Abstract:
A fully-swallowable endoscopic system includes a rod-shaped endoscope body which can be swallowed entirely by a patient to be examined so as to be placed in a body cavity, the rod-shaped endoscope body including two bendable portions having different lengths which are respectively provided close to the opposite ends of the rod-shaped endoscope body; and an external device provided separately from the rod-shaped endoscope body having no mechanical connection with the rod-shaped endoscope body. The rod-shaped endoscope body is provided therein with at least one light emitter, at least one observing system, a transmitter for transmitting a radio wave which carries an image formed by the observing system, and a power supplying device. The external device includes a receiver for receiving the radio wave which carries the image.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a fully-swallowable endoscopic system which can be retained in the patient&#39;s body for a long time, wherein few blind spots occur in an endoscopy examination. 
     2. Description of the Related Art 
     In an endoscopy examination, in general, an insertion portion connected to an operation portion is introduced into a patient&#39;s body through his or her mouth to observe a target inner part of the body. In the case of observing an inner part of a largely-bent tubular passage in a body such as part of the large intestine, the occurrence of blind spots in the endoscopy examination cannot be avoided. 
     The body insertion portion of the endoscope must be sometimes inserted and retained in the body for a long time to observe the progress of a diseased part within the body or obtain and/or record somatoscopic information of a patient under ordinary every-day living conditions. However, the insertion and retainment of the endoscope in the body through the patient&#39;s mouth causes the patient to suffer from significant pain. 
     To relieve pain from the patient, it is known to use a capsule type endoscope which is provided at an intermediate portion of a flexible continuous member, as disclosed in Japanese Unexamined Patent Publication No. 64-76822. A patient to be examined swallows a soft ball formed at a tip end of the flexible continuous member the night before the day of examination, so that the soft ball is discharged from the patient&#39;s anus the next day. An operator pulls or moves the tip end and the tail end of the flexible continuous member to thereby move or guide the capsule connected to the intermediate portion of the flexible continuous member. 
     In the capsule type of endoscope described above, the pain that the patient suffers can be eased in comparison with conventional endoscopes. However, the patient must always carry the flexible continuous member whose one end extends out of his or her mouth for more than 12 hours. Consequently, it is impossible for the patient to take a meal or speak. Under these circumstances, no substantial pain relieving effect can be expected. Moreover, it is generally difficult to control the position of the endoscope when in the form of a capsule. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a fully-swallowable endoscopic system which can relieve a patient to be examined from pain and which makes it possible to observe the target inner part of the body surely and precisely. 
     To achieve the object mentioned above, according to the present invention, a fully-swallowable endoscopic system is provided, which includes a rod-shaped endoscope body which can be swallowed entirely by a patient to be examined so as to be placed in a body cavity, the rod-shaped endoscope body including two bendable portions having different lengths which are respectively provided close to the opposite ends of the rod-shaped endoscope body, each of the two bendable portions being bendable along a curve of the body cavity; and an external device provided separately from the rod-shaped endoscope body having no mechanical connection with the rod-shaped endoscope body. The rod-shaped endoscope body is provided therein with at least one light emitter, at least one observing system, a transmitter for transmitting a radio wave which carries an image formed by the observing system, and a power supplying device. The external device includes a receiver for receiving the radio wave which carries the image. 
     Preferably, the rod-shaped endoscope body includes a flexible portion which bends when an external force is applied thereto, the flexible portion being positioned between the two bendable portions to connect the two bendable portions, and wherein each of the two bendable portions includes a bending portion which can be radio-controlled to bend by an operation of the external device. The rod-shaped endoscope body is provided therein with a radio-controlled driving device which receives a radio operational signal transmitted from the external device to bend the bending portion in accordance with the radio operational signal, and the external device includes an operational portion which is operated to transmit the radio operational signal to the radio-controlled driving device. 
     In an embodiment, the rod-shaped endoscope body includes more than one light emitter and more than one observing system which are positioned at different locations. 
     Preferably, the radio-controlled driving device includes a plurality of drive wires made of a shape memory alloy, and a selective-heating device which selectively heats the plurality of drive wires to bend the bending portion. 
     The power supplying device can be a built-in battery. 
     In an embodiment, the external device includes a microwave transmitter for transmitting a microwave to the rod-shaped endoscope body, wherein the power supplying device converts the microwave into electrical current to supply the electrical current to the rod-shaped endoscope body. 
     Preferably, the observing system includes an objective optical system and a CCD image sensor. 
     Preferably, the external device includes a monitor which visually indicates the image. 
     According to another aspect of the present invention, a fully-swallowable endoscopic system is provided, which includes a rod-shaped endoscope body having a first bending portion, a flexible portion and a second bending portion which are arranged in that order, one of the first and second bending portions being longer than the other; and a radio controller for manipulating each of the first and second bending portions so as to bend by radio-control. The rod-shaped endoscope body is provided therein with at least one light emitter for illuminating a target inner part of a living body, at least one image pick-up device for taking an image of the target inner part illuminated by the at least one light emitter, and a transmitter for transmitting a radio wave which carries the image taken by the image pick-up device. 
     In an embodiment, the rod-shaped endoscope body further includes a first hard portion fixed to one of the opposite ends of the rod-shaped endoscope body, and one of the at least one light emitter and one of the at least one image pick-up device are fixed to the first hard portion. 
     Preferably, the rod-shaped endoscope body further includes a second hard portion fixed to the other of the opposite ends of the rod-shaped endoscope body, and another of the at least one light emitter and another of the at least one image pick-up device are fixed to the second hard portion. 
     Preferably, the radio controller includes a monitor and a receiver for receiving the radio wave to indicate the image on the monitor. 
     In an embodiment, the radio controller further includes a second transmitter for transmitting a microwave to the rod-shaped endoscope body, and wherein the rod-shaped endoscope body is provided therein with a power supplying device which receives the microwave to convert the microwave into electrical current which is to be used as a power source of the rod-shaped endoscope body. 
     The present disclosure relates to subject matter contained in Japanese Patent Application No.11-160029 (filed on Jun. 7, 1999) which is expressly incorporated herein by reference in its entirety. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be discussed below in detail with reference to the drawings, in which: 
     FIG. 1 is a schematic view of an embodiment of a fully-swallowable endoscopic system having a rod-shaped endoscope body and an external device, according to the present invention; 
     FIG. 2 is a schematic cross sectional view of the first embodiment of the rod-shaped endoscope body, according to the present invention; 
     FIG. 3 is a schematic cross sectional view of part of the rod-shaped endoscope body shown in FIG. 2, taken along a different plane; 
     FIG. 4 is a schematic cross sectional view of the rod-shaped endoscope body shown in FIG. 2, showing a radio-controlled bending device thereof; 
     FIG. 5 is an explanatory view of the rod-shaped endoscope body shown in FIG. 2, showing the difference in length between the first and second bending portions; 
     FIG. 6 is an explanatory view of the rod-shaped endoscope body which is positioned between the esophagus and the stomach, showing a state where the inside of the stomach is observed with the front observing system while making the posture of the endoscope stable by the rear bending portion of the endoscope; 
     FIG. 7 is an explanatory view of the rod-shaped endoscope body which is positioned in the stomach, showing a state where the inside of the stomach is observed with the front observing system while making the posture of the endoscope stable by the rear bending portion of the endoscope; 
     FIG. 8 is an explanatory view of the rod-shaped endoscope body which is positioned in a tubular passage in a body, showing a state where the inside thereof is observed with the front observing system with the rear bending portion being fixed to an inner wall of the tubular passage by bending the rear bending portion; 
     FIG. 9 is a schematic cross sectional view of fundamental components of the second embodiment of the rod-shaped endoscope body, positioned in a tubular passage in a body, according to the present invention; 
     FIG. 10 is a block diagram of a process which is performed after the external device receives a signal output from the rod-shaped endoscope body; 
     FIG. 11 is an explanatory view of part of the second embodiment of the bending portion of the rod-shaped endoscope body, showing an arrangement of the bendable drive wires provided in the bending portion; 
     FIG. 12 is a schematic side view of part of the first embodiment of the bending portion, with parts omitted for clarity, in the case where the bending portion is designed to be bendable in a single plane; and 
     FIG. 13 is a schematic side view of part of the second embodiment of the bending portion, in the case where the bending portion is designed to be bendable in two planes perpendicular to each other. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows an embodiment of a fully-swallowable endoscopic system which includes a rod-shaped endoscope body  10  and an external device  11 . A patient to be examined swallows the rod-shaped endoscope body  10  before an endoscopic examination is performed with the endoscope  10 . The external device  11  functions as a wireless controller (radio controller) and a power supply for the endoscope  10 . 
     FIGS. 2 through 5 show the first embodiment of the rod-shaped endoscope body  10 . The rod-shaped endoscope body  10  is provided with a first hard portion (unbendable portion)  12 , a first bending portion  13 , a flexible portion  14 , a second bending portion  15  and a second hard portion (unbendable portion)  16 , in this order from the front end (the left end as viewed in FIG.  2 ). The first bending portion  13  and the flexible portion  14  constitute a bendable portion, and the second bending portion  15  and the flexible portion  14  constitute another bendable portion. The rod-shaped endoscope body  10  is entirely covered by an elastic covering  28  whose outer surface is smooth and well-slidable (see FIG.  12 ). The first and second hard portions  12  and  16  are each made of a hard material (e.g., a hard plastic) which is not macroscopically deformable. The flexible portion  14  is designed to be bendable along the shape of a digestive tract when it is inserted in a body cavity. 
     Each of the hard portions  12  and  16  is provided therein with an observing system  17 , an illumination window  18  and an air supply port  19 . Each observing system  17  includes an objective optical system  17   a  and a CCD image sensor  17   b . The flexible portion  14  is provided therein with an amplifier circuit  14   a , a transmitter/receiver device  14   b , a power supplying device  14   c , a control circuit  14   d , a compressed air tank  14   e  and a microwave receiver  14   g  as shown in FIG.  3 . Each CCD image sensor  17   b  is connected to the amplifier circuit  14   a  via a corresponding signal line  20 . The amplifier circuit  14   a  is connected to the transmitter/receiver device  14   b , which is positioned in the flexible portion  14 . Each of the hard portions  12  and  16  is provided therein with an LED (light emitter)  18   a  which is secured to the corresponding illumination window  18 . Each ED  18   a  is connected to the control circuit  14   d  via a corresponding signal line  20  (see FIG.  3 ). 
     Each air supply port  19  is connected to the outer end of a corresponding air supply tube  21 . The inner end of each air supply tube  21  is connected to a corresponding valve  14   f  of the compressed air tank  14   e . Each valve  14   f  is controlled to open or shut by the control circuit  14   d . The power supplying device  14   c  is connected to the transmitter /receiver device  14   b  and the control circuit  14   d . The power supplying device  14   c  converts a microwave received by the microwave receiver  14   g  into electrical current to supply the same to the transmitter/receiver device  14   b  and the control circuit  14   d . The microwave received by the microwave receiver  14   g  is transmitted from the external device  11 . 
     FIG. 12 shows part of the first embodiment of each of the first and second bending portions  13  and  15  in the case where each bending portion is designed to be bendable in a single plane. The first embodiment of each bending portion is provided with an articulated series of ring joints  26 . Adjacent ring joints  26  are connected with each other by a shaft  26   a  so that each of the adjacent ring joints  26  can rotate about the shaft  26   a . All the shafts  26   a  are parallel to one another so as to lie in a common plane. The articulated series of ring joints  26  having such a structure is covered by a steel wired tube  27 . This steel wired tube  27  is covered by the aforementioned elastic covering  28 . Each of the first and second bending portions  13  and  15  is designed to be more flexible and bendable than the flexible portion  14  to bend from the flexible portion  14 . Namely, each of the opposite ends of the rod-shaped endoscope body  10  is designed as a bendable portion. The length of the second bending portion  15  is greater than that of the first bending portion  13  (see FIGS.  4  and  5 ). 
     The rod-shaped endoscope body  10  is provided therein with a plurality of bendable drive wires (two drive wires in the first embodiment of the first bending portion  13 )  22   a  which extend within the first bending portion  13  and the flexible portion  14  (see FIG.  4 ). Each drive wire  22   a  is made of a shape memory alloy (SMA) which bends when supplied with electrical current to be heated thereby. The rod-shaped endoscope body  10  is further provided therein with a selective-heating device  23  which is connected to the transmitter/receiver device  14   b . The drive wires  22   a , the selective heating device  23 , and the transmitting/receiving device  14   b  constitute a radio-controlled driving device. The outer ends of the drive wires  22   a  are each secured to the first hard portion  12 , while the inner ends of the drive wires  22   a  are each secured to the selective-heating device  23 . 
     The two drive wires  22   a  are diametrically arranged at opposite sides of the axis of the cylindrical first bending portion  13 . The selective-heating device  23  is a circuit which selectively supplies electrical current to the two drive wires  22   a  to heat the same in accordance with control signals output from the transmitter/receiver device  14   b , which makes it possible to bend the first bending portion  13  in a plane in which the two drive wires  22   a  lie. 
     When it is required that the first bending portion  13  be bendable only in a single plane, it is sufficient that the rod-shaped endoscope body  10  be provided with the first embodiment of the first bending portion  13 , as shown in FIG. 12, which can bend only in a single plane. When it is required that the first bending portion  13  be bendable in two planes perpendicular to each other, the first bending portion  13  needs to have a structure such as shown in FIG.  13 . FIG. 13 shows part of the second embodiment of each of the first and second bending portions  13  and  15  in the case where it is designed to be bendable in two planes perpendicular to each other. The second embodiment of each bending portion is provided with an articulated series of ring joints  26 ′. Adjacent ring joints  26 ′ are connected with each other by a first shaft  26   a  or a second shaft  26   b  so that each of the adjacent ring joints  26 ′ can rotate about each of the shafts  26   a  and  26   b . The first and second shafts  26   a  and  26   b  extend in directions perpendicular to each other and are alternately arranged. In FIG. 13, neither the steel wired tube  27  nor the aforementioned elastic covering  28  is illustrated for clarity of illustration. In the second embodiment of the first bending portion  13 , four bendable drive wires  22   a  extend within the first bending portion  13  and the flexible portion  14  (see FIG.  11 ). The outer ends of the four drive wires  22   a  are each secured to the first hard portion  12  at 90 intervals about the axis of the first hard portion  12 . The inner ends of each pair of drive wires  22   a  which are diametrically opposite to each other are secured to the selective-heating device  23 . In the second embodiment of the first bending portion  13 , although only two drive wires  22   a  are shown in FIG. 4, the remaining two drive wires  22   a  are provided in a similar manner. 
     Similar to the first bending portion  13 , the rod-shaped endoscope body  10  is provided therein with another plurality of bendable drive wires (two drive wires in the first embodiment of the second bending portion  15 )  22   b  which extend within the second bending portion  15  and the flexible portion  14  (see FIG.  4 ). Each drive wire  22   b  is made of a shape memory alloy (SMA) which bends when supplied with electrical current to be heated thereby. The outer ends of the drive wires  22   b  are each secured to the selective-heating device  23 , while the inner ends of the same are each secured to the second hard portion  16 . 
     The two drive wires  22   b  are diametrically arranged at opposite sides of the axis of the cylindrical second bending portion  15 . The selective-heating device  23  is a circuit which selectively supplies electrical current to the two drive wires  22   b  to heat the same in accordance with control signals output from the transmitter/receiver device  14   b , which makes it possible to bend the second bending portion  15  in a plane in which the two drive wires  22   b  lie. 
     When it is required that the second bending portion  15  be bendable only in a single plane, it is sufficient that the rod-shaped endoscope body  10  be provided with the first embodiment of the second bending portion  15 , as shown in FIG. 12, which can bend only in a single plane. When it is required that the second bending portion  15  be bendable in two planes perpendicular to each other, the second bending portion  15  needs to have a structure such as shown in FIG. 13, similar to the second embodiment of the first bending portion  13 . In the second embodiment of the second bending portion  15 , similar to the second embodiment of the first bending portion  13 , four bendable drive wires  22   b  extend within the second bending portion  15  and the flexible portion  14  (see FIG.  11 ). The outer ends of the four drive wires  22   b  are each secured to the second hard portion  16 . The inner ends of each pair of drive wires  22   b  which are diametrically opposite to each other are secured to the selective-heating device  23 . In the second embodiment of the second bending portion  15 , although only two drive wires  22   b  are shown in FIG. 4, the remaining two drive wires  22   b  are provided in a similar manner. 
     The external device  11  shown in FIG. 1 is provided with an external receiving portion  11   a , a monitor  11   b , a bending portion controller portion (operational portion)  11   c , an external transmitting portion  11   d , a valve controlling portion  11   h  and a microwave transmitting portion (microwave transmitter)  11 i. The external device  11  is further provided with a video circuit  11   e , an analyzing device  11   f  and an analyzed-data storing device  11   g  (see FIG.  10 ). The external device  11  transmits the aforementioned microwave, which is used as a power supply for the rod-shaped endoscope body  10 , from the microwave transmitting portion  11   i  to the rod-shaped endoscope body  10 . This transmitted microwave is received by the microwave receiver  14   g  and is converted into electrical current by the power supplying device  14   c . The power supplying device  14   c  supplies the electrical current to the transmitter/receiver device  14   b  and the control circuit  14   d . By manually operating the bending portion controller portion  11   c  and the valve controlling portion  11   h  of the external device  11 , radio operational signals for operating the first or second bending portion  13  or  15  and the valve  14   f  are generated by the external device  11  to be transmitted to the rod-shaped endoscope body  10  via the external transmitting portion  11   d . The external receiving portion  11   a  receives image signals (radio waves) transmitted from the transmitter/receiver device  14   b . The received image signals are displayed on the monitor  11   b  to be observed by an operator. 
     In the fully-swallowable endoscope constructed as above, a patient to be examined swallows the rod-shaped endoscope body  10  entirely from the front end thereof, i.e., from the first hard portion  12 . After being swallowed entirely, the rod-shaped endoscope body  10  is radio-controll ed to proceed gradually along the alimentary canal by peristalsis. When the first hard portion  12  reaches the stomach as shown in FIG. 6, the second bending portion  15 , which is positioned at the rear end of the rod-shaped endoscope body  10 , can be fixed to an inner wall of the esophagus by bending the second bending portion  15 . This makes it easy to observe the inside of the stomach with the rod-shaped endoscope body  10 . In the case where the endoscope  10  is in a narrow tubular passage in a body, the endoscope  10  can be stably held thereinside by pressing the second bending portion  15  against an inner wall of the canal by bending the second bending portion  15  so that the inside of the canal can be widely observed by manipulating the first bending portion  13 . Since the second bending portion  15  is designed to be longer than the first bending portion  13  so as to bend largely, the target inner part of the body can be observed with the observing system  17  in the first hard portion  12  by manipulating the first bending portion  13  while the endoscope  10  is stably held by the widely-bent second bending portion  15  (see FIG.  7 ). 
     In the present embodiment of the fully-swallowable endoscopic system, the transmitter/receiver device  14   b  of the rod-shaped endoscope body  10  receives the radio operational signals transmitted from the external transmitting portion  11   d  of the external device  11  so that each of the fundamental operational elements of the rod-shaped endoscope body  10  can be radio-controlled by operating the external device  11 . The power supplying device  14   c  supplies electrical current to the transmitter /receiver device  14   b  and the control circuit  14 d by converting the received microwave into electrical current, so that the operator does not have to care about the remaining battery power of the rod-shaped endoscope body  10 . 
     This makes it possible to observe the target inner part of the body sufficiently. 
     Each LED  18   a , which receives power from the power supplying device  14   c  via the corresponding signal line  20 , emits light outwardly through the corresponding illumination window  18 . The object image upon which the illumination light of each LED  18   a  is impinged is formed on the sensitive surface of the corresponding CCD image sensor  17   b  through the corresponding objective optical system  17   a . The image signal supplied from each CCD image sensor  17   b  is amplified by the amplifier circuit  14   a . This amplified image signal is transmitted from the transmitter/receiver device  14   b  to be subsequently received by the external receiving portion  11   a  of the external device  11 . The image signal received by the external device  11  is processed by the video circuit  11   e  to be observed on the monitor  11   b  (see FIG.  10 ). The operator operates the bending portion controller portion  11   c  of the external device  11  to bend the first bending portion  13  or the second bending portion  15  via the selective-heating device  23 , which is controlled by the radio operational signals transmitted from the external transmitting portion  11   d , to thereby change the direction of the objective optical system  17   a  to observe the target inner part of the body. At this time, if a tubular passage in a body is made to inflate by sending the compressed air in compressed air tank  14   e  from the corresponding air supply port  19  to the tubular passage via the corresponding air supply tube  21  by operating the valve controlling portion  11   h  of the external device  11 , so that the transmitter /receiver device  14   b  receives radio operational signals transmitted from the external transmitting portion  11   d , so as to operate the corresponding valve  14   f , the distance between the first or second hard portion  12  or  16  and the inner wall of the tubular passage becomes large, which makes it easy to observe the inner wall of the tubular passage. 
     A measuring device  25  for measuring information about a living body such as pH value, temperature, the amount of oxygen contained in blood, the hardness of the surface of cells, and the like, can be incorporated in the rod-shaped endoscope body  10  (see FIG.  3 ). In this case, the measured information can be transmitted from the transmitter/receiver device  14   b  to be received by the external receiving portion  11   a  of the external device  11 . The received information can be analyzed and stored if the analyzing device  11   f  analyzes the received information while the analyzed-data storing device  11   g  stores the analyzed information (see FIG.  10 ). 
     FIG. 9 shows the second embodiment of the rod-shaped endoscope body  10 . This rod-shaped endoscope body  10  is provided with a balloon  24  provided at one end (the front end in this particular embodiment shown in FIG. 9) of the rod-shaped endoscope body  10 . The rod-shaped endoscope body  10  can be provided with two balloons respectively provided at the opposite ends of the rod-shaped endoscope body  10 . The balloon  24  can be inflated by sending the compressed air in the compressed air tank  14   e  into the balloon  24 , by operating the valve controlling portion  11   h  of the external device  11 , so that the transmitter/receiver device  14   b  receives radio operational signals transmitted from the external transmitting portion  11   d , so as to operate the valve  14   f . For instance, in the case where the second embodiment of the rod-shaped endoscope body  10  is in a tubular passage in a body, if the balloon  24  is inflated, the distance between the hard portion  12  and the inner wall of the tubular passage becomes large, which makes it easy to observe the inner wall of the tubular passage. 
     The power supplying device  14   c  of the rod-shaped endoscope body  10  can be replaced by a built-in battery to simplify the structure of endoscopic system. 
     As can be understood from the foregoing, according to the fully-swallowable endoscopic system of the present invention, since the rod-shaped endoscope body is entirely positioned in a body cavity without any cables or wires which connect the rod-shaped endoscope body with the external device, a patient to be examined does not suffer from pain even if the endoscope is retained in the patient&#39;s body for a long time. Furthermore, since the bending portion provided at one end of the endoscope is designed to be longer or shorter than the bending portion provided at the other end of the endoscope, it is easy to stably hold the endoscope at a desired position. 
     Obvious changes may be made in the specific embodiments of the present invention described herein, such modifications being within the spirit and scope of the invention claimed. It is indicated that all matter contained herein is illustrative and does not limit the scope of the present invention.