Patent Application
20090253956
1. Field of the Invention
The present invention relates to a capsule endoscope which allows an observation of an inside of a subject body in a state of floating on a liquid fed into the subject body and an intra-stomach observing method.
2. Description of the Related Art
Recently, a capsule endoscope including an imaging function and a wireless communication function has appeared in the field of endoscopes. The capsule endoscope has a configuration of travelling inside of organs such as the esophagus, the stomach, and the small intestine (inside of a body cavity) according to their peristalsis and of sequentially capturing images by using the imaging function during an observation period which starts when the capsule endoscope is swallowed for the purpose of an observation (examination) from a mouth of a test subject as a subject body (human body) and ends when it is naturally excreted from a living body of the test subject.
Here, a technology of making a capsule endoscope, whose specific gravity is set to less than one and which is swallowed with a liquid (drinking water), float on the liquid inside the stomach to which the liquid is Led, and enabling an observation of a wall of the stomach is disclosed in International Publication Pamphlet No. 02/95351 (PCT National Publication No. 2004-529718).
However, the capsule endoscope houses contents including an imaging unit, an illumination unit, a wireless communication unit, a battery, and the like in a capsule casing; and a specific gravity of the contents is usually not less than one in most cases. Therefore, it is necessary to form the capsule casing in a size larger than the required size to make the specific gravity of the capsule endoscope less than one, so that the capsule endoscope has a problem of having a difficulty in swallowing from an oral cavity of the test subject as shown in International Publication Pamphlet No. 02/95351 (PCT National Publication No. 2004-529718).
A capsule endoscope according to an aspect of the present invention includes a capsule casing which contains therein contents including an imaging unit and is inserted into an inside of a subject body; a hollow volume changing unit which is connected to the capsule casing, and changes a connection position with the capsule casing to change a volume of the capsule casing; and an actuator which is connected to the capsule casing and changes the connection position.
An intra-stomach observing method according to another aspect of the present invention includes making a capsule endoscope before an examination at a predetermined temperature; making a subject swallow the capsule endoscope; making the subject take in a water whose temperature is lower than the predetermined temperature; increasing a volume of the capsule endoscope; and observing an inside of a stomach by the capsule endoscope.
An intra-stomach observing method according to still another aspect of the present invention includes storing a capsule endoscope under an environment of a predetermined temperature; making a subject swallow the capsule endoscope; making the subject take in a water whose temperature is lower than the predetermined temperature; increasing a volume of the capsule endoscope; and observing an inside of a stomach by the capsule endoscope.
An intra-stomach observing method according to still another aspect of the present invention includes making a subject swallow a capsule endoscope; making the subject take in a water of a predetermined temperature and filling an inside of a stomach with a liquid; increasing a volume of the capsule endoscope; and observing the inside of the stomach by the capsule endoscope.
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.
Exemplary embodiments of a capsule endoscope will be explained below with reference to the accompanying drawings.
A first embodiment of the present invention will be explained first.
As shown in
Here, the capsule endoscope 1 according to the first embodiment is explained by taking, as one example, an application to a compound-eye capsule endoscope which can capture images at both sides in a longitudinal axis direction of the capsule, and includes a capsule casing 11 whose size is small enough to be swallowed from the oral cavity 2a of the subject body 2 and contents 12 including an imaging unit, an illumination unit, a wireless communication unit, a substrate member, a battery, and the like which are embedded in the capsule casing 11.
The capsule casing 11 includes semispherical, transparent or translucent head covers 11a and 11b and a body cover 11c which has a cylindrical shape and is formed of a colored material which does not allow a visible light to pass through. The capsule casing 11 according to the embodiment, since the body cover 11c is divided into two pieces in the axial direction, is formed by separated two casings, that is, a first casing 11A and a second casing 11B Both of the divided surfaces of the divided body cover 11c are configured to be bottomed and to seal insides of the casings 11A and 11B in a liquid-tight manner, respectively.
The illumination unit in the contents 12 is constituted by a light emitting element such as an LED which emits an illumination light for illuminating a site to be imaged in the subject body 2 via the head covers 11a and 11b. The imaging unit in the contents 12 includes an imaging element such as a CCD and a CMOS sensor which receives a reflection light by the illumination light via the head covers 11a and 11b and captures images of the site to be imaged, an image forming lens, and the like. The contents 12 are separated and embedded into the two casings 11A and 11B respectively to fit a symmetrical structure of the compound-eye capsule endoscope, and each casing includes contents whose specific gravity in total is not less than one and higher than that of the water 3.
In addition to the configuration described above, the capsule endoscope 1 according to the embodiment includes a volume changing unit 13 and a shape memory alloy spring 14 as an actuator which activates the volume changing unit 13. The volume changing unit 13 is schematically a tank having a hollow rigid body of a cylindrical shape, arranged between the casings 11A and 11B with respect to the volume changing unit 13, and connected to be freely movable inward and outward with respect to the casings 11A and 11B along the longitudinal axis direction with an air-tight state with respect to the bottomed parts of the casings 11A and 11B maintained By this, the volume changing unit 13 can be displaced to a storage position where the volume changing unit 13 is stored half and half by the casings 11A and 11B as shown in
The shape memory alloy spring 14, both ends thereof being connected to freely turn with respect to the bottomed parts of the casings 11A and 11B, causes the volume changing unit 13 to be displaced to the storage position by presenting a memorized shape of a folded shape as shown in
Besides, the capsule endoscope 1 according to the embodiment includes, on a front surface, a sealing member 15 which seals the casings 11A and 11B to be a connected state so that the volume changing unit 13 is maintained at the storage position against the memorized shape of the shape memory alloy spring 14 that causes the displacement to the exposure position under a condition of a normal temperature before the capsule endoscope 1 is swallowed by the subject body 2. The sealing member 15 is formed of an edible material such as a wafer which dissolves by stomach juices and the like by being inserted into the subject body 2.
In this configuration, since the casings 11A and 11B are sealed by the sealing member 15, the volume changing unit 13 is maintained at the storage position against the memorized shape of the shape memory alloy spring 14 though the capsule endoscope 1 before starting an examination is under the condition of the normal temperature and the shape memory alloy spring 14 will try to present the memorized shape of the expanded open shape when the normal temperature is, for example, at about 25° C. By this, the capsule endoscope 1 can be maintained in a size of the state shown in
At a time of starting the examination, the capsule endoscope 1 in the state as shown in
Thereafter, when the time is right, the water 3 at 25° C. is taken little by little to be fed into the stomach 2b. On this occasion, though the specific gravity of the capsule endoscope 1 is not less than one and the capsule endoscope 1 does not float on a surface of the water 3 fed into the stomach 2b, the capsule endoscope 1 becomes a state of lying on its side in which the ventilation hole 13a is oriented upward according to the position of the center of gravity G. Then, the shape memory alloy spring 14 of the lying capsule endoscope 1 comes to be present in the fed water 3 (the water 3 is assumed to be an amount not causing the capsule endoscope 1 to go under the water as shown in
When an appropriate amount of the water 3 is further fed into the stomach 2b under this condition, the capsule endoscope 1 whose specific gravity is lowered to be less than one can image and observe the wall of the stomach while floating on the surface of the fed water 3 as shown in
After the examination is completed, the water 3 is discharged from the inside of the stomach 2b to a side of the small intestine. By this, the capsule endoscope 1 remaining in the stomach 2b is subjected to the environment of the body temperature of the subject body 2 and the shape memory alloy spring 14 makes the displacement from the expanded open shape to a direction to be folded to present the memorized shape of the bent shape. In response to this folding displacement of the shape memory alloy spring 14, the separated casings 11A and 11B are also displaced to a direction to be in contact with each other and the volume changing unit 13 connected between the casings 11A and 11D also makes the displacement to the storage position as shown in
As described, since the shape memory alloy spring 14 presents the memorized shape of causing the volume changing unit 13 to be displaced to the storage position where the volume changing unit 13 is stored in the capsule endoscope 1 based on the body temperature of the subject body 2 when the capsule endoscope 1 according to the embodiment is inserted into the subject body 2, a volume condition which does not impair the insertion property into the subject body 2 can be realized. Besides, since the shape memory alloy spring 14 presents the memorized shape of causing the volume changing unit 13 to be displaced to the exposure position where the volume changing unit 13 is exposed to the outside of the casing of the capsule endoscope 1 and the casing volume is increased based on the temperature of the water 3 fed appropriately into the subject body 2 after the capsule endoscope 1 is inserted into the subject body 2, the volume changing unit 13 makes the displacement to the exposure position to increase the casing volume while absorbing the outer air into the inside through the ventilation hole 13a in the subject body 2, so that an observation in a state where the capsule endoscope 1 with a low specific gravity in total floats on the water 3 can be performed even when the specific gravity of the contents 12 is high.
In addition, a common linear actuator may be provided instead of the shape memory alloy spring 14. A temperature sensor may further be equipped for controlling an operation of the linear actuator based on a temperature. By this, the volume changing unit 13 can be controlled with a greater flexibility.
A second embodiment of the present invention will be explained next.
In the second embodiment, a volume changing unit 16 which is a tank formed of a hollow soft member of an accordion shape is provided instead of the volume changing unit 13 which is a tank having a rigid body of a cylindrical shape. The volume changing unit 16 is arranged between the casings 11A and 11B with respect to the capsule casing 11 and connected, to be stretchable along the longitudinal axis direction, to the bottomed parts of the casings 11A and 11B with an air-tight state maintained. By this, the volume changing unit 16 can be displaced to a storage position where the volume changing unit 16 shrinks to be stored between the casings 11A and 11B as shown in
In this configuration, since the casings 11A and 11B are sealed by the sealing member 15, the volume changing unit 16 is maintained at the storage position against the memorized shape of the shape memory alloy spring 14 though the capsule endoscope 1 before starting an examination is under the condition of the normal temperature and the shape memory alloy spring 14 will try to present the memorized shape of the expanded open shape when the normal temperature is, for example, at about 25° C. By this, the capsule endoscope 1 can be maintained in a size of the state shown in
At a time of starting the examination, the capsule endoscope 1 in the state as shown in
Thereafter, when the time is right, the water 3 at 25° C. is taken little by little to be fed into the stomach 2b. On this occasion, though the specific gravity of the capsule endoscope 1 is not less than one and the capsule endoscope 1 does not float on a surface of the water 3 fed into the stomach 2b, the capsule endoscope 1 becomes a state of lying on its side in which the ventilation hole 16a is oriented upward according to the position of the center of gravity G. Then, the shape memory alloy spring 14 of the lying capsule endoscope 1 comes to be present in the fed water 3 (the water 3 is assumed to be an amount not causing the capsule endoscope 1 to go under the water as shown in
When an appropriate amount of the water 3 is further fed into the stomach 2b under this condition, the capsule endoscope 1 whose specific gravity is lowered to be less than one can image and observe the wall of the stomach while floating on the surface of the fed water 3 as shown in
After the examination is completed, the water 3 is discharged from the inside of the stomach 2b to a side of the small intestine. By this, the capsule endoscope 1 remaining in the stomach 2b is subjected to the environment of the body temperature of the subject body 2 and the shape memory alloy spring 14 makes the displacement from the expanded open shape to a direction to be folded and present the memorized shape of the bent shape. In response to this folding displacement of the shape memory alloy spring 14, the separated casings 11A and 11B are also displaced to a direction to be in contact with each other and the volume changing unit 16 connected between the casings 11A and 11B also makes the displacement to the storage position as shown in
Though the sealing by the sealing member 15 is adopted not to cause the capsule endoscope 1 before being swallowed to be displaced to a state of an increased volume in the first and the second embodiments, the capsule endoscope 1 may be, for example, stored under an environment of a constant temperature until a time right before being swallowed, so that the sealing member 15 may be eliminated Or more specifically, the subject body 2 may hold the capsule endoscope 1 by hand and the like right before the swallowing to keep the capsule endoscope 1 under the body temperature environment, so that the sealing member 15 may be eliminated.
Besides, when there is a possibility that the water 3 comes into the inside of the volume changing units 13 and 16 respectively through the ventilation holes 13a and 16a due to a rotation and the like of the capsule endoscope 1, a sheet member such as a Gore-Tex (registered trademark) which allows only a gas to path through may be attached onto the ventilation holes 13a and 16a respectively of the volume changing units 13 and 16 to prevent an intrusion of the water 3. In addition, the displacement operation to the exposure position may be configured to be performed through an adjustment based on an inner pressure of the capsule endoscope 1 without providing the ventilation holes 13a and 16a. By this, the structure can be simplified.
Moreover, though the explanation in the first and the second embodiments is made as an application example to the compound-eye capsule endoscope, a single-eye capsule endoscope is similarly applicable. Specifically, in the case of using the single-eye capsule endoscope, the capsule casing may not be divided into two pieces like the casings 11A and 11B, a volume changing unit may be connected, to be displaced at an air-tight state, to one end which is not the side of capturing images, and a shape memory alloy spring connecting a capsule casing and a distal end side of the volume changing unit may be provided.
A capsule endoscope and an intra-stomach observing method according to the present invention have advantageous effects that since an actuator changes a connecting position of a volume changing unit with a capsule casing based on a body temperature of a subject body when the capsule endoscope is inserted into the subject body to change a volume of the casing, a volume condition which does not impair a property of an insertion into the subject body can be realized, when a liquid is arbitrarily fed into the subject body after the capsule endoscope is inserted into the subject body, the actuator changes the connecting position of the volume changing unit with the capsule casing based on a temperature of the liquid to change and increase the casing volume, and thereby a total specific gravity can be reduced and an observation can be performed with the capsule endoscope floating on the liquid even when a specific gravity of contents is high.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-257270 | Sep 2006 | JP | national |
This application is based upon and claims the benefit of priority from PCT Application Now PCT/JP2007/068373, filed on Sep. 21, 2007, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2007/068373 | Sep 2007 | US |
| Child | 12407913 | US |
