 from the magnetic
field generating coil 214a. Under the control of the control unit
211, the flux density measuring unit 213a measures the flux density
of the magnet 227, and calculates the residual flux density of the
magnet 227. The magnetic moment calculating unit 213b of the
magnetic moment measuring unit 213 multiplies the value of the
residual flux density measured by the flux density measuring unit
213a by the value of the volume of the magnet 227 according to the
magnet volume information 210a. In this manner, the magnetic moment
calculating unit 213b calculates the magnetic moment of the magnet
227 (state A2).
[0232] After that, the magnetic moment measuring unit 213 transmits
the value of the magnetic moment of the magnet 227 calculated by
the magnetic moment calculating unit 213b as the measurement value
of the magnetic moment to the control unit 211. The control unit
211 obtains the measurement value of the magnetic moment of the
magnet 227 from the magnetic moment measuring unit 213. Based on
the obtained measurement value of the magnetic moment, the
operating condition setting unit 212 sets the field intensity
condition for the magnetically guiding device 304 to magnetically
guide the capsule medical device 202 inside the body of the test
subject.
[0233] The capsule medical device 202 checked by the checking
device 201 is taken out of the package 203, and is introduced into
an internal organ of the test subject via the oral route.
Accordingly, immediately before the capsule medical device 202 is
introduced into the body of the test subject, the checking device
201 can check the characteristics (such as the magnetic moment) of
the magnet 227 and the resonance characteristics (such as the
frequency) of the resonance circuit 228 inside the capsule medical
device 202. Before the magnetically guiding device 304 starts
magnetically guiding the capsule medical device 202, the checking
device 201 can set the field intensity condition in advance, based
on the characteristics of the magnet 227 (to be more specific, the
magnetic moment of the magnet 227). Further, the checking device
201 can set the frequency condition for the position detecting
device 305 in advance, based on the resonance characteristics of
the resonance circuit 228 (to be more specific, the result of the
FFT processing performed by the induced magnetic field calculating
unit 216b or the like).
[0234] Based on the field intensity condition set by the checking
device 201, the magnetically guiding device 304 can easily set the
initial operating condition for magnetically guiding the capsule
medical device 202 inside the body of the test subject.
Accordingly, the magnetically guiding device 304 can magnetically
guide the capsule medical device with high efficiency, without
unnecessary consumption of electric power due to excessive
application of a magnetic field to the capsule medical device 202.
Based on the frequency condition that is set by the checking device
201, the position detecting device 305 can easily set the operating
condition for detecting at least one of the position and
orientation of the capsule medical device 202 inside the body of
the test subject. Accordingly, the position detecting device 305
can detect the position and orientation of the capsule medical
device 202 inside the body of the test subject with high precision,
in accordance with the resonance characteristics of the capsule
medical device 202.
[0235] As described above, in the sixth embodiment of the present
invention, the residual flux density of the magnet inside the
capsule medical device kept by a user such as a medical doctor or a
nurse is measured by the flux density measuring unit. Based on the
result of the measurement of the residual flux density, the
magnetic moment of the magnet is calculated by the magnetic moment
calculating unit. Accordingly, the characteristics of the magnet
(such as the magnetic moment of the internal magnet at that time)
inside the capsule medical device that is difficult to visually
recognize from the outside of the capsule medical device can be
readily checked. Thus, a checking device that can check the
characteristics of the magnet inside the capsule medical device
immediately before the capsule medical device is introduced into
the body of a test subject can be realized.
[0236] By using the checking device in accordance with the sixth
embodiment, a user can recognize the characteristics of the magnet
of the capsule medical device to be magnetically guided by the
magnetically guiding device at that time by means of information
displayed on the display unit. Based on the result of the check
made on the magnet characteristics, the initial operating condition
for the magnetically guiding device can be set. Accordingly, the
magnetically guiding device can apply the required minimum magnetic
field to the capsule medical device inside the body of a test
subject, and can magnetically guide the capsule medical device
inside the body of the test subject with high efficiency, without
unnecessary consumption of electric power.
[0237] In the sixth embodiment, the characteristics of the magnet
of the capsule medical device that has been sterilized and is
accommodated in the package are checked. Accordingly, the magnetic
moment of the magnet inside the capsule medical device can be
measured without taking the capsule medical device out of the
package. Thus, the sterilized state of the capsule medical device
can be maintained until immediately before the capsule medical
device is introduced into the body of the test subject.
[0238] Further, in the sixth embodiment, the capsule medical device
to be checked is rotatably supported by the housing unit, and a
magnetic field from the outside acts on the magnet inside the
capsule medical device, so as to cause the magnetization direction
of the magnet to shift toward the flux density measuring unit. With
this arrangement, the magnetization direction of the magnet can
easily shift toward the flux density measuring unit, when the
residual flux density of the magnet inside the capsule medical
device is measured. Accordingly, the residual flux density can be
accurately measured.
[0239] Also, in the magnetically guiding system in accordance with
the sixth embodiment, the operating condition setting unit sets the
field intensity condition for the magnetically guiding device,
based on the result of the measurement carried out by the flux
density measuring unit. The output unit then transmits the field
intensity condition to the magnetically guiding device.
Accordingly, the checking device of the present invention checks
the characteristics of the magnet in the capsule medical device,
and the magnetically guiding device can easily set the field
intensity condition based on the result of the setting operation by
the operating condition setting unit, as the initial operating
condition for magnetically guiding the capsule medical device
inside the body of the test subject. As a result, the magnetically
guiding device can easily perform efficient magnetic guiding of the
capsule medical device inside the body of the test subject.
[0240] Further, in the sixth embodiment, the resonance
characteristics of the resonance circuit inside the capsule medical
device are measured by the resonance characteristics measuring
unit, so that a user can check the resonance characteristics of the
resonance circuit immediately before the capsule medical device is
introduced into the body of the test subject. Based on the result
of the operation to check the resonance characteristics, the
initial operating condition for the magnetically guiding device can
be properly set by means of information displayed on the display
unit. Based on the initial operating condition, the position
detecting unit of the magnetically guiding device can obtain the
information about the inherent characteristics of the resonance
circuit inside the capsule medical device. Accordingly, the
position detecting unit can detect the position and orientation of
the capsule medical device by adjusting the measurement frequency
to the resonance point of the resonance circuit. As a result, there
is no need to widen the measurement frequency spacing by taking
frequency shifts into account, and the position of the capsule
medical device inside the body of the test subject can be detected
with high precision.
[0241] Also, in the magnetically guiding system in accordance with
the sixth embodiment, the operating condition setting unit sets the
frequency condition for the magnetically guiding device, based on
the result of the measurement carried out by the resonance
characteristics measuring unit. The output unit then transmits the
frequency condition to the magnetically guiding device. With this
arrangement, the checking device in accordance with this embodiment
checks the resonance characteristics of the capsule medical device,
and the position detecting unit of the magnetically guiding device
sets the frequency condition based on the result of the setting
operation by the operating condition setting unit, as the initial
operating condition (the measurement frequency) for detecting the
position of the capsule medical device inside the body of the test
subject. As a result, the magnetically guiding device can readily
detect the position of the capsule medical device inside the body
of the test subject with high precision.
[0242] Next, a seventh embodiment of the present invention will be
described. In the above described sixth embodiment, the capsule
medical device 202 to be checked is rotatably supported by the
housing unit 204, and the magnetization direction of the magnet 227
inside the capsule medical device 202 is controlled to shift toward
the flux density measuring unit 213a by virtue of the action of the
guiding magnetic field M1 generated from the magnetic field
generating coil 214a. In the seventh embodiment, on the other hand,
the capsule medical device to be checked is fixed by a housing
unit, and a measuring device of a flux density measuring unit
rotatively moves around the capsule medical device, to sequentially
measure flux densities of the magnet inside the capsule medical
device.
[0243] FIG. 22 is a block diagram schematically showing an example
structure of a checking device in accordance with the seventh
embodiment of the present invention. As shown in FIG. 22, the
checking device 431 in accordance with the seventh embodiment is
the same as the checking device 201 of the sixth embodiment, except
that the housing unit 204 is replaced with a housing unit 432, the
magnet characteristics measuring unit 205 is replaced with a magnet
characteristics measuring unit 433, and the control unit 211 is
replaced with a control unit 437. In this checking device 431, the
magnet characteristics measuring unit 433 includes a magnetic
moment measuring unit 434 in place of the magnetic moment measuring
unit 213 of the sixth embodiment, and a drive system 435 and a rail
436 in place of the magnetization direction control unit 214. A
magnetically guiding system in accordance with the seventh
embodiment is the same as the magnetically guiding system 301 of
the sixth embodiment (see FIG. 20), except that the checking device
201 is replaced with the checking device 431. The other
configurations of this embodiment are the same as those of the
sixth embodiment, and the same components as those of the sixth
embodiment are denoted by the same reference numerals as those used
in the sixth embodiment.
[0244] The housing unit 432 functions as a supporting unit that
supports the capsule medical device 202 to be checked. More
specifically, the housing unit 432 defines the direction of the
package 203, and has a concave portion that has such a shape as to
be engaged with the external shape of the package 203. The housing
unit 432 secures and detachably supports the package fitted with
the concave portion. In this manner, the housing unit 432 houses
the capsule medical device 202, while securing and supporting the
capsule medical device 202 via the package 203.
[0245] The magnet characteristics measuring unit 433 measures the
characteristics of the magnet 227 provided inside the capsule
medical device 202. More specifically, the magnet characteristics
measuring unit 433 measures the magnetic moment as an example of
the characteristics of the magnet 227 inside the capsule medical
device 202 secured and supported by the housing unit 432 via the
package 203. As shown in FIG. 22, the magnet characteristics
measuring unit 433 includes the magnetic moment measuring unit 434
that measures the magnetic moment of the magnet 227, the drive
system 435 that rotatively moves a measuring device 434b of a flux
density measuring unit 434a of the magnetic moment measuring unit
434, and the rail 436 that forms the pathway for the drive system
435.
[0246] The magnetic moment measuring unit 434 measures the magnetic
moment of the magnet 227 by measuring the residual flux density of
the magnet 227 inside the capsule medical device 202. The magnetic
moment measuring unit 434 includes the flux density measuring unit
434a that measures the residual flux density of the magnet 227 and
the magnetic moment calculating unit 213b.
[0247] The flux density measuring unit 434a includes the
independent measuring device 434b, and uses the measuring device
434b to measure the residual flux density of the magnet 227 inside
the capsule medical device 202. More specifically, the measuring
device 434b is radio-connected or wire-connected to the flux
density measuring unit 434a in a communicable manner, and is
mounted on the drive system 435. The measuring device 434b
sequentially measures flux densities of the magnet 227 inside the
capsule medical device 202, while being rotatively moved around the
housing unit 432 by the drive system 435, with the capsule medical
device 202 being the center of the rotational movement. With the
use of the measuring device 434b, the flux density measuring unit
434a sequentially measures the magnetic flux densities of the
magnet 227 at various positions around the housing unit 432. The
flux density measuring unit 434a obtains the largest value of the
flux densities of the magnet 227 measured at the various positions
around the housing unit 432, and regards the largest value as the
value of the residual flux density of the magnet 227. The flux
density measuring unit 434a then transmits the result of the
measurement of the residual flux density of the magnet 227 measured
in the above manner to the magnetic moment calculating unit 213b.
The value of the residual flux density of the magnet 227 measured
by the flux density measuring unit 434a is used by the magnetic
moment calculating unit 213b to calculate the magnetic moment of
the magnet 227 as described above.
[0248] The drive system 435 and the rail 436 are designed for
rotatively move the measuring device 434b of the flux density
measuring unit 434a around the capsule medical device 202 to be
checked. More specifically, the drive system 435 may be embodied
with the use of wheels and an actuator, and the measuring device
434b of the flux density measuring unit 434a is fixed onto the
drive system 435. The rail 436 forms the pathway for the drive
system 435, and is placed along a circle formed around the central
axis CL1 of the package 203 housed in the housing unit 432
(desirably, around the central axis CL2 of the capsule medical
device 202 inside the package 203). The drive system 435 travels on
the rail 436, so as to rotatively move the measuring device 434b
around the housing unit 432, with the capsule medical device 202
(the magnet 227, to be more specific) being the center of the
rotational movement.
[0249] The actuator of the drive system 435 may be a drive motor
including an electromagnet or the like, but it is desirable that
the actuator of the drive system 435 is a nonmagnetic actuator such
as an ultrasonic motor or an artificial muscle actuator, so as to
achieve higher precision in the flux density measurement by the
measuring device 434b.
[0250] The control unit 437 controls the magnetic moment measuring
unit 434 and the drive system 435 to measure the magnetic moment of
the magnet 227. In this case, the control unit 437 controls the
drive system 435 to rotatively move along the rail 436 and around
the housing unit 432 at least once. The control unit 437 also
controls the flux density measuring unit 434a to sequentially
measure flux densities of the magnet 227 at various positions
around the housing unit 432 with the use of the measuring device
434b. The control unit 437 also recognizes the moving distance of
the drive system 435 on the rail 436. The control unit 437 then
controls the flux density measuring unit 434a to select the
residual flux density having the value equivalent to the largest
value among the results of the measurement carried out by the
measuring device 434b (or the values of the flux densities of the
magnet 227 measured at various positions around the housing unit
432) when the drive system 435 finishes moving around the housing
unit 432 at least once. By controlling the magnetic moment
measuring unit 434 and the drive system 435 in this manner, the
control unit 437 obtains the magnetic moment of the magnet 227
inside the capsule medical device 202. Except for the functions to
control the flux density measuring unit 434a and the drive system
435, the control unit 437 has the same functions as those of the
control unit 211 of the checking device 201 in accordance with the
sixth embodiment.
[0251] Next, the operation of the checking device 431 in accordance
with the seventh embodiment of the present invention will be
described. FIG. 23 is a schematic view showing an example case
where the checking device in accordance with the seventh embodiment
of the present invention measures the magnetic moment of the magnet
inside the capsule medical device. Referring now to FIG. 23, the
operation by the checking device 431 to measure the magnetic moment
of the magnet 227 inside the capsule medical device 202 will be
described in detail.
[0252] As described above, the capsule medical device 202 to be
checked is housed in the concave portion of the housing unit 432,
while accommodated in the package 203 (see FIG. 22). In this case,
the housing unit 432 secures and supports the capsule medical
device 202 via the package 203.
[0253] Under the control of the control unit 437, the drive system
435 travels on the rail 436, and moves around the housing unit 432
at least once, with the capsule medical device 202 being the center
of the rotational movement. The measuring device 434b sequentially
measures flux densities of the magnet 227 at various positions
around the housing unit 432 at predetermined time intervals, while
being moved around the housing unit 432 at least once by the drive
system 435, with the magnet 227 inside the capsule medical device
202 being the center of the rotational movement. In this case, the
measuring device 434b rotatively moves in a circle having a radial
direction that is coincident with the magnetization direction of
the magnet 227. As shown in FIG. 23, the measuring unit 434b
sequentially passes through positions D1 through D4 located around
the housing unit 432, and sequentially measures the flux densities
of the magnet 227 at the positions D1 through D4, for example.
[0254] Here, the flux densities of the magnet 227 around the
housing unit 432 vary at the positions, and the magnet 227 has the
highest flux density at the position located in the magnetization
direction of the magnet 227 (the position D1 in FIG. 23). In the
magnetic moment measuring unit 434, the flux density measuring unit
434a obtains the flux densities sequentially measured at the
respective positions D1 through D4 by the measuring device 434b,
and selects the flux density measured at the position D1, which has
the largest value among those measured flux densities. In this
manner, the flux density measuring unit 434a regards the flux
density at the position D1 as the residual flux density of the
magnet 227. The flux density measuring unit 434a then transmits the
value of the residual flux density to the magnetic moment
calculating unit 213b. As in the sixth embodiment, the magnetic
moment calculating unit 213b multiplies the volume of the magnet
227 according to the magnet volume information 210a by the value of
the residual flux density measured by the flux density measuring
unit 434a, so as to calculate the magnetic moment of the magnet
227. After that, the value of the magnetic moment of the magnet 227
measured by the magnetic moment measuring unit 434 is transmitted
to the control unit 437.
[0255] The flux density measuring unit 434a may either
intermittently or continuously measure the flux densities of the
magnet 227 at various positions around the housing unit 432 with
the use of the measuring device 434b. In other words, the measuring
device 434b may sequentially measure flux densities at the various
positions (the positions D1, D2, D3, and D4 shown in FIG. 23, for
example) around the housing unit 432 every time a predetermined
period of times has passed or every time the drive system 435 has
traveled a predetermined distance, while rotatively moving around
the housing unit 432. Alternatively, the measuring device 434b may
continuously measure flux densities over the entire circle
surrounding the housing unit 432.
[0256] As described above, in the seventh embodiment of the present
invention, the housing unit secures and supports the capsule
medical device to be checked via the package. The measuring device
of the flux density measuring unit sequentially measures the flux
densities of the magnet inside the capsule medical device at
various positions around the housing unit, while being rotatively
moved by the drive system around the housing unit, with the capsule
medical device being the center of the rotational movement. The
flux density measuring unit selects the largest value among the
flux densities measured by the measuring device, and regards the
largest value as the residual flux density of the magnet. The other
configurations of this embodiment are the same as those of the
sixth embodiment. Accordingly, the residual flux density of the
magnet can be measured, even though the magnetization direction of
the magnet inside the capsule medical device to be checked is not
controlled by a magnetic field. As a result, the same effects as
those of the sixth embodiment can be achieved, and a checking
device that consumes less electric power can be easily
realized.
[0257] Next, an eighth embodiment of the present invention will be
described. In the above described sixth and seventh embodiments,
the magnetic moment of the magnet 227 is measured as the
characteristics of the magnet 227 inside the capsule medical device
202. In the eighth embodiment, on the other hand, the relative
angle difference between the reference direction of the image
capturing unit 222 (the vertical direction of the light receiving
face, for example) and the magnetization direction of the magnet
227 inside the capsule medical device 202 is also measured as the
characteristics of the magnet 227.
[0258] FIG. 24 is a block diagram schematically showing an example
structure of a checking device in accordance with the eighth
embodiment of the present invention. As shown in FIG. 24, the
checking device 541 in accordance with the eighth embodiment is the
same as the checking device 201 of the sixth embodiment, except
that the housing unit 204 is replaced with a housing unit 542, the
magnet characteristics measuring unit 205 is replaced with a magnet
characteristics measuring unit 543, and the control unit 211 is
replaced with a control unit 547. A magnetically guiding system in
accordance with the eighth embodiment of the present invention is
the same as the magnetically guiding system 301 of the sixth
embodiment (see FIG. 20), except that the checking device 201 is
replaced with the checking device 541. The other configurations of
this embodiment are the same as those of the sixth embodiment, and
the same components as those of the sixth embodiment are denoted by
the same reference numerals as those used in the sixth
embodiment.
[0259] The housing unit 542 has the same structure and functions as
those of the housing unit 204 of the checking device 201 of the
sixth embodiment, except for an image member 542a. The image member
542a is a plate-like or sheet-like member on which an image having
an orientation is drawn. As shown in FIG. 24, the image member 542a
is fixed in the housing unit 542 in such a manner as to be in the
image viewing field of the image capturing unit 222 inside the
capsule medical device 202. The image drawn on the image member
542a is a pattern with which the reference direction such as the
vertical direction of the drawn image can be easily defined. For
example, the image may be a striped pattern as shown in FIG.
25.
[0260] The striped pattern shown in FIG. 25 is merely an example of
the image drawn on the image member 542a. The image drawn on the
image member 542a may be any pattern other than a striped pattern,
may be a symbol, a numeric character, or a character, or may be a
combination of those symbols and characters, as long as the
reference direction such as the vertical direction of the image can
be easily detected.
[0261] The magnet characteristics measuring unit 543 measures the
magnetic moment of the magnet 227, and the relative angle
difference between the reference direction of the image capturing
unit 222 and the magnetization direction of the magnet 227 inside
the capsule medical device 202. The magnet characteristics
measuring unit 543 regards the magnetic moment and the relative
angle difference as the characteristics of the magnet 227 provided
inside the capsule medical device 202. More specifically, the
magnet characteristics measuring unit 543 measures the
characteristics of the magnet 227 inside the capsule medical device
202 that is rotatably supported by the housing unit 542 via the
package 203. As shown in FIG. 24, the magnet characteristics
measuring unit 543 includes the magnetization direction control
unit 214 described in the sixth embodiment, and the magnetic moment
measuring unit 434, the drive system 435, and the rail 436
described in the seventh embodiment. The magnet characteristics
measuring unit 543 further includes an image acquiring unit 544
that acquires each image captured by the image capturing unit 222,
and an angle measuring unit 545 that measures the angle between the
reference direction of the image capturing unit 222 and the
magnetization direction of the magnet 227.
[0262] The image acquiring unit 544 has a receiving antenna 544a,
and exchanges image data with the capsule medical device 202 via
the receiving antenna 544a. More specifically, the image acquiring
unit 544 receives images (images of the image member 542a) captured
by the image capturing unit 222 of the capsule medical device 202
inside the package 203 housed in the housing unit 542, via the
receiving antenna 544a. Under the control of the control unit 547,
the image acquiring unit 544 acquires an image of the image member
542a captured by the image capturing unit 222 when the reference
direction of the image capturing unit 222 is coincident with the
reference direction of the image member 542a (the image captured
here will be hereinafter referred to as the reference image). The
image acquiring unit 544 also acquires an image of the image member
542a captured by the image capturing unit 222 when the reference
direction of the image member 542a is coincident with the
magnetization direction of the magnet 227 (the image captured here
will be hereinafter referred to as the comparative image). The
image acquiring unit 544 transmits the reference image and the
comparative image obtained from the capsule medical device 202 to
the angle measuring unit 545.
[0263] Under the control of the control unit 547, the angle
measuring unit 545 measures the angle between the reference
direction of the image capturing unit 222 and the magnetization
direction of the magnet 227, based on the reference image and the
comparative image received from the image acquiring unit 544. Here,
the reference direction of the image capturing unit 222 is the
vertical direction of the light receiving face of the solid-state
image sensor 222b (see FIG. 19), for example. In this case, the
vertical direction of the image captured by the image capturing
unit 222 is defined by the reference direction of the image
capturing unit 222. The angle between the reference direction of
the image capturing unit 222 and the magnetization direction of the
magnet 227 represents the relative angle difference between the
reference direction of the image capturing unit 222 and the
magnetization direction of the magnet 227, and is regarded as one
aspect of the characteristics of the magnet 227. The angle
measuring unit 545 transmits the result of the measurement of the
angle formed between the reference direction of the image capturing
unit 222 and the magnetization direction of the magnet 227, to the
control unit 547.
[0264] In the magnet characteristics measuring unit 543, the
magnetization direction control unit 214 includes the magnetic
field generating coil 214a, the signal generating unit 214b, and
the driving unit 214c, as described above. The magnetization
direction control unit 214 applies the guiding magnetic field M1 to
the magnet 227 inside the capsule medical device 202, so as to
relatively change the magnetization direction of the magnet 227
with respect to the housing unit 542, as described above. By doing
so, the magnetization direction control unit 214 controls the
magnetization direction of the magnet 227 to shift in a desired
direction.
[0265] As in the above described seventh embodiment, the drive
system 435 travels on the rail 436, with the measuring device 434b
being mounted thereon. The drive system 435 rotatively moves around
the housing unit 542, with the capsule medical device 202 being the
center of the rotational movement. The flux density measuring unit
434a sequentially measures flux densities of the magnet 227 at
various positions around the housing unit 542 with the use of the
measuring device 434b. The flux density measuring unit 434a then
selects the largest value among the measured flux densities, and
regards the largest value as the value of the residual flux density
of the magnet 227. Using the measurement value of the residual flux
density, the magnetic moment calculating unit 213b calculates the
magnetic moment of the magnet 227, and transmits the value of the
calculated magnetic moment to the control unit 547.
[0266] The flux density measuring unit 434a may directly measure
the residual flux density of the magnet 227 with the use of the
measuring device 434b located in the magnetization direction of the
magnet 227, instead of sequentially measuring the flux densities of
the magnet 227 at various positions around the housing unit 542. In
such a case, the drive system 435 travels on the rail 436, and
moves the measuring device 434b to a position situated in the
magnetization direction of the magnet 227, under the control of the
control unit 547. The flux density measuring unit 434a sets the
measurement value of the flux density obtained with the use of the
measuring device 434b located in the magnetization direction of the
magnet 227, as the measurement value of the residual flux density
of the magnet 227, under the control of the control unit 547.
[0267] The control unit 547 controls the guiding magnetic field M1
of the magnetization direction control unit 214, so that the
reference direction of the image capturing unit 222 is coincident
with the reference direction of the image member 542a. In this
case, the control unit 547 obtains the image data (the images of
the image member 542a captured by the image capturing unit 222)
from the image acquiring unit 544 via the angle measuring unit 545,
and compares the obtained image data with preset reference image
data. The control unit 547 controls the field intensity or the
magnetization direction of the guiding magnetic field M1, so that
the obtained image data is coincident with the reference image
data. By doing so, the control unit 547 causes the reference
direction of the image capturing unit 222 and the reference
direction of the image member 542a to be coincident with each
other. With the reference direction of the image member 542a being
set in advance, the control unit 547 controls the field intensity
or the magnetization direction of the guiding magnetic field M1, so
that the reference direction of the image member 542a is coincident
with the magnetization direction of the magnet 227.
[0268] The control unit 547 also controls the image acquiring unit
544 to sequentially acquire the images captured by the image
capturing unit 222 from the capsule medical device 202 via the
receiving antenna 544a. The control unit 547 then controls the
angle measuring unit 545 to measure (calculate) the angle formed
between the reference direction of the image capturing unit 222 and
the magnetization direction of the magnet 227, based on the
reference image and the comparative image acquired by the image
acquiring unit 544. By controlling the image acquiring unit 544 and
the angle measuring unit 545 in this manner, the control unit 547
obtains the measurement value of the angle formed between the
reference direction of the image capturing unit 222 and the
magnetization direction of the magnet 227, or the measurement value
of the relative angle difference between the reference direction of
the image capturing unit 222 and the magnetization direction of the
magnet 227.
[0269] The control unit 547 further controls the magnetic moment
measuring unit 434 and the drive system 435 to measure the magnetic
moment of the magnet 227. In this case, the control unit 547 may
control the magnetic moment measuring unit 434 and the drive system
435, like the control unit 437 of the checking device 431 in the
seventh embodiment, or may control the drive system 435 to move the
measuring device 434b to a position situated in the magnetization
direction of the magnet 227. The control unit 547 may also control
the flux density measuring unit 434a to measure the residual flux
density of the magnet 227 with the use of the measuring unit 434b
located in the magnetization direction of the magnet 227.
[0270] The control unit 547 also includes an operating condition
setting unit 546 in place of the operating condition setting unit
212 of the checking device 201 of the sixth embodiment. The
operating condition setting unit 546 obtains the result of the
measurement carried out by the angle measuring unit 545. Based on
the measurement result (to be more specific, the measurement value
of the angle formed between the reference direction of the image
capturing unit 222 and the magnetization direction of the magnet
227), the operating condition setting unit 546 sets a condition for
correcting the magnetization direction of the magnetically guiding
device 304. The condition for correcting the magnetization
direction is the operating condition for correcting the relative
angle difference between the reference direction of the image
capturing unit 222 and the magnetization direction of the magnet
227 inside the capsule medical device 202 to be magnetically guided
by the magnetically guiding device 304. The control unit 547
controls the display unit 208 to display the magnetization
direction correcting condition set by the operating condition
setting unit 546 as one of the operating conditions set for the
magnetically guiding device 304. The control unit 547 also controls
the output unit 209 to output the magnetization direction
correcting condition to the magnetically guiding device 304.
[0271] Upon receipt of the magnetization direction correcting
condition, the magnetic-guiding control unit 304d (see FIG. 20) of
the magnetically guiding device 304 corrects the angle difference
between the reference direction of the image capturing unit 222 and
the magnetization direction of the magnet 227 inside the capsule
medical device 202 introduced into the body of a test subject, or
the angle difference between the reference direction (the vertical
direction of the screen, for example) of an in-vivo image of the
test subject captured by the image capturing unit 222 and the
magnetization direction of the magnet 227. By doing so, the
magnetic-guiding control unit 304d also controls the magnetic
guiding of the capsule medical device 202 inside the body of the
test subject. In this manner, the magnetic-guiding control unit
304d can cause the vertical and horizontal directions of the
in-vivo image shown on the screen to be coincident with the
vertical and horizontal directions of the magnetic guiding of the
capsule medical device 202.
[0272] Except for the function to control the magnet
characteristics measuring unit 543, the control unit 547 has the
same control functions as those of the control unit 211 of the
checking device 201 of the sixth embodiment. Also, the operating
condition setting unit 546 includes the field intensity calculating
unit 212a and the frequency calculating unit 212b, and sets the
field intensity condition for the magnetically guiding device 304
and the frequency condition for the position detecting device 305,
like the operating condition setting unit 212 in the sixth and
seventh embodiments.
[0273] Next, the operation of the checking device 541 in accordance
with the eighth embodiment of the present invention will be
described. FIG. 26 is a schematic view illustrating the operation
by the checking device of the eighth embodiment of the present
invention to measure the angle formed between the reference
direction of the magnet and the reference direction of the image
capturing unit inside the capsule medical device. Referring now to
FIG. 26, the operation by the checking device 541 to measure the
angle .theta. formed between the reference direction F1 of the
image capturing unit 222 and the magnetization direction F2 of the
magnet 227 inside the capsule medical device 202 will be described
in detail, with an example case where the reference direction of
the image member 542a is the vertical direction of the image drawn
thereon.
[0274] The capsule medical device 202 inside the package 203 housed
in the housing unit 542 as shown in FIG. 24 is switched on and off
by a magnetic field or an optical signal applied from a
predetermined external device. The capsule medical device 202
captures images of the image member 542a with the use of the image
capturing unit 222. Every time an image is captured, the capsule
medical device 202 radio-transmits the image to the outside via the
transmission unit 224 (see FIG. 19).
[0275] In this situation, the control unit 547 of the checking
device 541 controls the image acquiring unit 544 and the angle
measuring unit 545, to sequentially acquire images of the image
member 542a captured by the image capturing unit 222. The control
unit 547 controls the guiding magnetic field M1 of the
magnetization direction control unit 214, so that the obtained
image data is coincident with the reference image data. In this
case, the magnetization direction control unit 214 applies the
guiding magnetic field M1 to the magnet 227 inside the capsule
medical device 202, so that the reference direction of the image
capturing unit 222 is coincident with the reference direction (the
vertical direction) of the image member 542a. With the reference
direction F1 being coincident with the reference direction of the
image member 542a, the image capturing unit 222 captures an image
of the image member 542a (the reference image P1). The image
capturing unit 544 then acquires the reference image P1 captured by
the image capturing unit 222 from the capsule medical device 202
via the receiving antenna 544a, and transmits the reference image
P1 to the angle measuring unit 545. The vertical direction of the
reference image P1 is coincident with the reference direction F1 of
the image capturing unit 222, as shown in FIG. 26.
[0276] The control unit 547 then controls the guiding magnetic
field M1 of the magnetization direction control unit 214, so that
the magnetization direction F2 of the magnet 227 is coincident with
the reference direction of the image member 542a. In this case, the
magnetization direction control unit 214 applies the guiding
magnetic field M1 to the magnet 227 inside the capsule medical
device 202, so that the magnetization direction F2 of the magnet
227 is coincident with the reference direction of the image member
542a. If the reference direction F1 of the image capturing unit 222
has a rotational displacement relative to the magnetization
direction F2 of the magnet 227, the image capturing unit 222
captures an image of the image member 542a (the comparative image
P2), with the magnetization direction F2 of the magnet 227 being
coincident with the reference direction of the image member 542a,
or with the image capturing unit 222 tilting (rotating) at the
angle .theta. with respect to the reference direction of the image
member 542a. The image acquiring unit 544 acquires the comparative
image P2 captured by the image capturing unit 222 from the capsule
medical device 202 via the receiving antenna 544a, and transmits
the obtained comparative image P2 to the angle measuring unit 545.
Here, the vertical direction of the comparative image P2 is
coincident with the magnetization direction F2 of the magnet 227,
as shown in FIG. 26.
[0277] Based on the reference image P1 and the comparative image P2
obtained from the image acquiring unit 544 as described above, the
angle measuring unit 545 measures the angle .theta. between the
reference direction F1 of the image capturing unit 222 and the
magnetization direction F2 of the magnet 227. More specifically,
the angle measuring unit 545 calculates the angle between the
striped pattern of the reference image P1 and that of the
comparative image P2. If the reference image P1 and the comparative
image P2 are superimposed on each other, the striped pattern of the
comparative image P2 is tilted relative to the striped pattern of
the reference image P1 indicated by the diagonal lines in FIG. 26.
The angle between the reference image P1 and the comparative image
P2 is the angle .theta. between the reference direction F1 of the
image capturing unit 222 and the magnetization direction F2 of the
magnet 227. By calculating the angle between the reference image P1
and the comparative image P2, the angle measuring unit 545 measures
the angle .theta. between the reference direction F1 of the image
capturing unit 222 and the magnetization direction F2 of the magnet
227. The angle measuring unit 545 then transmits the measurement
value of the angle .theta. to the control unit 547.
[0278] The control unit 547 obtains the result (the angle .theta.)
of the measurement carried out by the angle measuring unit 545, as
the relative angle difference between the reference direction F1 of
the image capturing unit 222 and the magnetization direction F2 of
the magnet 227. Based on the angle .theta. as the result of the
measurement carried out by the angle measuring unit 545, the
operating condition setting unit 546 sets the magnetization
direction correcting condition for the magnetically guiding device
304, as described above. The control unit 547 obtains the magnetic
moment calculated by the magnetic moment calculating unit 213b
using the value obtained by the flux density measuring unit 434a
when the measuring device 434b is located in the magnetization
direction F2 of the magnet 227. The control unit 547 regards the
obtained magnetic moment as the measured magnetic moment of the
magnet 227.
[0279] As described above, in the eighth embodiment of the present
invention, the image member on which an image having an orientation
is drawn is placed and fixed in the housing unit that rotatably
houses the capsule medical device to be checked. The image
acquiring unit acquires the reference image that is the image of
the image member captured by the image capturing unit when the
reference direction of the image capturing unit inside the capsule
medical device is coincident with the reference direction of the
image member, and the comparative image that is the image of the
image member captured by the image capturing unit when the
reference direction of the image member is coincident with the
magnetization direction of the magnet inside the capsule medical
device. Based on the reference image and the comparative image, the
angle between the reference direction of the image capturing unit
and the magnetization direction of the magnet is measured. When the
measuring device is moved to a position situated in the
magnetization direction of the magnet by the drive system, the
residual flux density of the magnet is measured. The other
configurations of this embodiment are the same as those of the
sixth embodiment. Accordingly, the relative angle difference
between the reference direction of the image capturing unit and the
magnetization direction of the magnet inside the capsule medical
device, as well as the magnetic moment of the magnet, can be
measured. As a result, it is possible to not only achieve the same
effects as those of the sixth embodiment, but also form a checking
device that can check the relative angle difference between the
vertical direction of each image captured by the image capturing
unit and the magnetization direction of the magnet inside the
capsule medical device.
[0280] With the use of the checking device in accordance with the
eighth embodiment, a user can check the display information shown
on the display unit, so as to recognize the magnetization direction
correcting condition required for the magnetically guiding device
to correct the relative angle difference between the reference
direction of the image capturing unit and the magnetization
direction of the magnet when the capsule medical device is
magnetically guided. Accordingly, the user can set the
magnetization direction correcting condition for the magnetically
guiding device in the initial stage. As a result, the magnetically
guiding device can magnetically guide the capsule medical device
inside the body of a test subject accurately in response to an
operation instruction, while correcting the angle difference
between the magnetization direction of the magnet and the reference
direction (the vertical direction of the screen, for example) of
each in-vivo image of the test subject captured by the image
capturing unit inside the capsule medical device introduced into
the body of the test subject.
[0281] Also, as the output unit transmits the magnetization
direction correcting condition to the magnetically guiding device,
the initial magnetization direction correcting condition can be
easily set for the magnetically guiding device to magnetically
guide the capsule medical device inside the body of the test
subject. As a result, a magnetically guiding system that can be
more easily operated to magnetically guide the capsule medical
device inside the body of a test subject can be readily
realized.
[0282] Next, a ninth embodiment of the present invention will be
described. In the above described eighth embodiment, the relative
angle difference between the reference direction of the image
capturing unit 222 and the magnetization direction of the magnet
227 is measured based on the reference image and the comparative
image captured by the image capturing unit 222 inside the capsule
medical device 202. In the ninth embodiment, on the other hand, the
angle between the magnetization direction of the magnet 227 and the
reference direction of the image member 542a observed when the
image capturing unit 222 captures the reference image is measured
as the relative angle difference between the reference direction of
the image capturing unit 222 and the magnetization direction of the
magnet 227.
[0283] FIG. 27 is a block diagram schematically showing' an example
structure of a checking device in accordance with the ninth
embodiment of the present invention. As shown in FIG. 27, the
checking device 651 in accordance with the ninth embodiment is the
same as the checking device 541 of the eighth embodiment, except
the magnet characteristics measuring unit 543 is replaced with a
magnet characteristics measuring unit 653, and the control unit 547
is replaced with a control unit 657. In this checking device 651,
the magnet characteristics measuring unit 653 does not include the
angle measuring unit 545. Under the control of the control unit
657, the image capturing unit 544 acquires image data captured by
the image capturing unit 222 from the capsule medical device 202.
Every time image data is acquired, the image acquiring unit 544
transmits the acquired image data to the control unit 657. The
storage unit 210 further stores reference image information 210c
that is the data about the reference image obtained when the image
capturing unit 222 captures an image of the image member 542a, with
the reference direction (the vertical direction, for example) of
the image member 542a being coincident with the reference direction
of the image capturing unit 222. A magnetically guiding system in
accordance with the ninth embodiment is the same as the
magnetically guiding system of the eighth embodiment, except that
the checking device 541 is replaced with the checking device 651.
The other configurations of this embodiment are the same as those
of the eighth embodiment, and the same components as those of the
eighth embodiment are denoted by the same reference numerals as
those used in the eighth embodiment.
[0284] The magnet characteristics measuring unit 653 does not
include the angle measuring unit 545, and measures the magnetic
moment of the magnet 227 as the characteristics of the magnet 227
inside the capsule medical device 202. The image acquiring unit 544
acquires the image data captured by the image capturing unit 222
inside the capsule medical device 202. In this case, the image
acquiring unit 544 acquires the image data captured by the image
capturing unit 222 from the capsule medical device 202, under the
control of the control unit 657, as described above. Every time
image data is acquired, the image acquiring unit 544 transmits the
image data to the control unit 657. Except for this function, the
magnet characteristics measuring unit 653 has the same functions as
those of the magnet characteristics measuring unit 543 of the
checking device 541 of the eighth embodiment.
[0285] The control unit 657 controls the image acquiring unit 544
to acquire the image data captured by the image capturing unit 222
from the capsule medical device 202. By doing so, the control unit
657 sequentially obtains the image data captured by the image
capturing unit 222 via the image acquiring unit 544. The control
unit 657 reads the reference image information 210c from the
storage unit 210, and controls the guiding magnetic field M1 of the
magnetization direction control unit 214, so that the reference
image information 210c is coincident with the image data obtained
from the image acquiring unit 544 (the data about the image
captured by the image capturing unit 222). In this case, the
control unit 657 controls the field intensity or the magnetization
direction of the guiding magnetic field M1, so that the reference
image information 210c is coincident with the obtained image data.
By doing so, the control unit 657 causes the reference direction of
the image capturing unit 222 to match the reference direction of
the image member 542a.
[0286] The control unit 657 includes an operating condition setting
unit 656 in place of the operating condition setting unit 546 of
the checking device 541 of the eighth embodiment. The operating
condition setting unit 656 includes the field intensity calculating
unit 212a and the frequency calculating unit 212b, and further
includes an angle calculating unit 656c. With the reference
direction of the image member 542a being set in advance, the angle
calculating unit 656c calculates the angle between the
magnetization direction of the magnet 227 and the reference
direction of the image member 542a observed when the image
capturing unit 222 captures an image that is coincident with the
reference image information 210c or captures the reference image.
In a state where the image capturing unit 222 captures the
reference image of the image member 542a, the reference direction
of the image capturing unit 222 is coincident with the reference
direction (the vertical direction, for example) of the image member
542a. More specifically, the angle calculated by the angle
calculating unit 656c is the angle between the reference direction
of the image capturing unit 222 and the magnetization direction of
the magnet 227, and represents the relative angle difference
between the reference direction of the image capturing unit 222 and
the magnetization direction of the magnet 227. The operating
condition setting unit 656 sets the magnetization direction
correcting condition for the magnetically guiding device 304, based
on the result of the calculation performed by the angle calculating
unit 656c (or based on the angle between the reference direction of
the image capturing unit 222 and the magnetization direction of the
magnet 227).
[0287] Except for the function to control the image acquiring unit
544, the control unit 657 has the same functions as those of the
control unit 547 of the checking device 541 of the eighth
embodiment. Except for the function to calculate the relative angle
difference between the reference direction of the image capturing
unit 222 and the magnetization direction of the magnet 227, the
operating condition setting unit 656 has the same functions as
those of the operating condition setting unit 546 of the checking
device 541 of the eighth embodiment.
[0288] Next, the operation of the checking device 651 in accordance
with the ninth embodiment of the present invention will be
described. FIG. 28 is a schematic view illustrating the operation
by the checking device of the ninth embodiment of the present
invention to calculate the angle between the reference direction of
the magnet and the reference direction of the image capturing unit
inside the capsule medical device. Referring now to FIG. 28, the
operation by the checking device 651 to measure the angle .theta.
formed between the reference direction F1 of the image capturing
unit 222 and the magnetization direction F2 of the magnet 227
inside the capsule medical device 202 will be described in detail,
with taking a case where the reference direction of the image
member 542a is the vertical direction of the image drawn thereon as
an example.
[0289] The capsule medical device 202 inside the package 203 housed
in the housing unit 542 as shown in FIG. 27 is switched on and off
by a magnetic field or an optical signal applied from a
predetermined external device. The capsule medical device 202
captures images of the image member 542a with the use of the image
capturing unit 222. Every time an image is acquired, the capsule
medical device 202 radio-transmits the image to the outside via the
transmission unit 224 (see FIG. 19).
[0290] In this situation, the control unit 657 of the checking
device 651 controls the image acquiring unit 544, to sequentially
acquire images of the image member 542a captured by the image
capturing unit 222. The control unit 657 reads the reference image
information 210c from the storage unit 210, and compares the read
reference image information 210c with the images obtained from the
image acquiring unit 544 (the images of the image member 542a
captured by the image capturing unit 222).
[0291] If the reference direction F1 of the image capturing unit
222 is tilted relative to the reference direction F11 (the vertical
direction) of the image member 542a as shown in FIG. 28, the image
capturing unit 222 captures an image P11 (hereinafter referred to
as the rotated image) of the image member 542a, with its reference
direction being rotated with respect to the reference direction F11
of the image member 542a. The control unit 657 obtains the rotated
image P11 captured by the image capturing unit 222 via the image
acquiring unit 544, and compares the rotated image P11 with the
reference image information 210c. Since the rotated image P11 is
not coincident with the reference image information 210c, the
control unit 657 controls the field intensity or the magnetization
direction of the guiding magnetic field M1, based on the relative
angle difference between the rotated image P11 and the reference
image information 210c. By doing so, the control unit 657 causes
the reference direction F1 of the image capturing unit 222 to be
coincident with the reference direction F11 of the image member
542a.
[0292] When the reference direction F1 of the image capturing unit
222 is coincident with the reference direction F11 of the image
member 542a (see FIG. 28), the image capturing unit 222 captures an
image that is coincident with the reference image information 210c,
or captures a reference image P12 of the image member 542a. In this
situation, the control unit 657 of the checking device 651 obtains
the reference image P12 captured by the image capturing unit 222
via the image capturing unit 544, and compares the obtained
reference image P12 with the reference image information 210c.
Since the reference image P12 is coincident with the reference
image information 210c, the control unit 657 obtains the
magnetization direction F2 of the magnet 227 observed when the
image capturing unit 222 captures the reference image P12, based on
the control information about the guiding magnetic field M1
observed at the same time.
[0293] In the checking device 651, the angle calculating unit 656c
calculates the angle .theta. between the magnetization direction F2
of the magnet 227 and the reference direction F11 of the image
member 542a observed when the image capturing unit 222 captures the
reference image P12. The angle calculating unit 656c calculates the
angle .theta. as the angle between the reference direction F1 of
the image capturing unit 222 and the magnetization direction F2 of
the magnet 227 (or the relative angle difference between the
reference direction F1 and the magnetization direction F2). As
described above, the operating condition setting unit 656 sets the
magnetization direction correcting condition for the magnetically
guiding device 304, based on the angle .theta., which is the result
of the calculation performed by the angle calculating unit
656c.
[0294] As described above, in the ninth embodiment of the present
invention, the magnetization direction of the magnet inside the
capsule medical device is controlled, so that the image data
obtained by capturing an image of the image member by the image
capturing unit inside the capsule medical device is coincident with
the reference image information. The angle between the
magnetization direction of the magnet and the reference direction
of the image member observed when the image capturing unit captures
the reference image is calculated as the relative angle difference
between the reference direction of the image capturing unit and the
magnetization direction of the magnet. The other configurations of
this embodiment are the same as those of the eighth embodiment.
Accordingly, a checking device that can achieve the same effects as
those of the eighth embodiment can be realized with a simple device
structure.
[0295] Next, a tenth embodiment of the present invention will be
described. In the above described sixth embodiment, the magnetic
moment of the magnet 227 is calculated with the use of the residual
flux density of the magnet 227 inside the capsule medical device
202. In the tenth embodiment, on the other hand, the magnetic
torque that is generated when a magnetic field is applied to the
capsule medical device 202 is measured, and the magnetic moment of
the magnet 227 is measured based on the result of the magnetic
torque measurement.
[0296] FIG. 29 is a block diagram schematically showing an example
structure of a checking device in accordance with the tenth
embodiment of the present invention. As shown in FIG. 29, the
checking device 761 in accordance with the tenth embodiment is the
same as the checking device 201 of the sixth embodiment, except
that the housing unit 204 is replaced with a housing unit 762, the
magnet characteristics measuring unit 205 is replaced with a magnet
characteristics measuring unit 763, and the control unit 211 is
replaced with a control unit 767. In this checking device 761, the
magnet characteristics measuring unit 763 includes a magnetic
moment measuring unit 766 in place of the magnetic moment measuring
unit 213 of the sixth embodiment. The magnetic moment measuring
unit 766 includes: a magnetic torque measuring unit 764 that
measures the magnetic torque generated when a magnetic field is
applied to the capsule medical device 202; and a magnetic moment
calculating unit 765 that calculates the magnetic moment of the
magnet 227 inside the capsule medical device 202, based on the
result of the measurement carried out by the magnetic torque
measuring unit 764. A magnetically guiding system in accordance
with the tenth embodiment of the present invention is the same as
the magnetically guiding system 301 of the sixth embodiment (see
FIG. 20), except that the checking device 201 is replaced with the
checking device 761. The other configurations of this embodiment
are the same as those of the sixth embodiment, and the same
components as those of the sixth embodiment are denoted by the same
reference numerals as those used in the sixth embodiment.
[0297] The housing unit 762 functions as the supporting unit that
supports the capsule medical device 202 to be checked. More
specifically, the housing unit 762 defines the direction of the
package 203, and has a concave portion that has such a shape as to
be engaged with the external shape of the package 203. The housing
unit 762 has a supporting unit 762a formed on one of the two wall
portions through which the central axis CL1 of the package 203
engaged with the concave portion extends. The supporting unit 762a
can be put in and out by a spring or the like. A through hole that
is parallel to the central axis CL1 is formed on the other one of
the two wall portions. A measuring device 764a of the magnetic
torque measuring unit 764 is rotatably inserted through the through
hole of the housing unit 762. The housing unit 762 rotatably
supports the package engaged with the concave portion, with the use
of the supporting unit 762a and a bearing structure or the like. In
this manner, the housing unit 762 rotatably supports and houses the
capsule medical device 202 via the package 203.
[0298] The magnet characteristics measuring unit 763 measures the
characteristics of the magnet 227 provided inside the capsule
medical device 202. More specifically, the magnet characteristics
measuring unit 763 measures the magnetic moment as an example of
the characteristics of the magnet 227. As shown in FIG. 29, the
magnet characteristics measuring unit 763 includes: the
magnetization direction control unit 214 that applies the guiding
magnetic field M1 to the capsule medical device 202; and the
magnetic moment measuring unit 766 that measures the magnetic
moment of the magnet 227, based on the magnetic torque of the
magnet 227 inside the capsule medical device 202 generated by
applying the guiding magnetic field M1.
[0299] The magnetic moment measuring unit 766 measures the magnetic
moment of the magnet 227 by measuring the magnetic torque of the
magnet 227 inside the capsule medical device 202. The magnetic
moment measuring unit 766 includes: the magnetic torque measuring
unit 764 that measures the magnetic torque of the magnet 227
generated by the action of the guiding magnetic field M1 applied by
the magnetization direction control unit 214; and the magnetic
moment calculating unit 765 that calculates the magnetic moment of
the magnet 227, based on the result of the measurement carried out
by the magnetic torque measuring unit 764.
[0300] The magnetic torque measuring unit 764 includes the
measuring device 764a inserted through the through hole of the
housing unit 762, and uses the measuring device 764a to measure the
magnetic torque of the magnet 227 inside the capsule medical device
202. More specifically, the measuring device 764a is rotatably
inserted through the through hole of the housing unit 762, and is
detachably fitted and inserted into a concave portion at an end
portion of the package 203. In this manner, the measuring unit 764a
is relatively fixed to the package 203. The magnetic torque
measuring unit 764 rotatably supports the measuring device 764a,
and measures the torque of the package 203 rotating around the
central axis CL1 together with the capsule medical device 202 by
virtue of the effect of the guiding magnetic field M1 of the
magnetization direction control unit 214. The capsule medical
device 202 is relatively fixed to the package 203. Accordingly, the
torque of the package 203 measured by the magnetic torque measuring
unit 764 is the torque of the capsule medical device 202 rotating
by virtue of the effect of the guiding magnetic field M1 of the
magnetization direction control unit 214, and is equivalent to the
magnetic torque of the magnet 227 inside the capsule medical device
202. The magnetic torque measuring unit 764 transmits the magnetic
torque of the magnet 227 to the magnetic moment calculating unit
765.
[0301] The magnetic moment calculating unit 765 calculates the
magnetic moment of the magnet 227, based on the result of the
measurement carried out by the magnetic torque measuring unit 764.
More specifically, the magnetic moment calculating unit 765 obtains
the value of the magnetic torque of the magnet 227 inside the
capsule medical device 202, from the magnetic torque measuring unit
764. The magnetic moment calculating unit 765 also obtains the
field intensity observed when the magnetic torque of the magnet 227
is measured, from the control unit 767. The field intensity
observed when the magnetic torque is measured is the field
intensity of the guiding magnetic field M1 the magnetization
direction control unit 214 applies to the capsule medical device
202 when the magnetic torque measuring unit 764 measures the
magnetic torque of the magnet 227. The magnetic moment calculating
unit 765 divides the value of the magnetic torque of the magnet 227
by the field intensity observed at the time of the magnetic torque
measurement. By doing so, the magnetic moment calculating unit 765
calculates the magnetic moment of the magnet 227. The magnetic
moment calculating unit 765 then transmits the calculated value of
the magnetic moment as the measured value of the magnetic moment of
the magnet 227 to the control unit 767.
[0302] In the magnet characteristics measuring unit 763, the
magnetization direction control unit 214 generates the guiding
magnetic field M1 that is a rotating magnetic field of
predetermined field intensity, under the control of the control
unit 767. The magnetization direction control unit 214 applies the
guiding magnetic field M1 to the capsule medical device 202. In
this case, the guiding magnetic field M1 as a rotating magnetic
field acts on the magnet 227 inside the capsule medical device 202,
and causes the package 203 to rotate together with the capsule
medical device 202 around the central axis CL1. In this manner, the
magnetic torque of the package 203, which is the magnetic torque of
the magnet 227 inside the capsule medical device 202, is
generated.
[0303] The control unit 767 controls the magnetization direction
control unit 214 (to be specific, the signal generating unit 214b)
to generate the rotating magnetic field (the guiding magnetic field
M1) of the predetermined magnetic intensity that can rotate the
package 203 together with the capsule medical device 202 around the
central axis CL1. The control unit 767 then controls the magnetic
torque measuring unit 764 to measure the magnetic torque of the
magnet 227 inside the capsule medical device 202 that is generated
by virtue of the effect of the guiding magnetic field M1. The
control unit 767 also controls the magnetic moment calculating unit
765 to calculate the magnetic moment of the magnet 227, based on
the result of the measurement carried out by the magnetic torque
measuring unit 764. By doing so, the control unit 767 obtains the
measured value of the magnetic moment of the magnet 227 from the
magnetic moment calculating unit 765. Except for the functions to
control the magnetization direction control unit 214, the magnetic
torque measuring unit 764, and the magnetic moment calculating unit
765, the control unit 767 has the same functions as those of the
control unit 211 of the checking device 201 of the sixth
embodiment.
[0304] As well as the value of the magnetic moment of the magnet
227 measured by the magnetic moment measuring unit 766, the control
unit 767 may obtain the result of the measurement carried out by
the magnetic torque measuring unit 764 as an aspect of the
characteristics of the magnet 227. The result of the measurement
carried out by the magnetic torque measuring unit 764 is the value
of the magnetic torque of the magnet 227 inside the capsule medical
device 202 measured when the rotating magnetic field of the
predetermined field intensity is applied. The value of the measured
magnetic torque may be used as the parameter in the operation by
the field intensity calculating unit 212a to calculate the field
intensity, or may be transmitted from the output unit 209 as the
reference parameter in the magnetic guiding of the capsule medical
device 202 to the magnetically guiding device 304.
[0305] As described above, in the tenth embodiment of the present
invention, the magnetization direction control unit applies a
rotating magnetic field of predetermined field intensity to the
capsule medical device to be checked. The magnetic torque measuring
unit measures the magnetic torque of the magnet inside the capsule
medical device that is generated by virtue of the effect of the
rotating magnetic field. The magnetic moment calculating unit
calculates the magnetic moment of the magnet inside the capsule
medical device, based on the result of the measurement calculated
by the magnetic torque measuring unit. The other configurations of
this embodiment are the same as those of the sixth embodiment.
Accordingly, the same effects as those of the sixth embodiment can
be achieved, and it is possible to form a checking device that can
further measure the magnetic torque of the capsule medical device
generated when the rotating magnetic field of the predetermined
field intensity is applied, with the characteristics of the magnet
inside the capsule medical device being the magnetic torque.
[0306] In each of the sixth through tenth embodiments, the capsule
medical device housed in a package is checked. However, the present
invention is not limited to that, and the capsule medical device
may be taken out of the package, and is housed in a housing unit.
The capsule medical device supported directly by the housing unit
may be checked.
[0307] In each of the sixth through tenth embodiments, the
operating condition information such as the field intensity
condition and the frequency condition that are set by the operating
condition setting unit is transmitted to the magnetically guiding
device and the position detecting device via the output unit. The
magnetically guiding device and the position detecting device then
set the initial operating conditions. However, the present
invention is not limited to that arrangement. The operating
conditions that are set for the magnetically guiding device by the
operating condition setting unit may be displayed on the display
unit, and a user may input the information displayed on the display
unit into the magnetically guiding device, so as to set the initial
operating conditions in the magnetically guiding device. Also, the
operating conditions that are set for the position detecting device
by the operating condition setting unit may be displayed on the
display unit, and a user may input the information displayed on the
display unit into the position detecting device, so as to set the
initial operating conditions in the position detecting device.
[0308] In each of the seventh through ninth embodiments, the flux
density measuring unit 434a measures the residual flux density of
the magnet 227 inside the capsule medical device 202 via the
measuring device 434b that is rotatively moved around the capsule
medical device 202 by the drive system 435. However, the present
invention is not limited to that arrangement. The rotating magnetic
field of the magnetization direction control unit 214 may be
applied to the magnet 227 inside the capsule medical device 202, so
as to rotate the capsule medical device 202 at least once, instead
of rotatively moving the measuring device 434b of the flux density
measuring unit 434a. The flux density measuring unit of the
checking device of the present invention may sequentially measure
flux densities of the magnet 227 inside the capsule medical device
202 in such a rotating state, and may set the largest value of the
flux densities as the residual flux density of the magnet 227.
[0309] In each of the sixth through tenth embodiments, the capsule
medical device 202 having the magnet 227 inside the capsule-like
casing 220 in such a manner that the radial direction of the
capsule-like casing 220 is coincident with the magnetization
direction is described as an example of the subject to be tested by
the checking device of the present invention. However, the present
invention is not limited to that arrangement, and the capsule
medical device to be checked by the checking device of the present
invention may be a capsule medical device that has a magnet
provided therein in such a manner that the magnetization direction
is coincident with a desired comparative direction with respect to
the capsule-like casings such as the longitudinal direction of the
capsule-like casing. In such a case, the center of the rotation of
the capsule medical device to be checked is not limited to the
longitudinal axis of the capsule-like casing, and may be the
magnetization direction of the internal magnet.
[0310] In each of the seventh through ninth embodiments, the
measuring device 434b of the flux density measuring unit 434a is
rotatively moved about the central axis CL1 of the package 203.
However, the present invention is not limited to that arrangement,
and the measuring device 434b of the flux density measuring unit
434a may be rotatively moved about a desired axis that is a pathway
passing through a position in the magnetization direction of the
magnet 227 inside the capsule medical device 202 to be checked.
[0311] In each of the sixth through tenth embodiments, the capsule
medical device 202 that captures in-vivo images of a test subject
is described as an example of the capsule medical device to be
checked by the checking device of the present invention. However,
the present invention is not limited to that arrangement, and the
capsule medical device to be checked may be any kind of medical
device, as long as it has at least one magnet (magnetic material)
for allowing the magnetic guiding by the magnetically guiding
device. For example, the capsule medical device to be checked may
be a capsule-type pH measuring device that measures the pH value in
a living body, or may be a capsule-type medication device that has
the function to disperse or inject medicine into a living body.
Alternatively, the capsule medical device to be checked may be a
capsule-type collecting device that collects a substance from a
living body. Further, the capsule medical device to be checked by
the checking device of any of the sixth, seventh, and tenth
embodiments may not include the image capturing function.
[0312] In each of the sixth and eighth through tenth embodiments,
the magnetization direction of the magnet 227 inside the capsule
medical device 202 is controlled by the magnetization direction
control unit 214 including the magnetic field generating coil 214a
that generates a magnetic field through a power supply. However,
the present invention is not limited to that arrangement. A
permanent magnet may be placed in the vicinity of the magnet 227
inside the capsule medical device 202 to be checked, and the
magnetization direction of the magnet 227 may be controlled by the
magnetic field of the permanent magnet.
[0313] In the eighth embodiment, the angle measuring unit 545
calculates the angle between the reference image and the
comparative image obtained by the image acquiring unit 544 from the
capsule medical device 202, and measures the angle difference
between the reference direction of the image capturing unit 222 and
the magnetization direction of the magnet 227 inside the capsule
medical device 202. However, the present invention is not limited
to that arrangement. The storage unit 210 stores beforehand the
reference image data that is the data about an image that is
captured by the image capturing unit 222 when the reference
direction of the image capturing unit 222 is coincident with the
reference direction of the image member 542a. The angle measuring
unit 545 obtains the reference image data in the storage unit 210
from the control unit 547. The angle measuring unit 545 obtains the
data about the comparative data from the image acquiring unit 544,
and calculates the angle between the data obtained from the image
acquiring unit 544 (the data about the image captured by the image
capturing unit 222) and the preset reference image data. By doing
so, the angle measuring unit 545 may measure the angle difference
between the reference direction of the image capturing unit 222 and
the magnetization direction of the magnet 227 inside the capsule
medical device 202.
[0314] In the tenth embodiment, the magnetic moment of the magnet
227 is measured based on the measured value of the magnetic torque
of the magnet 227. However, the angle difference between the
reference direction of the image capturing unit 222 and the
magnetization direction of the magnet 227 inside the capsule
medical device 202 may also be measured, as described in the eighth
and ninth embodiments. In other words, the checking device of the
eighth or ninth embodiment may be combined with the checking device
of the tenth embodiment. In such a case, the checking device 761 of
the tenth embodiment may include the image member 542a, the image
acquiring unit 544, the angle measuring unit 545, the operating
condition setting unit 546, and the likes, like the checking device
of the eighth embodiment. Alternatively, the checking device 761 of
the tenth embodiment may include the image member 542a, the image
acquiring unit 544, the operating condition setting unit 656, and
the likes, like the checking device of the ninth embodiment.
[0315] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the scope
of the general inventive concept as defined by the appended claims
and their equivalents.
* * * * *