An endoscope comprises: an insertion portion that is to be inserted into a coelom; a treatment instrument elevation support, pivotally provided at a distal end of the insertion portion, that is used to guide a treatment instrument introduced at the distal end; and an observation section that obtains an image observed at the distal end, wherein, when the treatment instrument elevation support is reclined, part of the treatment instrument elevation support is included in the image obtained by the observation section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope, and more in particular, to an endoscope that includes a treatment instrument elevation support for guiding a treatment instrument that is introduced via a treatment instrument insertion channel.

2. Description of the Invention

An endoscope roughly comprises: an insertion portion, to be inserted into a coelom; a control portion, connected to the base end of the insertion portion; and a connector, attached to the control portion by a cord. The insertion portion is constituted by connecting, in the named order from near the distal end, a head made of a hard material; a bending portion; and an introduction portion, which is the proximal end of the insertion portion. The head includes an observation portion, for observations performed inside a body; and a treatment instrument guide portion, for guiding a treatment instrument, which is inserted at the control portion, through a treatment instrument insertion channel.

In the treatment instrument guide portion, a treatment instrument is introduced through an opening that communicates with the treatment instrument insertion channel, and is guided in a predetermined direction by a treatment instrument elevation support. The treatment instrument elevation support is coupled with a wire that is connected to an elevation lever provided for the control portion, and can be rotated by using the elevation lever. The treatment instrument elevation support can be raised by using the elevation lever, and with the treatment instrument elevation support being up, in a predetermined direction, the treatment instrument can be stably guided. JP-UM-A-60-180401 is relevant to the present invention.

When the treatment instrument elevation support is elevated at a predetermined angle or greater, the distal end projects outward, beyond the outer circumference of the head. In this state, were the insertion portion to be inserted into or removed from the coelom, the projected treatment instrument elevation support would injure the surface of the coelom. Therefore, for safety, before the insertion or extraction of the insertion portion is performed, it must be confirmed that the treatment instrument elevation support is reclined.

A determination of whether the treatment instrument elevation support is reclined or is elevated, can be made by observing an image. According to the description of an endoscope disclosed in JP-UM-A-60-180401, when the treatment instrument elevation support is elevated, an image of at least part of the support can be captured in the observation view field.

With the structure described in JP-UM-A-60-180401, an image of part of the treatment instrument elevation support in the elevated state is included in the view field; however, when the treatment instrument elevation support is reclined, an image is not always captured in the view field. As is described above, the treatment instrument elevation support must be reclined when the insertion portion is inserted or removed, and there is a demand that the reclined state of the treatment instrument elevation support be properly confirmed before an insertion/removal operation is performed.

SUMMARY OF THE INVENTION

To resolve this problem, it is one objective of the present invention to provide an innovative and improved endoscope whereby it can be properly confirmed that a treatment instrument elevation support is reclined.

To achieve this objective, according to one aspect of the invention, an endoscope comprises: an insertion portion that is to be inserted into a coelom; a treatment instrument elevation support, pivotally provided at a distal end of the insertion portion, that is used to guide a treatment instrument introduced at the distal end; and an observation section that obtains an image observed at the distal end, wherein, when the treatment instrument elevation support is reclined, part of the treatment instrument elevation support is included in the image obtained by the observation section. With this arrangement, when the treatment instrument elevation support is reclined, this state can be always included in an image that is observed, so that the reclined state of the treatment instrument elevation support can be appropriately confirmed.

It is preferable that the endoscope further comprise: an identification section that employs the image to determine whether the treatment instrument elevation support has been reclined. With this arrangement, the identification section can be employed to easily determine whether the treatment instrument elevation support has been reclined.

The identification section may comprise a marker that is provided on the part of the treatment instrument elevation support, to determine whether the treatment instrument elevation support has been reclined, and that is captured in an image obtained when the treatment instrument elevation support is reclined. With this arrangement, when the marker is monitored in the image, whether the treatment instrument elevation support has been reclined can be easily ascertained.

The identification section may further comprise a position indicator that designates a location of the marker that is displayed in the image when the treatment instrument elevation support is reclined. With this arrangement, when the locations of the position indicator and the marker match, it is determined that the treatment instrument elevation support has been reclined. In this manner, identification of the state can more exactly be performed.

In an elevated state of the treatment instrument elevation support, part of the treatment instrument elevation support may be included in the image obtained by the observation portion, and the identification section further comprises: a reclined position indicator that indicates a first position of the marker that is displayed in the image when the treatment instrument elevation support is reclined; and an elevation position indicator that indicates a second position of the marker that is displayed in the image when the treatment instrument elevation support is elevated. With this arrangement, part of the treatment instrument elevation support is included in the image either when the support has been elevated or reclined, and the state of the treatment instrument elevation support can be clearly ascertained.

BRIEF DESCRIPTION OF THE INVENTION

The preferred embodiments of the present invention will now be described in detail while referring to the accompanying drawings. In this specification and the drawings, the same reference numerals are used to denote components having substantially the same functions, and repetitive explanations will not be given for them.

An ultrasonic endoscope100according to a first embodiment of the invention will now be explained while referring toFIG. 1. While an ultrasonic endoscope is employed in the following embodiments, the present invention is not limited to an ultrasonic endoscope, and can also be applied for a common endoscope.FIG. 1is a schematic diagram showing the structure of the ultrasonic endoscope100according to the first embodiment. The ultrasonic endoscope100comprises: an elongated and flexible insertion portion102to be inserted into a coelom; a control portion104connected to the proximal end of the insertion portion102; a universal cord106extended from the side of the control portion104; and a connector (not shown) provided at the distal end of the universal cord106and connected to a light source or an ultrasonic observation apparatus (neither of them shown) The connector may be connected to an image processing apparatus or to a display device such as a monitor (neither of which is shown).

The insertion portion102is constituted by connecting, in the named order and from near the distal end, a head114that consists of a hard resin member, a bending portion116that is bendable and is located at the proximal end of the head114, and a long and flexible introduction portion118, having a small diameter, that extends from the proximal end of the bending portion116to the distal end of the control portion104.

The control portion104includes: an angle knob120, for bending the bending portion116in a desired direction; an elevation lever121, for elevating a treatment instrument elevation support; an air/water button122, for supplying air and water used to clean the windows of an observation portion and a lighting portion that are provided for the head114; and a suction button124, for performing a suction operation.

A treatment instrument insertion port126is provided on the side of the control portion104, near the distal end, for the insertion of a treatment instrument, such as forceps, into a target portion in a coelom. The treatment instrument insertion port126communicates with a treatment instrument insertion channel (not shown inFIG. 1) that is extended inside the insertion portion102and that communicates with the opening of a treatment instrument guide portion (not shown inFIG. 1) provided for the head114.

The structures of the head114and the bending portion116will now be described while referring toFIGS. 2 to 4.FIG. 2is a perspective view of the structures of the head114and the bending portion116of the ultrasonic endoscope100in this embodiment.FIGS. 3,4A and4B are partially cut away side views of the head114at positions A-A, B-B and C-C inFIG. 2.

As is shown inFIG. 2, the bending portion116has a joint ring structure wherein a plurality of joint rings116aare sequentially connected in the axial direction. Inside the joint rings116a, arranged at predetermined intervals in the axial direction of the inner wall, are multiple operation wires, the proximal ends of which are connected to a pulley (not shown) that is rotated by the angle knob120of the control portion104. With this structure, when the pulley is turned by manipulating the angle knob120, the operation wires are pulled and bend the bending portion116in a desired direction.

The head114is constituted by connecting an ultrasound test mechanism130, provided near the distal end, and an endoscopic observation mechanism140, provided nearer the proximal end than the ultrasound test mechanism130. The ultrasound mechanism130is, for example, an ultrasonic oscillation testing mechanism that includes an ultrasound transducer132for examining the state of internal tissue. The ultrasound transducer132has, for example, a convex structure where in multiple rectangular ultrasonic oscillators, for the transmission and reception of ultrasonic waves, are convexly arranged.

A treatment instrument guide portion142for guiding a treatment instrument is provided in the center of the upper face of the endoscopic observation mechanism140, and an observation portion, which obtains an image observed by the head114, and first and second lighting portions are provided on either side of the treatment instrument guide portion142. For the ultrasonic endoscope100, multiple lighting portions are provided in order to reduce uneven lighting. The structure of the endoscopic observation mechanism140will now be described in detail.

Viewed from the distal end of the head114in the axial direction, a first tilted face146and a second tilted face148, which rise obliquely upward toward the distal end, are formed on the right and left sides of the treatment instrument guide portion142. As is shown inFIG. 2, in the first tilted face146, from the top, an observation window150, an air/water supply port152and a first lighting window154are formed in the named order, and in the second tilted face148, a second lighting window156is formed.

The observation window150is used to obtain an image of what is being observed, and constitutes the end face of the observation portion of the ultrasonic endoscope100. As is shown inFIG. 3, the observation portion includes: the observation window150; an object lens158, located inside the observation window150; a CCD (Charge Coupled Device)160, which is a solid-state imaging device located at a focal position for the object lens158; and an electric wire162, connected to the CCD160.

The air/water supply port152is a nozzle opening through which air is fed or a cleaner is sprayed to clean the observation window150.

The first lighting window154is a window through which light is emitted to illuminate an observed portion in the field of view, and constitutes the end face of the first lighting portion. As is shown inFIG. 3, the first lighting portion includes the first lighting window154and a light guide164, which is an optical fiber bundle located inside the first lighting window154. The light guide164, which is passed through the control portion104and the universal cord106, is connected to a light source and transmits light emitted by the light source to the first lighting window154.

The second lighting window156is a window through which light is emitted to illuminate an observed portion in the field of view, and constitutes the end face of the second lighting portion. The second lighting portion also includes a light guide, and is structured the same as the first lighting portion. In this embodiment, the second lighting window156is projected farther towards the distal end than is the observation window150in the first tilted face146. However, the structural arrangement is not limited to this, and the second lighting window156and the observation window150can be arbitrarily positioned.

As is described above, all of the observation window150, the first lighting window154and the second lighting window156that are arranged in the individual tilted faces are directed obliquely upward toward the distal end at substantially the same tilting angle relative to the axial direction of the head114. With this structure, the observation direction for the observed portion and the directions in which light is emitted by the first and second lighting portions are also obliquely upward toward the distal end, and the light axial direction of the field of view substantially matches the light axial direction of the emitted light. Since the light axial direction is aligned in this embodiment, lighting can be efficiently performed.

The treatment instrument guide portion142will now be described while referring toFIGS. 4A and 4B. The treatment instrument guide portion142mainly includes: a treatment instrument elevation support170, which can be freely elevated or reclined in order to guide a treatment instrument in a predetermined direction; and an elevation support storage space172, which is recessed, for storing the treatment instrument elevation support170. Part of the proximal end of the elevation support storage space172is an opening, and as is shown inFIG. 4A, communicates with a treatment instrument insertion channel174.

The upper face of the treatment instrument elevation support170is a guide face for guiding a treatment instrument, and, as is shown inFIG. 4A, the proximal end is pivotally supported at a shaft176that is attached, almost vertically, to the shaft of the head114. The shaft176is connected to the arched lower end of a coupling member180having an almost elliptic shape shown inFIG. 4B, which is arranged in the axial direction of the shaft176at a predetermined distance from the treatment instrument elevation support170. The coupling member180is pivotally positioned in a guide groove178having an almost fan shape, and an operation wire182is connected to the upper portion of the coupling member180. By pulling or pushing the operation wire182, the arched lower end of the coupling member180is slid across the inner wall of the guide groove178, and is pivoted along the contact face. The operation wire182is connected to the elevation lever121provided for the control portion104, and is pulled or pushed by manipulating the elevation lever121.

The raising and the reclining of the treatment instrument elevation support170can be performed by manipulating the elevation lever121. For example, in the state inFIG. 4B, when the operation wire182is pulled by manipulating the elevation lever121, the coupling member180is turned, and accordingly, the shaft176is rotated and the treatment instrument elevation support170is elevated. The angle of elevation of the treatment instrument elevation support170can be adjusted and corresponds to the degree to which the elevation lever121is turned.

InFIG. 4A, the state wherein the treatment instrument elevation support170is up is indicated by a double-doted chain line, and the state wherein the support170is reclined is indicated by a solid line. In the reclined state, the treatment instrument elevation support170is brought into contact with the bottom of the elevation support storage space172, and the distal end of the support170is located at the lowest position within the pivoting range. At this time, the treatment instrument elevation support170is stored completely in the elevation support storage space172, and does not project outward beyond the outer circumference of the head114. Further, as is apparent fromFIG. 4A, when the treatment instrument elevation support170is raised at a predetermined angle or greater, the distal end of the support170projects outward beyond the outer circumference of the head114. When the insertion portion102is inserted or removed in this state, the surface of the body would be damaged. Therefore, before inserting or extracting the insertion portion102, the treatment instrument elevation support170should be reclined. Only after this state has been confirmed, should the insertion/extraction be performed.

Therefore, the ultrasonic endoscope100of this embodiment is designed so that, when the treatment instrument elevation support170has been reclined, part of the treatment instrument elevation support170is captured in an image observed by the observation portion. While referring toFIGS. 5A and 5B, an explanation will now be given for an image observed when the treatment instrument elevation support170has been reclined and when the elevation support170has been raised.FIGS. 5A and 5Bare specific diagrams showing images observed by the ultrasonic endoscope100of this embodiment. The state shown inFIG. 5Ais the one obtained when the treatment instrument elevation support170has been reclined, and the state inFIG. 5Bis the one obtained when it has been raised.

In this embodiment, a rectangular position indicator184is displayed in the center on the right side of an observed image that is shaped by removing the upper and lower ends of a circle. The position indicator184may be displayed by forming a mask image using an image processing apparatus, or by employing a focusing glass, such as a reticle. Furthermore, for the ultrasonic endoscope100of this embodiment, one part of the ultrasound test mechanism130is included in the observed image, so that the portion currently being examined can be confirmed in the observed image.

Apparent fromFIG. 5A, a part of the treatment instrument elevation support170in the reclined state is displayed in the center to the right of the observed image, a treatment instrument186is projected, and a circular marker188is positioned in the position indicator184. The marker188is provided in a part of the treatment instrument elevation support170that is to be entered in the observed image in the reclined state. The marker188is used to determine, based on an observed image, whether the treatment instrument elevation support170is reclined.

As is shown inFIG. 6, the marker188can be located at a distal end170aof the treatment instrument elevation support170, nearer the observation portion.FIG. 6is a cross-sectional view of the structure that includes the light axis of the observation portion and the longitudinal axis of the treatment instrument elevation support170. An imaging face160aof the CCD160is indicated by a broken line, and the observation field of view through the observation window150is indicated by a dotted chain line.

InFIG. 5B, the treatment instrument186is entered in the observed image, and the treatment instrument elevation support170in the elevated state and the marker188are not seen. As is described above, according to the embodiment, in the elevated state, the treatment instrument elevation support170is not entered in the observed image, and in the reclined state, a part of the elevation support170is entered in the observed image and the marker188is located in the position indicator184. That is, the position indicator184represents the location of the marker188in the observed image when the treatment instrument elevation support170is reclined, and is an identification portion, based on the observed image, used to determine whether the treatment instrument elevation support170is reclined.

By referring toFIGS. 5A and 5B, whether the treatment instrument elevation support170has been reclined can be easily ascertained by examining the presence/absence of the elevation support170in the observed image, and the presence/absence of the marker188in the position indicator184. Therefore, according to this embodiment, it can be precisely confirmed that the treatment instrument elevation support170has been reclined, and the safety for the insertion and extraction of the insertion portion102can be increased.

After the treatment instrument elevation support170in the reclined state inFIG. 4A, indicated by a solid line, is elevated, a part of the treatment instrument elevation support170and the marker188may be seen in the image observed until the entire elevation support170is reclined into the elevation support storage space172and does not project outward beyond the outer circumference of the head114. With this arrangement, so long as part of the treatment instrument elevation support170and the marker188can be confirmed in the image observed, the treatment instrument elevation support170is not projected outward beyond the outer circumference of the head114, so that the insertion and extraction of the insertion portion102are enabled.

A second embodiment of the present invention will now be described. An ultrasonic endoscope for the second embodiment is substantially the same as the one for the first embodiment, with the exception that, in the second embodiment, part of a treatment instrument elevation support270is seen in an image observed both in the raised state and the laid-down state, so that the state of the elevation support270can be identified based on the image observed. Only that which differs from the first embodiment will be explained, and no further explanation will be given for corresponding structures.

For this embodiment, images observed when the treatment instrument elevation support270is elevated and reclined will be described while referring toFIGS. 7A and 7B.FIGS. 7A and 7Bare specific diagrams showing images observed by the ultrasonic endoscope of this embodiment. The image inFIG. 7Ais obtained when the treatment instrument elevation support270is reclined, and the image inFIG. 7Bis obtained when the elevation support270is elevated. In this embodiment, in the center on the right of an image shaped like a circle with the upper and lower ends removed, two differently colored bar-shaped position indicators284and285are displayed vertically at a predetermined distance. The position indicators284and285are formed and displayed in the same manner as is the position indicator184for the first embodiment. Also in this embodiment, part of the ultra sound test mechanism130is displayed so that the portion currently being examined is confirmed in the image observed.

As is apparent fromFIG. 7A, one part of the treatment instrument elevation support270in the reclined state is seen in the center on the right of the image observed, and the treatment instrument186is projected. Further, a circular marker288, which is provided in part of the treatment instrument elevation support270, is located immediately on the left of the lower position indicator284. InFIG. 7B, one part of the treatment instrument elevation support270in the raised state is seen in the center on the right of the observed image, and the circular marker288is located immediately to the left of the upper position indicator285.

That is, the position indicator284is a reclined position indicator that indicates the location of the marker288that is seen in an image observed when the treatment instrument elevation support270is reclined. The position indicator285is a raised position indicator that indicates the location of the marker288that is seen in an image observed when the treatment instrument elevation support270is elevated. The marker288and the position indicators284and285function as an identification section for determining, based on the image observed, whether the treatment instrument elevation support270is reclined. As is described above, in this embodiment wherein, both in the elevated state and the reclined state, part of the treatment instrument elevation support270is seen in the image observed, it can also be precisely confirmed, based on the image observed, that the treatment instrument elevation support270is reclined, and the safety for the insertion and the extraction of the insertion portion can be increased.

The preferred embodiments of the present invention have been described while referring to the accompanying drawings. However, the present invention is not limited to these embodiments. It will be obvious to one having ordinary skill in the art that the present invention can be variously modified or altered within the scope described in the claims, and it can be understood that these modifications or alterations belong to the technical scope of the invention.

The colors and shapes of the marker and the position indicators are not limited to those in the embodiments, and can be arbitrarily designated. For example, green may be employed as the color for the position indicator284that indicates the position of the treatment instrument elevation support in the reclined state, and red may be employed for the position indicator285that indicates the position of the treatment instrument elevation support in the elevated state.

An ultrasonic endoscope has been employed for the embodiments. However, the present invention is not limited to this, and can also be applied for a common endoscope that does not include an ultrasound test mechanism.

For an ultrasonic endoscope, multiple wires are led out of an ultrasonic testing mechanism and extended below the treatment instrument guide portion of an endoscope observation mechanism. In order to obtain space for these wires, the treatment instrument storage space of the ultrasonic endoscope is formed so it is shallower than is one for a common endoscope, so that the treatment instrument elevation support tends to be projected outward beyond the outer circumference of the head. For this reason, applying the present invention for an ultrasonic endoscope is very effective.

Recently, in order to reduce the load imposed on a patient, a reduction in the diameter of an insertion portion has also been for a common endoscope, and the diameter of the head also tends to be reduced. On the other hand, a specific distance in the axial direction is required for the treatment instrument elevation support in order to guide a treatment instrument, so that as the diameter of the endoscope is reduced, the treatment instrument elevation support for the endoscope is more likely to be projected outward beyond the outer circumference of the head, as with the ultrasonic endoscope. Therefore, as the reduction of the diameter is continued, the problem described for the invention can not be disregarded even for a common endoscope, and use of the present invention becomes effective.

The shape of the distal end of the treatment instrument elevation support is not limited to that shown inFIG. 6, and as is shown inFIG. 8, the distal end may be formed along the angle of the observation field of view.FIG. 8is a cross-sectional view of the structure, including the light axis of the observation portion and the longitudinal axis, of a treatment instrument elevation support370. The imaging face160aof the CCD160is indicated by a broken line, and the viewing range through observation window150is indicated by a dotted chain line. In this case, there is an advantage in that the moment whereat the treatment instrument begins to be guided from the treatment instrument elevation support370can be observed.

A biopsy tool having a sharp distal end is especially employed for the ultrasonic endoscope. So long as the moment whereat the biopsy tool begins to be guided from the treatment instrument guidance portion can be observed, the direction in which the biopsy tool is guided can be confirmed, and the position of the biopsy tool can be precisely adjusted before it reaches a diseased part.

As is described above, according to the endoscope of the invention, an image that is observed can be employed to easily ascertain whether the treatment instrument elevation support has been reclined. Thus, for the insertion and removal of the insertion portion, the safety can be increased.

The present invention can be applied for an endoscope wherein a treatment instrument elevation support for guiding a treatment instrument is provided at the head of an insertion portion.