US20080188710A1 - Capsule medical apparatus and body-cavity observation method - Google Patents

Abstract

Provided is a capsule medical apparatus including a capsule body, a control member, and an observing member. The capsule body is to be introduced into a lumen of a subject. The control member controls a movement of the capsule body in the lumen by a flow of a fluid introduced in the lumen. The observing member is fixed inside the capsule body and observes a direction of the flow of the fluid and a direction different from the flow of the fluid according to the movement of the capsule body.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a capsule medical apparatus such as a capsule endoscope for traveling in a lumen with a liquid such as water, which is introduced into a subject, to observe inside the lumen and a body-cavity observation method.
• 2. Description of the Related Art
• Recently, in a field of endoscopes, a capsule endoscope having an imaging function and a radio communication function has been appearing. This capsule endoscope includes a structure for displacing along with peristaltic movement in an internal organ (in a lumen) such as the esophagus, stomach and small intestine and sequentially taking images with its imaging function until it is naturally discharged from the body of the subject, after swallowed by the subject through his or her mouth for the observation (examination).
• WO 02/95351 discloses a technique suited for observing the large intestine, in which the specific gravity of the capsule endoscope is set as same as that of the liquid therearound or1 which is same as that of water so that, when a subject swallows the capsule endoscope with the liquid, the capsule endoscope floats in the liquid and travels quickly in the body-cavity to the large intestine. When the capsule endoscope is attached to the wall surface of the body-cavity, only close narrow area is imaged; however, according to WO 02/95351, since the capsule endoscope floats in the liquid to observe, an observing field is maintained and every part can be observed.
• Regarding observations of inside hollow organs such as the large intestine with the use of such a capsule endoscope, an entire of the lumen may be needed to be observed in some cases and a particular portion such as a polyp (lumen wall) may be needed to be observed in other cases. In order to meet such demands, for example, WO03/11103 discloses a capsule endoscope having at least one illumination source, at least one imaging sensor, and at least two optic systems. Further, WO 02/54932 discloses a capsule endoscope having at least one imaging device and an optic system including a plurality of optical paths. According to WO 03/11103 and WO 02/54932, the capsule endoscope is capable of imaging the lumen not only in the axial direction of the lumen but also in an inner wall direction of the lumen in the hollow organ.
• However, according to the capsule endoscope of WO03/11103 and WO 02/54932, the system depends on the structure of the imaging optical system in the capsule endoscope and in order to optimize imaging direction to perform a proper observation in the lumen in its axial direction and the inner wall direction, more optic systems or optical paths are required to be set. Thus, the structure becomes more complex and enlarged so that the proper size of the capsule endoscope to be introduced into a subject cannot be maintained.
SUMMARY OF THE INVENTION
• A capsule medical apparatus according to one aspect of the present invention includes a capsule body to be introduced into a lumen of a subject; a control member controlling a movement of the capsule body in the lumen by a flow of a fluid introduced in the lumen; and an observing member fixed inside the capsule body and observing a direction of the flow of the fluid and a direction different from the flow of the fluid according to the movement of the capsule body.
• A body-cavity observation method according to another aspect of the present invention includes the steps of: ingesting a capsule medical apparatus; ingesting a fluid having a specific gravity which is substantially same as that of the capsule medical apparatus; controlling, by the capsule medical apparatus, movement in a lumen by a flow of the fluid; observing, by the capsule medical apparatus, a direction of the flow of the fluid; and observing, by the capsule medical apparatus, a direction different from the direction of the flow of the fluid.
• The above and other objects, 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
• FIG. 1 is a schematic block diagram showing a use example of a capsule endoscope according to a first embodiment of the present invention;
• FIG. 2 is a schematic block diagram showing a use example of a capsule endoscope according to a first modification;
• FIG. 3 is a schematic block diagram showing a use example of a capsule endoscope according to a second modification;
• FIG. 4 is a schematic rear view of the capsule endoscope;
• FIG. 5 is a schematic perspective view showing the capsule endoscope according to a second embodiment of the present invention;
• FIG. 6 is a rear view of the capsule endoscope inFIG. 5;
• FIGS. 7A,7B and7C are schematic block diagrams showing a use example of the capsule endoscope;
• FIG. 8 is a schematic block diagram showing a use example of a capsule endoscope according to a third modification;
• FIG. 9 is a schematic block diagram showing a use example of a capsule endoscope according to a fourth modification;
• FIG. 10 is a schematic block diagram showing a use example of a capsule endoscope according to a fifth modification;
• FIG. 11 is a rear view of the capsule endoscope inFIG. 10;
• FIG. 12 is a schematic block diagram showing a use example of a capsule endoscope according to a sixth modification;
• FIG. 13 is a rear view of the capsule endoscope inFIG. 12; and
• FIGS. 14A,14B and14C are schematic block diagrams showing a use example of a capsule endoscope according to a seventh modification.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Embodiments of a capsule medical apparatus and a body-cavity observation method according to the present invention will be described with reference to the drawings. The embodiments describe examples of the present invention applied to a capsule endoscope as a capsule medical apparatus. It will be appreciated that the present invention is not limited to the following embodiments and can be implemented with modifications within the spirit of the present invention.
• FIG. 1 is a schematic block diagram showing a use example of a capsule endoscope according to a first embodiment of the present invention. Thecapsule endoscope10 of the first embodiment includes acapsule body20 insertable into a lumen of asubject1 to be tested, an observingmember30 installed in thecapsule body20, other installed elements such as a radio transmission unit, a battery, an image processing unit, which are not shown, and arotary guide member40 disposed on outer face of thecapsule body20.
• Thecapsule body20 is made in a size capable of being swallowed by thesubject1 through his or her mouth into a body cavity of thesubject1. Thecapsule body20 is formed in a domed capsule shape, in which ends of hemispherical domes are integrated by a cylindrical member therebetween and the direction connecting the ends of the hemispherical domes represents a longitudinal direction.
• Here, thecapsule endoscope10 of the first embodiment is configured to propel in thelumen2 of thesubject1, for example, the large intestine, as floating in afluid3 that is introduced in thelumen2. Thecapsule body20, which includes installed elements such as the observingmember30, is configured to have a specific gravity that is substantially one with respect to thefluid3, substantially the same as thefluid3. Thefluid3 is a fluid, which is capable of being swallowed by thesubject1 through his or her mouth and is clear to the wavelength of a light source used by the observingmember30 for imaging. In the first embodiment, drinkable water having specific gravity close to one is used as an example of thefluid3. A gravity center G of thecapsule body20 containing the observingmember30 and other elements is set as the center of the capsule body20 (the center on the longitudinal axis L passing through the center of the cylinder).
• Further, the observingmember30 is an imaging member for imaging an image of the inside of the lumen and, according to the fist embodiment, is composed of fist andsecond imaging members31,32 which are fixed at a position one-sided with respect to the longitudinal axial direction in thecapsule body20. Thefirst imaging member31, which is not shown, includes a light source for illuminating an imaging region, a solid-state imaging device such as CCD or CMOS imager for receiving catoptric light from the imaging region generated by the illuminating light of the light source to image the inside of the lumen, and an imaging optic system such as an imaging lens for producing an optical image of the imaging region to the solid-state imaging device. As shown with dashed lines inFIG. 1, thefirst imaging member31 is disposed so as to provide an imaging field in the longitudinal axial direction of thecapsule body20. Further, thesecond imaging member32, which is not shown, includes a light source for illuminating an imaging region, a solid-state imaging device such as CCD or CMOS imager for receiving catoptric light from the imaging region generated by the illuminating light of the light source to image the inside of the lumen, and an imaging optic system such as an imaging lens for producing an optical image of the imaging region to the solid-state imaging device. As shown with the dashed lines inFIG. 1, thesecond imaging member32 is disposed so as to provide an imaging field in a direction oblique to the longitudinal axis direction of thecapsule body20. Here, thefirst imaging member31 is set to be a far focus to focus on a distant point and thesecond imaging member32 is set to be a near focus to focus on a close point. The imaging field of thesecond imaging member32 may be in a horizontal direction with respect to the vertical axial direction of thecapsule body20. Here, thecapsule body20 includes a member having clearness or translucency at least at regions corresponding to the imaging fields of the first andsecond imaging members31,32.
• Further, therotary guide member40 is configured to work as a control member for controlling movement of thecapsule body20 in thelumen2, which is moved by the flow of thefluid3 introduced into thelumen2. According to the first embodiment, therotary guide member40 is configured to rotate thecapsule body20 with the flow of thefluid3 about the longitudinal axis of thecapsule body20 in a circumferential direction. Therotary guide member40 is composed of a spiral member formed of acontinuous projection41 with projection amount which is capable of interfering the flow of thefluid3, spirally formed around the outer surface of thecapsule body20. The cross-sectional shape of theprojection41 may be formed in a hemicycle or a rectangle shape. Further, the interval of the spiral, the number of the spiral, the angle of the spiral or the like of theprojection41 can be set arbitrarily.
• An image processing unit which is installed in thecapsule body20, which is not shown, provides necessary processing on the images of the inside of the lumen taken by the first andsecond imaging members31,32. A radio transmission unit, which is not shown, radio-outputs lumen image data which has been subjected to necessary processing by the image processing unit to a receiver (not shown) or the like disposed outside thesubject1. A battery, which is not shown, supplies necessary power to an electrical drive unit such as the light source or solid-state imaging device in thecapsule body20.
• Next, an observation of inside of thelumen2, for example, the large intestine, with the use of thecapsule endoscope10 of the first embodiment will be described. Basically, thecapsule endoscope10 and thefluid3 are swallowed by the subject1 to substantially fill thelumen2 such as the large intestine as an observed portion in the subject1 with thefluid3 so that thecapsule endoscope10 travels as floating in thefluid3. Then the inside image of the lumen is taken by the first andsecond imaging members31,32 to observe the lumen. Thecapsule endoscope10 and theliquid3 may be swallowed at the same time or may be swallowed in any order.
• Here, as shown by arrows inFIG. 1, thefluid3 introduced in thelumen2 flows along the axis of thelumen2 toward an exit of the lumen. When thecapsule endoscope10 is in such a flow of thefluid3, since thecapsule body20 has therotary guide member40 of the spirally formedprojection41 on the outer face and therotary guide member40 interferes the flow of thefluid3, thecapsule endoscope10 is controlled to move along the flow as rotating in the circumferential direction about the longitudinal axis L. The first andsecond imaging members31,32 take images inside thelumen2 in such movements of thecapsule body20. In other words, thefirst imaging member31 takes images of thelumen2, as rotating, in front (or back) in the axial direction that is the direction of the flow of thefluid3. Thesecond imaging member32 sequentially takes images of aninternal surface2aof thelumen2, which is located in different direction from the flow of thefluid3, as moving around therein. Further, since the focus position of thefirst imaging member31, which images thelumen2 in the axial direction, is set at a long distance, a far focused and fine image of the inside of the entire lumen can be obtained. Since the focus position of thesecond imaging member32, which images theinternal surface2aas moving around therein, is set at a short distance, a near focused and fine internal surface image can be obtained and a particular portion such as apolyp2bcan surely be observed.
• As described above, according to thecapsule endoscope10 of the first embodiment, the observing fields in thelumen2 can be dynamically changed to be optimized by controlling thecapsule body20 to move as rotating in a circumferential direction with the use of the flow of thefluid3. With this structure, the entire parts in thelumen2 can surely be observed without complicating the structure of an observing member (imaging member), which is to be installed in thecapsule body20. Further, according to thecapsule endoscope10 of the first embodiment, the gravity center G is set at the substantially center of thecapsule body20 and the specific gravity with respect to thefluid3 is set as substantially one. Accordingly, thecapsule body20 is in a mobile state and rotatable smoothly in the circumferential direction when therotary guide member40 interferes the flow of thefluid3. With this structure, the above described observing operation can be certainly performed.
• FIG. 2 is a schematic block diagram showing a use example of the capsule endoscope according to a first modification. According to acapsule endoscope11 of the first modification, arotary guide member42 is formed with a plurality ofnoncontiguous projections43 so as to form an intermissive spiral shape. In this way, therotary guide member42 may be formed in an intermissive spiral shape with thenoncontiguous projections43 if therotary guide member42 is configured to interface the flow of thefluid3 to rotate thecapsule body20 in a circumferential direction about the longitudinal axis L. Such arotary guide member42 may be formed more easily than the rotary guide member of thecontinuous projection41.
• The rotary guide member is not limited to what is formed spirally with theprojections41,43 and may be, for example, formed with a recess, which is spirally formed on the outer surface of thecapsule body20 to interface the flow of thefluid3. Further, according to the first embodiment and the first modification, the observing member30 (the first andsecond imaging members31,32) is not limited to be disposed only at one end in thecapsule body20 and the observingmembers30 may be fixed at both ends as a compound-eye-type structure. In addition, thefirst imaging member31 and thesecond imaging member32 may be arranged at different ends.
• FIG. 3 is a schematic block diagram showing a use example of a capsule endoscope according to a second modification andFIG. 4 is a schematic rear view of the capsule endoscope. Acapsule endoscope12 according to the second modification includes apropeller44 as arotary guide member45, which is integrally provided on the outer surface of a rear portion (the portion where the observingmember30 is not provided) of thecapsule body20. When thecapsule endoscope12 having such structure receives a flow of thefluid3 in thelumen2, thepropeller44 as therotary guide member45 rotates as interfering the flow of thefluid3 so that thecapsule body20 moves forward in thelumen2 as rotating, together with thepropeller44, in a circumferential direction about the longitudinal axis L. Accordingly, same as the case of the first embodiment, the inside of thelumen2 may surely be observed.
• Next, a capsule endoscope according to a second embodiment of the present invention will be described.FIG. 5 is a schematic perspective view showing the capsule endoscope according to the second embodiment,FIG. 6 is a rear view of the capsule endoscope inFIG. 5, andFIGS. 7A,7B and7C are schematic block diagrams showing a use example of the capsule endoscope. Acapsule endoscope50 according to the second embodiment includes acapsule body60 which is insertable into a lumen of a subject1, an observingmember70 installed in thecapsule body60, other installed elements, which are not shown, such as a radio transmission unit, a battery or an image processing unit, and arotary guide member80 disposed on the outer surface of thecapsule body70.
• Thecapsule body60 is basically same as thecapsule body20. Thecapsule body60 is made in a size capable of being swallowed by the subject1 through his or her mouth into a cavity. Thecapsule body60 is formed in a domed capsule shape, in which ends of hemispherical domes are integrated by a cylindrical member therebetween and the direction connecting the ends of the hemispherical domes is a longitudinal direction.
• Here, thecapsule endoscope50 of the second embodiment moves in alumen2, for example, the large intestine of the subject1, as floating in thefluid3 introduced into thelumen2. Thecapsule body60, which includes elements such as the observingmember70 therein, is configured to have a specific gravity that is substantially one with respect to thefluid3, substantially the same as that of thefluid3. Thefluid3 is a liquid, which is capable of being swallowed by the subject1 through his or her mouth and is clear to the wavelength of a light source used by the observingmember30 for imaging. In the second embodiment, drinkable water having specific gravity close to one is used as an example of thefluid3. The gravity center G of thecapsule body60 containing the observingmember30 and other elements is set as the center of the capsule body60 (the center on the longitudinal axis L passing through the center of the cylinder).
• Further, the observingmember70 is an imaging member for imaging an image of the inside of the lumen and, according to the second embodiment, is composed of animaging member71 that is fixed at a position one-sided with respect to the longitudinal axial direction in thecapsule body60. Theimaging member71, which is not shown, includes a light source for illuminating an imaging region, a solid-state imaging device such as CCD or CMOS imager for receiving catoptric light from the imaging region generated by the illuminating light of the light source to image the inside of the lumen, and an imaging optical system such as an imaging lens for producing an optical image of the imaging region to the solid-state imaging device. As shown with dashed lines inFIGS. 7A to 7C, theimaging member71 is disposed so as to provide an imaging field in the longitudinal axial direction of thecapsule body60. Here, thecapsule body60 includes a member having clearness or translucency at least at regions corresponding to the imaging field of theimaging member71.
• Further, therotary guide member80 is configured to work as a control member for controlling movement of thecapsule body20 in thelumen2, which is moved by the flow of thefluid3 introduced into thelumen2. According to the second embodiment, therotary guide member80 is configured to rotate thecapsule body60 with the flow of thefluid3 about an axis S passing through the gravity center G of thecapsule body60 and substantially perpendicular to the longitudinal axis L in a circumferential direction. Therotary guide member80 is composed ofprojections81,82 in a pocketform having openings81a,82aon the outer surface of thecapsule body60 to form a pair of one-way resistive elements. Theopenings81a,82aare opened along the longitudinal axial direction and toward the center portion of thecapsule body60. Thesepocket projections81,82 are disposed at a position off the center of the longitudinal axis L on the outer surface of thecapsule body60 so as to be point symmetric with respect to the gravity center G of thecapsule body60. Further, thesepocket projections81,82 are formed symmetrically when they are divided into two pieces at a plane face including the longitudinal axis L of thecapsule body60 and disposed to be point symmetric with respect to the gravity center G of thecapsule body60. Here, thepocket projections81,82 work as resistive elements and generate reaction force when theopenings81a,82aare opened toward upstream to face to the flow of thefluid3, and, on the other hand, thepocket projections81,82 do not work as resistive elements when theopenings81a,82aare opened toward downstream and does not face to the flow of thefluid3 and have directionality to generate reaction force to the flow of thefluid3.
• Next, an observation of inside of thelumen2, for example, the large intestine with the use of thecapsule endoscope50 of the second embodiment will be described. Basically, thecapsule endoscope50 and thefluid3 are swallowed from a mouth to substantially fill thelumen2 such as the large intestine as an observed portion in the subject1 with thefluid3 so that thecapsule endoscope50 travels as floating in thefluid3 while animaging member71 takes images of the inside of thelumen2. Thecapsule endoscope50 and theliquid3 may be swallowed at the same time or may be swallowed in any order.
• Here, as shown by arrows inFIG. 7A, thefluid3 introduced in thelumen2 flows toward an exit of the lumen. When thecapsule endoscope50 is in such a flow of thefluid3, since thecapsule body60 has therotary guide member80 of thepocket projections81,82 on its outer face, one of theprojection81 or theprojection82 faces to the flow of thefluid3 to generate a reaction force. Accordingly, thecapsule body60 is controlled to move along the flow as rotating radially about an axis S that passes through the gravity center G of thecapsule body60 and substantially perpendicular to the longitudinal axis L.
• For example, as shown inFIG. 7A, when the opening81aof theprojection81 faces to the flow of thefluid3, theprojection81 generates an reaction force against the flow of thefluid3 and works as a trigger to rotate thecapsule body60 in the clockwise direction about the axis S. Thecapsule body60 rotates in the clockwise direction about the axis S (rolls forward) along the flow of thefluid3, as shown inFIG. 7B. In this operation, theother projection82 does not generate a reaction force since the opening82adoes not face to the flow. Then, when thecapsule body60 continues to rotate, as shown inFIG. 70C, the opening82aof theother projection82 comes to face to the flow of thefluid3 and theprojection82 generates a reaction force against the flow of thefluid3 to rotate thecapsule body60 in the clockwise direction about the axis S. With repeating this operation, thecapsule body60 travels forwardly in thelumen2 as rotating about the axis S by the flow of thefluid3.
• Theimaging member71 takes images of the inside of thelumen2 in such a movement of thecapsule body60. In other words, theimaging member71 sequentially takes images ofinternal surfaces2aof thelumen2 at front side and back side of an axis of thelumen2 that is the flowing direction of thefluid3 and at different directions from the flowing direction of thefluid3 as rotating forwardly and following the rotating trajectory. With this structure, the entire area in thelumen2 and particular parts of theinternal surface2acan be observed.
• When the flow of thefluid3 is small, since the resistance received by theprojection81 or82 facing to the flow becomes small, thecapsule body60 does not rotate about the axis S. Accordingly, when the flow is small, theimaging member71 takes images in axial direction of thelumen2 and, when the flow has certain strength or more, theimaging member71 observes particular portion of theinternal surface2a. When the flow of thefluid3 has a periodicity, both entire images and partial images can be observed more efficiently.
• As described above, according to thecapsule endoscope50 of the second embodiment, thecapsule body60 is moved as rotating radially about the axis S (rotating forwardly) with the use of the flow of thefluid3. With this structure, an observing field in thelumen2 can dynamically be changed to be optimized even when thecapsule endoscope50 has a structure including a single observingmember70 for a direct view. Thus, the entire area in thelumen2 can be surely observed without complicating the structure of an observing member (imaging member), which is to be installed in thecapsule body60. Further, according to thecapsule endoscope50 of the second embodiment, the gravity center G is set at the substantially center of thecapsule body60 and the specific gravity with respect to thefluid3 is set as substantially one. Accordingly, thecapsule body60 is in a mobile state and rotatable in the radial direction about the axis S smoothly when thepocket projections81,82 constituting therotary guide member80 alternately face to the flow of thefluid3. With this structure, the above described observing operation can certainly be performed.
• FIG. 8 is a schematic block diagram showing a use example of a capsule endoscope according to a third modification. Acapsule endoscope51 of the third modification has a pair ofpocket projections81,82 constituting arotary guide member80 in whichopenings81a,82aare opened toward ends along the longitudinal axial direction. With thecapsule endoscope51 having the structure described in the third modification, operations and effects same as those of the second embodiment can be obtained.
• FIG. 9 is a schematic block diagram showing a use example of a capsule endoscope according to a fourth modification. Acapsule endoscope52 of the fourth modification includes animaging member71 as a first observing member and a second observingmember72 for forming at another imaging field in a longitudinal direction of thecapsule body60, which is fixed another end of thecapsule body60. A compound-eye-type observing member70 is composed of the first andsecond imaging members71,72.
• Here, similarly to thefirst imaging member71, the second observingmember72, which is not shown, includes a light source for illuminating an imaging region, a solid-state imaging device such as CCD or CMOS imager for receiving catoptric light from the imaging region generated by the illuminating light of the light source to image the inside of the lumen, and an imaging optical system such as an imaging lens for producing an optical image of the imaging region to the solid-state imaging device. Further, thefirst imaging member71 is set to be a far focus to focus on a entire image of thelumen2 and thesecond imaging member72 is set to be a near focus to observe the internal surface or the like of thelumen2. Here, thecapsule body60 also includes a member having clearness or translucency for a region corresponding to the imaging field of thesecond imaging member72.
• With thecapsule endoscope52 having the structure described in the fourth modification, operations and effects same as those of the second embodiment can be obtained. Particularly, since thecapsule endoscope52 of the third modification has a compound-eye-type structure with the first andsecond imaging members71,72 having different focusing lengths, when thecapsule body60 rotates radially about the axis S by the flow of thefluid3, the first andsecond imaging members71,72 sequentially take images in thelumen2 as following the rotating trajectory. In this case, since the focus position of thefirst imaging member71 is set at a long distance, a far focused and fine image of the inside of the entire lumen can be obtained by extracting a well-focused image from the obtained images. Further, since the focus position of thesecond imaging member72 is set at a short distance, a near focused and fine internal surface image can be obtained and a particular portion such as a polyp can surely be observed by extracting a well-focused image from the obtained images.
• FIG. 10 is a schematic block diagram showing a use example of a capsule endoscope according to a fifth modification andFIG. 11 is a rear view of the capsule endoscope. Acapsule endoscope53 of the fifth modification includes a pair ofgrooves83,84 as a pair of one-way resistive elements constituting arotary guide member80, as substitutes for the pair ofpocket projections81,82. Thegrooves83,84 are formed in a manner being opened near the end portions on the outer surface of thecapsule body60 along the longitudinal axial direction and toward the side of the end portions. Inner walls of thegrooves83,84 work as fluid contact faces83a,84b. Thegrooves83,84 are arranged to be point symmetric with respect to the gravity center G of thecapsule body60. Further, the cross-sectional shape of thegrooves83,84 may be triangular or U-shaped which are symmetrical when they are divided into two at a flat face including the longitudinal axis L of thecapsule body60 and arranged to be point symmetric with respect to the gravity center G.
• Here, thegrooves83,84 work as resistive elements to generate a reaction force when the fluid contact faces83a,84aface toward the upstream and face to the flow of thefluid3, and thegrooves83,84 do not work as resistive element when the fluid contact face83a,84aface toward the downstream and do not face to the flow of thefluid3 and have directionality to generate reaction force to the flow of thefluid3. With thecapsule endoscope53 having the structure described in the fifth modification, operations and effects same as those of the second embodiment can be obtained.
• FIG. 12 is a schematic block diagram showing a use example of a capsule endoscope according to a sixth modification andFIG. 13 is a rear view of the capsule endoscope. Acapsule endoscope54 of the sixth modification includes a pair ofholes85,86 as a pair of one-way resistive elements constituting arotary guide member80, as substitutes for the pair ofpocket projections81,82. Theholes85,86 are formed in a manner opened near the end portions on the outer surface of thecapsule body60 along the longitudinal axial direction and toward the side of the end portions. The holes.85,86 are arranged to be point symmetric with respect to the gravity center G of thecapsule body60. Further, the cross-sectional shape of theholes85,86 may be triangular or round shape, which are symmetrical when they are divided into two at a flat face including the longitudinal axis L of thecapsule body60, and arranged to be point symmetric with respect to the gravity center G.
• Here, theholes85,86 work as resistive elements to generate a reaction force when the openings opened toward the upstream and face to the flow of thefluid3, and theholes85,86 do not work as resistive element when the openings open toward the downstream and do not face to the flow of thefluid3 and have directionality to generate reaction force to the flow of thefluid3. With thecapsule endoscope54 having the structure described in the sixth modification, operations and effects same as those of the second embodiment can be obtained.
• Here, according to the third to sixth modifications of the second embodiment, therotary guide member80 is composed of a pair of one-way resistive elements formed by the pair of thepocket projections81,82,grooves83,84, or holes85,86. However, therotary guide member80 composed of a pair of one-way resistive elements in which a plurality of projections, grooves, or holes are symmetrically disposed in combination in each side may be employed.
• Further, the projected resistive element may be openable and closable (projected and retracted) with respect to the outer surface of the capsule body. In other words, when thefluid3 is still (or its flow is small), the resistive element is closed (installed in the capsule body) and when a large flow is generated, the resistive element is opened (projected) corresponding to the flow. With this structure, since projections are projected only when they are need, the capsule endoscope can be easily swallowed by thesubject1.
• FIGS. 14A to 14C are schematic block diagrams showing a capsule endoscope according to a seventh modification. Acapsule endoscope55 of the seventh modification includes aweight91 installed in thecapsule body60 and aslide space92 for sliding the position of theweight91 in the longitudinal axial direction of thecapsule body60. Here, theweight91 slides in theslide space92 due to the flow of thefluid3 to thecapsule body60 so that the position of the gravity center of thecapsule body60 is changed.
• When thecapsule endoscope55 having such a structure is introduced in thelumen2 and stays in thefluid3, for example, theweight91 is located at a position one-sided in theslide space92, as shown inFIG. 14A, and thecapsule endoscope55 flows in thefluid3 in a manner of being tilted due to the position of the gravity center, as shown inFIG. 14A. When the flow of thefluid3 works on thecapsule body60 in such a condition, thecapsule body60 rotates forwardly to be a substantially horizontal state, as shown inFIG. 14B. With such movement of thecapsule body60, theweight91 slides to the center of theslide space92 and further moves to the other end of theslide space92. According to the dynamical changes of the position of the gravity center, thecapsule body60 moves to continue the rotation, as shown inFIG. 14C. By repeating this operation, thecapsule body60 travels in thelumen2 due to the flow of thefluid3 as rotating forwardly. Accordingly, with thecapsule endoscope55 having the structure described in the seventh modification, operations and effects same as those of the second embodiment can be obtained.
• 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 spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Claims (22)

1. A capsule medical apparatus comprising:

a capsule body to be introduced into a lumen of a subject;

a control member controlling a movement of the capsule body in the lumen by a flow of a fluid introduced in the lumen; and

an observing member fixed inside the capsule body and observing a direction of the flow of the fluid and a direction different from the flow of the fluid according to the movement of the capsule body.

2. The capsule medical apparatus according toclaim 1, wherein the control member is a rotary guide member which rotates the capsule body by the flow of the fluid in a circumferential direction about a longitudinal axis of the capsule body.

3. The capsule medical apparatus according toclaim 2, wherein the rotary guide member includes a spiral member provided on an outer surface of the capsule body so as to interfere the flow of the fluid.

4. The capsule medical apparatus according toclaim 3, wherein the spiral member is a spirally-formed projection.

5. The capsule medical apparatus according toclaim 4, wherein the spirally-formed projection is a single continuous projection.

6. The capsule medical apparatus according toclaim 4, wherein the spirally-formed projection includes a plurality of discontinuous projections.

7. The capsule medical apparatus according toclaim 1, wherein the observing member includes a first imaging member forming an imaging field in a longitudinal direction of the capsule body and a second imaging member forming an imaging field in a direction different from the direction of the imaging field of the first imaging member.

8. The capsule medical apparatus according toclaim 7, wherein the first imaging member has a far focus and the second observing member has a near focus.

9. The capsule medical apparatus according toclaim 7, wherein the second observing member has the imaging field oblique to the longitudinal axial direction of the capsule body.

10. The capsule medical apparatus according toclaim 7, wherein the second imaging member has the imaging field perpendicular to the longitudinal axial direction in the capsule body.

11. The capsule medical apparatus according toclaim 1, wherein the control member is a rotary guide member which rotates the capsule body in a radial direction about an axis passing through the gravity center of the capsule body and perpendicular to the longitudinal axis by the flow of the fluid.

12. The capsule medical apparatus according toclaim 11, wherein the rotary guide member includes a pair of one-way resistive elements, the resistive elements having a same shape and being located on an outer surface of the capsule body to be point symmetric with respect to the gravity center of the capsule body, and the resistive elements having directionality for generating a reaction force toward the flow of the fluid.

13. The capsule medical apparatus according toclaim 12, wherein the one-way resistive elements are projections.

14. The capsule medical apparatus according toclaim 13, wherein the projections can be projected and retracted with respect to the outer surface of the capsule body.

15. The capsule medical apparatus according toclaim 13, wherein the projections are pocket projections each having an opening opened along the longitudinal axial direction.

16. The capsule medical apparatus according toclaim 12, wherein each of the one-way resistive elements is a groove opened toward an end portion of the capsule body along the longitudinal axial direction.

17. The capsule medical apparatus according toclaim 12, wherein each of the one-way resistive elements is a hole opened toward an end portion of the capsule body along the longitudinal axial direction.

18. The capsule medical apparatus according toclaim 11, wherein the observing member includes an imaging member which forms an imaging field in the longitudinal axial direction of the capsule body.

19. The capsule medical apparatus according toclaim 11, wherein the observing member includes two imaging members each being respectively fixed at both end portions of the capsule body in the longitudinal axial direction.

20. The capsule medical apparatus according toclaim 19, wherein the imaging members are a first imaging member and a second imaging member, respectively the first imaging member being fixed at an end of the capsule body in the longitudinal axial direction and having a far focus, and the second imaging member being fixed at another end of the capsule body in the longitudinal axial direction and having a near focus.

21. The capsule medical apparatus according toclaim 1, wherein the capsule body has a specific gravity which is substantially one with respect to the fluid introduced into the subject, and the gravity center of the capsule body is in a substantial center of the capsule body.

22. A body-cavity observation method, comprising the steps of:

ingesting a capsule medical apparatus;

ingesting a fluid having a specific gravity which is substantially same as that of the capsule medical apparatus;

controlling the capsule medical apparatus movement in a lumen, by a flow of the fluid;

observing, by the capsule medical apparatus, a direction of the flow of the fluid; and

observing, by the capsule medical apparatus, a direction different from the direction of the flow of the fluid.

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